Developmental Dynamics and G-Matrices: Can Morphometric Spaces be Used to Model Phenotypic Evolution?

Modern morphometrics, especially geometric morphometrics, is a powerful tool for modeling the evolution and development of the phenotype. Complicated morphological transformations can be simulated by using standard evolutionary genetic equations for processes such as selection and drift in the same morphospaces that are used for empirical morphometric studies. Such applications appear to be consistent with the theory of quantitative evolution of the phenotype. Nevertheless, concerns exist whether simulations of phenotypic changes directly in morphospaces is realistic because trajectories traced in such spaces describe continuous gradations in the phenotype and because the gain and loss of structures is often impossible because morphospaces are necessarily constructed from variables shared in common by all the phenotypes being considered. Competing models of phenotypic change emphasize morphological discontinuity and novelty. Recently developed models of phenotypic evolution that introduce a “phenotypic landscape” between evolutionary genetic constructs like the adaptive landscape and morphospace may correct this shortcoming.     

Can Evidence from Genome-Wide Association Studies and Positive Natural Selection Surveys Be Used to Evaluate the Thrifty Gene Hypothesis in East Asians?

Body fat deposition and distribution differ between East Asians and Europeans, and for the same level of obesity, East Asians are at higher risks of Type 2 diabetes (T2D) and other metabolic disorders. This observation has prompted the reclassifications of body mass index thresholds for the definitions of “overweight” and “obese” in East Asians. However, the question remains over what evolutionary mechanisms have driven the differences in adiposity morphology between two population groups that shared a common ancestor less than 80,000 years ago. The Thrifty Gene hypothesis has been suggested as a possible explanation, where genetic factors that allowed for efficient food-energy conversion and storage are evolutionarily favoured by conferring increased chances of survival and fertility. Here, we leveraged on the existing findings from genome-wide association studies and large-scale surveys of positive natural selection to evaluate whether there is currently any evidence to support the Thrifty Gene hypothesis. We first assess whether the existing genetic associations with obesity and T2D are located in genomic regions that are reported to be under positive selection, and if so, whether the risk alleles sit on the extended haplotype forms. In addition, we interrogate whether these risk alleles are the derived forms that differ from the ancestral alleles, and whether there is significant evidence of population differentiation at these SNPs between East Asian and European populations. Our systematic survey did not yield conclusive evidence to support the Thrifty Gene hypothesis as a possible explanation for the differences observed between East Asians and Europeans.     

Can a Welfarist Approach be Used to Justify a Moral Duty to Cognitively Enhance Children?

The desire to self‐improve is probably as old as humanity: most of us want to be smarter, more athletic, more beautiful, or more talented. However, in the light of an ever increasing array of possibilities to enhance our capacities, clarity about the purpose and goal of such efforts becomes crucial. This is especially true when decisions are made for children, who are exposed to their parents’ plans and desires for them under a notion of increasing wellbeing. In recent years, cognitive enhancement has become a popular candidate for the promotion of wellbeing; welfarists even impose a moral duty on parents to cognitively enhance their children for the sake of their wellbeing. In this article, I aim to show that welfarists are mistaken in inferring such a moral obligation from the potential benefit of cognitive enhancement. In support of this, I offer three arguments: (a) the vagueness of wellbeing as a theoretical concept means it becomes impossible to apply in practice; (b) the link between cognition and wellbeing is far from unequivocal; and (c) quantification issues with regard to cognition make a duty impossible to discharge. In conclusion, I reject the welfarist approach as a justification for a parental moral obligation to cognitively enhance children.     

Can percentage infection and dwarfing be used to differentiate aggressiveness in Plasmopara halstedii?

Aggressiveness was studied in seven Plasmopara halstedii (sunflower downy mildew) parental isolates of races 100, 300, 304, 314, 704, 710 and 714 using five single zoosporangium isolates per parental isolate. Aggressiveness criteria, including percentage infection and dwarfing (reduction of hypocotyl length), were analysed in one sunflower inbred line showing a high level of quantitative resistance. Analysis of five single zoosporangium isolates of each parental isolate showed variability within parental isolate for the two aggressiveness criteria, but not for all parental isolates for percentage infection and vice versa for the reduction of hypocotyl length. Percentage infection showed high values irrespective of the parental isolate used. However, all the parental isolates caused a large reduction in seedling size except for the isolate of race 314. Although percentage infection and reduction of hypocotyl length could be used to differentiate aggressiveness in P. halstedii, it seems that these criteria played a limited role to define P. halstedii isolates according to their aggressiveness.     

Can Ebola virus evolve to be less virulent in humans?

