Phytotoxic properties of Drosophyllum lusitanicum leaf extracts and its main compound plumbagin     

Sandra Gonçalves  Marco Ferraz  Anabela Romano 《Scientia Horticulturae》2009

The aim of this work was to evaluate the phytotoxic properties of aqueous and hexane extracts from the insectivorous plant Drosophyllum lusitanicum (L.) Link using lettuce and bread wheat as model species. The results obtained confirmed that both germination and seedling growth bioassays were sensitive and able to detect the heterotoxicity potential of D. lusitanicum extracts. Aqueous and hexane extracts at several concentrations significantly inhibited the seed germination of lettuce and wheat, although wheat was less sensitive. The inhibitory effects of plumbagin, the major compound found in D. lusitanicum hexane extracts, were also evaluated. Comparing the results of the assays obtained with extracts and plumbagin it was postulated that plumbagin is the principal compound responsible for the phytotoxic effects of the extracts on lettuce but not on wheat. Therefore, although the phytotoxic potential of D. lusitanicum was demonstrated, further studies are needed to clearly specify the compounds responsible for the inhibitory effects and to ensure if the results obtained with the model species are reproducible to weed species in field conditions.  相似文献   

Is intraspecific variation in diet and morphology related to environmental gradients? Exploring Liem's paradox in a cichlid fish     

Sandra A. BINNING  Lauren J. CHAPMAN 《Integrative zoology》2010,5(3):241-255

Interspecific studies have demonstrated that trophic morphology and ecology are not always tightly matched: a phenomenon rarely reported at the intraspecific level. In the present study, we explored relationships among diet, morphology and the environment in a widespread cichlid fish, Astatoreochromis alluaudi (Pellegrin 1904), from 6 sites in southern Uganda to test for evidence of eco-morphological matching at the interdemic level. Previous studies of Astatoreochromis alluaudi have demonstrated developmental plasticity in trophic morphology in response to diet: a mollusk diet produces specimens with large pharyngeal jaws and muscles, whereas a soft-food diet produces smaller pharyngeal jaws and corresponding changes in musculature. Sites were chosen to maximize variability in environmental variables that might directly or indirectly affect trophic morphology. We found significant differences in pharyngeal jaw and muscle morphology among populations. Similarly, we found differences in diets among sites: mollusks were found in the stomachs of fish from only 2 populations sampled, despite the presence of mollusks in 5 of the 6 sites. Although trophic morphology did match the observed diet in 2 sites, diet did not correlate with either morphology or environmental variables across sites, nor were environmental variables correlated with morphological variation among sites. These results suggest that mismatch can occur among different populations of a single species for reasons such as seasonality in resources, developmental plasticity and/or complex indirect interactions. Intraspecific mechanisms should be further studied in order to better understand the complex relationships between morphological specialization and ecological generalization.  相似文献   

Cryopreservation of YamúBrycon siebenthalae Milt     

Pablo E.  Cruz-Casallas  Sandra C.  Pardo-Carrasco  José A.  Arias-Castellanos  Pedro E.  Lombo-Castellanos  Dora A.  Lombo-Rodríguez  Jaime E.  Pardo-Mariño 《Journal of the World Aquaculture Society》2004,35(4):529-535

The yamú Brycon siebenthalae is an endemic fish of the Orinoco river basin, but wild stocks are decreasing because of the disruption of their habitat. We evaluated a protocol for the cryopreservation of yamú sperm to contribute to the preservation of this endangered genetic resource. Milt was mixed with a cryoprotectant medium (5.5% glucose, 12% egg yolk, and 5%, 10%, or 15% dimethyl sulfoxide - DMSO) in a ratio 1:4 (milt:medium), stored in 0.5-mL French straws, frozen in nitrogen liquid vapor (-76 C), then immersed and stored in liquid nitrogen for 10 d or 12 mo. Motility of thawed spermatozoa was higher ( P < 0.001) in 10% DMSO medium than 5% DMSO or 15% DMSO mediums; but lower than the control ( P < 0.001). With sperm cryopreserved, the highest level of fertilization was achieved with 10% DMSO ( P < 0.001) after 10 d or 12 mo of cryopreservation. Fertilization of eggs inseminated with 6.4 × 10⁹ spermatozoa per g of eggs was higher ( P <0.05) than with 1.6 × 10⁹ spermatozoa per g of eggs. There was no difference (P > 0.05) in fertilization between insemination doses of 3.2 × 10⁹ and 6.4 × 10⁹ spermatozoa per g of eggs. Cryopreservation of yamu milt can be performed successfully with a simple medium combined with 10% of DMSO as cryoprotectant. The highest level of fertility was achieved using between 3 × 10⁹ and 6 × 10⁹ spermatozoa per g of fresh eggs.  相似文献   

