4,521 research outputs found

    The release of a captive-raised female African Elephant <em>(Loxodonta africana</em>) in the Okavango Delta, Botswana

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    Wild female elephants live in close-knit matrilineal groups and housing captive elephants in artificial social groupings can cause significant welfare issues for individuals not accepted by other group members. We document the release of a captive-raised female elephant used in the safari industry because of welfare and management problems. She was fitted with a satellite collar, and spatial and behavioural data were collected over a 17-month period to quantify her interactions with the wild population. She was then monitored infrequently for a further five-and-a-half years. We observed few signs of aggression towards her from the wild elephants with which she socialized. She used an area of comparable size to wild female elephants, and this continued to increase as she explored new areas. Although she did not fully integrate into a wild herd, she had three calves of her own, and formed a social unit with another female and her calf that were later released from the same captive herd. We recommend that release to the wild be considered as a management option for other captive female elephants

    Iowa Pasture Management Guide

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    While there is a great deal of information available on pasture management and utilization, there is no one existing publication that could serve as a comprehensive source of advice on the subject for Iowa farmers. Using feedback from a focus group, a handbook to aid Iowa farmers in pasture management has been prepared

    Highly effective yet simple transmembrane anion transporters based upon ortho-phenylenediamine bis-ureas

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    Simple, highly fluorinated receptors are shown to function as highly effective transmembrane anion antiporters with the most active transporters rivalling the transport efficacy of natural anion transporter prodigiosin for bicarbonate

    Elucidation of the anaerobic pathway for the corrin component of cobalamin (vitamin B12)

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    It has been known for the past 20 years that two pathways exist in nature for the de novo biosynthesis of the coenzyme form of vitamin B12, adenosylcobalamin, representing aerobic and anaerobic routes. In contrast to the aerobic pathway, the anaerobic route has remained enigmatic because many of its intermediates have proven technically challenging to isolate, because of their inherent instability. However, by studying the anaerobic cobalamin biosynthetic pathway in Bacillus megaterium and using homologously overproduced enzymes, it has been possible to isolate all of the intermediates between uroporphyrinogen III and cobyrinic acid. Consequently, it has been possible to detail the activities of purified cobinamide biosynthesis (Cbi) proteins CbiF, CbiG, CbiD, CbiJ, CbiET, and CbiC, as well as show the direct in vitro conversion of 5-aminolevulinic acid into cobyrinic acid using a mixture of 14 purified enzymes. This approach has resulted in the isolation of the long sought intermediates, cobalt-precorrin-6A and -6B and cobalt-precorrin-8. EPR, in particular, has proven an effective technique in following these transformations with the cobalt(II) paramagnetic electron in the dyz orbital, rather than the typical dz2. This result has allowed us to speculate that the metal ion plays an unexpected role in assisting the interconversion of pathway intermediates. By determining a function for all of the pathway enzymes, we complete the tool set for cobalamin biosynthesis and pave the way for not only enhancing cobalamin production, but also design of cobalamin derivatives through their combinatorial use and modification

    A four year longitudinal sero-epidemiological study of bovine herpesvirus type-1 (BHV-1) in adult cattle in 107 unvaccinated herds in south west England

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    Background: Bovine herpesvirus type-1 (BHV-1) is an important pathogen of cattle that presents with a variety of clinical signs, including the upper respiratory tract infection infectious bovine rhinotracheitis (IBR). A seroepidemiological study of BHV-1 antibodies was conducted in England from 2002 – 2004: 29,782 blood samples were taken from 15,736 cattle from 114 herds which were visited on up to three occasions. Antibody concentration was measured using a commercial ELISA. Farm management information was collected using an interview questionnaire, and herd size and cattle movements were obtained from the cattle tuberculosis testing database and the British Cattle Movement Service. Hierarchical statistical models were used to investigate associations between cattle and herd variables and the continuous outcome percentage positive (PP) values from the ELISA test in unvaccinated herds. Results: There were 7 vaccinated herds, all with at least one seropositive bovine. In unvaccinated herds 83.2% had at least one BHV-1 seropositive bovine, and the mean cattle and herd BHV-1 seroprevalence were 42.5% and 43.1% respectively. There were positive associations between PP value, age, herd size, presence of dairy cattle. Adult cattle in herds with grower cattle had lower PP values than those in herds without grower cattle. Purchased cattle had significantly lower PP values than homebred cattle, whereas cattle in herds that were totally restocked after the foot-and-mouth epidemic in 2001 had significantly higher PP values than those in continuously stocked herds. Samples taken in spring and summer had significantly lower PP values than those taken in winter, whereas those taken in autumn had significantly higher PP values than those taken in winter. The risks estimated from a logistic regression model with a binary outcome (seropositive yes/no) were similar. Conclusion: The prevalence of BHV-1 seropositivity in cattle and herds has increased since the 1970s. Although the study population prevalence of BHV-1 was temporally stable during study period, the associations between serological status and cattle age, herd size, herd type, presence of young stock and restocked versus continuously stocked herds indicate that there is heterogeneity between herds and so potential for further spread of BHV-1 within and between herds

    A four year longitudinal sero-epidemiology study of Neospora caninum in adult cattle from 114 cattle herds in south west England : associations with age, herd and dam-offspring pairs

