Strain differences in baroceptor reflex in adult wistar kyoto rats

OBJECTIVES: A subset of normotensive Sprague-Dawley rats show lower baroreflex sensitivity; however, no previous study investigated whether there are differences in baroreflex sensitivity within this subset. Our study compared baroreflex sensitivity among conscious rats of this specific subtype. METHODS: Male Wistar Kyoto (WKY) rats (16 weeks old) were studied. Cannulas were inserted into the abdominal aortic artery through the right femoral artery to measure mean arterial pressure (MAP) and heart rate (HR). Baroreflex gain was calculated as the ratio between change in HR and MAP variation (&#916;HR/&#916;MAP) in response to a depressor dose of sodium nitroprusside (SNP, 50 µg/kg, i.v.) and a pressor dose of phenylephrine (PE, 8 µg/kg, i.v.). Rats were divided into four groups: 1) low bradycardic baroreflex (LB), baroreflex gain (BG) between -1 and -2 bpm/mmHg tested with PE; 2) high bradycardic baroreflex (HB), BG < -2 bpm/mmHg tested with PE; 3) low tachycardic baroreflex (LT), BG between -1 and -2 bpm/mmHg tested with SNP and; 4) high tachycardic baroreflex (HT), BG < -2 bpm/mmHg tested with SNP. Significant differences were considered for p < 0.05. RESULTS: Approximately 37% of the rats showed a reduced bradycardic peak, bradycardic reflex and decreased bradycardic gain of baroreflex while roughly 23% had a decreased basal HR, tachycardic peak, tachycardic reflex and reduced sympathetic baroreflex gain. No significant alterations were noted with regard to basal MAP. CONCLUSION: There is variability regarding baroreflex sensitivity among WKY rats from the same laboratory

A set of multiplex panels of microsatellite markers for rapid molecular characterization of rice accessions

Background: This study aimed to analyze the efficiency of three new microsatellite multiplex panels, which were designed to evaluate a total of 16 loci of the rice genome, based on single PCR reactions of each panel. A sample of 548 accessions of traditional upland rice landraces collected in Brazil in the last 25 years was genotyped, a database of allelic frequencies was established, estimates of genetic parameters were performed and analysis of genetic structure of the collection was developed. Results: The three panels yielded a combined matching probability of 6.4 × 10-21, polymorphism information content (PIC) of 0.637, and a combined power of exclusion greater than 99.99%. A few samples presented a genetic background of indica rice. The 16 SSR loci produced a total of 229 alleles. Gene diversity values averaged 0.667, and PIC values averaged 0.637. Genetic structure analysis of the collection using a Bayesian approach detected three possible major clusters, with an overall FST value of 0.177. Important inputs on the knowledge about upland rice germplasm differentiations which happened in Brazil in the last few centuries were also achieved and are discussed. Conclusion: The three multiplex panels described here represent a powerful tool for rice genetic analysis, offering a rapid and efficient option for rice germplasm characterization. The data gathered demonstrates the feasibility of genotyping extensive germplasm collections using panels of multiplexed microsatellite markers. It contributes to the advancement of research on large scale characterization and management of germplasm banks, as well as identification, protection and assessments of genetic relationship of rice germplasm

Redes de Parentesco como sistemas dinâmicos

Redes de parentesco têm sido modeladas, desde os primeiros trabalhos pioneiros de Lewis Morgan e William Rivers, através de estruturas que se assemelham ao que, em teoria dos grafos, chamamos de grafos mistos, em que as relações de filiação são arcos direcionados, e os casamentos arestas "bidirecionadas". Outros significados podem ser dados às ligações, como sugere David Schneider em seus trabalhos a partir dos anos 70 do século passado. Isso dá origem a um modelo estático do parentesco, em que as relações surgem (por exemplo, no nascimento) e não se alteram durante a vida da pessoa. Este modelo nos parece insuficiente para capturar a riqueza do parentesco em suas manifestações empíricas nas diversas culturas existentes. Em muitas delas as relações entre os entes evoluem no tempo, e o modelo que representa o parentesco deve ser dinâmico, evoluindo também. A morte de uma pessoa faz com que a rede de parentesco se reconstrua para explicar e sustentar as novas classificações e funções dos indivíduos. Em Matemática, sistemas dinâmicos são estudados há mais de 100 anos, desde o trabalho seminal de Henri Poincaré. Essa natureza dinâmica se observa em diversos fenômenos da natureza, como a população de uma determinada espécie, o movimento do pêndulo de um relógio, o fluxo de água em um encanamento, etc. Nossa abordagem para o estudo do parentesco, como sistema dinâmico, deve ser capaz de reunir, em um mesmo plano analítico, objetos ecléticos como um conjunto de categorias semânticas nativas, um conjunto de normas e preferências matrimoniais e um conjunto de dados genealógicos empíricos de um dado povo, sem pressupor determinação entre eles

