The studies in the meta-analysis included 9 publications that used CT measures of total lateral ventricle volume analyzed as a subgroup , and all other brain structures were examined using MRI. For continuous outcome measures, Hedges g was used, which is the Cohen effect size with a correction for bias from small sample sizes. For categorical outcome measures, the odds ratio was used. Outcome measures were recorded from each study and were independently checked to ensure accuracy.
For a given brain structure, if 2 or more studies by the same research group reported similar patient or control demographics, we contacted the authors of those studies to determine whether there was overlap in the sample and, if this was the case, included only the largest relevant study. A total of measures from 52 studies were excluded for this reason. A meta-analysis for each brain structure was performed using the metan command in Stata 9. Outcome measures were combined using a random-effects inverse-weighted variance model.
A minority of imaging studies presented measures from subgroups of patients. For these studies, we entered the subgroups in the meta-analysis as if they were separate studies and, in each case, the number of individuals in the control group was considered the sample size of the control group divided by the number of patient subgroups. This method has been used in a previous meta-analysis. To test for between-study heterogeneity, the Cochran Q test statistic was calculated. The effect of small-study bias which may include publication bias was investigated for regions in which the pooled effect size revealed a significant group difference between MDD patients and controls and when at least 5 studies were included in the meta-analysis to ensure that the test was sufficiently powered.
Small-study bias was assessed using the Egger regression test. The number of brain regions and clinical variables included in the database allows a potentially high number of correlations to be examined, which may lead to type I errors. Thus, the analysis was limited to the effect of clinical variables on total hippocampal volume. We selected this region because of the robust evidence of volumetric reduction in MDD 12 , 13 and because many studies have measured this structure, ensuring adequate statistical power.
A random effects meta-regression was implemented metareg command in Stata 9. In addition, we combined studies that directly compared the same MDD subgroups eg, depressed vs remitted patients in a supplementary meta-analysis. Finally, we determined whether the reduction in hippocampal volume remained when the meta-analysis was restricted to the following MDD patient groups: To test how robust the results were to variations in the meta-analysis method, the effect of the following was examined: We adopted the second approach, which has the advantage of including more studies and brain structures because there are very few direct comparisons.
Thus, to compare the results from the MDD meta-analysis with those of a previous meta-analysis of BD studies, 9 we combined the effect sizes from BD patients vs controls with MDD patients vs controls effectively, a meta-analysis of studies on patients with affective disorder and performed a stratified meta-analysis using a z test to compare across the 2 disorders. To match the method exactly, the BD meta-analysis was reanalyzed, using the technique of combining left and right brain structural measures adopted in the present MDD meta-analysis.
To reduce the number of comparisons, we focused on brain regions that were significantly different from those of controls before Bonferroni correction in either the MDD or BD meta-analysis. We adopted a 2-stage process to ensure that significant differences between the groups that were identified in the stratified meta-analysis were not the result of variations in patient demographics or scanning parameters rather than MDD or BD diagnosis.
First, for each brain structure, we examined whether the following summary variables were significantly different between MDD and BD studies, using an independent-samples t test: Second, when a significant difference was identified between BD and MDD studies for those variables, a meta-regression was performed separately in MDD and BD studies to examine the effect of the variable on the given brain structure.
Demographic and clinical data from the database are reported, followed by results from the MDD meta-analyses and comparison with the BD meta-analysis. Details from studies that included a total of patients with MDD and controls were entered into the database. Table 1 summarizes the variables recorded.
The mean SD slice thickness was 9. The studies included in the meta-analysis 29 - are listed in Table 2. Compared with controls, patients with MDD had larger lateral ventricular and cerebrospinal fluid CSF volumes and smaller volumes of the total caudate, putamen, globus pallidus, thalamus, hippocampus, frontal lobe, orbitofrontal gray matter, and gyrus rectus Figure 1 and Table 3. Patients with MDD had moderately increased rates of MRI signal hyperintensities, but this was dependent on the measurement technique used.
When hyperintensity rating scales were used, periventricular hyperintensities were increased Figure 1 and Table 3 ; when categorical classification was used patient classified as having hyperintensities or no hyperintensities , subcortical gray matter hyperintensities were increased Figure 2 and Table 4.
When percentage change was used as the effect size for continuous data, there was a reduction in the volume of the right orbitofrontal cortex and an increase in deep white matter hyperintensities as measured by rating scales in patients with MDD, and the decrease previously observed in the globus pallidus became a trend. If ratio, length, and area measurements were excluded, lateral, ventricle measures using CT imaging could not be included because all studies reported a ventricle to brain ratio measure; no other changes were noted. There was no change in the results when the correlation coefficient between left and right regions was set to 0, 0.
Nine regions included in both the MDD and BD meta-analyses showed significant differences from controls, allowing a comparison to be made Table 5. Compared with BD patients or controls, patients with MDD had significantly reduced volumes of the caudate, putamen, globus pallidus, and hippocampus. Compared with MDD patients or controls, patients with BD had significantly reduced cross-sectional areas of the corpus callosum and increased rates of deep white matter hyperintensities.
Compared with controls, both MDD and BD patients showed ventricular dilation and increased rates of subcortical gray matter hyperintensities, but there was no significant difference between the patient groups. When we examined differences in study characteristics between BD and MDD investigations for each of the 6 brain regions identified in the previous paragraph, there were significant differences in terms of patient age 5 regions , sex 3 regions , and medication use 5 regions , but no significant differences in terms of scanner field strength or slice thickness.
From the follow-up meta-regression analyses, there was no significant effect of patient age, sex, or medication use on any of the 6 regions in either BD or MDD studies. In patients with MDD compared with controls, we identified increased lateral ventricle and CSF volume; reduced volume of the basal ganglia, thalamus, hippocampus, frontal lobe, orbitofrontal cortex, and gyrus rectus; and increased rates of periventricular and subcortical gray matter hyperintensities.
Within mood disorders, basal ganglia and hippocampal volume reductions appear to be specific to MDD, and reduced corpus callosum cross-sectional area and increased rates of deep white matter hyperintensities appear to be specific to BD. These findings may provide evidence for the involvement of the hypothalamic-pituitary-adrenal axis in MDD.
The anterior pituitary produces adrenocorticotropic hormone, and it is conceivable that an increased volume of the pituitary may be associated with increased adrenocorticotropic hormone production. A primary role of adrenocorticotropic hormone is stimulation of the adrenal cortex, which responds by producing glucocorticoids. There is strong evidence that glucocorticoid levels are increased in MDD, and prolonged high levels may damage hippocampal neurons. However, because of the weight of evidence supporting the involvement of the hypothalamic-pituitary-adrenal axis, we entered these studies into an additional meta-analysis not previously reported.
The finding that hippocampal volume was significantly smaller in patients with a depressed compared with remitted state raises the possibility that reductions in hippocampal volume may normalize during remission, and it is tempting to speculate that this may be the result of neurogenesis in the dentate gyrus. Although we did not detect an association between antidepressant use and hippocampal volume, there is growing evidence that antidepressants may upregulate neurogenesis. Malberg et al reported that chronic antidepressant therapy increased neurogenesis in rats and an antipsychotic medication had no effect.
