Migratory animals likely play an important role in the geographic spread of parasites. In fact, a common assumption is that parasites are potentially transmitted by migratory animals at temporary stopover sites along migratory routes, yet very few studies have assessed whether transmission at stopover sites can or does occur. We investigated the potential for a group of vector-transmitted parasites, the avian haemosporidians, to be transmitted during migratory stopover periods at Rushton Woods Preserve in Pennsylvania, USA.
View Article and Find Full Text PDFObjective: Navigating obstacles involves adjusting walking patterns, particularly when stepping over them. This task may be particularly challenging for people with Parkinson disease (PD) for several reasons. This review aims to compare the spatiotemporal gait parameters of people with and without PD while stepping over obstacles.
View Article and Find Full Text PDFAnimals are frequently coinfected with multiple parasites concurrently, and advances in our sampling of these complex intra-host parasite communities have revealed important ecological impacts on their hosts. However, the spatial distributions and environmental determinants of parasite coinfection remain infrequently studied. Here, we investigated the drivers of haemosporidian blood parasite coinfection in the Bicknell's thrush () and grey-cheeked thrush (), parapatric sister species that occur across a broad latitudinal range in northern North America.
View Article and Find Full Text PDFSuitable habitat fragment size, isolation, and distance from a source are important variables influencing community composition of plants and animals, but the role of these environmental factors in determining composition and variation of host-associated microbial communities is poorly known. In parasite-associated microbial communities, it is hypothesized that evolution and ecology of an arthropod parasite will influence its microbiome more than broader environmental factors, but this hypothesis has not been extensively tested. To examine the influence of the broader environment on the parasite microbiome, we applied high-throughput sequencing of the V4 region of 16S rRNA to characterize the microbiome of 222 obligate ectoparasitic bat flies (Streblidae and Nycteribiidae) collected from 155 bats (representing six species) from ten habitat fragments in the Atlantic Forest of Brazil.
View Article and Find Full Text PDFUsing low-coverage whole-genome sequencing, analysis of vocalizations, and inferences from natural history, we document a first-generation hybrid between a rose-breasted grosbeak () and a scarlet tanager (). These two species occur sympatrically throughout much of eastern North America, although were not previously known to interbreed. Following the field identification of a putative hybrid, we use genetic and bioacoustic data to show that a rose-breasted grosbeak was the maternal parent and a scarlet tanager was the paternal parent of the hybrid, whose song was similar to the latter species.
View Article and Find Full Text PDFThe factors that influence whether a parasite is likely to cause death in a given host species are not well known. Generalist parasites with high local abundances, broad distributions and the ability to infect a wide phylogenetic diversity of hosts are often considered especially dangerous for host populations, though comparatively little research has been done on the potential for specialist parasites to cause host mortality. Here, using a novel database of avian mortality records, we tested whether phylogenetic host specialist or host generalist haemosporidian blood parasites were associated with avian host deaths based on infection records from over 81 000 examined hosts.
View Article and Find Full Text PDFIntroduction: The COVID-19 crisis resulted in a worldwide shift from in-person instruction to remote instruction, in order to mitigate the spread of the virus. The aim of this study was to survey Doctor of Physical Therapy (DPT) students' perceptions of learning during the instructional shift as well as assess the impact of this shift on learning outcomes.
Subjects: One hundred twenty-five students enrolled in the DPT program were recruited to participate in this study.
Proc Natl Acad Sci U S A
March 2021
Geographic turnover in community composition is created and maintained by eco-evolutionary forces that limit the ranges of species. One such force may be antagonistic interactions among hosts and parasites, but its general importance is unknown. Understanding the processes that underpin turnover requires distinguishing the contributions of key abiotic and biotic drivers over a range of spatial and temporal scales.
