Genetic and environmental contributions to hay fever among young adult twins

DEFF Research Database (Denmark)

Thomsen, Simon Francis; Suppli Ulrik, Charlotte; Kyvik, Kirsten Ohm

2006-01-01

environment, whereas the aetiology of 'sporadic' hay fever was mainly genetic. CONCLUSIONS: The susceptibility to develop hay fever is attributable to major genetic influences. However, effects of family environment and upbringing are also of importance in families where asthma is present. These results......BACKGROUND: The susceptibility to develop hay fever is putatively the result both of genetic and environmental causes. We estimated the significance and magnitude of genetic and environmental contributions to hay fever among young adult twins. METHODS: From the birth cohorts 1953-82 of The Danish...... effects accounted for 29% of the individual susceptibility to hay fever. The same genes contributed to the susceptibility to hay fever both in males and in females. In families with asthma, the susceptibility to develop hay fever was, in addition to genes, to a great extent ascribable to family...

Early archosauromorph remains from the Permo-Triassic Buena Vista Formation of north-eastern Uruguay

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Martín D. Ezcurra

2015-02-01

Full Text Available The Permo-Triassic archosauromorph record is crucial to understand the impact of the Permo-Triassic mass extinction on the early evolution of the group and its subsequent dominance in Mesozoic terrestrial ecosystems. However, the Permo-Triassic archosauromorph record is still very poor in most continents and hampers the identification of global macroevolutionary patterns. Here we describe cranial and postcranial bones from the Permo-Triassic Buena Vista Formation of northeastern Uruguay that contribute to increase the meagre early archosauromorph record from South America. A basioccipital fused to both partial exoccipitals and three cervical vertebrae are assigned to Archosauromorpha based on apomorphies or a unique combination of characters. The archosauromorph remains of the Buena Vista Formation probably represent a multi-taxonomic assemblage composed of non-archosauriform archosauromorphs and a ‘proterosuchid-grade’ animal. This assemblage does not contribute in the discussion of a Late Permian or Early Triassic age for the Buena Vista Formation, but reinforces the broad palaeobiogeographic distribution of ‘proterosuchid grade’ diapsids in Permo-Triassic beds worldwide.

The HayWired Earthquake Scenario

Science.gov (United States)

Detweiler, Shane T.; Wein, Anne M.

2017-04-24

ForewordThe 1906 Great San Francisco earthquake (magnitude 7.8) and the 1989 Loma Prieta earthquake (magnitude 6.9) each motivated residents of the San Francisco Bay region to build countermeasures to earthquakes into the fabric of the region. Since Loma Prieta, bay-region communities, governments, and utilities have invested tens of billions of dollars in seismic upgrades and retrofits and replacements of older buildings and infrastructure. Innovation and state-of-the-art engineering, informed by science, including novel seismic-hazard assessments, have been applied to the challenge of increasing seismic resilience throughout the bay region. However, as long as people live and work in seismically vulnerable buildings or rely on seismically vulnerable transportation and utilities, more work remains to be done.With that in mind, the U.S. Geological Survey (USGS) and its partners developed the HayWired scenario as a tool to enable further actions that can change the outcome when the next major earthquake strikes. By illuminating the likely impacts to the present-day built environment, well-constructed scenarios can and have spurred officials and citizens to take steps that change the outcomes the scenario describes, whether used to guide more realistic response and recovery exercises or to launch mitigation measures that will reduce future risk.The HayWired scenario is the latest in a series of like-minded efforts to bring a special focus onto the impacts that could occur when the Hayward Fault again ruptures through the east side of the San Francisco Bay region as it last did in 1868. Cities in the east bay along the Richmond, Oakland, and Fremont corridor would be hit hardest by earthquake ground shaking, surface fault rupture, aftershocks, and fault afterslip, but the impacts would reach throughout the bay region and far beyond. The HayWired scenario name reflects our increased reliance on the Internet and telecommunications and also alludes to the

EL BIENESTAR SUBJETIVO ANTE LAS BUENAS PRÁCTICAS EDUCATIVAS CON TIC: SU INFLUENCIA EN PROFESORADO INNOVADOR

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Jesús Valverde Berrocoso

2013-01-01

Full Text Available El objetivo de este estudio, que forma parte de una investigación más amplia sobre la innovación educativa y la integración de las Tecnologías de la Información y la Comunicación (TIC en el aula [1], es conocer el grado de «bienestar subjetivo» autopercibido por profesorado innovador y asociado a su realización de «buenas prácticas educativas con TIC». El bienestar subjetivo es un concepto que se extrae de las percepciones de las personas sobre su existencia o su visión subjetiva de su experiencia vital y profesional. En una muestra de profesorado innovador (N=41 de centros educativos seleccionados por sus «buenas prácticas con TIC», se aplicó un cuestionario para medir qué motivaciones, emociones y competencias están presentes en una práctica innovadora con tecnologías, así como el grado de satisfacción personal y profesional logrado tras la aplicación de estas buenas prácticas. Los resultados revelan las motivaciones que mueven al profesorado a implicarse en actividades docentes innovadoras, las percepciones de satisfacción y las emociones en las que se fundamenta su grado de bienestar subjetivo vinculado con las buenas prácticas educativas con TIC. Las motivaciones que impulsan la innovación o las buenas prácticas educativas con TIC son de carácter práctico (mejora del trabajo docente y mayor interés del alumnado, ético (deber y responsabilidad de uso por parte del profesorado y personal (superación de retos para lograr una mayor competencia digital. El profesorado manifiesta mayoritariamente emociones positivas relacionadas con el uso educativo de las TIC (orgullo, satisfacción, autoestima, autoconfianza y felicidad, autopercepción de logro de metas profesionales y una mayor eficacia en su actividad docente. El profesorado percibe que sus buenas prácticas inciden en la actitud positiva de sus compañeros hacias las innovaciones con TIC, el apoyo del equipo directivo hacia estos proyectos y a una mayor

Lo que todos debemos saber de las buenas prácticas clínicas

OpenAIRE

Lyda Osorio

2015-01-01

Cada vez son más los países que adoptan las guías de buenas prácticas clínicas como parte de la reglamentación de los estudios clínicos para el registro de productos farmacéuticos y de otros relacionados con la salud. Por ello, todos los involucrados en la investigación y el desarrollo de dichos productos tienen la obligación de conocerlas, implementarlas y velar por su cumplimiento. Sin embargo, las buenas prácticas clínicas son solo una de las iniciativas que buscan alcanzar los más altos e...

Digestibility by lambs offered alfalfa hay treated with a propionic acid hay preservative and baled at different concentrations of moisture

Science.gov (United States)

Eighteen crossbred wether lambs (76.1 ± 8.18 lb initial BW) were used for a 2 period digestion study to evaluate the effect of hay preservative concentration (0, 0.56, or 0.98% buffered propionic acid) and hay moisture concentration at baling (19.6, 23.8, or 27.4% moisture) on digestibility of alfal...

Round-bale feeder design affects hay waste and economics during horse feeding.

Science.gov (United States)

Martinson, K; Wilson, J; Cleary, K; Lazarus, W; Thomas, W; Hathaway, M

2012-03-01

Many horse owners find round bales convenient, less labor intensive, and more affordable than other hay types, but report an inability to control horse BW gain and excessive hay waste. The objectives were to compare hay waste, hay intake, and payback of 9 round-bale feeders and a no-feeder control when used during horse feeding. Nine round-bale feeders were tested: Cinch Net, Cone, Covered Cradle, Hayhut, Hay Sleigh, Ring, Tombstone, Tombstone Saver, and Waste Less. Each feeder design was placed on the ground in a dirt paddock. Five groups of 5 horses were fed in rotation for a 4-d period with each feeder. Every fourth day, groups were rotated among paddocks and a new round bale was placed in each feeder. In the 5 paddocks used, 5 feeders were installed for d 1 through 20, and the remaining 4 feeders and no-feeder control were installed for d 21 through 40. Groups of horses were sequentially assigned to feeders using two 5 × 5 Latin squares, the first for d 1 through 20, the second for d 21 through 40. Horse groups of similar age, BW, breed, and sex were formed from 25 Quarter Horse and Thoroughbred geldings and open mares (means: 11 yr; 541 kg of BW). Hay on the ground surrounding the feeder was collected daily, dried, and weighed. The total amount of hay removed around each feeder for a 4-d period was considered waste. Dry matter intake was estimated as the difference between hay disappearance and waste. Number of months for the reduction in waste to repay feeder cost (payback) were calculated using hay valued at $110/t, and improved feeder efficiency over the control. Feeder design did not affect hay intake (P > 0.05); all feeders resulted in an estimated hay intake of 2.0 to 2.4% BW; the no-feeder control resulted in a reduced intake of 1.3% BW (P = 0.001). Mean percentage of hay waste differed among feeders (P feeder control, 57%. Feeder design also affected payback (P feeder design affected hay waste and payback, but not estimated hay intake or BW change

SEGURIDAD ALIMENTARIA Y NUTRICIONAL EN LA REGIÓN CARIBE: CONSECUENCIAS DE LA DESNUTRICIÓN Y BUENAS PRÁCTICAS COMO SOLUCIONES

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Sofía Lissbrant

2015-01-01

Full Text Available Este trabajo presenta tres Buenas Prácticas que pueden brindar soluciones a la situación alarmante de inseguridad alimentaria y desnutrición que existe en la región Caribe colombiana, a pesar de tener alta potencialidad de producción de alimentos. Para identificar las Buenas Prácticas se indagaron a cerca de 400 profesionales de entidades públicas, privadas y ONG. Esa encuesta reveló tres ejemplos destacados de Buenas Prácticas que, con métodos distintos, generaron cambios positivos en la Seguridad Alimentaria y Nutricional de los habitantes de Sucre y Cesar. Adicionalmente, se sugirió que las tres Buenas Prácticas pueden ser replicadas y con poca dificultad incorporadas en los Planes de Desarrollo Departamentales. Si las iniciativas identificadas cuentan con el apoyo de los tomadores de decisiones, tienen potencial para fortalecer a los pequeños productores, reducir la inseguridad alimentaria y mejorar el estado nutricional de la población.

Substituting oat hay or maize silage for portion of alfalfa hay affects growth performance, ruminal fermentation, and nutrient digestibility of weaned calves

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Yang Zou

2018-03-01

Full Text Available Objective The impact of forage feeding strategy on growth performance, ruminal fermentation and nutrient digestibility in post-weaning calves was investigated. Methods Forty-five female Holstein calves (body weight [BW] = 79.79±0.38 kg were enrolled in the 35-d study at one week after weaning and randomly assigned to one of three dietary treatments. All diets were fed as total mixed ration containing 60% (dry matter [DM] basis of basal starter feed and 40% (DM basis of forage, but varied in composition of forage source including i alfalfa (40% DM, AH; ii alfalfa hay (26.7% DM+oat hay (13.3% DM; OH; iii alfalfa hay (26.7% DM+corn silage (13.3% DM; WS. Results Dry matter intake was not different among treatment groups (p>0.05. However, BW (p<0.05 and average daily gain (p<0.05 of calves fed AH and OH were greater than WS-fed calves, whereas heart girth was greater in OH-fed calves than those fed AH and WS (p<0.05. Ruminal fermentation parameters including proportion of butyric acid, acetated-to-propionate ratio, concentration of total volatile fatty acid, protozoal protein, bacterial protein, and microbial protein in rumen were the highest in OH (p<0.05 and the lowest in WS. Compared with the AH and WS, feeding oat hay to postweaning calves increased crude protein digestibility (p<0.05, and decreased duration of diarrhea (p<0.05 and fecal index (p<0.05. Conclusion Our results suggested that partially replacing alfalfa hay with oat hay improved ruminal fermentation, nitrogen utilization, and reduced incidence of diarrhea in post-weaning dairy calves.

FastStats: Allergies/Hay Fever

Science.gov (United States)

... this? Submit What's this? Submit Button NCHS Home Allergies and Hay Fever Recommend on Facebook Tweet Share ... 12 months: 7.5% Number with reported respiratory allergies in the past 12 months: 7.6 million ...

Analysis of the potentiality haying of native forage species in semiarid region

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Enoque de Sousa Leão

2017-10-01

Full Text Available The objective of this study was to evaluate the potential hay production from Spiny Amaranth (Amaranthus spinosus, Hairy Woodrose (Merremia aegyptia, Malva (Sida galheirensis, Mucuna (Mucuna pruriens and Ervanço (Froelichia humboldtiana, native forage species of the semiarid region of Brazil by observing morphological components of the plant, such as the dehydration curve, crude protein loss (CPL curve, chemical composition of plant and hay and hay degradability in situ. There were differences (P < 0.05 among species on leaf, stem and inflorescence quantification with Ervanço, Hairy Woodrose, and Mucuna having a greater number of leaves. There was a linearly increasing response for the dehydration curve of the five forage plants species. Mucuna forage had the greatest hay point at 800 g kg-1 dried matter (DM after 11.8 hours and Woodrose had a lower dehydration efficiency, which required 25 hours of sun exposure. There was no difference in CPL. Mucuna had the lowest crude protein (CP, neutral detergent fiber (NDF and acid detergent fiber (ADF content, 8.4, 67.7 and 73.8 g kg DM-1 in hay in relation to the plant, respectively. Ervanço, Spiny Amaranth, Hairy Woodrose and Malva hay had more of soluble fraction “a” of DM of 31.0, 26.2, 22.1 and 9.7 g kg-1 DM than Mucuna, respectively. Spiny Amaranth and Malva hay had values of 335.4 and 193.2 g kg-1 DM of fraction “b” more than Ervanço hay, respectively. For fraction “a’’ of CP, Spiny Amaranth and Hairy Woodrose hay obtained 312.6 and 227.4 g kg-1 CP more than that observed for Malva, respectively. Mucuna had better hay potential among the forage studied in the semiarid region of Brazil.

Substituting oat hay or maize silage for portion of alfalfa hay affects growth performance, ruminal fermentation, and nutrient digestibility of weaned calves

Science.gov (United States)

Zou, Yang; Zou, XinPing; Li, XiZhi; Guo, Gang; Ji, Peng; Wang, Yan; Li, ShengLi; Wang, YaJing; Cao, ZhiJun

2018-01-01

Objective The impact of forage feeding strategy on growth performance, ruminal fermentation and nutrient digestibility in post-weaning calves was investigated. Methods Forty-five female Holstein calves (body weight [BW] = 79.79±0.38 kg) were enrolled in the 35-d study at one week after weaning and randomly assigned to one of three dietary treatments. All diets were fed as total mixed ration containing 60% (dry matter [DM] basis) of basal starter feed and 40% (DM basis) of forage, but varied in composition of forage source including i) alfalfa (40% DM, AH); ii) alfalfa hay (26.7% DM)+oat hay (13.3% DM; OH); iii) alfalfa hay (26.7% DM)+corn silage (13.3% DM; WS). Results Dry matter intake was not different among treatment groups (p>0.05). However, BW (pcalves fed AH and OH were greater than WS-fed calves, whereas heart girth was greater in OH-fed calves than those fed AH and WS (pfeeding oat hay to postweaning calves increased crude protein digestibility (pcalves. PMID:28728373

FORMACIÓN CONTINUA DE LOS DOCENTES DE LA INSTITUCIÓN EDUCATIVA “SAN LUIS GONZAGA FE Y ALEGRÍA 22”, PARA MEJORAR, EL TRABAJO EN EQUIPO Y LA CALIDAD EDUCATIVA

OpenAIRE

Alarcón Zamora, José Presvítero; Fé y Alegría; Chávarry Ysla, Patricia del Rocio; Universidad Señor de Sipán

2015-01-01

Hoy en día, en la práctica, encontramos comunidades educativas desmotivadas, desorganizadas y  conflictivas que actúan sin ninguna planificación, no hay un trabajo en equipo, no existe buenas relaciones humanas. En conclusión falta identidad y ética. El problema que se aborda esta centrado en analizar la carencia de una política de formación docente continúa a nivel de las instituciones educativas que puedan responder a la demanda educativa de los docentes. En la Insti

Guía de buenas prácticas de seguridad informática en el tratamiento de datos de salud para el personal sanitario en atención primaria

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Ana Sánchez-Henarejos

2014-04-01

Full Text Available Con la introducción de la historia clínica digital surge la necesidad de reforzar la seguridad de los datos personales de salud para garantizar su privacidad. A pesar de la gran cantidad de medidas de seguridad técnicas y de recomendaciones existentes para el ámbito sanitario, hay un aumento en las violaciones de la privacidad de los datos personales de los pacientes en centros sanitarios, en muchos casos como consecuencia de errores o descuidos de los profesionales sanitarios. En este trabajo se presenta una guía de buenas prácticas de seguridad informática en la manipulación de los datos personales de salud por parte del personal sanitario, elaborada a partir de recomendaciones, normativa y estándares nacionales e internacionales. El material presentado en este trabajo puede emplearse tanto en la formación como en auditorías de seguridad informática a trabajadores de los centros de atención primaria.

Influence of feeding hay on the alopecia of breeding guinea pigs.

Science.gov (United States)

Gerold, S; Huisinga, E; Iglauer, F; Kurzawa, A; Morankic, A; Reimers, S

1997-08-01

Animals with partial alopecia were seen frequently in a breeding colony of guinea pigs. No pathologic aetiology could be determined. An influence of nutrition on the density of the hair coat was considered. Breeding groups were fed one of the commercial guinea pig diets of differing composition, with or without the addition of hay. Observation occurred over a period of months and the quality of the hair coat was evaluated periodically using a semi-quantitative scoring system. More extensive and more frequent fur defects were found is guinea pigs receiving a breeding diet with a high content of crude protein (23%) and a low level of crude fibre (12%), offered hay only restrictively compared with animals receiving a diet with a lower content of crude protein (15.5%) and a higher level of crude fibre (19.5%), offered the same amount of hay. The amount of hay offered is of paramount importance. Animals fed only the diet with the higher level of crude fibre (19.5%), according to the manufacturer's instructions as a complete food, without the addition of hay, showed a less dense hair coat within 4 weeks. In our colony a group of five breeding animals and their young required 200 g of hay daily in order to improve their hair coat quality to normal. Conversely, animals receiving less hay had progressively deteriorating hair coat density. Not only the amount of hay offered, but also the accessibility for all animals plays a role in preventing alopecia in guinea pigs. In larger cages (twice the usual ground surface area) fur defects were seen when the same amount of hay (200 g) was offered in only one central area, rather than spread out evenly throughout the cage. Hair loss was observed to be the result of trichophagia between adult animals kept in the same cage. The need for crude fibre of breeding animals does not appear to be completely met by pellets rich in fibre segments.

Evaluar en contextos de exclusión educativa: buenas prácticas e inclusión social

OpenAIRE

Amores Fernández, Francisco Javier; Ritacco Real, Maximiliano

2011-01-01

Desde un punto de vista educativo, las buenas prácticas en el ámbito de la evaluación en los centros escolares ubicados en contextos de exclusión social, responden a criterios como la flexibilidad, la adaptabilidad y la individualización, entre otros. Nuestro interés en la identificación de buenas prácticas se ha centrado en aquellas que, dentro de los programas y medidas encaminados a reducir o erradicar el fracaso escolar, están relacionadas con el proceso evaluativo y tienen en cuenta las ...

Algunas experiencias para la difusión de buenas prácticas docentes en la enseñanza universitaria.

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Carla Costa Sanz

2011-11-01

Full Text Available El presente escrito es una reseña del libro Buenas prácticas docentes en la universidad. Modelos y experiencias en la Universidad de Barcelona, que pretende dar a conocer el análisis de diversos proyectos que versan sobre la mejora de la docencia universitaria con el objetivo final de difundir unas buenas prácticas docentes en el marco de la enseñanza superior.

Sheep fed with banana leaf hay reduce ruminal protozoa population.

Science.gov (United States)

Freitas, Cláudio Eduardo Silva; Duarte, Eduardo Robson; Alves, Dorismar David; Martinele, Isabel; D'Agosto, Marta; Cedrola, Franciane; de Moura Freitas, Angélica Alves; Dos Santos Soares, Franklin Delano; Beltran, Makenzi

2017-04-01

A ciliate protozoa suppression can reduce methane production increasing the energy efficiency utilization by ruminants. The physicochemical characteristics of rumen fluid and the profile of the rumen protozoa populations were evaluated for sheep fed banana leaf hay in replacement of the Cynodon dactylon cv. vaqueiro hay. A total of 30 male sheep were raised in intensive system during 15 days of adaptation and 63 days of experimental period. The animals were distributed in a completely randomized design that included six replicates of five treatments with replacement levels (0, 25, 50, 75, and 100%) of the grass vaquero for the banana leaf hay. Samples of fluid were collected directly from the rumen with sterile catheters. Color, odor, viscosity, and the methylene blue reduction potential (MBRP) were evaluated and pH estimated using a digital potentiometer. After decimal dilutions, counts of genus protozoa were performed in Sedgewick Rafter chambers. The averages of pH, MBRP, color, odor, and viscosity were not influenced by the inclusion of the banana leaf hay. However, the total number of protozoa and Entodinium spp. population significantly decreased at 75 and 100% inclusions of banana leaf hay as roughage.

Residue studies of Methabenzthiazuron in Soil, Lentils and Hay

International Nuclear Information System (INIS)

Al-Maghrabi, K.I.

2002-01-01

Over two years, replicate plots of lentils (Lens culinaris L.) were treated before seeding with methabenzthiazuron at a rate of 0.5 kg a.i. ha-1. In each year representative soil, lentil and hay samples were randomly collected from plots of each treatment. Soil samples were tested for residues 24 hours after treatment and harvest. Lentil and hay samples were tested at harvest. A cleanup step was conducted after extraction. Gas chromatograph equipped with a nitrogen/phosphorus detector was used to detect methabenzthiazuron. Overall average of residue levels in soil decreased significantly from 1.16+-0.15 mg kg, 24 hours after treatment, 0.12 +-0.01 mg kg at harvest. No significant difference in the maximum average residue was found in lentil and hay samples collected from various plots and tested at harvest (0.10+-0.01 and 0.19 +-0.02 mg kg in lentils and hay, respectively). Recovery tests were conducted with each group of samples tested in order to determine the efficiency of analytical procedure. (author)

The HayWired earthquake scenario—We can outsmart disaster

Science.gov (United States)

Hudnut, Kenneth W.; Wein, Anne M.; Cox, Dale A.; Porter, Keith A.; Johnson, Laurie A.; Perry, Suzanne C.; Bruce, Jennifer L.; LaPointe, Drew

2018-04-18

The HayWired earthquake scenario, led by the U.S. Geological Survey (USGS), anticipates the impacts of a hypothetical magnitude-7.0 earthquake on the Hayward Fault. The fault is along the east side of California’s San Francisco Bay and is among the most active and dangerous in the United States, because it runs through a densely urbanized and interconnected region. One way to learn about a large earthquake without experiencing it is to conduct a scientifically realistic scenario. The USGS and its partners in the HayWired Coalition and the HayWired Campaign are working to energize residents and businesses to engage in ongoing and new efforts to prepare the region for such a future earthquake.

INTAKE AND APPARENT DIGESTIBILITY OF Andropogon gayanus HAY AT THREE DIFFERENT AGES

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André Cayô Cavalcanti

2016-10-01

Full Text Available The aim of this study was to evaluate the voluntary intake and apparent digestibility of dry matter, crude protein, fiber fractions, energy, and the nitrogen balance of Andropogon gayanus hay at three different stages (56, 84 and 112 days. The statistical design was completely randomized, with three treatments and six replicates. Dry matter, fiber fractions, and energy apparent digestibility were higher (P<0.05 for hay harvested at 56 and 84 days. Crude protein intake and apparent digestibility of A. gayanus hay harvested at 56 days of growth were greater (P<0.05 than the hay harvested at 84 and 112 days. The A. gayanus hay showed the best voluntary intake and digestibility at 56 and 84 days of age. Keywords: forage; nutritive value; sheep.

Seguridad alimentaria y nutricional en la región caribe: consecuencias de la desnutrición y buenas prácticas como soluciones

OpenAIRE

Sofia Lissbrant

2014-01-01

Este trabajo presenta tres Buenas Prácticas que pueden brindar soluciones a la situación alarmante de inseguridad alimentaria y desnutrición que existe en la región Caribe colombiana, a pesar de tener alta potencialidad de producción de alimentos. Para identificar las Buenas Prácticas se indagaron a cerca de 400 profesionales de entidades públicas, privadas y ONG. Esa encuesta reveló tres ejemplos destacados de Buenas Prácticas que, con métodos distintos, generaron cambios positivos en la Seg...

Hay que preparar a Colombia para el turismo de naturaleza

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María Teresa Becerra

2002-11-01

Full Text Available El turismo que se basa en su entorno natural es responsable por aproximadamente el 40% de los ingresos de turismo y es un mercado en crecimiento. Sin embargo, el turismo ha sido una actividad que ha generado graves impactos ambientales y sociales a nivel mundial. En el contexto ambiental ha transformado áreas de alto valor de conservación en ciudades de cemento y ladrillo, ha contaminado los recursos hídricos, ha erosionado terrenos, ha disminuido los hábitats de muchos animales ante la presencia no planificada de las actividades humanas y ha interrumpido el flujo de especies y de información genética ante la construcción de carreteras, complejos turísticos y otras edificaciones, entre otros impactos. En el contexto social, ha transformado culturalmente a muchas poblaciones locales, sin que hayan tenido la posibilidad y la capacidad de decidir sobre sus mejores opciones económicas y sociales. En muchos casos las poblaciones locales no han tenido la oportunidad, por fallas institucionales y de mercado, de participar activamente en la captura de beneficios de la actividad turística. Estos son ejemplos de los impactos negativos de la globalización cuando no hay la información, la capacidad y la participación ciudadana para la toma de decisión acertadas. Este artículo demuestra, mediante el uso de casos prácticos, cómo un turismo de naturaleza bien manejado, que permita la toma de buenas decisiones por parte de las personas relacionadas directa e indirectamente de sus actividades y que disminuya al máximo sus impactos negativos sociales y ambientales, es una actividad deseable para el desarrollo sostenible de una región y un país como Colombia.

Effect of mid-summer haying on growth and reproduction in prairie forbs

Science.gov (United States)

Becky Begay; Helen M. Alexander; Erin Questad

2011-01-01

Mid-summer haying is a common management practice for prairies; plant species could differ in the effect of haying on subsequent growth and reproduction. We examined the effect of haying on prairie species by performing a clipping experiment. For each of seven species, sixteen plants were chosen and half were randomly assigned to a clipping treatment and half to a...

A different voice: Mary Hays's the Memoirs of Emma Courtney.

Science.gov (United States)

Sharma, A

2001-01-01

Mary Hays wrote in the decade of the 1790s, a period of intense creative flowering in England. Writing in a period enshrined to the works of the canonical Wordsworth and Coleridge, Hays explored through her Jacobinical novel, The Memoirs of Emma Courtney, the contentious relationship between self and society. Like other Jacobin women writers - Elizabeth Inchbald, Charlotte Smith and Mary Wollstonecraft - Mary Hays too used her novel to explode the insidious connection between education and gender construction. Emma Courtney is a landmark novel that wrestles with the paradigm of decorum and propriety which disallows women from voicing their aspirations. In the process, Hays merges the plots of the domestic novel of courtship and love with the novel of ideas to create a searing portrait of women's intellectual confinement and psychic dissonance in a society that only projects them in terms of their gender construction. Memoirs of Emma Courtney is a remarkable novel in its depiction of the emotional imbalance created by thwarted desire: intellectual and sexual.

Environmental impact assessment of alfalfa (Medicago sativa L.) hay production.

Science.gov (United States)

Bacenetti, Jacopo; Lovarelli, Daniela; Tedesco, Doriana; Pretolani, Roberto; Ferrante, Valentina

2018-09-01

On-farm production of hay and high-protein-content feed has several advantages such as diversification of on-farm cultivated crops, reduction of off-farm feed concentrates transported over long distances and a reduction in runoff during the winter season if grown crops are perennial. Among those crops cultivated for high-protein-content feed, alfalfa (Medicago sativa L.) is one of the most important in the Italian context. Nevertheless, up to now, only a few studies have assessed the environmental performance of alfalfa hay production. In this study, using the Life Cycle Assessment approach, the environmental impact of alfalfa hay production in Northern Italy was analyzed. More in detail, two production practices (without and with irrigation) were compared. The results show that alfalfa hay production in irrigated fields has a better environmental performance compared to non-irrigated production, mainly because of the yield increase achieved with irrigation. In particular, for the Climate Change impact category, the impact is equal to 84.54 and 80.21kgCO 2 /t of hay for the scenario without and with irrigation, respectively. However, for two impact categories (Ozone Depletion and Human Toxicity-No Cancer Effect), the impact of irrigation completely offsets the yield increase, and the cultivation practice without irrigation shows the best environmental performance. For both scenarios, the mechanization of harvest is the main environmental hotspot, mostly due to fuel consumption and related combustion emissions. Wide differences were highlighted by comparing the two scenarios with the Ecoinvent process of alfalfa hay production; these differences are mostly due to the cultivation practice and, in particular, to the more intensive fertilization in Swiss production. Copyright © 2018 Elsevier B.V. All rights reserved.

Toxicosis in dairy cattle exposed to poison hemlock (Conium maculatum) in hay: isolation of Conium alkaloids in plants, hay, and urine.

Science.gov (United States)

Galey, F D; Holstege, D M; Fisher, E G

1992-01-01

Cattle in two herds developed signs of bloating, increased salivation and lacrimation, depression, respiratory distress, ataxia, and death after ingestion of hay that contained large amounts of poison hemlock (Conium maculatum). Twenty of 30 Angus cows and calves were affected in the first herd (2 died). In the second herd, 5 of 30 Holstein heifers were affected (1 died). The Conium alkaloids, coniine and gamma-coniceine, were quantified in the hay, the plants from the responsible hayfield, and the urine of affected animals.

Hay fever & homeopathy: a case series evaluation.

Science.gov (United States)

Pandey, Vinita

2016-05-01

Seasonal allergic rhinitis (hay fever) is common and can considerably reduce the quality of life of sufferers. Despite the wide everyday application and promising results with homeopathy, scientific evidence of its effectiveness for most ailments is scarce. The assessment of the clinical effectiveness of homeopathic remedies in the alleviation of hay fever symptoms in a typical clinical setting. We performed a clinical observational study of eight patients in the treatment of hay fever symptoms over a two-year period (2012 and 2013) using Measure Yourself Medical Outcome Profile (MYMOP) self-evaluation questionnaires at baseline and again after two weeks and four weeks of homeopathic treatment. The individualized prescription - either a single remedy or multiple remedies - was based on the totality of each patient's symptoms. The average MYMOP scores for the eyes, nose, activity and wellbeing had improved significantly after two and four weeks of homeopathic treatment. The overall average MYMOP profile score at baseline was 3.83 (standard deviation, SD, 0.78). After 14 and 28 days of treatment the average score had fallen to 1.14 (SD, 0.36; PHomeopathy. Published by Elsevier Ltd. All rights reserved.

Bitumen on Water: Charred Hay as a PFD (Petroleum Flotation Device

Directory of Open Access Journals (Sweden)

Nusrat Jahan

2015-10-01

Full Text Available Global demand for petroleum keeps increasing while traditional supplies decline. One alternative to the use of conventional crude oils is the utilization of Canadian bitumen. Raw bitumen is a dense, viscous, semi-liquid that is diluted with lighter crude oil to permit its transport through pipelines to terminals where it can then be shipped to global markets. When spilled, it naturally weathers to its original form and becomes dense enough to sink in aquatic systems. This severely limits oil spill recovery and remediation options. Here we report on the application of charred hay as a method for modifying the surface behavior of bitumen in aquatic environments. Waste or surplus hay is abundant in North America. Its surface can easily be modified through charring and/or chemical treatment. We have characterized the modified and charred hay using solid-state NMR, contact angle measurements and infrared spectroscopy. Tests of these materials to treat spilled bitumen in model aquatic systems have been undertaken. Our results indicate that bitumen spills on water will retain their buoyancy for longer periods after treatment with charred hay, or charred hay coated with calcium oxide, improving recovery options.

UNA APROXIMACIÓN AL CONOCIMIENTO DE UNA PROFESORA UNIVERSITARIA, AGENTE DE BUENAS PRÁCTICAS DOCENTES, UTILIZANDO MAPAS CONCEPTUALES

Directory of Open Access Journals (Sweden)

Fermín González García

2010-01-01

Full Text Available Se muestra en este trabajo un modelo de conocimiento construido sobre buenas prácticas docentes de una profesora universitaria, responsable de la asignatura "Circuitos y Sistemas I", correspondiente al primer curso (y primer cuatrimestre de la titulación de Ingeniería Técnica de Telecomunicación: Sonido e Imagen. El modelo fue realizado en el marco de una investigación que se ha llevado a cabo por 6 universidades españolas. El trabajo identifica, analiza, explicita y representa con la ayuda del programa informático CMap Tools el pensamiento pedagógico y la práctica docente de un profesor universitario caracterizado por su buena práctica, a partir de entrevistas en profundidad. El modelo de conocimiento construido de las buenas prácticas de este profesor, fácilmente accesible a través de Internet, constituye un excelente ejemplo que puede orientar tanto al profesor novel como a profesores experimentados que quieran mejorar la calidad de la docencia que imparten.

Las buenas practicas espanolas 1998

Directory of Open Access Journals (Sweden)

Nasarre y de Goicoechea, Fernando

2000-02-01

Full Text Available The II HABITAT Conference held at Istanbul on June 1996, adopted the Habitat Program -Global Action Plan, in within which two performance lines are especially reinforced to reach the two main goals of suitable e housing for all and sustainable human settlements: the collaboration and participation among all the levels of the government and the civil society and, the recognition of the importance of the urban policies. In this framework is addressed the International Award Best Practices for the Improvement of the Life Conditions that, sponsored by the municipality of Dubai, is celebrated every two years and is awarded to the 10 selected by an International Independent Jury. The goal of the Competition is to promote policies and strategies more effective for the sustainable development of the humanity and their settlements, through the transmission of information and knowledge on experiences and solutions proved in the practice. The obtained results in the last international competition, with 32 of the presented Practices included in the Data Base of the United Nations Good Practices, 18 classified among the 100 best (3 of them included among the 40 finalists and finally, one, among the 10 awarded (Programs for the improvement of the urban environment of Malaga, allow us to look forward with satisfaction the panorama of the urban policy in our country.La Conferencia HABITAT II celebrada en Estambul en junio de 1996 adopto el Programa Hábitat-Plan Global de Acción-, dentro del cual se refuerzan especialmente dos líneas de actuación: la colaboración y participación entre todos los niveles de gobierno y la sociedad civil y el reconocimiento de la importancia de las políticas urbanas para alcanzar los dos objetivos principales: vivienda adecuada para todos y asentamientos humanos sostenibles. En este marco se inscribe el Concurso Internacional de Buenas Practicas para la Mejora de las Condiciones de Vida que, patrocinado par la municipalidad

The effect of lucerne ( Medicago sativa ) hay quality on milk ...

African Journals Online (AJOL)

The influence of lucerne hay quality on the milk production potential and milk composition of Jersey cows was investigated. Three different grades of lucerne hay (Prime, Grade 1, Grade 2; selected according to the New Lucerne Quality Index) were included in a total mixed ration (TMR) and fed to lactating cows. The three ...

Laboratory Exercise to Evaluate Hay Preservatives.

Science.gov (United States)

McGraw, R. L.; And Others

1990-01-01

Presented is a laboratory exercise designed to demonstrate the effects of moisture on hay preservation products in a manner that does not require large amounts of equipment or instructor time. Materials, procedures, and probable results are discussed. (CW)

Steam explosion pretreatment for enhancing biogas production of late harvested hay.

Science.gov (United States)

Bauer, Alexander; Lizasoain, Javier; Theuretzbacher, Franz; Agger, Jane W; Rincón, María; Menardo, Simona; Saylor, Molly K; Enguídanos, Ramón; Nielsen, Paal J; Potthast, Antje; Zweckmair, Thomas; Gronauer, Andreas; Horn, Svein J

2014-08-01

Grasslands are often abandoned due to lack of profitability. Extensively cultivating grassland for utilization in a biogas-based biorefinery concept could mend this problem. Efficient bioconversion of this lignocellulosic biomass requires a pretreatment step. In this study the effect of different steam explosion conditions on hay digestibility have been investigated. Increasing severity in the pretreatment induced degradation of the hemicellulose, which at the same time led to the production of inhibitors and formation of pseudo-lignin. Enzymatic hydrolysis showed that the maximum glucose yields were obtained under pretreatment at 220 °C for 15 min, while higher xylose yields were obtained at 175 °C for 10 min. Pretreatment of hay by steam explosion enhanced 15.9% the methane yield in comparison to the untreated hay. Results indicate that hay can be effectively converted to methane after steam explosion pretreatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Distribution and dynamics of the invasive native hay-scented fern

Science.gov (United States)

Songlin Fei; Peter Gould; Melanie Kaeser; Kim. Steiner

2010-01-01

The spread and dominance of the invasive native hay-scented fern in the understory is one of the most significant changes to affect the forest ecosystems in the northeastern United States in the last century. We studied changes in the distribution and dynamics of hay-scented fern at a large scale over a 10-yr period in Pennsylvania. The study included 56 stands...

76 FR 45878 - Alticor, Inc., Including Access Business Group International LLC and Amway Corporation, Buena...

Science.gov (United States)

2011-08-01

...,420B] Alticor, Inc., Including Access Business Group International LLC and Amway Corporation, Buena Park, CA; Alticor, Inc., Including Access Business Group International LLC and Amway Corporation...., Including Access Business Group International LLC and Amway Corporation, Including On-Site Leased Workers...

Motivation for hay: effects of a pelleted diet on behavior and physiology of horses.

Science.gov (United States)

Elia, Jamie B; Erb, Hollis N; Houpt, Katherine Albro

2010-12-02

The natural diet of free-ranging horses is grass, which is typically high in fiber and calorically dilute, however diets for high performance domestic horses are often low in fiber and calorically dense. The aim of the study was to determine the motivation of horses for hay when fed a low roughage diet. Their motivation could be used to determine if low roughage diets compromise the welfare of horses. Eight mares were fed two different diets in counterbalanced order: ad libitum orchard grass hay; a complete pelleted feed (pellets). Each trial lasted three weeks, with a one-week transition period between diets. To determine the motivation of horses for fiber they were taught to press a panel to obtain a food reward. The fixed ratio (FR) was increased using a progressive ratio ((1,2,4,7,11…) technique. When fed pellets, the horses worked for a median FR of 1 (Range=1-497) to attain pellets, and when fed hay, they worked for a median FR of 25.5 (4-497) to attain pellets. When fed hay, the horses worked for a median FR of 0 (0-0) to attain hay, and when fed pellets, they worked for a FR of 13 (2-79) to attain hay. These results indicate a greater motivation for hay, a high fiber diet, when fed a low fiber diet. The horses spent 10 (5-19.4)% of their time during a 24-hour period eating pellets compared to 61.5 (29-76) % of their time eating hay. Horses spent 58% of their time standing when fed the pellets and only 37% of their time standing when fed hay. Searching behavior (i.e. sifting through wood shaving bedding for food particles) took up 11.5 (1.4-32) % of the horse's day when fed pellets, but only 1.2 (0-3.5) % of the daily time budget when fed hay. Horses chew more times when eating a hay diet (43,476chews/day) than when eating a pellet diet (10,036chews/day). Fecal pH was lower in horses fed the pelleted diet. Copyright © 2010 Elsevier Inc. All rights reserved.

Effects of hay management and native species sowing on grassland community structure, biomass, and restoration.

Science.gov (United States)

Foster, Bryan L; Kindscher, Kelly; Houseman, Greg R; Murphy, Cheryl A

2009-10-01

Prairie hay meadows are important reservoirs of grassland biodiversity in the tallgrass prairie regions of the central United States and are the object of increasing attention for conservation and restoration. In addition, there is growing interest in the potential use of such low-input, high-diversity (LIHD) native grasslands for biofuel production. The uplands of eastern Kansas, USA, which prior to European settlement were dominated by tallgrass prairie, are currently utilized for intensive agriculture or exist in a state of abandonment from agriculture. The dominant grasslands in the region are currently high-input, low-diversity (HILD) hay fields seeded to introduced C3 hay grasses. We present results from a long-term experiment conducted in a recently abandoned HILD hay field in eastern Kansas to evaluate effects of fertilization, haying, and native species sowing on community dynamics, biomass, and potential for restoration to native LIHD hay meadow. Fertilized plots maintained dominance by introduced grasses, maintained low diversity, and were largely resistant to colonization throughout the study. Non-fertilized plots exhibited rapid successional turnover, increased diversity, and increased abundance of C4 grasses over time. Haying led to modest changes in species composition and lessened the negative impact of fertilization on diversity. In non-fertilized plots, sowing increased representation by native species and increased diversity, successional turnover, and biomass production. Our results support the shifting limitations hypothesis of community organization and highlight the importance of species pools and seed limitations in constraining successional turnover, community structure, and ecosystem productivity under conditions of low fertility. Our findings also indicate that several biological and functional aspects of LIHD hay meadows can be restored from abandoned HILD hay fields by ceasing fertilization and reintroducing native species through

Aproximación a un modelo integrado de buenas prácticas de innovación docente que apoyan la construcción y el desarrollo de las competencias genéricas

OpenAIRE

Bravo Ibarra, Edna Rocío; Simó Guzmán, Pep; Amante García, Beatriz

2010-01-01

El objetivo principal de esta investigación es el diseño de un modelo de buenas prácticas de innovación docente, que sirva de apoyo a los profesores en la adaptación de asignaturas, preparación de actividades, desarrollo, evaluación y seguimiento de competencias genéricas. este modelo de buenas prácticas ha sido desarrollado en cuatro fases: 1) fundamentación teórica, 2) identificación de buenas prácticas de innovación docente, 3) construcción del modelo de buenas prácticas y, ...

Genome-wide association analysis identifies 11 risk variants associated with the asthma with hay fever phenotype.

Science.gov (United States)

Ferreira, Manuel A R; Matheson, Melanie C; Tang, Clara S; Granell, Raquel; Ang, Wei; Hui, Jennie; Kiefer, Amy K; Duffy, David L; Baltic, Svetlana; Danoy, Patrick; Bui, Minh; Price, Loren; Sly, Peter D; Eriksson, Nicholas; Madden, Pamela A; Abramson, Michael J; Holt, Patrick G; Heath, Andrew C; Hunter, Michael; Musk, Bill; Robertson, Colin F; Le Souëf, Peter; Montgomery, Grant W; Henderson, A John; Tung, Joyce Y; Dharmage, Shyamali C; Brown, Matthew A; James, Alan; Thompson, Philip J; Pennell, Craig; Martin, Nicholas G; Evans, David M; Hinds, David A; Hopper, John L

2014-06-01

To date, no genome-wide association study (GWAS) has considered the combined phenotype of asthma with hay fever. Previous analyses of family data from the Tasmanian Longitudinal Health Study provide evidence that this phenotype has a stronger genetic cause than asthma without hay fever. We sought to perform a GWAS of asthma with hay fever to identify variants associated with having both diseases. We performed a meta-analysis of GWASs comparing persons with both physician-diagnosed asthma and hay fever (n = 6,685) with persons with neither disease (n = 14,091). At genome-wide significance, we identified 11 independent variants associated with the risk of having asthma with hay fever, including 2 associations reaching this level of significance with allergic disease for the first time: ZBTB10 (rs7009110; odds ratio [OR], 1.14; P = 4 × 10(-9)) and CLEC16A (rs62026376; OR, 1.17; P = 1 × 10(-8)). The rs62026376:C allele associated with increased asthma with hay fever risk has been found to be associated also with decreased expression of the nearby DEXI gene in monocytes. The 11 variants were associated with the risk of asthma and hay fever separately, but the estimated associations with the individual phenotypes were weaker than with the combined asthma with hay fever phenotype. A variant near LRRC32 was a stronger risk factor for hay fever than for asthma, whereas the reverse was observed for variants in/near GSDMA and TSLP. Single nucleotide polymorphisms with suggestive evidence for association with asthma with hay fever risk included rs41295115 near IL2RA (OR, 1.28; P = 5 × 10(-7)) and rs76043829 in TNS1 (OR, 1.23; P = 2 × 10(-6)). By focusing on the combined phenotype of asthma with hay fever, variants associated with the risk of allergic disease can be identified with greater efficiency. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Mental health associations with eczema, asthma and hay fever in children

DEFF Research Database (Denmark)

Hammer-Helmich, Lene; Linneberg, Allan; Obel, Carsten

2016-01-01

OBJECTIVE: This study aimed to examine the association of eczema, asthma and hay fever with mental health in a general child population and to assess the influence of parental socioeconomic position on these associations. METHODS: We conducted a cross-sectional health survey of children aged 3, 6......, 11 and 15 years in the City of Copenhagen, Denmark. Individual questionnaire data on eczema, asthma, and hay fever and mental health problems assessed using the Strengths and Difficulties Questionnaire (SDQ) was linked to register data on demographics and parental socioeconomic position. 9215 (47...... with eczema, asthma or hay fever had more emotional, conduct and hyperactivity problems, but not peer problems, compared with children without these diseases. Atopic diseases added equally to the burden of mental health problems independent of socioeconomic position....

Long-term agricultural management maximizing hay production can significantly reduce belowground C storage

NARCIS (Netherlands)

Sochorová, L.; Jansa, J.; Verbruggen, E.; Hejcman, M.; Schellberg, J.; Kiers, E.T.

2016-01-01

Liming and fertilization of grasslands have been used for centuries to sustain hay production. Besides improving hay yields, these practices induce compositional shifts in plant and soil microbial communities, including symbiotic arbuscular mycorrhizal (AM) fungi. However, in spite of increasing

BUENAS PRÁCTICAS APLICADAS A LA IMPLEMENTACION COLABORATIVO DE APLICATIVOS WEB

Directory of Open Access Journals (Sweden)

Manuel Guillermo García Sandoval

2016-02-01

Full Text Available RESUMEN La implementación de buenas prácticas para el desarrollo de software, son una compilación de métodos o técnicas que permiten llevar a cabo de manera óptima el conjunto de actividades que comprenden el desarrollo de un sistema de información. En el campo de desarrollo de software colaborativo, estas prácticas son empleadas con el fin de que las actividades realizadas por cada miembro de un equipo de trabajo, y esté tengan concordancia con las actividades realizadas por los demás miembros. Esto se realiza mediante el seguimiento de las normas correspondientes, que al ser implementadas, generan un proyecto comprensible por quienes conforman el equipo de trabajo. El no seguimiento de las mismas, puede generar retrasos e incluso fracaso en un proyecto de desarrollo colaborativo, debido qué al no establecer una metodología específica para la solución de un problema, cada miembro del equipo puede tomar diferentes caminos para la solución del mismo, pudiendo las discrepancias entre los mismos, provocar futuros problemas de compatibilidad dentro del sistema a implementar. Este proyecto pretende llevar a cabo el establecimiento de una metodología de desarrollo, que involucre una serie de actividades para la implementación colaborativa de un aplicativo web en el entorno colaborativo cloud9, basada en las buenas prácticas, con la posterior aplicación y evaluación de la misma, de acuerdo con los resultados obtenidos.

Effect of hay on performance of Holstein calves at suckling and post-weaning

Directory of Open Access Journals (Sweden)

Robson Kyoshi Ueno

2014-10-01

Full Text Available The objective of this work was to evaluate the performance of Holstein calves in suckling and post-weaning phases, intensively managed during suckling in the absence or presence of hay. Twenty-four male Holstein calves, at an average age of 15 days and initial weight of 43 kg were used in the experiment. The experimental design was completely randomized, consisting of two treatments and six replications. The treatments were as follows: 1 suckling with milk substitute + initial concentrate for calves, ad libitum + temperate grass hay (oat/ryegrass, ad libitum; 2 suckling with milk substitute + initial concentrate for calves, ad libitum. No significant difference was found between treatments for weight gain and feed conversion. However, the supply of hay caused an increase in daily dry matter intake (2.127 vs 1.894 kg. The intake of hay promoted greater stimulus to consumption of concentrate and greater weight at weaning.

Buenas prácticas en educación infantil y materiales didácticos. Análisis de tres estudios de caso

OpenAIRE

Alvarez Seoane, Denebola; Rodríguez Rodríguez, Jesús; Romero Tena, Rosalía (Coordinador)

2016-01-01

En esta comunicación analizamos los materiales didácticos para educación infantil empleados en escuelas seleccionadas por sus buenas prácticas educativas. Esta aproximación al campo de estudio de los recursos educativos es parte del proyecto de investigación “Diseño Curricular y Buenas Prácticas en Educación Infantil: una visión internacional, multiculutral e interdisciplinar”, coordinado por el Catedrático Miguel Zabalza. El objetivo de investigación es a...

Effect of dietary restriction and hay inclusion in the diet of slow-growing broilers

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Karla P. Picoli

2014-11-01

Full Text Available The objective of this study was to evaluate the effect of dietary restriction and inclusion of alfalfa (Medicago sativa L. and Bermudagrass (Cynodon dactylon cv Coastal hays in the diets of ISA Label JA57 slow-growing male broilers on performance, gastrointestinal tract characteristics, and economic viability. A total of 272 broilers at 21 days old were distributed in a randomized experimental design with four treatments, four replicates, and 17 birds per experimental unit. The treatments consisted of ad libitum concentrated feed (control intake, feed restriction (80% of the control intake, and feed restrictions with supplementation of alfalfa hay (80% of the control intake+20% alfalfa or Bermudagrass hay (80% control intake+20% Bermuda. Dietary restriction, with and without hay inclusion, negatively affected (P<0.05 the weight gain of the birds; however, feed conversion was improved (P<0.05 for animals that underwent only restricted feeding, which also had the best economic indices. Birds subjected to dietary restriction and inclusion of hays showed changes (P<0.05 in the gastrointestinal organs and intestinal morphology.

Buenas prácticas en la gestión de la investigación

OpenAIRE

Luján Mora, Sergio

2016-01-01

Conferencia "Buenas prácticas en la gestión de la investigación" impartida en la Universidad Católica Santiago de Guayaquil (Guayaquil, Ecuador) el 1 de abril de 2016 en el marco del II Encuentro de vicerrectores de investigación y posgrado, organizado por la Red Ecuatoriana de Universidades y Escuelas Politécnicas para Investigación y Posgrados (REDU).

Educar en valores para una buena convivencia en Educación Infantil

OpenAIRE

Rivera Ramón, Belén

2017-01-01

Este Trabajo de Fin de Grado pretende mostrar la importancia que tiene una educación en valores desde la primera etapa educativa, para que haya una buena convivencia tanto dentro como fuera del aula. La propuesta didáctica que se lleva a cabo se realiza en el 2º ciclo de Educación Infantil, a través de unos cuentos y actividades, integrando dicho contenido en rutinas diarias. Que los niños y niñas adquieran ciertos valores desde sus primeras edades, les va proporcionando una actitud de aut...

Buenas prácticas en la didáctica del Trabajo Social

OpenAIRE

Ramos Feijóo, Clarisa; Lorenzo García, Josefa; Dellavalle, Marilena; Ariño Altuna, Miren; Munuera Gómez, Pilar

2013-01-01

La importancia de la innovación educativa en la formación de profesionales de Trabajo Social nos enfrenta a la necesidad de crear sinergias para adecuar los contenidos a las vicisitudes de la compleja realidad social. La producción de conocimiento científico específico del área, va acompañada de la demanda de una capacitación en competencias que favorezcan la intervención social. El presente trabajo presenta un análisis descriptivo de cuatro actividades docentes identificadas como buenas prác...

Dung matters : An experimental study into the effectiveness of using dung from hay-fed livestock to reconstruct local vegetation

NARCIS (Netherlands)

Schepers, Mans; Van Haaster, Henk

2015-01-01

This paper explores the relationship between standing vegetation and dung from hay-fed cattle and sheep. In an experimental study, hay is retrieved from a known hay field, surrounded by a semi-open landscape of hedgerows, forests and heather fields. The hay is fed to cattle and sheep, after which

Fermentation characteristics in hay from Cynodon and crop stubble treated with exogenous enzymes

Directory of Open Access Journals (Sweden)

Yânez André Gomes Santana

Full Text Available ABSTRACT The effect of treatment with xylanase and β-glucanase was evaluated for gas production and the ruminal degradation of nutrients from the hay of Tifton 85 grass and the stubble of maize, sorghum, peanut, sunflower and sesame crops. Two commercial fibrolytic enzymes were used (Dyadic xylanase PLUS - Xylanase; BrewZyme LP-β-glucanase, added to the hay at doses of 7.5 units of endoglucanase and 0.46 units of xylanase per 500 mg/gDM, for the cellulase and xylanase products respectively. The chemical composition of the hay was determined for no enzyme application and 24 hours after enzyme treatment, and the in vitro gas production and in situ microbial degradation was estimated for dry matter, organic matter, neutral detergent fibre and truly-degradable organic matter after 24 hours of incubation in the rumen. Enzyme treatment of the hay from Tifton 85 grass and the stubble of maize, sorghum, sunflower, peanut and sesame crops with the exogenous fibrolytic enzymes β-glucanase and xylanase influences in vitro gas production, and the in situ degradation of dry matter, organic matter, neutral detergent fibre and truly-degradable organic matter in the rumen. This variation can be attributed to differences in the chemical composition of the hay from the grass and the crop stubble, and to the different ways the enzymes act upon the cell wall.

Effects of feeding ratio of beet pulp to alfalfa hay or grass hay on ruminal mat characteristics and chewing activity in Holstein dry cows.

Science.gov (United States)

Izumi, Kenichi; Unno, Chigusa

2010-04-01

The influence of the feeding ratio of a non-forage fiber source and hay on ruminal mat characteristics and chewing activity was evaluated in dairy dry cows. Cows were fed four different diets: the ratios of alfalfa hay (AH) to beet pulp (BP) were 8:2 (dry matter basis, A8B2) and 2:8 (A2B8), and those of grass hay (GH) to BP were 8:2 (G8B2) and 2:8 (G2B8). Total eating time was decreased with increasing BP content (P rumination time for AH was shorter than that for GH (P content (P ruminal mat was detected by using a penetration resistance test of the rumen digesta. Penetration resistance value (PRV) of ruminal mat was highest with the G8B2 diet and PRV decreased with increasing BP content (P ruminal mat was greater for increasing BP content (P ruminal mat PRV on total rumination time resulted in a high positive correlation (r = 0.744; P ruminal mat stimulated rumination activity and a ruminal mat could be formed, although it was soft even when cows were offered a large quantity of BP.

Treatment of hay fever.

Science.gov (United States)

Wood, S F

1989-01-01

The range of treatments for hay fever available to the general practitioner has changed considerably in recent years. New antihistamines have addressed the problem of sedation and moved towards one daily dose; nasally applied corticosteroids avoid the need for systemic steroid therapy and its potential adverse effect; and regulatory decisions have set a trend away from immunotherapy in general practice. However, knowledge about the mechanism of action of immunotherapy is increasing and new developments with improved safety profiles include allergen polymers, allergoids, oral immunotherapy and nasal immunotherapy. Choice of treatment depends, as always, on the individual circumstances of the patient and his or her disease. PMID:2556545

Characterisation of Arabica Coffee Pulp - Hay from Kintamani - Bali as Prospective Biogas Feedstocks

Directory of Open Access Journals (Sweden)

Hendroko Setyobudi Roy

2018-01-01

Full Text Available The huge amount of coffee pulp waste is an environmental problem. Anaerobic fermentation is one of the alternative solutions. However, availability of coffee pulp does not appear for year-round, whereas biogas needs continuous feedstocks for digester stability. This research uses coffee pulp from Arabica Coffee Factory at Mengani, Kintamani, Bali–Indonesia. The coffee pulp was transformed into coffee pulp-hay product by sun drying for preservations to extend the raw materials through the year. Characterization of coffee pulp-hay was conducted after to keep for 15 mo for review the prospect as biogas feedstocks. Several parameters were analyzed such as C/N ratio, volatile solids, carbohydrate, protein, fat, lignocellulose content, macro-micro nutrients, and density. The review results indicated that coffee pulp-hay is prospective raw material for biogas feedstock. This well-proven preservation technology was able to fulfill the continuous supply. Furthermore, some problems were found in the recent preliminary experiment related to the density and fungi growth in the conventional laboratory digester. Further investigation was needed to implement the coffee pulp – hay as biogas feedstocks.

Health service use among children with and without eczema, asthma, and hay fever

Directory of Open Access Journals (Sweden)

Hammer-Helmich L

2016-09-01

Full Text Available Lene Hammer-Helmich,1,2 Allan Linneberg,1,3,4 Simon Francis Thomsen,5,6 Line Tang,1 Charlotte Glümer1,7 1Research Center for Prevention and Health, The Capital Region of Denmark, Copenhagen, 2Department of Real World Evidence and Epidemiology, H. Lundbeck A/S, Valby, 3Department of Clinical Experimental Research, Rigshospitalet, 4Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 5Department of Dermatology, Bispebjerg Hospital, 6Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 7Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark Background: Atopic diseases, for example, eczema, asthma, and hay fever, are among the most common chronic diseases of childhood. Knowledge on health service use among children with atopic disease is limited. This study aimed to investigate the total use and costs of health services for children with and without eczema, asthma, and hay fever in a Danish general population. Methods: We conducted a health survey with four complete birth cohorts from the City of Copenhagen. Individual questionnaire data on eczema, asthma, and hay fever for children aged 3, 6, 11, and 15 years were linked to register information on use and costs of health services and prescribed medication and parental education. In total 9,720 children participated (50.5%. Results: We found increased health service use (number of additional consultations per year [95% confidence interval] among children with current eczema symptoms (1.77 [1.29–2.26], current asthma symptoms (2.53 [2.08–2.98], and current hay fever symptoms (1.21 [0.74–1.67], compared with children without these symptoms. We also found increased use of prescribed medication and most subtypes of health services. Current asthma symptoms and current eczema symptoms, but not current hay fever symptoms, increased the health

Hay se agt Bybelse beginsels vir die ekonomiese lewe

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J.S. van Zyl

1996-03-01

Full Text Available Hay’s eight Biblical principles for economic lifeDonald Hay used the idea of stewardship to derive eight Biblical principles for economic life. The purpose of this article is to contribute commentary on and criticism of Hay's approach. The eight Biblical principles cover three main issues, namely creation and man's dominion, man and his work, and the distribution of goods. While social principles can be in conflict with each other, Biblical principles ought not to be in conflict. The test to determine whether the principles have been correctly derived is to revert back to the original text constantly. Upon further reflection it is possible to arrive at further applications of Biblical principles in relation to the sphere of economic life.

Rapid analysis of hay attributes using NIRS. Final report, Task II alfalfa supply system

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-10-24

This final report provides technical information on the development of a near infrared reflectance spectroscopy (NIRS) system for the analysis of alfalfa hay. The purpose of the system is to provide consistent quality for processing alfalfa stems for fuel and alfalfa leaf meal products for livestock feed. Project tasks were to: (1) develop an NIRS driven analytical system for analysis of alfalfa hay and processed alfalfa products; (2) assist in hiring a qualified NIRS technician and recommend changes in testing equipment necessary to provide accurate analysis; (3) calibrate the NIRS instrument for accurate analyses; and (4) develop prototype equipment and sampling procedures as a first step towards development of a totally automated sampling system that would rapidly sample and record incoming feedstock and outbound product. An accurate hay testing program was developed, along with calibration equations for analyzing alfalfa hay and sun-cured alfalfa pellets. A preliminary leaf steam calibration protocol was also developed. 7 refs., 11 figs., 10 tabs.

Volatile fatty acid profile for grass hay or alfalfa hay fed to alpacas (Vicugna pacos).

Science.gov (United States)

Oldham, C L; Robinson, T F; Hunter, Z R; Taylor, L; White, J; Johnston, N P

2014-10-01

The purpose of this study was to determine the diurnal composition and concentration of volatile fatty acids (VFA) and to determine VFA composition and concentration differences between stomach compartment 1 (C1) and caecum of alpacas fed grass and alfalfa hay. The study was divided into two experiments. In Experiment 1 (EXP 1), 10 male alpacas (3+ years old, 65 kg BW) were divided into two groups, housed in drylot pens, provided ad libitum water and fed alfalfa (AH) or grass hay (GH) for 30 days. The alpacas were slaughtered and the digestive tract collected, divided into sub-tract sections, weighed and digesta sampled for pH, dry matter (DM) and NDF. Volatile fatty acid composition and concentration were determined on C1 and caecal material. Four adult male (3+ years old, 60 kg BW), C1 fistulated alpacas were housed in metabolism crates and divided into two forage groups for Experiment 2 (EXP 2). Alpacas were fed the forages as in EXP 1. Diurnal C1 VFA samples were drawn at 1, 3, 6, 9, 12, 18 and 24 h post-feeding. There were no differences between forages for tract weight, C1 and caecum digesta DM or NDF. Differences were noted (p alpacas and the diurnal VFA patterns. Composition of VFA is similar to other ruminant species. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

Passage kinetics of digesta in horses fed with coastcross hay ground to different degrees

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Vinicius Pimentel Silva

2014-10-01

Full Text Available This study was conducted to evaluate the kinetics, physicochemical characteristics and particle size of digesta in the right ventral colon (RVC of horses fed coastcross hay ground to different degrees. Four horses fitted with cannulae in the RVC were used and were fed the following forms of hay: long, chopped, ground to 5 mm and ground to 3 mm. A Latin Square 4x4 study design was used. Each experimental period included 10 days for diet adaptation, four days for feces collection and one day for digesta collection. The kinetics of the particulate and solute phases of digesta were evaluated based on the mean retention time (MRT, passage rate (k and transit time (TT using two external markers: Cr-NDF and Co-EDTA. The TT of solid phase digesta was 3 hours longer (P0.05 in k or MRT in either the liquid or solid phase of digesta as a function of the different degrees of hay grinding. However, the liquid phase of digesta presented a higher k than the solid phase, with values of 3.28 and 2.73 h-1 being obtained, respectively. The smallest particle size and the lowest neutral detergent fiber contents in colon digesta were observed when hay ground to 3 mm was offered, leading to values of 0.51 mm and 53.46%, respectively. Grinding the hay increased the transit time of the liquid phase in the digestive tract of the horses, whereas no change in the kinetics of the solid phase digesta was observed. The grinding of hay reduced the NDF and the average particle size in the right ventral colon.

Ammoniated babassu palm hay in anglo-nubian goat diets

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Antonia Leidiana Moreira

Full Text Available ABSTRACT Leaves of babassu may be used in diets for goats under maintenance, however, it is a low-quality roughage due to its high fiber content. The chemical treatment by ammonia causes reduction in the proportion of the cell wall, in addition to providing non-protein nitrogen for the microbial protein synthesis in the rumen. Babassu palm hay ammoniated with 4% urea (BHAU4% was evaluated in this study as a substitute for guinea grass hay in the maintenance diets of goats in terms of intake, digestibility in vivo, and the partitioning of energy and nitrogen compounds. Twenty Anglo-Nubian male goats were used in a randomised block design with four treatments (diets containing 0, 33, 66, or 100% BHAU4% and five replicates (animals/block. The chemical compositions of the feeds, leftovers, faeces, nitrogen and crude energy of the urine were evaluated. In addition, the rumen fluid pH, the rumen N-NH3, and the blood serum urea were evaluated. The digestibility of the dry matter (DM, organic matter (OM, crud protein (CP, neutral detergent fiber (NDFap and detergent acid (ADFap, corrected for ash and protein, declined (P<0.05 0.0939, 0.0722, 0.0953, 0.1113, and 0.2666%, respectively, with the 1% inclusion of babassu palm hay in the diet. A negative linear effect (P<0.05 was observed in the ingested nitrogen (N, excretion of N in the urine, retained N, and N balance, with decreases of 0.15711, 0.0225 and 0.1071 g/day and 0.1388%, respectively, per percentage unit of the babassu palm hay included in the diet. The intake and digestibility of the DM and nutrients are reduced with the inclusion of BHAU4% in maintenance diets for goats, with positive nitrogen balance and stability of the ruminal pH and N-NH3 as well as blood urea, which presented values within the normal physiological range for goats.

Chevilly Larue, L'Hay les Roses: twin geothermal plants

International Nuclear Information System (INIS)

Jeanson, E.

1995-01-01

The Chevilly Larue/L'Hay les Roses (Paris region, France) low energy geothermal plants are interconnected and thus represent the greatest geothermal heat network in Europe. The two plants are 2.5 km apart and supply 13000 collective lodgings in energy using a 60 km network with a 75 MW power. Gas or fuel auxiliary heating systems are used in winter to increase water temperature up to 105 C, but the part of energy released by geothermics remains of about 70 to 80%. The network will be extended in the next years to Fresnes and Villejuif neighbouring towns. In 1996, the SEMHACH company, which manage the two plants, will put into service a mixed electricity and heat production plant in L'Hay les Roses. (J.S.). 2 photos

Desarrollo de Herramientas Enfocadas en Ayudar a las Pymes de Desarrollo de Software en la Implementación de Buenas Prácticas de Gestión de Proyectos

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Yolanda-Meredith García

2017-05-01

Full Text Available La Industria del desarrollo de software constituye un factor clave en la economía. En Latinoamérica este sector se compone por el 99% de pymes. Esto resalta la importancia de la implementación de buenas prácticas de ingeniería de software en las pymes para asegurar su mejora continua. En este contexto, existen diversos modelos y estándares que contienen buenas prácticas enfocadas en mejorar los procesos de desarrollo de software tales como CMMI, ISO-12207, ISO-15504, etc. Sin embargo, para aplicar dichos modelos, las pymes requieren adaptarlos según su tamaño y tipo de negocio. Por lo tanto, se apoyan de técnicas y herramientas para la implementación de buenas prácticas contenidas en ellos. El objetivo de este artículo es presentar una herramienta que facilita la implementación de buenas prácticas para realizar una la gestión de riesgos básica en una pyme.

