Microbiomes in Birds: A Review of Links to Health and Reproduction.

Microbiomes have emerged as a key component essential for maintaining the health of an organism. Additionally, the roles of microbiomes are multifaceted, some unique to specific body areas and organs while others, particularly the gut microbiome, having broader effects on the entire organism. Comparative literature is emerging that compares microbiomes across mammals and birds. Domestic poultry have been the most extensively studied relative to their role in production agriculture. These data have provided a great deal of information about the effects of diet and nutritional requirements relative to the gut microbiome, productivity, and resilience to diseases. Conversely, limited such research has been conducted on wild birds, despite them inhabiting a broad array of ecological niches and environments, providing a rich diversity in their adaptations to different habitats. Migratory birds and raptors are of particular interest. Migratory birds encounter a range of ecosystems and provide a link between allopatric populations. Raptors occupy high positions in the food chain, with potential exposure to biomagnification of environmental contaminants and pathogens. This review overviews our current understanding of the structure and function of avian microbiomes as related to avian health and reproduction in domestic and wild birds, highlighting knowledge gaps in need of further investigation for more effective conservation of rapidly declining avian populations.

A utilization distribution for the global population of Cape Vultures (Gyps coprotheres) to guide wind energy development.

The rapid development of wind energy in southern Africa represents an additional threat to the already fragile populations of African vultures. The distribution of the vulnerable Cape Vulture Gyps coprotheres overlaps considerably with wind energy development areas in South Africa, creating conflicts that can hinder both vulture conservation and sustainable energy development. To help address this conflict and aid in the safe placement of wind energy facilities, we map the utilization distribution (UD) of this species across its distributional range. Using tracking data from 68 Cape Vultures collected over the last 20 years, we develop a spatially explicit habitat use model to estimate the expected UDs around known colonies. Scaling the UDs by the number of vultures expected to use each of the colonies, we estimate the Cape Vulture population utilization distribution (PUD) and determine its exposure to wind farm impacts. To complement our results, we model the probability of a vulture flying within the rotor sweep area of a wind turbine throughout the species range and use this to identify areas that are particularly prone to collisions. Overall, our estimated PUD correlates well with reporting rates of the species from the Southern African Bird Atlas Project, currently used to assess potential overlap between Cape Vultures and wind energy developments, but it adds important benefits, such as providing a spatial gradient of activity estimates over the entire species range. We illustrate the application of our maps by analyzing the exposure of Cape Vultures in the Renewable Energy Development Zones (REDZs) in South Africa. This application is a scalable procedure that can be applied at different planning phases, from strategic, nationwide planning to project-level assessments.

Old World Vultures Reflect Effects of Environmental Pollutants Through Human Encroachment.

African wildlife face challenges from many stressors including current and emerging contaminants, habitat and resource loss, poaching, intentional and unintentional poisoning, and climate-related environmental change. The plight of African vultures exemplifies these challenges due to environmental contaminants and other stressors acting on individuals and populations that are already threatened or endangered. Many of these threats emanate from increasing human population size and settlement density, habitat loss from changing land use for agriculture, residential areas, and industry, and climate-related changes in resource availability. Environmental chemicals that are hazardous include legacy chemicals, emerging chemicals of concern, and high-volume-use chemicals that are employed as weed killers and in other agricultural applications. Furthermore, there are differences in risk for species living in close proximity to humans or in areas affected by habitat loss, climate, and industry. Monitoring programs are essential to track the status of nesting pairs, offspring survival, longevity, and lifetime productivity. This is important for long-lived birds, such as vultures, that may be especially vulnerable to chronic exposure to chemicals as obligate scavengers. Furthermore, their position in the food web may increase risk due to biomagnification of chemicals. We review the primary chemical hazards to Old World vultures and the interacting stressors affecting these and other birds. Habitat is a major consideration for vultures, with tree-nesters and cliff-nesters potentially experiencing different risks of exposure to environmental chemicals. The present review provides information from long-term monitoring programs and discusses a range of these threats and their effects on vulture populations. Environ Toxicol Chem 2022;41:1586-1603. © 2022 SETAC.

Detecting myasthenia gravis as a cause of unclear dysphagia with an endoscopic tensilon test.

AIMS: The flexible endoscopic evaluation of swallowing-tensilon test (FTT) was developed to diagnose myasthenia gravis (MG) in patients with unclear pharyngeal dysphagia. The purpose of this study was to determine sensitivity and specificity of the FTT and compare its diagnostic validity with that of other diagnostic markers. METHODS: In this single-centre pragmatic clinical cohort study, a total of 100 patients with unclear pharyngeal dysphagia were eligible to undergo FTT. All patients were subjected to FTT and subsequently followed up clinically. FTT was considered positive if a significant improvement of pharyngeal swallowing function could be objectified endoscopically upon administration of edrophonium chloride. In addition, repetitive nerve stimulation test and serum MG antibody analysis were conducted. RESULTS: All subjects (mean age 62.5 ± 14.1 years, female 33) underwent FTT without any complications. According to the results of the diagnostic procedures and based on long-term clinical follow-up for at least 3 years, 51 patients were finally diagnosed with MG. The sensitivity and specificity for the FTT was 88.2% and 95.9%, respectively. Application of the Cochran's Q test showed statistically significant heterogeneity among the diagnostic tests, with results indicating FTT performance to be more accurate than the repetitive nerve stimulation results (p < 0.001) and comparable with serum antibody tests (p > 0.99). CONCLUSION: FTT has excellent clinical properties to be used routinely in the assessment of dysphagia with isolated or predominant pharyngeal muscle involvement allowing rapid and accurate diagnosis of MG.

