135 research outputs found
Parasitismo natural por helmintos gastrintestinais em búfalos criados em Presidente Médici, Rondônia, Brasil.
O parasitismo natural por helmintos gastrintestinais foi acompanhado em um rebanho bubalino criado no campo experimental da Embrapa Rondônia, em Presidente Médici, RO, através da pesquisa de ovos destes parasitas em amostras de fezes de búfalas e suas respectivas crias. As amostras de fezes foram colhidas semanalmente, diretamente da ampola retal, de búfalas no terço final da gestação. Após o parto, além das búfalas, foram colhidas amostras de fezes dos bezerros, desde o primeiro dia de vida, duas vezes por semana até o 42º dia, e a partir daí semanalmente, até a 30ª semana. As amostras de fezes foram processadas de acordo com as técnicas de Gordon e Whitlock, modificadas e de flutuação simples, adaptada para as amostras com pequenas quantidades de fezes colhidas dos bezerros. Foram consideradas positivas as amostras que apresentaram pelo menos um ovo de helminto ou oocisto de Emeria spp. Nas amostras de fezes das búfalas foi observada uma prevalência de 3,3% para estrongilídeos e 16,6% para Eimeria spp. Nas mostras dos bezerros foi encontrada uma prevalência de 100% para Toxocara vitulorum e para a Eimeria spp., enquanto que para o Strongyloides papillosus e estrongilídeos foi de 36,6% e 76,6%, respectivamente. A média de semanas em que os bezerros permaneceram infectados foi de 8,1, 10,2, 0,4 e 2,4 semanas para T. vitulorum, Eimeria spp., S. papillosus e estrongilídeos, respectivamente. A partir da 18ª semana de vida dos bezerros não foram mais encontrados ovos de T. vitulorum nas amostras de fezes. Ovos de S. papillosus, estrongilídeos e oocisto de Eimeria spp. foram encontrados nas amostras de fezes dos bezerros a partir da sexta, nona e quarta semana de vida dos animais, respectivamente, permanecendo presentes nos exames coprológicos até a 30ª semana.bitstream/item/46295/1/bpd66-bufalo-1.pd
Controle do Toxocara vitulorum em búfalos jovens em Presidente Médici.
Este trabalho teve por objetivo verificar o uso de princípios ativos, comumente utilizados no controle das helmintoses de bovinos, em bezerros bubalinos para o controle de helmintoses gastrintestinais por meio dos testes de redução da contagem de ovos por grama de fezes (OPG) e de eficácia dos tratamentos utilizados.bitstream/item/38601/1/cot357-bufalos.pd
Preliminary evidence that both blue and red light can induce alertness at night
<p>Abstract</p> <p>Background</p> <p>A variety of studies have demonstrated that retinal light exposure can increase alertness at night. It is now well accepted that the circadian system is maximally sensitive to short-wavelength (blue) light and is quite insensitive to long-wavelength (red) light. Retinal exposures to blue light at night have been recently shown to impact alertness, implicating participation by the circadian system. The present experiment was conducted to look at the impact of both blue and red light at two different levels on nocturnal alertness. Visually effective but moderate levels of red light are ineffective for stimulating the circadian system. If it were shown that a moderate level of red light impacts alertness, it would have had to occur via a pathway other than through the circadian system.</p> <p>Methods</p> <p>Fourteen subjects participated in a within-subject two-night study, where each participant was exposed to four experimental lighting conditions. Each night each subject was presented a high (40 lx at the cornea) and a low (10 lx at the cornea) diffuse light exposure condition of the same spectrum (blue, λ<sub>max </sub>= 470 nm, or red, λ<sub>max </sub>= 630 nm). The presentation order of the light levels was counterbalanced across sessions for a given subject; light spectra were counterbalanced across subjects within sessions. Prior to each lighting condition, subjects remained in the dark (< 1 lx at the cornea) for 60 minutes. Electroencephalogram (EEG) measurements, electrocardiogram (ECG), psychomotor vigilance tests (PVT), self-reports of sleepiness, and saliva samples for melatonin assays were collected at the end of each dark and light periods.</p> <p>Results</p> <p>Exposures to red and to blue light resulted in increased beta and reduced alpha power relative to preceding dark conditions. Exposures to high, but not low, levels of red and of blue light significantly increased heart rate relative to the dark condition. Performance and sleepiness ratings were not strongly affected by the lighting conditions. Only the higher level of blue light resulted in a reduction in melatonin levels relative to the other lighting conditions.</p> <p>Conclusion</p> <p>These results support previous findings that alertness may be mediated by the circadian system, but it does not seem to be the only light-sensitive pathway that can affect alertness at night.</p
Promoción de la recuperación ambiental en propiedades de producción de leche de búfalo en la Amazonía Occidental Brasilera.