Understanding Ebola virus (EBOV) virulence evolution not only is timely but also raises specific questions because it causes one of the most virulent human infections and it is capable of transmission after the death of its host. Using a compartmental epidemiological model that captures three transmission routes (by regular contact, via dead bodies and by sexual contact), we infer the evolutionary dynamics of case fatality ratio on the scale of an outbreak and in the long term. Our major finding is that the virus's specific life cycle imposes selection for high levels of virulence and that this pattern is robust to parameter variations in biological ranges. In addition to shedding a new light on the ultimate causes of EBOV's high virulence, these results generate testable predictions and contribute to informing public health policies. In particular, burial management stands out as the most appropriate intervention since it decreases the of the epidemics, while imposing selection for less virulent strains.     

DXA: Can It Be Used as a Criterion Reference for Body Fat Measurements in Children?

Objective: Dual‐energy X‐ray absorptiometry (DXA) is often cited as a criterion method for body composition measurements. We have previously shown that a new DXA software version (Hologic Discovery V12.1) will affect whole‐body bone mineral results for subjects weighing <40 kg. We wished to reanalyze pediatric whole‐body scans in order to assess the impact of the new software on pediatric soft‐tissue body composition estimates. Methods and Procedures: We reanalyzed 1,384 pediatric scans (for ages 1.7–17.2 years) using Hologic software V12.1, previously analyzed using V11.2. Regression analysis and ANCOVA were used to compare body fat (total body fat (TBF), percentage fat (%BF)), and non‐bone lean body mass (LBM) for the two versions, adjusting for gender, age and weight. Results: Software V12.1 yielded values that were higher for TBF, lower for LBM, and unchanged for DXA‐derived weight in subjects weighing <40 kg. Body composition values for younger, smaller subjects were most affected, and girls were more affected than boys. Using the new software, 14% of the girls and 10% of the boys were reclassified from the “normal” %BF range to “at risk of obesity,” while 7 and 5%, respectively, were reclassified as obese. Discussion: Hologic's newest DXA software has a significant effect on soft‐tissue results for children weighing <40 kg. The effect is greater for girls than boys. Comparison of TBF estimates with previous studies that use older DXA instruments and software should be done with caution. DXA has not yet achieved sufficient reliability to be considered a “gold standard” for body composition assessment in pediatric studies.     

Can respect be key to gender justice?

Equality and respect are, together with dignity, considered foundational values in international human rights discourse. While equality in particular has been established as a widely accepted goal in the women's rights movement, respect is, however, less commonly invoked. Based on long‐term ethnographic fieldwork conducted among the Arsi Oromo of Ethiopia, this article examines the notion of wayyuu, a tacit moral model of respect and sacredness that is central to institutions and norms that have secured women certain rights and power. These norms and institutions represent a challenge to the liberal feminist conceptualization of gender equality that dominates international women's rights discourse. Drawing on theories of respect and on feminist and anthropological discussions of equality, I argue that even though there are certain limitations inherent in wayyuu, the sacredness it entails and the implications this has had for women's status and power among the Arsi Oromo call for an exploration of respect not as an alternative to equality, but as a complementary notion which to a greater extent could be included in global discussions of gender justice.     

Can results from limnocorral experiments be transferred to in situ conditions?

In 1982–1984 eight limnocorral (LC) experiments, each lasting for two weeks, were performed in mesotrophic Lake Lucerne, Switzerland, to study the effects of biomanipulation (removal of crustaceans by 95 µm filter nets) on zooplankton — phytoplankton relationships and epilimnetic carbon and phosphorus fluxes. Seston concentrations and to a lesser extent primary production rates were reduced in control LCs through zooplankton grazing, and settling flux increased through fecal pellet production. But C and P regeneration were not significantly affected.We found several indications that the LCs, despite of their large size ( 70 m³, 3 m in diameter and 11 m long) were artificial systems when compared to the surrounding lake: The eddy diffusion was diminished by about one order of magnitude, nutrients depleted (but phosphorus was supplied to the LCs), the phyto- and zooplankton showed lower standing crops in the control LCs than in the lake, the phytoplankton showed a shift from nannoplankton to netplankton, the crustacean zooplankton was mostly limited in their vertical migration, and the POC and PP sedimentation rates were increased. Moreover, in our set of experiments we always found outliers, which may have been caused by the different in situ conditions at the beginning of the experiments, and further enhanced by the complexity of the enclosed system.The problems of the LC-technique, such as replicability, scaling (size and time) and data extrapolation are discussed. The impact of crustacean zooplankton on particulate matter, i.e. seston reduction and sedimentation enhancement, can be extrapolated on a qualitative rather than on a quantitative basis for the Lake Lucerne ecosystem.     

Can Volatile Organic Metabolites Be Used to Simultaneously Assess Microbial and Mite Contamination Level in Cereal Grains and Coffee Beans?