Cytotoxic and hemolytic activities of extracts of the fish parasite dinoflagellate amyloodinium ocellatum

The dinoflagellate Amyloodinium ocellatum is the etiological agent of a parasitic disease named amyloodiniosis. Mortalities of diseased fish are usually attributed to anoxia, osmoregulatory impairment, or opportunistic bacterial infections. Nevertheless, the phylogenetic proximity of A. ocellatum to a group of toxin-producing dinoflagellates from Pfiesteria, Parvodinium and Paulsenella genera suggests that it may produce toxin-like compounds, adding a new dimension to the possible cause of mortalities in A. ocellatum outbreaks. To address this question, extracts prepared from different life stages of the parasite were tested in vitro for cytotoxic effects using two cell lines derived from branchial arches (ABSa15) and the caudal fin (CFSa1) of the gilthead seabream (Sparus aurata), and for hemolytic effects using erythrocytes purified from the blood of gilthead seabream juveniles. Cytotoxicity and a strong hemolytic effect, similar to those observed for Karlodinium toxins, were observed for the less polar extracts of the parasitic stage (trophont). A similar trend was observed for the less polar extracts of the infective stage (dinospores), although cell viability was only affected in the ABSa15 line. These results suggest that A. ocellatum produces tissue-specific toxic compounds that may have a role in the attachment of the dinospores’ and trophonts’ feeding process.info:eu-repo/semantics/publishedVersio

Identification of drought-responsive genes in roots of upland rice (Oryza sativa L)

Made available in DSpace on 2018-05-30T00:52:09Z (GMT). No. of bitstreams: 1 SP19617ID30907.pdf: 1707482 bytes, checksum: 941f31dca42cba7961c00d079f3b738b (MD5) Previous issue date: 2009-02-04bitstream/item/177854/1/SP-19617-ID-30907.pd

Electronic excitation of furfural as probed by high-resolution vacuum ultraviolet spectroscopy, electron energy loss spectroscopy, and ab initio calculations

13 págs.; 7 figs.; 8 tabs.© 2015 AIP Publishing LLC. The electronic spectroscopy of isolated furfural (2-furaldehyde) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 3.5-10.8 eV energy-range, with absolute cross section measurements derived. Electron energy loss spectra are also measured over a range of kinematical conditions. Those energy loss spectra are used to derive differential cross sections and in turn generalised oscillator strengths. These experiments are supported by ab initio calculations in order to assign the excited states of the neutral molecule. The good agreement between the theoretical results and the measurements allows us to provide the first quantitative assignment of the electronic state spectroscopy of furfural over an extended energy range.F.F.S. and P.L.V. acknowledge the Portuguese Foundation for Science and Technology (FCT-MEC) through Grant Nos. SFRH/BPD/68979/2010 and SFRH/BSAB/105792/2014, respectively, the research Grant Nos. PTDC/FIS-ATO/1832/ 2012 and UID/FIS/00068/2013. P.L.V. also acknowledges his Visiting Research Fellow position at Flinders University, Adelaide, South Australia. The Patrimoine of the University of Liège, the Fonds National de la Recherche Scientifique, and the Fonds de la Recherche Fondamentale Collective of Belgium have also supported this research. E.L. and R.F.C.N. thank CNPq (Brazil) and the Science Without Borders Programme for opportunities to study abroad. The authors wish to acknowledge the beam time at the ISA synchrotron at Aarhus University, Denmark. The research leading to these results has received funding from the European Community’s Seventh Framework Programme (Grant No. FP7/2007-2013) CALIPSO under Grant Agreement No. 312284. D.B.J. thanks the Australian Research Council for financial support provided through a Discovery Early Career Research Award. M.J.B. also thanks the Australian Research Council for some financial support, while M.J.B. and M.C.A.L. acknowledge the Brazilian agencies CNPq and FAPEMIG for financial support. F.B. and G.G. acknowledge partial financial support from the Spanish Ministry MINECO (Project No. FIS2012-31230) and the EU COST Action No. CM1301 (CELINA). Finally, R.F.C., M.T.do N.V., M.H.F.B., and M.A.P.L. acknowledge support from the Brazilian agency CNPq.Peer Reviewe

