Maintenance of Genetic Diversity Despite Population Fluctuations in the Lesser Prairie-Chicken ().

Assessments of genetic diversity, structure, history, and effective population size ( ) are critical for the conservation of imperiled populations. The lesser prairie-chicken () has experienced declines due to habitat loss, degradation, and fragmentation in addition to substantial population fluctuations with unknown effects on genetic diversity. Our objectives were to: (i) compare genetic diversity across three temporally discrete sampling periods (2002, 2007-2010, and 2013-2014) that are characterized by low or high population abundance; (ii) examine genetic diversity at lek and lek cluster spatial scales; (ii) identify potential bottlenecks and characterize genetic structure and relatedness; and (iii) estimate the regional .

The Impact of Video Laryngoscopy on the Clinical Learning Environment of Emergency Medicine Residents: A Report of 14,313 Intubations.

Background: The introduction of video laryngoscopy (VL) may impact emergency medicine (EM) residents' intubation practices.

Methods: We analyzed 14,313 intubations from 11 EM training sites, July 1, 2002, to December 31, 2012, assessing the likelihood of first-attempt success and likelihood of having a second attempt, by rank and device. We determined whether direct laryngoscopy (DL) first-attempt success decreased as VL became more prevalent using a logistic regression model with proportion of encounters initiated with VL at that center in the prior 90 and 365 days as predictors of DL first-attempt success.

Land Use, anthropogenic disturbance, and riverine features drive patterns of habitat selection by a wintering waterbird in a semi-arid environment.

River ecosystems in semi-arid environments provide an array of resources that concentrate biodiversity, but also attract human settlement and support economic development. In the southwestern United States, land-use change, drought, and anthropogenic disturbance are compounding factors which have led to departures from historical conditions of river ecosystems, consequently affecting wildlife habitat, including important wintering areas for migratory birds. The Rio Grande (River) in central New Mexico is the lifeblood of the Middle Rio Grande Valley (MRGV), maintaining large urban and agricultural centers and riparian and wetland resources, which disproportionately support a diversity of wildlife.

Decreasing maternal myostatin programs adult offspring bone strength in a mouse model of osteogenesis imperfecta.

During fetal development, the uterine environment can have effects on offspring bone architecture and integrity that persist into adulthood; however, the biochemical and molecular mechanisms remain unknown. Myostatin is a negative regulator of muscle mass. Parental myostatin deficiency (Mstn) increases muscle mass in wild-type offspring, suggesting an intrauterine programming effect.

Corn rootworm-active RNA DvSnf7: Repeat dose oral toxicology assessment in support of human and mammalian safety.

Genetically modified (GM) crops have been developed and commercialized that utilize double stranded RNAs (dsRNA) to suppress a target gene(s), producing virus resistance, nutritional and quality traits. MON 87411 is a GM maize variety that leverages dsRNAs to selectively control corn rootworm through production of a 240 base pair (bp) dsRNA fragment targeting for suppression the western corn rootworm (Diabrotica virgifera virgifera) Snf7 gene (DvSnf7). A bioinformatics assessment found that endogenous corn small RNAs matched ∼450 to 2300 unique RNA transcripts that likely code for proteins in rat, mouse, and human, demonstrating safe dsRNA consumption by mammals.

A novel method of demonstrating the molecular and functional equivalence between in vitro and plant-produced double-stranded RNA.

A biotechnology-derived corn variety, MON 87411, containing a suppression cassette that expresses an inverted repeat sequence that matches the sequence of western corn rootworm (WCR; Diabrotica virgifera virgifera) has been developed. The expression of the cassette results in the formation of a double-stranded RNA (dsRNA) transcript containing a 240 bp fragment of the WCR Snf7 gene (DvSnf7) that confers resistance to corn rootworm by suppressing levels of DvSnf7 mRNA in WCR after root feeding. Internationally accepted guidelines for the assessment of genetically modified crop products have been developed to ensure that these plants are as safe for food, feed, and environmental release as their non-modified counterparts (Codex, 2009).

Myostatin deficiency partially rescues the bone phenotype of osteogenesis imperfecta model mice.

