How much multiple paternity should we expect? A study of birds and contrast with mammals.

Parentage analyses via molecular markers have revealed multiple paternity within the broods of polytocous species, reshaping our understanding of animal behavior, ecology, and evolution. In a meta-analysis of multiple paternity in bird and mammal species, we conducted a literature search and found 138 bird and 64 mammal populations with microsatellite DNA paternity results. Bird populations averaged 19.5% multiple paternity and mammals more than twice that level (46.1%). We used a Bayesian approach to construct a null model for how multiple paternity should behave at random among species, under the assumption that all mated males have equal likelihood of siring success, given mean brood size and mean number of sires. We compared the differences between the null model and the actual probabilities of multiple paternity. While a few bird populations fell close to the null model, most did not, averaging 34.0-percentage points below null model predictions; mammals had an average probability of multiple paternity 13.6-percentage points below the null model. Differences between bird and mammal species were also subjected to comparative phylogenetic analyses that generally confirmed our analyses that did not adjust for estimated historical relationships. Birds exhibited extremely low probabilities of multiple paternity, not only compared to mammals but also relative to other major animal taxa. The generally low probability of multiple paternity in birds might be produced by a variety of factors, including behaviors that reflect sexual selection (extreme mate guarding or unifocal female choice) and sperm competition (e.g., precedence effects favoring fertilization by early or late matings).

Effect of age on wingbeat frequency of Aedes aegypti and potential application for age estimation of mosquitoes.

To combat mosquito-borne diseases, a variety of vector control tools have been implemented. Estimating age structure in populations of vector species is important for understanding transmission potential. Age-grading techniques have been used as critical methods for evaluating the efficacy of vector control tools. However, methods like mark-release-recapture and ovarian dissection are laborious and require a high level of training. For decades, scientists have discussed the wide array of acoustic signatures of different mosquito species. These distinguishable wingbeat signatures with spatiotemporal classification allow mosquitoes of the same species to locate one another for mating. In recent years, the use of sensitive acoustic devices like mobile phones have proved effective. Wingbeat signatures can be used to identify mosquito species without the challenge of intensive field collections and morphological and molecular identifications. In this study, laboratory Aedes aegypti (L.) female and male wingbeats were recorded using mobile phones to determine whether sex and age differences with chronological time, and across different physiological stages, can be detected. Our results indicate significantly different wingbeat signatures between male and female Ae. aegypti, and a change of wingbeat frequencies with age and reproduction stage in females.

Disparities in Cognitive Impairment With Anticholinergic Drug Use: A Population-Based Study.

OBJECTIVES: We aim to evaluate the association between anticholinergic drug (ACH) use and cognitive impairment and the effect of disparity parameters (sex, race, income, education, and rural or urban areas) on this relationship. METHODS: The analyses included 13,623 adults aged ≥65 years from the REasons for Geographic And Racial Differences in Stroke study (recruited 2003-2007). The ACH use was defined by the 2015 Beers Criteria, and cognitive impairment was measured by the Six-Item Cognitive Screener. Multivariable logistic regression models assessed disparities in cognitive impairment with ACH use, iteratively adjusting for disparity parameters and other covariates. The full models included interaction terms between ACH use and other covariates. A similar approach was used for class-specific ACH exposure and cognitive impairment analyses. RESULTS: Approximately 14% of the participants used at least 1 ACH listed in the Beers Criteria. Antidepressants were the most frequently prescribed ACH class. A significant sex-race interaction illustrated that females compared with males (in Blacks: odds ratio [OR] = 1.28, 95% confidence interval [CI] 1.10-1.49 and in Whites: OR = 1.96, 95% CI 1.74-2.20), especially White females (Black vs White: OR = 0.71, 95% CI 0.64-0.80), were more likely to receive ACHs. Higher odds of cognitive impairment were observed among ACH users compared with the nonusers (OR = 1.26, 95% CI 1.01-1.58). In our class-level analyses, only antidepressant users (OR = 1.60, 95% CI 1.14-2.25) showed a significant association with cognitive impairment in the fully adjusted model. CONCLUSIONS: We observed demographic and socioeconomic differences in ACH use and in cognitive impairment, individually.