Mid-late Holocene environments of Agua Buena locality (34050'S; 69056'W), Mendoza, Argentina

International Nuclear Information System (INIS)

Navarro, Diego; Paez, M M; Mehl, A; Zarate, M A

2010-01-01

In southern South America the acquisition of high-quality Holocene paleoclimate data is a priority due to the paucity of complete, continuous and well dated records. Here we report preliminary results from a combined sedimentological and palynological study of an alluvial fan sequence and the laterally connected sedimentary deposits of the Vega de la Cueva profile at Agua Buena east of the Andes in central Argentina. The main geomorphological units of the area were identified and mapped based on satellite image analysis and multiple field surveys. The sedimentological and pollen results allowed us to reconstruct the development of some environments. The Agua Buena record corresponds to the distal facies of the Arroyo Bayo alluvial fan starting the aggradation process prior to ca. 4100 cal yr BP. The organic-rich levels found were formed during the development of wetlands (vegas) dominated by Cyperaceae, Juncaceae and Poaceae. These highly productive environments with almost permanent water saturation were important between 4100 and 2800 cal yr BP, indicating more stable conditions. After 2800 cal yr BP, the organic content was comparatively lower with increasing sedimentation rates that are indicative of higher fluvial discharges. This information is fundamental to interpret both the pollen and charcoal records of the area and to evaluate their representativeness and potential to reconstruct past local and/or regional vegetation.

Los procesos de globalización y transferencia tecnológica

OpenAIRE

Luis Murillo Orozco.

2000-01-01

Este artículo presente un breve análisis del significado de globalización y de transferencia tecnológica, dos procesos indisolubles y concatenados entre sí que deben ser tomados como medios fundamentales y no como fines para enfrentar el giro de la competencia económica actual. Esta competencia se ha trasladado del ámbito empresarial y de país, al ámbito de la integración económica. Hay que tomar en cuenta que no Se puede lograr una buena posición en el ámbito internacional sin una buena y ad...

Rumen volatile fatty acids and milk composition from cows fed hay, haylage, or urea-treated corn silage.

Science.gov (United States)

Schingoethe, D J; Voelker, H H; Beardsley, G L; Parsons, J G

1976-05-01

Alfalfa-brome hay, haylage, .5% urea-treated corn silage, or .5% urea plus 1% dried whey-treated corn silage was fed as the only forage to one of four groups of 10 lactating cows per group for a lactation trial of 10 wk. Rumen samples were collected via stomach tube 3 to 4 h after the morning feeding. The pH of the rumen samples from cows fed hay was higher than for cows fed haylage, urea-treated corn silage, and urea-whey corn silage, 6.69 versus 6.36, 6.40, and 6.50. Total volatile fatty acids and propionate were highest from cows fed urea-whey corn silage and were higher on all three fermented forages than cows fed hay. Acetate/propionate ratio was highest from cows fed hay and lowest from cows fed corn silages. Butyrate was highest from cows fed haylage or hay. Milk protein composition was not affected by ration although nonprotein nitrogen of milk was highest from cows fed the urea-treated corn silages. Oleic acid and total unsaturated fatty acids were lowest in milk fat from cows fed hay while palmitic acid was highest from cows fed hay and haylage. These results suggest that type of forage fed may cause small changes in rumen fermentation and in milk composition. The importance of these changes is unknown but may affect properties of dairy products produced from this milk.

Fibrolytic enzyme and ammonia application effects on the nutritive value, intake, and digestion kinetics of bermudagrass hay in beef cattle.

Science.gov (United States)

Romero, J J; Zarate, M A; Queiroz, O C M; Han, J H; Shin, J H; Staples, C R; Brown, W F; Adesogan, A T

2013-09-01

The objectives were to compare the effect of exogenous fibrolytic enzyme (Biocellulase A20) or anhydrous ammonia (4% DM) treatment on the nutritive value, voluntary intake, and digestion kinetics of bermudagrass (Cynodon dactylon cultivar Coastal) hay harvested after 2 maturities (5- and 13-wk regrowths). Six individually housed, ruminally cannulated Brangus steers (BW 325 ± 10 kg) were used in an experiment with a 6 × 6 Latin square design with a 3 (additives) × 2 (maturities) factorial arrangement of treatments. Each period consisted of 14 d of adaptation and 7, 4, 1, 1, and 4 d for measuring in vivo digestibility, in situ degradability, no measurements, rumen liquid fermentation and passage indices, and rate of solid passage, respectively. Steers were fed hay for ad libitum intake and supplemented with sugarcane molasses and distillers grain (supplement total of 2.88 kg DM/d). Enzyme did not affect the nutritional composition of hay but ammonia treatment decreased hay NDF, hemicellulose, and ADL concentrations and increased the CP concentration particularly for the mature lignified 13-wk hay. The enzyme increased NDF and hemicellulose digestibility of the 5-wk hay but decreased those of the 13-wk hay. Ammoniation decreased intake of hay but increased digestibility of DM, OM, NDF, hemicellulose, ADF, and cellulose and increased the ruminal in situ soluble and potentially digestible fractions and the rate of DM degradation of the 13-wk hay. Also, ammoniation increased the concentrations of ruminal NH3, total VFA, acetate, and butyrate but enzyme treatment did not. Neither enzyme addition nor ammoniation affected rate of liquid and solid passage. In conclusion, ammoniation decreased the concentration of most fiber fractions, decreased the intake of hays, and increased their CP concentration, in vivo digestibility, and in situ degradability at both maturities whereas enzyme application increased fiber digestibility of the 5-wk hay but decreased it in the case of

Buenas prácticas en el ámbito educativo y su orientación a la gestión del conocimiento

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Doris Jerí Rodríguez

2008-12-01

Full Text Available El artículo aporta diversas aproximaciones sobre uno de los conceptos que ha ido cobrando fuerza en la literatura educativa interesada en reconocer los avances de las escuelas: las buenas prácticas. Para ello el texto contribuye, sobre la base de la bibliografía actual, a rescatar las definiciones y alcances de este enfoque centrado en las buenas prácticas educativas. El artículo logra además presentar las contribuciones de este enfoque en el ámbito de la gestión del conocimiento en las organizaciones educativas y, en particular, se presentan sus aportes en relación con la gestión del proceso de enseñanza-aprendizaje.

[A review on studies and applications of near infrared spectroscopy technique(NIRS) in detecting quality of hay].

Science.gov (United States)

Ding, Wu-Rong; Gan, You-Min; Guo, Xu-Sheng; Yang, Fu-Yu

2009-02-01

The quality of hay can directly affect the price of hay and also livestock productivity. Many kinds of methods have been developed for detecting the quality of hay and the method of near infrared spectroscopy (NIRS) has been widely used with consideration of its fast, effective and nondestructive characteristics during detecting process. In the present paper, the feasibility and effectiveness of application of NIRS to detecting hay quality were expounded. Meanwhile, the advance in the study of using NIRS to detect chemical compositions, extent of incursion by epiphyte, amount of toxicant excreted by endogenetic epiphyte and some minim components that can not be detected by using chemical methods were also introduced detailedly. Based on the review of the progresses in using NIRS to detect the quality of hay, it can be concluded that using NIRS to detect hay quality can avoid the disadvantages of time wasting, complication and high cost when using traditional chemical method. And for better utilization of NIRS in practice, some more studies still need to be implemented to further perfect and improve the utilization of NIRS for detecting forage quality, and more accurate modes and systematic analysis software need to be established in times to come.

BUENAS PRÁCTICAS DE AULAS VIRTUALES EN LA DOCENCIA UNIVERSITARIA SEMIPRESENCIAL

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Manuel Area Moreira

2010-02-01

Full Text Available En este artículo presentamos el diseño y resultados de un estudio realizado en la Universidad de La Laguna (ULL destinado a identificar buenas prácticas de aulas virtuales en la docencia universitaria desarrolladas bajo la modalidad de blended learning o enseñanza semipresencial. El estudio se desarrolló en el primer trimestre del año 2008 y analizó una importante muestra de las aulas virtuales (N= 107 existentes en el Campus Virtual de dicha universidad en el periodo 2005-07. Se seleccionaron seis ejemplos de aulas virtuales, clasificados por campos científicos, caracterizadas por la incorporación de recursos de información, de comunicación y de aprendizaje experiencial.

The HayWired Earthquake Scenario—Earthquake Hazards

Science.gov (United States)

Detweiler, Shane T.; Wein, Anne M.

2017-04-24

The HayWired scenario is a hypothetical earthquake sequence that is being used to better understand hazards for the San Francisco Bay region during and after an earthquake of magnitude 7 on the Hayward Fault. The 2014 Working Group on California Earthquake Probabilities calculated that there is a 33-percent likelihood of a large (magnitude 6.7 or greater) earthquake occurring on the Hayward Fault within three decades. A large Hayward Fault earthquake will produce strong ground shaking, permanent displacement of the Earth’s surface, landslides, liquefaction (soils becoming liquid-like during shaking), and subsequent fault slip, known as afterslip, and earthquakes, known as aftershocks. The most recent large earthquake on the Hayward Fault occurred on October 21, 1868, and it ruptured the southern part of the fault. The 1868 magnitude-6.8 earthquake occurred when the San Francisco Bay region had far fewer people, buildings, and infrastructure (roads, communication lines, and utilities) than it does today, yet the strong ground shaking from the earthquake still caused significant building damage and loss of life. The next large Hayward Fault earthquake is anticipated to affect thousands of structures and disrupt the lives of millions of people. Earthquake risk in the San Francisco Bay region has been greatly reduced as a result of previous concerted efforts; for example, tens of billions of dollars of investment in strengthening infrastructure was motivated in large part by the 1989 magnitude 6.9 Loma Prieta earthquake. To build on efforts to reduce earthquake risk in the San Francisco Bay region, the HayWired earthquake scenario comprehensively examines the earthquake hazards to help provide the crucial scientific information that the San Francisco Bay region can use to prepare for the next large earthquake, The HayWired Earthquake Scenario—Earthquake Hazards volume describes the strong ground shaking modeled in the scenario and the hazardous movements of

Uudised : Isaac Hayes loobub koka rollist. Bergeni festival soomestub

Index Scriptorium Estoniae

2006-01-01

Satiirilises animaseriaalis "South Park" mustanahalise koolikoka rollis lugenud soulilauljast Isaak Hayes'ist. 24. maist 6. juunini kestval Bergeni kultuurifestivalil Norras tulevad esitusele Jean Sibeliuse sümfooniad, Magnus Lindbergi heliteosed, koreograaf Tomi Paasoneni teos "Olotila" ja pianist Juho Pohjoneni klverikontsert

Digestibility Nutrient Contents on Acacia Seyal, Balanities Aegyptiaca and Chloris Gayana Hay

International Nuclear Information System (INIS)

Kiliti, J.K

2002-01-01

A study was carried to determine the nutrients and their digestibility in Acacia seyal and Balanities aegyptiaca legume browses and compared with Chloris gayana hay. Samples were taken from these two leguminous forages at Mogotio and Emining divisions of Koibatek district and fed to sheep in a change over design. The sheep were housed in individual pens and fitted with faecal collection bags. They were fed and faeces collected twice daily. An adaptation period of 14 days, Faecal collection of 7 days and changeover of 10 days were enforced. Nutrients analysed for during digestibility included DM, OM, CP, NDF, Hemicellulose and Cellulose. The nutrients compositions were 651, 916, 112, 370, 339, 59 and 84; 665, 920, 152, 443, 341, 89 and 80, 845, 924, 68, 730, 463, 57, and 76 for DM, OM, CP, NDF, ADF, and ash in Acacia seal, Balanities aegyptiaca and Chloris gayana hay. The in vivio digestibility results were different (p<0.05) for all nutrients. The digestibilities of DM, OM, CP NDF, Hemicellulose and Cellulose in Acacia seyal, Balanities aegyptiaca and Chloris gayana hay were 54.7, 66.5, 32.8, 40.3, 51.7, and 82.7; 48.5, 58.9, 67.4, 36.9, 36.3, and 40.6 and 48.1, 50.4, 41.7, 53.7, 63.0 and 62.3% respectively. The two legume forages had nutrients that had higher digestibility than hay except for fibre

Ruminal degradability of oat (Avena sativum L., Coast cross (Cynodon dactilon L., and Esmeralda grass (Joysia japonica hay pellet or not/ Degradabilidade ruminal dos fenos de aveia (Avena sativum L, Coast cross (Cynodon dactilon L., e grama Esmeralda (Joysia japonica peletizado ou não

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Teresa Cristina Alves

2006-06-01

Full Text Available The objective of this work was to evaluate the ruminal degradability of dry matter (DM, crude protein (CP, neutral detergent fiber (NDF and acid detergent fiber (ADF of the oat hay (OH, Coast cross hay (CCH, pellet Esmeralda grass hay (PEH and Esmeralda grass hay (EH. The in situ technique was used, with four bovines, castrated, rumen fistulated, distributed in an Latin square 4x4 experimental design. The material was incubated in the rumen in the times 0, 6, 24, 48, 72 and 144 hours. There was no difference between hays on the degradation rate (c, %/h for the CP, NDF and ADF. For the DM, the OH and PEH presented higher degradation rate. There was difference on the effective degradability (ED, % of the hays, and the observed values were: OH, 48.74%; PEH, 42.44%; EH, 35.13%; CCH, 30.24%. It can be concluded that oat hay presented the highest values for the soluble fraction and for the ED of all nutrients evaluated. The pellet process of the Esmeralda grass resulted in higher ED of the DM and of the fiber, with no alteration on the CP ED.O objetivo deste trabalho foi avaliar a degradabilidade ruminal da matéria seca (MS, proteína bruta (PB, fibra em detergente neutro (FDN e fibra em detergente ácido (FDA do feno de aveia (FA, feno de Coast cross (FCC, feno de grama Esmeralda peletizado (FEP e feno de grama Esmeralda (FE. Foi utilizada a técnica in situ com quatro bovinos machos, castrados, fistulados no rúmen, distribuídos em um delineamento experimental em quadrado latino 4x4. O material foi incubado no rúmen nos tempos de 0, 6, 24, 48, 72 e 144 horas. Não houve diferença entre os fenos na taxa de degradação (c, %/h para a PB, FDN e FDA. Para a MS, o FA e FEP apresentaram maior taxa de degradação. Houve diferença na degradabilidade efetiva (DE da MS dos fenos sendo os valores observados: FA, 48,74%; FEP, 42,44%; FE, 35,13%; FCC, 30,24%. Conclui-se que o feno de aveia obteve maiores valores para a fração solúvel e maior

Effects of feeding steers extruded flaxseed on its own before hay or mixed with hay on animal performance, carcass quality, and meat and hamburger fatty acid composition.

Science.gov (United States)

Vahmani, P; Rolland, D C; McAllister, T A; Block, H C; Proctor, S D; Guan, L L; Prieto, N; López-Campos, Ó; Aalhus, J L; Dugan, M E R

2017-09-01

The objective of the present experiment was to determine if carcass quality and fatty acid profiles of longissimus thoracis (LT) and hamburger would be affected by feeding steers extruded flaxseed on its own followed by hay (non-TMR) compared to when hay and extruded flaxseed were fed together (TMR). Forty-eight steers in six pens were assigned to TMR or non-TMR for an average of 242days. Dry matter intake was lower for non-TMR versus TMR steers (10.56 vs. 11.42kg/d; P=0.02), but final live weight (610±0.50kg) and average daily gain (1.18±0.02kg/d) did not differ. Compared to TMR, feeding non-TMR enriched LT and hamburger with α-linolenic acid (ALA; 18:3n-3) by 14%, vaccenic acid (VA; t11-18:1) by 44%, rumenic acid (RA; c9,t11-18:2) by 40%, and conjugated linolenic acid (CLnA) by 58%. Overall, feeding extruded flaxseed separately from hay in a non-TMR was more effective at enhancing deposition of ALA, VA, RA and CLnA in beef. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Ética y estética de la conducta en los manuales de buenas maneras españoles Ética y estética de la conducta en los manuales de buenas maneras españoles

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Fernando Ampudia de Haro

2007-03-01

Full Text Available The aim of the article is to give the reader a general idea as to established relationships between ethics and appearances in social conduct as they have appeared in various good manuals on social behaviour from medieval times to present.In relation to this, many proposals from varying viewpoints have been presented dealing with the decline of moral content in such manuals. Ultimately these manuals propose two comprehensive models concerning the relationship between ethics and appearances, refered to as aristotalian and kantian respectively.El propósito del artículo es efectuar una aproximación general al tipo de relación que se establece entre ética y estética de la conducta tal y como ésta ha sido planteada en los diferentes manuales de buenas maneras que se han publicado en España desde la Baja Edad Media hasta nuestros días. Se proponen, a partir de esos mismos manuales, dos modelos comprensivos de las relaciones entre ética y estética del comportamiento aquí denominados aristotélico y kantiano respectivamente. Por último, se presentan diversas propuestas explicativas en torno a la disolución del contenido moral de las buenas maneras en tales manuales.

Sporotrichosis outbreak and mouldy 
hay in NSW.

Science.gov (United States)

Dhingra, Deeksha; Durrheim, David; Porigneaux, Philippe

2015-04-01

Sporotrichosis is a subacute/chronic fungal infection caused by Sporothrix schenckii. The fungus thrives on organic matter including hay, wood, moss, soil and plants. Zoonotic transmission has also been reported. Lesions present as superficial skin nodules that become purulent and ulcerate. Lymphocutaneous spread is common. Haematogenous spread is uncommon and case fatality is rare. The aim of this article is to describe an outbreak of sporotrichosis in New South Wales. A cluster of six cases was identified in the NSW mid-north coast area in the first half of 2013. Telephone interviews were conducted in an attempt to identify possible exposures. General practitioners were contacted to report on patients with chronic non-healing skin lesions. A batch of mouldy hay supplied by a local farmer was identified as the potential source of exposure. Despite effective treatment with oral antifungals, diagnosis of sporotrichosis is often delayed and prolonged courses of antibiotics are unnecessarily prescribed. Timely detection and management (including referral to a dermatologist or infectious diseases specialist) significantly reduces morbidity. Personal protection is the key to prevention.

34 CFR 664.40 - Can participation in a Fulbright-Hays Group Projects Abroad be terminated?

Science.gov (United States)

2010-07-01

... PROJECTS ABROAD PROGRAM What Conditions Must Be Met by a Grantee? § 664.40 Can participation in a Fulbright-Hays Group Projects Abroad be terminated? (a) Participation may be terminated only by the J. William... 34 Education 3 2010-07-01 2010-07-01 false Can participation in a Fulbright-Hays Group Projects...

Greenhouse gas fluxes of grazed and hayed wetland catchments in the U.S. Prairie Pothole Ecoregion

Science.gov (United States)

Finocchiaro, Raymond G.; Tangen, Brian A.; Gleason, Robert A.

2014-01-01

Wetland catchments are major ecosystems in the Prairie Pothole Region (PPR) and play an important role in greenhouse gases (GHG) flux. However, there is limited information regarding effects of land-use on GHG fluxes from these wetland systems. We examined the effects of grazing and haying, two common land-use practices in the region, on GHG fluxes from wetland catchments during 2007 and 2008. Fluxes of methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2), along with soil water content and temperature, were measured along a topographic gradient every other week during the growing season near Ipswich, SD, USA. Closed, opaque chambers were used to measure fluxes of soil and plant respiration from native sod catchments that were grazed or left idle, and from recently restored catchments which were seeded with native plant species; half of these catchments were hayed once during the growing season. Catchments were adjacent to each other and had similar soils, soil nitrogen and organic carbon content, precipitation, and vegetation. When compared with idle catchments, grazing as a land-use had little effect on GHG fluxes. Likewise, haying had little effect on fluxes of CH4 and N2O compared with non-hayed catchments. Haying, however, did have a significant effect on combined soil and vegetative CO2 flux in restored wetland catchments owing to the immediate and comprehensive effect haying has on plant productivity. This study also examined soil conditions that affect GHG fluxes and provides cumulative annual estimates of GHG fluxes from wetland catchment in the PPR.

Game and Digital Culture: A Study on Hay Day Game

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Mia Angeline

2016-01-01

Full Text Available Digital games are a commercial product developed and distributed by media companies and often uses characters or scenarios of movies, books, and comics. The digital game play comes from individual media consumption patterns. Playing digital games also offer experience and satisfaction based on interactive communication technologies and immersive gameplay. In this digital age, digital games became more social-based, which means they implement the need to invite friends on social media to come into play and help each other in the game. The problems of this study was to determine what factors make Hay Day popular among the players and to find out how Hay Day changing the social patterns interaction of the players. This study aims to look at the functions of digital games in the context of communication with relations in social media and why certain games can achieve very high popularity, while other games failed miserably. This research focuses on Hay Day. The method used is descriptive qualitative approach with case study method. Data collection is using interviews with players active in the game, as well as observation and literature studies. The results showed that a game may gain popularity if someone has a social media environment prior to play. Interactive concept, simulation, and fantasy game technology are also the reason Hay Day became very popular. The perception that the digital game player who formerly regarded as anti-social experience has shifted in the concept of digital game-based social bookmark. Players who have a lot of friends in games are seen as someone who has a lot of friends and a high social level. This is in line with the functions of a traditional game in Indonesian culture, where the region has a wide variety of games to be played together and motivate positive social interaction. Function of digital games also increased, other than playing the game as entertainment, but also now the game became one of the effective

Feeding behavior of lambs fed with diets containing mulberry hay

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Luís Gabriel Alves Cirne

2014-02-01

Full Text Available The experiment was conducted to evaluate the feeding behavior of lambs fed with diets containing 0, 12.5 and 25.0% of mulberry hay as a substitute for the concentrate. Twenty four Ile de France lambs, non castrated, with 25 kg of body weight and four months old, confined, in a completely randomized design, were used. The feeding daily time (242.01 minutes, rumination (435.48 minutes and leisure (762.50 minutes, the numbers of cakes ruminated per day (658.36 and the time spent per cake (40.03 sec were not affected (P>0.05 by different levels of hay in mulberry concentrate. The dry matter voluntary intake (1.258 kg/day and neutral detergent fiber intake (0.302 kg/day, as well as the efficiency of dry matter intake and rumination (316.24 and 173.54 g/h, respectively and efficiency of neutral detergent fiber intake and rumination (75.89 and 41.68 g/h, respectively were similar in all treatments. The ruminating chew expressed in hour/day (11.29 and the number of chews expressed per cake (72.65 and per day (47.638.06, as well as the number and the feeding time (22.02 meals and 11.23 min/meal, rumination (25.95 ruminations and 17.29 min/rumination and idle (41.81 idle and 18.30 min/idle time, were also not affected (P>0.05. The inclusion of mulberry hay did not change the rumination expressed in g of DM and NDF/cake (1.91 and 0.46, respectively and min/kg of DM and NDF (361.51 and 1.505.78, respectively, as well as the total chew expressed in min/kg of DM and NDF (563.70 and 2.347.19, respectively. The use of mulberry hay partially replacing the concentrated, does not change the feeding behavior of feedlot lambs.

The combined effects of family size and farm exposure on childhood hay fever and atopy.

Science.gov (United States)

Genuneit, Jon; Strachan, David P; Büchele, Gisela; Weber, Juliane; Loss, Georg; Sozanska, Barbara; Boznanski, Andrzej; Horak, Elisabeth; Heederik, Dick; Braun-Fahrländer, Charlotte; von Mutius, Erika

2013-05-01

Exposure to farming environments and siblings is associated with reduced risks of childhood hay fever and atopy. We explored the independence and interaction of these protective effects in the GABRIELA study. Questionnaire surveys on farming, asthma, and allergies were conducted in four central European areas among 79,888 6-12-yr-old children. Aeroallergen-specific serum IgE was measured in a stratified sample of 8,023 children. Multiple logistic regression was used to compare gradients in allergy prevalence by sibship size across three categories of exposure to farming environments. The prevalence of hay fever ranged from 2% (95% confidence interval 1.6%; 2.7%) among farmers' children with more than two siblings to 12% (11.2%; 13.0%) among children with no farm exposure and no siblings. Farming families were larger on average. More siblings and exposure to farming environments independently conferred protection from hay fever and atopy. There was no substantial effect modification between family size and exposure to farming environments. The odds ratios for hay fever per additional sibling were 0.79 among unexposed non-farm children, 0.77 among farm-exposed non-farm children, and 0.72 among children from farming families (2df interaction test: p = 0.41). The inverse association of exposure to farming environments with hay fever is found in all sizes of family, with no substantial tendency to saturation or synergism. This suggests that different biological mechanisms may underlie these two protective factors. Combinations of a large family and exposure to farming environments markedly reduce the prevalence of hay fever and indicate the strength of its environmental determinants. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

PENGARUH CARA PENGAWETAN TERHADAP KOMPOSISI KIMIA DAN EFISIENSI DALAM BENTUK HAY DAN SILASE PADA DAUN 16 PROVENAN GAMAL (GLIRICIDIA SEPIUM

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A. W. Puger

2012-09-01

Full Text Available RINGKASAN Percobaan yang bertujuan untuk mengetahui pengaruh cara pengawetan terhadap kandungan zat-zat makanan dan efisiensinya pada daun 16 provenan gamal telah dilaksanakan selama 3 bulan. Penelitian menggunakan rancangan acak lengkap yang terdiri atas 3 perlakuan pengawetan (gamal segar, gamal hay, dan gamal silase dan 3 blok sebagai ulangan. Setiap perlakuan terdiri atas 16 provenan, yaitu 6 dari Mexico (M, 4 dari Guatemala (G, dan satu provenan masing-masing dari Colombia (C, Indonesia (I, Nicaragua (N, Panama (P, Costa Rica (R, dan Venezuela (V. Sampel setiap daun (helai dan tangkai provenan sebelum dan setelah diawetkan dianalisis kandungan zat-zat makanannya dan dihitung efisiensinya setelah dibuat hay dan silase. Kandungan DM dan CP dari hay adalah tertinggi (P0,05 setelah diawetkan menjadi hay dan silase, sedangkan efisiensi DM, OM, dan CP dari hay lebih tinggi (P<0,05 daripada silase. Provenan P13, R12, dan M34 mengandung zat-zat makanan lebih tinggi; sementara provenan G14 dan G17 lebih efisien bila diawetkan dalam bentuk hay dan silase. Pada pertanian lahan kering pengawetan gamal dalam bentuk hay lebih efektif dan efisien jika dibandingkan dengan dalam bentuk silase.

Weaned beef calves fed selenium-biofortified alfalfa hay have an enriched nasal microbiota compared with healthy controls.

Science.gov (United States)

Hall, Jean A; Isaiah, Anitha; Estill, Charles T; Pirelli, Gene J; Suchodolski, Jan S

2017-01-01

Selenium (Se) is an essential trace mineral important for immune function and overall health of cattle. The nasopharyngeal microbiota in cattle plays an important role in overall respiratory health, especially when stresses associated with weaning, transport, and adaptation to a feedlot affect the normal respiratory defenses. Recent evidence suggests that cattle diagnosed with bovine respiratory disease complex have significantly less bacterial diversity. The objective of this study was to determine whether feeding weaned beef calves Se-enriched alfalfa (Medicago sativa) hay for 9 weeks in a preconditioning program prior to entering the feedlot alters nasal microbiota. Recently weaned beef calves (n = 45) were blocked by sex and body weight, randomly assigned to 3 treatment groups with 3 pens of 5 calves per treatment group, and fed an alfalfa hay based diet for 9 weeks. Alfalfa hay was harvested from fields fertilized with sodium selenate at a rate of 0, 45.0 or 89.9 g Se/ha. Blood samples were collected biweekly and analyzed for whole-blood Se concentrations. Nasal swabs were collected during week 9 from one or two calves from each pen (total n = 16). Calculated Se intake from dietary sources was 3.0, 15.6, and 32.2 mg Se/head/day for calves consuming alfalfa hay with Se concentrations of 0.34 to 2.42 and 5.17 mg Se/kg dry matter, respectively. Whole-blood Se concentrations after 8 weeks of feeding Se-fertilized alfalfa hay were dependent upon Se-application rates (0, 45.0, or 89.9 g Se/ha) and were 155, 345, and 504 ng/mL (PLinear Microbial DNA was extracted from nasal swabs and amplified and sequenced. Alpha rarefaction curves comparing the species richness (observed OTUs) and overall diversity (Chao1, Observed OTU, and Shannon index) between calves fed selenium-biofortified alfalfa hay compared with control calves showed that Se-supplementation tended to be associated with an enriched nasal microbiota. ANOSIM of unweighted UniFrac distances showed that calves

Weaned beef calves fed selenium-biofortified alfalfa hay have an enriched nasal microbiota compared with healthy controls

Science.gov (United States)

Hall, Jean A.; Isaiah, Anitha; Estill, Charles T.; Pirelli, Gene J.; Suchodolski, Jan S.

2017-01-01

Selenium (Se) is an essential trace mineral important for immune function and overall health of cattle. The nasopharyngeal microbiota in cattle plays an important role in overall respiratory health, especially when stresses associated with weaning, transport, and adaptation to a feedlot affect the normal respiratory defenses. Recent evidence suggests that cattle diagnosed with bovine respiratory disease complex have significantly less bacterial diversity. The objective of this study was to determine whether feeding weaned beef calves Se-enriched alfalfa (Medicago sativa) hay for 9 weeks in a preconditioning program prior to entering the feedlot alters nasal microbiota. Recently weaned beef calves (n = 45) were blocked by sex and body weight, randomly assigned to 3 treatment groups with 3 pens of 5 calves per treatment group, and fed an alfalfa hay based diet for 9 weeks. Alfalfa hay was harvested from fields fertilized with sodium selenate at a rate of 0, 45.0 or 89.9 g Se/ha. Blood samples were collected biweekly and analyzed for whole-blood Se concentrations. Nasal swabs were collected during week 9 from one or two calves from each pen (total n = 16). Calculated Se intake from dietary sources was 3.0, 15.6, and 32.2 mg Se/head/day for calves consuming alfalfa hay with Se concentrations of 0.34 to 2.42 and 5.17 mg Se/kg dry matter, respectively. Whole-blood Se concentrations after 8 weeks of feeding Se-fertilized alfalfa hay were dependent upon Se-application rates (0, 45.0, or 89.9 g Se/ha) and were 155, 345, and 504 ng/mL (PLinear calves fed selenium-biofortified alfalfa hay compared with control calves showed that Se-supplementation tended to be associated with an enriched nasal microbiota. ANOSIM of unweighted UniFrac distances showed that calves fed high Se-biofortified alfalfa hay clustered separately when compared with control calves in the PCoA plot (R = 0.216, P = 0.04). The bacterial orders Lactobacillales and Flavobacteriales were increased in healthy

The effect of five different wetting treatments on the nutrient content and microbial concentration in hay for horses.

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Meriel Jean Scott Moore-Colyer

Full Text Available Five different hays were used to determine the effect of 5 different soaking and steaming treatments on the water soluble carbohydrate and microbial (bacteria and mould contents of UK hay. Hays were subjected to the following 5 treatments: 1. Dry; 2. Steamed for 50 minutes in the Haygain- 600 steamer; 3. Soaked in water at 16°C for 9 hours; 4. Steamed then soaked and 5. Soaked then steamed. Post treatment hays were tested for water soluble carbohydrates, bacteria and mould contents. Differences between means were determined using ANOVA and least significant difference with hay (5, bale (3 and treatment (5 as fixed factors, thus n = 75. Protein and ash proportions were unaltered in any of the treatments. Soaked, steamed then soaked and soaked then steamed treatments were all equally effective at reducing water soluble carbohydrates, with significantly (P<0.05 lower mean contents (79-83 g/kg DM compared with 126 and 122 g/kg dry matter (DM for dry and steamed respectively. Steamed and soaked then steamed had significantly (P<0.05 less bacteria (1.04×103 and 4.9×102 CFU/g DM compared with soaked which increased CFU/g DM from 6.0×104 in dry hay up to 3.5×105. Mould contents CFU/g DM were significantly (P<0.05 reduced by steaming (2 and soaking then steaming (1.9 but no difference was seen between dry (1148, soaked (692 or steamed then soaked (501. Soaking for 9 hours followed by steaming for 50 minutes in the Haygain steamer was the most effective method for reducing water soluble carbohydrates and microbial contamination in hay. Soaking or steaming+soaking lowered water soluble carbohydrates but significantly reduced the hygienic quality of the hay which could potentially compromise the health of the horse.

Actitudes docentes hacia las TIC en centros de buenas prácticas educativas con orientación inclusiva

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José M.ª FERNÁNDEZ BATANERO

2013-01-01

Full Text Available El presente artículo recoge los resultados de un estudio cuyo objetivo ha sido determinar las actitudes del profesorado hacia el uso e integración de las Tecnologías de la Información y Comunicación (TIC en aulas inclusivas, así como la identificación de aquellos factores que favorecen buenas prácticas educativas con apoyo de dichas tecnologías. Respecto del tipo de diseño, se trata de un estudio de casos múltiple, concretamente de dos centros educativos, de titularidad pública, de Educación Secundaria Obligatoria de la ciudad de Sevilla (España. La selección de los casos se hizo teniendo en cuenta el criterio de ser dos centros educativos de orientación inclusiva y estar catalogados por la Administración Educativa Andaluza como de «buenas prácticas». Las técnicas utilizadas para la recogida de la información han sido el cuestionario y el grupo de discusión. Los resultados señalan, por un lado, que de manera general los docentes poseen actitudes positivas hacia las TIC, especialmente el profesorado de género masculino y aquellos que cuentan con mayores posibilidades de interacción con las mismas. Por otro lado, el hecho de contar con medios materiales suficientes; dar importancia al constructivismo; adaptar las tareas y actividades a las características del alumnado; estimular el trabajo autónomo y colaborativo; y la capacidad para fomentar políticas y culturas inclusivas entre redes de centros educativos se presentan como factores importantes para desarrollar buenas prácticas educativas con apoyo de TIC.

Effects of phenolic acid structures on meadow hay digestibility

NARCIS (Netherlands)

Rodrigues, M.A.M.; Guedes, C.M.; Cone, J.W.; Gelder, van A.H.; Ferreira, L.M.M.; Sequeira, C.A.

2007-01-01

The objectives were to evaluate effects of phenolic acid content and composition on the digestibility of six meadow hays from Northern Portugal. Digestibility was assessed by gas production, in vitro and in situ degradation methods. Four cows fed diets at energy maintenance were used for in situ

Buena fortuna y felicidad en la ética cartesiana

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Marvin Estrada

2017-12-01

Full Text Available En este artículo pretendo principalmente mostrar por qué Descartes afirma que la buena fortuna no es necesaria para alcanzar la felicidad. Primero mostraré la diferencia que  Descartes establece entre felicidad y dicha. Luego mostraré que Descartes considera que la felicidad solo puede obtenerse mediante la práctica de la virtud ya que esta constituye el bien supremo al que puede aspirar cada individuo y expondré las razones que apoyan esta afirmación.  Al estar la virtud enteramente en nuestro poder se ve claramente que el favor de la fortuna no es necesario para alcanzar la felicidad. También mostraré que si bien los bienes de la fortuna pueden producir contento, no son necesarios para lograr la felicidad del individuo. Sin embargo, Descartes indica que estos bienes sí son importantes para lograr alcanzar el bien supremo del conjunto de todos los seres humanos. Finalmente expondré brevemente que, según Descartes, la virtud también es necesaria para poder disfrutar adecuadamente del favor de la fortuna.

The ecological behaviour of 55Fe in plants and in the flesh of cattle and game

International Nuclear Information System (INIS)

Barwinek, F.; Kreuzer, W.; Sansoni, B.; Kernforschungsanlage Juelich G.m.b.H.

1980-01-01

98 samples of shrub lichens taken between 1965 and 1970, including 69 from the Federal Republic of Germany and 15 from Finland, mainly of the genus Cladonia, particularly the species Cladonia rangiferina and Cladonia silvatica, 5 samples of moss, 2 of heather and 4 of hay, and also meat samples taken from 12 Bavarian cattle slaughtered in the spring of 1970, 7 stags killed in the Eastern Carpathians in the autumn of 1969 and one chamois shot in the Lower Tauern mountains in the autumn of 1970, were all analysed for their contents of 55 Fe and stable Fe. The lichens contained between 0.7 - in 1970 - and a maximum of 139.0 nCi 55 Fe/kg dry matter - in 1965, or between 0.09 and 6.9 nCi/g ash. Their stable Fe contents varied between 0.234 and 1.990 mg/g dry matter or between 16.3 and 59.7 mg/Fe/g ash. Specific 55 Fe activities of between 231 pCi 55 Fe/mg Fe (1964) and 1.6 pCi 55 Fe/mg Fe (1970) can be calculated from these values. There were no obvious differences between the 55 Fe contamination of lichens of different species. This was also true of their contents of stable Fe. Cladonia furcata had the highest contents of 55 Fe and stable Fe, both relatively and absolutely. From 1965 onwards the 55 Fe-activities in the lichens examined declined in line with the drop in 55 Fe in the fall-out. (orig./AJ.) [de

The nutritional value of peanut hay (Arachis hypogaea L.) as an alternate forage source for sheep

NARCIS (Netherlands)

Khan, M.T.; Khan, N.A.; Bezabih, M.; Qureshi, M.S.; Rahman, A.

2013-01-01

The aim of this study was to evaluate the nutritional and feeding value of peanut hay (Arachis hypogaea L.) produced under tropical environment as an alternate forage resource for sheep. Peanut hay was appreciably high in crude protein [CP; 105 g/kg dry matter (DM)] and lower in neutral detergent

Weaned beef calves fed selenium-biofortified alfalfa hay have an enriched nasal microbiota compared with healthy controls.

Directory of Open Access Journals (Sweden)

Jean A Hall

Full Text Available Selenium (Se is an essential trace mineral important for immune function and overall health of cattle. The nasopharyngeal microbiota in cattle plays an important role in overall respiratory health, especially when stresses associated with weaning, transport, and adaptation to a feedlot affect the normal respiratory defenses. Recent evidence suggests that cattle diagnosed with bovine respiratory disease complex have significantly less bacterial diversity. The objective of this study was to determine whether feeding weaned beef calves Se-enriched alfalfa (Medicago sativa hay for 9 weeks in a preconditioning program prior to entering the feedlot alters nasal microbiota. Recently weaned beef calves (n = 45 were blocked by sex and body weight, randomly assigned to 3 treatment groups with 3 pens of 5 calves per treatment group, and fed an alfalfa hay based diet for 9 weeks. Alfalfa hay was harvested from fields fertilized with sodium selenate at a rate of 0, 45.0 or 89.9 g Se/ha. Blood samples were collected biweekly and analyzed for whole-blood Se concentrations. Nasal swabs were collected during week 9 from one or two calves from each pen (total n = 16. Calculated Se intake from dietary sources was 3.0, 15.6, and 32.2 mg Se/head/day for calves consuming alfalfa hay with Se concentrations of 0.34 to 2.42 and 5.17 mg Se/kg dry matter, respectively. Whole-blood Se concentrations after 8 weeks of feeding Se-fertilized alfalfa hay were dependent upon Se-application rates (0, 45.0, or 89.9 g Se/ha and were 155, 345, and 504 ng/mL (PLinear < 0.0001. Microbial DNA was extracted from nasal swabs and amplified and sequenced. Alpha rarefaction curves comparing the species richness (observed OTUs and overall diversity (Chao1, Observed OTU, and Shannon index between calves fed selenium-biofortified alfalfa hay compared with control calves showed that Se-supplementation tended to be associated with an enriched nasal microbiota. ANOSIM of unweighted Uni

Hay intake improves performance and rumen development of calves fed higher quantities of milk.

Science.gov (United States)

Khan, M A; Weary, D M; von Keyserlingk, M A G

2011-07-01

Research to date has suggested that access to forage before weaning can limit rumen development in calves, but no research has yet addressed the role of forage for calves fed higher quantities of milk. This study compared performance and rumen development of calves provided high volumes (equivalent to approximately 20% of calf birth weight) of milk with and without access to hay. At d 3 of age, individually housed calves were randomly assigned to treatment (either ad libitum access to chopped grass hay or no forage; n=15 calves per treatment, 10 heifers, and 5 bulls). All calves were provided ad libitum access to water and starter throughout the study. All calves were offered 8L of milk/d from a nipple bottle from d 3 to 35, 4 L/d from d 36 to 53, and 2L/d until weaning at d 56. Solid feed intake and growth parameters were monitored from d 3 to 70. At d 70, males from both treatments were slaughtered to measure rumen development parameters. Overall dry matter (DM) intake from solid feed did not differ between treatments before wk 5. However, during wk 6 to 10, calves fed forage consumed more total DM (starter plus hay) than did calves fed no forage. Hip and wither height, heart girth, and body barrel at d 3, 56, and 70 did not differ between treatments. Reticulorumen weight was heavier in calves fed hay versus those fed only starter (12.77±1.29 vs. 7.99±0.69 kg with digesta; 1.89±0.05 vs.1.60±0.09 kg without digesta). Body weight without digesta was similar in calves fed forage or no forage. Mean rumen pH was higher in calves fed hay compared with those fed no forage (5.49±0.08 vs. 5.06±0.04). In conclusion, provision of chopped hay to calves fed high volumes of milk can promote solid feed DM intake and rumen development without affecting BW gain. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Similarity, Induction, Naming, and Categorization (SINC): Generalization or Inductive Reasoning? Reply to Heit and Hayes (2005)

Science.gov (United States)

Sloutsky, Vladimir M.; Fisher, Anna V.

2006-01-01

This article is a response to E. Heit and B. K. Hayes's comment on the target article "Induction and Categorization in Young Children: A Similarity-Based Model" (V. M. Sloutsky & A. V. Fisher, 2004a). The response discusses points of agreement and disagreement with Heit and Hayes; phenomena predicted by similarity, induction, naming, and…

Fulbright-Hays Seminars Abroad Program: Malaysia 1995. Participants' Reports.

Science.gov (United States)

Malaysian-American Commission on Educational Exchange, Kuala Lumpur.

These reports and lesson plans were developed by teachers and coordinators who traveled to Malaysia during the summer of 1995 as part of the U.S. Department of Education's Fulbright-Hays Seminars Abroad Program. Sections of the report include: (1) "Gender and Economics: Malaysia" (Mary C. Furlong); (2) "Malaysia: An Integrated,…

Electromyographic evaluation of masseter muscle activity in horses fed (i) different types of roughage and (ii) maize after different hay allocations.

Science.gov (United States)

Vervuert, I; Brüssow, N; Bochnia, M; Cuddeford, D; Coenen, M

2013-06-01

The aims of this study were to monitor electromyographic (EMG) activity of masseter muscle in healthy horses fed (i) different types of roughage and (ii) maize after different hay allocations. Four horses were offered the following three diets ad libitum: hay, haylage or straw/alfalfa chaff (SAC). In a second trial, four horses were fed cracked maize (CM) and hay in three different orders: (i) CM after a 12-h overnight fast; (ii) CM immediately after restricted hay intake (0.6 kg hay/100 kg BW); or 3) CM after hay intake ad libitum. The activity of the masseter muscle was determined by EMG (IED(®) ), and the following were measured: amplitude (muscle action potential = MAP, maximum voltage) and duration of MAP (s). The intake of hay or haylage was associated with intense masseter muscle activity (MAP: hay, 10 ± 1.7 V; haylage, 11 ± 3.3 V; and duration of MAP: hay, 0.31 ± 0.04 s; haylage, 0.30 ± 0.04 s). Similar intense chewing was measured for SAC (MAP 13 ± 3.8 V), although duration of the chewing cycle was relatively short (0.22 ± 0.03 s, diet p haylage or SAC was associated with intensive masseter muscle activity that was likely to stimulate salivary flow rate. In contrast to roughage, concentrates like CM are consumed rapidly with less intensive masseter muscle activity. This situation is associated with a low salivary flow that may have an adverse effect on gastric function. © 2012 Blackwell Verlag GmbH.

The Glaser–Hay reaction

DEFF Research Database (Denmark)

Vilhelmsen, Mie Højer; Jensen, Jonas; Tortzen, Christian

2013-01-01

The oxidative Glaser–Hay coupling of two terminal alkynes to furnish a butadiyne is a key reaction for acetylenic scaffolding. Although the reaction is performed under rather simple conditions [CuCl/TMEDA/O2 (air)], the mechanism is still under debate. Herein we present detailed studies...... on the scope of this reaction by using both 13C NMR and UV/Vis spectroscopic methods. The former method was used to study the kinetics of the coupling of aryl-substituted alkynes as the aryl carbon resonances of the reactants and products have similar NOEs and relaxation times. The reaction was found...... to be zero-order with respect to the terminal alkyne reactant under standard preparative conditions. Moreover, as the reaction proceeded, a clear change to slower reaction kinetics was observed, but it was still apparently zero-order. The onset of this change was found to depend on the catalyst loading...

Mineral content of hay harvested in Bavarian and Swiss horse farms. Predictive value of cutting time, number of cut, botanical composition, origin and fertilization.

Science.gov (United States)

Kienzle, E; Möllmann, F; Nater, S; Wanner, M; Wichert, B

2008-12-01

Hay samples from 29 horse farms in Southern Upper Bavaria and 31 horse farms in Switzerland were taken and analysed for minerals such as calcium, magnesium, phosphorus and potassium. The content of herbs and legumes in the hay was determined and the Weende analysis was performed. Comparison between Bavaria and Switzerland resulted in comparable calcium contents of approximately 4 g Ca/kg dry matter (DM) in grass hay. Hay with more than 10% of herbs and legumes found only in Switzerland showed higher Ca contents of >7 g Ca/kg DM in hay. The mineral contents of phosphorus and potassium were lower in hay from Switzerland (P: 1.8 +/- 0.7 g/kg DM, K: 15.4 +/- 5.1 g/kg DM) than from Bavaria (P: 3.8 +/- 0.6 g/kg DM, K: 20.0 +/- 6.0 DM), whereas the magnesium content of the hay showed no difference between the regions ( approximately 1.5 g Mg/kg DM). Very late first grass hay cuts showed low magnesium and calcium (<4 g/kg DM) contents. Further minerals in the hay for horses differed from those in dairy cattle in the same region. Fertilization showed only small effects on the mineral contents of the hay produced for horses. Therefore, in calculation of ration and production of supplements for horses, these differences should be taken into account.

An Investigation of Hayes and Wheelwright’s Practices: Empirical Evidence from The Indonesia’s Oil and Gas Industry

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Wakhid Slamet Ciptono

2009-05-01

Full Text Available The research extracts sixty seven Hayes and Wheelwright’s practices from the Hayes and Wheel-wright’s six principles. These items formed the basis of a questionnaire sent to over 2800 managers at the SBUs level in the Indonesia’s oil and gas companies. The empirical result indicates that All Hayes and Wheelwright’s six principles collectively have positive impact on an overall construct that may be termed world-class company (WCC. Result also points out that Hayes and Wheelwright’s six principles can be reduced into four meaningful factors of world-class company—as operations strategies—for the Indonesia’s oil and gas industry— Workforce skills and capabilities, Management technical competence, Competing through quality, and Workforce participation. These meaningful factors of WCC were shown to be reliable and valid, and offer new insights into the understanding of operations strategy implementation in an oil and gas industry.Based on the oil and gas managers (the SBU level, operations strategies (four meaningful factors of WCC can be viewed as the effective use of production and operations capability and technology for achieving business and corporate goals. Operations strategy, therefore, is to help a company’s operations organization define the common ground where it can play a proactive and collaborative role with other company functions or cross-functional relationships (Hayes et al., 1996.  Oil and gas managers in Indonesia can use these meaningful factors in concert with other critical qual-ity management practices to help them in there word-class company initiatives. Researchers can also use these factors to build structural model linking such factors to various organizational performance measures (i.e., Critical Success Factors of TQM, Operational Excellence, Six Sigma Quality Management, and Good Corporate Governance.Keywords: Hayes and wheelwright’s six principles, Hayes and Wheelwright practices, World

Comparison of silage and hay of dwarf Napier grass (Pennisetum purpureum) fed to Thai native beef bulls.

Science.gov (United States)

Mapato, Chaowarit; Wanapat, Metha

2018-03-23

Both quantity and quality of forages are important in dry season feeding. Eight Thai native beef bulls were arranged in a Completely randomized design to evaluate dwarf Napier namely Sweet grass (Pennisetum purpureum cv. Mahasarakham) preserved as silage or hay on feed intake, digestibility, and rumen fermentation. The animals were fed with forage ad libitum supplemented with concentrate mixture at 1.0% of BW for 21 days; data were collected during the last 7 days. The results showed that there were differences (P  0.05) in animals fed silage and hay. Sweet grass is better preserved as hay rather than silage.

On the structure and spin states of Fe(III)-EDDHA complexes.

Science.gov (United States)

Gómez-Gallego, Mar; Fernández, Israel; Pellico, Daniel; Gutiérrez, Angel; Sierra, Miguel A; Lucena, Juan J

2006-07-10

DFT methods are suitable for predicting both the geometries and spin states of EDDHA-Fe(III) complexes. Thus, extensive DFT computational studies have shown that the racemic-Fe(III) EDDHA complex is more stable than the meso isomer, regardless of the spin state of the central iron atom. A comparison of the energy values obtained for the complexes under study has also shown that high-spin (S = 5/2) complexes are more stable than low-spin (S = 1/2) ones. These computational results matched the experimental results of the magnetic susceptibility values of both isomers. In both cases, their behavior has been fitted as being due to isolated high-spin Fe(III) in a distorted octahedral environment. The study of the correlation diagram also confirms the high-spin iron in complex 2b. The geometry optimization of these complexes performed with the standard 3-21G* basis set for hydrogen, carbon, oxygen, and nitrogen and the Hay-Wadt small-core effective core potential (ECP) including a double-xi valence basis set for iron, followed by single-point energy refinement with the 6-31G* basis set, is suitable for predicting both the geometries and the spin-states of EDDHA-Fe(III) complexes. The presence of a high-spin iron in Fe(III)-EDDHA complexes could be the key to understanding their lack of reactivity in electron-transfer processes, either chemically or electrochemically induced, and their resistance to photodegradation.

Supplementary feeding of roe deer (Capreolus capreolus L with late harvested hay. A pilot study

Directory of Open Access Journals (Sweden)

C. Rehbinder

1985-05-01

Full Text Available In order to increase the fodder available for roedeer during wintertime, late harvested hay was placed on racks early in November in three consecutive years. Freeezing kept the hay dry and fresh during all three winters. In the first winter, with much snow, the bulk of the hay was consumed whereas consumption in the two subsequent mild winters was low and selective. The crude protein content of the hay was low (3.5 - 8.4% dry matter. Metabolizable energy estimated from digestion in vitro was 3.5 — 5.6 MJ per kg dry matter. Rumen liquor from roe deer during a mild winter gave lower in vitro digestion than liquor from sheep fed with ordinary rations. The value of this poor hay for roe deer is discussed with respect to the animals requirements, seasonal adaption, the energy and protein content of the hay, water consumption and normal behavior. The results indicate that late harvested hay may be more suitable than regularly harvested hay or concentrates to help roe deer to survive spells of severe winter conditions. With late harvested hay placed out at several localized feeding sites, the risks of indigestion and dehydration, associated with a more concentrated, feed, are minimized and the ranking among the roe deer in particular will be less important and thus more animals will have improved prospects of gaining access to the fodder.Tilskottsutfodring av rådjur (Capreolus capreolus L med sent skordat ho. En pilotstudie.Abstract in Swedish / Sammanfattning: I avsikt att, for rådjur, oka mångden tillgångligt foder under vintertid, skordades och håssjades ho i borjan av november under tre på varandra foljande år. Hoet fros torn och holl sig fårskt alla vintrarna. Forstå vintern med mycket sno konsumerades huvuddelen av hoet medan de två foljande milda vintrarna konsumptionen var låg och selektiv. Mångden råprotein i hoet var lågt (3.5 — 8.4 % i torrsubstans. Innehållet av omsåttbar energi beråknad från digestion in vitro var 3

Religious Literacy or Spiritual Awareness? Comparative Critique of Andrew Wright's and David Hay's Approaches to Spiritual Education

Science.gov (United States)

Filipsone, Anta

2009-01-01

On the basis of a comparison of the educational approaches of Andrew Wright and David Hay this paper illustrates the persisting problem of dichotomising cognitive and trans-cognitive aspects of spiritual development and education. Even though both Wright and Hay speak of the same topic--spirituality and spiritual education--they define these terms…

Transparencia, buenas prácticas y gestión de la calidad en la actividad de la Administración Pública gallega

OpenAIRE

Almeida Cerreda, Marcos; Santiago Iglesias, Diana

2010-01-01

Este artículo analiza la regulación gallega con respecto a la trasparencia, buenas prácticas y calidad en su Gestión Pública para clarificar su alcance, sus efectos y el grado de puesta en práctica.

A model for assessing Medicago Sativa L. hay quality | Scholtz ...

African Journals Online (AJOL)

A study was conducted to identify chemical parameters and/or models for assessing. Medicago sativa L. (L) hay quality, using near infrared reflectance spectroscopy (NIRS) analysis and Cornell Net Carbohydrate and Protein System (CNCPS) milk prediction as a criterion of accuracy. Milk yield (MY) derived from the ...

BUENAS PRÁCTICAS TIC. LA ALFABETIZACIÓN DIGITAL EN MAYORES

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Félix Huelves Martín

2010-12-01

Full Text Available Los equipos informáticos y sus periféricos están diseñados para el uso de un único usuario, constan de un único teclado, ratón; y de una única pantalla. De modo que en una clase de iniciación a la informática, la mejor opción parece ser un equipo por persona. Así, aparentemente, al interactuar individualmente se avanzará más. ¿Pero, y si no es posible contar con suficientes medios? ¿Es realmente imprescindible el “monopuesto” para lograr un aprendizaje significativo? Gracias a la experiencia durante varios cursos de alfabetización digital con adultos utilizando una metodología afín a los objetivos expondremos una buena práctica formativa, haciendo frente a factores adversos como la escasez de recursos. Sin lugar a dudas, sin descuidar la psicología del adulto, educando la adquisición de capacidades tecnológicas haciendo a la persona autónoma en su aprendizaje.

Mental health associations with eczema, asthma and hay fever in children:a cross-sectional survey

OpenAIRE

Hammer-Helmich, Lene; Linneberg, Allan; Obel, Carsten; Thomsen, Simon Francis; Tang Møllehave, Line; Glümer, Charlotte

2016-01-01

Objective This study aimed to examine the association of eczema, asthma and hay fever with mental health in a general child population and to assess the influence of parental socioeconomic position on these associations. Methods We conducted a cross-sectional health survey of children aged 3, 6, 11 and 15?years in the City of Copenhagen, Denmark. Individual questionnaire data on eczema, asthma, and hay fever and mental health problems assessed using the Strengths and Difficulties Questionnair...

Report on intercomparison IAEA/V-10 of the determination of trace elements in hay powder

International Nuclear Information System (INIS)

Pszonicki, L.; Hanna, A.N.

1985-07-01

Hay plays an important role in the natural production circle of human nutrition. The level of its pollution is an important factor which can effect various branches of the food industry. The aim of the reported exercise organized by the IAEA was to provide the participating laboratories an opportunity to check their analytical performance by comparing their results with the results of other laboratories and to establish the concentration level of trace elements for certification purposes. The hay powder was analyzed by 50 laboratories from 25 countries for 42 elements. Neutron activation, atomic absorption, atomic emission and X-ray spectroscopy were predominantly used as analytical methods. The results provided by the participants of the reported intercomparison exercise have enabled to certify the concentration of eighteen trace and minor elements and to establish non-certified information values for the concentration of an additional twelve elements in Hay Powder IAEA/V-10

Desarrollo de Herramientas Enfocadas en Ayudar a las Pymes de Desarrollo de Software en la Implementación de Buenas Prácticas de Gestión de Proyectos

OpenAIRE

Yolanda-Meredith García; Mirna Muñoz; Jezreel Mejía; Juan-Manuel Martínez; Gloria-Piedad Gasca; Jesús-Andrés Hincapié

2017-01-01

La Industria del desarrollo de software constituye un factor clave en la economía. En Latinoamérica este sector se compone por el 99% de pymes. Esto resalta la importancia de la implementación de buenas prácticas de ingeniería de software en las pymes para asegurar su mejora continua. En este contexto, existen diversos modelos y estándares que contienen buenas prácticas enfocadas en mejorar los procesos de desarrollo de software tales como CMMI, ISO-12207, ISO-15504, etc. Sin embargo, para ap...

Sample preparation of Medicago sativa L. hay for chemical analysis ...

African Journals Online (AJOL)

The objective of this study was to quantify the effect of the grinding procedure on the moisture and crude protein concentration of a ground Medicago sativa L. hay sample for quality grading. An additional aim was to investigate the accuracy of electronic moisture testers (EMT). Variance of analyses revealed significant ...

Metodologías y buenas prácticas tecnológicas en los procesos de enseñanza - aprendizaje en la Media Técnica de desarrollo de software

OpenAIRE

Vásquez Amaya, Lina Marcela

2014-01-01

Las metodologías y buenas prácticas tecnológicas implementadas en el proceso de enseñanza -aprendizaje en la modalidad de desarrollo de software ha tomado importancia ya que es un proceso que permite mejorar las demandas que plantea la sociedad, es así como su estudio es de vital importancia debido a que se podrá analizar e implementar metodologías y buenas prácticas tecnológicas que generen métodos de formación y acompañamiento que garanticen una apropiada unificación durante la formación pr...

Buenas Prácticas docentes/discentes de motivación y participación del aprendizaje

OpenAIRE

Rizo-Baeza, Mercedes; Gutiérrez-Hervás, Ana; Salazar-Agulló, Modesta; Martínez-Amorós, Natalia; Cortés Castell, Ernesto; Cortes, F. Xavier

2017-01-01

Actualmente se ha producido un cambio social importante en las aulas de la Universidad, donde se observa que una buena parte del alumnado no presta atención, interés y menos el planteamiento de dudas sobre lo expuesto por el profesor. La exposición tradicional mediante diapositivas, pizarra o lectura del tema, conduce al alumnado a mantener su interés menos de 1/3 de la duración de la clase. Este cambio debe plantearse en las aulas y en los nuevos enfoques del aprendizaje, dejando ser al estu...

Manual de buenas prácticas de comunicación interna en la Biblioteca Universitaria (BUA)

OpenAIRE

Biblioteca Universitaria

2017-01-01

Todo cuanto hace la biblioteca es comunicación, voluntaria o involuntariamente. La comunicación no es una actividad opcional. La biblioteca comunica sí o sí, lo sepa o no, lo quiera o no, consciente o inconscientemente… (adaptación al campo de la biblioteca de las palabras de Daniel Scheisohn). Con estas premisas comenzamos este Manual de buenas prácticas de comunicación interna en la BUA, con el objetivo de orientar, de una manera sencilla y práctica, hacia las herramientas, técnicas y canal...

The effect of feeding barley or hay alone or in combination with molassed sugar beet pulp on the metabolic responses in plasma and caecum of horses

DEFF Research Database (Denmark)

Jensen, R B; Austbø, Dag; Blache, D

2016-01-01

only (HAY), hay and molassed SBP (HAY + SBP), hay and pelleted barley (BAR), and hay, pelleted barley and molassed SBP (BAR + SBP). The amount of barley (2 g starch/kg body weight (BW)) fed in the test meals was similar for the BAR and BAR + SBP diets. Each diet was fed for 16 days followed by data...... to the large intestine in response to the dietary carbohydrate composition. In conclusion, there was no effect of adding molassed SBP to a meal of barley compared to feeding barley alone, and fluctuations in plasma and caecal variables were more stable when feeding hay and molassed SBP than feeding barley...

Precision and accuracy of the NDF rumen degradability of hays measured by the Daisy fermenter

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C. Zanfi

2010-04-01

Full Text Available An inventory of 162 hay samples from Austrian permanent grasslands was used to obtain information about the precision of the in vitro NDF degradability (NDFd measured by the Daisy fermenter and its accuracy to predict in situ NDFd. The within forage standard error of the in vitro NDFd triplicate, obtained in five consecutive incubations, was equal to 2.8%, while the effect of the four jar positions in the fermenter was not significant. The cutting frequency had a great impact on the in situ effective NDFd of hays, which ranged (P<0.01 from values of 32.9, 43.1 and 48.3% in hays obtained from 2, 3 and 4 cuts/season, respectively. The regression analysis between the in vitro and in situ NDFd values (measured at 48h and effective, k=3%/h allowed to obtain medium degrees of correlation (r2 = 0.69 – 0.71; P<0.01 and low levels of accuracy (RSE = 4.0 -4.6 %.

In vitro rumen fermentation kinetics of diets containing oldman saltbush hay and forage cactus, using a cattle inoculum

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M.S.L. Tosto

2015-02-01

Full Text Available The aim of this experiment was to evaluate, by means of the semi-automated in vitro gas production technique, fermentation kinetics of carbohydrates and degradability of dry matter (DM and organic matter (OM of diets containing oldman saltbush hay levels (8.4; 18.8; 31.2 and 48.3% associated to forage cactus in natura. Pressure readings of the gases were done with a pressure transducer at 2, 4, 6, 8, 10, 12, 17, 20, 24, 28, 34, 48, 72 and 96h post-inoculation. The rumen kinetics was described by the following parameters: maximum potential of gas production, lag time and production rates of gas (k, fibrous carbohydrates (FC and non-fibrous carbohydrates (NFC. It could be observed that the addition of oldman saltbush hay to the diets promoted a quadratic effect in the production of gases originated from NFC. However, there was no significant effect on the production of gases originated from FC and on production rates of gases from NFC and FC. The degradability of DM and OM did not differ due to the addition of oldman saltbush hay. The use of 8.4% hay and 74.9% forage cactus promoted the maximum potential of production of gases from the fibrous fraction of diets containing cactus and oldman saltbush hay.

FT-IR spectroscopic analysis for studying Clostridium cell response to conversion of enzymatically hydrolyzed hay

Science.gov (United States)

Grube, Mara; Gavare, Marita; Nescerecka, Alina; Tihomirova, Kristina; Mezule, Linda; Juhna, Talis

2013-07-01

Grass hay is one of assailable cellulose containing non-food agricultural wastes that can be used as a carbohydrate source by microorganisms producing biofuels. In this study three Clostridium strains Clostridium acetobutylicum, Clostridium beijerinckii and Clostridium tetanomorphum, capable of producing acetone, butanol and ethanol (ABE) were adapted to convert enzymatically hydrolyzed hay used as a growth media additive. The results of growth curves, substrate degradation kinetics and FT-IR analyses of bacterial biomass macromolecular composition showed diverse strain-specific cell response to the growth medium composition.

Substitution of lucerne hay by ammoniated wheat straw in growth ...

African Journals Online (AJOL)

Lucerne hay (LH) was substituted by urea-ammoniated wheat straw (AWS) in four lamb-growth diets, all containing 60% roughage. ... Die ekonomiese voordeel van die verplasing van 'n hoë kwaliteit ruvoer, soos LH, met'n goedkoper bron (AKS), moet opgeweeg word teen die laer DMI en GDT, sowel as die nadelige effek ...

Formación en buenas prácticas docentes para la educación virtual

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Rodrigo Alberto Duran Rodríguez

2015-09-01

Full Text Available La educación virtual está confrontando problemas de calidad por la falta de planificación y control de indicadores claves tales como la planta docente contratada y las estrategias instrumentadas en el proceso de enseñanza y aprendizaje. El presente artículo tiene como propósitos: primero, explorar el potencial de las buenas prácticas docentes en la educación virtual y segundo, medir el grado de adopción de estas buenas prácticas por parte de los participantes en el corto, mediano y largo plazo. Se trabajó un estudio de caso específico con once candidatos a Máster en Docencia Superior de la Universidad Tecnológica Oteima en la República de Panamá y los resultados demuestran que el 72% de los participantes adoptarían la estrategia en el largo plazo (en dos o más años, mientras que un promedio del 50% de los equipos de trabajo adoptarían la estrategia en el largo plazo. Por ende, existe disposición en los segmentos individual y grupal de adoptar este tipo de estrategias en la planificación y diseño de cursos virtuales, lo que podría significar un aporte futuro a la calidad de la modalidad virtual. Sin embargo, por tratarse de un estudio de caso específico con una muestra limitada de n =11, no se pretende generalizar las conclusiones por lo que es necesario ampliar la muestra en otras investigaciones y recoger más datos.

Análisis de las buenas prácticas de participación ciudadana en las unidades de gestión clínica del Servicio Andaluz de Salud

OpenAIRE

M. Eugenia Gómez Martínez; Guadalupe Pastor Moreno; Olivia Pérez Corral; M. Teresa Iriarte de los Santos; Ángel Luis Mena Jiménez; M. Cecilia Escudero Espinosa; Inmaculada García Romera; Martín Germán Blanco García; Amelia Martín Barato

2017-01-01

Objetivo: Conocer buenas prácticas de participación ciudadana en las unidades de gestión clínica (UGC) del Servicio Andaluz de Salud (SAS) y explorar factores percibidos por profesionales de UGC del SAS que pueden influir en la existencia y la distribución de buenas prácticas de participación ciudadana. Método: Estudio con metodología mixta realizado en Andalucía en dos fases (2013-2015). En la fase 1 (estudio cuantitativo) se realizó un cuestionario online a directores/as de UGC con una c...

