RESUMEN
It is widely believed that the mechanism for spin pumping in ferromagnet-nonmagnet bilayers is the exchange interaction between the ferromagnet and nonmagnetic material. We observe 1000-fold exponential decay of spin pumping from thin Y3Fe5O12 films to Pt across insulating barriers, from which exponential decay lengths of 0.16, 0.19, and 0.23 nm are extracted for oxide barriers having band gaps of 4.91, 3.40, and 2.36 eV, respectively. This archetypal signature of quantum tunneling through a barrier underscores the importance of exchange coupling for spin pumping and reveals its dependence on the characteristics of the barrier material.
RESUMEN
A 3-yr study utilized 300 Angus-based, spring-born heifers to evaluate postweaning heifer development systems on gain, reproductive performance, and feed efficiency as a pregnant heifer. Heifers were blocked by BW and randomly assigned to graze corn residue (CR), upland range (RANGE), or were fed 1 of 2 diets in a drylot differing in energy levels: high (DLHI) or low (DLLO). Heifers developed on DLHI and DLLO were managed within the drylot for 166 d in yr 1, 150 d in yr 2, and 162 d in yr 3. Heifers developed on RANGE grazed winter range for an equivalent amount of days each yr as the DLHI and DLLO heifers. Heifers assigned to CR grazed for 103 d in yr 1, 84 d in yr 2, and 97 d in yr 3 before being transported to graze winter range for the remainder of the treatment period. All heifers were managed as a single group following the treatment period. Artificial insemination and natural mating were utilized during breeding. Percent of mature BW prior to the breeding season was greater ( = 0.02) for DLHI (67%) compared with RANGE (59%) and CR (58%). Pregnancy rates to AI were not different ( = 0.51) among treatments (59 ± 6%), and final pregnancy rates were also not different (87 ± 4%, = 0.54). A subset of AI-pregnant heifers from each treatment were placed in a Calan gate feeding system. Heifers were allowed a 20-d acclimation period before beginning the 90 d trial at approximately 170 d in gestation. Heifers were offered ad libitum hay; amount offered was recorded daily and orts collected weekly. Initial BW was not different ( = 0.58) among treatments (459 ± 11 kg). Body weight at the end of the trial (497 ± 17 kg) was also not different ( = 0.41). Intake was not different ( = 0.33), either as DMI (10.00 ± 1.07 kg) or residual feed intake (0.018 ± 0.190). There was no difference in ADG ( = 0.36, 0.42 ± 0.23 kg/d) among treatments. Although the total development cost was not different among treatments ( = 0.99), there was a $41 difference ( < 0.01) between the mean of the most expensive diet (DLHI) and the mean of the two least expensive diets (CR and RANGE). Developing heifers to a greater prebreeding BW did not influence subsequent AI or overall pregnancy rates or feed efficiency as a pregnant heifer.
Asunto(s)
Alimentación Animal/análisis , Bovinos/fisiología , Ingestión de Alimentos/fisiología , Fenómenos Fisiologicos Nutricionales Maternos , Reproducción , Aclimatación , Alimentación Animal/economía , Crianza de Animales Domésticos/economía , Crianza de Animales Domésticos/métodos , Animales , Peso Corporal , Cruzamiento , Bovinos/crecimiento & desarrollo , Dieta/economía , Dieta/veterinaria , Femenino , Embarazo , Índice de Embarazo , Distribución Aleatoria , Estaciones del Año , Zea maysRESUMEN
A 3-yr study was conducted to determine the effect of supplemental protein source on ADG, feed intake, calf birth BW, and subsequent pregnancy rate in pregnant beef heifers. Crossbred, Angus-based, AI-pregnant heifers (yr 1, n = 38; yr 2, n = 40; and yr 3, n = 36) were stratified by BW (450 ± 10 kg) and placed in a Calan Broadbent individual feeding system at approximately d 142 of gestation. Following a 25-d adaptation period, an 84-d feeding trial was conducted. Heifers were offered ad libitum grass hay (8 to 11% CP, DM basis) and no supplement (CON), 0.83 kg/d distillers-based supplement (HI), or 0.83 kg/d dried corn gluten-based supplement (LO). Supplements were formulated to be isocaloric, isonitrogenous (28% CP, DM basis), and equal in lipid content but differed in RUP, with HI (59% RUP) having greater levels of RUP than LO (34% RUP). Dry matter intake was also calculated based on feed NE values to account for different energy levels of the supplement compared with the control diet. Control heifers tended (P = 0.09) to consume less total DM than either supplement treatment. However, forage-only DMI was greater (P < 0.01) for CON heifers (9.94 ± 0.12 kg) compared with HI or LO heifers (8.50 and 8.34 ± 0.12 kg, respectively). Net energy DMI was less (P < 0.01) for CON heifers (4.98 ± 0.23 kg) compared with HI or LO heifers (5.43 and 5.35 ± 0.23 kg, respectively). Control heifers gained less (P < 0.01; 0.59 ± 0.14 kg/d) than either HI (0.82 ± 0.14 kg/d) or LO heifers (0.78 ± 0.14 kg/d), resulting in lower (501 ± 9 kg) BW (P < 0.01) than HI (519 ± 9 kg) heifers at the end of the feeding period. Calf birth BW was similar (P = 0.99) among treatments. At prebreeding, CON heifers weighed less (P < 0.03) than LO heifers. Cow BW was similar (P = 0.48) among treatments at pregnancy diagnosis, and final pregnancy rate was also similar (87%; P = 0.22). Protein supplementation increased ADG in pregnant heifers; however, calf birth BW and subsequent pregnancy rates were similar.
