RESUMO
Magnetars are strongly magnetized, isolated neutron stars1-3 with magnetic fields up to around 1015 gauss, luminosities of approximately 1031-1036 ergs per second and rotation periods of about 0.3-12.0 s. Very energetic giant flares from galactic magnetars (peak luminosities of 1044-1047 ergs per second, lasting approximately 0.1 s) have been detected in hard X-rays and soft γ-rays4, and only one has been detected from outside our galaxy5. During such giant flares, quasi-periodic oscillations (QPOs) with low (less than 150 hertz) and high (greater than 500 hertz) frequencies have been observed6-9, but their statistical significance has been questioned10. High-frequency QPOs have been seen only during the tail phase of the flare9. Here we report the observation of two broad QPOs at approximately 2,132 hertz and 4,250 hertz in the main peak of a giant γ-ray flare11 in the direction of the NGC 253 galaxy12-17, disappearing after 3.5 milliseconds. The flare was detected on 15 April 2020 by the Atmosphere-Space Interactions Monitor instrument18,19 aboard the International Space Station, which was the only instrument that recorded the main burst phase (0.8-3.2 milliseconds) in the full energy range (50 × 103 to 40 × 106 electronvolts) without suffering from saturation effects such as deadtime and pile-up. Along with sudden spectral variations, these extremely high-frequency oscillations in the burst peak are a crucial component that will aid our understanding of magnetar giant flares.
Assuntos
Astros Celestes , AtmosferaRESUMO
Eight postpubertal Holstein heifers (455 +/- 4.0), fit with rumen cannulas, were used in 2 experiments to investigate the effects of altering dietary protein type on nutrient digestibility, rumen fermentation, and nitrogen utilization. Heifers were fed diets containing low or high levels of soluble (SP) and low or high levels of rumen-undegradable protein (RUP) in a 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. The treatment rations in experiment 1 were formulated with corn silage composing the majority of the forage fraction, whereas in experiment 2, grass hay composed the highest proportion of ration DM. Blood and rumen samples were collected over 2 d and total fecal and urine collections were conducted for 4 d. Dry matter, organic matter, and neutral detergent fiber digestibility were not different in either experiment 1 or 2. Increasing the proportion of dietary crude protein that was SP increased mean daily rumen ammonia concentrations in each experiment, although no other rumen parameter differed. Excretion of urinary nitrogen in experiment 1 was highest for diets with low SP and low RUP and with high SP and high RUP, which resulted in these rations being the least efficient in retention of apparently digested nitrogen. The proportion of consumed or absorbed nitrogen retained in experiment 2 was not significantly different between treatments. Responses to alterations in crude protein degradability are observable in postpubertal heifers; however, the level of response may depend on the diet in which protein degradability is altered.
Assuntos
Bovinos/fisiologia , Proteínas Alimentares/administração & dosagem , Rúmen/metabolismo , Maturidade Sexual , Amônia/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos/crescimento & desenvolvimento , Digestão , Feminino , Fermentação , Nitrogênio/metabolismo , Poaceae , Rúmen/química , Silagem , Solubilidade , Zea maysRESUMO
OBJECTIVE: To determine a method for comparing counts of Streptococcus uberis in sand and sawdust and account for the influence of weight or volume of the bedding material. SAMPLE POPULATION: 2 sources of kiln-dried sawdust and 2 sources of washed sand. PROCEDURES: Sterilized bedding material (100 ml) was weighed and uniformly distributed in an aluminum pan. Each sterilized bedding material was inoculated with a mean of 3.6 X 10(6) (experiment 1) or 2.4 X 10(7) (experiment 2) colony-forming units (CFU) of S uberis/ml of bedding material. Without allowing time for replication of S uberis, inoculated bedding materials were washed with sterile saline (0.9% NaCl) solution. A 200-ml aliquot of wash solution was serially diluted up to 2,500 times with additional saline solution and inoculated on plates containing tryptose agar with 5% sheep blood. After incubation for 48 hours, number of CFU of S uberis was counted. This procedure was replicated 19 and 16 times for each bedding material in experiments 1 and 2, respectively. RESULTS: Evaluation of Bonferroni 95% confidence intervals revealed significant differences for counts of S uberis calculated on a weight basis between sand and sawdust. CONCLUSIONS AND CLINICAL RELEVANCE: Comparison of counts of S uberis determined on a volume basis for sand and sawdust accentuates to a lesser degree the weight difference of the bedding materials and ensures a more appropriate comparison of number of S uberis.
