2,353 research outputs found

    Effects of proportional assisted ventilation on exercise performance in idiopathic pulmonary fibrosis patients

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    SummaryBackgroundPatients with idiopathic pulmonary fibrosis (IPF) present an important ventilatory limitation reducing their exercise capacity. Non-invasive ventilatory support has been shown to improve exercise capacity in patients with obstructive diseases; however, its effect on IPF patients remains unknown.ObjectiveThe present study assessed the effect of ventilatory support using proportional assist ventilation (PAV) on exercise capacity in patients with IPF.MethodsTen patients (61.2±9.2 year-old) were submitted to a cardiopulmonary exercise testing, plethysmography and three submaximal exercise tests (60% of maximum load): without ventilatory support, with continuous positive airway pressure (CPAP) and PAV. Submaximal tests were performed randomly and exercise capacity, cardiovascular and ventilatory response as well as breathlessness subjective perception were evaluated. Lactate plasmatic levels were obtained before and after submaximal exercise.ResultsOur data show that patients presented a limited exercise capacity (9.7±3.8mLO2/kg/min). Submaximal test was increased in patients with PAV compared with CPAP and without ventilatory support (respectively, 11.1±8.8min, 5.6±4.7 and 4.5±3.8min; p<0.05). An improved arterial oxygenation and lower subjective perception to effort was also observed in patients with IPF when exercise was performed with PAV (p<0.05). IPF patients performing submaximal exercise with PAV also presented a lower heart rate during exercise, although systolic and diastolic pressures were not different among submaximal tests. Our results suggest that PAV can increase exercise tolerance and decrease dyspnoea and cardiac effort in patients with idiopathic pulmonary fibrosis

    Long-term perturbations due to a disturbing body in elliptic inclined orbit

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    In the current study, a double-averaged analytical model including the action of the perturbing body's inclination is developed to study third-body perturbations. The disturbing function is expanded in the form of Legendre polynomials truncated up to the second-order term, and then is averaged over the periods of the spacecraft and the perturbing body. The efficiency of the double-averaged algorithm is verified with the full elliptic restricted three-body model. Comparisons with the previous study for a lunar satellite perturbed by Earth are presented to measure the effect of the perturbing body's inclination, and illustrate that the lunar obliquity with the value 6.68\degree is important for the mean motion of a lunar satellite. The application to the Mars-Sun system is shown to prove the validity of the double-averaged model. It can be seen that the algorithm is effective to predict the long-term behavior of a high-altitude Martian spacecraft perturbed by Sun. The double-averaged model presented in this paper is also applicable to other celestial systems.Comment: 28 pages, 6 figure

    Characteristics of carcass and non-carcass components of lambs fed diets containing silages of forages adapted to the semi-arid environment

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    The aim of this study was to evaluate the effects of diets containing silages of forages that are adapted to the semi-arid environment on the characteristics of the carcass and of non-carcass components of 32 mixed-breed lambs at approximately six months old, with an average live weight of 17.61 ± 2.63 kg. Lambs were assigned to four treatments (diets containing silages of Atriplex nummularia Lind, Cenchrus ciliaris, Gliricidia sepium and Manihot sp.) in a completely randomized design with eight replicates. Animals fed the diet containing old man saltbush showed higher values for the intakes of dry matter (1.080 g/day), crude protein (190 g/day) and total digestible nutrients (740 g/day), body condition score (2.81 points), fatness (2.87 points), carcass conformation (3.19 points), live weight (29.1 kg), empty bodyweight (23.41 kg), weights of the commercial cuts neck, shoulder and ribs (0.46, 0.82 and 1.12 kg, respectively), and skin weight (1.972 kg). No differences were found between the diets for carcass dressing percentage, external and internal carcass lengths, leg length and circumference, rump circumference and width, chest width and depth, full bodyweight, empty bodyweight, cooling losses, pH before and after cooling, loin, and leg. Silages of old man saltbush, buffelgrass, gliricidia and pornunça are recommended for inclusion in lamb diets. Diets with old man saltbush silage provide the best results for characteristics of the carcass and of non-carcass components besides weight gain, which can reach up to 200 g/day depending on the formulation.Keywords: Carcass composition, feedlot, saltbush, shee

    Impact of Caffeine Consumption on Type 2 Diabetes-Induced Spatial Memory Impairment and Neurochemical Alterations in the Hippocampus.

