724 research outputs found
Ploidy composition in all-hybrid frog populations in relation to ecological conditions
Question: What explains the differences in ratios of diploid (LR) and two types of triploid
frogs (LLR, LRR) among all-hybrid frog populations?
Hypothesis: Ecological conditions favouring one (LL) or the other (RR) parental species also
favour those triploids that carry two copies of the respective genome (dosage effect), whereas
diploids dominate under intermediate conditions.
Organism: European water frog (Pelophylax esculentus).
Field site: Thirty-four natural ponds in the province of Skåne, southern Sweden.
Methods: We caught more than 3000 frogs, determined their genotypes with microsatellites,
and related the ploidy composition to several uncorrelated ecological parameters, including
pond morphology, vegetation, and physical and chemical water parameters.
Conclusions: We found a shift from predominantly LLR in small isolated ponds to more LRR
in large wetland ponds. This parallels the preferences of the parental species LL and RR
for small and large bodies of water, respectively. The effects that pond vegetation and
physico-chemical water parameters exert on the parental species were not found in all-hybrid
populations. This suggests that environmental parameters affect the genotype composition of
all-hybrid populations less than populations containing the parental species. Pond-to-pond
differences in LR, LLR, and LRR proportions seem to be better explained by differences in
gamete production and thus inheritance patterns
Técnica de criação de Grapholita molesta (Busck, 1916) (Lepidoptera: Tortricidae) em laboratório utilizando dieta artificial para a produção de insetos visando estudos de comportamento e controle.
Uma técnica para criação e obtenção de todas as fases de desenvolvimento da mariposa-oriental Grapholita molesta (Busck, 1916) (Lepidoptera: Tortricidae) em laboratório (24 +- 2ºC; UR: 70 +- 10%; fotofase: 16h) utilizando dieta artificial foi avaliada e descrita.bitstream/CNPUV/9452/1/bop013.pdfISSN 1981-1004. DisponÃvel também no formato online
Overlapping and specific neural correlates for empathizing, affective mentalizing, and cognitive mentalizing: A coordinate-based meta-analytic study
Novas alternativas para o monitoramento e controle de anastrepha fraterculus (wied., 1830) (diptera: tephritidae) na fruticultura de clima temperado.
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Detection of seven β2-agonists in teeth by LC-MS/MS: preliminary results.
β2-agonists are powerful tocolytic (the only use permitted in cattle) and bronchodilator agents, butmay also be administered as growth promoters to improve the production of lean meat increasing alsothe lipolytic activity. Although the European Union (EU), China and other Asian countries have bannedthe use of β2-agonists for growth promoting purposes (European Union, 2003), the United States ofAmerica (USA) authorised ractopamine as a feed additive for swine, cattle and turkey. These veterinarydrugs, generally show high clearance rates in the conventional biological matrices, as well as urine, liverand muscle, making difficult their detection (Wu, 2014). For this reason, we suggested bovine teeth asa new unconventional matrix of accumulation in a more long-time window, for the detection ofcimaterol, clenbuterol, isoxsuprine, mabuterol, ractopamine, salbutamol and terbutaline. In literature,the few studies on teeth are limited to human (Andra, 2015) and are absent for veterinary medicine.The samples extracted by a simple liquid extraction step with ethyl acetate:tert-butyl methyl ether (4:1,v/v) after washing and pulverization of teeth, through a ball mill, were analysed using a liquidchromatography tandem mass spectrometry (LC-MS/MS) confirmatory method validated according tothe Commission Decision 2002/657/EC criteria (European Union, 2002). Teeth from 8 veal calves,administered per os with 80 mg day-1 oral ractopamine for 32 days, and from seven random bovinesfrom the food chain were collected at the slaughterhouse to test the suitability of this matrix. Theresults demonstrated ractopamine presence in teeth from the treated animals (average concentration8.90 ng g-1). Isoxsuprine was found in a control sample (13.67 ng g-1), demonstrating the effectivenessof this matrix as a powerful tool to ensure illegal treatment
Eficiência de atrativos alimentares na captura de adultos de Anastrepha fraterculus (Wied., 1830) (Diptera: Tephritidae) na cultura da ameixeira (Prunus domestica).
Neste trabalho, foi avaliada a eficiência de atrativos alimentares no monitoramento de adultos de Anastrepha fraterculus na cultura da ameixeira
Highlight on the Mechanism of Linear Polyamidoamine Degradation in Water
This paper aims at elucidating the degradation mechanism of linear polyamidoamines (PAAs) in water. PAAs are synthesized by the aza-Michael polyaddition of prim-monoamines or bis-sec-amines with bisacrylamides. Many PAAs are water-soluble and warrant potential for biotechnological applications and as flame-retardants. PAAs have long been known to degrade in water at pH 65 7, but their degradation mechanism was never explored in detail. Filling this gap was necessary to assess the suitability of PAAs for the above applications. To this aim, a small library of nine PAAs was expressly synthesized and their degradation mechanism in aqueous solution studied by 1H-NMR in different conditions of pH and temperature. The main degradation mechanism was in all cases the retro-aza-Michael reaction triggered by dilution but, in some cases, hints were detected of concurrent hydrolytic degradation. Most PAAs were stable at pH 4.0; all degraded at pH 7.0 and 9.0. Initially, the degradation rate was faster at pH 9.0 than at pH 7.0, but the percent degradation after 97 days was mostly lower. In most cases, at pH 7.0 the degradation followed first order kinetics. The degradation rates mainly depended on the basicity of the amine monomers. More basic amines acted as better leaving groups
Occurrence of antibiotics in mussels and clams from various FAO areas
Filter feeders, like mussels and clams, are suitable bioindicators of environmental pollution. These shellfish, when destined for human consumption, undergo a depuration step that aims to nullify their pathogenic microorganism load and decrease chemical contamination. Nevertheless, the lack of contamination by drugs may not be guaranteed. Antimicrobials are a class of drugs of particular concern due to the increasing phenomenon of antibiotic resistance. Their use in breeding and aquaculture is a major cause of this. We developed a multiclass method for the HPLC\ue2\u80\u93MS/MS analysis of 29 antimicrobials, validated according to the Commission Decision 2002/657/UE guidelines, and applied it to 50 mussel and 50 clam samples derived from various Food and Agricultural Organisation marine zones. The results obtained, indicate a negligible presence of antibiotics. Just one clam sample showed the presence of oxytetracycline at a concentration slightly higher than the European Union Maximum residue limit set for fish
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