Exploring the relationship between production intensity and land use: A meta-analytic approach with shrimp aquaculture.

Shrimp are one of the fastest growing commodities in aquaculture and have a considerable land footprint. Here, we explored the impact of utilizing different production methods (extensive vs intensive) for expanding shrimp production on the cumulative land footprint of shrimp aquaculture. A meta-analytic approach was utilized to simultaneously estimate model coefficients to explore three relationships: production intensity and total land burden, production intensity and the proportion of land at the farm, and production intensity and the farmland burden. A literature review was conducted and a total of 7 datasets, 22 subsets, and 973 individual farms were included in this study. The global models were as follows: model 1 → ln (total land burden) = 0.1165-0.3863 * ln (production intensity), model 2 → proportion of direct (farm) land use:total land use = 0.7592-0.1737 * ln (production intensity), model 3 → ln (direct land use) = 0.1991-0.9674 * ln (production intensity). Production expansion was modeled under different scenarios. The most land intensive projections involved using only extensive systems to increase production when compared to a business-as-usual scenario. The least land intensive scenario involved utilizing intensive systems. A scenario where farmland was not expanded used 17% less land and 28% less land to produce 7.5 and 10 million tons of shrimp, respectively, when compared to business-as-usual scenarios. These estimates are limited by uncertainty in shrimp feed composition but demonstrate the effect of production intensity on the overall land footprint of shrimp production.

Modeling the Effect of HIV/AIDS Stigma on HIV Infection Dynamics in Kenya.

Stigma toward people living with HIV/AIDS (PLWHA) has impeded the response to the disease across the world. Widespread stigma leads to poor adherence of preventative measures while also causing PLWHA to avoid testing and care, delaying important treatment. Stigma is clearly a hugely complex construct. However, it can be broken down into components which include internalized stigma (how people with the trait feel about themselves) and enacted stigma (how a community reacts to an individual with the trait). Levels of HIV/AIDS-related stigma are particularly high in sub-Saharan Africa, which contributed to a surge in cases in Kenya during the late twentieth century. Since the early twenty-first century, the United Nations and governments around the world have worked to eliminate stigma from society and resulting public health education campaigns have improved the perception of PLWHA over time, but HIV/AIDS remains a significant problem, particularly in Kenya. We take a data-driven approach to create a time-dependent stigma function that captures both the level of internalized and enacted stigma in the population. We embed this within a compartmental model for HIV dynamics. Since 2000, the population in Kenya has been growing almost exponentially and so we rescale our model system to create a coupled system for HIV prevalence and fraction of individuals that are infected that seek treatment. This allows us to estimate model parameters from published data. We use the model to explore a range of scenarios in which either internalized or enacted stigma levels vary from those predicted by the data. This analysis allows us to understand the potential impact of different public health interventions on key HIV metrics such as prevalence and disease-related death and to see how close Kenya will get to achieving UN goals for these HIV and stigma metrics by 2030.

Contrasting patterns of 2-methylisoborneol (MIB) vs. geosmin across depth in a drinking water reservoir are mediated by cyanobacteria and actinobacteria.