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    Diabetes affects the morphology and plasticity of the hippocampus, and leads to learning and memory deficits. Caffeine has been proposed to prevent memory impairment upon multiple chronic disorders with neurological involvement. We tested whether long-term caffeine consumption prevents type 2 diabetes (T2D)-induced spatial memory impairment and hippocampal alterations, including synaptic degeneration, astrogliosis, and metabolic modifications. Control Wistar rats and Goto-Kakizaki (GK) rats that develop T2D were treated with caffeine (1 g/L in drinking water) for 4 months. Spatial memory was evaluated in a Y-maze. Hippocampal metabolic profile and glucose homeostasis were investigated by &lt;sup&gt;1&lt;/sup&gt; H magnetic resonance spectroscopy. The density of neuronal, synaptic, and glial-specific markers was evaluated by Western blot analysis. GK rats displayed reduced Y-maze spontaneous alternation and a lower amplitude of hippocampal long-term potentiation when compared to controls, suggesting impaired hippocampal-dependent spatial memory. Diabetes did not impact the relation of hippocampal to plasma glucose concentrations, but altered the neurochemical profile of the hippocampus, such as increased in levels of the osmolites taurine (P &lt; 0.001) and myo-inositol (P &lt; 0.05). The diabetic hippocampus showed decreased density of the presynaptic proteins synaptophysin (P &lt; 0.05) and SNAP25 (P &lt; 0.05), suggesting synaptic degeneration, and increased GFAP (P &lt; 0.001) and vimentin (P &lt; 0.05) immunoreactivities that are indicative of astrogliosis. The effects of caffeine intake on hippocampal metabolism added to those of T2D, namely reducing myo-inositol levels (P &lt; 0.001) and further increasing taurine levels (P &lt; 0.05). Caffeine prevented T2D-induced alterations of GFAP, vimentin and SNAP25, and improved memory deficits. We conclude that caffeine consumption has beneficial effects counteracting alterations in the hippocampus of GK rats, leading to the improvement of T2D-associated memory impairment

    Genetic characterization of Toxoplasma gondii isolates from pigs intended for human consumption in Brazil

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    AbstractThis study genetically Toxoplasma gondii isolates obtained from pigs intended for human consumption in northeastern Brazil; multilocus PCR-RFLP and sequencing techniques were utilized. Bioassays were conducted using the brain and tongue of 20 pig heads purchased at butcher shops in the city of Ilheus, Bahia, Brazil. Overall, 11 T. gondii isolates designated TgPgBr06-16 were identified. Application of multilocus PCR-RFLP with seven molecular markers (SAG1, SAG2, SAG3, BTUB, C22-8, PK1 and Apico) identified six different genotypes. Isolates TgPgBr 06, 08, 11, 12, 14 and 15 were indistinguishable by this technique, forming a single genotype; the remaining isolates were characterized as distinct genotypes. However, when five genetic markers (SAG1, SAG2, SAG3, BTUB and c22-8) were employed in multilocus PCR-sequencing, all eleven strains of T. gondii were shown to be different. All isolates differed from Type I, II and III clonal genotypes using both genotyping techniques. These results demonstrate that the multilocus PCR-RFLP assay underestimated the true diversity of the T. gondii population in this study. Thus, DNA sequencing is the preferred technique to infer the genetic diversity and population structure of T. gondii strains from Brazil. Moreover, it is necessary to develop new molecular markers to group and characterize atypical T. gondii isolates from South America

    Feasibility of planctomycetes as a nutritional or supplementary food source for Daphnia spp

