scholarly journals An ESS model for divorce strategies in birds

1999 ◽  
Vol 354 (1380) ◽  
pp. 223-236 ◽  
Author(s):  
John M. McNamara ◽  
Pär Forslund ◽  
Alison Lang

We present a theoretical investigation of divorce. Arguments are couched in terms of birds, but should be applicable to other groups of organisms. We model a population in which there is a range of both male and female qualities, and decisions on whether to divorce are made by both members of a breeding pair. The reproductive success of a pair is additive in male and female qualities in the baseline case, but we also consider the effect of quality interactions. The availability of new mates depends on the divorce strategy of all population members. We allow for the possibility that mate choice is associative in quality, although we do not explicitly model the mate choice process. Using a game–theoretical model which incorporates these factors we investigate the following issues: the form of the evolutionary stable strategy, and the implications of this strategy for quality correlations in breeding pairs and for the distribution of qualities among unpaired individuals; divorce rates, reproductive success and mate quality changes over the lifetime of an individual, and the dependence of these qualtities on the individual's quality; mean population divorce rates and their dependence on costs of divorce, longevity and the extent of quality variation in the two sexes; initiators of divorce and reproductive success before and after divorce.

Author(s):  
R. F. Bils ◽  
W. F. Diller ◽  
F. Huth

Phosgene still plays an important role as a toxic substance in the chemical industry. Thiess (1968) recently reported observations on numerous cases of phosgene poisoning. A serious difficulty in the clinical handling of phosgene poisoning cases is a relatively long latent period, up to 12 hours, with no obvious signs of severity. At about 12 hours heavy lung edema appears suddenly, however changes can be seen in routine X-rays taken after only a few hours' exposure (Diller et al., 1969). This study was undertaken to correlate these early changes seen by the roengenologist with morphological alterations in the lungs seen in the'light and electron microscopes.Forty-two adult male and female Beagle dogs were selected for these exposure experiments. Treated animals were exposed to 94.5-107-5 ppm phosgene for 10 min. in a 15 m3 chamber. Roentgenograms were made of the thorax of each animal before and after exposure, up to 24 hrs.


Metabolites ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 206
Author(s):  
Leon Deutsch ◽  
Damjan Osredkar ◽  
Janez Plavec ◽  
Blaž Stres

Spinal muscular atrophy (SMA) is a genetically heterogeneous group of rare neuromuscular diseases and was until recently the most common genetic cause of death in children. The effects of 2-month nusinersen therapy on urine, serum, and liquor 1H-NMR metabolomes in SMA males and females were not explored yet, especially not in comparison to the urine 1H-NMR metabolomes of matching male and female cohorts. In this prospective, single-centered study, urine, serum, and liquor samples were collected from 25 male and female pediatric patients with SMA before and after 2 months of nusinersen therapy and urine samples from a matching healthy cohort (n = 125). Nusinersen intrathecal application was the first therapy for the treatment of SMA by the Food and Drug Administration (FDA) and the European Medicines Agency (EMA). Metabolomes were analyzed using targeted metabolomics utilizing 600 MHz 1H-NMR, parametric and nonparametric multivariate statistical analyses, machine learning, and modeling. Medical assessment before and after nusinersen therapy showed significant improvements of movement, posture, and strength according to various medical tests. No significant differences were found in metabolomes before and after nusinersen therapy in urine, serum, and liquor samples using an ensemble of statistical and machine learning approaches. In comparison to a healthy cohort, 1H-NMR metabolomes of SMA patients contained a reduced number and concentration of urine metabolites and differed significantly between males and females as well. Significantly larger data scatter was observed for SMA patients in comparison to matched healthy controls. Machine learning confirmed urinary creatinine as the most significant, distinguishing SMA patients from the healthy cohort. The positive effects of nusinersen therapy clearly preceded or took place devoid of significant rearrangements in the 1H-NMR metabolomic makeup of serum, urine, and liquor. Urine creatinine was successful at distinguishing SMA patients from the matched healthy cohort, which is a simple systemic novelty linking creatinine and SMA to the physiology of inactivity and diabetes, and it facilitates the monitoring of SMA disease in pediatric patients through non-invasive urine collection.