Unlabelled: Mice with osteogenesis imperfecta (+/oim), a disorder of bone fragility, were bred to mice with muscle over growth to test whether increasing muscle mass genetically would improve bone quality and strength. The results demonstrate that femora from mice carrying both mutations have greater mechanical integrity than their +/oim littermates.

Introduction: Osteogenesis imperfecta is a heritable connective tissue disorder due primarily to mutations in the type I collagen genes resulting in skeletal deformity and fragility.

Hindlimb Skeletal Muscle Function and Skeletal Quality and Strength in +/G610C Mice With and Without Weight-Bearing Exercise.

Osteogenesis imperfecta (OI) is a heterogeneous heritable connective tissue disorder associated with reduced bone mineral density and skeletal fragility. Bone is inherently mechanosensitive, with bone strength being proportional to muscle mass and strength. Physically active healthy children accrue more bone than inactive children.

Gender-dependence of bone structure and properties in adult osteogenesis imperfecta murine model.

Osteogenesis imperfecta (OI) is a dominant skeletal disorder characterized by bone fragility and deformities. Though the oim mouse model has been the most widely studied of the OI models, it has only recently been suggested to exhibit gender-dependent differences in bone mineralization. To characterize the impact of gender on the morphometry/ultra-structure, mechanical properties, and biochemical composition of oim bone on the congenic C57BL/J6 background, 4-month-old oim/oim, +/oim, and wild-type (wt) female and male tibiae were evaluated using micro-computed tomography, three-point bending, and Raman spectroscopy.

Seasonality of acute otitis media and the role of respiratory viral activity in children.

Background: Acute otitis media (AOM) occurs as a complication of viral upper respiratory tract infections in young children. AOM and respiratory viruses both display seasonal variation. Our objective was to examine the temporal association between circulating respiratory viruses and the occurrence of pediatric ambulatory care visits for AOM.

Effect of food restriction and leptin supplementation on fetal programming in mice.

Metabolic disease is a significant global health and economic problem. In a phenomenon referred to as fetal programming, offspring of underweight or overweight mothers have an increased incidence of adulthood obesity and metabolic disease. Undernourished individuals have decreased levels of leptin, a regulator of energy balance, whereas obese people develop hyperleptinemia and leptin resistance.

Developmental exposure to xenoestrogens at low doses alters femur length and tensile strength in adult mice.

Developmental exposure to high doses of the synthetic xenoestrogen diethylstilbestrol (DES) has been reported to alter femur length and strength in adult mice. However, it is not known if developmental exposure to low, environmentally relevant doses of xenoestrogens alters adult bone geometry and strength. In this study we investigated the effects of developmental exposure to low doses of DES, bisphenol A (BPA), or ethinyl estradiol (EE(2)) on bone geometry and torsional strength.

Dietary fluoride restriction does not alter femoral biomechanical strength in col1a2-deficient (oim) mice with type I collagen glomerulopathy.

Osteogenesis imperfecta (OI) is a clinically and genetically heterogeneous disease due primarily to mutations in the type I procollagen genes, COL1A1 and COL1A2, causing bone deformity and numerous lifetime fractures. OI murine (oim) model mice carry a mutation in the col1a2 gene causing aberrant production of homotrimeric type I collagen [α1(I)(3)], leading to bone fragility and glomerular accumulation of type I collagen. Previous studies demonstrated that heterozygous (+/oim) and homozygous (oim/oim) mice have elevated tibiae fluoride concentrations but reduced femoral biomechanics.

DNA carrier testing and newborn screening for maple syrup urine disease in Old Order Mennonite communities.

Maple syrup urine disease (MSUD) is an inherited metabolic disorder caused by mutations in the branched chain alpha-keto acid dehydrogenase complex. Worldwide incidence of MSUD is 1:225,000 live births. However, within Old Order Mennonite communities, the incidence is 1:150 live births and results from a common tyrosine to asparagine substitution (Y438N) in the E1alpha subunit of branched chain alpha-keto acid dehydrogenase.

Variable bone fragility associated with an Amish COL1A2 variant and a knock-in mouse model.