More recently, a postmortem study reported that depressed patients who had been treated with antidepressants had an increased number of neural progenitor cells in the dentate gyrus compared with untreated patients or controls. In previous meta-analyses, Videbech and Ravnkilde 12 reported that increased duration of illness was associated with smaller right hippocampal volume, and McKinnon et al 14 did not find hippocampal reduction in first episodes of MDD. Conversely, we did not find an association with duration of illness and determined that hippocampal volume reduction was present in patients at first episode.
However, in our analysis, the effect size in first-episode studies 0. Four frontal regions were smaller in MDD patients compared with controls. Although we could not confirm that the subgenual prefrontal cortex was reduced in volume in MDD, it is possible that functional, 59 , rather than structural, abnormalities are of greater prominence in this region. The most significant effect sizes were observed in the orbitofrontal cortex and gyrus rectus. Deficits of prefrontal cortical activation in MDD are relatively consistent in functional neuroimaging studies, and postmortem studies have reported reduced neuronal and glial density in the dorsal lateral and orbitofrontal cortex.
We confirm the findings of a previous meta-analysis, 13 which reported reduced volume of the caudate and putamen in patients with MDD, but we also found significant volume reductions of the globus pallidus. Although the basal ganglia have primarily been linked to motor function, the ventral striatum, including the nucleus accumbens, has been strongly associated with limbic systems, particularly reward networks. Although increased rates of hyperintensities are considered an established finding in MDD, particularly in older patients, our meta-analysis showed only modest increases compared with healthy controls.
The reported effect sizes in this meta-analysis were smaller than those in 2 earlier meta-analyses 16 , of depression studies. Our meta-analysis included only studies on patients with MDD; however, both previous meta-analyses included studies that evaluated MDD and BD patients as a single group, - which may have inflated the effect size. Indeed, our study indicates that patients with BD have more than a 2-fold increase in rates of deep white matter hyperintensities compared with MDD patients Table 5. We excluded reports on VBM from the meta-analysis; however, a qualitative review of these studies partially supports our findings.
In 12 VBM studies that examined gray matter volume, the most consistent findings were hippocampal volume reduction 7 studies - and volumetric reductions within the frontal lobe 7 studies. Based on findings from a large number of independent studies in the meta-analysis comparison, MDD is associated with reductions in basal ganglia and hippocampal volume, and BD is more strongly associated with white matter abnormalities, specifically deep white matter hyperintensities and reduced corpus callosum area.
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In terms of similarities, both disorders showed ventricular enlargement and increased rates of subcortical gray matter hyperintensities. The positive association between patient age and hippocampal volume in the BD sample reinforces the identified difference in hippocampal volume between patients with MDD and those with BD; if studies on BD had recruited older patients in the same way as MDD studies did, the difference would have been greater. The larger extent of gray matter volume reductions in MDD was surprising, given that BD is considered a more chronic illness and is associated with an earlier age at onset 2 and more episodes of major depression compared with MDD.
Because studies of twins have shown that there are both overlapping and distinct genetic risk factors for BD and MDD, it is possible that the unique genetic factors for each disorder are associated with the distinct structural abnormalities identified in this meta-analysis. Although the case-control meta-analysis is statistically highly powered, the meta-regression analysis of clinical variables lacks power and may be prone to type I and type II errors.
Klinik und Poliklinik für Psychiatrie, Psychosomatik und Psychotherapie (PPP)
This strategy reduces the number of comparisons and associated type I errors; however, it is possible that brain regions that distinguish the disorders were overlooked. Although we attempted to take into account differences in medications between the groups, it was not possible to account for this entirely because of the limited information reported in studies.
A previous meta-analysis of BD studies 9 and other studies , have shown that use of lithium may increase gray matter volume, and it is possible that lithium may be masking abnormalities that would have been observed if patients with BD were not using this medication. Therefore, it is possible that the differences in brain structure between MDD patients who do not convert and BD patients are more pronounced than the differences reported in this study. In conclusion, in this meta-analysis, we have shown robust structural brain abnormalities in MDD and particular changes in brain volume that may distinguish MDD from BD.
Further studies may reveal whether these abnormalities are a risk factor for developing MDD, when they first occur, and whether they are predictive of treatment response. April 22, ; final revision received September 28, ; accepted November 30, Dr Kempton had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. The sponsors of the study had no role in the design or conduct of this study; in the collection, management, analysis, and interpretation of the data; or in the preparation, review, or approval of the manuscript.
National Comorbidity Survey Replication. The epidemiology of major depressive disorder: Lifetime and month prevalence of bipolar spectrum disorder in the National Comorbidity Survey replication. Clinical features of bipolar depression versus major depressive disorder in large multicenter trials. National trends in the outpatient treatment of depression. Trends in the treatment of bipolar disorder by outpatient psychiatrists. Bipolar and major depressive disorder: Volumetric neuroimaging investigations in mood disorders: Meta-analysis, database, and meta-regression of 98 structural imaging studies in bipolar disorder.
Magnetic resonance imaging studies in bipolar disorder and schizophrenia: Gray matter, white matter, brain, and intracranial volumes in first-episode bipolar disorder: Hippocampal volume and depression: Brain volume abnormalities in major depressive disorder: A meta-analysis examining clinical predictors of hippocampal volume in patients with major depressive disorder. Amygdala volume in major depressive disorder: MRI findings in patients with affective disorder: A wiki for the life sciences where authorship matters.
A comparison of self-report and clinical diagnostic interviews for depression: A rating scale for depression. J Neurol Neurosurg Psychiatry. Statistical Methods for Meta-analysis. Meta-analysis of magnetic resonance imaging brain morphometry studies in bipolar disorder. Meta-analysis in clinical trials.
Meta-analysis of regional brain volumes in schizophrenia. Methods for Meta-analysis in Medical Research. Measuring inconsistency in meta-analyses. Bias in meta-analysis detected by a simple, graphical test. Ventricular enlargement in major depression. Ventricular and sulcal size at the onset of psychosis. Ventricular abnormalities in affective disorder: Subcortical hyperintensity on magnetic resonance imaging: The ventricular-brain ratio VBR in functional psychoses: Brain imaging abnormalities in mental disorders of late life.
A magnetic resonance imaging study of putamen nuclei in major depression. MRI of corpus callosum and septum pellucidum in depression. White matter hyperintensity signals in psychiatric and nonpsychiatric subjects. Leukoencephalopathy and major depression: Magnetic resonance imaging of the caudate nuclei in depression: All-night electroencephalographic sleep and cranial computed tomography in depression: Eur Arch Psychiatry Clin Neurosci.
Posterior fossa abnormalities in major depression: Hypercortisolemia and hippocampal changes in depression. Neuroanatomical substrates of depression in the elderly. Diminished subcortical nuclei volumes in Parkinson's disease by MR imaging. J Neural Transm Suppl. Magnetic resonance and positron emission tomography imaging of the corpus callosum: Reduction of cerebral blood flow in older depressed patients.
