The effects of agricultural fields and human settlements on the use of rivers by wildlife in the mid-Zambezi valley,Zimbabwe     

Fritz  Hervé  Saïd  Sonia  Renaud  Pierre-Cyril  Mutake  Snoden  Coid  Craig  Monicat  François 《Landscape Ecology》2003,18(3):293-302

After the eradication of the Tse-Tse fly in the Mid-Zambezi valley, human settlements and fields extended mainly along the main rivers. In order to investigate the consequences of this human development on wildlife diversity we monitored three rivers of the Mid-Zambezi valley in Zimbabwe: Angwa, Manyame and Kadzi. The rivers were divided in segments of 200 m which were checked for spoors in order to assess the number of species and the number of individuals that used the segments. Human settlements were also recorded. We used a GIS to define the spatial characteristics of the fields present along the rivers, and related them to the distribution and abundance of wild species spoors in the river beds and banks. Our results show that the number of species in one segment of the river decreased with the increasing size of the field area bordering the segment. For all the major ungulate species, the numbers of individuals recorded per segment decreased with increasing field area. A similar trend was observed for small and medium-sized carnivores, though they were in lower numbers when present. Our analyses thus confirm that the extension of human agriculture in wildlife areas has an impact on most wild species, but we also define some threshold value of field size above which there seem to be an acceleration of the decrease in wildlife density and diversity: 3.2 ha for medium and small herbivores and carnivores; only the elephant seem to tolerate larger field area with a threshold value of 32 ha.This revised version was published online in May 2005 with corrections to the Cover Date.  相似文献   

Influence of four soil maintenance practices on Collembola communities in a Mediterranean vineyard   总被引：1，自引：0，他引：1  

Anglique Renaud  Nicole Poinsot-Balaguer  Jrme Cortet  Jean Le Petit 《Pedobiologia》2004,48(5-6):623-630

We studied the influence of four soil maintenance practices on Collembola communities in the soil of a Mediterranean vineyard: (a) postemergence herbicide with glyphosate; (b) postemergence and pre-emergence herbicides with glyphosate, terbuthylazine, diuron and oryzalin; (c) natural flora and (d) tillage to a depth of 10–15 cm. Total Collembola abundance, species diversity and species richness significantly varied between the four practices. Notably, the practice using postemergence and pre-emergence herbicides had significantly lower values. Identification of Collembola at species level allowed an interspecies comparison and revealed significant differences for the most common species between the four practices, with each practice being characterized by a different set of species. None of the species were found to be significantly more abundant in the plots treated with postemergence and pre-emergence herbicides.  相似文献   

Assessment of regional systolic and diastolic myocardial function using tissue Doppler and strain imaging in dogs with dilated cardiomyopathy   总被引：1，自引：0，他引：1  

Chetboul V  Gouni V  Sampedrano CC  Tissier R  Serres F  Pouchelon JL 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2007,21(4):719-730

BACKGROUND: Tissue Doppler Imaging (TDI) or strain (St) imaging could provide sensitive indices for early detection and treatment follow-up of canine dilated cardiomyopathy (DCM). Analysis of TDI and St features in dogs with overt DCM is a prerequisite before using these new criteria in prospective screenings of predisposed families or in clinical trials. HYPOTHESIS: Radial and longitudinal right and left myocardial motion, assessed by TDI and St variables, is altered in dogs with DCM. ANIMALS: Case records for 26 dogs; 14 with DCM and 12 healthy controls of comparable age and weight were reviewed. METHODS: A retrospective analysis was conducted of conventional echocardiography, 2-dimensional color TDI, and St imaging data. RESULTS: The DCM group was characterized by decreases in radial and longitudinal systolic velocity gradients of the left ventricular free wall (LVFW), radial and longitudinal absolute values of peak systolic St of the LVFW, and longitudinal systolic right ventricular (RV) velocities (all P < .001 versus control) associated with longitudinal postsystolic contraction waves in 7/14 dogs. Early diastolic LVFW velocities also were decreased for longitudinal (P < .01) and radial (P < .05) motions. All radial LVFW, longitudinal basal LVFW, and RV systolic velocities were negatively correlated with heart rate (P < .01). CONCLUSIONS AND CLINICAL IMPORTANCE: LV contractility along both the short and long axes is impaired in dogs with spontaneous DCM, as is systolic RV and diastolic LVFW function. These myocardial alterations are associated with an inverse force-frequency relationship. Studies now are needed to determine the comparative sensitivity of TDI and St variables for the early detection of canine DCM.  相似文献   

