1,219 research outputs found

    Policing the Races: Attempts to Enforce Racial Purity in Virginia (1630 -1930)

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    This paper examines Virginia\u27s Racial Purity Laws enacted to deny equal opportunity to black men and women who could pass as whites from the early 1600s to the U. S. Supreme Court decision (Loving v. Virginia) in 1967. When physi­cal charac­teristics failed to match the legal definition of race, the state used records of vital statistics for boundary mainte­nance. Birth certificates, in particu­lar, served as internal passports to school assignments, work eligibility, and marriage, denying citizens defined as Negro life chances available to whites. It was also found that over time the definition of Negro was expanded to include citizens with smaller proportions of African or even Native American blood in their ancestry. An example is presented illustrating how racial identity was defined and enforced

    Object identification and characterization with hyperspectral imagery to identify structure and function of Natura 2000 habitats

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    Habitat monitoring of designated areas under the EU Habitats Directive requires every 6 years information on area, range, structure and function for the protected (Annex I) habitat types. First results from studies on heathland areas in Belgium and the Netherlands show that hyperspectral imagery can be an important source of information to assist the evaluation of the habitat conservation status. Hyperspectral imagery can provide continuous maps of habitat quality indicators (e.g., life forms or structure types, management activities, grass, shrub and tree encroachment) at the pixel level. At the same time, terrain managers, nature conservation agencies and national authorities responsible for the reporting to the EU are not directly interested in pixels, but rather in information at the level of vegetation patches, groups of patches or the protected site as a whole. Such local level information is needed for management purposes, e.g., exact location of patches of habitat types and the sizes and quality of these patches within a protected site. Site complexity determines not only the classification success of remote sensing imagery, but influences also the results of aggregation of information from the pixel to the site level. For all these reasons, it is important to identify and characterize the vegetation patches. This paper focuses on the use of segmentation techniques to identify relevant vegetation patches in combination with spectral mixture analysis of hyperspectral imagery from the Airborne Hyperspectral Scanner (AHS). Comparison with traditional vegetation maps shows that the habitat or vegetation patches can be identified by segmentation of hyperspectral imagery. This paper shows that spectral mixture analysis in combination with segmentation techniques on hyperspectral imagery can provide useful information on processes such as grass encroachment that determine the conservation status of Natura 2000 heathland areas to a large extent. A limitation is that both advanced remote sensing approaches and traditional field based vegetation surveys seem to cause over and underestimations of grass encroachment for specific categories, but the first provides a better basis for monitoring if specific species are not directly considered

    Evaluation of hypophysectomy for treatment of hypersomatotropism in 25 cats

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    Background: Successful treatment of cats with hypersomatotropism by transsphenoidal hypophysectomy is described in small numbers of cats. Objectives: To describe the endocrine profile, survival, and remission rates of hypersomatotropism and diabetes mellitus in a cohort of cats with hypersomatotropism that underwent hypophysectomy between 2008 and 2020. Animals: Twenty-five client-owned cats with spontaneous hypersomatotropism. Methods: Retrospective study. Diagnosis of hypersomatotropism was based on clinical signs, plasma insulin-like growth factor-1 (IGF-1) concentration, and imaging of the pituitary gland. Growth hormone (GH) and IGF-1 concentrations were measured repeatedly after surgery. Survival times were calculated based on follow-up information from owners and referring veterinarians. Results: Median postoperative hospital stay was 7 days (range, 3-18 days). One cat died within 4 weeks of surgery. Median plasma GH concentration decreased significantly from 51.0 ng/mL (range, 5.0-101.0 ng/mL) before surgery to 3.8 ng/mL (range, 0.6-13.0 ng/mL) at 5 hours after surgery. Remission of hypersomatotropism, defined as normalization of plasma IGF-1 concentration, occurred in 23/24 cats (median, 34 ng/mL; range, 14-240 ng/mL) and 22/24 cats entered diabetic remission. Median survival time was 1347 days (95% confidence interval, 900-1794 days; range, 11-3180 days) and the overall 1-, 2-, and 3-year all-cause survival rates were 76%, 76%, and 52%, respectively. Conclusions and Clinical Importance: This study shows the beneficial outcome of hypophysectomy in cats with hypersomatotropism, marked by low death rate and a high percentage of diabetic remission and definitive cure

    The effect of depth on the morphology, bacterial clearance, and respiration of the mediterranean sponge chondrosia reniformis (Nardo, 1847)