MRI high-intensity signals in late-life depression and Alzheimer's disease: Am J Geriatr Psychiatry. Magnetic resonance imaging and mood disorders: Diagnostic specificity of focal white matter abnormalities in bipolar and unipolar mood disorder. Differences in qualitative brain morphology findings in schizophrenia, major depression, bipolar disorder, and normal volunteers. Brain morphology assessed by computed tomography in patients with geriatric depression, patients with degenerative dementia, and normal control subjects.
Increased prefrontal sulcal prominence in relatively young patients with unipolar major depression. MRI signal hyperintensities in geriatric depression. MRI changes in schizophrenia in late life: Cognition and white matter hyperintensities in older depressed patients. Unreliability of TRH test but not dexamethasone suppression test as a marker of depression in chronic vasculopathic patients. Subgenual prefrontal cortex abnormalities in mood disorders. Quantitative anatomic measures and comorbid medical illness in late-life major depression.
Quantitative magnetic resonance imaging in geriatric depression and primary degenerative dementia. A quantitative magnetic resonance imaging study of cerebral and cerebellar gray matter volume in primary unipolar major depression: Late-onset minor and major depression: Magnetic-resonance morphometry in patients with major depression. A quantitative magnetic resonance imaging study of caudate and lenticular nucleus gray matter volume in primary unipolar major depression: Amygdala core nuclei volumes are decreased in recurrent major depression.
Neuropsychological functioning and MRI signal hyperintensities in geriatric depression. White matter hyperintensities and gray matter lesions in physically healthy depressed subjects. Absence of striatal volume differences between depressed subjects with no comorbid medical illness and matched comparison subjects. Hippocampal volume reduction in major depression.
Atrophy and high intensity lesions: Hippocampal volume in primary unipolar major depression: MRI study of thalamic volumes in bipolar and unipolar patients and healthy individuals. A controlled study of MRI signal hyperintensities in older depressed patients with and without hypertension. J Am Geriatr Soc. A factor model of the functional psychoses and the relationship of factors to clinical variables and brain morphology. Subcortical hyperintensities on magnetic resonance imaging: Hippocampal morphometry in depressed patients and control subjects: Decreased pituitary volume in patients with bipolar disorder.
Volumetric reduction in left subgenual prefrontal cortex in early onset depression. Anatomical MRI study of subgenual prefrontal cortex in bipolar and unipolar subjects. Reduced volume of orbitofrontal cortex in major depression. Enlargement of the amygdala in patients with a first episode of major depression. Prefrontal cortical volume in childhood-onset major depression: CSF spaces of the Sylvian fissure region in severe melancholic depression. Structural magnetic resonance imaging in patients with first-episode schizophrenia, psychotic and severe non-psychotic depression and healthy controls: Br J Psychiatry Suppl.
Smaller frontal lobe white matter volumes in depressed adolescents. Anatomic location and laterality of MRI signal hyperintensities in late-life depression. As a result, self-compatibility should be common among colonizing species. This idea, labelled 'Baker's law', has been influential in discussions of sexual- system and mating-system evolution. However, its generality has been questioned, because models of the evolution of dispersal and the mating system predict an association between high dispersal rates and outcrossing rather than selfing, and because of many apparent counter examples to the law.
The contrasting predictions made by models invoking Baker's law versus those for the evolution of the mating system and dispersal urges a reassessment of how we should view both these traits. Here, I review the literature on the evolution of mating and dispersal in colonizing species, with a focus on conceptual issues. I argue for the importance of distinguishing between the selfing or outcrossing rate and a simple ability to self-fertilize, as well as for the need for a more nuanced consideration of dispersal.
Colonizing species will be characterized by different phases in their life pattern: This dynamic means that the sorting of mating-system and dispersal traits should change over time, making simple predictions difficult. MATE incorporates a standard management approach and a standard architecture designed to implement a cradle-to-grave approach to the acquisition of ATE and to significantly reduce the life cycle cost of weapons systems support.
The guides also provide the necessary specifications for industry to build MATE -qualifiable equipment. Effects of maternal lines and mating systems on lamb carcass merit. The objective of this study was to analyze the carcass composition of lambs produced from different mating systems. ICON will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.
The explorer will help determine the physics of Earth's space environment and pave the way for mitigating its effects on our technology, communications systems and society. Global biogeography of mating system variation in seed plants. Latitudinal gradients in biotic interactions have been suggested as causes of global patterns of biodiversity and phenotypic variation. Plant biologists have long speculated that outcrossing mating systems are more common at low than high latitudes owing to a greater predictability of plant-pollinator interactions in the tropics; however, these ideas have not previously been tested.
Here, we present the first global biogeographic analysis of plant mating systems based on published studies from taxa. We found a weak decline in outcrossing rate towards higher latitudes and among some biomes, but no biogeographic patterns in the frequency of self-incompatibility. Incorporating life history and growth form into biogeographic analyses reduced or eliminated the importance of latitude and biome in predicting outcrossing or self-incompatibility. Our results suggest that biogeographic patterns in mating system are more likely a reflection of the frequency of life forms across latitudes rather than the strength of plant-pollinator interactions.
Combined with a second metallic plate, the pore-filled metallic plates form a bipolar plate with an empty cavity in the center. Mammals and birds regularly express mate preferences and make mate choices. It has been proposed that intense romantic love, a human cross-cultural universal, is a developed form of this attraction system. Activation specific to the beloved occurred in the brainstem right ventral tegmental area and right postero-dorsal body of the caudate nucleus.
These and other results suggest that dopaminergic reward and motivation pathways contribute to aspects of romantic love. We also used fMRI to study 15 men and women who had just been rejected in love. These data contribute to our view that romantic love is one of the three primary brain systems that evolved in avian and mammalian species to direct reproduction. The sex drive evolved to motivate individuals to seek a range of mating partners; attraction evolved to motivate individuals to prefer and pursue specific partners; and attachment evolved to motivate individuals to remain together long enough to complete species-specific parenting duties.
These three behavioural repertoires appear to be based on brain systems that are largely distinct yet interrelated, and they interact in specific ways to orchestrate reproduction, using both hormones and monoamines. Romantic attraction in humans and its antecedent in other mammalian species play a primary role: Male resource defense mating system in primates? An experimental test in wild capuchin monkeys. Ecological models of mating systems provide a theoretical framework to predict the effect of the defendability of both breeding resources and mating partners on mating patterns.
In resource-based mating systems , male control over breeding resources is tightly linked to female mating preference. To date, few field studies have experimentally investigated the relationship between male resource control and female mating preference in mammals due to difficulties in manipulating ecological factors e. Results did not support the within-group male resource defense hypothesis, as female sexual preferences for alpha males did not vary based on food defendability.