Effect of plasma transfusion on serum amyloid A concentration in healthy neonatal foals and foals with failure of transfer of passive immunity     

Megan Palmisano  Laura Javsicas  Justin McNaughten  Lisa Gamsjäger  David L. Renaud  Diego E. Gomez 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2023,37(2):697-702

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Use of Akaike information criteria for model selection and inference. An application to assess prevention of gastrointestinal parasitism and respiratory mortality of Guinean goats in Kolda,Senegal     

Lancelot R  Lesnoff M  McDermott JJ 《Preventive veterinary medicine》2002,55(4):993-240

A field experiment was carried out in Kolda (southern Senegal) from July 1986 to July 1988. Its goals were to: (1) describe the patterns of mortality of female Guinean goats by age, season and year; (2) assess preventive measures against respiratory diseases and gastrointestinal parasitism in reducing mortality; and (3) estimate the overall impact of these measures on survival to 1 year of age. Preventive measures for respiratory disease included vaccination against peste des petits ruminants (PPR) and pneumonic pasteurellosis (Pasteurella multocida types A and D). Control of gastrointestinal parasites was by deworming does with morantel (7.5 mg kg⁻¹, three times during the rainy season). The effects of vaccines and deworming were tested in a randomised factorial field experiment with villages being the experimental units. A total of 19 villages, 113 goat herds and 1458 goats were included in the study.

Generalised linear models of survival for five cohorts of goats (defined by five different birth seasons) used a binomial assumption for the response distribution and a complementary log–log link. Explanatory variables included age, season, year, vaccination, deworming and their interactions. A complex a priori model was built on the basis of previous epidemiological knowledge; a purposively selected set of simpler models was compared to this full model by the Akaike information criterion (AIC) and derived statistics. Inference on 1-year survival and treatment effects accounted for model-selection uncertainty. It was carried out with a bootstrap procedure and used information from the whole set of selected models.

Large variations in mortality by year and season were observed but no regular seasonal pattern was apparent. Mortality probabilities of kids in dewormed groups decreased quickly after birth, but remained elevated up to 9 months of age in the non-dewormed groups. Deworming lowered the risk of mortality. Vaccination alone was not protective (except during an observed outbreak of PPR).  相似文献   

Radial strain and strain rate by two-dimensional speckle tracking echocardiography and the tissue velocity based technique in the dog     

Valrie Chetboul DVM  PhD  Dipl-ECVIM-CA  Francois Serres DVM  Vassiliki Gouni DVM  Renaud Tissier DVM  PhD  Jean-Louis Pouchelon DVM  PhD 《Journal of Veterinary Cardiology》2007,9(2):69-81

ObjectivesTwo-dimensional (2D) speckle tracking echocardiography (STE) is a new angle-independent ultrasound technique based on tracking of speckles within the myocardium on 2D grayscale images. The aims of this prospective study were as follows: (1) to assess the variability of left ventricular peak systolic radial strain (St) and strain rate (SR) in awake dogs using STE (Protocol 1); and (2) to quantify these variables in a healthy canine population and compare them with tissue Doppler imaging (TDI)-based St and SR values (Protocol 2).BackgroundSt and SR may be assessed using TDI, which is limited by angle dependency.Animals, materials and methodsThirty-six STE examinations were performed on 6 healthy dogs for Protocol 1 and 37 healthy dogs were recruited for Protocol 2. In both studies, STE measurements were obtained offline from the right parasternal short-axis view by the same trained observer using automatic frame-to-frame tracking of grayscale speckle patterns.ResultsAll within- and between-day coefficients of variation were <10% (Protocol 1). In Protocol 2, St (46.7 ± 12.2%) and SR (2.7 ± 0.6 s⁻¹) measured by STE were correlated with heart rate (p < 0.01), but not with the ratio of early mitral inflow velocity to early mitral annular velocity. There was a good correlation between STE and TDI for both St and SR values (p < 0.001).ConclusionsSTE is a repeatable and reproducible non-Doppler method for assessing radial St and SR. The combination of these indices with conventional echo-Doppler variables could provide a new approach for accurately quantifying canine systolic function.  相似文献   