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    Daphnia magna is widely used as a standard organism in ecotoxicology assays. It plays a key role in energy transfer in freshwater food webs as a primary consumer, grazing on microalgae, yeast and bacteria. Daphnids are commonly reared in the laboratory using microalgae cultures but alternative or complementary sources are important to reduce the dependency on a single food source. The role played in nature by planctomycetes as a food source for other higher trophic levels is still unknown. In this study, we aimed to evaluate the potential of Rhodopirellula rubra strain LF2 as a nutritional or a supplementary food source for D. magna and Daphnia longispina. Life-history assays were conducted with daphnids fed with R. rubra in exponential and stationary growth phases, in three concentrations. Additionally, its adequacy as a supplement to the microalga Raphidocelis subcapitata was tested. In general, both daphnids showed impairment in all the parameters evaluated, especially when fed with R. rubra. However, when daphnids were fed with the two food sources, no changes were recorded for the rate of population increase. At the tested concentrations, R. rubra was not a good alternative food source in the daphnid diet. © EDP Sciences, 2016.This research was partially supported by the Strategic Funding UID/Multi/04423/2013 through national funds provided by FCT (Foundation for Science and Technology) and the European Regional Development Fund (ERDF), in the framework of the programme PT2020

    O AVANÇO DA OCUPAÇÃO ANTRÓPICA EM ÁREA DE RISCO NA SERRA DO TEPEQUÉM - RR

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    A serra do Tepequém, no Norte do estado de Roraima, tem passado por intensas modificações em sua paisagem ocasionada tanto por ação natural como antrópica. A ocupação na região tem contribuído para retirada da vegetação e abertura de estradas, o que intensifica a vulnerabilidade do solo e os impactos ambientais e antrópicos. Na serra, as construções ocupam áreas próximas a encostas, rede de drenagem e feições erosivas lineares que apresentam dinâmica constante em decorrência da ação climática

    Effects of feed particle size on energy values for broiler chickens at various ages

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    The objective of this study was to evaluate the effects of various geometric mean diameters (GMDs) of particles of corn, pelleted soybean meal and a corn-soy mixture in the proportion of 70% and 30%, respectively, on the nutritional value of the feeds. The study evaluated energy consumption, the contents of apparent metabolizable energy (AME) and AME corrected for nitrogen balance (AMEn) and the metabolizability coefficients for broiler chickens at various ages. A total of 540 Cobb 500 male broilers were housed in metabolic cages (experimental units). Trials were performed separately with each feed. A completely randomized design was used with four treatments, namely corn with 573, 636, 851, and 1012 μm GMDs; pelleted soybean meal with 538, 550, 665, and 741 μm GMDs; and the corn-soy mixture with 627, 658, 893, and 1040 μm GMDs. Birds were evaluated on days 1 - 10, 11 - 20, 21 - 30, and 31 - 40. Larger GMDs resulted in lower energy consumption. From 1 to 10 days, birds consumed less metabolizable energy than older birds. Birds fed corn from days 1 to 10 had higher metabolizable energy (P &lt;0.05) with increasing GMD up to 1042 μm. However, the results varied, depending on the feed and its combinations. The use of coarse particles could reduce the costs of grinding, and would have few effects on the metabolizable energy of broiler chickens

    In Vitro Activity Of Artemisia Annua L (asteraceae) Extracts Against Rhipicephalus (boophilus) Microplus [atividade In Vitro De Extratos De Artemisia Annua L (asteraceae) Sobre Rhipicephalus (boophilus) Microplus]

