147 research outputs found

    Distributing transmitters to maximize population-level representativeness in automated radio telemetry studies of animal movement

    Get PDF
    Telemetry is a powerful and indispensable tool for evaluating wildlife movement and distribution patterns, particularly in systems where opportunities for direct observation are limited. However, the effort and expense required to track individuals often results in small sample sizes, which can lead to biased results if the sample of tracked individuals does not fully capture spatial, temporal, and individual variability within the target population. To better understand the influence of sampling design on results of automated radio telemetry studies, we conducted a retrospective power analysis of very high frequency (VHF) radio telemetry data from the Motus Wildlife Tracking System for two species of birds along the United States Atlantic coast: a shorebird, the piping plover (Charadrius melodus), and a nearshore seabird, the common tern (Sterna hirundo). We found that ~ 100–150 tracked individuals were required to identify 90% of locations known to be used by the tracked population, with 40–50 additional individuals required to include 95% of used locations. For any number of individuals, the percentage of stations included in the sample was higher for common terns than for piping plovers when tags were deployed within a single site and year. Percentages of stations included increased for piping plovers when birds were tagged over multiple sites and, to a lesser extent, years, and increased with average length of the tracking period. The probability that any given receiver station used by the population would be included in a subsample increased with the number of birds tracked, station proximity to a migratory stopover or staging site, number of receiving antennas per station, and percentage of the tracked population present. Our results provide general guidance for the number and distribution of tagged birds required to obtain representative VHF telemetry data, while also highlighting the importance of accounting for station network configuration and species-specific differences in behavior when designing automated radio telemetry studies to address specific research questions. Our results have broad applications to remotely track movements of small-bodied migratory wildlife in inaccessible habitats, including predicting and monitoring effects of offshore wind energy development

    Researchers Experience Multiple Embodiments in a Cross-Cultural, Intergenerational Event to Support Girls Challenging Gender-Based Violence

    Get PDF
    Many challenges exist to conducting participatory research and consultation with young people, especially with those considered vulnerable or at risk. Beyond respecting the safety and wellbeing of young research participants, researchers must be aware of barriers to youth engagement and be attuned to the many forms of youth resistance. As young people are seeking more control over their lives, traditional knowledge hierarchies between adults and youth are shifting. In July 2018, an event entitled Circles Within Circles brought together Indigenous and non-Indigenous girls and young women from South Africa, Canada, Russia, Sweden, and Kenya to learn from each other’s participatory art-making and create a network for challenging gender-based violence (GBV). This article provides insight into the often-invisible experience of the “supporting cast” in events like Circles Within Circles. The co-authors are doctoral and postdoctoral researchers who contributed to organization and acted as facilitators, notetakers, and participants. The co-authors conduct participatory analyses of journal entries they wrote throughout the event, and jointly reflect on the activities and their feelings about their roles. Reflecting, for example, on gut feelings about young participants’ use of voice and silence during adult-led activities, the co-authors discuss their reading of girls’ demonstrations of resistance. This embodied knowledge, further cultivated by attuning to shared experience, is explored in this collaborative auto-ethnography. Examining the complexities of this cross-cultural and intergenerational event, the co-authors contend that when supporting girls and young people subverting dominant narratives of GBV, researchers’ embodied reflexivity is crucial for positively contributing to girl-led change

    CULTURAS DE INVERNO NA SUPRESSÃO DE PLANTAS DANINHAS: RELAÇÃO COM O DESENVOLVIMENTO INICIAL DA CULTURA DA SOJA (Glycine max)

    Get PDF
    As plantas daninhas competem diretamente com as culturas implantadas, e essa competição, muitas vezes, pode causar problemas irreversĂ­veis. Esse trabalho tem como objetivo avaliar o efeito de diferentes espĂ©cies de coberturas de solo cultivadas consorciadas ou em cultivo solteiro, sob a supressĂŁo de plantas daninhas e desenvolvimento inicial da cultura da soja (Glycine max). O experimento foi conduzido no ano agrĂ­cola de 2020/2021, na Área Experimental da Fazenda Escola da Universidade de Cruz Alta, na cidade de Cruz Alta/RS. Onde foram semeados 8 (oito) tratamentos, constituĂ­dos por 7 (sete) plantas de coberturas de inverno, utilizadas isoladas e em consĂłrcio e 1 tratamento deixado em pousio (Testemunha), no perĂ­odo do inverno. No pleno florescimento das mesmas, foram feitas coletas para quantificar a massa seca e massa verde produzida. E posterior realizou-se a dessecação e a semeadura da soja. Aos 7 e 15 DAE (Dias ApĂłs a EmergĂȘncia), foram realizadas analises para avaliar o desenvolvimento inicial da cultura, sendo aos 7 DAE quantificado o nĂșmero de plĂąntulas emergidas, e aos 15 DAE analisadas altura de plantas. O uso de plantas de coberturas de solo representa grande vantagem ao produtor, no sentido que reduz o potencial de competição das plantas daninhas.  Cobertura de inverno proporcionada pelo consĂłrcio de aveia preta (Avena strigosa) + nabo forrageiro (Raphanus sativus) + ervilhaca (Vicia sativa) desempenha papel supressor sobre plantas daninhas infestantes, em especial a buva (Conyza spp.), permitindo melhor desenvolvimento inicial da cultura da soja

    The \u3cem\u3eChlamydomonas\u3c/em\u3e Genome Reveals the Evolution of Key Animal and Plant Functions

    Get PDF
    Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the ∌120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella

    Understanding watershed hydrogeochemistry: 2. Synchronized hydrological and geochemical processes drive stream chemostatic behavior

    Get PDF
    This article is a companion to Bao et al. [2017], doi: 10.1002/2016WR018934.Why do solute concentrations in streams remain largely constant while discharge varies by orders of magnitude? We used a new hydrological land surface and reactive transport code, RT‐Flux‐PIHM, to understand this long‐standing puzzle. We focus on the nonreactive chloride (Cl) and reactive magnesium (Mg) in the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO). Simulation results show that stream discharge comes from surface runoff (Qs), soil lateral flow (QL), and deeper groundwater (QG), with QL contributing >70%. In the summer, when high evapotranspiration dries up and disconnects most of the watershed from the stream, Cl is trapped along planar hillslopes. Successive rainfalls connect the watershed and mobilize trapped Cl, which counteracts dilution effects brought about by high water storage (Vw) and maintains chemostasis. Similarly, the synchronous response of clay dissolution rates (Mg source) to hydrological conditions, maintained largely by a relatively constant ratio between “wetted” mineral surface area Aw and Vw, controls Mg chemostatic behavior. Sensitivity analysis indicates that cation exchange plays a secondary role in determining chemostasis compared to clay dissolution, although it does store an order‐of‐magnitude more Mg on exchange sites than soil water. Model simulations indicate that dilution (concentration decrease with increasing discharge) occurs only when mass influxes from soil lateral flow are negligible (e.g., via having low clay surface area) so that stream discharge is dominated by relatively constant mass fluxes from deep groundwater that are unresponsive to surface hydrological conditions.EAR 07‐25019EAR 12‐39285EAR 13‐3172

    International collaborative study to assess cardiovascular risk and evaluate long-term health in cats with preclinical hypertrophic cardiomyopathy and apparently healthy cats:The REVEAL Study

    Get PDF
    Background: Hypertrophic cardiomyopathy is the most prevalent heart disorder in cats and principal cause of cardiovascular morbidity and mortality. Yet, the impact of preclinical disease is unresolved. Hypothesis/Objectives: Observational study to characterize cardiovascular morbidity and survival in cats with preclinical nonobstructive (HCM) and obstructive (HOCM) hypertrophic cardiomyopathy and in apparently healthy cats (AH). Animals: One thousand seven hundred and thirty client-owned cats (430 preclinical HCM; 578 preclinical HOCM; 722 AH). Methods: Retrospective multicenter, longitudinal, cohort study. Cats from 21 countries were followed through medical record review and owner or referring veterinarian interviews. Data were analyzed to compare long-term outcomes, incidence, and risk for congestive heart failure (CHF), arterial thromboembolism (ATE), and cardiovascular death. Results: During the study period, CHF, ATE, or both occurred in 30.5% and cardiovascular death in 27.9% of 1008 HCM/HOCM cats. Risk assessed at 1, 5, and 10 years after study entry was 7.0%/3.5%, 19.9%/9.7%, and 23.9%/11.3% for CHF/ATE, and 6.7%, 22.8%, and 28.3% for cardiovascular death, respectively. There were no statistically significant differences between HOCM compared with HCM for cardiovascular morbidity or mortality, time from diagnosis to development of morbidity, or cardiovascular survival. Cats that developed cardiovascular morbidity had short survival (mean \ub1 standard deviation, 1.3 \ub1 1.7 years). Overall, prolonged longevity was recorded in a minority of preclinical HCM/HOCM cats with 10% reaching 9-15 years. Conclusions and Clinical Importance: Preclinical HCM/HOCM is a global health problem of cats that carries substantial risk for CHF, ATE, and cardiovascular death. This finding underscores the need to identify therapies and monitoring strategies that decrease morbidity and mortality

    Medial longitudinal arch development of school children : The College of Podiatry Annual Conference 2015: meeting abstracts

    Get PDF
    Background Foot structure is often classified into flat foot, neutral and high arch type based on the variability of the Medial Longitudinal Arch (MLA). To date, the literature provided contrasting evidence on the age when MLA development stabilises in children. The influence of footwear on MLA development is also unknown. Aim This study aims to (i) clarify whether the MLA is still changing in children from age 7 to 9 years old and (ii) explore the relationship between footwear usage and MLA development, using a longitudinal approach. Methods We evaluated the MLA of 111 healthy school children [age = 6.9 (0.3) years] using three parameters [arch index (AI), midfoot peak pressure (PP) and maximum force (MF: % of body weight)] extracted from dynamic foot loading measurements at baseline, 10-month and 22-month follow-up. Information on the type of footwear worn was collected using survey question. Linear mixed modelling was used to test for differences in the MLA over time. Results Insignificant changes in all MLA parameters were observed over time [AI: P = .15; PP: P = .84; MF: P = .91]. When gender was considered, the AI of boys decreased with age [P = .02]. Boys also displayed a flatter MLA than girls at age 6.9 years [AI: mean difference = 0.02 (0.01, 0.04); P = .02]. At baseline, subjects who wore close-toe shoes displayed the lowest MLA overall [AI/PP/MF: P < .05]. Subjects who used slippers when commencing footwear use experienced higher PP than those who wore sandals [mean difference = 31.60 (1.44, 61.75) kPa; post-hoc P = .04]. Discussion and conclusion Our findings suggested that the MLA of children remained stable from 7 to 9 years old, while gender and the type of footwear worn during childhood may influence MLA development. Clinicians may choose to commence therapy when a child presents with painful flexible flat foot at age 7 years, and may discourage younger children from wearing slippers when they commence using footwear

    Distinct Steps of Neural Induction Revealed by Asterix, Obelix and TrkC, Genes Induced by Different Signals from the Organizer

    Get PDF
    The amniote organizer (Hensen's node) can induce a complete nervous system when grafted into a peripheral region of a host embryo. Although BMP inhibition has been implicated in neural induction, non-neural cells cannot respond to BMP antagonists unless previously exposed to a node graft for at least 5 hours before BMP inhibitors. To define signals and responses during the first 5 hours of node signals, a differential screen was conducted. Here we describe three early response genes: two of them, Asterix and Obelix, encode previously undescribed proteins of unknown function but Obelix appears to be a nuclear RNA-binding protein. The third is TrkC, a neurotrophin receptor. All three genes are induced by a node graft within 4–5 hours but they differ in the extent to which they are inducible by FGF: FGF is both necessary and sufficient to induce Asterix, sufficient but not necessary to induce Obelix and neither sufficient nor necessary for induction of TrkC. These genes are also not induced by retinoic acid, Noggin, Chordin, Dkk1, Cerberus, HGF/SF, Somatostatin or ionomycin-mediated Calcium entry. Comparison of the expression and regulation of these genes with other early neural markers reveals three distinct “epochs”, or temporal waves, of gene expression accompanying neural induction by a grafted organizer, which are mirrored by specific stages of normal neural plate development. The results are consistent with neural induction being a cascade of responses elicited by different signals, culminating in the formation of a patterned nervous system
    • 

    corecore