2009 ◽  
Vol 96 (1) ◽  
pp. 98-103 ◽  
Author(s):  
Maha Zewail-Foote ◽  
Abby Diehl ◽  
Anastasia Benson ◽  
Kuan H. Lee ◽  
Fay A. Guarraci

PLoS ONE ◽  
2017 ◽  
Vol 12 (12) ◽  
pp. e0189679 ◽  
Author(s):  
Flora Borne ◽  
Katja R. Kasimatis ◽  
Patrick C. Phillips

2015 ◽  
Vol 11 (1) ◽  
pp. 17-21
Author(s):  
Y.R. de Souza ◽  
F.B. Feitosa

This study aimed to investigate the gender difference in the manifestation of physical stress in a strenuous military training on Amazon jungle, using alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) markers, measured before and after an adaptation to jungle training. The sample consisted of 49 military volunteers, 35 male and 14 female, recently moved to the Amazon region. All plasma levels rose after the training. Serum ALT (male and female) and AST (male and female), although borderline, remained within normal limits. Already plasma levels of CK (both male and female) and LDH (male and female) largely exceeded the normal range. The average of all markers listed in female gender remained below the levels of the male gender. However, significant differences in biomarkers ALT, AST and CK between genders were found. The study points out that, in a jungle environment, biometric markers ALT, AST, CK and LDH are efficient for monitoring chronic physical stress in both genders, when used in combination. The influence of the weather on the occurrence of physical stress in unacclimated people of both genders, and the lower responses in the levels of ALT, AST, LDH and CK in females were discussed basing on the scientific literature.


2020 ◽  
Vol 126 (5) ◽  
pp. 957-969
Author(s):  
Enya N Quiroz-Pacheco ◽  
Francisco Mora ◽  
Karina Boege ◽  
César A Domínguez ◽  
Ek del-Val

Abstract Background and Aims The implications of herbivory for plant reproduction have been widely studied; however, the relationship of defoliation and reproductive success is not linear, as there are many interacting factors that may influence reproductive responses to herbivore damage. In this study we aimed to disentangle how the timing of foliar damage impacts both male and female components of fitness, and to assess when it has greater impacts on plant reproductive success. Methods We measured herbivore damage and its effects on floral production, male and female floral attributes as well as fruit yield in three different phenological phases of Casearia nitida (Salicaceae) over the course of two consecutive years. Then we tested two models of multiple causal links among herbivory and reproductive success using piecewise structural equation models. Key Results The effects of leaf damage differed between reproductive seasons and between male and female components of fitness. Moreover, the impact of herbivory extended beyond the year when it was exerted. The previous season’s cumulated foliar damage had the largest impact on reproductive characters, in particular a negative effect on the numbers of inflorescences, flowers and pollen grains, indirectly affecting the numbers of infructescences and fruits, and a positive one on the amount of foliar damage during flowering. Conclusions For perennial and proleptic species, the dynamics of resource acquisition and allocation patterns for reproduction promote and extend the effects of herbivore damage to longer periods than a single reproductive event and growing season, through the interactions among different components of female and male fitness.


2021 ◽  
Author(s):  
Thomas E White ◽  
Amy Locke ◽  
Tanya Latty

Abstract Structurally coloured sexual signals are a conspicuous and widespread class of ornament used in mate choice, though the extent to which they encode information on the quality of their bearers is not fully resolved. Theory predicts that signalling traits under strong sexual selection as honest indicators should evolve to be more developmentally integrated and exaggerated than nonsexual traits, thereby leading to heightened condition dependence. Here we test this prediction through examination of the sexually dimorphic faces and wings of the cursorial fly Lispe cana. Males and females possess structural UV-white and golden faces, respectively, and males present their faces and wings to females during close-range, ground-based courtship displays, thereby creating the opportunity for mutual inspection. Across a field-collected sample of individuals, we found that the appearance of the faces of both sexes scaled positively with individual condition, though along separate axes. Males in better condition expressed brighter faces as modelled according to conspecific flies, whereas condition scaled with facial saturation in females. We found no such relationships for their wing interference pattern nor abdomens, with the latter included as a nonsexual control. Our results suggest that the structurally coloured faces, but not the iridescent wings, of male and female Lispe cana are reliable guides to individual quality and support the broader potential for structural colours as honest signals. They also highlight the potential for mutual mate choice in this system, while arguing for one of several alternate signalling roles for wing interferences patterns among the myriad taxa which bear them.


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