WorldWideScience

Sample records for citotoxicidad natural inducida

  1. Estudio de la influencia de la refrigeracion con aire de forma natural e inducida en el comportamiento de instalaciones fotovoltaicas

    Science.gov (United States)

    Mazon Hernandez, Rocio

    panels are analysed to compare and select the best configuration. The presented research provides a deep knowledge of how they work as well as information and results for an improvement in future designs of building integrated photovoltaic systems. Este estudio se centra en analizar la influencia negativa de la temperatura en la produccion electrica de paneles fotovoltaicos al estar emplazados sobre cubierta de acero, como sucede en naves industriales y sobre un invernadero. Se estudian diferentes configuraciones que permitan refrigerar los paneles, reduciendo su temperatura y mejorar su rendimiento. Para abordar este problema, se han construido dos instalaciones experimentales, fieles a plantas solares en funcionamiento. Una instalacion engloba dos paneles fotovoltaicos sobre estructura fija al suelo. Uno de los paneles esta integrado sobre una superficie paralela y metalica. Entre ambas superficies existe un espacio que posibilita circular aire, permitiendo refrigerar el panel por conveccion natural, o conveccion forzada impulsando el aire con un ventilador. El otro panel, libre por su cara posterior y se ha considerado de referencia. Se ha estudiado el comportamiento del panel integrado sobre cubierta para diferentes secciones de aire y velocidades inducidas, comparandolo con el panel de referencia. Se ha desarrollado un modelo experimental que nos permite determinar la temperatura del panel en funcion de las variables que influyen en su refrigeracion. Adicionalmente, se han analizado los datos de una planta solar en funcionamiento, con paneles de igual caracteristicas, obteniendo correlaciones entre la temperatura del panel y las variables electricas y comparandolos con las obtenidas en la instalacion experimental. La segunda instalacion experimental reproduce parte de una instalacion solar sobre un invernadero, formada por cuatro paneles fotovoltaicos colocados sobre el plastico del invernadero, existiendo un canal divergente entre ambas superficies. Se estudia la

  2. Atenuación natural y remediación inducida en suelos contaminados con hidrocarburos Natural attenuation and induced remediation in hydrocarbon polluted soils

    Directory of Open Access Journals (Sweden)

    Romina Romaniuk

    2007-12-01

    Full Text Available Los hidrocarburos derivados del petróleo constituyen la principal fuente de energía para la humanidad y son, a su vez, importantes contaminantes ambientales. En esta experiencia, se estimó y comparó la tasa de descomposición de dos tipos de hidrocarburos (gasoil y aceite de carter por medio de las técnicas de atenuación natural y de la incorporación de un producto comercial específico en un suelo franco extraído del horizonte A de un Argiudol típico. Simultáneamente se evaluó el efecto de dichas prácticas tecnológicas sobre algunas variables edáficas. Los tratamientos fueron: [suelo sin contaminante testigo], [suelo + gasoil] [suelo + aceite de carter], [suelo + gasoil + producto], [suelo + aceite de carter + producto] y [suelo + producto]. La toma de muestra se realizó en la siguiente serie de tiempo [0;15; 30; 60; y 180 días]. La tasa de degradación de los hidrocarburos presentes en el gasoil y aceite de carter por la técnica de atenuación natural fue más lenta y menos efectiva que la obtenida al incorporar el producto comercial, alcanzando en este caso los valores finales más bajos de hidrocarburos totales de petróleo. Entre las variables edáficas, el carbono oxidable y la respiración de la biomasa del suelo mostraron los mayores valores medios en los tratamientos de suelo contaminado. La incorporación del producto comercial produjo una disminución significativa en dichos valores, un aumento en la conductividad eléctrica, pero no influyó sobre el pH y el fósforo extractable del suelo.The petroleum derived hydrocarbons represent the main energy source for the humanity and they are in turn, an important environmental polluting source. In this experience it was estimated and compared the rate of decomposition of two hydrocarbons (diesel and crankcase oil, by natural attenuation, and with the incorporation of a specific commercial product in a Typic Argiudoll. The effect of these practices was also evaluated on some

  3. Agroquímicos en Argentina: Genotoxicidad y citotoxicidad inducida por principios activos y sus formulaciones comerciales

    OpenAIRE

    Larramendy, Marcelo L; Molinari, Gabriela; González, Norma V; Pilili, Juan P; Candioti, Josefina Vera; Reigosa, Miguel A; Soloneski, Sonia

    2010-01-01

    Uno de los objetivos principales de nuestro laboratorio es evaluar comparativamente los efectos geno-citotóxicos ejercidos in vitro e in vivo sobre células de vertebrados por principios activos de agroquímicos y sus formulaciones comerciales de uso masivo en Argentina. Entre los mismos caben mencionarse, los herbicidas 2,4-D y 2,4-D DMA®, dicamba y Banvel®, el fungicida zineb y Azzurro®, los insecticidas carbofurán y Furadan®, pirimicarb y Aficida®, como también el endectocida ivermectina e I...

  4. Osteomalacia inducida por tumor: hemangiopericitoma rinosinusal

    Directory of Open Access Journals (Sweden)

    Enriqueta M. Serafini

    2013-02-01

    Full Text Available La osteomalacia inducida por tumor es una rara enfermedad del metabolismo óseo caracterizada por el aumento en la excreción de fosfato a nivel renal seguido de hipofosfatemia. Es causada por agentes fosfatúricos producidos por determinados tumores. La resección total del tumor resulta en la completa reversión de las anormalidades bioquímicas, la desaparición de las manifestaciones clínicas y los hallazgos en los estudios por imágenes. Presentamos el caso de un varón de 61 años con cuadro clínico y laboratorio compatibles con osteomalacia oncogénica inducida por tumor mesenquimático de localización rinosinusal. En nuestro caso el diagnóstico histológico correspondió a una neoplasia de tipo vascular: hemangiopericitoma.

  5. Alteraciones hepáticas inducidas por la nutrición parenteral

    OpenAIRE

    J Salas Salvado; A Recaséns Garica

    1993-01-01

    Liver disorders induced by parenteral nutrition Alteraciones hepáticas inducidas por la nutrición parenteral Liver disorders induced by parenteral nutrition Alteraciones hepáticas inducidas por la nutrición parenteral

  6. Avaliação comparativa da citotoxicidade dos cimentos MTA Fillapex e AH Plus: revisão integrativa

    OpenAIRE

    Marinho, Jéssica Cristina Soares; Cunha, Ludmila de Almeida; Lacerda, Mariane Floriano Lopes Santos; Lacerda, Gabriel Pinheiro; Coelho, Renato Girelli; Girelli, Caroline Felipe Magalhães

    2017-01-01

    Objetivo: O objetivo deste estudo foi realizar uma revisão integrativa comparando a citotoxicidade dos cimentos MTA Fillapex e AH Plus aos tecidos periapicais. Métodos: Foram utilizados artigos na íntegra, nos idiomas português e inglês, publicados durante os períodos de 2010 a 2017, selecionados na base de dados Scielo e Pubmed, utilizando os seguintes descritores: AH Plus, MTA Fillapex e citotoxicidade. Foram excluídos, os trabalhos no idioma não inglês, artigos sem resumo, trabalhos realiz...

  7. Citotoxicidad y genotoxicidad en células humanas expuestas in vitro a glifosato.

    Directory of Open Access Journals (Sweden)

    Claudia Milena Monroy

    2005-09-01

    Full Text Available Introducción. El glifosato es un herbicida de amplio espectro, no selectivo, utilizado para eliminar malezas indeseables en ambientes agrícolas y forestales. La acción herbicida corresponde a la inhibición de la biosíntesis de aminoácidos aromáticos en las plantas. Al no ser este mecanismo compartido por los seres humanos es considerado como de bajo riesgo para la salud de los mismos. Sin embargo, investigaciones recientes indican que puede alterar otros procesos celulares en animales lo que puede presentar un factor de riesgo a nivel ambiental y de salud en las zonas donde se emplea este herbicida. Objetivo. El objetivo del presente estudio fue evaluar la citotoxicidad y la genotoxicidad del glifosato en células humanas normales (GM38 y en células humanas de fibrosarcoma (HT1080. Materiales y métodos. La citotoxicidad aguda y crónica se determinó al exponer las células en cultivo a diferentes concentraciones de glifosato, y se analizó la viabilidad celular con cristal violeta y colorante de exclusión azul de tripano, respectivamente. La genotoxicidad se determinó por medio del ensayo del cometa y los datos se analizaron usando la prueba de Dunnet. Resultados. En la citotoxicidad crónica las células GM38 y las HT1080 presentaron un efecto dependiente de la dosis después del tratamiento con glifosato en concentraciones de 5,2 a 8,5 mM y 0,9 a 3,0 mM, respectivamente. En la citotoxicidad aguda, las células GM38 y las HT1080 expuestas a un rango de concentraciones de 4,0 a 7,0 mM, 4,5 a 5,75 mM y 4,0 a 7,0 mM, respectivamente, presentaron una viabilidad mayor al 80%. Se evidenció daño en el ADN después del tratamiento con glifosato en concentraciones de 4,0 a 6,5 mM para las células GM38 y de 4,75 a 5,75 mM para las células HT1080. Conclusiones. Se sugiere que el mecanismo de acción del glifosato no se limita únicamente a las plantas sino que puede alterar la estructura del ADN en otros tipos de células como son las de

  8. Frecuencia espontánea e inducida de micronúcleos transplacentarios en ratones Balb/c

    Directory of Open Access Journals (Sweden)

    Daniel Francisco Arencibia Arrebola

    2011-01-01

    Full Text Available Introducción: El ensayo de micronúcleos transplacentario, ha sido desarrollado con el objetivo de evaluar el potencial genotóxico en la descendencia y demostrar la capacidad de un agente de causar daños cromosómicos durante el período prenatal. Éste realiza el registro de aberraciones cromosómicas, demostrando si una sustancia determinada puede ser clastogénica o aneugénica en el feto, a través de la exposición materna. Objetivo: Por lo cual en el presente trabajo se tuvo como objetivo determinar la frecuencia espontánea e inducida de micronúcleos transplacentarios en ratones de la línea Balb/c. Pretendiendo vincular de esta forma el efecto genotóxico y reproductivo de una droga a evaluar por esta metodología. Materiales y métodos: Se formaron 4 grupos experimentales, el primero un control negativo (simulacro, el segundo control solvente NaCl (0,9%, en el tercero se utilizo la ciclofosfamida en dosis de 50 mg/kg, y el cuarto se utilizó la bleomicina en dosis de 20 mg/kg. Todos los grupos se administraron por vía intraperitoneal los días 14, 15 y 16 de la gestación y 24 h después de la última inoculación se procedió al sacrificio de las gestantes por dislocación cervical. Obteniéndose las muestras de médula ósea materna e hígado fetal. Resultados: Se obtuvo como resultado los valores espontáneos e inducidos de los índices de citotoxicidad y de genotoxicidad, así como el total de micronúcleos divididos según niveles de daños.Discusión y conclusiones: Se observo mayor inducción de daño en células hepáticas fetales que en médula ósea materna. Además se demostró que la ciclofosfamida es capaz de inducir mayor citotoxicidad y genotoxicidad que la bleomicina tanto en células de la médula ósea materna como en células hepáticas fetales. Por tanto se demostró el poder clastogénico transplacentario de ambos mutágenos vinculando este ensayo de genotoxicidad a la reproducción. Además estos resultados se

  9. Agranulocitosis inducida por metimazol en pacientes con enfermedad de Graves

    Directory of Open Access Journals (Sweden)

    Helard Manrique-Hurtado

    2013-04-01

    Full Text Available Objetivo: Describir las características clínicas y epidemiológicas de los pacientes con enfermedad de Graves que presentaron agranulocitosis inducida por metimazol. Material y métodos: Estudio retrospectivo, tipo serie de casos. Se revisaron las historias clínicas de todos los pacientes con diagnóstico de agranulocitosis inducida por metimazol, atendidos en el Hospital Nacional Arzobispo Loayza, entre enero 2002 y diciembre 2008. Se buscó asociación entre las variables demográficas y clínicas con la mortalidad y el tiempo de recuperación. Resultados: Treinta (0,60% pacientes con enfermedad de Graves fueron hospitalizados con el diagnóstico de agranulocitosis inducida por metimazol. La mediana de la edad fue 33,5 años y 86,67% fueron mujeres. Al ingreso, todos los pacientes presentaron fiebre y dolor de garganta. El manejo incluyó aislamiento invertido, suspensión del metimazol, administración de antibióticos y glucocorticoides. Doce (40% pacientes recibieron GM-CSF. El número de granulocitos se normalizó después de 10,59 días y cuatro (13,33% pacientes murieron por infecciones bacterianas y sepsis. En todos los casos, el tratamiento definitivo fue yodo radioactivo. No hubo diferencia significativa en la edad, sexo, dosis de metimazol, duración del tratamiento y uso de factor estimulante colonia, entre los pacientes fallecidos y los sobrevivientes. Además, el uso de factor estimulante de colonia no redujo el tiempo de recuperación de la agranulocitosis. Conclusión: La agranulocitosis inducida por metimazol es un evento adverso serio y potencialmente mortal. En este grupo de pacientes, la mortalidad fue elevada y el uso de factor estimulante de colonia no disminuyó el tiempo de recuperación.

  10. Evaluación de la citotoxicidad y bioseguridad de un extracto de polifenoles de huesos de aceitunas

    OpenAIRE

    C. Veciana Galindo; E. Cortés Castell; L. Torro Montell; E. Sirvent Segura; M. M. Rizo Baeza; V. Gil Guillén

    2014-01-01

    El olivo constituye una fuente de compuestos bioactivos, tanto en su fruto, como en sus subproductos. Algunos de sus compuestos han mostrado beneficios para la salud, siendo objetivo de este trabajo la evaluación de la bioseguridad in vitro e in vivo de extractos de huesos de aceituna ricos en polifenoles. Material y métodos: Se ha evaluado la citotoxicidad mediante adición de extracto de hueso de olivas disuelto en PBS(0-400 mg/l) a un cultivo de la línea celular THP1-XBlue-CD14 y evaluación...

  11. Osteoporosis secundaria y Osteoporosis inducida por glucocorticoides (OIG

    Directory of Open Access Journals (Sweden)

    Elías Forero Illera

    2006-01-01

    Full Text Available La osteoporosis es un problema de salud pública importante a nivel mundial, y su prevalencia está aumentando. La osteoporosis secundaria se puede producir por varias patologías y el uso de ciertos medicamentos. Los glucocorticoides son un grupo de fármacos usados extensamente en la práctica médica debido a su indiscutible utilidad. La osteoporosis inducida por glucocorticoides es un problema de salud pública. Aunque la patogénesis de la pérdida producida por los glucocorticoides en el hueso no se conoce totalmente, investigaciones recientes han proporcionado nuevas conocimientos en los mecanismos de estos fármacos a nivel celular y molecular. Diversas guías han sido propuestas por diversos grupos para el tratamiento de la OIG; desafortunadamente, las guías del tratamiento no se utilizan adecuadamente en los pacientes.

  12. O impacto do último enxágue na citotoxicidade de produtos críticos passíveis de processamento

    Directory of Open Access Journals (Sweden)

    Rafael Queiroz de Souza

    2015-12-01

    Full Text Available RESUMO Objetivo Avaliar a citotoxicidade de produtos submetidos à contaminação desafio, limpeza baseada em procedimento operacional padrão (POP validado e enxágue final em diferentes tipos de água: de torneira, deionizada, destilada, tratada por osmose reversa e ultrapurificada. Método Estudo experimental e laboratorial. Foram utilizadas como amostras 130 cânulas de hidrodissecção, 26 por grupo experimental, caracterizados, de acordo com a água utilizada no último enxágue. As amostras foram submetidas à contaminação desafio interna e externamente por uma solução contendo 20% sangue de carneiro desfibrinado e 80% de Cloreto de Sódio a 0,9%. Em seguida, tiveram o lúmen preenchido por solução viscoelástica, permanecendo em contato com o contaminante por 50 minutos, sendo então, processadas, de acordo com um POP validado. A citotoxicidade foi avaliada pela captura do corante vital vermelho neutro. Resultados Ausência de citotoxicidade nos extratos das amostras. Conclusão As amostras não demonstraram citotoxicidade, independentemente da qualidade de água utilizada no último enxágue. Os resultados apresentados puderam ser alcançados unicamente por meio do uso de um procedimento operacional padrão de limpeza validado, baseado em literatura científica, em recomendações oficiais e na legislação relacionada.

  13. MODELO EXPERIMENTAL DE GLOMERULONEFRITIS MEMBRANOSA INDUCIDA CON ALBUMINA BOVINA

    Directory of Open Access Journals (Sweden)

    Fontenla M

    2013-07-01

    Full Text Available El objetivo del presente trabajo fue diseñar un modelo experimental de Glomerulonefritis Membranosa (GM en ratas Wistar, inducida con Seroalbúmina Bovina (BSA, y validarlo mediante la determinación de parámetros bioquímicos, histológicos, ultraestructurales y detección de inmunocomplejos por inmunofluorescencia (IF. Los animales del grupo experimental fueron inmunizados por vía subcutánea, con dosis de 3 mg c/u de BSA/PBS con adyuvante de Freund. Se efectuaron diferentes esquemas de inmunización. Cuando el título de anticuerpos fue ≥1/2, comenzó la administración diaria de 2 mg, por vía endovenosa de BSA/PBS, durante 15 días. Se evaluó la funcionalidad renal por la proteinuria; después de la 5° semana, desde su aparición, se determinó: depuración (clearance de creatinina, uremia, proteinemia y perfil lipídico. Los dos riñones se usaron para estudios histológicos, ultraestructurales y detección de inmunocomplejos por IF. Los resultados mostraron que la inmunización fue efectiva con 5 R E S U M E N inoculaciones c/15 días. En los animales nefróticos la proteinuria, depuración (clearance de creatinina, proteinemia , uremia y el perfil lipídico presentaron alteraciones significativas (p<0.0001. Al microscopio óptico se observó hipercelularidad, engrosamiento difuso de las membranas basales de los capilares glomerulares y diferentes grados de atrofia, esclerosis e hialinización de los glomérulos. Por IF se detectó inmunocomplejos IgG en el 100 % de los glomérulos. Ultraestructuralmente, se observaron depósitos subepiteliales electrodensos en la membrana basal engrosada, compatibles con inmunocomplejos . Se encontraron alteraciones en la estructura de los podocitos. En conclusión, los estudios bioquímicos, estructurales y ultraestructurales permitieron inferir la inducción de un síndrome nefrótico experimental. Concluimos que el protocolo utilizado tiene validez para la inducción de una glomerulonefritis

  14. El aceite de pescado atenua las crisis convulsivas inducidas por hipertermia en ratas neonatas

    Directory of Open Access Journals (Sweden)

    Leopoldo E. Flores M.

    2008-01-01

    Full Text Available Un alto porcentaje (50-60% del cerebro en los mamíferos son principalmente grasas o lípidos, de éstos, el 35% son ácidos grasos esenciales, en particular los llamados omegas (O, como el Acido Docosahexanoico (DHA y el Eicosapentanoico (EPA llamados omega 3 (O-3. Diversos estudios han mostrado beneficios en la salud con la implementación de los O-3 como agentes terapéuticos en alteraciones cardiovasculares, renales, dérmicas, metabólicas, neurodegenerativas e inmunológicas. Evidencias experimentales sugieren un beneficio potencial del aceite de pescado (APE como neuroprotector debido al alto contenido de DHA y EPA. Sin embargo, es poco lo que se conoce en cuanto a los efectos que pudieran tener sobre alteraciones nerviosas, como las crisis convulsivas. En este contexto, se ha reportado que el tipo más común de trastorno epiléptico observado en los niños son las crisis convulsivas provocadas por fiebre (CF. La incidencia es de 3-5%, con ocurrencia entre los 5 meses y 5 años de edad, y se ha propuesto que esta alteración en la vida temprana pudiera tener efectos a largo plazo, manifestándose como un síndrome de epilepsia en la vida adulta. El objetivo del presente estudio fue evaluar el efecto del APE sobre las convulsiones inducidas por hipertermia experimental en un grupo de ratas Wistar macho de 5 días de edad (grupo SAPE cuyas madres consumieron una dieta base más un suplemento de APE (suministrado desde su infancia hasta la etapa de crianza. Este grupo se comparó con otro grupo de ratas de la misma edad y cepa (grupo SAPA cuyas madres consumieron una dieta base más un suplemento de aceite de palma (suministrado desde su infancia hasta la etapa de crianza, y con un tercer grupo de ratas (grupo CTRL cuyas madres consumieron la dieta base más agua bidestilada como suplemento. Las ratas tratadas con APE presentaron mayor resistencia a la elevación de la temperatura corporal inducida por la hipertermia, una menor frecuencia

  15. Estrategias para el tratamiento de la disfunción sexual inducida por la medicación antidepresiva

    Directory of Open Access Journals (Sweden)

    Matthew J. Taylor

    2014-01-01

    Conclusiones de los autores: Las pruebas actualmente disponibles son muy limitadas. En los hombres con disfunción eréctil inducida por antidepresivos, el agregado de sildenafil o tadalafil parece ser una estrategia eficaz. En las mujeres con disfunción sexual inducida por antidepresivos, el agregado de bupropión a dosis mayores parece ser el enfoque más alentador estudiado hasta el presente.

  16. Citotoxicidad del cadmio en hepatocitos de ratón albino y sus posibles implicaciones en ambientes tropicales

    OpenAIRE

    Letty Marcano; Clarisa de R. Faría; Ingrid Carruyo; Xiomara Montiel

    2006-01-01

    Se realizó un análisis de las alteraciones fenotípicas, estructurales y ultraestructurales inducidas por Cd+2 en hepatocitos de ratón albino suizo. El metal fue suministrado vía oral en solución acuosa de CdCl2 durante 100 días a concentraciones de 50 ppm, 100 ppm y 150 ppm, en los controles la solución de cadmio fue sustituida por agua destilada. Las muestras fueron procesadas utilizando la técnica de inclusión en parafina y teñidas con hematoxilina- eosina para microscopía óptica y por la t...

  17. Valoración de dos métodos de tinción en ensayos de citotoxicidad sobre líneas celulares tumorales

    Directory of Open Access Journals (Sweden)

    Linamaría Escobar M

    2009-07-01

    Full Text Available En la estimación de la posible citotoxicidad de extractos o compuestos en proceso de prospección se emplean métodos de tinción celular como aproximación indirecta para la medición masa celular viable. En ensayos de citotoxicidad sobre las líneas celulares SiHa, MCF-7 y MKN-45 se comparan el método de tinción sulforoda-mina B (SRB, que es un ensayo de tipo terminal, con el uso de resazurina propuesta como poco tóxica para las células. La comparación de los métodos se hizo en términos de porcentaje de supervivencia donde se evaluó la sensibilidad de las líneas a tres compuestos sintéticos durante un periodo de tratamiento de 48 horas usando como referencia de actividad doxorrubicina HCl, un medicamento empleando en cáncer. Los datos obtenidos en los dos tipos de ensayos sometidos a una prueba de correlación mostraron que no hay diferencias significati-vas en ambos métodos permitiendo la comparación entre estos bajo las condiciones usadas.

  18. Evaluation of Brazilian medical devices using agar diffusion cytotoxicity assay Avaliação de dispositivos médicos brasileiros utilizando o ensaio de citotoxicidade pela difusão em ágar

    Directory of Open Access Journals (Sweden)

    Mirian N. P. Vidal

    2009-04-01

    Full Text Available Over the last decades, governmental actions and mechanisms created to protect consumer rights have been linked to a growing effort to guarantee the quality and reliability of products. Samples of condoms (latex, medical devices and blood bags (PVC - polyvinyl chloride have been tested using the agar diffusion assay. This assay evaluates the cytotoxicity induced by biomaterials by measuring the biological reactivity of mammalian cell cultures in contact with these materials. PVC is used in the production of medical devices because of its specific properties, such as flexibility, obtained after the addition of plasticizers (phthalates, which can cause toxicity even at low doses. Latex is a natural elastomer used for surgical gloves and condoms with a formulation that includes dispersion of liquid latex and chemicals, such as antioxidants and a vulcanizing accelerator, both of which are able to induce cytotoxicity. Samples were analyzed by the National Institute of Quality Control in Health - INCQS of the Oswaldo Cruz Foundation (Fiocruz in accordance with the governmental sanitary surveillance actions on respect to the quality control. We observed an increase in the quality of the products in relation to the results of the agar diffusion assay during the period between 2000 and 2007. This situation, together with other actions, reflects in an improvement in the quality of products that can be translated in the health of the population.Durante as últimas décadas, a disseminação de ações governamentais e os mecanismos criados para proteger os direitos dos consumidores se associaram em crescentes esforços para garantir a qualidade e confiabilidade dos produtos. As amostras de preservativos (látex, dispositivos médicos e bolsas de sangue (PVC - cloreto polivinílico foram testadas utilizando o ensaio de difusão em ágar. O teste avalia a citotoxicidade induzida por biomateriais, medindo a reatividade biológica de culturas de células de mam

  19. Citotoxicidad y genotoxicidad de las aguas de los ríos Jequetepeque y Moche mediante el bioindicador ambiental Vicia faba L.

    Directory of Open Access Journals (Sweden)

    Raúl Antonio Beltrán Orbegoso

    2017-01-01

    Full Text Available La evaluación de la toxicidad de las aguas de los ríos como método complementario al análisis físico, químico y biológico proporciona una información integral de la calidad del agua, por tanto, el objetivo del estudio fue determinar los niveles de citotoxicidad y genotoxicidad de las aguas de las cuencas alta, media y baja de los ríos Moche y Jequetepeque, usando el bioindicador ambiental Vicia faba L. “haba” (2n = 12. Se germinaron semillas de V. faba L.; luego las raicillas emergentes se expusieron, durante tres horas, a siete tratamientos: T1 (100 ml de agua destilada, T2 (1 ml agua de río Jequetepeque / 99 ml de agua destilada, T3 (5 ml agua de río Jequetepeque/ 95 ml de agua destilada, T4 (10 ml agua de río Jequetepeque/ 90 ml de agua destilada, T5 (1 ml agua de río Moche/ 99 ml de agua destilada, T6 (5 ml agua de río Moche/ 95 ml de agua destilada y T7 (10 ml agua de río Moche/ 90 ml de agua destilada. Los ápices de las raicillas fueron sometidos a la técnica de Tjio y Levan. El agua de la cuenca media del río Moche del T7, presenta una alta citotoxicidad (índice mitótico de 5,4 % y alteraciones de los índices de fases y un alto efecto genotóxico; las aguas del río Jequetepeque no evidencian efecto citotóxico ni genotóxico de importancia.

  20. Determination of forces induced by steam flow in turbines; Determinacion de fuerzas inducidas por flujo de vapor en turbinas

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Castrejon, Juan Carlos

    2008-09-15

    blades, has a harmonic pattern. The pressure field variation as time function is uniform: the peaks and valleys across the axial clearance are always in phase. However the instant picture of the pressure field it's different: the peaks and valleys are not in phase and the number of peaks and valley changed across the clearance. In the case of the forces acting on blades, a Fourier on the forces calculated was used to determine the coefficients and frequency of a Fourier equation which can be used to calculate the alternating stresses on the blade in order to predict the useful life blades. [Spanish] Las vibraciones inducidas por flujo de vapor en turbinas representan uno de los problemas que enfrenta la operacion de turbinas de vapor cuya capacidad rebasa los 300 MW. Ademas estas constituyen uno de los limites tecnologicos para el desarrollo de turbinas de vapor de mas de 1 GW. Este tipo de fenomeno tiene su origen en la interaccion del rotor con el fluido que se encuentra en sus proximidades. El flujo de vapor dentro de la turbina es complejo, ya que es turbulento e inestable. A medida que el flujo pasa una etapa de estator o de rotor, se generan secundarios, vortices en los filos de salida, estelas con caracteristicas de flujo diferentes al flujo principal en los pasajes. Estas variaciones en el flujo son las que inducen vibraciones forzadas en los alabes. Ademas existen varios factores que contribuyen a la aplicacion de vibraciones en alabes inducidas por flujo como son: inestabilidad del flujo de vapor en los claros de los sellos, secuencia de apertura de las valvulas, estelas de las toberas, obstrucciones en algunas de las toberas y diferente espaciamiento en las toberas. Las vibraciones por flujo pueden ser peligrosas si su frecuencia coincide con la frecuencia natural del sistema, provocando efectos mas nocivos que las vibraciones por desbalance o por desalineamiento, pues tienen amplitudes mas grandes y provocan esfuerzos alternantes en los componentes del

  1. Osteomalacia inducida por tumor: hemangiopericitoma rinosinusal Tumor-induced osteomalacia: rhinosinusal hemangiopericytoma

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    Enriqueta M. Serafini

    2013-02-01

    Full Text Available La osteomalacia inducida por tumor es una rara enfermedad del metabolismo óseo caracterizada por el aumento en la excreción de fosfato a nivel renal seguido de hipofosfatemia. Es causada por agentes fosfatúricos producidos por determinados tumores. La resección total del tumor resulta en la completa reversión de las anormalidades bioquímicas, la desaparición de las manifestaciones clínicas y los hallazgos en los estudios por imágenes. Presentamos el caso de un varón de 61 años con cuadro clínico y laboratorio compatibles con osteomalacia oncogénica inducida por tumor mesenquimático de localización rinosinusal. En nuestro caso el diagnóstico histológico correspondió a una neoplasia de tipo vascular: hemangiopericitoma.Tumor-induced osteomalacia is a rare disease of bone metabolism. The characteristic of this disease is an increase in phosphate excretion followed by hypophosphatemia, due to phosphaturic agents produced by different types of tumors. Tumor resection results in complete resolution of clinical, biochemical and radiological abnormalities. We present the case of a 61 year old man with signs, symptoms and laboratory findings consistent with oncogenic osteomalacia due to a rhino-sinusal mesenchymal tumor. The histological diagnosis showed a vascular neoplasm: hemangiopericytoma.

  2. Avaliação da citotoxicidade de dois sistemas adesivos Evaluation of the cytotoxicity of two dentin-bonding systems

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    Flávio Fernando DEMARCO

    1998-10-01

    Full Text Available Avaliamos a citotoxicidade in vitro de dois sistemas adesivos (Scotchbond Multipurpose Plus e Clearfil Liner Bond 2 utilizando fibroblastos NIH-3T3. Culturas celulares confluentes entraram em contato com os sistemas adesivos completos e com seus componentes individuais ("primer" e adesivo. As substâncias foram aplicadas sobre lamínulas de vidro e, a seguir, introduzidas nos cultivos celulares. Adicionalmente, testamos a citotoxicidade da resina composta (Z100; do cimento de hidróxido de cálcio (Hidro C e do ácido fosfórico. Como controle utilizamos culturas que receberam lamínulas de vidro sem substâncias. Com exceção do ácido fosfórico, que permaneceu por 20 segundos, todos os materiais foram deixados por 24 horas, período após o qual determinamos a porcentagem de viabilidade celular pelo método da exclusão de células coradas pelo azul de trypan. Os dados dos diferentes grupos foram submetidos a análise estatística (ANOVA e teste de Tukey. Foi possível observar que todas as culturas tratadas apresentaram menor porcentagem de viabilidade celular em relação ao grupo controle, com exceção das culturas tratadas pelo Ca(OH2, que apresentaram valores similares de viabilidade celular. A aplicação da resina composta, do ácido fosfórico, do "primer" e do adesivo do sistema adesivo Scotchbond Multipurpose Plus empregados individualmente levaram as culturas a apresentar viabilidade celular similar àquela do grupo do Ca(OH2. Os dois sistemas adesivos, bem como o "primer" e o adesivo do sistema Clearfil Liner Bond 2, quando aplicados individualmente, causaram citotoxicidades similares, levando a porcentagens de viabilidade celular menores do que aquela encontrada com o Ca(OH2. Não foram encontradas diferenças estatisticamente significantes nos efeitos citotóxicos causados pelos diversos componentes dos dois sistemas adesivos testados.The purpose of the present study was to evaluate the cytotoxicity of two different dentin

  3. Citotoxicidad del cadmio en hepatocitos de ratón albino y sus posibles implicaciones en ambientes tropicales

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    Letty Marcano

    2006-06-01

    Full Text Available Se realizó un análisis de las alteraciones fenotípicas, estructurales y ultraestructurales inducidas por Cd+2 en hepatocitos de ratón albino suizo. El metal fue suministrado vía oral en solución acuosa de CdCl2 durante 100 días a concentraciones de 50 ppm, 100 ppm y 150 ppm, en los controles la solución de cadmio fue sustituida por agua destilada. Las muestras fueron procesadas utilizando la técnica de inclusión en parafina y teñidas con hematoxilina- eosina para microscopía óptica y por la técnica convencional para microscopía electrónica de transmisión. Identificamos cambios fenotípicos (diferencias entre talla y peso y fisiológicos (debilidad muscular e intranquilidad; a nivel histológico, pérdida de la disposición trabecular y de la arquitectura lobulillar, focos de aglomerados linfocíticos, vacuolización, dilatación de sinosoides y de la vena central. El estudio ultraestructural señala diversas alteraciones tales como: nucléolo con un elevado número de centros fibrilares (50 ppm; voluminosas gotas de lípidos en el citoplasma, retículo endoplasmático rugoso distendido, vacuolización citoplasmática, lisosomas y peroxisomas alterados (100 ppm; núcleos contraídos con cromatina condensada, dilatación en el espacio intracelular y áreas de pérdida mitocondrial y fibrilar (150 ppm. Sugerimos que el cadmio ejerce un efecto tóxico en las células hepáticas el cual se hace más severo con el aumento de la concentración, llevando a la necrosis celular.Cadmium citotoxicity in mice hepatocytes and impications on tropical environments. We analyzed phenotypic, structural and ultrastructural alterations induced by Cd+2 in hepatocytes extracted from Swiss Albino mice. Cadmium was given orally in watery solution of CdCl2 during 100 days at concentrations of 50 ppm, 100 ppm and 150 ppm. In controls, distilled water alone was used. The samples were processed with the paraffin inclusion and hematoxilin-eosin coloration

  4. Citotoxicidad de extractos de plantas medicinales sobre la línea celular de carcinoma de pulmón humano A549

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    Alexis Díaz García

    2011-03-01

    Full Text Available OBJETIVO: evaluar el efecto de 10 extractos de plantas medicinales sobre el crecimiento de la línea celular humana de carcinoma de pulmón A549. METODOS: el efecto de los extractos sobre la células tumorales se midió a través de un ensayo colorimétrico mediante el empleo del bromuro de 3-(4,5-dimetil-tiazol-2-yl-2,5-difenil tetrazolio a concentraciones entre 3,9-250 µg/mL durante 72 h y se calculó la concentración citotóxica media para cada uno. RESULTADOS: del total de los extractos evaluados solo cuatro (Parthenium hysterophorus, Bixa orellana, Momordica charantia y Cucurbita maxima evidenciaron concentraciones citotóxicas medias inferiores a 100 µg/mL. Excepto Parthenium hysterophorus, las restantes se emplean en la medicina tradicional para el tratamiento del cáncer. Los extractos de Cecropia peltata, Melia azedarach, Annona glabra, Artemisia absintium, Lepidium virginicum y Bidens pilosa no mostraron efectos citotóxicos significativos. CONCLUSIONES: Los extractos de plantas que se emplean en la medicina tradicional para el tratamiento del cáncer, mostraron citotoxicidad sobre las células tumorales. El conocimiento etnobotánico representa una herramienta importante en la selección de plantas medicinales, en la búsqueda de nuevos compuestos para el tratamiento del cáncer.

  5. Capacidad antiteratogénica del resveratrol en diabetes inducida por estreptozotocina en ratas

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    Ninna Leslie Trejo-González

    Full Text Available Objetivos. Evaluar la capacidad antihiperglucémica y antiteratogénica del resveratrol en ratas inducidas a diabetes por estreptozotocina. Materiales y métodos. Estudio de tipo experimental. Se tuvieron tres grupos, de cinco ratas Wistar preñadas cada uno, dos de los cuales fueron tratados el cuarto día de gestación con una dosis de estreptozotocina de 50 mg/kg, disuelta en tampón de citratos, y el otro fue considerado como control, y solo se le administró el tampón de citratos. A uno de los grupos inducidos con estreptozotocina se le administró resveratrol a dosis de 100 mg/kg durante los días 8 al 12 de gestación, cuando sucede la neurulación. Los fetos se obtuvieron el día 19 de gestación y se les realizó un análisis morfológico, y en el hígado fetal se determinó la actividad de las enzimas depuradoras de especies reactivas catalasa, superóxido dismutasa y glutatión peroxidasa. Resultados. La administración de resveratrol (DM+R revierte los parámetros a valores similares a los del grupo control. Las actividades de catalasa y de glutatión peroxidasa, se vieron incrementadas en el grupo tratado con resveratrol con respecto al grupo diabético, en cuanto a la frecuencia de malformaciones en el grupo control y en el grupo tratado con resveratrol no presentaron malformaciones, mientras que en las ratas con diabetes inducida, se encontró una elevada frecuencia de malformaciones. Conclusiones. El resveratrol muestra propiedades antiteratogénicas a través de la disminución del estrés oxidativo que se presenta a causa de la hiperglucemia materna

  6. Respuesta del sistema antioxidante en varones sanos, frente a hiperglicemia aguda inducida

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    Raquel Oré

    2009-09-01

    Full Text Available Objetivo: determinar la respuesta del sistema antioxidante en varones sanos, frente a la hiperglicemia aguda inducida. Diseño: estudio prospectivo, descriptivo, longitudinal, experimental. Lugar: Instituto Nacional de Biología Andina, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material biológico: Sangre y suero de sujetos aparentemente sanos. Intervenciones: A 13 sujetos adultos clínicamente sanos, entre 20 y 41años, después de 10 horas de ayuno, se administró glucosa vía endovenosa, mediante el método de clamp hiperglicémico, a 125 mg/dL por encima del valor basal, durante 120 minutos. Se realizó mediciones de la glicemia a 0, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110 y 120 minutos. Se tomó la muestra sanguínea con anticoagulante EDTA y otra de sangre total, para obtención de suero, para las pruebas bioquímicas a los 0, 60 y 120 minutos. Principales medidas de resultados: Modificaciones de la glicemia y lipoperoxidación en suero, glutatión y actividad superóxido dismutasa en glóbulos rojos lisados e índices de estrés oxidativo. Resultados: El nivel de glucosa durante el clamp hiperglicémico, luego de alcanzar el ‘equilibrio’, fue 197±17,58 mg/dL. La lipoperoxidación aumentó de 2,54 + 0,51 a 2,90 + 0,58 umol/L, de 0 a 60 minutos, y a 2,66 + 0,55 umol/L a los 120 minutos. El glutatión se redujo en 8,10% a la hora, aumentando 7,08% a los 120 minutos. La actividad superóxido dismutasa se elevó 0,54% a los 60 minutos y 5,66% a los 120 minutos, sobre el basal. Los índices de valoración del estrés oxidativo tuvieron correlación r Pearson positiva, en nivel alto a muy alto. Conclusiones: la hiperglicemia aguda inducida hasta 2 horas elevó el estrés oxidativo, promoviendo generación de defensa antioxidante, con síntesis de glutatión reducido de novo y mayor actividad de la superóxido dismutasa.

  7. In vitro antimalarial activity and cytotoxicity of some selected cuban medicinal plants Actividad antimalárica in vitro y citotoxicidad de algunas plantas medicinales Cubanas seleccionadas

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    Aymé Fernández-Calienes Valdés

    2010-08-01

    Full Text Available Terrestrial plants have been demonstrated to be sources of antimalarial compounds. In Cuba, little is known about antimalarial potentials of plant species used as medicinals. For that reason, we evaluated the antimalarial activity of 14 plant species used in Cuba as antimalarial, antipyretic and/or antiparasitic. Hydroalcoholic extracts were prepared and tested in vitro for the antimalarial activity against Plasmodium falciparum Ghana strain and over human cell line MRC-5 to determine cytotoxicity. Parasite multiplication was determined microscopically by the direct count of Giemsa stained parasites. A colorimetric assay was used to quantify cytotoxicity. Nine extracts showed IC50 values lower than 100 µg/mL against P. falciparum, four extracts were classified as marginally active (SI 10. B. vulgaris showed the most potent and specific antiplasmodial action (IC50 = 4.7 µg/mL, SI = 28.9. Phytochemical characterization of active extracts confirmed the presence of triterpenoids in B. vulgaris and polar compounds with phenol free groups and fluorescent metabolites in both extracts as major phytocompounds, by thin layer chromatography. In conclusion, antimalarial use of B. vulgaris and P. hysterophorus was validated. B. vulgaris and P. granatum extracts were selected for follow-up because of their strong antimalarial activity.Las plantas terrestres han demostrado ser fuentes de compuestos antimaláricos. En Cuba, el conocimiento sobre el potencial antimalárico de las plantas medicinales es escaso. Por esta razón, evaluamos la actividad antimalárica de 14 especies de plantas usadas en Cuba como antimaláricas, antipiréticas y/o antiparasitarias. Se prepararon extractos hidroalcohólicos y se probaron in vitro frente a la cepa Ghana de Plasmodium falciparum para la actividad antimalárica y frente a la línea celular humana MRC-5 para determinar citotoxicidad. La multiplicación de los parásitos se determinó microscópicamente mediante el

  8. Cardiomiopatía inducida por estrés (Takotsubo en una paciente con anorexia nerviosa

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    Sabrina Vadalá

    2014-06-01

    Full Text Available Presentamos el caso de una mujer con diagnóstico de anorexia nerviosa que desarrolló cardiomiopatía de takotsubo precipitada por estrés emocional y alteraciones del medio interno. Evolucionó favorablemente con manejo conservador. Los casos de cardiomiopatía inducida por estrés, descriptos en pacientes con trastornos de la conducta alimentaria, suelen alcanzar mayor gravedad y se asocian con la prolongación del intervalo QT por desequilibrios electrolíticos, arritmias ventriculares e hipoglucemia. Se realiza una revisión del compromiso cardiovascular en pacientes con anorexia nerviosa.

  9. Citotoxicidade e genotoxicidade da água do rio Subaé (Humildes, Bahia, Brasil usando Allium cepa L. como bioindicador

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    Jacqueline Ramos Machado Braga

    2015-01-01

    Full Text Available Ao longo dos anos, o rio Subaé na Bahia tem sido impactado por atividade industrial pelo lançamento de efluentes tóxicos em suas águas. O presente estudo analisou os efeitos citotóxicos e genotóxicos provocados pela água do trecho deste rio que banha o município de Humildes-BA, utilizando o teste do Allium cepa. Amostras de água foram obtidas em três pontos de coleta (PI, PII e PIII para as análises de parâmetros fisico-químicos. Bulbos de A. cepa foram colocados por 72 h para germinação nas amostras de água em triplicata. As radículas foram submetidas por 12-h a 4 oC, fixadas em Carnoy por 12-h e coradas com técnica de Feulgen. Foram analisadas 6.500 células/tratamento. A citotoxicidade foi avaliada pelo índice mitótico (IM e a genotoxicidade, por anormalidades cromossômicas (AC. Os testes fisico-químicos revelaram que PI e PIII apresentavam valores de OD, DBO5 e DQO alterados. O teste de toxicidade indicou que houve inibição do crescimento das raízes nos pontos PI (10,3 % e PII (10,6 %, quando comparados ao controle negativo (11,9 %. No PI, foram encontrados 6,2 % de ACs, 6 % em PII e 5,4 % em PIII, valores acima do controle positivo (3 %, evidenciando o efeito genotóxico nos pontos estudados. A partir dos resultados, pode-se inferir que as águas do Rio Subaé podem conter substâncias que provavelmente estão afetando o ciclo celular do A. cepa, sendo importante que outras análises sejam realizadas em diferentes estações do ano, para melhor monitoramento das condições ambientais locais.

  10. Estudio de la Citotoxicidad de Cerámicas Biomórficas de SiC Recubiertas con Vidrio Bioactivo

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    Borrajo, J. P.

    2006-04-01

    Full Text Available In the past years there was a need to develop new tough bioactive materials capable to resist high loads when implanted in the body, that led to the production of bioactive coatings on metallic substrates. A new approach, which consists of biomorphic silicon carbide (SiC coated with bioactive glass by Pulsed Laser Deposition (PLD, was recently presented. This new material joins the high mechanical strength, lightness and porosity of biomorphic SiC and the bioactive properties of PLD glass films. In this work, a multiple evaluation of this new material is presented starting from the biomorphic SiC morphology and porosity, following with the bioactivity in simulated body fluid of the coatings, and ending with a deep in vitro study with MG-63 cells. The citotoxicity of the SiC coated and uncoated and the cell proliferation and attachment were studied.

    La necesidad de desarrollar nuevos implantes basados en materiales bioactivos que sean capaces de soportar grandes cargas mecánicas ha llevado a la producción de sustratos metálicos recubiertos con cerámicas bioactivas. Recientemente se ha propuesto un dispositivo alternativo que consiste en un sustrato de carburo de silicio (SiC biomórfico recubierto con vidrio bioactivo, mediante la técnica de Depósito por Láser Pulsado (PLD, y que dispone de la resistencia mecánica adecuada, además de gran ligereza y una porosidad intrínseca muy favorable de cara a la implantación. En este trabajo se presenta un estudio interdisciplinar de este nuevo material centrado en la morfología y porosidad de sustratos de SiC provenientes de diferentes maderas, la bioactividad de los recubrimientos producidos por PLD y en la evaluación in vitro con células de osteosarcoma MG-63 con la que se ha determinado la citotoxicidad de estos materiales y se ha estudiado la influencia de los mismos en la adhesión y la proliferación celular.

  11. Disfunción tiroidea inducida por amiodarona en la práctica clínica

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    José Luis Paz-Ibarra

    2011-01-01

    Full Text Available La amiodarona (AMD es una droga antiarrítmica potente (clase III usada en la práctica clínica para la profilaxis y el tratamiento de muchos disturbios del ritmo cardiaco, desde la fibrilación auricular paroxística hasta las taquiarritmias ventriculares que amenazan la vida. Frecuentemente causa cambios en las pruebas de función tiroidea principalmente relacionados a la inhibición de la actividad de la 5'-deiodinasa, resultando en una disminución de la generación de T3 desde T4 y el consecuente incremento en la producción de T3 reversa y una disminución de su aclaramiento. En 14 a 18% de pacientes tratados con AMD hay una disfunción tiroidea manifiesta, ya sea tirotoxicosis inducida por amiodarona (TIA o hipotiroidismo inducido por amiodarona (HIA. Tanto TIA como HIA pueden desarrollarse en glándulas aparentemente normales o en glándulas con anormalidades preexistentes clínicamente silentes. La TIA está primariamente relacionada a la síntesis de hormonas tiroideas inducida por el exceso de yodo en una glándula tiroidea anormal (TIA tipo 1 o a una tiroiditis destructiva relacionada a la amiodarona (TIA tipo 2, aunque frecuentemente ocurren formas mixtas. La tiroiditis de Hashimoto preexistente es un factor de riesgo definido para la ocurrencia de HIA. La patogenia del HIA es la falla para escapar del efecto agudo de Wolff-Chaikoff inducido por el yodo, debido a los defectos en la hormonogénesis tiroidea y, en pacientes con pruebas de autoanticuerpos tiroideos positivos, para tiroiditis de Hashimoto concomitante. La TIA es más común en zonas deficientes de yodo mientras que el HIA es usualmente visto en zonas suficientes en yodo. En contraste al HIA, la TIA es una condición difícil de diagnosticar y tratar, y usualmente se recomienda la descontinuación de la amiodarona. En esta revisión se analiza, de acuerdo a los datos actuales, las alteraciones en las pruebas de función tiroidea vistas en pacientes eutirodeos bajo

  12. Cadmium cytotoxicity in albino mice hepatocytes and its possible implications on tropical environments; Citotoxicidad del cadmio en hepatocitos de raton albino y sus posibles implicaciones en ambientes tropicales

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    Marcano, Letty; Carruyo, Ingrid; Montiel, Xiomara [Univ. del Zulia, Facultad Experimental de Ciencias, Dept. de Biologia (Venezuela); com, letty_marcano@hotmail; Faria, Clarisa de R [Univ. del Zulia, Facultad de Medicina, Catedra de Histologia, Maracaibo, Zulia (Venezuela)

    2006-06-15

    Analyzed phenotypic, structural and ultrastructural alterations induced by Cd{sup +2} in hepatocytes extracted from Swiss Albino mice. Cadmium was given orally in watery solution of CdCl{sub 2} during 100 days at concentrations of 50 ppm, 100 ppm and 150 ppm. In controls, distilled water alone was used. The samples were processed with the paraffin inclusion and hematoxylin-eosin coloration techniques for light microscopy. The conventional technique was used for transmission electron microscopy . Phenotypic (size and weight differences) and physiologic changes (muscular weakness, unrest) were found; at the structural level it was noticed loss of trabecular disposition and of lobular architecture, lymphocyte agglomeration, vacuolisation, dilatation of sinusoid and central vein, among others. The ultrastructural study evidenced alterations coincident with those seen with light microscopy, which were accentuated with the increase of metal concentration: nucleolus with a high number of fibrillar centers (50 ppm); voluminous lipidic drops in the cytoplasm, loose endoplasmic rough reticulum, cytoplasmic vacuolisation, altered lysosomes and peroxisomes (100 ppm); contracted nucleis with condensed chromatin, dilatation of intracellular space and mitochondria, and loss of fibrillar areas (150 ppm). Cadmium produces a toxic effect in the hepatic cells; the effect is more severe at higher concentration, leading to cellular necrosis. (author) [Spanish] Se realizo un analisis de las alteraciones fenotipicas, estructurales y ultraestructurales inducidas por Cd{sup +2} en hepatocitos de raton albino suizo. El Cadmio fue suministrado via oral en solucion acuosa de CdCl{sub 2} durante 100 dias a concentraciones de 50 ppm, 100 ppm y 150 ppm. En los controles la solucion de cadmio fue sustituida por agua destilada. Las muestras fueron procesadas utilizando la tecnica de inclusion en parafina y tenidas con hematoxilina-eosina para microscopia optica y por la tecnica convencional para

  13. Paciente con trombocitopenia trombótica inducida por heparina en hemodiálisis: abordaje de la anticoagulación del circuito

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    Mirian García Martínez

    Full Text Available Resumen El tratamiento renal sustitutivo de hemodiálisis es una técnica de depuración sanguínea extraterrenal, que requiere proteger al circuito extracorpóreo del paciente. Actualmente la heparina es el anticoagulante endovenoso de elección para evitar este tipo de complicaciones intradiálisis, siendo necesaria la individualización de las dosis por paciente. La trombocitopenia trombótica inducida por heparina es uno de los posibles efectos secundarios producidos por la administración de heparina. La bivalirudina es un inhibidor directo y específico de la trombina, útil en diferentes procedimientos, siendo utilizado en pacientes con problemas con la heparina y con fracaso renal crónico terminal que requieren terapias de diálisis continuas. Caso clínico: Paciente de 46 años, con múltiples antecedentes personales. Al inicio de su proceso debutó con una Gangrena de Fournier secundaria a isquemia de extremidades inferiores, por lo que precisó tratamiento anticoagulante. Hasta la fecha no presentó alergias medicamentosas conocidas. Posteriormente se objetivó plaquetopenia progresiva con diagnóstico de trombocitopenia inducida por heparina tipo II por lo que se restringió la heparina de bajo peso molecular y la heparina sódica, indicándose anticoagulación con Sintrom y Bivalirudina en casos de procedimientos con alto riesgo de sangrado. Conclusiones: Los pacientes de hemodiálisis en nuestro hospital, tienen como pauta habitual de anticoagulación la heparina. En este caso el diagnostico precoz de la trombocitopenia trombótica inducida por la heparina, fue crucial para evitar daños mayores, siendo el equipo de enfermería la piedra angular en el tratamiento en la sala de hemodiálisis.