We discuss possible reasons for our results, including the possibility of other direct and indirect benefits females receive in exercising mate choice, the potential lack of tolerance over food directed towards females by alpha males, and phylogenetic constraints. Effect of component design in retrieved bipolar hip hemiarthroplasty systems. Primary articulation of bipolar hemiarthroplasty systems is at the femoral head-liner interface. The purpose of this study was to compare observed damage modes on 36 retrieved bipolar systems with implant, demographic, intraoperative, and radiographic data to elucidate the effects of component design, specifically locking mechanism, on clinical performance.
Retrieved bipolar hip hemiarthroplasty systems of 3 different design types were obtained, disassembled, and evaluated macro- and microscopically for varying modes of wear, including abrasion, burnishing, embedding, scratching, and pitting. Clinical record review and radiographic analysis were performed by a senior orthopedic surgery resident. Average bipolar hip hemiarthroplasty system term of service was 46 months range, 0.
All devices contained wear debris captured within the articulating space between the femoral head and liner. In addition, implant design and observed damage modes, including pitting and third-body particle embedding, were significantly associated with radiographically observed osteolysis. Mating systems of Cuphea laminuligera and Cuphea lutea.
In this paper, the mating systems of experimental populations of C. Outcrossing rates t were estimated for four populations of C. Populations were grown at densities of 1. Pollen and ovule frequencies and single locus and multilocus outcrossing rates were estimated for each population using the mixed- mating model. Multilocus estimates of t ranged from 0. Outcrossing rates increased as density increased within C. Toward a complex system understanding of bipolar disorder: A chaotic model of abnormal circadian activity rhythms in euthymic bipolar disorder.
In the absence of a comprehensive neural model to explain the underlying mechanisms of disturbed circadian function in bipolar disorder, mathematical modeling is a helpful tool. Here, circadian activity as a response to exogenous daily cycles is proposed to be the product of interactions between neuronal networks in cortical cognitive processing and subcortical pacemaker areas of the brain. To investigate the dynamical aspects of the link between disturbed circadian activity rhythms and abnormalities of neurotransmitter functioning in frontal areas of the brain, we developed a novel mathematical model of a chaotic system which represents fluctuations in circadian activity in bipolar disorder as changes in the model's parameters.
A novel map-based chaotic system was developed to capture disturbances in circadian activity across the two extreme mood states of bipolar disorder.test2.web-kovalev.ru/assets/71-hydroxychloroquine-sulfate-meilleur.php
Psychiatrie und Poliklinik
The model uses chaos theory to characterize interplay between neurotransmitter functions and rhythm generation; it aims to illuminate key activity phenomenology in bipolar disorder, including prolonged sleep intervals, decreased total activity and attenuated amplitude of the diurnal activity rhythm. To test our new cortical-circadian mathematical model of bipolar disorder, we utilized previously collected locomotor activity data recorded from normal subjects and bipolar patients by wrist-worn actigraphs.
All control parameters in the proposed model have an important role in replicating the different aspects of circadian activity rhythm generation in the brain. Although neuroimaging research has strongly implicated a reciprocal interaction between cortical and subcortical regions as pathogenic in bipolar disorder, this is the first model to mathematically represent this.
Most patients suffer from medical and other psychiatric comorbidities, which worsen the psychiatric symptoms and decrease the likelihood of remission. Cardiovascular disease is the major cause of high mortality rates in these patients, with 1. The rates of cardiovascular risk factors and their resulting increased mortality rates are similar to those found in schizophrenia.
Therefore, the current perspective is that bipolar disorder is not only a psychiatric disorder, but rather a multi- system illness, affecting the entire body. The optimal treatment for these patients should include diagnosis, monitoring and treatment of both psychiatric and physical symptoms, which would improve their prognosis. Mate -Selection Systems and Criteria: Variation according to Family Structure.
Autonomous mate selection based on romantic attraction is more likely to be institutionalized in societies with nuclear family systems. Neolocal residence customs increase the probability that mate selection is autonomous but decrease the probability that it is based on romantic attraction.
The shapes of single event transients in linear bipolar circuits are distorted by exposure to total ionizing dose radiation. Some transients become broader and others become narrower. Such distortions may affect SET system error rates in a radiation environment. If the transients are broadened by TID, the error rate could increase during the course of a mission, a possibility that has implications for hardness assurance. Nickel-hydrogen bipolar battery systems.
Nickel-hydrogen cells are currently being manufactured on a semi-experimental basis. Rechargeable nickel-hydrogen systems are described that more closely resemble a fuel cell system than a traditional nickel-cadmium battery pack. This has been stimulated by the currently emerging requirements related to large manned and unmanned low earth orbit applications. The resultant nickel-hydrogen battery system should have a number of features that would lead to improved reliability, reduced costs as well as superior energy density and cycle lives as compared to battery systems constructed from the current state-of-the-art nickel-hydrogen individual pressure vessel cells.
Nickel-hydrogen bipolar battery system. This was stimulated by the currently emerging requirements related to large manned and unmanned low Earth orbit applications. Host social organization and mating system shape parasite transmission opportunities in three European bat species. For non-mobile parasites living on social hosts, infection dynamics are strongly influenced by host life history and social system.
We explore the impact of host social systems on parasite population dynamics by comparing the infection intensity and transmission opportunities of three mite species of the genus Spinturnix across their three European bat hosts Myotis daubentonii, Myotis myotis, Myotis nattereri during the bats' autumn mating season. Mites mainly reproduce in host maternity colonies in summer, but as these colonies are closed, opportunities for inter-colony transmission are limited to host interactions during the autumn mating season.
The three investigated hosts differ considerably in their social system , most notably in maternity colony size, mating system , and degree of male summer aggregation. We observed marked differences in parasite infection during the autumn mating period between the species, closely mirroring the predictions made based on the social systems of the hosts. Increased host aggregation sizes in summer yielded higher overall parasite prevalence and intensity, both in male and female hosts.
Moreover, parasite levels in male hosts differentially increased throughout the autumn mating season in concordance with the degree of contact with female hosts afforded by the different mating systems of the hosts. Critically, the observed host-specific differences have important consequences for parasite population structure and will thus affect the coevolutionary dynamics between the interacting species.
Therefore, in order to accurately characterize host-parasite dynamics in hosts with complex social systems , a holistic approach that investigates parasite infection and transmission across all periods is warranted. Bones were grinded into powder by freeze-mill. Complete STR typing results were obtained from 8 samples. The domestication syndrome of many plants includes changes in their mating systems.
The evolution of the latter is shaped by ecological and genetic factors that are particular to an area. Thus, the reproductive biology of wild relatives must be studied in their natural distribution to understand the mating system of a crop species as a whole. Gossypium hirsutum upland cotton includes both domesticated varieties and wild populations of the same species. Most studies on mating systems describe cultivated cotton as self-pollinated, while studies on pollen dispersal report outcrossing; however, the mating system of upland cotton has not been described as mixed and little is known about its wild relatives.
Using classic reproductive biology methods, our data demonstrate that upland cotton presents a mixed mating system throughout the complex. This characterization of the diversity of the wild relatives in their natural distribution, as well as their interactions with the crop, will be useful to design and implement adequate strategies for conservation and biosecurity.
