Biopolymers Used for Receptor Immobilization for Nickel-Detection Biosensors in Food.

Food is humans' main source of nickel intake, which is responsible for the prevalence of allergic contact dermatitis and other pathological afflictions. While robust, the classical methods for nickel detection-atomic absorption spectrometry and inductively coupled plasma mass spectrometry-are expensive and laborious; in contrast, modern methods that utilize sensors-of which most are electrochemical-have rapid run times, are cost-effective, and are easily assembled. Here, we describe the use of four biopolymers (alginate, agar, chitosan, and carrageenan) for receptor immobilization on biosensors to detect nickel ions and use an optimization approach with three biopolymer concentrations to assay analytical performance profiles.

Global Challenges to Public Health Care Systems during the COVID-19 Pandemic: A Review of Pandemic Measures and Problems.

Beginning in December 2019, the world faced a critical new public health stressor with the emergence of SARS-CoV-2. Its spread was extraordinarily rapid, and in a matter of weeks countries across the world were affected, notably in their ability to manage health care needs. While many sectors of public structures were impacted by the pandemic, it particularly highlighted shortcomings in medical care infrastructures around the world that underscored the need to reorganize medical systems, as they were vastly unprepared and ill-equipped to manage a pandemic and simultaneously provide general and specialized medical care.

Development, Optimization, Characterization, and Application of Electrochemical Biosensors for Detecting Nickel Ions in Food.

Nickel is naturally present in drinking water and many dietary items, which expose the general population to nickel ingestion. This heavy metal can have a variety of harmful health effects, causing allergies and skin disorders (i.e.

Changes in Dietary Patterns and Clinical Health Outcomes in Different Countries during the SARS-CoV-2 Pandemic.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to an excess in community mortality across the globe. We review recent evidence on the clinical pathology of COVID-19, comorbidity factors, immune response to SARS-CoV-2 infection, and factors influencing infection outcomes. The latter specifically includes diet and lifestyle factors during pandemic restrictions.

Opsin clines in butterflies suggest novel roles for insect photopigments.

Opsins are ancient molecules that enable animal vision by coupling to a vitamin-derived chromophore to form light-sensitive photopigments. The primary drivers of evolutionary diversification in opsins are thought to be visual tasks related to spectral sensitivity and color vision. Typically, only a few opsin amino acid sites affect photopigment spectral sensitivity.

Ancient homology underlies adaptive mimetic diversity across butterflies.

Convergent evolution provides a rare, natural experiment with which to test the predictability of adaptation at the molecular level. Little is known about the molecular basis of convergence over macro-evolutionary timescales. Here we use a combination of positional cloning, population genomic resequencing, association mapping and developmental data to demonstrate that positionally orthologous nucleotide variants in the upstream region of the same gene, WntA, are responsible for parallel mimetic variation in two butterfly lineages that diverged >65 million years ago.

Rapid diversification and not clade age explains high diversity in neotropical Adelpha butterflies.

Latitudinal gradients in species richness are among the most well-known biogeographic patterns in nature, and yet there remains much debate and little consensus over the ecological and evolutionary causes of these gradients. Here, we evaluated whether two prominent alternative hypotheses (namely differences in diversification rate or clade age) could account for the latitudinal diversity gradient in one of the most speciose neotropical butterfly genera (Adelpha) and its close relatives. We generated a multilocus phylogeny of a diverse group of butterflies in the containing tribe Limenitidini, which has both temperate and tropical representatives.

Landscape genetics of alpine Sierra Nevada salamanders reveal extreme population subdivision in space and time.

Quantifying the influence of the landscape on the genetic structure of natural populations remains an important empirical challenge, particularly for poorly studied, ecologically cryptic species. We conducted an extensive microsatellite analysis to examine the population genetics of the southern long-toed salamander (Ambystoma macrodactylum sigillatum) in a naturally complex landscape. Using spatially explicit modelling, we investigated the influence of the Sierra Nevada topography on potential dispersal corridors between sampled populations.

Range-wide genetic differentiation among North American great gray owls (Strix nebulosa) reveals a distinct lineage restricted to the Sierra Nevada, California.

Investigations of regional genetic differentiation are essential for describing phylogeographic patterns and informing management efforts for species of conservation concern. In this context, we investigated genetic diversity and evolutionary relationships among great gray owl (Strix nebulosa) populations in western North America, which includes an allopatric range in the southern Sierra Nevada in California. Based on a total dataset consisting of 30 nuclear microsatellite DNA loci and 1938-base pairs of mitochondrial DNA, we found that Pacific Northwest sampling groups were recovered by frequency and Bayesian analyses of microsatellite data and each population sampled, except for western Canada, showed evidence of recent population bottlenecks and low effective sizes.

A single origin of Batesian mimicry among hybridizing populations of admiral butterflies (Limenitis arthemis) rejects an evolutionary reversion to the ancestral phenotype.

Batesian mimicry is a fundamental example of adaptive phenotypic evolution driven by strong natural selection. Given the potentially dramatic impacts of selection on individual fitness, it is important to understand the conditions under which mimicry is maintained versus lost. Although much empirical and theoretical work has been devoted to the maintenance of Batesian mimicry, there are no conclusive examples of its loss in natural populations.

Landscape genetics and least-cost path analysis reveal unexpected dispersal routes in the California tiger salamander (Ambystoma californiense).

A major goal of landscape genetics is to understand how landscapes structure genetic variation in natural populations. However, landscape genetics still lacks a framework for quantifying the effects of landscape features, such as habitat type, on realized gene flow. Here, we present a methodology for identifying the costs of dispersal through different habitats for the California tiger salamander (Ambystoma californiense), an endangered species restricted to grassland/vernal pool habitat mosaics.

Historical isolation, range expansion, and secondary contact of two highly divergent mitochondrial lineages in spotted salamanders (Ambystoma maculatum).

The high species diversity of aquatic and terrestrial faunas in eastern North America has been attributed to range reductions and allopatric diversification resulting from historical climate change. The role these processes may have played in speciation is still a matter of considerable debate; however, their impacts on intraspecific genetic structure have been well documented. We use mitochondrial DNA sequences to reconstruct an intraspecific phylogeny of the widespread North American spotted salamander, Ambystoma maculatum, and test whether phylogenetic patterns conform to regional biogeographical hypotheses about the origins of diversity in eastern North America.

Lethal and sublethal effects of polychlorinated biphenyls on Rana sylvatica tadpoles.

In static experiments, we exposed tadpoles of the wood frog (Rana sylvatica) to sediment collected from a riverine wetland in the St. Lawrence River basin that is highly contaminated with polychlorinated biphenyls (PCBs). Significant mortality occurred early in the experiment and was not explained by a simple dose-dependent relationship.