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    The activity of plant extracts on parasites may indicate groups of substances that are potentially useful for controlling Rhipicephalus (Boophilus) microplus. The aim of the present study was to investigate the in vitro action of Artemisia annua extracts on this tick. The concentrations of the sesquiterpene lactones artemisinin and deoxyartemisinin present in plant extracts were quantified via high-performance liquid chromatography. Four extracts produced from the concentrated crude extract (CCE) were evaluated on larvae using the impregnated paper method, with readings after 24 hours of incubation. The engorged females were immersed in the CCE and in its four derived extracts for five minutes, with incubation for subsequent analysis of biological parameters. The extracts were not effective on the larvae at the concentrations tested (3.1 to 50 mg.mL-1). The CCE showed greater efficacy on engorged females (EC50 of 130.6 mg.mL-1 and EC90 of 302.9 mg.mL-1) than did the derived extracts. These results tend to confirm that the action of artemisinin on engorged females of R. (B.) microplus is conditional to their blood intake. In this case, in vitro methods would be inadequate for effective evaluation of the action of A. annua on R. (B.) microplus.2013135Amaral, N.K., Guidelines for the evaluation of ixodicides against the cattle tick Boophilus microplus (Canestrini, 1887) (Acari: Ixodidae) (1993) Revista Brasileira De Parasitologia Veterinária, 2 (2), pp. 144-151(2009) Anuário Da Pecuária Brasileira, p. 360. , ANUALPEC, Sao Paulo: Angra FNP PesquisasBorges, L.M.F., Acao do extrato hexanico de frutos maduros de Melia azedarach (Meliaceae) sobre Boophilus microplus (Acari: Ixodidae) em bezerros infestados artificialmente (2005) Revista De Patologia Tropical, 34 (1), pp. 53-59Cala, A.C., (2010) Avaliação Da Atividade De Artemisia Annua L., Melia Azedarach L. E Trichilia Claussenii C. Sobre Nematódeos Gastrintestinais De Ovinos, p. 64. , Dissertacao (Mestrado)- Universidade Estadual Paulista, Faculdade de Ciencias Agrarias e Veterinarias, JaboticabalCeleghini, R.M.S., Desenvolvimento e validacao de metodologia analitica por CLAE-IR para determinacao de artemisinina em Artemisia annua L (2009) Química Nova, 32 (4), pp. 875-878Chagas, A.C.S., Efeito acaricida de oleos essenciais e concentrados emulsionaveis de Eucalyptus em Boophilus microplus (2002) Brazilian Journal of Veterinary Research and Animal Science, 39 (5), pp. 247-253Chagas, A.C.S., Sensibilidade do carrapato Boophilus microplus a solventes (2003) Ciência Rural, 33 (1), pp. 109-114Creek, D.J., Kinetics of ironmediated artemisinin degradation:Effect of solvent composition and iron salt (2005) Journal of Pharmaceutical Sciences, 94 (8), pp. 1820-1829Drummond, R.O., Boophilus annulatus and B. Microplus: Laboratory tests of insecticides (1973) Journal of Economic Entomology, 66 (1), pp. 130-133Ekanem, A.P., Brisibe, E.A., Effects of ethanol extract of Artemisia annua L. Against monogenean parasites of Heterobranchus longifilis (2010) Parasitology Research, 106 (5), pp. 1135-1139Fernandes, F.F., Freitas, E.P.S., Acaricidal activity of an oleoresinous extract from Copaifera reticulata (Leguminosae: Caesalpinioideae against larvae of the southern cattle tick, Riphicephalus (Boophilus) microplus (Acari:Ixodidae) (2007) Veterinary Parasitology, 147 (1-2), pp. 150-154Ferreira, J.F.S., Agrotechnological aspects of the anti-malarial plant Artemisia annua and its potential use in animal health in Appalachia (2006) International Symposium on Perfume, Aromatic and Medicinal Plants, (2-4), pp. 797-804. , Revue de Regions Arides - Numero special - Actes du seminaire international les Plants a Parfum, Aromatiques et Medicinales (English version: International Center for Agricultural Research in Dry AreasFerreira, J.F.S., Nutrient Deficiency in the Production of Artemisinin, Dihydroartemisinic Acid, and Artemisinic Acid in Artemisia annua L (2007) Journal of Agricultural and Food Chemistry, 55 (5), pp. 1686-1694Ferreira, J.F.S., Gonzalez, J.M., Chemical and biological stability of artemisinin in bovine rumen fluid and its kinetics in goats (Capra hircus) (2008) Revista Brasileira De Parasitologia Veterinária, 17 (SUPPL. 