The hypothesis that patterns of sex-biased dispersal are related to social mating system in mammals and birds has gained widespread acceptance over the past 30 years. However, two major complications have obscured the relationship between these two behaviors: Here, we present a phylogenetic analysis of the relationship between mating system and sex-biased dispersal in mammals and birds. Results indicate that the evolution of female-biased dispersal in mammals may be more likely on monogamous branches of the phylogeny, and that females may disperse farther than males in socially monogamous mammalian species.
However, we found no support for a relationship between social mating system and sex-biased dispersal in birds when the effects of phylogeny are taken into consideration. We caution that although there are larger-scale behavioral differences in mating system and sex-biased dispersal between mammals and birds, mating system and sex-biased dispersal are far from perfectly associated within these taxa. Observations of bipolar outflows, including jets often with clumpy concentrations of matter, have been made for a wide variety of astronomical systems.
In most but not all of the systems , an accretion disk is present. It is proposed that the general process responsible for bipolar ejection involves the conversion of rotational energy into magnetic energy, usually in the form of a polar magnetic torus, deep in the interiors of the systems involved.
If the buoyancy of the torus resullts in draining the field lines of most of the matter which they thread, then the acceleration of the remaining matter in the toroidal bubble may produce velocities in excess of the escape velocity from the surface of the system.
It is contemplated that this process will be repeated many times in most systems. A discussion is given of the application of these ideas to protostars, to stars evolved beyond the main sequence, to neutron stars, and to black holes on both stellar and galactic scales. Hotshots, hotspots, and female preference in the organization of lek mating systems.
We critically review the female-preference and hotspot models, the two most widely accepted recent explanations of lek organization. On the basis of what we believe are the inadequacies of these models-too great a reliance on the presumed acuity of female discrimination, the assumption that females have full freedom of choice within the lek, and insufficient recognition of the importance of male-male interactions-we develop an alternative set of hypotheses, which we call the hotshot model, to explain the development and maintenance of lek behavior.
Our model attributes strong male mating skew to the interaction between 1 simplified and conservative mating rules of females and 2 social dominance among males. We demonstrate the importance of male-male dominance relationships in lek and non-lek court mating systems. We then argue that a strong mating skew among males forces novice males entering a population to adopt a long-term mating strategy that involves delayed breeding floating and subordinate lek behavior. The structure of leks is created by a complex of malemale interactions, with conflict between hotshots who attempt to control lek mating and subordinates, who may benefit from disrupting lek activities.
Explanations for the number of males in an arena and inter-arena distances are based on modifications of the hotspot and female-preference models. We suggest specific field tests to help distinguish which hypothesis best models the behavioral interactions that produce lek mating. Individuals with bipolar disorder and their relationship with the criminal justice system: Bipolar disorder is a severe and prevalent psychiatric disease. Poor outcomes include a high frequency of criminal acts, imprisonments, and repeat offenses. This critical review of the international literature examined several aspects of the complex relationship between individuals with bipolar disorder and the criminal justice system: In prison, patients' bipolar disorder symptoms can complicate their relationship with prison administrators, leading to an increased risk of multiple incarcerations.
Moreover, the risk of suicide increases for these prisoners. Criminal acts are common among patients with bipolar disorder and are often associated with problems such as addiction. Thus it is important to improve the diagnosis and treatment of inmates with bipolar disorder. Mating system and the evolution of sex-specific mortality rates in two nymphalid butterflies.
Life-history theory predicts that organisms should invest resources into intrinsic components of lifespan only to the degree that it pays off in terms of reproductive success. The benefit of a long life may differ between the sexes and different mating systems may therefore select for different sex-specific mortality rates. In insects with polyandrous mating systems , females mate throughout their lives and male reproductive success is likely to increase monotonously with lifespan.
In monandrous systems , where the mating season is less protracted because receptive females are available only at the beginning of the flight season, male mating success should be less dependent on a long lifespan. Here, we show, in a laboratory experiment without predation, that the duration of the mating season is longer in the polyandrous comma butterfly, Polygonia c-album, than in the monandrous peacock butterfly, Inachis io, and that, in line with predictions, male lifespan is shorter than female lifespan in I. Despite the diverse array of mating systems and life histories which characterise the parasitic Hymenoptera, sexual selection and sexual conflict in this taxon have been somewhat overlooked.
For instance, parasitoid mating systems have typically been studied in terms of how mating structure affects sex allocation. In the past decade, however, some studies have sought to address sexual selection in the parasitoid wasps more explicitly and found that, despite the lack of obvious secondary sexual traits, sexual selection has the potential to shape a range of aspects of parasitoid reproductive behaviour and ecology.
Moreover, various characteristics fundamental to the parasitoid way of life may provide innovative new ways to investigate different processes of sexual selection. The overall aim of this review therefore is to re-examine parasitoid biology with sexual selection in mind, for both parasitoid biologists and also researchers interested in sexual selection and the evolution of mating systems more generally. We will consider aspects of particular relevance that have already been well studied including local mating structure, sex allocation and sperm depletion.
We go on to review what we already know about sexual selection in the parasitoid wasps and highlight areas which may prove fruitful for further investigation. In particular, sperm depletion and the costs of inbreeding under chromosomal sex determination provide novel opportunities for testing the role of direct and indirect benefits for the evolution of mate choice. Water turbidity by algal blooms causes mating system breakdown in a shallow-water fish, the sand goby Pomatoschistus minutus. Eutrophication as a result of human activity has resulted in increased algal blooms and turbidity in aquatic environments.
We investigated experimentally the effect of algal turbidity on the mating system and sexual selection in the sand goby, Pomatoschistus minutus Pallas , a marine fish with a resource-defence mating system and paternal care. Owing to male-male competition and female choice, large males can monopolize multiple mates , while some males do not achieve mating at all. We show that the number of eggs laid was the same in both turbid and clear tanks but that mating success was more evenly distributed among males in turbid than in clear water. The opportunity for sexual selection was lower in turbid conditions.
In turbid conditions mating success was less skewed towards large males. Our results suggest that increased turbidity can change mating systems and decrease the opportunity for sexual selection as well as selection intensity. Bateman's principles continue to play a major role in the characterization of genetic mating systems in natural populations. The modern manifestations of Bateman's ideas include the opportunity for sexual selection i. I s - the variance in relative mating success , the opportunity for selection i.
I - the variance in relative reproductive success and the Bateman gradient i.
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These variables serve as the foundation for one convenient approach for the quantification of mating systems. The first challenge is that confidence intervals for these variables are not easy to calculate. The second, more serious, problem is that direct estimates of mating system variables from open populations will typically be biased if some potential progeny or adults are missing from the analysed sample. Heterothallic Type of Mating System for Cordyceps cardinalis. Cordyceps cardinalis successfully produced its fruiting bodies from multi-ascospore isolates.
However, subcultures of multi-ascospore isolates could not produce fruiting bodies after few generations. Fruiting body production also differed from sector to sector of the same isolate. Single ascospore isolates were then co-inoculated in combinations of two to observe the fruiting characteristics. Combinations of certain isolates produced perithecial stromata formation, whereas other combinations did not produce any fruiting bodies.