View Article and Find Full Text PDFTurnover in species composition between sites, or beta diversity, is a critical component of species diversity that is typically influenced by geography, environment, and biotic interactions. Quantifying turnover is particularly challenging, however, in multi-host, multi-parasite assemblages where undersampling is unavoidable, resulting in inflated estimates of turnover and uncertainty about its spatial scale. We developed and implemented a framework using null models to test for community turnover in avian haemosporidian communities of three sky islands in the southwestern United States.
View Article and Find Full Text PDFThe eukaryotic blood parasite genus Trypanosoma includes several important pathogens of humans and livestock, but has been understudied in wildlife broadly. The trypanosomes that infect birds are in particular need of increased attention, as these parasites are abundant and globally distributed, yet few studies have addressed their evolutionary origins and diversity using modern molecular and analytical approaches. Of specific interest are the deep evolutionary relationships of the avian trypanosomes relative to the trypanosome species that are pathogenic in humans, as well as their species level diversity in regions where they have been understudied such as North America.
View Article and Find Full Text PDFIntroduction: Dysferlin-deficient murine muscle sustains severe damage after repeated eccentric contractions.
Methods: With a robotic dynamometer, we studied the response of dysferlin-sufficient and dysferlin-deficient mice to 12 weeks of concentrically or eccentrically biased contractions. We also studied whether concentric contractions before or after eccentric contractions reduced muscle damage in dysferlin-deficient mice.
Introduction: The aim of this study was to quantify the extent of donor-cell-derived myogenesis achieved by a novel surgical technique known as Minimally Invasive Muscle Embedding (MIME).
Materials And Methods: Through MIME, we implanted a single extensor digitorum longus muscle from donor mice (N = 2) that expressed a red fluorescent protein (RFP), into the left tibialis anterior (TA) muscle of immunodeficient host mice (N = 4) that expressed a green fluorescent protein (GFP). Soon after MIME, we injected a myotoxin (barium chloride), into the host TA muscle, to trigger concerted muscle degeneration and regeneration.
Geographic variation in environmental conditions as well as host traits that promote parasite transmission may impact infection rates and community assembly of vector-transmitted parasites. Identifying the ecological, environmental and historical determinants of parasite distributions and diversity is therefore necessary to understand disease outbreaks under changing environments. Here, we identified the predictors and contributions of infection probability and phylogenetic diversity of Leucocytozoon (an avian blood parasite) at site and species levels across the New World.
View Article and Find Full Text PDFCo-infections with multiple parasite taxa are ubiquitous in nature and have the potential to impact the co-evolutionary dynamics between host and parasite, though patterns of phylogenetic community structure of co-infecting parasites and the processes that generate these patterns have rarely been studied across diverse host-parasite communities. Here, we tested for the roles of host and parasite evolutionary history as well as environmental variables as drivers of phylogenetic community structure among co-infecting haemosporidian (malaria) parasites and their avian hosts in the North American boreal forest, a region characterized by an extraordinarily high blood parasite co-infection rate. We used multiple methods to identify non-random patterns of co-infection among parasite species and determined whether these patterns were influenced more by co-evolutionary host associations or environmental variables.
View Article and Find Full Text PDFVariation in susceptibility is ubiquitous in multi-host, multi-parasite assemblages, and can have profound implications for ecology and evolution in these systems. The extent to which susceptibility to parasites is phylogenetically conserved among hosts can be revealed by analysing diverse regional communities. We screened for haemosporidian parasites in 3983 birds representing 40 families and 523 species, spanning ~ 4500 m elevation in the tropical Andes.
View Article and Find Full Text PDFHaemosporidian parasites of birds are ubiquitous in terrestrial ecosystems, but their coevolutionary dynamics remain poorly understood. If species turnover in parasites occurs at a finer scale than turnover in hosts, widespread hosts would encounter diverse parasites, potentially diversifying as a result. Previous studies have shown that some wide-ranging hosts encounter varied haemosporidian communities throughout their range, and vice-versa.
View Article and Find Full Text PDFObjective: To describe systematic reviews (SRs) of the use of exoskeletons for gait and mobility by persons with neurologic disorders and to evaluate their quality as guidance for research and clinical practice.