La cultura organizacional y su influencia en las buenas prácticas para la gestión del conocimiento en las Pymes de Colombia

Directory of Open Access Journals (Sweden)

CARLOS EDUARDO MARULANDA ECHEVERRY

Full Text Available El objetivo del presente trabajo es la exposición de la relación existente entre la cultura organizacional y las buenas prácticas para la gestión del conocimiento en las Pymes de Colombia, la cual parte de un modelo de evaluación de gestión del conocimiento que fue aplicado a 321 empresas. Para el efecto, se utilizaron métodos de análisis y síntesis y un tipo de estudio descriptivo exploratorio y correlacional. Se concluye que la cultura modera de forma positiva y significativa las buenas prácticas para la gestión de conocimiento. Este estudio se espera que aporte al desarrollo de las pequeñas y medianas empresas del país para formular acciones que permitan potenciar su crecimiento.

“Buen o buena docente” desde la perspectiva de estudiantes que han egresado de educación secundaria

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Robert Caballero-Montañez

2006-09-01

Full Text Available “Buen o buena docente” es aquella persona que ha marcado e influido de manera trascendental en la vida personal y académica de sus estudiantes y cuya imagen permanece en su memoria escolar como un recuerdo prolongado y altamente positivo. En consecuencia, conocer cuáles son sus rasgos centrales y por qué impactaron de tal manera en sus estudiantes merece ser más investigado como un aporte al campo de estudio sobre la docencia en educación básica. En este marco, el objetivo central de esta investigación empírica ha sido analizar las características del “buen o buena docente” desde la percepción de sujetos egresados de educación secundaria de escuelas públicas y privadas de Lima (Perú. Los resultados de este estudio cualitativo, basado en entrevistas semiestructuradas a ocho estudiantes que han egresado, ha permitido describir, por un lado, los rasgos del buen personal docente en relación a su alumnado, caracterizado por un estilo vinculante expresado en el compromiso con este, en una percepción positiva y actitud motivadora y una calidad afectiva en la interacción profesorado-alumnado; y, por otro lado, rasgos en relación con su profesión como: su pasión por enseñar; su dominio sobre contenidos y la organización de la clase. El estudio concluye que el hecho que todos los egresados y egresadas hayan podido recordar al menos a un profesor o profesora como buen o buena docente revela la heterogeneidad de tipos de docentes que exige superar generalizaciones negativas y que la imagen docente es una construcción colectiva en varias promociones. Una de las implicaciones de este estudio es recuperar la voz de los exalumnos y exalumnas, tanto para el campo de las investigaciones como en el de la política educativa, por contener un valioso potencial para mejorar nuestra comprensión de la experiencia escolar y de la relación docente-estudiantes.

Supplementation of Farta sheep fed hay with graded levels of concentrate mix consisting of noug seed meal and rice bran.

Science.gov (United States)

Asmare, Bimrew; Melaku, Solomon; Peters, Kurt J

2010-10-01

The study was carried out at Woreta, Ethiopia, to determine feed intake, digestibility, body weight (BW) change, and profitability of Farta sheep fed pasture hay alone or supplemented with graded levels of concentrate mix (CM) consisting of noug seed meal (NSM) and rice bran in 2:1 ratio. Twenty yearling intact male Farta sheep with BW of 16.9 +/- 1.68 kg (mean +/- SD) were used in randomized complete block design arranged into five blocks of four animals. The dietary treatments consisting of sole natural pasture hay (T1, control), hay +200 g of CM dry matter (DM) (T2, low), hay +300 g of CM DM (T3, medium), and hay +400 g of CM DM (T4, high) were randomly assigned to sheep within each block. Common salt and water were available to animals all the time. The supplements were offered twice daily in equal portions at 0800 and 1600 h. Supplementation with the CM increased (P profitability. Among the supplemented treatments, the high level of supplementation resulted in better (P profitability. Thus, the high level of supplementation is recommended based on biological performance and profitability under conditions of this study.

A broader definition of occupancy: Comment on Hayes and Monfils

Science.gov (United States)

Quresh S. Latif; Martha M. Ellis; Courtney L. Amundson

2016-01-01

Occupancy models are widely used to analyze presence-absence data for a variety of taxa while accounting for observation error (MacKenzie et al. 2002, 2006; Tyre et al. 2003; Royle and Dorazio 2008). Hayes and Monfils (2015) question their use for analyzing avian point count data based on purported violations of model assumptions incurred by avian mobility....

Interactions of alfalfa hay and sodium propionate on dairy calf performance and rumen development.

Science.gov (United States)

Beiranvand, H; Ghorbani, G R; Khorvash, M; Nabipour, A; Dehghan-Banadaky, M; Homayouni, A; Kargar, S

2014-01-01

The objective of this experiment was to investigate the effects of different levels of alfalfa hay (AH) and sodium propionate (Pro) added to starter diets of Holstein calves on growth performance, rumen fermentation characteristics, and rumen development. Forty-two male Holstein calves (40±2kg of birth weight) were used in a complete randomized design with a 3×2 factorial arrangement of treatments. Dietary treatments were as follows: (1) control = concentrate only; (2) Pro = concentrate with 5% sodium propionate [dry matter (DM) basis]; (3) 5% AH = concentrate + 5% alfalfa hay (DM basis); (4) 5% AH + Pro = concentrate + 5% alfalfa hay + 5% sodium propionate (DM basis); (5) 10% AH = concentrate + 10% alfalfa hay (DM basis); and (6) 10% AH + Pro = concentrate + 10% alfalfa hay + 5% sodium propionate (DM basis). All calves were housed in individual pens bedded with sawdust until 10wk of age. They were given ad libitum access to water and starter throughout the experiment and were fed 2L of milk twice daily. Dry matter intake was recorded daily and body weight weekly. Calves from the control, 10% AH, and 10% AH + Pro treatments were euthanized after wk 10, and rumen wall samples were collected. Feeding of forage was found to increase overall dry matter intake, average daily gain, and final weight; supplementing sodium propionate had no effect on these parameters. Calves consuming forage had lower feed efficiency than those on the Pro diet. Rumen fluid in calves consuming forage had higher pH and greater concentrations of total volatile fatty acids and molar acetate. Morphometric parameters of the rumen wall substantiated the effect of AH supplementation, as plaque formation decreased macroscopically. Overall, the interaction between forage and sodium propionate did not affect calf performance parameters measured at the end of the experiment. Furthermore, inclusion of AH in starter diets positively enhanced the growth performance of male Holstein calves and influenced

Food hygiene assessment in catering establishments in Hay Hassani district-Casablanca.

Science.gov (United States)

Kadmiri, Nadia El; Bakouri, Halima; Bassir, Fatima; Barmaki, Saadia; Rachad, Laila; Nadifi, Sellama; Kadmiri, Omar El; Amina, Bouleghmane

2016-01-01

Contaminated food is responsible for a significant amount of illnesses. In Morocco, it has become a worrying concern. Numerous awareness campaigns are conducted to warn the population against the risks of such scourge in ways that will prevent foodborne illness. Lawful commissions are in charge of examining and ensuring food safety in production and catering establishments, in addition to the assessment of food poisoning risks. The aim of this study is to evaluate the hygienic quality of food handling, preparation, and storage in catering establishments within Hay Hassani prefecture in Casablanca. During the period 2006-2012 a total of 1765 food samples were taken and examined for microbiological quality tests. As analyzed, 562 per 1765 samples are declared unhealthy for consumption. We note that some products were highly contaminated as compared to other products (p <0.001), specifically vegetable dishes, and meat dishes. In Hay Hassani district food is generally prepared and sold under unhygienic conditions, adequate corrective measures have been announced to improve hygienic practices.

Implementación de buenas prácticas de promoción de personal y su relación con la cultura y el compromiso con la organización

Directory of Open Access Journals (Sweden)

Merlin Patricia Grueso Hinestroza

2010-04-01

Full Text Available La investigación genera hipótesis y prueba un modelo de relaciones entre los valores de la cultura organizacional, la implementación de una buena práctica de promoción de personal desde la perspectiva de género y el compromiso con la organización. Para la prueba de hipótesis se emplea un modelo de ecuaciones estructurales y se realiza una encuesta a 425 empleados. Los resultados llevan a concluir que los valores distancia al poder y orientación de largo plazo predicen la implementación de buenas prácticas de promoción de personal; los componentes del compromiso con la organización no evidenciaron asociaciones significativas con la implementación de una buena práctica de promoción de personal. El estudio contribuye al desarrollo de un cuerpo de investigación en torno a las implicaciones de la perspectiva de género en las organizaciones.

Radioimmunological allergy diagnostics in infants suffering from asthmatoid bronchitis, bronchial asthma, and hay fever

International Nuclear Information System (INIS)

Siafarikas, K.; Glaubitt, D.; Wanzeck, E.; Staedtische Krankenanstalten Krefeld

1975-01-01

The occurence of circulating specific antibodies against milk protein, hen protein, fish (cod), against cat, dog and horse epithelium as well as against 2 types of house dust was investigated with 11 children in the age of 1-6 years having asthmatoid bronchitis, 23 children aging from 2-15 years with bronchial asthma and 3 children aging from 6-13 years with hay fever, using the radioallergosorbens test (RAST). Children having asthmatoid bronchitis for the first time exhibited a smaller number and a lesser extent of positive radioallergosorben test results then children with bronchial asthma. The children with hay fever exhibited exclusively negative test results. (orig./LN) [de

Barreras para la integración de buenas prácticas con TIC. Estudio de caso.

OpenAIRE

Siria Padilla Partida; Carlos Iván Moreno; Rosario Hernández Castañeda

2015-01-01

Esta investigación analiza las barreras u obstáculos para la integración de las buenas prácticas educativas con TIC, en la segunda más grande universidad pública de México: La Universidad de Guadalajara. Se analiza el caso del Centro Universitario de Ciencias Económico Administrativas (CUCEA), el cual es uno de los 15 centros universitarios que integran la red universitaria de la UdeG. Para esta investigación fue diseñado un cuestionario cerrado, tipo rubrica, con una escala de 5 puntos que i...

Predicting TDN losses from heat damaged hays and haylages with NIR

Science.gov (United States)

During the storage of hay or haylage, heating damage may occur and lead to losses of available protein and digestible nutrients. Recent research indicates that losses of TDN may be more significant economically than losses of available protein. Our objectives for this study were to establish a near-...

Hayes Receives 2012 Ronald Greeley Early Career Award in Planetary Science: Citation

Science.gov (United States)

Leshin, Laurie A.

2013-10-01

Alexander G. Hayes Jr. received the 2012 Ronald Greeley Early Career Award in Planetary Science at the 2012 AGU Fall Meeting, held 3-7 December in San Francisco, Calif. The award recognizes significant early-career contributions to planetary science.

Quality of aged shoulder from lambs fed with different oldman saltbush hay levels (Atriplex nummularia

Directory of Open Access Journals (Sweden)

Tharcilla Isabella Rodrigues Costa Alvarenga

2014-12-01

Full Text Available This study assessed the effects of different levels of oldman saltbush hay and ageing time on the physical characteristics of Santa Inês lamb meat. Sixty shoulders from 32 male lambs fed with 30, 40, 50 or 60% oldman saltbush hay for 60 days were vacuum-packaged and stored in a refrigerator at 0 ± 1°C for 0, 7 or 14 days of ageing. The shear force, cooking loss and water holding capacity were 3.06kgf cm-2, 37.28% and 76.71%, respectively, and there were no significant changed by studied factors (P>0.05

BUENAS PRÁCTICAS, UNA SOLUCIÓN PARA UN MEJOR DESARROLLO DE SOFTWARE

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Liliana del Carmen Ramírez-M

2014-12-01

Full Text Available Este articulo tiene como objetivo principal dar a conocer una serie de buenas prácticas planteadas para un mejor desarrollo de software, basadas en las metodologías agiles más representativas se han propuesto unos valores, unas características, unos roles, unas prácticas y un ciclo de vida para el desarrollo de un proyecto de software, con lo cual se busca abarcar todo el proceso desde que surge una necesidad por parte de un cliente, hasta el momento en se tiene la seguridad de que el cliente está totalmente satisfecho con el producto. Estas prácticas planteadas buscan comprometer al equipo de trabajo e integrarlo al proyecto de una manera beneficiosa para las personas participantes, ya que pueden estar desde el inicio hasta la fase final del proyecto cumpliendo un rol u otro específicamente, logrando con esto reducción de tiempo, costos y otros.

VARIABLES DOCENTES Y DE CENTRO QUE GENERAN BUENAS PRÁCTICAS CON TIC TEACHER AND SCHOOL VARIABLES THAT GENERATE GOOD PRACTICES WITH ICT

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Pilar Colás Bravo

2010-02-01

Full Text Available En este artículo se presentan los resultados de un estudio de casos llevado a cabo mediante entrevistas narrativas, cuyo objetivo es identificar los factores condicionantes de las buenas prácticas con TIC. Las buenas prácticas con TIC están relacionadas con dos áreas científicas de estudio. Una referida a la integración de las TIC en los sistemas educativos y, otra ligada a procesos de innovación. En esta aportación se presenta el estado de la cuestión respecto a factores condicionantes de las buenas prácticas desde ambas perspectivas. A partir de ahí situamos el marco teórico de este trabajo desde la perspectiva del profesorado. El análisis cualitativo realizado mediante el software científico Atlas.Ti 5.0 saca a la luz variables personales y contextuales asociadas a los procesos de innovación. In this article the results of a case study carried out are presented by means of narrative interviews, whose objective is to identify the determining factors of the good practices with ICT. The good practices with ICT are related to two scientific areas of study. One, above mentioned, related to the integration of the ICT in the educational systems and, another, connected with processes of innovation. In this contribution we present the state of the question related to determining factors of the good practices from both points of view. From there we situate the theoretical framework of this work since the perspective of the teachers. The qualitative analysis carried out by means of the program AtlasTi identifies personal and contextual factors associated to the processes of innovation.

Diversity of lowland hay meadows and pastures in Western and Central Europe

NARCIS (Netherlands)

Rodríguez-Rojo, Maria Pilar; Jiménez-Alfaro, Borja; Jandt, Ute; Bruelheide, Helge; Rodwell, John S.; Schaminée, Joop H.J.; Perrin, Philip M.; Kacki, Zygmunt; Willner, Wolfgang; Fernández-González, Federico; Chytrý, Milan

2017-01-01

Questions: Which are the main vegetation types of lowland hay meadows and pastures in Western and Central Europe? What are the main environmental gradients that drive patterns of species composition? Is it possible to classify these grasslands to phytosociological alliances that reflect management

Fulbright-Hays Seminars Abroad Program 1992: Morocco and Tunisia. Final Projects.

Science.gov (United States)

AMIDEAST, Washington, DC.

The projects described in this document were submitted by U.S. teachers who spent time in Morocco and Tunisia as part of the 1992 Fulbright-Hays Seminars Abroad Program. The following are among the titles of the projects included: "Formal Education in Rural Morocco: Problems and Constraints" (Victoria Baker); "Continuity and Change…

Nutritional value of silk flower hay for lambs Valor nutritional do feno de flor-de-seda para cordeiros

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Aderbal Marcos de Azevêdo Silva

2010-12-01

Full Text Available It was evaluated four levels of silk flower (Calotropis procera S.W. hay (SFH as a substitute of sorghum (Sorghum bicolor hay (SBH in diet for lambs. Nutritional value of silk-flower hay was determined based on aparent digestibility and on metabolic, productive and economical performance of Santa Inês lambs. It was used twenty-four castrated males at 15.72 ± 1.92 kg body weight randomly distributed in four diets with silk-fklower and sorghum hay ratios (100:0, 66:33, 33:66, 0:100, and supplemented with a concentrate mixture based on 50% roughage:50% concentrate (weight/weight. Increase in the levels of silk-flower hay in the diet reduced weight gain and nutrient intake and it increased feed conversion and digestibility coeficients of all the nutrients. Nitrogen balance was similar in all levels of silk-flower hay, although there was a tendency of reduction in nitrogen retention at levels 66% and 100% of silk-flower hay. At the levels 0 and 33% of silk-flower hay in the diet, dry matter ingestion (170 and 180 g/day, daily average weight gain (84 and 89 g/kg0.75and feed conversion (4.99 and 5.02 were satisfactory. Silk-flower hay can represent up to 16.5% of the total food ingestion or 33% of the roughage in diet for lambs.Avaliaram-se quatro níveis de feno de flor-de-seda (Calotropis procera S.W. em substituição ao feno de sorgo (Sorghum bicolor na dieta de cordeiros. O valor nutricional do feno de flor-de-seda foi determinado com base na digestibilidade aparente e no desempenho metabólico, produtivo e econômico de cordeiros Santa Inês. Utilizaram-se 24 machos castrados com peso corporal de 15,72 kg ± 1,92 kg distribuídos aleatoriamente em quatro dietas com relações entre feno de flor-de-seda e de sorgo (100:0, 66:33, 33:66 e 0:100 e suplementadas com uma mistura concentrada à base de 50% de volumos e 50% de concentrado (peso/peso. O aumento nos níveis de feno de flor-de-seda na dieta diminuiu o ganho de peso e a ingestão de

Komposisi Kimia, Degradasi Nutrien dan Produksi Gas Metana in Vitro Rumput Tropik yang Diawetkan dengan Metode Silase dan Hay

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B. Santoso

2008-08-01

Full Text Available Six grass species (Pennisetum purpureum, Pennisetum purpureophoides, Sorghum sudanense, Brachiaria brizantha, Imperata cylindrica, and Panicum maximum were harvested at 49 days and preserved as silage or as hay. Samples of silage and hay were evaluated by an in vitro gas production and in vitro nutrient degradability. Total gas production at 24 and 48 h as well as CH4 were higher (P<0.01 in silage than in hay. Brachiaria brizantha had the highest (P<0.01 gas production compared to other species, whereas P. purpureum had the highest CH4 production (mM/g organic matter degraded. Dry matter (DM and organic matter (OM degradations were higher (P<0.01 in silage than hay. When compared with hay, silage had higher (P<0.01 ammonia-N concentration (20.3 vs. 10.6 mg/100 ml and higher (P<0.05 butyric acid concentration (7.9 vs. 7.0 mM. Non-fiber carbohydrate (NFC and crude protein contents were positively correlated with gas production (r = 0.51; P<0.05 and CH4 production (r = 0.64; P<0.01 at 48 h of in vitro incubation. However total gas and CH4 productions were negatively correlated with neutral detergent fiber (NDF content. There were positive correlation between DM (r = 0.90; P<0.01, OM (r = 0.93; P<0.01, and NDF (r = 0.84; P<0.01 degradations and gas production.

Variants, Layers of Authorial Intervention, and Texts in Lope de Vega’s La buena guarda and La encomienda bien guardada autograph manuscript

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Stefania Capoia

2014-01-01

Full Text Available In this article I study, analyze and classify the variant readings and the different layers of authorial intervention that appear in Lope de Vega’s La buena guarda and La encomienda bien guardada manuscript. I contend that the second version of the work should be edited, a possibility thus far neglected by modern editors.

Magnetic Properties and Microstructure of FeOx/Fe/FePt and FeOx/FePt Films

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Jai-Lin Tsai

2013-01-01

Full Text Available The Fe(6 nm/FePt film with perpendicular magnetization was deposited on the glass substrate. To study the oxygen diffusion effect on the coupling of Fe/FePt bilayer, the plasma oxidation with 0.5~7% oxygen flow ratio was performed during sputtered part of Fe layer and formed the FeOx(3 nm/Fe(3 nm/FePt trilayer. Two-step magnetic hysteresis loops were found in trilayer with oxygen flow ratio above 1%. The magnetization in FeOx and Fe/FePt layers was decoupled. The moments in FeOx layer were first reversed and followed by coupled Fe/FePt bilayer. The trilayer was annealed again at 500°C and 800°C for 3 minutes. When the FeOx(3 nm/Fe(3 nm/FePt trilayer was annealed at 500°C, the layers structure was changed to FeOx(6 nm/FePt bilayer due to oxygen diffusion. The hard-magnetic FeOx(6 nm/FePt film was coupled with single switching field. The FeOx/(disordered FePt layer structure was observed with further annealing at 800°C and presented soft-magnetic loop. In summary, the coupling between soft-magnetic Fe, FeOx layer, and hard-magnetic L10 FePt layer can be controlled by the oxygen diffusion behavior, and the oxidation of Fe layer was tuned by the annealing temperature. The ordered L10 FePt layer was deteriorated by oxygen and became disordered FePt when the annealed temperature was up to 800°C.

Effects of alfalfa hay and its physical form (chopped versus pelleted) on performance of Holstein calves.

Science.gov (United States)

Jahani-Moghadam, M; Mahjoubi, E; Hossein Yazdi, M; Cardoso, F C; Drackley, J K

2015-06-01

Inclusion of forage and its physical form in starter may affect rumen development, average daily gain (ADG), and dry matter intake (DMI) of dairy calves. To evaluate the effects of forage and its physical form (chopped vs. pelleted) on growth of calves under a high milk feeding regimen, 32 Holstein calves (38.8±1.1kg) were assigned at birth to 1 of 3 treatments in a completely randomized block design. Dietary treatments (% of dry matter) were (1) 100% semi-texturized starter (CON); (2) 90% semi-texturized starter + 10% chopped alfalfa hay (mean particle size=5.4mm) as a total mixed ration (TMR; CH); and (3) 90% semi-texturized starter + 10% pelleted alfalfa (mean=5.8mm) hay as a TMR (PH). Data were subjected to mixed model analysis with contrasts used to evaluate effect of forage inclusion. Calves were weaned at 76 d of age and the experiment finished 2 wk after weaning. Individual milk and solid feed consumption were recorded daily. Solid feed consumption and ADG increased as age increased (effect of week), but neither forage inclusion nor physical form of forage affected these variables pre- or postweaning. Plasma urea N was affected by treatments such that the CON group had a lower concentration than forage-fed groups. Forage inclusion, but not physical form, resulted in increased total protein in plasma. Although days with elevated rectal temperature, fecal score, and general appearance were not affected by dietary treatments, calves fed alfalfa hay during the first month of life had fewer days with respiratory issues, regardless of physical form of hay. We concluded that provision of forage does have some beneficial effects in calves fed large amounts of milk replacer, but pelleted alfalfa hay did not result in any improvement in calf performance or health. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

A broader definition of occupancy: A reply to Hayes and Monofils

Science.gov (United States)

Fatif, Quresh; Ellis, Martha M.; Amundson, Courtney L.

2015-01-01

Occupancy models are widely used to analyze presence–absence data for a variety of taxa while accounting for observation error (MacKenzie et al. 2002, 2006; Tyre et al. 2003; Royle and Dorazio 2008). Hayes and Monfils (2015) question their use for analyzing avian point count data based on purported violations of model assumptions incurred by avian mobility. Animal mobility is an important consideration, not just for occupancy models, but for a variety of population and habitat models (Boyce 2006, Royle et al. 2009, Manning and Goldberg 2010, Dormann et al. 2013, Renner et al. 2015). Nevertheless, we believe the ultimate conclusions of Hayes and Monfils are shortsighted mainly due to a narrow interpretation of occupancy. Rather than turn away from the use of occupancy models, we believe they remain an appropriate method for analyzing many data sets collected from avian point count surveys. Further, we suggest that there is value in having a broader and more nuanced interpretation of occupancy that incorporates the potential for animal movement. 

Reproductive performance of reindeer fed all-grain and hay-grain rations

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J. M. Blanchard

1986-06-01

Full Text Available Reproductive performance of grain-fed reindeer {Rangifer tarandus was evaluated over a 2-year period. Groups of pregnant reindeer were fed one of three rations, (1 100% whole-grain barley, (2 98.9% whole-grain barley and 1.2% mineral and trace element supplement, and (3 70% whole-grain barley and 30% finely-chopped bluegrass hay. Reindeer fed unsupplemented whole-barley failed to produce a single live calf. The addition of mineral and trace element supplement to the ration did not result in any significant improvement in reproductive performance. Eighty-five percent of the reindeer consuming unsupplemented and supplemented all-barley rations became pregnant; however, 76% of the pregnancies resulted in stillborn calves. One-hundred percent of the cows maintained on the grain/hay ration produced live calves. We speculate that reproductive failure in reindeer cows maintained on all-grain rations is most likely a result of a diet induced disfunction in maternal rumen and/or carbohydrate metabolism rather than a micro-nutrient deficiency. More research is neeeded to determine which metabolic pathways are affected.

Kajian Mutu dan Palatibilitas Silase dan Hay Ransum Komplit Berbasis Sampah Organik Primer pada Kambing Peranakan Etawah

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Yusmadi Yusmadi

2008-04-01

Full Text Available The quality and palatibility of silage and hay complete ration based on organic primer garbage in peranakan etawah (PE poad ABSTRACT. This research was conducted to study the quality and palatability of silage and hay complete ration based on organic primer garbage in nine heads of Peranakan Etawah (PE Goat. The quality of silage and hay was evaluated By measuring pH, total number of lactic acid Bacteria (LAB, palatability, dry matter (DM and organic matter (OM aroma and color of silage. Nine heads of peranakan etawah were grouped based on their lactation periode and randomly assigned to one of tree dietary treatments. The treatments were (1 Control rations; (2 silage complete ration (SRK; and (3 Hay complete ration (HRK. The results indicated that the silage had PH 4.15 and total number of LAB was 2.4 x 10 cfu/g of silage. Dry matter and organic matter digestibility of SRK were better than those of HRK. The palatability of SRK was higher than HRK but less than control. Storage of SRK for did not change dry matter and organic matter content. Organoleptic analysis indicated that texture and color of HRK were changed at after storage, while SRK was still constant. It is concluded that silage composed of organic primer garbage has high quality in terms of physical, chemical and microbial characteristics, prolong storage.

POLÍTICA HABITACIONAL EM GOIÂNIA: ESTUDO DE CASO DO RESIDENCIAL BUENA VISTA IV (2009-2013).

OpenAIRE

Oliveira, Eliane Alves de

2014-01-01

Esta dissertação tem como objetivo avaliar a pós-ocupação do Residencial Buena Vista IV, Goiânia, Goiás, em relação ás condições que o ambiente construído oferece em bens e serviços, equipamentos comunitários e infraestrutura básica. O Residencial foi inaugurado em 2009, localizado na Região Oeste da capital, integrante do Programa de Habitação de Interesse Social (PHIS) para atender as famílias que residiam em assentamentos precários em áreas de risco, áreas públicas, priva...

BUENAS PRÁCTICAS Y PROGRAMAS EXTRAORDINARIOS DE ATENCIÓN AL ALUMNADO EN RIESGO DE EXCLUSIÓN EDUCATIVA

OpenAIRE

Juan Manuel Escudero Muñoz

2009-01-01

En los últimos años, las buenas prácticas se han convertido en una perspectiva teórica y práctica aplicada a diversos ámbitos de las políticas sociales y educativas contra la exclusión. De forma singular también se ha desarrollado en relación con la vulnerabilidad y la exclusión educativa. Tras revisar algunas aproximaciones y hacerse eco de sus posibilidades y limitaciones teóricas y prácticas, el artículo propone un modelo marco que identifica diversos niveles y dimensiones del concepto de ...

Análisis de una buena alimentación en los alumnos de Educación Primaria

OpenAIRE

Sánchez Cancillo, Adrián

2015-01-01

La importancia que tiene una buena alimentación en el periodo escolar es vital para un desarrollo físico y emocional del niño. El presente Trabajo hace referencia a los hábitos alimenticios, en concreto al hábito alimentario infantil, llevado a cabo por los niños y guiada por sus progenitores, durante su etapa escolar. En primer lugar se presenta una investigación sobre la alimentación habitual del alumnado de Educación Primaria. Para ello se ha llevado a cabo un sondeo que busca averigua...

El Documento de las Américas: Buenas Prácticas Clínicas para Autoridades Reguladoras

OpenAIRE

Ricardo Palacios

2009-01-01

En 1996, cuando se adoptaron las Normas de Buenas Prácticas Clínicas de la Conferencia Internacional de Armonización (ICH, por su sigla en inglés), se proyectó facilitar la acción de autoridades reguladoras sobre los diferentes actores de la investigación clínica. Estas normas fueron creadas e incorporadas a la legislación de las tres regiones del mundo (Estados Unidos, Unión Europea y Japón) que producen la mayor parte de medicamentos, vacunas, biológicos, pruebas diagnósticas y equipos méd...

Towards a political ontology of state power: a comment on Colin Hay's article.

Science.gov (United States)

Jessop, Bob

2014-09-01

This article offers some critical realist, strategic-relational comments on Colin Hay's proposal to treat the state as an 'as-if-real' concept. The critique first develops an alternative account of ontology, which is more suited to analyses of the state and state power; it then distinguishes the 'intransitive' properties of the real world as an object of investigation from the 'transitive' features of its scientific investigation and thereby provides a clearer understanding of what is at stake in 'as-if-realism'; and it ends with the suggestion that a concern with the modalities of state power rather than with the state per se offers a more fruitful approach to the genuine issues raised in Hay's article and in his earlier strategic-relational contributions to political analysis. © London School of Economics and Political Science 2014.

Estimating the causal effect of body mass index on hay fever, asthma and lung function using Mendelian randomization

DEFF Research Database (Denmark)

Skaaby, T; Taylor, A E; Thuesen, B H

2018-01-01

effects. We examined the causal effect of BMI on asthma, hay fever, allergic sensitization, serum total immunoglobulin E (IgE), forced expiratory volume in one-second (FEV1) and forced vital capacity (FVC). METHODS: We included 490 497 participants in the observational and 162 124 participants...... support the conclusion that increasing BMI is causally related to higher prevalence of asthma and decreased lung function, but not with hay fever or biomarkers of allergy....

Buenas preguntas del estudiantado en clases de biología, a partir de cuestiones socio-científicas

OpenAIRE

Rojas Conejera, Alejandra

2017-01-01

Actualmente se habla de la importancia que tiene el desarrollo de la competencia de elaborar buenas preguntas en la clase de ciencia por parte del estudiantado, puesto que éstas confieren un rol protagónico en los procesos de enseñanza y aprendizaje de las ciencias. Por esto, conseguir estrategias concretas que promuevan mejores preguntas, se plantea como un desafío para la investigación en didáctica de las ciencias. Esta investigación analiza cómo actividades escritas que utilizan c...

Buenas preguntas del estudiantado en clases de biología, a partir de cuestiones socio-científicas

OpenAIRE

Rojas Conejera, Alejandra

2017-01-01

Actualmente se habla de la importancia que tiene el desarrollo de la competencia de elaborar buenas preguntas en la clase de ciencia por parte del estudiantado, puesto que éstas confieren un rol protagónico en los procesos de enseñanza y aprendizaje de las ciencias. Por esto, conseguir estrategias concretas que promuevan mejores preguntas, se plantea como un desafío para la investigación en didáctica de las ciencias. Esta investigación analiza cómo actividades escritas que utilizan cuestiones...

Effect of increasing the level of alfalfa hay in finishing beef heifer diets on intake, sorting, and feeding behavior.

Science.gov (United States)

Madruga, A; González, L A; Mainau, E; Ruíz de la Torre, J L; Rodríguez-Prado, M; Manteca, X; Ferret, A

2018-02-15

Eight rumen cannulated Simmental heifers (BW = 281.4 ± 7.28 kg) were randomly assigned to one of four experimental treatments in a 4 × 4 replicated Latin square design to ascertain the effects of increasing levels of alfalfa hay on intake, sorting, and feeding behavior in comparison to barley straw as forage source. Treatments tested were four total mixed rations with: 1) 10% barley straw (10BS) with 7.0% NDF from forage, 2) 13% alfalfa hay (13AH) and less NDF from forage (5.7%) than 10BS, 3) 16% alfalfa hay (16AH) and the same NDF from forage (7.0%) as 10BS, and 4) 19% alfalfa hay (19AH) and more NDF from forage (8.3%) than 10BS. Each experimental period consisted of 3 wk for adaptation and 1 wk for sampling. Increasing the proportion of alfalfa hay in the diet linearly increased (P comparison to the 10BS diet. In the same way, intake of long, medium, and short particle size was greater in this diet. Moreover, heifers fed 19AH sorted for medium particle size and tended to sort for long and short particles size, and against fine particle size. Sorting behavior and meal length increased in the 19AH diet, which leads us to think that sorting feed ingredients requires time and therefore lengthens the meal. Time spent ruminating was greater in heifers fed 19AH, thus reducing the risk of ruminal acidosis when animals are fed high concentrate diets.

Organic vs. conventional grassland management: do (15)N and (13)C isotopic signatures of hay and soil samples differ?

Science.gov (United States)

Klaus, Valentin H; Hölzel, Norbert; Prati, Daniel; Schmitt, Barbara; Schöning, Ingo; Schrumpf, Marion; Fischer, Markus; Kleinebecker, Till

2013-01-01

Distinguishing organic and conventional products is a major issue of food security and authenticity. Previous studies successfully used stable isotopes to separate organic and conventional products, but up to now, this approach was not tested for organic grassland hay and soil. Moreover, isotopic abundances could be a powerful tool to elucidate differences in ecosystem functioning and driving mechanisms of element cycling in organic and conventional management systems. Here, we studied the δ(15)N and δ(13)C isotopic composition of soil and hay samples of 21 organic and 34 conventional grasslands in two German regions. We also used Δδ(15)N (δ(15)N plant - δ(15)N soil) to characterize nitrogen dynamics. In order to detect temporal trends, isotopic abundances in organic grasslands were related to the time since certification. Furthermore, discriminant analysis was used to test whether the respective management type can be deduced from observed isotopic abundances. Isotopic analyses revealed no significant differences in δ(13)C in hay and δ(15)N in both soil and hay between management types, but showed that δ(13)C abundances were significantly lower in soil of organic compared to conventional grasslands. Δδ(15)N values implied that management types did not substantially differ in nitrogen cycling. Only δ(13)C in soil and hay showed significant negative relationships with the time since certification. Thus, our result suggest that organic grasslands suffered less from drought stress compared to conventional grasslands most likely due to a benefit of higher plant species richness, as previously shown by manipulative biodiversity experiments. Finally, it was possible to correctly classify about two third of the samples according to their management using isotopic abundances in soil and hay. However, as more than half of the organic samples were incorrectly classified, we infer that more research is needed to improve this approach before it can be efficiently

Organic vs. Conventional Grassland Management: Do 15N and 13C Isotopic Signatures of Hay and Soil Samples Differ?

Science.gov (United States)

Klaus, Valentin H.; Hölzel, Norbert; Prati, Daniel; Schmitt, Barbara; Schöning, Ingo; Schrumpf, Marion; Fischer, Markus; Kleinebecker, Till

2013-01-01

Distinguishing organic and conventional products is a major issue of food security and authenticity. Previous studies successfully used stable isotopes to separate organic and conventional products, but up to now, this approach was not tested for organic grassland hay and soil. Moreover, isotopic abundances could be a powerful tool to elucidate differences in ecosystem functioning and driving mechanisms of element cycling in organic and conventional management systems. Here, we studied the δ15N and δ13C isotopic composition of soil and hay samples of 21 organic and 34 conventional grasslands in two German regions. We also used Δδ15N (δ15N plant - δ15N soil) to characterize nitrogen dynamics. In order to detect temporal trends, isotopic abundances in organic grasslands were related to the time since certification. Furthermore, discriminant analysis was used to test whether the respective management type can be deduced from observed isotopic abundances. Isotopic analyses revealed no significant differences in δ13C in hay and δ15N in both soil and hay between management types, but showed that δ13C abundances were significantly lower in soil of organic compared to conventional grasslands. Δδ15N values implied that management types did not substantially differ in nitrogen cycling. Only δ13C in soil and hay showed significant negative relationships with the time since certification. Thus, our result suggest that organic grasslands suffered less from drought stress compared to conventional grasslands most likely due to a benefit of higher plant species richness, as previously shown by manipulative biodiversity experiments. Finally, it was possible to correctly classify about two third of the samples according to their management using isotopic abundances in soil and hay. However, as more than half of the organic samples were incorrectly classified, we infer that more research is needed to improve this approach before it can be efficiently used in practice

Effects of feeding pregnant beef cows selenium-enriched alfalfa hay on selenium status and antibody titers in their newborn calves.

Science.gov (United States)

Wallace, L G; Bobe, G; Vorachek, W R; Dolan, B P; Estill, C T; Pirelli, G J; Hall, J A

2017-06-01

In newborn dairy calves, it has been demonstrated that supranutritional maternal and colostral Se supplementation using Se yeast or sodium selenite, respectively, improves passive transfer of IgG. In beef cattle, agronomic biofortification with Se is a more practical alternative for Se supplementation, whereby the Se concentration of hay is increased through the use of Se-containing fertilizer amendments. It has been previously demonstrated that agronomic Se biofortification is an effective strategy to improve immunity and performance in Se-replete weaned beef calves. The objective of this experiment was to determine the effects of feeding beef cows Se-enriched alfalfa () hay during the last 8 to 12 wk of gestation on passive transfer of antibodies to calves. At 10 wk ± 16 d before calving, 45 cows were assigned to 1 of 3 treatment groups with 3 pens (5 cows/pen) per treatment: Control cows were fed non-Se-fortified alfalfa hay plus a mineral supplement containing 120 mg/kg Se from sodium selenite, Med-Se cows were fed alfalfa hay fertilized with 45.0 g Se/ha as sodium selenate, and High-Se cows were fed alfalfa hay fertilized with 89.9 g Se/ha as sodium selenate; both the Med-Se and the High-Se groups received mineral supplement without added Se. Colostrum and whole blood (WB) were collected from cows at calving, and WB was collected from calves within 2 h of calving and at 12, 24, 36, and 48 h of age. Concentrations of IgG1 and J-5 antibody in cow colostrum and calf serum were quantified using ELISA procedures. Selenium concentrations linearly increased in WB ( cows and in WB of newborn calves ( cows fed Se-biofortified alfalfa hay, but J-5 antibody ( = 0.43) concentrations were not. Calf serum IgG1 ( = 0.43) and J-5 antibody ( = 0.44) concentrations during the first 48 h of age were not affected by prior Se treatment of cows. These data suggest that feeding Se-biofortified alfalfa hay promotes the accumulation of Se and antibodies in colostrum but does not

Willet M. Hays, great benefactor to plant breeding and the founder of our association.

Science.gov (United States)

Troyer, A F; Stoehr, H

2003-01-01

Willet M. Hays was a great benefactor to plant breeding and the founder of the American Genetic Association (AGA). We commemorate the AGA's centennial. We mined university archives, U.S. Department of Agriculture (USDA) yearbooks, plant breeding textbooks, scientific periodicals, and descendants for information. Willet Hays first recognized the individual plant as the unit of selection and started systematic pure-line selection and progeny tests in 1888. He developed useful plant breeding methods. He selected superior flax (Linum usitatissimum L.), wheat (Triticum vulgare L.), corn (Zea mays L.), barley (Hordeum vulgare L.), and oat (Avena sativa L.) varieties, and discovered Grimm alfalfa (Medicago sativa L.); all became commercially important. He initiated branch stations for better performance testing. Willet Hays befriended colleagues in other universities, in federal stations, in a London conference, and in Europe. He gathered and spread the scientific plant breeding gospel. He also improved rural roads and initiated animal breeding records and agricultural economics records. He started the AGA in 1903, serving as secretary for 10 years. He became assistant secretary of agriculture in 1904. He introduced the project system for agricultural research. He authored or coauthored the Nelson Amendment, the Smith-Lever Act, the Smith-Hughes Act, and the protocol leading to the United Nations Food and Agriculture Organization-all involved teaching agricultural practices that improved the world.

The bacterial population adherent to plant particles in the rumen of reindeer fed lichen, timothy hay or silage

Directory of Open Access Journals (Sweden)

Monica Alterskjær Olsen

1998-02-01

Full Text Available Male reindeer (Rangifer tarandus tarandus calves taken from a natural winter pasture were given ad lib. access to lichen (n = 3, timothy silage (n = 3 and hay (n = 3 for 7 weeks. Median numbers of viable anaerobic bacteria adherent to the plant particles (cells/g wet weight of rumen solids, growing on a habitat simulating medium (M8V, were significantly higher (P = 0.05 in the rumen of reindeer fed lichen (26.5 x 109- 53.0 x 109 and hay (4.0 x 109- 40.5 x 109, compared to reindeer fed silage (1.15 x 109 - 3.25 x 109. Anaerobic bacterial strains (n = 551 from the plant particles obtained from the rumen of the nine reindeer examined, were isolated using an acid swollen cellulose medium (M8SC and tested for their ability to hydrolyse carboxymethyl cellulose (CMC. The proportion of CMC hydrolysing adherent bacteria isolated from M8SC was significantly higher in reindeer fed hay (21.5% compared ro animals fed lichen (5.3% and silage (2.7% (P = 0.05. The CMC hydrolysing bacterial srrains (n=42 isolated from reindeer fed hay where characterised as non-cellulolytic Butyrivibrio fibrisolvens (9.5%, cellulolytic B. fibrisolvens (50.0%, Clostridium sp. (2.4% and unknowns (38.1%, while CMC hydrolysing strains (n=11 isolated from animals fed lichen and strains (n=4 isolated from animals fed silage where all characterised as B. fibrisolvens. None of the bacterial strains isolated from the rumen solids of reindeer fed lichen or silage were found to be cellulolytic. This study suggests that both lichen and timothy silage have a negative influence, compared to hay, on the numbers of cellulolytic bacteria adherent to the plant particles in the rumen of reindeer.

75 FR 26945 - International Education Programs Service-Fulbright-Hays Group Projects Abroad Program

Science.gov (United States)

2010-05-13

.... Schools and/or departments of education have a role to play in creating greater exposure since they are... DEPARTMENT OF EDUCATION International Education Programs Service--Fulbright-Hays Group Projects... Postsecondary Education, Department of Education. ACTION: Notice of proposed priorities. SUMMARY: The Assistant...

Effect of inclusion of oyster mushroom substrate on the in vitro fermentation kinetics of Brachiaria brizantha hay

Directory of Open Access Journals (Sweden)

Ricardo da Silva Oliveira

2015-07-01

Full Text Available The objective of this study was to evaluate the effect of inclusion of exhausted substrate of Pleurotus ostreatus on the in vitro fermentation of Brachiaria brizantha hay-based diets. The experiment was conducted using the semi-automated gas production technique. The ruminal inoculum was collected from three fistulated cattle kept on Brachiaria brizantha pasture. Brachiaria brizantha hay and exhausted substrate of Pleurotus production were used for composition of the diets: ES (100% exhausted substrate, BH (100% Brachiaria brizantha hay, ES5 (5% ES + 95% BH, ES20 (20% ES + 80% BH, and ES30 (30% ES + 70% BH. The experimental design was a 5x3 factorial scheme consisting of five treatments and three ruminal inocula. The degradation kinetics of dry matter (DM was determined after 96 hours of fermentation [D (96h]. No significant differences in the cumulative volume of gas (A were observed between BH (262.6 mL/g DM, ES5 (284.3 mL/g MS, ES20 (256.6 mL/g MS and ES30 (261.7 mL/g MS, indicating that inclusion of the substrate did not affect hay fermentation. A lower gas volume (165.9 mL and lower degradability (52% were observed for the ES diet, showing a lower nutritional value of this substrate compared to Brachiaria brizantha hay, probably due to the action of enzymes that degrade structural carbohydrates found in the mycelia of Pleurotus. The ES diet exhibited a shorter colonization time (L=2.6 h; P<0.05, a finding that may be attributed to the interaction between the mycelium and substrate, facilitating initial colonization. The inclusion of exhausted substrate did not increase microbial growth or degradation compared to the BH diet, but seems to have favored initial colonization of this substrate. The use of ES does not negatively affect colonization and may be used as an ingredient of ruminant diets.

Asthma, hay fever, and food allergy are associated with caregiver-reported speech disorders in US children.

Science.gov (United States)

Strom, Mark A; Silverberg, Jonathan I

2016-09-01

Children with asthma, hay fever, and food allergy may have several factors that increase their risk of speech disorder, including allergic inflammation, ADD/ADHD, and sleep disturbance. However, few studies have examined a relationship between asthma, allergic disease, and speech disorder. We sought to determine whether asthma, hay fever, and food allergy are associated with speech disorder in children and whether disease severity, sleep disturbance, or ADD/ADHD modified such associations. We analyzed cross-sectional data on 337,285 children aged 2-17 years from 19 US population-based studies, including the 1997-2013 National Health Interview Survey and the 2003/4 and 2007/8 National Survey of Children's Health. In multivariate models, controlling for age, demographic factors, healthcare utilization, and history of eczema, lifetime history of asthma (odds ratio [95% confidence interval]: 1.18 [1.04-1.34], p = 0.01), and one-year history of hay fever (1.44 [1.28-1.62], p speech disorder. Children with current (1.37 [1.15-1.59] p = 0.0003) but not past (p = 0.06) asthma had increased risk of speech disorder. In one study that assessed caregiver-reported asthma severity, mild (1.58 [1.20-2.08], p = 0.001) and moderate (2.99 [1.54-3.41], p speech disorder; however, severe asthma was associated with the highest odds of speech disorder (5.70 [2.36-13.78], p = 0.0001). Childhood asthma, hay fever, and food allergy are associated with increased risk of speech disorder. Future prospective studies are needed to characterize the associations. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

El bienestar subjetivo ante las buenas prácticas educativas con TIC: su influencia en profesorado innovador

OpenAIRE

Valverde Berrocoso, Jesús; Fernández Sánchez, María Rosa; Revuelta Domínguez, Francisco Ignacio

2013-01-01

El objetivo de este estudio, que forma parte de una investigación más amplia sobre la innovación educativa y la integración de las Tecnologías de la Información y la Comunicación (TIC) en el aula [1], es conocer el grado de «bienestar subjetivo» autopercibido por profesorado innovador y asociado a su realización de «buenas prácticas educativas con TIC». El bienestar subjetivo es un concepto que se extrae de las percepciones de las personas sobre su existencia o su visión subjetiva de su exper...

The effect of a hay grid feeder on feed consumption and measurement of the gastric pH using an intragastric electrode device in horses: a preliminary report.

Science.gov (United States)

Aristizabal, F; Nieto, J; Yamout, S; Snyder, J

2014-07-01

Obesity and gastric ulceration are highly prevalent in horses. Management modifications for preventing squamous gastric ulceration include frequent feeding and free access to pasture; however, these practices may predispose horses to obesity. To compare the percentage of hay consumed, intragastric pH and horse activity between feeding from the ground and a hay grid feeder. Crossover experimental study. A pH electrode was inserted into the stomach to record the intragastric pH for 48 h. Horses received 1% of their body weight in grass hay twice a day. Horses were assigned to be fed from the ground or a commercial hay grid feeder for 24 h and then switched to the opposite protocol for an additional 24 h. Horses were continuously video-recorded and the percentage of time spent eating or drinking, walking or standing, and lying down were calculated. Two point data were compared by paired t test and pH over time was compared by repeated measures ANOVA. Horses consumed significantly greater amounts of grass hay when fed on the ground compared with a hay grid feeder (n = 9; PpH values (n = 6; P = 0.97), mean intragastric pH over time (n = 6; P = 0.45) the length of time the pH was below 4.0 (n = 6; P = 0.54), and the percentage of time horses spent eating or drinking (n = 9; P = 0.52), walking or standing (n = 9; P = 0.3), or lying down (n = 9; P = 0.4). Within each group horses spent more time eating during the day compared with the night (n = 9; hay grid feeder P = 0.003; ground feeding P = 0.007). The hay grid feeder studied may be used to reduce the amount of hay ingested by horses without reducing the time horses spend eating. © 2013 EVJ Ltd.

The HayWired earthquake scenario—Engineering implications

Science.gov (United States)

Detweiler, Shane T.; Wein, Anne M.

2018-04-18

The HayWired Earthquake Scenario—Engineering Implications is the second volume of U.S. Geological Survey (USGS) Scientific Investigations Report 2017–5013, which describes the HayWired scenario, developed by USGS and its partners. The scenario is a hypothetical yet scientifically realistic earthquake sequence that is being used to better understand hazards for the San Francisco Bay region during and after a magnitude-7 earthquake (mainshock) on the Hayward Fault and its aftershocks.Analyses in this volume suggest that (1) 800 deaths and 16,000 nonfatal injuries result from shaking alone, plus property and direct business interruption losses of more than $82 billion from shaking, liquefaction, and landslides; (2) the building code is designed to protect lives, but even if all buildings in the region complied with current building codes, 0.4 percent could collapse, 5 percent could be unsafe to occupy, and 19 percent could have restricted use; (3) people expect, prefer, and would be willing to pay for greater resilience of buildings; (4) more than 22,000 people could require extrication from stalled elevators, and more than 2,400 people could require rescue from collapsed buildings; (5) the average east-bay resident could lose water service for 6 weeks, some for as long as 6 months; (6) older steel-frame high-rise office buildings and new reinforced-concrete residential buildings in downtown San Francisco and Oakland could be unusable for as long as 10 months; (7) about 450 large fires could result in a loss of residential and commercial building floor area equivalent to more than 52,000 single-family homes and cause property (building and content) losses approaching $30 billion; and (8) combining earthquake early warning (ShakeAlert) with “drop, cover, and hold on” actions could prevent as many as 1,500 nonfatal injuries out of 18,000 total estimated nonfatal injuries from shaking and liquefaction hazards.

Shared genetic origin of asthma, hay fever and eczema elucidates allergic disease biology

NARCIS (Netherlands)

Ferreira, Manuel A; Vonk, Judith M; Baurecht, Hansjörg; Marenholz, Ingo; Tian, Chao; Hoffman, Joshua D; Helmer, Quinta; Tillander, Annika; Ullemar, Vilhelmina; van Dongen, Jenny; Lu, Yi; Rüschendorf, Franz; Esparza-Gordillo, Jorge; Medway, Chris W; Mountjoy, Edward; Burrows, Kimberley; Hummel, Oliver; Grosche, Sarah; Brumpton, Ben M; Witte, John S; Hottenga, Jouke-Jan; Willemsen, Gonneke; Zheng, Jie; Rodríguez, Elke; Hotze, Melanie; Franke, Andre; Revez, Joana A; Beesley, Jonathan; Matheson, Melanie C; Dharmage, Shyamali C; Bain, Lisa M; Fritsche, Lars G; Gabrielsen, Maiken E; Balliu, Brunilda; Nielsen, Jonas B; Zhou, Wei; Hveem, Kristian; Langhammer, Arnulf; Holmen, Oddgeir L; Løset, Mari; Abecasis, Gonçalo R; Willer, Cristen J; Arnold, Andreas; Homuth, Georg; Schmidt, Carsten O; Thompson, Philip J; Martin, Nicholas G; Duffy, David L; Novak, Natalija; Boomsma, Dorret I

2017-01-01

Asthma, hay fever (or allergic rhinitis) and eczema (or atopic dermatitis) often coexist in the same individuals, partly because of a shared genetic origin. To identify shared risk variants, we performed a genome-wide association study (GWAS; n = 360,838) of a broad allergic disease phenotype that

Intake and ingestive behavior of lambs fed diets containing ammoniated buffel grass hay.

Science.gov (United States)

Perazzo, Alexandre Fernandes; de Paula Homem Neto, Sansão; Ribeiro, Ossival Lolato; Santos, Edson Mauro; de Carvalho, Gleidson Giordano Pinto; de Oliveira, Juliana Silva; Bezerra, Higor Fábio Carvalho; Campos, Fleming Sena; de Freitas Junior, José Esler

2017-04-01

This study aimed to evaluate the effect of diets with ammoniated buffel grass hay on the ingestive behavior of feedlot lambs. Thirty-two sheep of no defined breed with an average body weight of 17.7 ± 1.8 kg were used. A completely randomized design with four treatments (0, 18, 36, and 54 g/kg dry matter (DM) basis) and eight repetitions was used. Ingestive behavior, rumination, and idle time were similar (P > 0.05) among the diets containing ammoniated buffel grass hay, with mean values of 294.5, 554.44, and 594.25 min per day, respectively. Regarding the chews, all of the variables resulted in similar behavior (P > 0.05). The quadratic effect (P  0.05) on the efficiency of DM and NDF consumption. However, the rumination efficiency of DM and NDF showed a quadratic effect (P ingestive behavior by increasing the rumination efficiency, increased intake, and feed utilization.

CHANGES OF IMMUNE INDEXES DURING SUBLINGUAL ALLERGEN-SPECIFIC IMMUNOTHERAPY IN CHILDREN WITH HAY FEVER

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I. M. Gaiduk

2013-01-01

Full Text Available Aims of study: evaluation of immunological parameters in course of sublingual allergen-specific immunotherapy with tree pollen mixture in children with hay fever.Materials and methods: the study included one-hundred patients 5 to 18 years of age with hay fever (pollen rhinitis, rhinoconjunctivitis and/or asthma. Allergen-specific immunotherapy was administered pre-seasonally for three consecutive years. Cytokinechanges were studied in blood serum and in lavages from nasal cavity. Samples assessed before treatment and after 2nd and 3rd courses SLIT completion.Results: increased serum concentrations of IL-10, IFNγ, and decreased IL-4 contents were revealed in the course of treatment. No significant changes in cytokineconcentrations were detectable in nasal lavages.Conclusions: the changes revealed correspond to a shift of T cell response profile towards Th1 pathway, thus confirming pathogenetic effects of sublingual allergen-specific

Ron Hays: A Story of Art as Self Treatment for Alzheimer's Disease

Science.gov (United States)

Jones, Robin M. N.; Hays, Nancy Scheller

2016-01-01

Ronald E. Hays is the former Director of the Hahnemann Creative Arts in Therapy Department at Drexel University in Philadelphia, Pennsylvania, and the cofounder of the graduate art therapy program at Eastern Virginia Medical School in Norfolk, Virginia. At the age of 62 he was diagnosed with early onset Alzheimer's disease, a form of dementia. In…

Effects of alfalfa germplasm and stage of maturity on digestive process and productive response of dairy cows fed alfalfa hay-based diets

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Igino Andrighetto

2010-01-01

Full Text Available The effects on the digestive process and the productive performances of dairy cows fed diets containing alfalfa hay from  different germplasms and maturity were assessed in the present study. Three different lots of first-cut alfalfa hay were  used in the study: the improved variety “Boreal”, harvested at two consecutive maturity stages (early flowering and full  flowering and the ecotype “Vogherese”, at full flowering. Cutting the plant at an earlier stage of maturity improved hay  quality in comparison with the more mature forages (crude protein: 21.4 vs 16.5% DM; P  DM; P  er lignin content for the latter (8.6 vs 8.2% DM; P  tating cows were formulated using an equal amount of corn silage and the maximum inclusion of one of the tested hays  as forage base. The better quality of the early cut hay made it possible to increase its inclusion in the diet up to 44% of  total dietary DM, while the two more mature hays covered only 36% of total DM of the respective diets. According to a  3 x 3 Latin square design, the diets were fed to 3 Italian Brown cows (initial average days in milk 121 ± 24 and milk  yield 20 kg ± 1.3 fitted with ruminal cannula in 3 consecutive periods of 28 d each. Alfalfa stage of maturity and  germplasm did not affect dietary DM intake (average 16 kg/d. Degradability parameters of dietary DM, calculated by in  situ nylon bags technique, showed similar kinetics of rumen disappearance for all diets. No differences were noticed in  the ruminal rate of passage of the solid phase among diets, while the liquid phase showed a slower rate of passage for  the early flowering hay diet. Consistent with the degradation process, the stage of maturity or the alfalfa germplasm did  not affect the rumen fluid data or the in vivo digestibility coefficients of the diets. Milk yield did not show any change due  to either alfalfa maturity or cultivar, while milk protein was lowered when cows received the early cut hay

Wheat straw, household waste and hay as a source of lignocellulosic biomass for bioethanol and biogas production

DEFF Research Database (Denmark)

Tomczak, Anna; Bruch, Magdalena; Holm-Nielsen, Jens Bo

2010-01-01

To meet the increasing need for bioenergy three lignocellulosic materials: raw hay, pretreated wheat straw and pretreated household waste were considered for the production of bioethanol and biogas. Several mixtures of household waste supplemented with different fractions of wheat straw and hay...... in fermentation process with Saccharomyces cerevisiae were investigated. Wheat straw and household wastes were pretreated using IBUS technology, patented by Dong Energy, which includes milling, stem explosion treatment and enzymatic hydrolysis. Methane production was investigated using stillages, the effluents...... from bioethanol fermentation experiment. Previous trial of biogas production from above mentioned household wastes was enclosed....

Effect of feeding selenium-fertilized alfalfa hay on performance of weaned beef calves.

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Jean A Hall

Full Text Available Selenium (Se is an essential micronutrient in cattle, and Se-deficiency can affect morbidity and mortality. Calves may have greater Se requirements during periods of stress, such as during the transitional period between weaning and movement to a feedlot. Previously, we showed that feeding Se-fertilized forage increases whole-blood (WB Se concentrations in mature beef cows. Our current objective was to test whether feeding Se-fertilized forage increases WB-Se concentrations and performance in weaned beef calves. Recently weaned beef calves (n = 60 were blocked by body weight, randomly assigned to 4 groups, and fed an alfalfa hay based diet for 7 wk, which was harvested from fields fertilized with sodium-selenate at a rate of 0, 22.5, 45.0, or 89.9 g Se/ha. Blood samples were collected weekly and analyzed for WB-Se concentrations. Body weight and health status of calves were monitored during the 7-wk feeding trial. Increasing application rates of Se fertilizer resulted in increased alfalfa hay Se content for that cutting of alfalfa (0.07, 0.95, 1.55, 3.26 mg Se/kg dry matter for Se application rates of 0, 22.5, 45.0, or 89.9 g Se/ha, respectively. Feeding Se-fertilized alfalfa hay during the 7-wk preconditioning period increased WB-Se concentrations (P Linear<0.001 and body weights (P Linear = 0.002 depending upon the Se-application rate. Based upon our results we suggest that soil-Se fertilization is a potential management tool to improve Se-status and performance in weaned calves in areas with low soil-Se concentrations.

Comparison of hay and haylage from permanent Alpine meadows in winter dairy cow diets.

Science.gov (United States)

Borreani, G; Giaccone, D; Mimosi, A; Tabacco, E

2007-12-01

In an Alpine environment, diets based on local forage resources are needed to maintain the link with the territory and confer special characteristics to typical cheeses. Harvesting at a late stage of maturity, high mechanical losses, and frequent rainfall often make the hay that is harvested of a poor quality. The aim of this study was to evaluate the effects of 2 different conservation methods (late hay, LH, vs. early haylage, ES) of natural permanent meadows on milk production in dairy cows, on the chemical and microbiological characteristics of the milk, and on the quality of the cheese over the winter period. Haylage and hay were harvested from the same permanent meadow at the Vittorino Vezzani experimental farm in Sauze d'Oulx (45 degrees 02'N, 6 degrees 53'E, Italy). The ES forage was cut 4 wk earlier than traditional hay, wilted for 30 h, baled at a dry matter (DM) content of about 50%, wrapped with 6 layers of stretch film, and stored in a protected area. The LH forage was harvested later, when the weather conditions were favorable and, after a 3-d wilting, it was baled and stored indoors. After an 8-mo storage period, the ES had a greater crude protein concentration, organic matter digestibility, and net energy for lactation than LH and a lower neutral detergent fiber and acid detergent fiber. Forty multiparous lactating Aosta Red Pied cows were used in a 19-d period crossover design to assess the nutritional value of the stored forages. The diets included ES fed ad libitum and 3.5 kg of DM per cow of concentrate or LH fed ad libitum and 5.1 kg of DM per cow of concentrate. The dietary DM was 90.1% for the LH and 59.9% for the ES. The diets contained 12.6 and 13.0% crude protein and 48.6 and 48.0% neutral detergent fiber, for the LH and ES, respectively. The forage intake was greater in the ES treatment than in the LH treatment. The ES treatment produced more milk (1.7 kg/d) and more 3.5% fat-corrected milk (1.5 kg/d) than the cows on the LH treatment. The

Mental health associations with eczema, asthma and hay fever in children: a cross-sectional survey.

Science.gov (United States)

Hammer-Helmich, Lene; Linneberg, Allan; Obel, Carsten; Thomsen, Simon Francis; Tang Møllehave, Line; Glümer, Charlotte

2016-10-14

This study aimed to examine the association of eczema, asthma and hay fever with mental health in a general child population and to assess the influence of parental socioeconomic position on these associations. We conducted a cross-sectional health survey of children aged 3, 6, 11 and 15 years in the City of Copenhagen, Denmark. Individual questionnaire data on eczema, asthma, and hay fever and mental health problems assessed using the Strengths and Difficulties Questionnaire (SDQ) was linked to register data on demographics and parental socioeconomic position. 9215 (47.9%) children were included in the analyses. Linear regression analyses showed that children with current eczema symptoms had higher SDQ scores (mean difference, 95% CI) of emotional problems (0.26, 0.12 to 0.39), conduct problems (0.19, 0.09 to 0.29) and hyperactivity problems (0.32, 0.16 to 0.48); children with current asthma symptoms had higher SDQ scores of emotional problems (0.45, 0.32 to 0.58), conduct problems (0.28, 0.18 to 0.38) and hyperactivity problems (0.52, 0.35 to 0.69); and children with current hay fever symptoms had higher SDQ scores of emotional problems (0.57, 0.42 to 0.72), conduct problems (0.22, 0.11 to 0.33), hyperactivity problems (0.44, 0.26 to 0.61) and peer problems (0.14, 0.01 to 0.26), compared with children without current symptoms of the relevant disease. For most associations, parental socioeconomic position did not modify the effect. Children with eczema, asthma or hay fever had more emotional, conduct and hyperactivity problems, but not peer problems, compared with children without these diseases. Atopic diseases added equally to the burden of mental health problems independent of socioeconomic position. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

The HayWired Scenario - How Can the San Francisco Bay Region Bounce Back Better?

Science.gov (United States)

Hudnut, K. W.; Wein, A. M.; Cox, D. A.; Perry, S. C.; Porter, K.; Johnson, L. A.; Strauss, J. A.

2017-12-01

The HayWired scenario is a hypothetical yet scientifically realistic and quantitative depiction of a moment magnitude (Mw) 7.0 earthquake occurring on April 18, 2018, at 4:18 p.m. on the Hayward Fault in the east bay part of the San Francisco Bay area, California. The hypothetical earthquake has its epicenter in Oakland, and strong ground shaking from the scenario causes a wide range of severe impacts throughout the greater bay region. In the scenario, the Hayward Fault is ruptured along its length for 83 kilometers (about 52 miles). Building on a decades-long series of efforts to reduce earthquake risk in the SF Bay area, the hypothetical HayWired earthquake is used to examine the well-known earthquake hazard of the Hayward Fault, with a focus on newly emerging vulnerabilities. After a major earthquake disaster, reestablishing water services and food-supply chains are, of course, top priorities. However, problems associated with telecommunication outages or "network congestion" will increase and become more urgent as the bay region deepens its reliance on the "Internet of Things." Communications at all levels are crucial during incident response following an earthquake. Damage to critical facilities (such as power plants) from earthquake shaking and to electrical and telecommunications wires and fiber-optic cables that are severed where they cross a fault rupture can trigger cascading Internet and telecommunications outages, and restoring these services is crucially important for emergency-response coordination. Without good communications, emergency-response efficiency is reduced, and as a result, life-saving response functions can be compromised. For these reasons, the name HayWired was chosen for this scenario to emphasize the need to examine our interconnectedness and reliance on telecommunications and other lifelines (such as water and electricity). Earthquake risk in the SF Bay area has been greatly reduced as a result of previous concerted efforts; for

The influence of feedback on hay pastures. | N.F.G. | African Journal ...

African Journals Online (AJOL)

The feeding of hay to sheep or cattle on an Eragrostis curvula pasture during the winter months has a most beneficial effect on the response of the pasture to fertilization in subsequent seasons. Low rates of feedback (10 t/ha) had an effect for two seasons whilst the effect of 30 t/ha lasted for at least three seasons and was ...

Interaction of bale size and preservative rate for large-round bales of alfalfa hay

Science.gov (United States)

Recently, two studies conducted at the US Dairy Forage Research Center have reported inconsistent storage responses following the application of propionic-acid-based preservatives to alfalfa or alfalfa-orchardgrass hays. One of these studies utilized 5-foot-diameter round bales, and produced disappo...

Buenas prácticas y nuevas tecnologías en la cooperación penal en el MERCOSUR

Directory of Open Access Journals (Sweden)

Juan José Cerdeira

2017-11-01

Full Text Available El presente aborda las diferentes problemáticas que presenta la cooperación jurídica en materia penal desde la perspectiva internacional del espacio MERCOSUR y Estados Asociados y la importancia que revisten las buenas prácticas y las nuevas tecnologías para el cabal desenvolvimiento de dicha cooperación internacional como instrumento de combate contra el crimen. En el desarrollo se expondrán los desafíos que se presentan actualmente en el marco regional, atento sus características como esquema de integración y seguidamente se expondrán algunas propuestas y soluciones como aporte.