Taste and odor episodes caused by off-flavor secondary metabolites, such as 2-methylisoborneol (MIB) and geosmin, pose one of the greatest challenges for drinking water utilities around the world. The prevalence of these compounds is predicted to increase in the future as a function of nutrient enrichment and elevated temperatures of surface drinking water sources. We conducted a manipulative field experiment in a drinking water reservoir to elucidate patterns for two taste and odor compounds, MIB and geosmin, as well as two taxa known to produce these compounds, phytoplankton (more specifically, cyanobacteria) and actinobacteria, across different depths in response to nutrient enrichment with two common dissolved nitrogen forms, organic urea or inorganic nitrate. In general, we found that MIB levels increased by greater than 250% with nutrient enrichment mediated by increased phytoplankton biomass. However, the effect of the fertilization treatments on MIB decreased with depth with a 35% reduction at 7 m versus 1.5 m. In contrast, geosmin levels reached a maximum at the lowest measured depth (7 m), were unaffected by the fertilization treatments, and followed a similar pattern to the abundance of actinobacteria. Thus, our data suggest that the positive response of phytoplankton (e.g., cyanobacteria, such as Oscillatoria species) to the fertilization treatments is likely responsible for increased MIB, while geosmin concentrations may be a function of actinobacteria-mediated decomposition in the hypolimnion in our study system.

Multiple paternity and the number of offspring: A model reveals two major groups of species.

Parentage analyses via microsatellite markers have revealed multiple paternity within the broods of polytocous species of mammals, reptiles, amphibians, fishes and invertebrates. The widespread phenomenon of multiple paternity may have attending relationships with such evolutionary processes as sexual selection and kin selection. However, just how much multiple paternity should a species exhibit? We developed Bayesian null models of how multiple paternity relates to brood sizes. For each of 114 species with published data on brood sizes and numbers of sires, we compared our null model estimates to published frequencies of multiple paternity. The majority of species fell close to our null model, especially among fish and invertebrate species. Some species, however, had low probabilities of multiple paternity, far from the predictions of the null model, likely due to sexual selection and environmental constraints. We suggest a major division among species' mating systems between those with close to random mating and high levels of multiple paternity, and those with constraints that produce low levels of multiple paternity.

Disparities in all-cause mortality with potentially inappropriate medication use: Analysis of the Reasons for Geographic and Racial Differences in Stroke study.

OBJECTIVES: Health disparities across different socioeconomic subgroups have been reported in previous studies. Mortality with potentially inappropriate medication (PIM) use may be subject to similar disparities. We aimed to assess the association between PIM use and all-cause mortality and the effect of disparity parameters (sex, race, income, education, and location of residence) on this relationship. METHODS: This longitudinal cohort study included 26,399 U.S. adults aged 45 years and older from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, of which 13,475 participants were aged 65 years and older (recruited 2003-2007). PIM use and drug-drug interactions (DDIs) were identified through the 2015 Beers Criteria and a clinically significant DDIs list by the American Family Physicians, respectively. Cox regression was used to assess disparities in mortality with PIM use, iteratively adjusting for disparity parameters and other covariates. The full models included interaction terms between PIM use and other covariates. A similar method was used for the analyses of disparities in mortality with DDIs. RESULTS: Approximately 87% of older adults used at least 1 drug listed in the Beers Criteria, and 3.8% of all participants used 2 or more drugs with DDIs. In the adjusted analysis, an increased risk of mortality was observed among whites with PIM use (hazard ratio [HR] = 1.27 [95% CI 1.10-1.47]). The higher mortality rate was observed among blacks without PIM use (1.34 [1.09-1.65]). Lower income and education were independent predictors for higher mortality. CONCLUSION: Racial differences in all-cause mortality with PIM use were observed. Further research is needed to better understand the contributing factors of such disparities to develop appropriate interventions.

Thermal Responses Differ across Levels of Biological Organization.