Assuntos
Reservatórios de Doenças/veterinária , Abrigo para Animais , Streptococcus/crescimento & desenvolvimento , Animais , Contagem de Colônia Microbiana/veterinária , Poeira , Dióxido de Silício , Streptococcus/isolamento & purificação , MadeiraRESUMO
College students (20 Latin American exchange students, 18 Asian exchange students, and 20 students born in the United States) participated in a study of the effects of culture on attitudes and perceptions of spousal abuse. Subjects completed a 23-item questionnaire developed to ascertain subjects' attitudes about spousal abuse, retaliatory behaviors, and the legal implications of those behaviors. Analyses showed many significant differences in attitudes towards and perceptions of spousal abuse. This suggests that attitudes and perceptions of spousal abuse are culturally related.
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Asiático/psicologia , Atitude , Comparação Transcultural , Hispânico ou Latino/psicologia , Maus-Tratos Conjugais/psicologia , População Branca/psicologia , Adulto , Diversidade Cultural , Feminino , Humanos , Masculino , Maus-Tratos Conjugais/etnologia , Estudantes/psicologiaAssuntos
Peso ao Nascer , Fenômenos Fisiológicos da Nutrição do Lactente , Equilíbrio Ácido-Base , Glicemia/análise , Estatura , Cálcio/sangue , Dióxido de Carbono/sangue , Desenvolvimento Embrionário e Fetal , Epinefrina/farmacologia , Feminino , Idade Gestacional , Glucagon/farmacologia , Humanos , Hipoglicemia/etiologia , Recém-Nascido , Recém-Nascido Prematuro , Magnésio/sangue , Masculino , Fatores SexuaisRESUMO
BACKGROUND: Allergic diseases have become a major public health problem in developed countries; yet, no reliable, safe and consistently effective treatment is available. DNA immunization has been shown to prevent and balance established allergic responses, however, the high dose of conventional DNA vaccines necessary for the induction of anti-allergic reactions and their poor immunogenicity in primates require the development of new allergy DNA vaccines. We evaluated protective and therapeutic effects of a Semliki-Forest Virus replicase-based vs a conventional DNA vaccine in BALB/c mice using the model allergen beta-galactosidase. METHODS: Immunoglobulin (Ig)E suppression was determined by a basophil release assay as an in vitro correlate for allergen-specific crosslinking capacity of IgE reflecting the in vivo situation in an allergic individual. Th1 memory responses were measured by cytokine detection via enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot assay (ELISPOT). RESULTS: Nanogram amounts of a replicase-based vector triggered a Th1 response comparable with that achieved with the injection of 20,000-times more copies of a conventional DNA plasmid, and induced IgE suppression in both a protective and a therapeutic setting. CONCLUSIONS: Replicase-based DNA vaccines fulfill the stringent criteria for an allergy DNA vaccine, i.e. low dose, strong Th1 immunogenicity and memory, lack of 'therapy-induced' IgE production and anaphylactic side effects. Moreover, by triggering apoptosis in transfected cells, their unique 'immunize and disappear' feature minimizes the hypothetical risks of genomic integration or induction of autoimmunity.
Assuntos
Hipersensibilidade Imediata/prevenção & controle , Vacinas de DNA , Alérgenos/imunologia , Animais , Basófilos/imunologia , Linhagem Celular Tumoral , Cricetinae , Citocinas/imunologia , Feminino , Imunoglobulina G/sangue , Interferon gama/deficiência , Interferon gama/genética , Subunidade p40 da Interleucina-12/deficiência , Subunidade p40 da Interleucina-12/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Ratos , Replicon , Baço/citologia , Baço/imunologia , Células Th1/imunologia , beta-Galactosidase/imunologiaRESUMO
The fungus Fusarium oxysporum produced a D-amino acid oxidase (EC 1. 4.3.3) in a medium containing glucose as the carbon and energy source and ammonium sulfate as the nitrogen source. The specific D-amino acid oxidase activity was increased up to 12.5-fold with various D-amino acids or their corresponding derivatives as inducers. The best inducers were D-alanine (2.7 microkat/g of dry biomass) and D-3-aminobutyric acid (2.6 microkat/g of dry biomass). The addition of zinc ions was necessary to permit the induction of peroxisomal D-amino acid oxidase. Bioreactor cultivations were performed on a 50-liter scale, yielding a volumetric D-amino acid oxidase activity of 17 microkat liter(-1) with D-alanine as an inducer. Under oxygen limitation, the volumetric activity was increased threefold to 54 microkat liter(-1) (3,240 U liter(-1)).
