Site‐fidelity and movement patterns of bottlenose dolphins (Tursiops truncatus) in central Argentina: essential information for effective conservation          下载免费PDF全文

Els Vermeulen  Alejandro Balbiano  Florencia Belenguer  Daniel Colombil  Mauricio Failla  Edgardo Intrieri  Stefan Bräger 《水产资源保护:海洋与淡水生态系统》2017,27(1):282-292

Hematotoxicity in workers exposed to low levels of benzene   总被引：1，自引：0，他引：1  

Lan Q  Zhang L  Li G  Vermeulen R  Weinberg RS  Dosemeci M  Rappaport SM  Shen M  Alter BP  Wu Y  Kopp W  Waidyanatha S  Rabkin C  Guo W  Chanock S  Hayes RB  Linet M  Kim S  Yin S  Rothman N  Smith MT 《Science (New York, N.Y.)》2004,306(5702):1774-1776

Benzene is known to have toxic effects on the blood and bone marrow, but its impact at levels below the U.S. occupational standard of 1 part per million (ppm) remains uncertain. In a study of 250 workers exposed to benzene, white blood cell and platelet counts were significantly lower than in 140 controls, even for exposure below 1 ppm in air. Progenitor cell colony formation significantly declined with increasing benzene exposure and was more sensitive to the effects of benzene than was the number of mature blood cells. Two genetic variants in key metabolizing enzymes, myeloperoxidase and NAD(P)H:quinone oxidoreductase, influenced susceptibility to benzene hematotoxicity. Thus, hematotoxicity from exposure to benzene occurred at air levels of 1 ppm or less and may be particularly evident among genetically susceptible subpopulations.  相似文献   

Habitat,geophysical, and eco-social connectivity: benefits of resilient socio–ecological landscapes     

Butler  Eric P.  Bliss-Ketchum  Leslie L.  de Rivera  Catherine E.  Dissanayake  Sahan T. M.  Hardy  Carole L.  Horn  Dorothy A.  Huffine  Ben  Temple  Amanda M.  Vermeulen  Michael E.  Wallace  Hailey 《Landscape Ecology》2022,37(1):1-29

Landscape Ecology - Connections among ecosystems and their components are critical to maintaining ecological functions and benefits in human-modified landscapes, including urban areas. However, the...  相似文献   

Combinatorial synthesis and sensorial properties of 21 mercapto esters     

Vermeulen C  Collin S 《Journal of agricultural and food chemistry》2003,51(12):3618-3622

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Onset and duration of immunity against Babesia canis infection in dogs vaccinated with antigens from culture supernatants     

Schetters TP  Kleuskens JA  Scholtes NC  van de Crommert J  Krijnen E  Moubri K  Gorenflot A  Vermeulen AN 《Veterinary parasitology》2006,138(1-2):140-146

It has previously been shown that dogs can be vaccinated against heterologous Babesia canis infection using a vaccine containing soluble parasite antigens (SPA) from in vitro cultures of B. canis and B. rossi that are adjuvanted with saponin. In the present study the onset and duration of immunity of vaccinated dogs were studied. Results showed that 3-26 weeks after initial vaccination, dogs effectively limit the level of SPA in plasma upon challenge infection, which was reflected in limited duration and extent of clinical manifestations. There was no statistically significant effect of vaccination on the parasite load in the circulation, which was determined from blood smears. It was further shown that the level of immunity of primary vaccinated dogs (priming and booster vaccination with a 6-week interval) and that of repeatedly vaccinated dogs (a single additional vaccination 6 months after primary vaccination) is comparable. From this study it is concluded that vaccination with this preparation induces protective immunity against clinical babesiosis from 3 weeks after booster vaccination onwards, and remains effective for a period of at least another 6 months. A single booster vaccination is sufficient to maintain immunity for at least another 6 months.  相似文献   

The synergistic necrohemorrhagic action of Clostridium perfringens perfringolysin and alpha toxin in the bovine intestine and against bovine endothelial cells     

Stefanie Verherstraeten  Evy Goossens  Bonnie Valgaeren  Bart Pardon  Leen Timbermont  Karen Vermeulen  Stijn Schauvliege  Freddy Haesebrouck  Richard Ducatelle  Piet Deprez  Filip Van Immerseel 《Veterinary research》2013,44(1):45

Bovine necrohemorrhagic enteritis is a major cause of mortality in veal calves. Clostridium perfringens is considered as the causative agent, but there has been controversy on the toxins responsible for the disease. Recently, it has been demonstrated that a variety of C. perfringens type A strains can induce necrohemorrhagic lesions in a calf intestinal loop assay. These results put forward alpha toxin and perfringolysin as potential causative toxins, since both are produced by all C. perfringens type A strains. The importance of perfringolysin in the pathogenesis of bovine necrohemorrhagic enteritis has not been studied before. Therefore, the objective of the current study was to evaluate the role of perfringolysin in the development of necrohemorrhagic enteritis lesions in calves and its synergism with alpha toxin. A perfringolysin-deficient mutant, an alpha toxin-deficient mutant and a perfringolysin alpha toxin double mutant were less able to induce necrosis in a calf intestinal loop assay as compared to the wild-type strain. Only complementation with both toxins could restore the activity to that of the wild-type. In addition, perfringolysin and alpha toxin had a synergistic cytotoxic effect on bovine endothelial cells. This endothelial cell damage potentially explains why capillary hemorrhages are an initial step in the development of bovine necrohemorrhagic enteritis. Taken together, our results show that perfringolysin acts synergistically with alpha toxin in the development of necrohemorrhagic enteritis in a calf intestinal loop model and we hypothesize that both toxins act by targeting the endothelial cells.  相似文献   

