Scanning Electron Microscopy and EDX Spectroscopy of Commercial Swabs Used for COVID-19 Lateral Flow Testing.

The chemical composition of COVID test swabs has not been examined beyond the manufacturer's datasheets. The unprecedented demand for swabs to conduct rapid lateral flow tests and nucleic acid amplification tests led to mass production, including 3D printing platforms. Manufacturing impurities could be present in the swabs and, if so, could pose a risk to human health.

Bacterial dysbiosis and epithelial status of the California sea lion (Zalophus californianus) in the Gulf of California.

Despite the high incidence of urogenital carcinoma (UGC) in California sea lions stranded along California, no UGC has been reported in other areas of their distribution; however, cell morphologies typical of premalignant states have been found. Risk factors for UGC include high of organochlorines and infection with a gammaherpesvirus, OtHV-1, but the importance of the bacteriome for epithelial status remains unknown. We characterized the genital bacteriome of adult female California sea lions along their distribution in the Gulf of California and examined whether the diversity and abundance of the bacteriome varied spatially, whether there were detectable differences in the bacteriome between healthy and altered epithelia, and whether the bacteriome was different in California sea lions infected with OtHV-1 or papillomavirus.

Potential health risks of mRNA-based vaccine therapy: A hypothesis.

Therapeutic applications of synthetic mRNA were proposed more than 30 years ago, and are currently the basis of one of the vaccine platforms used at a massive scale as part of the public health strategy to get COVID-19 under control. To date, there are no published studies on the biodistribution, cellular uptake, endosomal escape, translation rates, functional half-life and inactivation kinetics of synthetic mRNA, rates and duration of vaccine-induced antigen expression in different cell types. Furthermore, despite the assumption that there is no possibility of genomic integration of therapeutic synthetic mRNA, only one recent study has examined interactions between vaccine mRNA and the genome of transfected cells, and reported that an endogenous retrotransposon, LINE-1 is unsilenced following mRNA entry to the cell, leading to reverse transcription of full length vaccine mRNA sequences, and nuclear entry.

Phylogenomic Discordance in the Eared Seals is best explained by Incomplete Lineage Sorting following Explosive Radiation in the Southern Hemisphere.

The phylogeny and systematics of fur seals and sea lions (Otariidae) have long been studied with diverse data types, including an increasing amount of molecular data. However, only a few phylogenetic relationships have reached acceptance because of strong gene-tree species tree discordance. Divergence times estimates in the group also vary largely between studies.

The demographic decline of a sea lion population followed multi-decadal sea surface warming.

The population growth of top predators depends largely on environmental conditions suitable for aggregating sufficient and high-quality prey. We reconstructed numerically the size of a resident population of California sea lions in the Gulf of California during 1978-2019 and its relation with multi-decadal sea surface temperature anomalies. This is the first multi-decadal examination of the sea surface temperature of the Gulf of California and of one of its major predators.

Gut Bacterial Families Are Associated with Body Composition and Metabolic Risk Markers in School-Aged Children in Rural Mexico.

Differences in gut microbiota composition have been associated with obesity and metabolic alterations in children. The aim of this study was to analyze the abundance of the main bacterial families of the gut among children according to their body composition and metabolic markers. A cross-sectional study was conducted with 93 school-aged children (8.

Does sociality drive diversity and composition of airway microbiota in cetaceans?

The number of social contacts of mammals is positively correlated with the diversity of their gut microbes. There is some evidence that sociality also affects microbes in the respiratory tract. We tested whether the airway microbiota of cetacean species differ depending on the whales' level of sociality.

Early sexual dimorphism in the developing gut microbiome of northern elephant seals.

The gut microbiome is an integral part of a species' ecology, but we know little about how host characteristics impact its development in wild populations. Here, we explored the role of such intrinsic factors in shaping the gut microbiome of northern elephant seals (Mirounga angustirostris) during a critical developmental window of 6 weeks after weaning, when the pups stay ashore without feeding. We found substantial sex differences in the early-life gut microbiome, even though males and females could not yet be distinguished morphologically.

Physiological Thresholds in the Context of Marine Mammal Conservation.

There is growing evidence of the adverse effects of global environmental change on marine mammals, particularly in terms of changes in abundance, distribution, habitat use, migratory phenology, feeding habits, risk of infectious diseases, bioaccumulation of contaminants, declines in reproductive success, and reductions in genetic diversity. These anthropogenic stressors have led to an evident conservation crisis: a quarter of the extant marine mammal species that have been assessed and now considered at risk of extinction. However, we still know very little about the subtle, subclinical effects of environmental stressors on various aspects of physiology that could impacts their survival and long-term fertility, or that could impact the performance of future generations.