Microstructure and magneto-dielectric properties of the chitosan/gelatin-YIG biocomposites
This work is devoted to the preparation of yttrium iron garnet (YIG) ferrimagnetic biocomposites based in biodegradable chitosan and gelatin. The aim was to produce composite films containing controlled amounts of YIG to obtain a new biological material with magneto-dielectric features. Structural characterization of the biocomposites was made by scanning electron microscopy, X-ray diffraction, infrared absorption spectroscopy and thermal analysis, while the dielectric and magnetic properties were obtained from dielectric spectroscopy and magnetic hysteresis loops, respectively. The versatility of the films obtained makes them possible candidates for use as biomaterials or electronic device
Desenvolvimento ponderal de Búfalos em conservação da raça Carabao criados sistema extensivo.
O objetivo deste estudo foi avaliar o desenvolvimento ponderal de búfalos Carabao, para peso ao nascer e às idades padrões de peso aos 205 dias, peso aos 365 dias, peso aos 550 dias e peso aos 730 dias de idade. Os pesos foram registrados dos animais participantes do projeto de conservação de recursos genéticos de animais de grande porte na Amazônia oriental, do Banco de Germoplasma Animal da Amazônia Oriental ? BAGAM, da Embrapa Amazônia Oriental, Ilha de Marajó, em Salvaterra ? PA. Os animais foram submetidos a um manejo extensivo, em savanas mal drenadas, em pastagens nativas, onde predominam dentre as gramíneas dos gêneros Andropogon, Trachypogon, Paspalum, dentre outros e dentre as leguminosas os gêneros Cassia, Stylosanthes. Os animais também foram, suplementados com mineralização à base de fósforo e sal comum iodado. Os valores encontrados de acordo com as idades padrões foram: 34,07 + 6,05 kg para peso ao nascer (PN) E 119,11 + 22,65 kg, 173,46 + 36,82 kg, 192,42 + 44,25 kg e 235,59 + 44,54 kg para, respectivamente 205, 365, 550 e 730 dias de idade. Os resultados sugerem que a raça pode ser uma boa escolha para a seleção de animais destinados a produção de corte
Natural Plasmodium infection in monkeys in the state of Rondônia (Brazilian Western Amazon).
Background: Simian malaria is still an open question concerning the species of Plasmodium parasites and species of New World monkeys susceptible to the parasites. In addition, the lingering question as to whether these animals are reservoirs for human malaria might become important especially in a scenario of eradication of the disease. To aid in the answers to these questions, monkeys were surveyed for malaria parasite natural infection in the Amazonian state of Rondônia, Brazil, a state with intense environmental alterations due to human activities, which facilitated sampling of the animals. Methods: Parasites were detected and identified in DNA from blood of monkeys, by PCR with primers for the 18S rRNA, CSP and MSP1 genes and sequencing of the amplified fragments. Multiplex PCR primers for the 18S rRNA genes were designed for the parasite species Plasmodium falciparum and Plasmodium vivax, Plasmodium malariae/Plasmodium brasilianum and Plasmodium simium. Results: An overall infection rate of 10.9% was observed or 20 out 184 monkey specimens surveyed, mostly by P. brasilianum. However, four specimens of monkeys were found infected with P. falciparum, two of them doubly infected with P. brasilianum and P. falciparum. In addition, a species of monkey of the family Aotidae, Aotus nigriceps, is firstly reported here naturally infected with P. brasilianum. None of the monkeys surveyed was found infected with P. simium/P. vivax. Conclusion: The rate of natural Plasmodium infection in monkeys in the Brazilian state of Rondônia is in line with previous surveys of simian malaria in the Amazon region. The fact that a monkey species was found that had not previously been described to harbour malaria parasites indicates that the list of monkey species susceptible to Plasmodium infection is yet to be completed. Furthermore, finding monkeys in the region infected with P. falciparum clearly indicates parasite transfer from humans to the animals. Whether this parasite can be transferred back to humans and how persistent the parasite is in monkeys in the wild so to be efficient reservoirs of the disease, is yet to be evaluated. Finding different species of monkeys infected with this parasite species suggests indeed that these animals can act as reservoirs of human malaria
Características fenotípicas do mini cavalo puruca (Equus caballus) da Ilha do Marajó, Pará, Brasil.
Características fenotípicas de equinos (Equus caballus) da raça marajoara em conservação na Ilha de Marajó.
Non-minimal coupling of the Higgs boson to curvature in an inflationary universe
In the absence of new physics around 10^10 GeV, the electroweak vacuum is at best metastable. This represents a major challenge for high scale in ationary models as, during the early rapid expansion of the universe, it seems difficult to understand how the Higgs vacuum would not decay to the true lower vacuum of the theory with catas- trophic consequences if inflation took place at a scale above 10^10 GeV. In this paper we show that the non-minimal coupling of the Higgs boson to curvature could solve this problem by generating a direct coupling of the Higgs boson to the inflationary potential thereby stabilizing the electroweak vacuum. For specific values of the Higgs field initial condition and of its non-minimal coupling, inflation can drive the Higgs field to the electroweak vacuum quickly during inflation
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