  14. Efecto hipoglucemiante del extracto etanólico de Geranium ruizii Hieron. (pasuchaca en la hiperglucemia inducida por aloxano en ratas

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    Oscar Herrera-Calderon

    2015-04-01

    Full Text Available Introducción: Geranium ruizii (Pasuchaca es una planta medicinal utilizada tradicionalmente como hipoglucemiante en el departamento de Ancash, Perú. Objetivo: Evaluar el efecto hipoglucemiante del extracto etanólico de Geranium ruizii administrada en ratas con hiperglicemia inducida por aloxano. Diseño: Experimental. Institución: Laboratorio de Farmacología Experimental, Facultad de Medicina Humana, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material biológico: Planta entera de Geranium ruizii, ratas Holtzman hembras de ocho semanas con 200 ± 20 g de peso corporal. Intervenciones: La hiperglicemia fue inducida con aloxano. Las ratas incluidas en el estudio presentaron una glicemia > 200 mg/dL. Se formaron seis grupos de seis ratas cada uno. El grupo I recibió agua destilada 2 mL; los grupo II, III y IV recibieron Geranium ruizii 50 mg/kg; 150 mg/kg y 300 mg/kg, respectivamente (vía oral; al grupo V se administró glibenclamida 5 mg/kg y al grupo VI insulina 4UI/kg. Principales medidas de los resultados: Glucemia (mg/ dL, porcentaje de inhibición del radical DPPH, especies reactivas al ácido tiobarbitúrico (TBARS (nmoles/mL, estudio histológico de páncreas. Resultados: La dosis de 150 mg/kg de G. ruizii redujo 65,58% los valores de glicemia a las 2 h post administración (Kruskal Wallis; p< 0,001, redujo TBARS en 22,34% e inhibió el radical DPPH en 23,66%; el tejido pancreático se mantuvo en buen estado de conservación. Conclusiones: El extracto etanólico de Geranium ruizii (pasuchaca tuvo efecto hipoglicemiante en ratas con hiperglucemia inducida con aloxano.

  15. Compuestos fenólicos de la fracción metanólica de Bidens pilosa, sobre la neoplasia gástrica, inducida en ratas

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    Jorge Arroyo

    2007-06-01

    Full Text Available Objetivo: Determinar la influencia del extracto etanólico y la fracción metanólica conteniendo compuestos fenólicos y flavonoides de la planta entera de Bidens pilosa L sobre la neoplasia gástrica inducida en ratas con N-nitroso-N-metilurea (NMU. Diseño: Experimental. Lugar: Instituto de Investigaciones Clínicas-Bioterio Facultad de Medicina UNMSM. Material biológico: Ratas albinas cepa Holtzmann machos. Intervenciones: Según Ferraz de Souza y col., 2002, se dispuso de un grupo control normal, un grupo con NMU y grupos de NMU más tratamientos de extracto etanólico y fracción metanólica, a dosis de 300 mg/kg. Para la significancia estadística se consideró la p<0,05. Principales medidas de resultados: Progresión de la neoplasia gástrica inducida en ratas. Resultados: Indican displasia y estadios iniciales de carcinoma en los estómagos de las ratas, lo que fue menos evidente en los animales con tratamiento, siendo mejor el grupo que recibió fracción metanólica. El marcador de estrés oxidativo disminuyó en los grupos que recibieron tratamiento con la planta, resultando mejor la fracción metabólica. Se observó menor cantidad de micronúcleos (genotoxicidad en los animales que recibieron tratamiento. Conclusiones: El extracto etanólico y la fracción metanólica de Bidens pilosa L en las condiciones experimentales han detenido la progresión de la neoplasia gástrica inducida en ratas.

  16. El tratamiento con progesterona previene las alteraciones motoras inducidas por la intoxicación con semillas de cícada (Dioon spinulosum) en la rata macho

    OpenAIRE

    E Rivadeneyra-Domínguez; M Saavedra; JF Rodríguez-Landa

    2009-01-01

    El consumo crónico de semillas de cícadas ha sido asociado con enfermedades neurodegenerativas, las cuales predominan en el género masculino. En México, las semillas de cícada (Dioon spinulosum) son usadas como sustituto de maíz y a nivel experimental producen un déficit motor; probablemente causado por sus componentes neurotóxicos. En este sentido, la progesterona ejerce efectos neuroprotectores contra traumatismo cerebral, hipoxia, así como la muerte neuronal inducida por colchicina en el S...

  17. Efecto de Gentianella alborosea en esteatosis hepática no alcohólica inducida por dieta hiperlipídica en ratas holtzman hembras

    OpenAIRE

    L Ugaz-Soto; JH Zafra-Tanaka; María E. Tapia Vicente

    2013-01-01

    Objetivo: Determinar el efecto del extracto de Gentianella alborosea como tratamiento contra esteatosis hepática no alcohólica (EHNA)  inducida por dieta hiperlipídica en ratas Holtzman hembras. Métodos: Diseño: Estudio experimental incompleto. Lugar: Universidad Nacional Mayor de San Marcos, Lima, Perú. Participantes: Ratas Holtzman hembras. Intervenciones: Se utilizó 32 ratas repartidas en 4 grupos (n=8) distribuidos aleatoriamente: grupo control negativo, control positivo con dieta hiperli...

  18. Papel del endotelio en hipertensión inducida por el embarazo: ¿alteraciones comunes a las de la aterosclerosis?

    OpenAIRE

    López-Jaramillo, Patricio; Sotomayor-Rubio, Katherine; Sotomayor-Rubio, Arístides; López-López, Cristina

    2014-01-01

    La hipertensión inducida por el embarazo, cuya forma proteinúrica es denominada preeclampsia (PE), es una alteración que ocurre en el segundo trimestre del embarazo, y se caracteriza por la presencia de hipertensión y proteinuria. Durante el embarazo normal ocurren cambios fisiológicos adaptativos que incluyen insulino-resistencia (IR), hiperlipidemia, hipercoagulabilidad, inflamación y un estado circulatorio hiperdinámico. Estos cambios se expresan de una forma exagerada en las mujeres que d...

  19. Arteriopatía periférica crónica inducida por cocaína

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    Sonia Pankl

    2012-02-01

    Full Text Available La trombosis periférica aguda inducida por cocaína ha sido descripta en la literatura, siendo una complicación poco común. Si bien existen comunicaciones que reflejan los efectos crónicos de la cocaína sobre el sistema arterial periférico, no hay casos publicados de tal complicación en ausencia de otros factores de riesgo. Se presenta el caso de una mujer de 22 años de edad con antecedentes de consumo de cocaína intranasal de 3 gramos por semana durante un año, que consultó por claudicación intermitente a los 200 metros asociada a dolor y parestesias en miembro inferior izquierdo de 2 meses de evolución. El ecodoppler arterial evidenció una estenosis mayor del 70% en la arteria femoral superficial izquierda. Se realizaron estudios complementarios descartando otras etiologías probables. Se inició tratamiento con ácido acetilsalicílico, cilostazol y ejercicio reglado, asociado a terapia de apoyo para mantenimiento del cese del consumo de cocaína, con buena respuesta. Se destaca la importancia de la difusión de información a los pacientes, dado que la mayoría de la población desconoce las complicaciones cardiovasculares de dicha adicción. Es indispensable indagar sobre el consumo de cocaína en pacientes jóvenes con arteriopatía sin factores de riesgo aparentes.

  20. Efecto hipolipidémico del extracto acuoso de las hojas de Artocarpus altilis "árbol del pan" en Rattus norvegicus con hiperlipidemia inducida

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    Julio Campos Florián

    2013-01-01

    Full Text Available La presente investigación tuvo como objetivo demostrar la actividad hipolipidémica del extracto acuoso de las hojas del árbol del pan, Artocarpus altilis, en un modelo de hiperlipidemia aguda inducida con tritón X-305, utilizando como especímenes Rattus norvegicus machos, peso promedio 204,5 g, a los que se les administró por vía oral 0,05 g/100 g y 0,2 g/100 g del extracto acuoso de A. altilis; se incluyó un grupo control negativo que recibió solución salina fisiológica y un grupo control positivo hiperlipidémico. Luego de 24 horas de administrar los tratamientos, se realizaron las mediciones en suero de las concentraciones de colesterol y triglicéridos. Encontramos reducciones significativas (p < 0,01 tanto de las cifras de colesterol, como de triglicéridos en relación a las concentraciones obtenidas en el grupo control positivo. También encontramos diferencia significativa (p < 0,01 entre las concentraciones de triglicéridos de los animales tratados con las dos dosis del extracto acuoso de A. altilis. Concluimos que el extracto acuoso de las hojas de A. altilis presenta efecto hipolipidémico a las dosis ensayadas para el modelo de hiperlipidemia inducida con tritón X-305.

  1. Modificaciones hematológicas inducidas por eritropoyetina frente a hipoxia normobárica intermitente Hematologic changes induced by erythropoietin versus intermittent normobaric hypoxia

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    F. Sanchis-Gomar

    2010-12-01

    Full Text Available

    Publicaciones recientes reflejan la preocupación de las autoridades antidopaje por el uso de sistemas simuladores de altitud y la posibilidad de considerarlos métodos dopantes. El objetivo de nuestro estudio fue el de comparar las modificaciones hematológicas inducidas por dos tratamientos con eritropoyetina recombinante humana (rHuEpo a diferentes dosis, frente a un protocolo de hipoxia normobárica intermitente (HNI en un modelo animal.
    Veinticuatro ratas Wistar macho jóvenes fueron divididas en 3 grupos experimentales: grupo sometido a HNI (12h pO2 12% /12h pO2 21% (n=8; grupo tratado con una dosis de 300 UI de rHuEpo (n=8 y grupo tratado con 500 UI de rHuEpo (n=8. Se extrajeron dos muestras de sangre a cada uno de los grupos experimentales (antes y después de los tratamientos. Nuestros resultados muestran incrementos muy similares, y estadísticamente significativos, en los valores de hemoglobina, de hematocrito y de reticulocitos, tanto en el grupo HNI como en el grupo tratado con 300 UI de rHuEpo tras los 15 días de tratamiento. El tratamiento con 500 UI de rHuEpo produjo un incremento significativamente mayor.
    La principal conclusión de nuestro estudio es que las modificaciones de los parámetros hematológicos obtenidas mediante un protocolo de HNI son similares a las obtenidas con un tratamiento con 300 UI de rHuEpo.
    Palabras clave: Hemoglobina, hematocrito, reticulocitos, dopaje

    Recent publications reflect the anti-doping authorities’ concern about the use of altitude simulator systems, since these technologies could be considered as doping methods. The major aim of our study was to compare the effect of two different rHuEpo treatments with a normobaric intermittent hypoxic (NIH protocol regarding the modifications of hemoglobin, hematocrit and reticulocytes values in an animal model. Although these hematological parameters are of secondary nature, some international sport federations

  2. Efecto antioxidante y hepatoprotector del Petroselinum sativum (perejil en ratas, con intoxicación hepática inducida por paracetamol

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    Luzmila Troncoso

    2007-12-01

    Full Text Available Objetivo: Determinar el efecto antioxidante y hepatoprotector del perejil (Petroselinum sativum en ratas con intoxicación hepática inducida por paracetamol. Lugar: Centro de Investigación de Bioquímica y Nutrición - "Laboratorio de Bioquímica Clínica y Nutricional "Leonidas Delgado Butrón" "Emilio Guija Poma" - Universidad Nacional Mayor de San Marcos. Lima, Perú. Diseño: Estudio analítico, transversal, prospectivo y cuasi-experimental. Material: Ratas albinas Holtzman machos adultas. Métodos: Se utilizó 40 ratas de 2 meses de edad, con pesos entre 280 y 320 g, distribuidas aleatoriamente en cuatro grupos de 10 animales cada uno. Todos los grupos recibieron la misma dieta y agua ad libitum, además de los respectivos tratamientos, los cuales fueron administrados por vía oral diariamente, durante 5 días: paracetamol (administrado en una dosis de 200 mg/kg de peso corporal para inducir la intoxicación hepática y, al mismo tiempo, un hepatoprotector, ya fuera farmacológico (fármaco hepatoprotector (FHP: Purinor® o natural (perejil; además, un grupo de paracetamol solo y otro de control. Al término del período experimental, los animales fueron sacrificados. En suero sanguíneo se determinó aspartato aminotransferasa (AST, alanina aminotransferasa (ALT, gamma glutamil transferasa (GGT, grupos sulfhidrilo, proteínas totales y albúmina sérica; y en el homogenizado citosólico de hígado, fracción posmitocondrial, se determinó superóxido dismutasa, catalasa, glucosa-6-fosfato deshidrogenasa, grupos sulfidrilo, especies reactivas al ácido tiobarbitúrico (TBARS o radicales libres y proteínas. Además, se realizó el estudio histopatológico del hígado, para identificar signos de necrosis y signos de regeneración posnecrótica. Principales medidas de resultados: Efecto antioxidante y hepatoprotector del perejil. Resultados: El perejil mostró un mejor efecto hepatoprotector que el FHP, frente a la acción nociva del

  3. natural

    Directory of Open Access Journals (Sweden)

    Elías Gómez Macías

    2006-01-01

    Full Text Available Partiendo de óxido de magnesio comercial se preparó una suspensión acuosa, la cual se secó y calcinó para conferirle estabilidad térmica. El material, tanto fresco como usado, se caracterizó mediante DRX, área superficial BET y SEM-EPMA. El catalizador mostró una matriz de MgO tipo periclasa con CaO en la superficie. Las pruebas de actividad catalítica se efectuaron en lecho fijo empacado con partículas obtenidas mediante prensado, trituración y clasificación del material. El flujo de reactivos consistió en mezclas gas natural-aire por debajo del límite inferior de inflamabilidad. Para diferentes flujos y temperaturas de entrada de la mezcla reactiva, se midieron las concentraciones de CH4, CO2 y CO en los gases de combustión con un analizador de gases tipo infrarrojo no dispersivo (NDIR. Para alcanzar conversión total de metano se requirió aumentar la temperatura de entrada al lecho a medida que se incrementó el flujo de gases reaccionantes. Los resultados obtenidos permiten desarrollar un sistema de combustión catalítica de bajo costo con un material térmicamente estable, que promueva la alta eficiencia en la combustión de gas natural y elimine los problemas de estabilidad, seguridad y de impacto ambiental negativo inherentes a los procesos de combustión térmica convencional.

  4. Efecto del extracto del fruto de Physalis peruviana "tomatillo" en Mus musculus var. swis con hiperlipidemia inducida.

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    Julio Campos Florián

    2011-01-01

    Full Text Available El objetivo de la presente i nvestigación fue determinar la actividad hipolipidémica del fruto de Physalis peruviana “tomatillo” en un modelo de hiperlipidemia aguda inducida con tritón. Se utilizaron Mus musculus var. swis machos como animales de experimentación. Se trabajó con cuatro grupos de ratones, el grupo blanco recibió agua destilada por vía oral y solución salina fisiológica por vía intraperitoneal, el grupo control recibió agua destilada por vía oral y tritón por vía intraperitoneal, el grupo problema 1 recibió por vía oral 0.05g/100g del extracto de Physalis peruviana y tritón por vía intraperitoneal y el grupo problema 2 recibió por vía oral 0.2g/100g del extracto de Physalis peruviana y tritón por vía intraperitoneal. Luego de 24 horas de administrar los tratamientos se re alizaron las mediciones en suero de las concentraciones de colesterol y triglicéridos. Los niveles promedio de colesterol (mg/dL fueron: 58.87±11.54 (blanco, 121.71±15.00 (control, 58.08±9. 21 (problema 1 y 66.78±16.77 (problema 2. Los niveles promedio de triglicéridos (g/L fueron: 0.48±0.07 (blanco, 1.84±0.18 (control, 0.34±0.10 (problema 1 y 0.94±0.25 (problema 2. Se encontró reducciones significativas (p<0.000, tanto de las concentraciones de colesterol como de triglicéridos en relación a las o btenidas en el grupo tratado sólo con tritón.

  5. El coactivador de receptores nucleares RAC3 tiene un rol protector de la Apoptosis inducida por distintos estímulos RAC3 nuclear receptor co-activator has a protective role in the apoptosis induced by different stimuli

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    Georgina P. Coló

    2007-10-01

    Full Text Available RAC3 pertenece a la familia de coactivadores de receptores nucleares p160, y se encuentra sobreexpresado en varios tumores. Demostramos previamente que RAC3 es coactivador del factor de transcripción anti-apoptótico NF-kapa;B. En este trabajo investigamos su rol en la apoptosis inducida por H2O2 en una línea celular no tumoral derivada de riñón embrionario humano (HEK293, y por el ligando inductor de apoptosis relacionado a TNF (TRAIL en una línea de leucemia mieloide crónica humana (K562, naturalmente resistente a la muerte por este estímulo. Observamos que las células tumorales K562 poseen niveles altos de RAC3 comparados con las células no tumorales HEK293. La sobreexpresión normal de coactivador o por transfección, inhibe la apoptosis mediante una disminución de la activación de caspasas, translocación del factor inductor de apoptosis (AIF al núcleo, aumento de la actividad de NF-kapa;B y las quinasas AKT y p38 y disminución de la quinasa ERK. Lo opuesto fue observado por disminución de RAC3 mediante la técnica de ARN interferente (RNAi en K562, aumentando así la apoptosis inducida por TRAIL. Estas evidencias sugieren que una sobreexpresión de RAC3 contribuye al desarrollo de tumores, participando en las cascadas que controlan la muerte celular por mecanismos no estrictamente dependientes de hormonas esteroideas y/o de acetilación, constituyendo esto un posible blanco de ataque para el tratamiento de tumores.RAC3 belongs to the family of p160 nuclear receptors coactivators and it is over-expressed in several tumors. We have previously shown that RAC3 is a NF-kappa;B coactivator. In this paper, we investigated the role of RAC3 in cell-sensitivity to apoptosis, using H2O2 in the human embryonic kidney cell line (HEK293, and tumor necrosis factor-related apoptosis inducing ligand (TRAIL in a human chronic myeloid leukemia cell line (K562 naturally resistant to TRAIL. We observed that the tumoral K562 cells have high levels

  6. Carbonatogénesis inducida en un perfil de suelo tropical

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    Yamile Valencia González

    2014-01-01

    Full Text Available En los suelos puede generarse un proceso común en la naturaleza denominado “biomineralización”o “bioprecipitación”, mediante el cual los organismos vivos presentes en él forman precipitados minerales cristalinos o amorfos. Este proceso es muy importante para la ingeniería geotécnica, ya que los minerales precipitados pueden llenar los vacíos o ligar las partículas de suelo mejorando las propiedades geológico-geotécnicas del material; sin embargo, el proceso demora muchísimos años para ocurrir de forma natural. Es por eso, que con esta investigación se buscó inducir en pocos días (15 días la precipitación de minerales de carbonato de calcio, a partir de la adición de un nutriente precipitador sobre las bacterias nativas existentes en un perfil de suelo tropical, mejorando sus propiedades ingenieriles por medio de la disminución del índice de vacíos, la retracción, la permeabilidad, el colapso, la erodabilidad y la degradación, y del aumento de la cohesión y la fricción, causando menor impacto ambiental que otras técnicas usadas comúnmente en la ingeniería.

  7. Muerte celular inducida por condiciones ambientales adversas en Calibrachoa parviflora (Petunia

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    Daniela Montes Berrueta

    2012-03-01

    Full Text Available Se ha descrito que condiciones ambientales extremas tales como altas temperaturas, luz ultravioleta y el efecto invernadero, alteran la tasa de crecimiento de las plantas. En este trabajo se investigó el efecto agudo de dos condiciones ambientales extremas tales como la limitación de nutrientes y la acidificación del suelo con ácido sulfúrico, un compuesto comúnmente depositado en los suelos como consecuencia de la llamada lluvia ácida, sobre la tasa de muerte y proliferación celular en petunias (Calibrachoa parviflora. Para tales efectos, grupos de petunias fueron sometidas a tres condiciones diferentes: grupo A o control, mantenida en condiciones óptimas y de suministro de nutrientes, grupo B en ausencia de nutrientes y de luz natural, y grupo C expuestas a agua acidificada con ácido sulfúrico. En un seguimiento hasta 72 horas, se analizaron muestras de pétalos, hojas y tallos de cada una de las plantas y, posterior a la extracción de los núcleos, estos fueron teñidos con ioduro de propidio, un agente intercalante del ADN, y analizados mediante citometría de flujo y microscopía de fluorescencia. Los resultados muestran que ambas condiciones extremas generan un desbalance en el proceso de muerte/sobrevida de las petunias, pero a diferencia de las plantas del grupo B, las plantas del grupo C no incrementaron la tasa de proliferación celular. Estos resultados sugieren que las plantas que crecen en suelos ácidos pierden la capacidad compensatoria ante la señal de estrés que se genera a consecuencia de la exposición aguda a concentraciones tóxicas de ácido sulfúrico. Cell death induced by adverse environmental conditions in Calibrachoa parviflora (petunia Abstract It has been previously reported that extreme environmental conditions such as high temperatures, ultraviolet light and the greenhouse effect, alter the rate of growth in plants. In this study we investigated the acute effect of two extreme environmental conditions

  8. Efecto protector en cirrosis hepática inducida en ratas del extracto etanólico de las hojas de Piper aduncum comparado con silimarina

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    Jorge Arroyo

    2012-04-01

    Full Text Available Objetivos: Evaluar la eficacia protectora del extracto etanólico de hojas de Piper aduncum (matico y su fitomedicamento en cápsulas, en la cirrosis hepática inducida en ratas. Diseño: Experimental. Lugar: Facultad Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material biológico: Hojas de Piper aduncum, y Rattus norvegicus, cepa Holtzman. Intervenciones: Las hojas fueron recolectadas en el distrito de Huariaca, departamento de Pasco. El fitomedicamento en cápsulas se preparó a partir del extracto etanólico de la planta. La cirrosis fue inducida con fenobarbital 0,5 mg/mL, diluida en el agua de beber por 15 días, y luego, tetracloruro de carbono 0,2mL/kg en aceite de oliva 1:1, oralmente por 7 días. Se colectó una muestra de sangre para determinar perfil hepático y malondialdehído; los animales fueron sacrificados extrayéndose el hígado para estudio histopatológico. Los datos fueron evaluados mediante técnicas multivariadas, con valor p < 0,05. Principales medidas de resultados: Grado de lesión hepática, marcadores bioquímicos, estrés oxidativo. Resultados: El extracto y el fitomedicamento a 200 mg/kg disminuyeron los valores de TGP (p < 0,621, bilirrubina total (p < 0,385 y bilirrubina directa (p < 0,283 e incrementaron las proteínas totales (p < 0,539 y albúmina (p < 0,114, similar al grupo silimarina. El colágeno, la fibrosis y el nivel de daño hepático se vieron aumentados con tetracloruro de carbono; estos indicadores se redujeron con los diferentes tratamientos y la silimarina. El marcador de estrés oxidativo se redujo con los tratamientos aplicados (p < 0,002. Conclusiones: El extracto etanólico de las hojas de Piper aduncum (matico y su fitomedicamento ejercieron efecto protector de la cirrosis inducida en ratas, comparativamente con la silimarina.

  9. Costo-efectividad de medios de contraste isoosmolales e hiposmolales en pacientes con alto riesgo de nefropatía inducida por medio de contraste

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    Liliana Alejandra Chicaíza-Becerra

    2012-06-01

    Full Text Available Introducción. Los medios de contraste pueden provocar falla renal aguda por toxicidad directa sobre las células tubulares e isquemia medular renal. Los pacientes diabéticos y los hospitalizados presentan mayor riesgo de desarrollar nefropatía inducida por medios de contraste que la población general. Objetivo. Establecer el costo-efectividad de los medios de contraste isosmolales e hiposmolales en pacientes con alto riesgo. Materiales and métodos. El análisis se basó en una revisión sistemática de la literatura científica, comparando los efectos nefrotóxicos de los medios isosmolales e hipoosmolales. Se consideraron sólo los costos directos, obtenidos del manual tarifario. Se calcularon las tasas del incremento del costoefectividad, las curvas de eficiencia y de aceptabilidad. Se hicieron análisis univariados de sensibilidad para costos y efectos, así como probabilísticos. Se aplicaron tasas de descuento de 0 y 3 % a losresultados. Se usó como umbral de costo-efectividad por año de vida ganado, el producto interno bruto per cápita. Resultados. Las alternativas con Iopamidol y Iodixanol dominan a las demás porque reducen el riesgo de nefropatía inducida por contraste a un menor costo. La razón del incremento del costo-efectividad del iodixanol comparado con el iopamidol es de US$ 14.660 por año de vida ganado que más que duplica el umbral. Conclusión. El medio de baja osmolalidad, iopamidol, parece ser costo-efectivo comparado con iohexol u otros medios hiposmolares (iopromide, iobitridol, iomeprol, iopentol y ioxilan, en pacientes con alto riesgo de nefropatía inducida por contraste. La elección del medio hiposmolar, depende de la disponibilidad a pagar o del costo por ampolleta.   doi: http://dx.doi.org/10.7705/biomedica.v32i2.367

  10. Citotoxicidad de extractos de plantas medicinales sobre la línea celular de carcinoma de pulmón humano A549 Cytotoxicity of medicinal plant extracts on the human lung carcinoma cell line A549

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    Alexis Díaz García

    2011-03-01

    Full Text Available OBJETIVO: evaluar el efecto de 10 extractos de plantas medicinales sobre el crecimiento de la línea celular humana de carcinoma de pulmón A549. METODOS: el efecto de los extractos sobre la células tumorales se midió a través de un ensayo colorimétrico mediante el empleo del bromuro de 3-(4,5-dimetil-tiazol-2-yl-2,5-difenil tetrazolio a concentraciones entre 3,9-250 µg/mL durante 72 h y se calculó la concentración citotóxica media para cada uno. RESULTADOS: del total de los extractos evaluados solo cuatro (Parthenium hysterophorus, Bixa orellana, Momordica charantia y Cucurbita maxima evidenciaron concentraciones citotóxicas medias inferiores a 100 µg/mL. Excepto Parthenium hysterophorus, las restantes se emplean en la medicina tradicional para el tratamiento del cáncer. Los extractos de Cecropia peltata, Melia azedarach, Annona glabra, Artemisia absintium, Lepidium virginicum y Bidens pilosa no mostraron efectos citotóxicos significativos. CONCLUSIONES: Los extractos de plantas que se emplean en la medicina tradicional para el tratamiento del cáncer, mostraron citotoxicidad sobre las células tumorales. El conocimiento etnobotánico representa una herramienta importante en la selección de plantas medicinales, en la búsqueda de nuevos compuestos para el tratamiento del cáncer.OBJECTIVES: to evaluate the effect of 10 Cuban medicinal plant extracts on the human lung tumor cell line A549. METHODS: the effect of the plant extracts on tumor cells was determined by a colorimetric assay using the 3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT at concentrations ranging from 3,9-250 µg/mL for 72 hours and the mean cytotoxic concentration was calculated for each of them. RESULTS: the ethanolic extracts of Parthenium hysterophorus, Bixa orellana, Momordica charantia and Cucurbita maxima showed mean cytotoxic concentrations under 100 µg/mL. Except for P. hysterophorus, the others are used in traditional medicine to fight

  11. Efecto hipolipidémico del extracto acuoso de las hojas de Artocarpus altilis "árbol del pan" en Rattus norvegicus con hiperlipidemia inducida

    OpenAIRE

    Julio Campos Florián

    2013-01-01

    La presente investigación tuvo como objetivo demostrar la actividad hipolipidémica del extracto acuoso de las hojas del árbol del pan, Artocarpus altilis, en un modelo de hiperlipidemia aguda inducida con tritón X-305, utilizando como especímenes Rattus norvegicus machos, peso promedio 204,5 g, a los que se les administró por vía oral 0,05 g/100 g y 0,2 g/100 g del extracto acuoso de A. altilis; se incluyó un grupo control negativo que recibió solución salina fisiológica y un grupo control po...

  12. Efecto antihipertensivo del extracto de Piper aduncum ‘matico’ sobre la hipertensión inducida por L-NAME en ratones

    Directory of Open Access Journals (Sweden)

    Jorge Arroyo

    2012-10-01

    Full Text Available Introducción: El Piper aduncum es una planta conocida como matico. Se le atribuye efectos antihipertensivo, antiinflamatorio, cicatrizante. Objetivos: Determinar el efecto antihipertensivo del extracto de Piper aduncum ‘matico’, sobre la hipertensión inducida por L-NAME, en ratones. Diseño: Experimental. Lugar: Facultades de Medicina y de Farmacia y Bioquímica, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material biológico: Extracto etanólico de las hojas de Piper aduncum y ratas. Intervenciones: Se utilizó seis grupos de seis ratones Muss musculus cada uno, uno sin hipertensión (control negativo y cuatro con hipertensión inducida por L-NAME: un control positivo y tres grupos para las dosis de 50, 150 y 300 mg/kg, respectivamente. El tratamiento se realizó por vía oral, una vez por día, durante 25 días. Las mediciones de la presión arterial sistólica (PAS, presión arterial diastólica (PAD y presión arterial media (PAM fueron realizadas dos veces por semana (martes y viernes y se consideró las mediciones entre los días 19 y 23 de iniciado el tratamiento. Principales medidas de resultados: Actividad antihipertensiva. Resultados: En los días 19 y 23 se observó los mejores niveles de presión arterial en el grupo control y los experimentales, correspondiendo a las mediciones 6 y 7. La eficacia antihipertensiva para enalapril fue 24,1 a 20,6%, respectivamente, seguida por matico, entre 24,9 y 13,7% (p<0,05. Conclusiones: En las condiciones experimentales, se demostró la actividad antihipertensiva del extracto etanólico de hojas de Piper aduncum ‘matico’.

  13. Efecto de Gentianella alborosea en esteatosis hepática no alcohólica inducida por dieta hiperlipídica en ratas holtzman hembras

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    L Ugaz-Soto

    2013-01-01

    Full Text Available Objetivo: Determinar el efecto del extracto de Gentianella alborosea como tratamiento contra esteatosis hepática no alcohólica (EHNA  inducida por dieta hiperlipídica en ratas Holtzman hembras. Métodos: Diseño: Estudio experimental incompleto. Lugar: Universidad Nacional Mayor de San Marcos, Lima, Perú. Participantes: Ratas Holtzman hembras. Intervenciones: Se utilizó 32 ratas repartidas en 4 grupos (n=8 distribuidos aleatoriamente: grupo control negativo, control positivo con dieta hiperlipídica, dosis 1 (35 mg/kg y dosis 2 (70 mg/kg. Se indujo EHNA con dieta hiperlipídica (Carbohidratos: 26%, Lípidos: 59% y Proteínas: 15% Calorías durante un período de 21 días, ad libitum. Luego, se administró el extracto acuoso de Gentianella alborosea por 4 días. Finalmente, se extrajeron los hígados para evaluar las alteraciones histopatológicas del parénquima hepático. Principales medidas de resultados: Se realizó el conteo microscópico de hepatocitos afectados con macrovacuolas, y los resultados fueron comparados mediante las pruebas de ANOVA (p<0,05 y HSD de Tukey (p<0,05. Resultados: Se encontró diferencias significativas (p<0.05 en el porcentaje de hepatocitos afectados entre los grupos dosis 1 (3.25 ± 2.27 y el control positivo (7.50 ± 3.76. Además, no se encontró diferencia significativa entre los grupos dosis 1 y dosis 2. Conclusiones: No se pudo determinar el efecto de Gentianella alborosea sobre la esteatosis hepática no alcohólica inducida por dieta hiperlipídica en ratas Holtzman hembra, por lo que se recomiendan estudios posteriores.

  14. EFECTO DE GENTIANELLA ALBOROSEA EN ESTEATOSIS HEPÁTICA NO ALCOHÓLICA INDUCIDA POR DIETA HIPERLIPÍDICA EN RATAS HOLTZMAN HEMBRAS

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    L. Ugaz-Soto

    2012-01-01

    Full Text Available Objetivo: Determinar el efecto del extracto de Gentianella alborosea como tratamiento contra esteatosis hepática no alcohólica (EHNA inducida por dieta hiperlipídica en ratas Holtzman hembras. Métodos: Diseño: Estudio experimental incompleto. Lugar: Universidad Nacional Mayor de San Marcos, Lima, Perú. Participantes: Ratas Holtzman hembras. Intervenciones: Se utilizó 32 ratas repartidas en 4 grupos (n=8 distribuidos aleatoriamente: grupo control negativo, control positivo con dieta hiperlipídica, dosis 1 (35 mg/kg y dosis 2 (70 mg/kg. Se indujo EHNA con dieta hiperlipídica (Carbohidratos: 26%, Lípidos: 59% y Proteínas: 15% Calorías durante un período de 21 días, ad libitum. Luego, se administró el extracto acuoso de Gentianella alborosea por 4 días. Finalmente, se extrajeron los hígados para evaluar las alteraciones histopatológicas del parénquima hepático. Principales medidas de resultados: Se realizó el conteo microscópico de hepatocitos afectados con macrovacuolas, y los resultados fueron comparados mediante las pruebas de ANOVA (p<0,05 y HSD de Tukey (p<0,05. Resultados: Se encontró diferencias significativas (p<0.05 en el porcentaje de hepatocitos afectados entre los grupos dosis 1 (3.25 ± 2.27 y el control positivo (7.50 ± 3.76. Además, no se encontró diferencia significativa entre los grupos dosis 1 y dosis 2. Conclusiones: No se pudo determinar el efecto de Gentianella alborosea sobre la esteatosis hepática no alcohólica inducida por dieta hiperlipídica en ratas Holtzman hembra, por lo que se recomiendan estudios posteriores.

  15. Períodos perturbados: disipación de energía y corrientes geomagnéticas inducidas

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    Patricia A. Larocca

    2010-06-01

    Full Text Available Se estudia, en un evento típico (12-13 de junio de 2005 las energías entrante y disipada en la magnetosfera ( y Ut respectivamente y el aumento de corrientes inducidas en un gasoducto ubicado en altas latitudes. Se analizan para el período citado los índices geomagnéticos AE y Dst, y la componente Bz del campo geomagnético interplanetario como indicadores del desarrollo del período perturbado. Se calculan los tiempos de decaimiento del anillo de corriente utilizando distintas aproximaciones de acuerdo con las fases de la tormenta. Durante este período se observaron variaciones geomagnéticas importantes que originaron corrientes geomagnéticas inducidas significativas sobre el gasoducto de la empresa Transcanada ubicado en la zona del valle del río Ottawa; pudiendo ser afectada la vida útil del mismo.In a typical event (12-13 June 2005, solar wind energy rate and total energy dissipation rate in the magnetosphere (e and Ut respectively and increased induced currents in a gas pipe located in the auroral zone are studied. For the period geomagnetic indices AE and Dst, and the Bz component of the interplanetary geomagnetic field are analyzed as indicators of the development of the troubled period. Ring current decay times are calculated using different approaches in accordance with the phases of the storm. During this period there were significant geomagnetic variations due to geomagnetic substorms and induced currents on the pipeline located in the Otawa River Valley, this fact could produce corrosion increases in its structure.

  16. Hiperalgesia Inducida por Opioides

    OpenAIRE

    Jiménez Salazar, Andrés

    2013-01-01

    Los opioides producen analgesia a través de un efecto inhibitorio sobre el sistema nociceptivo principalmente. Hasta la fecha, los opioides siguen siendo los analgésicos más potentes para el manejo de dolor moderado a severo. La Asociación Internacional del Estudio del Dolor (IASP, en inglés) define hiperalgesia como "un aumento de la respuesta a un estímulo que normalmente es doloroso". En contraste, está bien establecido que la terapia crónica con opioides se asocia con el desarrollo de ...

  17. Comparação de métodos para testar a citotoxicidade "in vitro" de materiais biocompatíveis Comparison of methods to test an "in vitro" test of cytotoxicity of biocompatible hospital materials

    Directory of Open Access Journals (Sweden)

    Aurea Silveira Cruz

    1998-04-01

    Full Text Available OBJETIVO: Comparar a sensibilidade do método de difusão em ágar e do método de extração utilizando as linhagens celulares RC-IAL (células fibroblásticas de rim de coelho e HeLa (células epiteliais de carcinoma do colo do útero humano, na avaliação da citotoxicidade "in vitro" de materiais de uso médico-hospitalar. MATERIAL E MÉTODO: Foram testadas 50 amostras escolhidas por sorteio, entre as já conhecidamente positivas e negativas e identificadas como: algodão, espuma, borracha, látex, celulose e acrílico. Além, das amostras citadas foram testadas experimentalmente várias concentrações de SDS (duodecil sulfato de sódio nas culturas celulares RC-IAL e HeLa. RESULTADOS: Das 50 amostras testadas , 44 (88% foram positivas para os dois métodos. Mas quando comparado o SDS nos dois métodos foram observados resultados positivos nas concentrações de 0,5 a 0,05 µg/ml no método de difusão em ágar e no método de extração somente foi observado efeito citotóxico até a concentração de 0,25 µg/ml. CONCLUSÃO: Os resultados encontrados são similares aos observados por outros autores que testaram materiais como, por exemplo, ligas metálicas. Quando foi usado o SDS observou-se, nas duas linhagens celulares, diferenças favoráveis ao método de difusão em ágar em duas concentrações, isto é, a sensibilidade deste método foi significantemente maior, por inspecção, em relação ao método de extração, além de se constituir em método mais simples de ser realizado.OBJECTIVE: A comparison of the sensitivity of the agar diffusion method with that of extraction using cell-lines RC-IAL (fibroblastic of rabbit kidney and HeLa (epithelial carcionoma cells from the cervix uteri of the humam uterus, in the in vitro evaluation of materials of medical and hospital. MATERIAL AND METHODS: Fifteen samples chosen at random, from among the already known positives and negatives in our stock, were tested and identified as cotton

  18. Citotoxicidade de plantas com indicativo etnográfico para a desinfecção de água Cytotoxicity of plants as an ethnographic indicator for water disinfection

    Directory of Open Access Journals (Sweden)

    A.R. Gonçalves

    2009-01-01

    Full Text Available A água para o consumo humano e animal é um patrimônio cada vez mais escasso que é necessário preservar. O processo de desinfecção utilizado atualmente tem como base desinfetantes clorados, que em combinação com resíduos orgânicos, resultam em trihalometanos (potencialmente oncogênicos. A proposta deste trabalho foi avaliar a citotoxicidade de cinco extratos de plantas, capazes de promover desinfecção da água, frente a seis linhagens celulares, a saber: Vero (ATCC CCl81 African green monkey cells; MDBK (ATCC CCL 24 Martin Darby Bonne Kidney cells; MDCK (ATCC CCL 34 Canis familiaris kidney cells; CRFK (ATCC CCL 94 Felix catus kidney cells; PK 15 (ATCC CCL 33 Sus scrofa kidney cells; RK13 (ATCC CCL 37 Orytolagus cuniculus Kidney cells, e avaliar cultivos celulares mais sensíveis para o teste de toxicidade de extratos de plantas. Destes extratos, o mais tóxico foi o de Erva de Formigueiro (Chenopodium álbum diante de todas as células testadas. O extrato de chapéu de couro (Sagittaria montevidensis foi medianamente tóxico e os demais baleeira (Cordia curassavica, folha da fortuna (Bryophyllum pinnatum [Kurz] e sete sangrias (Cuphea carthagenensis [Jacq.] J.F. Macbride foram os menos tóxicos. Este resultado foi estatisticamente significativo (p=0,99, quando se comparou o extrato das plantas frente às concentrações e às células estudadas. Entre as células utilizadas, as mais sensíveis foram a VERO (rim de macaco e a CRFK (rim de gato quando comparadas com as demais foram (MDBK, MDCK, PK 15, RK 13, com diferença significativa (p=0,99. Conclui-se que há necessidade de serem avaliados os extratos vegetais quanto a toxicidade, antes do emprego como recursos de saúde, e que algumas células são mais eficazes que outras na detecção de efeito citopatogênico.Freshwater for human and animal consumption is an increasingly rare patrimony that needs to be preserved. The currently adopted disinfection process uses chloride

  19. Pregancy-induced hypertension and birthweight Hipertensión inducida por el embarazo y peso de los productos al nacer

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    Nicolás Padilla Raygoza

    2013-03-01

    Full Text Available Objective. The objective of this work was to measure the existing association between preg­nancy-induced hypertension and birthweight at the Celaya General Hospital. Study design. Cross-sectional, observational, analytic study. Subjects: Registries of women admitted to the Celaya General Hospital for delivery during 2008. Variables: Pregnancy-induced hypertension (blood pressure of 140/90 mmHg or higher after 20 weeks of gestation, sub-classified as gestational hypertension (blood pressure of 140/90 mmHg or higher without proteinuria and toxemia (blood pressure of 140/90 mmHg or higher with proteinuria; birthweight ( 3 500 g. Statistical analysis: it was calculated the Analysis of Variance (ANOVA test was performed between the status of arterial hypertension and birthweight, and was adjusted using gestational age. Results. From the sample of 5 478 registries, 14.73% (n = 807 of women had pregnancy-induced hypertension; from them, 10.92% (n = 598 had gestational hypertension and 3.82% (n = 209 preclampsia/eclampsia. Newborns from hypertensive mothers had an average birthweight of 3 049.27 ± 600.22 g, while the birth­weight of newborns from normotensive mothers was 3 104.94 ± 502.57 g, considering: ANOVA F = 1.49, p = 0.00001: adjusted by gestational age, F = 1.51, p = 0.0168. Conclu­sion. Newborns of normotensive and gestational hypertensive mothers showed differences in birthweight; gestational age acted as a confounder.Objetivo. Medir la asociación que existe entre la hipertensión inducida por el embarazo y el peso al nacer de los neonatos, en el Hospital General de Celaya. Tipo de estudio. Observacio­nal, transversal y analítico. Sujetos: 1 Registros de mujeres embarazadas (n = 5 478, admi­tidas para su resolución obstétrica, en el Hospital General de Celaya durante el año 2008, y 2 registros del peso al nacer de los neonatos de estas mujeres. Variables: 1 Hipertensión inducida por el embarazo (presión arterial de 140/90 mmHg o

  20. Efecto hepatoprotector del extracto hidroetanólico atomizado del maíz morado (Zea mays L. en lesiones hepáticas inducidas en ratas

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    Renán Hañari-Quispe

    2015-04-01

    Full Text Available Objetivos: Evaluar el efecto hepatoprotector del extracto hidroetanólico atomizado de Zea mays variedad morado sobre lesiones hepáticas inducidas en ratas. Diseño: Experimental. Institución: Laboratorio de Farmacología Experimental, Facultad de Medicina Humana, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material biológico: Extracto hidroetanólico atomizado de maíz morado (EAM. Intervenciones: Se formó seis grupos de ratas machos (n=10, por cada grupo, se les administró fenobarbital a concentración de 0,5 g/L en agua potable ad líbitum por 15 días; posteriormente se administró tetracloruro de carbono (CCl a una dosis de 0,2 mL/kg, por vía oral. El diseño experimental fue el siguiente: G1: suero fisiológico (SSF; G2: CCl0,2 mL/kg (T;4G3: T+ 4 silimarina 25 mg/kg; G4: T + EAM 500 mg/kg; G5: T + EAM 1 000 mg/kg; G6: T + EAM 2 000 mg/kg. Principales medidas de resultados: Perfil hepático, especies reactivas al ácido tiobarbitúrico (TBARS en suero, índice hepático, observación histológica. Resultados: Se observó aumento significativo (p<0,05 en la actividad de alanina amino transferasa (ALT entre el grupo G2 y los grupos G3 y G4 (p<0,001. Hubo disminución significativa (p<0,05 de fosfatasa alcalina (FAL en el grupo G2 con respecto G1. El nivel de TBARS fue menor en el grupo que recibió 1 000 mg/kg de EAM con respecto al control. Las actividades de HDL-C y triglicéridos no mostraron diferencias significativas. Se ha observado la reducción de 60% de la lesión hepática, evidenciado con menor daño del hepatocito al estudio histológico. Conclusiones: El extracto hidroetanólico atomizado de maíz morado a la dosis de 1 000 mg/kg disminuyó las lesiones hepáticas inducidas en ratas.

  1. Disminución del daño oxidativo y efecto hipoglicemiante de la maca (Lepidium meyenii Walp en ratas con diabetes inducida por streptozotocina

    Directory of Open Access Journals (Sweden)

    María Elena Rodrigo

    2011-01-01

    Full Text Available Introducción: La maca es consumida desde tiempos ancestrales como parte de la dieta. Se le ha atribuido propiedades medicinales y se encuentra incluida en la medicina tradicional peruana. Estudios recientes describen que la admistración de maca reduce la glicemia en animales normoglicémicos, pero los mecanismos involucrados no están muy claros. Objetivos: Determinar el efecto hipoglicemiante y antioxidante de la harina de maca (Lepidium meyenii Walp del ecotipo amarillo, en ratas con diabetes inducida por estreptozotocina. Diseño: Experimental. Institución: Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material biológico: Harina de maca amarilla y ratas albinas Holtzmann machos con diabetes inducida. Intervenciones: Se administró la harina de maca amarilla a las ratas distribuidas en 4 grupos: grupo I control (solo dieta; II, harina de maca 4 g/día; III, harina de maca 6 g/día; y IV, dieta + glibenclamida 10 mg/kg de peso; el experimento duró 46 días. Se evaluó diariamente la glicemia y el peso; al final del experimento se determinó en sangre los niveles de insulina, parámetros de daño oxidativo (vitamina C y se midió la peroxidación lipídica (TBARS, como indicador del proceso oxidativo. Principales medidas de los resultados: Modificación de los niveles de glicemia, insulina, vitamina C y formación del complejo MDA-TBARS. Resultados: La administración de harina de maca en la dieta (4 a 6 g/día de animales diabéticos redujo la glicemia en 50%, incrementó los niveles de insulina 22% y mejoró los niveles de vitamina C respecto al grupo control. La administración de maca 4 g/día disminuyó el daño oxidativo, pues redujo la formación del complejo MDA-TBARS en 54% con respecto al grupo control. Conclusiones: La administración de harina de maca amarilla a animales diabéticos mejoró el metabolismo de la glucosa, regulando la glicemia y

  2. Detección y estudio mediante Fluorescencia Inducida por Láser de radicales libres formados por Disociación Multifotónica Infrarroja

    Science.gov (United States)

    Santos, M.; Díaz, L.; Torresano, J. A.; Rubio, L.; Samoudi, B.

    Una de las principales aplicaciones actuales de los procesos de disociación multifotónica inducidos por radiación láser infrarroja (DMI) es la producción de radiales libres, con el fin de estudiar sus propiedades cinéticas y espectroscópicas. La disociación de moléculas poliatómicas en el IR con láseres de CO2 tiene lugar desde la superficie de energía molecular mas baja y conduce generalmente a la formación de fragmentos en el estado electrónico fundamental, con diversos grados de excitación vibracional. En el Grupo de Procesos Multifotónicos del Instituto de Estructura de la Materia del C.S.I.C. hemos puesto a punto la técnica de Fluorescencia Inducida por Láser (LIF) para la detección y análisis en tiempo real de los fragmentos producidos en la DMI inducida mediante uno o dos campos láseres de diferentes longitudes de onda. Objetivos de nuestro trabajo han sido el estudio de los canales de disociación mayoritarios y de las especies transitoria producidas, así como de la distribución de energía interna con que éstas son generadas. En particular hemos detectado mediante LIF las especies: C2, CF, CH, SiH2, CF2, CH2, SiHCl, y CF3 a partir de la disociación de, entre otras, las siguientes moléculas: C2H3Br, C3F6, C4H8Si, C2H5ClSi y CH5ClSi. En este trabajo presentamos algunos de los resultados obtenidos mediante el estudio por LIF de estos radicales: estudio temporal de la señal LIF obtenida con determinación de tiempos de vida, espectros de excitación y fluorescencia, temperaturas vibracionales de formación, variación de la intensidad LIF con el tiempo de retraso entre los láseres de disociación y prueba, etc.

  3. Efectos en ratas de los alcoholes de cera de abejas (D-002 sobre la colitis ulcerativa inducida por sulfato de dextrano y etanol

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    Vivian Molina-Cuevas

    Full Text Available Objetivos. Investigar los efectos del D-002, mezcla de seis alcoholes alifáticos primarios de alto peso molecular, obtenida de la cera de abejas (Apis mellifera, sobre la colitis ulcerativa (CU inflamatoria severa inducida por sulfato de dextrano (DSS y etanol en ratas (Ratus ratus. Materiales y métodos. Las ratas se distribuyeron aleatoriamente en seis grupos: un control cero al que no se provocó daño, y cinco a los que se les indujo la CU: un control negativo (vehículo, tres tratados con D-002 (25, 100 y 400 mg/kg y un control positivo con sulfazalacina (200 mg/kg (sustancia de referencia. Se cuantificaron las manifestaciones clínicas (variación del peso corporal, presencia de diarrea y de sangrado rectal, el puntaje de daño macroscópico e histológico, y la actividad de mieoloperoxidasa (MPO. Resultados. El tratamiento oral con D-002 (25, 100 y 400 mg/kg previno significativamente la disminución del peso corporal. La dosis de 400 mg/kg redujo la presencia de diarreas y sangrado rectal, aunque su comparación con el control negativo solo alcanzó significación estadística sobre las diarreas. El D-002 (25, 100 y 400 mg/kg redujo significativamente el puntaje de las lesiones macroscópicas (40,0; 43,3 y 47,2% de inhibición, respectivamente, el puntaje de daño histológico (31,5; 53,7 y 67,1% de inhibición, respectivamente y la actividad de MPO (73,2; 83,6 y 85,0% de inhibición, respectivamente, comparado con el grupo control negativo. La sulfazalacina redujo significativamente todas las variables estudiadas. Conclusiones. El D-002 (25, 100 y 400 mg/kg protegió significativamente la mucosa colónica en ratas con CU inflamatoria severa inducida por DSS y etanol.