A novel approach based on headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC–ToFMS) was developed for the simultaneous screening of microbial and mite contamination level in cereals and coffee beans. The proposed approach emerges as a powerful tool for the rapid assessment of the microbial contamination level (ca. 70 min versus ca. 72 to 120 h for bacteria and fungi, respectively, using conventional plate counts), and mite contamination (ca. 70 min versus ca. 24 h). A full-factorial design was performed for optimization of the SPME experimental parameters. The methodology was applied to three types of rice (rough, brown, and white rice), oat, wheat, and green and roasted coffee beans. Simultaneously, microbiological analysis of the samples (total aerobic microorganisms, moulds, and yeasts) was performed by conventional plate counts. A set of 54 volatile markers was selected among all the compounds detected by GC×GC–ToFMS. Principal Component Analysis (PCA) was applied in order to establish a relationship between potential volatile markers and the level of microbial contamination. Methylbenzene, 3-octanone, 2-nonanone, 2-methyl-3-pentanol, 1-octen-3-ol, and 2-hexanone were associated to samples with higher microbial contamination level, especially in rough rice. Moreover, oat exhibited a high GC peak area of 2-hydroxy-6-methylbenzaldehyde, a sexual and alarm pheromone for adult mites, which in the other matrices appeared as a trace component. The number of mites detected in oat grains was correlated to the GC peak area of the pheromone. The HS-SPME/GC×GC–ToFMS methodology can be regarded as the basis for the development of a rapid and versatile method that can be applied in industry to the simultaneous assessment the level of microbiological contamination and for detection of mites in cereals grains and coffee beans.     

Can Global Weed Assemblages Be Used to Predict Future Weeds?

Predicting which plant taxa are more likely to become weeds in a region presents significant challenges to both researchers and government agencies. Often it is done in a qualitative or semi-quantitative way. In this study, we explored the potential of using the quantitative self-organising map (SOM) approach to analyse global weed assemblages and estimate likelihoods of plant taxa becoming weeds before and after they have been moved to a new region. The SOM approach examines plant taxa associations by analysing where a taxon is recorded as a weed and what other taxa are recorded as weeds in those regions. The dataset analysed was extracted from a pre-existing, extensive worldwide database of plant taxa recorded as weeds or other related status and, following reformatting, included 187 regions and 6690 plant taxa. To assess the value of the SOM approach we selected Australia as a case study. We found that the key and most important limitation in using such analytical approach lies with the dataset used. The classification of a taxon as a weed in the literature is not often based on actual data that document the economic, environmental and/or social impact of the taxon, but mostly based on human perceptions that the taxon is troublesome or simply not wanted in a particular situation. The adoption of consistent and objective criteria that incorporate a standardized approach for impact assessment of plant taxa will be necessary to develop a new global database suitable to make predictions regarding weediness using methods like SOM. It may however, be more realistic to opt for a classification system that focuses on the invasive characteristics of plant taxa without any inference to impacts, which to be defined would require some level of research to avoid bias from human perceptions and value systems.     

Chirality and Drugs Used in Psychiatry: Nice to Know or Need to Know?

1. Many drugs used to treat psychiatric disorders contain a chiral center or a center of unsaturation and are marketed as a mixture of the resultant enantiomers or geometric isomers, respectively. These enantiomers or geometric isomers may differ markedly with regard to their pharmacodynamic and/or pharmacokinetic properties.2. Examples of the effects of chiral centers or geometric centers on such properties are given for drugs from the following classes: antidepressants (tricyclics, selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, viloxazine, bupropion, trazodone, mianserin, venlaflaxine); benzodiazepines, zoplicone, and antipsychotics.3. As described in this review, there are several notable examples of psychiatric drugs currently available where the individual enantiomers or geometric isomers differ considerably with regard to factors such as effects on amine transport systems, interactions with receptors and metabolizing enzymes, and clearance rates from the body. Indeed, relatively recent developments in analytical and preparative resolution of racemic and geometric drug mixtures and increased interest in developing new drugs which interact with specific targets, which have been described in detail at the molecular level, have resulted in increased emphasis on stereochemistry in drug development.     

Feral Horse Population Model and Body Condition: Useful Management Tools in Tornquist Park,Argentina?

Feral invasive mammals challenge management strategies worldwide including the feral horse (Equus caballus) population in Tornquist Park, Argentina. In this study, I constructed population matrix models using demography data collected between 1995 and 2002. I validated the models with independent counts from 2008 to 2016. I individually identified feral horses and recorded them as I walked a fixed path that covered 20 km². I performed an elasticity analysis to estimate the influence of the demographic parameters on population growth rate. In addition, I explored whether body condition score could be a proxy for carrying capacity. Model projections with the highest values of fecundity and survival exhibited by females of all ages during 1995–2002 fit the counts from 2008 to 2016, when growth rate was moderate (λ = 1.10), very well. Elasticity of adult female survival (0.54) was 4 times higher than for fecundity and survival of all other ages. Body condition of adult females at the end of winter, 2012–2013, after reductions in density, was improved compared with 2001–2002 when the population approached carrying capacity. The validated population model together with body condition score could allow managers to take more informed decisions when planning the control of feral horses in Tornquist Park. This approach could also be applied to other small, closed, feral horse populations and other large-mammal populations. © 2020 The Wildlife Society.