Transcriptional Profiles of California Sea Lion Peripheral NK and CD T Cells Reflect Ecological Regionalization and Infection by Oncogenic Viruses.

The California sea lion is one of the few wild mammals prone to develop cancer, particularly urogenital carcinoma (UGC), whose prevalence is currently estimated at 25% of dead adult sea lions stranded along the California coastline. Genetic factors, viruses and organochlorines have been identified as factors that increase the risk of occurrence of this pathology. Given that no cases of UGC have as yet been reported for the species along its distribution in Mexican waters, the potential relevance of contaminants for the development of urogenital carcinoma is highlighted even more as blubber levels of organochlorines are more than two orders of magnitude lower in the Gulf of California and Mexican Pacific than in California.

Demographic histories and genetic diversity across pinnipeds are shaped by human exploitation, ecology and life-history.

A central paradigm in conservation biology is that population bottlenecks reduce genetic diversity and population viability. In an era of biodiversity loss and climate change, understanding the determinants and consequences of bottlenecks is therefore an important challenge. However, as most studies focus on single species, the multitude of potential drivers and the consequences of bottlenecks remain elusive.

Effects of polychlorinated biphenyls (PCB) on California sea lion (Zalophus californianus) lymphocyte functions upon in vitro exposure.

Polychorinated biphenyl (PCB) congeners are a cause for concern due to their persistence in the environment, their lipophilic properties that cause them to bio-accumulate in top predators, and their adverse effects on mammalian health. For example, the common urogenital carcinoma reported in California sea lions (Zalophus californianus) (CSL) is associated with high tissue levels of PCBs, but the mechanisms responsible for this association are unknown. This study investigated the effect of exposure to six PCB congeners and a congener mix at low and environmentally relevant concentrations on NK cell-like and T cell activity using in vitro assays on cryopreserved lymph node mononuclear cells isolated from dead CSL.

Hepatic DNA damage in harbour porpoises (Phocoena phocoena) stranded along the English and Welsh coastlines.

One level at which persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons PAHs) can exert damage is by causing DNA strand-breaks or nucleotide base modifications, which, if unrepaired, can lead to embryonic mutations, abnormal development and cancer. In marine ecosystems, genotoxicity is expected to be particularly strong in long-lived apex predators due to pollutant bioaccumulation. We conducted P-postlabeling analyses optimized for the detection and quantification of aromatic/hydrophobic DNA adducts in the livers of 40 sexually-mature North Atlantic harbour porpoises (Phocoena phocoena) stranded along the English and Welsh coastlines.

MHC class II DRB diversity predicts antigen recognition and is associated with disease severity in California sea lions naturally infected with Leptospira interrogans.

We examined the associations between California sea lion MHC class II DRB (Zaca-DRB) configuration and diversity, and leptospirosis. As Zaca-DRB gene sequences are involved with antigen presentation of bacteria and other extracellular pathogens, we predicted that they would play a role in determining responses to these pathogenic spirochaetes. Specifically, we investigated whether Zaca-DRB diversity (number of genes) and configuration (presence of specific genes) explained differences in disease severity, and whether higher levels of Zaca-DRB diversity predicted the number of specific Leptospira interrogans serovars that a sea lion's serum would react against.

Changes in mucosal and serum immunoglobulin levels of California sea lions during early development.

To date, most studies on pinniped immunoglobulins have focused on circulating antibodies. However, systemic and local immune activities differ in terms of maturation, intensity, and types of effectors that participate. Here, we examined levels of three immunoglobulin isotypes, IgG, IgM and IgA, in the blood and mucosal membranes of free-living California sea lion pups.

Atypical Red Blood Cells Are Prevalent in California Sea Lion Pups Born during Anomalous Sea Surface Temperature Events.

To date, there is limited knowledge of the effects that abnormal sea surface temperature (SST) can have on the physiology of neonate pinnipeds. However, maternal nutritional deficiencies driven by alimentary restrictions would expectedly impact pinniped development and fitness, as an adequate supply of nutrients is essential for growth and proper functioning of all body systems, including red blood cell synthesis and clearance. Here, we investigated red blood cell morphology of California sea lion (CSL) pups from the San Benito Archipelago born during the 2014 and 2015 anomalously high SST events recorded in the northeastern Pacific Ocean.