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    To support the successful application of sponges for water purification and collagen production, we evaluated the effect of depth on sponge morphology, growth, physiology, and functioning. Specimens of Eastern Mediterranean populations of the sponge Chondrosia reniformis (Nardo, 1847) (Demospongiae, Chondrosiida, Chondrosiidae) were reciprocally transplanted between 5 and 20 m depth within the KaŠ-Kekova Marine Reserve Area. Control sponges at 5 m had fewer but larger oscula than their conspecifics at 20 m, and a significant inverse relationship between the osculum density and size was found in C. reniformis specimens growing along a natural depth gradient. Sponges transplanted from 20 to 5 m altered their morphology to match the 5 m control sponges, producing fewer but larger oscula, whereas explants transplanted from 5 to 20 m did not show a reciprocal morphological plasticity. Despite the changes in morphology, the clearance, respiration, and growth rates were comparable among all the experimental groups. This indicates that depth-induced morphological changes do not affect the overall performance of the sponges. Hence, the potential for the growth and bioremediation of C. reniformis in mariculture is not likely to change with varying culture depth. The collagen content, however, was higher in shallow water C. reniformis compared to deeper-growing sponges, which requires further study to optimize collagen production.This research was executed within the Connected Circularity program, financed by strategic funding of Wageningen University and Research and the knowledge base of the Ministry of Agriculture, Nature, and FoodQuality (KB40), and was part of the ERA-NET project Biogenink (project 4195), funded by the EuropeanCommission in conjunction with the Dutch Science Foundation NWO and the Portuguese Foundation for Science and Technology (FCT) (project M-ERA-NET-2/0022/2016)

    What are the prospects for citizen science in agriculture? Evidence from three continents on motivation and mobile telephone use of resource-poor farmers

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    As the sustainability of agricultural citizen science projects depends on volunteer farmers who contribute their time, energy and skills, understanding their motivation is important to attract and retain participants in citizen science projects. The objectives of this study were to assess 1) farmers’ motivations to participate as citizen scientists and 2) farmers’ mobile telephone usage. Building on motivational factors identified from previous citizen science studies, a questionnaire based methodology was developed which allowed the analysis of motivational factors and their relation to farmers’ characteristics. The questionnaire was applied in three communities of farmers, in countries from different continents, participating as citizen scientists. We used statistical tests to compare motivational factors within and among the three countries. In addition, the relations between motivational factors and farmers characteristics were assessed. Lastly, Principal Component Analysis (PCA) was used to group farmers based on their motivations. Although there was an overlap between the types of motivations, for Indian farmers a collectivistic type of motivation (i.e., contribute to scientific research) was more important than egoistic and altruistic motivations. For Ethiopian and Honduran farmers an egoistic intrinsic type of motivation (i.e., interest in sharing information) was most important. While fun has appeared to be an important egoistic intrinsic factor to participate in other citizen science projects, the smallholder farmers involved in this research valued ‘passing free time’ the lowest. Two major groups of farmers were distinguished: one motivated by sharing information (egoistic intrinsic), helping (altruism) and contribute to scientific research (collectivistic) and one motivated by egoistic extrinsic factors (expectation, expert interaction and community interaction). Country and education level were the two most important farmers’ characteristics that explain around 20% of the variation in farmers motivations. For educated farmers, contributing to scientific research was a more important motivation to participate as citizen scientists compared to less educated farmers. We conclude that motivations to participate in citizen science are different for smallholders in agriculture compared to other sectors. Citizen science does have high potential, but easy to use mechanisms are needed. Moreover, gamification may increase the egoistic intrinsic motivation of farmers

    Prevalence of persistent hypertension and situational hypertension in a population of elderly cats in The Netherlands

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    OBJECTIVES: Systemic arterial hypertension is increasingly recognised and can have serious adverse consequences in cats. Unfortunately, the act of measuring blood pressure itself may cause an increase in blood pressure, known as situational hypertension. It is currently unknown how often this phenomenon occurs. The aim of this study was to evaluate the prevalence of persistent hypertension and situational hypertension in an elderly population of cats in a first-opinion clinic and to assess which factors were associated with systolic hypertension. METHODS: In this prospective study, systolic blood pressure was measured in 185 cats aged ⩾10 years using the Doppler sphygmomanometry method according to the recommendations of the American College of Veterinary Internal Medicine consensus statement. Age, sex, body weight, body condition score, position during blood pressure measurement and apparent stress level were assessed. If a systolic blood pressure >160 mmHg was found, measurements were repeated to evaluate if persistent hypertension or situational hypertension was present. The first set of blood pressure measurements were used for all the statistical analyses. RESULTS: The median systolic blood pressure for this population was 140 mmHg. The prevalence of persistent hypertension was at least 14.6% and situational hypertension at least 5.4%. Factors significantly associated with hypertension were age, higher apparent stress levels and a sitting position during measurement. Sex, body weight or body condition score did not significantly influence systolic blood pressure. CONCLUSIONS AND RELEVANCE: Both persistent hypertension and situational hypertension are common in elderly cats. There are no reliable parameters to distinguish between the two, underlining the importance of a standard protocol and repeating measurements during a follow-up visit when hypertension is found. Age, demeanour and body position during blood pressure measurement influenced blood pressure in this population of elderly cats

    Monitoring en evaluatie agenda vitaal platteland : tussenrapportage over activiteiten 2004

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    Het Natuurplanbureau en Expertisecentrum LNV ontwikkelen een monitoring- en evaluatiesysteem (ME) voor de Agenda Vitaal Platteland (AVP). Het project omvat een zevental deelprojecten en zal eind 2005 worden afgerond. Dit rapport geeft resultaten van vier projecte
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