These results show that C. It was also shown that single ascospore isolates are hermaphrodites. Organisms are predicted to behave more favourably towards relatives, and kin-biased cooperation has been found in all domains of life from bacteria to vertebrates. Cooperation based on genetic recognition cues is paradoxical because it disproportionately benefits individuals with common phenotypes, which should erode the required cue polymorphism. Theoretical models suggest that many recognition loci likely have some secondary function that is subject to diversifying selection, keeping them variable.
Here, we use individual-based simulations to investigate the hypothesis that the dual use of recognition cues to facilitate social behaviour and disassortative mating e. Our model shows that when organisms mate disassortatively with respect to their recognition cues, cooperation and recognition locus diversity can persist at high values, especially when outcrossed matings produce more surviving offspring.
Mating system affects cue diversity via at least four distinct mechanisms, and its effects interact with other parameters such as population structure. Also, the attrition of cue diversity is less rapid when cooperation does not require an exact cue match. Using a literature review, we show that there is abundant empirical evidence that heritable recognition cues are simultaneously used in social and sexual behaviour.
Our models show that mate choice is one possible resolution of the paradox of genetic kin recognition, and the literature review suggests that genetic recognition cues simultaneously inform assortative cooperation and disassortative mating in a large range of taxa. However, direct evidence is scant and there is substantial scope for future work. This contribution summarizes that which has been learned in recent years and presents new data that clearly show that the mating system of P. Lifetime mating duration is the most important proximate determinant of male fitness. Males employing alternative mating tactics obtain copulations of varying duration in relation to the following sequence: The number of salivary masses which males provide to females during their lifetime is significantly correlated with the lifetime condition index.
The condition index depends on the fighting prowess of males and their ability to find food items. Thus saliva secretion of Panorpa is considered a Zahavian handicap, which can serve as an honest quality indicator used by mating females. Our results confirm four main predictions of the indicator model of the theory of sexual selection: The evolutionary consequences of the mating pattern and the sperm competition mechanism in P.
The influence of pleiotropy between viability and pollen fates on mating system evolution. Floral displays are functionally and genetically integrated structures, so modifications to display will likely affect multiple fitness components pleiotropy , including pollen export and self-pollination, and therefore selfing rate. Consequently, the great diversities of floral displays and of mating systems found among angiosperms have likely co-evolved.
I extend previous models of mating system evolution to determine how pleiotropy that links viability e. I show that the outcome depends on how pollen shifts from being exported, unused, or used for selfing. Furthermore, pleiotropy that affects viability can explain observations not addressed by previous theory, including the evolution of mixed mating despite high inbreeding depression in the absence of pollen-limitation.
Therefore, pleiotropy may play a key role in explaining selfing rates for such species that exhibit otherwise enigmatic mating systems. Estimation of mating system parameters in plant populations using marker loci with null alleles. The extension permits the estimation of the rate of self-fertilization s and allele frequencies Pi at loci in outcrossing pollen, at marker loci having recessive null alleles. The algorithm makes use of maternal and filial genotypic arrays obtained by the electrophoretic analysis of cohorts of progeny.
The genotypes of maternal plants must be known. Explicit equations are given for cases when the genotype of the maternal gamete inherited by a seed can gymnosperms or cannot angiosperms be determined. The procedure can accommodate any number of codominant alleles, but only one recessive null allele at each locus. An example, using actual data from Pinus banksiana, is presented to illustrate the application of this EM algorithm to the estimation of mating system parameters using marker loci having both codominant and recessive alleles.
To explore a new method in order to extract DNA from bones and teeth automatically. Samples of 33 bones and 15 teeth were acquired by freeze-mill method and manual method, respectively. There was no statistical difference between the two methods in the DNA concentration of bones. Both bones and teeth got the good STR typing by freeze-mill method, and the DNA concentration of teeth was higher than those by manual method.
Design and research on the two-joint mating system of underwater vehicle. In the 21st century, people have come to the era of ocean science and ocean economy. With the development of ocean science and technology and the thorough research on the ocean, underwater mating technique has been widely used in such fields as sunk ship salvage, deep ocean workstation, submarine lifesaving aid and military affairs.
In this paper, researches are made home and abroad on mating technology. Two-joint mating system of underwater vehicle is designed including plane system , three-dimensional assembly system and control system in order to increase the capacity of adapting platform obliquity and adopting rotational skirt scheme. It is clear that the system fits the working space of underwater vehicle passageway and there is no interference phenomenon in assembly design.
The finite element model of the system shell and the pressurization of the joint are established. The results of the finite element computing and the pressing test are accordant, and thus it can testify that the shell material meet the need of intension and joint pressurization is reliable.
Modeling of the control system is accomplished, and simulation and analysis are made, which can provide directions for the controller design of mating system of underwater vehicles. Estimation of mating system parameters in an evolving gynodioecous population of cultivated sunflower Helianthus annuus L. Cultivated plants have been molded by human-induced selection, including manipulations of the mating system in the twentieth century. How these manipulations have affected realized parameters of the mating system in freely evolving cultivated populations is of interest for optimizing the management of breeding populations, predicting the fate of escaped populations and providing material for experimental evolution studies.
To produce modern varieties of sunflower Helianthus annuus L. Populations deriving from hybrid-F1 varieties are gynodioecious because of the segregation of a nuclear restorer of male fertility. Using both phenotypic and genotypic data at 11 microsatellite loci, we analyzed the consanguinity status of plants of the first three generations of such a population and estimated parameters related to the mating system. According to theoretical models, the female advantage and the inbreeding depression at the seed production stage were too low to allow the persistence of male sterility.
We discuss our methods of parameter estimation and the potential of such study system in evolutionary biology. Effective size of density-dependent two-sex populations: Density dependence in vital rates is a key feature affecting temporal fluctuations of natural populations. This has important implications for the rate of random genetic drift. Mating systems also greatly affect effective population sizes, but knowledge of how mating system and density regulation interact to affect random genetic drift is poor. Using theoretical models and simulations, we compare N e in short-lived, density-dependent animal populations with different mating systems.
We study the impact of a fluctuating, density-dependent sex ratio and consider both a stable and a fluctuating environment. The magnitude of this decrease was affected by mating system and life history. Environmental stochasticity amplifies temporal fluctuations in population size and is thus vital to consider in estimation of effective population sizes over longer time periods. Our results on the reduced loss of genetic variation at small densities, particularly in polygamous populations, indicate that density regulation may facilitate adaptive evolution at small population sizes.
Host mating system and the prevalence of a disease in a plant population. A modified susceptible—infected—recovered SIR host—pathogen model is used to determine the influence of plant mating system on the outcome of a host—pathogen interaction. Unlike previous models describing how interactions between mating system and pathogen infection affect individual fitness, this model considers the potential consequences of varying mating systems on the prevalence of resistance alleles and disease within the population.
