Habitat selection of brown-headed nuthatches at multiple spatial scales

Title from PDF of title page (University of Missouri--Columbia, viewed on September 12, 2013).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Thesis advisors: Dr. Dylan C. Kesler, Frank R. Thompson III, Ph.D.Includes bibliographical references.M.S. University of Missouri--Columbia, 2013.Dissertations, Academic -- University of Missouri--Columbia -- Fisheries and wildlife sciences."May 2013"Resources shape the movements and space use of birds. In turn, birds differ in their relative fitness, in part as a consequence of movement and space use decisions. The saga of each individual plays out across time and space, generating the dynamic pattern known as a species' geographic range. Then, changes in geographic range dimensions alter the selective environment encountered by individuals, potentially driving evolutionary change in movement modes. Thus, understanding resource selection requires knowledge of both individual behavior and landscape patterns of patch occupancy. This thesis describes resource selection from both perspectives. We conducted two concurrent studies in a cooperatively breeding bird (Brown-headed Nuthatches, Sitta pusilla). We radio-tracked 22 Brown-headed Nuthatches, and related their space use to available resources within their respective home ranges. These associations controlled for the influence of the nest site as a central place; thus use of these resources reflected their perceived value to nuthatches. Areas of high use were associated with recently-killed trees, recent prescribed fire, pine dominance, and grassy herbaceous cover in descending order of importance. We also modeled patch occupancy across a range extension front created by habitat restoration. We found that high quality habitat near the range limit was vacant while marginal habitat was occupied, contrary to the standard model of range extension wherein habitats are occupied in order of quality. The pattern we observed is consistent with a range extension front that has been shaped by constraints on effective dispersal. This pattern may be quite common among birds given that many species are sedentary and that long-distance dispersers may have lower survival or fail to reproduce

A scale for quantifying behavior based on aggressiveness in bats

Behavior and personality play a crucial role in the evolution and ecology of animal species. We have limited knowledge of bat personality traits, partially due to the time, equipment, and facilities needed to measure them. To help fill this gap, we developed a scale for quantifying aggressiveness in bats that can be used during ordinary fieldwork and handling by researchers. This scale is based on observations of the following ecologically relevant and easily observed behaviors in wild-captured bats during routine handling: amount and intensity of physical struggling, teethbaring, and biting. We then applied this scale to 35 wild-caught individual bats belonging to three different species or species groups (Chaerephon pumilus, n=29; Scotophilus dinganii, n=3; and pipistrelloid bats, n=3) and measured agreement between observers using intraclass correlation coefficients (ICCs). We found that agreement between observers was good to excellent. This scale of aggressiveness provides an important, practical tool for researchers to reliably quantify this personality trait in wild bats that requires no additional equipment and minimal additional handling time. Collecting data on aggressive behavior during handling has the potential to increase our understanding of both intra- and interspecific variation in aggressiveness in bats, as well as the influence of this trait on many aspects of bat ecology. Finally, collecting data using this scale can facilitate comparisons between studies and promote research at broader spatial and temporal scales than commonly used in behavioral ecology studies.The National Science Foundation Graduate Research Fellowship, a Student Research Grant from Bat Conservation International, a National Geographic Young Explorer’s Grant and a grant from The Explorers Club Exploration Fund – Mamont Scholars Program.https://secemu.org/en/journal-of-bat-research-and-conservationam2022Mammal Research InstituteZoology and Entomolog

CRISPR transcriptional repression devices and layered circuits in mammalian cells

A key obstacle to creating sophisticated genetic circuits has been the lack of scalable device libraries. Here we present a modular transcriptional repression architecture based on clustered regularly interspaced palindromic repeats (CRISPR) system and examine approaches for regulated expression of guide RNAs in human cells. Subsequently we demonstrate that CRISPR regulatory devices can be layered to create functional cascaded circuits, which provide a valuable toolbox for engineering purposes.National Institutes of Health (U.S.) (Grant 5R01CA155320-04)National Institutes of Health (U.S.) (Grant P50 GM098792)Korea (South). Ministry of Science, Information and Communication Technolgy. Intelligent Synthetic Biology Center of Global Frontier Project (2013M3A6A8073557

Vitamin A deficiency and inflammatory markers among preschool children in the Republic of the Marshall Islands

BACKGROUND: The exclusion of individuals with elevated acute phase proteins has been advocated in order to improve prevalence estimates of vitamin A deficiency in surveys, but it is unclear whether this will lead to sampling bias. The purpose of the study was to determine whether the exclusion of individuals with elevated acute phase proteins is associated with sampling bias and to characterize inflammation in children with night blindness. METHODS: In a survey in the Republic of the Marshall Islands involving 281 children, aged 1–5 years, serum retinol, C-reactive protein (CRP), and α(1)-acid glycoprotein (AGP) were measured. RESULTS: Of 281 children, 24 (8.5%) had night blindness and 165 (58.7%) had serum retinol <0.70 μmol/L. Of 248 children with AGP and CRP measurements, 123 (49.6%) had elevated acute phase proteins (CRP >5 mg/L and/or AGP >1000 mg/L). Among children with and without night blindness, the proportion with serum retinol <0.70 μmol/L was 79.2% and 56.8% (P = 0.03) and with anemia was 58.3% and 35.7% (P = 0.029), respectively. The proportion of children with serum retinol <0.70 μmol/L was 52.0% after excluding children with elevated acute phase proteins. Among children with and without elevated acute phase proteins, mean age was 2.8 vs 3.2 years (P = 0.016), the proportion of boys was 43.1% vs. 54.3% (P = 0.075), with no hospitalizations in the last year was 11.0% vs 23.6% (P = 0.024), and with anemia was 43.8% vs 31.7% (P = 0.05), respectively. CONCLUSIONS: Exclusion of children with inflammation in this survey of vitamin A deficiency does not improve prevalence estimates for vitamin A deficiency and instead leads to sampling bias for variables such as age, gender, anemia, and hospitalization history