In vitro assessment of the feline cell-mediated immune response against feline panleukopeniavirus, calicivirus and felid herpesvirus 1 using 5-bromo-2'-deoxyuridine labeling     

Vermeulen BL  Gleich SE  Dedeurwaerder A  Olyslaegers DA  Desmarets LM  Dewerchin HL  Nauwynck HJ 《Veterinary immunology and immunopathology》2012,146(2):177-184

In this study an in vitro assay was optimized to detect feline proliferating lymphocytes as an assessment for the cell-mediated immune response. For this purpose, 5-bromo-2'-deoxyuridine (BrdU) labeling was chosen because of its sensitivity and the possibility of further characterization of proliferating cells. The assay was optimized by selecting the best batch and concentration of fetal bovine serum, β-mercaptoethanol concentration, cell density, BrdU incubation time and antigen presenting cell type. Cats were vaccinated with the attenuated Nobivac vaccine Tricat and the peripheral blood lymphocyte proliferation responses were quantified upon in vitro restimulation with inactivated and infectious feline panleukopenia virus (FPV), feline calicivirus (FCV) and felid herpesvirus 1 (FeHV-1). Proliferation signals were detected with inactivated FeHV-1 in the CD8(+) but not in the CD8(-) T lymphocyte population, with inactivated FCV and FPV in both CD8(-) and CD8(+) T lymphocyte populations. Restimulation with infectious FCV caused significant proliferation in the CD8(-) T lymphocyte population only while infectious FPV and FeHV-1 seemed to suppress lymphocyte proliferation in both T cell populations. Additional IFN-γ quantification in the culture supernatant revealed a large correlation between the proliferation signals and IFN-γ production, indicating that BrdU labeling is a very reliable technique to assess and characterize feline lymphoproliferative responses to viral antigens in vitro.  相似文献   

Towards commercial aquaponics: a review of systems,designs, scales and nomenclature     

Harry W. Palm  Ulrich Knaus  Samuel Appelbaum  Simon Goddek  Sebastian M. Strauch  Tycho Vermeulen  M. Haїssam Jijakli  Benz Kotzen 《Aquaculture International》2018,26(3):813-842

Aquaponics is rapidly developing as the need for sustainable food production increases and freshwater and phosphorous reserves shrink. Starting from small-scale operations, aquaponics is at the brink of commercialization, attracting investment. Arising from integrated freshwater aquaculture, a variety of methods and system designs has developed that focus either on fish or plant production. Public interest in aquaponics has increased dramatically in recent years, in line with the trend towards more integrated value chains, greater productivity and less harmful environmental impact compared to other production systems. New business models are opening up, with new customers and markets, and with this expansion comes the potential for confusion, misunderstanding and deception. New stakeholders require guidelines and detail concerning the different system designs and their potentials. We provide a definitive definition of aquaponics, where the majority (>?50%) of nutrients sustaining the optimal plant growth derives from waste originating from feeding aquatic organisms, classify the available integrated aquaculture and aquaponics (open, domestic, demonstration, commercial) systems and designs, distinguish four different scales of production (≤?50, >?50–≤?100 m², >?100–≤?500 m², >?500 m²) and present a definite nomenclature for aquaponics and aquaponic farming allowing distinctions between the technologies that are in use. This enables authorities, customers, producers and all other stakeholders to distinguish between the various systems, to better understand their potentials and constraints and to set priorities for business and regulations in order to transition RAS or already integrated aquaculture into commercial aquaponic systems.  相似文献   

Genetic and morphological diversity of mono-spore isolates of glomerella cingulata associated with coffee berry disease     

H. Vermeulen  B. De Ferrante  A. J. Gielink 《European journal of plant pathology / European Foundation for Plant Pathology》1984,90(5):213-223

In earlier experiments the perfect state,Glomerella cingulata, had been found associated withColletotrichum coffeanum. As the linkage betweenG. cingulata and the coffee berry disease (CBD) pathogen had still been doubtful, further investigations were done. It was found that mono-spore cultures derived fromG. cingulata perithecia from two different CBD isolates were not compatible. This would suggest genetic differences between these two CBD pathogens.Preliminary tests with mono-ascospore isolates of oneG. cingulata source resulted in a wide range of segregation types. It has not yet been possible to obtain a conidial form fromG. cingulata, which has the morphological and pathogenic characteristics ofC. coffeanum. The results of the experiments suggest, however, that a CBD pathogen may arise through genetic segregation from aG. cingulata state.  相似文献   

Purification of Cowdria ruminantium by density gradient centrifugation     

A W Neitz  N M Vermeulen  G J Viljoen 《The Onderstepoort journal of veterinary research》1987,54(3):223-231

The isolation of Cowdria ruminantium by differential and isopycnic density gradient centrifugation is reviewed with special reference to the suitability of Percoll as density gradient medium. Infected sheep brain, Amblyomma hebraeum nymphae and various mouse organs were used as starting material. By these methods, partially purified viable populations of the organism with distinctly different densities were obtained. The conclusions are based upon results of analyses of density fractions by inoculation into sheep or mice, protein determination, electron microscopy and enzyme-linked immunosorbent assay. Morphological differences were observed in the density fractions obtained from infected brain tissue and A. hebraeum.  相似文献