  4. Efectos en ratas de los alcoholes de cera de abejas (D-002 sobre la colitis ulcerativa inducida por sulfato de dextrano y etanol

    Directory of Open Access Journals (Sweden)

    Vivian Molina-Cuevas

    Full Text Available RESUMEN Objetivos. Investigar los efectos del D-002, mezcla de seis alcoholes alifáticos primarios de alto peso molecular, obtenida de la cera de abejas (Apis mellifera, sobre la colitis ulcerativa (CU inflamatoria severa inducida por sulfato de dextrano (DSS y etanol en ratas (Ratus ratus. Materiales y métodos. Las ratas se distribuyeron aleatoriamente en seis grupos: un control cero al que no se provocó daño, y cinco a los que se les indujo la CU: un control negativo (vehículo, tres tratados con D-002 (25, 100 y 400 mg/kg y un control positivo con sulfazalacina (200 mg/kg (sustancia de referencia. Se cuantificaron las manifestaciones clínicas (variación del peso corporal, presencia de diarrea y de sangrado rectal, el puntaje de daño macroscópico e histológico, y la actividad de mieoloperoxidasa (MPO. Resultados. El tratamiento oral con D-002 (25, 100 y 400 mg/kg previno significativamente la disminución del peso corporal. La dosis de 400 mg/kg redujo la presencia de diarreas y sangrado rectal, aunque su comparación con el control negativo solo alcanzó significación estadística sobre las diarreas. El D-002 (25, 100 y 400 mg/kg redujo significativamente el puntaje de las lesiones macroscópicas (40,0; 43,3 y 47,2% de inhibición, respectivamente, el puntaje de daño histológico (31,5; 53,7 y 67,1% de inhibición, respectivamente y la actividad de MPO (73,2; 83,6 y 85,0% de inhibición, respectivamente, comparado con el grupo control negativo. La sulfazalacina redujo significativamente todas las variables estudiadas. Conclusiones. El D-002 (25, 100 y 400 mg/kg protegió significativamente la mucosa colónica en ratas con CU inflamatoria severa inducida por DSS y etanol.

  5. Citotoxicidade e genotoxicidade de nanotubos de carbono

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    Leonardo P. Franchi

    2012-01-01

    Full Text Available There are many controversies regarding the cyto- and genotoxicity of carbon nanotubes (CNTs. In this work, we discuss that many of the incongruous arguments are probably associated with the poor physical-chemical characterization of the CNT samples used in many publications. This manuscript presents examples of carbon nanostructures observed under high resolution electron microscopy that can be found in typical CNT samples, and shows which roles in cyto- and genotoxicity need to be better investigated. Issues concerning chemical treatment are addressed and examples of misunderstandings that can occur during the studies of cyto- and genotoxicity of CNT samples are given.

  6. Papel del endotelio en hipertensión inducida por el embarazo: ¿alteraciones comunes a las de la aterosclerosis?

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    Patricio López-Jaramillo

    2014-10-01

    Full Text Available La hipertensión inducida por el embarazo, cuya forma proteinúrica es denominada preeclampsia (PE, es una alteración que ocurre en el segundo trimestre del embarazo, y se caracteriza por la presencia de hipertensión y proteinuria. Durante el embarazo normal ocurren cambios fisiológicos adaptativos que incluyen insulino-resistencia (IR, hiperlipidemia, hipercoagulabilidad, inflamación y un estado circulatorio hiperdinámico. Estos cambios se expresan de una forma exagerada en las mujeres que desarrollan PE, alteraciones que están presentes también en el clúster de factores de riesgo que conforman el denominado síndrome metabólico (SM, el cual es un factor de riesgo para el desarrollo de diabetes mellitus tipo 2 (DM2 y enfermedad cardiovascular (ECV. En la presente revisión proponemos que la disfunción endotelial es la alteración común que explica la presencia de estas dos enfermedades comunes en América Latina.

  7. Cardiopatía inducida por estrés (Tako-Tsubo. Nueva hipótesis fisiopatológica

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    Carlos E. Gadda

    2010-01-01

    Full Text Available RESUMENLa miocardiopatía inducida por estrés tiene como factor común su casi exclusiva apariciónen mujeres posmenopáusicas que acaban de sufrir una situación de estrés de gran envergaduray que clínicamente presentan un evento coronario agudo muy similar a un infartoagudo de miocardio. Al ser estudiadas de urgencia por cateterismo o ecocardiografía, en elventrículo izquierdo se observa un área de acinesia o discinesia focalizada habitualmente enla “punta”, pero con coronarias angiográficamente normales o, a lo sumo, mínimamentecomprometidas.Las coronarias pronunciadamente flexuosas también son habituales en mujeresposmenopáusicas y las arterias con estas características, al acodarse en forma extrema,pueden generar kinkings. Durante una crisis adrenérgica, estos kinkings llegan a estrangularla arteria y comprometer el flujo más allá de la sístole, lo cual, sumado a los efectos de lascatecolaminas, generaría la alteración focal y transitoria de la contractilidad que caracterizaal Tako-Tsubo.Queda claro que para afirmar esta hipótesis deben explorarse futuros pacientes en búsquedade este patrón anatómico.REV ARGENT CARDIOL 2010;78:43-45.

  8. El género afecta las propiedades contráctiles del músculo sóleo en diabetes inducida experimentalmente en ratas

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    Adolfo Virgen Ortiz

    2015-06-01

    Full Text Available Ratas hembras y machos, de tres meses de edad, fueron separados en dos grupos: no diabéticas (ND, peso corporal, 274 ± 9 g; nivel de glucosa en la sangre, 4,94 ± 0,22 mmol/L; n = 16 y diabéticas (D; peso corporal, 207 ± 8 g; nivel de glucosa en sangre, 28,39 ± 0,94 mmol/L; n = 16. La diabetes fue inducida por una sola dosis de 60 mg/Kg de estreptozotocina administrada intraperitonealmente. Las ratas ND recibieron el mismo volumen de vehículo. Después de 4 semanas los animales fueron considerados diabéticos si su nivel de glucosa era ≥ 20 mmol/L. La masa y la contracción del músculo sóleo fueron mayores en machos ND que en las hembras ND. En las ratas macho D disminuyó su masa muscular en un 34% y la fuerza de contracción disminuyó en un 33%; mientras que en las hembras D disminuyeron 15% y 10% respectivamente.

  9. Efecto antioxidante del extracto acuoso de propóleos sobre la hepatotoxicidad inducida por el octilfenol en ratas macho Antioxidant effect of aqueous extract of propolis on hepatotoxicity induced by octylphenol in male rats

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    Eman M Saleh

    2012-12-01

    Full Text Available El 4-terc-octilfenol (4-terc-OP es un alquilfenol que afecta a la salud humana mediante la estimulación de la producción de radicales libres. El extracto acuoso de propóleos es un producto natural rico en favonoides que tienen actividad antioxidante. Este estudio fue diseñado para investigar la capacidad del extracto de propóleos de reducir la hepatotoxicidad inducida por el 4-terc-OP en ratas macho. Los animales fueron asignados a 5 grupos y tratados durante 6 semanas. Grupo 1: control; grupo 2: 100 mg de 4-terc-OP/kg/día; grupo 3: 100 mg de extracto de propóleos/kg/día; grupo 4: 100 mg de 4-terc-OP/ kg/día más 100 mg de extracto de propóleos/kg/día, grupo 5: 100 mg de 4-terc-OP/kg/día durante 6 semanas, seguidos de 100 mg de extracto de propóleos/kg/día durante 6 semanas. El grupo 4-terc-OP mostró niveles signifcativamente elevados de AST, ALT, ALP, GGT, bilirrubina, creatinina, urea, lípidos totales, colesterol total, triglicéridos, LDL-C y MDA, con una disminución signi-fcativa de proteínas totales, albúmina, globulina, HDL-C, la capacidad antioxidante total, SOD, CAT y GST, en comparación con el grupo control. La administración de extracto de propóleos, ya sea solo o combinado con 4-terc-OP redujo la hepatotoxicidad inducida por 4-terc-OP. Los estudios de fragmentación del ADN apoyan el efecto deletéreo observado por el tratamiento con 4-terc-OP y el efecto protector del extracto de propóleos, sobre las proteínas y las enzimas celulares hepáticas. Los resultados histopatológicos revelaron la hepatotoxicidad por 4-terc-OP y efecto protector inducido por el extracto de propóleos. En conclusión, el extracto de propóleos podría reducir el daño hepático y los efectos celulares de toxicidad en las células del hígado inducidos por 4-terc-OP.4-tertiary-octylphenol (4-tert-OP is an alkylphenol that affects human health by stimulating free radical production. Aqueous propolis extract is a natural product rich in

  10. Effect of post-polymerization heat treatments on the cytotoxicity of two denture base acrylic resins Efeito de tratamentos térmicos após a polimerização sobre a citotoxicidade de duas resinas acrílicas para base de próteses

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    Janaina Habib Jorge

    2006-06-01

    biocompatibilidade e das propriedades físicas. Para assegurar a utilização desses materiais, testes preliminares de citotoxicidade in vitro têm sido desenvolvidos para avaliação da biocompatibilidade. Um dos ensaios biológicos sugeridos para a análise da citotoxicidade é o teste de incorporação de ³H-timidina, o qual mede o número de células por meio da síntese de DNA. OBJETIVO: O objetivo do presente estudo foi avaliar, por meio do teste de incorporação de ³H-timidina, a citotoxicidade de duas resinas acrílicas para base de próteses submetidas aos tratamentos em microondas e em banho de água após a polimerização. MATERIAL E MÉTODO: Nove corpos-de-prova em forma de discos (10 x 1 mm foram confeccionados com as resinas acrílicas Lucitone 550 e QC 20 de acordo com as instruções dos fabricantes, e foram armazenados em água destilada a 37ºC por 48 h. Os corpos-de-prova foram divididos em três grupos: 1 tratamento em forno de microondas por 3 min a 500 W; 2 tratamento em banho de água a 55ºC por 60 min; e 3 sem tratamento térmico. Extratos foram preparados pela colocação de 3 discos em tubos de ensaio estéreis com 9 mL de meio de cultura Eagle e incubação a 37ºC por 24 h. O efeito citotóxico dos extratos foi avaliado utilizando o teste de incorporação de ³H-timidina. RESULTADOS: Os resultados indicaram que os componentes liberados pelas resinas foram citotóxicos para as células L929 exceto para as amostras tratadas em banho de água (p<0.05. Em comparação com o grupo sem tratamento, o banho de água diminuiu a citotoxicidade das resinas acrílicas. CONCLUSÃO: O tratamento em microondas não influenciou a citotoxicidade das resinas acrílicas para bases de próteses.

  11. Evaluation of cytotoxicity of two endodontic cements in a macrophage culture Avaliação da citotoxicidade de dois cimentos endodônticos em cultura de macrófagos

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    Celso Emanoel de Souza Queiroz

    2005-09-01

    obtenção do hermético selamento marginal, sendo sua biocompatibilidade dependente do somatório das respostas de cada célula presente na região periapical. Por conseguinte, o objetivo deste estudo foi avaliar em cultura de macrófagos peritoneais de seis camundongos Swiss, a citotoxicidade de dois cimentos endodônticos, um à base de resina epóxica (Sealer 26 e outro contendo óxido de zinco e eugenol (Endofill, quanto a indução da produção de óxido nítrico. Após a presa e pulverização, alíquotas de 100ml da suspensão contendo 18mg/mL dos respectivos cimentos foram adicionados em placa de cultura de tecido de 96 poços, contendo a cultura de macrófagos na concentração de 5,0X10(6 células/ml. Após 48 horas de incubação, a 37ºC, em 5% de CO2, foi feita a leitura em um leitor ELISA automático para se averiguar a liberação de óxido nítrico. Verificou-se, para o cimento Sealer 26, que a produção de óxido nítrico oscilou de 36,1 a 313,0 mimols, com média de 143,82±111,03, enquanto para o Endofill estes valores foram significativamente menores (p=0.01, variando de 50,8 a 125,7, com média de 80.33±28,42 mols. Nos grupos controles positivo e negativo a média de liberação de óxido nítrico foi de 162,75mimols e 4,42mimols, respectivamente. Não houve diferença significativa entre o grupo controle positivo e o cimento Sealer 26 (p>0.05. Portanto, o cimento Sealer 26 causou, significativamente, maior toxicidade aos macrófagos, possivelmente devido aos seus componentes, a exemplo da resina epóxica e ao formaldeído, liberados durante a sua reação de polimerização.

  12. Detecção da citotoxicidade de materiais biocompatíveis nas linhagens celulares MRC-5, HeLa e RC-IAL MRC-5, HeLa and RC-IAL cell lines sensitivity for detection of cytotoxicity of biocompatible materials

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    Aurea S. Cruz

    1992-04-01

    Full Text Available A sensibilidade de uma linhagem celular diplóide e duas heteroplóides, para a detecção de citotoxicidade através do método de difusão em camada de ágar sobre culturas celulares, foi avaliada experimentalmente com solução de ácido ascórbico em diferentes concentrações e, na prática, frente a 562 amostras de 21 diferentes materiais industriais enviados para análise na Seção de Culturas Celulares do Instituto Adolfo Lutz. A linhagem celular heteroplóide designada RC-IAL apresentou, em relação às linhagens MRC-5 e HeLa, maior sensibilidade porque revelou a presença de efeito citotóxico nas menores concentrações utilizadas (10 e 25 ug/ml do ácido ascórbico e apresentou maior diâmetro do halo citotóxico em 15 amostras e igual diâmetro em 16 das 43 amostras (7,6% que resultaram positivas. Nas 43 amostras positivas, a linhagem MRC-5 não revelou citotoxicidade em 3 amostras de espuma e 1 de resina acrílica. O polivinilcloreto (PVC e o polietileno, raramente revelaram positividade, enquanto plástico, algodão e resinas acrílicas revelaram citotoxicidade ao redor de 5%. Em vista dos resultados é discutida a proposta da utilização da linhagem RC-IAL e HeLa para a continuidade das futuras análises solicitadas ao Instituto Adolfo LutzThe sensitivity of diploid and heteroploid cell lines for detection of cytotoxicity using the agar diffusion method on cell culture, was tested with ascorbic acid solution of different concentrations. A total of 562 samples of 21 various materials were tested. The heteroploid cell line, RC-IAL, showed in relation to the MRC-5 and HeLa cell lines, greater sensitivity because it showed the presence of cytotoxic effect with the lowest concentration used (10 and 25ug/ml of ascorbic acid and showed greater diameter of cytotoxic halo in 15 samples and equal diameter in 16 of the 43 positive samples (7.6%. Out of 43 positive samples, the MRC-5 line did not show cytotoxicity in 3 sponge samples and

  13. Determinación de la profundidad y duración de la neutropenia inducida por ciclofosfamida en ratones hembras MPF de la cepa Udea: ICR(cd-1

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    Omar Vesga

    2004-02-01

    Full Text Available

    El modelo murino de infección del muslo emplea animales neutropénicos para poder determinar la eficacia intrínseca de los antibióticos in vivo. Sin embargo, no se ha definido el número de neutrófilos y la duración de la neutropenia inducida por ciclofosfamida (CFM intraperitoneal (IP, información fundamental
    para valorar la reproducibilidad y confiabilidad del modelo.

     

     

  14. “Corrosión Inducida por Bacterias Sulfato Reductoras Termófilas de 60°C en la Unión Soldada del Acero API 5L- X60.”

    OpenAIRE

    Romero Romero, Justo Román

    2012-01-01

    En esta investigación se estudio el efecto de la corrosión inducida por Bacterias Sulfato Reductoras (BSR) termófilas a 60oC en el metal base (MB) y la unión soldada (US) del acero API X-60. Las bacterias sulfato reductoras fueron aisladas en el medio sólido postgate con la técnica de estriado, y fueron resembradas hasta obtener la misma morfología. El medio postgate fue seleccionado entre otros medios de cultivo, por el óptimo crecimiento que presento la BSR. Se preparar...

  15. Culture supernatants from V. cholerae O1 ElTor strains isolated from different geographic areas induce cell vacuolation and cytotoxicity Cepas de V. cholerae O1 biotipo ElTor aisladas de diferente origen geográfico inducen vacuolización celular y citotoxicidad

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    Jorge E Vidal

    2009-02-01

    Full Text Available OBJECTIVE: To investigate whether the HlyA-induced vacuolating effect is produced by V. cholerae O1 ElTor strains isolated from different geographic origins, including Mexico. MATERIAL AND METHODS: Supernatant-induced haemolysis, vacuolating activity and cytotoxicity in Vero cells were recorded. PCR, RFLP analysis and molecular cloning were performed. RESULTS: All ElTor strains analyzed induced cellular vacuolation. Ribotype 2 strains isolates from the U.S. gulf coast yielded the highest titer of vacuolating activity. Eight of nine strains were haemolytic, while all strains were PCR positive for the hlyA gene. We cloned the hlyA gene from two ElTor strains, a toxigenic (2514-88, ctxAB+ and a non-toxigenic Mexican strain (CM 91-3, ctxAB-. Supernatant from those recombinant E. coli strains induced haemolysis, cell vacuolation and cytotoxicity. RFLP-PCR analysis revealed similarities in the hlyA gene from all strains tested. CONCLUSION: The HlyA-induced vacuolating effect is a widespread phenotype of epidemic V. cholerae O1 ElTor strains.OBJETIVO: Analizar el efecto vacuolizante de cepas de V. cholerae O1 ElTor aisladas de diferente origen geográfico, incluyendo México. MATERIAL Y MÉTODOS: Se realizaron pruebas de hemolisis, vacuolización y citotoxicidad en células Vero, así como PCR, análisis por RFLP y clonación molecular. RESULTADOS: Todas las cepas indujeron el efecto vacuolizante. Las cepas del ribotipo 2, aisladas de las costas del Golfo en Estados Unidos, presentaron títulos altos de vacuolización. El gen hlyA fue amplificado en las nueve cepas mediante PCR, aunque sólo ocho fueron hemolíticas. Se clonó el gen hlyA de una cepa toxigénica (2514-88, ctxAB+ y de una cepa no toxigénica aislada en México (CM 91-3, ctxAB-. El sobrenadante de las clonas recombinantes indujo hemólisis, efecto vacuolizante y citotoxicidad. El RFLP mostró alta similitud del gen hlyA de las cepas estudiadas. CONCLUSIÓN: El efecto vacuolizante es un

  16. Efecto del extracto metanólico de Jatropha macrantha Müll. Arg., en la disfunción eréctil inducida en ratas

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    Aldo Tinco

    2011-07-01

    Full Text Available Objetivos: Determinar el efecto del extracto metanólico de Jatropha macrantha Müll. Arg. ‘huanarpo macho’ en la disfunción eréctil inducida en ratas. Diseño: Experimental. Institución: Laboratorio de Farmacología, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú; Laboratorio de Farmacia, Universidad Nacional de San Cristóbal de Huamanga, Ayacucho, Perú. Material biológico: Extracto metanólico de Jatropha macrantha Müll Arg. ‘huanarpo macho’; ratas wistar de 300+/-50 g. Intervenciones: La obtención de la muestra se realizó en la Provincia de Vilcas Huamán - Ayacucho. Se evaluó el comportamiento sexual y la concentración de óxido nítrico y el efecto vasorrelajante en el cuerpo cavernoso aislado de pene de ratas, siendo los grupos de estudio: grupo 1 agua 10 mL/kg; grupo 2 sildenafilo 5 mg/kg; grupos 3, 4 y 5 extracto metanólico 100, 200 y 300 mg/kg. Se aisló órganos en los grupos de 50, 100 y 300 ug/mL de extracto, L- arginina 300 uM, acetilcolina 30uM, epinefrina u/mL y sildenafilo (3,2 × 10-5 mg/mL. Principales medidas de resultados: Flavonoides aislados, comportamiento sexual de ratas, niveles plasmáticos de óxido nítrico y relajación del músculo cavernoso. Resultados: Por cromatografía se encontró estructuras tipo flavonas, y mediante espectroscopia UV y reacciones de desplazamiento se identificó 6-hidroxi-4’,5,7-trimetoxi flavona, 4’,7-dihidroxi-5,6-dimetoxiflavona, 7-hidroxi-3’,4’,5’,5,8 pentametoxiflavona, 4’,7-dihidroxi-3’,5,6-trimetoxiflavona, DL50 1357 mg/kg. El comportamiento sexual fue dosis dependiente; la administración de 300 mg/kg de la planta por vía oral incrementó la frecuencia de monta en 75% y elevó los niveles de óxido nítrico en 85%, en tanto que la dosis de 200 mg/kg lo hizo en 71,1% y 32,4%, respectivamente (p<0,05. Conclusiones: En ratas con disfunción eréctil inducida, el extracto metanólico de Jatropha macrantha Müll Arg.

  17. El estrés oxidativo: detonante fisiopatológico en la cardiomiopatía dilatada inducida por doxorrubicina

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    Ronal Aroche Aportela

    2011-12-01

    Full Text Available

    La cardiomiopatía dilatada inducida por doxorrubicina constituye uno de los principales efectos indeseables del tratamiento de pacientes con tumores malignos. El estrés oxidativo constituye uno de los mecanismos fisiopatológicos que desempeñan un papel fundamental en la instauración de la enfermedad causada por este antibiótico del grupo de las antraciclinas. La comprensión de estos mecanismos fisiopatológicos resulta de vital importancia para llevar a cabo estrategias de intervención farmacológica y nutricional para contribuir a palear los efectos nocivos de este antineoplásico. En el presente trabajo se realizó una actualización bibliográfica sobre el tema y se proponen ideas que pueden ser útiles para la comunidad científica que está enfrascada en el tratamiento de esta enfermedad crónica, y que se propone mejorar la calidad de vida de los pacientes que la padecen.

    Oxidative Stress: Pathophysiologic Trigger in Doxorubicin-induced Dilated Cardiomyopathy

    Doxorubicin-induced dilated cardiomyopathy is one of the main adverse effects in the treatment of patients with malignant tumours. Oxidative stress is one of the pathophysiological mechanisms that play a key role in the establishment of the disease caused by this anthracycline-type antibiotic. Understanding these pathophysiologic mechanisms becomes of vital importance in order to carry out pharmacological and nutritional intervention strategies to help paddling the harmful effects of this antineoplastic. As part of this research we conducted an updating literature review on the subject and provided ideas that can be useful for the scientific community engaged in the treatment of this chronic disease, which aims to improve the life quality of patients suffering from it.

  18. Influencia mutua de la deformación y composición química sobre la precipitación inducida en aceros microaleados

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    Quispe, A.

    2005-12-01

    Full Text Available By means of torsion tests and applying the "back extrapolation" method, the static recrystallization kinetics in microalloyed steels with vanadium (V, niobium (Nb and titanium (Ti has been determined and, recrystallization-precipitation-time-temperature (RPTT diagrams have been plotted also graphically, which show the Recrystallization- Precipitation interaction. These diagrams show that the effect of the deformation on the precipitation kinetics depends of the microalloy content. In this sense, a new expression is proposed to relate the influence of the deformation and the chemical composition on the minimum incubation of the precipitation kinetics.

    Mediante ensayos de torsión y usando el método back extrapolation se ha determinado la cinética de recristalización estática de aceros microaleados con vanadio (V, niobio (Nb y titanio (Ti y, a partir de las mismas, ha sido posible dibujar los diagramas recristalizaciónprecipitación- tiempo-temperatura (RPTT, que muestran gráficamente la interacción recristalización-precipitación. Estos diagramas muestran que el efecto de la deformación en la cinética de precipitación depende del contenido de microaleante. En este sentido, se propone una nueva expresión para relacionar la influencia de la deformación y del contenido de microaleante sobre el periodo mínimo de incubación de la precipitación inducida.

  19. Influence of the surgical manipulation of the colon in colonic induced carcinogenesis in rats Influencia de la manipulación quirúrgica del colon en la carcinogénesis cólica inducida en ratas

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    J. F. Noguera Aguilar

    2004-05-01

    Full Text Available Aim: to investigate the influence of different experimental manipulations in a model of colonic experimental carcinogenesis with pharmacological induction in the rat. Experimental design: a total of 90 Sprague-Dawley male rats, divided into three groups, were used: non-surgical (n = 30; surgical with colonic trauma (n = 20, and surgical with colo-colonic anastomosis (n = 40. Carcinogenic induction was carried out with 1-2 dimethylhydrazine dihydrochloride. Colonic adenocarcinomas were identified and the number of tumors, as well as tumoral surface and percentage of tumoral surface was established. One-way ANOVA and Chi-square were employed for the statistical analysis. Results: the number of tumors was greater in the surgical group than in the control group, and tumors preferentially develop-ed around the manipulated colon. Surface and tumoral percentage were greater in the surgical group than in the control group, being also greater in the anastomosis group than in the group with colonic trauma. Within anastomosis groups, a greater tumor surface and percentage was found in the group with titanium than in the group with reabsorbable material. Conclusions: the experimental manipulation of the colon in rats enhances drug-induced colon carcingenesis. The creation of an anastomosis further increases the carcinogenic process compared with simulated anastomosis. This process is also enhanced by the quantity of suture material included in the anastomosis, and by the non-reabsorbable nature of the materials used in the anastomotic line.Objetivo: valorar la influencia de las distintas manipulaciones experimentales en un modelo de carcinogénesis cólica experimental con inducción farmacológica en la rata. Diseño experimental: se emplearon 90 ratas Sprague-Dawley macho, divididas en tres grupos: no quirúrgico (n=30; quirúrgico con traumatismo cólico (n=20, y quirúrgico con anastomosis colocólica (n=40. La inducción carcinogénica se realizó con

  20. Efecto terapéutico del extracto etanólico de Erythroxylum coca spp. en anemia ferropénica inducida en ratas Holtzman macho

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    Evelyn F. Gonzales-Carazas

    2013-01-01

    Full Text Available Introducción: La hoja de coca ha sido usada tradicionalmente con fines medicinales y contiene altos niveles de hierro. Objetivos: Determinar el efecto del extracto etanólico de Erythroxylum coca spp. frente a anemia ferropénica inducida por dieta deficiente en hierro, en ratas Holtzman macho. Diseño: Experimental. Lugar: Laboratorio del Instituto de Patología, Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Material biológico: Dieciocho ratas Holtzman macho de 16 días de edad recién destetadas. Intervenciones: Se formó tres grupos de seis ratas cada uno: a grupo hierro suficiente (HS, recibió 25 g/d de alimento balanceado durante 7 semanas; b grupo hierro deficiente (HD, recibió 25 g/d de dieta ferropénica durante 7 semanas; y, c el grupo hierro deficiente - extracto E. coca (HD-EC, recibió 25 g/d de dieta ferropénica durante 7 semanas y a partir de la semana 5 se agregó 18 g/d de extracto de E. coca. Principales medidas de resultados: Nivel sérico de hemoglobina, peso y talla. Resultados: Al finalizar el tratamiento, se observó aumento significativo de la hemoglobina en el grupo HD-EC (p=0,04. Se encontró diferencia significativa en los niveles séricos de hemoglobina entre los grupos HD-EC y HD (p=0,0062. No se encontró diferencia significativa en los valores de hemoglobina entre los grupos HD-EC y HS (p= 0,06. No se evidenció diferencia en el peso y la talla entre los grupos HD y HD-EC (p=0,20 y p=0,23, respectivamente. Conclusiones: E. coca presenta efecto antianémico experimental, sustentado en los resultados de los niveles de hemoglobina.

  1. Los niveles de anticuerpos anti factor plaquetario 4-heparina y el índice 4T para trombocitopenia inducida por heparina

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    Marta E. Martinuzzo

    2012-02-01

    Full Text Available La trombocitopenia inducida por heparina (HIT es un efecto adverso del tratamiento con heparina, mediada por anticuerpos anti complejo factor plaquetario 4 (PF4-heparina (HPIA. La HIT es frecuentemente moderada pero pueden desarrollarse complicaciones trombóticas. El diagnóstico precoz es importante. La detección de HPIA por ELISA tiene alta sensibilidad pero baja especificidad (títulos bajos sin significación clínica. El índice de las 4T (índice 4T puede detectar pacientes con alto riesgo de HIT. El propósito del estudio fue correlacionar los niveles de HPIA y el índice 4T de un grupo de pacientes derivados a nuestro centro. Evaluamos 84 pacientes, 34 de ellos desarrollaron trombosis. Cada médico completó un cuestionario clínico que fue remitido con la muestra a nuestro centro. Los cuestionarios fueron analizados por un investigador externo y el índice 4T se calculó previamente al ensayo. Los HPIA se determinaron por un ELISA (Asserachrom HPIA que detecta los 3 isotipos, IgG, IgM e IgA, único reactivo disponible en Argentina. Los resultados se expresaron como porcentaje de absorbancia (%ABS. La correlación del índice 4T con los HPIA fue 0.472 (rho spearman, p < 0.001. Los pacientes con índice 4T ≥ 6 presentaban %ABS mayores que los ≤ 5 (67 vs. 39, p < 0.001. Aquéllos con trombosis presentaron títulos mayores que los que no la desarrollaron (%ABS 59 vs. 39, p = 0.017. En conclusión: Los títulos altos de HPIA medidos por ELISA, que detecta los 3 isotipos, correlacionaron claramente con el índice 4T ≥ 6 y fueron más frecuentes en los pacientes con trombosis, coincidiendo con lo ya descripto para ensayos de ELISA específicos para isotipo IgG.

  2. Análisis proteómico de la resistencia inducida por micorrización al patógeno foliar Sclerotinia sclerotiorum en frijol (Phaseolus vulgaris l.)

    OpenAIRE

    Quintero Zamora, Edalhí

    2014-01-01

    En los últimos años se han reportado diversos estudios sobre la resistencia inducida por micorrización al ataque de patógenos, en éstos se han determinado los cambios de expresión de genes y proteínas que ocurren en las raíces de plantas colonizadas por hongos micorrízicos arbusculares. Recientemente, se han iniciado estudios para entender cómo afecta esta interacción a la parte aérea de la planta. En nuestro grupo de investigación se llevó a cabo el estudio del efecto de la micorrizaci...

  3. Determinação da segurança biológica do xampu de cetoconazol: teste de irritação ocular e avaliação do potencial de citotoxicidade in vitro Determination of the biological reactivity of ketoconazole in shampoo: draize eye test and cytotoxity test

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    Inara Staub

    2007-06-01

    Full Text Available Cetoconazol é um agente antifúngico, que pode ser incorporado em diferentes formas farmacêuticas, como, por exemplo, xampus e cremes. O objetivo do trabalho foi avaliar a segurança biológica in vivo (teste de irritação ocular e in vitro (teste de citotoxicidade do xampu de cetoconazol degradado sob ação da luz. Para tanto, a formulação foi exposta à radiação UV-C (254 nm e foram empregados dois métodos para a determinação quantitativa do cetoconazol: CLAE e ensaio microbiológico. Os resultados demonstraram alteração do cetoconazol em presença da luz - presença de picos secundários no cromatograma e diminuição da atividade antifúngica - entretanto, não demonstraram alteração na segurança biológica entre xampu de cetoconazol e xampu de cetoconazol contendo produtos de degradação.Ketoconazole is an antifungal agent and can be incorporated into several dosage forms, as an example it could be mentioned shampoos and creams. The aim of this work was to assess the biological reactivity in vivo (Draize eye test and in vitro (cytotoxity test of ketoconazole in shampoo degradeted under action of light. The formulation was exposed to UV-C (254 nm radiation and two methods were used for the quantitative determination of ketoconazole: HPLC and microbiological assay. The results showed alteration in ketoconazole in presence of light - secondary peaks in chromatogram and decrease in antifungal activity - however, no alteration on the biological reactivity between ketoconazole shampoo and ketoconazole shampoo containing degradation products was observed.

  4. Hipoglucemia inducida por carcinoma adrenal

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    Jimena Soutelo

    2013-08-01

    Full Text Available El carcinoma suprarrenal es una neoplasia maligna infrecuente y de mal pronóstico. La presentación clínica más común es originada por la producción hormonal excesiva, mientras que el desarrollo de hipoglucemia sintomática es excepcional. Presentamos el caso de una mujer de 37 años que ingresó al hospital por síntomas de hipoglucemias graves, hipertensión arterial, hipopotasemia y amenorrea secundaria. En el laboratorio se halló hipoglucemia con insulina inhibida y niveles de andrógenos en rango tumoral. La tomografía computarizada (TC de abdomen y pelvis mostró voluminosa formación heterogénea de aspecto sólido sin plano de clivaje con respecto al parénquima hepático e intenso realce con contraste. Luego de la extirpación de la masa retroperitoneal, evolucionó con valores de glucemia y potasemia normales, estabilizó la presión arterial y recuperó los ciclos menstruales.

  5. Evaluación de la reproducción inducida del blanquillo ( Sorubim cuspicaudus Littmann, Burr Nass, 2000 con ovaprim®.

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    Víctor Atencio G

    2003-01-01

    Full Text Available El blanquillo ( Sorubim suspicaudus Littmann, Burr &Nass, 2000 presenta características de importanciapara la acuicultura, destacándose la calidad de sucarne y el alto valor comercial. No se reproduce enconfinamiento, por lo que es necesario sureproducción inducida con sustancias hormonales.Responde bien a la inducción con extracto de pituitariade capa (EPC; sin embargo, no se ha evaluado suinducción con extracto de análogos deGonodotropine Releasing Hormone de salmón(sGnRH-a y domperidone en un vehículo inerte. Porlo tanto, entre mayo y noviembre/02, se evaluó eldesempeño reproductivo del blanquillo inducido condiferentes dosificaciones de Ovaprim®: 0.25 (T2,0.050 (T3 y 0.75 ml/kg de peso vivo (T4, aplicadoen una sola dosificación, por inyección en la basede la aleta pectoral. Además, un grupo fue inducidocon 8 mg EPC/kg de peso vivo (TI, en dos inyeccionesde 10 y7 90% de la dosis total, con intervalo de 6horas, por vía intramuscular. Se indujeron entre seisy nueve hembras por tratamiento con igual númerode machos. El desempeño reproductivo fue evaluadomediante el índice de ovulación (hembras ovuladas/hembras tratadas, tasa de fertilización medida a las4 horas pos-eclosión (HPF, tasa de eclosión medidaa las 10 HPF y la fecundidad tanto absoluta comorelativa. El Ovaprim® mostró ser efectivo para inducirla ovulación del blanquillo en las dosificacionesevaluadas (0.25 a 0.75 mL/kg, con respuestassimilares en el desempeño reproductivo a lasobtenidas en EPC. La ovulación con Ovaprim® seobtuvo entre las 12.8 y 14.0 horas con temperaturapromedio del agua de 27.3ºC. El índice de ovulaciónosciló entre 66.7% (T2 y 83.3% (T3; la tasa defertilización osciló entre 88.0% (T3 y 42.0% (T1; latasa de eclosión osciló entre 83.7% (T3 y 40.3%(T1;la fecundidad absoluta osciló entre 40370.6 (T1 y82992.5 ovocitos/hembra (T2; la fecundad relativa,expresada en gramos de ovocitos/kg de hembra,osciló entre 32.1 (T3 y 63.1(T2; el di

  6. Citotoxicity of food dyes sunset yellow (E-110, bordeaux red (E-123, and tatrazine yellow (E-102 on Allium cepa L. root meristematic cells Citotoxicidade dos corantes alimentares amarelo crepúsculo (E-110, vermelho bordeaux (E-123 e amarelo tartrazina (E-102 em células meristemáticas de raízes de Allium cepa L.

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    Keiva Maria Silva Gomes

    2013-03-01

    Full Text Available The objective of this study was to evaluate the cytotoxic effect of the food dyes sunset yellow, bordeaux red, and tartrazine yellow on the cellular cycle of Allium cepa L. Each dye was evaluated at the doses of 0.4 and 4.0 mL, at the exposure times of 24 and 48 hours in root tip cells of Allium cepa L. Slides were prepared and cells were analyzed during the whole cell cycle for cellular aberrations totaling 5,000 total cells for each dose evaluated. The mitotic index was calculated, and statistical analysis was performed using the Chi-squared test (p Este estudo teve por objetivo avaliar o efeito citotóxico dos corantes alimentares amarelo crepúsculo, vermelho bordeaux e amarelo tartrazina sobre o ciclo celular de Allium cepa L. Cada corante foi avaliado nas doses de 0,4 e 4,0 mL, nos tempos de exposição de 24 e 48 horas, em células de pontas de raízes de Allium cepa L. Prepararam-se lâminas e analisaram-se células, em todo o ciclo celular, e a presença de aberrações celulares, totalizando 5.000 células para cada dose avaliada. Foi calculado o índice mitótico e a análise estatística foi feita por meio do teste quiquadrado (p < 0,05. Os resultados mostraram que os três corantes, nas doses e tempos de exposição avaliados, foram citotóxicos às células do sistema-teste utilizado. Estudos adicionais de citotoxicidade devem ser conduzidos para se somar a estes resultados e, assim, avaliar, com propriedade, a ação destes três corantes em nível celular.

  7. Estudio de la influencia del Cu y Ni en la cinética de transformación martensítica inducida por deformación en fundiciones nodulares austemperadas

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    Guzmán, D.

    2013-06-01

    Full Text Available The objective of this work was to study the influence of copper and nickel on the kinetics of strain-induced martensite in austempered ductile cast iron. The austempered ductile cast irons were obtained from two ductile cast irons with different copper and nickel contents by means of austempering treatment. The deformation was carried out using a rolling mill. The quantification of the phases was obtained by means of X ray diffraction, while the microstructural characterization was carried out using optical and scanning electron microscopy. It was proved that the kinetics of strain-induced martensite in austempered ductile cast iron can be modeled using the equations proposed by Olson- Cohen and Chang et al. Based on the results obtained from these analyses, it is possible to conclude that the nickel and copper complicate the martensite transformation because these elements increase the staking fault energy of the austenite and its thermodynamic stability.El objetivo de este trabajo fue estudiar el efecto del cobre y níquel en la cinética de la transformación martensítica inducida por deformación en fundiciones nodulares austemperadas. Las fundiciones utilizadas se fabricaron mediante austemperado, a partir de dos fundiciones nodulares, con diferentes contenidos de cobre y níquel. La deformación se realizó en un laminador de rodillo. La cuantificación de las fases se realizó mediante difracción de rayos X, mientras que la caracterización microestructural se efectuó utilizando microscopía óptica y electrónica de barrido. Se comprobó que la cinética de transformación martensítica inducida por deformación en fundiciones nodulares austemperadas puede ser modelada mediante los modelos de Olson-Cohen y Chang et al. Basándose en los resultados obtenidos de estos ajustes, se concluye que tanto el níquel como el cobre dificultan la transformación martensítica debido a que estos elementos aumentan la energía de falla de

  8. Trolox reduces the effect of ethanol on acetylcholine-induced contractions and oxidative stress in the isolated rabbit duodenum El Trolox reduce el efecto del etanol sobre las contracciones inducidas a la acetilcolina y el estrés oxidativo en duodeno aislado de conejo

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    Diego S. Fagundes

    2011-08-01

    Full Text Available Trolox is a hydrophilic analogue of vitamin E and a free radical scavenger. Ethanol diminishes the amplitude of spontaneous contractions and acetylcholine (ACh-induced contractions in rabbit duodenum. The aim of this work was to study the effect of Trolox on the alterations induced by ethanol on contractility and lipid peroxidation in the duodenum. The duodenal contractility studies in vitro were carried out in an organ bath and the levels of malondialdehyde and 4-hydroxyalkenals (MDA+4-HAD were measured by spectrophotometry. Trolox increased the reduction induced by ethanol on the amplitude of spontaneous contractions in longitudinal muscle but not in circular muscle. Trolox 4 mM decreased the effects of ethanol on ACh-induced contractions and on MDA+4-HDA concentrations. We conclude that Trolox might prevent oxidative stress induced by ethanol in the duodenum.El Trolox es un análogo hidrofílico de la vitamina E y un agente que secuestra radicales libres. El etanol disminuye la amplitud de las contracciones espontáneas y las contracciones inducidas a la acetilcolina en el duodeno de conejo. El objetivo de este trabajo era estudiar el efecto del Trolox en las alteraciones inducidas por el etanol sobre la contractilidad y la peroxidación lipídica en el duodeno. Los estudios de contractilidad duodenal in vitro se realizaron en un baño de órganos y los niveles de MDA+4-HDA se midieron por espectofotometría. El Trolox aumentó la reducción inducida por el etanol sobre la amplitud de las contracciones espontáneas en el músculo longitudinal pero no en el músculo circular de duodeno. El Trolox 4 mM redujo los efectos del etanol sobre las contracciones inducidas a la acetilcolina y sobre las concentraciones de MDA+4-HDA. Se concluye que el Trolox podría prevenir el estrés oxidativo inducido por el etanol en el duodeno.

  9. Effect of rofecoxib on colon chemical carcinogenesis at colonic anastomotic area in the rat Influencia del rofecoxib en la carcinogénesis cólica perianastomótica inducida en ratas

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    J. F. Noguera Aguilar

    2005-06-01

    durante 18 semanas y se analizaron los tumores cólicos inducidos en la semana 20 del postoperatorio. El principal parámetro evaluado fue el porcentaje de tejido cólico neoplásico, que relaciona la superficie tumoral con la superficie del colon. Resultados: el rofecoxib a dosis de 0,0058 ppm redujo significativamente la carcinogénesis cólica inducida en ratas, tanto a nivel perianastomótico como en el resto del colon (p < 0,01. A nivel extraanastomótico, el rofecoxib a dosis de 2,5 mg/kg fue significativamente superior en su efecto inhibidor al rofecoxib a dosis de 1,2 mg/kg o 0,0027 ppm (p < 0,005. Conclusiones: el rofecoxib produce una disminución en la carcinogénesis cólica farmacológicamente inducida en ratas. Este efecto se mantiene en el área perianastomótica, por lo que puede ser interesante investigar su implicación en el cáncer colorrectal intervenido con riesgo de recidiva locorregional.

  10. Compactación inducida por el tránsito vehicular sobre un suelo en producción hortícola Induced compaction by the vehicular traffic in a soil for horticultural crop production

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    Antonino Marcelo Terminiello

    2000-01-01

    Full Text Available Se realizaron ensayos en campo con el objeto de caracterizar el estado de compactación de un suelo en producción hortícola inducida por el tránsito, luego del desarrollo del ciclo de un cultivo de repollo (Brassica oleracea L. grupo capitata y su incidencia sobre el rendimiento. Se efectuaron determinaciones de resistencia a la penetración, densidad aparente y humedad gravimétrica sobre el suelo y biomasa aérea al finalizar el ciclo del cultivo en los sectores de mayor y menor número de pasajes de vehículos. Los valores de resistencia a la penetración fueron de 1,7 y 1,3 MPa, significativamente mayores para el tratamiento de más de 7 y 3 pasadas respectivamente en el rango de profundidad de 0-100 mm . No se manifestaron diferencias en el parámetro densidad aparente en la totalidad del perfil. Se encontraron diferencias estadísticamente significativas en biomasa aérea, para el tratamiento de 3 pasadas (1902.6 g planta-1, en relación al de mas de 7 pasadas (1447,9 g planta-1. El pasaje repetido sobre los surcos originan incrementos en la resistencia a la penetración a nivel superficial. El peso fresco y la materia seca del cultivo son afectados por el número de pasadas de los tractores y máquinas agrícolas.Field test were carried out with the objective of characterizing the state of compaction in horticultural soil induced by traffic, after the development of a cabbage crop (Brassica oleracea L. group capitata cycle, and its incidence on yield. Measurements of penetration resistance, bulk density, and moisture content in soil were made and aeread biomass at the end of the cycle crop in sectors with larger and smaller number of vehicles passes. Values of penetration resistance of 1.7 and 1.3 MPa were found for treatment with more than 7 passes and 3 passes respectively in the depth range of 0-100 mm. No significant differences were found in bulk density parameter in the entire soil profile. Statistically significant differences

  11. Mitogen activated protein kinases blockade improves lipopolysaccharide-induced ileal motor disturbances El bloqueo de las proteínas cinasas activadas por mitógenos mejora las alteraciones motoras inducidas por el lipopolisacárido en íleon

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    Sergio Gonzalo

    2012-06-01

    Full Text Available Background: several diseases such as sepsis can affect the ileum. Lipopolysaccharide (LPS, an endotoxin present in the cell wall of gram negative bacteria, is a causative agent of sepsis. Objectives: the aims of this study were: a to investigate the role of mitogen activated protein kinases (MAPKs in the effect of LPS on the acetylcholine-induced contractions of rabbit ileum; and b to study the localization of MAPKs in the ileum. Material and methods: ileal contractility was studied in an organ bath and MAPKs were localized by immunohistochemistry. Results: acetylcholine-induced contractions decreased with LPS. SB203580, SP600125 and U0126 blocked the effect of LPS on the acetylcholine-induced contractions. Phosphorylated p38 and ERK were detected in neurons of myenteric plexus and phosphorylated p38 and JNK in smooth muscle cells of ileum. Conclusion: we can suggest that p38, JNK, and ERK MAPKs are involved in the mechanism of action of LPS in the ileum.Introducción: varias enfermedades como la sepsis pueden afectar al íleon. El lipopolisacárido (LPS, una endotoxina presente en la pared celular de las bacterias gram-negativas, es un agente causal de la sepsis. Objetivos: los objetivos del presente estudio fueron: a investigar el papel de las proteína cinasas activadas por mitógenos (MAPKs en los efectos del LPS en las contracciones inducidas por acetilcolina en el íleon de conejo; y b estudiar la localización de las MAPKs en el íleon. Material y métodos: la contractilidad ileal se estudió en un baño de órganos y las MAPKs se localizaron mediante inmunohistoquímica. Resultados: el LPS disminuyó las contracciones inducidas por acetilcolina. El SB203580, el SP600125 y el U0126 bloquearon los efectos del LPS sobre las contracciones inducidas por acetilcolina. La p38 y la ERK fosforiladas se detectaron en las neuronas del plexo mientérico y la p38 y la JNK fosforiladas en las células del músculo liso del íleon. Conclusi

  12. Determinación del índice de resistencia a la insulina mediante homa y su relación con el riesgo de hipertensión inducida por el embarazo Insulin resistance index assessment by homa and its relation with the risk of pregnancy induced hypertension

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    Jesús Sierra-Laguado

    Full Text Available Objetivo: investigar si el grado de resistencia a la insulina determinado por el índice HOMA, predice de manera temprana el desarrollo de hipertensión inducida por el embarazo en gestantes colombianas. Diseño-métodos: se realizó un estudio de casos y controles anidado en una cohorte prospectiva de 438 mujeres primigestantes, normotensas y con edad gestacional menor de 30 semanas. Se determinó el índice HOMA a partir de la medición de glucemia e insulina plasmática en ayunas, por métodos de glucosa oxidasa y quimioluminiscencia, respectivamente. Resultados: veintitrés mujeres desarrollaron hipertensión inducida por el embarazo (5,25%. Se seleccionaron de forma aleatoria dos embarazadas normotensas como controles por cada caso, pareadas por edad materna y gestacional al momento de su inclusión. Las mujeres que posteriormente desarrollaron hipertensión inducida por el embarazo presentaron mayores niveles de HOMA (1,48 ± 0,98 vs. 0,96 ± 0,70, pObjective: to assess whether insulin resistance determined by homeostatic model assessment (HOMA is an early predictor of the development of pregnancy induced hypertension in Colombian pregnant women. Methods: we conducted a nested case control study in a prospective cohort of four hundred and thirty eigth normotensive primigravidae women, with gestational age < 30 weeks. The HOMA was calculated using fasting plasma concentrations of glucose and insulin, determined by glucose-oxidase and chemoluminiscence methods, respectively. Results: twenty-three pregnant women developed pregnancy induced hypertension (5.25%. Two normotensive pregnant women were selected as controls for each case, matched by gestational and maternal age at enrollment. The women who subsequently developed pregnancy induced hypertension had higher levels of HOMA (1.48 ± 0.98 vs 0.96 ± 0.70, p<0.001, which was associated with an increased risk of developing pregnancy induced hypertension (OR: 3.8, IC95%: 1.1-12.8 p=0

  13. Tratamiento de agua potable por filtración inducida en una laguna costera en el sur de Brasil Bank filtration drinking water treatment in a costal lagoon in south Brazil

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    Luis Guillermo Romero Esquivel

    2012-12-01

    Full Text Available La filtración inducida (FI consiste en obtener agua potable de pozos situados en acuíferos de aluvión u otro tipo de depósitos no consolidados conectados hidráulicamente con una fuente de agua superficial. La posibilidad de aplicar esta técnica en las riberas de la laguna Lagoa do Peri, Brasil, se evaluó a nivel piloto. Por medio de observación y de análisis granulométricos se determinó que el fondo de la laguna y el acuífero aledaño presentan una textura arenosa. Además, ensayos de permeámetro de carga constante, de tubo de carga variable y de bombeo, mostraron que la conductividad hidráulica en las mismas zonas se encuentra cercana a 10-4 m/s, misma magnitud encontrada en otras latitudes donde la FI se aplica con éxito. El agua captada en un pozo a 20 m de la Lagoa do Peri presentó valores de turbidez y color aparente acordes con los patrones de calidad locales. Se observó un aumento en la dureza y la alcalinidad, atribuido a la erosión de los materiales del subsuelo, sin llegar a superar lo estipulado en la legislación. Finalmente, el agua producida por la FI mostró ser de mejor calidad en términos de turbidez y color aparente que el agua de la laguna tratada por filtración directa en una estación de tratamiento (ETA ubicada en el lugar. El agua producida por la FI presentó condiciones anóxicas que harían necesario el postratamiento por aireación y filtración, proceso en el cual se podría aprovechar la infraestructura de la ETA existente.Bank filtration (BF consists in obtaining drinking water from wells in alluvial aquifers or other unconsolidated deposits hydraulically connected with a surface water source. The possibility of applying this technique was evaluated in a pilot scale on the banks of the Lagoa do Peri lagoon, Brazil. Observation and grain size analysis showed that the bottom of the lagoon and the adjacent aquifer have sandy texture. In addition, tests of constant head permeameter, standpipe falling

  14. Vasculitis inducida por metimazol: Reporte de caso

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    Miguel Pinto

    2011-07-01

    Full Text Available Se reporta el caso de una paciente con enfermedad de Graves, que presentó vasculitis asociada al uso de metimazol. Mujer de 14 años, que acudió a consulta por presentar intolerancia al calor, tremor distal y palpitaciones. El examen físico mostró bocio difuso, y el perfil tiroideo, TSH suprimida y hormonas tiroideas elevadas. Los anticuerpos antiperoxidasa tiroidea fueron positivos. Se inició tratamiento con metimazol y beta bloqueadores. Después de 20 días, la paciente regresó por presentar malestar general, fiebre, poliartralgia, lesiones cutáneas maculopapulares y edema de miembros inferiores. Los anticuerpos antinucleares fueron negativos y los anticuerpos anticitoplasma de los neutrófilos (ANCA, positivos. Se suspendió el metimazol y se inició prednisona. Después de 10 días de tratamiento, las molestias desaparecieron y la paciente recibió I 131.Las vasculitis asociadas al uso de tionamidas son poco frecuentes, no dependen de la dosis y están asociadas a la presencia de anticuerpos tipo ANCA. Clásicamente, afectan a los vasos pequeños de la piel; sin embargo, también pueden afectar los riñones y pulmones. El cuadro clínico se caracteriza por artralgias y mialgias. En algunos casos puede ocurrir insuficiencia renal de grado variable. En la mayoría de casos, el cuadro remite con la suspensión de la droga; pero, en algunos se requiere el uso de glucocorticoides o inmunosupresores.(Rev Med Hered 2011;22:147-150.