Book reviews     

Abeles  Tom P.  Schor  Joel  Russo  Sandra 《Agriculture and Human Values》1994,11(1):55-65

Agriculture and Human Values -  相似文献   

Evaluation of prevalence and risk factors for methicillin-resistant Staphylococcus aureus colonization in veterinary personnel attending an international equine veterinary conference     

Anderson ME  Lefebvre SL  Weese JS 《Veterinary microbiology》2008,129(3-4):410-417

Infection and colonization with methicillin-resistant Staphylococcus aureus (MRSA) are now increasingly being reported in animals and people who work with animals, including horses and horse personnel. The objectives of this study were to evaluate the prevalence of MRSA colonization in veterinary personnel attending an international equine veterinary conference, and to identify risk factors for MRSA colonization in this group. Volunteers were recruited at the conference to provide a single nasal swab and complete a questionnaire regarding contact with the human health care system, contact with horses, and personal hand hygiene. Colonization with MRSA was found in 26/257 (10.1%) of study participants. Multivariable analysis showed an increased risk of MRSA colonization associated with having been diagnosed with or having treated a patient diagnosed with MRSA colonization or infection in the last year (odds ratio [OR] 8.41, 95% confidence interval [CI] 1.51–49.92, P = 0.015; OR 3.27, 95% CI 1.05–10.11, P = 0.039, respectively), whereas hand washing between infectious cases (OR 0.27, 95% CI 0.11–0.72, P = 0.009) and hand washing between farms (OR 0.35, 95% CI 0.14–0.98, P = 0.047) were protective. The prevalence of MRSA colonization among equine veterinary personnel found in this study was high compared to that of other studies of the general population. These data support previous suggestions that equine veterinary personnel are at increased risk of colonization with MRSA. This is the first study to demonstrate a statistically significant association between hand hygiene practices and a measurable clinical outcome in veterinary medicine.  相似文献   

Purdue University graduate certificate program in Veterinary Homeland Security     

Amass SF  Blossom TD  Ash M  McCay D  Mattix ME 《Journal of veterinary medical education》2008,35(2):235-240

Our nation lacks a critical mass of professionals trained to prevent and respond to food- and animal-related emergencies. Training veterinarians provides an immediate means of addressing this shortage of experts. Achievement of critical mass to effectively address animal-related emergencies is expedited by concurrent training of professionals and graduate students in related areas. Purdue University offers a Web-based Graduate Certificate in Veterinary Homeland Security to address this special area of need. The program is a collaborative effort among the Purdue University School of Veterinary Medicine, the Purdue Homeland Security Institute, the Indiana State Board of Animal Health, the Indiana State Police, and others with the overall goal of increasing capacity and preparedness to manage animal-related emergencies. Individuals with expertise in veterinary medicine, public health, animal science, or homeland security are encouraged to participate. The Web-based system allows courses to be delivered efficiently and effectively around the world and allows participants to continue their graduate education while maintaining full-time jobs. Participants enhance their understanding of natural and intentional threats to animal health, strengthen their skills in managing animal-health emergencies, and develop problem-solving expertise to become effective members of animal emergency response teams and of their communities. Students receive graduate credit from Purdue University that can be used toward the certificate and toward an advanced graduate degree. Currently, 70 participants from 28 states; Washington, DC; Singapore; and Bermuda are enrolled.  相似文献   