Evaluation of the in vitro trypanocidal activity of triterpenes uvaol, betulinic acid and its semi-synthetic derivatives against the Y strain of Trypanosoma cruzi / Avaliação da atividade tripanocida in vitro dos triterpenos uvaol, ácido betulínico e seus derivados semissintéticos contra a cepa Y de Trypanosoma cruzi

Chagas disease is a neglected tropical disease that affects millions of people worldwide. Trypanosoma cruzi (T. cruzi) is the causative agent of Chagas disease and its transmission occurs through blood meal by triatomine bugs, being oral transmission the most common form. More than 100 years after the disease´s discovery, benzonidazole is the only efficient drug against T. cruzi; however, this drug has numerous serious side effects and is only efficient in the acute phase of the disease. Natural products, such as triterpenes, have been an important source of new substances to combat human parasitology. In this study, two triterpenes, uvaol and betulinic acid, were tested against the parasite T. cruzi. The best results of in vitro tests were observed for uvaol with an IC50 value of 70.3 µM against the trypomastigost forms and an IC50 value of 90.6 µM against the amastigost forms. Three semi-synthetic derivatives of betulinic acid were obtained; the acetylated derivative showed excellent results against trypomastigotes forms (IC50 = 15.67 µM), but was not active against the amastigotes forms. The cytotoxic MTT test was also performed on LLCMK2 cells (Macaca mullata kidney epithelial cells) and betulinic acid showed the highest selectivity index (SI) with a value of 1.3

Aporte e decomposição de serapilheira em área em restauração no Cerrado

The litterfall is a very important component within a forest ecosystem, as it is responsible for the cycling of nutrients, in addition to indicating the productive capacity of the forest. The amount of litterfall varies according to the community and its successional stage. The different litterfall fractions have different structure and chemical composition and, therefore, decompose at different speeds. In view of this, the present study aimed to evaluate the contribution and decomposition of litter in an area of secondary vegetation undergoing restoration. An input of 33,941 kg ha-1 year-1 was observed, with the leaves compartment corresponding to the largest portion (69.68%), followed by branches (20.09%) and miscellaneous (10.22%). As for litter decomposition, a value for the decomposition constant K of 0.004227 g g-1 day-1 was found, and the half-life estimated at 164 days. The results found indicate a seasonal supply pattern, with peaks in the dry period, responding to the Cerrado's climatic seasonality and a rapid return of nutrients to the soil.  A serapilheira é um componente de suma importância dentro de um ecossistema florestal, pois responde pela ciclagem de nutrientes, além de indicar a capacidade produtiva da floresta. A quantidade de serapilheira acumulada varia de acordo com a comunidade florestal e com seu estádio sucessional. As diferentes frações da serapilheira têm estrutura e composição química distintas e, portanto, decompõem-se em diferentes velocidades. Diante disto, o presente trabalho teve como objetivo avaliar o aporte e decomposição da serapilheira em área de vegetação secundária em restauração. Foi observado um aporte de 33.941 kg ha-1 ano-1, sendo o compartimento folhas correspondente a maior porção (69,68%), seguida de galhos (20,09%) e miscelânea (10,22%). Quanto a decomposição da serapilheira, foi encontrado um valor da constante de decomposição K de 0,004227 g g-1 dia-1, e o tempo de meia vida estimado em 164 dias. Os resultados encontrados indicam um padrão sazonal de aporte, com picos no período seco, respondendo à sazonalidade climática do Cerrado e um rápido retorno dos nutrientes ao solo