Effects of a propionic acid-based preservative on storage characteristics, nutritive value, and energy content for alfalfa hays packaged in large, round bales

Science.gov (United States)

During 2009 and 2010, alfalfa (Medicago sativa L.) hays from two cuttings that were harvested from the same field site were used to evaluate the effects of a propionic acid-based preservative on the storage characteristics and nutritive value of hays stored as large, round bales. A total of 87 large...

Leite produzido e saciedade da criança na percepção da nutriz durante o aleitamento materno exclusivo

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Juliana Cristina dos Santos Monteiro

2011-01-01

Full Text Available Los objetivos fueron analizar la percepción materna sobre la leche producida y su relación con la duración y conducción de la lactancia exclusiva. Estudio transversal, descriptivo analítico, com 231 nodrizas acompañando sus hijos menores de 4 meses en una Unidad de Salud en Ribeirao Preto, Brazil. Los datos fueron analizados mediante comparación entre medias, test exacto de Fisher y regresión logística. 71% de las participantes reportaron producir buena leche, percibiendo el niño satisfecho después de mamar. La percepción de la leche fue estadísticamente significativa cuando asociada a saciedad del niño. Las nodrizas que perciben el niño insatisfecho tienen 32 veces chance de mala percepción sobre su leche. Hubo diferencia significativa entre intervalos de mamadas para mujeres que tenían o no buena percepción sobre la leche. La satisfacción del niño fue el indicador más utilizado para evaluar la leche. Hay que estimular la capacidad de las mujeres para buena producción de leche.

Intake, Rumen Degradation and Utilisation of Urea-Ammoniated Grass Hay by Kacang Goats as Affected by Supplementation of Sun-dried Fish or Fishmeal

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MR Weibsjerg

2012-05-01

Full Text Available Six mature male Kacang goats were involved in an experiment arranged following a duplicate 3 x 3 Latin Square Design. The objectives of this experiment was to study the effect of supplementation of dried fish as compared to fishmeal on intake, digestion, rumen environment and nitrogen used by the local meat type Kacang goats maintained on urea-treated low quality grass hay. The treatments were G: goats were fed with ad libitum access of urea treated grass hay and 100 g/d putak, SDF: G plus 18.4 g sun dried fish, and FM: G plus 19.7 g/d fishmeal. The supplement in SDF and FM were at equal CP level. Intake of urea treated grass hay tended to increase (P=0.08 with supplementation. Dry matter digestibility particularly that of CP was improved by supplementation. Rumen environment was slightly modified by supplementation. Rumen pH was reduced while ammonia concentration was increased. Rumen degradation of the treated grass hay did not differ when incubated in the rumen of goats with different diets. Nitrogen balance was significantly improved (P<0.05 by fishmeal supplementation. In all parameters measured in this experiment, the incremental effects did not differ between fishmeal type. This indicate that there is no further advantage of preparing fishmeal other than sun-drying in improving the utilisation of low quality urea-treated grass hay.

Evaluation of methodological aspects of digestibility meaurements in ponies fed different grass hays

NARCIS (Netherlands)

Schaafstra, F.J.W.C.; Doorn, van D.A.; Schonewille, J.T.; Wartena, F.C.; Zoon, van M.; Blok, M.C.; Hendriks, W.H.

2015-01-01

Methodological aspects of digestibility measurements of feedstuffs for equines were studied in four Welsh pony geldings consuming four grass-hay diets in a 4 × 4 Latin square design. Diets contained either a low (L), medium (M), high (H), or very high (VH) ADF content (264, 314, 375, or 396 g·kg-1

Mixing and photoreactivity of dissolved organic matter in the Nelson/Hayes estuarine system (Hudson Bay, Canada)

Science.gov (United States)

Guéguen, C.; Mokhtar, M.; Perroud, A.; McCullough, G.; Papakyriakou, T.

2016-09-01

This work presents the results of a 4-year study (2009-2012) investigating the mixing and photoreactivity of dissolved organic matter (DOM) in the Nelson/Hayes estuary (Hudson Bay). Dissolved organic carbon (DOC), colored DOM, and humic-like DOM decreased with increasing salinity (r2 = 0.70-0.84). Removal of DOM was noticeable at low to mid salinity range, likely due to degradation and/or adsorption to particles. DOM photobleaching rates (i.e., decrease in DOM signal resulting from exposure to solar radiation) ranged from 0.005 to 0.030 h- 1, corresponding to half-lives of 4.9-9.9 days. Dissolved organic matter from the Nelson and Hayes Rivers was more photoreactive than from the estuary where the photodegradation of terrestrial DOM decreased with increasing salinity. Coincident with the loss of CDOM absorption was an increase in spectral slope S, suggesting a decrease in DOM molecular weight. Marked differences in photoreactivity of protein- and humic-like DOM were observed with highly humidified material being the most photosensitive. Information generated by our study will provide a valuable data set for better understanding the impacts of future hydroelectric development and climate change on DOM biogeochemical dynamics in the Nelson/Hayes estuary and coastal domain. This study will constitute a reference on terrestrial DOM fate prior to building additional generating capacity on the Nelson River.

Economic consequences of earthquakes: bridging research and practice with HayWired

Science.gov (United States)

Wein, A. M.; Kroll, C.

2016-12-01

The U.S. Geological Survey partners with organizations and experts to develop multiple hazard scenarios. The HayWired earthquake scenario refers to a rupture of the Hayward fault in the Bay Area of California and addresses the potential chaos related to interconnectedness at many levels: the fault afterslip and aftershocks, interdependencies of lifelines, wired/wireless technology, communities at risk, and ripple effects throughout today's digital economy. The scenario is intended for diverse audiences. HayWired analyses translate earthquake hazards (surface rupture, ground shaking, liquefaction, landslides) into physical engineering and environmental health impacts, and into societal consequences. Damages to life and property and lifeline service disruptions are direct causes of business interruption. Economic models are used to estimate the economic impacts and resilience in the regional economy. The objective of the economic analysis is to inform policy discourse about economic resilience at all three levels of the economy: macro, meso, and micro. Stakeholders include businesses, economic development, and community leaders. Previous scenario analyses indicate the size of an event: large earthquakes and large winter storms are both "big ones" for California. They motivate actions to reduce the losses from fire following earthquake and water supply outages. They show the effect that resilience can have on reducing economic losses. Evaluators find that stakeholders learned the most about the economic consequences.

Viga on öelda, et me ei vaja PRi / Roger Hayes, Alasdair Sutherland ; interv. Tiiu Värbu

Index Scriptorium Estoniae

Hayes, Roger

2001-01-01

Eesti Suhtekorraldajate Liidu 5. aastapäeva seminaril osalevad Rahvusvahelise Kommunikatsiooni Instituudi direktor R. Hayes ja maailma ühe juhtiva suhtekorraldusfirma Manning, Selvage & Lee asepresident A. Sutherland

Microbial load and phytochemicals stability of camel hay (Cymbopogon Schoenanthus L) leaves as affected by gamma irradiation

International Nuclear Information System (INIS)

Musa, H. A. A.; Ahmed, E. E.; Osman, G. A. M.; Ludwig-muller, J.

2010-01-01

The influence of gamma irradiation on microbial load and chemical quality of camel hay (Cymbopogon schoenanthus) leaves was evaluated at doses of 0, 5,10, and 15 kGy in a cobalt-60 package irradiator. The results revealed that, immediately after irradiation, gamma irradiation was found to cause significant reduction in microbial load proportionate to the doses delivered. TLC analysis indicated that irradiation of camel hay leaves extract with 15 kGy doses of gamma radiation had no effect on flavonoids concentrations, however, increase in total phenols and tannins was observed. In addition, the chemical constituents of camel hay leaves as represented by HPLC retention time (min) at different wave lengths showed that the compounds of retention time 8.42, 29.08, 8.38, 16.93, 14.80 and 42.80 min remained approximately unchanged, while the compound of retention times 16.95 min was eliminated. The compounds of retention times 9.66, 2.03 and 29.35 min were decreased from 16.56 to 11.77, 14.06 to 9.88 and 8.25 to 2.88 min respectively. An increase in the chemical constituents, was observed in the compounds of the retention times 14.37 and 35.42 min from 33.76 to 40.11 and 5.64 to 10.05, respectively. (Author)

Comportamiento del consumidor de productos agroecológicos frente a la aplicación de buenas prácticas agrícolas

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Jorge Merino Toro

2016-06-01

Full Text Available La presente investigación evalúa el comportamiento del consumidor de productos agroecológicos comercializados por productores de PACAT (Corporación de Asociaciones de Productores Agroecológicos y Comercio Asociativo de Tungurahua frente a la aplicación de Buenas Prácticas Agrícolas (BPA, tomando como punto de partida el aumento descontrolado de ferias que comercializan productos bajo la denominación de agroecológicos en la provincia de Tungurahua. La principal herramienta utilizada en esta investigación fue la encuesta, aplicada a una muestra de 217 consumidores y 33 productores agroecológicos, con el uso de esta herramienta se determinó el comportamiento del consumidor de la Plaza Pachano y además se analizó la aplicación de Buenas Prácticas Agrícolas. Se reconoce la alta calidad como la principal razón para consumir productos agroecológicos, la frescura constituye la característica física que más atrae, y el producto más comprado fueron las hortalizas. Respecto a productores se determinó que aplican correctamente BPA. Palabras clave: Economía del consumidor, mercados agrarios y marketing, análisis de la oferta y de la demanda, producción, consumo.

Mid-late Holocene environments of Agua Buena locality (34{sup 0}50'S; 69{sup 0}56'W), Mendoza, Argentina

Energy Technology Data Exchange (ETDEWEB)

Navarro, Diego; Paez, M M [Laboratorio de Paleoecologia y Palinologia, Departamento de Biologia, Universidad Nacional de Mar del Plata, Funes 3350, (B7602AYL) Mar del Plata, Buenos Aires (Argentina); Mehl, A; Zarate, M A, E-mail: dnavarro@mdp.edu.a, E-mail: navarro.dd@gmail.co [INCITAP - Instituto de Ciencias de la Tierra y Ambientales de La Pampa. CONICET- Universidad Nacional de La Pampa, Uruguay 151, (L6300CLB) Santa Rosa, La Pampa (Argentina)

2010-03-15

In southern South America the acquisition of high-quality Holocene paleoclimate data is a priority due to the paucity of complete, continuous and well dated records. Here we report preliminary results from a combined sedimentological and palynological study of an alluvial fan sequence and the laterally connected sedimentary deposits of the Vega de la Cueva profile at Agua Buena east of the Andes in central Argentina. The main geomorphological units of the area were identified and mapped based on satellite image analysis and multiple field surveys. The sedimentological and pollen results allowed us to reconstruct the development of some environments. The Agua Buena record corresponds to the distal facies of the Arroyo Bayo alluvial fan starting the aggradation process prior to ca. 4100 cal yr BP. The organic-rich levels found were formed during the development of wetlands (vegas) dominated by Cyperaceae, Juncaceae and Poaceae. These highly productive environments with almost permanent water saturation were important between 4100 and 2800 cal yr BP, indicating more stable conditions. After 2800 cal yr BP, the organic content was comparatively lower with increasing sedimentation rates that are indicative of higher fluvial discharges. This information is fundamental to interpret both the pollen and charcoal records of the area and to evaluate their representativeness and potential to reconstruct past local and/or regional vegetation.

Los procesos de globalización y transferencia tecnológica

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Luis Murillo Orozco.

2000-06-01

Full Text Available Este artículo presente un breve análisis del significado de globalización y de transferencia tecnológica, dos procesos indisolubles y concatenados entre sí que deben ser tomados como medios fundamentales y no como fines para enfrentar el giro de la competencia económica actual. Esta competencia se ha trasladado del ámbito empresarial y de país, al ámbito de la integración económica. Hay que tomar en cuenta que no Se puede lograr una buena posición en el ámbito internacional sin una buena y adecuada productividad, la cual sólo será posible con un eficiente proceso de transferencia tecnológica. En este trabajo se establecerán las características de mayor importancia de ambos procesos, tomando como referencia el caso centroamericano.

A single dose desensitization for summer hay fever. Results of a double blind study-1988.

Science.gov (United States)

Fell, P; Brostoff, J

1990-01-01

A new type of desensitising vaccine, enzyme potentiated was subjected to a double-blind randomised study during the hay fever season. The vaccine is a convenient single injection given in March and the results show good protection throughout the grass pollen season.

Personas y comunidades: Actas del Segundo Congreso Internacional de Buenas Prácticas en Patrimonio Mundial: (29 -30 de abril, 1 y 2 de mayo de 2015)

OpenAIRE

Castillo Mena, Alicia R. (ed.)

2015-01-01

Este volumen está compuesto por una introducción y los textos de las comunicaciones y pósteres del congreso internacional, con una participación de 30 países y casi 100 centros de investigación. Recoge un documento de Buenas Prácticas sobre el tema.

Digestibility and performance of lambs fed diets containing old man saltbush hay

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Greicy Mitzi Bezerra Moreno

2017-03-01

Full Text Available The aim of this study was to evaluate feed intake, digestibility, nitrogen balance, water balance, and performance of lambs fed diets containing old man saltbush hay associated with a concentrate. Thirty-two castrated feedlot Santa Inês lambs at approximately eight months of age, with 22 ± 1.97 kg body weight, were distributed into a completely randomized experimental design. Acid detergent fiber intake increased (P < 0.05, whereas non-fibrous carbohydrates intake decreased (P < 0.01. Inclusion of old man saltbush in the diet reduced (P < 0.01 the digestibility of dry and organic matter, neutral and acid detergent fiber, and non-fibrous carbohydrates. The intakes of digestible dry and organic matter, ether extract, total carbohydrates, and digestible non-fibrous carbohydrates also decreased (P < 0.01. Inclusion of old man saltbush did not influence water consumption from the trough by the sheep, averaging 4,327.20 mL/day?1. Body weight at slaughter and daily weight gain decreased linearly (P < 0.05 and feed conversion worsened as old man saltbush hay was added to the diet. Inclusion of old man saltbush at up to 40% replacing the concentrate in feedlot lamb diets does not compromise the performance of these animals.

Hay-Wells syndrome is caused by heterozygous missense mutations in the SAM domain of p63.

NARCIS (Netherlands)

McGrath, J.A.; Duijf, P.H.; Doetsch, V.; Irvine, A.D.; Waal, R.M.W. de; Vanmolkot, K.R.; Wessagowit, V.; Kelly, A.E.; Atherton, D.J.; Griffiths, W.A.; Orlow, S.J.; Haeringen, A. van; Ausems, M.G.E.M.; Yang, A.; McKeon, F.; Bamshad, M.; Brunner, H.G.; Hamel, B.C.J.; Bokhoven, J.H.L.M. van

2001-01-01

Hay-Wells syndrome, also known as ankyloblepharon-ectodermal dysplasia-clefting (AEC) syndrome (OMIM 106260), is a rare autosomal dominant disorder characterized by congenital ectodermal dysplasia, including alopecia, scalp infections, dystrophic nails, hypodontia, ankyloblepharon and cleft lip

Hay-Wells syndrome is caused by heterozygous missense mutations in the SAM domain of p63

NARCIS (Netherlands)

McGrath, JA; Duijf, PHG; Doetsch, [No Value; Irvine, AD; de Waal, R; Vanmolkot, KRJ; Wessagowit, [No Value; Kelly, A; Atherton, DJ; Griffiths, WAD; Orlow, SJ; van Haeringen, A; Ausems, MGEM; Yang, A; McKeon, F; Bamshad, MA; Brunner, HG; Hamel, BCJ; van Bokhoven, H

2001-01-01

Hay-Wells syndrome, also known as ankyloblepharon-ectodermal dysplasia-clefting (AEC) syndrome (OMIM 106260), is a rare autosomal dominant disorder characterized by congenital ectodermal dysplasia, including alopecia, scalp infections, dystrophic nails, hypodontia, ankyloblepharon and cleft lip

1.8. Brand*, HA Badenhorst, FK 8iebrits and EH Kemm JP Hayes et ...

African Journals Online (AJOL)

Brand*, H.A. Badenhorst, F.K. 8iebrits and E.H. Kemm. Animal and Dairy Science Research Institute, Private Bag X2, Irene 1675, Republic of South Africa. J.P. Hayes. Department of Poultry Science, University of Stellenbosch, Stellenbosch 7600, Republic of South Africa. The experiment was conducted to compare the ...

Digestibility of Buffel grass (Cenchrus ciliaris)-based diets supplemented with four levels of Gliricidia sepium hay in hair sheep lambs

DEFF Research Database (Denmark)

Avilés-Nieto, Jonathan N.; Valle-Cerdán, José L.; Castrejón-Pineda, Francisco

2013-01-01

The objective of this experiment was to evaluate the effect of supplementing increasing levels of Gliricidia sepium hay (GS) with different levels of inclusion of Buffel grass (BG) hay on digestibility by hair sheep lambs (2.5 to 3.5 months of age). Eight male lambs were used in a replicated 4 × 4...... were not affected by treatments. The intake of crude protein (CP), organic matter (OM), and gross energy was higher (P lambs fed with T4 diet than control. NDF and ADF digestibilities were higher (P

ITINERARIOS DE LA BUENA ENSEÑANZA A PARTIR DE LOS RELATOS BIOGRÁFICOS DOCENTES

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Zelmira Álvarez

2010-01-01

Full Text Available En la investigación cualitativa en educación, el enfoque biográfico y narrativo ha logrado su identidad propia. Siguiendo esta línea, se indaga aquí, por medio de entrevistas semi-flexibles, en las biografías de una selección de buenos docentes de la Facultad de Humanidades de la Universidad Nacional de Mar del Plata, Argentina. Éstos fueron identificados a través de cuestionarios semi-abiertos administrados a estudiantes avanzados de los Profesorados de esta Facultad. Del análisis de las conversaciones, se han seleccionado seis casos que confieren a sus recorridos de vida públicos y privados la acepción de itinerarios físicos o intelectuales. La interpretación de los datos transforma a estos relatos en historias de vida y sugiere el entretejido de las buenas prácticas con las trayectorias. Se construye así en la educación superior -donde la enseñanza en el aula es privada- un conocimiento local pero colegiado.

Replacing cottonseed meal with ground Prosopis juliflora pods; effect on intake, weight gain and carcass parameters of Afar sheep fed pasture hay basal diet.

Science.gov (United States)

Yasin, Mohammed; Animut, Getachew

2014-08-01

The experiment was conducted to determine the supplementary feeding value of ground Prosopis juliflora pod (Pjp) and cottonseed meal (CSM) and their mixtures on feed intake, body weight gain and carcass parameters of Afar sheep fed a basal diet of pasture hay. Twenty-five yearling fat-tailed Afar rams with mean initial live weight 17.24 ± 1.76 kg (mean ± SD) were used in a randomized complete block design. Animals were blocked on their initial body weight. The experiment was conducted for 12 weeks and carcass evaluation followed. Treatments were hay alone ad libitum (T 1) or with 300 g CSM (T 2), 300 g Pjp (T 5), 2:1 ratio (T 3) and 1:2 ratio of CSM : Pjp (T 4). The CP contents of the hay, CSM and Pjp were 10.5, 44.5 and 16.7 %, respectively. Hay DM intake was higher (P < 0.05) for non-supplemented and total DM intake was lower in non-supplemented. Average daily weight gain (ADG) was lower (P < 0.05) for T 1 compared to all supplemented treatments except T 5. Hot carcass weight and rib-eye muscle area also followed the same trend like that of ADG. Compared with feeding hay alone, supplementing with CSM or a mixture of CSM and Pjp appeared to be a better feeding strategy, biologically, for yearling Afar rams.

Effect of early experience and adaptation period on voluntary intake, digestion, and growth in Barbarine lambs given tannin-containing (Acacia cyanophylla Lindl. foliage) or tannin-free (oaten hay) diets

Energy Technology Data Exchange (ETDEWEB)

Ben Salem, H. [Institut National de la Recherche Agronomique de Tunisie, Laboratoire des Productions Animales et Fourrageres, Ariana (Tunisia)]. E-mail: bensalem.hichem@iresa.agrinet.tn; Nefzaouia, A.; Ben Salem, I. [Institut National de la Recherche Agronomique de Tunisie, Laboratoire des Productions Animales et Fourrageres, Ariana (Tunisia); Makkar, H.P.S. [Animal Production and Health Section, Joint FAO/IAEA Division, International Atomic Energy Agency, Vienna (Austria); Hochlef, H. [Institut National de la Recherche Agronomique de Tunisie, Laboratoire des Productions Animales et Fourrageres, Ariana (Tunisia); Ecole Superieure d' Agriculture de Mateur, Mateur (Tunisia); Ben Salem, L. [Office de l' Elevage et des Paturages, Tunis (Tunisia)

2005-08-19

Our objective was to determine whether experience early in life and adaptation time (up to 72 days) to tannin-rich diets affect feed intake, digestion, nitrogen balance, and growth in Barbarine lambs given tannin-containing (Acacia cyanophylla Lindl., acacia) or tannin-free (oaten hay) diets later in life. Twelve experienced lambs (live-weight, LW: 13.2 {+-} 2.0 kg) were divided into two equal groups. Each group received air-dried acacia (tannin-containing diet) or oaten hay (hay, tannin free-diet) ad libitum. Twelve other inexperienced lambs (LW 12.3 {+-} 2.5 kg) were also divided into two equal groups. Each group received one of the above two diets. All animals were 4 months old at the start of this experiment and were supplemented with 300 g concentrate. To investigate the carry-over effect of tannins, the acacia-diet was removed on day 73, thus all lambs received thereafter the hay-diet for a further 24 days before starting a 6-day faecal collection period. Irrespective to early experience and adaptation time, the nutritive value of hay-diet was higher than that of acacia-diet and consequently lambs given hay performed better than those receiving acacia (P = 0.0001). Animals exposed to tannins early in life exhibited higher digestible crude protein intake (P = 0.0389), retained more N (P = 0.0963) and excreted more allantoin in urine (P = 0.0248) than the inexperienced lambs. Except plasma urea (P = 0.2923), the adaptation period to experimental diets affected significantly all measured parameters (P 0.0001). Animals adapted to diets for only 6 days exhibited the lowest acacia or hay intake and the highest diet digestibility compared to those adapted to these diets for 24, 48 or 72 days. Weight losses of inexperienced lambs adapted to acacia-diet for 6 days were associated with negative nitrogen balance. Sheep which received the acacia-diet, followed by the hay diet, had similar hay intake, diet digestibility, N balance and growth rate as compared to those

Effect of early experience and adaptation period on voluntary intake, digestion, and growth in Barbarine lambs given tannin-containing (Acacia cyanophylla Lindl. foliage) or tannin-free (oaten hay) diets

International Nuclear Information System (INIS)

Ben Salem, H.; Nefzaouia, A.; Ben Salem, I.; Makkar, H.P.S.; Hochlef, H.; Ben Salem, L.

2005-01-01

Our objective was to determine whether experience early in life and adaptation time (up to 72 days) to tannin-rich diets affect feed intake, digestion, nitrogen balance, and growth in Barbarine lambs given tannin-containing (Acacia cyanophylla Lindl., acacia) or tannin-free (oaten hay) diets later in life. Twelve experienced lambs (live-weight, LW: 13.2 ± 2.0 kg) were divided into two equal groups. Each group received air-dried acacia (tannin-containing diet) or oaten hay (hay, tannin free-diet) ad libitum. Twelve other inexperienced lambs (LW 12.3 ± 2.5 kg) were also divided into two equal groups. Each group received one of the above two diets. All animals were 4 months old at the start of this experiment and were supplemented with 300 g concentrate. To investigate the carry-over effect of tannins, the acacia-diet was removed on day 73, thus all lambs received thereafter the hay-diet for a further 24 days before starting a 6-day faecal collection period. Irrespective to early experience and adaptation time, the nutritive value of hay-diet was higher than that of acacia-diet and consequently lambs given hay performed better than those receiving acacia (P = 0.0001). Animals exposed to tannins early in life exhibited higher digestible crude protein intake (P = 0.0389), retained more N (P = 0.0963) and excreted more allantoin in urine (P = 0.0248) than the inexperienced lambs. Except plasma urea (P = 0.2923), the adaptation period to experimental diets affected significantly all measured parameters (P 0.0001). Animals adapted to diets for only 6 days exhibited the lowest acacia or hay intake and the highest diet digestibility compared to those adapted to these diets for 24, 48 or 72 days. Weight losses of inexperienced lambs adapted to acacia-diet for 6 days were associated with negative nitrogen balance. Sheep which received the acacia-diet, followed by the hay diet, had similar hay intake, diet digestibility, N balance and growth rate as compared to those offered

Electro-microscopic observations of liver lesions after intravenous inoculation of mouldy hay extracts.

Science.gov (United States)

Shadmi, A; Griffel, B

1985-01-01

With the aid of the electron microscope, a number of histopathological changes in the liver of mice caused by mycotoxins from mouldy hay were examined and studied. These changes were observed in the mitochondria, the cell nucleus, and the cell membranes, and included fatty and parenchymal degeneration, plasma granulation, vacuolisation and vesiculation, glycogen secretion, incorporation into RNA, karyolysis and karyolaxis, and space of Disse constriction.

Del indicativo de la fe al imperativo de la ética

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Tony Mifsud

2012-01-01

Full Text Available Después del Concilio Vaticano II, la reflexión de la Teología Moral abandona definitivamente un talante legalista a favor de un discurso enraizado en el horizonte bíblico de una respuesta humana a la llamada divina. Sin embargo, esta matriz bíblica no se entiende como una especie de "moral revelada", sino más bien como un ethos bíblico que da cuenta de una "realidad revelada" a la luz de la Buena Noticia y sus consecuencias en el estilo de vida de la comunidad de los discípulos. De esta manera, el indicativo de la fe se torna un imperativo ético.After the Second Vatican Council, the reflection of Moral Theology definitely abandons its legalistic spirit in favor of a discourse rooted in the biblical perspective of a human response to the divine call. However, this biblical matrix is not understood as a type of "revealed morality" but rather as a biblical ethos that accounts for a "revealed reality" in light of the Good News and its consequences on the lifestyle of the disciples' community. Thus, the indicative of faith becomes an ethical imperative.

Degradabilidade ruminal do feno de alguns alimentos volumosos para ruminantes Ruminal degradability of some roughage hays for ruminants feeding

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G.G.P. Carvalho

2006-08-01

Full Text Available Avaliou-se a degradabilidade ruminal da matéria seca (MS, proteína bruta (PB, fibra em detergente neutro (FDN, da fibra em detergente ácido (FDA e hemicelulose dos fenos de capim-elefante (Pennisetum purpureum, palma (Opuntia ficus, guandu (Cajanus cajan e parte aérea da mandioca (Manihot esculenta utilizando três bovinos mestiços machos, castrados, canulados no rúmen e mantidos em regime de pasto. Amostras de 4g de cada alimento foram incubadas em duplicata no rúmen dos animais, nos períodos de 0, 6, 12, 24, 36, 48 e 72 horas. A degradabilidade potencial da PB dos fenos de capim-elefante e guandu foi semelhante, 83,9 e 81,2%, respectivamente. Os maiores valores foram observados para os fenos de palma (94,2% e parte aérea da mandioca (91,7%. A degradabilidade efetiva (DE foi obtida considerando as taxas de passagem de 2, 5 e 8%/hora. A maior DE observada para MS (60,5%, PB (81,1%, FDN (21,6%, FDA (27,9% e HEM (58,0%, na taxa de passagem de 5%/h, ocorreu com o feno de palma.The ruminal degradability of dry matter (DM, crude protein (CP, neutral detergent fiber (NDF, acid detergent fiber (ADF and hemicellulose (HEM of elephantgrass (Pennisetum purpureum, forage cactus (Opuntia ficus, pigeon pea (Cajanus cajan and cassava foliage (Manihot esculenta hays was evaluated using three cannulated crossbred steers, kept on pasture. Samples of four grams of each hay were incubated in the rumen for 0, 6, 12, 24, 36, 48 and 72 hours. The CP potential degradability (PD for elephantgrass and pigeon pea hays was similar, 83.9 and 81.2%, respectively. Higher values were observed either for forage cactus (94.2% or cassava foliage (91.7% hays. The effective degradability (ED was obtained considering the passage rates of 2, 5 and 8%/hour. The forage cactus hay, at a passage rate of 5%/h, showed the highest ED for DM (60.5%, CP (81.1%, NDF (21.6%, ADF (27.9% and HEM (58.0%.

A Systems Biology Approach Reveals Differences in the Dynamics of Colonization and Degradation of Grass vs. Hay by Rumen Microbes with Minor Effects of Vitamin E Supplementation

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Alejandro Belanche

2017-08-01

Full Text Available Increasing the efficiency of utilization of fresh and preserved forage is a key target for ruminant science. Vitamin E is often used as additive to improve product quality but its impact of the rumen function is unknown. This study investigated the successional microbial colonization of ryegrass (GRA vs. ryegrass hay (HAY in presence of zero or 50 IU/d supplementary vitamin E, using a rumen simulation technique. A holistic approach was used to link the dynamics of feed degradation with the structure of the liquid-associated (LAB and solid-associated bacteria (SAB. Results showed that forage colonization by SAB was a tri-phasic process highly affected by the forage conservation method: Early colonization (0–2 h after feeding by rumen microbes was 2× faster for GRA than HAY diets and dominated by Lactobacillus and Prevotella which promoted increased levels of lactate (+56% and ammonia (+18%. HAY diets had lower DM degradation (-72% during this interval being Streptococcus particularly abundant. During secondary colonization (4–8 h the SAB community increased in size and decreased in diversity as the secondary colonizers took over (Pseudobutyrivibrio promoting the biggest differences in the metabolomics profile between diets. Secondary colonization was 3× slower for HAY vs. GRA diets, but this delay was compensated by a greater bacterial diversity (+197 OTUs and network complexity resulting in similar feed degradations. Tertiary colonization (>8 h consisted of a slowdown in the colonization process and simplification of the bacterial network. This slowdown was less evident for HAY diets which had higher levels of tertiary colonizers (Butyrivibrio and Ruminococcus and may explain the higher DM degradation (+52% during this interval. The LAB community was particularly active during the early fermentation of GRA and during the late fermentation for HAY diets indicating that the availability of nutrients in the liquid phase reflects the dynamics

Effect of lactic acid-lactobacillus preservative and moisture concentration at baling on intake and digestibility of crabgrass hay by lambs and in-situ digestibility by heifers

Science.gov (United States)

Crabgrass is a warm-season annual forage that has greater nutritive value than most other warm-season grasses and is highly palatable, but curing time for crabgrass hay is typically longer than for bermudagrass. Crabgrass hay was either not treated or treated with a lactic acid-lactobacillus preserv...

Armonización de estándares de calidad para ensayos clínicos. Norma ISO 9001-Guía de Buena Práctica Clínica

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Sandra Álvarez Guerra

2011-09-01

Full Text Available El proceso de ensayo clínico necesario para autorizar el uso de nuevos medicamentos en humanos es extenso y complejo. Para garantizar la calidad y estandarizar este proceso, la Conferencia Internacional de Armonización ha establecido la Guía E6 para la Buena Práctica Clínica, la cual ha sido asumida y adaptada por las agencias reguladoras nacionales para estandarizar este proceso en sus países. Otra norma que permite garantizar calidad es la ISO 9001:2008, que establece requisitos para implementar Sistema de Gestión de Calidad. El objetivo de este trabajo consistió en establecer elementos comunes que demuestren la armonización entre la Buena Práctica Clínica de la Conferencia Internacional de Armonización, la Buena Práctica Clínica cubana y la ISO 9001:2008 para su implementación en sistemas de calidad para los ensayos clínicos. Para ello se realizó el estudio de estos estándares analizando qué tienen en común en su aplicación para el proceso de ensayo clínico. Se determinó que el cliente, los proveedores, el enfoque de proceso, la documentación, la dirección, las revisiones, la forma de realización de la investigación y la mejora de la calidad son puntos comunes para los cuales se establecen requisitos a cumplir. Esto permitió afirmar que los estándares estudiados al ser usados de conjunto en el proceso de ensayo clínico, contribuyen a elevar la calidad, pues no existe ningún aspecto contemplado en ellos que refleje contradicción sino aspectos comunes que permiten su armonización y uso.

Buenas prácticas para la selección de recursos educativos abiertos: experiencias del MOOC innovación educativa con REA

OpenAIRE

Acuña Sossa, Mildred; Gil Rendón, María Eugenia; Sandoval Poveda, Alicia María

2016-01-01

El artículo expone la indagación acerca de los Recursos Educativos Abiertos (REA) con la colaboración interuniversitaria entre el Instituto Tecnológico de Estudios Superiores de Monterrey, México, y la Universidad Estatal a Distancia de Costa Rica. Esta temática ha sido poco estudiada y ambas universidades se vieron en la necesidad de conocer cómo se realiza la selección de estos recursos. Asimismo, expresa las buenas prácticas de selección de REA utilizadas por los participantes en el curso ...

Sam Harris La promoción del humanismo exige el fin de la fe

Directory of Open Access Journals (Sweden)

Javier Monserrat Monserrat

2015-01-01

Full Text Available El tipo de ateísmo de San Harris es distinto del de otros autores porque se funda exclusivamente en la ponderación de la fe religiosa irracional como fuente de la violencia, del terror, del enfrentamiento social —interior a las naciones e internacional— que acaba por hacer imposible toda forma de cohesión social. Es evidente que Harris da por descontado que las creencias religiosas son irracionales y esto por dos razones. Primero porque la razón, en la ciencia y en la filosófica, no puede aducir argumento alguno para pensar que Dios o los dioses sean reales y existentes. Segundo porque las afirmaciones mismas de las religiones presentan un contenido que, por las buenas, no se puede creer, repugna inmediatamente a la razón, como puedan ser, por ejemplo, hablar de una «encarnación» de Dios o de que Mahoma ascendió al Cielo a lomos de un caballo alado, y otras afirmaciones de similar irracionalidad.

Desarrollo alternativo de sistemas de contención con llantas de desecho

OpenAIRE

Rodríguez González, Óscar Egidio

2014-01-01

Este trabajo describe una técnica para la estabilización de taludes por medio de llantas de desecho, contribuyendo así con el medio ambiente. La técnica es una buena solución para disminuir los grandes depósitos de llantas que hay en Colombia y en el mundo, pues estos acumulamientos de llantas constituyen una problemática de salud pública, son caldo de cultivo para los mosquitos y otros vectores que propagan enfermedades. También se presenta una serie de ejemplos aplicativos que se han desarr...

Hacking y ciberdelito

OpenAIRE

Giménez Solano, Vicente Miguel

2011-01-01

Investigar el delito desde cualquier perspectiva es una tarea compleja; de eso no hay duda. Las dificultades que surgen al tratar de aplicar el método científico a la Delincuencia Transnacional y al Crimen Organizado en buena parte ya fueron establecidas en estudios anteriores, pero enfrentar este tipo de delincuencia a todo nivel es la tarea a la que se ve avocada le Ministerio Público por mandato constitucional y por disposición legal. Ahora bien el fenómeno descrito en los últimos tiemp...

Hay fever, a post industrial revolution epidemic: a history of its growth during the 19th century.

Science.gov (United States)

Emanuel, M B

1988-05-01

Although other forms of allergic disease were described in antiquity, hay fever is surprisingly modern. Very rare descriptions can be traced back to Islamic texts of the 9th century and European texts of the 16th century. It was only in the early 19th century that the disease was carefully described and at that time was regarded as most unusual. By the end of the 19th century it had become commonplace in both Europe and North America. This paper attempts to chart the growth of hay fever through the medical literature of the 19th century. It is hoped that an understanding of the increase in prevalence between 1820 and 1900 may provide an insight for modern researchers and give some clues into possible reasons for the epidemic nature of the disease today.

Do glyphosate resistant feral plants and hay fields spread the transgene to conventional alfalfa seed fields?

Science.gov (United States)

In addition to meeting domestic needs, large amounts of alfalfa seed and hay produced in the US are being exported overseas. Because alfalfa is an insect pollinated crop, gene flow is a concern. Adding to this alfalfa readily naturalizes along roadsides, irrigation ditches, and unmanaged habitats; a...

Association between parental socioeconomic position and prevalence of asthma, atopic eczema and hay fever in children

DEFF Research Database (Denmark)

Hammer-Helmich, Lene; Linneberg, Allan; Thomsen, Simon Francis

2014-01-01

with a decreased risk of atopic eczema and eczema symptoms. There was no independent association between household income and any of the outcomes. CONCLUSIONS: The prevalence of asthma and hay fever, but not atopic eczema, increased with increasing age. Atopic eczema was associated with high parental educational...

Characterization of dispersion, attenuation, and anisotropy at the Buena Vista Hills field, California

Science.gov (United States)

Hackert, C.L.; Parra, J.O.; Brown, R.L.; Collier, H.A.

2001-01-01

We create a log of intrinsic dispersion and attenuation for the Antelope Shale formation of the Buena Vista Hills field, San Joaquin Valley, California. High dispersion (or low Q) values correlate with thin sand and carbonate beds within the Antelope Shale. These beds are at least ten times as permeable as the host shale formation, so this effect provides a possible avenue for seismic prediction of permeability. The dispersion log is formed through comparison of crosswell seismic velocities (measured at approximately 1 kHz) and sonic log velocities (measured at approximately 10 kHz). In order to provide a proper basis for comparison, the sonic log must first be adjusted for field anisotropy, scaling effects, and resolution of measurement. We estimate a local shale anisotropy of about 20% based on correlations generated from published measurements of other shale fields. We apply resolution enhancement to capture the thin sand and carbonate beds, and windowed Backus averaging to match the measurement scales. A modeling study verifies the technique, and shows that beds of thickness greater than 30 cm have a measurement signature. The actual resolution is on the order of the crosswell Fresnel length, or about 7 m for the model study.

Ética de la investigación. Las buenas prácticas

Directory of Open Access Journals (Sweden)

López de la Vieja, M.ª Teresa

2008-04-01

Full Text Available The Act 14/2007 regulates biomedical research, including research with stem cells and cloning for therapeutic purposes. The Spanish legislation about those controversial topics could also exemplify the changing perspective about ethical codes and ethical committees, because now they are not only centered on rights, and guarantees for the subjects involved in experimentation, but on good practice. Research Ethics has usually been related to norms, and especially to respect for human rights in the biomedical field. From the Nurmberg Code, the Helsinki Declaration, the Oviedo Convention to the Addition Protocol on biomedical research, the perspective of rights prevailed over a wider perspective, which now aims to promote the researchers’ commitment and their responsibilities to health and welfare; the welfare of every subject, humans, and non-humans, and in every context, including the developing countries. The UNESCO Declaration could expand this perspective, including social justice issues in the agenda of research Ethics, usually centered on autonomy, as basic principle, and on the human rights approach. The article would analyze the good practice approach, with guidelines expanding the agenda of research Ethics in order to promote a better governance of scientific practice.La Ley 14/2007 regula la investigación biomédica, incluida la investigación con células troncales y la clonación con fines terapéuticos. La legislación española sobre estos temas tan controvertidos puede ejemplificar también ciertos cambios en el enfoque sobre códigos éticos y comités de Ética; ahora éstos no sólo se centran en los derechos y las garantías para los sujetos participantes en la experimentación, sino también en las buenas prácticas. La Ética de la investigación ha estado casi siempre asociada con las normas y, en especial, con el respeto por los derechos humanos en el ámbito de la Biomedicina. Desde el Código de Nürnberg, la Declaraci

Effects on the equine colon ecosystem of grass silage and haylage diets after an abrupt change from hay.

Science.gov (United States)

Muhonen, S; Julliand, V; Lindberg, J E; Bertilsson, J; Jansson, A

2009-07-01

The objective of this study was to investigate the effect of an abrupt change from grass hay (81% DM) to grass silage (36% DM) or grass haylage (55% DM), fed at similar DM intakes, and to compare the effects of silage and haylage on the composition and activities of the colon microflora. The forages were from the same swath harvested on the same day. Four adult colon-fistulated geldings were randomly assigned to diets in a crossover design. The study started with a preperiod when all 4 horses received the hay diet, followed by an abrupt feed change to the haylage diet for 2 horses and the silage diet for 2 horses. All 4 horses then had a new second preperiod of hay, followed by an abrupt feed change to the opposite haylage and silage diet. The periods were 21 d long, and the forage-only diets were supplemented with minerals and salt. The abrupt feed changes were made at 0800 h. Colon samples were taken before the abrupt feed change, 4 and 28 h after the feed change, and 8, 15, and 21 d after the feed change, all at 1200 h. Colon bacterial counts, VFA, pH, and DM concentrations were unchanged throughout the first 28 h after the abrupt feed change from hay to haylage and silage. Also, fecal pH and DM concentrations were unchanged during the first 28 h. During the weekly observations, colon lactobacilli counts increased (P = 0.023) in horses receiving the silage diet and were greater than on the haylage diet at 21 d. Streptococci counts decreased (P = 0.046) in horses receiving the haylage diet and were less than on the silage diet at 15 and 21 d. Total VFA concentrations and colon and fecal pH did not differ between diets and were unchanged throughout the weekly observations. The DM concentration of colon digesta and feces decreased (P = 0.030 and 0.049, respectively) on both diets during the weekly observations. The results suggest that in horses fed at the maintenance level of energy intake, an abrupt feed change from grass hay to grass silage or grass haylage from

Buenas prácticas en integración de las TIC en educación en Andalucía : dos estudios de caso

OpenAIRE

Boza Carreño, Ángel; Toscano Cruz, María O

2011-01-01

Este trabajo muestra resultados parciales del Proyecto de Investigación de Excelencia “Buenas prácticas en integración de TICs en centros de Educación Primaria y Secundaria de Andalucía” (P07- HUM-03035), financiado por la Consejería de Innovación, Ciencia y Empresa. Se trata de un estudio de casos múltiple, del que presentamos aquí dos casos de centros de Educación Primaria, en los que se han utilizado diversas estrategias cualitativas (entrevistas abiertas, observaciones partici...

Análisis de impacto y desarrollo de buenas práctica de auditoría en bases de datos Oracle 11G

OpenAIRE

Delgado Picazo, Mario

2009-01-01

Este proyecto consiste en realizar un análisis y un estudio de los diferentes tipos de auditoría en Oracle 11g, con el objetivo de estudiar las características de las herramientas disponibles, así como su viabilidad. Mediante experimentación, se estudiará el comportamiento y el rendimiento de las diferentes modalidades de auditoría que Oracle 11g ofrece como motor de la base de datos, obteniendo resultados y comparativas que se utilizarán para preparar un manual de buenas prácticas acerca de ...

Climatic change: back to the IIF talk at La Haye; Changements climatiques: retour sur la communication de l'IIF a La Haye

Energy Technology Data Exchange (ETDEWEB)

Dupont, J.L.

2002-07-01

This document reprints the communication given by F. Billiard, head of the international institute of refrigeration (IIF), at the COP-6 conference of La Haye (November 2000). In his talk, F. Billiard explains the contribution of the refrigeration industry to the global warming which is mainly due to the leaks of refrigerants (CFC, HCFC, HFC) and to the carbon dioxide emissions corresponding to the electric power consumption of refrigerating machineries, air-conditioners and heat pumps. Thus, the abatement of these greenhouse gas emissions requires an improvement of the confinement of the refrigeration equipments and a continuous optimization of their energy efficiency. A second part analyzes the key points of this communication and the choice of some objective appreciation criteria for the remedial actions to be implemented. A glossary completes the document. (J.S.)

At the Crossroads between Paris, Texas and the Buena Vista Social Club, Havana: Wim Wenders and Ry Cooder as Collaborators

Directory of Open Access Journals (Sweden)

Stephen Gregory

2008-02-01

Full Text Available I take the image of the crossroads first as a way of elucidating the approach Wim Wenders takes to making films and Ry Cooder to making music, and to the implicit politics that can be derived from their practice. I then look at Paris, Texas as a crossroads film to examine how the thematic and formal properties of the film can throw light on the nature of Cooder’s and Wenders’s collaboration on it. This is then used as a base from which to launch an attempt to demolish once and for all the widely held view that Buena Vista Social Club was an example of cultural imperialism.

Growth performance of indigenous sheep fed Sporobolus virginicus grass hay grown in saline desert lands and irrigated with high salt content ground water.

Science.gov (United States)

Alhadrami, G A; Al-Shorepy, S A; Yousef, A M

2010-12-01

Twenty-eight indigenous ewe lambs (6 months of age and 14.4 kg body weight (BW)) were used to evaluate the effect of feeding Sporobolus grass hay (SGH) as the only source of forage on growth, and feed and water intakes. The ewe lambs were randomly and equally allocated to two treatment groups (14 lambs/group). The ewe lambs in group 1 (treatment 1) received SGH, while lambs in group 2 (treatment 2) received Rhodes grass hay (RGH) as the only source of forage. Water was available at all times for both treatment groups. Sporobolus grass was irrigated with brackish water of high salt content (20,000 ppm) and grown in saline desert lands (sabkha) in the United Arab Emirates. The average daily dry matter intake was significantly (P  .05) between the two groups at all stages. From these data, we conclude that SGH can replace Rhodes hay in sheep diet without significant effect on sheep performance.

Moessbauer-spectroscopic study of structure and magnetism of the exchange-coupled layer systems Fe/FeSn{sub 2}, and Fe/FeSi/Si and the ion-implanted diluted magnetic semiconductor SiC(Fe); Moessbauerspektroskopische Untersuchung von Struktur und Magnetismus der austauschgekoppelten Schichtsysteme Fe/FeSn{sub 2} und Fe/FeSi/Si und des ionenimplantierten verduennten magnetischen Halbleiters SiC(Fe)

Energy Technology Data Exchange (ETDEWEB)

Stromberg, Frank

2009-07-07

In line with this work the structural and magnetic properties of the exchange coupled layered systems Fe/FeSn{sub 2} and Fe/FeSi/Si and of the Fe ion implanted diluted magnetic semiconductor (DMS) SiC(Fe) were investigated. The main measuring method was the isotope selective {sup 57}Fe conversion electron Moessbauer spectroscopy (CEMS), mostly in connection with the {sup 57}Fe tracer layer technique, in a temperature range from 4.2 K to 340 K. Further measurement techniques were X-ray diffraction (XRD), electron diffraction (LEED, RHEED), SQUID magnetometry and FMR (Ferromagnetic Resonance). In the first part of this work the properties of thin AF FeSn{sub 2}(001) films and of the exchange-bias system Fe/FeSn{sub 2}(001) on InSb(001) were investigated. With the application of {sup 57}Fe-tracer layers and CEMS both the Fe-spin structure and the temperature dependence of the magnetic hyperfine field (B{sub hf}) of FeSn{sub 2} could be examined. The evaporation of Fe films on the FeSn{sub 2} films produced in the latter ones a high perpendicular spin component at the Fe/FeSn{sub 2} interface. In some distance from the interface the Fe spins rotate back into the sample plane. Furthermore {sup 57}Fe-CEMS provided a correlation between the absolute value of the exchange field vertical stroke He vertical stroke and the amount of magnetic defects within the FeSn{sub 2}. Temperature dependent CEMS-measurements yielded informations about the spin dynamics within the AF. The transition temperatures T{sub B}{sup *}, which were interpreted as superparamagnetic blocking temperatures, obtain higher values compared to the temperatures T{sub B} of the exchange-bias effect, obtained with magnetometry measurements. The second part of this work deals with the indirect exchange coupling within Fe/FeSi/Si/FeSi/Fe multilayers and FeSi diffusion barriers. The goal was to achieve Fe free Si interlayers. The CEMS results show that starting from a thickness of t{sub FeSi}=10-12 A of the

Supplementation of native grass hay with cowpea (Vigna unguiculata hay, wilted leucaena (Leucaena leucocephala forage, wilted tagasaste (Chamaecytisus palmensis forage or a wheat middling for young Friesian x Zebu (Boran crossbred steers

Directory of Open Access Journals (Sweden)

Tuomo Varvikko

1992-03-01

Full Text Available A 100-day experiment of a randomized block design was conducted with forty Friesian x Zebu (Boran crossbred growing steers to compare the value of wheat middling, an agro-industrial by-product (diet W, cowpea (Vigna unguiculata hay (diet C, and wilted forages of leucaena (Leucaena leucocephala, diet L and tagasaste (Chamaecytisus palmensis, diet T as cattle feed. These feeds were fed daily at a level of 1.5 kg (on an air dry basis to supplement the basal diet (diet H of native hay. A mineral supplement containing 50 g bone meal and 10 g common salt was also given daily. The steers were group-fed, but during the last two weeks at the end of the experiment the animals were housed individually in feeding pens to estimate the feed intake and apparent digestibilities of the diets. The animals were weighed at the beginning of the experiment, thereafter every two weeks, and finally at the end of the experiment. The animals consumed all the offered supplements, except for tagasaste forage, of which one third remained unconsumed. The mean daily total dry matter intake during the individual feeding period ranged from 4.0 to 5.0 kg between the diets (P

MFM study of NdFeB and NdFeB/Fe/NdFeB thin films

International Nuclear Information System (INIS)

Gouteff, P.C.; Folks, L.; Street, R.

1998-01-01

Domain structures of NdFeB thin films, ranging in thickness between 1500 and 29 nm, have been studied qualitatively by magnetic force microscopy (MFM). Samples were prepared using a range of sputtering conditions resulting in differences in properties such as texture, coercivity and magnetic saturation. MFM images of all the films showed extensive interaction domain structures, similar to those observed in nanocrystalline bulk NdFeB. An exchange-coupled NdFeB/Fe/NdFeB trilayer with layer thicknesses 18 nm/15 nm/18 nm, respectively, was also examined using MFM. (orig.)

Preparation and Mechanical Properties of TiC-Fe Cermets and TiC-Fe/Fe Bilayer Composites

Science.gov (United States)

Zheng, Yong; Zhou, Yang; Li, Runfeng; Wang, Jiaqi; Chen, Lulu; Li, Shibo

2017-10-01

TiC-Fe cermets and TiC-Fe/Fe bilayer composites consisting of a pure Fe layer and a TiC-Fe cermets layer were fabricated by hot-pressing sintering. The pure Fe layer contributes to the toughness of composites, and the TiC-Fe cermets layer endows the composites with an improved tensile strength and hardness. The effect of TiC contents (30-60 vol.%) on the mechanical properties of TiC-Fe cermets and TiC-Fe/Fe bilayer composites was investigated. Among the TiC-Fe cermets, the 40 vol.% TiC-Fe cermets possessed the highest tensile strength of 581 MPa and Vickers hardness of 5.1 GPa. The maximum fracture toughness of 17.0 MPa m1/2 was achieved for the TiC-Fe cermets with 30 vol.% TiC. For the TiC-Fe/Fe bilayer composites, the 40 vol.% TiC-Fe/Fe bilayer composite owns the maximum tensile strength of 588 MPa, which is higher than that of 40 vol.% TiC-Fe cermets. In addition, the 33.5% increment of tensile strength of 30 vol.% TiC-Fe/Fe bilayer composite comparing with the 30 vol.% TiC-Fe cermets, which is attributed to the 30 vol.% TiC-Fe/Fe bilayer composite exhibited the largest interlaminar shear strength of 335 MPa. The bilayer composites are expected to be used as wear resistance components in some heavy wear conditions.

Replacement of alfalfa hay (Medicago sativa L.) with subabul (Leucaena leucocephala) leaf meal in diets of Najdi goats: effect on digestion activity of rumen microorganisms.

Science.gov (United States)

Mohammadabadi, Tahereh; Jolazadeh, Alireza

2017-08-01

This study investigated the effect of replacing alfalfa hay by subabul leaf meal (SLM) on digestion, fermentation parameters and rumen bacteria and fungi activity of Najdi goats. Six Najdi goats (150 ± 15 days of age and initial body weight of 35 ± 1.1 kg) were randomly assigned to one of two dietary treatments in a balanced completely randomized design (three goats per treatment) for 56 days. Experimental treatments included alfalfa hay as control group and diet containing SLM (SLM replacing alfalfa hay at 50% level). Bacterial and fungi activity and rumen fermentation parameters of animals fed experimental diets were determined. Dry matter disappearance (DMD) was unaffected by replacing SLM with alfalfa hay for both rumen bacteria and fungi in different incubation times, except for 48 h of incubation in specific culture medium of mixed rumen bacteria, which decreased for SLM group (P > 0.05). NDF disappearance (NDFD) and ADF disappearance (ADFD) after 24 and 48 h of incubation in specific culture medium of mixed rumen bacteria was not affected by experimental diets (P > 0.05). However, 72 h after incubation, NDFD in SLM treatment decreased (P > 0.05). Gas production parameters of rumen bacteria were similar for both experimental diets, but partitioning factor (PF), efficiency microbial biomass production (EMBP), microbial protein production (MP), and organic matter truly digested (OMTD) decreased (p alfalfa hay by SLM had no major effect on rumen microorganisms' activity of Najdi goats, so it may be used as an alternative for alfalfa (at 50% level) in susceptible areas.

Sin latencia no hay adolescencia. There is not adolescence without latency.

OpenAIRE

Fernández Fuente, Sofia

2009-01-01

There is not adolescence without latency.Resumen ¿Cuándo comienza la adolescencia? ¿Hay un tiempo para saber de la sexualidad? Si este saber se da en la infancia. ¿Cuáles son sus consecuencias? ¿Qué relación tiene este saber con lo que se nombra como alta erotizacion? Consentir ser objeto del deseo del Otro. ¿Qué tiene con la repetición y qué es lo que se repite? Estas son preguntas que se abordan a partir de una lectura de los textos freudianos y una interpretación a partir de conceptos laca...

Chemical composition, intake by sheep, and in situ disappearance in cannulated cows of bermudagrass hayed at two moisture concentrations and treated with a non-viable lactobacillus-lactic acid preservative

Science.gov (United States)

Bermudagrass [Cynodon dactylon (L.) Pers.] is commonly used for grazing and haying in the southern USA, but hay curing can be challenging due to frequent rainfall events during spring and early summer. An existing stand of ‘Greenfield’ bermudagrass was divided into 12 plots using a randomized comple...

ORGANIZATIONAL GOOD PRACTICES FOR THE INTEGRATION OF THE ICT IN THE EDUCATION SYSTEM OF EXTREMADURA BUENAS PRÁCTICAS ORGANIZATIVAS PARA LA INTEGRACIÓN DE LAS TIC EN EL SISTEMA EDUCATIVO EXTREMEÑO

Directory of Open Access Journals (Sweden)

Mª José Sosa Díaz

2010-02-01

Full Text Available The present paper tries to release some organizational Good Practices for the integration of the ICT's carried out by the Education System in Extremadura. For this, in a first moment, a theoretical review about the concept of Good Practices has been done, establishing some indicators which permit us identify Good Practices regarding the application of the ICT within Primary and Secondary schools, and specially pointing out the indicators that refer to organizational aspects in the educational establishments and classrooms. Secondly, the politics for the integration of New Technologies conducted by Junta de Extremadura are analyzed, emphasizing the figure of the ICT Coordinator as a quality measure, as well as the technological tools for school management and controlling the classes. Finally, we present the results obtained from several interviews that were made to different members of the school community, all in a broader investigation where diverse case studies of Primary and Secondary schools considered as Good Practices with ICT were effectuated.En el presente trabajo se pretende dar a conocer Buenas Prácticas de tipo organizativo para la integración de las TIC que ha llevado a cabo el Sistema Educativo Extremeño. Para ello, en un primer momento, se ha realizado una revisión teórica sobre el concepto de Buenas Prácticas, estableciendo algunos indicadores que nos permitan identificar Buenas Prácticas en el uso de las TIC en los centros educativos de Primaria y Secundaria, y destacando especialmente aquellos indicadores que hacen referencia a aspectos organizativos del centro y de las aulas. En segundo lugar, se ha efectuado un análisis de la política de integración de las tecnologías que ha llevado a cabo la Junta de Extremadura, enfatizando en la figura del/la Coordinador/a TIC como medida de calidad, así como en las herramientas tecnológicas de gestión del centro y control del aula. Por último, se presentan algunos resultados

Modeling of drainage and hay production over the Crau aquifer for analyzing the impact of global change on aquifer recharge

Science.gov (United States)

Olioso, Albert; Lecerf, Rémi; Baillieux, Antoine; Chanzy, André; Ruget, Françoise; Banton, Olivier; Lecharpentier, Patrice; Alkassem Alosman, Mohamed; Ruy, Stéphane; Gallego Elvira, Belen

2013-04-01

The recharge of the aquifer in the Crau plain (550 km2, Southern Rhone Valley, France) depends on the irrigation of 15000 ha of meadow using water withdrawn from the River Durance through a dense network of channels. Traditional irrigation practice, since the XVIth century, has consisted in flooding the grassland fields with a large amount of water, the excess being infiltrated toward the water table. Today, the Crau aquifer holds the main resource in water in the area (300 000 inhabitants) but changes in the agricultural practices and progressive replacement of the irrigated meadows by urbanized area threaten the sustainability of groundwater. The distributed modeling of irrigated meadows together with the modeling of groundwater has been undertaken for quantifying the contribution of the irrigation to the recharge of the aquifer and to investigate possible evolution of hay production, water drainage, evapotranspiration and water table under scenarios of climate and land-use changes. The model combines a crop model (STICS) that simulates hay production, evapotranspiration and water drainage, a multisimulation tool (MultiSimLib) that allows to run STICS over each agricultural field in the aquifer perimeter, a groundwater model MODFLOW to simulate the water table from recharge data (simulated drainage). Specific models were developed for simulating the spatial distribution of climate, including scenario of changes for the 2025 - 2035 time period, soil properties (influenced by irrigation), and agricultural practices (calendar and amount), in particular irrigation and hay cutting. This step was crucial for correctly simulating hay production level and amount of water used for irrigation. Model results were evaluated thanks to plot experiments and information from farmers (biomass production, downward water flow, quantity of irrigated water, cutting calendar...), a network of piezometers and remote sensing maps of evapotranspiration. Main results included: - the

Fe atom exchange between aqueous Fe2+ and magnetite.

Science.gov (United States)

Gorski, Christopher A; Handler, Robert M; Beard, Brian L; Pasakarnis, Timothy; Johnson, Clark M; Scherer, Michelle M

2012-11-20

The reaction between magnetite and aqueous Fe(2+) has been extensively studied due to its role in contaminant reduction, trace-metal sequestration, and microbial respiration. Previous work has demonstrated that the reaction of Fe(2+) with magnetite (Fe(3)O(4)) results in the structural incorporation of Fe(2+) and an increase in the bulk Fe(2+) content of magnetite. It is unclear, however, whether significant Fe atom exchange occurs between magnetite and aqueous Fe(2+), as has been observed for other Fe oxides. Here, we measured the extent of Fe atom exchange between aqueous Fe(2+) and magnetite by reacting isotopically "normal" magnetite with (57)Fe-enriched aqueous Fe(2+). The extent of Fe atom exchange between magnetite and aqueous Fe(2+) was significant (54-71%), and went well beyond the amount of Fe atoms found at the near surface. Mössbauer spectroscopy of magnetite reacted with (56)Fe(2+) indicate that no preferential exchange of octahedral or tetrahedral sites occurred. Exchange experiments conducted with Co-ferrite (Co(2+)Fe(2)(3+)O(4)) showed little impact of Co substitution on the rate or extent of atom exchange. Bulk electron conduction, as previously invoked to explain Fe atom exchange in goethite, is a possible mechanism, but if it is occurring, conduction does not appear to be the rate-limiting step. The lack of significant impact of Co substitution on the kinetics of Fe atom exchange, and the relatively high diffusion coefficients reported for magnetite suggest that for magnetite, unlike goethite, Fe atom diffusion is a plausible mechanism to explain the rapid rates of Fe atom exchange in magnetite.

The Moessbauer effect in Fe(III) HEDTA, Fe(III) EDTA, and Fe(III) CDTA compounds

International Nuclear Information System (INIS)

Prado, F.R.

1989-01-01

The dependence of Moessbauer spectra with pH value of Fe(III)HEDTA and Fe(III)CDTA compounds is studied. Informations on formation processes of LFe-O-FeL (L=ligand) type dimers by the relation of titration curves of Fe(III)EDTA, Fe(III)HEDTA and Fe(III)CDTA compounds with the series of Moessbauer spectra, are obtained. Some informations on Fe-O-Fe bond structure are also obtained. Comparing the titration curves with the series of Moessbauer spectra, it is concluded that the dimerization process begins when a specie of the form FeXOH α (X = EDTA, HEDTA, CDTA; α = -1, -2) arises. (M.C.K.) [pt

Niños con necesidades educativas especiales y terapias asistidas con animales

OpenAIRE

García Novillo, Blanca

2013-01-01

Este es un Trabajo Final del Grado, centrado en los alumnos de “necesidades educativas especiales” y en lo importante de elegir una buena metodología para dar respuesta a sus necesidades integrando animales de compañía en su día a día, construyendo de esta forma una escuela inclusiva. En cada escuela y en cada clase hay un ciclo de evaluación, planificación, enseñanza y revisión de las necesidades de todos los niños. Esos estudios generales tienen en cuenta el amplio abanico de habilidades, a...

Clínica. Localizaciones: rodilla, cadera, manos, columna, otras localizaciones

OpenAIRE

Martín, Álvaro Pérez

2014-01-01

La clínica que presentan estos pacientes difiere mucho de unos a otros, dependiendo especialmente de la localización de la artrosis, y no hay buena correlación entre la afectación radiológica y el dolor. Generalmente, la clínica es de inicio gradual y evolución lenta, aunque progresiva, y las articulaciones más afectadas son las rodillas, las caderas, las manos y la columna vertebral. Los principales síntomas y signos son el dolor, la rigidez, la deformidad articular y la crepitación. El dolo...

Effectiveness of FeEDDHA, FeEDDHMA, and FeHBED in Preventing Iron-Deficiency Chlorosis in Soybean.

Science.gov (United States)

Bin, Levi M; Weng, Liping; Bugter, Marcel H J

2016-11-09

The performance of FeHBED in preventing Fe deficiency chlorosis in soybean (Glycine max (L.) Merr.) in comparison to FeEDDHA and FeEDDHMA was studied, as well as the importance of the ortho-ortho and ortho-para/rest isomers in defining the performance. To this end, chlorophyll production (SPAD), plant dry matter yield, and the mass fractions of important mineral elements in the plant were quantified in a greenhouse pot experiment. All three Fe chelates increased SPAD index and dry matter yield compared to the control. The effect of FeHBED on chlorophyll production was visible over a longer time span than that of FeEDDHA and FeEDDHMA. Additionally, FeHBED did not suppress Mn uptake as much as the other Fe chelates. Compared to the other Fe chelates, total Fe content in the young leaves was lower in the FeHBED treatment; however, total Fe content was not directly related to chlorophyll production and biomass yield. For each chelate, the ortho-ortho isomer was found to be more effective than the other isomers evaluated.

Evaluation of the effect of fortified and concentrated hay supplementation on the production of bovine milk (Bos taurus L. during the dry season in the Achaca-Tiahuanacu community

Directory of Open Access Journals (Sweden)

Patty-Quispe Magda Hortencia

2017-04-01

Full Text Available The present study was carried out in the Achaca Community of the Municipality of Tiahuanacu, with the objective of evaluating the effect of supplementation with fortified and concentrated hay on milk production, feed conversion, total solids and production costs in three periods (Control, adaptation and supplementation during the dry season (October and November. 12 Holstein mestizo cows were used between 4 and 6 months of lactation. The design used was completely randomized blocks with factorial arrangement of 2Ax3Bx (3 with three replicates. The average milk yield of 4.69 kg of cows supplemented with fortified hay and 6.24 kg with concentrate were higher than the production of 3.94 and 5.11 kg respectively in the adaptation period and finally the production of 3.58 and 3.42 kg in the control period. The feed conversion with fortified hay supplementation of 2.60 kg was greater than 2.12 and 1.90 kg respectively. While feed conversion between supplements was 1.61 and 1.78 kg with concentrate in the adaptation period and finally with 2.12 and 2.60 kg with fortified hay in the supplementation period. The total solids content of 10.52 ºBrix was superior to the adaptation period of 10.30 ºBrix and control with 10.05 ºBrix. Meanwhile, total solids between supplements were 10.19 ºBrix with fortified hay and 10.39 ºBrix with concentrate.

Malaysia/Singapore: Where Asian Cultures Meet. Participants' Papers. Fulbright-Hays Seminars Abroad Program, 2001 (Malaysia and Singapore).

Science.gov (United States)

Malaysian-American Commission on Educational Exchange, Kuala Lumpur.

The general objective of the Fulbright-Hays Seminars Abroad Program is to help U.S. educators enhance their international understanding and increase their knowledge of the people and culture of other countries. This particular program offered participants an overview of life in Malaysia and Singapore through seminars and other activities.…

Associations of genetic determinants of serum vitamin B12 and folate concentrations with hay fever and asthma

DEFF Research Database (Denmark)

Skaaby, Tea; Taylor, Amy E; Jacobsen, Rikke K

2017-01-01

Background/objectives: Studies of the effect of vitamin B12 and folate on the risk of asthma and hay fever have shown inconsistent results that may be biased by reverse causation and confounding. We used a Mendelian randomization approach to examine a potential causal effect of vitamin B12 and fo...