  15. Las defensas inducidas en trigos comerciales

    OpenAIRE

    Càrdenas, David; Giménez, Daniel O.; Castro, Ana María

    2015-01-01

    Las plantas presentan múltiples tipos de estrategias de defensas ante sus patógenos y plagas y frente a estreses ambientales. En muchos casos las defensas constitutivas acarrean costos metabólicos altos que provocan mermas del rendimiento cuando no ocurren en el ciclo de cultivo ataquesde plagas o patógenos. Las defensas inducibles en cambio sólo se activan ante elicitores específicos producidos por la interacción con los agresores bióticos, si bien conllevan gastos energéticos sólo ocurre an...

  16. Osteonecrosis de hueso maxilar inducida por bisfosfonatos

    OpenAIRE

    Vera Sempere, Francisco José

    2016-01-01

    Los bisfosfonatos son un grupo de fármacos, análogos de los pirofosfatos, utilizados en administración oral en el tratamiento de la osteoporosis, así como en formulaciones intravenosas para el tratamiento del dolor óseo y de la hipercalcemia ligada a la enfermedad tumoral metastasica (generalmente en el contexto de mieloma múltiple / cáncer de mama o próstata avanzados), actuando como un inhibidor de la reabsorción ósea, mediada por osteoclastos, así como de la apoptosis de los osteobl...

  17. Natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, J W

    1967-08-01

    This report on the natural gas industry of Canada includes: composition and uses of natural gas, production statistics, exploration and development, reserve estimates, natural gas processing, transportation, and marketing. For the Canadian natural gas industry, 1966 was a year of moderate expansion in all phases, with a strong demand continuing for sulfur and liquid hydrocarbons produced as by-products of gas processing. Value of natural gas production increased to $199 million and ranked sixth in terms of value of mineral ouput in Canada. Currently, natural gas provides over 70% of Canada's energy requirements. Proved remaining marketable reserves are estimated to be in excess of a 29-yr supply.

  18. Natural Gas

    OpenAIRE

    Bakar, Wan Azelee Wan Abu; Ali, Rusmidah

    2010-01-01

    Natural gas fuel is a green fuel and becoming very demanding because it is environmental safe and clean. Furthermore, this fuel emits lower levels of potentially harmful by-products into the atmosphere. Most of the explored crude natural gas is of sour gas and yet, very viable and cost effective technology is still need to be developed. Above all, methanation technology is considered a future potential treatment method for converting the sour natural gas to sweet natural gas.

  19. PLURALIZING NATURE

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    Denmark is widely recognised for its democratic approach to planning and the idea of planning for the common good. This interest in the common good and common values seems also to be reflected in the way which nature restoration is planned and managed – one common nature directed by the public...... authorities. But nature restoration is far from being a neural undertaking. Just like any other type of heritage production it can be the source of dissonance – ‘our’ nature is not necessary ‘their’ nature. Often this dissonance is managed in ways, which are not particular sensitive to site......-specificity. As exemplified by the Skjern River Restoration Project (1999-2003), one interpretation of the landscape sometimes suppresses other valid interpretations neglecting its diverse history. However, evidence from Switzerland suggests that planning for the common good, in the case of nature restoration, does...

  20. Natural Philosophy

    OpenAIRE

    Blair, Ann M.

    2006-01-01

    Natural philosophy” is often used by European historians as an umbrella term to designate the study of nature before it can easily be identified with what we call “science” today, to avoid the modern and potentially anachronistic connotations of that term. But “natural philosophy” (and its equivalents in different languages) was also an actor's category, a term commonly used throughout the early modern period and typically defined quite broadly as the study of natural bodies. As the central ...

  1. Dissonant Nature

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2013-01-01

    Nature restoration is far from being a neural undertaking. Just like any other type of heritage production it can be the source of dissonance – ‘our’ nature is not necessary ‘their’ nature. Often this dissonance is managed in ways, which are not particular sensitive to site-specificity. As exempl...... and allows for multiple interpretations to coexist. Evidence can be found in the Re-naturalization of River Aire (2002-2015), a restoration project, which reveals approaches that could be labelled landscape architecture specific....

  2. Temporal naturalism

    Science.gov (United States)

    Smolin, Lee

    2015-11-01

    Two people may claim both to be naturalists, but have divergent conceptions of basic elements of the natural world which lead them to mean different things when they talk about laws of nature, or states, or the role of mathematics in physics. These disagreements do not much affect the ordinary practice of science which is about small subsystems of the universe, described or explained against a background, idealized to be fixed. But these issues become crucial when we consider including the whole universe within our system, for then there is no fixed background to reference observables to. I argue here that the key issue responsible for divergent versions of naturalism and divergent approaches to cosmology is the conception of time. One version, which I call temporal naturalism, holds that time, in the sense of the succession of present moments, is real, and that laws of nature evolve in that time. This is contrasted with timeless naturalism, which holds that laws are immutable and the present moment and its passage are illusions. I argue that temporal naturalism is empirically more adequate than the alternatives, because it offers testable explanations for puzzles its rivals cannot address, and is likely a better basis for solving major puzzles that presently face cosmology and physics. This essay also addresses the problem of qualia and experience within naturalism and argues that only temporal naturalism can make a place for qualia as intrinsic qualities of matter.

  3. Matematica Natural.

    Science.gov (United States)

    Lozano, Patricia; Medearis, Linda

    Matematica Natural (Natural Mathematics) is a mathematics curriculum for young children based on the assumption that they learn mathematics through concrete, real life, relevant experiences and that educational differences rather than cultural differences influence math achievement. The curriculum uses hands-on materials and activities to teach…

  4. Natural radiation

    International Nuclear Information System (INIS)

    Feliciano, Vanusa Maria Delage

    2016-01-01

    Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included

  5. Framing nature

    NARCIS (Netherlands)

    Jansen, Peter

    2017-01-01

    This PhD thesis is about communication concerning nature in the Netherlands. The purpose of this exploratory study is to take both a theoretical and an empirical look at whether (implicit) religious elements play a role in this communication about nature in the Netherlands.

    In this PhD

  6. Natur formet

    DEFF Research Database (Denmark)

    Søberg, Martin

    2011-01-01

    Anmeldelse af Malene Hauxner, "Fra naturlig natur til SUPERNATUR – Europæisk landskabsarkitektur 1967-2007 set fra Danmark", Risskov: Ikaros Press, 2011.......Anmeldelse af Malene Hauxner, "Fra naturlig natur til SUPERNATUR – Europæisk landskabsarkitektur 1967-2007 set fra Danmark", Risskov: Ikaros Press, 2011....

  7. Natural radiation; A radiacao natural

    Energy Technology Data Exchange (ETDEWEB)

    Feliciano, Vanusa Maria Delage

    2016-07-01

    Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included.

  8. Natural Communities

    Data.gov (United States)

    Kansas Data Access and Support Center — This dataset shows the locations of known tracts of high quality natural communities in Kansas, generalized to the PLSS section. It is not a compehensive dataset of...

  9. Sciences & Nature

    African Journals Online (AJOL)

    AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL ... Sciences & Nature, the Scientific Journal edited by the University of ... Subjects covered include agronomy, sciences of the earth, environment, biological, ...

  10. Pluralising Nature

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2017-01-01

    suppress other valid perceptions, in conflict with the need for different groups of people to be able to identify with the same territory. However, planning for the common good, in the case of nature restoration, does not necessarily mean planning for one common nature. Understanding and working......Denmark is recognised for its democratic approach to planning, and for the idea of planning for the common good. This interest in the common good and in common values also seems to be reflected in the way that the restoration of nature is planned and managed, suggesting that there is one common...... “nature” that everyone can agree on. But nature restoration is far from being an unproblematic undertaking. As with any other type of heritage production, it can be the source of dissonance. As exemplified by the Skjern River Restoration Project, one perception of a landscape and its value as “nature” can...

  11. Writing Nature

    Directory of Open Access Journals (Sweden)

    Kristin Asdal

    2014-06-01

    Full Text Available This special issue of the Nordic Journal of Science and Technology Studies is interested in how nature, in different versions and forms, is invited into our studies, analyses, and stories. How is it that we “write nature”? How is it that we provide space for, and actually describe the actors, agents, or surroundings, in our stories and analyses? The articles in the issue each deal with different understandings of both the practices of writing and the introduction of various natures into these. In this introduction to the issue the editors engage with actor-network theory as a material semiotic resource for writing nature. We propose to foreground actor-network theory as a writing tool, at the expense of actor-network theory as a distinct vocabulary. In doing this and pointing out the semiotic origins to material-semiotics we also want to problematize a clear-cut material approach to writing nature.

  12. Natural aphrodisiacs.

    Science.gov (United States)

    Shamloul, Rany

    2010-01-01

    The search for a remedy or a prescription that can enhance sexual function and/or treat male erectile dysfunction has been an obsession throughout known history. Whether it was an Eastern civilization or a Western one, religious or atheist, man's aspiration for a better or best "manhood" has been a history-time goal. This review will discuss the current research done on the most popular natural aphrodisiacs and examine the weight of evidence to support or discourage the use of any of these substances to enhance sexual desire and/or function. Review of the current evidence on the use of natural substances as aphrodisiacs. Efficacy of natural aphrodisiacs in enhancing sexual function in men and women. There is little evidence from literature to recommend the usage of natural aphrodisiacs for the enhancement of sexual desire and/or performance. Data on yohimbine's efficacy does not support the wide use of the drug, which has only mild effects in the treatment of psychogenic ED. Although there's a positive trend towards recommending ginseng as an effective aphrodisiac, however, more in depth studies involving large number of subjects and its mechanism of action are needed before definite conclusions could be reached. Data on the use of natural aphrodisiacs in women is limited. The current body of objective evidence does not support the use of any natural aphrodisiac as an effective treatment for male or female sexual dysfunctions. Potent men and men with ED will continue the search for natural aphrodisiacs despite the current disappointing data on their effectiveness. Care should be taken regarding the fraud addition of sildenafil analogues to natural aphrodisiacs.

  13. Emancipating Nature

    DEFF Research Database (Denmark)

    Munk, Anders Kristian

    2012-01-01

    The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations of it – hydrodyn......The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations...... of it – hydrodynamic equations – which have their own anticipations and place their own demands on their modellers. Through the experience of a flood modelling apprenticeship I argue that the taking-place of such anticipations paradoxically relies on the birth of a hybrid, the model-modeller, and thus on a nature...

  14. Natural aerodynamics

    CERN Document Server

    Scorer, R S

    1958-01-01

    Natural Aerodynamics focuses on the mathematics of any problem in air motion.This book discusses the general form of the law of fluid motion, relationship between pressure and wind, production of vortex filaments, and conduction of vorticity by viscosity. The flow at moderate Reynolds numbers, turbulence in a stably stratified fluid, natural exploitation of atmospheric thermals, and plumes in turbulent crosswinds are also elaborated. This text likewise considers the waves produced by thermals, transformation of thin layer clouds, method of small perturbations, and dangers of extra-polation.Thi

  15. Provincialising Nature

    DEFF Research Database (Denmark)

    Provincialising Nature: Multidisciplinary Approaches to the Politics of the Environment in Latin America offers a timely analysis of some of the crucial challenges, contradictions and promises within current environmental discourses and practices in the region. This book shows both challenging...... scenarios and original perspectives that have emerged in Latin America in relation to the globally urgent issues of climate change and the environmental crisis. Two interconnected analytical frameworks guide the discussions in the book: the relationship between nature, knowledge and identity and their role...

  16. Estudio del D-004 sobre la defensa antioxidante endógena en ratas con hiperplasia prostática inducida por inyección de testosterona Study of D-004 on the endogenous antioxidant defence in rats presenting with prostate hyperplasia induced by testosterone injection

    Directory of Open Access Journals (Sweden)

    Yohani Pérez Guerra

    2010-06-01

    Full Text Available La hiperplasia prostática benigna, enfermedad común en hombres mayores de 50 años de edad, se caracteriza por el crecimiento incontrolado de la glándula prostática y la presencia de síntomas del tracto bajo urinario. El estrés oxidativo ha sido recientemente asociado con la causa de esta enfermedad. El D-004, extracto lipídico del fruto de la Roystonea regia, ha mostrado reducir la hiperplasia prostática inducida por testosterona en roedores y producir efectos antioxidantes in vitro e in vivo, pero sus efectos sobre las enzimas del sistema antioxidante endógeno no han sido estudiados. Este trabajo investigó los efectos del tratamiento oral con D-004, durante 14 días, sobre las enzimas superóxido dismutasa y catalasa en ratas con hiperplasia prostática inducida por testosterona. Los animales se distribuyeron en 4 grupos: un control negativo y tres inyectados con testosterona: uno tratado con el vehículo (control positivo y dos con D-004 (400 y 800 mg/kg, respectivamente. Se determinó la capacidad antioxidante total del plasma y las actividades de las enzimas superóxido dismutasa y catalasa en eritocitos lisados y plasma, respectivamente. El tratamiento oral con D-004 (400 y 800 mg/kg previno de modo marcado y significativo el agrandamiento de la próstata inducido con testosterona en ratas, y aumentó significativamente la capacidad antioxidante del plasma y la actividad de la catalasa, sin modificar la actividad de la superóxido dismutasa. Estos resultados sugieren que la actividad antioxidante del D-004 está relacionada, al menos parcialmente, con la estimulación de algunas enzimas del sistema antioxidante endógeno.Benign prostatic hyperplasia, a common disease in men aged over 50 is characterized by uncontrolled growth of prostatic gland and the presence of low urinary tract symptoms. The oxidative stress has been recently associated with the disease cause. The D-004, a lipid extract from Roystonea regia, reduces the

  17. Nature Watch

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 3. Nature Watch Diversity of Bats. G Marimuthu. Feature Article Volume 1 Issue 3 March 1996 pp 103-110. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/03/0103-0110. Author Affiliations.

  18. Nature's Palette

    Science.gov (United States)

    McBride, Brooke B.; Brewer, Carol A.

    2010-01-01

    Flower petals, acorn hats, exoskeletons of beetles, and lichens are just a few of the objects students may find in a surprising array of vivid colors. These tiny examples from nature's palette can be discovered in a school yard, a park, or even along the edges of a paved sidewalk...it simply takes careful observation! This article describes a…

  19. Nature Watch

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 9. Nature Watch - Coral Reefs and their Fauna: An Underwater Fantasyland. Anuradha Bhat. Feature Article Volume 9 Issue 9 September 2004 pp 62-73. Fulltext. Click here to view fulltext PDF. Permanent link:

  20. Nature Watch

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 3. Nature Watch: Symbiosis in Coastal Marine Communities. Neelam Pereira. Feature Article Volume 20 Issue 3 March 2015 pp 245-253. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. Nature Watch

    Indian Academy of Sciences (India)

    ... Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 5. Nature Watch - Thinking Like a Tahr: When Males and Females go their Separate Ways. M D Madhusudan. Feature Article Volume 3 Issue 5 May 1998 pp 43-47 ...

  2. Natural Propositions

    DEFF Research Database (Denmark)

    Stjernfelt, Frederik

    Preface -- Introduction -- The generality of signs -- Dicisigns -- Some consequences of the dicisign doctrine -- Dicisigns and cognition -- Natural propositions--the evolution of semiotic self-control -- Dicisigns beyond language -- Operational and optimal iconicity in Peirce's diagrammatology...... -- Cows, red cows, and red herrings -- Corollarial and theorematic experiments with diagrams -- Strategies of research: Peirce's enlightenment maxims -- Perspective -- References -- Index....

  3. Nature Watch

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 7. Nature Watch - Singapore's Jurong BirdPark: A Study Model. Abraham Verghese. Feature Article Volume 6 Issue 7 July 2001 pp 74-88. Fulltext. Click here to view fulltext PDF. Permanent link:

  4. Kritikkens natur

    DEFF Research Database (Denmark)

    Schatz-Jakobsen, Claus

    1999-01-01

    Artiklen introducerer det nye forskningsfelt inden for samtænkning af litteratur, kultur og natur, den såkaldt økologiske kritik, og kaster et kritisk blik på  dens brug af romantisk litteratur som proto-økologisk kanon....

  5. Nature Watch

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 7. Nature Watch - The Odyssey of the Olive Ridley. Kartik Shanker. Feature Article Volume 4 Issue 7 July 1999 pp 68-78. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/004/07/0068-0078 ...

  6. Nature Watch

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 8. Nature Watch - Secrets of the Shieldtails. Kartik Shanker. Feature Article Volume 1 Issue 8 August 1996 pp 64-70. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/08/0064-0070 ...

  7. Nature Watch

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... ... 20; Issue 1. Nature Watch: A Tale of Two Turtles. V Deepak. Feature Article Volume 20 Issue 1 January 2015 pp 47-54. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/020/01/0047-0054. Keywords. Ecology; endemic; India; turtles; tortoises; Western Ghats.

  8. Provincialising Nature

    DEFF Research Database (Denmark)

    Provincialising Nature: Multidisciplinary Approaches to the Politics of the Environment in Latin America offers a timely analysis of some of the crucial challenges, contradictions and promises within current environmental discourses and practices in the region. This book shows both challenging...... scenarios and original perspectives that have emerged in Latin America in relation to the globally urgent issues of climate change and the environmental crisis. Two interconnected analytical frameworks guide the discussions in the book: the relationship between nature, knowledge and identity and their role...... in understanding recent and current practices of climate change and environmental policy. The different chapters in this volume contribute to this debate by offering multidisciplinary perspectives on particular aspects of these two frameworks and through a multidirectional outlook that links the local, national...

  9. Unbounded Naturalism

    Directory of Open Access Journals (Sweden)

    Andrew Taggart

    2008-10-01

    Full Text Available nbsp;font face="Times, serif"font size="3"In the Anglo-American reception of John McDowellrsquo;s /font/fontfont face="Times, serif"font size="3"emMind and World/em/font/fontfont face="Times, serif"font size="3", there has been little attention paid to the developmental aspect of his lsquo;partially re-enchantedrsquo; naturalism. In lsquo;Naturalism Unboundedrsquo;, I argue that McDowellrsquo;s story of our normal upbringing (/font/fontfont face="Times, serif"font size="3"emBildung/em/font/fontfont face="Times, serif"font size="3" presents problems for his claim that we have a lsquo;standing obligationrsquo; to reflect on our perceptual experiences. I follow this critique up with a Hegelian-inspired attempt to retain and revise the vital points he makes about experience./font/font

  10. Natural games

    International Nuclear Information System (INIS)

    Anttila, Jani; Annila, Arto

    2011-01-01

    A course of a game is formulated as a physical process that will consume free energy in the least time. Accordingly, the rate of entropy increase is the payoff function that will subsume all forms of free energy that motivate diverse decisions. Also other concepts of game theory are related to their profound physical counterparts. When the physical portrayal of behavior is mathematically analyzed, the course of a game is found to be inherently unpredictable because each move affects motives in the future. Despite the non-holonomic character of the natural process, the objective of consuming free energy in the least time will direct an extensive-form game toward a Lyapunov-stable point that satisfies the minimax theorem. -- Highlights: → Behavior in the context of game theory is described as a natural process. → The rate of entropy increase, derived from statistical physics of open systems, is identified as the payoff function. → Entropy as the payoff function also clarifies motives of collaboration and subjective nature of decision making. → Evolutionary equation of motion that accounts for the course of a game is inherently unpredictable.

  11. Risks Associated with Unconventional Gas Extraction Projects. Induced Seismicity, NORM and Ecological Risks; Riesgos Asociados a los Proyectos de Extracción de Gas no Convencional. Sismicidad Inducida, NORM y Riesgos Ecológicos

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigo-Naharro, J.; Hurtado, A.; Eguilior, S.; Recreo, F.

    2015-07-01

    The latest technological advances in hydraulic fracturing (fracking) and horizontal drilling are globally driving the commercial extraction of unconventional resources. Although there is still no commercial exploitation of these resources within the EU, the fact that there are potential reserves in some countries, such as Spain, stimulates the need of performing preliminary studies to define the characteristics that an unconventional gas extraction project should consider. The object of these features are the safety of the project, thus minimizing the probabilities of negative environmental impacts, and especially since there is not any EU Framework Directive focusing on the regulation of the operation of such fossil fuels. A project of this nature, involving natural systems, must start from the knowledge of these systems and from an assessment of its features in order to reach the environmental safety of the operations. Moreover, the implementation of risk management systems, along with the existence of an appropriate legislation and supervision are key elements in the development of unconventional gas extraction projects that are environmentally friendly. The present report includes, among the overall risks associated with such projects, those related to: i) the induced seismicity; ii) the Naturally-Occurring Radioactive Materials (NORM); and iii) the ecology.

  12. Cytotoxicity evaluation of Diethyltoluamide (DEET) in Perna perna (Linnaeus, 1758) mussels non-irradiated and irradiated with {sup 60}Co gamma radiation; Avaliacao da citotoxicidade do dietiltoluamida (DEET) em mexilhoes Perna perna (Linnaeus, 1758) irradiados e nao irradiados com radiacao gama de {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Martini, Gisela de Assis

    2013-07-01

    Recent studies have identified the presence of several emerging pollutants in aquatic environments. The occurrence in different environmental matrices has been continuously reported, highlighting the need for toxicity studies. The DEET (N,N-diethyl-meta-toluamide) is the active ingredient used in most insect repellents, and is present in many commercially available formulations. Apart from chemical pollutants, aquatic organisms are subject to exposure of ionizing radiation from natural sources or in the vicinity of nuclear power plants. The present study evaluated the toxicity of DEET in organisms irradiated and non-irradiated with {sup 60}Co gamma radiation, and the effects that radiation causes in lysosomes of hemocytes of Perna perna mussel. For this purpose, assays were performed to identify the acute toxicity of DEET concentration and the dose of gamma radiation able to cause mortality. Subsequently, cytotoxicity assays were carried out to assess the stability of the lysosomal membrane in organisms exposed to ionizing radiation and DEET. According to the results obtained in acute toxicity tests, the concentration of DEET that causes mortality of 50% exposed organisms (LC50) is 114,27 mg L{sup -1}, and the radiation dose that causes mortality (LD50) is 1068 Gy. In the cytotoxicity assays, the concentration of the non-observed effect (NOEC) for irradiated and non-irradiated organisms 0.0001 mg L-1 and observed effect concentration (LOEC) at concentrations above this. The IC25 (72h) for non-irradiated organisms was 0.0003 mg L-1 and IC50 (72h) was 0.0008 mg L{sup -1} for irradiated and non-irradiated organisms. Despite of the concentrations of effect found in this study were higher than in the environment, both measurements are in the same order of magnitude and should be also take into account the possible synergistic effects of DEET with other contaminants in the aquatic environment. (author)

  13. Natural games

    Science.gov (United States)

    Anttila, Jani; Annila, Arto

    2011-10-01

    A course of a game is formulated as a physical process that will consume free energy in the least time. Accordingly, the rate of entropy increase is the payoff function that will subsume all forms of free energy that motivate diverse decisions. Also other concepts of game theory are related to their profound physical counterparts. When the physical portrayal of behavior is mathematically analyzed, the course of a game is found to be inherently unpredictable because each move affects motives in the future. Despite the non-holonomic character of the natural process, the objective of consuming free energy in the least time will direct an extensive-form game toward a Lyapunov-stable point that satisfies the minimax theorem.

  14. Natural uranium

    International Nuclear Information System (INIS)

    Ammerich, Marc; Frot, Patricia; Gambini, Denis-Jean; Gauron, Christine; Moureaux, Patrick; Herbelet, Gilbert; Lahaye, Thierry; Pihet, Pascal; Rannou, Alain

    2014-08-01

    This sheet belongs to a collection which relates to the use of radionuclides essentially in unsealed sources. Its goal is to gather on a single document the most relevant information as well as the best prevention practices to be implemented. These sheets are made for the persons in charge of radiation protection: users, radioprotection-skill persons, labor physicians. Each sheet treats of: 1 - the radio-physical and biological properties; 2 - the main uses; 3 - the dosimetric parameters; 4 - the measurement; 5 - the protection means; 6 - the areas delimitation and monitoring; 7 - the personnel classification, training and monitoring; 8 - the effluents and wastes; 9 - the authorization and declaration administrative procedures; 10 - the transport; and 11 - the right conduct to adopt in case of incident or accident. This sheet deals specifically with natural uranium

  15. Next nature : nature changes along with us

    NARCIS (Netherlands)

    Mensvoort, van K.M.; Grievink, H.J.

    2011-01-01

    We debate saving nature, we dream about escaping to nature, but rarely do we ask "What is nature?". The Next Nature book radically shifts your notion of nature. Where technology and nature are traditionally seen as opposed, they now appear to merge or even trade places. With our urge to design our

  16. Natural isotopes

    International Nuclear Information System (INIS)

    Vogel, J.C.

    1986-01-01

    14 C dates between 600 and 900 AD were obtained for early Iron Age sites in Natal, and from 1300 to 1450 AD for rock engraving sites in Bushmanland. Palaeoenvironmental data derived from the dating of samples related to sedimentary and geomorphic features in the central and northern Namib Desert enabled the production of a tentative graph for the changes in humidity in the region over the past 40000 years. These results suggest that relatively humid conditions came to an end in the Namib at ±25000 BP (before present). The increased precision of the SIRA mass spectrometer enabled the remeasurement of 13 C and 18 O in the Cango stalagmite. This data confirmed that the environmental temperatures in the Southern Cape remained constant to within ±1 o C during the past 5500 years. Techniques and applications for environmental isotopes in hydrology were developed to determine the origin and movement of ground water. Isotopic fractionation effects in light elements in nature were investigated. The 15 N/ 14 N ratio in bones of animals and humans increases in proportion to the aridity of the environment. This suggests that 15 N in bone from dated archaeological sites could be used to detect changes in past climatic conditions as naturally formed nitrate minerals are higly soluble and are only preserved in special, very dry environments. The sources and sinks of CO 2 on the South African subcontinent were also determined. The 13 C/ 12 C ratios of air CO 2 obtained suggest that the vegetation provides the major proportion of respired CO 2 . 9 refs., 1 fig

  17. Cuidando de paciente com câncer de mama e osteonecrose mandibular induzida por bisfostonato: relato de experiência Cuidando de pacientes con cáncer de mama y osteonecrosis mandibular inducida por bisfosfonatos: relato de experiencia Providing care for patients with breast cancer and mandible ostheonecrosis induced by bisphosphonates: an experience report

    Directory of Open Access Journals (Sweden)

    Verônica Paula Torel de Moura

    2009-02-01

    Full Text Available OBJETIVO: Descrever as ações desenvolvidas pela enfermeira junto a uma paciente com câncer de mama e metástase óssea que apresentou necrose mandibular induzida pelo uso de bisfosfonato. RESULTADOS: As intervenções de enfermagem incluíram o ensino e reforço das orientações sobre higiene oral, destacando a escovação adequada, bochechos com solução antisséptica sem álcool, bem como sobre o controle da dor. CONCLUSÃO: Destaca-se a importância da atuação multiprofissional e da consulta de enfermagem no seguimento dessas pacientes para detecção precoce e controle dessa complicação.OBJETIVO: Describir las acciones de enfermería implementadas por la enfermera a una paciente con cáncer con metástasis ósea que presentó necrosis mandibular inducida por el uso de bisfosfonatos. RESULTADOS: Las intervenciones de enfermería incluyeron la enseñanza y el refuerzo de las orientaciones sobre la higiene oral, dando destaque al adecuado cepillado de los dientes, gárgaras con solución antiséptica sin alcohol y al control del dolor. CONCLUSIÓN: Es destacada el importancia de la actuación multiprofesional y de la consulta de enfermería en el seguimiento de esas pacientes, visando la detección temprana y el control de esa complicación.OBJECTIVE: To describe a nurse experience in providing care for a patient with cancer of the breast and bone metastasis who presented mandibular ostheonecrosis induced by the use of bisphosphonates. RESULTS: Nursing interventions included the re-enforcement of the guidelines for oral hygiene, highlighting the appropriate teeth-brushing technique, gargling with antiseptic solution without alcohol, as approach to pain management. CONCLUSION: There is a need for multidisciplinary and nursing consultations for early detection and control of potential complications.

  18. Meteorites as space probes for cosmic rays; Les meteorites en tant que sondes spatiales pour les rayons cosmiques; Meteority v kachestve prob mezhplanetnogo prostranstva dlya izucheniya kosmicheskikh luchej; Los meteoritos como sondas espaciales para evaluar la actividad inducida por los rayos cosmicos

    Energy Technology Data Exchange (ETDEWEB)

    Schaeffer, O A; Stoenner, R W; Davis, R Jr [Chemistry Department, Brookhaven National Laboratory, Upton, L. I., NY (United States)

    1962-01-15

    'activite imputable a l'argon-37 (periode: 35 jours) et a l'argon-39 (periode: 325 ans). Ils comparent ces activites relatives aux taux de production de ces isotopes que l'on obtient en bombardant un echantillon de la meteorite avec des protons ayant une energie de 3 GeV. Les auteurs concluent que, dans les limites d'erreur, le flux de rayons cosmiques est le meme dans la ceinture asteroide que dans le voisinage de l'orbite terrestre. (author) [Spanish] Para determinar la constancia espacial de la radiacion cosmica de elevada energia en el interior del sistema solar, los autores midieron la radiactividad, inducida por los rayos cosmicos, de un elemento de periodo corto y de un elemento de periodo largo en un meteorito caido recientemente. El experimento se basa en el hecho de que los meteoritos siguen orbitas muy excetricas y, por ello, pueden ser utilizados como sondas espaciales en la region situada entre la orbita terrestre y el cinturon de asteroides. La actividad de periodo corto se produce mientras el meteorito se encuentra en las proximidades de la orbita terrestre, en tanto que la actividad de periodo largo es inducida en toda la orbita descrita por el meteorito. Los autores efectuaron las mediciones en el condrito Hamlet que cayo en Indiana el 13 de octubre de 1.959. Evaluaron las actividades astribuibles al argon-37 (periodo: 35 dias) y al argon-39 (periodo: 325 anos). Compararon los valores relativos de estas actividades con los indices de produccion de esos isotopos que se alcanzan bombardeando una muestra del meteorito con protones de 3 GeV. Se llega a la conclusion de que la intensidad de la radiacion cosmica es igual, dentro de los limites de error, en el cinturon de asteroides que en las proximidades de la orbita terrestre. (author) [Russian] Byl proizveden opyt ispytaniya prostranstvennogo postoyanstva kosmicheskogo izlucheniya vysokikh ehnergij v solnechnoj sisteme putem zamera iskusstvennoj korotkozhivushchej i dol- gozhivushchej radioaktivnosti kosmicheskikh

  19. Nature and nature values in organic agriculture

    DEFF Research Database (Denmark)

    Hansen, Lene; Noe, Egon; Højring, Katrine

    2006-01-01

    The relationship between agriculture and nature is a centra issue in the current agricultural debate. Organic farming has ambitions and a special potential in relation to nature. Consideration for nature is part of the guiding principals of organic farming and many organic farmers are committed...... to protecting natural qualities. However, the issue of nature, landscape, and land use is not straightforward. Nature is an ambiguous concept that involves multiple interests and actors reaching far beyond farmers. The Danish research project ......

  20. Actividad antimalárica in vitro y citotoxicidad de algunas plantas medicinales Cubanas seleccionadas

    OpenAIRE

    Valdés, Aymé Fernández-Calienes; Martínez, Judith Mendiola; Lizama, Ramón Scull; Gaitén, Yamilet Gutiérrez; Rodríguez, Deyanira Acuña; Payrol, Juan Abreu

    2010-01-01

    Terrestrial plants have been demonstrated to be sources of antimalarial compounds. In Cuba, little is known about antimalarial potentials of plant species used as medicinals. For that reason, we evaluated the antimalarial activity of 14 plant species used in Cuba as antimalarial, antipyretic and/or antiparasitic. Hydroalcoholic extracts were prepared and tested in vitro for the antimalarial activity against Plasmodium falciparum Ghana strain and over human cell line MRC-5 to determine cytotox...

  1. Nanopartículas de oro: aplicaciones y citotoxicidad in vitro

    OpenAIRE

    Mateo, Diego; Morales, Paloma; Ávalos, Alicia; Haza, Ana I

    2013-01-01

    En los últimos años, la evolución en el desarrollo de productos elaborados a partir de nanotecnología ha experimentado un espectacular crecimiento. En particular, las nanopartículas de oro han despertado gran interés en los sectores biomédico y alimentario, donde se ha descrito su utilización en el tratamiento frente al cáncer o como parte integrante de envases resistentes a la abrasión, con propiedades antimicrobianas. Por tanto, se cree que la exposición humana a las nanopartículas de oro a...

  2. Exercício físico previne alterações cardiometabólicas induzidas pelo uso crônico de glicocorticóides Ejercicio físico previene alteraciones cardiometabólicas inducidas por el uso crónico de glucocorticoides Exercise prevents cardiometabolic alterations induced by chronic use of glucocorticoids

    Directory of Open Access Journals (Sweden)

    Carlos Hermano da Justa Pinheiro

    2009-10-01

    , diabetes, dislipidemia, esteatosis hepática e hipertensión arterial. OBJETIVOS: Evaluar el efecto de la práctica regular de ejercicio físico aeróbico sobre las alteraciones cardiometabólicas inducidas por administración crónica de dexametasona (Dex - 0,5 mg/kg/día i.p en ratones. MÉTODOS: Se dividieron ratones Wistar machos (n = 24 en cuatro grupos: Grupo control; Grupo entrenado; Grupo tratado con Dex y Grupo tratado con Dex y entrenado. El entrenamiento físico (iniciado 72 horas después de la primera dosis de Dex se realizó 3 veces por semana, hasta el final del tratamiento. Al final de ese período, se realizaron las siguientes evaluaciones bioquímicas: glicemia en ayunas, test de tolerancia a la glucosa y análisis del perfil lipídico en sangre que incluyó colesterol total (CT, LDL-c, HDL-c, VLDL-c y triglicéridos (TG. También se evaluaron, el peso del músculo gastrocnemio, análisis histopatológico del hígado y los índices cardiometabólicos (CT/HDL-c, LDL-c/HDL-c y TG/HDL-c. RESULTADOS: Se observó hiperglicemia, menor tolerancia a la glucosa, elevación de CT, LDL-c, VLDL-c y TG, disminución del HDL-c, presencia de esteatosis hepática, hipotrofia muscular y elevación de los índices CT/HDL-c, LDL-c/HDL-c y TG/HDL-c en los animales tratados con Dex. El ejercicio físico redujo la hiperglicemia, mejoró la tolerancia a la glucosa, redujo la dislipidemia y previno la esteatosis hepática, la hipotrofia muscular y redujo los índices CT/HDL-c, LDL-c/ HDL-c ye TG/HDL-c. Con todo, no hubo efecto significativo del entrenamiento físico sobre el HDL-c. CONCLUSIÓN: El ejercicio físico aeróbico tiene efecto protector con las alteraciones cardiometabólicas inducidas por el uso crónico de glucocorticoides.BACKGROUND: Chronically, glucocorticoids induce adverse cardiometabolic alterations including insulin resistance, diabetes, dyslipidemia, liver steatosis and arterial hypertension. OBJECTIVES: To evaluate the effect of regular practice of aerobic

  3. Nature and nature values in organic agriculture

    DEFF Research Database (Denmark)

    Hansen, Lene; Noe, Egon; Højring, Katrine

    2006-01-01

    The relationship between agriculture and nature is a centra issue in the current agricultural debate. Organic farming has ambitions and a special potential in relation to nature. Consideration for nature is part of the guiding principals of organic farming and many organic farmers are committed...

  4. Insuficiencia renal aguda inducida por mordedura de serpiente Bothrops

    Directory of Open Access Journals (Sweden)

    Gustavo A. Aroca Martínez

    2014-01-01

    Full Text Available Mujer de 58 años de edad, remitida a urgencias por presentar cuadro clínico de insuficiencia renal aguda (IRA secundaria a mordedura de serpiente (Bothrops Atrox. Ingresa hipotensa con elevación de azoados e hiperkalemia, ecografía renal dentro de parámetros normales. Se maneja terapia dialítica con lo cual presenta mejoría clínica. En este reporte se detallan aspectos del diagnóstico, manejo clínico y posibles mecanismos fisiopatológicos que explican el daño renal.

  5. Three Sorts of Naturalism

    DEFF Research Database (Denmark)

    Fink, Hans

    2006-01-01

    In "Two sorts of Naturalism" John McDowell is sketching his own sort of naturalism in ethics as an alternative to "bald naturalism". In this paper I distinguish materialist, idealist and absolute conceptions of nature and of naturalism in order to provide a framework for a clearer understanding...

  6. Natural gas trends

    International Nuclear Information System (INIS)

    Anderson, A.

    1991-01-01

    This book provides data on many facets of the natural gas industry. Topics include: Canadian, Mexican; US natural gas reserves and production; Mexican and US natural gas consumption; market conditions for natural gas in the US; and Canadian natural gas exports

  7. A Natural Language Architecture

    OpenAIRE

    Sodiya, Adesina Simon

    2007-01-01

    Natural languages are the latest generation of programming languages, which require processing real human natural expressions. Over the years, several groups or researchers have trying to develop widely accepted natural language languages based on artificial intelligence (AI). But no true natural language has been developed. The goal of this work is to design a natural language preprocessing architecture that identifies and accepts programming instructions or sentences in their natural forms ...

  8. Virginia Natural Heritage Program

    Science.gov (United States)

    Heritage About Natural Heritage Overview, Mission Natural Heritage Inventory Community Ecology Program ) | Strategic Plan (PDF) | Executive Progress Report (PDF) | Code of Ethics (PDF) Your browser does not support

  9. Natural Colorants: Food Colorants from Natural Sources.

    Science.gov (United States)

    Sigurdson, Gregory T; Tang, Peipei; Giusti, M Mónica

    2017-02-28

    The color of food is often associated with the flavor, safety, and nutritional value of the product. Synthetic food colorants have been used because of their high stability and low cost. However, consumer perception and demand have driven the replacement of synthetic colorants with naturally derived alternatives. Natural pigment applications can be limited by lower stability, weaker tinctorial strength, interactions with food ingredients, and inability to match desired hues. Therefore, no single naturally derived colorant can serve as a universal alternative for a specified synthetic colorant in all applications. This review summarizes major environmental and biological sources for natural colorants as well as nature-identical counterparts. Chemical characteristics of prevalent pigments, including anthocyanins, carotenoids, betalains, and chlorophylls, are described. The possible applications and hues (warm, cool, and achromatic) of currently used natural pigments, such as anthocyanins as red and blue colorants, and possible future alternatives, such as purple violacein and red pyranoanthocyanins, are also discussed.

  10. Regularities, Natural Patterns and Laws of Nature

    Directory of Open Access Journals (Sweden)

    Stathis Psillos

    2014-02-01

    Full Text Available  The goal of this paper is to sketch an empiricist metaphysics of laws of nature. The key idea is that there are regularities without regularity-enforcers. Differently put, there are natural laws without law-makers of a distinct metaphysical kind. This sketch will rely on the concept of a natural pattern and more significantly on the existence of a network of natural patterns in nature. The relation between a regularity and a pattern will be analysed in terms of mereology.  Here is the road map. In section 2, I will briefly discuss the relation between empiricism and metaphysics, aiming to show that an empiricist metaphysics is possible. In section 3, I will offer arguments against stronger metaphysical views of laws. Then, in section 4 I will motivate nomic objectivism. In section 5, I will address the question ‘what is a regularity?’ and will develop a novel answer to it, based on the notion of a natural pattern. In section 6, I will raise the question: ‘what is a law of nature?’, the answer to which will be: a law of nature is a regularity that is characterised by the unity of a natural pattern.

  11. Natural and near natural tropical forest values

    Science.gov (United States)

    Daniel H. Henning

    2011-01-01

    This paper identifies and describes some of the values associated with tropical rain forests in their natural and near-natural conditions. Tropical rain forests are moist forests in the humid tropics where temperature and rainfall are high and the dry season is short. These closed (non-logged) and broad-leaved forests are a global resource. Located almost entirely in...

  12. Natural gas in India

    International Nuclear Information System (INIS)

    Lefevre, Thierry; Todoc, Jessie L.

    1999-11-01

    Contains Executive Summary and Chapters on: Country background; Overview of the energy sector; Natural gas supply; Natural gas infrastructure; Natural gas infrastructure; Natural gas demand; Outlook-government policy reform and industry development, and Appendices on Global and regional energy and gas trends; Overview of India's investment policy, incentives and regulation; The ENRON Dabhol power project. (Author)

  13. Three Sorts of Naturalism

    OpenAIRE

    Fink, Hans

    2006-01-01

    In "Two sorts of Naturalism" John McDowell is sketching his own sort of naturalism in ethics as an alternative to "bald naturalism". In this paper I distinguish materialist, idealist and absolute conceptions of nature and of naturalism in order to provide a framework for a clearer understanding of what McDowell's own naturalism amounts to. I argue that nothing short of an absolute naturalism will do for a number of McDowell's own purposes, but that it is far from obvious that this is his posi...

  14. Natural gas monthly

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the Natural Gas Monthly features articles designed to assist readers in using and interpreting natural gas information.

  15. The Nature of Natural Hazards Communication (Invited)

    Science.gov (United States)

    Kontar, Y. Y.

    2013-12-01

    Some of the many issues of interest to natural hazards professionals include the analysis of proactive approaches to the governance of risk from natural hazards and approaches to broaden the scope of public policies related to the management of risks from natural hazards, as well as including emergency and environmental management, community development and spatial planning related to natural hazards. During the talk we will present results of scientific review, analysis and synthesis, which emphasize same new trends in communication of the natural hazards theories and practices within an up-to-the-minute context of new environmental and climate change issues, new technologies, and a new focus on resiliency. The presentation is divided into five sections that focus on natural hazards communication in terms of education, risk management, public discourse, engaging the public, theoretical perspectives, and new media. It includes results of case studies and best practices. It delves into natural hazards communication theories, including diffusion, argumentation, and constructivism, to name a few. The presentation will provide information about: (1) A manual of natural hazards communication for scientists, policymakers, and media; (2) An up-to-the-minute context of environmental hazards, new technologies & political landscape; (3) A work by natural hazards scientists for geoscientists working with social scientists and communication principles; (4) A work underpinned by key natural hazards communication theories and interspersed with pragmatic solutions; (5) A work that crosses traditional natural hazards boundaries: international, interdisciplinary, theoretical/applied. We will further explore how spatial planning can contribute to risk governance by influencing the occupation of natural hazard-prone areas, and review the central role of emergency management in risk policy. The goal of this presentation is to contribute to the augmentation of the conceptual framework

  16. Copolymerization of Ethylene Induced by Cobalt-60 Gamma Radiation; Copolymerisation de l'ethylene induite par des rayons gamma du cobalt-60; Sopolimerizatsiya ehtilena pod dejstviem gamma-izlucheniya ot istochnika ks'yali-60; Copolimerizacion del etileno inducida por las radiaciones gamma del cobalto-60

    Energy Technology Data Exchange (ETDEWEB)

    Steinberg, M.; Colombo, P. [Brookhaven National Laboratory, Long Island, NY (United States)

    1963-11-15

    }C et a des pressions initiales allant jusqu'a 680 atm. On a procede aux experiences, en milieu statique, dans des systemes a deux phases, a l'exception du systeme ethylene-oxyde de carbone. La separation des copolymeres a ete obtenue par des methodes d'extraction par solvant et de precipitation fractionnee. L'identification a ete faite au moyen de la spectroscopic aux infrarouges. La composition a ete determinee par analyse elementaire. Les auteurs donnent une evaluation partielle de certains produits de la reaction, y compris les points de fusion cristalline, les densites, les caracteristiques de solubilite et les poids moleculaires. La copolymerisation de l'ethylene a ete etablie avec chacun des monomeres suivants : styrene, methacrylate de methyle, acetate de vinyle, acrylonitrile, acetate d'allyle, isobutylene, chlorotiifluoroethylene, transbutene-2, acrylate de methyle, isoprene, propylene, chlorure de vinyle, butene-1, cis-butene-2, oxyde de carbone, pyrrolidone de vinyle, methyle- vinyle-cetone et divinyle-benzene. Les auteurs ont trouve que les donnees experimentales obtenues dans l'etude du systeme ethylene-oxyde de carbone suivaient une forme lineaire de l'equation de composition du copolymere. Pour le rapport {alpha} des constantes de vitesse specifiques de l'oxyde de carbone et de l'ethylene, ils ont determine la valeur 22,0, ce qui montre que l'oxyde de carbone en tant que monomere est active a tel point qu'il se fixe a l'extremite d'une chaftie de radicaux libres d'ethylene 22 fois plus vite que ne le fait un monomere d'ethylene. (author) [Spanish] Los autores estudiaron la copolimerizacion del etileno, inducida por las radiaciones gamma, con una serie de diversos monometos, a 20{sup o}C y presiones iniciales de hasta 680 atm. Los experimentos se llevaron a cabo estaticamente en sistemas bifasicos, salvo en el caso del etileno-oxido de carbono. La separacion de los copolimeros se llevo a cabo por extraccion mediante disolventes y por precipitacion

  17. Há uma associação entre anti-inflamatórios não-esteroides e nefropatia induzida por contraste? ¿Hay una asociación entre antiinflamatorios no esteroides y nefropatía inducida por contraste? Is there an association between non-steroidal anti-inflammatory drugs and contrast nephropathy?

    Directory of Open Access Journals (Sweden)

    Luciano Passamani Diogo

    2010-12-01

    Full Text Available FUNDAMENTO: A associação entre o uso de anti-inflamatórios não-esteroides (AINEs e insuficiência renal aguda ou crônica é bem documentada, mas evidências sobre a associação entre AINEs e nefropatia induzida por contraste (NIC não são encontradas na literatura. OBJETIVO: Avaliar uma possível associação entre AINEs e NIC. MÉTODOS: Em um estudo de coorte, através da entrevista clínica de pacientes que foram submetidos à cateterização cardíaca, analisamos o uso de AINEs e sua associação com desenvolvimento de NIC, através da alteração dos níveis de creatinina sérica ou taxa de filtração glomerular em 48 ou 72 horas. RESULTADOS: No período de julho de 2005 a julho de 2006, 236 pacientes foram incluídos no estudo, dos quais 29 foram posteriormente excluídos. A incidência de NIC foi 10,37% (20 de 207 e 42% dos pacientes estavam recebendo AINEs até o momento da avaliação. Não houve associação entre o uso de AINEs e o desenvolvimento de NIC com OR de 1,293; IC95% (0,46-4,2. O estudo detectou fatores de risco conhecidos para o desenvolvimento de NIC, tais como diabete, com OR de 2,77; IC95% (1,05-7,47 e insuficiência renal crônica com OR de 3,48; IC95% (1,1-11,07 e também sugeriu uma ação protetora da hidratação com solução salina com OR de 0,166; IC95% (0,03-0,92. CONCLUSÃO: Com base nos dados obtidos, concluímos que não houve associação entre NIC e uso prévio de AINEs, pelo menos com um OR > 2,85, o qual nossa amostra detectou.FUNDAMENTO: La asociación entre el uso de antiinflamatorios no esteroides (AINEs e insuficiencia renal aguda o crónica está bien documentada, pero evidencias sobre la asociación entre AINEs y nefropatía inducida por contraste (NIC no son encontradas en la literatura. OBJETIVO: Evaluar una posible asociación entre AINEs y NIC. MÉTODOS: En un estudio de cohorte, a través de la entrevista clínica de pacientes que fueron sometidos a cateterismo cardíaco, analizamos el

  18. Alteração da relação testosterona: cortisol induzida pelo treinamento de força em mulheres Alteración de la relación testosterona: cortisol inducida por el entrenamiento de fuerza en mujeres Alteration of testosterone: cortisol ratio induced by resistance training in women

    Directory of Open Access Journals (Sweden)

    Marco Carlos Uchida

    2004-06-01

    Full Text Available A razão entre a concentração de testosterona e cortisol (T:C é freqüentemente utilizada como indicativo do nível de estresse imposto pelo exercício. Alterações na concentração destes hormônios são responsáveis por modular diversas respostas induzidas pelo treinamento, como hipertrofia e ganho de força. O objetivo do presente estudo foi examinar a influência do protocolo de treinamento de força, conhecido como múltiplas-séries (MS, sobre o ganho de força, de resistência muscular localizada e a relação entre a concentração de hormônios catabólicos (cortisol e anabólicos (testosterona. Para testar esta hipótese cinco jovens do sexo feminino com um ano de experiência em treinamento de força foram submetidas ao protocolo MS. As amostras de sangue foram coletadas antes e imediatamente após o exercício, no primeiro dia e após oito semanas de treinamento. Os testes de 1-RM e de repetições máximas foram realizados também no início e ao final das oito semanas de treinamento de força. Não foram observadas alterações na massa corporal, no IMC, na percentagem de massa gorda e na força máxima (1-RM no supino, no agachamento e na rosca direta. O número de repetições máximas a 50% de 1-RM foi aumentado apenas para o supino (p La razón entre testosterona y cortisol (T:C es frecuentemente utilizada como indicador del nivel de stress impuesto por el ejercicio. Las alteraciones de las concentraciones de estas hormonas son las responsables por modular diversas respuestas inducidas por el entrenamiento, como son la hipertrofia y el aumento de la fuerza. El objetivo del presente estudio fué examinar la influencia del protocolo de entrenamiento de fuerza, conocido como series multiples (MS, sobre la ganancia de fuerza, la resistencia muscular localizada y la relación entre las concentraciones de las hormonas catabólicas (cortisol y anabólicas (testoterona. Para testar esta hipótesis, cinco jovenes del sexo feminino

  19. Alterações em variáveis motoras e metabólicas induzidas pelo treinamento durante um macrociclo em jogadores de handebol Alteraciones en las variables motoras y metabólicas inducidas por el entrenamiento durante un macro ciclo en jugadores de balonmano Changes in metabolic and motor performance variables induced by training in handball players

    Directory of Open Access Journals (Sweden)

    Juvenilson de Souza

    2006-06-01

    Full Text Available A monitoração do treinamento é uma prática comum no desporto. Essa monitoração deve ser baseada em testes específicos e que reflitam as adaptações às diversas etapas de treinamento, permitindo, assim, ajustes no programa deste. Assim, este estudo teve como objetivo analisar as alterações em variáveis motoras e metabólicas induzidas pelo treinamento durante um macrociclo em jogadores de handebol. Os atletas foram submetidos a um programa de preparação fundamentado no modelo de periodização proposto por Verkhoshanski(7 e adaptado por Oliveira(8. Foram estudados 11 jogadores de handebol, que realizaram treinamentos diários, na faixa etária de 20 a 32 anos, massa corporal média de 89,5 ± 10,4kg (70,2 a 105,1kg, e estatura média de 184,4 ± 6,7cm (171,8 a 198cm, filiados à equipe "UniFil/Londrina" do município de Londrina - PR. Os handebolistas foram submetidos a duas baterias de testes: a primeira no início do segundo macrociclo de treinamento e a segunda após 16 semanas, antecedendo o início da liga nacional. Para análise dos dados foi utilizado teste t para medidas repetidas com p La monitorización del entrenamiento es una práctica común en el deporte. Esa monitorización debe basarse en pruebas específicas y que reflejen las adaptaciones a las diversas etapas del entrenamiento, permitiendo así, ajustes en el programa del mismo. Así, este estudio ha tenido como objetivo analizar las alteraciones en las variables motoras y metabólicas inducidas por el entrenamiento durante un macro ciclo en jugadores de balonmano. Los atletas fueron sometidos a un programa de preparación basado en el modelo de periodicidad propuesto por Verkhoshanski(7 y adaptado por Oliveira(8. Fueron estudiados 11 jugadores de balonmano que realizaron entrenamiento diario, con edades entre 20 y 32 años, masa corporal media de 89,5 ± 10,4 kg (70,2 y 105,1 kg, y estatura media de 184,4 ± 6,7 cm (171,8 y 198 cm, afiliados al equipo "Uni

  20. Breast reconstruction - natural tissue

    Science.gov (United States)

    ... flap; TRAM; Latissimus muscle flap with a breast implant; DIEP flap; DIEAP flap; Gluteal free flap; Transverse upper gracilis flap; TUG; Mastectomy - breast reconstruction with natural tissue; Breast cancer - breast reconstruction with natural tissue

  1. Natural short sleeper

    Science.gov (United States)

    Sleep - natural short sleeper ... 7 to 9 hours of sleep each night. Short sleepers sleep less than 75% of what is normal for their age. Natural short sleepers are different from people who chronically do ...