Evidence of genetic structure in the wide-ranging bearded vulture (Gypaetus barbatus (Linnaeus, 1758)).

BACKGROUND: The bearded vulture is sparsely distributed across a wide geographic range that extends over three continents (Africa, Europe and Asia). Restriction to high-altitude mountainous habitats, low breeding rates, lack of food and a heightened level of persecution have left many local populations severely diminished or extinct. Understanding the genetic connectivity and population structure of this threatened vulture species is critical for accurately assessing their conservation status, and for appropriately managing local populations through captive breeding programmes or translocations. Previous genetic assessments of the species were mainly focused on the European and Asian populations and included limited representation of the geographically isolated southern African population. A single mitochondrial study, which focused on the African populations of the bearded vulture, detected limited genetic differentiation between populations in Ethiopia and southern Africa, with reduced haplotype diversity in the southern Africa population. In this study, we extend the previous genetic assessments of the species by examining the phylogeography and genetic connectivity of global G. barbatus populations using a panel of 14 microsatellite loci. RESULTS: Analyses revealed spatially correlated genetic differentiation between regional populations and low levels of gene flow between these population fragments. In contrast to the mitochondrial data, the microsatellite data support the management of genetically different populations as separate entities. CONCLUSIONS: Low genetic diversity and geographic isolation are known to adversely affect the evolutionary potential of a species in the long-term. The high inbreeding found in the southern African G. barbatus and, to a lesser extent, the northern African populations highlights the need for conservation programmes to effectively manage populations of this species and maintain extant genetic diversity.

Dysphagia in Patients With Severe Coronavirus Disease 2019-Potential Neurologic Etiologies.

IMPORTANCE: Dysphagia is a common complication of critical illness, and many known risk factors are also present in critically ill coronavirus disease 2019 victims. OBJECTIVES: To investigate dysphagia in patients with severe coronavirus disease 2019. DESIGN SETTING AND PARTICIPANTS: In this case series, we report results of dedicated evaluation of swallowing function in six consecutive, tracheotomized coronavirus disease 2019 patients after they had survived acute respiratory distress syndrome and were weaned from the respirator. MAIN OUTCOMES AND MEASURES: Dysphagia was assessed with flexible endoscopic evaluation of swallowing. RESULTS: Three patients suffered from severe dysphagia and airway compromise precluding decannulation, whereas in the other, three swallowing was less critically impaired, and the tracheal cannula could be removed. Four patients presented with additional laryngeal dysfunctions not typically seen in acute respiratory distress syndrome survivors. CONCLUSION AND RELEVANCE: Dysphagia with impaired airway protection is a key feature in coronavirus disease 2019 acute respiratory distress syndrome survivors. Apart from critical illness polyneuropathy, coronavirus disease 2019-related involvement of the peripheral and central nervous system may contribute to swallowing impairment and laryngeal dysfunction.

Measurement of Oxygen Desaturation Is Not Useful for the Detection of Aspiration in Dysphagic Stroke Patients.

BACKGROUND: Dysphagia is one of the most dangerous symptoms of acute stroke. Various screening tools have been suggested for the early detection of this condition. In spite of conflicting results, measurement of oxygen saturation (SpO2) during clinical swallowing assessment is still recommended by different national guidelines as a screening tool with a decline in SpO2 ≥2% usually being regarded as a marker of aspiration. This paper assesses the sensitivity of SpO2 measurements for the evaluation of aspiration risk in acute stroke patients. METHODS: Fifty acute stroke patients with moderate to severe dysphagia were included in this study. In all patients, fiberoptic endoscopic evaluation of swallowing (FEES) was performed according to a standardised protocol. Blinded to the results of FEES, SpO2 was monitored simultaneously. The degree of desaturation during/after swallows with aspiration was compared to the degree of desaturation during/after swallows without aspiration in a swallow-to-swallow analysis of each patient. To minimise potential confounders, every patient served as their control. RESULTS: In each subject, a swallow with and a swallow without aspiration were analysed. Overall, aspiration seen in FEES was related to a minor decline in SpO2 (mean SpO2 without aspiration 95.54 ± 2.7% vs. mean SpO2 with aspiration 95.28 ± 2.7%). However, a significant desaturation ≥2% occurred only in 5 patients during/after aspiration. There was no correlation between aspiration/dysphagia severity or the amount of aspirated material and SpO2 levels. CONCLUSIONS: According to this study, measurement of oxygen desaturation is not a suitable screening tool for the detection of aspiration in stroke patients.

Differential range use between age classes of southern African Bearded Vultures Gypaetus barbatus.