¿Para quién y para qué son buenas las buenas prácticas? Unión Europea, integración de (in migrantes y despolitización/tecnificación de las políticas hegemónicas: un estudio de caso

Directory of Open Access Journals (Sweden)

Luca Sebastiani

2017-01-01

Full Text Available Entre finales de los años noventa y comienzos del nuevo siglo se ha ido afirmando un marco político en el ámbito de la Unión Europea, el cual fomenta el alcance de un entendimiento común de la integración de inmigrantes y promueve la coordinación, financiación e intercambio de información y “buenas prácticas” entre los diferentes niveles institucionales afectados, a través de herramientas de “políticas blandas” (soft policy. En este artículo analizaré y discutiré algunas de las consecuencias más relevantes originadas del entendimiento del concepto de “integración” por los principales actores implicados en este proceso, utilizando como ejemplo el caso de las “buenas prácticas” debido a su importancia dentro de los mecanismos de la “gobernanza multinivel” comunitaria. A través de este análisis, resaltaré que en el contexto comunitario, la noción de integración ha sido construida a través de un ejercicio de (aparente despolitización y tecnificación, cuyos resultados sin embargo son contradictorios -puesto que el elemento político a menudo retorna y se manifiesta “en el trasfondo”, “al margen” y “dentro” de lo técnico- a la vez que eficaces -en tanto en cuanto este ejercicio ha conseguido impulsar y moldear ciertas formas de saber, hablar y actuar sobre la integración de inmigrantes, naturalizando determinadas relaciones de poder existentes en la sociedad- . El material empírico para el presente artículo está basado en el trabajo de campo realizado en Bruselas entre 2011 y 2012 para la investigación doctoral. Consiste en entrevistas a los actores sociales y políticos más importantes del marco comunitario de la integración, en la observación de distintos encuentros y en la lectura de fuentes variadas.

Nutritional Value And Yield of Kallar Grass (Leptochloa Fusca Linn) Hay and Its Effect on Reproductive Performance of Awassi Ewes Using Progesterone Radioimmunoassay

International Nuclear Information System (INIS)

Al-Masri, M R..; Zarkawi, M.; Khalifa, K.

2007-01-01

Nutritional value of Kallar grass (Leptochloa fusca Linn) hay (whole plant), a salt-tolerant plant, was estimated by determinning its composition (ash, crude protein CP, crude fibre CF, ether extract EE, neutral-detergent fiber NDF, acid-detergent fiber ADF, acid-detergent lignin ADL); and the in vitro organic matter digestibility (IVOMD), metabolizable energy (ME), net energy of lactation (NEL) and gross energy (GE). Moreover, dry matter, energy and protein yields per hectar were also estimated. The effects of feeding Kallar grass hay to pregnant Awassi ewes on reproductive performance, serum progesterone changes using radioimmunoassay, and on birth and weaning weights of lambs born were also determined. Experimental ewes received daily 300 g of Kallar grass hay in addition to lentil straw and concentrates to cover their nutritional requirements. The results indicated that the nutritive components of Kallar grass were (g kg -1 dry matter): ash 96, CP 93, CF 290, EE 21, NDF 755, ADF 416 and ADL 94. IVOMD was 49.3%, and energy values (MJ kg -1 dry matter) were: GE 26.88, ME 6.41 and NEL 3.02. Dry matter and crude protein yields of Kallar grass hay were 7875 and 732 kg ha -1 , respectively, and the energy produced (MJ ha -1 ) was: GE 211680, ME 50479 and NEL 23783. Kallar grass had no effects on the reproductive performance of pregnant Awassi ewes duration, of pregnancy (150.1 ± 2.2 days), progesterone patterns, birth (4.7±1.0 kg) or on weaning weights (22.7 ± ≤ 5.5 kg) of lambs.

Effects of a propionic-acid based preservative on storage characteristics of alfalfa-orchardgrass hay in large-rectangular bales

Science.gov (United States)

For many years, various formulations of organic acids have been marketed as preservatives, most specifically for use on hays that could not be field-dried to moisture concentrations low enough to reduce or eliminate spontaneous heating during storage. These preservatives are often propionic-acid-bas...

Correlations of intake, digestibility and performance with the ingestive behavior of lambs fed diets containing ammoniated buffel grass hay

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Alexandre Fernandes Perazzo

2016-06-01

Full Text Available This study aimed to evaluate the correlations of intake, digestibility and performance with the ingestive behavior of lambs fed diets containing ammoniated buffel grass hay. Buffel grass hay was treated with four levels of urea (0, 18, 36 and 54 g/kg DM basis and eight repetitions. Thirty-two sheep with no defined breed and an average body weight of 17.7 ± 1.8 kg were distributed in a completely randomized design. It was observed positive correlations were found between the feeding time and the intake of dry matter (r = 0.3120, organic matter (r = 0.3242, neutral detergent fiber (r = 0.3800, total carbohydrates (r = 0.3343 and total digestible nutrients (r = 0.3233. Positive correlations (P < 0.05 were found among the rumination efficiencies, g of DM/h and g of NDF/h with nutrient intake variables, except for ether extract intake. Positive correlations were observed (P < 0.05 between both total weight gain (TWG and average daily gain (ADG and the rumination efficiency, g of DM/h (r = 0.3330 and g of NDF/h (r = 0.3304. The feeding and rumination efficiencies have a positive relationship with the total digestible nutrients. The correlation among intake, digestibility and performance variables with the ingestive behavior, it was important for the understanding of diet containing ammoniated buffel grass hay, in which the positive correlation of rumination efficiency with intake and weight gain explained the favorable effect on productive performance of feedlot sheep.

Effects of different levels of sunflower residue silage replacement with alfalfa hay on Azari male buffalo calves fattening performance

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S. Razzagzadeh

2010-02-01

Full Text Available An experiment was conducted to study the effects of replacing alfalfa hay with different levels of sunflower residual silage (SRS on fattening performance of Azari male buffalo calves. Thirty calves with 138.33 Kg of BW fed experimental diets in a completely randomized design with 5 groups and 6 replicates. The five groups (1, 2, 3, 4 and 5 included 0 (control, 25, 50, 75 and 100 percent replacement of alfalfa hay with SRS, respectively in basal diet. The results showed that dry matter intake (DMI was significantly different between the groups (p<0.05. The highest and the lowest DMI were shown at the groups 1 and 5, respectively, however there was no significant difference between the groups 2, 3, and 4 with control. Daily weight gain (DWG was significantly different between the groups (p<0.05. Group 5 had significantly lower DWG than groups 1, 2 and 3, furthermore there were no significant difference between groups 1, 2, 3 and 4. Feed conversion ratio (FCR was significantly different among the groups (p<0.05. There was no significant difference among the groups 1, 2, 3 and 4. But these groups had significantly better FCR than the group 5. The best FCR was obtained for group3. It may conclude that alfalfa hay can be substituted with SRS at 50 % level with no negative effects on Azari male buffalo calves fattening performance.

Structure and magnetism in Co/X, Fe/Si, and Fe/(FeSi) multilayers

Science.gov (United States)

Franklin, Michael Ray

Previous studies have shown that magnetic behavior in multilayers formed by repeating a bilayer unit comprised of a ferromagnetic layer and a non-magnetic spacer layer can be affected by small structural differences. For example, a macroscopic property such as giant magnetoresistance (GMR) is believed to depend significantly upon interfacial roughness. In this study, several complimentary structural probes were used to carefully characterize the structure of several sputtered multilayer systems-Co/Ag, Co/Cu, Co/Mo, Fe/Si, and Fe//[FeSi/]. X-ray diffraction (XRD) studies were used to examine the long-range structural order of the multilayers perpendicular to the plane of the layers. Transmission electron diffraction (TED) studies were used to probe the long-range order parallel to the layer plane. X-ray Absorption Fine Structure (XAFS) studies were used to determine the average local structural environment of the ferromagnetic atoms. For the Co/X systems, a simple correlation between crystal structure and saturation magnetization is discovered for the Co/Mo system. For the Fe/X systems, direct evidence of an Fe-silicide is found for the /[FeSi/] spacer layer but not for the Si spacer layer. Additionally, differences were observed in the magnetic behavior between the Fe in the nominally pure Fe layer and the Fe contained in the /[FeSi/] spacer layers.

Effects of feeding different proportions of silver leaf desmodium (Dismodium uncinatum) with banana (Musa paradisiaca) leaf on nutrient utilization in Horro sheep fed a basal diet of natural grass hay.

Science.gov (United States)

Chali, Diriba; Nurfeta, Ajebu; Banerjee, Sandip; Eik, Lars Olav

2018-03-02

The objective was to evaluate feed intake, digestibility, body weight change and carcass characteristics of sheep fed a basal diet of hay supplemented with banana leaves and silver leaf desmodium. Thirty yearling lambs with an average initial body weight of 15.85 ± 1.6 kg were grouped into six blocks of five rams in each block. The treatments were: hay alone (T1), hay + 100% banana leaf (T2), hay + 67% banana leaf + 33% desmodium leaf (T3), hay + 33% banana leaf + 67% desmodium leaf (T4) and hay + 100% desmodium leaf (T5). Three hundred grams of treatment diets were offered daily on as fed basis. The feeding and digestibility trial lasted for 84 and 7 days, respectively, followed by carcass evaluation. The total dry matter (DM) intake for T3, T4 and T5 were greater (P T4 > T3 > T2 > T1. Rams lambs receiving supplementary diets had higher (P<0.05) DM, OM, CP, neutral detergent fiber and acid detergent fiber digestibility compared with the control diet. The empty body weight and slaughter weight was highest (P<0.05) in rams receiving T3, T4 and T5 diets. The average daily gain and feed conversion efficiency was highest (P<0.05) in rams receiving the supplementary diets. The DP on the basis of hot carcass weight linearly increased with increasing levels of desmodium. Rams reared on supplementary diet had higher (P<0.05) rib eye area compared with the control diet. In conclusion, when banana leaf is used as a supplement to poor quality grass, better response was obtained when fed in combination with desmodium.

Diversification of mowing regime increases arthropods diversity in species-poor cultural hay meadows

Czech Academy of Sciences Publication Activity Database

Čížek, O.; Zámečník, J.; Tropek, Robert; Kočárek, P.; Konvička, Martin

2012-01-01

Roč. 16, č. 2 (2012), s. 215-226 ISSN 1366-638X R&D Projects: GA MŠk LC06073; GA ČR GD206/08/H044; GA MŽP SP/2D3/62/08 Grant - others:Czech Agency for Nature Conservation(CZ) PPK-35a/62/06 Institutional research plan: CEZ:AV0Z50070508 Keywords : hay meadows * arthropods conservation * mowing regimes Subject RIV: EH - Ecology, Behaviour Impact factor: 1.801, year: 2012 http://www.muzeumhk.cz/files/jaroslav_zamecnik/2012_cizek_zamecnik.pdf

Morocco and Senegal: Faces of Islam in Africa. Fulbright-Hays Summer Seminars Abroad, 1999 (Morocco and Senegal).

Science.gov (United States)

Center for International Education (ED), Washington, DC.

These projects were completed by participants in the Fulbright-Hays summer seminar in Morocco and Senegal in 1999. The participants represented various regions of the United States and different grade levels and subject areas. The 13 curriculum projects in the collection are: (1) "Doorway to Morocco: A Student Guide" (Sue Robertson); (2)…

IL-33 polymorphisms are associated with increased risk of hay fever and reduced regulatory T cells in a birth cohort.

Science.gov (United States)

Schröder, Paul C; Casaca, Vera I; Illi, Sabina; Schieck, Maximilian; Michel, Sven; Böck, Andreas; Roduit, Caroline; Frei, Remo; Lluis, Anna; Genuneit, Jon; Pfefferle, Petra; Roponen, Marjut; Weber, Juliane; Braun-Fahrländer, Charlotte; Riedler, Josef; Lauener, Roger; Vuitton, Dominique Angèle; Dalphin, Jean-Charles; Pekkanen, Juha; von Mutius, Erika; Kabesch, Michael; Schaub, Bianca

2016-11-01

IL-33 polymorphisms influence the susceptibility to asthma. IL-33 indirectly induces Th2-immune responses via dendritic cell activation, being important for development of atopic diseases. Furthermore, IL-33 upregulates regulatory T cells (Tregs), which are critical for healthy immune homeostasis. This study investigates associations between IL-33 polymorphisms during the development of childhood atopic diseases and underlying mechanisms including immune regulation of Tregs. Genotyping of IL-33-polymorphisms (rs928413, rs1342326) was performed by MALDI-TOF-MS in 880 of 1133 PASTURE/EFRAIM children. In 4.5-year-old German PASTURE/EFRAIM children (n = 99), CD4 + CD25 high FOXP3 + Tregs were assessed by flow cytometry following 24-h incubation of PBMCs with PMA/ionomycin, LPS or without stimuli (U). SOCS3, IL1RL1, TLR4 mRNA expression and sST2 protein levels ex vivo were measured in PASTURE/EFRAIM children by real-time PCR or ELISA, respectively. Health outcomes (hay fever, asthma) were assessed by questionnaires at the age of 6 years. rs928413 and rs1342326 were positively associated with hay fever (OR = 1.77, 95%CI = 1.02-3.08; OR = 1.79, 95%CI = 1.04-3.11) and CD4 + CD25 high FOXP3 + Tregs (%) decreased in minor allele homozygotes/heterozygotes compared to major allele homozygotes (p(U) = 0.004; p(LPS) = 0.005; p(U) = 0.001; p(LPS) = 0.012). SOCS3 mRNA expression increased in minor allele homozygotes and heterozygotes compared with major allele homozygotes for both IL-33-polymorphisms (p(rs928413) = 0.032, p(rs1342326) = 0.019) and negatively correlated to Tregs. IL-33-polymorphisms rs928413 and rs1342326 may account for an increased risk of hay fever with the age of 6 years. Lower Tregs and increased SOCS3 in combined heterozygotes and minor allele homozygotes may be relevant for hay fever development, pointing towards dysbalanced immune regulation and insufficient control of allergic inflammation. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

In situ degradability and selected ruminal constituents of sheep fed with peanut forage hay.

Science.gov (United States)

Fernandes, Gisele Machado; Possenti, Rosana Aparecida; Teixeira de Mattos, Waldssimiler; Schammass, Eliana Aparecida; Junior, Evaldo Ferrari

2013-01-01

Because legumes are a very important feed source for ruminants, the aim of this study was to evaluate the ideal inclusion level of hay Arachis pintoi cv. Belmonte in sheep diets by measuring the dry matter intake (DMI), concentration of volatile fatty acids, ammonia-nitrogen concentration, ruminal pH and the in situ degradability of dry matter (DM) and crude protein (CP). In the experiment with four sheep, a 4 × 4 Latin Square design was used with four periods and four treatments (0%, 30%, 60% and 100% Arachis replacing grass hay). Significant interactions were observed between treatments and sampling times for ammonia-nitrogen and acetate, propionate and butyrate concentration and the acetate:propionate ratio. The ruminal pH and total volatile fatty acids concentration were not affected by interaction between treatments and sampling time. The degradation of DM and CP was similar, rising with the increasing content of Arachis, showing a linear effect. The treatment containing 60% of Arachis showed best results, with good levels of daily weight gain and higher ruminal concentrations of volatile fatty acids. The legume showed high levels of CP, high digestibility and appropriate levels of fibre, with excellent standards of degradation and ruminal characteristics. The use of the legume  Arachis for ruminants is a promising option of nutrient supply to meet production demands of these animals.

Challenges of Globalization: Morocco and Tunisia. Curriculum Projects. Fulbright-Hays Summer Seminars Abroad Program, 2001 (Morocco and Tunisia).

Science.gov (United States)

2002

This publication contains a collection of curriculum projects developed by educators who were participants in the 2001 Fulbright-Hays Summer Seminars Abroad Program in Morocco and Tunisia. The 13 curriculum projects in the publication are entitled: "Women in Morocco, Artists and Artisans" (Virginia da Costa); "Cultures of…

El deber de información contractual y sus límites

Directory of Open Access Journals (Sweden)

Carlos Alberto Chinchilla Imbett

2011-12-01

Full Text Available El presente artículo trata del alcance y de los límites del deber de información, para lo cual, se establece que el deber de información es una obligación emanada de la buena fe y su cumplimiento permite el pleno uso de la libertad contractual en cuanto facilita decidir la conveniencia del negocio, prevenir los riesgos, determinar el alcance de las obligaciones y derechos asumidos. Adicionalmente se establece que la información suministrada deberá ser clara, oportuna y transparente, de manera que permita que el deber de información se cumpla de forma substancial y no meramente formal. Por último, el autor devela los límites que impone la buena fe al deber de información en forma tal de dotar a dicho deber de contenido, eficacia y precisión.

Strong 3D and 1D magnetism in hexagonal Fe-chalcogenides FeS and FeSe vs. weak magnetism in hexagonal FeTe.

Science.gov (United States)

Parker, David S

2017-06-13

We present a comparative theoretical study of the hexagonal forms of the Fe-chalcogenides FeS, FeSe and FeTe with their better known tetragonal forms. While the tetragonal forms exhibit only an incipient antiferromagnetism and experimentally show superconductivity when doped, the hexagonal forms of FeS and FeSe display a robust magnetism. We show that this strong magnetism arises from a van Hove singularity associated with the direct Fe-Fe c-axis chains in the generally more three-dimensional NiAs structure. We also find that hexagonal FeTe is much less magnetic than the other two hexagonal materials, so that unconventional magnetically-mediated superconductivity is possible, although a large T c value is unlikely.

Towards Detection of Cutting in Hay Meadows by Using of NDVI and EVI Time Series

Directory of Open Access Journals (Sweden)

Andrej Halabuk

2015-05-01

Full Text Available The main requirement for preserving European hay meadows in good condition is through prerequisite cut management. However, monitoring these practices on a larger scale is very difficult. Our study analyses the use of MODIS vegetation indices products, namely EVI and NDVI, to discriminate cut and uncut meadows in Slovakia. We tested the added value of simple transformations of raw data series (seasonal statistics, first difference series, compared EVI and NDVI, and analyzed optimal periods, the number of scenes and the effect of smoothing on classification performance. The first difference series transformation saw substantial improvement in classification results. The best case NDVI series classification yielded overall accuracy of 85% with balanced rates of producer’s and user’s accuracies for both classes. EVI yielded slightly lower values, though not significantly different, although user accuracy of cut meadows achieved only 67%. Optimal periods for discriminating cut and uncut meadows lay between 16 May and 4 August, meaning only seven consecutive images are enough to accurately detect cutting in hay meadows. More importantly, the 16-day compositing period seemed to be enough for detection of cutting, which would be the time span that might be hopefully achieved by upcoming on-board HR sensors (e.g., Sentinel-2.

Strong 3D and 1D magnetism in hexagonal Fe-chalcogenides FeS and FeSe vs. weak magnetism in hexagonal FeTe

Energy Technology Data Exchange (ETDEWEB)

Parker, David S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-06-13

We present a comparative theoretical study of the hexagonal forms of the Fe-chalcogenides FeS, FeSe and FeTe with their better known tetragonal forms. While the tetragonal forms exhibit only an incipient antiferromagnetism and experimentally show superconductivity when doped, the hexagonal forms of FeS and FeSe display a robust magnetism. We show that this strong magnetism arises from a van Hove singularity associated with the direct Fe-Fe c-axis chains in the generally more three-dimensional NiAs structure. We also find that hexagonal FeTe is much less magnetic than the other two hexagonal materials, so that unconventional magnetically-mediated superconductivity is possible, although a large T_c value is unlikely.

Utilization of conserved Lucerne Hay as a Protein Supplement in the Diet of Calves on Smallholder Farms of Kenya

International Nuclear Information System (INIS)

Kiragu, J.W.; Tamminga, S.; Mitaru, B.N.

1999-01-01

The nutritive value and the conserved lucerne hay as a protein supplement in the diet of calves reared on the smallholder farms of Kenya was studied in relation to feed intake, growth rate and efficiency of feed utilization. Forty Friesian calves aged one week were allocate in a completely randomised design experiment to the following five dietary treatments: Napier Grass only (N) and supplemented with 33% lucerne (NL33), 50% lucerne (NL50), 67% lucerne (NL67) and 100% lucerne hay (L100) in the diet of calves. Results showed that increasing the level of lucerne supplementation in the ratio of dairy calves from 50 to 100% lucerne hay significantly (P <0.01) increased the crude protein content the mixed ration from 13.8 t o 16.88% CP which would meet the protein, requirement of the growing ruminants. The growth rate of calves increased linearly (P < 0.001) with the levels of lucerne supplements fro 50 to 100 % lucerne hay resulting in 0.02 kg gain more growth per day per kg additional feed supplement given. The cost of production per kg gain decreased with increase in the level of lucerne supplementation and cost of could further reduced by farmers growing lucerne on the smallholder farms for use in compounding home-made ration at the farm level. Result of these study further shows that lucerne as a leguminous forage has ability to fix Nitrogen in the soil which has significantly effect on soil fertility, increased crop yields and reduction in the cost of fertilisers. It is recommended that an acre of lucerne could yield five to seven tons of dry matter per year sufficient to rear a herd of 15 to 20 calves for a period of 1 year. This research has further shown that a pure stand of lucerne crop which is very deep rooted crop has a longevity of five to seven years in the same field and that pest and diseases are not of a serious problem to lucerne, thus making it excellent supplementary legume to the Napier grass in the diet of calves on smallholder farms of Kenya

Changes in fibre-adherent and fluid-associated microbial communities and fermentation profiles in the rumen of cattle fed diets differing in hay quality and concentrate amount.

Science.gov (United States)

Klevenhusen, Fenja; Petri, Renee M; Kleefisch, Maria-Theresia; Khiaosa-Ard, Ratchaneewan; Metzler-Zebeli, Barbara U; Zebeli, Qendrim

2017-09-01

The rumen microbiota enable important metabolic functions to the host cattle. Feeding of starch-rich concentrate feedstuffs to cattle has been demonstrated to increase the risk of metabolic disorders and to significantly alter the rumen microbiome. Thus, alternative feeding strategies like the use of high-quality hay, rich in sugars, as an alternative energy source need to be explored. The aim of this study was to investigate changes in rumen microbial abundances in the liquid and solid-associated fraction of cattle fed two hay qualities differing in sugar content with graded amounts of starchy concentrate feeds using Illumina MiSeq sequencing and quantitative polymerase chain reaction. Operational taxonomic units clustered separately between the liquid and the solid-associated fraction. Phyla in the liquid fraction were identified as mainly Firmicutes, Proteobacteria and Bacteroidetes, whereas main phyla of the fibre-associated fraction were Bacteroidetes, Fibrobacteres and Firmicutes. Significant alterations in the rumen bacterial communities at all taxonomic levels as a result of changing the hay quality and concentrate proportions were observed. Several intermicrobial correlations were found. Genera Ruminobacter and Fibrobacter were significantly suppressed by feeding sugar-rich hay, whereas others such as Selenomonas and Prevotella proliferated. This study extends the knowledge about diet-induced changes in ruminal microbiome of cattle. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Influence of FeEDDS, FeEDTA, FeDTPA, FeEDDHA, and FeSO4 on Marigold Growth and Nutrition, and Substrate and Runoff Chemistry

Science.gov (United States)

Objectives of the study were to determine effects of Fe source on plant growth, plant nutrition, substrate chemistry and runoff chemistry. Iron source (FS) treatments consisted of Fe-aminopolycarboxylic acid (APCA) complexones iron ethylenediaminetetraacetic acid (FeEDTA), iron [S, S']-ethylenediam...

Estudio hidrogeológico y de calidad de agua en el sector oriental de la Sierra de San Javier entre las localidades de Yerba Buena y el Manantial. Provincia de Tucuman, Republica Argentina

Directory of Open Access Journals (Sweden)

D’Urso, C. H.

2005-12-01

Full Text Available The study area is located in the center west of the county of Tucumán, in the NW of Argentina. It extends from the oriental border of San Javier’s mountain between the towns of Yerba Buena and Manantial. In the piedmont zone and plain, have settled down diverse urban, agricultural centers and an important industrial complex that are supplied by underground water. The objective of this paper is to define the different geologic factors that impact in the behavior of the underground water and to define areas with appropriate hydrogeological characteristics for its use. The investigation determined that the water contained in the aquifers is of good quality and due to the high permeability, important flows can be obtained, that guarantee the supply to the population, agriculture and industry.La zona de estudio está ubicada en el centro oeste de la provincia de Tucumán, en el noroeste de Argentina. Se extiende desde el borde oriental de la sierra de San Javier entre las localidades de Yerba Buena y el Manantial. En el piedemonte y llanura se han establecido diversos centros urbanos, agrícolas y un importante complejo industrial que se abastecen de agua subterránea. El objetivo del trabajo es delimitar los distintos factores geológicos que inciden en el comportamiento del agua subterránea y tratar de definir zonas con características hidrogeológicas apropiadas para su aprovechamiento. De esta investigación se determinó que el agua que contienen los acuíferos es de buena calidad y debido a la elevada permeabilidad de los mismos, se pueden obtener importantes caudales, con lo que se garantiza el abastecimiento a la población, agricultura e industria.

Anomalous superconducting spin-valve effect in NbN/FeN/Cu/FeN/FeMn multilayers

Energy Technology Data Exchange (ETDEWEB)

Hwang, Tae Jong; Kim, Dong Ho [Yeungnam University, Gyeongsan (Korea, Republic of)

2017-09-15

We have studied magnetic and transport properties of NbN/FeN/Cu/FeN/FeMn spin-valve structure. In-plane magnetic moment exhibited typical hysteresis loops of spin valves in the normal state of NbN film at 20 K. On the other hand, the magnetic hysteresis loop in the superconducting state exhibited more complex behavior in which exchange bias provided by antiferrmagnetic FeMn layer to adjacent FeN layer was disturbed by superconductivity. Because of this, the ideal superconducting spin-valve effect was not detected. Instead the stray field originated from unsaturated magnetic states dominated the transport properties of NbN/FeN/Cu/FeN/FeMn multilayer.

U.S. Department of Education Fulbright-Hays Seminars Abroad Program, Malaysia June 26 - July 24, 1993. Participants' Reports.

Science.gov (United States)

Malaysian-American Commission on Educational Exchange, Kuala Lumpur.

This document contains reports by 14 participants of a Fulbright-Hays seminar in Malaysia. Participants were introduced to Malaysia and the Malaysian way of life through talks, discussion and field trips to schools, and educational institutions and cultural centers throughout the country. At every location the group was given presentations on…

Proyecto “Buenos hábitos, buena salud”. Estrategias para promover una alimentación saludable en la ESO

OpenAIRE

Rey Girón, Paula

2017-01-01

La alimentación es uno de los factores que afectan a la salud, y por ello hay que cuidarla. Es de vital importancia llevar a cabo una alimentación saludable, y por esta se entiende aquella que es suficiente, equilibrada, variada y segura; qué está adaptada al comensal y al entorno; y qué es sensorialmente satisfactoria. Para adquirir unos buenos hábitos alimentarios es necesaria una correcta educación nutricional, impartida desde edades tempranas. Y esto es lo que se pretende con la elaboraci...

Soft magnetic properties of hybrid ferromagnetic films with CoFe, NiFe, and NiFeCuMo layers

Energy Technology Data Exchange (ETDEWEB)

Choi, Jong-Gu [Eastern-western Biomedical Engineering, Sangji University, Wonju 220-702 (Korea, Republic of); Hwang, Do-Guwn [Dept. of Oriental Biomedical Engineering, Sangji University, Wonju 220-702 (Korea, Republic of); Rhee, Jang-Roh [Dept. of Physics, Sookmyung Women' s University, Seoul 140-742 (Korea, Republic of); Lee, Sang-Suk, E-mail: sslee@sangji.ac.kr [Dept. of Oriental Biomedical Engineering, Sangji University, Wonju 220-702 (Korea, Republic of)

2011-09-30

Two-layered ferromagnetic alloy films (NiFe and CoFe) with intermediate NiFeCuMo soft magnetic layers of different thicknesses were investigated to understand the relationship between coercivity and magnetization process by taking into account the strength of hard-axis saturation field. The thickness dependence of H{sub EC} (easy-axis coercivity), H{sub HS} (hard-axis saturation field), and {chi} (susceptibility) of the NiFeCuMo thin films in glass/Ta(5 nm)/[CoFe or NiFe(5 nm-t/2)]/NiFeCuMo(t = 0, 4, 6, 8, 10 nm)/[CoFe or NiFe(5 nm-t/2)]/Ta(5 nm) films prepared using the ion beam deposition method was determined. The magnetic properties (H{sub EC}, H{sub HS}, and {chi}) of the ferromagnetic CoFe, NiFe three-layers with an intermediate NiFeCuMo super-soft magnetic layer were strongly dependent on the thickness of the NiFeCuMo layer.

MIL-100-Fe derived N-doped Fe/Fe3C@C electrocatalysts for efficient oxygen reduction reaction

Science.gov (United States)

Guo, Dakai; Han, Sancan; Wang, Jiacheng; Zhu, Yufang

2018-03-01

N-doped porous Fe/Fe3C@C electrocatalysts were prepared by the pyrolysis of the hexamethylenetetramine (HMT)-incorporated MIL-100-Fe at different temperatures (700-1000 °C) under N2 atmosphere. Rotary evaporation of MIL-100-Fe and HMT solution could make more N-enriched HMT molecules enter into the pores of MIL-100-Fe, thus improving nitrogen contents of the final pyrolyzed samples. All pyrolyzed samples show porous textures with middle specific surface areas. The X-ray photoelectron spectroscopy (XPS) results demonstrate the successful introduction of N atoms into carbon framework. Sample Fe-N2-800 prepared by annealing the precursors with the HMT/MIL-100-Fe weight ratio of 2 at 800 °C exhibits the best electrocatalytic activity towards the oxygen reduction reaction (ORR) in terms of onset potential and current density because of high graphitic N and pyridinic N content. The enwrapped Fe/Fe3C nanoparticles and Fe-Nx active sites in these samples could also boost the ORR activity synergistically. Moreover, sample Fe-N2-800 demonstrates a dominant four electron reduction process, as well as excellent long-term operation stability and methanol crossover resistance. Thus, the N-doped Fe/Fe3C@C composites derived from the HMT-incorporated MIL-100-Fe are promising electrocatalysts to replace Pt/C for ORR in practical applications.

The 54Fe(d,t)53Fe reaction and the neutron configuration in 54Fe

International Nuclear Information System (INIS)

England, J.B.A.; Ophel, T.R.; Johnston, A.; Zeller, A.F.

1980-07-01

The 54 Fe(d,t) 53 Fe reaction has been used to study the levels populated in 54 Fe in an attempt to establish the neutron configuration in 54 Fe. The states observed show clear evidence for a 2p-4h admixture in 54 Fe. In particular, the strength of the first 3/2 - level relative to the 7/2 - ground state transition is 3-4 times that in neighbouring N = 28 nuclei

EVALUACIÓN DEL CONOCIMIENTO SOBRE BUENAS PRÁCTICAS DE MANIPULACIÓN DE ALIMENTOS DEL PERSONAL DE COCINA DE LOS HOTELES 5 ESTRELLAS, ISLA DE MARGARITA, VENEZUELA

OpenAIRE

Iriarte R, María M; Fermín, Orlando

2003-01-01

RESUMEN El objetivo de la investigación fue verificar el conocimiento que tiene el personal que prepara alimentos para buffet, sobre buenas prácticas de manipulación de alimentos. Se aplicó un cuestionario a empleados de cinco hoteles de 5 estrellas de la Isla de Margarita, escogidos por medio de un muestreo intencional. Se evaluaron seis tópicos relacionados con la manipulación de alimentos y el perfil social de los empleados. El 68,9% de los 101 participantes se catalogó con conocimientos N...

Statistical modeling of the reactions Fe(+) + N2O → FeO(+) + N2 and FeO(+) + CO → Fe(+) + CO2.

Science.gov (United States)

Ushakov, Vladimir G; Troe, Jürgen; Johnson, Ryan S; Guo, Hua; Ard, Shaun G; Melko, Joshua J; Shuman, Nicholas S; Viggiano, Albert A

2015-08-14

The rates of the reactions Fe(+) + N2O → FeO(+) + N2 and FeO(+) + CO → Fe(+) + CO2 are modeled by statistical rate theory accounting for energy- and angular momentum-specific rate constants for formation of the primary and secondary cationic adducts and their backward and forward reactions. The reactions are both suggested to proceed on sextet and quartet potential energy surfaces with efficient, but probably not complete, equilibration by spin-inversion of the populations of the sextet and quartet adducts. The influence of spin-inversion on the overall reaction rate is investigated. The differences of the two reaction rates mostly are due to different numbers of entrance states (atom + linear rotor or linear rotor + linear rotor, respectively). The reaction Fe(+) + N2O was studied either with (6)Fe(+) or with (4)Fe(+) reactants. Differences in the rate constants of (6)Fe(+) and (4)Fe(+) reacting with N2O are attributed to different contributions from electronically excited potential energy surfaces, such as they originate from the open-electronic shell reactants.

Spin structure of exchange biased heterostructures. Fe/MnF{sub 2} and Fe/FeF{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Sahoo, B

2006-12-18

In this work, the {sup 57}Fe probe layer technique is used in order to investigate the depth- and temperature-dependent Fe-layer spin structure of exchange biased Fe/MnF{sub 2} and Fe/FeF{sub 2} (pseudo-twinned) antiferromagnetic (AFM) systems by conversion electron Moessbauer spectroscopy (CEMS) and nuclear resonant scattering (NRS) of synchrotron radiation. Two kinds of samples with a 10 A {sup 57}Fe probe layer directly at or 35 A away from the interface, labeled as interface and center sample, respectively, were studied in this work. The results obtained by CEMS for Fe/MnF{sub 2} suggests that, at 80 K, i.e., above T{sub N}=67 K of MnF{sub 2}, the remanent state Fe-layer spin structure of the two studied samples are slightly different due to their different microstructure. In the temperature range from 300 K to 80 K, the Fe-layer spin structure does not change just by zero-field cooling the sample in remanence. For Fe/FeF{sub 2}, a continuous non-monotonic change of the remanent-state Fe spin structure was observed by cooling from 300 K to 18 K. NRS of synchrotron radiation was used to investigate the temperature- and depth-dependent Fe-layer spin structure during magnetization reversal in pseudo-twinned Fe/MnF{sub 2}. A depthdependent Fe spin structure in an applied magnetic field (applied along the bisector of the twin domains) was observed at 10 K, where the Fe spins closer to the interface are not aligned along the field direction. The depth-dependence disappears at 150 K. (orig.)

Effect of undigested neutral detergent fiber content of alfalfa hay on lactating dairy cows: Feeding behavior, fiber digestibility, and lactation performance.

Science.gov (United States)

Fustini, M; Palmonari, A; Canestrari, G; Bonfante, E; Mammi, L; Pacchioli, M T; Sniffen, G C J; Grant, R J; Cotanch, K W; Formigoni, A

2017-06-01

The objective of this study was to investigate the effects of 2 alfalfa hays differing in undigested neutral detergent fiber content and digestibility used as the main forage source in diets fed to high producing cows for Parmigiano-Reggiano cheese production. Diets were designed to have 2 different amounts of undigestible NDF [high (Hu) and low (Lu)], as determined by 240-h in vitro analysis (uNDF 240 ). Alfalfa hay in vitro digestibility [% of amylase- and sodium sulfite-treated NDF with ash correction (aNDFom)] at 24 and 240 h was 40.2 and 31.2% and 53.6 and 45.7% for low- (LD) and high-digestibility (HD) hays, respectively. The 4 experimental diets (Hu-HD, Lu-HD, Hu-LD, and Lu-LD) contained 46.8, 36.8, 38.8, and 30.1% of alfalfa hay, respectively, 8.6% wheat straw, and 35.3% corn (50% flake and 50% meal; DM basis). Soy hulls and soybean meal were used to replace hay to balance protein and energy among diets. Eight multiparous Holstein cows (average milk production = 46.0 ± 5.2 kg/d, 101 ± 38 d in milk, and 662 ± 42 kg of average body weight) were assigned to a 4 × 4 Latin square design, with 2 wk of adaptation and a 1-wk collection period. Dry matter and water intake, rumination time, ruminal pH, and milk production and composition were measured. Diets and feces were analyzed for NDF on an organic matter basis (aNDFom), acid detergent fiber, acid detergent lignin, and uNDF 240 to estimate total-tract fiber digestibility. Dry matter intake and rumination times were higher in HD diets compared with LD diets, regardless of forage amount. Rumination time was constant per unit of dry matter intake but differed when expressed as a function of uNDF 240 , aNDFom, or physically effective NDF intake. No differences were found among treatments on average ruminal pH, but the amount of time with pH digestible neutral detergent fiber fraction digestibility was higher for the LD diets (88.3 versus 85.8% aNDFom in HD), for which lower feed intakes were also observed. The

How oxygen attacks [FeFe] hydrogenases from photosynthetic organisms

Science.gov (United States)

Stripp, Sven T.; Goldet, Gabrielle; Brandmayr, Caterina; Sanganas, Oliver; Vincent, Kylie A.; Haumann, Michael; Armstrong, Fraser A.; Happe, Thomas

2009-01-01

Green algae such as Chlamydomonas reinhardtii synthesize an [FeFe] hydrogenase that is highly active in hydrogen evolution. However, the extreme sensitivity of [FeFe] hydrogenases to oxygen presents a major challenge for exploiting these organisms to achieve sustainable photosynthetic hydrogen production. In this study, the mechanism of oxygen inactivation of the [FeFe] hydrogenase CrHydA1 from C. reinhardtii has been investigated. X-ray absorption spectroscopy shows that reaction with oxygen results in destruction of the [4Fe-4S] domain of the active site H-cluster while leaving the di-iron domain (2FeH) essentially intact. By protein film electrochemistry we were able to determine the order of events leading up to this destruction. Carbon monoxide, a competitive inhibitor of CrHydA1 which binds to an Fe atom of the 2FeH domain and is otherwise not known to attack FeS clusters in proteins, reacts nearly two orders of magnitude faster than oxygen and protects the enzyme against oxygen damage. These results therefore show that destruction of the [4Fe-4S] cluster is initiated by binding and reduction of oxygen at the di-iron domain—a key step that is blocked by carbon monoxide. The relatively slow attack by oxygen compared to carbon monoxide suggests that a very high level of discrimination can be achieved by subtle factors such as electronic effects (specific orbital overlap requirements) and steric constraints at the active site. PMID:19805068

Fe-vacancy and superconductivity in FeSe-based superconductors

Science.gov (United States)

Wang, C. H.; Chen, T. K.; Chang, C. C.; Lee, Y. C.; Wang, M. J.; Huang, K. C.; Wu, P. M.; Wu, M. K.

2018-06-01

This review summarizes recent advancements in FeSe and related systems. The FeSe and related superconductors are currently receiving considerable attention for the high Tcs observed and for many similar features to the high Tc cuprate superconductors. These similarities suggest that understanding the FeSe based compounds could potentially help our understanding of the cuprates. We shall first review the common features observed in the FeSe-based system. It was found that with a careful control of material synthesizing processes, numerous rich phases have been observed in the FeSe-based system. Detailed studies show that the Fe-vacancy ordered phases found in the FeSe based compounds, which are non-superconducting Mott insulators, are the parent compounds of the superconductors. Superconductivity emerges from the parent phases by disordering the Fe vacancy order, often by a simple annealing treatment. Recent high temperature X-ray diffraction experiments show that the degree of structural distortion associated with the disorder of Fe-vacancy is closely related to volume fraction of the superconductivity observed. These results suggest the strong lattice to spin coupling are important for the occurrence of superconductivity in FeSe based superconductors.

Exchange bias variations of the seed and top NiFe layers in NiFe/FeMn/NiFe trilayer as a function of seed layer thickness

International Nuclear Information System (INIS)

Sankaranarayanan, V.K.; Yoon, S.M.; Kim, C.G.; Kim, C.O.

2005-01-01

Development of exchange bias at the seed and top NiFe layers in the NiFe (t nm)/FeMn(10 nm)/NiFe(5 nm) trilayer structure is investigated as a function of seed layer thickness, in the range of 2-20 nm. The seed NiFe layer shows maximum exchange bias at 4 nm seed layer thickness. The bias shows inverse thickness dependence with increasing thickness. The top NiFe layer on the other hand shows only half the bias of the seed layer which is retained even after the sharp fall in seed layer bias. The much smaller bias for the top NiFe layer is related to the difference in crystalline texture and spin orientations at the top FeMn/NiFe interface, in comparison to the bottom NiFe/FeMn interface which grows on a saturated NiFe layer with (1 1 1) orientation

Structural and magnetic properties of NdFeB and NdFeB/Fe films with Mo addition

Energy Technology Data Exchange (ETDEWEB)

Urse, M; Grigoras, M; Lupu, N; Chiriac, H, E-mail: urse@phys-iasi.ro [National Institute of R and D for Technical Physics, 47 Mangeron Blvd., 700050 Iasi (Romania)

2011-07-06

The influence of the Mo addition on the microstructure and magnetic properties of Nd-Fe-B and Nd-Fe-B/Fe films was studied. The coercivity is a key parameter in the control of technical performances of Nd-Fe-B films. A small amount of about 1 at.% Mo can enhance the coercivity of Nd-Fe-B film by controlling the growth of soft and hard magnetic grains. A coercivity of 22.1 kOe, a remanence ratio, M{sub r}/M{sub s}, of 0.83 and a maximum energy product of 8 MGOe were obtained for Ta/[NdFeBMo(1at.%)(540nm)/Ta films annealed at 650{sup 0}C for 20 minutes due to Mo precipitates formed at the Nd{sub 2}Fe{sub 14}B phase boundaries which prevent the nucleation and expansion of the magnetic domains. Simultaneous use of Mo as addition and the stratification of Nd-Fe-B-Mo films using Fe as spacer layer are important tools for the improvement of the hard magnetic properties of Nd-Fe-B films. The Ta/[NdFeBMo(1at.%)(180nm)/Fe(1nm)]x3/Ta multilayer film annealed at 620{sup 0}C exhibits an increase in the coercivity from 12.1 kOe to 22.8 kOe, in the remanence ratio from 0.77 to 0.80, and in the maximum energy product from 4.5 to 7.1 MGOe in comparison with Ta/Nd-Fe-B/Ta film. As compared to Ta/Nd-Fe-B/Ta film, the Ta/[NdFeBMo(1at.%)(180nm)/Fe(1nm)]x3/Ta film presents a decrease in the crystallization temperature of about 30{sup 0}C.

Isotopic fractionation associated with [NiFe]- and [FeFe]-hydrogenases

Energy Technology Data Exchange (ETDEWEB)

Yang, Hui; Gandhi, Hasand; Cornish, Adam J.; Moran, James J.; Kreuzer, Helen W.; Ostrom, Nathaniel; Hegg, Eric L.

2016-01-30

Hydrogenases catalyze the reversible formation of H2 from electrons and protons with high efficiency. Understanding the relationships between H2 production, H2 uptake, and H2-H2O exchange can provide insight into the metabolism of microbial communities in which H2 is an essential component in energy cycling. In this manuscript, we used stable H isotopes (1H and 2H) to probe the isotope effects associated with three [FeFe]-hydrogenases and three [NiFe]-hydrogenases. All six hydrogenases displayed fractionation factors for H2 formation that were significantly less than 1, producing H2 that was severely depleted in 2H relative to the substrate, water. Consistent with differences in their active site structure, the fractionation factors for each class appear to cluster, with the three [NiFe]-hydrogenases (α = 0.27-0.40) generally having smaller values than the three [FeFe]-hydrogenases (α = 0.41-0.55). We also obtained isotopic fractionation factors associated with H2 uptake and H2-H2O exchange under conditions similar to those utilized for H2 production, providing us with a more complete picture of the three reactions catalyzed by hydrogenases. The fractionation factors determined in our studies can be used as signatures for different hydrogenases to probe their activity under different growth conditions and to ascertain which hydrogenases are most responsible for H2 production and/or uptake in complex microbial communities.

Multielemental analysis of IAEA intercomparison standard Hay Powder, V-10 and some edible plant leaves by neutron activation. [Br,Ce,Cl,Cr,Cu,Fe,Ga,Hg,K,La,Mn,Mo,Na,P,Sc,Zn

Energy Technology Data Exchange (ETDEWEB)

Samudralwar, D L; Wankhade, H K; Garg, A N

1987-12-01

Instrumental neutron activation analysis was employed for the multielement determination of an IAEA intercomparison standard Hay Powder, V-10 and some edible plant leaves consumed in India. The samples were irradiated with thermal neutrons at a flux approx. = 10/sup 12/ n x cm/sup -2/ x s/sup -1/ in a reactor for 5 minutes, 1, 2, 5, 10 and 15 hours and counted by high resolution ..gamma..-ray spectrometry. Nearly 18 elements were determined. Good agreement is observed for most of the elements in several NBS standards and the proposed CRM V-10. Some edible vegetable plant leaves were also analyzed. (author) 32 refs.; 3 tabs.

Influence of an Fe cap layer on the structural and magnetic properties of Fe49Pt51/Fe bi-layers

International Nuclear Information System (INIS)

Chao-Yang, Duan; Bin, Ma; Zong-Zhi, Zhang; Qing-Yuan, Jin; Fu-Lin, Wei

2009-01-01

The influences of an Fe cap layer on the structural and magnetic properties of FePt/Fe bi-layers are investigated. Compared with single FePt alloy films, a thin Fe layer can affect the crystalline orientation and improve the chemical ordering of L1 0 FePt films. Moreover, the coercivity increases when a thin Fe layer covers the FePt layer. Beyond a critical thickness, however, the Fe cover layer quickens the magnetization reversal of Fe 49 Pt 51 /Fe bi-layers by their exchange coupling

Estudio de prevalencia de desnutrición en Atención Primaria del Departamento Valencia Dr Peset

OpenAIRE

Cantero Llorca, Juana

2015-01-01

Según la OMS hay numerosos datos científicos que demuestran que la importancia una alimentación equilibrada y de una buena nutrición, radica en ser uno de los pilares de la salud y del desarrollo. También reconoce que debido al aumento de la esperanza de vida y a la disminución de la tasa de fecundidad, se esta produciendo un envejecimiento de la población alarmante, con una previsión de duplicar los > de 60 años y cuadruplicar los > 80 años entre los años 2000 y 2050. A medida que las person...

Microstructure and properties of multiphase sintered cermets Fe-Fe{sub 2}B; Mikrostruktura i wlasnosci spiekanych reakcyjnie cermetali Fe-Fe{sub 2}B

Energy Technology Data Exchange (ETDEWEB)

Nowacki, J. [Wydzial Inzynierii Materialowej, Politechnika Szczecinska, Szczecin (Poland); Klimek, L. [Instytut Inzynierii Materialowej i Technik Bezwiorowych, Politechnika Lodzka, Lodz (Poland)

1998-12-31

The process of multiphase sintering of iron in the vacuum has been analysed. As a result of the process iron-iron boride cermets have been produced. Fe-Fe{sub 2}B cermets were obtained as a result of sintering of the Fe and B pure elements in the vacuum. Attemps at sintering in the solid phase and with the participation of the liquid phase, the Fe-Fe{sub 2}B eutectic, have been made. Metallographic qualitative and quantitative studies, X-ray structural qualitative and qauantitative analysis allowed to determine the structure of Fe{sub 2}B cermets, as well as a description of the kinetics of quantitative changes in phase proportions in the course of sintering. It has been found that their structure varies widely depending on sintering parameters and the composition of the sinters. Measurements of the Fe-Fe{sub 2}B cermets hardness and measurements on wear during dry friction by the pin-on-disc method have shown distinct advantages of the cermets as a modern constructional materials. The hardness of Fe-Fe{sub 2}B cermets, depending on their chemical composition and sintering parameters, ranges widely from 150 to 1500 HV, and their resistance to wear is comparable to that of diffusively boronized steels. FeFe{sub 2}B cermets are a composite material in which iron boride, Fe{sub 2}B, with a hardness of about 1800 HV plays the role of the reinforcement,while iron-iron boride, Fe-Fe{sub 2}B, with a hardness of about 500 HV plays the role of matrix. The eutectic in the spaces between iron boride grains is composed of boron solid solution plates in iron with a hardness of arround 250 HV, and iron boride, Fe{sub 2}B, plates with a hardness of approximaly 1800 HV. The combination of such different materials, a hard reinforcement and a relatively plastic matrix produces favourable properties of the cermet thus produced high hardness (1500 HV) constant over whole cross section of the material, resistance of abrasive wear and acceptable ductility. The properties mentioned above

Equilibrium Fe isotope fractionation between inorganic aqueous Fe(III) and the siderophore complex, Fe(III)-desferrioxamine B

DEFF Research Database (Denmark)

Dideriksen, Knud; Baker, Joel A.; Stipp, Susan Louise Svane

2008-01-01

be controlled by isotope fractionation between the free and complexed iron.We have determined the equilibrium Fe isotope fractionation induced by organic ligand activity in experiments with solutions having co-existing inorganic Fe(III) species and siderophore complexes, Fedesferrioxamine B (at pH 2). The two......-type fractionation during precipitation, this experiment yielded an isotope fractionation factor of a56Fesolution-solid=1.00027. Calculations based on these results indicate that isotopic re-equilibration is unlikely to significantly affect our determined equilibrium Fe isotope fractionation between inorganically...... and organically complexed Fe. To determine the equilibrium Fe isotope fractionation between inorganically and organically bound Fe(III), experiments with variable proportions of inorganic Fe were carried out at 25 °C. Irrespective of the proportion of inorganic Fe, equilibrium fractionation factors were within...

Effect of Lactic Acid Lactobacillus Preservative and Moisture Level at Baling on In-situ Digestibility of Crabgrass Hay by Heifers.

Science.gov (United States)

Common crabgrass (Digitaria ciliaris [Retz.] Koel.) is a warm-season annual that offers an advantage over many perennial warm-season grasses because of its greater nutritive value and high palatability. However, little is known about how baling crabgrass hay at high moisture affects ruminal forage ...

Effectiveness of FeEDDHA, FeEDDHMA, and FeHBED in Preventing Iron-Deficiency Chlorosis in Soybean

NARCIS (Netherlands)

Bin, Levi M.; Weng, Liping; Bugter, Marcel H.J.

2016-01-01

The performance of FeHBED in preventing Fe deficiency chlorosis in soybean (Glycine max (L.) Merr.) in comparison to FeEDDHA and FeEDDHMA was studied, as well as the importance of the ortho-ortho and ortho-para/rest isomers in defining the performance. To this end, chlorophyll production (SPAD),

Raman-spectroscopic (Fe/Fe+Mg, CO2) and Structural studies of Mg-Fe cordierites

International Nuclear Information System (INIS)

Haefeker, U.

2013-01-01

In the course of this dissertation synthetic hexagonal and orthorhombic Mg-Fe-cordierites have been investigated with Raman-spectroscopy and XRD methods. Cordierite´s Mg- and Fe-end-members as well as their Mg-Fe solid solutions with the chemical formula (Mg, Fe 2+ ) 2 Al 4 Si 5 O 18 *nH 2 O have been synthesized. Raman-data of synthetic hydrous Mg- and Fe-cordierites have been obtained in the wavenumber-region 100-1250 cm-1 and the experimental data were then compared with the results of quantum-mechanical calculations. 86 theoretical bands could be related to specific vibrational modes of the tetrahedral and octahedral sites of the cordierite structure. Maximum and mean deviation between experimentally-derived bands and calculated modes were ±7 cm -1 for Mg-cordierite and ±19 cm -1 for Fe-cordierite. Spectra comparison revealed a trend of peak downshifting as a consequence of Fe-incorporation. The calculations now allow more accurate interpretation of the Raman spectra with respect to structural changes of cordierite, resulting from Al-Si ordering and Mg-Fe exchange. Atomic motions in cordierite have been compared with those of the structurally similar mineral beryl. Investigations of 16 H 2 O-bearing synthetic well-ordered Mg-Fe-cordierites (XFe =0-1) with micro-Raman spectroscopy revealed a linear correlation between the Fe/Mg ratio and the position of certain Raman peaks. The peaks (wave-number Mg-/Fe-cordierite) at 122/111, 262/257, 430/418, 579/571, 974/967, and 1012/1007 cm -1 were selected for a detailed deconvolution analysis . The shifts of these peaks were then plotted vs. XFe and regression of the data lead to the formulation of a set of linear equations. In addition, the effect of different H 2 O contents and the degree of Al-Si ordering on the Fe/Mg determination were also investigated. Testing the calibration against data from six well-characterized natural cordierite samples yielded excellent agreement. Existing calibration diagrams for CO 2

Gas Exchanges and Dehydration in Different Intensities of Conditioning in Tifton 85 Bermudagrass: Nutritional Value during Hay Storage

Directory of Open Access Journals (Sweden)

M. Pasqualotto

2015-06-01

Full Text Available The present study aimed at evaluating the intensity of Tifton 85 conditioning using a mower conditioner with free-swinging flail fingers and storage times on dehydration curve, fungi presence, nutritional value and in vitro digestibility of Tifton 85 bermudagrass hay dry matter (DM. The dehydration curve was determined in the whole plant for ten times until the baling. The zero time corresponded to the plant before cutting, which occurred at 11:00 and the other collections were carried out at 8:00, 10:00, 14:00, and 16:00. The experimental design was randomised blocks with two intensities of conditioning (high and low and ten sampling times, with five replications. The high and low intensities related to adjusting the deflector plate of the free iron fingers (8 and 18 cm. In order to determine gas exchanges during Tifton 85 bermudagrass dehydration, there were evaluations of mature leaves, which were placed in the upper middle third of each branch before the cutting, at every hour for 4 hours. A portable gas analyser was used by an infrared IRGA (6400xt. The analysed variables were photosynthesis (A, stomatal conductance (gs, internal CO2 concentration (Ci, transpiration (T, water use efficiency (WUE, and intrinsic water use efficiency (WUEi. In the second part of this study, the nutritional value of Tifton 85 hay was evaluated, so randomised blocks were designed in a split plot through time, with two treatments placed in the following plots: high and low intensity of cutting and five different time points as subplots: cutting (additional treatment, baling and after 30, 60, and 90 days of storage. Subsequently, fungi that were in green plants as well as hay were determined and samples were collected from the grass at the cutting period, during baling, and after 30, 60, and 90 days of storage. It was observed that Tifton 85 bermudagrass dehydration occurred within 49 hours, so this was considered the best time for drying hay. Gas exchanges were

Giant magnetoimpedance effect in sputtered single layered NiFe film and meander NiFe/Cu/NiFe film

International Nuclear Information System (INIS)

Chen, L.; Zhou, Y.; Lei, C.; Zhou, Z.M.; Ding, W.

2010-01-01

Giant magnetoimpedance (GMI) effect on NiFe thin film is very promising due to its application in developing the magnetic field sensors with highly sensitivity and low cost. In this paper, the single layered NiFe thin film and NiFe/Cu/NiFe thin film with a meander structure are prepared by the MEMS technology. The influences of sputtering parameters, film structure and conductor layer width on GMI effect in NiFe single layer and meander NiFe/Cu/NiFe film are investigated. Maximum of the GMI ratio in single layer and sandwich film is 5% and 64%, respectively. The results obtained are useful for developing the high-performance magnetic sensors based on NiFe thin film.

Effect of a commercial anion dietary supplement on acid-base balance, urine volume, and urinary ion excretion in male goats fed oat or grass hay diets.

Science.gov (United States)

Stratton-Phelps, Meri; House, John K

2004-10-01

To determine whether feeding a commercial anionic dietary supplement as a urinary acidifier to male goats may be useful for management of urolithiasis. 8 adult sexually intact male Toggenburg, Saanen, and Nubian goats. Goats were randomly assigned by age-, breed-, and weight-matched pairs to an oat or grass hay diet that was fed for 12 days. On days 13 to 14 (early sample collection time before supplementation), measurements were made of blood and urine sodium, potassium, calcium, magnesium, chloride, phosphorus, and sulfur concentrations; blood and urine pH; urine production; and water consumption. During the next 28 days, the anionic dietary supplement was added to the oat and grass hay diets to achieve a dietary cation-anion difference of 0 mEq/100g of dry matter. Blood and urine samples were analyzed during dietary supplementation on days 12 to 13 (middle sample collection time) and 27 to 28 (late sample collection time). Blood bicarbonate, pH, and urine pH of goats fed grass hay and goats fed oat hay were significantly decreased during the middle and late sample collection times, compared with the early sample collection time. Water consumption and urine production in all goats increased significantly during the late sample collection time, compared with the early sample collection time. The anionic dietary supplement used in our study increases urine volume, alters urine ion concentrations, and is an efficacious urinary acidifier in goats. Goats treated with prolonged anionic dietary supplementation should be monitored for secondary osteoporosis from chronic urinary calcium loss.

Effects of including saponins (Micro-aid®) on intake, rumen fermentation, and digestibility in steers fed low-quality prairie hay

Science.gov (United States)

Sixteen ruminally-cannulated crossbred steers (529 ± 45 kg initial body weight, BW) were used to evaluate in situ dry matter (DM), neutral detergent fiber (aNDF), and N degradation characteristics of low quality prairie hay, blood urea nitrogen (BUN) and rumen fermentation parameters in steers provi...

Molecular [(Fe3)–(Fe3)] and [(Fe4)–(Fe4)] coordination cluster pairs as single or composite arrays.

Science.gov (United States)

Sañudo, E Carolina; Uber, Jorge Salinas; Pons Balagué, Alba; Roubeau, Olivier; Aromí, Guillem

2012-08-06

The synthesis of molecular cluster pairs is a challenge for coordination chemists due to the potential applications of these species in molecular spintronics or quantum computing. The ligand H(4)L, 1,3-bis-(3-oxo-3-(2-hydroxyphenyl)-propionyl)-2-methoxybenzene, has been successfully used to obtain a series of such complexes using the basic Fe(III) trinuclear carboxylates as starting materials. Synthetic control has allowed the isolation of the two molecular cluster pairs that form the composite [Fe(4)O(2)(PhCO(2))(6)(H(2)L)(pz)](2)[Fe(3)O(PhCO(2))(5)(py)(H(2)L)](2) (1). The dimers of trinuclear units, [Fe(3)O(PhCO(2))(5)(H(2)O)(H(2)L)](2) (2) and [Fe(3)O(o-MePhCO(2))(5)(H(2)L)(py)](2) (3), and the dimers of tetranuclear units, [Fe(4)O(2)(PhCO(2))(6)(H(2)L)(pz)](2) (4) and [Fe(4)O(2)(o-MePhCO(2))(6)(H(2)L)(pz)](2) (5), are presented here. The magnetic properties of the reported aggregates show that they are pairs of semi-independent clusters weakly interacting magnetically as required for two-qubit quantum gates.

A [4Fe-4S]-Fe(CO)(CN)-l-cysteine intermediate is the first organometallic precursor in [FeFe] hydrogenase H-cluster bioassembly

Science.gov (United States)

Rao, Guodong; Tao, Lizhi; Suess, Daniel L. M.; Britt, R. David

2018-05-01

Biosynthesis of the [FeFe] hydrogenase active site (the 'H-cluster') requires the interplay of multiple proteins and small molecules. Among them, the radical S-adenosylmethionine enzyme HydG, a tyrosine lyase, has been proposed to generate a complex that contains an Fe(CO)2(CN) moiety that is eventually incorporated into the H-cluster. Here we describe the characterization of an intermediate in the HydG reaction: a [4Fe-4S][(Cys)Fe(CO)(CN)] species, 'Complex A', in which a CO, a CN- and a cysteine (Cys) molecule bind to the unique 'dangler' Fe site of the auxiliary [5Fe-4S] cluster of HydG. The identification of this intermediate—the first organometallic precursor to the H-cluster—validates the previously hypothesized HydG reaction cycle and provides a basis for elucidating the biosynthetic origin of other moieties of the H-cluster.

Study on adsorption of 99Tc on Fe, Fe2O3 and Fe3O4

International Nuclear Information System (INIS)

Liu Dejun; Fan Xianhua; Zhang Yingjie; Yao Jun; Zhou Duo; Wang Yong

2004-01-01

The absorption behavior of 99 Tc on Fe, Fe 2 O 3 and Fe 3 O 4 powders from aqueous 99 TcO 4 - solutions is studied by batch method in atmospheric conditions. After the adsorption reaches equilibrium, the valence state of 99 Tc in the aqueous solution is examined by extraction with tetraphenylarsonium chloride. The experimental results show that the adsorption ratio of 99 Tc on iron powders decreases with the increase of pH (in the range of 5-8) and of CO 3 2- concentration (in the range of 1 x 10 -8 -1 x 10 -2 mol/L). In opposite, the two factors have no significant influence on the absorption of 99 Tc on both Fe 2 O 3 and Fe 3 O 4 powders. The adsorption isotherms of 99 TcO 4 - on Fe, Fe 2 O 3 and Fe 3 O 4 powders can be well described by the Freundlich's equation. The major valence state of 99 Tc is deduced to be Tc(IV) when iron powders is used as the absorbent. In the case of Fe 2 O 3 or Fe 3 O 4 as an absorbent, the 99 Tc remains as the TcO 4 - form

Atom exchange between aqueous Fe(II) and structural Fe in clay minerals.

Science.gov (United States)

Neumann, Anke; Wu, Lingling; Li, Weiqiang; Beard, Brian L; Johnson, Clark M; Rosso, Kevin M; Frierdich, Andrew J; Scherer, Michelle M

2015-03-03

Due to their stability toward reductive dissolution, Fe-bearing clay minerals are viewed as a renewable source of Fe redox activity in diverse environments. Recent findings of interfacial electron transfer between aqueous Fe(II) and structural Fe in clay minerals and electron conduction in octahedral sheets of nontronite, however, raise the question whether Fe interaction with clay minerals is more dynamic than previously thought. Here, we use an enriched isotope tracer approach to simultaneously trace Fe atom movement from the aqueous phase to the solid ((57)Fe) and from the solid into the aqueous phase ((56)Fe). Over 6 months, we observed a significant decrease in aqueous (57)Fe isotope fraction, with a fast initial decrease which slowed after 3 days and stabilized after about 50 days. For the aqueous (56)Fe isotope fraction, we observed a similar but opposite trend, indicating that Fe atom movement had occurred in both directions: from the aqueous phase into the solid and from the solid into aqueous phase. We calculated that 5-20% of structural Fe in clay minerals NAu-1, NAu-2, and SWa-1 exchanged with aqueous Fe(II), which significantly exceeds the Fe atom layer exposed directly to solution. Calculations based on electron-hopping rates in nontronite suggest that the bulk conduction mechanism previously demonstrated for hematite1 and suggested as an explanation for the significant Fe atom exchange observed in goethite2 may be a plausible mechanism for Fe atom exchange in Fe-bearing clay minerals. Our finding of 5-20% Fe atom exchange in clay minerals indicates that we need to rethink how Fe mobility affects the macroscopic properties of Fe-bearing phyllosilicates and its role in Fe biogeochemical cycling, as well as its use in a variety of engineered applications, such as landfill liners and nuclear repositories.

Process and genes for expression and overexpression of active [FeFe] hydrogenases

Science.gov (United States)

Seibert, Michael; King, Paul W; Ghirardi, Maria Lucia; Posewitz, Matthew C; Smolinski, Sharon L

2014-09-16

A process for expression of active [FeFe]-hydrogenase in a host organism that does not contain either the structural gene(s) for [FeFe]-hydrogenases and/or homologues for the maturation genes HydE, HydF and HyG, comprising: cloning the structural hydrogenase gene(s) and/or the maturation genes HydE, HydF and HydG from an organisms that contains these genes into expression plasmids; transferring the plasmids into an organism that lacks a native [FeFe]-hydrogenase or that has a disrupted [FeFe]-hydrogenase and culturing it aerobically; and inducing anaerobiosis to provide [FeFe] hydrogenase biosynthesis and H?2#191 production.

Photoelectron spectroscopy study of Fe-diluted Au-Fe alloys

CERN Document Server

Nahm, T U; Choi, B; Park, J S; Oh, S J; Cho, E J

2003-01-01

The electronic structure of Fe-diluted Au-Fe alloys has been studied by taking core-level and valence-band spectra using x-ray photoemission spectroscopy and synchrotron radiation. From the core-level spectroscopy, we found that the Fe 2p spectrum is composed of d sup 6 and d sup 7 multiplets from Fe impurity atoms. This behaviour is qualitatively discussed within the context of electron-electron interaction. In order to explore the electron-correlation effects in the valence band, we obtained Fe 3d partial spectral weights by taking advantage of the Cooper-minimum phenomenon of an Au 5d photoionization cross section. It was found that the spin-down states have an appreciable amount of spectral weights throughout the host Au 5d band, contrary to previous one-electron calculations predicting two-peak structure of the Fe 3d states. We suggest that this discrepancy results from the correlation effect of the Fe 3d electrons.

Colorimeter determination of Fe(II)/Fe(III) ratio in glass

International Nuclear Information System (INIS)

Baumann, E.W.; Coleman, C.J.; Karraker, D.G.; Scott, W.H.

1987-01-01

A colorimetric method has been developed to determine the Fe(II)/Fe(III) ratio in glass containing nuclear waste. Fe(II) is stabilized with pentavalent vanadium during dissolution in sulfuric and hydrofluoric acids. The chromogen is FerroZine (Hach Chemical Company), which forms a magenta complex with Fe(II). The two-step color development consists of determining the Fe(II) by adding FerroZine, followed by determining total Fe after the Fe(III) present is reduced with ascorbic acid. The method was validated by analyzing mixtures of ferrous/ferric solutions and nonferrous glass frit, and by comparison with Moessbauer spectroscopy. The effect of gamma radiation was established. The procedure is generally applicable to nonradioactive materials such as minerals and other glasses

Children and adolescents' health-related quality of life in relation to eczema, asthma and hay fever: results from a population-based cross-sectional study.