  2. Vermont Natural Resources Atlas

    Data.gov (United States)

    Vermont Center for Geographic Information — The purpose of the�Natural Resources Atlas�is to provide geographic information about environmental features and sites that the Vermont Agency of Natural Resources...

  3. Natural Weathering Exposure Station

    Data.gov (United States)

    Federal Laboratory Consortium — The Corps of Engineers' Treat Island Natural Weathering Exposure Station is a long-term natural weathering facility used to study concrete durability. Located on the...

  4. Natural gas annual 1995

    International Nuclear Information System (INIS)

    1996-11-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1995 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1991 to 1995 for each Census Division and each State. Annual historical data are shown at the national level

  5. Natural gas annual 1993

    International Nuclear Information System (INIS)

    1994-01-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1993 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. Tables summarizing natural gas supply and disposition from 1989 to 1993 are given for each Census Division and each State. Annual historical data are shown at the national level

  6. Natural gas annual 1991

    International Nuclear Information System (INIS)

    1992-01-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1991 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. Tables summarizing natural gas supply and disposition form 1987 to 1991 are given for each Census Division and each State. Annual historical data are shown at the national level

  7. Natural gas for vehicles

    International Nuclear Information System (INIS)

    Prieur, A.

    2006-01-01

    Following a decade-long upsurge in the use of natural gas in the energy sector (heating and especially electricity), new outlets for natural gas are being developed in the transport sector. For countries endowed with substantial local resources, development in this sector can help reduce oil dependence. In addition, natural gas is often used to reduce pollution, particularly in cities

  8. Natural gas annual 1991

    International Nuclear Information System (INIS)

    1993-01-01

    The Natural Gas Annual 1991 provides information on the supply and disposition of natural gas to a wide audience including industry, consumers Federal and State agencies, and education institutions. This report, the Natural Gas Annual 1991 Supplement: Company Profiles, presents a detailed profile of selected companies

  9. Naturalisms and religion

    NARCIS (Netherlands)

    Drees, Willem

    1997-01-01

    Such terms as materialism, naturalism, and near synonyms evoke strong negative reactions among many believers. However, the notion of naturalism has various meanings; implications for religion differ for the several varieties of naturalism. In this paper I analyze epistemological and ontological

  10. NATURAL GAS TRANSPORTATION

    OpenAIRE

    Stanis³aw Brzeziñski

    2007-01-01

    In the paper, Author presents chosen aspects of natural gas transportation within global market. Natural gas transportation is a technicaly complicated and economicly expensive process; in infrastructure construction and activities costs. The paper also considers last and proposed initiatives in natural gas transportation.

  11. Natural gas marketing II

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This book covers all aspects of gas marketing, from the basic regulatory structure to the latest developments in negotiating agreements and locating markets. Topics include: Federal regulation of the gas industry; Fundamentals of gas marketing contracts; FERC actions encouraging competitive markets; Marketing conditions from the pipelines' perspective; State non-utility regulation of natural gas production, transportation, and marketing; Natural gas wellhead agreements and tariffs; Natural gas processing agreements; Effective management of producer's natural gas contracts; Producer-pipeline litigation; Natural gas purchasing from the perspective of industrial gas users; Gas marketing by co-owners: problems of disproportionate sales, gas balancing, and accounting to royalty owners; Alternatives and new directions in marketing

  12. Nature in Preschool

    DEFF Research Database (Denmark)

    Husted, Mia; Frøkjær, Thorleif

    Nature and nature phenomena’ has formed a specific curriculum theme in Danish preschool since early childhood curriculum was prescribed by law in 2004. However, recent evaluations show that the implementation of an early childhood curriculum has not produced an increased pedagogical focus...... on ‘nature and nature phenomena’ in preschools (EVA 2012). This finding, along with an increased political interest in goals and measurable outcome of early childhood curriculum (Broström 2012), will be the starting point in our ambition to carry out a more thorough qualitative investigation into links...... between preschool teachers’ understanding and interest in teaching nature and the rather poor evaluation....

  13. Learning from nature: Nature-inspired algorithms

    DEFF Research Database (Denmark)

    Albeanu, Grigore; Madsen, Henrik; Popentiu-Vladicescu, Florin

    2016-01-01

    .), genetic and evolutionary strategies, artificial immune systems etc. Well-known examples of applications include: aircraft wing design, wind turbine design, bionic car, bullet train, optimal decisions related to traffic, appropriate strategies to survive under a well-adapted immune system etc. Based......During last decade, the nature has inspired researchers to develop new algorithms. The largest collection of nature-inspired algorithms is biology-inspired: swarm intelligence (particle swarm optimization, ant colony optimization, cuckoo search, bees' algorithm, bat algorithm, firefly algorithm etc...... on collective social behaviour of organisms, researchers have developed optimization strategies taking into account not only the individuals, but also groups and environment. However, learning from nature, new classes of approaches can be identified, tested and compared against already available algorithms...

  14. Novel natural food antimicrobials.

    Science.gov (United States)

    Juneja, Vijay K; Dwivedi, Hari P; Yan, Xianghe

    2012-01-01

    Naturally occurring antimicrobial compounds could be applied as food preservatives to protect food quality and extend the shelf life of foods and beverages. These compounds are naturally produced and isolated from various sources, including plants, animals and microorganisms, in which they constitute part of host defense systems. Many naturally occurring compounds, such as nisin, plant essential oils, and natamycin, have been widely studied and are reported to be effective in their potential role as antimicrobial agents against spoilage and pathogenic microorganisms. Although some of these natural antimicrobials are commercially available and applied in food processing, their efficacy, consumer acceptance and regulation are not well defined. This manuscript reviews natural antimicrobial compounds with reference to their applications in food when applied individually or in combination with other hurdles. It also reviews the mechanism of action of selected natural antimicrobials, factors affecting their antimicrobial activities, and future prospects for use of natural antimicrobials in the food industry.

  15. On nature and bioethics.

    Science.gov (United States)

    Peterson, Paul Silas

    2010-01-01

    The account of nature and humanity's relationship to nature are of central importance for bioethics. The Scientific Revolution was a critical development in the history of this question and many contemporary accounts of nature find their beginnings here. While the innovative approach to nature going out of the seventeenth century was reliant upon accounts of nature from the early modern period, the Middle Ages, late-antiquity and antiquity, it also parted ways with some of the understandings of nature from these epochs. Here I analyze this development and suggests that some of the insights from older understandings of nature may be helpful for bioethics today, even if there can be no simple return to them.

  16. A Natural Love of Natural Products

    OpenAIRE

    Kingston, David G. I.

    2008-01-01

    Recent research on the chemistry of natural products from the author?s group that led to the receipt of the ACS Ernest Guenther Award in the Chemistry of Natural Products is reviewed. REDOR NMR and synthetic studies established the T-taxol conformation as the bioactive tubulin-binding conformation, and these results were confirmed by the synthesis of compounds which clearly owed their activity or lack of activity to whether or not they could adopt the T-taxol conformation. Similar studies wit...

  17. Natural Information Processing Systems

    OpenAIRE

    John Sweller; Susan Sweller

    2006-01-01

    Natural information processing systems such as biological evolution and human cognition organize information used to govern the activities of natural entities. When dealing with biologically secondary information, these systems can be specified by five common principles that we propose underlie natural information processing systems. The principles equate: (1) human long-term memory with a genome; (2) learning from other humans with biological reproduction; (3) problem solving through random ...

  18. Natural gas annual 1997

    International Nuclear Information System (INIS)

    1998-10-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1997 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1993 to 1997 for each Census Division and each State. Annual historical data are shown at the national level. 27 figs., 109 tabs

  19. Natural Ventilation in Atria

    DEFF Research Database (Denmark)

    Svidt, Kjeld; Heiselberg, Per; Hendriksen, Ole Juhl

    This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions.......This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions....

  20. Nature-based integration

    DEFF Research Database (Denmark)

    Pitkänen, Kati; Oratuomi, Joose; Hellgren, Daniela

    Increased attention to, and careful planning of the integration of migrants into Nordic societies is ever more important. Nature based integration is a new solution to respond to this need. This report presents the results of a Nordic survey and workshop and illustrates current practices of nature...... based integration by case study descriptions from Denmark, Sweden Norway and Finland. Across Nordic countries several practical projects and initiatives have been launched to promote the benefits of nature in integration and there is also growing academic interest in the topic. Nordic countries have...... the potential of becoming real forerunners in nature based integration even at the global scale....

  1. Natural gas annual 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1997 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1993 to 1997 for each Census Division and each State. Annual historical data are shown at the national level. 27 figs., 109 tabs.

  2. Natural gas outlook

    International Nuclear Information System (INIS)

    Molyneaux, M.P.

    1998-01-01

    An overview of natural gas markets in Canada and in the United States was provided. The major factors that determine the direction of natural gas prices were depicted graphically. Price volatility has decreased in recent months. As expected, April through November total energy consumption reached historically high levels. Demand for natural gas during the summer of 1997 was not as strong as anticipated. Nuclear energy appears to be on the slippery slope, with natural gas-driven electricity projects to fill the void. Hydroelectricity had a strong showing in 1997. Prospects are less bright for 1998 due to above average temperatures. Canadian natural gas export capacity has increased 5.5 times between 1986 and estimated 1999 levels. Despite this, in 1997, deliveries to the United States were marginally behind expectations. Natural gas consumption, comparative fuel prices, natural gas drilling activity, natural gas storage capacity, actual storage by region, and average weekly spot natural gas prices, for both the U. S. and Canada, were also provided. With regard to Canada, it was suggested that Canadian producers are well positioned for a significant increase in their price realization mostly because of the increase in Canada's export capacity in 1997 (+175 Mmcf/d), 1998 (1,060 Mmcf/d) and potentially in 1999 or 2000, via the Alliance Pipeline project. Nevertheless, with current production projections it appears next to impossible to fill the 10.9 Bcf/d of export capacity that will be potentially in place by the end of 1999. tabs., figs

  3. Nephrotoxicity of Natural Products.

    Science.gov (United States)

    Nauffal, Mary; Gabardi, Steven

    2016-01-01

    The manufacture and sale of natural products constitute a multi-billion dollar industry. Nearly a third of the American population admit to using some form of complementary or alternative medicine, with many using them in addition to prescription medications. Most patients fail to inform their healthcare providers of their natural product use and physicians rarely inquire. Annually, thousands of natural product-induced adverse events are reported to Poison Control Centers nationwide. Natural product manufacturers are not responsible for proving safety and efficacy, as the FDA does not regulate them. However, concerns exist surrounding the safety of natural products. This review provides details on natural products that have been associated with renal dysfunction. We have focused on products that have been associated with direct renal injury, immune-mediated nephrotoxicity, nephrolithiasis, rhabdomyolysis with acute renal injury, hepatorenal syndrome, and common adulterants or contaminants that are associated with renal dysfunction. The potential for natural products to cause renal dysfunction is justifiable. It is imperative that natural product use be monitored closely in all patients. Healthcare practitioners must play an active role in identifying patients using natural products and provide appropriate patient education. © 2016 S. Karger AG, Basel.

  4. Nature as Dissonant Heritage

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    accepts that nature it not existing outside culture as something that be restored to its original state, but a contemporary product created and managed with certain objectives in mind, nature restoration like heritage production are prone to same kind of dissonance – our nature is not necessary...... their nature. According to Ashworth cultural dissonance can be managed in a number of different way depending on which type of plural society is preferred. Many of these management strategies consciously or unconsciously involve some form of denial, neglect, destruction, reinterpretation or marginalizing...

  5. Oklo natural reactor

    International Nuclear Information System (INIS)

    Fujii, Isao

    1985-01-01

    In 1954, Professor Kazuo, Kuroda of Arkansas University in USA published the possibility that spontaneously generated natural nuclear reactors existed in prehistoric age. In 1972, 18 years after that, Commissariat a l'Energie Atomique published that in the Oklo uranium deposit in Gabon, Africa, a natural nuclear reactor was found. This fact was immediately informed to the whole world, but in Japan, its details have not necessarily been well known. The chance of investigating into this fact and visiting the Oklo deposit by the favor of COMUF, the owner of the Oklo deposit, was given, therefore, the state of the natural reactors, which has been known so far, is reported. At present, 12 natural reactors have been found in the vicinity of the Oklo deposit. The natural reactors were generated spontaneously in uranium deposits about 1.7 billion years ago when the isotopic abundance of U-235 was 3 %, and the chain reaction started naturally. When the concentration of U-235 lowered, the reaction stopped naturally. The abnormality in the U-235 abundance in natural uranium was found, and the cause was pursued. The evidence of the existence of natural reactors was shown. (Kako, I.)

  6. A mathematical nature walk

    CERN Document Server

    Adam, John A

    2009-01-01

    How heavy is that cloud? Why can you see farther in rain than in fog? Why are the droplets on that spider web spaced apart so evenly? If you have ever asked questions like these while outdoors, and wondered how you might figure out the answers, this is a book for you. An entertaining and informative collection of fascinating puzzles from the natural world around us, A Mathematical Nature Walk will delight anyone who loves nature or math or both. John Adam presents ninety-six questions about many common natural phenomena--and a few uncommon ones--and then shows how to answer them using mostly b

  7. Cross-Sections for Low-Energy Neutron-Induced Fission; Sections Efficaces de Fission pour des Neutrons de Faible Energie; 0421 0415 0427 0415 041d 0418 042f 0414 0415 041b 0415 041d 0418 042f , 0412 042b 0417 0412 0410 041d 041d 041e 0413 041e 041d 0415 0419 0422 0420 041e 041d 0410 041c 0418 041d 0418 0417 K 041e 0419 042d 041d 0415 0420 0413 0418 0418 ; Secciones Eficaces en la Fision Inducida por Neutrones de Baja Energia

    Energy Technology Data Exchange (ETDEWEB)

    Rae, E. R. [Atomic Energy Research Establishment, Harwell, Didcot, Berks. (United Kingdom)

    1965-07-15

    The cross-sections of the heavy nuclei for neutron-induced fission are of fundamental importance to the technology of nuclear energy production. The manner in which these cross-sections vary with the neutron energy and with the mass and charge of the target nuclei also provides much information on the structure of heavy nuclei. In the case of a thermally fissile target nucleus, as the neutron energy is increased from thermal the cross-section first exhibits an inverse velocity dependence, followed by a region in which sharp resonance peaks appear, and finally a continuum region where the cross-section exhibits relatively smooth steps and breaks. All these phenomena can be explained in principle, but certain features of the data have proved very difficult to explain quantitatively. Recent cross-section measurements, stimulated by the needs of reactor technology, have concentrated on improving the energy resolution and accuracy of the data on fuel materials, and this has led to a more detailed study of the resonance region, which is of considerable interest for reactor Doppler effect calculations. More accurate measurements at rather higher energies have established the existence of appreciable fission cross-sections below the so-called fission threshold in certain cases. Careful measurements of this nature have in turn stimulated interest in the interpretation of the cross-sections in terms of nuclear models on a firm quantitative basis. This paper outlines the main features of neutron-induced-fission cross-sections and their interpretation. Some emphasis is placed on recent improvements in the quality of the measurements and in attempts at quantitative interpretation of certain aspects of the data. (author) [French] Les sections efficaces de fission des noyaux lourds ont une importance essentielle pour la technologie de la production d'energie d'origine nucleaire. La maniere dont ces sections efficaces varient Selon l'energie des neutrons et Selon la masse et la

  8. Nature as Measure

    DEFF Research Database (Denmark)

    Peters, Terri

    2011-01-01

    The potential for biomimicry lies far beyond the direct imitation of natural forms. Guest-editor Terri Peters describes how Janine Benyus, the biologist and innovation consultant, is using biomimicry to create performance metrics from natural technologies and processes for assessing aspects...

  9. Modeling Natural Selection

    Science.gov (United States)

    Bogiages, Christopher A.; Lotter, Christine

    2011-01-01

    In their research, scientists generate, test, and modify scientific models. These models can be shared with others and demonstrate a scientist's understanding of how the natural world works. Similarly, students can generate and modify models to gain a better understanding of the content, process, and nature of science (Kenyon, Schwarz, and Hug…

  10. Greenland and Natural Resources

    DEFF Research Database (Denmark)

    Lyck, Lise

    Greenland policy can delay and maybe change the future of the forecasted development of the use of natural resources. This book is relevant for anyone interested in Greenland in general and the development of Greenland both politically and economically and in relation natural resources....

  11. Natural - synthetic - artificial!

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2010-01-01

    The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

  12. European natural gas

    International Nuclear Information System (INIS)

    Thackeray, Fred

    1999-11-01

    Contains Executive Summary and Chapters on: Main issues; Natural gas consumption and supply: statistics and key features of individual countries; Sectoral natural gas consumption; Indigenous production; Imports; Prices and taxes; The spot market: The interconnector; Forecasts of production and consumption and contracted imports; Progress of markets liberalisation; Effects of environmentalist developments; Transmission networks and storage; Some principal players. (Author)

  13. Nature Foil Reliefs

    Science.gov (United States)

    Lane, Shaw J.

    2012-01-01

    Nature has always been a source of inspiration for artists across the centuries. Artists such as Leonardo da Vinci, Georgia O'Keeffe, Ansel Adams, and Andy Goldsworthy all drew inspiration for their work from nature. Seeds come from the dried pods, which when planted and cared for, bear fruit. In this article, the author describes how her…

  14. Plutonium in nature

    International Nuclear Information System (INIS)

    Madic, C.

    1994-01-01

    Plutonium in nature comes from natural sources and anthropogenic ones. Plutonium at the earth surface comes principally from anthropogenic sources. It is easily detectable in environment. The plutonium behaviour in environment is complex. It seems necessary for the future to reduce releases in environment, to improve predictive models of plutonium behaviour in geosphere, to precise biological impact of anthropogenic plutonium releases

  15. Exposure to natural radiation

    International Nuclear Information System (INIS)

    Green, B.M.R.

    1985-01-01

    A brief report is given of a seminar on the exposure to enhanced natural radiation and its regulatory implications held in 1985 at Maastricht, the Netherlands. The themes of the working sessions included sources of enhanced natural radiation, parameters influencing human exposure, measurement and survey programmes, technical countermeasures, risk and assessment studies, philosophies of dose limitations and national and international policies. (U.K.)

  16. Nature and landscape protection

    International Nuclear Information System (INIS)

    Klinda, J.; Lieskovska, Z.

    1998-01-01

    In accordance with National Council of the Slovak Republic Act N. 287/1994 Coll. on Nature and Landscape Protection, the system of complex nature landscape protection has been designed based on five levels of protection. Categories of protected areas as well as cultural monuments in the Slovak Republic are reviewed.Slovak contribution to the world heritage is included

  17. Growing natural gas usage

    International Nuclear Information System (INIS)

    Saarni, T.

    1996-01-01

    Finnish natural gas usage topped the 3.3 billion cubic metre mark last year, up 3.6 % on the 1994 figure. Growth has increased now for 12 years in a row. Thanks to offtake by large individual users, the pipeline network has been expanded from South-East Finland to the Greater Helsinki area and central southern Finland. Natural gas plays a much larger role in this region than the 10 % accounted for by natural gas nationally would indicate. The growth in the share of Finland's energy use accounted for by natural gas has served to broaden the country's energy supply base. Natural gas has replaced coal and oil, which has considerably reduced the level of emissions resulting form energy generation

  18. Unnaturalised racial naturalism.

    Science.gov (United States)

    Hochman, Adam

    2014-06-01

    Quayshawn Spencer (2014) misunderstands my treatment of racial naturalism. I argued that racial naturalism must entail a strong claim, such as "races are subspecies", if it is to be a substantive position that contrasts with anti-realism about biological race. My recognition that not all race naturalists make such a strong claim is evident throughout the article Spencer reviews (Hochman, 2013a). Spencer seems to agree with me that there are no human subspecies, and he endorses a weaker form of racial naturalism. However, he supports his preferred version of 'racial naturalism' with arguments that are not well described as 'naturalistic'. I argue that Spencer offers us an unnaturalised racial naturalism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. "Diseases and natural kinds".

    Science.gov (United States)

    Sulmasy, Daniel P

    2005-01-01

    David Thomasma called for the development of a medical ethics based squarely on the philosophy of medicine. He recognized, however, that widespread anti-essentialism presented a significant barrier to such an approach. The aim of this article is to introduce a theory that challenges these anti-essentialist objections. The notion of natural kinds presents a modest form of essentialism that can serve as the basis for a foundationalist philosophy of medicine. The notion of a natural kind is neither static nor reductionistic. Disease can be understood as making necessary reference to living natural kinds without invoking the claim that diseases themselves are natural kinds. The idea that natural kinds have a natural disposition to flourish as the kinds of things that they are provides a telos to which to tether the notion of disease - an objective telos that is broader than mere survival and narrower than subjective choice. It is argued that while nosology is descriptive and may have therapeutic implications, disease classification is fundamentally explanatory. Sickness and illness, while referring to the same state of affairs, can be distinguished from disease phenomenologically. Scientific and diagnostic fallibility in making judgments about diseases do not diminish the objectivity of this notion of disease. Diseases are things, not kinds. Injury is a concept parallel to disease that also makes necessary reference to living natural kinds. These ideas provide a new possibility for the development of a philosophy of medicine with implications for medical ethics.

  20. Almacenamiento de gas natural

    Directory of Open Access Journals (Sweden)

    Tomás Correa

    2008-12-01

    Full Text Available The largest reserves of natural gas worldwide are found in regions far of main cities, being necessary different alternatives to transport the fluid to the consumption cities, such as pipelines, CNG or ships, LNG, depending on distances between producing regions and demanding regions and the producing volumes. Consumption regions have three different markets to naturalgas; residential and commercial, industrial and power generation sector. The residential and commercial is highly seasonal and power generation sector is quite variable depending on increases of temperature during summer time. There are also external issuesthat affect the normal gas flow such as fails on the national system or unexpected interruptions on it, what imply that companies which distribute natural gas should design plans that allow supplying the requirements above mentioned. One plan is using underground natural gas storage with capacities and deliverability rates enough to supply demands. In Colombia there are no laws in this sense but it could be an exploration to discuss different ways to store gas either way as underground natural gas storage or above superficies. Existing basically three different types of underground natural gas storage; depleted reservoirs, salt caverns and aquifers. All ofthem are adequate according to geological characteristics and the needs of the distributors companies of natural gas. This paper is anexploration of technical and economical characteristics of different kind of storages used to store natural gas worldwide.

  1. Natural gas in Mexico

    International Nuclear Information System (INIS)

    Ramirez, M.

    1999-01-01

    A series of overhead viewgraphs accompanied this presentation which focused on various aspects of the natural gas industry in Mexico. Some of the viewgraphs depicted statistics from 1998 regarding natural gas throughput from various companies in North America, natural gas reserves around the world, and natural gas reserves in Mexico. Other viewgraphs depicted associated and non-associated natural gas production from 1988 to 1998 in million cubic feet per day. The Burgos Basin and the Cantarell Basin gas production from 1997 to 2004 was also depicted. Other viewgraphs were entitled: (1) gas processing infrastructure for 1999, (2) cryogenic plant at Cd. PEMEX, (3) average annual growth of dry natural gas production for 1997-2004 is estimated at 5.2 per cent, (4) gas flows for December 1998, (5) PGPB- interconnect points, (6) U.S. Mexico gas trade for 1994-1998, (7) PGPB's interconnect projects with U.S., and (8) natural gas storage areas. Technological innovations in the industry include more efficient gas turbines which allow for cogeneration, heat recovery steam generators which reduce pollutant emissions by 21 per cent, cold boxes which increase heat transfer efficiency, and lateral reboilers which reduce energy consumption and total costs. A pie chart depicting natural gas demand by sector shows that natural gas for power generation will increase from 16 per cent in 1997 to 31 per cent in 2004. The opportunities for cogeneration projects were also reviewed. The Comision Federal de Electricidad and independent power producers represent the largest opportunity. The 1997-2001 investment program proposes an 85 per cent sulphur dioxide emission reduction compared to 1997 levels. This presentation also noted that during the 1998-2001 period, total ethane production will grow by 58 tbd. 31 figs

  2. Closer to Nature?

    DEFF Research Database (Denmark)

    Borkfelt, Sune; Kondrup, Sara; Röcklinsberg, Helena

    2015-01-01

    discourses in order to sell one image of animal welfare in intensive animal production while the actual production at the same time presupposes a quite different paradigm of animal welfare. Specifically, product advertising utilizes representations tied to concepts of naturalness in depictions of both animal...... lives and product processes as “natural”. Product marketing suggests a coherence between nature, production process (farm, animal), and end product, thereby creating associations that the lives of production animals are lived in nature and that their products bring a wholesome and sustainable...

  3. Natural radiation environment

    International Nuclear Information System (INIS)

    Vohra, K.G.; Mishra, U.C.; Pillai, K.C.; Sadasivan, S.

    1982-01-01

    The volume presented contains papers presented at the Second Special Symposium on Natural Radiation Environment held at Bombay, India, during January 1981. The papers deal with such topics as : 1)high natural radiation background areas; 2)environmental natural radioactivity; 3)measurement techniques; 4)technologically enhanced radioactivity; 5)indoor radiation environment; 6)radon and daughters in ambient air, and 7)applications in Geosciences. Each of the 87 papers presented has been abstracted and indexed for the U.S. Department of Energy Technical Information Center's Energy Data Base

  4. EEC's: natural uramium supplies

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The demand for nuclear fuel to supply the nuclear plants within the ECC (31,200 MW at the end of last year) totalled nearly 9,600 tons of natural uranium and 4,900 of separation work units (SWU). Once reactors currently under construction come into service, the demand for natural uranium will reach 13,200 tons by 1985 and that for SWUs to 8,600. If one takes the years 1981 to 1985, total natural uranium needs during this period will be 56,300 tons and those for SWUs 35.100 [fr

  5. Living in cities, naturally.

    Science.gov (United States)

    Hartig, Terry; Kahn, Peter H

    2016-05-20

    Natural features, settings, and processes in urban areas can help to reduce stress associated with urban life. In this and other ways, public health benefits from, street trees, green roofs, community gardens, parks and open spaces, and extensive connective pathways for walking and biking. Such urban design provisions can also yield ecological benefits, not only directly but also through the role they play in shaping attitudes toward the environment and environmental protection. Knowledge of the psychological benefits of nature experience supports efforts to better integrate nature into the architecture, infrastructure, and public spaces of urban areas. Copyright © 2016, American Association for the Advancement of Science.

  6. The unnatural racial naturalism.

    Science.gov (United States)

    Spencer, Quayshawn

    2014-06-01

    In the recent article, "Against the New Racial Naturalism", Adam Hochman (2013, p. 332) argues that new racial naturalists have been too hasty in their racial interpretation of genetic clustering results of human populations. While Hochman makes a number of good points, the purpose of this paper is to show that Hochman's attack on new racial naturalists is misguided due to his definition of 'racial naturalism'. Thus, I will show that Hochman's critique is merely a consequence of an unnatural interpretation of racial naturalism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Diagrams of natural deductions

    Energy Technology Data Exchange (ETDEWEB)

    Popov, S V

    1982-01-01

    The concept of natural deductions was investigated by the author in his analysis of the complexity of deductions in propositional computations (1975). Here some natural deduction systems are considered, and an analytical procedure proposed which results in a deduction diagram for each system. Each diagram takes the form of an orientated, charge graph, features of which can be used to establish the equivalence of classes of deductions. For each of the natural deduction systems considered, a system of equivalent transformation schemes is derived, which is complete with respect to the given definition of equivalence. 2 references.

  8. Web life: Ask Nature

    Science.gov (United States)

    2012-11-01

    Ask Nature is a site devoted to biomimicry, an interdisciplinary field in which practitioners study how animals and plants solve problems, and then use those solutions to develop better human technologies.

  9. Natural Gas Acquisition Program

    Data.gov (United States)

    General Services Administration — The "NGAP" system is a web based application which serves NGAP GSA users for tracking information details for various natural gas supply chain elements like Agency,...

  10. Sciences & Nature: Submissions

    African Journals Online (AJOL)

    Sciences & nature publish original works in French or in English that have not been ... This page should provide a summary (200 words maximum) in French and English .... one copy of the journal where his article is published, and 10 offprints.

  11. Natural Hazards Image Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Photographs and other visual media provide valuable pre- and post-event data for natural hazards. Research, mitigation, and forecasting rely on visual data for...

  12. The Nature of Grammar

    Institute of Scientific and Technical Information of China (English)

    王楠

    2012-01-01

    This paper describes the nature of grammar as "universalness". The universal grammar indicates that all the languages in the world have identical grammar. This is discussed from three aspects, which gives insight into grammar acquisition.

  13. Art, Technology and Nature

    DEFF Research Database (Denmark)

    Camilla Skovbjerg Paldam and Jacob Wamberg trace the Kantian heritage of radically separating art and technology, and inserting both at a distance to nature, suggesting this was a transient chapter in history. Thus, they argue, the present renegotiation between art, technology and nature is reminiscent......Since 1900, the connections between art and technology with nature have become increasingly inextricable. Through a selection of innovative readings by international scholars, this book presents the first investigation of the intersections between art, technology and nature in post-medieval times....... Transdisciplinary in approach, this volume’s 14 essays explore art, technology and nature’s shifting constellations that are discernible at the micro level and as part of a larger chronological pattern. Included are subjects ranging from Renaissance wooden dolls, science in the Italian art academies, and artisanal...

  14. Historic Natural Vegetation

    Data.gov (United States)

    California Natural Resource Agency — In 2001, the US Fish and Wildlife Service (USFWS) and the U.S. Bureau of Reclamation (BOR) contracted with the California State University, Chico Research Foundation...

  15. Vermont Designated Natural Areas

    Data.gov (United States)

    Vermont Center for Geographic Information — Under Natural Areas Law (10 Vermont Statutes Annotated, Chapter 83 � 2607) the FPR commissioner, with the approval of the governor, may designate and set aside areas...

  16. Radon - natural health threat

    International Nuclear Information System (INIS)

    Wrixon, Anthony

    1985-01-01

    Natural sources of radiation attract little attention, yet a survey has found radon gas in buildings at levels which put the occupants at some risk. The author wants safety standards set without undue delay. (author)

  17. Natural gas pricing

    International Nuclear Information System (INIS)

    Freedenthal, C.

    1993-01-01

    Natural gas pricing is the heart and soul of the gas business. Price specifically affects every phase of the industry. Too low a price will result in short supplies as seen in the mid-1970s when natural gas was scarce and in tight supply. To fully understand the pricing of this energy commodity, it is important to understand the total energy picture. In addition, the effect and impact of world and US economies, and economics in general are crucial to understanding natural gas pricing. The purpose of this presentation will be to show the parameters going into US natural gas pricing including the influence of the many outside industry factors like crude oil and coal pricing, market drivers pushing the gas industry, supply/demand parameters, risk management for buyers and sellers, and other elements involved in pricing analysis

  18. Natural Gas STAR Program

    Science.gov (United States)

    EPA’s Voluntary Methane Programs encourage oil and natural gas companies to adopt cost-effective technologies and practices that improve operational efficiency and reduce emissions of methane, a potent greenhouse gas.

  19. Natural gas for vehicles

    International Nuclear Information System (INIS)

    Chauveron, S. de

    1996-01-01

    This article presents compressed natural gas for vehicles (CNG), which can provide considerable advantages both as an alternative fuel and as a clean fuel. These assets are not only economic but also technical. The first part deals with what is at stake in developing natural gas as a motor fuel. The first countries to use CNG were those with natural gas resources in their subsoil. Today, with a large number of countries having to cope with growing concern about increasing urban pollution, natural gas is also seen as a clean fuel that can help cut vehicle pollutant emissions dramatically. In the second part a brief technical descriptions is given of CNG stations and vehicles, with the aim of acquainting the reader with some of CNG's specific technical features as compared to gasoline and diesel oil. Here CNG technologies are seen to be very close to the more conventional ones. (author)

  20. Natural polymers: an overview

    CSIR Research Space (South Africa)

    John, MJ

    2012-08-01

    Full Text Available The scarcity of natural polymers during the world war years led to the development of synthetic polymers like nylon, acrylic, neoprene, styrene-butadiene rubber (SBR) and polyethylene. The increasing popularity of synthetic polymers is partly due...

  1. Solitonic natural orbitals

    Science.gov (United States)

    Cioslowski, Jerzy

    2018-04-01

    The dependence of the natural amplitudes of the harmonium atom in its ground state on the confinement strength ω is thoroughly investigated. A combination of rigorous analysis and extensive, highly accurate numerical calculations reveals the presence of only one positive-valued natural amplitude ("the normal sign pattern") for all ω ≥1/2 . More importantly, it is shown that unusual, weakly occupied natural orbitals (NOs) corresponding to additional positive-valued natural amplitudes emerge upon sufficient weakening of the confinement. These solitonic NOs, whose shapes remain almost invariant as their radial positions drift toward infinity upon the critical values of ω being approached from below, exhibit strong radial localization. Their asymptotic properties are extracted from the numerical data and their relevance to calculations on fully Coulombic systems is discussed.

  2. Biomimetics: nature based innovation

    National Research Council Canada - National Science Library

    Bar-Cohen, Yoseph

    2012-01-01

    "Based on the concept that nature offers numerous sources of inspiration for inventions related to mechanisms, materials, processes, and algorithms, this book covers the topic of biomimetics and the inspired innovation...

  3. Natural gas benefits

    International Nuclear Information System (INIS)

    1999-01-01

    The General Auditor in the Netherlands studied the natural gas policy in the Netherlands, as has been executed in the past decades, in the period 1997-1999. The purpose of the study is to inform the Dutch parliament on the planning and the backgrounds of the natural gas policy and on the policy risks with respect to the benefits for the Dutch State, taking into account the developments in the policy environment. The final conclusion is that the proposed liberalization of the national natural gas market will result in a considerable deprivation of income for the State in case the benefit policy is not adjusted. This report includes a reaction of the Dutch Minister of Economic Affairs and an afterword of the General Auditor. In the appendix an outline is given of the natural gas policy

  4. Natural Gas Market Hubs

    Data.gov (United States)

    Department of Homeland Security — A hub is a physical transfer point for natural gas where several pipelines are connected. A market center is a hub where the operator offers services that facilitate...

  5. Managing soil natural capital

    DEFF Research Database (Denmark)

    Cong, Ronggang; Termansen, Mette; Brady, Mark

    2017-01-01

    Farmers are exposed to substantial weather and market related risks. Rational farmers seek to avoid large losses. Future climate change and energy price fluctuations therefore make adaptating to increased risks particularly important for them. Managing soil natural capital—the capacity of the soil...... to generate ecosystem services of benefit to farmers—has been proven to generate the double dividend: increasing farm profit and reducing associated risk. In this paper we explore whether managing soil natural capital has a third dividend: reducing the downside risk (increasing the positive skewness of profit......). This we refer to as the prudence effect which can be viewed as an adaptation strategy for dealing with future uncertainties through more prudent management of soil natural capital. We do this by developing a dynamic stochastic portfolio model to optimize the stock of soil natural capital—as indicated...

  6. Lesson "Balance in Nature

    Science.gov (United States)

    Chapanova, V.

    2012-04-01

    Lesson "Balance in Nature" This simulation game-lesson (Balance in Nature) gives an opportunity for the students to show creativity, work independently, and to create models and ideas. It creates future-oriented thought connected to their experience, allowing them to propose solutions for global problems and personal responsibility for their activities. The class is divided in two teams. Each team chooses questions. 1. Question: Pollution in the environment. 2. Question: Care for nature and climate. The teams work on the chosen tasks. They make drafts, notes and formulate their solutions on small pieces of paper, explaining the impact on nature and society. They express their points of view using many different opinions. This generates alternative thoughts and results in creative solutions. With the new knowledge and positive behaviour defined, everybody realizes that they can do something positive towards nature and climate problems and the importance of individuals for solving global problems is evident. Our main goal is to recover the ecological balance, and everybody explains his or her own well-grounded opinions. In this work process the students obtain knowledge, skills and more responsible behaviour. This process, based on his or her own experience, dialogue and teamwork, helps the participant's self-development. Making the model "human↔ nature" expresses how human activities impact the natural Earth and how these impacts in turn affect society. Taking personal responsibility, we can reduce global warming and help the Earth. By helping nature we help ourselves. Teacher: Veselina Boycheva-Chapanova " Saint Patriarch Evtimii" Scholl Str. "Ivan Vazov"-19 Plovdiv Bulgaria

  7. More natural gas

    International Nuclear Information System (INIS)

    Leprince, P.; Valais, M.

    1993-01-01

    This paper reports that large resources and growing markets are the salient prospects of natural gas for the coming decades. The greater impact of natural gas on the worldwide energy market can become a reality if several scientific disciplines can be mobilized in order to succeed in cutting production costs. Modeling, mechanics of complex fluids, and physical chemistry of interfaces are basic disciplines for understanding and mastering the gas processing technologies

  8. Natural rubber: leather composites

    OpenAIRE

    Ravichandran,K.; Natchimuthu,N.

    2005-01-01

    Leather is a fibrous protein consisting of collagen in a three dimensionally crosslinked network. Chrome tanning of leather improves the appearance of leather but at the same time emits both solid and liquid chrome leather wastes. Scrap rubber recycling using untreated and neutralized leather fibrous particles in natural rubber has been studied. Vulcanization, mechanical, morphological and swelling properties of the natural rubber - scrap rubber composites containing neutralized leather have ...

  9. Natural Hazards, Second Edition

    Science.gov (United States)

    Rouhban, Badaoui

    Natural disaster loss is on the rise, and the vulnerability of the human and physical environment to the violent forces of nature is increasing. In many parts of the world, disasters caused by natural hazards such as earthquakes, floods, landslides, drought, wildfires, intense windstorms, tsunami, and volcanic eruptions have caused the loss of human lives, injury, homelessness, and the destruction of economic and social infrastructure. Over the last few years, there has been an increase in the occurrence, severity, and intensity of disasters, culminating with the devastating tsunami of 26 December 2004 in South East Asia.Natural hazards are often unexpected or uncontrollable natural events of varying magnitude. Understanding their mechanisms and assessing their distribution in time and space are necessary for refining risk mitigation measures. This second edition of Natural Hazards, (following a first edition published in 1991 by Cambridge University Press), written by Edward Bryant, associate dean of science at Wollongong University, Australia, grapples with this crucial issue, aspects of hazard prediction, and other issues. The book presents a comprehensive analysis of different categories of hazards of climatic and geological origin.

  10. Natural Resource Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Green, T. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Schwager, K. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

    2016-10-01

    This comprehensive Natural Resource Management Plan (NRMP) for Brookhaven National Laboratory (BNL) was built on the successful foundation of the Wildlife Management Plan for BNL, which it replaces. This update to the 2003 plan continues to build on successes and efforts to better understand the ecosystems and natural resources found on the BNL site. The plan establishes the basis for managing the varied natural resources located on the 5,265-acre BNL site, setting goals and actions to achieve those goals. The planning of this document is based on the knowledge and expertise gained over the past 15 years by the Natural Resources management staff at BNL in concert with local natural resource agencies including the New York State Department of Environmental Conservation, Long Island Pine Barrens Joint Planning and Policy Commission, The Nature Conservancy, and others. The development of this plan works toward sound ecological management that not only benefits BNL’s ecosystems but also benefits the greater Pine Barrens habitats in which BNL is situated. This plan applies equally to the Upton Ecological and Research Reserve (Upton Reserve). Any difference in management between the larger BNL area and the Upton Reserve are noted in the text.

  11. The system of nature

    CERN Document Server

    D'Holbac, Baron

    1999-01-01

    "The source of Man's unhappiness is his ignorance of Nature."D'Holbach believed that the misery he saw in mankind around him was caused by religion and its superstitious beliefs - that there was a God who controlled destiny and would reward or punish individuals. The System of Nature was written to replace these delusions with a schema of understanding based solely on the physical workings of nature. "Let Man study this nature, let him learn her laws, contemplate her energies." For d'Holbach the soul is only the physical body, understood from a certain point of view, which dies when the body dies. All the events and the nature of the world can be understood in terms of the motion and properties of matter; even the tiniest causes contribute to huge events - a simple change in the diet of an Emperor (or some other such insignificant cause), he suggests might have been capable of "saving kingdoms." For him, nature's laws are fixed and necessary, and if Man wants to find happiness it is best to accept this - if g...

  12. Natural gas prices

    International Nuclear Information System (INIS)

    Johnson, W.A.

    1990-01-01

    Since the 1970s, many electric utilities and industrial boiler fuel users have invested in dual fuel use capability which has allowed them to choose between natural gas, residual fuel oil, and in some instances, coal as boiler fuels. The immediate reason for this investment was the need for security of supply. Wellhead regulation of natural gas prices had resulted in shortages during the 1970s. Because many industrial users were given lowest priority in pipeline curtailments, these shortages affected most severely boiler fuel consumption of natural gas. In addition, foreign supply disruptions during the 1970s called into question the ready availability of oil. Many boiler fuel users of oil responded by increasing their ability to diversify to other sources of energy. Even though widespread investment in dual fuel use capability by boiler fuel users was initially motivated by a need for security of supply, perhaps the most important consequence of this investment was greater substitutability between natural gas and resid and a more competitive boiler fuel market. By the early 1980s, most boiler fuel users were able to switch from one fuel to another and often did for savings measured in pennies per MMBtu. Boiler fuel consumption became the marginal use of both natural gas and resid, with coal a looming threat on the horizon to both fuels

  13. Natural Dietary Phytosterols.

    Science.gov (United States)

    Racette, Susan B; Lin, Xiaobo; Ma, Lina; Ostlund, Richard E

    2015-01-01

    Most clinical phytosterol studies are performed by adding purified supplements to smaller phytosterol amounts present in the natural diet. However, natural dietary phytosterols themselves may also have important effects on cholesterol metabolism. Epidemiological work using food frequency questionnaires to estimate dietary intake suggest that extremes of normal consumption may be associated with 3-14% changes in LDL cholesterol. Standardized food databases do not have enough phytosterol values to allow calculation of phytosterol intake for individuals outside of specialized studies. Natural diets contain phytosterol amounts ranging from less than 60 mg/2000 kcal to over 500 mg/2000 kcal. Physiological studies in which whole body cholesterol metabolism is investigated show large effects of natural dietary phytosterols on cholesterol absorption efficiency, cholesterol biosynthesis and cholesterol excretion which exceed the magnitude of changes in LDL cholesterol. The dual effects of natural phytosterols on both LDL-C and whole body cholesterol metabolism need to be considered in relating them to potential protection from coronary heart disease risk.

  14. Symmetries in nature

    International Nuclear Information System (INIS)

    Mainzer, K.

    1988-01-01

    Symmetry, disymmetry, chirality etc. are well-known topics in chemistry. But they cannot only be found on the molecular level of matter. Atoms and elementary particles in physics are also characterized by particular symmetry groups. Even living organisms and populations on the macroscopic level have functional properties of symmetry. The whole physical, chemical, and biological evolution seems to be regulated by the emergence of new symmetries and the breaking down of old ones. One is reminded of Heisenberg's famous statement: 'Die letzte Wurzel der Erscheinungen ist also nicht die Materie, sondern das mathematische Gesetz, die Symmetrie, die mathematische Form' (Wandlungen in den Grundlagen der Naturwissenschaften, 1959). Historically the belief in symmetry and simplicity of nature has a long philosophical tradition from the Pythagoreans, Plato and Greek astronomers to Kepler and modern scientists. Today, 'symmetries in nature' is a common topic of mathematics, physics, chemistry, and biology. A lot of Nobel prizes were given in honour of inquiries concerning symmetries in nature. The fascination of symmetries is not only motivated by science, but by art and religion too. Therefore 'symmetris in nature' is an interdisciplinary topic which may help to overcome C.P. Snow's 'Two Cultures' of natural sciences and humanities. (author) 17 refs., 21 figs

  15. Symmetries in nature

    Energy Technology Data Exchange (ETDEWEB)

    Mainzer, K

    1988-05-01

    Symmetry, disymmetry, chirality etc. are well-known topics in chemistry. But they cannot only be found on the molecular level of matter. Atoms and elementary particles in physics are also characterized by particular symmetry groups. Even living organisms and populations on the macroscopic level have functional properties of symmetry. The whole physical, chemical, and biological evolution seems to be regulated by the emergence of new symmetries and the breaking down of old ones. One is reminded of Heisenberg's famous statement: 'Die letzte Wurzel der Erscheinungen ist also nicht die Materie, sondern das mathematische Gesetz, die Symmetrie, die mathematische Form' (Wandlungen in den Grundlagen der Naturwissenschaften, 1959). Historically the belief in symmetry and simplicity of nature has a long philosophical tradition from the Pythagoreans, Plato and Greek astronomers to Kepler and modern scientists. Today, 'symmetries in nature' is a common topic of mathematics, physics, chemistry, and biology. A lot of Nobel prizes were given in honour of inquiries concerning symmetries in nature. The fascination of symmetries is not only motivated by science, but by art and religion too. Therefore 'symmetris in nature' is an interdisciplinary topic which may help to overcome C.P. Snow's 'Two Cultures' of natural sciences and humanities. (author) 17 refs., 21 figs.

  16. Natural gas purchasing

    International Nuclear Information System (INIS)

    Freedenthal, C.

    1993-01-01

    In recent years, natural gas has gained new momentum because of changes in marketing and regulations. The gas industry has always received an inordinate amount of regulatory control starting at the well head where the gas is produced to the consuming burner tip. Regulations have drastically impacted the availability of gas. Changes in the marketing and regulations have made the natural gas market sensitive at the point of production, the well head. Now, with plentiful supply and ease of transportation to bring the gas from the producing fields to the consumer, natural gas markets are taking advantage of the changed conditions. At the same time, new markets are developing to take advantage of the changes. This section shows consumers, especially the energy planners for large buyers of fuel, the advantages, sources and new methods of securing natural gas supplies. Background on how natural gas is produced and marketed are given. This section lists marketing sources, regulatory agencies and information groups available to help buyers and consumers of this important fuel for US industries and residences. 7 figs., 8 tabs

  17. Naturalness and Animal Welfare.

    Science.gov (United States)

    Yeates, James

    2018-04-05

    Naturalness is considered important for animals, and is one criterion for assessing how we care for them. However, it is a vague and ambiguous term, which needs definition and assessments suitable for scientific and ethical questions. This paper makes a start on that aim. This paper differentiates the term from other related concepts, such as species-typical behaviour and wellbeing. It identifies contingent ways in which naturalness might be used, as: (i) prompts for further welfare assessment; (ii) a plausible hypothesis for what safeguards wellbeing; (iii) a threshold for what is acceptable; (iv) constraints on what improvements are unacceptable; and (v) demarcating what is not morally wrong, because of a lack of human agency. It then suggests an approach to evaluating animals' behaviour that is quantitative, is based on reality, and which assesses naturalness by degrees. It proposes classing unaffected wild populations as natural by definition. Where animals might have been affected by humans, they should be compared to the closest population(s) of unaffected animals. This approach could allow us both to assess naturalness scientifically, and to make practical decisions about the behaviour of domestic animals.

  18. Natural gas deregulation

    International Nuclear Information System (INIS)

    Ronchi, M.