Формирование эмоциональной культуры как компонента инновационной культуры студентов

Homozygosity has long been associated with rare, often devastating, Mendelian disorders1 and Darwin was one of the first to recognise that inbreeding reduces evolutionary fitness2. However, the effect of the more distant parental relatedness common in modern human populations is less well understood. Genomic data now allow us to investigate the effects of homozygosity on traits of public health importance by observing contiguous homozygous segments (runs of homozygosity, ROH), which are inferred to be homozygous along their complete length. Given the low levels of genome-wide homozygosity prevalent in most human populations, information is required on very large numbers of people to provide sufficient power3,4. Here we use ROH to study 16 health-related quantitative traits in 354,224 individuals from 102 cohorts and find statistically significant associations between summed runs of homozygosity (SROH) and four complex traits: height, forced expiratory lung volume in 1 second (FEV1), general cognitive ability (g) and educational attainment (nominal p<1 × 10−300, 2.1 × 10−6, 2.5 × 10−10, 1.8 × 10−10). In each case increased homozygosity was associated with decreased trait value, equivalent to the offspring of first cousins being 1.2 cm shorter and having 10 months less education. Similar effect sizes were found across four continental groups and populations with different degrees of genome-wide homozygosity, providing convincing evidence for the first time that homozygosity, rather than confounding, directly contributes to phenotypic variance. Contrary to earlier reports in substantially smaller samples5,6, no evidence was seen of an influence of genome-wide homozygosity on blood pressure and low density lipoprotein (LDL) cholesterol, or ten other cardio-metabolic traits. Since directional dominance is predicted for traits under directional evolutionary selection7, this study provides evidence that increased stature and cognitive function have been positively selected in human evolution, whereas many important risk factors for late-onset complex diseases may not have been

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

The human cytomegalovirus ul11 protein interacts with the receptor tyrosine phosphatase cd45, resulting in functional paralysis of t cells

Human cytomegalovirus (CMV) exerts diverse and complex effects on the immune system, not all of which have been attributed to viral genes. Acute CMV infection results in transient restrictions in T cell proliferative ability, which can impair the control of the virus and increase the risk of secondary infections in patients with weakened or immature immune systems. In a search for new immunomodulatory proteins, we investigated the UL11 protein, a member of the CMV RL11 family. This protein family is defined by the RL11 domain, which has homology to immunoglobulin domains and adenoviral immunomodulatory proteins. We show that pUL11 is expressed on the cell surface and induces intercellular interactions with leukocytes. This was demonstrated to be due to the interaction of pUL11 with the receptor tyrosine phosphatase CD45, identified by mass spectrometry analysis of pUL11-associated proteins. CD45 expression is sufficient to mediate the interaction with pUL11 and is required for pUL11 binding to T cells, indicating that pUL11 is a specific CD45 ligand. CD45 has a pivotal function regulating T cell signaling thresholds; in its absence, the Src family kinase Lck is inactive and signaling through the T cell receptor (TCR) is therefore shut off. In the presence of pUL11, several CD45-mediated functions were inhibited. The induction of tyrosine phosphorylation of multiple signaling proteins upon TCR stimulation was reduced and T cell proliferation was impaired. We therefore conclude that pUL11 has immunosuppressive properties, and that disruption of T cell function via inhibition of CD45 is a previously unknown immunomodulatory strategy of CMV

CD200 receptor restriction of myeloid cell responses antagonizes antiviral immunity and facilitates cytomegalovirus persistence within mucosal tissue

CD200 receptor (CD200R) negatively regulates peripheral and mucosal innate immune responses. Viruses, including herpesviruses, have acquired functional CD200 orthologs, implying that viral exploitation of this pathway is evolutionary advantageous. However, the role that CD200R signaling plays during herpesvirus infection in vivo requires clarification. Utilizing the murine cytomegalovirus (MCMV) model, we demonstrate that CD200R facilitates virus persistence within mucosal tissue. Specifically, MCMV infection of CD200R-deficient mice (CD200R-/-) elicited heightened mucosal virus-specific CD4 T cell responses that restricted virus persistence in the salivary glands. CD200R did not directly inhibit lymphocyte effector function. Instead, CD200R-/- mice exhibited enhanced APC accumulation that in the mucosa was a consequence of elevated cellular proliferation. Although MCMV does not encode an obvious CD200 homolog, productive replication in macrophages induced expression of cellular CD200. CD200 from hematopoietic and non-hematopoietic cells contributed independently to suppression of antiviral control in vivo. These results highlight the CD200-CD200R pathway as an important regulator of antiviral immunity during cytomegalovirus infection that is exploited by MCMV to establish chronicity within mucosal tissue