Science.gov (United States)

Matterne, Uwe; Schmitt, Jochen; Diepgen, Thomas L; Apfelbacher, Christian

2011-10-01

Several studies have looked at the relationship between childhood atopic disease and health-related quality of life (HRQoL), but existing research is limited by selected populations, small samples or lack to consider each of the three atopic conditions simultaneously. Impact of 4-week and 12-month occurrences of the three conditions on HRQoL were analysed by the use of complex sample general linear models alone and adjusted for the other atopic conditions, sociodemographics and mental health in a population-based sample (n = 6,518) of children and adolescents aged 11-17. In univariate analyses, total HRQoL was significantly impacted by eczema and hay fever but not asthma with stronger effects for 4-week occurrence. In multivariate analyses, 12-month occurrence of hay fever and 4-week occurrence of eczema and hay fever significantly impacted on total HRQoL. Although most of the variance in HRQoL was explained by mental health, independent effects of the atopic conditions remained. Atopic conditions impact HRQoL over and above mental health. When analysing the relationship between atopic conditions and HRQoL, it is important to consider more immediate versus less immediate effects of the conditions. Extent of impairment and the domains affected appear to vary when different time intervals are used.

Effects of supplementation level and particle size of alfalfa hay on growth characteristics and rumen development in dairy calves

NARCIS (Netherlands)

Mirzaei, M.; Khorvash, M.; Ghorbani, G.R.; Kazemi-Bonchenari, M.; Riasi, A.; Nabipour, A.; Borne, van den J.J.G.C.

2015-01-01

The aim of this study was to assess the effects of particle size (PS) of alfalfa hay on growth characteristics and rumen development in dairy calves at two levels of alfalfa supplementation. Fifty newborn dairy calves (42.7 ± 2.2 kg BW) were used in a 2 × 2 factorial arrangement with the factors

Nature of impurities in fertilizers containing EDDHMA/Fe(3+), EDDHSA/Fe(3+), and EDDCHA/Fe(3+) chelates.

Science.gov (United States)

Alvarez-Fernández, Ana; Cremonini, Mauro A; Sierra, Miguel A; Placucci, Giuseppe; Lucena, Juan J

2002-01-16

Iron chelates derived from ethylenediaminedi(o-hydroxyphenylacetic) acid (EDDHA), ethylenediaminedi(o-hydroxy-p-methylphenylacetic) acid (EDDHMA), ethylenediaminedi(2-hydroxy-5-sulfophenylacetic) acid (EDDHSA), and ethylenediaminedi(5-carboxy-2-hydroxyphenylacetic) acid (EDDCHA) are remarkably efficient in correcting iron chlorosis in plants growing in alkaline soils. This work reports the determination of impurities in commercial samples of fertilizers containing EDDHMA/Fe(3+), EDDHSA/Fe(3+), and EDDCHA/Fe(3+). The active components (EDDHMA/Fe(3+), EDDHSA/Fe(3+), and EDDCHA/Fe(3+)) were separated easily from other compounds present in the fertilizers by HPLC. Comparison of the retention times and the UV-visible spectra of the peaks obtained from commercial EDDHSA/Fe(3+) and EDDCHA/Fe(3+) samples with those of standard solutions showed that unreacted starting materials (p-hydroxybenzenesulfonic acid and p-hydroxybenzoic acid, respectively) were always present in the commercial products. 1D and 2D NMR experiments showed that commercial fertilizers based on EDDHMA/Fe(3+) contained impurities having structures tentatively assigned to iron chelates of two isomers of EDDHMA. These findings suggest that current production processes of iron chelates used in agriculture need to be improved.

Melting relations in the Fe-rich portion of the system FeFeS at 30 kb pressure

Science.gov (United States)

Brett, R.; Bell, P.M.

1969-01-01

The melting relations of FeFeS mixtures covering the composition range from Fe to Fe67S33 have been determined at 30 kb pressure. The phase relations are similar to those at low pressure. The eutectic has a composition of Fe72.9S27.1 and a temperature of 990??C. Solubility of S in Fe at elevated temperatures at 30 kb is of the same order of magnitude as at low pressure. Sulfur may have significantly lowered the melting point of iron in the upper mantle during the period of coalescence of metal prior to core formation in the primitive earth. ?? 1969.

Comparison of Ab initio low-energy models for LaFePO, LaFeAsO, BaFe2As2, LiFeAs, FeSe, and FeTe. Electron correlation and covalency

International Nuclear Information System (INIS)

Miyake, Takashi; Nakamura, Kazuma; Arita, Ryotaro; Imada, Masatoshi

2010-01-01

Effective low-energy Hamiltonians for several different families of iron-based superconductors are compared after deriving them from the downfolding scheme based on first-principles calculations. Systematic dependences of the derived model parameters on the families are elucidated, many of which are understood from the systematic variation of the covalency between Fe-3d and pnictogen-/chalcogen-p orbitals. First, LaFePO, LaFeAsO (1111), BaFe 2 As 2 (122), LiFeAs (111), FeSe, and FeTe (11) have overall similar band structures near the Fermi level, where the total widths of 10-fold Fe-3d bands are mostly around 4.5 eV. However, the derived effective models of the 10-fold Fe-3d bands (d model) for FeSe and FeTe have substantially larger effective onsite Coulomb interactions U - 4.2 and 3.4 eV, respectively, after the screening by electrons on other bands and after averaging over orbitals, as compared to ∼2.5 eV for LaFeAsO. The difference is similar in the effective models containing p orbitals of As, Se or Te (dp or dpp model), where U ranges from ∼4 eV for the 1111 family to ∼7 eV for the 11 family. The exchange interaction J has a similar tendency. The family dependence of models indicates a wide variation ranging from weak correlation regime (LaFePO) to substantially strong correlation regime (FeSe). The origin of the larger effective interaction in the 11 family is ascribed to smaller spread of the Wannier orbitals generating larger bare interaction, and to fewer screening channels by the other bands. This variation is primarily derived from the distance h between the pnictogen/chalcogen position and the Fe layer: The longer h for the 11 family generates more ionic character of the bonding between iron and anion atoms, while the shorter h for the 1111 family leads to more covalent-bonding character, the larger spread of the Wannier orbitals, and more efficient screening by the anion p orbitals. The screened interaction of the d model is strongly orbital

Magnetostrictive GMR spin valves with composite FeGa/FeCo free layers

Energy Technology Data Exchange (ETDEWEB)

Liu, Luping [Key Laboratory of Magnetic Materials and Devices & Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Institute of Materials Science, School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Zhan, Qingfeng, E-mail: zhanqf@nimte.ac.cn, E-mail: runweili@nimte.ac.cn; Yang, Huali; Li, Huihui; Zhang, Shuanglan; Liu, Yiwei; Wang, Baomin; Li, Run-Wei, E-mail: zhanqf@nimte.ac.cn, E-mail: runweili@nimte.ac.cn [Key Laboratory of Magnetic Materials and Devices & Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Tan, Xiaohua [Institute of Materials Science, School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China)

2016-03-15

We have fabricated strain-sensitive spin valves on flexible substrates by utilizing the large magnetostrictive FeGa alloy to promote the strain sensitivity and the composite free layer of FeGa/FeCo to avoid the drastic reduction of giant magnetoresistance (GMR) ratio. This kind of spin valve (SV-FeGa/FeCo) displays a MR ratio about 5.9%, which is comparable to that of the conventional spin valve (SV-FeCo) with a single FeCo free layer. Different from the previously reported works on magnetostrictive spin valves, the SV-FeGa/FeCo displays an asymmetric strain dependent GMR behavior. Upon increasing the lateral strain, the MR ratio for the ascending branch decreases more quickly than that for the descending branch, which is ascribed to the formation of a spiraling spin structure around the FeGa/FeCo interface under the combined influences of both magnetic field and mechanical strain. A strain sensitivity of GF = 7.2 was achieved at a magnetic bias field of -30 Oe in flexible SV-FeGa/FeCo, which is significantly larger than that of SV-FeCo.

Magnetostrictive GMR spin valves with composite FeGa/FeCo free layers

International Nuclear Information System (INIS)

Liu, Luping; Zhan, Qingfeng; Yang, Huali; Li, Huihui; Zhang, Shuanglan; Liu, Yiwei; Wang, Baomin; Li, Run-Wei; Tan, Xiaohua

2016-01-01

We have fabricated strain-sensitive spin valves on flexible substrates by utilizing the large magnetostrictive FeGa alloy to promote the strain sensitivity and the composite free layer of FeGa/FeCo to avoid the drastic reduction of giant magnetoresistance (GMR) ratio. This kind of spin valve (SV-FeGa/FeCo) displays a MR ratio about 5.9%, which is comparable to that of the conventional spin valve (SV-FeCo) with a single FeCo free layer. Different from the previously reported works on magnetostrictive spin valves, the SV-FeGa/FeCo displays an asymmetric strain dependent GMR behavior. Upon increasing the lateral strain, the MR ratio for the ascending branch decreases more quickly than that for the descending branch, which is ascribed to the formation of a spiraling spin structure around the FeGa/FeCo interface under the combined influences of both magnetic field and mechanical strain. A strain sensitivity of GF = 7.2 was achieved at a magnetic bias field of -30 Oe in flexible SV-FeGa/FeCo, which is significantly larger than that of SV-FeCo.

Magnetostrictive GMR spin valves with composite FeGa/FeCo free layers

Science.gov (United States)

Liu, Luping; Zhan, Qingfeng; Yang, Huali; Li, Huihui; Zhang, Shuanglan; Liu, Yiwei; Wang, Baomin; Tan, Xiaohua; Li, Run-Wei

2016-03-01

We have fabricated strain-sensitive spin valves on flexible substrates by utilizing the large magnetostrictive FeGa alloy to promote the strain sensitivity and the composite free layer of FeGa/FeCo to avoid the drastic reduction of giant magnetoresistance (GMR) ratio. This kind of spin valve (SV-FeGa/FeCo) displays a MR ratio about 5.9%, which is comparable to that of the conventional spin valve (SV-FeCo) with a single FeCo free layer. Different from the previously reported works on magnetostrictive spin valves, the SV-FeGa/FeCo displays an asymmetric strain dependent GMR behavior. Upon increasing the lateral strain, the MR ratio for the ascending branch decreases more quickly than that for the descending branch, which is ascribed to the formation of a spiraling spin structure around the FeGa/FeCo interface under the combined influences of both magnetic field and mechanical strain. A strain sensitivity of GF = 7.2 was achieved at a magnetic bias field of -30 Oe in flexible SV-FeGa/FeCo, which is significantly larger than that of SV-FeCo.

Confirmed Datura poisoning in a horse most probably due to D. ferox in contaminated tef hay : clinical communication

Directory of Open Access Journals (Sweden)

R. Gerber

2006-06-01

Full Text Available Two out of a group of 23 mares exposed to tef hay contaminated with Datura ferox (and possibly D. stramonium developed colic. The 1st animal was unresponsive to conservative treatment, underwent surgery for severe intestinal atony and had to be euthanased. The 2nd was less seriously affected, responded well to analgesics and made an uneventful recovery. This horse exhibited marked mydriasis on the first 2 days of being poisoned and showed protracted, milder mydriasis for a further 7 days. Scopolamine was chemically confirmed in urine from this horse for 3 days following the colic attack, while atropine could just be detected for 2 days. Scopolamine was also the main tropane alkaloid found in the contaminating plant material, confirming that this had most probably been a case of D. ferox poisoning. Although Datura intoxication of horses from contaminated hay was suspected previously, this is the 1st case where the intoxication could be confirmed by urine analysis for tropane alkaloids. Extraction and detection methods for atropine and scopolamine in urine are described employing enzymatic hydrolysis followed by liquid-liquid extraction and liquid chromatography tandem mass spectrometry (LC/MS/MS.

Surface runoff fluxes of nutrients in montane forests in Piedras Blancas region, Antioquia (Colombia)

International Nuclear Information System (INIS)

Ruiz Suescun, Oscar Andres; Acosta Jaramillo, Juan Jose; Leon Pelaez, Juan Diego

2005-01-01

In natural montane oak forests (Quercus humboldtii Bonpl.), pine (Pinus patula Schltdl and cham.) and cypress (Cupressus lusitanica Mill.) plantations in the region of Piedras Blancas, Antioquia, surface runoff flows (SRF) were measured over 16 months. Runoff was measured using 2 m wide x 10 m long runoff bounded plots, collector tanks and a volumetric counter system. Nutrient flows for the oak forest, pine and cypress plantations were, respectively: P total (0,51, 0,08 and 0,42 kg ha-y), Ca (0,13, 0,21 and 1,27 kg ha- y); Mg (0,07, 0,07 and 0,34 kg ha-y); K (0,89, 0,71 and 2,60 kg ha-y); Fe (0,04, 0,04 and 0,47 kg ha-y) and Mn (0,01, 0,01 and 0,08 kg ha-y)

Computed oscillator strengths and energy levels for Fe III, Fe IV, Fe V, and Fe VI with calculated wavelengths and wavelengths derived from established data

International Nuclear Information System (INIS)

Fawcett, B.C.

1989-01-01

Calculated weighted oscillator strengths are tabulated for spectral lines of Fe III, Fe IV, Fe V, and Fe VI. The lines belong to transition arrays 3d 6 -3d 5 4p and 3d 5 4s-3d 5 4p in Fe III, 3d 5 -3d 4 4p and 3d 4 4s-3d 4 4p in Fe IV, 3d 4 -3d 3 4p and 3d 3 4s-3d 3 4p in Fe V, and 3d 3 -3d 2 4p and 3d 2 4s-3d 2 4p in Fe VI. For the calculations, Slater parameters are optimized on the basis of minimizing the discrepancies between observed and computed wavelengths. Configuration interaction was included among the 3d n , 3d n-1 4s, 3d n-2 4s 2 , 3d n-1 4d, and 3d n-1 5s even configurations and among the 3d n-1 4p, 3d n-2 4s4p, and 3d n-1 5p odd configurations, with 3p 5 3d n+1 added for Fe VI. Calculated wavelengths are compared with observational data, and the compositions of energy levels are listed. This completes a series of similar computations for these complex configurations covering Fe I to Fe VI

Solar heaters, should they be seen or not?; Calentadores solares, mostrarlos u ocultarlos?

Energy Technology Data Exchange (ETDEWEB)

Garcia Martinez, Octavio [Modulo Solar, S.A. de C.V., Cuernavaca, Morelos (Mexico)

2000-07-01

Talking about Solar Heaters, architects have two opposite points of view about aesthetics. Some architects are convinced that the collector field should be integrated into the original design or in buildings already built, these fields should be adapted and fully shown. On the other hand, there are those who prefer collectors not to be seen. This work, based on our experience since 1975, will show with photographOut experience since 1975 will be show with solutions that have satisfy each part. With worldwide expectations of massive use of solar energy in the first decade of the millennium, we think that is important to discuss whether: SOLAR HEATERS, should they be seen or not?. [Spanish] Con respecto a los aspectos esteticos de los equipos solares, en el medio arquitectonico existen dos corrientes plenamente contrapuestas: 1.- Aquellos que estan convencidos que hay que integrar los campos de colectores al diseno original o que hay que resolver en las edificaciones existentes la adaptacion de los mismos mostrandolos plenamente y 2.- Aquellos que prefieren ocultarlos. En este trabajo, basado en experiencias desde 1975, mostrara, mediante imagenes, ejemplos de soluciones que hay satisfecho a cada corriente. Con las expectativas mundiales del uso masivo de la energia solar en la primera decada del milenio, seria importante, de una buena vez, encauzar la polemica: EQUIPOS SOLARES SE DEBEN VER O NO?.

Clarifying roughness and atomic diffusion contributions to the interface broadening in exchange-biased NiFe/FeMn/NiFe heterostructures

Energy Technology Data Exchange (ETDEWEB)

Nascimento, V.P., E-mail: valberpn@yahoo.com.br [Departamento de Física, Universidade Federal do Espírito Santo, 29075-910 Vitória (Brazil); Merino, I.L.C.; Passamani, E.C. [Departamento de Física, Universidade Federal do Espírito Santo, 29075-910 Vitória (Brazil); Alayo, W. [Departamento de Física, Universidade de Pelotas, 96010-610 Pelotas (Brazil); Tafur, M. [Instituto de Ciências Exatas, Universidade Federal de Itajubá, 37500-903 Itajubá (Brazil); Pelegrini, F. [Instituto de Física, Universidade Federal de Goiás, 74001-970 Goiânia (Brazil); Magalhães-Paniago, R. [Universidade Federal de Minas Gerais, Belo Horizonte (Brazil); Alvarenga, A.D. [Instituto Nacional de Metrologia, 25250-020 Xerém (Brazil); Saitovitch, E.B. [Coordenação de Física Experimental e Baixas Energias, Centro Brasileiro de Pesquisas Físicas, 22290-180 Rio de Janeiro (Brazil)

2013-09-02

NiFe(30 nm)/FeMn(13 nm)/NiFe(10 nm) heterostructures prepared by magnetron sputtering at different argon working pressures (0.27, 0.67 and 1.33 Pa) were systematically investigated by using specular and off-specular diffuse X-ray scattering experiments, combined with ferromagnetic resonance technique, in order to distinguish the contribution from roughness and atomic diffusion to the total structural disorder at NiFe/FeMn interfaces. It was shown that an increase in the working gas pressure from 0.27 to 1.33 Pa causes an enhancement of the atomic diffusion at the NiFe/FeMn interfaces, an effect more pronounced at the top FeMn/NiFe interface. In particular, this atomic diffusion provokes a formation of non-uniform magnetic dead-layers at the NiFe/FeMn interfaces (NiFeMn regions with paramagnetic or weak antiferromagnetic properties); that are responsible for the substantial reduction of the exchange bias field in the NiFe/FeMn system. Thus, this work generically helps to understand the discrepancies found in the literature regarding the influence of the interface broadening on the exchange bias properties (e.g., exchange bias field) of the NiFe/FeMn system. - Highlights: • Roughness and atomic diffusion contributions to the interface broadening • Clarification of the exchange bias field dependence on the interface disorder • Ferromagnetic, paramagnetic and antiferromagnetic phases at the magnetic interface • Magnetic dead layers formed by increasing the argon work pressure • Atomic diffusion in heterostructures prepared at higher argon pressure.

Formulation of enzyme blends to maximize the hydrolysis of alkaline peroxide pretreated alfalfa hay and barley straw by rumen enzymes and commercial cellulases.

Science.gov (United States)

Badhan, Ajay; Wang, Yuxi; Gruninger, Robert; Patton, Donald; Powlowski, Justin; Tsang, Adrian; McAllister, Tim

2014-04-26

Efficient conversion of lignocellulosic biomass to fermentable sugars requires the synergistic action of multiple enzymes; consequently enzyme mixtures must be properly formulated for effective hydrolysis. The nature of an optimal enzyme blends depends on the type of pretreatment employed as well the characteristics of the substrate. In this study, statistical experimental design was used to develop mixtures of recombinant glycosyl hydrolases from thermophilic and anaerobic fungi that enhanced the digestion of alkaline peroxide treated alfalfa hay and barley straw by mixed rumen enzymes as well as commercial cellulases (Accelerase 1500, A1500; Accelerase XC, AXC). Combinations of feruloyl and acetyl xylan esterases (FAE1a; AXE16A_ASPNG), endoglucanase GH7 (EGL7A_THITE) and polygalacturonase (PGA28A_ASPNG) with rumen enzymes improved straw digestion. Inclusion of pectinase (PGA28A_ASPNG), endoxylanase (XYN11A_THITE), feruloyl esterase (FAE1a) and β-glucosidase (E-BGLUC) with A1500 or endoglucanase GH7 (EGL7A_THITE) and β-xylosidase (E-BXSRB) with AXC increased glucose release from alfalfa hay. Glucose yield from straw was improved when FAE1a and endoglucanase GH7 (EGL7A_THITE) were added to A1500, while FAE1a and AXE16A_ASPNG enhanced the activity of AXC on straw. Xylose release from alfalfa hay was augmented by supplementing A1500 with E-BGLUC, or AXC with EGL7A_THITE and XYN11A_THITE. Adding arabinofuranosidase (ABF54B_ASPNG) and esterases (AXE16A_ASPNG; AXE16B_ASPNG) to A1500, or FAE1a and AXE16A_ASPNG to AXC enhanced xylose release from barley straw, a response confirmed in a scaled up assay. The efficacy of commercial enzyme mixtures as well as mixed enzymes from the rumen was improved through formulation with synergetic recombinant enzymes. This approach reliably identified supplemental enzymes that enhanced sugar release from alkaline pretreated alfalfa hay and barley straw.

Estado nutricional y aspectos alimentarios de mujeres indígenas del departamento de Presidente Hayes, Paraguay

OpenAIRE

Gloria Echagüe; Valentina Díaz; Laura Mendoza; Pamela Mongelos; Graciela Giménez; Malvina Paez; Florentina Laspina; Amalia Castro; María Isabel Rodríguez; Patricia Araújo; Wilberto Castro; Ramón Marecos; Santiago Evers; Gerardo Deluca; Alejandra Picconi

2015-01-01

Introducción: Las comunidades indígenas presentan un mayor riesgo de inseguridad alimentaria y malnutrición, menor disponibilidad de recursos, y una creciente dependencia de alimentos más baratos aunque con un alto grado de procesamiento. Objetivo: Identificar el estado nutricional y aspectos alimentarios en mujeres indígenas de tres comunidades del Departamento de Presidente Hayes, Chaco Paraguayo. Metodología: Estudio observacional de diseño transversal con componente analítico, que incluyó...

Point defects in B.C.C. Fe-Al, Fe-Co, and Fe-Co-V ordered alloys

International Nuclear Information System (INIS)

Riviere, J.P.; Dinhut, J.F.

1982-01-01

Radiation damage produced at 20 K by 2.5 MeV electrons is studied in three B 2 type Fe-40 at % Al, Fe-Co, Fe-Co-V ordered alloys. The resistivity damage in Fe-40 at % Al ordered single crystals is found less effective in the directions. The results suggest that replacement collision chains are difficult to propagate along the direction. Frenkel pair creation superimposed with disordering can account for the resistivity damage in the initially ordered Fe-Co alloy. Informations concerning replacement collision sequences in direction are derived. During the recovery of all the alloys, three main stages are observed and an ordering enhancement occurs. (author)

Thermodynamics of the Mo-Fe-C and W-Fe-C systems

International Nuclear Information System (INIS)

Kleykamp, H.

1978-01-01

A study on the reaction behaviour of the components of the Mo 2 C-Fe and WC-Fe systems is presented. Both systems are stable if the mono-phase carbides are in equilibrium with the Fe-C solid solution within fixed carbon concentrations, the limits of which are calculated in this paper. Gibbs energies of formation at 1273 K of the intermetallic phases, of the binary and of the ternary carbides in the Mo-Fe-C and W-Fe-C systems were determined. The Fe corner in the phase diagrams of both systems and the calculated C boundaries in the two-phase field γ-Fe(Mo,C)-Mo 2 C and the γ-Fe(W,C)-WC, respectively, based on this study, are shown in figures. (GSC) [de

Construyendo buenos ciudadanos con buenas prácticas en salud: dengue e influenza AH1N1 en Cali, Colombia

Directory of Open Access Journals (Sweden)

Alejandro Arango

2013-06-01

Full Text Available Este artículo discute la relación entre la dimensión biológica de las enfermedades y los hábitos de auto-cuidado o “conductas saludables”. Su pregunta central indaga por cómo un fenómeno aparentemente biológico genera ciertas “buenas prácticas” en torno a la salud, defendiendo la idea de la enfermedad como un asunto socio-cultura, más que un mero hecho biológico. El estudio aquí presentado se apoya en una investigación realizada en la ciudad de Cali y enfocada en dos enfermedades, dengue e influenza AH1N1, entre 2009 y 2010. El examen de la relevancia adquirida por estas dos dolencias, mostrará cómo la biología y las prácticas de auto-cuidado tienen una estrecha relación entre sí.

Tesis doctoral: Buenas prácticas de gestión, satisfacción laboral, Burnout e intención de abandono en profesionales del sector del fitness

OpenAIRE

Barranco Gil, David

2013-01-01

Introducción: El sector del fitness en España se está convirtiendo en una de las alternativas de práctica de actividad física más comunes. Por este motivo, parece de especial interés el conocer el estado de los recursos humanos que desempeñan su labor profesional en este sector. La finalidad principal de esta investigación fue la de determinar la interacción entre la presencia de buenas prácticas de gestión relacionadas con los recursos humanos, el síndrome de Burnout, los niveles de satisfac...

Transferencia de buenas prácticas sobre gestión de recursos humanos en empresas españolas en el Golfo Pérsico o Arábigo

OpenAIRE

García Ramírez, María José

2015-01-01

La Buenas Prácticas en Gestión de Recursos Humanos es un tema importante en la gestión empresarial, clave para triunfar en el periodo de internacionalización y expatriación de las empresas. Es imprescindible la transmisión de un modelo de gestión de recursos humanos adecuado que incluya las mejores prácticas o aquellas que están dentro de los llamados sistemas STAR (Sistemas de Trabajo de Alto Rendimiento) y que representen una ventaja competitiva para la empresa. En este trabajo se plantea u...

La validez del Manual de Buenas Prácticas Comerciales para el Sector de los Supermercados y/o Similares y sus Proveedores de la Superintendencia de Control del Poder de Mercado

OpenAIRE

Cordero Cuesta, Ana Belén

2016-01-01

This academic work aims to solve the legal problematic towards the Manual de Buenas Prácticas Comerciales para el Sector de Supermercados y Proveedores legal efectiveness. Subjects such as legal capacity to legislate non technical laws, Superintendencia del Control de Poder de Mercado and Junta de Regulación´s (Antitrust Authorities) legal capacity and legal remedies in order to reestablish the legal equilibrium among others themes are adressed here. El presente trabajo aborda la problema ...

GÉNERO Y EDUCACIÓN FÍSICA. ANÁLISIS DE BUENAS PRÁCTICAS COEDUCATIVAS

Directory of Open Access Journals (Sweden)

Joaquín Piedra

2013-01-01

Full Text Available Este trabajo, dentro del proyecto de investigación TEON XXI, analiza y describe buenas prácticas de Educación Física con perspectiva de género. Aplicamos la teoría sociológica de doing gender al desarrollo de criterios sobre cómo construir una nueva cultura de género en las escuelas, implicando los planos socioculturales, relacionales e individuales en un microanálisis etnográfico. Se interpreta el ajuste entre dichas prácticas y las necesidades del contexto educativos en que tienen lugar. Se investigan cuatro modelos de prácticas, la selección muestral es de tipo teórico, aplicando una estrategia de máxima variación apoyado en un proceso de vagabundeo y localización en bola de nieve de informantes y ejemplos claves; proceso que culmina con la selección, grabación y análisis de los casos ilustrativos. Se utilizan indicadores concretos y contextualizados para a la interpretación analítica, tales como: eficacia, efecto transformador, sostenibilidad, legitimidad y replicabilidad. El trabajo de campo implica analizar fuentes documentales, así como registros de observaciones participantes y entrevistas en profundidad a expertos/as, mediante análisis de contenido. Los resultados permiten dotar al profesorado de ejemplos, pero también aportar criterios, modelos e indicadores para que el profesorado pueda reflexionar sobre la calidad y bondad de sus prácticas considerando determinadas circunstancias contextuales y necesidades específicas.

Al/Fe isomorphic substitution versus Fe{sub 2}O{sub 3} clusters formation in Fe-doped aluminosilicate nanotubes (imogolite)

Energy Technology Data Exchange (ETDEWEB)

Shafia, Ehsan [Politecnico di Torino, Department of Applied Science and Technology and INSTM Unit of Torino-Politecnico (Italy); Esposito, Serena [Università degli Studi di Cassino e del Lazio Meridionale, Department of Civil and Mechanical Engineering (Italy); Manzoli, Maela; Chiesa, Mario [Università di Torino, Dipartimento di Chimica and Centro Interdipartimentale NIS (Italy); Tiberto, Paola [Electromagnetism, I.N.Ri.M. (Italy); Barrera, Gabriele [Università di Torino, Dipartimento di Chimica and Centro Interdipartimentale NIS (Italy); Menard, Gabriel [Harvard University, Department of Chemistry and Chemical Biology (United States); Allia, Paolo, E-mail: paolo.allia@polito.it [Politecnico di Torino, Department of Applied Science and Technology and INSTM Unit of Torino-Politecnico (Italy); Freyria, Francesca S. [Massachusetts Institute of Technology, Department of Chemistry (United States); Garrone, Edoardo; Bonelli, Barbara, E-mail: barbara.bonelli@polito.it [Politecnico di Torino, Department of Applied Science and Technology and INSTM Unit of Torino-Politecnico (Italy)

2015-08-15

Textural, magnetic and spectroscopic properties are reported of Fe-doped aluminosilicate nanotubes (NTs) of the imogolite type, IMO, with nominal composition (OH){sub 3}Al{sub 2−x}Fe{sub x}O{sub 3}SiOH (x = 0, 0.025, 0.050). Samples were obtained by either direct synthesis (Fe-0.025-IMO, Fe-0.050-IMO) or post-synthesis loading (Fe-L-IMO). The Fe content was either 1.4 wt% (both Fe-0.050-IMO and Fe-L-IMO) or 0.7 wt% (Fe-0.025-IMO). Textural properties were characterized by High-Resolution Transmission Electron Microscopy, X-ray diffraction and N{sub 2} adsorption/desorption isotherms at 77 K. The presence of different iron species was studied by magnetic moment measurements and three spectroscopies: Mössbauer, UV–Vis and electron paramagnetic resonance, respectively. Fe{sup 3+}/Al{sup 3+} isomorphic substitution (IS) at octahedral sites at the external surface of NTs is the main process occurring by direct synthesis at low Fe loadings, giving rise to the formation of isolated high-spin Fe{sup 3+} sites. Higher loadings give rise, besides IS, to the formation of Fe{sub 2}O{sub 3} clusters. IS occurs up to a limit of Al/Fe atomic ratio of ca. 60 (corresponding to x = 0.032). A fraction of the magnetism related to NCs is pinned by the surface anisotropy; also, clusters are magnetically interacting with each other. Post-synthesis loading leads to a system rather close to that obtained by direct synthesis, involving both IS and cluster formations. Slightly larger clusters than with direct synthesis samples, however, are formed. The occurrence of IS indicates a facile cleavage/sealing of Al–O–Al bonds: this opens the possibility to exchange Al{sup 3+} ions in pre-formed IMO NTs, a much simpler procedure compared with direct synthesis.

Diffusion of Nb in Fe and in some Fe alloys

International Nuclear Information System (INIS)

Kurokawa, S.; Ruzzante, J.E.; Hey, A.M.; Dyment, F.

1981-01-01

Diffusion data of microalloying elements such as Nb, V, Ti, are required when analysing the transformation and recrystallization behaviour of HSLA steels in order to optimize grain refinement and precipitation hardening. The diffusion behaviour of Nb in pure Fe, Fe 1.5 Mn, Fe 0.6 Si and Fe 1.5 Mn 0.6 Si has been measured between 1080 and 1200 0 C. Results indicate that Si increases Nb diffusivity while Mn decreases it. The sequence of diffusion coeficients values is: D sup(Nb) sub(Fe 1.5 Mn) [pt

First principles calculations of the magnetic and hyperfine properties of Fe/N/Fe and Fe/O/Fe multilayers in the ground state of cohesive energy

Science.gov (United States)

dos Santos, A. V.; Samudio Pérez, C. A.; Muenchen, D.; Anibele, T. P.

2015-01-01

The ground state properties of Fe/N/Fe and Fe/O/Fe multilayers were investigated using the first principles calculations. The calculations were performed using the Linearized Augmented Plane Wave (LAPW) method implemented in the Wien2k code. A supercell consisting of one layer of nitride (or oxide) between two layers of Fe in the bcc structure was used to model the structure of the multilayer. The research in new materials also stimulated theoretical and experimental studies of iron-based nitrides due to their variety of structural and magnetic properties for the potential applications as in high strength steels and for high corrosion resistance. It is obvious from many reports that magnetic iron nitrides such as γ-Fe4N and α-Fe16N2 have interesting magnetic properties, among these a high magnetisation saturation and a high density crimp. However, although Fe-N films and multilayers have many potential applications, they can be produced in many ways and are being extensively studied from the theoretical point of view there is no detailed knowledge of their electronic structure. Clearly, efforts to understand the influence of the nitrogen atoms on the entire electronic structure are needed as to correctly interpret the observed changes in the magnetic properties when going from Fe-N bulk compounds to multilayer structures. Nevertheless, the N atoms are not solely responsible for electronics alterations in solid compounds. Theoretical results showed that Fe4X bulk compounds, where X is a variable atom with increasing atomic number (Z), the nature of bonding between X and adjacent Fe atoms changes from more covalent to more ionic and the magnetic moments of Fe also increase for Z=7, i.e. N. This is an indicative that atoms with a Z number higher than 7, i.e., O, can produce several new alterations in the entire magnetic properties of Fe multilayers. This paper presents the first results of an ab-initio electronic structure calculations, performed for Fe-N and Fe

Influence of the surface topography, morphology and structure on magnetic properties of ion beam sputtered iron layers, Fe/Cr/Fe- and Fe/MgO/Fe multilayers; Untersuchung der Morphologie und magnetische Eigenschaften von ionenstrahl-gesputterten Eisen-Einzelschichten, Fe/Cr/Fe- und Fe/MgO/Fe-Schichtsystemen

Energy Technology Data Exchange (ETDEWEB)

Steeb, Alexandra

2007-04-05

In this PhD Thesis, the influence of the surface topography, morphology and structure on magnetic properties of ion beam sputtered iron layers on GaAs is examined. To analyze the structure of the produced iron films, low energy electron diffraction and scanning tunneling microscopy is employed. The utilized methods to investigate the magnetic properties are Kerr- and SQUID-magnetometry and ferromagnetic resonance. It is demonstrated that on untreated as well as on presputtered and heated GaAs substrates the sputtered iron films grow epitaxially. The least surface roughness of 1 A exhibit iron films grown on untreated GaAs, while iron films on heated GaAs have the highest roughness of 30 A. The largest crystal anisotropy constant is found for the presputtered GaAs/Fe-System. For this preparation method, two monolayers of iron are determined to be magnetically dead layers. At a film thickness of 100 A, 83% of the value for saturation magnetization of bulk iron are achieved. The small observed FMR-linewidths confirm the good bulk properties of the ion beam sputtered iron. Furthermore, an antiferromagnetic interlayer exchange coupling in sputtered Fe/Cr/Fe-films was achieved. For a thickness of 12 to 17 A of the chrome interlayer, a coupling strength up to 0.2 mJ/m{sup 2} is found. To account for the small coupling strength, a strong intermixing at the interface is assumed. Finally, epitaxial Fe/MgO/Fe/FeMn multilayers are deposited on GaAs. After the structuring, it is possible to detect tunneling processes in the tunneling contacts with current-voltage measurements. The tunnel magneto resistance values of 2% are small, which can be explained by the absence of sharp, well-defined interfaces between the Fe/FeMn and the Fe/MgO interfaces. These results demonstrate, that analog to MBE the ion beam sputtering method realizes good magnetic bulk properties. However, interface sensitive phenomena are weakened because of a strong intermixing at the interfaces. (orig.)

Fe65-PTB2 Dimerization Mimics Fe65-APP Interaction

Directory of Open Access Journals (Sweden)

Lukas P. Feilen

2017-05-01

Full Text Available Physiological function and pathology of the Alzheimer’s disease causing amyloid precursor protein (APP are correlated with its cytosolic adaptor Fe65 encompassing a WW and two phosphotyrosine-binding domains (PTBs. The C-terminal Fe65-PTB2 binds a large portion of the APP intracellular domain (AICD including the GYENPTY internalization sequence fingerprint. AICD binding to Fe65-PTB2 opens an intra-molecular interaction causing a structural change and altering Fe65 activity. Here we show that in the absence of the AICD, Fe65-PTB2 forms a homodimer in solution and determine its crystal structure at 2.6 Å resolution. Dimerization involves the unwinding of a C-terminal α-helix that mimics binding of the AICD internalization sequence, thus shielding the hydrophobic binding pocket. Specific dimer formation is validated by nuclear magnetic resonance (NMR techniques and cell-based analyses reveal that Fe65-PTB2 together with the WW domain are necessary and sufficient for dimerization. Together, our data demonstrate that Fe65 dimerizes via its APP interaction site, suggesting that besides intra- also intermolecular interactions between Fe65 molecules contribute to homeostatic regulation of APP mediated signaling.

Fe65-PTB2 Dimerization Mimics Fe65-APP Interaction.

Science.gov (United States)

Feilen, Lukas P; Haubrich, Kevin; Strecker, Paul; Probst, Sabine; Eggert, Simone; Stier, Gunter; Sinning, Irmgard; Konietzko, Uwe; Kins, Stefan; Simon, Bernd; Wild, Klemens

2017-01-01

Physiological function and pathology of the Alzheimer's disease causing amyloid precursor protein (APP) are correlated with its cytosolic adaptor Fe65 encompassing a WW and two phosphotyrosine-binding domains (PTBs). The C-terminal Fe65-PTB2 binds a large portion of the APP intracellular domain (AICD) including the GYENPTY internalization sequence fingerprint. AICD binding to Fe65-PTB2 opens an intra-molecular interaction causing a structural change and altering Fe65 activity. Here we show that in the absence of the AICD, Fe65-PTB2 forms a homodimer in solution and determine its crystal structure at 2.6 Å resolution. Dimerization involves the unwinding of a C-terminal α-helix that mimics binding of the AICD internalization sequence, thus shielding the hydrophobic binding pocket. Specific dimer formation is validated by nuclear magnetic resonance (NMR) techniques and cell-based analyses reveal that Fe65-PTB2 together with the WW domain are necessary and sufficient for dimerization. Together, our data demonstrate that Fe65 dimerizes via its APP interaction site, suggesting that besides intra- also intermolecular interactions between Fe65 molecules contribute to homeostatic regulation of APP mediated signaling.

The Hayes principles: learning from the national pilot of information technology and core generalisable theory in informatics.

Science.gov (United States)

de Lusignan, Simon; Krause, Paul

2010-01-01

There has been much criticism of the NHS national programme for information technology (IT); it has been an expensive programme and some elements appear to have achieved little. The Hayes report was written as an independent review of health and social care IT in England. To identify key principles for health IT implementation which may have relevance beyond the critique of NHS IT. We elicit ten principles from the Hayes report, which if followed may result in more effective IT implementation in health care. They divide into patient-centred, subsidiarity and strategic principles. The patient-centred principles are: 1) the patient must be at the centre of all information systems; 2) the provision of patient-level operational data should form the foundation - avoid the dataset mentality; 3) store health data as close to the patient as possible; 4) enable the patient to take a more active role with their health data within a trusted doctor-patient relationship. The subsidiarity principles set out to balance the local and health-system-wide needs: 5) standardise centrally - patients must be able to benefit from interoperability; 6) provide a standard procurement package and an approved process that ensures safety standards and provision of interoperable systems; 7) authorise a range of local suppliers so that health providers can select the system best meeting local needs; 8) allow local migration from legacy systems, as and when improved functionality for patients is available. And finally the strategic principles: 9) evaluate health IT systems in terms of measureable benefits to patients; 10) strategic planning of systems should reflect strategic goals for the health of patients/the population. Had the Hayes principles been embedded within our approach to health IT, and in particular to medical record implementation, we might have avoided many of the costly mistakes with the UK national programme. However, these principles need application within the modern IT

Formation mechanisms of neutral Fe layers in the thermosphere at Antarctica studied with a thermosphere-ionosphere Fe/Fe+ (TIFe) model

Science.gov (United States)

Chu, Xinzhao; Yu, Zhibin

2017-06-01

With a thermosphere-ionosphere Fe/Fe+ (TIFe) model developed from first principles at the University of Colorado, we present the first quantitative investigation of formation mechanisms of thermospheric Fe layers observed by lidar in Antarctica. These recently discovered neutral metal layers in the thermosphere between 100 and 200 km provide unique tracers for studies of fundamental processes in the space-atmosphere interaction region. The TIFe model formulates and expands the TIFe theory originally proposed by Chu et al. that the thermospheric Fe layers are produced through the neutralization of converged Fe+ layers. Through testing mechanisms and reproducing the 28 May 2011 event at McMurdo, we conceive the lifecycle of meteoric metals via deposition, transport, chemistry, and wave dynamics for thermospheric Fe layers with gravity wave signatures. While the meteor injection of iron species is negligible above 120 km, the polar electric field transports metallic ions Fe+ upward from their main deposition region into the E-F regions, providing the major source of Fe+ (and accordingly Fe) in the thermosphere. Atmospheric wave-induced vertical shears of vertical and horizontal winds converge Fe+ to form dense Fe+ layers. Direct electron-Fe+ recombination is the major channel to neutralize Fe+ layers to form Fe above 120 km. Fe layer shapes are determined by multiple factors of neutral winds, electric field, and aurora activity. Gravity-wave-induced vertical wind plays a key role in forming gravity-wave-shaped Fe layers. Aurora particle precipitation enhances Fe+ neutralization by increasing electron density while accelerating Fe loss via charge transfer with enhanced NO+ and O2+ densities.Plain Language SummaryThe discoveries of neutral metal layers reaching near 200 km in the thermosphere have significant scientific merit because such discoveries challenge the current understandings of upper atmospheric composition, chemistry, dynamics, electrodynamics, and

Effects of Fe fine powders doping on hot deformed NdFeB magnets

International Nuclear Information System (INIS)

Lin, Min; Wang, Huijie; Zheng, Jingwu; Yan, Aru

2015-01-01

The composite NdFeB magnets with blending melt-spun flakes and Fe fine powders were prepared by the hot-pressed and hot-deformed route. Characterizations of the hot-deformed NdFeB magnets affected by the doped Fe powders were tested. The doped Fe powders decrease the hot-deformed pressure when the strain is between 15 and 50%. XRD patterns show that the doped Fe powders have little influence on the c-axis alignment of hot-deformed NdFeB magnets in the press direction. The B r and the (BH) max get improved when the doped Fe powders are less than 3 wt%. The doped Fe of hot-deformed NdFeB magnets exists in the elongated state and the spherical state surrounded by the Nd-rich phase. With the Fe fraction increasing, the potential of magnet moves to the positive direction and the diameter of the Nyquist arc becomes larger, which indicate that the corrosion resistance improved effectively. The bending strength was enhanced by the elongated α-Fe phase embedded in the matrix 2:14:1 phase. - Highlights: • The doped Fe powders have little influence on the c-axis alignment of magnets. • The elongated Fe powders are more than the spherical Fe powders in the magnets. • The corrosion resistance is improved effectively with the increasing Fe fraction. • The bending strength is enhanced by the elongated α-Fe phase embedded in the matrix

Effects of Fe fine powders doping on hot deformed NdFeB magnets

Energy Technology Data Exchange (ETDEWEB)

Lin, Min, E-mail: linm@nimte.ac.cn [Ningbo Institute of Material Technology & Engineering Chinese Academy of Science, Ningbo 315201 (China); Wang, Huijie [Ningbo Jinji Strong Magnetic Material Company, Ningbo 315041 (China); Zheng, Jingwu [Zhejiang University of Technology, Hangzhou 310014 (China); Yan, Aru [Ningbo Institute of Material Technology & Engineering Chinese Academy of Science, Ningbo 315201 (China)

2015-04-01

The composite NdFeB magnets with blending melt-spun flakes and Fe fine powders were prepared by the hot-pressed and hot-deformed route. Characterizations of the hot-deformed NdFeB magnets affected by the doped Fe powders were tested. The doped Fe powders decrease the hot-deformed pressure when the strain is between 15 and 50%. XRD patterns show that the doped Fe powders have little influence on the c-axis alignment of hot-deformed NdFeB magnets in the press direction. The B{sub r} and the (BH){sub max} get improved when the doped Fe powders are less than 3 wt%. The doped Fe of hot-deformed NdFeB magnets exists in the elongated state and the spherical state surrounded by the Nd-rich phase. With the Fe fraction increasing, the potential of magnet moves to the positive direction and the diameter of the Nyquist arc becomes larger, which indicate that the corrosion resistance improved effectively. The bending strength was enhanced by the elongated α-Fe phase embedded in the matrix 2:14:1 phase. - Highlights: • The doped Fe powders have little influence on the c-axis alignment of magnets. • The elongated Fe powders are more than the spherical Fe powders in the magnets. • The corrosion resistance is improved effectively with the increasing Fe fraction. • The bending strength is enhanced by the elongated α-Fe phase embedded in the matrix.

Pr2Fe14B/α-Fe nanocomposites for thermal applications

International Nuclear Information System (INIS)

Silva, Suelanny Carvalho da

2012-01-01

In this work, Pr x Fe 94 - x B 6 (x = 6, 8, 10 and 12) nanostructured powders were prepared by a combination of hydrogenation, disproportionation, desorption and recombination (HDDR) process with high energy milling applied to the mixture of an as-cast alloy (Pr 14 Fe 80 B 6 ) and α-Fe. The produced nanoparticles showed magnetic properties comparable to those reported in hyperthermia studies. The optimal time to obtain the magnetic nanoparticles is 5 hours (at 900 rpm). It was verified that longer milling times cause an increase in carbon percentage on the particles. The carbon is derived from oleic acid added as a surfactant in the milling step. The nanocomposites exhibit coercive force ranging from 80 Oe (6.5 kAm -1 ) to 170 Oe (13.5 kAm -1 ) and magnetic moments in the range of 81 129 Am2kg -1 . From the X-ray diffraction analyses, only two phases were found in all samples: α-Fe and the magnetic phase Pr 2 Fe 14 B. Individual nanoparticles with diameter of about 20 nm were verified. The samples studied presented heating when exposed to an alternating magnetic field (f = 222 kHz e H max ∼3.7 kAm -1 ) comparable to reported in literature. Temperature variations (ΔT) of the powders were: 51 K for Pr 6 Fe 88 B 6 , 41 K for Pr 8 Fe 86 B 6 , 38 K for Pr 10 Fe 8 4 B 6 and T = 34 K for Pr 12 Fe 82 B 6 . The specific absorption rates (SARs) of the powders were 201 Wkg -1 for Pr 6 Fe 88 B 6 composition, 158 Wkg -1 on the composition Pr 8 Fe 86 B 6 , and 114 Wkg -1 for Pr 10 Fe 84 B 6 and Pr 12 Fe 82 B 6 compositions. (author)

Microstructure and properties of multiphase sintered cermets Fe-Fe2B

International Nuclear Information System (INIS)

Nowacki, J.; Klimek, L.

1998-01-01

The process of multiphase sintering of iron in the vacuum has been analysed. As a result of the process iron-iron boride cermets have been produced. Fe-Fe 2 B cermets were obtained as a result of sintering of the Fe and B pure elements in the vacuum. Attemps at sintering in the solid phase and with the participation of the liquid phase, the Fe-Fe 2 B eutectic, have been made. Metallographic qualitative and quantitative studies, X-ray structural qualitative and qauantitative analysis allowed to determine the structure of Fe 2 B cermets, as well as a description of the kinetics of quantitative changes in phase proportions in the course of sintering. It has been found that their structure varies widely depending on sintering parameters and the composition of the sinters. Measurements of the Fe-Fe 2 B cermets hardness and measurements on wear during dry friction by the pin-on-disc method have shown distinct advantages of the cermets as a modern constructional materials. The hardness of Fe-Fe 2 B cermets, depending on their chemical composition and sintering parameters, ranges widely from 150 to 1500 HV, and their resistance to wear is comparable to that of diffusively boronized steels. FeFe 2 B cermets are a composite material in which iron boride, Fe 2 B, with a hardness of about 1800 HV plays the role of the reinforcement,while iron-iron boride, Fe-Fe 2 B, with a hardness of about 500 HV plays the role of matrix. The eutectic in the spaces between iron boride grains is composed of boron solid solution plates in iron with a hardness of arround 250 HV, and iron boride, Fe 2 B, plates with a hardness of approximaly 1800 HV. The combination of such different materials, a hard reinforcement and a relatively plastic matrix produces favourable properties of the cermet thus produced high hardness (1500 HV) constant over whole cross section of the material, resistance of abrasive wear and acceptable ductility. The properties mentioned above, resulting from the cermet

Tuning high frequency magnetic properties and damping of FeGa, FeGaN and FeGaB thin films

Directory of Open Access Journals (Sweden)

Derang Cao

2017-11-01

Full Text Available A series of FeGa, FeGaN and FeGaB films with varied oblique angles were deposited by sputtering method on silicon substrates, respectively. The microstructure, soft magnetism, microwave properties, and damping factor for the films were investigated. The FeGa films showed a poor high frequency magnetic property due to the large stress itself. The grain size of FeGa films was reduced by the additional N element, while the structure of FeGa films was changed from the polycrystalline to amorphous phase by the involved B element. As a result, N content can effectively improve the magnetic softness of FeGa film, but their high frequency magnetic properties were still poor both when the N2/Ar flow rate ratio is 2% and 5% during the deposition. The additional B content significantly led to the excellent magnetic softness and the self-biased ferromagnetic resonance frequency of 1.83 GHz for FeGaB film. The dampings of FeGa films were adjusted by the additional N and B contents from 0.218 to 0.139 and 0.023, respectively. The combination of these properties for FeGa films are helpful for the development of magnetostrictive microwave devices.

Radiocaesium transfer to ewes fed contaminated hay after the Chernobyl accident: effect of vermiculite and AFCF (ammonium ferricyanoferrate) as countermeasures

International Nuclear Information System (INIS)

Daburon, F.; Archimbaud, Y.; Cousi, J.; Fayart, G.; Hoffschir, D.; Chevallereau, I.; Le Creff, H.; Gueguen, L.

1991-01-01

Contaminated hay harvested in the south-east of France in June 1986 was fed to lactating and non-lactating ewes for 50-60 days. The mean transfer coefficients observed were 0.075 days litre -1 to milk and 0.11 days kg -1 to meat. Adding vermiculite to feed pellets decreased the transfer coefficients by a factor of 2.5 to both milk and meat if given at 30 g day -1 ; a factor of 8 difference was reached using 60 g day -1 added vermiculite or 2 g day -1 ammonium ferricyanoferrate (AFCF). No adverse effects on intake rates, animal weight or milk production were observed during the administration period (90-100 days, 50-60 days during the oral contamination and 40 days during the depletion period), whatever the treatment. Three lactating goats were fed the same contaminated hay, but chopped and mixed with powdered maize, for 15 days. The mean milk transfer coefficient was lower than that for ewes at 0.032 days litre -1 . (author)

Derrame pericárdico con inminente taponamiento cardiaco secundario a inhibidor de la tirosina quinasa. Reporte de un caso

Directory of Open Access Journals (Sweden)

Andrés F. Buitrago, MD

2011-03-01

Full Text Available La leucemia es una enfermedad maligna que se caracteriza por una proliferación no controlada de una clona iniciada en una etapa precoz de la diferenciación linfoide. Es importante determinar si hay una alteración genética conocida como cromosoma Filadelfia, para pronóstico y tratamiento. El imatinib, un inhibidor de la tirosina kinasa, tiene buena respuesta terapéutica y pocos efectos adversos. Uno de frecuente aparición es la serositis manifestada como derrame pleural, aunque es de menor incidencia asociada con derrame pericárdico. El tratamiento se debe individualizar, pero en caso de inminente taponamiento cardiaco se realiza pericardiocentesis.

Interparticle interactions of FePt core and Fe{sub 3}O{sub 4} shell in FePt/Fe{sub 3}O{sub 4} magnetic nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Akbari, Hossein, E-mail: Akbari.ph@iauardabil.ac.ir [Department of Physics, Ardabil Branch, Islamic Azad University, Ardabil (Iran, Islamic Republic of); Zeynali, Hossein [Department of Physics, Kashan Branch, Islamic Azad University, Kashan (Iran, Islamic Republic of); Bakhshayeshi, Ali [Department of Physics, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of)

2016-02-22

Monodisperse FePt nanoparticles were successfully synthesized using simple wet chemical method. Fe{sub 3}O{sub 4} was used as a magnetic shell around each FePt nanoparticles. In FePt/Fe{sub 3}O{sub 4} core/shell system, core thickness is 2 nm and shell thickness varies from zero to 2.5 nm. A theoretical model presented to calculate the shell thickness dependence of Coercivity. Presented model is compared with the results from Stoner–Wohlfarth model to interpret the shell thickness dependence of Coercivity in FePt/Fe{sub 3}O{sub 4} core/shell nanoparticles. There is a difference between the results from Stoner–Wohlfarth model and experimental data when the shell thickness increases. In the presented model, the effects of interparticle exchange and random magneto crystalline anisotropy are added to the previous models of magnetization reversal for core/shell nanostructures in order to achieve a better agreement with experimental data. For magnetic shells in FePt/Fe{sub 3}O{sub 4} core/shell, effective coupling between particles increases with increasing shell thickness which leads to Coercivity destruction for stronger couplings. According to the boundary conditions, in the harder regions with higher exchange stiffness, there is small variation in magnetization and so the magnetization modes become more localized. We discussed both localized and non-localized magnetization modes. For non-zero shell thickness, non-localized modes propagate in the soft phase which effects the quality of particle exchange interactions. - Highlights: • Monodisperse FePt nanoparticles were successfully synthesized using simple wet chemical method. • Fe{sub 3}O{sub 4} was used as a magnetic shell around each FePt nanoparticles. • A theoretical model presented to calculate the shell thickness dependence of Coercivity. • Magnetic shells increase effective coupling between particles with increasing shell thickness. • Magnetization modes are more localized in the regions with

Strengthening mechanisms of Fe nanoparticles for single crystal Cu–Fe alloy

International Nuclear Information System (INIS)

Shi, Guodong; Chen, Xiaohua; Jiang, Han; Wang, Zidong; Tang, Hao; Fan, Yongquan

2015-01-01

A single crystal Cu–Fe alloy with finely dispersed precipitate Fe nanoparticles was fabricated in this study. The interface relationship of iron nanoparticle and copper matrix was analyzed with a high-resolution transmission electron microscope (HRTEM), and the effect of Fe nanoparticles on mechanical properties of single crystal Cu–Fe alloy was discussed. Results show that, the finely dispersed Fe nanoparticles can be obtained under the directional solidification condition, with the size of 5–50 nm and the coherent interface between the iron nanoparticle and the copper matrix. Single crystal Cu–Fe alloy possesses improved tensile strength of 194.64 MPa, and total elongation of 44.72%, respectively, at room temperature, in contrast to pure Cu sample. Nanoparticles which have coherent interface with matrix can improve the dislocation motion state. Some dislocations can slip through the nanoparticle along the coherent interface and some dislocations can enter into the nanoparticles. Thus to improve the tensile strength of single crystal Cu–Fe alloy without sacrificing the ductility simultaneously. Based on the above analyses, strengthening mechanisms of Fe nanoparticles for single crystal Cu–Fe alloy was described

The effect of cellulose crystallinity on the in vitro digestibility and fermentation, kinetics of meadow hay and barley, wheat and rice straws

NARCIS (Netherlands)

Cone, J.W.; Gelder, van A.H.; Fonseca, A.; Ferreira, L.M.M.; Sequeria, C.A.

2003-01-01

The effect of cellulose crystallinity on in vitro digestibility (IVD) and fermentation kinetics was investigated in samples of meadow hay and barley, wheat and rice straws. A saturated solution of potassium permanganate was used to isolate the celluloses, and their crystallinity was evaluated in a

Datura contamination of hay as the suspected cause of an extensive outbreak of impaction colic in horses : clinical communication

Directory of Open Access Journals (Sweden)

T.W. Naudé

2005-06-01

Full Text Available atura poisoning of horses is extensively reviewed. An outbreak of intractable impaction colic affecting 18 of 83 horses was stopped by withdrawing dried tef hay contaminated with young Datura plants. The dried, botanically identified Datura stramonium and D. ferox contained respectively 0.15 % mass/mass (m/m hyoscyamine as well as 0.16 % m/m hyoscine (scopolamine and only hyoscine at a concentration of 0.11 % m/m. Immature, unidentifiable plants resembling D. stramonium, contained 0.14 % m/m and 0.12 % m/m of the 2 respective tropane alkaloids. The outbreak was characterised by protracted and repeated colic attacks due to impaction of the large colon and/or caecum without any other anti-muscarinic signs. Comparative analyses of single specimens of dried seed of the 2 species collected from both fertilised and waste areas revealed that young South African Datura spp. had levels of tropane alkaloids comparable to those in the well-known toxic seed and were, consequently, equally toxic. The inherent danger of tef hay being contaminated with Datura is emphasised. To our knowledge this is the 1st field case of poisoning in horses ascribed to the vegetative parts of Datura spp.

Tissue composition of the leg and meat quality of sheep fed castor bean hulls in replacement of tifton hay

Directory of Open Access Journals (Sweden)

Stela Antas Urbano

2013-10-01

Full Text Available The effects of replacing Tifton hay with castor bean hulls (0, 33, 66 and 100% on the leg tissue composition, chemical composition, physicochemical parameters and sensorial traits of sheep meat were studied. A total of 28 non-castrated sheep averaging seven months in age with an average initial weight of 19.5±4.3 kg were assigned to a randomized block design with four treatments and seven replicates and were slaughtered after 70 days of confinement. At slaughter, body weight and leg, muscle and bone weights decreased linearly, whereas the muscle-to-bone ratio increased linearly according to the treatments. There was a quadratic effect on yellow intensity (maximum of 8.05 with replacement of 54.5% and the percentage of cooking losses (minimum of 33.8% with replacement of 45.17%. The treatment employed did not affect either the chemical composition or sensorial traits of the lamb meat. Although replacing Tifton hay with castor bean hulls alters the tissue composition of the leg as well as some physicochemical parameters of the meat, the sensory analysis indicated good acceptability of the meat, regardless of the inclusion of this byproduct.

Experimental phases diagram Zr-Fe and Zr-Sn-Fe of the Fe rich zone at a temperature of 1100oC

International Nuclear Information System (INIS)

Nieva, N.; Jimenez, J.; Gomez, A; Granovsky, M.S

2010-01-01

Zr-based alloys are frequently used in the nuclear energy industry; among these are the Zr-based Zircaloys whose main alloys are Sn and Fe. In order to experimentally evaluate part of the diagram of the binary Zr-Fe phases and the ternary Zr-Sn-Fe in the Fe-rich zone, different binary alloys in the area closest to the composition of the ZrFe 2 and Zr 6 Fe 23 compounds were designed as well as a ternary alloy of Zr-Sn-Fe in the Fe-rich region of the ternary system. All the alloys underwent a two month heat treatment at a temperature of 1100 o C. Later the phases that were present were identified using different complementary techniques (mainly X-ray diffraction and microanalysis). The clear presence of the Zr 6 Fe 23 phase was not observed in any of the alloys. A new ternary phase consisting approximately of Zr 2 0Sn 14 Fe 66 was verified in the ternary alloy

Modification of interlayer exchange coupling in Fe/V/Fe trilayers using hydrogen

Energy Technology Data Exchange (ETDEWEB)

Skoryna, J., E-mail: jskoryna@ifmpan.poznan.pl [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17 St., 60-179 Poznań (Poland); Marczyńska, A. [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17 St., 60-179 Poznań (Poland); Lewandowski, M. [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85 St., 61-614 Poznań (Poland); Smardz, L. [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17 St., 60-179 Poznań (Poland)

2015-10-05

Highlights: • Magnetic films and multilayers. • Thin films. • Hydrogen absorbing materials. • Magnetic measurements. • Exchange coupling. - Abstract: Fe/V/Fe trilayers with constant-thickness Fe and step-like wedged V sublayers were prepared at room temperature using UHV magnetron sputtering. The bottom Fe layer grows onto oxidised Si(1 0 0) substrate and shows relatively high coercivity. The top Fe layer grows on vanadium spacer and shows considerably lower coercivity. The planar growth of the Fe and V sublayers was confirmed in-situ by X-ray photoelectron spectroscopy. Results show that the Fe sublayers are weakly exchange coupled for d{sub V} > 1.4 nm. Results on the coercivity studies as a function of the V interlayer thickness show near d{sub V} ∼ 1.95 nm (∼2.45 nm) weak antiferromagnetic (ferromagnetic) coupling, respectively. The hydrogenation of the Fe/V/Fe trilayers leads to increase of the strength of the ferromagnetic interlayer exchange coupling.

Adhesive and Cohesive Strength in FeB/Fe2B Systems

Science.gov (United States)

Meneses-Amador, A.; Blancas-Pérez, D.; Corpus-Mejía, R.; Rodríguez-Castro, G. A.; Martínez-Trinidad, J.; Jiménez-Tinoco, L. F.

2018-05-01

In this work, FeB/Fe2B systems were evaluated by the scratch test. The powder-pack boriding process was performed on the surface of AISI M2 steel. The mechanical parameters, such as yield stress and Young's modulus of the boride layer, were obtained by the instrumented indentation technique. Residual stresses produced on the boride layer were estimated by using the x-ray diffraction (XRD) technique. The scratch test was performed in order to evaluate the cohesive/adhesive strength of the FeB/Fe2B coating. In addition, a numerical evaluation of the scratch test on boride layers was performed by the finite element method. Maximum principal stresses were related to the failure mechanisms observed by the experimental scratch test. Shear stresses at the interfaces of the FeB/Fe2B/substrate system were also evaluated. Finally, the results obtained provide essential information about the effect of the layer thickness, the residual stresses, and the resilience modulus on the cohesive/adhesive strength in FeB/Fe2B systems.

Protonation/reduction dynamics at the [4Fe-4S] cluster of the hydrogen-forming cofactor in [FeFe]-hydrogenases.

Science.gov (United States)

Senger, Moritz; Mebs, Stefan; Duan, Jifu; Shulenina, Olga; Laun, Konstantin; Kertess, Leonie; Wittkamp, Florian; Apfel, Ulf-Peter; Happe, Thomas; Winkler, Martin; Haumann, Michael; Stripp, Sven T

2018-01-31

The [FeFe]-hydrogenases of bacteria and algae are the most efficient hydrogen conversion catalysts in nature. Their active-site cofactor (H-cluster) comprises a [4Fe-4S] cluster linked to a unique diiron site that binds three carbon monoxide (CO) and two cyanide (CN - ) ligands. Understanding microbial hydrogen conversion requires elucidation of the interplay of proton and electron transfer events at the H-cluster. We performed real-time spectroscopy on [FeFe]-hydrogenase protein films under controlled variation of atmospheric gas composition, sample pH, and reductant concentration. Attenuated total reflection Fourier-transform infrared spectroscopy was used to monitor shifts of the CO/CN - vibrational bands in response to redox and protonation changes. Three different [FeFe]-hydrogenases and several protein and cofactor variants were compared, including element and isotopic exchange studies. A protonated equivalent (HoxH) of the oxidized state (Hox) was found, which preferentially accumulated at acidic pH and under reducing conditions. We show that the one-electron reduced state Hred' represents an intrinsically protonated species. Interestingly, the formation of HoxH and Hred' was independent of the established proton pathway to the diiron site. Quantum chemical calculations of the respective CO/CN - infrared band patterns favored a cysteine ligand of the [4Fe-4S] cluster as the protonation site in HoxH and Hred'. We propose that proton-coupled electron transfer facilitates reduction of the [4Fe-4S] cluster and prevents premature formation of a hydride at the catalytic diiron site. Our findings imply that protonation events both at the [4Fe-4S] cluster and at the diiron site of the H-cluster are important in the hydrogen conversion reaction of [FeFe]-hydrogenases.

Lattice locations and properties of Fe in Co/Fe co-implanted ZnO

DEFF Research Database (Denmark)

Gunnlaugsson, H.P.; Johnston, K.; Mølholt, T.E.

2012-01-01

The lattice locations and electronic configurations of Fe in 57Co/57Fe implanted ZnO (to (5‐6) × 1014 Fe/cm−2) have been studied by 57Fe Mössbauer emission spectroscopy. The spectra acquired upon room temperature implantation show ∼20% of the probe atoms as Fe2+ on perturbed Zn sites and the rema......The lattice locations and electronic configurations of Fe in 57Co/57Fe implanted ZnO (to (5‐6) × 1014 Fe/cm−2) have been studied by 57Fe Mössbauer emission spectroscopy. The spectra acquired upon room temperature implantation show ∼20% of the probe atoms as Fe2+ on perturbed Zn sites...... and the remaining fraction as Fe2+ in damage sites of interstitial character. After annealing at 773 K, ∼20% remain on crystalline sites, while the damage fraction has partly disappeared and instead a ∼30% fraction occurs as high‐spin Fe3+, presumably in precipitates. This suggests that precipitation of Co/Fe in ZnO...... likely takes place at relatively low temperatures, thus explaining some of the discrepancies in the literature regarding magnetic properties of 3d metal‐doped ZnO....

Moessbauer Study of Electrodeposited Fe/Fe-Oxide Multilayers

International Nuclear Information System (INIS)

Kuzmann, E.; Homonnay, Z.; Klencsar, Z.; Vertes, A.; Lakatos-Varsanyi, M.; Miko, A.; Varga, L.K.; Kalman, E.; Nagy, F.