    1993-01-01

    With the aim of establishing realistic options for deregulation in the natural gas industry, this paper first considers the structural evolution of this industry and evidences how it differs from the petroleum industry with which it exhibits some essential characteristics in common. This comparison is made in order to stress that, contrary to popular belief, that which is without doubt good for the petroleum industry is not necessarily so also for the natural gas industry. The paper concludes with separate analyses of the natural gas markets in the principal industrialized countries. Arguments are provided to show that the 'soft' deregulation option for the natural gas industry is not feasible, and that 'total' deregulation instead, backed by the passing of a suitable package of anti-trust laws 'unbundling' the industry's four major activities, i.e., production, storage, primary and secondary distribution, is the preferable option. The old concept of guaranteed supplies for minor users of natural gas should give way to the laws of supply and demand governing inter-fuel competition ensured through the strict supervision of vigilance committees

  19. Okulo natural reactors

    International Nuclear Information System (INIS)

    Yamakawa, Minoru

    1993-01-01

    French CEA has reported in 1972 that natural nuclear reactors existed in Okulo uranium deposit in Gabon in Africa, that caused nuclear fission chain reaction (Okulo phenomena) spontaneously two billion years ago. The fission products and transuranic elements produced by the natural reactors have been preserved in strata without movement while subjected to geological phenomena for such very long years. 16 zones of the natural reactors have been discovered so far. The geological features of the Okulo uranium deposit are explained. The total amount of 235 U lost by the chain reaction was estimated to be about 6t, and the fission products were about 6t. The Okulo phenomena offered the valuable results of the synthetic formation disposal test that the nature has carried out for such long years. The significance of the study on natural analog is discussed. Organic substances and the mechanism of holding and movement of uranium and fission nuclides, the stability of uraninite and the age measurement of the deposit by Nd-Sm process are reported as the main results. (K.I.)

  20. Hauntings of Human Nature

    DEFF Research Database (Denmark)

    Clasen, Mathias

    2017-01-01

    The central conflicts of Stephen King’s horror novel The Shining are rooted in human nature and reflect evolutionarily recurrent adaptive problems—the problem of balancing conflicting evolved motives, such as motives for selfish status striving versus motives for affiliative nurturing behavior......, and the problem of surviving the hostile forces of nature. Moreover, the supernatural elements of the novel resonate with evolved intuitions about non-material, moral forces at work in the world. That is why the novel continues to engage readers worldwide. Most critics, however, have overlooked or distorted...... the psychological underpinnings of the novel and the crucial function of the supernatural elements in the meaning structure of the novel. Hence we need an evolutionary psychological perspective which builds on recent findings in the sciences of human nature to account for the novel’s meaning, effects, and continued...

  1. Nature/culture/seawater.

    Science.gov (United States)

    Helmreich, Stefan

    2011-01-01

    Seawater has occupied an ambiguous place in anthropological categories of "nature" and "culture." Seawater as nature appears as potentiality of form and uncontainable flux; it moves faster than culture - with culture frequently figured through land-based metaphors - even as culture seeks to channel water's (nature's) flow. Seawater as culture manifests as a medium of pleasure, sustenance, travel, disaster. I argue that, although seawater's qualities in early anthropology were portrayed impressionistically, today technical, scientific descriptions of water's form prevail. For example, processes of globalization - which may also be called "oceanization" - are often described as "currents," "flows," and "circulations." Examining sea-set ethnography, maritime anthropologies, and contemporary social theory, I propose that seawater has operated as a “theory machine” for generating insights about human cultural organization. I develop this argument with ethnography from the Sargasso Sea and in the Sea Islands. I conclude with a critique of appeals to water's form in social theory.

  2. nature in the city

    Directory of Open Access Journals (Sweden)

    Elena Grigoryeva

    2016-08-01

    The object of the issue is a wonderful museum on the Kulikovo Field designed by Sergey Gnedovsky. The unusual architecture of the new museum makes it akin to the earth’s tectonic fault caused by an intolerable tension in expectation of the battle (pp. 113-123. Oleg Yavein and Ilya Lezhava bring us back to the classic of the 20th century Mies van der Rohe and his unique dialogue with nature (pp. 162-175. Relationship between architecture and nature is a rich and limitless theme, like both of these substances. That is why the new Project Baikal issue contains, as usual, more questions than answers. Such is the nature of our journal.

  3. Natural Gas Regulation

    International Nuclear Information System (INIS)

    1995-01-01

    The regulation of Natural Gas. Natural gas Regulation clarifies and consolidates the legal and institutional framework for development of the industry through six principal elements: 1) Establishment of a vision of the industry. 2) Development of regulatory objectives. 3) Determination of relationships among industry participants. 4) Clear specification of the role of PEMEX in the industry. 5) Definition of the functions of the Regulatory authority. 6) Creation of a transition regime. In parallel with the development of the substantive legal framework, the law of the Comision Reguladora de Energia (CRE) was also enacted by Congress in October 1995 to strength the institutional framework and implement the legal changes. This law defines the CRE as an agency of the Energy Ministry with technical, operational, and budgetary autonomy, and responsibility for implementing natural gas industry regulation. (Author)

  4. Natural resource damage assessment

    International Nuclear Information System (INIS)

    Seddelmeyer, J.

    1991-01-01

    The assessment and collection of natural resource damages from petroleum and chemical companies unfortunate enough to have injured publicly owned natural resources is perhaps the most rapidly expanding area of environmental liability. The idea of recovering for injury to publicly owned natural resources is an extension of traditional common law tort concepts under which a person who negligently injures another or his property is called upon to compensate the injured party. Normally, once liability has been established, it is a fairly straightforward matter to calculate the various elements of loss, such as the cost to repair or replace damaged property, or medical expenses, and lost income. More difficult questions, such as the amount to be awarded for pain and suffering or emotional distress, are left to the jury, although courts limit the circumstances in which the jury is permitted to award such damages

  5. Livelihoods and natural resources

    DEFF Research Database (Denmark)

    Cotta, Jamie Nicole

    generation and shock coping. In addition, a multi-method approach (utilizing income, transect inventory and free-list data) demonstrates the significant economic importance of agroforestry environments, particularly managed fallows, when compared with natural forests. Interventions aimed at sustaining...... by both high vulnerability (e.g., residents with flood-vulnerable cultivation) and limited availability/diversity of environmentally-sourced coping products. Finally, future research and development initiatives should take into account not just natural forests or agricultural systems, but also......This dissertation research contributes to the emerging body of knowledge on the economic contributions of natural resources to rural livelihoods, including their role in household shock coping, in the humid tropics. Data from one of the first comprehensive household income quantifications...

  6. Natural photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Vigneron, Jean Pol, E-mail: jean-pol.vigneron@fundp.ac.be [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium); Simonis, Priscilla [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium)

    2012-10-15

    Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

  7. Antiplasmodial Natural Products

    Directory of Open Access Journals (Sweden)

    Cláudio R. Nogueira

    2011-03-01

    Full Text Available Malaria is a human infectious disease that is caused by four species of Plasmodium. It is responsible for more than 1 million deaths per year. Natural products contain a great variety of chemical structures and have been screened for antiplasmodial activity as potential sources of new antimalarial drugs. This review highlights studies on natural products with antimalarial and antiplasmodial activity reported in the literature from January 2009 to November 2010. A total of 360 antiplasmodial natural products comprised of terpenes, including iridoids, sesquiterpenes, diterpenes, terpenoid benzoquinones, steroids, quassinoids, limonoids, curcubitacins, and lanostanes; flavonoids; alkaloids; peptides; phenylalkanoids; xanthones; naphthopyrones; polyketides, including halenaquinones, peroxides, polyacetylenes, and resorcylic acids; depsidones; benzophenones; macrolides; and miscellaneous compounds, including halogenated compounds and chromenes are listed in this review.

  8. Natural rubber: leather composites

    Directory of Open Access Journals (Sweden)

    K. Ravichandran

    2005-06-01

    Full Text Available Leather is a fibrous protein consisting of collagen in a three dimensionally crosslinked network. Chrome tanning of leather improves the appearance of leather but at the same time emits both solid and liquid chrome leather wastes. Scrap rubber recycling using untreated and neutralized leather fibrous particles in natural rubber has been studied. Vulcanization, mechanical, morphological and swelling properties of the natural rubber - scrap rubber composites containing neutralized leather have been discussed. Use of chrome leather particles has been found to improve the consumption of scrap rubber powder in natural rubber formulations. Polymer composites based on leather wastes as fillers are reported to be useful for many applications such as in construction materials, automobile interior moldings, heat and sound insulating boards, shoe soles, flooring materials and moldings with good anti-static properties, air permeability and good appearances.

  9. Canadian natural gas

    International Nuclear Information System (INIS)

    Lucas, D.A.

    1991-01-01

    Canada's natural gas industry enjoys a quiet confidence as it looks ahead to the 1990s. In this paper, the author explains why, despite some critical uncertainties, the optimism endures. Reviewing the current conditions of supply, production, consumption, pipelines, and pipeline expansion plans, the author contends that the New World of the 1990s will belong to natural gas. The author's assessment of natural gas markets proceeds far beyond the borders of Canada. The author examines the determinants of gas prices throughout North America and he identifies the one force that promises to seize almost complete control of gas prices throughout the continent. While the analysis points out the attributes of this new pricing regime, it also names the obstacles that could prevent this emerging mechanism from assuming its anticipated position

  10. Natural photonic crystals

    International Nuclear Information System (INIS)

    Vigneron, Jean Pol; Simonis, Priscilla

    2012-01-01

    Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

  11. Natural gas's hottest spot

    International Nuclear Information System (INIS)

    Peterson, T.

    1993-01-01

    This paper reviews the growing power and economic strength of Enron Corp., a natural gas distributor and exploration company. The paper reviews the policy of the company to exploit deregulation at home and privatization of all sorts of energy companies abroad. Enron is actively building its own power plants in the US and has successfully boosted their profits by 20 percent in what was considered a flat natural gas market. The paper goes on to discuss the company's view of the new energy tax and how it should benefit natural gas companies as a whole. Finally the paper reviews the contracting procedures of the company to secure long-term fixed price contracts in a volatile market which precludes most companies from taking the risk

  12. Anthropologie de la nature

    OpenAIRE

    Descola, Philippe

    2010-01-01

    En apparence, l’anthropologie de la nature est une sorte d’oxymore puisque, depuis plusieurs siècles en Occident, la nature se caractérise par l’absence de l’homme, et l’homme par ce qu’il a su surmonter de naturel en lui. Mais la nature n’existe pas comme une sphère de réalités autonomes pour tous les peuples. En postulant une distribution universelle des humains et des non-humains dans deux domaines ontologiques séparés, nous sommes bien mal armés pour analyser tous ces systèmes d’objectiva...

  13. The natural radiation background

    International Nuclear Information System (INIS)

    Duggleby, J.C.

    1982-01-01

    The components of the natural background radiation and their variations are described. Cosmic radiation is a major contributor to the external dose to the human body whilst naturally-occurring radionuclides of primordial and cosmogenic origin contribute to both the external and internal doses, with the primordial radionuclides being the major contributor in both cases. Man has continually modified the radiation dose to which he has been subjected. The two traditional methods of measuring background radiation, ionisation chamber measurements and scintillation counting, are looked at and the prospect of using thermoluminescent dosimetry is considered

  14. Natural User Interfaces

    OpenAIRE

    Câmara , António

    2011-01-01

    Dissertação de Mestrado em Engenharia Informática apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra This project’s main subject are Natural User Interfaces. These interfaces’ main purpose is to allow the user to interact with computer systems in a more direct and natural way. The popularization of touch and gesture devices in the last few years has allowed for them to become increasingly common and today we are experiencing a transition of interface p...

  15. Atmospheric natural radioactivity outdoors

    International Nuclear Information System (INIS)

    Renoux, A.

    1985-01-01

    Following a short account of natural atmospheric radioactivity, radon concentrations are given as well as their variations with time obtained by means of a original apparatus developped in Brest. The radioactive equilibrium of radon and its daughters is then considered, many experiments demonstrating that equilibrium is seldom reached even for 218 Po (RaA). Finally, some characteristics of natural radioactive aerosols are studied: charge, particle size distribution (demonstrating they are fine aerosols since only 30 per cent are made of particles with radii exceeding 0,1 μm) [fr

  16. Natural atmospheric radioactivity

    International Nuclear Information System (INIS)

    Renoux, A.

    1986-01-01

    After having summed up the different old or new units, used in radioactivity and radioprotection, the origins of atmospheric radioactivity are reported. Next the authors deal with the air content in radon, thoron and their radioactive descendants, insisting on the variations of the radon air content and on the radioactive balance between radon and its descendants. Then a few notions concerning the natural radioactive aerosol are developed: electric charge state, granulometric distribution. The possible effects of natural atmospheric radioactivity on man are studied with a distinction between inner irradiation and outer irradiation, an average assessment is shown. Finally the important problem of radon in inhabitations is approached [fr

  17. Monitoring natural phytoplankton communities

    DEFF Research Database (Denmark)

    Haraguchi, L.; Jakobsen, H. H.; Lundholm, Nina

    2017-01-01

    -consuming and/or expensive, limiting sampling frequency. The use of faster methods, such as flow cytometry, has become more frequent in phytoplankton studies, although comparisons between this technique and traditional ones are still scarce. This study aimed to assess if natural phytoplankton communities...... carbon biomass with PFCM, applying the same conversion factors as for microscopy. Biomasses obtained with PFCM, estimated from live cells, were higher than microscopy for natural samples. We conclude that PFCM results are comparable to classical techniques, yet the data from PFCM had poor taxonomic...

  18. Training and natural immunity

    DEFF Research Database (Denmark)

    Pedersen, Bente Klarlund; Helge, Jørn Wulff; Richter, Erik

    2000-01-01

    these subjects were used to eliminate day-to-day variation in the immunological tests. Independently of diet, training increased the percentage of CD3-CD16+ CD56+ natural killer (NK) cells from [mean (SEM)] 14 (1) % to 20 (3) % (P = 0.05), whereas the NK-cell activity, either unstimulated or stimulated...... influence natural immunity, and suggest that ingestion of a fat-rich diet during training is detrimental to the immune system compared to the effect of a carbohydrate-rich diet....

  19. Natural Heavy Supersymmetry

    CERN Document Server

    Batell, Brian; McCullough, Matthew

    2015-01-01

    We study how, as a result of the scanning of supersymmetry breaking during the cosmological evolution, a relaxation mechanism can naturally determine a hierarchy between the weak scale and the masses of supersymmetric particles. Supersymmetry breaking is determined by QCD instanton effects, in an extremely minimal setup in which a single field drives the relaxation and breaks supersymmetry. Since gauginos are lighter than the other supersymmetric particles by a one-loop factor, the theory is a realisation of Split Supersymmetry free from the naturalness problem.

  20. The natural gas market

    International Nuclear Information System (INIS)

    Lagrasta, F.; Kaminski, V.; Prevatt, R.

    1999-01-01

    This chapter presents a brief history of the natural gas market highlighting the changes in the gas market and examining risk management in practice detailing the types of price risks, and the use of hedging using forwards and swaps. Options to manage risk are identified, and the role of risk management in financing, the role of the intermediary, and the market outlook are discussed. Panels describing the market structure, storage and natural gas risk management, the art of risk management, the winter 1995-96 basis blowout, spark spreads, the UK gas market and Europe, and weather derivatives are presented

  1. Natural Selection and Morality

    Directory of Open Access Journals (Sweden)

    Alejandro Rosas

    2006-12-01

    Full Text Available Resumen:En este ensayo abordo los intentos, relativamente recientes, de dar una explicación de la moralidad como adaptación por selección natural. Mi exposición tiene una introducción y cuatro partes: en la primera explico en qué consiste la paradoja del altruismo biológico. En la segunda expongo la solución que apela a la selección de grupos, recientemente resurgida; la solución que presuntamente aplicó Charles Darwin cuando formuló sus reflexiones biológicas sobre la moralidad humana. En la tercera expongo la solución sociobiológica, que opta por negar que la selección natural pueda explicar directamente la moralidad humana. La moralidad se presenta más bien como opuesta a la naturaleza diseñada por selección natural. En la cuarta parte desarrollo brevemente una explicación de la moralidad como adaptación que beneficia a los individuos. No opone la moralidad a la naturaleza, ni apela a la selección de grupos. Se sirve de un mecanismo de selección que opera a través de preferencias en la interacción social.Abstract:In this essay, I address recent attempts to account for morality as an adaptation due to natural selection. After a brief introduction, my exposition has four sections. I first explain the paradox of biological altruism. Second, I explain the solution to the paradox in terms of group selection. This solution was presumably applied by Darwin himself as he discussed human morality, and it has experienced a recent revival, though it remains suspicious to most biologists. In the third section I offer a socio-biological solution that opts for denying that morality can be explained by any form of natural selection. Morality is opposed to human nature as designed by natural selection. In the fourth, I argue for an explanation in terms of individual selection. It does not oppose morality to nature, and does not need the workings of group selection; rather, it operates through the agents’ psychological preferences

  2. MENOPAUSE AND NATURAL HEALING

    Directory of Open Access Journals (Sweden)

    Lucija Vrabič Dežman

    2008-12-01

    The studies could not decisively confirm the effectiveness of various phytoestrogens inamelioration of climacteric symptoms. Most studies have proven the effectiveness of thenatural medication made of Cimicifuga racemosa and its safe short-term use. Gynecologists should be familiar with the basics of phytotherapy and the results of clinical studiesin this field in order to confidently advise women to use the natural medications in caseswhere despite the climacteric symptoms they cannot or will not use HRT, consequentlygreatly reducing the quality of their lives. In cases where climacteric symptoms are mild tomoderate, some menopausal societies around the globe suggest trying natural medicationfirst, and only later implementing HRT

  3. Battles Fought in Nature

    DEFF Research Database (Denmark)

    Poulsen, Dorthe Varning; Stigsdottir, Ulrika S.

    2015-01-01

    Using horticultural activities and nature experiences to aid the recovery of returning soldiers has a long history. An increasing number of practical experiences and a few research studies confirm the fact that it may well be beneficial. A review by Varning Poulsen et al. (Under review) describes......, based on evidence and practical experience, to develop a transparent nature-based treatment program for war veterans suffering from PTSD. The treatment took place at the University of Copenhagen’s forest therapy garden. A qualitative research study documented and investigated the project. The lessons...

  4. Natural language modeling

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, J.K. [Sandia National Labs., Albuquerque, NM (United States)

    1997-11-01

    This seminar describes a process and methodology that uses structured natural language to enable the construction of precise information requirements directly from users, experts, and managers. The main focus of this natural language approach is to create the precise information requirements and to do it in such a way that the business and technical experts are fully accountable for the results. These requirements can then be implemented using appropriate tools and technology. This requirement set is also a universal learning tool because it has all of the knowledge that is needed to understand a particular process (e.g., expense vouchers, project management, budget reviews, tax, laws, machine function).

  5. Nature of Human Rights

    Directory of Open Access Journals (Sweden)

    Carlos López Dawson

    2016-07-01

    Full Text Available In the formation of a new Constitution the constituents will require to know or reach an agreement on the nature of human rights; then, to determine how the State will enforce the respect to those rights. To do so, it is necessary to resort to the history and evolution of these rights, and the present work aims to contribute to an efficient productive debate about the nature of human rights, so that citizens can decide on the understanding that this is a thoughtful democratic and humanistic founded decision. The analysis is in the actual technical-ideological republican system which correspond to the current state of international law

  6. Natural gas for vehicles

    International Nuclear Information System (INIS)

    Tissot-Favre, V.; Sudour, D.; Binutti, M.; Zanetta, P.; Rieussec, J.L.

    2005-01-01

    As a true alternative to oil products, and environment friendly fuel, Natural Gas for Vehicles complies with requirements for sustainable development. In addition, it is part of the European Union policy which underlines the importance of energy diversification through alternative fuels. This workshop will look into the current offer to the public transport segment, waste collection vehicles, and commercial vehicle fleets. Actions taken to spread the use of natural gas to all types of cars will also be covered. This article gathers 5 presentations about this topic given at the gas conference

  7. Enhance Nature Exploration with Technology

    Science.gov (United States)

    Holloway, Patricia; Mahan, Carol

    2012-01-01

    Kids and nature seem like a natural combination, but what was natural a generation ago is different today. Children are spending less time outdoors but continue to need nature for their physical, emotional, and mental development. This fact has led author Richard Louv to suggest that today's children are suffering from "nature-deficit disorder"…

  8. Patterns in natural systems

    NARCIS (Netherlands)

    Sewalt, L.

    2016-01-01

    In the thesis, `Patterns in natural systems’ the formation and evolution of patterns as solutions of several partial differential systems are studied. These mathematical systems model three different biological and ecological processes. First, the way that plankton concentrates in the water column,

  9. Natural history of COPD

    DEFF Research Database (Denmark)

    Vestbo, Jørgen; Lange, Peter

    2016-01-01

    The natural history of chronic obstructive pulmonary disease (COPD) is usually described with a focus on change in forced expiratory volume in 1 s (FEV1 ) over time as this allows for exploration of risk factors for an accelerated decline-and thus of developing COPD. From epidemiological studies we...

  10. THE NATURE OF COMPREHENSION.

    Science.gov (United States)

    CLELAND, DONALD L.

    THE NATURE OF COMPREHENSION IS DEFINED AND CLARIFIED. THE LITERATURE IS SURVEYED TO SHOW THAT THE DEVELOPMENT OF CONCEPTS IS IMPORTANT IN INTELLECTUAL ACTIVITIES. IT IS POINTED OUT THAT CONCEPTS ARE BUILT FROM PERCEPTS, IMAGES, SENSATION, AND MEMORIES, AND THAT THE STEPS WHICH ARE EMPLOYED AS CONCEPTS ARE BUILT AND REFINED AND INCLUDE PERCEIVING,…

  11. Cultivating human nature

    NARCIS (Netherlands)

    Derksen, Maarten

    2007-01-01

    Evolutionary psychology claims to offer a unified perspective on human nature and culture, which can serve to further the integration of psychology and the social sciences. I describe four approaches to evolutionary psychology, and note increasing attention to the agency of the individual in

  12. Reinventing Natural Selection

    Science.gov (United States)

    Geraedts, Caspar L.; Boersma, Kerst Th.

    2006-01-01

    Although many research studies report students' Lamarckian misconceptions, only a few studies present learning and teaching strategies that focus on the successful development of the concept of natural selection. The learning and teaching strategy for upper secondary students (aged 15-16) presented in this study conducted in The Netherlands is…

  13. Surfaces with Natural Ridges

    DEFF Research Database (Denmark)

    Brander, David; Markvorsen, Steen

    2015-01-01

    We discuss surfaces with singularities, both in mathematics and in the real world. For many types of mathematical surface, singularities are natural and can be regarded as part of the surface. The most emblematic example is that of surfaces of constant negative Gauss curvature, all of which...

  14. Natural attenuation of herbicides

    DEFF Research Database (Denmark)

    Tuxen, Nina; Højberg, Anker Lajer; Broholm, Mette Martina

    2002-01-01

    A field injection experiment in a sandy, aerobic aquifer showed that two phenoxy acids MCPP (mecoprop) and dichlorprop were degraded within I in downgradient of the injection wells after an apparent lag period. The plume development and microbial measurements indicated that microbial growth gover....... The observations may be important for application of natural attenuation as a remedy in field scale systems....

  15. Wasserpflanzen in der Natur

    DEFF Research Database (Denmark)

    Pedersen, Ole; Christensen, Claus

    2011-01-01

    Unsere Aquarienpflanzen kommen in der Natur vor oder sind Zuchtformen natürlicher Arten. Dennoch konnten erst sehr wenige Aquarianer diese Pflanzen in ihrer natürlichen Umgebung beobachten. Oft stellten sie fest, dass die Pflanzen meist ganz anders aussehen als im Aquarium. Neben einem ständigen...

  16. Patagonia: nature and territories

    Directory of Open Access Journals (Sweden)

    Alejandro Fabián Schweitzer

    2014-12-01

    This paper analyzes the place occupied by Patagonia in today’s fin de siècle scenario of commodities, hegemony crisis and multi-polar world emergence concurring with the convergence of consumerist guidelines, all of which would apparently lead to an in-depth socio-ecological crisis as well as to an accelerated dispute over nature and territory sense.

  17. Nature teaching structures

    DEFF Research Database (Denmark)

    Wester, Ture

    2002-01-01

    -living nature a number of striking statical and kinematical peculiarities have been observed. The paper will try to isolate and describe some of these observations and their relation to our engineered structures based on human thinking. The paper will deal with basic aspects as geometry, topology, redundancy...

  18. Demystifying Nature of Science

    Science.gov (United States)

    Lederman, Judith; Bartels, Selina; Lederman, Norman; Gnanakkan, Dionysius

    2014-01-01

    With the emergence of the "Next Generation Science Standards" ("NGSS"; NGSS Lead States 2013), it is apparent that teaching and learning about nature of science (NOS) continues to be an important goal of science education for all K-12 students. With this emphasis on NOS, early childhood teachers are asking how to design…

  19. Radioactivity: A Natural Phenomenon.

    Science.gov (United States)

    Ronneau, C.

    1990-01-01

    Discussed is misinformation people have on the subject of radiation. The importance of comparing artificial source levels of radiation to natural levels is emphasized. Measurements of radioactivity, its consequences, and comparisons between the risks induced by radiation in the environment and from artificial sources are included. (KR)

  20. Natural gas industry regulations

    International Nuclear Information System (INIS)

    Clo, A.

    1999-01-01

    In the reception of the EU Directive on the internal gas market, it is quite necessary to avoid the mistakes already made in the case of electricity. A possible cause is there suggested which may help rearrange the natural gas industry and market in Italy. It's four points are: general interests, national peculiarities, public policies, regulatory framework [it

  1. How Is Nature Asymmetric?

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 6. How Is Nature Asymmetric? - Discrete Symmetries in Particle Physics and their Violation ... Indian Institute of Technology, Chennai. Aligarh Muslim University. University of Rajasthan, Jaipur. Indian Institute of Science, Bangalore 560012, India.

  2. Natural radiation environment III

    International Nuclear Information System (INIS)

    Gesell, T.F.; Lowder, W.M.

    1980-01-01

    Separate abstracts were prepared for the 52 research papers presented at this symposium in April 1978. The major topics in this volume deal with penetrating radiation measurements, radiation surveys and population exposure, radioactivity in the indoor environment, and technologically enhanced natural radioactivity

  3. Natural radiation environment III

    International Nuclear Information System (INIS)

    Gesell, T.F.; Lowder, W.M.

    1980-01-01

    Separate abstracts were prepared for the 57 research papers presented at this symposium in April 1978 at Houston, Texas. This symposium provided a common forum for scientists in several disciplines that deal with natural radiation because there is an increasing interest in the environment as it pertains to human health and the competition for scarce energy and material resources

  4. SUIKERBOSRAND NATURE RESERVE

    African Journals Online (AJOL)

    reserve, the total length being 66 km with six overnight huts. There are also the BokmakiePie. Nature Troil. and the Cheetah Interpretive Troil. which can be used by day visitors. The former has two loops, one of 10 km and another of 17 km. The. Cheetah Troil. is much shorter and various points of interest are interpreted en ...

  5. Rehabilitating Afghanistan's natural resources

    Science.gov (United States)

    George Hernandez

    2011-01-01

    The Soviet Union invaded Afghanistan in late 1979. During the next 23 years, the war between the Mujahideen Resistance and the Soviet forces, the ensuing civil war, and eventual take over by the Taliban caused enormous harm to the natural resources of Afghanistan. In 2003, the USDA Forest Service (USFS) was asked by the USDA Foreign Agricultural Service to provide...

  6. Sciences & Nature: Site Map

    African Journals Online (AJOL)

    Journal Home · Journals · Sciences & Nature · About · Log In · Register · Advanced Search · By Author · By Title. Issues. Current Issue · Archives · Open Journal Systems · Help. ISSN: 1812-0741. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL ...

  7. Nature remedies human damage

    International Nuclear Information System (INIS)

    Heikkonen, H.

    1994-01-01

    Ecolution Ltd puts its emphasis on technologies which use nature's own methods. This technology is best suited to the bioremediation of old industrial sites, saw mills or oil- contaminated areas. The results of biopurification are consistently good and, in comparison with burning, the costs are low

  8. Shooting mechanisms in nature

    NARCIS (Netherlands)

    Sakes, Aimée; Wiel, van der Marleen; Henselmans, Paul W.J.; Leeuwen, van Johan L.; Dodou, Dimitra; Breedveld, Paul

    2016-01-01

    Background In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working principles of shooting mechanisms in fungi, plants, and animals in the light of the specific functional demands that these

  9. Venezuela natural gas outlook

    International Nuclear Information System (INIS)

    Silva, P.

    1991-01-01

    This paper reports on the natural gas outlook for Venezuela. First of all, it is very important to remember that in the last few years we have had frequent and unforeseen changes in the energy, ecological, geopolitical and economical fields which explain why all the projections of demand and prices for hydrocarbons and their products have failed to predict what later would happen in the market. Natural gas, with its recognized advantages over other traditional competitors such as oil, coal and nuclear energy, is identified as the component that is acquiring more weight in the energy equation, with a strengthening projection, not only as a resource that covers demand but as a key element in the international energy business. In fact, natural gas satisfies 21% of overall worldwide energy consumption, with an annual increase of 2.7% over the last few years, which is higher than the global energy growth of other fossil fuels. This tendency, which dates from the beginning of the 1980's, will continue with a possibility of increasing over the coming years. Under a foreseeable scenario, it is estimated that worldwide use of natural gas will increase 40% over the next 10 years and 75% on a longer term. Specifically for liquid methane (LNG), use should increase 60% during this last decade. The LPG increase should be moderate due to the limited demand until 1995 and to the stable trends that will continue its use until the end of this century

  10. Knowledge and Natural Resources

    DEFF Research Database (Denmark)

    Bertelsen, Rasmus Gjedssø; Justinussen, Jens Christian Svabo

    2016-01-01

    Arctic economies are generally natural resource based economies, whether they are indigenous economies largely dependent on living on the land or industrialized economies depending on marine resources, mineral resources or fossil or renewable energy resources. However, the central role of knowledge...

  11. Natural gas annual 1992

    International Nuclear Information System (INIS)

    1993-01-01

    This document provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. This report, Volume 2, presents historical data for the Nation from 1930 to 1992, and by State from 1967 to 1992. The Supplement of this report presents profiles of selected companies

  12. Nature in the City.

    Science.gov (United States)

    Melber, Leah W.

    2000-01-01

    Presents three science activities targeted to help urban students learn about nature: (1) observing coloration patterns of pigeons; (2) measuring local rainfall and comparing it to other areas; and (3) conducting a biodiversity study by observing a patch of lawn. (YDS)

  13. A new nature

    DEFF Research Database (Denmark)

    Abraham, Anders

    ”A New Nature - 9 ARCHITECTURAL CONDITIONS BETWEEN LIQUID AND SOLID” opbygger en tankegang om arkitektur som tilstande i modsætning til arkitektur som form og type.  Ved at se på verden som tilstande og organiseringer mellem ”flydende” og ”fast”, homogent og heterogent m.v., er det muligt...

  14. Nature Identical Prosody

    DEFF Research Database (Denmark)

    Juel Henrichsen, Peter

    2012-01-01

    ; such as low naturalness (DiSyn) and dependence on huge amounts of background data (UnitSyn). We present a hybrid model based on high-level speech data. As preliminary tests show, prosodic models combining DiSyn style at the phone level with UnitSyn style at the supra-segmental levels may approach Unit...

  15. Nature as Inspiration

    Science.gov (United States)

    Tank, Kristina; Moore, Tamara; Strnat, Meg

    2015-01-01

    This article describes the final lesson within a seven-day STEM and literacy unit that is part of the Picture STEM curriculum (pictureSTEM. org) and uses engineering to integrate science and mathematics learning in a meaningful way (Tank and Moore 2013). For this engineering challenge, students used nature as a source of inspiration for designs to…

  16. Nature, Education and Things

    Science.gov (United States)

    Rømer, Thomas Aastrup

    2013-01-01

    In this essay it is argued that the educational philosophy of John Dewey gains in depth and importance by being related to his philosophy of nature, his metaphysics. The result is that any experiental process is situated inside an event, an existence, a thing, and I try to interpret this "thing" as schools or major cultural events such…

  17. Logic and Natural selection

    Czech Academy of Sciences Publication Activity Database

    Peregrin, Jaroslav

    2010-01-01

    Roč. 4, č. 2 (2010), s. 207-223 ISSN 1661-8297 R&D Projects: GA ČR(CZ) GAP401/10/1279 Institutional research plan: CEZ:AV0Z9009908 Keywords : logic * natural selection * modus potens * inferentialism Subject RIV: AA - Philosophy ; Religion

  18. New force in nature?

    International Nuclear Information System (INIS)

    Fischbach, E.; Sudarsky, D.; Szafer, A.; Talmadge, C.; Aronson, S.H.

    1986-01-01

    We review recent experimental and theoretical work dealing with the proposed fifth force. Further analysis of the original Eoetvoes experiments has uncovered no challenges to our original assertion that these data evidence a correlation characteristic of the presence of a new coupling to baryon number or hypercharge. Various models suggest that the proposed fifth force could be accomodated naturally into the existing theoretical framework

  19. Natural hazards science strategy

    Science.gov (United States)

    Holmes, Robert R.; Jones, Lucile M.; Eidenshink, Jeffery C.; Godt, Jonathan W.; Kirby, Stephen H.; Love, Jeffrey J.; Neal, Christina A.; Plant, Nathaniel G.; Plunkett, Michael L.; Weaver, Craig S.; Wein, Anne; Perry, Suzanne C.

    2012-01-01

    The mission of the U.S. Geological Survey (USGS) in natural hazards is to develop and apply hazard science to help protect the safety, security, and economic well-being of the Nation. The costs and consequences of natural hazards can be enormous, and each year more people and infrastructure are at risk. USGS scientific research—founded on detailed observations and improved understanding of the responsible physical processes—can help to understand and reduce natural hazard risks and to make and effectively communicate reliable statements about hazard characteristics, such as frequency, magnitude, extent, onset, consequences, and where possible, the time of future events.To accomplish its broad hazard mission, the USGS maintains an expert workforce of scientists and technicians in the earth sciences, hydrology, biology, geography, social and behavioral sciences, and other fields, and engages cooperatively with numerous agencies, research institutions, and organizations in the public and private sectors, across the Nation and around the world. The scientific expertise required to accomplish the USGS mission in natural hazards includes a wide range of disciplines that this report refers to, in aggregate, as hazard science.In October 2010, the Natural Hazards Science Strategy Planning Team (H–SSPT) was charged with developing a long-term (10-year) Science Strategy for the USGS mission in natural hazards. This report fulfills that charge, with a document hereinafter referred to as the Strategy, to provide scientific observations, analyses, and research that are critical for the Nation to become more resilient to natural hazards. Science provides the information that decisionmakers need to determine whether risk management activities are worthwhile. Moreover, as the agency with the perspective of geologic time, the USGS is uniquely positioned to extend the collective experience of society to prepare for events outside current memory. The USGS has critical statutory

  20. Natural products as photoprotection.

    Science.gov (United States)

    Saewan, Nisakorn; Jimtaisong, Ampa

    2015-03-01

    The rise in solar ultraviolet radiation on the earth's surface has led to a depletion of stratospheric ozone over recent decades, thus accelerating the need to protect human skin against the harmful effects of UV radiation such as erythema, edema, hyperpigmentation, photoaging, and skin cancer. There are many different ways to protect skin against UV radiation's harmful effects. The most popular way to reduce the amount of UV radiation penetrating the skin is topical application of sunscreen products that contain UV absorbing or reflecting active molecules. Based on their protection mechanism, the active molecules in sunscreens are broadly divided into inorganic and organic agents. Inorganic sunscreens reflect and scatter UV and visible radiation, while organic sunscreens absorb UV radiation and then re-emit energy as heat or light. These synthetic molecules have limited concentration according to regulation concern. Several natural compounds with UV absorption property have been used to substitute for or to reduce the quantity of synthetic sunscreen agents. In addition to UV absorption property, most natural compounds were found to act as antioxidants, anti-inflammatory, and immunomodulatory agents, which provide further protection against the damaging effects of UV radiation exposure. Compounds derived from natural sources have gained considerable attention for use in sunscreen products and have bolstered the market trend toward natural cosmetics. This adds to the importance of there being a wide selection of active molecules in sunscreen formulations. This paper summarizes a number of natural products derived from propolis, plants, algae, and lichens that have shown potential photoprotection properties against UV radiation exposure-induced skin damage. © 2015 Wiley Periodicals, Inc.

  1. Immigration, social cohesion, and naturalization

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2010-01-01

    social trust do not connect with issues of naturalization at all. Other conceptions of social cohesion are either politically controversial, problematic as part of the justification of stricter naturalization requirements, or in fact justify less demanding naturalization requirements....

  2. Design, science and naturalism

    Science.gov (United States)

    Deming, David

    2008-09-01

    The Design Argument is the proposition that the presence of order in the universe is evidence for the existence of God. The Argument dates at least to the presocratic Greek philosophers, and is largely based on analogical reasoning. Following the appearance of Aquinas' Summa Theologica in the 13th century, the Christian Church in Europe embraced a Natural Theology based on observation and reason that allowed it to dominate the entire world of knowledge. Science in turn advanced itself by demonstrating that it could be of service to theology, the recognized queen of the sciences. During the heyday of British Natural Theology in the 17th and 18th centuries, the watchmaker, shipbuilder, and architect analogies were invoked reflexively by philosophers, theologians, and scientists. The Design Argument was not systematically and analytically criticized until David Hume wrote Dialogues on Natural Religion in the 1750s. After Darwin published Origin of Species in 1859, Design withered on the vine. But in recent years, the Argument has been resurrected under the appellation "intelligent design," and been the subject of political and legal controversy in the United States. Design advocates have argued that intelligent design can be formulated as a scientific hypothesis, that new scientific discoveries validate a design inference, and that naturalism must be removed as a methodological requirement in science. If science is defined by a model of concentric epistemological zonation, design cannot be construed as a scientific hypothesis because it is inconsistent with the core aspects of scientific methodology: naturalism, uniformity, induction, and efficient causation. An analytical examination of claims by design advocates finds no evidence of any type to support either scientific or philosophical claims that design can be unambiguously inferred from nature. The apparent irreducible complexity of biological mechanisms may be explained by exaptation or scaffolding. The argument

  3. Natural light illumination system.

    Science.gov (United States)

    Whang, Allen Jong-Woei; Chen, Yi-Yung; Yang, Shu-Hua; Pan, Po-Hsuan; Chou, Kao-Hsu; Lee, Yu-Chi; Lee, Zong-Yi; Chen, Chi-An; Chen, Cheng-Nan

    2010-12-10

    In recent years, green energy has undergone a lot of development and has been the subject of many applications. Many research studies have focused on illumination with sunlight as a means of saving energy and creating healthy lighting. Natural light illumination systems have collecting, transmitting, and lighting elements. Today, most daylight collectors use dynamic concentrators; these include Sun tracking systems. However, this design is too expensive to be cost effective. To create a low-cost collector that can be easily installed on a large building, we have designed a static concentrator, which is prismatic and cascadable, to collect sunlight for indoor illumination. The transmission component uses a large number of optical fibers. Because optical fibers are expensive, this means that most of the cost for the system will be related to transmission. In this paper, we also use a prismatic structure to design an optical coupler for coupling n to 1. With the n-to-1 coupler, the number of optical fibers necessary can be greatly reduced. Although this new natural light illumination system can effectively guide collected sunlight and send it to the basement or to other indoor places for healthy lighting, previously there has been no way to manage the collected sunlight when lighting was not desired. To solve this problem, we have designed an optical switch and a beam splitter to control and separate the transmitted light. When replacing traditional sources, the lighting should have similar characteristics, such as intensity distribution and geometric parameters, to those of traditional artificial sources. We have designed, simulated, and optimized an illumination lightpipe with a dot pattern to redistribute the collected sunlight from the natural light illumination system such that it equals the qualities of a traditional lighting system. We also provide an active lighting module that provides lighting from the natural light illumination system or LED auxiliary

  4. Querying Natural Logic Knowledge Bases

    DEFF Research Database (Denmark)

    Andreasen, Troels; Bulskov, Henrik; Jensen, Per Anker

    2017-01-01

    This paper describes the principles of a system applying natural logic as a knowledge base language. Natural logics are regimented fragments of natural language employing high level inference rules. We advocate the use of natural logic for knowledge bases dealing with querying of classes...... in ontologies and class-relationships such as are common in life-science descriptions. The paper adopts a version of natural logic with recursive restrictive clauses such as relative clauses and adnominal prepositional phrases. It includes passive as well as active voice sentences. We outline a prototype...... for partial translation of natural language into natural logic, featuring further querying and conceptual path finding in natural logic knowledge bases....

  5. Hybrid Natural Inflation

    Science.gov (United States)

    Ross, Graham G.; Germán, Gabriel; Vázquez, J. Alberto

    2016-05-01

    We construct two simple effective field theory versions of Hybrid Natural Inflation (HNI) that illustrate the range of its phenomenological implications. The resulting inflationary sector potential, V = Δ4(1 + acos( ϕ/f)), arises naturally, with the inflaton field a pseudo-Nambu-Goldstone boson. The end of inflation is triggered by a waterfall field and the conditions for this to happen are determined. Also of interest is the fact that the slow-roll parameter ɛ (and hence the tensor r) is a non-monotonic function of the field with a maximum where observables take universal values that determines the maximum possible tensor to scalar ratio r. In one of the models the inflationary scale can be as low as the electroweak scale. We explore in detail the associated HNI phenomenology, taking account of the constraints from Black Hole production, and perform a detailed fit to the Planck 2015 temperature and polarisation data.

  6. Hybrid Natural Inflation

    International Nuclear Information System (INIS)

    Ross, Graham G.; Germán, Gabriel; Vázquez, J. Alberto

    2016-01-01

    We construct two simple effective field theory versions of Hybrid Natural Inflation (HNI) that illustrate the range of its phenomenological implications. The resulting inflationary sector potential, V=Δ"4(1+acos (ϕ/f)), arises naturally, with the inflaton field a pseudo-Nambu-Goldstone boson. The end of inflation is triggered by a waterfall field and the conditions for this to happen are determined. Also of interest is the fact that the slow-roll parameter ϵ (and hence the tensor r) is a non-monotonic function of the field with a maximum where observables take universal values that determines the maximum possible tensor to scalar ratio r. In one of the models the inflationary scale can be as low as the electroweak scale. We explore in detail the associated HNI phenomenology, taking account of the constraints from Black Hole production, and perform a detailed fit to the Planck 2015 temperature and polarisation data.

  7. Natural analogue working group

    International Nuclear Information System (INIS)

    Come, B.; Chapman, N.

    1986-01-01

    A Natural Analogue Working Group was established by the Commission of the European Communities in 1985. The purpose of this group is to bring together modellers with earth scientists and others, so that maximum benefit can be obtained from natural analogue studies with a view to safe geological disposal of radioactive waste. The first meeting of this group was held in Brussels from November 5 to 7, 1985. The discussions mainly concerned the identification of the modellers' needs and of the earth scientists' capacity to provide for them. Following the debates, a written statement was produced by the Group; this document forms the core of the present Report. Notes and outlines of many of the presentations made are grouped in four appendixes. The valuable contribution of all those involved in the meeting is gratefully acknowledged

  8. Natural Blue Food Colour

    DEFF Research Database (Denmark)

    Roda-Serrat, Maria Cinta

    In recent years, there has been a growing tendency to avoid the use of artificial colorants and additives in food products, especially after some studies linked their consumption with behavioural changes in children. However, the incorporation of colorants from natural origin remains a challenge...... for food technologists, as these are typically less vivid and less stable than their synthetic alternatives. Regarding blue colorants, phycocyanins from cyanobacteria are currently in the spotlight as promising new natural blue colorants. Phycocyanins are proteins which blue colour results from...... the presence of the chromophore phycocyanobilin (PCB), a covalently attached linear tetrapyrrole. The applications of phycocyanins as food colorants are however limited, as they show poor stability in certain conditions of pH, light and temperature. Cleavage of PCB from the protein followed by careful product...

  9. Epidemics after Natural Disasters

    Science.gov (United States)

    Gayer, Michelle; Connolly, Maire A.

    2007-01-01

    The relationship between natural disasters and communicable diseases is frequently misconstrued. The risk for outbreaks is often presumed to be very high in the chaos that follows natural disasters, a fear likely derived from a perceived association between dead bodies and epidemics. However, the risk factors for outbreaks after disasters are associated primarily with population displacement. The availability of safe water and sanitation facilities, the degree of crowding, the underlying health status of the population, and the availability of healthcare services all interact within the context of the local disease ecology to influence the risk for communicable diseases and death in the affected population. We outline the risk factors for outbreaks after a disaster, review the communicable diseases likely to be important, and establish priorities to address communicable diseases in disaster settings. PMID:17370508

  10. Challenging Exclusionary Naturalism

    Directory of Open Access Journals (Sweden)

    Nathan Robert Cockram

    2014-03-01

    Full Text Available The purpose of this paper is to reconstruct Hilary Kornblith’s (2002 argument for excluding conceptual analysis from epistemological inquiry, and then provide three objections to it. More specifically, Kornblith argues that epistemological properties such as ‘knowledge’ reduce to natural kinds (with a constitutive essence which can only be discovered and investigated using the a posteriori methods of the natural sciences. Thus, he continues, conceptual analysis can’t properly illuminate the target domain. The three objections to Kornblith’s argument which I present are as follows: (i Multiple Realizeability, (ii Psychological Explanation, (iii Starting Points. On strength of these objections, I conclude that Kornblith’s brand of a posteriori epistemology both eliminates our ability to make epistemic evaluations in general, and also implies a strong form of scepticism.

  11. Oil and natural gas

    International Nuclear Information System (INIS)

    Riddell, C.H.

    1993-01-01

    The natural gas industry and market prospects in Canada are reviewed from a producer's point of view. In the first eight months of 1993, $2.3 billion in new equity was raised for natural gas exploration and production, compared to $900 million in 1991 and $1.2 billion in 1992. The number of wells drilled in the western Canada basin is expected to reach 8,000-9,000 in 1993, up from 5,600 in 1992, and Canadian producers' share of the North American natural gas market will probably reach 20% in 1993, up from 13% in 1986. Potential and proved gas supply in North America is ca 750 trillion ft 3 , of which ca 30% is in Canada. Factors affecting gas producers in Canada are the deregulated nature of the market, low costs for finding gas (finding costs in the western Canada basin are the lowest of any basin in North America), and the coming into balance of gas supply and demand. The former gas surplus has been reduced by expanding markets and by low prices which reduced the incentive to find new reserves. This surplus is largely gone, and prices have started rising although they are still lower than the pre-deregulation prices. Progress is continuing toward an integrated North American gas market in which a number of market hubs allow easy gas trading between producers and consumers. Commodity exchanges for hedging gas prices are beginning operation and electronic trading of gas contracts and pipeline capacity will also become a reality. 4 figs

  12. Natural SUSY endures

    Energy Technology Data Exchange (ETDEWEB)

    Papucci, Michele; Ruderman, Joshua T. [Lawrence Berkeley National Laboratory, CA (United States). Theoretical Physics Group; California Univ., Berkeley, CA (United States). Dept. of Physics; Weiler, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); European Organization for Nuclear Research, Geneva (Switzerland). Theoretical Physics Div.

    2011-10-31

    The first 1 fb{sup -1} of LHC searches have set impressive limits on new colored particles decaying to missing energy. We address the implication of these searches for naturalness in supersymmetry (SUSY). General bottom-up considerations of natural electroweak symmetry breaking show that higgsinos, stops, and the gluino should not be too far above the weak scale. The rest of the spectrum, including the squarks of the first two generations, can be heavier and beyond the current LHC reach. We have used collider simulations to determine the limits that all of the 1 fb{sup -1} searches pose on higgsinos, stops, and the gluino. We find that stops and the left-handed sbottom are starting to be constrained and must be heavier than about 200-300 GeV when decaying to higgsinos. The gluino must be heavier than about 600-800 GeV when it decays to stops and sbottoms. While these findings point toward scenarios with a lighter third generation split from the other squarks, we do find that moderately-tuned regions remain, where the gluino is just above 1 TeV and all the squarks are degenerate and light. Among all the searches, jets plus missing energy and same-sign dileptons often provide the most powerful probes of natural SUSY. Overall, our results indicate that natural SUSY has survived the first 1 fb{sup -1} of data. The LHC is now on the brink of exploring the most interesting region of SUSY parameter space. (orig.)

  13. Harnessing natural ventilation benefits.

    Science.gov (United States)

    O'Leary, John

    2013-04-01

    Making sure that a healthcare establishment has a good supply of clean fresh air is an important factor in keeping patients, staff, and visitors, free from the negative effects of CO2 and other contaminants. John O'Leary of Trend Controls, a major international supplier of building energy management solutions (BEMS), examines the growing use of natural ventilation, and the health, energy-saving, and financial benefits, that it offers.

  14. Symbolic Natural Language Processing

    OpenAIRE

    Laporte , Eric

    2005-01-01

    The connection between language processing and combinatorics on words is natural. Historically, linguists actually played a part in the beginning of the construction of theoretical combinatorics on words. Some of the terms in current use originate from linguistics: word, prefix, suffix, grammar, syntactic monoid... However, interpenetration between the formal world of computer theory and the intuitive world of linguistics is still a love story with ups and downs. We will encounter in this cha...

  15. Nature's Greatest Puzzles

    International Nuclear Information System (INIS)

    Quigg, Chris

    2005-01-01

    It is a pleasure to be part of the SLAC Summer Institute again, not simply because it is one of the great traditions in our field, but because this is a moment of great promise for particle physics. I look forward to exploring many opportunities with you over the course of our two weeks together. My first task in talking about Nature's Greatest Puzzles, the title of this year's Summer Institute, is to deconstruct the premise a little bit

  16. Natural matrix standards

    International Nuclear Information System (INIS)

    Bowen, V.T.

    1976-01-01

    Environmental radiochemistry needs, for use in analytical intercomparision and as standard reference materials, very large homogeneous samples of a variety of matrices, each naturally contaminated by a variety of longer-lived radionuclides, at several different ranges of concentrations. The reasons for this need are discussed, and the minimum assortment of matrices of radionuclides, and of concentrations is established. Sources of suitable materials are suggested, and the international approach to meeting this need is emphasized

  17. Extremes in nature

    CERN Document Server

    Salvadori, Gianfausto; Kottegoda, Nathabandu T

    2007-01-01

    This book is about the theoretical and practical aspects of the statistics of Extreme Events in Nature. Most importantly, this is the first text in which Copulas are introduced and used in Geophysics. Several topics are fully original, and show how standard models and calculations can be improved by exploiting the opportunities offered by Copulas. In addition, new quantities useful for design and risk assessment are introduced.

