980 resultados para Gravity and Anharmonicity
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Two experiments were carried out to study the effect of breeder age on incubation parameters (hatchability, eggshell thickness, egg surface temperature and chick weight). In Exp. 1, fertile eggs (30- and 60-wk-old breeders) were incubated at three different temperatures (36.8, 37.8 and 38.8 ºC). Eggshell surface temperature was measured by attaching a thermocouple to the shell and data were collected in a datalogger every ten minutes. This study was conducted according to a 3 x 2 factorial design (three temperatures and two breeder ages). Data revealed that eggshell surface temperature changed according to incubation temperature, with the main increase occurring between 10 and 13 days of incubation, and that the maximum increase in eggshell surface temperature was not higher than +0.6 ºC, irrespective of incubator temperature. The incubator temperature affected total incubation period and hatchability (%) at 38.8 ºC, independent of breeder age. Heavier eggs resulted in heavier chicks, irrespective of incubator temperature. In Exp 2, the eggs (30- and 60-wk-old breeders) were incubated at 37.8 ºC and eggs characteristics (weight, specific gravity, total hatchability and chicks weight) were evaluated according to a randomized experimental design. The data showed that breeder age affected eggshell thickness and chick weight (heavier eggs resulted in heavier chicks), but not specific gravity, eggshell surface temperature or hatchability. The findings of this study revealed that hatchability can be influenced by incubation temperature, but not by the breeder age. Breeder age can affect eggshell thickness, egg weight and eggshell surface temperature, but not specific gravity.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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An experiment was conduced to evaluate the inclusion of sunflower meal (SBM) in commercial layer diets formulated on total or digestible amino acids basis. One hundred forty-four 41-week-old Lohmann LSL layers were distributed in a completely randomized experimental design in a 2 x 4 factorial arrangement with three replications of six birds each. Treatments consisted of a combination of four SBM inclusion levels SBM(0%, 4%, 8%, and 12%) and feed formulation according two amino acid recommendations (total or digestible). The experimental period was divided into five periods of fourteen days. Performance parameters (egg production, feed intake, feed conversion, egg mass) were evaluated for each period. In the last two days of each period, three eggs per replication were collected to evaluate egg quality (Haugh units, specific gravity, egg weight, eggshell thickness, and eggshell percentage). Hens fed on total amino acid recommendation presented the highest values for egg weight. Diets formulated on digestible amino acids basis showed an improvement in eggshell percentage and egg specific gravity. SBM addition in commercial layer diets did not influence performance; however, increasing SBM dietary levels SBM improved eggshell quality.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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An experiment was conducted to evaluate different commercial laying hen diets formulated based on recommendations for total and digestible amino acids. One hundred and twenty Lohmann LSL commercial laying hens aged 25 weeks were distributed in a completely randomized experimental design involving five replications of six birds in four treatments. Diet formulation on a total amino acid basis followed the recommendations of NRC (1994) and Rostagno et al. (2000), whereas formulation on digestible amino acids basis was according to Rostagno et al. (2000) and Degussa (1997) recommendations. The experimental period was divided into five periods of fourteen days. Performance parameters (egg production, feed intake, feed conversion, egg mass) were evaluated for each period, and on the last two days of each period, three eggs per replication were collected to evaluate egg quality parameters (Haugh unit, egg specific gravity, egg weight, eggshell thickness and percentage). Means were compared by orthogonal contrasts. Results on feed intake, egg production, egg mass, feed conversion and egg specific gravity showed that total amino acid recommendations promoted better bird responses than digestible amino acid recommendations.
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This paper proposes a different experimental setup compared with the traditional ones, in order to determine the acceleration of gravity, which is carried out by using a fluid at a constant rotation. A computerized rotational system-by using a data acquisition system with specific software, a power amplifier and a rotary motion sensor-is employed in order to evaluate the angular velocity and g. An equation to determine g is inferred from fluid mechanics. For this purpose, the fluid's parabolic shape inside a cylindrical receptacle is considered using a rotational movement.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The rotational motion of an artificial satellite is studied by considering torques produced by gravity gradient and direct solar radiation pressure. A satellite of circular cylinder shape is considered here, and Andoyers variables are used to describe the rotational motion. Expressions for direct solar radiation torque are derived. When the earth's shadow is not considered, an analytical solution is obtained using Lagrange's method of variation of parameters. A semi-analytical procedure is proposed to predict the satellite's attitude under the influence of the earth's shadow. The analytical solution shows that angular variables are linear and periodic functions of time while their conjugates suffer only periodic variations. When compared, numerical and analytical solutions have a good agreement during the time range considered.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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A ingestão de substâncias cáusticas constitui importante situação de emergência, tendo em vista a gravidade de suas seqüelas. OBJETIVO: Estudar as alterações morfológicas e funcionais do esôfago de coelhos submetidos à infusão esofágica com soda cáustica (NaOH). MÉTODOS: 88 coelhos foram divididos em 4 grupos: G1 (n=22) foi submetido à infusão esofágica com água destilada; G2, G3 e G4 foram submetidos a infusão esofágica com NaOH a 2%, 4% e 6%, respectivamente. Alterações morfológicas foram estudadas em 12 animais de cada grupo e as alterações manométricas, nos 10 animais restantes. Foram feitas análises do esfíncter inferior do esôfago (EIE), número e amplitude das contrações no terço distal do esôfago. Estes estudos foram realizados antes (momento 1 - M1) e aos 30 minutos, 6 horas e 24 horas após a infusão esofágica (momentos M2, M3 e M4, respectivamente). RESULTADOS: Avaliação macroscópica: G1 - sem alterações; G2 - edema, hiperemia e descamação; G3 - aumento do calibre do esôfago, úlceras, descamação da mucosa; G4 - lesões semelhantes as do G3, porém mais intensas, áreas de extensa hemorragia. Avaliação funcional: a pressão no EIE foi mais elevada em M2 no grupo 2; o número das contrações no terço distal do esôfago foi menor em G3 e G4, e a amplitude das contrações foi menor em G4. CONCLUSÕES: 1) a infusão esofágica com NaOH constitui excelente modelo experimental de esofagite cáustica no coelho; 2) a infusão esofágica com NaOH causa lesões na parede do esôfago, com gravidade proporcional a concentração da solução; 3) a infusão causou espasmo do EIE em M2 e redução do número e amplitude das contrações no terço distal do esôfago.