2005-01-01

Iron has been deposited electrochemically by short current pulses in Na-saccharin containing FeII-chloride and sulphate solution electrolytes. Combined electrochemical techniques with initial pulse plating of iron nanolayer and its subsequent anodic oxidation under potential control have been used for production of Fe/Fe-oxide multilayers. 57Fe CEM spectra of pulse plated iron revealed the presence of a minor doublet attributed mainly to γ-FeOOH in addition to the dominant sextet of α-iron. In the case of anodically oxidized pulse plated iron and of samples after repeated deposition of anodically oxidized pulse plated iron an additional minor doublet, assigned to ferrous chloride, also appears in the Moessbauer spectra. A significant change in the magnetic anisotropy of α-iron was observed with the anodic oxidation. The thickness of the layers were estimated from the CEM spectrum data by a modified computer program of the Liljequist method. The coercive field and the power loss versus frequency data showed that the pulse plated iron cores are good inductive elements up to several kHz frequencies

Colorimetric determination of Fe2+/Fe3+ ratio in radioactive glasses

International Nuclear Information System (INIS)

Coleman, C.J.; Baumann, E.W.; Bibler, N.E.

1992-01-01

In the vitrification of nuclear wastes, the Fe 2+ /Fe 3+ ratio in the glass is a measure of the redox properties of the glass melt. It is necessary to measure this ratio to ensure that the melt redox properties are suitable for the glass melter. A colorimetric method for measuring the Fe 2+ /Fe 3+ ratio in highly radioactive glasses was developed and tested remotely in a shielded cell. The tests were performed on glasses similar in composition and radioactivity to those that will be produced in the Savannah River Site Defense Waste Processing Facility. The first step of the method is dissolution of finely crushed glass with a hydrofluoric/sulfuric acid mixture with ammonium vanadate added to preserve the Fe 2+ content of the glass during the dissolution. Boric acid is then added to complex fluoride and to destroy iron-fluoride complexes. After adjusting the solution to pH 5, FerroZine TM (trademark of the Hach Company, Loveland, CO) reagent is added to form a magenta-colored complex with Fe 2+ . The absorbance at 562 nm is measured by using a fiber optic-coupled photodiode array spectrophotometer. Ascorbic acid is then used to reduce all the iron in solution to Fe 2+ and the absorbance is again measured. The difference in absorbance measurements corresponds to the Fe 3+ in the sample and the Fe 2+ /Fe 3+ ratio can be calculated

Behaviour of Fe4O5-Mg2Fe2O5 solid solutions and their relation to coexisting Mg-Fe silicates and oxide phases

Science.gov (United States)

Uenver-Thiele, Laura; Woodland, Alan B.; Miyajima, Nobuyoshi; Ballaran, Tiziana Boffa; Frost, Daniel J.

2018-03-01

Experiments at high pressures and temperatures were carried out (1) to investigate the crystal-chemical behaviour of Fe4O5-Mg2Fe2O5 solid solutions and (2) to explore the phase relations involving (Mg,Fe)2Fe2O5 (denoted as O5-phase) and Mg-Fe silicates. Multi-anvil experiments were performed at 11-20 GPa and 1100-1600 °C using different starting compositions including two that were Si-bearing. In Si-free experiments the O5-phase coexists with Fe2O3, hp-(Mg,Fe)Fe2O4, (Mg,Fe)3Fe4O9 or an unquenchable phase of different stoichiometry. Si-bearing experiments yielded phase assemblages consisting of the O5-phase together with olivine, wadsleyite or ringwoodite, majoritic garnet or Fe3+-bearing phase B. However, (Mg,Fe)2Fe2O5 does not incorporate Si. Electron microprobe analyses revealed that phase B incorporates significant amounts of Fe2+ and Fe3+ (at least 1.0 cations Fe per formula unit). Fe-L2,3-edge energy-loss near-edge structure spectra confirm the presence of ferric iron [Fe3+/Fetot = 0.41(4)] and indicate substitution according to the following charge-balanced exchange: [4]Si4+ + [6]Mg2+ = 2Fe3+. The ability to accommodate Fe2+ and Fe3+ makes this potential "water-storing" mineral interesting since such substitutions should enlarge its stability field. The thermodynamic properties of Mg2Fe2O5 have been refined, yielding H°1bar,298 = - 1981.5 kJ mol- 1. Solid solution is complete across the Fe4O5-Mg2Fe2O5 binary. Molar volume decreases essentially linearly with increasing Mg content, consistent with ideal mixing behaviour. The partitioning of Mg and Fe2+ with silicates indicates that (Mg,Fe)2Fe2O5 has a strong preference for Fe2+. Modelling of partitioning with olivine is consistent with the O5-phase exhibiting ideal mixing behaviour. Mg-Fe2+ partitioning between (Mg,Fe)2Fe2O5 and ringwoodite or wadsleyite is influenced by the presence of Fe3+ and OH incorporation in the silicate phases.

57Fe Moessbauer and magnetic studies of ErFe12-xNbx

International Nuclear Information System (INIS)

Wang, J L; Campbell, S J; Cadogan, J M; Tegus, O; Edge, A V J

2005-01-01

The structural and magnetic properties of ErFe 12-x Nb x compounds (x 0.6, 0.7 and 0.8) have been investigated by x-ray diffraction, ac susceptibility and dc magnetization measurements and 57 Fe Moessbauer spectroscopy. Refinements of the x-ray diffraction patterns show that the Nb atoms preferentially occupy the 8i sites; this can be understood in the terms of enthalpy effects and differences in the metallic radii. The average Fe-Fe distance at the different sites is found to behave as d Fe-Fe (8i)> d Fe-Fe (8j)> d Fe-Fe (8f). The unit cell volume increases slightly with increasing Nb content, consistent with the larger radius of Nb compared with Fe. A spin reorientation from easy-axis at room temperature to easy-cone at low temperatures has been detected for all compounds. The spin reorientation temperatures T sr in ErFe 12-x Nb x compounds remain essentially unchanged (T sr ∼42-44 K) with increasing Nb concentration, whereas a significant decrease in T sr (T sr1 ∼236-204 K; T sr2 ∼154-94 K) is obtained in DyFe 12-x Nb x from x = 0.6 to 0.8. This can be understood by taking the different crystal-field terms responsible for the spin reorientation in the two systems into account. We find that the spin-reorientation process is particularly sensitive to the sixth-order term B 60 O 60 of the crystal field acting on the Er 3+ ion, due to its large and positive value of γ J . 57 Fe hyperfine interaction parameters and magnetic moments values have been determined for the 8i, 8j and 8f sites from the Moessbauer spectra. The weighted average 57 Fe hyperfine field values were found to follow a T 2 dependence; this suggests that a single-particle excitation mechanism is responsible for reduction of the 3d-sublattice magnetization with increasing temperature

Hyperfine fields of Fe in Nd2Fe14BandSm2Fe17N3

Science.gov (United States)

Akai, Hisazumi; Ogura, Masako

2015-03-01

High saturation magnetization of rare-earth magnets originates from Fe and the strong magnetic anisotropy stems from f-states of rare-earth elements such as Nd and Sm. Therefore the hyperfine fields of both Fe and rare-earth provide us with important pieces of information: Fe NMR enable us to detect site dependence of the local magnetic moment and magnetic anisotropy (Fe sites also contribute to the magnetic anisotropy) while rare-earth NQR directly give the information of electric field gradients (EFG) that are related to the shape of the f-electron cloud as well as the EFG produced by ligands. In this study we focus on the hyperfine fields of materials used as permanent magnets, Nd2Fe14BandSm2Fe17N3 from theoretical points of view. The detailed electronic structure together with the hyperfine interactions are discussed on the basis of the first-principles calculation. In particular, the relations between the observed hyperfine fields and the magnetic properties are studies in detail. The effects of doping of those materials by other elements such as Dy and the effects of N adding in Sm2Fe17N3 will be discussed. This work was supported by Elements Strategy Initiative Center for Magnetic Materials Project, the Ministry of Education, Culture, Sports, Science and Technology, Japan.

Ferromagnetic resonance on oxideless magnetic Fe and FeRh nanoparticles; Ferromagnetische Resonanz an oxidfreien magnetischen Fe und FeRh Nanopartikeln

Energy Technology Data Exchange (ETDEWEB)

Trunova, Anastasia

2009-05-25

This work is dedicated to investigations of structural and magnetic properties of the colloidal Fe/Fe{sub x}O{sub y} nanocubes (13 nm) and the Fe{sub x}Rh{sub 100-x} core/shell nanoparticles (2 nm). As compared with other works, where the measurements on oxidized nanoparticles were carried out, we additionally performed investigations on nanoparticles in an oxide free state. In order to make the measurements on oxide free particles possible, oxygen- and hydrogenplasma was used to remove the ligands and reduce the oxide shell of the Fe nanocubes. The oxide free Fe nanocubes were covered with a Ag/Pt protective coating to prevent them from new oxidation. This method allowed carrying out the magnetic measurements on oxide free Fe nanocubes. Micromagnetic simulations as well as simulations of the high frequency susceptibility were used for the data analysing. It was found that both the g-factor g=2.09{+-}0.01 and the anisotropy constant K{sub 4}=(4.8{+-}0.5).10{sup 4} J/m{sup 3} coincide with that of bulk iron. However, the saturation magnetization M{sub S}(5 K)=(1.2{+-}0.12).10{sup 6} A/m differs from the bulk value by 30%. The reduction by 30% compared to the bulk value in the case of nanoparticles may be caused by the following possible reasons: a) the presence of inner oxide layer (approx. 10 at.%) that cannot be reduced; b) the anti-parallel order between magnetic moments of iron core and magnetic moments of antiferomagnetic iron oxide; c) some structural changes of the surface after plasma treatment. The obtained damping parameter {alpha}=0.03{+-}0.005 is ten times larger than that of the Fe layers as it is known for nanoparticles systems in general. The core/shell Fe{sub x}Rh{sub 100-x} nanoparticles (x=80,50) were produced under Ar-atmosphere and were sealed into a quartz tube to prevent oxidation. The analysis of g-factors shows that the value for the FePh nanoparticles with Fe-rich core is larger (g=2.08{+-}0.01) than that for the nanoparticles with Rh

Valor nutritivo e utilização do feno de leucena (Leucaena leucocephala cv. Cunningham para coelhos em crescimento Nutritional feeding value and use of Leucaena hay (Leucaena leucocephala cv. Cunningham for growing rabbits

Directory of Open Access Journals (Sweden)

Denise Fontana Figueiredo

2000-05-01

Full Text Available Dois experimentos foram realizados com o objetivo de avaliar a utilização do feno de leucena (Leucaena leucocephala cv.Cunningham para coelhos em crescimento. No ensaio de digestibilidade foram utilizados 28 coelhos da raça Nova Zelândia Branco, com 40 dias de idade, distribuídos em um delineamento experimental inteiramente casualizado, com dois tratamentos e 14 repetições. Foram utilizadas duas dietas, uma referência e uma teste na qual o feno de leucena substituiu 25% da matéria seca da dieta-referência. Os teores de matéria seca digestível, matéria orgânica digestível, proteína digestível, fibra em detergente neutro digestível e energia digestível do feno de leucena foram, respectivamente, de 26,87%; 25,30%; 5,32%; 14,66% e 1.286Kcal/kg. No experimento de desempenho foram utilizados 80 coelhos da raça Nova Zelândia Branco, de 35 a 70 dias de idade. Os animais foram distribuídos num delineamento experimental inteiramente casualizado, com cinco tratamentos (cinco níveis de inclusão de feno de leucena: 0, 25, 50, 75 e 100%, em substituição ao feno de alfafa, oito repetições e dois animais por unidade experimental. Os níveis crescentes de substituição do feno de alfafa pelo feno de leucena, não afetaram o desempenho dos coelhos durante o período experimental. Os dados mostram que o feno de leucena substituiu eficientemente o feno de alfafa em dietas para coelhos em crescimento.Two trial were carried out to determine the performance of rabbits fed on diets which included Leucaena hay (Leucaena leucocephala cv. Cunninghan. Twenty-eight 40-day old White New Zealand rabbits were employed for the digestibility trial, in a completely randomized design with two treatments and 14 replications. Reference and test diets were used in which Leucaena hay replaced 25% of the dry matter in the reference diet. Digestible dry matter, digestible organic matter, digestible protein, digestible F.D.N. and digestible energy contents of

Kerr microscopy study of exchange-coupled FePt/Fe exchange spring magnets

Energy Technology Data Exchange (ETDEWEB)

Hussain, Zaineb; Kumar, Dileep [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452001 (India); Reddy, V. Raghavendra, E-mail: varimalla@yahoo.com [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452001 (India); Gupta, Ajay [Amity Center for Spintronic Materials, Amity University, Noida 201303 (India)

2017-05-15

Magnetization reversal and magnetic microstructure of top soft magnetic layer (Fe) in exchange spring coupled L1{sub 0} FePt/Fe is studied using high resolution Kerr microscopy. With remnant state of the hard magnetic layer (L1{sub 0} FePt) as initial condition, magnetization loops along with magnetic domains are recorded for the top soft magnetic layer (Fe) using Kerr microscopy. Considerable shifting of Fe layer hysteresis loop from center which is similar to exchange bias phenomena is observed. It is also observed that one can tune the magnitude of hysteresis shift by reaching the remanent state from different saturating fields (H{sub SAT}) and also by varying the angle between measuring field and H{sub SAT}. The hysteresis loops and magnetic domains of top soft Fe layer demonstrate unambiguously that soft magnetic layer at remanent state in such exchange coupled system is having unidirectional anisotropy. An analogy is drawn and the observations are explained in terms of established model of exchange bias phenomena framed for field-cooled ferromagnetic - antiferromagnetic bilayer systems. - Highlights: • Kerr microscopy of top soft magnetic Fe layer in exchange spring coupled L1{sub 0} FePt (30 nm)/Fe (22 nm) is reported. • Considerable shifting of Fe layer hysteresis loop from center which is similar to exchange bias phenomena is observed. • Tuneable nature of magnitude of hysteresis shift is shown. • It is unambiguously shown that the top soft Fe magnetic layer at remanent state is having unidirectional anisotropy.

Fe2O3/Reduced Graphene Oxide/Fe3O4 Composite in Situ Grown on Fe Foil for High-Performance Supercapacitors.

Science.gov (United States)

Zhao, Chongjun; Shao, Xiaoxiao; Zhang, Yuxiao; Qian, Xiuzhen

2016-11-09

A Fe 2 O 3 /reduced graphene oxide (RGO)/Fe 3 O 4 nanocomposite in situ grown on Fe foil was synthesized via a simple one-step hydrothermal growth process, where the iron foil served as support, reductant of graphene oxide, Fe source of Fe 3 O 4 , and also the current collector of the electrode. When it directly acted as the electrode of a supercapacitor, as-synthesized Fe 2 O 3 /RGO/Fe 3 O 4 @Fe exhibited excellent electrochemical performance with a high capability of 337.5 mF/cm 2 at 20 mA/cm 2 and a superior cyclability with 2.3% capacity loss from the 600th to the 2000th cycle.

Ferromagnetic resonance study of sputtered NiFe/V/NiFe heterostructures

Energy Technology Data Exchange (ETDEWEB)

Alayo, W., E-mail: willian.rodriguez@ufpel.edu.br [Departamento de Física – IFM, Universidade Federal de Pelotas, 96010-900 Rio Grande do Sul (Brazil); Pelegrini, F. [Instituto de Física, Universidade Federal de Goiás, Goiânia, 74001-970 (Brazil); Baggio-Saitovitch, E. [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro, RJ, 22290-180 (Brazil)

2015-03-01

The Ni{sub 81}Fe{sub 19}/V/Ni{sub 81}Fe{sub 19} heterostructures has been produced by magnetron sputtering and analyzed by ferromagnetic resonance. Two systems were investigated: the non symmetrical NiFe(50 Å)/V(t)/NiFe(30 Å) trilayers and the symmetrical NiFe(80 Å)/V(t)/NiFe(80 Å) trilayers, with variable ultrathin V thickness t. Ferromagnetic exchange coupling was evidenced for t below 10 Å by the excitation of the optic mode, in the case of the non symmetrical samples, and by the observation of a single resonance mode for the symmetrical trilayers. For larger V thickness, all samples exhibited two modes, which were attributed to the resonance of the individual NiFe layers with different effective magnetizations. The analysis with the equilibrium and resonance conditions provided the exchange coupling constants and effective magnetizations. - Highlights: • We present a study of symmetrical and non symmetrical NiFe/V/NiFe trilayers deposited on Si single crystals by ferromagnetic resonance (FMR) at room temperature. • For the non symmetrical trilayers, the FMR spectra show the optic and acoustic modes for samples with very thin V layer thicknesses, evidencing ferromagnetic exchange coupling, whereas, for larger V thickness, the spectra exhibited two well resolved modes associated to each independent NiFe layer. For the symmetrical trilayers, strong ferromagnetic exchange coupling is evidenced by the observation of a single resonance mode. • The analysis with the equilibrium condition and dispersion relation provides the exchange coupling constants and effective magnetizations.

Fe-Vacancy-Induced Ferromagnetism in Tetragonal FeSe Thin Films

International Nuclear Information System (INIS)

Yong-Feng, Li; Gui-Bin, Liu; Li-Jie, Shi; Bang-Gui, Liu

2009-01-01

Motivated by recent experiments, we investigate structural, electronic, and magnetic properties of tetragonal FeSe with Fe vacancies using the state-of-the-art first-principles method. We show that Fe vacancies tend to stay in the same one of the two sublattices and thus induce ferromagnetism in the ground-state phase. Our calculated net moment is in good agreement with the experimental data available. Therefore, the ferromagnetism observed in tetragonal FeSe thin films is explained. It could be made controllable soon for spintronic applications

Mössbauer Studies of Core-Shell FeO/Fe3O4 Nanoparticles

Science.gov (United States)

Kamzin, A. S.; Valiullin, A. A.; Khurshid, H.; Nemati, Z.; Srikanth, H.; Phan, M. H.

2018-02-01

FeO/Fe3O4 nanoparticles were synthesized by thermal decomposition. Electron microscopy revealed that these nanoparticles were of the core-shell type and had a spherical shape with an average size of 20 nm. It was found that the obtained FeO/Fe3O4 nanoparticles had exchange coupling. The effect of anisotropy on the efficiency of heating (hyperthermic effect) of FeO/Fe3O4 nanoparticles by an external alternating magnetic field was examined. The specific absorption rate (SAR) of the studied nanoparticles was 135 W/g in the experiment with an external alternating magnetic field with a strength of 600 Oe and a frequency of 310 kHz. These data led to an important insight: the saturation magnetization is not the only factor governing the SAR, and the efficiency of heating of magnetic FeO/Fe3O4 nanoparticles may be increased by enhancing the effective anisotropy. Mössbauer spectroscopy of the phase composition of the synthesized nanoparticles clearly revealed the simultaneous presence of three phases: magnetite Fe3O4, maghemite γ-Fe2O3, and wustite FeO.

Neutron irradiation effects in Fe and Fe-Cr at 300 °C

International Nuclear Information System (INIS)

Chen, Wei-Ying; Miao, Yinbin; Gan, Jian; Okuniewski, Maria A.; Maloy, Stuart A.; Stubbins, James F.

2016-01-01

Fe and Fe-Cr (Cr = 10–16 at.%) specimens were neutron-irradiated at 300 °C to 0.01, 0.1 and 1 dpa. The TEM observations indicated that the Cr significantly reduced the mobility of dislocation loops and suppressed vacancy clustering, leading to distinct damage microstructures between Fe and Fe-Cr. Irradiation-induced dislocation loops in Fe were heterogeneously observed in the vicinity of grown-in dislocations, whereas the loop distribution observed in Fe-Cr is much more uniform. Voids were observed in the irradiated Fe samples, but not in irradiated Fe-Cr samples. Increasing Cr content in Fe-Cr results in a higher density, and a smaller size of irradiation-induced dislocation loops. Orowan mechanism was used to correlate the observed microstructure and hardening, which showed that the hardening in Fe-Cr can be attributed to the formation of dislocation loops and α′ precipitates. -- Graphical abstract: Addition of Cr in Fe suppressed the mobility of mobile 1/2<111> dislocation loops and increased the proportion of immobile <100> dislocation loops, leading to a transition of loop distribution from highly heterogeneous to uniform. Display Omitted

Fe-N and (Fe, Ni)-N Fine Powders for Magnetic Recording

International Nuclear Information System (INIS)

Chen Ziyu; Li Fashen

1998-01-01

Combining Moessbauer spectroscopy with magnetic property measurement, we have studied Fe-N and (Fe, Ni)-N powders for magnetic recording. The typical particles of the core (α-Fe)/shell (γ'-Fe 4 N) structure have been successfully prepared. All the products are stabilized in a multi-organic solution. It has been found that the coercivity can be changed from 300 to 800 Oe by adjusting the shape of the particles. The special saturation magnetization of the particles can be adjusted from 120 to 180emu/g and their chemical stability is improved by substituting nickel for iron in γ'-Fe 4 N. Following experiments for corrosion resistance, it is expected that (Fe, Ni)-N and the core/shell particles will be applied as recording media in the near future

Fe-N and (Fe, Ni)-N Fine Powders for Magnetic Recording

Energy Technology Data Exchange (ETDEWEB)

Chen Ziyu; Li Fashen [Lanzhou University, Department of Physics (China)

1998-12-15

Combining Moessbauer spectroscopy with magnetic property measurement, we have studied Fe-N and (Fe, Ni)-N powders for magnetic recording. The typical particles of the core ({alpha}-Fe)/shell ({gamma}'-Fe{sub 4}N) structure have been successfully prepared. All the products are stabilized in a multi-organic solution. It has been found that the coercivity can be changed from 300 to 800 Oe by adjusting the shape of the particles. The special saturation magnetization of the particles can be adjusted from 120 to 180emu/g and their chemical stability is improved by substituting nickel for iron in {gamma}'-Fe{sub 4}N. Following experiments for corrosion resistance, it is expected that (Fe, Ni)-N and the core/shell particles will be applied as recording media in the near future.

Exchange biased FeNi/FeMn bilayers with coercivity and switching field enhanced by FeMn surface oxidation

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A. V. Svalov

2013-09-01

Full Text Available FeNi/FeMn bilayers were grown in a magnetic field and subjected to heat treatments at temperatures of 50 to 350 °C in vacuum or in a gas mixture containing oxygen. In the as-deposited state, the hysteresis loop of 30 nm FeNi layer was shifted. Low temperature annealing leads to a decrease of the exchange bias field. Heat treatments at higher temperatures in gas mixture result in partial oxidation of 20 nm thick FeMn layer leading to a nonlinear dependence of coercivity and a switching field of FeNi layer on annealing temperature. The maximum of coercivity and switching field were observed after annealing at 300 °C.

Spin-dependent electronic transport characteristics in Fe4N/BiFeO3/Fe4N perpendicular magnetic tunnel junctions

Science.gov (United States)

Yin, Li; Wang, Xiaocha; Mi, Wenbo

2018-01-01

Perpendicular magnetic tunnel junctions (MTJs) have attracted increasing attention owing to the low energy consumption and wide application prospects. Herewith, against Julliere's formula, an inverse tunnel magnetoresistance (TMR) appears in tetragonal Fe4N/BiFeO3/Fe4N perpendicular MTJs, which is attributed to the binding between the interface resonant tunneling state and central (bordered) hot spots. Especially, antiferromagnetic BiFeO3 shows an extra spin-polarized resonant state in the barrier, which provides a magnetic-barrier factor to affect the tunneling transport in MTJs. Meanwhile, due to the spin-polarized transport in Fe4N/BiFeO3/Fe4N MTJs, the sign of TMR can be tuned by the applied bias. The tunable TMR and resonant magnetic barrier effect pave the way for clarifying the tunneling transport in other junctions and spintronic devices.

The Hayes principles: learning from the national pilot of information technology and core generalisable theory in informatics

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Simon de Lusignan

2010-06-01

Conclusions Had the Hayes principles been embedded within our approach to health IT, and in particular to medical record implementation, we might have avoided many of the costly mistakes with the UK national programme. However, these principles need application within the modern IT environment. Closeness to the patient must not be interpreted as physical but instead as a virtual patient-centred space; data will be secure within the cloud and we should dump the vault and infrastructure mentality. Health IT should be developed as an adaptive ecosystem.

Effect of Fe-Mn addition on microstructure and magnetic properties of NdFeB magnetic powders

Science.gov (United States)

Kurniawan, C.; Purba, A. S.; Setiadi, E. A.; Simbolon, S.; Warman, A.; Sebayang, P.

2018-03-01

In this paper, the effect of Fe-Mn alloy addition on microstructures and magnetic properties of NdFeB magnetic powders was investigated. Varied Fe-Mn compositions of 1, 5, and 10 wt% were mixed with commercial NdFeB type MQA powders for 15 minutes using shaker mill. The characterizations were performed by powder density, PSA, XRD, SEM, and VSM. The Fe-Mn addition increased the powder density of NdFeB/Fe-Mn powders. On the other side, particle size distribution slightly decreased as the Fe-Mn composition increases. Magnetic properties of NdFeB/Fe-Mn powders changed with the increasing of Fe-Mn content. SEM analysis showed the particle size of NdFeB/Fe-Mn powder was smaller as the Fe-Mn composition increases. It showed that NdFeB/Fe-Mn particles have different size and shape for NdFeB and Fe-Mn particles separately. The optimum magnetic properties of NdFeB/Fe-Mn powder was achieved on the 5 wt% Fe-Mn composition with remanence M r = 49.45 emu/g, coercivity H c = 2.201 kOe, and energy product, BH max = 2.15 MGOe.

Ab initio calculations of the Fe(II) and Fe(III) isotopic effects in citrates, nicotianamine, and phytosiderophore, and new Fe isotopic measurements in higher plants

Science.gov (United States)

Moynier, Frédéric; Fujii, Toshiyuki; Wang, Kun; Foriel, Julien

2013-05-01

Iron is one of the most abundant transition metal in higher plants and variations in its isotopic compositions can be used to trace its utilization. In order to better understand the effect of plant-induced isotopic fractionation on the global Fe cycling, we have estimated by quantum chemical calculations the magnitude of the isotopic fractionation between different Fe species relevant to the transport and storage of Fe in higher plants: Fe(II)-citrate, Fe(III)-citrate, Fe(II)-nicotianamine, and Fe(III)-phytosiderophore. The ab initio calculations show firstly, that Fe(II)-nicotianamine is ˜3‰ (56Fe/54Fe) isotopically lighter than Fe(III)-phytosiderophore; secondly, even in the absence of redox changes of Fe, change in the speciation alone can create up to ˜1.5‰ isotopic fractionation. For example, Fe(III)-phytosiderophore is up to 1.5‰ heavier than Fe(III)-citrate2 and Fe(II)-nicotianamine is up to 1‰ heavier than Fe(II)-citrate. In addition, in order to better understand the Fe isotopic fractionation between different plant components, we have analyzed the iron isotopic composition of different organs (roots, seeds, germinated seeds, leaves and stems) from six species of higher plants: the dicot lentil (Lens culinaris), and the graminaceous monocots Virginia wild rye (Elymus virginicus), Johnsongrass (Sorghum halepense), Kentucky bluegrass (Poa pratensis), river oat (Uniola latifolia), and Indian goosegrass (Eleusine indica). The calculations may explain that the roots of strategy-II plants (Fe(III)-phytosiderophore) are isotopically heavier (by about 1‰ for the δ56Fe) than the upper parts of the plants (Fe transported as Fe(III)-citrate in the xylem or Fe(II)-nicotianamine in the phloem). In addition, we suggest that the isotopic variations observed between younger and older leaves could be explained by mixing of Fe received from the xylem and the phloem.

Análisis de impacto y potencial de transferibilidad de Buenas Prácticas latinoamericanas

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Susana Simón Tenorio

2014-06-01

Full Text Available ResumenLa escala y el rápido proceso de urbanización de América Latina suponen un reto para las políticas urbanas. El trabajo analiza la tipología, los agentes implicados y los resultados de las políticas urbanas desarrolladas desde la Conferencia de Estambul (1996 de cara a establecer un proceso de reflexión previo a la Conferencia Hábitat III que se celebrará en 2016. Para ello se han identificado  las ciudades más exitosas en el Concurso de Buenas Prácticas y se ha analizado el impacto de las experiencias y su adecuación con los problemas urbanos.Palabras clavePrograma Hábitat, indicadores urbanos, políticas urbanas, Belo Horizonte, Córdoba, Medellín, Montevideo, Santiago de Chile.AbstractThe size, as well as the fast urbanisation process in Latin-América, mean a challenge for Urban Policies. This paper analyses the typology, the skate-holders involved and the results of the developed urban policies since "The Istanbul Conference" in 1996. This is in order to establish a reflection process before the "Habitat Conference III" which will be held in 2016. To that effect, the most successful cities from the Good Practices Competition have been analysed as well as the impact of these experiences and their adequacy to the urban problems. KeywordsHabitat Program, urban indicator, urban policies, Belo Horizonte, Córdoba, Medellín, Montevideo, Santiago de Chile.

Effects of metal ions on the reactivity and corrosion electrochemistry of Fe/FeS nanoparticles.

Science.gov (United States)

Kim, Eun-Ju; Kim, Jae-Hwan; Chang, Yoon-Seok; Turcio-Ortega, David; Tratnyek, Paul G

2014-04-01

Nano-zerovalent iron (nZVI) formed under sulfidic conditions results in a biphasic material (Fe/FeS) that reduces trichloroethene (TCE) more rapidly than nZVI associated only with iron oxides (Fe/FeO). Exposing Fe/FeS to dissolved metals (Pd(2+), Cu(2+), Ni(2+), Co(2+), and Mn(2+)) results in their sequestration by coprecipitation as dopants into FeS and FeO and/or by electroless precipitation as zerovalent metals that are hydrogenation catalysts. Using TCE reduction rates to probe the effect of metal amendments on the reactivity of Fe/FeS, it was found that Mn(2+) and Cu(2+) decreased TCE reduction rates, while Pd(2+), Co(2+), and Ni(2+) increased them. Electrochemical characterization of metal-amended Fe/FeS showed that aging caused passivation by growth of FeO and FeS phases and poisoning of catalytic metal deposits by sulfide. Correlation of rate constants for TCE reduction (kobs) with electrochemical parameters (corrosion potentials and currents, Tafel slopes, and polarization resistance) and descriptors of hydrogen activation by metals (exchange current density for hydrogen reduction and enthalpy of solution into metals) showed the controlling process changed with aging. For fresh Fe/FeS, kobs was best described by the exchange current density for activation of hydrogen, whereas kobs for aged Fe/FeS correlated with electrochemical descriptors of electron transfer.

Asymmetric interfaces in Fe/Ag and Ag/Fe bilayers prepared by molecular beam evaporation

Energy Technology Data Exchange (ETDEWEB)

Tunyogi, A. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary)]. E-mail: tunyogi@rmki.kfki.hu; Paszti, F. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary); Osvath, Z. [MTA Research Institute for Technical Physics and Materials Science, P.O. Box 49, H-1525 Budapest (Hungary); Tancziko, F. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary); Major, M. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary); Szilagyi, E. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary)

2006-08-15

Single layers of Fe and Ag, as well as Fe/Ag (iron deposited first) and Ag/Fe bilayers were prepared by molecular beam evaporation onto Si. The samples were investigated with backscattering spectrometry (BS) and atomic force microscopy (AFM). BS spectra of Fe/Ag and Ag/Fe indicate a significant difference at the interface. In the case of Fe/Ag the Ag peak has a long tail at the interface, while for Ag/Fe the interface is abrupt. The tail in the Fe/Ag spectrum is too large to be caused by double or plural scattering. According to AFM, the effect of surface roughness is also negligible. In spite of the fact that Fe and Ag are completely immiscible in equilibrium, this tail, however, suggests that some Ag is located in the Fe layer. After annealing, both samples show mixing between the two layers; this is much larger again for Fe/Ag.

Influence of ruthenium ions on the precipitation of α-FeOOH, α-Fe2O3 and Fe3O4 in highly alkaline media

International Nuclear Information System (INIS)

Krehula, Stjepko; Music, Svetozar

2006-01-01

The influence of ruthenium ions on the precipitation of goethite (α-FeOOH), α-Fe 2 O 3 and Fe 3 O 4 in highly alkaline media was investigated by 57 Fe Moessbauer and FT-IR spectroscopies, thermal field emission scanning electron microscope (FE SEM) and EDS. The presence of Ru-dopant strongly affected the precipitation of α-FeOOH at highly alkaline pH, i.e. the formation of α-Fe 2 O 3 was also noticed. A decrease of hyperfine magnetic field (HMF) at RT from 35.1 T (undoped α-FeOOH) to 31.3 T for sample with [Ru]/([Ru] + [Fe]) = 0.0196 was assigned to the incorporation of ruthenium ions into the α-FeOOH structure. Moessbauer spectroscopy showed the formation of stoichiometric Fe 3 O 4 for [Ru]/([Ru] + [Fe]) = 0.0291-0.0909. α-Fe 2 O 3 and Fe 3 O 4 did not show a tendency to the formation of solid solutions with ruthenium ions. FE SEM observations of the samples showed that reference α-FeOOH sample contained acicular particles of good uniformity, which increased the length up to ∼5 times with increase of concentration of ruthenium ions. On the other hand, large octahedral Fe 3 O 4 crystals (particles) were associated with small particles of ruthenium (hydrous) oxide with a size in the range ∼100 nm or less. A possible catalytic action of ruthenium that created reduction conditions for Fe 3+ ions and formation of Fe 2+ ions for precipitation of Fe 3 O 4 was discussed

Experimental and thermodynamic assessments of substitutions in the AlFeSi, FeMnSi, FeSiZr and AlCaFeSi systems (65 wt % Si) - solidification simulation

International Nuclear Information System (INIS)

Gueneau, C.; Ansara, I.

1994-01-01

The substitutions of Al Si, Fe Mn and Fe Zr in some intermetallic compounds of the Al-Fe-Si, Fe-Mn-Si and Fe-Si-Zr systems are modelled in the Si-rich corner using a two sublattice model. The solidification paths of the studied alloys are determined at equilibrium. The ascalculated phase volume fractions of the alloys are compared to the experimental ones. Finally, a solidification simulation using the Gulliver-Scheil's model is performed in order to explain the formation of some precipitates experimentally observed. (authors). 14 figs., 19 refs

FeEDDHA-facilitated Fe uptake in relation to the behaviour of FeEDDHA components in the soil-plant system as a function of time and dosage.

OpenAIRE

Schenkeveld, W.D.C.; Temminghoff, E.J.M.; Reichwein, A.M.; Riemsdijk, van, W.H.

2010-01-01

FeEDDHA products are widely used to prevent and remedy Fe chlorosis in crops grown on calcareous soils. These products consist of a mixture of FeEDDHA components: racemic o,o-FeEDDHA, meso o,o-FeEDDHA, o,p-FeEDDHA and rest-FeEDDHA. The FeEDDHA components differ in physical and chemical properties, and as a consequence also in effectiveness as Fe fertilizer. In order to efficiently match dose, frequency and moment of FeEDDHA application with the Fe requirements of plants, it is important to un...

Enriquecimiento en Si mediante PVD de chapas magnéticas convencionales para aplicaciones a altas frecuencias

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Molina Aldareguía, J.

2000-06-01

Full Text Available The present work deals with the viability of a method for Si enrichment of conventional Fe-3%Si sheets, by means of physical vapour deposition of Si at its surface and subsequent diffusion heating. The aim is to obtain magnetic sheets with a Si content of 6.5wt%, for they show higher resistivity and null magnetostriction, leading to lower energy losses and solving the noise problems at high frequencies. The PVD deposited films, with ~5 μm thickness, show good adhesion to the substrate. Concerning the heat treatment, there is a critical heating rate between 5 and 15°/min, above which delamination of the film is observed without formation of intermetallics at the interface. At 3°/min the conditions for the formation of intermetallics are given. Direct heating up to 800°C leads to the formation of a Fe3Si(α1 surface layer, which, being brittle, does not delaminate during the heating process. Subsequent heating up to temperatures around 1200°C allows the homogenisation of the sheet composition. There is evidence of Kirkendall effect in the diffusion couple Fe3Si(α1/Fe(α, due to the fact that the diffusion of Fe in Fe3Si(α1 is faster than the diffusion of Si in Fe(α.

El presente trabajo estudia la viabilidad de un método para enriquecer en Si chapas de Fe-3%Si convencionales, depositando Si en su superficie mediante PVD y sometiéndolas a un tratamiento térmico de difusión. Se trata de obtener chapas magnéticas con un contenido en Si de un 6,5% en peso, ya que éstas presentan mayor resistividad y magnetoestricción nula, reduciendo las pérdidas y solucionando los problemas de ruido a altas frecuencias. Las capas depositadas por PVD, de espesores ~5 μm, presentan buena adherencia al substrato. En cuanto al tratamiento térmico, se observa que hay una velocidad de calentamiento crítica entre 5 y 15°/min, por encima de la cual la película se despega sin llegarse a formar intermetálicos en la intercara. A 3°/min se dan las

Movimientos sociorreligiosos y lucha política: el movimiento de 'La Buena Nueva' y la rebelión del '62 entre los Nivaclé del Chaco boreal paraguayo

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Ana María Spadaforo

1994-01-01

Full Text Available En el presente trabajo se analizan dos movimientos sociales que tuvieron lugar entre los indígenas nivaclé del Chaco paraguayo: El movimiento de La Buena Nueva acaecido durante la década del 50 y la rebelión indígena del 62. Ambos, uno desde lo religioso y el otro desde lo político, fueron respuesta a la situación de marginalidad creciente a la que se vió sometido el indígena.Se cuestionan determinadas posturas ortodoxas que tienden a ver los movimientos de tipo milenarista y de reivindicación étnica como fragmentarios, localistas y destinados al fracaso.

Synthesis and characterization of magnetic Fe/CNTs composites with controllable Fe nanoparticle concentration

International Nuclear Information System (INIS)

Zhao Fan; Duan Hongyan; Wang Weigao; Wang Jun

2012-01-01

Fe/CNTs composites, with different concentrations of Fe nanoparticles (NPs) on carbon nanotube (CNT) surfaces, were successfully fabricated via a facile solvothermal method. The lengths of CNTs are up to 10 μm and the mean diameter of the Fe nanoparticles is about 25 nm. The structures, composition and magnetic properties of the Fe/CNTs were characterized by XRD, FTIR, FE-SEM, TEM and PPMS. We found that the concentrations of Fe nanoparticles depositing on the CNTs could be controlled by adjusting the initial mass ratio of ferrocene to CNTs. The Fe/CNTs composites display good ferromagnetic properties at room temperature, with a saturation magnetization of 125 emu/g-Fe and a coercivity of 276 Oe. The Curie temperature of the sample is about 1038 K, slightly lower than that (1043 K) of the bulk iron.

Horticultura periurbana: Implementación de un programa de “buenas prácticas” en Pilar

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Luciana Galván

2010-07-01

Full Text Available La producción de verduras que se realiza en la periferia exterior del Área Metropolitana de Buenos Aires (AMBA constituye una actividad esencial a la hora de asegurar el abastecimiento alimentario cotidiano de 13 millones de habitantes. El trabajo se propone sistematizar la experiencia de implementación de un programa que se está llevando a cabo actualmente con 74 productores que se localizan en el partido de Pilar, uno de los más afectados por el avance de la urbanización. El mismo, denominado PRO.A.A.S. (Promoción de la Actividad Agropecuaria Sustentable, se ha instituido durante 2007 a través de un convenio formalizado entre la Municipalidad de Pilar y el Instituto Nacional de Tecnología Agropecuaria. Tiene como propósito que los horticultores, en su gran mayoría de origen boliviano, mejoren sus procedimientos a través de “buenas prácticas” tecno-productivas. El trabajo pretende determinar en qué medida este tipo de experiencias interpelan al investigador sobre los modos de la urbanización en una metrópolis como Buenos Aires considerando que el periurbano, un espacio de interfase urbano-rural, constituye un territorio “de borde”, con la carga simbólica y las dificultades de abordaje metodológico que su situación “transicional” trae aparejada.

Barreras para la integración de buenas prácticas con TIC. Estudio de caso.

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Siria Padilla Partida

2015-12-01

Full Text Available Esta investigación analiza las barreras u obstáculos para la integración de las buenas prácticas educativas con TIC, en la segunda más grande universidad pública de México: La Universidad de Guadalajara. Se analiza el caso del Centro Universitario de Ciencias Económico Administrativas (CUCEA, el cual es uno de los 15 centros universitarios que integran la red universitaria de la UdeG. Para esta investigación fue diseñado un cuestionario cerrado, tipo rubrica, con una escala de 5 puntos que iba desde no se ha iniciado hasta consolidado, para poder identificar cuáles eran los principales obstáculos percibidos por los profesores para integrar las TIC en las prácticas educativas. El cuestionario estuvo dividido en dos partes, la primera exploraba las barreras atribuidas a la institución educativa, y la segunda, las barreras atribuidas a los profesores. El muestreo fue representativo y aleatorio, con una muestra de 210 profesores de un total de 460. Los resultados identificaron como los mayores obstáculos: La falta de incentivos para integrar las TIC en la enseñanza con 382 puntos de un total de 1055, la falta de flexibilidad curricular con 483 puntos, y por último, la falta de confianza en la educación a distancia con 583 puntos.

ADESÃO E REAÇÕES DE USUÁRIOS AO TRATAMENTO DA MALÁRIA: IMPLICAÇÕES PARA A EDUCAÇÃO EM SAÚDE

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Annelita Almeida Oliveira Reiners

2010-01-01

Full Text Available Se trata de un estudio exploratorio descriptivo con el objetivo de describir la adhesión y las reacciones de los usuarios en relación al tratamiento contra la malaria en un municipio de Mato Grosso,Brasil. La recolección de los datos se hizo por medio de entrevistas semiestructuradas a 16 usuarios, y se analizaron utilizando el Análisis de Contenido. El estudio reveló que hay personas que adhieren en parte al tratamiento de la malaria y otras que buscan tratamientos alternativos. Los resultados mostraron que a los primeros signos y síntomas de la malaria, la mayoría de los usuarios buscan los servicios de salud, probablemente por tener conocimiento sobre la enfermedad, su transmisión y tratamiento; por la facilidad de acceso a la salud pública con diagnóstico y tratamiento gratuito, y por la buena relación con los trabajadores de la salud. Se concluyó que a pesar del éxito de algunas acciones del gobierno para controlar la malaria, hay necesidad de invertir en educación y vigilancia de la salud.

Convivencia escolar para la ciudadanía a la luz de las dimensiones declaradas por la UNESCO: percepción de los estudiantes de segundo ciclo

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Daniel Sáez Sotomayor

2018-02-01

Full Text Available El presente estudio busca evaluar la convivencia escolar para la ciudadanía en sus dimensiones de Inclusión, Democracia y Paz en estudiantes de segundo ciclo básico de dos establecimientos con indicadores de alta vulnerabilidad. Para el presente estudio se utilizó un instrumento validado por Chaparro, A., et al (2013 de la Universidad Autónoma de Baja California.La investigación es de carácter no experimental y de tipo Encuesta (Labarca, A. 2001. De acuerdo a Hernández (2000 es descriptiva. Su enfoque fue cuantitativo. La muestra de estudiantes a quienes se les aplicó el cuestionario estuvo conformada por 267 estudiantes. Como principales resultados se obtuvo que existe un trato respetuoso de los profesores a los estudiantes, que hay acciones docentes de buen trato y apoyo a estudiantes con dificultad y que existe confianza mutua entre estudiantes y docente. Como aspectos a mejorar se muestra que aun que las relaciones entre docentes y estudiantes son buenas no hay un trato equitativo con los estudiantes y no se percibe promoción de trabajo colaborativo entre estudiantes.

Víctimas y victimarios

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Luis Eduardo Morás

2014-04-01

Full Text Available Dr. Luis Eduardo Morás: Buenas noches, agradezco a los organizadores la invitación a participar de esta Jornada.Con la Dra. Mariana Malet pensamos dedicar veinte o treinta minutos cada uno, a efectos de dar dos miradas distintas sobre un mismo problema, problema que está en la tapa de todos los diarios, el gran problema de la sociedad uruguaya, problema que está muy presente en la campaña electoral, que es el tema, iba a decir menores, y ya ahí si se quiere hay una construcción sobre lo que voy a hablar. Podemos decir adolescentes en conflicto con la ley, pero en conflicto con la ley, no es sólo de los adolescentes, hay muchas otras instituciones y prácticas que están fuera de la ley.La idea mía es contextualizar desde la mirada sociológica, justamente ese problema, y luego la Dra. Malet va a hacer una mirada propia desde su disciplina y desde su práctica profesional.

Formation and stability of Fe-rich precipitates in dilute Zr(Fe) single-crystal alloys

International Nuclear Information System (INIS)

Zou, H.; Hood, G.M.; Roy, J.A.; Schultz, R.J.

1993-02-01

The formation and stability of Fe-rich precipitates in two α-Zr(Fe) single-crystal alloys with nominal compositions (I, 50 ppma Fe, and II, 650 ppma Fe) have been investigated (the maximum solid solubility of Fe in α-Zr is 180 ppma - 800 C). Optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have been used to examine the characteristics of Fe-rich precipitates. SEM and TEM micrographs show that in as-grown alloy II, Zr 2 Fe precipitates are located at 'stringers'. Precipitates were not observed in as-grown alloy I. During annealing, below the solvus, Fe diffuses to the surfaces to form Zr 3 Fe precipitates in both alloys. The precipitates on the surfaces of alloy I tend to be star-like (0001) or pyramidal (1010), and their distribution is heterogeneous. Dissolution of Zr 3 Fe surface precipitates of alloy I (annealing above the solvus) leaves precipitate-like features on the surfaces. Zr 2 Fe precipitates in as-grown alloy II can be dissolved only by β-phase annealing. (Author) 8 figs., 18 refs

FeEDDHA-facilitated Fe uptake in relation to the behaviour of FeEDDHA components in the soil-plant system as a function of time and dosage.

NARCIS (Netherlands)

Schenkeveld, W.D.C.; Temminghoff, E.J.M.; Reichwein, A.M.; Riemsdijk, van W.H.

2010-01-01

FeEDDHA products are widely used to prevent and remedy Fe chlorosis in crops grown on calcareous soils. These products consist of a mixture of FeEDDHA components: racemic o,o-FeEDDHA, meso o,o-FeEDDHA, o,p-FeEDDHA and rest-FeEDDHA. The FeEDDHA components differ in physical and chemical properties,

In vivo and in situ measurements of the digestive characteristics of sainfoin in comparison with lucerne fed to sheep as fresh forages at two growth stages and as hay.

Science.gov (United States)

Aufrère, J; Dudilieu, M; Poncet, C

2008-09-01

In vivo and in situ digestive characteristics of sainfoin (Onobrychis viciifolia L., a tannin-rich forage) and lucerne (Medicago sativa L., a tannin-free forage) were compared to evaluate the effects of condensed tannins (CT) and growth stage (vegetative v. early flowering) in experiment 1. In experiment 2, the hays of the two forages, harvested at early flowering, were compared. Ingestibility, organic matter digestibility (OMD) and nitrogen (N) retention were measured in sheep fed sainfoin and lucerne fresh forages and hays. The loss of dry matter (DM) and N from polyester bags suspended in the rumen, abomasum and small intestine was also measured using rumen fistulated sheep and other intestine fistulated sheep. Nitrogen content was lower in sainfoin than in lucerne. Content of CT in sainfoin decreased with growth stage (3.5 to 2.5 g CT/kg DM) and was lower for sainfoin hay (0.6 g CT/kg DM). Ingestibility and OMD did not differ between fresh-fed forage species. Total N tract digestibility in vivo was much lower for sainfoin than for lucerne fresh forages (mean value 0.540 v. 0.721, P forages. Nitrogen degradability in the rumen determined by the nylon bag technique (DegN) was lower for sainfoin than for lucerne when forages were studied both fresh (mean value 0.608 and 0.818, respectively) and as hays (0.631 and 0.767). The efficiency of forage N digestion (ENd) was higher for sainfoin at the vegetative stage. Compared with lucerne, sainfoin greatly increased the in situ estimate of forage N escaping the rumen but decreased its intestinal digestibility.

Identificación de factores críticos para implantar buenas prácticas agrícolas

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Nelson Gutiérrez Guzmán

2009-09-01

Full Text Available En este artículo se presenta la identificación de los factores críticos (FC que afectan la implantación de un programa de buenas prácticas agrícolas (BPA en productores de café y frutas del departamento del Huila, en Colombia, mediante la realización de un análisis factorial exploratorio utilizando como método de factorización el análisis de componentes principales (ACP; las ma- trices de datos se construyeron con los resultados de la aplicación de sendos instrumentos con estructura definida en las dos po- blaciones objeto de estudio, el instrumento Starbucks C.A.F.E. Practices –para pequeños caficultores en el caso de los producto- res de café– y EUREPGAP V2.1 Oct.2004 – Checklist-listado de verificación para frutas y hortalizas, aplicado a los productores de fruta. Los resultados de esta investigación permitieron la identificación de seis FC que deben de ser tenidos en cuenta al im- plantar un programa de BPA: infraestructura, actividades propias del proceso de producción establecido, toma y mantenimiento de registros, conciencia medioambiental, bienestar y seguridad de los trabajadores, y control de la calidad.

Fe(II)/Fe(III)-Catalyzed Intramolecular Didehydro-Diels-Alder Reaction of Styrene-ynes.

Science.gov (United States)

Mun, Hyeon Jin; Seong, Eun Young; Ahn, Kwang-Hyun; Kang, Eun Joo

2018-02-02

The intramolecular didehydro-Diels-Alder reaction of styrene-ynes was catalyzed by Fe(II) and Fe(III) to produce various naphthalene derivatives under microwave heating conditions. Mechanistic calculations found that the Fe(II) catalyst activates the styrenyl diene in an inverse-electron-demand Diels-Alder reaction, and the consecutive dehydrogenation reaction can be promoted by either Fe(II)-catalyzed direct dehydrogenation or an Fe(III)-catalyzed rearomatization/dehydrogenation pathway.

Mössbauer spectroscopic studies in U-Fe and U-Fe-Zr alloys

Energy Technology Data Exchange (ETDEWEB)

Panda, Alaka; Singh, L. Herojit; Rajagopalan, S.; Govindaraj, R., E-mail: govind@igcar.gov.in; Ramachandran, Renjith; Kalavathi, S.; Amarendra, G. [Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

2016-05-23

{sup 57}Fe Mössbauer studies have been carried out in an alloy of U and Fe with atomic percentage in the ratio of 68%:32% in order to understand the local structure and valence of Fe atoms associated with different phases that may get formed. The effect of changes in the hyperfine parameters such as isomer shift and quadrupole splitting at Fe sites due to additional alloying of Zr has been studied in an alloy of U, Fe and Zr in the ratio of 44%:33%:23% respectively with respect to that of the U-Fe alloy chosen in the present study. Possible effect of solute clustering in these systems has been addressed in an analogous alloy of uranium and zirconium using positron lifetime spectroscopy.

Reactions of laser-ablated iron atoms and cations with carbon monoxide: Infrared spectra of FeCO+, Fe(CO)2+, Fe(CO)x, and Fe(CO)x- (x=1-4) in solid neon

Science.gov (United States)

Zhou, Mingfei; Andrews, Lester

1999-06-01

Laser-ablated iron atoms, cations, and electrons have been reacted with CO molecules during condensation in excess neon. The FeCO molecule is observed at 1933.7 cm-1 in solid neon. Based on isotopic shifts and density functional calculations, the FeCO molecule has the same 3Σ- ground state in solid neon that has been observed at 1946.5 cm-1 in a recent high resolution gas phase investigation [Tanaka et al., J. Chem. Phys. 106, 2118 (1997)]. The C-O stretching vibration of the Fe(CO)2 molecule is observed at 1917.1 cm-1 in solid neon, which is in excellent agreement with the 1928.2 cm-1 gas phase value for the linear molecule. Anions and cations are also produced and trapped, absorptions at 1782.0, 1732.9, 1794.5, and 1859.7 cm-1 are assigned to the linear FeCO-, Fe(CO)2-, trigonal planar Fe(CO)3-, and C3v Fe(CO)4- anions, respectively, and 2123.0, 2134.0 cm-1 absorptions to the linear FeCO+ and Fe(CO)2+ cations. Doping these experiments with CCl4 virtually eliminates the anion absorptions and markedly increases the cation absorptions, which confirms the charge identifications. Higher iron carbonyl Fe(CO)3, Fe(CO)4, and Fe(CO)5 absorptions are produced on photolysis.

Desarrollo de materiales compuestos tipo Cermet de matriz Fe

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Gordo, E.

2004-04-01

Full Text Available The objective of this study aims to the development of Fe-matrix composites with high carbide content to achieve properties between high-speed steels (HSS and cemented carbides. Cemented carbides are harder and show higher wear resistance than HSS, but lower toughness. Besides, the substitution of Co or Ni for other binders is desirable due to the carcinogen character of these metals. In this work, a material constituted by an iron matrix and a 50 % wt of WC and TaC carbides is developed. Highenergy milling has been used to obtain composite powders presenting a good bonding and homogeneous distribution of the carbides in the matrix. Those powders were characterised and compacted by die pressing. The green compacts were sintered at different temperatures, and properties like hardness and density were determined. Also, the wear behaviour was studied and microstructural analysis by SEM was carried out to complete the study.

El objetivo de este trabajo es el desarrollo de materiales compuestos de matriz Fe con alto contenido en carburos con propiedades entre los aceros rápidos y los carburos cementados, ya que estos últimos son más duros y presentan mayor resistencia al desgaste que los primeros pero también menor tenacidad. Además, se hace deseable la sustitución de Co o Ni por otros aglomerantes debido a los riesgos medioambientales y para la salud que estos metales representan. En este trabajo se estudia la obtención de un material formado por una matriz de acero con adición de 50 % en masa de carburos de wolframio (WC y tantalio (TaC. Para ello se han utilizado técnicas de molienda de alta energía que permiten obtener un polvo compuesto con una buena unión metal-cerámica y una distribución homogénea de carburos en la matriz. Después de la caracterización del polvo compuesto se compactaron probetas en matriz uniaxial con objeto de estudiar la sinterabilidad del material. Los compactos fueron sinterizados en vacío a

Stability of the high pressure phase Fe3S2 up to Earth's core pressures in the Fe-S-O and the Fe-S-Si systems

Science.gov (United States)

Zurkowski, C. C.; Chidester, B.; Davis, A.; Brauser, N.; Greenberg, E.; Prakapenka, V. B.; Campbell, A.

2017-12-01

Earth's core is comprised of an iron-nickel alloy that contains 5-15% of a light element component. The abundance and alloying capability of sulfur, silicon and oxygen in the bulk Earth make them important core alloy candidates; therefore, the high-pressure phase equilibria of the Fe-S-O and Fe-S-Si systems are relevant for understanding the possible chemistry of Earth's core. Previously, a Fe3S2 phase was recognized as a low-pressure intermediate phase in the Fe-FeS system that is stable from 14-21 GPa, but the structure of this phase has not been resolved. We report in-situ XRD and chemical analysis of recovered samples to further examine the stability and structure of Fe3S2 as it coexists with other phases in the Fe-S-O and Fe-S-Si systems. In situ high P-T synchrotron XRD experiments were conducted in the laser-heated diamond anvil cell to determine the equilibrium phases in Fe75S7O18 and Fe80S5Si15 compositions between 30 and 174 GPa and up to 3000 K. In the S,O-rich samples, an orthorhombic Fe3S2 phase coexists with hcp-Fe, Fe3S and FeO and undergoes two monoclinic distortions between 60 and 174 GPa. In the S,Si-rich samples, the orthorhombic Fe3S2 phase was observed up to 115 GPa. With increasing pressure, the Fe3S2 phase becomes stable to higher temperatures in both compositions, suggesting possible Fe3(S,O)2 or Fe3(S,Si)2 solid solutions. SEM analysis of a laser heated Fe75S7O18 sample recovered from 40 GPa and 1450 K confirms a Fe3(S,O)2 phase with O dissolved into the structure. Based on the current melting data in the Fe-S-O and Fe-S-Si systems, the Fe3(S,O)2 stability field intersects the solidus in the outer core and could be a possible liquidus phase in Fe,S,O-rich planetary cores, whereas Fe3S is the stable sulfide at outer core pressures in Fe,S,Si-rich systems.

Moessbauer and XRD study of pulse plated Fe-P and Fe-Ni thin layers

International Nuclear Information System (INIS)

Miko, Annamaria; Kuzmann, Erno; Lakatos-Varsanyi, Magda; Kakay, Attila; Nagy, Ferenc; Varga, Lajos Karoly

2005-01-01

57 Fe conversion electron Moessbauer spectroscopy, X-ray diffraction, electrochemical and magnetic measurements were used to study pulse electroplated Fe-P and Ni-Fe coatings. XRD and 57 Fe CEMS measurements revealed the amorphous character of the novel pulse plated Fe-P alloys. CEM spectra indicated significant differences in the short range order and in the magnetic anisotropy between the Fe-P deposits pulse plated at medium long deposition time (t on = 2 ms), with short relaxation time (t off = 9 ms) and low current density (I p = 0.05 Acm -2 ) or at short deposition time (t on = 1 ms) with long relaxation time (t off = 250 ms) and high current density (I p = 1.0 Acm -2 ). The broad peaks centred around the fcc reflections in XRD of the pulse plated Ni-22 wt.% Fe deposit reflected a microcrystalline Ni-Fe alloy with a very fine, 5-8 nm, grain size. The CEM spectrum of the pulse plated Ni-22 wt.% Fe coating corresponded to a highly disordered solid solution alloy containing a minute amount of ferrihydrite. Extreme favourable soft magnetic properties were observed with these Ni-Fe and Fe-P pulse plated thin layers.

Anthelmintic effect of carob pods and sainfoin hay when fed to lambs after experimental trickle infections with Haemonchus contortus and Trichostrongylus colubriformis

Directory of Open Access Journals (Sweden)

Arroyo-Lopez Celia

2014-01-01

Full Text Available The aim of the study was to compare the in vivo anthelmintic activity of sainfoin hay (Onobrychis viciifolia and carob pod meal (Ceratonia siliqua against gastrointestinal nematodes. Seven days before infection, 64 naive lambs were assigned to four different groups: Group S received sainfoin hay and group CAR was fed with carob pods. The remaining lambs received lucerne hay (Medicago sativa and were assigned to positive (non-treated, NT and negative (treated, T control groups (treatment with albendazole. On day 0, lambs were artificially trickle infected for 6 weeks, with a mixture of infective larvae of Haemonchus contortus and Trichostrongylus colubriformis. Parasitological and pathophysiological parameters were measured repeatedly during the 2-month study. Compared to the NT group, decreases in egg excretion were observed in the CAR and S groups with significant differences only found for sainfoin (p < 0.05. At necropsy, group S showed decreases in the total worm numbers of both nematode species with significant differences for H. contortus. In contrast, no differences were noticed for the CAR group. Compared to the NT group, lower values for fecundity of female H. contortus were found in the S and CAR groups, however differences were non-significant. No differences in body weight gains were found between groups. Consistent results were found showing significantly higher packed cell volume (PCV values in the T and S groups compared to NT and CAR groups. Overall, these results confirm a positive effect associated with the feeding of lambs with tanniniferous resources on host resilience (PCV values and against gastrointestinal parasitic nematodes by affecting some biological traits of worm populations (e.g. eggs per gram of faeces and worm numbers. However, the anthelmintic effects differed between the two tannin-containing resources, which might be associated with the quantity and/or quality of secondary metabolites (condensed tannins and

Characterization of rust layer formed on Fe, Fe-Ni and Fe-Cr alloys exposed to Cl-rich environment by Cl and Fe K-edge XANES measurements

International Nuclear Information System (INIS)

Konishi, Hiroyuki; Mizuki, Jun'ichiro; Yamashita, Masato; Uchida, Hitoshi

2005-01-01

Chloride in atmosphere considerably reduces the corrosion resistance of conventional weathering steel containing a small amount of Cr. Ni is an effective anticorrosive element for improving the corrosion resistance of steel in a Cl-rich environment. In order to clarify the structure of the protective rust layer of weathering steel, Cl and Fe K-edge X-ray absorption near edge structure (XANES) spectra of atmospheric corrosion products (rust) formed on Fe, Fe-Ni and Fe-Cr alloys exposed to Cl-rich atmosphere were measured. The Fe K-XANES measurements enable the characterization of mixture of iron oxides such as rust. The chemical composition of the rust was determined by performing pattern fitting of the measured spectra. All the rust is composed mainly of goethite, akaganeite, lepidocrocite and magnetite. Among these iron oxides, akaganeite in particular is the major component in the rust. Additionally, the amount of akaganeite in the rust of Fe-Ni alloy is much greater than that in rust of Fe-Cr alloy. Akaganeite is generally considered to facilitate the corrosion of steel, but our results indicate that akaganeite in the rust of Fe-Ni alloy is quantitatively different from that in rust of Fe-Cr alloy and does not facilitate the corrosion of steel. The shoulder peak observed in Cl K-XANES spectra reveals that the rust contains a chloride other than akaganeite. The energy of the shoulder peak does not correspond to that of any well-known chlorides. In the measured spectra, there is no proof that Cl, by combining with the alloying element, inhibits the alloying element from acting in corrosion resistance. The shoulder peak appears only when the content of the alloying element is lower than a certain value. This suggests that the generation of the unidentified chloride is related to the corrosion rate of steel. (author)

Speciative Determination of Dissolved Inorganic Fe(II), Fe(III) and Total Fe in Natural Waters by Coupling CPE with FAAS

International Nuclear Information System (INIS)

Gurkan, R.; Altunay, N.

2013-01-01

A new cloud point extraction (CPE) method for the preconcentration of trace iron speciation in natural waters prior to determination by flame atomic absorption spectrometry (FAAS) was developed in the present study. In this method, Fe(II) sensitively and selectively reacts with Calcon carboxylic acid (CCA) in presence of cetylpyridinium chloride (CPC) yielding a hydrophobic complex at pH 10.5, which is then entrapped in surfactant-rich phase. Total Fe was accurately and reliably determined after the reduction of Fe(III) to Fe(II) with sulfite. The amount of Fe(III) in samples was determined from the difference between total Fe and Fe(II). CPC was used not only as an auxiliary ligand in CPE, but also as sensitivity enhancement agent in FAAS. The nonionic surfactant, polyethylene glycol tert-octylphenyl ether (Triton X-114) was used as an extracting agent. The analytical variables affecting CPE efficiency were investigated in detail. The preconcentration/enhancement factors of 50 and 82 respectively, were obtained for the preconcentration of Fe(II) with 50 mL solution. Under the optimized conditions, the detection limit of Fe(II) in linear range of 0.2-60 μg L/sup -1/ was 0.06 μg L/sup -1/. The relative standard deviation was 2.7 percentage (20 μg L/sup -1/, N: 5), recoveries for Fe(II) were in range of 99.0-102.0 percentage for all water samples including certified reference materials (CRMs). In order to verify its accuracy, two CRMs were analyzed and the results obtained were statistically in good agreement with the certified values. (author)

Sobre la determinación de la calidad de las escorias de horno alto y de las puzolanas

Directory of Open Access Journals (Sweden)

Wittekindt, W.

1964-06-01

Full Text Available Not availableEn la molienda de clínker portland con escoria de horno alto para obtener cemento portland de hierro y cemento de horno alto, uno está más seguro de la calidad del clínker que de la escoria. El análisis del clínker y el cálculo de los minerales de clínker, facilitado por este análisis, nos dice ya, en gran parte, si se puede fabricar con este clínker un cemento portland de mayor o menor resistencia, si pueden esperarse buenas resistencias iniciales o si hay que contar más bien con mayores resistencias finales, cual es la resistencia del cemento a los sulfatos, etc.

Libertad, ciencia y eficiencia: objetivos de la gerencia universitaria

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Jaime Sicard Ramírez

1997-02-01

La Reforma Educativa que implicó el intento de adecuar la preparación de las mentes a los esfuerzos de inserción colombiana dentro de la economía global, no solo no ha tenido éxito, - sino que a la par con la apertura económica, - enfrenta más obstáculos que incentivos. Mi percepción es que, el nuevo marco teórico-legal universitario ha sido manejado más por "la forma" que por su "fondo". Sigue la división absurda entre "Tecnocracia". Y los "técnicos (los que han ignorado aquello que NO HAY MAS PRACTICO QUE UNA BUENA TEORIA, insisten en la mecanización de la educación...

Properties of porous FeAlOy/FeAlx ceramic matrix composite ...

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science; Volume 36; Issue 7. Properties of porous FeAlO/FeAl ceramic matrix composite influenced by mechanical activation of FeAl powder. V Usoltsev S Tikhov A Salanov V Sadykov G Golubkova O Lomovskii. Volume 36 Issue 7 December 2013 pp 1195-1200 ...