If a single allele for disease resistance is sufficient to confer complete resistance in an individual and if both homozygote and heterozygote resistant individuals have the same mean birth and death rates, then, for any parameter set, the selfing rate does not affect the proportions of resistant, susceptible or infected individuals at equilibrium. If homozygote and heterozygote individual birth rates differ, however, the mating system can make a difference in these proportions. In that case, depending on other parameters, increased selfing can either increase or decrease the rate of infection in the population.
Results from this model also predict higher frequencies of resistance alleles in predominantly selfing compared to predominantly outcrossing populations for most model conditions. In populations that have higher selfing rates, the resistance alleles are concentrated in homozygotes, whereas in more outcrossing populations, there are more resistant heterozygotes. Mating system and ploidy influence levels of inbreeding depression in Clarkia Onagraceae.
Inbreeding depression is the reduction in offspring fitness associated with inbreeding and is thought to be one of the primary forces selecting against the evolution of self-fertilization. Studies suggest that most inbreeding depression is caused by the expression of recessive deleterious alleles in homozygotes whose frequency increases as a result of self-fertilization or mating among relatives.
This process leads to the selective elimination of deleterious alleles such that highly selfing species may show remarkably little inbreeding depression. Genome duplication polyploidy has also been hypothesized to influence levels of inbreeding depression, with polyploids expected to exhibit less inbreeding depression than diploids. We studied levels of inbreeding depression in allotetraploid and diploid species of Clarkia Onagraceae that vary in mating system each cytotype was represented by an outcrossing and a selfing species.
The outcrossing species exhibited more inbreeding depression than the selfing species for most fitness components and for two different measures of cumulative fitness. In contrast, though inbreeding depression was generally lower for the polyploid species than for the diploid species, the difference was statistically significant only for flower number and one of the two measures of cumulative fitness. Further, we detected no significant interaction between mating system and ploidy in determining inbreeding depression.
In sum, our results suggest that a taxon's current mating system is more important than ploidy in influencing levels of inbreeding depression in natural populations of these annual plants. Can bipolar disorder be viewed as a multi- system inflammatory disease?
Background Patients with bipolar disorder are known to be at high risk of premature death. Comorbid cardio-vascular diseases are a leading cause of excess mortality, well above the risk associated with suicide. In this review, we explore comorbid medical disorders, highlighting evidence that bipolar disorder can be effectively conceptualized as a multi- systemic inflammatory disease. Methods We conducted a systematic PubMed search of all English-language articles recently published with bipolar disorder cross-referenced with the following terms: Results Evidence gathered so far suggests that the multi- system involvement is present from the early stages, and therefore requires proactive screening and diagnostic procedures, as well as comprehensive treatment to reduce progression and premature mortality.
Exploring the biological pathways that could account for the observed link show that dysregulated inflammatory background could be a common factor underlying cardio-vascular and bipolar disorders. Limitations The current literature substantially lacks longitudinal and mechanistic studies, as well as comparison studies to explore the magnitude of the medical burden in bipolar disorder compared to major mood disorders as well as psychotic disorders.
It is also necessary to look for subgroups of bipolar disorder based on their rates of comorbid disorders. Conclusions Comorbid medical illnesses in bipolar disorder might be viewed not only as the consequence of health behaviors and of psychotropic medications, but rather as an early manifestation of a multi- systemic disorder. Medical monitoring is thus a critical component of case assessment. Neural bases of human mate choice: Mate choice is an example of sophisticated daily decision making supported by multiple componential processes. In mate -choice literature, different characteristics of the value dimensions, including the sex difference in the value dimensions, and the involvement of self-assessment due to the mutual nature of the choice, have been suggested.
We examined whether the brain-activation pattern during virtual mate choice would be congruent with these characteristics in terms of stimulus selectivity and activated brain regions. In measuring brain activity, young men and women were shown two pictures of either faces or behaviors, and they indicated which person they would choose either as a spouse or as a friend. Activation selective to spouse choice was observed face-selectively in men's amygdala and behavior-selectively in women's motor system. During both partner-choice conditions, behavior-selective activation was observed in the temporoparietal regions.
Taking the available knowledge of these regions into account, these results are congruent with the suggested characteristics of value dimensions for physical attractiveness, parenting resources, and beneficial personality traits for a long-lasting relationship, respectively. The medial prefrontal and posterior cingulate cortices were nonselectively activated during the partner choices, suggesting the involvement of a self-assessment process. The results thus provide neuroscientific support for the multi-component mate -choice mechanism.
Modelling the mating system of polar bears: Allee effects may render exploited animal populations extinction prone, but empirical data are often lacking to describe the circumstances leading to an Allee effect.
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Arbitrary assumptions regarding Allee effects could lead to erroneous management decisions so that predictive modelling approaches are needed that identify the circumstances leading to an Allee effect before such a scenario occurs. We present a predictive approach of Allee effects for polar bears where low population densities, an unpredictable habitat and harvest-depleted male populations result in infrequent mating encounters. We develop a mechanistic model for the polar bear mating system that predicts the proportion of fertilized females at the end of the mating season given population density and operational sex ratio.
The model is parametrized using pairing data from Lancaster Sound, Canada, and describes the observed pairing dynamics well. Female mating success is shown to be a nonlinear function of the operational sex ratio, so that a sudden and rapid reproductive collapse could occur if males are severely depleted.
The operational sex ratio where an Allee effect is expected is dependent on population density. We focus on the prediction of Allee effects in polar bears but our approach is also applicable to other species. Female mating preferences determine system -level evolution in a gene network model. Environmental patterns of directional, stabilizing and fluctuating selection can influence the evolution of system -level properties like evolvability and mutational robustness. Intersexual selection produces strong phenotypic selection and these dynamics may also affect the response to mutation and the potential for future adaptation.
In order to to assess the influence of mating preferences on these evolutionary properties, I modeled a male trait and female preference determined by separate gene regulatory networks. I studied three sexual selection scenarios: I measured the effects these mating preferences had on the potential for traits and preferences to evolve towards new states, and mutational robustness of both the phenotype and the individual's overall viability. All types of sexual selection increased male phenotypic robustness relative to a randomly mating population.
The Fisher model also reduced male evolvability and mutational robustness for viability. Under good genes sexual selection, males evolved an increased mutational robustness for viability. Females choosing their mates is a scenario that is sufficient to create selective forces that impact genetic evolution and shape the evolutionary response to mutation and environmental selection. These dynamics will inevitably develop in any population where sexual selection is operating, and affect the potential for future adaptation.
Origin and occurrence of sexual and mating systems in Crustacea: Crustaceans are known for their unrivalled diversity of sexual systems , as well as peculiar mating associations to achieve maximum mating success and fertilization accomplishment. Although sexes are separate in most species, various types of hermaphroditism characterize these predominantly aquatic arthropods. A low operational sex ratio between female and male, together with temporally limited receptivity of females towards males, imposes restrictions on the structuring of mating systems in crustaceans. The basic mating systems consist of monogamy, polygamy, mate guarding and pure searching.