Assuntos
D-Aminoácido Oxidase/biossíntese , Fusarium/enzimologia , Reatores Biológicos , Biotecnologia , OxigênioRESUMO
Four prepubertal Holstein heifers, average age 184 +/- 2.1 d and 169.1 +/- 15.8 kg of body weight, fitted with rumen cannulae were used to evaluate effects of altering the soluble CP and potentially rumen degradable protein fractions of diets containing 16% CP and 71.5% TDN. Parameters studied included rumen ammonia, volatile fatty acid production, N balance, total tract apparent digestibility, and urinary excretion of purine derivatives in a 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. Heifers were fed treatment rations containing 62.1 +/- 0.8 g CP/Mcal ME at 2.0% BW with altered soluble CP fractions (AB1) (33.6 or 40.6% of CP) and potentially rumen degradable protein fractions (B2B3) (20.9 or 28.2% of CP). Increased intake of AB1 increased rumen ammonia and decreased total volatile fatty acid concentrations with molar proportions of isovalerate and isobutyrate decreased. Increased intake of B2B3 tended to increase volatile fatty acid concentrations, increased molar proportions of propionate, and decreased the acetate to propionate ratio. Nitrogen utilization was not affected by increased intake of AB1 or B2B3, although increased intake of AB1 tended to increase urine urea excretion. Increasing solubility (40.6 versus 33.6% AB1) of dietary CP when feeding a 16% CP and 71.5% TDN ration, decreased total volatile fatty acid concentrations and molar proportions of isovalerate and isobutyrate. Feeding 62.1 +/- 0.8 g CP/Mcal ME with increased potentially rumen degradable protein (28.2 versus 20.9% B2BS) at 2.0% BW affected rumen fermentation but did not affect DM digestibility or N utilization.
Assuntos
Bovinos/crescimento & desenvolvimento , Dieta , Proteínas Alimentares/administração & dosagem , Proteínas Alimentares/metabolismo , Rúmen/metabolismo , Acetatos/análise , Alantoína/urina , Amônia/análise , Amônia/urina , Animais , Butiratos/análise , Digestão , Ácidos Graxos Voláteis/metabolismo , Feminino , Fermentação , Hemiterpenos , Concentração de Íons de Hidrogênio , Isobutiratos , Nitrogênio/metabolismo , Ácidos Pentanoicos/análise , Propionatos/análise , Purinas/urina , Maturidade Sexual , Solubilidade , Ureia/urina , Ácido Úrico/urinaRESUMO
Four prepubertal Holstein heifers, average age 146.0 +/- 3.6 d and 152.8 +/- 8.6 kg of body weight (BW), fitted with rumen cannulae were used to evaluate increasing levels of dietary protein with a constant metabolizable energy intake on rumen ammonia N concentrations, N balance, total tract apparent digestibility, and urinary excretion of purine derivatives in a 4 x 4 Latin square design with 20 d periods. Heifers were fed dietary crude protein levels (CP) of 11.9, 16.7, 18.1, and 20.1% CP with similar amounts of metabolizable energy (ME) (2.6 Mcal per kg of dry matter) at 2.0% BW as dry matter intake. Resulting protein to ME ratios (CP:ME) were 45.0, 63.3, 69.4, and 77.3 g of dietary CP per Mcal of ME. Rumen ammonia N and plasma urea nitrogen increased as CP level increased. Rumen pH, volatile fatty acids, and the acetate-to-propionate ratio were not affected with increasing CP levels. Greater urinary N excretion resulted in an increase in total N excretion with increasing CP levels. Apparent dry matter digestibility was similar for all diets, while apparent total tract N digestibility was lowest for the 11.9% CP level. Microbial N calculated from urinary excretion of purine derivatives increased with increasing CP levels. Holstein heifers between 153 and 196 kg consuming a diet at 2.0% BW as dry matter intake containing a CP level of 16.7% achieved a better synergistic relationship of dietary protein to energy (CP:ME of 63.3 g of CP per Mcal of ME) than the diets lower or higher in CP that were studied.
Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Bovinos/fisiologia , Proteínas Alimentares/administração & dosagem , Acetatos/análise , Amônia/análise , Animais , Nitrogênio da Ureia Sanguínea , Digestão , Ingestão de Energia , Ácidos Graxos Voláteis/análise , Feminino , Concentração de Íons de Hidrogênio , Nitrogênio/análise , Nitrogênio/metabolismo , Propionatos/análise , Rúmen/químicaRESUMO
Sixty Holstein heifers, 124.5 +/- 1.1 d of age and 124.9 +/- 2.5 kg of BW, were used to evaluate the influence of dietary crude protein to metabolizable energy ratio (CP:ME) on feed efficiency, structural growth, and body condition score. Treatment rations containing a specific CP:ME ratio were assigned to heifers in a complete randomized block design with treatment periods lasting 20 wk. The CP:ME ratios were 48.3, 59.1, 67.5, and 76.5 g of CP per Mcal of ME. The CP:ME ratios were altered by adjusting the concentration of CP (12.0,15.2, 17.4, and 19.7% CP) with similar amounts of ME (2.6 Mcal/kg DM) across all treatment rations. BW was recorded weekly on two consecutive days and used to adjust dry matter intake to allow approximately 0.80 kg/d gain. Average daily gain did not differ between the treatment rations, 0.74, 0.81, 0.81, 0.77 kg/d, low to highest CP:ME ratio, respectively. Dry matter intake showed a quadratic effect for the treatment rations, 3.30, 3.41, 3.48, and 3.39 kg/d, low to highest CP:ME ratio, respectively, and averaged 2.0% BW. Feed efficiency improved linearly with increasing CP:ME ratios, 4.76, 4.42, 4.35, and 4.33, respectively. The increased CP:ME ratios were accompanied by increasing levels of plasma urea N, 9.88, 13.34, 14.94, and 16.57 mg/dl, respectively. A trend toward linear increases in wither and hip height growth resulted with increasing CP:ME. Hip width growth was quadratic with increasing CP:ME ratios. Observed linear effects in feed efficiency and some structural growth measurements demonstrate positive results when feeding CP:ME ratios >48.3 to Holstein heifers between 125 and 234 kg of BW and gaining 0.80 kg/d.
Assuntos
Bovinos/crescimento & desenvolvimento , Proteínas Alimentares/administração & dosagem , Ingestão de Energia , Metabolismo Energético/fisiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Nitrogênio da Ureia Sanguínea , Constituição Corporal , Estatura , Proteínas Alimentares/metabolismo , Relação Dose-Resposta a Droga , Feminino , Distribuição Aleatória , Aumento de Peso/efeitos dos fármacosRESUMO
Dairy operations have a variety of resources and objectives, such that the most economical method of obtaining replacement heifers is only determined by individual analysis of costs. The objective of this study was the development of a cost analysis spreadsheet and validation of that spreadsheet on milking and custom heifer operations throughout Pennsylvania. A cost analysis spreadsheet was developed with an Excel '97 Microsoft file. The spreadsheet estimated the costs to raise a replacement heifer by specific age classes for feed, labor, health, reproduction, bedding, facilities, equipment, mortality, and interest costs. The simplistic and broad-based nature of the spreadsheet was a key component in the spreadsheet's flexibility to estimate costs for a variety of operational objectives, feeding management, housing systems, and labor management. A convenience sample of 16 milking operations and 14 custom heifer operations was evaluated to validate the cost analysis spreadsheet. Results from the validation are discussed to highlight the success and performance of the cost analysis spreadsheet. The average total cost to raise a replacement heifer for this data set was $1124.06 and $1019.20 for milking and custom heifer operations, respectively. Feed costs contributed 60.3 and 64.0% of the average total cost for milking and custom heifer operations, respectively. While no two operations are alike, individual operations possessing the ability to address costs to raise a replacement heifer can utilize critical information that can be used to improve operation profitability.