Obtention of the TiFe compound by high-energy milling of Ti+Fe and TiH{sub 2}+Fe powder mixtures; Obtencao do composto TiFe a partir da moagem de alta energia de misturas Ti+Fe e TiH{sub 2}+Fe

Energy Technology Data Exchange (ETDEWEB)

Falcao, R.B.; Dammann, E.D.C.C.; Rocha, C.J.; Leal Neto, R.M., E-mail: railson.falcao@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencias e Tecnologia de Materiais. Lab. de Intermetalicos

2010-07-01

In this work TiFe compound was obtained by two process routes involving high-energy ball milling: mechanical alloying from Ti and Fe powders (route 1) and mechanical milling from TiH{sub 2} and Fe powders, both followed by an annealing heat treatment. Shaker and planetary ball mills were utilized for times varying from 1-25 hours. Milled and annealed powders were characterized by SEM and X-ray diffraction analyses. TiFe compound was formed in both routes. A strong powder adherence in the milling vial and balls occurred with route 1 in both mills. Powder adherence was significantly reduced by using TiH{sub 2} (route 2) mainly in the planetary mill, in spite of TiFe formation has only occurred after the annealing treatment. (author)

Spectrophotometric speciation of Fe(II) and Fe(III) using hydrazone-micelle systems and flow injections

International Nuclear Information System (INIS)

Khojali, Inas Osman

1999-04-01

Two hydrazones were synthesised, namely salicylhyrazone (SH) and trihydroxyacetophenone (THAPH) were synthesised with the objective of developing a method for determining of Fe(II) and Fe(III) in the presence of each other and hence the total iron.those hydrazones were selected so as to combine the ability of phenolic compounds to complex Fe(III) ions and the complexing characteristics of hydrazones. The complexes of Fe(II) S H and Fe(III) S H as well those of Fe(II)-THAPH and Fe(III)-THAPH had shown maximum absorbance at λ=412 nm which was not not modified by presence of micelles i.e. sodium n-dodecyl sulphate (SDS) and n-hexa dodecyl pyridinium bromide. The maximum absorbance for all complexes takes place around a neutral pH. Generally, in addition, of n-hexa dodecylpyridinium bromide to fe(II)-SH and Fe(III)-SH absorbance of the complexes increases with increasing the concentration of the micelle. The effects of the addition of sodium n-dodecyle sulphate (SDS) to Fe(III)-SH is also studied. Generally, increasing the concentration of the micelle decrease the absorbance of the complexes. To study the effect of the presence of Fe(II) and Fe(III) on the determination of each other,mixtures of Fe(II)-SH and Fe(III)-SH are studied. However, the use of ascorbic acid as a reducing reagent for Fe(III) did not produce the needed results but non reducible results, which may be due to the masking effect of ascorbic acid and thus making the metal not available to the ligand. However, conversion of Fe(II) to Fe(III) prior to the determination was avoided as this requires the use of oxidant, which will oxidise the ligand as well. To establish the condition for the maximum absorbance of THAPH complexes, the effect of the base was investigated by using sodium and ammonium hydroxide. Generally, increasing the concentration of the base decreases the abosrbance. as expected, ammonium hydroxide produced positive results than sodium hydroxide. After establishing the optimum Fi

CO-Bridged H-Cluster Intermediates in the Catalytic Mechanism of [FeFe]-Hydrogenase CaI.

Science.gov (United States)

Ratzloff, Michael W; Artz, Jacob H; Mulder, David W; Collins, Reuben T; Furtak, Thomas E; King, Paul W

2018-06-20

The [FeFe]-hydrogenases ([FeFe] H 2 ases) catalyze reversible H 2 activation at the H-cluster, which is composed of a [4Fe-4S] H subsite linked by a cysteine thiolate to a bridged, organometallic [2Fe-2S] ([2Fe] H ) subsite. Profoundly different geometric models of the H-cluster redox states that orchestrate the electron/proton transfer steps of H 2 bond activation have been proposed. We have examined this question in the [FeFe] H 2 ase I from Clostridium acetobutylicum (CaI) by Fourier-transform infrared (FTIR) spectroscopy with temperature annealing and H/D isotope exchange to identify the relevant redox states and define catalytic transitions. One-electron reduction of H ox led to formation of H red H + ([4Fe-4S] H 2+ -Fe I -Fe I ) and H red ' ([4Fe-4S] H 1+ -Fe II -Fe I ), with both states characterized by low frequency μ-CO IR modes consistent with a fully bridged [2Fe] H . Similar μ-CO IR modes were also identified for H red H + of the [FeFe] H 2 ase from Chlamydomonas reinhardtii (CrHydA1). The CaI proton-transfer variant C298S showed enrichment of an H/D isotope-sensitive μ-CO mode, a component of the hydride bound H-cluster IR signal, H hyd . Equilibrating CaI with increasing amounts of NaDT, and probed at cryogenic temperatures, showed H red H + was converted to H hyd . Over an increasing temperature range from 10 to 260 K catalytic turnover led to loss of H hyd and appearance of H ox , consistent with enzymatic turnover and H 2 formation. The results show for CaI that the μ-CO of [2Fe] H remains bridging for all of the "H red " states and that H red H + is on pathway to H hyd and H 2 evolution in the catalytic mechanism. These results provide a blueprint for designing small molecule catalytic analogs.

Magnetic and structural characterizations on nanoparticles of FePt, FeRh and their composites

International Nuclear Information System (INIS)

Ko, Hnin Yu Yu; Suzuki, Takao; Nam, Nguyen T.; Phuoc, Nguyen N.; Cao Jiangwei; Hirotsu, Yoshihiko

2008-01-01

The various compositions of FePt and FeRh nanoparticles, and their composite particles have been fabricated by the solution-phase chemical method and their magnetic properties characterized. High-resolution transmission electron microscopic observations indicate that mono-dispersed FeRh and FePt/FeRh nanoparticles are fabricated with the average size of 3-5 nm. However, larger size particles are distributed in the annealed state. From X-ray diffraction results, the as-deposited FeRh nanoparticles reveal a chemically disordered fcc structure which can be transformed into CsCl-type structure through thermal annealing. Similarly, the annealed FePt nanoparticles show the L1 0 -phase fct structure although the fcc structure is apparent in the as-deposited state. It is also found that the first time in the exchange bias effect in the composite of ferromagnetic (FePt) and anti-ferromagnetic (FeRh) nanoparticles; result in a shift of the hysteresis loop after field cooling process

Effect of monensin withdrawal on intake, digestion, and ruminal fermentation parameters by Bos taurus indicus and Bos taurus taurus steers consuming bermudagrass hay

Science.gov (United States)

Effects of monensin withdrawal and cattle subspecies on the utilization of bermudagrass hay (14.3% CP, 72.3% NDF, and 36.9% ADF) were evaluated using ruminally cannulated steers (5 Bos Taurus indicus [BI] and 5 Bos taurus taurus [BT]). Subspecies were concurrently subjected to a 2-period, 2-treatme...

Diseño e implementación de un programa de buenas prácticas de almacenamiento en una industria multinacional cosmética. Caso aplicado a productos AVON Ecuador S.A.

OpenAIRE

Pereira Ordóñez, Gabriela Soledad

2014-01-01

Para Avon, su objetivo fundamental es conseguir la satisfacción de sus representantes, y para ello tenemos presente que la calidad de los productos es primordial para que este objetivo se cumpla; por ello la compañía se ve en la obligación sobre el cumplimiento de estándares de producto como en su manejo, almacenamiento y distribución. La implementación de las Buenas Prácticas de Almacenamiento se la realizó en el Centro de Distribución Avon Ecuador, partiendo de una necesidad ...

Moessbauer and XRD study of pulse plated Fe-P and Fe-Ni thin layers

Energy Technology Data Exchange (ETDEWEB)

Miko, Annamaria [Bay Zoltan Institute for Material Science (Hungary); Kuzmann, Erno, E-mail: kuzmann@para.chem.elte.hu [Eoetvoes Lorand University, Research Group for Nuclear Methods in Structural Chemistry, Hungarian Academy of Sciences, Department of Nuclear Chemistry (Hungary); Lakatos-Varsanyi, Magda [Bay Zoltan Institute for Material Science (Hungary); Kakay, Attila [Research Institute for Solid State Physics and Optics (Hungary); Nagy, Ferenc [Eoetvoes Lorand University, Research Group for Nuclear Methods in Structural Chemistry, Hungarian Academy of Sciences, Department of Nuclear Chemistry (Hungary); Varga, Lajos Karoly [Research Institute for Solid State Physics and Optics (Hungary)

2005-09-15

{sup 57}Fe conversion electron Moessbauer spectroscopy, X-ray diffraction, electrochemical and magnetic measurements were used to study pulse electroplated Fe-P and Ni-Fe coatings. XRD and {sup 57}Fe CEMS measurements revealed the amorphous character of the novel pulse plated Fe-P alloys. CEM spectra indicated significant differences in the short range order and in the magnetic anisotropy between the Fe-P deposits pulse plated at medium long deposition time (t{sub on} = 2 ms), with short relaxation time (t{sub off} = 9 ms) and low current density (I{sub p} = 0.05 Acm{sup -2}) or at short deposition time (t{sub on} = 1 ms) with long relaxation time (t{sub off} = 250 ms) and high current density (I{sub p} = 1.0 Acm{sup -2}). The broad peaks centred around the fcc reflections in XRD of the pulse plated Ni-22 wt.% Fe deposit reflected a microcrystalline Ni-Fe alloy with a very fine, 5-8 nm, grain size. The CEM spectrum of the pulse plated Ni-22 wt.% Fe coating corresponded to a highly disordered solid solution alloy containing a minute amount of ferrihydrite. Extreme favourable soft magnetic properties were observed with these Ni-Fe and Fe-P pulse plated thin layers.

Accumulation of Fe oxyhydroxides in the Peruvian oxygen deficient zone implies non-oxygen dependent Fe oxidation

Science.gov (United States)

Heller, Maija I.; Lam, Phoebe J.; Moffett, James W.; Till, Claire P.; Lee, Jong-Mi; Toner, Brandy M.; Marcus, Matthew A.

2017-08-01

Oxygen minimum zones (OMZs) have been proposed to be an important source of dissolved iron (Fe) into the interior ocean. However, previous studies in OMZs have shown a sharp decrease in total dissolved Fe (dFe) and/or dissolved Fe(II) (dFe(II)) concentrations at the shelf-break, despite constant temperature, salinity and continued lack of oxygen across the shelf-break. The loss of both total dFe and dFe(II) suggests a conversion of the dFe to particulate form, but studies that have coupled the reduction-oxidation (redox) speciation of both dissolved and particulate phases have not previously been done. Here we have measured the redox speciation and concentrations of both dissolved and particulate forms of Fe in samples collected during the U.S. GEOTRACES Eastern tropical Pacific Zonal Transect (EPZT) cruise in 2013 (GP16). This complete data set allows us to assess possible mechanisms for loss of dFe. We observed an offshore loss of dFe(II) within the oxygen deficient zone (ODZ), where dissolved oxygen is undetectable, accompanied by an increase in total particulate Fe (pFe). Total pFe concentrations were highest in the upper ODZ. X-ray absorption spectroscopy revealed that the pFe maximum was primarily in the Fe(III) form as Fe(III) oxyhydroxides. The remarkable similarity in the distributions of total particulate iron and nitrite suggests a role for nitrite in the oxidation of dFe(II) to pFe(III). We present a conceptual model for the rapid redox cycling of Fe that occurs in ODZs, despite the absence of oxygen.

Structural and magnetic study of mechanically deformed Fe rich FeAlSi ternary alloys

International Nuclear Information System (INIS)

Legarra, E.; Apiñaniz, E.; Plazaola, F.

2012-01-01

Highlights: ► Addition of Si to binary Fe–Al alloys makes the disordering more difficult. ► Si addition opposes the large volume increase found in FeAl alloys with deformation. ► Disordering induces a redistribution of non-ferrous atoms around Fe atoms in Fe 75 Al 25−x Si x and Fe 70 Al 30−x Si x . ► Addition of Si to binary Fe 75 Al 25 and Fe 70 Al 30 alloys opposes the magnetic behavior induced by Al in the magnetism of Fe. ► Si inhibits the para-ferro transition found in Fe 60 Al 40 alloy with disordering. - Abstract: In this work we study systematically the influence of different Al/Si ratios on the magnetic and structural properties of mechanically disordered powder Fe 75 Al 25−x Si x , Fe 70 Al 30−x Si x and Fe 60 Al 40−x Si x alloys by means of Mössbauer spectroscopy, X-ray diffraction and magnetic measurements. In order to obtain different stages of disorder the alloys were deformed by different methods: crushing induction melted alloys and ball milling annealed (ordered) alloys using different number of balls and speed. X-ray and Mössbauer data show that mechanical deformation induces the disordered A2 structure in these alloys. The results indicate that addition of Si to binary Fe–Al alloys makes the disordering more difficult. In addition, X-ray diffraction patterns show that the normalized lattice parameter variation of the disordered alloys of each composition decreases monotonically with Si content, indicating clearly that Si addition opposes the large volume increase found in FeAl alloys with deformation. The study of the hyperfine fields indicates that there is a redistribution of non-ferrous atoms around Fe atoms with the disordering; indeed, there is an inversion of the behavior of the hyperfine field of the Fe atoms. On the other hand, the magnetic measurements indicate that addition of Si to binary Fe 75 Al 25 and Fe 70 Al 30 alloys opposes the magnetic behavior induced by Al in the magnetism of Fe.

Spectral distribution of Fe2+ photoionization cross section in InP:Fe

International Nuclear Information System (INIS)

Iikawa, F.

1985-01-01

Measurements of Fe 2+ ( 5 E) photoionization cross section in InP at 80 0 K, using constant current photoconductivity technique, were done. The spectrum presents a threshold energy of ∼ 0,65 eV due to the transition from Fe 2+ charge state, in the ground state, to Fe 3+ with an electron emission for the minimum conduction band. In the measurement of photoluminescence at ∼ 2 0 K, a wide emission of Fe complexe with the strong lattice interaction. In order to analyse the experimental data of Fe 2+ cross section in InP, a theoretical model was used. (M.C.K.) [pt

Insights into Resistance to Fe Deficiency Stress from a Comparative Study of In Vitro-Selected Novel Fe-Efficient and Fe-Inefficient Potato Plants

Directory of Open Access Journals (Sweden)

Georgina A. Boamponsem

2017-09-01

Full Text Available Iron (Fe deficiency induces chlorosis (IDC in plants and can result in reduced plant productivity. Therefore, development of Fe-efficient plants is of great interest. To gain a better understanding of the physiology of Fe-efficient plants, putative novel plant variants were regenerated from potato (Solanum tubersosum L. var. ‘Iwa’ callus cultures selected under Fe deficient or low Fe supply (0–5 μM Fe. Based on visual chlorosis rating (VCR, 23% of callus-derived regenerants were classified as Fe-efficient (EF and 77% as Fe-inefficient (IFN plant lines when they were grown under Fe deficiency conditions. Stem height was found to be highly correlated with internodal distance, leaf and root lengths in the EF plant lines grown under Fe deficiency conditions. In addition, compared to the IFN plant lines and control parental biotype, the EF plants including the lines named A1, B2, and B9, exhibited enhanced formation of lateral roots and root hairs as well as increased expression of ferritin (fer3 in the leaf and iron-regulated transporter (irt1 in the root. These morphological adaptations and changes in expression the fer3 and irt1 genes of the selected EF potato lines suggest that they are associated with resistance to low Fe supply stress.

Interstitial Fe in MgO

CERN Document Server

Mølholt, T E; Gunnlaugsson, H P; Svane, A; Masenda, H; Naidoo, D; Bharuth-Ram, K; Fanciulli, M; Gislason, H P; Johnston, K; Langouche, G; Ólafsson, S; Sielemann, R; Weyer, G

2014-01-01

Isolated Fe-57 atoms were studied in MgO single-crystals by emission Mossbauer spectroscopy following implantation of Mn-57 decaying to Fe-57. Four Mossbauer spectral components were found corresponding to different Fe lattice positions and/or charge states. Two components represent Fe atoms substituting Mg as Fe2+ and Fe3+, respectively; a third component is due to Fe in a strongly implantation-induced disturbed region. The fourth component, which is the focus of this paper, can be assigned to Fe at an interstitial site. Comparison of its measured isomer shift with ab initio calculations suggests that the interstitial Fe is located on, or close to, the face of the rock-salt MgO structure. To harmonize such an assignment with the measured near-zero quadrupole interaction a local motion process (cage motion) of the Fe has to be stipulated. The relation of such a local motion as a starting point for long range diffusion is discussed.

A method for determination of [Fe3+]/[Fe2+] ratio in superparamagnetic iron oxide

Science.gov (United States)

Jiang, Changzhao; Yang, Siyu; Gan, Neng; Pan, Hongchun; Liu, Hong

2017-10-01

Superparamagnetic iron oxide nanoparticles (SPION), as a kind of nanophase materials, are widely used in biomedical application, such as magnetic resonance imaging (MRI), drug delivery, and magnetic field assisted therapy. The magnetic property of SPION has close connection with its crystal structure, namely it is related to the ratio of Fe3+ and Fe2+ which form the SPION. So a simple way to determine the content of the Fe3+ and Fe2+ is important for researching the property of SPION. This review covers a method for determination of the Fe3+ and Fe2+ ratio in SPION by UV-vis spectrophotometry based the reaction of Fe2+ and 1,10-phenanthroline. The standard curve of Fe with R2 = 0.9999 is used for determination the content of Fe2+ and total iron with 2.5 mL 0.01% (w/v) SPION digested by HCl, pH = 4.30 HOAc-NaAc buffer 10 mL, 0.01% (w/v) 1,10-phenanthroline 5 mL and 10% (w/v) ascorbic acid 1 mL for total iron determine independently. But the presence of Fe3+ interfere with obtaining the actual value of Fe2+ (the error close to 9%). We designed a calibration curve to eliminate the error by devising a series of solution of different ratio of [Fe3+]/[Fe2+], and obtain the calibration curve. Through the calibration curve, the error between the measured value and the actual value can be reduced to 0.4%. The R2 of linearity of the method is 0.99441 and 0.99929 for Fe2+ and total iron respectively. The error of accuracy of recovery and precision of inter-day and intra-day are both lower than 2%, which can prove the reliability of the determination method.

Electric-field tunable perpendicular magnetic anisotropy in tetragonal Fe4N/BiFeO3 heterostructures

Science.gov (United States)

Yin, Li; Wang, Xiaocha; Mi, Wenbo

2017-07-01

Electric field control on perpendicular magnetic anisotropy (PMA) is indispensable for spintronic devices. Herewith, in tetragonal Fe4N/BiFeO3 heterostructures with the FeAFeB/Fe-O2 interface, PMA in each Fe4N layer, not merely interfacial layers, is modulated by the electric field, which is attributed to the broken spin screening of the electric field in highly spin-polarized Fe4N. Moreover, the periodical dx y+dy z+dz2 and dx y+dx2-y2 orbital-PMA oscillation enhances the interactions between adjacent FeAFeB and (FeB)2N atomic layers, which benefits the electric field modulation on PMA in the whole Fe4N atomic layers. The electric-field control on PMA in Fe4N/BiFeO3 heterostructures is favored by the electric-field-lifted potential in Fe4N.

Magnetic nanowires (Fe, Fe-Co, Fe-Ni – magnetic moment reorientation in respect of wires composition

Directory of Open Access Journals (Sweden)

Kalska-Szostko Beata

2015-03-01

Full Text Available Magnetic nanowires of Fe, Fe-Co, and Fe-Ni alloy and layered structure were prepared by electrochemical alternating current (AC deposition method. The morphology of the nanowires in and without the matrix was studied by energy dispersive X-ray spectroscopy (EDX, scanning electron microscopy (SEM, and X-ray diffraction (XRD, respectively. The wires either show strong dependence on the combination of elements deposition (alloy or layered or chemical composition (Co or Ni. The magnetic properties of the nanostructures were determined on the basis of Mössbauer spectroscopy (MS.

Fe-Impregnated Mineral Colloids for Peroxide Activation: Effects of Mineral Substrate and Fe Precursor.

Science.gov (United States)

Li, Yue; Machala, Libor; Yan, Weile

2016-02-02

Heterogeneous iron species at the mineral/water interface are important catalysts for the generation of reactive oxygen species at circumneutral pH. One significant pathway leading to the formation of such species arises from deposition of dissolved iron onto mineral colloids due to changes in redox conditions. This study investigates the catalytic properties of Fe impregnated on silica, alumina, and titania nanoparticles (as prototypical mineral colloids). Fe impregnation was carried out by immersing the mineral nanoparticles in dilute Fe(II) or Fe(III) solutions at pH 6 and 3, respectively, in an aerobic environment. The uptake of iron per unit surface area follows the order of nTiO2 > nAl2O3 > nSiO2 for both types of Fe precursors. Impregnation of mineral particles in Fe(II) solutions results in predominantly Fe(III) species due to efficient surface-mediated oxidation. The catalytic activity of the impregnated solids to produce hydroxyl radical (·OH) from H2O2 decomposition was evaluated using benzoic acid as a probe compound under dark conditions. Invariably, the rates of benzoic acid oxidation with different Fe-laden particles increase with the surface density of Fe until a critical density above which the catalytic activity approaches a plateau, suggesting active Fe species are formed predominantly at low surface loadings. The critical surface density of Fe varies with the mineral substrate as well as the aqueous Fe precursor. Fe impregnated on TiO2 exhibits markedly higher activity than its Al2O3 and SiO2 counterparts. The speciation of interfacial Fe is analyzed with diffuse reflectance UV-vis analysis and interpretation of the data in the context of benzoic oxidation rates suggests that the surface activity of the solids for ·OH generation correlates strongly with the isolated (i.e., mononuclear) Fe species. Therefore, iron dispersed on mineral colloids is a significant form of reactive iron surfaces in the aquatic environment.

Rapid thermal annealing of FePt and FePt/Cu thin films

Energy Technology Data Exchange (ETDEWEB)

Brombacher, Christoph

2011-01-10

Chemically ordered FePt is one of the most promising materials to reach the ultimate limitations in storage density of future magnetic recording devices due to its high uniaxial magnetocrystalline anisotropy and a corrosion resistance superior to rare-earth based magnets. In this study, FePt and FePt/Cu bilayers have been sputter deposited at room temperature onto thermally oxidized silicon wafers, glass substrates and self-assembled arrays of spherical SiO{sub 2} particles with diameters down to 10 nm. Millisecond flash lamp annealing, as well as conventional rapid thermal annealing was employed to induce the phase transformation from the chemically disordered A1 phase into the chemically ordered L1{sub 0} phase. The influence of the annealing temperature, annealing time and the film thickness on the ordering transformation and (001) texture evolution of FePt films with near equiatomic composition was studied. Whereas flash lamp annealed FePt films exhibit a polycrystalline morphology with high chemical L1{sub 0} order, rapid thermal annealing can lead to the formation of chemically ordered FePt films with (001) texture on amorphous SiO{sub 2}/Si substrates. The resultant high perpendicular magnetic anisotropy and large coercivities up to 40 kOe are demonstrated. Simultaneously to the ordering transformation, rapid thermal annealing to temperatures exceeding 600 C leads to a break up of the continuous FePt film into separated islands. This dewetting behavior was utilized to create regular arrays of FePt nanostructures on SiO{sub 2} particle templates with periods down to 50 nm. The addition of Cu improves the (001) texture formation and chemical ordering for annealing temperatures T{sub a} {<=}600 C. In addition, the magnetic anisotropy and the coercivity of the ternary FePtCu alloy can be effectively tailored by adjusting the Cu content. The prospects of FePtCu based exchange spring media, as well as the magnetic properties of FePtCu nanostructures fabricated

High-frequency permeability of electroplated CoNiFe and CoNiFe-C alloys

International Nuclear Information System (INIS)

Rhen, Fernando M.F.; McCloskey, Paul; O'Donnell, Terence; Roy, Saibal

2008-01-01

We have investigated CoNiFe and CoNiFe-C electrodeposited by pulse reverse plating (PRP) and direct current (DC) techniques. CoNiFe(PRP) films with composition Co 59.4 Fe 27.7 Ni 12.8 show coercivity of 95 A m -1 (1.2 Oe) and magnetization saturation flux (μ 0 M s ) of 1.8 T. Resistivity of CoNiFe (PRP) is about 24 μΩ cm and permeability remains almost constant μ r ' ∼475 up to 30 MHz with a quality factor (Q) larger than 10. Additionally, the permeability spectra analysis shows that CoNiFe exhibits a classical eddy current loss at zero bias field and ferromagnetic resonance (FMR) when biased with 0.05 T. Furthermore, a crossover between eddy current and FMR loss is observed for CoNiFe-PRP when baised with 0.05 T. DC and PRP plated CoNiFe-C, which have resistivity and permeability of 85, 38 μΩ cm, μ r '=165 and 35 with Q>10 up to 320 MHz, respectively, showed only ferromagnetic resonance losses. The ferromagnetic resonance peaks in CoNiFe and CoNiFe-C are broad and resembles a Gaussian distribution of FMR frequencies. The incorporation of C to CoNiFe reduces eddy current loss, but also reduces the FMR frequency

NifI inhibits nitrogenase by competing with Fe protein for binding to the MoFe protein

International Nuclear Information System (INIS)

Dodsworth, Jeremy A.; Leigh, John A.

2007-01-01

Reduction of substrate by nitrogenase requires direct electron transfer from the Fe protein to the MoFe protein. Inhibition of nitrogenase activity in Methanococcus maripaludis occurs when the regulatory protein NifI 1,2 binds the MoFe protein. This inhibition is relieved by 2-oxoglutarate. Here we present evidence that NifI 1,2 binding prevents association of the two nitrogenase components. Increasing amounts of Fe protein competed with NifI 1,2 , decreasing its inhibitory effect. NifI 1,2 prevented the co-purification of MoFe protein with a mutant form of the Fe protein that forms a stable complex with the MoFe protein, and NifI 1,2 was unable to bind to an AlF 4 - -stabilized Fe protein:MoFe protein complex. NifI 1,2 inhibited ATP- and MoFe protein-dependent oxidation of the Fe protein, and 2OG relieved this inhibition. These results support a model where NifI 1,2 competes with the Fe protein for binding to MoFe protein and prevents electron transfer

Silencio en la contratación. Análisis del Código Civil peruano y de la Convención de Viena sobre compraventa interna- cional de mercaderías

Directory of Open Access Journals (Sweden)

Luis Cárdenas Rodríguez

2013-03-01

Full Text Available En este trabajo se enfoca el rol del silencio en la celebración de contratos. Más que un estudio de teoría general, se busca un acer- camiento práctico a la aplicación de la normativa del Derecho peruano y de la Convención de Viena. Para ello se incluyen alusiones a pronunciamientos jurisprudenciales sobre: contratos de seguro, fianza y compraventa internacional. Se brinda especial atención a los casos donde exista un uso para el comercio o una práctica entre las partes de contratación sin respuesta expresa. Asimismo, se explica la importancia de la buena fe en la calificación del silencio circunstanciado, pues en ocasiones se deriva de ella un deber o una carga de hablar en caso de que no se quiera que se dote al silencio de valor positivo conducente a la conclusión del contrato. Finalmente, se resalta el papel de la buena fe y la costumbre en pos de una actitud flexible frente a novedosos supuestos y perma- nentes exigencias que impone la práctica.

Effect of monensin inclusion on intake, digestion, and ruminal fermentation parameters by Bos taurus indicus and Bos taurus taurus steers consuming bermudagrass hay

Science.gov (United States)

Effects of monensin inclusion and cattle subspecies on utilization of bermudagrass hay (13.7% CP, 77.3% NDF, and 38.8% ADF) were evaluated using ruminally cannulated steers (5 Bos taurus indicus [BI] and 5 Bos taurus taurus [BT]; 398 kg BW). Subspecies were concurrently subjected to a 2-period, 2-t...

Na7 [Fe2S6 ] , Na2 [FeS2 ] and Na2 [FeSe2 ] : New 'reduced' sodium chalcogenido ferrates

Science.gov (United States)

Stüble, Pirmin; Peschke, Simon; Johrendt, Dirk; Röhr, Caroline

2018-02-01

Three new 'reduced' FeII containing sodium chalcogenido ferrates were obtained applying a reductive synthetic route. The mixed-valent sulfido ferrate Na7 [Fe2S6 ] , which forms bar-shaped crystals with metallic greenish luster, was synthesized in pure phase from natural pyrite and elemental sodium at a maximum temperature of 800 °C. Its centrosymmetric triclinic structure (SG P 1 bar , a = 764.15(2), b = 1153.70(2), c = 1272.58(3) pm, α = 62.3325 (7) , β = 72.8345 (8) , γ = 84.6394 (8) ° , Z = 3, R1 = 0.0185) exhibits two crystallographically different [Fe2S6 ] 7 - dimers of edge-sharing [FeS4 ] tetrahedra, with somewhat larger Fe-S distances than in the fully oxidized FeIII dimers of e.g. Na6 [Fe2III S6 ] . In contrast to the localized AFM ordered pure di-ferrates(III), the Curie-Weiss behavior of the magnetic susceptibility proves the rarely observed valence-delocalized S = 9/2 state of the mixed-valent FeIII /FeII dimer. The nearly spin-only value of the magnetic moment combined with the chemical bonding not generally differing from that in pure ferrates(II) and (III), provides a striking argument, that the reduction of the local Fe spin moments observed in all condensed sulfido ferrate moieties is connected with the AFM spin ordering. The two isotypic ferrates(II) Na2 [FeS2 ] and Na2 [FeSe2 ] with chain-like structural units (SG Ibam, a = 643.54(8)/ 660.81(1), b = 1140.2(2)/1190.30(2) c = 562.90(6)/585.59(1) pm, Z = 4, R1 = 0.0372/0.0466) crystallize in the K2 [ZnO2 ] -type structure. Although representing merely further members of the common series of chalcogenido metallates(II) Na2 [MIIQ2 ] , these two new phases, together with Na6 [FeS4 ] and Li2 [FeS2 ] , are the only examples of pure FeII alkali chalcogenido ferrates. The new compounds allow for a general comparison of di- and chain ferrates(II) and (III) and mixed-valent analogs concerning the electronic and magnetic properties (including Heisenberg super-exchange and double-exchange interactions

Structural and magnetic properties of Ce/Fe and Ce/FeCoV multilayers

Energy Technology Data Exchange (ETDEWEB)

Tixier, S; Boeni, P [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Mannix, D; Stirling, W G [Liverpool Univ. (United Kingdom); Lander, G H

1997-09-01

Ce/Fe and Ce/FeCoV multilayers have been grown by magnetron sputtering. The interfaces are well defined and the layers are crystalline down to an individual layer thickness of 20 A. Ce/FeCoV multilayers show sharper interfaces than Ce/Fe but some loss of crystallinity is observed. Hysteresis loops obtained by SQUID show different behaviour of the bulk magnetisation as a function of the layer thickness. Fe moments are found by Moessbauer spectroscopy to be perpendicular to the interfaces for multilayers with small periodicity. (author) 2 figs., 2 refs.

Electronic Properties of LiFePO4 and Li doped LiFePO4

International Nuclear Information System (INIS)

Zhuang, G.V.; Allen, J.L.; Ross, P.N.; Guo, J.-H.; Jow, T.R.

2005-01-01

The potential use of different iron phosphates as cathode materials in lithium-ion batteries has recently been investigated.1 One of the promising candidates is LiFePO4. This compound has several advantages in comparison to the state-of-the-art cathode material in commercial rechargeable lithium batteries. Firstly, it has a high theoretical capacity (170 mAh/g). Secondly, it occurs as mineral triphylite in nature and is inexpensive, thermally stable, non-toxic and non-hygroscopic. However, its low electronic conductivity (∼10-9 S/cm) results in low power capability. There has been intense worldwide research activity to find methods to increase the electronic conductivity of LiFePO4, including supervalent ion doping,2 introducing non-carbonaceous network conduction3 and carbon coating, and the optimization of the carbon coating on LiFePO4 particle surfaces.4 Recently, the Li doped LiFePO4 (Li1+xFe1-xPO4) synthesized at ARL has yield electronic conductivity increase up to 106.5 We studied electronic structure of LiFePO4 and Li doped LiFePO4 by synchrotron based soft X-ray emission (XES) and X-ray absorption (XAS) spectroscopies. XAS probes the unoccupied partial density of states, while XES the occupied partial density of states. By combining XAS and XES measurements, we obtained information on band gap and orbital character of both LiFePO4 and Li doped LiFePO4. The occupied and unoccupied oxygen partial density of states (DOS) of LiFePO4 and 5 percent Li doped LiFePO4 are presented in Fig. 1. Our experimental results clearly indicate that LiFePO4 has wideband gap (∼ 4 eV). This value is much larger than what is predicted by DFT calculation. For 5 percent Li doped LiFePO4, a new doping state was created closer to the Fermi level, imparting p-type conductivity, consistent with thermopower measurement. Such observation substantiates the suggestion that high electronic conductivity in Li1.05Fe0.95 PO4 is due to available number of charge carriers in the material

Effect of the oxidation rate and Fe(II) state on microbial nitrate-dependent Fe(III) mineral formation

Science.gov (United States)

Senko, John M.; Dewers , Thomas A.; Krumholz, Lee R.

2005-01-01

A nitrate-dependent Fe(II)-oxidizing bacterium was isolated and used to evaluate whether Fe(II) chemical form or oxidation rate had an effect on the mineralogy of biogenic Fe(III) (hydr)oxides resulting from nitrate-dependent Fe(II) oxidation. The isolate (designated FW33AN) had 99% 16S rRNA sequence similarity to Klebsiella oxytoca. FW33AN produced Fe(III) (hydr)oxides by oxidation of soluble Fe(II) [Fe(II)sol] or FeS under nitrate-reducing conditions. Based on X-ray diffraction (XRD) analysis, Fe(III) (hydr)oxide produced by oxidation of FeS was shown to be amorphous, while oxidation of Fe(II)sol yielded goethite. The rate of Fe(II) oxidation was then manipulated by incubating various cell concentrations of FW33AN with Fe(II)sol and nitrate. Characterization of products revealed that as Fe(II) oxidation rates slowed, a stronger goethite signal was observed by XRD and a larger proportion of Fe(III) was in the crystalline fraction. Since the mineralogy of Fe(III) (hydr)oxides may control the extent of subsequent Fe(III) reduction, the variables we identify here may have an effect on the biogeochemical cycling of Fe in anoxic ecosystems.

Magnetic properties of FeZr{sub 2} and Fe{sub 2}Zr intermetallic compounds

Energy Technology Data Exchange (ETDEWEB)

Prajapat, C. L., E-mail: prajapat@barc.gov.in; Singh, M. R.; Mishra, P. K. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai, INDIA-400085 (India); Chattaraj, D. [Product Development Division, Bhabha Atomic Research Centre, Mumbai, INDIA-400085 (India); Mishra, R. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai, INDIA-400085 (India); Ravikumar, G. [Scientific Information Resources Division, Bhabha Atomic Research Centre, Mumbai, INDIA-400085 (India)

2016-05-23

Magnetic properties of Fe-Zr system, viz., FeZr{sub 2} and Fe{sub 2}Zr have been studied. Both the compounds show soft ferromagnetic behavior. Curie temperature is well above the room temperature. Lower saturation magnetization for the zirconium rich sample, FeZr{sub 2}, could be due to possible donation of electrons from the Zr-rich neighbors to Fe atoms or diminution of long range magnetic order by defects.

Removal of FePO4 and Fe3(PO4)2 crystals on the surface of passive fillers in Fe0/GAC reactor using the acclimated bacteria

International Nuclear Information System (INIS)

Lai, Bo; Zhou, Yuexi; Yang, Ping; Wang, Juling; Yang, Jinghui; Li, Huiqiang

2012-01-01

Highlights: ► Fe 3 (PO 4 ) 2 and FePO 4 crystals would weaken treatment efficiency of Fe 0 /GAC reactor. ► Fe 3 (PO 4 ) 2 and FePO 4 crystals could be removed by the acclimated bacteria. ► FeS and sulfur in the passive film would be removed by the sulfur-oxidizing bacteria. ► Develop a cost-effective bio-regeneration technology for the passive fillers. - Abstract: As past studies presented, there is obvious defect that the fillers in the Fe 0 /GAC reactor begin to be passive after about 60 d continuous running, although the complicated, toxic and refractory ABS resin wastewater can be pretreated efficiently by the Fe 0 /GAC reactor. During the process, the Fe 3 (PO 4 ) 2 and FePO 4 crystals with high density in the passive film are formed by the reaction between PO 4 3− and Fe 2+ /Fe 3+ . Meanwhile, they obstruct the formation of macroscopic galvanic cells between Fe 0 and GAC, which will lower the wastewater treatment efficiency of Fe 0 /GAC reactor. In this study, in order to remove the Fe 3 (PO 4 ) 2 and FePO 4 crystals on the surface of the passive fillers, the bacteria were acclimated in the passive Fe 0 /GAC reactor. According to the results, it can be concluded that the Fe 3 (PO 4 ) 2 and FePO 4 crystals with high density in the passive film could be decomposed or removed by the joint action between the typical propionic acid type fermentation bacteria and sulfate reducing bacteria (SRB), whereas the PO 4 3− ions from the decomposition of the Fe 3 (PO 4 ) 2 and FePO 4 crystals were released into aqueous solution which would be discharged from the passive Fe 0 /GAC reactor. Furthermore, the remained FeS and sulfur (S) in the passive film also can be decomposed or removed easily by the oxidation of the sulfur-oxidizing bacteria. This study provides some theoretical references for the further study of a cost-effective bio-regeneration technology to solve the passive problems of the fillers in the zero-valent iron (ZVI) or Fe 0 /GAC reactor.

Optimization of Fe2+ supplement in anaerobic digestion accounting for the Fe-bioavailability.

Science.gov (United States)

Cai, Yafan; Zhao, Xiaoling; Zhao, Yubin; Wang, Hongliang; Yuan, Xufeng; Zhu, Wanbin; Cui, Zongjun; Wang, Xiaofen

2018-02-01

Fe is widely used as an additive in anaerobic digestion, but its bioavailability and the mechanism by which it enhances digestion are unclear. In this study, sequential extraction was used to measure Fe bioavailability, while biochemical parameters, kinetics model and Q-PCR (fluorescence quantitative PCR) were used to explore its mechanism of stimulation. The results showed that sequential extraction is a suitable method to assess the anaerobic system bioavailability of Fe, which is low and fluctuates to a limited extent (1.7 to -3.1wt%), indicating that it would be easy for Fe levels to be insufficient. Methane yield increased when the added Fe 2+ was 10-500mg/L. Appropriate amounts of Fe 2+ accelerated the decomposition of rice straw and facilitated methanogen metabolism, thereby improving reactor performance. The modified Gompertz model better fitted the results than the first-order kinetic model. Feasibility analysis showed that addition of Fe 2+ at ≤50mg/L was suitable. Copyright © 2017. Published by Elsevier Ltd.

Chemical consequences of the nuclear reactions 58Fe(n,γ)59Fe and 57Co(EC)57Fe in soluble Prussian Blue

DEFF Research Database (Denmark)

Fenger, Jes; Maddock, A. G.; Siekierska, K. E.

1970-01-01

KFe[Fe(CN)6],H2O was prepared with 58Fe in either the cation or the complex, and both samples were neutron-irradiated and analysed for free and complexed 59Fe. Parallel experiments were performed on K4[Fe(CN)6],3H2O. In Prussian Blue the retention in the hexacyano-complex is ca. 5% and can be inc...

Tratamento do feno de braquiária pelo fungo Pleurotus ostreatus Pretreatment effects on fiber degradation of brachiaria hay by Pleurotus ostreatus fungus

Directory of Open Access Journals (Sweden)

Patrick Schmidt

2003-12-01

Full Text Available A inoculação de forragens com fungos lignocelulolíticos é uma opção para melhorar a qualidade destas sem adição de produtos químicos. O tratamento do substrato influencia a ação do fungo e a qualidade final do produto. Neste experimento, aplicaram-se quatro tratamentos (compostagem do feno inteiro, compostagem do feno picado, hidratação do feno em água fria e hidratação do feno em água quente a um feno de Brachiaria decumbens. Aos tratamentos seguiu-se inoculação com o fungo Pleurotus ostreatus e incubação por 35 dias, sob temperatura controlada. Usou-se o delineamento inteiramente casualizado, com quatro repetições e medidas repetidas. Amostras foram colhidas semanalmente para acompanhar a degradação do substrato, mediante a análise química do feno. Observou-se aumento linear, com o decorrer do tempo, no teor de proteína bruta (PB e na proporção de lignina na parede celular (LIG-FDN, e decréscimo linear nos valores de fibra em detergente neutro (FDN, celulose e hemicelulose. Não se observou efeito de tratamento no teor de FDA. Os tratamentos com compostagem apresentaram maiores valores de PB, lignina e LIG-FDN e menores de FDN e hemicelulose. Não se observou diferença entre os tratamentos com hidratação. O tratamento do feno de braquiária com o fungo propiciou degradação da fração fibrosa e aumento no teor de PB, com efeito mais intenso nos tratamentos que usaram compostagem. A ação do fungo foi mais efetiva sobre a hemicelulose que sobre os demais componentes da fibra.The innoculation of forages with lignocellulolytic fungi is an option for improving quality without adding chemical products. Substrate quality influences fungal activity and endproduct quality. The effects of four treatments (composting of whole hay, composting of chopped hay, soaking in cool water and soaking in hot water on a Brachiaria decumbens hay were evaluated. The treatments were followed by innoculation with Pleurotus ostreatus

Perpendicular exchange coupling effects in ferrimagnetic TbFeCo/GdFeCo hard/soft structures

Science.gov (United States)

Wang, Ke; Wang, Yahong; Ling, Fujin; Xu, Zhan

2018-04-01

Bilayers consisting of magnetically hard TbFeCo and soft GdFeCo alloy were fabricated. Exchange-spring and sharp switching in a step-by-step fashion were observed in the TbFeCo/GdFeCo hard/soft bilayers with increasing GdFeCo thickness. A perpendicular exchange bias field of several hundred Oersteds is observed from the shift of minor loops pinned by TbFeCo layer. The perpendicular exchange energy is derived to be in the range of 0.18-0.30 erg/cm2. The exchange energy is shown to increase with the thickness of GdFeCo layer in the bilayers, which can be attributed to the enhanced perpendicular anisotropy of GdFeCo layer in our experimental range.

Exchange-coupled Fe3O4/CoFe2O4 nanoparticles for advanced magnetic hyperthermia

Science.gov (United States)

Glassell, M.; Robles, J.; Das, R.; Phan, M. H.; Srikanth, H.

Iron oxide nanoparticles especially Fe3O4, γ-Fe2O3 have been extensively studied for magnetic hyperthermia because of their tunable magnetic properties and stable suspension in superparamagnetic regime. However, their relatively low heating capacity hindered practical application. Recently, a large improvement in heating efficiency has been reported in exchange-coupled nanoparticles with exchange coupling between soft and hard magnetic phases. Here, we systematically studied the effect of core and shell size on the heating efficiency of the Fe3O4/CoFe2O4 core/shell nanoparticles. The nanoparticles were synthesized using thermal decomposition of organometallic precursors. Transmission electron microscopy (TEM) showed formation of spherical shaped Fe3O4 and Fe3O-/CoFe2O4 nanoparticles. Magnetic measurements showed high magnetization (≅70 emu/g) and superparamagnetic behavior for the nanoparticles at room temperature. Magnetic hyperthermia results showed a large increase in specific absorption rate (SAR) for 8nm Fe3O4/CoFe2O4 compared to Fe3O4 nanoparticles of the same size. The heating efficiency of the Fe3O4/CoFe2O4 with 1 nm CoFe2O4 (shell) increased from 207 to 220 W/g (for 800 Oe) with increase in core size from 6 to 8 nm. The heating efficiency of the Fe3O4/CoFe2O4 with 2 nm CoFe2O4 (shell) and core size of 8 nm increased from 220 to 460 W/g (for 800 Oe). These exchange-coupled Fe3O4/CoFe2O4 core/shell nanoparticles can be a good candidate for advanced hyperthermia application.

[{sup 18}F]FE-SUPPY and [{sup 18}F]FE-SUPPY:2 - metabolic considerations

Energy Technology Data Exchange (ETDEWEB)

Haeusler, Daniela [Dept. of Nuclear Medicine, Medical Univ. of Vienna, A-1090 Vienna (Austria); Dept. of Pharmaceutical Technology and Biopharmaceutics, Univ. of Vienna, A-1090 Vienna (Austria); Nics, Lukas [Dept. of Nuclear Medicine, Medical Univ. of Vienna, A-1090 Vienna (Austria); Dept. of Nutritional Sciences, Univ. of Vienna, A-1090 Vienna (Austria); Mien, Leonhard-Key [Dept. of Nuclear Medicine, Medical Univ. of Vienna, A-1090 Vienna (Austria); Dept. of Pharmaceutical Technology and Biopharmaceutics, Univ. of Vienna, A-1090 Vienna (Austria); Ungersboeck, Johanna [Dept. of Nuclear Medicine, Medical Univ. of Vienna, A-1090 Vienna (Austria); Dept. of Inorganic Chemistry, Univ. of Vienna, A-1090 Vienna (Austria); Lanzenberger, Rupert R. [Dept. of Psychiatry and Psychotherapy, Medical Univ. of Vienna, A-1090 Vienna (Austria); Shanab, Karem [Dept. of Drug and Natural Product Synthesis, Univ. of Vienna, A-1090 Vienna (Austria); Sindelar, Karoline M. [Dept. of Nuclear Medicine, Medical Univ. of Vienna, A-1090 Vienna (Austria); Viernstein, Helmut [Dept. of Pharmaceutical Technology and Biopharmaceutics, Univ. of Vienna, A-1090 Vienna (Austria); Wagner, Karl-Heinz [Dept. of Nutritional Sciences, Univ. of Vienna, A-1090 Vienna (Austria); Dudczak, Robert; Kletter, Kurt [Dept. of Nuclear Medicine, Medical Univ. of Vienna, A-1090 Vienna (Austria); Wadsak, Wolfgang [Dept. of Nuclear Medicine, Medical Univ. of Vienna, A-1090 Vienna (Austria); Dept. of Inorganic Chemistry, Univ. of Vienna, A-1090 Vienna (Austria); Mitterhauser, Markus [Dept. of Nuclear Medicine, Medical Univ. of Vienna, A-1090 Vienna (Austria); Dept. of Pharmaceutical Technology and Biopharmaceutics, Univ. of Vienna, A-1090 Vienna (Austria); Hospital Pharmacy of the General Hospital of Vienna, A-1090 Vienna (Austria)], E-mail: markus.mitterhauser@meduniwien.ac.at

2010-05-15

Introduction: Recently, [{sup 18}F]FE-SUPPY and [{sup 18}F]FE-SUPPY:2 were introduced as the first positron emission tomography (PET) tracers for the adenosine A{sub 3} receptor. Thus, aim of the present study was the metabolic characterization of the two adenosine A{sub 3} receptor PET tracers. Methods: In vitro carboxylesterase (CES) experiments were conducted using incubation mixtures containing different concentrations of the two substrates, porcine CES and phosphate-buffered saline. Enzymatic reactions were stopped by adding acetonitrile/methanol (10:1) after various time points and analyzed by a high-performance liquid chromatography (HPLC) standard protocol. In vivo experiments were conducted in male wild-type rats; tracers were injected through a tail vein. Rats were sacrificed after various time points (n=3), and blood and brain samples were collected. Sample cleanup was performed by an HPLC standard protocol. Results: The rate of enzymatic hydrolysis by CES demonstrated Michaelis-Menten constants in a micromolar range (FE-SUPPY, 20.15 {mu}M, and FE-SUPPY:2, 13.11 {mu}M) and limiting velocities of 0.035 and 0.015 {mu}M/min for FE-SUPPY and FE-SUPPY:2, respectively. Degree of metabolism in blood showed the following: 15 min pi 47.7% of [{sup 18}F]FE-SUPPY was intact compared to 33.1% of [{sup 18}F]FE-SUPPY:2; 30 min pi 30.3% intact [{sup 18}F]FE-SUPPY was found compared to 15.6% [{sup 18}F]FE-SUPPY:2. In brain, [{sup 18}F]FE-SUPPY:2 formed an early hydrophilic metabolite, whereas metabolism of [{sup 18}F]FE-SUPPY was not observed before 30 min pi Conclusion: Knowing that metabolism in rats is several times faster than in human, we conclude that [{sup 18}F]FE-SUPPY should be stable for the typical time span of a clinical investigation. As a consequence, from a metabolic point of view, one would tend to decide in favor of [{sup 18}F]FE-SUPPY.

Fe biomineralization mirrors individual metabolic activity in a nitrate-dependent Fe(II-oxidizer

Directory of Open Access Journals (Sweden)

Jennyfer eMIOT

2015-09-01

Full Text Available Microbial biomineralization sometimes leads to periplasmic encrustation, which is predicted to enhance microorganism preservation in the fossil record. Mineral precipitation within the periplasm is however thought to induce death, as a result of permeability loss preventing nutrient and waste transit across the cell wall. This hypothesis had however never been investigated down to the single cell level. Here, we cultured the nitrate reducing Fe(II oxidizing bacteria Acidovorax sp. strain BoFeN1 that have been previously shown to promote the precipitation of a diversity of Fe minerals (lepidocrocite, goethite, Fe phosphate encrusting the periplasm. We investigated the connection of Fe biomineralization with carbon assimilation at the single cell level, using a combination of electron microscopy and Nano-Secondary Ion Mass Spectrometry (NanoSIMS. Our analyses revealed strong individual heterogeneities of Fe biomineralization. Noteworthy, a small proportion of cells remaining free of any precipitate persisted even at advanced stages of biomineralization. Using pulse chase experiments with 13C-acetate, we provide evidences of individual phenotypic heterogeneities of carbon assimilation, correlated with the level of Fe biomineralization. Whereas non- and moderately encrusted cells were able to assimilate acetate, higher levels of periplasm encrustation prevented any carbon incorporation. Carbon assimilation only depended on the level of Fe encrustation and not on the nature of Fe minerals precipitated in the cell wall. Carbon assimilation decreased exponentially with increasing cell-associated Fe content. Persistence of a small proportion of non-mineralized and metabolically active cells might constitute a strategy of survival in highly ferruginous environments. Eventually, our results suggest that periplasmic Fe biomineralization may provide a signature of individual metabolic status, which could be looked for in the fossil record and in modern

Cysteine as a ligand platform in the biosynthesis of the FeFe hydrogenase H cluster.

Science.gov (United States)

Suess, Daniel L M; Bürstel, Ingmar; De La Paz, Liliana; Kuchenreuther, Jon M; Pham, Cindy C; Cramer, Stephen P; Swartz, James R; Britt, R David

2015-09-15

Hydrogenases catalyze the redox interconversion of protons and H2, an important reaction for a number of metabolic processes and for solar fuel production. In FeFe hydrogenases, catalysis occurs at the H cluster, a metallocofactor comprising a [4Fe-4S]H subcluster coupled to a [2Fe]H subcluster bound by CO, CN(-), and azadithiolate ligands. The [2Fe]H subcluster is assembled by the maturases HydE, HydF, and HydG. HydG is a member of the radical S-adenosyl-L-methionine family of enzymes that transforms Fe and L-tyrosine into an [Fe(CO)2(CN)] synthon that is incorporated into the H cluster. Although it is thought that the site of synthon formation in HydG is the "dangler" Fe of a [5Fe] cluster, many mechanistic aspects of this chemistry remain unresolved including the full ligand set of the synthon, how the dangler Fe initially binds to HydG, and how the synthon is released at the end of the reaction. To address these questions, we herein show that L-cysteine (Cys) binds the auxiliary [4Fe-4S] cluster of HydG and further chelates the dangler Fe. We also demonstrate that a [4Fe-4S]aux[CN] species is generated during HydG catalysis, a process that entails the loss of Cys and the [Fe(CO)2(CN)] fragment; on this basis, we suggest that Cys likely completes the coordination sphere of the synthon. Thus, through spectroscopic analysis of HydG before and after the synthon is formed, we conclude that Cys serves as the ligand platform on which the synthon is built and plays a role in both Fe(2+) binding and synthon release.

Anemia y deficiencia de hierro en mujeres en edad reproductiva usuarias del Hospital Regional de Villa Hayes, Paraguay

OpenAIRE

Jessica Riveros; Gloria Echagüe; Santiago Evers; Laura Mendoza

2015-01-01

La anemia es un problema de salud pública a nivel mundial. En Paraguay, existen datos limitados sobre la frecuencia de anemia en mujeres en edad reproductiva no gestantes. Este estudio piloto descriptivo de corte transverso tuvo como objetivo determinar la frecuencia de anemia y deficiencia de hierro, el estado nutricional, hábitos alimentarios y tóxicos en 99 mujeres no gestantes en edad reproductiva de 18 a 48 años que acudieron al Hospital Regional de Villa Hayes en Octubre del 2.014. La a...

Benefit from the association of small amounts of tannin-rich shrub foliage (Acacia cyanophylla Lindl.) with soya bean meal given as supplements to Barbarine sheep fed on oaten hay

International Nuclear Information System (INIS)

Ben Salem, H.; Makkar, H.P.S.; Nefzaoui, A.; Abidi, S.; Hassayoun, L.

2005-01-01

Two trials were conducted to test the hypotheses that (i) feeding small amount of a tanniniferous shrub foliage (Acacia cyanophylla Lindl., acacia) increases the proportion of rumen undegradable protein, and consequently benefits growth performance in Barbarine lamb; and (ii) such positive effect depends on the timing of feeding tannin source (i.e. acacia) relative to protein source (soya bean meal, SBM). Total (TT) and condensed tannin (CT) concentrations in air-dried acacia leaves used in this study averaged 29 g tannic acid and 48 g leucocyanidin equivalents per kg dry matter (DM), respectively. In trial 1, rumen fistulated ewes received oaten hay (hay) ad libitum and 200 g SBM (D1), D1 and 100 g acacia fed with the SBM (D2, mixed strategy) or as D2, but the SBM fed 1 h later than acacia when acacia was consumed completely (D3, sequential strategy). Hay intake, diet digestibility, rumen fermentation parameters (pH, ammonia nitrogen (NH 3 -N) and total volatile fatty acids) and in situ degradation of SBM nitrogen were similar between D1 and D2 (P > 0.05). However, the sequential strategy (D3) resulted in efficient use of N as reflected by the decrease of crude protein digestibility (CPD), plasma urea, NH 3 -N concentration and in situ degradation of SBM nitrogen. In trial 2, four groups each of six Barbarine lambs (initial LW 35.3 ± 3.7 kg) received for 90 days: hay ad libitum and 200 g SBM (D1), D1 and 20 g polyethylene glycol (PEG, MW 4000) mixed with SBM (D2), D1 and 100 g acacia with the SBM fed 1 h later when acacia was completely consumed (sequential strategy) (D3) or D3 and 20 g PEG fed with the SBM (D4). Polyethylene glycol was here used to deactivate tannins. Hay intake and DM, organic matter and neutral detergent fibre digestibility were similar among dietary treatment (P > 0.05). However, supplementing lambs with SBM and acacia without PEG (D3) resulted in a significant decrease (P 0.05). However, those supplemented with acacia without PEG (D3) had

DISEÑO Y EJECUCION DE UNA INTERVENCION ORIENTADA AL MEJORAMIENTO EN LA IMPLEMENTACION DE LAS BUENAS PRACTICAS DE FABRICACION (BPF) EN LOS SERVICIOS DE ALIMENTACION CONCESIONADOS DE ESTABLECIMIENTOS EDUCACIONALES DE LA FUNDACION INTEGRA

OpenAIRE

AYALA RIQUELME, JOSE MIGUEL

2013-01-01

El Programa de Alimentación del Preescolar (PAP) de la Fundación Integra, tiene como beneficiarios a más de 70.000 niños de los quintiles de ingreso más bajos del país, distribuidos en cerca de 900 establecimientos en todo Chile. En los últimos años, la inocuidad de alimentos ha tomado gran relevancia a nivel mundial debido al aumento en las Enfermedades Transmitidas por Alimentos (ETA). Entre las medidas para mejorar este panorama, se encuentran las Buenas Prácticas de Fabrica...

Chemical composition, fatty acid content and antioxidant potential of meat from goats supplemented with Moringa (Moringa oleifera) leaves, sunflower cake and grass hay.

Science.gov (United States)

Qwele, K; Hugo, A; Oyedemi, S O; Moyo, B; Masika, P J; Muchenje, V

2013-03-01

The present study determined the chemical composition, fatty acid (FA) content and antioxidant capacity of meat from goats supplemented with Moringa oleifera leaves (MOL) or sunflower cake (SC) or grass hay (GH). The meat from goat supplemented with MOL had higher concentrations of total phenolic content (10.62±0.27 mg tannic acid equivalent E/g). The MOL significantly scavenged 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic-acid (ABTS) radical to 93.51±0.19% (93.51±0.19%) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical to 58.95±0.3% than other supplements. The antioxidative effect of MOL supplemented meat on catalase (CAT), reduced glutathione (GSH), superoxide dismutase (SOD) and lipid oxidation (LO) was significantly (Pmeat from goat feed on grass hay or those supplemented with sunflower seed cake. The present study indicated that the anti-oxidative potential of MOL may play a role in improving meat quality (chemical composition, colour and lipid stability). Copyright © 2012 Elsevier Ltd. All rights reserved.

Resonant Ni and Fe KLL Auger spectra photoexcited from NiFe alloys

International Nuclear Information System (INIS)

Koever, L.; Cserny, I.; Berenyi, Z.; Egri, S.; Novak, M.

2005-01-01

Complete text of publication follows. KLL Auger spectra of 3d transition metal atoms in solid environment, measured using high energy resolution, give an insight into the details of the local electronic structure surrounding the particular atoms emitting the signal Auger electrons. Fine tuning the energy of the exciting monochromatic photons across the K-absorption edge, features characteristic to resonant phenomena can be identified in the spectra. The shapes of the resonantly photoexcited KLL Auger spectra induced from 3d transition metals and alloys are well interpreted by the single step model of the Auger process, based on the resonant scattering theory. The peak shapes are strongly influenced by the 4p partial density of unoccupied electronic states around the excited atom. High energy resolution studies of KLL Auger spectra of 3d transition metals using laboratory X-ray sources, however, request very demanding experiments and yield spectra of limited statistical quality making the evaluation of the fine details in the spectra difficult. The Tunable High Energy XPS (THE- XPS) instrument at BW2 offers optimum photon x and energy resolution for spectroscopy of deep core Auger transitions. For the present measurements high purity polycrystalline Ni and Fe sheets as well as NiFe alloy samples of different compositions (Ni 80 Fe 20 , Ni 50 Fe 50 , Ni 20 Fe 80 ) were used. The surfaces of the samples were cleaned by in-situ argon ion sputtering. The measurements of the Ni and Fe KL 23 L 23 Auger spectra of the metal and alloy samples were performed with the THE-XPS instrument using high electron energy resolution (0.2 eV). In Fig.1, the measured Fe KL 23 L 23 spectrum, photoexcited at the Fe K absorption edge from Fe metal, is compared with the respective spectrum excited from a Ni 50 Fe 50 alloy. A significant broadening of the 1 D 2 peak and an enhancement of the spectral intensity at the low energy loss part of this peak observed in the alloy sample, while the

Electrical resistivity surface for FeO-Fe2O3-P2O5 glasses

Science.gov (United States)

Vaughan, J. G.; Kinser, D. L.

1975-01-01

The dc electrical properties and microstructure of x(FeO-Fe2O3)-(100-x)P2O5 glasses were investigated up to a maximum of x = 75 mol %. Results indicate that, in general, the minimum resistivity of the glass does not occur at equal Fe(2+) and Fe(3+) concentrations, although for the special case where x = 55 mol % the minimum does occur at Fe(2+)/Fe total = 0.5, as reported by other investigators. Evidence presented shows that the position of the minimum resistivity is a function of total iron content. The minimum shifts to glasses richer in Fe(2+) at higher total iron concentrations.

CALCIUM SOURCE EFFECT ON APPARENT DIGESTIBILITY OF GRASS HAY Brachiaria decumbens Staph cv. Basiliski EFEITO DA FONTE DE CÁLCIO (calcário vs Lithothamnium calcareum) NA DIGESTIBILIDADE APARENTE DE CAPIM Brachiaria decumbens Staph cv. Basiliski

OpenAIRE

Deborah Gonçalves Rodrigues; Clizeide R. Oliveira; Benir de Oliveira; Celso de Paula Costa; Geisa Fleury Orsine

2007-01-01

An experiment was developed to determine the effect of addition of the marine alga Lithothamnium calcareum in the apparent digestibility of a low quality forage. Twelve adult lambs were kept in metabolical individual cages using a randomly design with three replications and four treatments as follows: I - Brachiaria decumbens grass hay, processed after the seed harvest; II - Hay plus 1000 ppm of calcium from CaCO3 ...

Role of PO4 tetrahedron in LiFePO4 and FePO4 system.

Science.gov (United States)

Zeng, Yuewu

2015-06-01

Using high resolution transmission electron microscopy with image simulation and Fourier analysis, the Li1- x FePO4 (x < 0.01), Li1- x FePO4 (x ∼ 0.5), and FePO4 particles, prepared by charging or discharging the 053048 electrochemical cells (thickness: 5 mm, width: 30 mm, height: 48 mm) and dismantled inside an Ar-filled dry box, were investigated. The high resolution images reveal: (1) the solid solution of Li1- x FePO4 (x < 0.01) contains some missing Li ions leading PO4 group distorted around M1 tunnel of the unit cell; (2) the texture of the particles of Li1- x FePO4 (x ∼0.5) has homogeneously distributed compositional domains of LiFePO4 and FePO4 resulting from spinodal decomposition which promote Li ion easily getting into the particle due to uphill diffusion, (3) the particles of FePO4 formed in charging have heavily distorted lattice and contain some isolated LiFePO4 , (4) interface between LiFePO4 and FePO4 and between amorphous and crystal region provides the lattice distortion of small polarons. © 2015 Wiley Periodicals, Inc.

Microstructure, magnetic and Moessbauer studies on spark-plasma sintered Sm-Co-Fe/Fe(Co) nanocomposite magnets

Energy Technology Data Exchange (ETDEWEB)

Rao, N V Rama; Saravanan, P; Gopalan, R; Raja, M Manivel; Rao, D V Sreedhara; Chandrasekaran, V [Defence Metallurgical Research Laboratory, Hyderabad-500 058 (India); Sivaprahasam, D [International Advanced Research Centre for Powder Metallurgy and New Materials Hyderabad-500 005 (India); Ranganathan, R [Saha Institute of Nuclear Physics, Kolkata-700 064 (India)], E-mail: rg_gopy@yahoo.com

2008-03-21

Nanocomposite powders comprising Sm-Co-Fe intermetallic phases and Fe(Co) were synthesized by high-energy ball milling and were consolidated into bulk magnets by the spark-plasma sintering (SPS) technique. While the microstructure of the SPS samples was characterized by transmission electron microscopy (TEM), the solubility of Fe in different phases was investigated using Moessbauer spectroscopy. TEM studies revealed that the spark-plasma sintered sample has Sm(Co,Fe){sub 5} as a major phase with Sm{sub 2}(Co,Fe){sub 17}, Sm(Co,Fe){sub 2} and Fe(Co) as secondary phases. The size of the nanocrystalline grains of all these phases was found to be in the range 50-100 nm. The Moessbauer spectra of the as-milled powders exhibited two different subspectra: a sextet corresponding to the Fe phase and a broad sextet associated with the Fe(Co) phase; while that of the SPS sample showed four different subspectra: a sextet corresponding to Fe and other three sextets corresponding to the Fe(Co), Sm(Co,Fe){sub 5} and Sm{sub 2}(Co,Fe){sub 17} phases; these results are in accordance with the TEM observation. Recoil magnetization and reversible susceptibility measurements revealed magnetically single phase behaviour of the SPS magnets.

Exchange bias in sputtered FeNi/FeMn systems: Effect of short low-temperature heat treatments

Energy Technology Data Exchange (ETDEWEB)

Savin, Peter, E-mail: peter.savin@urfu.ru [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Guzmán, Jorge [Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain); Lepalovskij, Vladimir [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Svalov, Andrey; Kurlyandskaya, Galina [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Departamento de Electricidad y Electrónica, Universidad del País Vasco (UPV/EHU), 48940 Leioa, Vizcaya (Spain); Asenjo, Agustina [Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain); Vas’kovskiy, Vladimir [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Vazquez, Manuel [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain)

2016-03-15

Short (5 min) post-deposition thermal treatments under magnetic field at low temperature (up to 200 °C) performed in exchange-coupled FeNi(40 nm)/FeMn(20 nm) bilayer thin films prepared by magnetron sputtering are shown to be effective to significantly modify their exchange field (from around 40 Oe down to 27 Oe) between FeNi and FeMn layers. A similar exchange field decrease was observed for the first deposited FeNi layer of the FeNi(40 nm)/FeMn(20 nm)/FeNi(40 nm) trilayer films after the same thermal treatments. The exchange field value for the second FeNi layer was not substantially changed. The X-ray diffraction patterns indicates that such a heat treatment has no effect on the grain size and crystalline texture of the films, while atomic force microscope studies reveal an increase of the surface roughness after the treatment which is more noticeable in the case of the trilayer film. Analysis of the experimental results leads us to conclude that the variations of the exchange field after heat treatment are likely caused by a modification of interfacial roughness and/or interfacial magnetic structure, but unlikely by the changes in the microstructure and/or changes of composition of the antiferromagnetic FeMn layer. - Highlights: • FeNi/FeMn bilayers and FeNi/FeMn/FeNi trilayers were prepared by magnetron sputtering. • Post-deposition heat treatments at the temperatures below 200 °C during 5 min were made. • Annealing reduces the exchange field for the first FeNi layer in trilayers. • The exchange field value for the second FeNi layer was not substantially changed. • Exchange field changes are most likely caused by a modification of interface roughness.