Understandably, ecological influences may also play a determinative role in the evolution of such sexual and mating systems in crustaceans. An important outcome of the crustacean sexual biology is the development of complex social structures in many aquatic species, in much the same way insects have established them in terrestrial conditions. In addition, groups like isopods and certain families of brachyuran crabs have shown terrestrial adaptation, exhibiting peculiar reproductive modes, sometimes reminiscent of their terrestrial counterparts, insects.
Many caridean shrimps, living in symbiotic relationship with other marine invertebrates in the coral reef habitats, have reached pinnacle of complexity in sexuality and peculiar mating behaviours, resulting in communal living and establishing advanced social systems , such as eusociality. Host mating system and the spread of a disease-resistant allele in a population.
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The model presented here modifies a susceptible-infected SI host-pathogen model to determine the influence of mating system on the outcome of a host-pathogen interaction. Both deterministic and stochastic individual-based versions of the model were used. This model considers the potential consequences of varying mating systems on the rate of spread of both the pathogen and resistance alleles within the population. We assumed that a single allele for disease resistance was sufficient to confer complete resistance in an individual, and that both homozygote and heterozygote resistant individuals had the same mean birth and death rates.
When disease invaded a population with only an initial small fraction of resistant genes, inbreeding selfing tended to increase the probability that the disease would soon be eliminated from a small population rather than become endemic, while outcrossing greatly increased the probability that the population would become extinct due to the disease. Verification for the Pressurized Mating Adapters. Effective size of two feral domestic cat populations Felis catus L: A variety of behavioural traits have substantial effects on the gene dynamics and genetic structure of local populations.
The mating system is a plastic trait that varies with environmental conditions in the domestic cat Felis catus allowing an intraspecific comparison of the impact of this feature on genetic characteristics of the population. The two cat populations studied were nearly closed, similar in size and survival parameters, but differed in their mating system.
Immigration appeared extremely restricted in both cases due to environmental and social constraints. Only the genetic results based on Waples' estimator were consistent with the ecological results, but failed to evidence an effect of the mating system. Results based on the estimation of Berthier et al. Such low reliability in the genetic results should retain attention for conservation purposes. Constraints imposed by pollinator behaviour on the ecology and evolution of plant mating systems. Most flowering plants rely on pollinators for their reproduction. Plant-pollinator interactions, although mutualistic, involve an inherent conflict of interest between both partners and may constrain plant mating systems at multiple levels: Here, we review experimental evidence that pollinator behaviour influences plant selfing rates in pairs of interacting species, and that plants can modify pollinator behaviour through plastic and evolutionary changes in floral traits.
We also examine how theoretical studies include pollinators, implicitly or explicitly, to investigate the role of their foraging behaviour in plant mating system evolution. In doing so, we call for more evolutionary models combining ecological and genetic factors, and additional experimental data, particularly to describe pollinator foraging behaviour.
Finally, we show that recent developments in ecological network theory help clarify the impact of community-level interactions on plant selfing rates and their evolution and suggest new research avenues to expand the study of mating systems of animal-pollinated plant species to the level of the plant-pollinator networks. Fungi of the genus Termitomyces live in an obligate symbiosis with termites of the subfamily Macrotermitinae. Many species of Termitomyces frequently form fruit bodies, which develop from the fungus comb within the nest.
In this study, we determined the mating system of a species of Termitomyces associated with the South African termite Macrotermes natalensis. Termite nests were excavated and a Termitomyces sp. For one strain, single basidiospore cultures were obtained from basidiomes growing from the fungus comb after incubation without termites. Using nuclear staining, we show that both comb cultures and single spore cultures have multinucleate cells and that the majority of spores has a single nucleus. These results unambiguously prove that the strain of Termitomyces studied here has a heterothallic mating system , with the fungus garden of the termite mound being in the heterokaryotic phase.
This is the first time the mating system of a Termitomnyces species has been studied. We studied genetic diversity and differentiation patterns in Neotropical plants to address effects of life history traits LHT and ecological attributes based on an exhaustive literature survey. In addition, we used phylogenetic generalized least squares pGLS to account for phylogenetic independence on predictor variables and verify the robustness of the results from significant GLMMs. After accounting for phylogenetic independence i. Plants specifically with outcrossing mating system had lower FST.
Moreover, AR was significantly related to pollination mode and geographical range and HeS for nuclear dominant markers was significantly related to habitat. Our findings showed that different results might be retrieved when phylogenetic non-independence is taken into account and that LHTs and ecological attributes affect substantially the genetic pattern in Neotropical plants, hence may drive key evolutionary processes in plants. Genetic mating systems and reproductive natural histories of fishes: Fish species have diverse breeding behaviors that make them valuable for testing theories on genetic mating systems and reproductive tactics.
Here we review genetic appraisals of paternity and maternity in wild fish populations. Behavioral phenomena quantified by genetic markers in various species include patterns of multiple mating by both sexes; frequent cuckoldry by males and rare cuckoldry by females in nest-tending species; additional routes to surrogate parentage via nest piracy and egg-thievery; egg mimicry by nest-tending males; brood parasitism by helper males in cooperative breeders; clutch mixing in oral brooders; kinship in schooling fry of broadcast spawners; sperm storage by dams in female-pregnant species; and sex-role reversal, polyandry, and strong sexual selection on females in some male-pregnant species.
Additional phenomena addressed by genetic parentage analyses in fishes include clustered mutations, filial cannibalism, and local population size. All results are discussed in the context of relevant behavioral and evolutionary theory. Mating systems of Psychotria tenuinervis Rubiaceae: The aim of this study was to determine and compare the mating systems among Psychotria tenuinervis populations at anthropogenic edges, natural edges, and the forest interior using allozyme electrophoresis of naturally pollinated progeny arrays.
However, there were no differences in either multilocus or single-locus rates among the three habitats, indicating that the contribution of biparental inbreeding to the apparent selfing rate in these populations was very low. The multilocus t m and single-locus t s outcrossing rates for the P.
In conclusion, edge creation seems not to influence its mating systems. Are sex ratio distorting endosymbionts responsible for mating system variation among dance flies Diptera: Maternally inherited bacterial endosymbionts are common in many arthropod species. Empidinae are well known for their unusual reproductive biology, including species with female-specific ornamentation and female-biased lek-like swarming behaviour. The cause of the repeated evolution of female ornaments in these flies remains unknown, but is probably associated with female-biased sex ratios in individual species.
In this study we assessed whether dance flies harbour sex ratio distorting endosymbionts that might have driven these mating system evolutionary changes. We measured the incidence and prevalence of infection by three endosymbionts that are known to cause female-biased sex ratios in other insect hosts Wolbachia, Rickettsia and Spiroplasma across 20 species of dance flies.
We found evidence of widespread infection by all three symbionts and variation in sex-specific prevalence across the taxa sampled. However, there was no relationship between infection prevalence and adult sex ratio measures and no evidence that female ornaments are associated with high prevalences of sex-biased symbiont infections. We conclude that the current distribution of endosymbiont infections is unlikely to explain the diversity in mating systems among dance fly species.
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