Current Status and Bottle Neck of Octopod Aquaculture: The Case of American Species     

Iker Uriarte  Jos Iglesias  Pedro Domingues  Carlos Rosas  María T. Viana  Juan C. Navarro  Pedro Seixas  Erica Vidal  Alberto Ausburger  Sandra Pereda  Flix Godoy  Kurt Paschke  Ana Farías  Alberto Olivares  Oscar Zuiga 《Journal of the World Aquaculture Society》2011,42(6):735-752

The increasing market demand for cephalopods and the experiences obtained with different species has boosted the interest in developing their culture in Latin America. In 2008, an international workshop was held in Puerto Montt, Chile, with 14 experts in experimental cephalopods aquaculture from Brazil, Chile, Spain, and Mexico. Several topics were approached within the holobenthic species Octopus maya and the merobenthic species Enteroctopus megalocyathus, Octopus vulgaris, and Robsonella fontaniana. Part of the conclusions demonstrated that the two greatest difficulties for their production were survival of paralarvae for merobenthic species, and survival of early juveniles for holobenthic species. Besides, there is a need to study the endogenous and exogenous factors affecting health and nutritional status of embryos, paralarvae, and juveniles. These stages, which may limit the culture, should be extensively studied in order to develop the appropriate environmental conditions and culture systems for the physiological and behavioral requirements, from egg incubation up to juveniles to reach a grow‐out phase.  相似文献   

Redox Status and Neuro Inflammation Indexes in Cerebellum and Motor Cortex of Wistar Rats Supplemented with Natural Sources of Omega-3 Fatty Acids and Astaxanthin: Fish Oil,Krill Oil,and Algal Biomass     

Tatiana G. Polotow  Sandra C. Poppe  Cristina V. Vardaris  Douglas Ganini  Maísa Guariroba  Rita Mattei  Elaine Hatanaka  Maria F. Martins  Eduardo F. Bondan  Marcelo P. Barros 《Marine drugs》2015,13(10):6117-6137

Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs) and the antioxidant carotenoid astaxanthin (ASTA). However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3)/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients) on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation), drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions.  相似文献   

The effect of density in larval rearing of the pullet carpet shell Venerupis corrugata (Gmelin, 1791) in a recirculating aquaculture system          下载免费PDF全文

Sandra Joaquim  Domitília Matias  Ana Margarete Matias  Alexandra Leitão  Florbela Soares  Marina Cabral  Luís Chícharo  Miguel B Gaspar 《Aquaculture Research》2016,47(4):1055-1066

The pullet carpet shell Venerupis corrugata is an economically valuable species in several European countries, however, nowadays stocks are under high fishing pressure. Hatchery production of juveniles for release is a major contributor to strengthen the stock and consequently improve the sustainability of the natural stocks. This study aimed to determine the feasibility of rearing V. corrugata larvae with different larval densities (10, 40 and 200 larvae per mL) in a recirculating aquaculture system (RAS), compared with the traditional larval rearing methodology (Batch). The mean survival, growth and metamorphic rate of V. corrugata larvae in RAS was higher (11.1%; 71.3 μm; 21.6% respectively) than in the Batch system, in all tested densities. The larval growth was not affected by the initial density until 40 larvae per mL, however, 200 larvae per mL decreased the larval growth in length nearly 54 μm. The larval rearing time was shortened in 2 days in the RAS system. The physical, chemical and microbiologic parameters suggested that the tested densities were not excessive to disturb the biofilter stability of RAS. The V. corrugata larval rearing performed at high larval stocking densities in RAS system present a reduction in the operating costs to produce this species.  相似文献   

Spatial distribution of Yellow Sigatoka Leaf Spot correlated with soil fertility and plant nutrition     

A. S. Freitas  E. A. Pozza  M. C. Alves  G. Coelho  H. S. Rocha  A. A. A. Pozza 《Precision Agriculture》2016,17(1):93-107

  相似文献