Data Sources: PubMed, EMBASE, Web of Science, CINAHL Complete, PsycINFO, Cochrane Database of Systematic Reviews, PEDro, and Google Scholar were searched from database inception to January 23, 2018.
Study Selection: A total of 331 deduplicated abstracts from bibliographic database and ancestor searching were independently screened by 2 reviewers, resulting in 109 articles for which full text was obtained.
Background: Pusher syndrome (PS) is a clinical disorder that causes decreased postural balance and active pushing away from the non-hemiparetic side in patients with right or left brain damage. Therapists are challenged by needing to manage both the hemiparetic and the pushing/non-hemiparetic sides. There is a minimal amount of evidence about effective treatment interventions for PS.
View Article and Find Full Text PDFBackground: Coalescent methods that use multi-locus sequence data are powerful tools for identifying putatively reproductively isolated lineages, though this approach has rarely been used for the study of microbial groups that are likely to harbor many unrecognized species. Among microbial symbionts, integrating genetic species delimitation methods with trait data that could indicate reproductive isolation, such as host specificity data, has rarely been used despite its potential to inform species limits. Here we test the ability of an integrative approach combining genetic and host specificity data to delimit species within the avian malaria parasite genus Leucocytozoon in central Alaska.
View Article and Find Full Text PDFThe evolutionary relationships among the apicomplexan blood pathogens known as the malaria parasites (order Haemosporida), some of which infect nearly 200 million humans each year, has remained a vexing phylogenetic problem due to limitations in taxon sampling, character sampling and the extreme nucleotide base composition biases that are characteristic of this clade. Previous phylogenetic work on the malaria parasites has often lacked sufficient representation of the broad taxonomic diversity within the Haemosporida or the multi-locus sequence data needed to resolve deep evolutionary relationships, rendering our understanding of haemosporidian life-history evolution and the origin of the human malaria parasites incomplete. Here we present the most comprehensive phylogenetic analysis of the malaria parasites conducted to date, using samples from a broad diversity of vertebrate hosts that includes numerous enigmatic and poorly known haemosporidian lineages in addition to genome-wide multi-locus sequence data.
View Article and Find Full Text PDFB6.A-Dysf /GeneJ (BLAJ) mice model human limb-girdle muscular dystrophy 2B (LGMD2B), which is linked to mutations in the dysferlin (DYSF) gene. We tested the hypothesis that, the calcium ion (Ca ) channel blocker diltiazem (DTZ), reduces contraction-induced skeletal muscle damage, in BLAJ mice.
View Article and Find Full Text PDFLiu, J, Lee, I, Feng, H-Z, Galen, SS, Hüttemann, PP, Perkins, GA, Jin, J-P, Hüttemann, M, and Malek, MH. Aerobic exercise preconception and during pregnancy enhances oxidative capacity in the hindlimb muscles of mice offspring. J Strength Cond Res 32(5): 1391-1403, 2018-Little is known about the effect of maternal exercise on offspring skeletal muscle health.
View Article and Find Full Text PDFPurpose: Media images and marketing materials suggest a future in which individuals with spinal cord injury (SCI) can utilize robotic exoskeletons to reengage in everyday activities, yet these narratives may not align with the current technological realities. The purpose of this paper is to present and describe the current use of robotic exoskeletons in rehabilitation and home settings and discuss the benefits and limitations of the devices.
Materials And Methods: We provide an overview of the features and limitations of the four robotic exoskeleton products (EKSO Bionics, ReWalk, Rex Bionics, and Indego) that are currently being used in in the United States in rehabilitation settings.
Most tropical bird species have narrow elevational ranges, likely reflecting climatic specialization. This is consistent with Janzen's Rule, the tendency for mountain passes to be effectively "higher" in the tropics. Hence, those few tropical species that occur across broad elevational gradients (elevational generalists) represent a contradiction to Janzen's Rule.
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