Retrospective study of 942 small-sized dogs: Prevalence of left apical systolic heart murmur and left-sided heart failure, critical effects of breed and sex     

Pierre Serfass DVM  Valrie Chetboul DVM  PhD  Dipl ECVIM  Carolina Carlos Sampedrano DVM  MS  Audrey Nicolle DVM  Thierry Benalloul DVM  Herv Laforge DVM  Christophe Gau DVM  Carole Hbert DVM  Jean-Louis Pouchelon DVM  PhD  Renaud Tissier DVM  PhD 《Journal of Veterinary Cardiology》2006,8(1):11-18

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Mechanical behaviour of saturated wood under compression Part 2: Behaviour of wood at low rates of strain some effects of compression on wood structure     

M. Renaud  M. Rueff  A. C. Rocaboy 《Wood Science and Technology》1996,30(4):237-243

Summary The mechanical behaviour of three species of hardwoods, soaked in different liquids, had been investigated at high rates of strain using a Hopkinson pressure bar system. In order to determine the influence of the rate of strain, samples from the same species were subjected to compression-tests at low rates of strain. It was noticed that, at low rates of strain, the saturated samples were always less stiff than the dry ones, which is in agreement with the literature, but differs from the behaviour at high rates of strain. This difference is attributed to the behaviour of the liquid present in the large cavities of the material, which must depend on the rate of strain. It was also noticed that the samples could support higher stresses at high rates of strain. Although permanent sets were measured after the tests, the samples were not always visibly damaged, but some typical failures were detected by means of microscopy. The damaged zones presented similar aspects, whatever the rate of strain.  相似文献   

Analysis of chip formation mechanisms and modelling of slabber process     

Renaud Pfeiffer  Robert Collet  Louis Etienne Denaud  Guillaume Fromentin 《Wood Science and Technology》2015,49(1):41-58

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The conservation of the endangered Mediterranean common dolphin (Delphinus delphis): Current knowledge and research priorities     

Adriana Vella  Sinéad Murphy  Joan Giménez  Renaud de Stephanis  Barbara Mussi  Joseph G. Vella  Kamel Larbi Doukara  Daniela Silvia Pace 《水产资源保护:海洋与淡水生态系统》2021,31(Z1):110-136

1. Preservation of endangered species is now recognized as a relevant component of regional and global conservation actions achieved through the maintenance of the remaining populations in a favourable conservation status. The Mediterranean common dolphin (Delphinus delphis) is listed as an Endangered subpopulation in the International Union for Conservation of Nature Red List, with declining numbers in some of the areas where it has been studied for numerous years. Prey depletion, fisheries bycatch, pollution, health risks, and climate change are among the recognized threats that the species is facing in the region.
2. The existing national, regional, and international legislation pertinent to Mediterranean countries should aid greater science–policy–management integration and support innovative research and monitoring towards effective conservation. The challenges inherent in studying the pelagic D. delphis should not preclude the use of long-term, year-round, multiplatform surveys, side by side with the latest molecular tools, which aid our understanding of its populations' genetic diversity, resistance to diseases, and resilience in a semi-enclosed fast-changing sea.
3. Addressing the multiplicity of problems confronting the species requires collaborative effort at all levels to share and merge resources, data, and expertise more efficiently. In this review, we provide an overview of the current knowledge on the Mediterranean common dolphin, the main threats, and knowledge gaps that are priorities for addressing its conservation, while providing clear recommendations for effectively safeguarding the species and its habitat at both local and regional levels.

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