Asunto(s)
Alimentación Animal , Animales Recién Nacidos/crecimiento & desarrollo , Peso al Nacer/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Bovinos/fisiología , Proteínas en la Dieta/farmacología , Ingestión de Alimentos/efectos de los fármacos , Preñez/efectos de los fármacos , Animales , Animales Recién Nacidos/fisiología , Peso al Nacer/fisiología , Peso Corporal/fisiología , Cruzamiento/métodos , Bovinos/crecimiento & desarrollo , Dieta/veterinaria , Suplementos Dietéticos , Ingestión de Alimentos/fisiología , Femenino , Masculino , Fenómenos Fisiologicos Nutricionales Maternos/fisiología , Paridad/efectos de los fármacos , Poaceae , Embarazo , Índice de Embarazo , Preñez/fisiología , Estaciones del Año , Zea maysRESUMEN
OBJECTIVE: Major pediatric textbooks advocate a chest radiograph as part of the diagnostic evaluation for a sepsis workup for febrile infants less than 3 months old. Very few studies have addressed the value of performing a chest radiograph in this situation. Two studies previously published lack the numbers to statistically justify a conclusion about the need to perform a chest radiograph in the febrile infant. METHODS: Evaluated were 197 febrile infants 3 months old or less with a history, physical examination, chest radiograph, and other laboratory studies to determine the cause of their fever. This group of infants was combined with the group of infants from two similar studies published previously in the literature using cumulative meta-analysis. The combined group resulted in 617 infants. RESULTS: The combined group of infants had 361 infants who had no clinical evidence of pulmonary disease on history or physical examination. All 361 infants had normal chest radiograph. These results gave a 95% confidence interval that the chance of a positive chest radiograph in a patient with no pulmonary symptoms would occur less than 1.02% of the time. CONCLUSIONS: The generally advocated policy of obtaining a chest radiograph as part of the sepsis workup in febrile infants should be discontinued, and chest radiographs should be obtained only in febrile infants who have clinical indications of pulmonary disease.
Asunto(s)
Fiebre de Origen Desconocido/etiología , Pulmón/diagnóstico por imagen , Infecciones del Sistema Respiratorio/epidemiología , Fiebre de Origen Desconocido/epidemiología , Humanos , Lactante , Valor Predictivo de las Pruebas , Probabilidad , Radiografía , Infecciones del Sistema Respiratorio/diagnóstico por imagenRESUMEN
We present a 54-year-old male heart transplant recipient who developed mediastinitis caused by Klebsiella oxytoca and Veillonella species. Culture of the donor's bronchus also grew K. oxytoca and a Veillonella species. Pulsed-field gel electrophoresis revealed that the K. oxytoca isolates had identical banding patterns. This case illustrates transmission of pathogenic bacteria via a contaminated organ.