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This study aimed at verifying the possibility of replacing calcitic limestone by marine calcium in the diet of layers. A total number of 321 Hi-sex hens, with 40 weeks of age at the beginning of the experiment, was used. A completely randomized experimental design was applied, with 5 treatments (0, 15, 30, 45, and 60 % of calcitic limestone replacement by marine calcium source) and eight replicates of eight birds each. Treatments significantly affected specific gravity (p<0.05), with the inclusion of 60% marine calcium (T5) presenting the worst result as compared to T1, which included only calcitic limestone as calcium source. It was concluded that marine calcium can replace up to 45% of calcitic limestone with no effects on performance or egg quality.
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A total number of 720 Japanese quail females, reared under identical management conditions, and receiving feed and water ad libitum, was used. Quails were housed and reared from 1-35 days of age in litter pens in a rearing house, and then were transferred to a quail layer house. This study aimed at verifying if different beak trimming method could optimize egg production and quality by reducing stress and cannibalism among birds. A completely randomized experimental design was used, with six treatments in a 2x3 factorial arrangement, with two beak trimming ages (14 and 21 days) and three beak trimming variants (non-trimmed, 1/3 of the beak trimmed, or 1/2 of the beak trimmed), 6 replicates of 20 birds each. Performance was evaluated by feed intake, percentage of lay, egg mass, feed conversion ratio per dozen and per kg eggs, and mortality. Performance was influenced by trimming variant, with the best results obtained by birds with intact and those with 1/3 of the beak trimmed. Better specific gravity was in quails submitted to beak trimming at 21 days of age, whereas other egg quality parameters did not present significant results. Based the results obtained in the present study, it is recommended to submit to beak trimming either at 14 or 21 days of age.
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The goals of this study were to evaluate techniques for collection of peritoneal fluid from calves, establish reference ranges for fibrinogen in peritoneal fluid during the 1st month of life, and determine if abomasal puncture would alter peritoneal fluid or hematologic variables. Twenty-two healthy Holstein calves underwent 3 peritoneal fluid collections on day 1, day 15, and day 30 of age. Fibrinogen concentration in peritoneal fluid was 0.20 g/dL and 0.10 g/dL (P < .05) for day 1 and day 30, respectively, and 0.10 at day 15 (P > .05) for calves without abomasal puncture. Plasma fibrinogen concentration was 0.60 g/dL and 0.70 g/dL (P < .05) for days 15 and 30, respectively, in calves without abomasal puncture. There were no significant differences (P <= .05) in peritoneal fluid and peripheral blood total protein and fibrinogen concentrations, specific gravity, total and differential cell count, or erythrocyte counts between calves with or without abomasal puncture. We concluded that the reference ranges established for fibrinogen and total protein concentration are important for accurate evaluation of peritoneal fluid in calves for further comparison with similar-aged animals with gastrointestinal-tract or abdominal-cavity disease. Additionally, accidental abomasal puncture does not alter values of fibrinogen, total protein, and nucleated cell Count in peritoneal fluid and does not cause apparent clinical abnormalities.
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Legume pulvini have a clearly delimited endodermis, whose variable content has been associated with the velocity and type of leaf movement: pulvini in leaves with fast nastic movement contain starch grains; pulvini in leaves with slow nastic movements have calcium oxalate crystals as well as starch grains in the endodermis. However, the studies carried out to date have involved few legume species. This study therefore purported to examine the consistency of this hypothesis in other legumes. Thus, the structure and content of the pulvinus endodermal cells of nine legumes of the Brazilian cerrado, with different types and velocities of leaf movement, were investigated: slow nyctinastic and heliotropic movements (Bauhinia rufa, Copaifera langsdorffii, Senna rugosa - Caesalpinioideae; Andira humilis and Dalbergia miscolobium - Faboideae; Stryphnodendron polyphyllum - Mimosoideae), slow heliotropic movement (Zornia diphylla - Faboideae), and fast seismonastic and slow nyctinastic and heliotropic movements (Mimosa rixosa and Mimosa flexuosa - Mimosoideae). Samples were prepared following standard plant anatomy and ultrastructure techniques. The endodermis of all the species contains starch grains. In the species displaying only slow movements, calcium oxalate prismatic crystals were observed in addition to starch grains, except in Zornia diphylla. in conclusion, oxalate crystals occur only in endodermal cells of pulvini that display slow movements, while starch grains are always present in pulvinus endodermal cells of plants with any kind of movement.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)