Climatic anomaly affects the immune competence of California sea lions.

The past decades have been characterized by a growing number of climatic anomalies. As these anomalies tend to occur suddenly and unexpectedly, it is often difficult to procure empirical evidence of their effects on natural populations. We analysed how the recent sea surface temperature (SST) anomaly in the northeastern Pacific Ocean affects body condition, nutritional status, and immune competence of California sea lion pups.

Melanin granules melanophages and a fully-melanized epidermis are common traits of odontocete and mysticete cetaceans.

Background: The cellular mechanisms used to counteract or limit damage caused by exposure of marine vertebrates to solar ultraviolet (UV) radiation are poorly understood. Cetaceans are vulnerable because they lack protective skin appendages and are obliged to surface continuously to breathe, thus being exposed repeatedly to UV light. Although molecular mechanisms of photoprotection of cetaceans have been studied, there is limited knowledge about their epidermal structure and photoprotective effectors.

Impact of the 2015 El Niño-Southern Oscillation on the Abundance and Foraging Habits of Guadalupe Fur Seals and California Sea Lions from the San Benito Archipelago, Mexico.

The abundance of California sea lions (Zalophus californianus) (CSLs) and Guadalupe fur seals (Arctocephalus philippii townsendi) (GFSs) from the San Benito Archipelago (SBA) was determined through nine monthly surveys in 2014-2015. Assessment of their foraging habits was examined based on the isotopic analysis of pups (maternal indicators) (SIAR/SIBER-R). Environmental variability between 2014 and 2015 was also analyzed, in terms of sea surface temperature (SST) and chlorophyll (Chl-a) concentration.

MHC class II transcription is associated with inflammatory responses in a wild marine mammal.

Inflammation is one of the most important non-specific and rapid responses that a vertebrate can elicit in response to damage or a foreign insult. To date, despite increasing evidence that the innate and adaptive branches of immunity are more intricately related than previously thought, few have examined interactions between the Major Histocompatibility Complex (MHC, a polymorphic region of the vertebrate genome that is involved with antigen presentation) and inflammation, and even less is known about these interactions in an eco-immunological context. Here, we examined the effect of MHC class II DRB gene multiplicity and transcription on phytohemagglutinin (PHA)-induced inflammation during the early stages of development of California sea lions.

Transformation of the genital epithelial tract occurs early in California sea lion development.

An unusually high prevalence of metastatic urogenital carcinoma has been observed in free-ranging California sea lions stranded off the coast of California in the past two decades. No cases have been reported for sea lions in the relatively unpolluted Gulf of California. We investigated occurrence of genital epithelial transformation in 60 sea lions (n=57 pups and 3 adult females) from the Gulf of California and examined whether infection by a viral pathogen previously found to be associated with urogenital carcinoma accounted for such alterations.

Context-dependent associations between heterozygosity and immune variation in a wild carnivore.

Background: A multitude of correlations between heterozygosity and fitness proxies associated with disease have been reported from wild populations, but the genetic basis of these associations is unresolved. We used a longitudinal dataset on wild Galapagos sea lions (Zalophus wollebaeki) to develop a relatively new perspective on this problem, by testing for associations between heterozygosity and immune variation across age classes and between ecological contexts.

Results: Homozygosity by locus was negatively correlated with serum immunoglobulin G production in pups (0-3 months of age), suggesting that reduced genetic diversity has a detrimental influence on the early development of immune defence in the Galapagos sea lion.

Activation of an inflammatory response is context-dependent during early development of the California sea lion.

Variations in immune function can arise owing to trade-offs, that is, the allocation of limited resources among costly competing physiological functions. Nevertheless, there is little information regarding the ontogeny of the immune system within an ecological context, and it is still unknown whether development affects the way in which resources are allocated to different immune effectors. We investigated changes in the inflammatory response during early development of the California sea lion (Zalophus californianus) and examined its association with body condition, as a proxy for the availability of energetic resources.

Evidence for a genetic basis of urogenital carcinoma in the wild California sea lion.

Although neoplasia is a major cause of mortality in humans and domestic animals, it has rarely been described in wildlife species. One of the few examples is a highly prevalent urogenital carcinoma in California sea lions (CSLs). Although the aetiology of this carcinoma is clearly multifactorial, inbreeding depression, as estimated using levels of microsatellite multilocus heterozygosity, is identified as predictive for this neoplasia.