Temperature is one of the most important environmental factors driving the genome-to-phenome relationship. Metabolic rates and related biological processes are predicted to increase with temperature due to the biophysical laws of chemical reactions. However, selection can also act on these processes across scales of biological organization, from individual enzymes to whole organisms. Although some studies have examined thermal responses across multiple scales, there is no general consensus on how these responses vary depending on the level of organization, or whether rates actually follow predicted theoretical patterns such as Arrhenius-like exponential responses or thermal performance curves (TPCs) that show peak responses. Here, we performed a meta-analysis on studies of ectotherms where biological rates were measured across the same set of temperatures, but at multiple levels of biological organization: enzyme activities, mitochondrial respiration, and/or whole-animal metabolic rates. Our final dataset consisted of 235 pairwise comparisons between levels of organization from 13 publications. Thermal responses differed drastically across levels of biological organization, sometimes showing completely opposite patterns. We developed a new effect size metric, "organizational disagreement" (OD) to quantify the difference in responses among levels of biological organization. Overall, rates at higher levels of biological organization (e.g., whole animal metabolic rates) increased more quickly with temperature than rates at lower levels, contrary to our predictions. Responses may differ across levels due to differing consequences of biochemical laws with increasing organization or due to selection for different responses. However, taxa and tissues examined generally did not affect OD. Theoretical TPCs, where rates increase to a peak value and then drop, were only rarely observed (12%), possibly because a broad range of test temperatures was rarely investigated. Exponential increases following Arrhenius predictions were more common (29%). This result suggests a classic assumption about thermal responses in biological rates is rarely observed in empirical datasets, although our results should be interpreted cautiously due to the lack of complete thermal profiles. We advocate for authors to explicitly address OD in their interpretations and to measure thermal responses across a wider, more incremental range of temperatures. These results further emphasize the complexity of connecting the genome to the phenome when environmental plasticity is incorporated: the impact of the environment on the phenotype can depend on the scale of organization considered.

Disparities in the appropriateness of medication use: Analysis of the REasons for Geographic And Racial Differences in Stroke (REGARDS) population-based cohort study.

BACKGROUND: Prior work has identified disparities in the quality and outcomes of healthcare across socioeconomic subgroups. Medication use may be subject to similar disparities. OBJECTIVE: To assess the association between demographic and socioeconomic factors (gender, age, race, income, education, and rural or urban residence) and appropriateness of medication use. METHODS: US adults aged ≥45 years (n = 26,798) from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study were included in the analyses, of which 13,623 participants aged ≥65 years (recruited 2003-2007). Potentially inappropriate medication (PIM) use in older adults and drug-drug interactions (DDIs) were identified through 2015 Beers Criteria and clinically significant drug interactions list by Ament et al., respectively as measures of medication appropriateness. Multivariable logistic regression was used to assess the association of disparity parameters with PIM use and DDIs. Interactions between race and other disparity variables were investigated. RESULTS: Approximately 87% of the participants aged ≥65 years used at least one drug listed in the Beers Criteria, and 3.8% of all participants used two or more drugs with DDIs. Significant gender-race interaction across prescription-only drug users revealed that white females compared with white males (OR = 1.33, 95% CI 1.20-1.48) and black males compared with white males (OR = 1.60, 95% CI 1.41-1.82) were more likely to receive PIM. Individuals with lower income and education also were more likely to use PIM in this sub-group. Females were less likely than males (female vs. male: OR = 0.55, 95% CI 0.48-0.63) and individuals resided in small rural areas as opposed to urban areas (small rural vs. urban: OR = 1.37, 95% CI 1.07-1.76) were more likely to have DDIs. CONCLUSION: Demographic and socioeconomic disparities in PIM use and DDIs exist. Future studies should seek to better understand factors contributing to the disparities in order to guide development of interventions.

Estimating a Key Parameter of Mammalian Mating Systems: The Chance of Siring Success for a Mated Male.

Studies of multiple paternity in mammals and other animal species generally report proportion of multiple paternity among litters, mean litter sizes, and mean number of sires per litter. It is shown how these variables can be used to produce an estimate of the probability of reproductive success for a male that has mated with a female. This estimate of male success is more informative about the mating system that alternative measures, like the proportion of litters with multiple paternity or the mean number of sires per litter. The probability of success for a mated male can be measured both theoretically and empirically, and gives an estimate of the intensity of sperm competition and of a male's "confidence of paternity" upon mating. The probability of success for mated males for ten "exemplar" species of mammals is estimated and they are compared for insights into the functioning of their mating systems.