Bearded Vulture Gypaetus barbatus movements were investigated in southern Africa to determine whether an individual's age, sex or breeding status influenced its ranging behaviour and to provide the information required to guide conservation activities. Data from satellite transmitters fitted to 18 individuals of four age classes were used to determine range size and use. Because of the nature of the movements of marked individuals, these data could be used to determine the overall foraging range of the entire population, which was estimated to be 51 767 km(2). Although juvenile, immature and sub-adult birds used different parts of the overall range, their combined foraging range was 65% (33 636 km(2)) of the overall range. Average adult home ranges (286 km(2)) were only around 1% the size of the average foraging ranges of non-adults (10 540 -25 985 km(2)), with those of breeding adults being even smaller (95 km(2)). Home ranges of breeding adults did not vary in size between seasons but adults utilized their home range more intensively whilst breeding, moving greater distances during the incubation and chick hatching period. Range size and use increased as non-adults aged. Immatures and sub-adults had larger range sizes during winter, but range use of non-adults did not vary seasonally. Range size and use did not differ between the sexes in any of the age classes. Information on home range size and use enables specific areas within the species' range to be targeted for management planning, education and conservation action.

Constitutive and dynamic phosphorylation and acetylation sites on NUCKS, a hypermodified nuclear protein, studied by quantitative proteomics.

Nuclear ubiquitous casein and cyclin-dependent kinases substrate (NUCKS) is a 27 kDa chromosomal protein of unknown function. Its amino acid composition as well as the structure of its DNA binding domain resembles that of high mobility group A (HMGA) proteins, chromosomal proteins known as modulators of chromatin conformation and regulators of transcription. Conformation and function of the HMGA proteins are regulated by phosphorylation and acetylation. So far 19 phosphorylation sites had been reported in NUCKS. In this study, we have identified all known and six additional phosphorylation sites, and also mapped multiple sites of acetylation, methylation and formylation. We measured cell cycle dependent changes of phosphorylation and acetylation of NUCKS in HeLa cells through stable isotope labeling by amino acids in cell culture (SILAC), using the dephosphorylated protein for normalization. We identified sites that were highly phosphorylated or dephosphorylated in mitotically arrested cells as well as sites that were constitutively phosphorylated. The extent of acetylation is reduced in mitotically and G1 arrested cells. Analysis of human cancer specimens revealed that in tissues the extent of acetylation, formylation and methylation is higher than in cultured cells. In breast cancer samples, seven acetylation, three methylation, and three formylation sites were mapped in NUCKS. Of the 243 amino acids, at least 36 can be modified with a total of 57 posttranslational modifications. Thus, NUCKS appears to have the highest ratio of modified to unmodified residues of any protein so far described.

Mass spectrometric mapping of linker histone H1 variants reveals multiple acetylations, methylations, and phosphorylation as well as differences between cell culture and tissue.

Posttranslational modifications of histones are involved in regulation of chromatin structure and gene activity. Whereas the modifications of the core histones H2A, H2B, H3, and H4 have been extensively studied, our knowledge of H1 modifications remained mainly limited to its phosphorylation. Here we analyzed the composition of histone H1 variants and their modifications in two human cell lines and nine mouse tissues. Use of a hybrid linear ion trap-orbitrap mass spectrometer facilitated assignment of modifications by high resolution and low ppm mass accuracy for both the precursor and product mass spectra. Across different tissues we identified a range of phosphorylation, acetylation, and methylation sites. We also mapped sites of ubiquitination and report identification of formylated lysine residues. Interestingly many of the mapped modifications are located within the globular domain of the histones at sites that are thought to be involved in binding to nucleosomal DNA. Investigation of mouse tissue in addition to cell lines uncovered a number of interesting differences. For example, whereas methylation sites are frequent in tissues, this type of modification was much less abundant in cultured cells and escaped detection. Our study significantly extends the known spectrum of linker histone variability.

Functional redundancy of NSCL-1 and NeuroD during development of the petrosal and vestibulocochlear ganglia.

To study the role of different members of the bHLH gene family for sensory organ development we have generated NSCL-1 and NeuroD compound-mutant mice. Double homozygous animals were characterized by a more severe reduction of the petrosal and vestibulocochlear ganglia than NeuroD-knockout mice. The more severe reduction of the petrosal and vestibulocochlear ganglia in double-knockout mice indicates overlapping functions of the two genes during neuronal development. Interestingly, we also found that the two genes are jointly regulated by thyroid hormone during sensory hair cell development. We further present a detailed expression analysis of NSCL-1 and NSCL-2 during sensory neuron development. NSCL-1 expression was detected in all developing cranial ganglia including the petrosal and vestibulocochlear ganglion, in inner and outer hair cells of the organ of Corti and in hair cells of the vestibular system. Expression domains in other sensory structures include the retina, Merkel cells of the developing skin and sensory cells of the tongue. The expression of NSCL-2 was restricted to developing cranial ganglia, the retina and the vestibular nerve. Both NSCL-1 and NSCL-2 genes are active only in postmitotic neurons, indicating a role for neuronal cell migration and/or differentiation within the sensory system.