  18. Intoxication with natural sources

    International Nuclear Information System (INIS)

    Toropilova, D.; Toropila, M.; Tomko, M.; Takac, L.; Fric, M.

    2015-01-01

    The authors of this article deal with intoxication of the organism with natural resources. As objects of our interest we chose some interchangeable types of fungi which cause severe intoxication of gastrointestinal tract: Scleroderma citrinum, Boletus luridus var. rubriceps (Maire) Dermek, Boletus satanas, Agaricus xanthodermus and poisonous plants affect mainly digestive tract such as Sambucus nigra L. (elderberry). Sambucus ebulus L. (European dwarf elder), Viburnum lantana L. (wayfaring tree), Viburnum opulus (guelder-rose), Rhamnus cathartica (purging buckthorn).

  19. Natural radiation exposure indoors

    International Nuclear Information System (INIS)

    Brown, L.; Cliff, K.D.; Wrixon, A.D.

    1981-01-01

    A brief review is presented of the state of knowledge of indoor natural radiation exposure in the U.K. and the current survey work the N.R.P.B. is carrying out in this field. Discussion is limited in this instance to the improvement in estimation of population exposure and the identification of areas and circumstances in which high exposure occur, rather than the study of properties of a building and methods of building affecting exposure to radiation. (U.K.)

  20. The nature of leadership

    OpenAIRE

    2012-01-01

    With contributions from leading authors in the most important areas of current research, this book provides insight into the streams that are driving leadership theory and practice today. The Nature of Leadership, Second Edition provides students with an updated and complete yet concise handbook that solidifies and integrates the vast and disparate leadership literature.Key Features of the Second Edition· Provides contributions from twenty-three subject-matter experts-ranging from the eminent...

  1. Microflyers: inspiration from nature

    Science.gov (United States)

    Sirohi, Jayant

    2013-04-01

    Over the past decade, there has been considerable interest in miniaturizing aircraft to create a class of extremely small, robotic vehicles with a gross mass on the order of tens of grams and a dimension on the order of tens of centimeters. These are collectively refered to as micro aerial vehicles (MAVs) or microflyers. Because the size of microflyers is on the same order as that of small birds and large insects, engineers are turning to nature for inspiration. Bioinspired concepts make use of structural or aerodynamic mechanisms that are observed in insects and birds, such as elastic energy storage and unsteady aerodynamics. Biomimetic concepts attempt to replicate the form and function of natural flyers, such as flapping-wing propulsion and external appearance. This paper reviews recent developments in the area of man-made microflyers. The design space for microflyers will be described, along with fundamental physical limits to miniaturization. Key aerodynamic phenomena at the scale of microflyers will be highlighted. Because the focus is on bioinspiration and biomimetics, scaled-down versions of conventional aircraft, such as fixed wing micro air vehicles and microhelicopters will not be addressed. A few representative bioinspired and biomimetic microflyer concepts developed by researchers will be described in detail. Finally, some of the sensing mechanisms used by natural flyers that are being implemented in man-made microflyers will be discussed.

  2. Petroleum and natural gas

    Energy Technology Data Exchange (ETDEWEB)

    060,

    1965-02-01

    Substantial increases in demand for Canadian petroleum and natural gas in both domestic and export markets resulted in another good year throughout the main sectors of the industry. In February, production averaged 850,000 bpd, or about 8% more than 1963 output of crude oil and natural gas liquids. Construction began on the first full scale plant for the extraction of oil from the Athabasca bituminous sands. In 1964, exploratory and development drilling in western Canada increased 10% from the previous year. A total of 15.5 million ft was drilled, the largest since the record drilling year of 1956. The main oil field development areas in Alberta were the House Mountain, Deer Mountain and Goose River Fields, and the Bantry-Taber heavy oil region in southeastern Alberta. Oil reserves were increased substantially by waterflood pressure maintenance projects in many of the older oil fields. The largest oil accumulation discovered in 1964 was the Syvia-Honda Field in the Devonian Gilwood sandstone in N.-central Alberta. Two graphs illustrate the crude petroleum in Canada in millions of barrels from 1940 to 1964, and natural gas in Canada in billions of cu ft from 1950 to 1964. The outlook for the industry in 1965 is good.

  3. NATURAL RESOURCES ASSESSMENT

    International Nuclear Information System (INIS)

    D.F. Fenster

    2000-01-01

    The purpose of this report is to summarize the scientific work that was performed to evaluate and assess the occurrence and economic potential of natural resources within the geologic setting of the Yucca Mountain area. The extent of the regional areas of investigation for each commodity differs and those areas are described in more detail in the major subsections of this report. Natural resource assessments have focused on an area defined as the ''conceptual controlled area'' because of the requirements contained in the U.S. Nuclear Regulatory Commission Regulation, 10 CFR Part 60, to define long-term boundaries for potential radionuclide releases. New requirements (proposed 10 CFR Part 63 [Dyer 1999]) have obviated the need for defining such an area. However, for the purposes of this report, the area being discussed, in most cases, is the previously defined ''conceptual controlled area'', now renamed the ''natural resources site study area'' for this report (shown on Figure 1). Resource potential can be difficult to assess because it is dependent upon many factors, including economics (demand, supply, cost), the potential discovery of new uses for resources, or the potential discovery of synthetics to replace natural resource use. The evaluations summarized are based on present-day use and economic potential of the resources. The objective of this report is to summarize the existing reports and information for the Yucca Mountain area on: (1) Metallic mineral and mined energy resources (such as gold, silver, etc., including uranium); (2) Industrial rocks and minerals (such as sand, gravel, building stone, etc.); (3) Hydrocarbons (including oil, natural gas, tar sands, oil shales, and coal); and (4) Geothermal resources. Groundwater is present at the Yucca Mountain site at depths ranging from 500 to 750 m (about 1,600 to 2,500 ft) below the ground surface. Groundwater resources are not discussed in this report, but are planned to be included in the hydrology

  4. NATURAL RESOURCES ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    D.F. Fenster

    2000-12-11

    The purpose of this report is to summarize the scientific work that was performed to evaluate and assess the occurrence and economic potential of natural resources within the geologic setting of the Yucca Mountain area. The extent of the regional areas of investigation for each commodity differs and those areas are described in more detail in the major subsections of this report. Natural resource assessments have focused on an area defined as the ''conceptual controlled area'' because of the requirements contained in the U.S. Nuclear Regulatory Commission Regulation, 10 CFR Part 60, to define long-term boundaries for potential radionuclide releases. New requirements (proposed 10 CFR Part 63 [Dyer 1999]) have obviated the need for defining such an area. However, for the purposes of this report, the area being discussed, in most cases, is the previously defined ''conceptual controlled area'', now renamed the ''natural resources site study area'' for this report (shown on Figure 1). Resource potential can be difficult to assess because it is dependent upon many factors, including economics (demand, supply, cost), the potential discovery of new uses for resources, or the potential discovery of synthetics to replace natural resource use. The evaluations summarized are based on present-day use and economic potential of the resources. The objective of this report is to summarize the existing reports and information for the Yucca Mountain area on: (1) Metallic mineral and mined energy resources (such as gold, silver, etc., including uranium); (2) Industrial rocks and minerals (such as sand, gravel, building stone, etc.); (3) Hydrocarbons (including oil, natural gas, tar sands, oil shales, and coal); and (4) Geothermal resources. Groundwater is present at the Yucca Mountain site at depths ranging from 500 to 750 m (about 1,600 to 2,500 ft) below the ground surface. Groundwater resources are not discussed in this

  5. Defining Nature-Based Preschools

    Science.gov (United States)

    Larimore, Rachel

    2016-01-01

    Nature-based early childhood education. Nature-based preschool. Nature preschool. Forest kindergarten. Nature kindergarten. Waldkindergarten. Forest school. These are a few of the program terms currently being discussed among early childhood environmental education professionals in the United States. Why is there so much discussion about the names…

  6. Nature, Nurture and Epigenetics

    Science.gov (United States)

    Crews, David; Gillette, Ross; Miller-Crews, Isaac; Gore, Andrea C.; Skinner, Michael K.

    2015-01-01

    Real life by definition combines heritability (e.g., the legacy of exposures) and experience (e.g. stress during sensitive or ‘critical’ periods), but how to study or even model this interaction has proven difficult. The hoary concept of evaluating traits according to nature vs. nurture continues to persist despite repeated demonstrations that it retards, rather than advances, our understanding of biological processes. Behavioral genetics has proven the obvious, that genes influences behavior and, vice versa, that behavior influences genes. The concept of Genes X Environment (G X E) and its modern variants was viewed as an improvement on nature-nurture but has proven that, except in rare instances, it is not possible to fractionate phenotypes into these constituent elements. The entanglement inherent in terms such as nature-nurture or GXE is a Gordian knot that cannot be dissected or even split. Given that the world today is not what it was less than a century ago, yet the arbitrator (differential survival and reproduction) has stayed constant, de novo principles and practices are needed to better predict what the future holds. Put simply, the transformation that is now occurring within and between individuals as a product of global endocrine disruption is quite independent of what has been regarded as evolution by selection. This new perspective should focus on how epigenetic modifications might revise approaches to understand how the phenotype and, in particular its components, is shaped. In this review we summarize the literature in this developing area, focusing on our research on the fungicide vinclozolin. PMID:25102229

  7. Nature, nurture and epigenetics.

    Science.gov (United States)

    Crews, David; Gillette, Ross; Miller-Crews, Isaac; Gore, Andrea C; Skinner, Michael K

    2014-12-01

    Real life by definition combines heritability (e.g., the legacy of exposures) and experience (e.g. stress during sensitive or 'critical' periods), but how to study or even model this interaction has proven difficult. The hoary concept of evaluating traits according to nature versus nurture continues to persist despite repeated demonstrations that it retards, rather than advances, our understanding of biological processes. Behavioral genetics has proven the obvious, that genes influence behavior and, vice versa, that behavior influences genes. The concept of Genes X Environment (G X E) and its modern variants was viewed as an improvement on nature-nurture but has proven that, except in rare instances, it is not possible to fractionate phenotypes into these constituent elements. The entanglement inherent in terms such as nature-nurture or G X E is a Gordian knot that cannot be dissected or even split. Given that the world today is not what it was less than a century ago, yet the arbitrator (differential survival and reproduction) has stayed constant, de novo principles and practices are needed to better predict what the future holds. Put simply, the transformation that is now occurring within and between individuals as a product of global endocrine disruption is quite independent of what has been regarded as evolution by selection. This new perspective should focus on how epigenetic modifications might revise approaches to understand how the phenotype and, in particular its components, is shaped. In this review we summarize the literature in this developing area, focusing on our research on the fungicide vinclozolin. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Why Nature Chose Selenium.

    Science.gov (United States)

    Reich, Hans J; Hondal, Robert J

    2016-04-15

    The authors were asked by the Editors of ACS Chemical Biology to write an article titled "Why Nature Chose Selenium" for the occasion of the upcoming bicentennial of the discovery of selenium by the Swedish chemist Jöns Jacob Berzelius in 1817 and styled after the famous work of Frank Westheimer on the biological chemistry of phosphate [Westheimer, F. H. (1987) Why Nature Chose Phosphates, Science 235, 1173-1178]. This work gives a history of the important discoveries of the biological processes that selenium participates in, and a point-by-point comparison of the chemistry of selenium with the atom it replaces in biology, sulfur. This analysis shows that redox chemistry is the largest chemical difference between the two chalcogens. This difference is very large for both one-electron and two-electron redox reactions. Much of this difference is due to the inability of selenium to form π bonds of all types. The outer valence electrons of selenium are also more loosely held than those of sulfur. As a result, selenium is a better nucleophile and will react with reactive oxygen species faster than sulfur, but the resulting lack of π-bond character in the Se-O bond means that the Se-oxide can be much more readily reduced in comparison to S-oxides. The combination of these properties means that replacement of sulfur with selenium in nature results in a selenium-containing biomolecule that resists permanent oxidation. Multiple examples of this gain of function behavior from the literature are discussed.

  9. NATURAL ANALOGUE SYNTHESIS REPORT

    International Nuclear Information System (INIS)

    Simmons, A.M.

    2004-01-01

    The purpose of this report is to present analogue studies and literature reviews designed to provide qualitative and quantitative information to test and provide added confidence in process models abstracted for performance assessment (PA) and model predictions pertinent to PA. This report provides updates to studies presented in the Yucca Mountain Site Description (CRWMS M and O 2000 [151945], Section 13) and new examples gleaned from the literature along with results of quantitative studies conducted specifically for the Yucca Mountain Project (YMP). The intent of the natural analogue studies was to collect corroborative evidence from analogues to demonstrate additional understanding of processes expected to occur during postclosure at a potential Yucca Mountain repository. The report focuses on key processes by providing observations and analyses of natural and anthropogenic (human-induced) systems to improve understanding and confidence in the operation of these processes under conditions similar to those that could occur in a nuclear waste repository. The process models include those that represent both engineered and natural barrier processes. A second purpose of this report is to document the various applications of natural analogues to geologic repository programs, focusing primarily on the way analogues have been used by the YMP. This report is limited to providing support for PA in a confirmatory manner and to providing corroborative inputs for process modeling activities. Section 1.7 discusses additional limitations of this report. Key topics for this report are analogues to emplacement-drift degradation, waste-form degradation, waste-package degradation, degradation of other materials proposed for the engineered barrier, seepage into drifts, radionuclide flow and transport in the unsaturated zone (UZ), analogues to coupled thermal-hydrologic-mechanical-chemical processes, saturated-zone (SZ) transport, impact of radionuclide release on the biosphere

  10. Liquid Natural Gas

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    After a brief introduction on the origins of the Liquid Natural Gas (LNG) industry the production and transportation of LNG are discussed. Special attention is paid to the importance of the safety aspect during every activity or handling of LNG. Next the most important trade flows for LNG are dealt with. Two zones can be distinguished: the western part of the Pacific and the Atlantic basin. Subsequently the main aspects of a LNG-project are mentioned, as well as the success factors. Finally the prospects for the LNG-industry are reviewed. 11 figs

  11. Natural Analogue Synthesis Report

    Energy Technology Data Exchange (ETDEWEB)

    A. M. Simmons

    2002-05-01

    The purpose of this report is to present analogue studies and literature reviews designed to provide qualitative and quantitative information to test and provide added confidence in process models abstracted for performance assessment (PA) and model predictions pertinent to PA. This report provides updates to studies presented in the ''Yucca Mountain Site Description'' (CRWMS M and O 2000 [151945], Section 13) and new examples gleaned from the literature, along with results of quantitative studies conducted specifically for the Yucca Mountain Site Characterization Project (YMP). The intent of the natural analogue studies was to collect corroborative evidence from analogues to demonstrate additional understanding of processes expected to occur during postclosure at a potential Yucca Mountain repository. The report focuses on key processes by providing observations and analyses of natural and anthropogenic (human-induced) systems to improve understanding and confidence in the operation of these processes under conditions similar to those that could occur in a nuclear waste repository. The process models include those that represent both engineered and natural barrier processes. A second purpose of this report is to document the various applications of natural analogues to geologic repository programs, focusing primarily on the way analogues have been used by the YMP. This report is limited to providing support for PA in a confirmatory manner and to providing corroborative inputs for process modeling activities. Section 1.7 discusses additional limitations of this report. Key topics for this report are analogues to emplacement drift degradation, waste form degradation, waste package degradation, degradation of other materials proposed for the engineered barrier, seepage into drifts, radionuclide flow and transport in the unsaturated zone (UZ), analogues to coupled thermal-hydrologic-mechanical-chemical processes, saturated zone (SZ) transport

  12. The nature of mathematics

    CERN Document Server

    Jourdain, Philip E B

    2007-01-01

    Anyone with an interest in mathematics will welcome the republication of this little volume by a remarkable mathematician who was also a logician, a philosopher, and an occasional writer of fiction and poetry. Originally published in 1913, and later included in the acclaimed anthology The World of Mathematics, Jourdain's survey shows how and why the methods of mathematics were developed, traces the development of mathematical science from the earliest to modern times, and chronicles the application of mathematics to natural science.Starting with the ancient Egyptians and Greeks, the author p

  13. Thermoluminescence from natural calcites

    International Nuclear Information System (INIS)

    Calderon, T.; Jaque, F.; Coy-yll, R.

    1984-01-01

    Thermoluminescence (TL) as well as absorption and EPR spectra of x-irradiated natural calcites have been obtained. Irradiation produces UV absorption bands and a decrease of the Mn 2+ EPR spectrum. A correlation of each TL peak with the bleaching steps of UV absorption bands and the recovering in intensity of the Mn 2+ EPR spectrum has been found. These experimental results support a new model for the radiation damage and thermoluminescence process in calcites. The main point in this model is that holes become trapped at impurities, and the electrons are trapped at dislocations in the form of CO 3 3- . (author)

  14. Eksistens og natur

    DEFF Research Database (Denmark)

    Pahuus, Mogens

    Eksistens og Natur er et centralt stykke livsfilosofi skrevet af en af dansk filosofis grand old men. Professor emeritus fra Aalborg Universitet Mogens Pahuus præsenterer her den grundidé om mennesket, at ethvert individ er formet i en dobbelthed mellem det givne i os - naturen - og det, at vi fo...... forholder os til det givne - eksistensen. Mogens Pahuus sammenfatter i denne bog sin livsfilosofiske tænkning, og han tør give sig i kast med en stor og systematisk fremstilling af menneskets væsen. Bogen er et modent værk med overskud og overblik....

  15. Western Australian natural gas

    International Nuclear Information System (INIS)

    Harman, Frank

    1994-01-01

    Western Australia has 80% of Australia's natural gas resources. These are currently exploited to supply the Western Australian market and LNG to Japan. Growth in the market is dependent on limited prospects for power generation and mineral resource processing. Future exploitation of gas resources will require new export LNG markets and/or the installations of a transcontinental pipeline to eastern Australia. The transcontinental option should only be considered after other options for energy supply in eastern Australia are eliminated. Competition to meet market growth in North-east Asia will be considerable and Australia lacks the policies to underpin future LNG capacity. (author)

  16. Natural radio-exposure

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Although the amounts are small, man is exposed on a daily basis to alpha, beta, and gamma radiation emitted by radioactive elements present in the earth's crust. The natural radioactive elements are measurable, either by physicochemical means or by radiometric methods and can be the cause of external or internal exposure in man. Also of importance is cosmic radiation. Of galactic or solar origin, primary cosmic rays cause external radiation exposure. The majority of these particles disintegrate rapidly. They reach the ground at a mean rate of the order of one particle per square centimeter per minute

  17. Natural gas technology

    International Nuclear Information System (INIS)

    Todaro, J.M.; Herbert, J.H.

    1997-01-01

    This presentation is devoted to a discussion regarding current and planned US fossil energy research and development for fiscal years 1996, 1997 and 1998. The principal focus of research in the immediate future will be: clean coal fuels, natural gas and oil exploration and production, especially reservoir life extension, advanced drilling completion and stimulation systems, advanced diagnostics and imaging systems, environmental compliance in technology development, regulatory streamlining and risk assessment. Program goals to 2010 were summarized as: increasing domestic oil and gas recovery; increasing recoverable reserves; decreasing cumulative industry environmental compliance costs; increasing revenues to the federal government; saving jobs in the U.S

  18. Efeito da perda ponderal induzida pela cirurgia bariátrica sobre a prevalência de síndrome metabólica Efecto de la pérdida ponderal inducida por la cirugía bariátrica sobre la prevalencia de síndrome metabólico Effects of weight loss induced by bariatric surgery on the prevalence of metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Francisco das Chagas Monteiro Júnior

    2009-06-01

    Full Text Available FUNDAMENTO: A síndrome metabólica (SM está frequentemente ligada ao excesso de peso e melhora com a perda ponderal, sendo esperado que essa melhora seja proporcional à intensidade dessa perda. OBJETIVO: Avaliar o impacto da perda ponderal induzida pela cirurgia bariátrica (CB sobre a prevalência da SM, em médio prazo. MÉTODOS: Foram analisados 35 pacientes submetidos à cirurgia de by-pass gastrojejunal em Y de Roux, no período de outubro de 2001 a outubro de 2005, em nosso HU, sendo 88,5% do sexo feminino, com uma média de idade de 37,8±11,1 anos e um IMC médio de 45,0±6,2 kg/m². Na primeira etapa da pesquisa, foram obtidos dados demográficos e clínico-antropométricos antes da realização da CB, incluindo os critérios para o diagnóstico da SM, de acordo com as diretrizes do NCEP dos Estados Unidos. Na segunda etapa, os pacientes operados foram reavaliados ambulatorialmente quanto à prevalência da SM. RESULTADOS:Antes da cirurgia, a SM foi diagnosticada em 27 pacientes (77,1%. Em reavaliação 34,4±15 meses após a cirurgia, observou-se uma queda do IMC médio para 28,3±5,0 kg/m² e a SM foi detectada em apenas dois pacientes (5,7% (pFUNDAMENTO: El síndrome metabólico (SM frecuentemente está vinculado al exceso de peso y mejora con la pérdida ponderal, esperándose que esta mejora sea proporcional a la intensidad de esa pérdida. OBJETIVO: Evaluar el impacto de la pérdida ponderal inducida por la cirugía bariátrica (CB sobre la prevalencia de la SM, a medio plazo. MÉTODOS: Se estudiaron 35 pacientes sometidos a cirugía de bypass gastroyeyunal en Y de Roux, en el período de octubre de 2001 a octubre de 2005, en nuestro HU, siendo el 88,5% del sexo femenino, con un promedio de edades de 37,8±11,1 años y un IMC promedio de 45,0±6,2 Kg/m². En la primera etapa de la investigación, se obtuvieron datos demográficos y clínico antropométricos antes de la realización de la CB, incluyendo los criterios para el

  19. Natural gas; Erdgas

    Energy Technology Data Exchange (ETDEWEB)

    Graf, Frank [DVGW-Forschungsstelle am KIT, Karlsruhe (Germany); Groeschl, Frank; Wetzel, Uwe [DVGW, Bonn (Germany); Heikrodt, Klaus [Hochschule Ostwestfalen-Lippe, Lemgo (Germany); Krause, Hartmut [DBI Gastechnologisches Institut, An-Institut der TU Bergakademie, Freiberg (Germany); Beestermoeller, Christina; Witschen, Bernhard [Team Consult G.P.E. GmbH, Berlin (Germany); Albus, Rolf; Burmeister, Frank [Gas- und Waerme-Institut Essen e.V., Essen (Germany)

    2015-07-01

    The reform of the EEG in Germany, a positive global development in natural gas, the decline in oil prices, questions about the security of supply in Europe, and not least the effect of the decision by E.on at the end of 2014 have moved the gas industry. Gas has the lowest CO{sub 2} emissions of fossil fuels. Flexibility, storability, useful for networks and the diversity in the application make it an ideal partner for renewable energy. However, these complementary properties are valued at wind and photovoltaics internationally and nationally different. The situation in the gas power plants remains tense. LNG - liquefied natural gas - is on the rise. [German] Die Reform des EEG in Deutschland, eine positive Entwicklung beim Gas weltweit, der Verfall der Oelpreises, Fragen zur Versorgungssicherheit in Europa und nicht zuletzt die Auswirkung der Entscheidung von E.on Ende 2014 haben die Gaswirtschaft bewegt. Gas weist die geringsten CO{sub 2}-Emissioen der fossilen Energietraeger auf. Flexibilitaet, Speicherbarkeit, Netzdienlichkeit sowie die Vielfalt in der Anwendung machen es zum idealen Partner der erneuerbaren Energien. Allerdings werden diese komplementaeren Eigenschaften zu Wind und Photovoltaik international und national unterschiedlich bewertet. Die Lage bei den Gaskraftwerken bleibt weiter angespannt. LNG - verfluessigtes Erdgas - ist auf dem Vormarsch.

  20. CERN in "Nature"

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    CERN is nestled within a verdant natural environment which, thanks to a conservation-oriented policy, is characterized by a remarkable biodiversity. The continued protection of that diversity calls for thoughtful, carefully planned measures.   CERN’s site is an extensive one: its 650 hectares include 210 hectares of buildings, roadways and parking lots, 100 hectares of fenced-off green area, and 340 hectares of non-fenced land, a patchwork of fields, woods and pasture. This land teems with a great variety of plants and animals, including some rare and unexpected species. In 2009 CERN received a certificate from the Swiss foundation Nature & économie for the Meyrin site, and the award was renewed in 2012 for three more years. “The green spaces inside the fenced area are tended by six ISS gardeners, whose duties also include keeping the sidewalks and footpaths clear of snow in winter. The Meyrin site also includes orchid sanctuaries, meadows and sheep pasture...

  1. Natural Circulation with Boiling

    Energy Technology Data Exchange (ETDEWEB)

    Mathisen, R P

    1967-09-15

    A number of parameters with dominant influence on the power level at hydrodynamic instability in natural circulation, two-phase flow, have been studied experimentally. The geometrical dependent quantities were: the system driving head, the boiling channel and riser dimensions, the single-phase as well as the two phase flow restrictions. The parameters influencing the liquid properties were the system pressure and the test section inlet subcooling. The threshold of instability was determined by plotting the noise characteristics in the mass flow records against power. The flow responses to artificially obtained power disturbances at instability conditions were also measured in order to study the nature of hydrodynamic instability. The results presented give a review over relatively wide ranges of the main parameters, mainly concerning the coolant performance in both single and parallel boiling channel flow. With regard to the power limits the experimental results verified that the single boiling channel performance was intimately related to that of the parallel channels. In the latter case the additional inter-channel factors with attenuating effects were studied. Some optimum values of the parameters were observed.

  2. Natural and artificial photoprotection

    International Nuclear Information System (INIS)

    Cripps, D.J.

    1981-01-01

    A solar simulator is described with collimated filtered radiation incorporating an optical integrator to more evenly diffuse the xenon 2.5 KW light source. Populations can be catogorized into skin types I-VI and the minimal erythema dose (MED) in each skin type measured in Joules/cm2 was compared to give a relative suntan photoprotection factor or SPF compared with type I (1.0) so that type II had an SPF of 1.67, type III SPF of 2.5, type IV V had an SPF of nearly 4, whereas the darker Negroid skin (type VI) had an SPF of 9.68, or nearly 10 times that of type I. In addition, various studies were performed to determine the natural protection factor after natural sunlight (3 1/2 mo of summer sun). In 21 subjects the mean SPF was 2.33 when compared to the MED on unexposed skin on the buttocks. Five subjects who had received a mean total dose of 3.49 J/cm2 of UVB within a 4-week period had a mean SPF of 8.01 and 5 subjects who had received a mean total dose of 20 J/cm2 of UVA with PUVA therapy within 2 weeks had a mean SPF of 2.7. These studies were compared with the photoprotection ability of topical chemical protective agents with a range of 4-15

  3. En-gauging naturalness

    Energy Technology Data Exchange (ETDEWEB)

    Bharucha, Aoife [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Technische Univ. Muenchen, Garching (Germany). Physik-Dept. T31; Goudelis, Andreas [Savoie Univ., CNRS, Annecy-le-Vieux (France). LAPTh; McGarrie, Moritz [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-10-15

    The discovery of a 125.5 GeV Higgs with standard model-like couplings and naturalness considerations motivate gauge extensions of the MSSM. We analyse two variants of such an extension and carry out a phenomenological study of regions of the parameter space statisfying current direct and indirect constraints, employing state-of-the-art two-loop RGE evolution and GMSB boundary conditions. We find that due to the appearance of non-decoupled D-terms it is possible to obtain a 125.5 GeV Higgs with stops below 2 TeV, while the uncolored sparticles could still lie within reach of the LHC. We compare the contributions of the stop sector and the non-decoupled D-terms to the Higgs mass, and study their effect on the Higgs couplings. We further investigate the nature of the next-to lightest supersymmetric particle, in light of the GMSB motivated searches currently being pursued by ATLAS and CMS.

  4. En-gauging naturalness

    International Nuclear Information System (INIS)

    Bharucha, Aoife; Goudelis, Andreas; McGarrie, Moritz

    2014-01-01

    The discovery of a 125.5 GeV Higgs with standard model-like couplings and naturalness considerations motivate gauge extensions of the MSSM. We analyse two variants of such an extension and carry out a phenomenological study of regions of the parameter space satisfying current direct and indirect constraints, employing state-of-the-art two-loop RGE evolution and GMSB boundary conditions. We find that due to the appearance of non-decoupled D-terms it is possible to obtain a 125.5 GeV Higgs with stops below 2 TeV, while the uncoloured sparticles could still lie within reach of the LHC. We compare the contributions of the stop sector and the non-decoupled D-terms to the Higgs mass, and study their effect on the Higgs couplings. We further investigate the nature of the next-to lightest supersymmetric particle, in light of the GMSB motivated searches currently being pursued by ATLAS and CMS. (orig.)

  5. Natural antioxidants in chemoprevention

    Energy Technology Data Exchange (ETDEWEB)

    Dragsted, L.O. [Danish Veterinary and Food Administration, Soeberg (Denmark). Inst. of Toxicology

    1998-12-31

    It is well documented that diets rich in fruits and vegetables can reduce the risk of most common cancers, and that some food items from this class may be protective against heart disease. Several explanations have been offered, one of which relates to the natural presence of potent antioxidants in plant products. Destructive oxidation of lipids, proteins, DNA, and other important biomolecules, often involving radical chain reactions, affect vital cellular structures and their normal functions. Such processes are involved in the development of cancer as well as heart disease, and it seems logical to assume that antioxidants might be preventive. Large human trials with natural antioxidants have not provided a uniform support, however, for the hypothesis that antioxidation per se may prevent cancer or coronary heart disease (CHD). One reason is that other effects, unrelated to antioxidation, may compromise their preventive effects. Another reason may be that many potent antioxidants can also act as pro-oxidants under certain conditions. The interpretation of animal trials is likewise often compromised by the fact that most antioxidants have other physiological effects which might very well explain their protective action or lead to toxic side-effects. (orig.)

  6. One for all? : connectedness to nature, inclusion of nature, environmental identity, and implicit association with nature

    NARCIS (Netherlands)

    Brügger, A; Kaiser, F.G.; Roczen, N.

    2011-01-01

    Pleasurable experiences in nature are suspected to promote a personal connection with nature, and subsequently, nature conservation in individuals. Using an Internet-based survey employing a convenience sample of the general population (N = 1,309), we developed a connection-with-nature instrument

  7. Constructing nature behind the glass

    Directory of Open Access Journals (Sweden)

    Samuel J.M.M. Alberti

    2008-07-01

    Full Text Available By way of introducing this special issue of Museum and Society, ‘Constructing nature behind glass’, this paper first surveys the literature devoted to analyses of natural history objects and collections. Such work is to be found in interesting places – not only in museum studies, history of science, and professional museum literature, but also in visual studies, anthropology and cultural geography. After exploiting this writing for different perspectives on the cultural and practical construction of museum nature, this paper moves on to consider one popular topic, taxidermy. The ambiguous nature of taxidermic mounts, or ‘remnant models’, leads to a discussion of the relative status of specimen and artefact. I identify four configurations of their relationship: museum nature as opposed to material culture; museum nature as material culture; museum nature and material culture sharing parallel processes; and finally, museum nature and material culture entangled. All offer perspectives on the construction of nature and culture behind glass.

  8. Nature's loss, Immunologists gain?

    Science.gov (United States)

    Aluvihare

    2000-01-01

    Nature Reviews Molecular Cell Biology Nature Publishing Group (2000). ISSN 1471-0072. Monthly First there was Annual Reviews, then came the monthly Elsevier Trends Journals, both of which try to identify hot topics in their chosen fields. The Current Opinion journals followed several years later, and Current Opinion in Cell Biology is presently one of the highest 'impact factor' review journals, with a distinguished board of editors and advisors and a systematic approach to regular coverage of the major fields of cell biology. Important topics are visited once a year, whether or not something specially exciting happened in the last 12 months. Add to this list Seminars in Cell and Developmental Biology, the FASEB journal and the countless minireviews in 'real' journals, and you begin to wonder how anyone finds any time for doing experiments, or indeed reading the primary literature. So, into this already crowded field arrive three important newcomers: Nature Reviews in Molecular Cell Biology, Genetics, and Neurosciences, of which the first two will probably interest readers of Journal of Cell Science the most. Backed by the name and money of Nature and edited by experienced Nature staff, it is hard to see how these publications can possibly do other than succeed with writers and readers alike. What's inside the first issue? The cover of Nature Reviews in Molecular Cell Biology presents a 3-colour montage of a blue cell nucleus surrounded by splotches of green GPI-anchored GFP overlaid by orange actin stress fibres that seem to come from somewhere else. This image trails a comprehensive review from Kai Simons and Derek Toomre about Lipid Rafts. There are another five major review articles: calcium puffs and sparks, rings around DNA, HIV inhibitors, kinesin and the circadian clock provide a rich and varied mix of topics from authors who know what they're talking about. Surrounding this core is an entertaining mixture of 'highlights' at the front: news and views about

  9. Natural gas : nirvana

    International Nuclear Information System (INIS)

    Stonehouse, D.

    2001-01-01

    Despite completing 8,900 gas wells in year 2000, the deliverability of natural gas out of the Western Canadian Sedimentary Basin (WCSB) was stagnant which has left many analysts wondering whether the basin has reached its limit. It also leaves many wondering if gas producers will be able to meet the strong demand for natural gas in the future. Nearly all new electrical generation being built in the U.S. is gas-based due to strict new environmental standards limiting the growth in hydro and coal-powered generation. Any future coal plants will use gasification technology and combined cycle turbines. Combined cycle turbines developed by Boeing and Lockheed are more efficient than combustion turbines, making gas more competitive with fuel alternatives. The lack of growth in natural gas supply has left storage levels near record lows. Demand is expected to increase in 2001 by 3.2 per cent to 23 trillion cubic feet in the U.S. Longer term, major new reserves must be brought on stream to meet this demand. It was noted that the easy discoveries within the WCSB have been made. The new plays are smaller, more technically complex and expensive which suggests that more investment is needed in training geologists, geophysicists and petroleum engineers to find new reserves. The Canadian Energy Research Institute agrees that there is enough gas in Alberta and British Columbia to meet current demands but efforts must shift towards drilling in the foothills front and northwest regions of Alberta to increase deliverability. Brief notes on several gas finds by various oil and gas companies in the area were presented. The article also discussed the huge untapped potential of northern reserves. Analysts have noted 44 Tcf of proven reserve, with a potential of 165 Tcf. In addition, new pipelines from the Alaskan North Slope and the Mackenzie Delta could transport nearly 2 Tcf annually to market. Wells drilled by Chevron and Paramount at Fort Liard in 1999 initially flowed at rates up to

  10. natural or artificial diets

    Directory of Open Access Journals (Sweden)

    A. O. Meyer-Willerer

    2005-01-01

    Full Text Available Se probaron alimentos artificiales y naturales con larva de camarón (Litopenaeus vannamei cultivados en diferentes recipientes. Estos fueron ocho frascos cónicos con 15L, ocho acuarios con 50L y como grupo control, seis tanques de fibra de vidrio con 1500L; todos con agua marina fresca y filtrada. La densidad inicial en todos los recipientes fue de 70 nauplios/L. Aquellos en frascos y acuarios recibieron ya sea dieta natural o artificial. El grupo control fue cultivado con dieta natural en los tanques grandes que utilizan los laboratorios para la producción masiva de postlarvas. El principal producto de excreción de larva de camarón es el ión amonio, que es tóxico cuando está presente en concentraciones elevadas. Se determinó diariamente con el método colorimétrico del indofenol. Los resultados muestran diferencias en la concentración del ión amonio y en la sobrevivencia de larvas entre las diferentes dietas y también entre los diferentes recipientes. En aquellos con volúmenes pequeños comparados con los grandes, se presentó mayor concentración de amonio (500 a 750µg/L, en aquellos con dietas naturales, debido a que este ión sirve de fertilizante a las algas adicionadas, necesitando efectuar recambios diarios de agua posteriores al noveno día de cultivo para mantener este ión a una concentración subletal. Se obtuvo una baja cosecha de postlarvas (menor a 15% con el alimento artificial larvario, debido a la presencia de protozoarios, alimentándose con el producto comercial precipitado en el fondo de los frascos o acuarios. Los acuarios con larvas alimentadas con dieta natural también mostraron concentraciones subletales de amonio al noveno día; sin embargo, la sobrevivencia fue cuatro veces mayor que con dietas artificiales. Los tanques control con dietas naturales presentaron tasas de sobrevivencia (70 ± 5% similares a la reportada por otros laboratorios.

  11. Natural gas monthly, April 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-06

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. There are two feature articles in this issue: Natural gas 1998: Issues and trends, Executive summary; and Special report: Natural gas 1998: A preliminary summary. 6 figs., 28 tabs.

  12. Is disease a natural kind?

    Science.gov (United States)

    D'Amico, R

    1995-10-01

    In The Nature of Disease, Lawrie Reznek argues that disease is not a natural kind term. I raise objections to Reznek's two central arguments for establishing that disease is not a natural kind. In criticizing his a priori, conceptual argument against naturalism, I argue that his conclusion rests on a weaker argument that appeals to the empirical diversity in the symptoms and manifestations of disease. I also raise questions about the account of natural kinds which Reznek utilizes and his point that conventions for classification are excluded by there being natural kinds.

  13. Liquefied Natural Gas Transfer

    Science.gov (United States)

    1980-01-01

    Chicago Bridge & Iron Company's tanks and associated piping are parts of system for transferring liquefied natural gas from ship to shore and storing it. LNG is a "cryogenic" fluid meaning that it must be contained and transferred at very low temperatures, about 260 degrees below Fahrenheit. Before the LNG can be pumped from the ship to the storage tanks, the two foot diameter transfer pipes must be cooled in order to avoid difficulties associated with sharp differences of temperature between the supercold fluid and relatively warm pipes. Cooldown is accomplished by sending small steady flow of the cryogenic substance through the pipeline; the rate of flow must be precisely controlled or the transfer line will be subjected to undesirable thermal stress.

  14. Natural gas powered bus

    International Nuclear Information System (INIS)

    Ambuehl, D.; Fernandez, J.

    2003-01-01

    This report for the Swiss Federal Office of Energy presents the results of a project carried out by the Swiss Federal Institute of Technology in Zurich to evaluate the performance of a natural-gas-powered bus in comparison with two diesel buses. The report provides details on the vehicles, their routes and the results of interviews made with both passengers and drivers. Details of measurements made on fuel consumption and pollutant emissions are presented in tabular and graphical form, as are those made on noise emissions inside and outside the vehicles. The conclusions of the project are presented including economic aspects of using gas as a motor fuel. Also, the views of passengers, who were more concerned with comfort aspects, and drivers, who were more interested in technical aspects, are quoted

  15. Gas hydrate in nature

    Science.gov (United States)

    Ruppel, Carolyn D.

    2018-01-17

    Gas hydrate is a naturally occurring, ice-like substance that forms when water and gas combine under high pressure and at moderate temperatures. Methane is the most common gas present in gas hydrate, although other gases may also be included in hydrate structures, particularly in areas close to conventional oil and gas reservoirs. Gas hydrate is widespread in ocean-bottom sediments at water depths greater than 300–500 meters (m; 984–1,640 feet [ft]) and is also present in areas with permanently frozen ground (permafrost). Several countries are evaluating gas hydrate as a possible energy resource in deepwater or permafrost settings. Gas hydrate is also under investigation to determine how environmental change may affect these deposits.

  16. OPEC and natural gas

    International Nuclear Information System (INIS)

    Samsam Bakhtiari, A.M.; Shahbudaghlou, F.

    1998-01-01

    This paper reviews the involvement of OPEC Member Countries in the natural gas industry in the past, present and future. It notes a tenfold increase in marketed production and a fourfold rise in re-injection since 1970. Collectively, Members now hold 41 per cent of the world's proven gas reserves and account for 20 per cent of exports. Individually, four of these countries hold position 2-5 in the world gas reserve rankings. Within OPEC, however, there remains an emphasis of oil over gas, not least because of oil's favourable position with regard to revenue-generation and profitability. As global demand continues on its upward growth curve in a more environmentally aware world, OPEC's gas horizons will widen. OPEC's strong reserve base will give its Members an undeniable role to play on the future global gas stage. However, these countries will give priority to domestic usage, particularly re-injection schemes

  17. Predicting natural catastrophes tsunamis

    CERN Multimedia

    CERN. Geneva

    2005-01-01

    1. Tsunamis - Introduction - Definition of phenomenon - basic properties of the waves Propagation and dispersion Interaction with coasts - Geological and societal effects Origin of tsunamis - natural sources Scientific activities in connection with tsunamis. Ideas about simulations 2. Tsunami generation - The earthquake source - conventional theory The earthquake source - normal mode theory The landslide source Near-field observation - The Plafker index Far-field observation - Directivity 3. Tsunami warning - General ideas - History of efforts Mantle magnitudes and TREMOR algorithms The challenge of "tsunami earthquakes" Energy-moment ratios and slow earthquakes Implementation and the components of warning centers 4. Tsunami surveys - Principles and methodologies Fifteen years of field surveys and related milestones. Reconstructing historical tsunamis: eyewitnesses and geological evidence 5. Lessons from the 2004 Indonesian tsunami - Lessons in seismology Lessons in Geology The new technologies Lessons in civ...

  18. Nordic urban nature recreation

    DEFF Research Database (Denmark)

    Cole, Scott; Lindhjem, Henrik; Zandersen, Marianne

    the associated nonmarket welfare benefits. The study stresses the need to collect user data to better understand visitation patterns, which can be combined with valuation methods to provide evidence of economic benefits associated with e.g., hiking, cycling, skiing, paddling and other recreation activities. Once......The Nordic countries continue to experience growth of urban areas, which provides benefits like economic growth, but also imposes economic costs in terms of reduced ecosystem services. This report focuses on urban nature recreation and highlights economic methods and data that can help capture...... these benefits are visible, decision-makers will have a better basis to balance economic growth with the environmental costs it imposes on urban ecosystem services....

  19. Natural Radioactivity in Bananas

    Science.gov (United States)

    Zagatto, V. A. B.; Medina, N. H.; Okuno, E.; Umisedo, N. K.

    2008-08-01

    The content of 40K natural radionuclide in bananas (Musa sapientum) from the Vale do Ribeira region, São Paulo, Brazil, has been measured. We have collected several samples of bananas prata and nanica, its peels, leaves, and also different soils where the banana tree was planted, such as soil with a standard amount of fertilizer, the fertilizer itself and also soil without fertilizer for comparison. We have used the gamma-ray spectroscopy technique with a NaI(T1) crystal inside a 12 cm thick lead shield to detect the gamma-radiation. The results indicate that only part of the available potassium is absorbed by the plant, which is mainly concentrated in the banana peel.

  20. Art and human nature

    Directory of Open Access Journals (Sweden)

    Mirta Toledo

    2008-06-01

    Full Text Available This article presents a visual artist’s point of view about art. This view confronts the Eurocentric traditional cannon with some ignored, but valuable traditions, thus proposing a contra-canon. These ideas are examined on the light of a variety of sources, including prehistoric, pre-Columbian, and 20th century art expressions, in a variety of media, from sculpture to literature. Recent art expressions are characterized by their incorporation of minority values and perspectives that challenge “universal” views. Using samples of works from Latino and African American artists, the author shows that, even today, art is a means to know the world and its people, to exhibit personal life, to create personal symbolism, and to show one’s identity or the search for it. Like the human nature it represents, art has multiple faces.

  1. Natural Radioactivity in Bananas

    International Nuclear Information System (INIS)

    Zagatto, V. A. B.; Medina, N. H.; Okuno, E.; Umisedo, N. K.

    2008-01-01

    The content of 40 K natural radionuclide in bananas (Musa sapientum) from the Vale do Ribeira region, Sao Paulo, Brazil, has been measured. We have collected several samples of bananas prata and nanica, its peels, leaves, and also different soils where the banana tree was planted, such as soil with a standard amount of fertilizer, the fertilizer itself and also soil without fertilizer for comparison. We have used the gamma-ray spectroscopy technique with a NaI(T1) crystal inside a 12 cm thick lead shield to detect the gamma-radiation. The results indicate that only part of the available potassium is absorbed by the plant, which is mainly concentrated in the banana peel

  2. Virtual-World Naturalism

    Directory of Open Access Journals (Sweden)

    Daniel Reynolds

    2010-07-01

    Full Text Available Sometimes a player will stray from the path described by a game, moving into new spaces, developing new possible modes of interaction, and often discovering the rougher edges of the game world, where physics models break down, textures become incongruous, and the pieces don’t quite fit together. Gameplay that seeks out these spaces and these phenomena, that searches for such clues to the underlying construction of the virtual environment, is a kind of virtual-world naturalism, at once a return to an investigative urge that has been subsumed to the exhaustive mapping and description of the real world and a form of resistance to the very idea of pre-defined paths of action, of externally imposed limits, in virtual worlds as well as in our own.

  3. Natural flexible dermal armor.

    Science.gov (United States)

    Yang, Wen; Chen, Irene H; Gludovatz, Bernd; Zimmermann, Elizabeth A; Ritchie, Robert O; Meyers, Marc A

    2013-01-04

    Fish, reptiles, and mammals can possess flexible dermal armor for protection. Here we seek to find the means by which Nature derives its protection by examining the scales from several fish (Atractosteus spatula, Arapaima gigas, Polypterus senegalus, Morone saxatilis, Cyprinius carpio), and osteoderms from armadillos, alligators, and leatherback turtles. Dermal armor has clearly been developed by convergent evolution in these different species. In general, it has a hierarchical structure with collagen fibers joining more rigid units (scales or osteoderms), thereby increasing flexibility without significantly sacrificing strength, in contrast to rigid monolithic mineral composites. These dermal structures are also multifunctional, with hydrodynamic drag (in fish), coloration for camouflage or intraspecies recognition, temperature and fluid regulation being other important functions. The understanding of such flexible dermal armor is important as it may provide a basis for new synthetic, yet bioinspired, armor materials. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Natural convection type reactor

    International Nuclear Information System (INIS)

    Nakayama, Takafumi; Horiuchi, Tetsuo; Moriya, Kimiaki; Matsumoto, Masayoshi; Akita, Minoru.

    1988-01-01

    Purpose: To improve the reliability by decreasing the number of dynamic equipments and safely shutdown the reactor core upon occurrence of accidents. Constitution: A pressure relief valve and a pressurizing tank or gravitational water falling tank disposed to the main steam pipe of a reactor are installed in combination. Upon loss-of-coolant accident, the pressure relief valve is opened to reduce the pressure in the reactor pressure vessel to the operation pressure for each of the tanks, thereby enabling to inject water in the pressurizing tank at first and, thereafter, water in the gravitational water falling tank successively to the inside of the pressure vessel. By utilizing the natural force in this way, the reliability can be improved as compared with the case of pumped water injection. Further, by injecting an aqueous boric acid to a portion of a plurality of tanks, if the control rod insertion becomes impossible, aqueous boric acid can be injected. (Takahashi, M.)

  5. Natural climate solutions

    Science.gov (United States)

    Griscom, Bronson W.; Adams, Justin; Ellis, Peter W.; Houghton, Richard A.; Lomax, Guy; Miteva, Daniela A.; Schlesinger, William H.; Shoch, David; Siikamäki, Juha V.; Smith, Pete; Woodbury, Peter; Zganjar, Chris; Blackman, Allen; Campari, João; Conant, Richard T.; Delgado, Christopher; Elias, Patricia; Gopalakrishna, Trisha; Hamsik, Marisa R.; Herrero, Mario; Kiesecker, Joseph; Landis, Emily; Laestadius, Lars; Leavitt, Sara M.; Minnemeyer, Susan; Polasky, Stephen; Potapov, Peter; Putz, Francis E.; Sanderman, Jonathan; Silvius, Marcel; Wollenberg, Eva; Fargione, Joseph

    2017-10-01

    Better stewardship of land is needed to achieve the Paris Climate Agreement goal of holding warming to below 2 °C; however, confusion persists about the specific set of land stewardship options available and their mitigation potential. To address this, we identify and quantify “natural climate solutions” (NCS): 20 conservation, restoration, and improved land management actions that increase carbon storage and/or avoid greenhouse gas emissions across global forests, wetlands, grasslands, and agricultural lands. We find that the maximum potential of NCS—when constrained by food security, fiber security, and biodiversity conservation—is 23.8 petagrams of CO2 equivalent (PgCO2e) y‑1 (95% CI 20.3–37.4). This is ≥30% higher than prior estimates, which did not include the full range of options and safeguards considered here. About half of this maximum (11.3 PgCO2e y‑1) represents cost-effective climate mitigation, assuming the social cost of CO2 pollution is ≥100 USD MgCO2e‑1 by 2030. Natural climate solutions can provide 37% of cost-effective CO2 mitigation needed through 2030 for a >66% chance of holding warming to below 2 °C. One-third of this cost-effective NCS mitigation can be delivered at or below 10 USD MgCO2‑1. Most NCS actions—if effectively implemented—also offer water filtration, flood buffering, soil health, biodiversity habitat, and enhanced climate resilience. Work remains to better constrain uncertainty of NCS mitigation estimates. Nevertheless, existing knowledge reported here provides a robust basis for immediate global action to improve ecosystem stewardship as a major solution to climate change.

  6. A Natural Logic for Natural-Language Knowledge Bases

    DEFF Research Database (Denmark)

    Andreasen, Troels; Styltsvig, Henrik Bulskov; Jensen, Per Anker

    2017-01-01

    We describe a natural logic for computational reasoning with a regimented fragment of natural language. The natural logic comes with intuitive inference rules enabling deductions and with an internal graph representation facilitating conceptual path finding between pairs of terms as an approach t...

  7. A Natural Logic for Natural-language Knowledge Bases

    DEFF Research Database (Denmark)

    Andreasen, Troels; Bulskov, Henrik; Jensen, Per Anker

    2017-01-01

    We describe a natural logic for computational reasoning with a regimented fragment of natural language. The natural logic comes with intuitive inference rules enabling deductions and with an internal graph representation facilitating conceptual path finding between pairs of terms as an approach t...