Consumer adaptation mediates top-down regulation across a productivity gradient.

Humans have artificially enhanced the productivity of terrestrial and aquatic ecosystems on a global scale by increasing nutrient loading. While the consequences of eutrophication are well known (e.g., harmful algal blooms and toxic cyanobacteria), most studies tend to examine short-term responses relative to the time scales of heritable adaptive change. Thus, the potential role of adaptation by organisms in stabilizing the response of ecological systems to such perturbations is largely unknown. We tested the hypothesis that adaptation by a generalist consumer (Daphnia pulicaria) to toxic prey (cyanobacteria) mediates the response of plankton communities to nutrient enrichment. Overall, the strength of Daphnia's top-down effect on primary producer biomass increased with productivity. However, these effects were contingent on prey traits (e.g., rare vs. common toxic cyanobacteria) and consumer genotype (i.e., tolerant vs sensitive to toxic cyanobacteria). Tolerant Daphnia strongly suppressed toxic cyanobacteria in nutrient-rich ponds, but sensitive Daphnia did not. In contrast, both tolerant and sensitive Daphnia genotypes had comparable effects on producer biomass when toxic cyanobacteria were absent. Our results demonstrate that organismal adaptation is critical for understanding and predicting ecosystem-level consequences of anthropogenic environmental perturbations.

Multiple paternity and number of offspring in mammals.

Many cooperative social attributes are being linked to characteristics of mating systems, particularly to the rate of multiple paternity that typifies a population. Under the logic that greater offspring production by females should engender greater competition among males to mate with females, it is predicted that multiple paternity should increase with litter sizes. We tested the predicted positive association of multiple paternity and litter size with a meta-analysis of 59 species of mammals. The probability of multiple paternity and mean litter size were positively correlated, but not significantly (Zr = 0.202). Also, the mean number of sires of litters increased with mean litter size, but not significantly (Zr = 0.235). We developed a combinatorial formula for the influence of number of male mates and litter size on the probability of multiple paternity. We used Bayesian Markov chain Monte Carlo simulations to generate an expectation for the form of the relationship between the probability of multiple paternity and mean litter size. Under the assumption of random samplings of numbers of mates, the expected association of the probability of multiple paternity and mean litter sizes among species was positive, curvilinear and relatively high. However, the empirical probabilities of multiple paternities were much less than expected, suggesting that behavioural factors (such as mating-associated behaviours) or ecological characteristics (such as population density) probably limit the number of male mates for reproductive females. The probability of multiple paternity in a population is an estimate of mating patterns that does not closely reflect the number of sires of individual litters. We suggest use of the estimated probability of mating success for males as an alternative measure of their contribution to the mating system.

Identification of NF-κB related genes in channel catfish and their expression profiles in mucosal tissues after columnaris bacterial infection.

Interactions of NF-κB family, IκB family and IKK complex are the key components of NF-κB pathway that is essential for many biological processes including innate and adaptive immunity, inflammation and stress responses. In spite of their importance, systematic analysis of these genes in fish has been lacking. Here we report a systematic study of the NF-κB related genes in channel catfish. Five NF-κB family genes, five IκB family genes and three IKK complex genes were identified in the channel catfish genome. Annotation of these 13 NF-κB related genes was further confirmed by phylogenetic and syntenic analysis. Negative selection was found to play a crucial role in the adaptive evolution of these genes. Expression profiles of NF-κB related genes after Flavobacterium columnare (columnaris) infection were determined by analysis of the existing RNA-Seq dataset. The majority of NF-κB related genes were significantly regulated in mucosal tissues of gill, skin and intestine after columnaris infection, indicating their potential involvement in host defense responses. Distinct expression patterns of NF-κB related genes were observed in susceptible and resistant catfish in response to columnaris infection, suggesting that expression of these genes may contribute to the variations in disease resistance/susceptibility of catfish.