Asunto(s)
Trasplante de Corazón/efectos adversos , Infecciones por Klebsiella/transmisión , Mediastinitis/microbiología , Humanos , Klebsiella/patogenicidad , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/microbiología , Donantes de Tejidos , Veillonella/patogenicidadRESUMEN
An experiment was conducted to investigate the influence of Captain's Log (a computerized cognitive-training system) on the behaviors and performance capabilities of 4 severely emotionally disturbed children with Attention Deficit Hyperactivity Disorder (ADHD), ages 7 to 11. Behavioral scales, spectral electroencephalograms, and intelligence and performance tests were assessed pre- and posttreatment. A behavioral point system and monitoring of progress on computer tasks were used throughout treatment to evaluate ongoing improvements. There were 64 training sessions administered over a 16-week period. Outcome of treatment was determined by computer advancement, changes in behavioral points, and pre- and postmeasures. Results support the expectation that children who were most successful in the training would demonstrate the highest levels of generalization of those skills that were the focus of treatment.
Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/terapia , Terapia Conductista , Instrucción por Computador , Educación Especial , Niño , Terapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Masculino , Tratamiento Domiciliario , Programas Informáticos , Resultado del TratamientoRESUMEN
Records collected between 1997 and 2010 were used to determine the effect of calving period on heifer (n = 1,019) and steer (n = 771) progeny from the Gudmundsen Sandhills Laboratory, Whitman, NE. Progeny were classified as being born in the first, second, or third 21-d period of the spring calving season within year. Heifer birth BW was lightest (P < 0.01) for heifers born in the first period. Birth to weaning ADG tended (P = 0.10) to be least for heifers born in the first calving period; however, weaning BW decreased (P = 0.03) with advancing calving period. Weaning to prebreeding ADG tended (P = 0.07) to be least for heifers born in the first period; however, prebreeding BW was greatest (P < 0.01) for calves born in the first period. Heifer ADG from the beginning of the breeding season to pregnancy diagnosis was greater (P = 0.03) for heifers born in the third vs. first calving period. Heifers cycling at the beginning of the breeding season decreased (P < 0.01) with advancing calving date (70, 58, and 39%, respectively) and 45 d pregnancy rates were lowest (P = 0.02) for heifers born in the third calving period (90, 86, and 78%, respectively). Birth date of the first calf of the heifer and birth BW decreased (P < 0.01) if the heifer was born in the first calving period. First calf progeny had the greatest (P ≤ 0.10) weaning BW if born to a heifer born in the first calving period. As steer calving period advanced, weaning BW decreased (P < 0.01). Calving period did not affect (P = 0.81) feedlot ADG. As calving period advanced, HCW, marbling score, and yield grade decreased (P < 0.01). The percentage of steers grading USDA small marbling was not affected (P = 0.13) by calving period; however, the percentage of steers grading USDA modest marbling or greater and the total carcass value declined (P ≤ 0.01) as calving period advanced. Heifer calves born during the first 21 d of the spring calving season had greater weaning, prebreeding, and precalving BW; greater percent cycling before breeding; and greater pregnancy rates compared with heifers born in the third period. First calf progeny also had an earlier birth date and greater weaning BW. Steer calves born during the first 21 d of the calving season had greater weaning, final, and carcass weights; greater marbling scores; a greater percentage grading USDA modest or greater; and greater carcass value. Calving period of progeny significantly impacts performance.
Asunto(s)
Bovinos/crecimiento & desarrollo , Destete , Aumento de Peso , Crianza de Animales Domésticos , Animales , Bovinos/fisiología , Femenino , Masculino , Nebraska , Parto , Embarazo , Índice de Embarazo , Estaciones del Año , Factores de TiempoAsunto(s)
Lesiones de Codo , Nervio Mediano , Niño , Codo/cirugía , Femenino , Humanos , Luxaciones Articulares , MasculinoRESUMEN
The Stone bunionectomy is an oblique resection of the metatarsal head designed to preserve the weight-bearing margin of the metatarsal shaft. In 132 patients treated by the Stone operation, only 77 per cent were satisfied with the overall results and 19 per cent had persistent pain. In addition, only 69 per cent were considered by the authors to have had an excellent result. These results do not compare favorably with those reported for the Keller procedure. Consequently, the Stone bunionectomy is not recommended.
Asunto(s)
Hallux Valgus/cirugía , Humanos , Métodos , Recurrencia , Cirugía Plástica , Articulación del Dedo del PieRESUMEN
Results of using the technique of the Association for the Study of Internal Fixation, when applied to fractures, include accurate anatomic reduction, secure fixation and allows early mobilization, resulting in rapid resumption of normal function. In a series of 71 (of 77) ankle fractures, followed for an average of 38 months, 93.5% had good or excellent clinical results.