  8. Which naturalism for bioethics? A defense of moderate (pragmatic) naturalism.

    Science.gov (United States)

    Racine, Eric

    2008-02-01

    There is a growing interest in various forms of naturalism in bioethics, but there is a clear need for further clarification. In an effort to address this situation, I present three epistemological stances: anti-naturalism, strong naturalism, and moderate pragmatic naturalism. I argue that the dominant paradigm within philosophical ethics has been a form of anti-naturalism mainly supported by a strong 'is' and 'ought' distinction. This fundamental epistemological commitment has contributed to the estrangement of academic philosophical ethics from major social problems and explains partially why, in the early 1980s, 'medicine saved the life of ethics'. Rejection of anti-naturalism, however, is often associated with strong forms of naturalism that commit the naturalistic fallacy and threaten to reduce the normative dimensions of ethics to biological imperatives. This move is rightly dismissed as a pitfall since ethics is, in part, a struggle against the course of nature. Rejection of naturalism has drawbacks, however, such as deterring bioethicists from acknowledging the implicit naturalistic epistemological commitments of bioethics. I argue that a moderate pragmatic form of naturalism represents an epistemological position that best embraces the tension of anti-naturalism and strong naturalism: bioethics is neither disconnected from empirical knowledge nor subjugated to it. The discussion is based upon historical writings in philosophy and bioethics.

  9. Natural gas monthly, October 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

  10. Natural gas monthly, May 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

  11. Natural gas monthly, June 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

  12. Natural gas monthly, August 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-24

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  13. Natural gas monthly, November 1993

    International Nuclear Information System (INIS)

    1993-01-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground state data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information

  14. Legal nature of affatomia

    Directory of Open Access Journals (Sweden)

    Stanković Miloš

    2015-01-01

    Full Text Available In Salian and Ripuarian Code affatomia represented a bilateral legal transaction that was aimed at changing of the scoped of heirs determined by the customs, at least insofar being applied in the absence of biological descendants only. However, almost all further similarities in the field cease at this point. The form for using affatomia with Ripuarian Franks was much simpler than the one with the Salian Franks. Unlike the Salian Franks, affatomia could by all odds be used by Ripuarian Franks spouses in determining each other for a heir. Legal nature of the Salian Franks affatomia is most similar to the mancipatio familiae type of will in the Roman law (which does not mean it emerged from this law, while its form in the Ripuarian Code is much closer to testamentary adoption. As with Ripuarian Franks, affatomia seems to have definitely produced legal effects only after the death of the disposant, while its legal effects with the Salian Code performed inter vivos. Contemporary authors are trying to designate the legal nature of legal affairs from the early development of human and legal civilization through modern institutes that represent the completion of their evolutionary path. Taking the inheritance contract of the German or Swiss law, or the future assets donation of the French law, for example, and then comparing them to affatomia and thinx is an anachronism. This is evident by the fact that the legal nature of these ancient Germanic institutes can not be viewed unilaterally, but always through a combination of those institutes which we know today as adoption, gift or mixed donation with retention of different modalities for the transferor or the testator (usually usufruct. In this sense, if we are looking for a inheritance agreement in the Middle Ages, the contract in which a person determines other person for his/her universal or singular successor in the modern sense, we will certainly not find one. However, if within this institute we

  15. Mother natural: Motivations and associations for consuming natural foods.

    Science.gov (United States)

    Moscato, Emily M; Machin, Jane E

    2018-02-01

    Natural is perceived as innately positive and is a widely sought-after attribute in food products. The natural food industry continues to grow in response to rising consumer demand. This qualitative study explored mothers' motivations for purchasing and consuming natural food products for themselves and their families. Mothers are an important population because of their disproportionate influence on household food consumption. We employed participant photography and a series of three weekly focus groups to derive a rich understanding of the activities surrounding and motivations behind seeking natural in everyday buying decisions. Five major themes were identified. First, natural nurtures well-being: physical, psychological, social, and emotional health. Second, natural behaves "supernaturally," allowing positive attributes to be transmitted from the source to the recipient. Third, natural is associated with authenticity, providing a sense of trust, transparency, and control. Fourth, consuming natural reinforces the socially constructed idea of a good mother. Lastly, the preference for natural does not always translate into purchase; mothers face compromises because of conflicting priorities and resources. Understanding mothers' multiple motivations provides deeper insight into the attraction for natural products. The findings have application in positioning interventions for more nutritional eating and revising regulations on the food label natural. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. US crude oil, natural gas, and natural gas liquids reserves

    International Nuclear Information System (INIS)

    1992-01-01

    This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1991, as well as production volumes for the United States, and selected States and State subdivisions for the year 1991. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), its two major components (nonassociated and associated-dissolved gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, two components of natural gas liquids, lease condensate and natural gas plant liquids, have their reserves and production data presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1991 is also presented

  17. Naturalness as an educational value

    DEFF Research Database (Denmark)

    Frølund, Sune

    2016-01-01

    Existentialism and postmodernism have both abandoned the idea of a human nature. Also, the idea of naturalness as a value for education has been targeted as a blind for conservative ideology. There are, however, good reasons to re-establish a sound concept of human naturalness. First of all...

  18. Natural radioactivity in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Petr, I [Ceske Vysoke Uceni Technicke, Prague (Czechoslovakia). Fakulta Jaderna a Fysikalne Inzenyrska

    1980-01-01

    The effects were analyzed of natural radionuclides and cosmic radiation on radiation burden in man. The contents are shown of natural radionuclides in the earth crust, water, atmosphere, food chain and human organism. Using the data, the annual doses from natural sources to the gonads (1025 ..mu..Sv/yr) and to the bone marrow (986 ..mu..Sv) are estimated.

  19. Natural gas for vehicles (NGV)

    International Nuclear Information System (INIS)

    Prieur, A.

    2006-01-01

    Following a decade-long upsurge in the use of natural gas in the energy sector (heating and especially electricity), new outlets for natural gas are being developed in the transport sector. For countries endowed with substantial local resources, development in this sector can help reduce oil dependence. In addition, natural gas is often used to reduce pollution, particularly in cities. (author)

  20. Natural family planning.

    Science.gov (United States)

    Brown, J B; Blackwell, L F; Billings, J J; Conway, B; Cox, R I; Garrett, G; Holmes, J; Smith, M A

    1987-10-01

    It is now well accepted that a woman can conceive from an act of intercourse for a maximum of only about 7 days of her menstrual cycle. The reliability of natural family planning depends on identifying this window of fertility without ambiguity. Several symptomatic markers, cervical mucus and basal body temperature, have been used extensively and with considerable success in most women but failures occur. Ovarian and pituitary hormone production show characteristic patterns during the cycle. Urinary estrogen and pregnanediol measurements yield reliable information concerning the beginning, peak, and end of the fertile period, provided that the assays are accurate and performed on timed specimens of urine. We have developed such enzyme immunoassays for urinary estrogen and pregnanediol glucuronides that can be performed at home. In the early versions of the assays, enzyme reaction rates were measured by eye, but more recently, a simple photoelectronic rate meter has been used. The final problem to be solved is not technologic but whether women are sufficiently motivated to expend the same time and effort each day for 10 days a month, with less cost, on fertility awareness as they spend on making a cup of tea.

  1. A natural ice boom

    Energy Technology Data Exchange (ETDEWEB)

    Hopper, H.R. [Manitoba Hydro, Winnipeg, MB (Canada)

    1998-10-01

    Planning for ice jams and ice movements are critical on the Nelson River in northern Manitoba in designing cofferdams. Experience on the St. Lawrence River demonstrated the possibility of exercising some control over ice action by judicious placement of log booms or ice control structures. The success of experiments with man-made controls led to field tests in which an ice sheet of sufficient magnitude and competence was introduced into the open water stream of the Nelson River. The ice sheet was subsequently jammed in a narrow channel, thereby creating a natural ice bridge or boom upstream of a proposed hydro development. Under favourable conditions, this boom would initiate the progression of the ice cover from its location upstream, cutting off the downstream reach from the ice producing potential of the upstream reach. Although ice would still be generated downstream, the length of the reach between the ice boom and the development site would be short enough that ice jamming at the development site would never occur. Although problems in blasting prevented the introduction of a competent ice sheet into the main stream of the river at the location chosen, sufficient confidence in the theory was gained to warrant further consideration. 4 refs., 1 tab., 10 figs.

  2. Management of natural resources

    International Nuclear Information System (INIS)

    Danielo, Olivier; Loubens, Audrey

    2016-08-01

    As a sustainable exploitation of fossil natural resources has become an ecological opportunity, this publication proposes a set of articles focused on the cases of gas, oils (conventional or not) and coal. A first article outlines the unavoidable environmental issue associated with the exploitation of fossil energies. The second one comments the meaning of fossil fuel availability, and more particularly the distinction between resources and reserves, and the transformation of resources into reserves for saving purposes. This last issue of transformation of resources into reserves is addressed by next articles which respectively focus on conventional gases and oils, on non conventional gases and oils, and on coal. Two articles then comment perspectives by 2040 by discussing the high tension between fossil resources and geopolitical situation, and by discussing whether a world energy transition is possible. The three last articles notice that the abundance of fossil energies is hiding the potential of renewable energies, discuss whether chemical industry could do without oil, and comment the fact that Russia strengthens its claims on Arctic territories

  3. NATURAL POLYACETYLENE COMPOUNDS

    Directory of Open Access Journals (Sweden)

    A. M. Nasukhova

    2014-01-01

    Full Text Available In article the review of the initial stage of researches of natural polyacetylene compounds is resulted. The high reactionary ability leading to fast oxidation and degradation of these compounds, especially at influence of Uf-light, oxygen of air, pH and other factors, has caused the serious difficulties connected with an establishment of structure and studying of their physical and chemical properties. Therefore the greatest quantity of works of this stage is connected with studying of essential oils of plants from families Apiaceae, Araliaceae, Asteraceae, Campanulaceae, Olacaceae, Pittosporaceae and Santalaceae where have been found out, basically, diacetylene compounds. About development of physical and chemical methods of the analysis of possibility of similar researches have considerably extended. More than 2000 polyacetylenes are known today, from them more than 1100 are found out in plants fam. Asteraceae. Revolution in the field of molecular biology has allowed to study processes of biosynthesis of these compounds intensively.

  4. Oil and natural gas

    International Nuclear Information System (INIS)

    Hamm, Keith

    1992-01-01

    The two major political events of 1991 produced a much less dramatic reaction in the global oil industry than might have been expected. The economic dislocation in the former USSR caused oil production to fall sharply but this was largely offset by a concurrent fall in demand. Within twelve months of the invasion of Kuwait, crude oil prices had returned to their pre-invasion level; there was no shortage of supply due to the ability of some producers to boost their output rapidly. Details are given of world oil production and developments in oil demand. Demand stagnated in 1991 due to mainly to the economic chaos in the former USSR and a slowdown in sales in the USA; this has produced problems for the future of the refining industry. By contrast, the outlook for the natural gas industry is much more buoyant. Most clean air or carbon emissions legislation is designed to promote the use of gas rather than other hydrocarbons. World gas production rose by 1.5% in 1991; details by production on a country by country basis are given. (UK)

  5. Repowering with natural gas

    International Nuclear Information System (INIS)

    Wilkinson, P.L.

    1992-01-01

    This chapter examines the concept of combined-cycle repowering with natural gas as one possible solution to the impending dilemma facing electric utilities - tight capacity margins in the 1990s and the inordinate expense of traditional powerplants. Combined-cycle repowering refers to the production of electricity through the integration of new and used equipment at an existing site, with the final equipment configuration resembling a new gas-fired combined-cycle unit (i.e., gas turbine, waste heat recovery unit and steam turbine/generator). Through the utilization of improved waste heat recovery and gas-fired equipment, repowering provides both additional capacity and increased generating efficiency. Three modes of repowering are considered: (1) peak turbine repowering refers to the addition of a steam turbine and heat recovery unit to an existing gas turbine, with the efficiency improvement allowing the unit to convert from peaking to baseload operation; (2) heat recovery repowering is the replacement of an old coal boiler with a gas turbine and heat recovery unit, leaving the existing steam turbine in place; and (3) boiler repowering, in which the exhaust from a new gas turbine is fed into an existing coal boiler, replacing existing forced-draft fans and air heaters. These three options are compared with the option of adding new coal-fired boilers on the basis of economics, energy efficiency and environmental impacts

  6. Naturalness and supersymmetry

    International Nuclear Information System (INIS)

    Agashe, K.; Univ. of California, Berkeley, CA

    1998-05-01

    In this thesis, the author argues that the supersymmetric Standard Model, while avoiding the fine tuning in electroweak symmetry breaking, requires unnaturalness/fine tuning in some (other) sector of the theory. For example, Baryon and Lepton number violating operators are allowed which lead to proton decay and flavor changing neutral currents. He studies some of the constraints from the latter in this thesis. He has to impose an R-parity for the theory to be both natural and viable. In the absence of flavor symmetries, the supersymmetry breaking masses for the squarks and sleptons lead to too large flavor changing neutral currents. He shows that two of the solutions to this problem, gauge mediation of supersymmetry breaking and making the scalars of the first two generations heavier than a few TeV, reintroduce fine tuning in electroweak symmetry breaking. He also constructs a model of low energy gauge mediation with a non-minimal messenger sector which improves the fine tuning and also generates required Higgs mass terms. He shows that this model can be derived from a Grand Unified Theory despite the non-minimal spectrum

  7. Turkey and natural gas

    International Nuclear Information System (INIS)

    Yardim, G.

    1992-01-01

    Turkey is a developing country with a population of 56 millions and approximately $ 2604 per capita income. Geographically she is located among the energy rich countries whereas almost half of her energy requirement is met by imports. Turkey is relatively well endowed with hydro-power and lignite resources, some limited amount of oil, gas and coal resources exist and there is significant geothermal potential in the country. Environmental issues are increasingly important consideration in energy policy decisions in the world. Energy production, transportation and use are contributing to environmental degradation to a certain extent. Protection of the environment and public health from pollution arising from energy production and consumption activities is one of the principles of Turkish national energy policy. In conjunction with this policy the 'Environment Law' was promulgated in 1983 and 'The Regulation on Protection of the Air Quality' in order to control all kinds of emissions in the form of soot, smoke, fines and particulate and to prevent the adverse impacts of the air pollution, was issued in October 1986. Policy of diversification of energy sources and the environmental issues which were explained above brought the natural gas usage into the energy scene in Turkey. 6 figs., 4 tabs

  8. Periurbanisation and natural hazards

    Directory of Open Access Journals (Sweden)

    Delphine Loison

    2009-03-01

    Full Text Available In mountainous areas in recent decades urbanisation has expanded to areas where low ground adjoins mountainsides that are unstable in a number of respects. Periurbanisation in mountain basins with unstable sides poses specific problems that local players have to address. The Lavanchon basin (southeast of Grenoble, which is subject to very rapid urban growth combined with particularly dynamic mountainsides, is representative of the way activity is being brought into closer contact with potential hazards. A diachronic study of changes in land use between 1956 and 2001 shows how valley infrastructures at the bottom of mountainsides have become increasingly dense. In this context, a survey was carried out among a number of residents in the Lavanchon basin in an attempt to evaluate the degree of awareness that the population has of the natural hazards to which it is exposed. The results show that slightly more than half of the population surveyed was aware of the problem of natural hazards being present in the area, with most inhabitants being more concerned about industrial and pollution hazards. New residents were unaware of or were unwilling to accept the reality of hazards. The low incidence of significant natural events, the effectiveness of the protective structures built, the absence of information provided by the public authorities and the division of the basin between several management bodies appear to have engendered a feeling of safety from natural phenomena. The geographical distribution of appreciation of the hazard clearly shows a distinction between those inhabitants living on the low ground and those at the bottom of the mountainsides, and this corresponds fairly closely with the historical and current location of the main potentially hazardous events that have occurred.Dans les territoires de montagne, les dernières décennies ont vu l’expansion de l’urbanisation vers les zones de contact entre la plaine et les versants, lieux

  9. Nature's Autonomous Oscillators

    Science.gov (United States)

    Mayr, H. G.; Yee, J.-H.; Mayr, M.; Schnetzler, R.

    2012-01-01

    Nonlinearity is required to produce autonomous oscillations without external time dependent source, and an example is the pendulum clock. The escapement mechanism of the clock imparts an impulse for each swing direction, which keeps the pendulum oscillating at the resonance frequency. Among nature's observed autonomous oscillators, examples are the quasi-biennial oscillation and bimonthly oscillation of the Earth atmosphere, and the 22-year solar oscillation. The oscillations have been simulated in numerical models without external time dependent source, and in Section 2 we summarize the results. Specifically, we shall discuss the nonlinearities that are involved in generating the oscillations, and the processes that produce the periodicities. In biology, insects have flight muscles, which function autonomously with wing frequencies that far exceed the animals' neural capacity; Stretch-activation of muscle contraction is the mechanism that produces the high frequency oscillation of insect flight, discussed in Section 3. The same mechanism is also invoked to explain the functioning of the cardiac muscle. In Section 4, we present a tutorial review of the cardio-vascular system, heart anatomy, and muscle cell physiology, leading up to Starling's Law of the Heart, which supports our notion that the human heart is also a nonlinear oscillator. In Section 5, we offer a broad perspective of the tenuous links between the fluid dynamical oscillators and the human heart physiology.

  10. SUSY naturalness without prejudice

    Science.gov (United States)

    Ghilencea, D. M.

    2014-05-01

    Unlike the Standard Model (SM), supersymmetric models stabilize the electroweak (EW) scale v at the quantum level and predict that v is a function of the TeV-valued SUSY parameters (γα) of the UV Lagrangian. We show that the (inverse of the) covariance matrix of the model in the basis of these parameters and the usual deviation δχ2 (from χmin2 of a model) automatically encode information about the "traditional" EW fine-tuning measuring this stability, provided that the EW scale v ˜mZ is indeed regarded as a function v =v(γ). It is known that large EW fine-tuning may signal an incomplete theory of soft terms and can be reduced when relations among γα exist (due to GUT symmetries, etc.). The global correlation coefficient of this matrix can help one investigate if such relations are present. An upper bound on the usual EW fine-tuning measure ("in quadrature") emerges from the analysis of the δχ2 and the s-standard deviation confidence interval by using v =v(γ) and the theoretical approximation (loop order) considered for the calculation of the observables. This upper bound avoids subjective criteria for the "acceptable" level of EW fine-tuning for which the model is still "natural."

  11. Forces of nature

    CERN Document Server

    AUTHOR|(CDS)2072602

    2016-01-01

    A breathtaking and beautiful exploration of our planet. This groundbreaking book, which accompanies the new BBC1 TV series, provides the deepest answers to the simplest questions. 'Why is the sky blue?' 'Why is the Earth round?' 'Why is every snowflake unique?' To answer these and many other questions, Professor Brian Cox will reveal some of the most extraordinary phenomena and events on Earth and in the Universe and beyond. From the immensity of Earth's globe to all the world's myriad snowflakes, the forces of nature shape everything we see. Pushed to extremes, the results are astonishing. From the realm of auroras to the heart of our planet, the ingredients that make everything on Earth connect each one of us in an eternal cycle of life. Brian will reveal why Earth is the most colourful world we know, exploring the white light of the sun as it travels through the darkness of space until it hits Earth's atmosphere where it begins a new journey, splitting into a rainbow of colours. From the great plains of th...

  12. Natural zeolite bitumen cracking

    Energy Technology Data Exchange (ETDEWEB)

    Kuznicki, S.M.; McCaffrey, W.C.; Bian, J.; Wangen, E.; Koenig, A. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

    2006-07-01

    A study was conducted to demonstrate how low cost heavy oil upgrading in the field could reduce the need for diluents while lowering the cost for pipelining. Low cost field upgrading could also contribute to lowering contaminant levels. The performance of visbreaking processes could be improved by using disposable cracking agents. In turn, the economics of field upgrading of in-situ derived bitumen would be improved. However, in order to be viable, such agents would have to be far less expensive than current commercial cracking catalysts. A platy natural zeolite was selected for modification and testing due to its unique chemical and morphological properties. A catalyst-bearing oil sand was then heat-treated for 1 hour at 400 degrees C in a sealed microreactor. Under these mild cracking conditions, the catalyst-bearing oil sand produced extractable products of much lower viscosity. The products also contained considerably more gas oil and middle distillates than raw oil sand processed under the same conditions as thermal cracking alone. According to model cracking studies using hexadecane, these modified mineral zeolites may be more active cracking agents than undiluted premium commercial FCC catalyst. These materials hold promise for partial upgrading schemes to reduce solvent requirements in the field. tabs., figs.

  13. Lorentz violation naturalness revisited

    Energy Technology Data Exchange (ETDEWEB)

    Belenchia, Alessio; Gambassi, Andrea; Liberati, Stefano [SISSA - International School for Advanced Studies, via Bonomea 265, 34136 Trieste (Italy); INFN, Sezione di Trieste, via Valerio 2, 34127 Trieste (Italy)

    2016-06-08

    We revisit here the naturalness problem of Lorentz invariance violations on a simple toy model of a scalar field coupled to a fermion field via a Yukawa interaction. We first review some well-known results concerning the low-energy percolation of Lorentz violation from high energies, presenting some details of the analysis not explicitly discussed in the literature and discussing some previously unnoticed subtleties. We then show how a separation between the scale of validity of the effective field theory and that one of Lorentz invariance violations can hinder this low-energy percolation. While such protection mechanism was previously considered in the literature, we provide here a simple illustration of how it works and of its general features. Finally, we consider a case in which dissipation is present, showing that the dissipative behaviour does not percolate generically to lower mass dimension operators albeit dispersion does. Moreover, we show that a scale separation can protect from unsuppressed low-energy percolation also in this case.

  14. Natural gas marketing and transportation

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This book covers: Overview of the natural gas industry; Federal regulation of marketing and transportation; State regulation of transportation; Fundamentals of gas marketing contracts; Gas marketing options and strategies; End user agreements; Transportation on interstate pipelines; Administration of natural gas contracts; Structuring transactions with the nonconventional source fuels credit; Take-or-pay wars- a cautionary analysis for the future; Antitrust pitfalls in the natural gas industry; Producer imbalances; Natural gas futures for the complete novice; State non-utility regulation of production, transportation and marketing; Natural gas processing agreements and Disproportionate sales, gas balancing, and accounting to royalty owners

  15. Who's afraid of natural gas?

    International Nuclear Information System (INIS)

    Patterson, W.

    1999-01-01

    Changes in our electricity systems provoked by natural gas power generation technology are paving the way for large-scale renewables use in the future. Natural gas and gas turbines are now such a cheap and easy option for electricity generation that they appear to cast a pall over renewables. The market share of gas-fired generation continues expanding inexorably. Its cost continues to fall, setting renewables an ever more demanding competitive target. Nevertheless, paradoxical though this may sound, natural gas is actually the natural ally of renewables. Despite the fierce competitive challenge it represents, natural gas may even be the most important single factor shaping a bright future for renewables. (author)

  16. Natural gas monthly, August 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-24

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. This month`s feature article is on US Natural Gas Imports and Exports 1994.

  17. Natural gas monthly, August 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-25

    The Natural Gas Monthly (NGM) is prepared in the Data Operations Branch of the Reserves and Natural Gas Division, Office of Oil and Gas, Energy Information Administration (EIA), US Department of Energy (DOE). The NGM highhghts activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  18. Natural gas vehicles in Italy

    International Nuclear Information System (INIS)

    Mariani, F.

    1991-01-01

    The technology of compressed natural gas (CNG) for road vehicles originated 50 years ago in Italy, always able to adapt itself to changes in energy supply and demand situations and national assets. Now, due to the public's growing concern for air pollution abatement and recent national energy policies calling for energy diversification, the commercialization of natural gas road vehicles is receiving new momentum. However, proper fuel taxation and an increased number of natural gas distribution stations are required to support this growing market potential. Operators of urban bus fleets stand to gain substantially from conversion to natural gas automotive fuels due to natural gas being a relatively cheap, clean alternative

  19. Natural gas monthly, May 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article this month is ``Restructuring energy industries: Lessons from natural gas.`` 6 figs., 26 tabs.

  20. Natural gas monthly, June 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article this month is the executive summary from Natural Gas 1994: Issues and Trends. 6 figs., 31 tabs.

  1. Reação cutânea grave induzida por carbamazepina no tratamento da neuralgia pós-herpética: relato de caso Reacción cutánea grave inducida por la carbamazepina en el tratamiento de la neuralgia postherpética: relato de caso Severe carbamazepine-induced cutaneous reaction in the treatment of post-herpetic neuralgia: case report

    Directory of Open Access Journals (Sweden)

    João Batista Santos Garcia

    2010-08-01

    da carbamazepina, que deve sempre ser supervisionado, especialmente em idosos.JUSTIFICATIVA Y OBJETIVOS: El herpes zoster tiene como principal complicación la neuralgia postherpética (NPH. Para su tratamiento se usa la carbamazepina (CBZ, un anticonvulsivo bien tolerado, pero que sin embargo está a menudo asociado a reacciones cutáneas graves, como por ejemplo, el síndrome de Stevens-Johnson (SSJ y la necrólisis epidérmica tóxica (NET. El objetivo de este trabajo es relatar un caso de SSJ/NET secundario al uso de CBZ en paciente con NPH. RELATO DEL CASO: Paciente del sexo femenino, con dolor continuo e intenso en la región torácica y dorso, ardor, punzada, descarga eléctrica, alteración de fuerza del miembro superior ipsilateral y sudoración. Presentaba lesiones de postillas y eritemas en la región dorsal del tórax, con alodinia y disestesias en el dermatoma acometido. Se inició CBZ 300 mg.día-1, amitriptilina (AMT12,5 mg por la noche e infiltración con anestésico local en la región afectada. Después de 15 días, el paciente decía sentir un fuerte malestar, fiebre, dolores musculares y artralgias con rash cutáneo ligero e inespecífico. Se le retiró la carbamazepina inmediatamente. Una semana después fue ingresado con urticaria y exantema generalizados, erupciones cutáneas eritematosas, burbujas y marcas purpúricas por todo el cuerpo. La impresión era de SSJ/NET inducida por carbamazepina. Hubo un progresivo empeoramiento del cuadro, con aumento del número y del tamaño de las lesiones cutáneas, además de rash eritematoso macular generalizado, áreas de necrosis y erosiones simétricas de la epidermis en la cara, cuello, tórax, dorso y miembros, llegando a más del 50% del área de superficie, además de la involucración de la mucosa bucal, conjuntival y genital con erosiones vesiculares. Presentó un empeoramiento funcional progresivo, evolucionando con choque séptico y fracaso multiorgánico, lo que produjo finalmente su deceso

  2. Natural radioactivity in water supplies

    International Nuclear Information System (INIS)

    Horner, J.K.

    1985-01-01

    This book outlines the scientific aspects of the control of natural radioactivity in water supplies, as well as the labyrinthine uncertainties in water quality regulation concerning natural radiocontamination of water. The author provides an introduction to the theory of natural radioactivity; addresses risk assessment, sources of natural radiocontamination of water, radiobiology of natural radioactivity in water, and federal water law concerning natural radiocontamination. It presents an account of how one city dealt with the perplexes that mark the rapidly evolving area of water quality regulation. The contents include: radioactivity and risk; an introduction to the atomic theory; an introduction to natural radioactivity; risk assessment; uranium and radium contamination of water; radiobiology of uranium and radium in water. Determination of risk from exposure to uranium and radium in water; the legal milieu; one city's experience; and summary: the determinants of evolving regulation

  3. Quantification of natural phenomena

    International Nuclear Information System (INIS)

    Botero Alvarez, Javier

    1997-01-01

    The science is like a great spider's web in which unexpected connections appear and therefore it is frequently difficult to already know the consequences of new theories on those existent. The physics is a clear example of this. The Newton mechanics laws describe the physical phenomena observable accurately by means of our organs of the senses or by means of observation teams not very sophisticated. After their formulation at the beginning of the XVIII Century, these laws were recognized in the scientific world as a mathematical model of the nature. Together with the electrodynamics law, developed in the XIX century, and the thermodynamic one constitutes what we call the classic physics. The state of maturity of the classic physics at the end of last century it was such that some scientists believed that the physics was arriving to its end obtaining a complete description of the physical phenomena. The spider's web of the knowledge was supposed finished, or at least very near its termination. It ended up saying, in arrogant form, that if the initial conditions of the universe were known, we could determine the state of the same one in any future moment. Two phenomena related with the light would prove in firm form that mistaken that they were, creating unexpected connections in the great spider's web of the knowledge and knocking down part of her. The thermal radiation of the bodies and the fact that the light spreads to constant speed in the hole, without having an absolute system of reference with regard to which this speed is measured, they constituted the decisive factors in the construction of a new physics. The development of sophisticated of measure teams gave access to more precise information and it opened the microscopic world to the observation and confirmation of existent theories

  4. Agrobacterium: nature's genetic engineer.

    Science.gov (United States)

    Nester, Eugene W

    2014-01-01

    Agrobacterium was identified as the agent causing the plant tumor, crown gall over 100 years ago. Since then, studies have resulted in many surprising observations. Armin Braun demonstrated that Agrobacterium infected cells had unusual nutritional properties, and that the bacterium was necessary to start the infection but not for continued tumor development. He developed the concept of a tumor inducing principle (TIP), the factor that actually caused the disease. Thirty years later the TIP was shown to be a piece of a tumor inducing (Ti) plasmid excised by an endonuclease. In the next 20 years, most of the key features of the disease were described. The single-strand DNA (T-DNA) with the endonuclease attached is transferred through a type IV secretion system into the host cell where it is likely coated and protected from nucleases by a bacterial secreted protein to form the T-complex. A nuclear localization signal in the endonuclease guides the transferred strand (T-strand), into the nucleus where it is integrated randomly into the host chromosome. Other secreted proteins likely aid in uncoating the T-complex. The T-DNA encodes enzymes of auxin, cytokinin, and opine synthesis, the latter a food source for Agrobacterium. The genes associated with T-strand formation and transfer (vir) map to the Ti plasmid and are only expressed when the bacteria are in close association with a plant. Plant signals are recognized by a two-component regulatory system which activates vir genes. Chromosomal genes with pleiotropic functions also play important roles in plant transformation. The data now explain Braun's old observations and also explain why Agrobacterium is nature's genetic engineer. Any DNA inserted between the border sequences which define the T-DNA will be transferred and integrated into host cells. Thus, Agrobacterium has become the major vector in plant genetic engineering.

  5. Can Realism Be Naturalized?

    Directory of Open Access Journals (Sweden)

    Christopher Norris

    2000-06-01

    Full Text Available Hilary Putnam has famously undergone some radical changes of mind with regard to the issue of scientific realism and its wider epistemological bearings. In this paper I defend the arguments put forward by early Putnam in his essays on the causal theory of reference as applied to natural-kind terms, despite his own later view that those arguments amounted to a form of 'metaphysical' realism which could not be sustained against various lines of sceptical attack. I discuss some of the reasons for Putnam's retreat, first to the theory of 'internal (or framework-relative realism proposed in his middle-period writings, and then to a commonsense pragmatist stance which claims to resituate this whole discussion on ground that has not been trodden into ruts by the contending philosophical schools. In particular I examine his protracted engagement with various forms of anti-realist doctrine (Michael Dummet’s most prominent among them, with Wittgenstein's thinking about language-games or meaning-as-use, and with a range of skeptical - relativist positions adopted in the wake of Quine’s influential attack on the two last 'dogmas' of logical empiricism. My paper seeks to show that Putnam has been over-impressed by some of the arguments — from these and other sources — which he takes to constitute a knock-down case against the kind of externalist and causal-realist approach developed in his early essays. It concludes by re-stating that position in summary form and relating it to other, more recent defences of causal realism in epistemology and philosophy of science.

  6. Socioconomic nature of terrorism

    Directory of Open Access Journals (Sweden)

    Valeriy Petrovich Chichkanov

    2013-12-01

    Full Text Available In the article, the theoretical and methodological foundations of investigation of the  socioeconomic nature of terrorism are considered. Hypothesis of research is the existence of methodological criteria of territory classification on the basis of external and internal terrorism. On the basis of the analysis of theoretical works of national and foreign authors, normative documents of state and international level the genesis of approaches to the understanding of the essence of modern terrorism, its contents, the subject-object relations and manifestation forms is received. As the result, according to the authors’ definition “terrorism” is understood as an ideology connected with deliberate violence or threats against the civilian population or property to influence on the government or the interstate organizations. In the work, the factors of development and spreading of terrorism in the Russian Federation’s regions are allocated and quantitatively proved. Weight parameters of the specified factors are determined. The methodological differentiation of the specified factors on factors of terrorism external (attacks from the outside and an internal form (distribution and realization of radical ideas within the region in the territory is the distinctive feature of the conducted research. During the research, the cluster analysis of a region is carried out to distribute of Russia’s regions according to the typological characteristic of the region of internal and external terrorism. The obtained data are verified in accordance with empirical data, the hypothesis of the existence of methodological criteria of the region classification on the basis of external and internal terrorism is proved.

  7. Infección inducida en el roedor selvático Dasyprocta leporina (Rodentia: Dasyproctidae, con huevos larvados de Lagochilascaris minor (Nematoda: Ascarididae Induced infection in the wild rodent Dasyprocta leporina (Rodentia: Dasyproctidae with larval eggs of Lagochilascaris minor (Nematoda: Ascarididae

    Directory of Open Access Journals (Sweden)

    S. Gregorio

    1990-12-01

    Full Text Available Ejemplares de Dasyprocta leporina Linnaeus, 1758 fueron criados alejados de su ambiente natural. A los 3 ó 4 meses de edad, se los inoculó por vía oral con huevos de Lagochilascaris minor Leiper, 1909 obtenidos de una paciente nativa. Los huevos se los incubó por más de 80 dias, para que de ellos fuese posible obtener por compresión mecánica, larvas que se mantuviesen vivas en medio acuoso por 48 horas o más. Sacrificados los animales a los 14 ó 46 dias posteriores a la infección, se hallaron en los músculos esqueléticos larvas ovilladas dentro de nódulos inflamatorios, los cuales no presentaban reacción a cuerpo extraño, abscedación o calcificación. El desarollo de los nódulos no parecía afectar la normalidad de los hospedadores. Las larvas obtenidas eran similares a las descritas por SPRENT como de tercer estadio para estos helmintos. Ratones blancos infectados con material similar, no presentaron nódulos en sus músculos ni se pudo recuperar de sus tejidos larva alguna. Por los hallazgos obtenidos con la infección de estos animales, se postula que el helminto no posee ciclo pulmonar y que su desarrollo requiere de un hospedador intermediario.Specimens of Dasyprocta leporina (Linnaeus, 1758 were raised out their natural environment. At three to four months of age they were orally inoculated with Lagochilascaris minor (Leiper, 1909 eggs obtained from a native patient. The eggs were incubated for more than 80 days so that it was possible to obtain, by mechanical compression, larvae that could be maintained alive in liquid medium for 48 hours or more. The animals were sacrificed 14-46 days after infection and tangled larva in inflammatory nodules were found in skeletal muscle without foreign body reaction, abscess formation or calcification. The development of the nodules did not seem to affect the hosts. The larvae obtained were similar to those described by SPRENT as the third stage of these helminths. When white mice were

  8. Natural history and temporalization: reflections on Buffon's Natural history

    OpenAIRE

    Galfione, María Verónica

    2015-01-01

    This article presents a rereading of Buffon´s Natural History in the light of the concepts of temporal reversibility and irreversibility. The goal is to determine to what extent Buffon introduces a transformationist concept of natural forms in this work. To that effect, the main points of classical natural history and the doctrine of preformed germs are analyzed. Subsequently, Buffon´s use of the temporal variable is considered. This examination shows that despite his rejection of the theory ...

  9. Naturalism and un-naturalism among the Cartesian physicians

    OpenAIRE

    Manning, Gideon

    2008-01-01

    Highlighting early modern medicine's program of explanation and intervention, I claim that there are two distinctive features of the physician's naturalism. These are, first, an explicit recognition that each patient had her own individual and highly particularized nature and, second, a self-conscious use of normative descriptions when characterizing a patient's nature as healthy (ordered) or unhealthy (disordered). I go on to maintain that in spite of the well documented Cartesian rejection ...

  10. Nature's palette: the search for natural blue colorants.

    Science.gov (United States)

    Newsome, Andrew G; Culver, Catherine A; van Breemen, Richard B

    2014-07-16

    The food and beverage industry is seeking to broaden the palette of naturally derived colorants. Although considerable effort has been devoted to the search for new blue colorants in fruits and vegetables, less attention has been directed toward blue compounds from other sources such as bacteria and fungi. The current work reviews known organic blue compounds from natural plant, animal, fungal, and microbial sources. The scarcity of blue-colored metabolites in the natural world relative to metabolites of other colors is discussed, and structural trends common among natural blue compounds are identified. These compounds are grouped into seven structural classes and evaluated for their potential as new color additives.

  11. Natural gas and Brazilian energetic matrix; Gas natural no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Ricardo Luchese de [White Martins S.A., Rio de Janeiro, RJ (Brazil)

    1997-07-01

    Recent projection of the market in global scale shows a tendency in natural gas using replacing mostly the fuel oil. Its market share well increase from 21.1% in 1994 to 24.0% in 2010. The annual energetic use will reach 29.23 x 10{sup 9} Gcal in 2010 (8990 million Nm{sup 3} natural gas/day) versus 18.90 x 10{sup 9} Gcal in 1994 (5810 million Nm{sup 3} natural gas/day). For Brazil, its consumption will increase from 8.7 million Nm{sup 3} natural gas/day in 1994 to 35.9 million Nm{sup 3} natural gas/day in 2010. Projects like Brazil-Bolivia natural gas pipeline, will supply 18 million Nm{sup 3} natural gas/day, which expected to start-up before the year 2000. This projects will supply the Brazilian southern regions, that do not consume natural gas at the current moment. Although there are many different kind of natural gas consumption in the industry this paper presents the technical and economical estimate of the injection in the blast furnace operating with coke or charcoal. The process simulation is done assisted by math modeling developed by White Martins/Praxair Inc. (author)

  12. Comparación entre dos biomodelos murinos (ratones Balb/c y ratas Sprague Dawley en el ensayo de micronúcleos transplacentarios

    Directory of Open Access Journals (Sweden)

    Daniel Francisco Arencibia Arrebola

    2012-03-01

    Full Text Available Objetivo: comparar fetos de ratones Balb/c y ratas Sprague Dawley como biomodelos en el ensayo de micronúcleos transplacentarios, determinando la frecuencia espontánea e inducida, y vincular el efecto genotóxico y reproductivo. Métodos: se formaron tres grupos experimentales/especie: control negativo (simulacro, control solvente NaCl (0,9 % y ciclofosfamida 50 mg/kg. Todos los grupos se administraron por vía intraperitoneal los días 14, 15 y 16 de la gestación, y 24 h después de la última inoculación en ratones y 48 h en ratas se procedió a realizar la eutanasia de las gestantes, para obtener las muestras de hígado fetal. Resultados: los fetos de ratas Sprague Dawley demostraron tener menores índices de citotoxicidad y de genotoxicidad, y se obtuvieron los resultados más bajos de micronúcleos endógenos. Los mejores resultados de inducción de citotoxicidad y genotoxicidad por la alta formación de micronúcleos con ciclofosfamida fueron en fetos de ratas Sprague Dawley, los que resultaron más susceptibles al daño genotóxico de este mutágeno. Se corroboró el poder clastogénico transplacentario de la ciclofosfamida, vinculando este ensayo de genotoxicidad a toxicología de la reproducción. Conclusiones: los resultados sugieren el mejor uso de fetos de ratas Sprague Dawley como biomodelo en este ensayo cuando es utilizada la ciclofosfamida como control positivo por la vía y dosis estudiada; además, se pudieran utilizar en la evaluación de nuevas drogas con carácter antigenotóxico por vía transplacentaria.

  13. The naturalism of the sciences.

    Science.gov (United States)

    Dawes, Gregory W; Smith, Tiddy

    2018-02-01

    The sciences are characterized by what is sometimes called a "methodological naturalism," which disregards talk of divine agency. In response to those who argue that this reflects a dogmatic materialism, a number of philosophers have offered a pragmatic defense. The naturalism of the sciences, they argue, is provisional and defeasible: it is justified by the fact that unsuccessful theistic explanations have been superseded by successful natural ones. But this defense is inconsistent with the history of the sciences. The sciences have always exhibited what we call a domain naturalism. They have never invoked divine agency, but have always focused on the causal structure of the natural world. It is not the case, therefore, that the sciences once employed theistic explanations and then abandoned them. The naturalism of the sciences is as old as science itself. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Natural gas monthly, February 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-25

    The NGM highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. The NGM also features articles designed to assist readers in using and interpreting natural gas information.

  15. CEC natural analogue working group

    International Nuclear Information System (INIS)

    Come, B.; Chapman, N.A.

    1986-01-01

    The second meeting of the CEC Natural Analogue Working Group took place on June 17-19, 1986, hosted by the Swiss NAGRA in Interlaken (CH). A review of recent progress in natural analogue programmes was carried out, and complemented by detailed discussions about geomicrobiology, archaeological analogues, natural colloids, and use of analogues to increase confidence in safety assessments for radioactive waste disposal. A statement drafted by the Group, and the presentations made, are put together in this report

  16. Essentials of natural gas microturbines

    CERN Document Server

    Boicea, Valentin A

    2013-01-01

    Addressing a field which, until now, has not been sufficiently investigated, Essentials of Natural Gas Microturbines thoroughly examines several natural gas microturbine technologies suitable not only for distributed generation but also for the automotive industry. An invaluable resource for power systems, electrical, and computer science engineers as well as operations researchers, microturbine operators, policy makers, and other industry professionals, the book: Explains the importance of natural gas microturbines and their use in distributed energy resource (DER) systemsDiscusses the histor

  17. Plutonium in nature; Le plutonium dans la nature

    Energy Technology Data Exchange (ETDEWEB)

    Madic, C.

    1994-12-31

    Plutonium in nature comes from natural sources and anthropogenic ones. Plutonium at the earth surface comes principally from anthropogenic sources. It is easily detectable in environment. The plutonium behaviour in environment is complex. It seems necessary for the future to reduce releases in environment, to improve predictive models of plutonium behaviour in geosphere, to precise biological impact of anthropogenic plutonium releases.

  18. Super Natural II--a database of natural products.

    Science.gov (United States)

    Banerjee, Priyanka; Erehman, Jevgeni; Gohlke, Björn-Oliver; Wilhelm, Thomas; Preissner, Robert; Dunkel, Mathias

    2015-01-01

    Natural products play a significant role in drug discovery and development. Many topological pharmacophore patterns are common between natural products and commercial drugs. A better understanding of the specific physicochemical and structural features of natural products is important for corresponding drug development. Several encyclopedias of natural compounds have been composed, but the information remains scattered or not freely available. The first version of the Supernatural database containing ∼ 50,000 compounds was published in 2006 to face these challenges. Here we present a new, updated and expanded version of natural product database, Super Natural II (http://bioinformatics.charite.de/supernatural), comprising ∼ 326,000 molecules. It provides all corresponding 2D structures, the most important structural and physicochemical properties, the predicted toxicity class for ∼ 170,000 compounds and the vendor information for the vast majority of compounds. The new version allows a template-based search for similar compounds as well as a search for compound names, vendors, specific physical properties or any substructures. Super Natural II also provides information about the pathways associated with synthesis and degradation of the natural products, as well as their mechanism of action with respect to structurally similar drugs and their target proteins. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  19. Connection to Nature: Children's Affective Attitude toward Nature

    Science.gov (United States)

    Cheng, Judith Chen-Hsuan; Monroe, Martha C.

    2012-01-01

    A connection to nature index was developed and tested to measure children's affective attitude toward the natural environment. The index was employed through a survey that investigates students' attitude toward Lagoon Quest, a mandatory environmental education program for all fourth-grade, public school students in Brevard County, Florida. Factor…

  20. Imagining Nature during Music Listening

    DEFF Research Database (Denmark)

    Bonde, Lars Ole; Beck, Bolette Daniels

    2018-01-01

    Nature, its delights and horrors, its creatures, its challenges and affordances play an underrated role in receptive music therapy, especially Guided Imagery and Music (GIM). In general, people from Western cultures are challenged in their mostly recreational relationship with nature, while ancient...... and traditional cultures worship nature as a place of holiness and wholeness. In GIM, a client or a group listens to music in a relaxed state and multi-modal imagery is evoked and supported by the music. The imagery is shared with the guide/therapist. This chapter will focus on ‘nature imagery’ in GIM through...... a primarily qualitative, exploratory study....

  1. Finland's leading natural gas company

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    The ownership structure of Finland's leading natural gas company, Gasum, changed fundamentally in 1999, and the company is now no longer a subsidiary of Fortum Corporation. 'Our new strong and broad ownership base will enable us to develop the natural gas business and pipeline network in Finland in response to the requirements of our Finnish customers', says Antero Jaennes, Gasum's Chairman and CEO, who stresses that Gasum is committed to remaining the leading developer of the Finnish natural gas market and the number-one gas supplier. Natural gas usage in Finland in 1999 totalled 3.9 billion m 3 (38.7 TWh), unchanged from 1998. Natural gas accounted for 11% of Finland's total primary energy need, as it did in 1998. The proportion of natural gas used in district heating rose by 2% to 36%, and moved down 2% in power generation to 10%. Industry's use of natural gas fell 1% to 17%. 75% of natural gas was used in combined heat and power (CHP) generation in industry and district heating. In 2000, Gasum expects to sell 4 billion m 3 of natural gas (40 TWh)

  2. Exploiting natural variation in Arabidopsis

    NARCIS (Netherlands)

    Molenaar, J.A.; Keurentjes, J.J.B.; Sanchez-Serrano, J.J.; Salinas, J.

    2014-01-01

    Natural variation for many traits is present within the species Arabidopsis thaliana. This chapter describes the use of natural variation to elucidate genes underlying the regulation of quantitative traits. It deals with the development and use of mapping populations, the detection and handling of

  3. North American Natural Gas Vision

    Science.gov (United States)

    2005-01-01

    hand sales of natural gas and LPG. 17 Decreto Legal, Diario Oficial , Noviembre 25, 1993. 37 Review Section 38 Figure 2. Mexican Natural Gas...California 500 Mexicali Baja California 29 Naco - Hermosillo Sonora 130 Nacozari de Garcia Sonora 85 Agua Prieta Sonora 173

  4. Czech Children's Drawing of Nature

    Science.gov (United States)

    Yilmaz, Zuhal; Kubiatko, Milan; Topal, Hatice

    2012-01-01

    Do world children draw nature pictures in a certain way? Range of mountains in the background, a sun, couple clouds, a river rising from mountains. Is this type of drawing universal in the way these nature items are organized on a drawing paper? The sample size from Czech Republic included 33 participants from two kindergartens. They were 5 and 6…

  5. Natural gas monthly, July 1990

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-03

    This report highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. A glossary is included. 7 figs., 33 tabs.

  6. Commentary: Biochemistry Re-Natured

    Science.gov (United States)

    White, Harold B.

    2010-01-01

    In his last commentary on "Biochemistry Denatured," this author dealt with his perception that college students today have spent too little of their childhood years playing outside in nature and as a consequence have not learned basic things about the world from personal experience. This "nature-deficit disorder" removes many opportunities for…

  7. Teaching about Natural Background Radiation

    Science.gov (United States)

    Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

    2013-01-01

    Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

  8. NATURE-RURAL SETTLEMENT INTERACTIONS

    Directory of Open Access Journals (Sweden)

    Zehra Eminağaoğlu

    2006-04-01

    Full Text Available Conservation and management of natural environments are generally brought up upon adverse developments against nature in the humannature interactions. Although individual actions are often considered to be more immediate innatıre-related issuesi ecologic problems tend to spread in time and lead to reginol or even global problems. For this reason, it stands imperative that economic, ecologic and aesthetic values of the environment we live in be protected and used sustainably. Being the scene of nature and the environment landscape signifies the whole with living and nonliving entities where we live in. Dameged and destroyed landscape scenes particularly in urban areas necessitaites the reconsideration of human-nature relations and nature-frendly life style. This study investigates the rural settlements that show harmony with nature and reflects qualities of natural environments on the dwellings. Particularly, with the examples of drawing and pictures it examines the associatiation of rural settlements with nature as well as the use of the green as an occasional or spacial element.

  9. Crack Velocities in Natural Rubber.

    Science.gov (United States)

    1982-05-01

    vulcanized natural rubber (3). The surprisingly low value for natural rubber was attributed to highly anisotropic elastic behavior at high strains...Dr. R.L. Rabie Hercules Incorporated WX-2, MS-952 Alleghany Ballistic Lab Los Alamos National Lab. P.O. Box 210 P.O. Box 1663 Washington, D.C. 21502

  10. Natural sources of ionizing radiations

    International Nuclear Information System (INIS)

    Marej, A.N.

    1984-01-01

    Natural sources of ionizing radiations are described in detail. The sources are subdivided into sources of extraterrestrial origin (cosmic radiation) and sources of terrestrial origin. Data on the concentration of different nuclides in rocks, various soils, ground waters, atmospheric air, tissues of plants and animals, various food stuffs are presented. The content of natural radionuclides in environmental objects, related to human activities, is discussed

  11. Multiscale scenarios for nature futures

    NARCIS (Netherlands)

    Rosa, Isabel M.D.; Pereira, Henrique Miguel; Ferrier, Simon; Alkemade, J.R.M.; Acosta, Lilibeth A.; Resit Akcakaya, H.; Belder, den E.; Fazel, Asghar M.; Fujimori, Shinichiro; Harfoot, Mike; Harhash, Khaled A.; Harrison, Paula A.; Hauck, Jennifer; Hendriks, Rob J.J.; Hernández, Gladys; Jetz, Walter; Karlsson-Vinkhuyzen, S.I.S.E.; Kim, Hyejin; King, Nicholas; Kok, Marcel; Kolomytsev, Grygoriy O.; Lazarova, Tanya; Leadley, Paul; Lundquist, Carolyn J.; García Márquez, Jaime; Meyer, Carsten; Navarro, Laetitia M.; Nesshöver, Carsten; Ngo, Hien T.; Ninan, Karachepone N.; Palomo, Maria G.; Pereira, Laura; Peterson, G.D.; Pichs, Ramon; Popp, Alexander; Purvis, Andy; Ravera, Federica; Rondinini, Carlo; Sathyapalan, Jyothis; Schipper, Aafke; Seppelt, Ralf; Settele, Josef; Sitas, Nadia; Vuuren, van D.

    2017-01-01

    Targets for human development are increasingly connected with targets for nature, however, existing scenarios do not explicitly address this relationship. Here, we outline a strategy to generate scenarios centred on our relationship
    with nature to inform decision-making at multiple scales.

  12. Multiscale scenarios for nature futures

    NARCIS (Netherlands)

    Rosa, Isabel M.D.; Pereira, Henrique M.; Ferrier, Simon; Alkemade, Rob; Acosta, Lilibeth A.; Akcakaya, H. Resit; Den Belder, Eefje; