The role of dispersal in population dynamics of breeding Ross's geese

Spatial variation in density of organisms can lead to challenges in estimation of population size. Associated vital rates responsible for this variation also may vary geographically and in response to local ecological conditions, with the result that subunits of a metapopulation may have different trajectories. Both temporal and spatial variation in population size occurs not only as a result of additions through birth and deletions through death, but also from gains and losses arising from immigration and emigration, respectively. Although virtually all organisms have evolved mechanisms for dispersal, the role of movement in population dynamics has received far less attention than have contributions from recruitment and losses to mortality. I used mark-recapture techniques to make inferences about the role of movement in local population dynamics of Ross’s Goose (Chen rossii) colonies by estimating rates of movement between breeding subpopulations in the Queen Maud Gulf metapopulation. I also assessed decision-based philopatry (i.e., the role of previous nesting outcome; sensu Hoover 2003) and a potential cost of reproduction to female geese through experimental manipulation of nesting success. Previous nest fate influenced intra-colony dispersal as failed nesters moved further between consecutive nest sites, but inter-colony movement was not affected by previous nest fate. Regardless of previous nest fate, Ross’s Geese did not exhibit philopatry to nest sites, or to breeding territories, suggesting that philopatry occurs at a larger spatial scale. Breeding success accounted for a detectable, but only small amount of variation

The Evolution of Compact Binary Star Systems

We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure

The Secret Life of the Anthrax Agent Bacillus anthracis: Bacteriophage-Mediated Ecological Adaptations

Ecological and genetic factors that govern the occurrence and persistence of anthrax reservoirs in the environment are obscure. A central tenet, based on limited and often conflicting studies, has long held that growing or vegetative forms of Bacillus anthracis survive poorly outside the mammalian host and must sporulate to survive in the environment. Here, we present evidence of a more dynamic lifecycle, whereby interactions with bacterial viruses, or bacteriophages, elicit phenotypic alterations in B. anthracis and the emergence of infected derivatives, or lysogens, with dramatically altered survival capabilities. Using both laboratory and environmental B. anthracis strains, we show that lysogeny can block or promote sporulation depending on the phage, induce exopolysaccharide expression and biofilm formation, and enable the long-term colonization of both an artificial soil environment and the intestinal tract of the invertebrate redworm, Eisenia fetida. All of the B. anthracis lysogens existed in a pseudolysogenic-like state in both the soil and worm gut, shedding phages that could in turn infect non-lysogenic B. anthracis recipients and confer survival phenotypes in those environments. Finally, the mechanism behind several phenotypic changes was found to require phage-encoded bacterial sigma factors and the expression of at least one host-encoded protein predicted to be involved in the colonization of invertebrate intestines. The results here demonstrate that during its environmental phase, bacteriophages provide B. anthracis with alternatives to sporulation that involve the activation of soil-survival and endosymbiotic capabilities

Non-pharmacological management of osteoporosis: a consensus of the Belgian Bone Club

This consensus article reviews the various aspects of the non-pharmacological management of osteoporosis, including the effects of nutriments, physical exercise, lifestyle, fall prevention, and hip protectors. Vertebroplasty is also briefly reviewed. Non-pharmacological management of osteoporosis is a broad concept. It must be viewed as an essential part of the prevention of fractures from childhood through adulthood and the old age. The topic also includes surgical procedures for the treatment of peripheral and vertebral fractures and the post-fracture rehabilitation. The present document is the result of a consensus, based on a systematic review and a critical appraisal of the literature. Diets deficient in calcium, proteins or vitamin D impair skeletal integrity. The effect of other nutriments is less clear, although an excessive consumption of sodium, caffeine, or fibres exerts negative effects on calcium balance. The deleterious effects of tobacco, excessive alcohol consumption and a low BMI are well accepted. Physical activity is of primary importance to reach optimal peak bone mass but, if numerous studies have shown the beneficial effects of various types of exercise on bone mass, fracture data as an endpoint are scanty. Fall prevention strategies are especially efficient in the community setting, but less evidence is available about their effectiveness in preventing fall-related injuries and fractures. The efficacy of hip protectors remains controversial. This is also true for vertebroplasty and kyphoplasty. Several randomized controlled studies had reported a short-term advantage of vertebroplasty over medical treatment for pain relief, but these findings have been questioned by recent sham-controlled randomized clinical studies

RELATEC : Revista latinoamericana de tecnología educativa

Resumen en inglésResumen basado en el de la publicaciónSe presentan los resultados obtenidos en un estudio llevado a cabo con una muestra de estudiantes egresados de la Facultad de Educación de la UEx, con el propósito de conocer su opinión acerca de la formación recibida durante su paso por la universidad y su valoración acerca de sus conocimientos en tecnología educativa. Para ello, recogimos información a través de la diseminación de un cuestionario formado por preguntas cerradas y abiertas y el desarrollo de grupos de discusión con alumnado egresado e informantes clave. De la información generada se extraen conclusiones y propuestas, con el propósito de incidir en la elaboración de los nuevos planes de estudio de Maestro/aES

Microphone variability and degradation: implications for monitoring programs employing autonomous recording units

Autonomous recording units (ARUs) are emerging as an effective tool for avian population monitoring and research. Although ARU technology is being rapidly adopted, there is a need to establish whether variation in ARU components and their degradation with use might introduce detection biases that would affect long-term monitoring and research projects. We assessed whether microphone sensitivity impacted the probability of detecting bird vocalizations by broadcasting a sequence of 12 calls toward an array of commercially available ARUs equipped with microphones of varying sensitivities under three levels (32 dBA, 42 dBA, and 50 dBA) of experimentally induced noise conditions selected to reflect the range of noise levels commonly encountered during avian surveys. We used binomial regression to examine factors influencing probability of detection for each species and used these to examine the impact of microphone sensitivity on the effective detection area (ha) for each species. Microphone sensitivity loss reduced detection probability for all species examined, but the magnitude of the effect varied between species and often interacted with distance. Microphone sensitivity loss reduced the effective detection area by an average of 25% for microphones just beyond manufacturer specifications (-5 dBV) and by an average of 66% for severely compromised microphones (-20 dBV). Microphone sensitivity loss appeared to be more problematic for low frequency calls where reduction in the effective detection area occurred most rapidly. Microphone degradation poses a source of variation in avian surveys made with ARUs that will require regular measurement of microphone sensitivity and criteria for microphone replacement to ensure scientifically reproducible results. We recommend that research and monitoring projects employing ARUs test their microphones regularly, replace microphones with declining sensitivity, and record sensitivity as a potential covariate in statistical analyses of acoustic data

Modeling detection probability to improve marsh bird surveys in southern Canada and the Great Lakes states

Marsh birds are notoriously elusive, with variation in detection probability across species, regions, seasons, and different times of day and weather. Therefore, it is important to develop regional field survey protocols that maximize detections, but that also produce data for estimating and analytically adjusting for remaining differences in detections. We aimed to improve regional field survey protocols by estimating detection probability of eight elusive marsh bird species throughout two regions that have ongoing marsh bird monitoring programs: the southern Canadian Prairies (Prairie region) and the southern portion of the Great Lakes basin and parts of southern Québec (Great Lakes-St. Lawrence region). We accomplished our goal using generalized binomial N-mixture models and data from ~22,300 marsh bird surveys conducted between 2008 and 2014 by Bird Studies Canada's Prairie, Great Lakes, and Québec Marsh Monitoring Programs. Across all species, on average, detection probability was highest in the Great Lakes-St. Lawrence region from the beginning of May until mid-June, and then fell throughout the remainder of the season until the end of June; was lowest in the Prairie region in mid-May and then increased throughout the remainder of the season until the end of June; was highest during darkness compared with light; and did not vary significantly according to temperature (range: 0-30°C), cloud cover (0%-100%), or wind (0-20 kph), or during morning versus evening. We used our results to formulate improved marsh bird survey protocols for each region. Our analysis and recommendations are useful and contribute to conservation of wetland birds at various scales from local single-species studies to the continental North American Marsh Bird Monitoring Program

Data from: Using citizen science monitoring data in species distribution models to inform isotopic assignment of migratory connectivity in wetland birds

Stable isotopes have been used to estimate migratory connectivity in many species. Estimates are often greatly improved when coupled with species distribution models (SDMs), which temper estimates in relation to occurrence. SDMs can be constructed using from point locality data from a variety of sources including extensive monitoring data typically collected by citizen scientists. However, one potential issue with SDM is that these data oven have sampling bias. To avoid this potential bias, an approach using SDMs based on marsh bird monitoring program data collected by citizen scientists and other participants following protocols specifically designed to maximize detections of species of interest at locations representative of the species range. We then used the SDMs to refine isotopic assignments of breeding areas of autumn-migrating and wintering Sora (Porzana carolina), Virginia Rails (Rallus limicola), and Yellow Rails (Coturnicops noveboracensis) based on feathers collected from individuals caught at various locations in the United States from Minnesota south to Louisiana and South Carolina. Sora were assigned to an area that included much of the western U.S. and prairie Canada, covering parts of the Pacific, Central, and Mississippi Flyways. Yellow Rails were assigned to a broad area along Hudson and James Bay in northern Manitoba and Ontario, as well as smaller parts of Quebec, Minnesota, Wisconsin, and Michigan, including parts of the Mississippi and Atlantic Flyways. Virginia Rails were from several discrete areas, including parts of Colorado, New Mexico, the central valley of California, and southern Saskatchewan and Manitoba in the Pacific and Central Flyways. Our study demonstrates extensive data from organized citizen science monitoring programs are especially useful for improving isotopic assignments of migratory connectivity in birds, which can ultimately lead to better informed management decisions and conservation actions

Capture of Breeding and Wintering Shorebirds with Leg-Hold Noose-Mats

Development of effective trapping techniques is important for conservation efforts, as marking and subsequent monitoring of individuals is necessary to obtain accurate estimates of demography, movements, and habitat use. We describe a leg-hold noose-mat trap for capturing breeding and nonbreeding shorebirds. Using this method, we trapped 50 Piping Plovers (Charadrius melodus), 2258 Snowy Plovers (C. alexandrinus), 38 Killdeers (C. vociferus), and 64 Dunlins (Calidris alpina) in the western and southern United States. The trap was lightweight, making it easy to transport and set up. It was effective on unvegetated substrates at both coastal and inland sites and could be modified for a variety of habitats. Furthermore, this trap allowed researchers to target specific groups of birds including territorial individuals. Easy removal of birds from traps minimized handling time, stress, and injury