Assuntos
Bovinos/crescimento & desenvolvimento , Custos e Análise de Custo , Indústria de Laticínios/economia , Software , Envelhecimento , Animais , Feminino , Lactação , DesmameRESUMO
Yeast (Saccharomyces cerevisiae) culture was added to a texturized calf starter at 0 (control), 1, or 2% of dry matter to determine effects on intake, growth, blood parameters, and rumen development. Seventy-five Holstein calves (38 male; 37 female) were started on the experiment at 2 +/- 1 d of age and were studied for 42 d. Starter intake was measured, and fecal scoring was conducted daily. Growth and blood parameter measurements were recorded at weekly intervals. A subset of 6 male calves (2 per treatment) was euthanized at 5 wk of age, and rumen tissue was sampled for rumen epithelial growth measurements. An additional 6 male calves were euthanized at 6 wk of age for rumen epithelial growth measurements. Inclusion of yeast culture at 2% of the starter ration significantly increased starter and total dry matter intake, average daily gain, and daily hip width change when compared with the control treatment. Average daily gain was improved by 15.6% for the 2% yeast treatment. Daily change in hip height was also significantly greater for calves receiving 2% supplemental yeast culture than for calves receiving 1%. No significant treatment differences were observed for any other variables. These data suggest that the addition of yeast culture in a dairy calf starter at 2% enhances dry matter intake and growth and slightly improves rumen development in dairy calves.
Assuntos
Animais Recém-Nascidos/crescimento & desenvolvimento , Bovinos/crescimento & desenvolvimento , Rúmen/crescimento & desenvolvimento , Saccharomyces cerevisiae , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Animais Recém-Nascidos/sangue , Bovinos/sangue , Ingestão de Alimentos , Fezes/química , Fezes/microbiologia , Feminino , Masculino , Distribuição Aleatória , Rúmen/microbiologia , Aumento de PesoRESUMO
In order to screen for new microbial D-amino acid oxidase activities a selective and sensitive peroxidase/o-dianisidine assay, detecting the formation of hydrogen peroxide was developed. Catalase, which coexists with oxidases in the peroxisomes or the microsomes and, which competes with peroxidase for hydrogen peroxide, was completely inhibited by o-dianisidine up to a catalase activity of 500 nkat ml(-)(1). Thus, using the peroxidase/o-dianisidine assay and employing crude extracts of microorganisms in a microplate reader, a detection sensitivity for oxidase activity of 0.6 nkat ml(-)(1) was obtained.Wild type colonies which were grown on a selective medium containing D-alanine as carbon, energy and nitrogen source were examined for D-amino acid oxidase activity by the peroxidase/o-dianisidine assay. The oxidase positive colonies possessing an apparent oxidase activity > 2 nkat g dry biomass(-)(1) were isolated. Among them three new D-amino acid oxidase-producers were found and identified as Fusarium oxysporum, Verticilium lutealbum and Candida parapsilosis. The best new D-amino oxidase producer was the fungus F. oxysporum with a D-amino acid oxidase activity of about 900 nkat g dry biomass(-)(1) or 21 nkat mg protein(-)(1). With regard to the use as a biocatalytic tool in biotechnology the substrate specificities of the three new D-amino acid oxidases were compared with those of the known D-amino acid oxidases from Trigonopsis variabilis, Rhodotorula gracilis and pig kidney under the same conditions. All six D-amino acid oxidases accepted the D-enantiomers of alanine, valine, leucine, proline, phenylalanine, serine and glutamine as substrates and, except for the D-amino acid oxidase from V. luteoalbum, D-tryptophane, D-tyrosine, D-arginine and D-histidine were accepted as well. The relative highest activities (>95%) were measured versus D-alanine (C. parapsilosis, F. oxysporum, T. variabilis), D-methionine (V. luteoalbum, R. gracilis), D-valine (T. variabilis, R. gracilis) and D-proline (pig kidney). The D-amino oxidases from F. oxysporum and V. luteoalbum were able to react with the industrially important substrate cephalosporin C although the D-amino acid oxidase from T. variabilis was at least about 20-fold more active with this substrate.As the results of our studies, a reliable oxidase assay was developed, allowing high throughput screening in a microplate reader. Furthermore, three new microbial D-amino acid oxidase-producers with interesting broad substrate specificities were introduced in the field of biotechnology.
RESUMO
This study used magnetic resonance imaging to assess disk-condyle relationships before and after arthroscopic surgery. Disk positions relative to condyles were found to be generally unchanged, despite the greater range of opening. Clinical findings were positive symptomatic changes with improved interincisal openings in 11 of 12 patients (92%). The results suggest that the clinical success of arthroscopic surgery as a treatment modality does not occur as a result of disk repositioning or recapturing.