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    Background: Neosporosis caused by the protozoan parasite Neospora caninum, is an economically important cause of abortion, stillbirth, low milk yield, reduced weight gain and premature culling in cattle. Consequently, a seroepidemiological study of N. caninum antibodies was conducted in England with 29,782 samples of blood taken from 15,736 cattle from 114 herds visited on three occasions at yearly intervals. Herds were categorised into lower (< 10%) and higher (≥ 10%) median herd seroprevalence. Hierarchical models were run to investigate associations between the sample to positive (S/P) ratio and herd and cattle factors. Results: Ninety-four percent of herds had at least one seropositive cow; 12.9% of adult cattle had at least one seropositive test. Approximately 90% of herds were seropositive at all visits; 9 herds (8%) changed serological status between visits. The median N. caninum seroprevalence in positive herds was 10% (range 0.4% to 58.8%). There was a positive association between the serostatus of offspring and dams that were ever seropositive. In the hierarchical model of low seroprevalence herds there was no significant association between S/P ratio and cattle age. There was a significantly lower S/P ratio in cattle in herds that were totally restocked after the foot-and-mouth epidemic of 2001 compared with those from continuously stocked herds and cattle purchased into these herds had a higher S/P ratio than homebred cattle. In the model of high seroprevalence herds the S/P ratio increased with cattle age, but was not associated with restocking or cattle origin. Conclusion: There were no strong temporal changes in herd seroprevalence of N. caninum but 90% of herds had some seropositive cattle over this time period. Vertical transmission from seropositive dams appeared to occur in all herds. In herds with a high seroprevalence the increasing S/P ratio in 2–4 year old cattle is suggestive of exposure to N. caninum: horizontal transmission between adult cattle, infection from a local source or recrudescence and abortions. Between-herd movements of infected cattle enhance the spread of N. caninum, particularly into low seroprevalence herds. Some restocked herds had little exposure to N. caninum, while in others infection had spread in the time since restocking

    A Heuristic Narrative Inquiry on the Conceptualization and Cultivation of Relational Trust Between Secondary Teachers and Administrators

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    Title from PDF of title page viewed June 1, 2020Dissertation advisors: Loyce Caruthers and Candace SchleinVitaIncludes bibliographical references (pages 223-250)Thesis (Ph.D.)--School of Education. University of Missouri--Kansas City, 2020The interactions of teachers and administrators may not account for as much time as the interactions between teachers and students, but there is great potential value in examining this relationship and examining its machinery. Of particular interest to this study were the stories teachers told about relational trust between teachers and administrators. Research exists that implies a strong connection between trust and performance in an organizational space (Cook, Murphy, & Hunt, 2000; Kraft, Marinell & Shen-Wei Yee, 2016; Lawson et al., 2017; Tschannen-Moran & Gareis, 2015a). Sallee’s (2014) work shows correlations between the principal-teacher relationship and teacher self-efficacy. This heuristic narrative inquiry enlivens and deepens the conversations about organizational trust in schools through its elicited teacher narratives, which shed light on the lived experiences of eight participants in one large, Midwestern, suburban high school, who share their “secret,” “sacred,” and “cover” stories and co-author an ethnographic portrait of their experience with the researcher. These stories are contextualized in the researcher’s own narrative frame, which layers his own personal meaning amidst their voices and storied truths about their relationships with administration. Using these teacher narratives along with site-based descriptive statistical measures on teacher principal trust, this study deepens the understanding of how trust—the “soft tissue” of an organization (Wilcox, Lawson, & Angelis, 2015, p. 28)—thickens or thins through a heuristic narrative inquiry. The unit of analysis for this study is teacher stories of relational trust. The narrative themes which emerged from these teacher stories include: (1) Role Rapport Harmony; (2) Eleemosynary Presence; (3) Ecology of Excellence; and (4) Authoring Invitational Space. The work of this dissertation offers perspective for educational leadership about how they are perceived, seen, and valued from the perspective of a school with average teacher-principal trust, high trust in colleagues, and average trust in students, according to Hoy and Tschannen-Moran’s (2007) Omnibus T-Scale. My decision to use a cartoon ethnograph as a representation of lived experience increases the accessibility of teachers’ voices through their stories about their relationship with their principals.Introduction -- Review of literature -- Methodology -- Findings and discussion -- Implications of findings --Appendix A. Teacher questionnaire: The Omnibus T-scale -- Appendix B. Interview guide -- Appendix C. Member checking email -- Appendix D. Interpretive code frequency tabl

    The role of kelp species as biogenic habitat formers in coastal marine ecosystems

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    Kelps are ecologically important primary producers and ecosystem engineers, and play a central role in structuring nearshore temperate habitats. They play an important role in nutrient cycling, energy capture and transfer, and provide biogenic coastal defence. Kelps also provide extensive substrata for colonising organisms, ameliorate conditions for understorey assemblages, and provide three-dimensional habitat structure for a vast array of marine plants and animals, including a number of commercially important species. Here, we review and synthesize existing knowledge on the functioning of kelp species as biogenic habitat providers. We examine biodiversity patterns associated with kelp holdfasts, stipes and blades, as well as the wider understorey habitat, and search for generality between kelp species and biogeographic regions. Environmental factors influencing biogenic habitat provision and the structure of associated assemblages are considered, as are current threats to kelp-dominated ecosystems. Despite considerable variability between species and regions, kelps are key habitat-forming species that support elevated levels of biodiversity, diverse and abundant assemblages and facilitate trophic linkages. Enhanced appreciation and better management of kelp forests are vital for ensuring sustainability of ecological goods and services derived from temperate marine ecosystems
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