1), pp. 103-109Furlong, J., O carrapato dos bovinos e a resistencia: Temos o que comemorar? (2007) A Hora Veterinária, 159, pp. 26-32Grisi, L., Impacto economico das principais ectoparasitoses em bovinos no Brasil (2002) A Hora Veterinária, 21 (125), pp. 8-10Heimerdinger, A., Extrato alcoolico de Capim-cidreira (Cymbopogon citratus) no controle do Boophilus microplus em bovinos (2006) Revista Brasileira De Parasitologia Veterinária, 15 (1), pp. 37-39Idris, U.A., Adam, S.E., Tartour, G., The anthelmintic efficacy of Artemisia herba-alba against Haemonchus contortus infection in goats (1982) Animal Health Quarterly, 22 (3), pp. 138-143Iqbal, Z., Anthelmintic activity of Artemisia brevifolia in sheep (2004) Journal of Ethnopharmacology, 93 (2), pp. 265-268Keiser, J., Artesunate and artemether are effective fasciolicides in the rat model and in vitro (2006) Journal of Antimicrobial Chemotherapy, 57 (6), pp. 1139-1145Keiser, J., Efficacy and safety of artemether against a natural Fasciola hepatica infection in sheep (2008) Parasitology Research, 103 (3), pp. 517-522Keiser, J., Utzinger, J., Food-borne trematodiasis: Current chemotherapy and advances with artemisinins and synthetic trioxolanes (2007) Trends In Parasitology, 23 (11), pp. 555-562Klayman, D.L., Qinghaosu (Artemisinin): Na antimalarial drug from China (1985) Science, 228 (4703), pp. 1049-1055La-Scalea, M.A., Silva, H.S.R.C., Ferreira, E., Reducao voltametrica de artemisinina e sua interacao com grupo heme (hemina) (2007) Brazilian Journal of Pharmaceutical Sciences, 43 (3), pp. 371-383Martins, R.M., Estudio in vitro de la accion acaricida del aceite esencial de la graminea Citronela de Java (Cymbopogon winterianus Jowitt) en la garrapata Boophilus microplus (2006) Revista Brasileira De Plantas Medicinais De Botucatu, 8 (2), pp. 71-78Meshnick, S.R., Second-generation antimamalarial endoperoxides (1996) Parasitology Today, 12 (2), pp. 79-82Ribeiro, V.L.S., Acaricidal properties of extracts from the aerial parts of Hypericum polyanthemum on the cattle tick Boophilus microplus (2007) Veterinary Parasitology, 147 (1-2), pp. 199-203Rodrigues, R.A.F., Otimizacao do processo de extracao e isolamento do antimalarico artemisinina a partir de Artemisia annua L (2006) Química Nova, 29 (2), pp. 368-372Silva, H.S.R.C., (2006) Antimaláricos Potenciais: Pró-fármacos Poliméricos E Formas De Liberação Controlada De Artemisinina, p. 209. , Tese (Doutorado)-Universidade de Sao Paulo, Sao PauloSimoes, C.M., (2004) Farmacognosia: Da Planta Ao Medicamento, p. 1102. , 5. ed. Porto Alegre: Editora da UFRGSFlorianopolis: Editora da UFSCTaranto, A.G., Estudo sobre o mecanismo de acao da artemisinina e dos endoperoxidos, a mais nova classe de agents antimalaricos (2006) Sitientibus, 34, pp. 47-58Tariq, K.A., Anthelmintic activity of extracts of Artemisia absinthium against ovine nematodes (2009) Veterinary Parasitology, 160 (1-2), pp. 83-8

    Universal Hidden Supersymmetry in Classical Mechanics and its Local Extension

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    We review here a path-integral approach to classical mechanics and explore the geometrical meaning of this construction. In particular we bring to light a universal hidden BRS invariance and its geometrical relevance for the Cartan calculus on symplectic manifolds. Together with this BRS invariance we also show the presence of a universal hidden genuine non-relativistic supersymmetry. In an attempt to understand its geometry we make this susy local following the analogous construction done for the supersymmetric quantum mechanics of Witten.Comment: 6 pages, latex, Volkov Memorial Proceeding
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