Osteogenesis imperfecta (OI) is a heritable form of bone fragility typically associated with a dominant COL1A1 or COL1A2 mutation. Variable phenotype for OI patients with identical collagen mutations is well established, but phenotype variability is described using the qualitative Sillence classification. Patterning a new OI mouse model on a specific collagen mutation therefore has been hindered by the absence of an appropriate kindred with extensive quantitative phenotype data.

Isotopic ecology ten years after a call for more laboratory experiments.

About 10 years ago, reviews of the use of stable isotopes in animal ecology predicted explosive growth in this field and called for laboratory experiments to provide a mechanistic foundation to this growth. They identified four major areas of inquiry: (1) the dynamics of isotopic incorporation, (2) mixing models, (3) the problem of routing, and (4) trophic discrimination factors. Because these areas remain central to isotopic ecology, we use them as organising foci to review the experimental results that isotopic ecologists have collected in the intervening 10 years since the call for laboratory experiments.

Should we use one-, or multi-compartment models to describe (13)C incorporation into animal tissues?

Understanding rates of isotopic incorporation and discrimination factors between tissues and diet is an important focus of ecologists seeking to use stable isotopes to track temporal changes in diet. We used a diet-shift experiment to measure differences among tissues in (13)C incorporation rates in house sparrows (Passer domesticus). We predicted faster incorporation rates in splanchnic than in structural tissues.

Transgenic over-expression of plasminogen activator inhibitor-1 results in age-dependent and gender-specific increases in bone strength and mineralization.

The plasminogen activation system (PAS) and its principal inhibitor, plasminogen activator inhibitor-1 (PAI-1), are recognized modulators of matrix. In addition, the PAS has previously been implicated in the regulation of bone homeostasis. Our objective was to study the influence of active PAI-1 on geometric, biomechanical, and mineral characteristics of bone using transgenic mice that over-express a variant of human PAI-1 that exhibits enhanced functional stability.

Metabolic substrate use and the turnover of endogenous energy reserves in broad-tailed hummingbirds (Selasphorus platycercus).

We fed broad-tailed hummingbirds (Selasphorus platycercus) diets of contrasting carbon isotope composition and measured changes in the delta(13)C of expired breath through time. By measuring the delta(13)C in the breath of fed and fasted birds we were able to quantify the fraction of metabolism fueled by assimilated sugars and endogenous energy reserves. These measurements also allowed us to estimate the fractional turnover of carbon in the hummingbirds' energy reserves.

The effect of cold-induced increased metabolic rate on the rate of 13C and 15N incorporation in house sparrows (Passer domesticus).

Animals with high metabolic rates are believed to have high rates of carbon and nitrogen isotopic incorporation. We hypothesized that (1) chronic exposure to cold, and hence an increase in metabolic rate, would increase the rate of isotopic incorporation of both 13C and 15N into red blood cells; and (2) that the rate of isotopic incorporation into red blood cells would be allometrically related to body mass. Two groups of sparrows were chronically exposed to either 5 or 22 degrees C and switched from a 13C-depleted C3-plant diet to a more 13C-enriched C4-plant one.

Keeling plots for hummingbirds: a method to estimate carbon isotope ratios of respired CO(2) in small vertebrates.

The carbon isotope composition of an animal's breath reveals the composition of the nutrients that it catabolizes for energy. Here we describe the use of Keeling plots, a method widely applied in ecosystem ecology, to measure the delta(13)C of respired CO(2) of small vertebrates. We measured the delta(13)C of Rufous Hummingbirds ( Selasphorus rufus) in the laboratory and of Mourning ( Zenaida macroura) and White-winged ( Z.

Latent tuberculosis: models, mechanisms, and novel prospects for eradication.

Latent tuberculosis (TB) infects one-third of the world. We present evidence for the existence of a latent state of TB in humans, cite new approaches to diagnosis and treatment, and identify several models that attempt to mimic the latent state. Persistent infection in mice and in vitro systems of microaerophilic and/or anaerobic growth and nutrient starvation have been the most productive models in yielding insights into the host and mycobacterial pathways involved in the latent state.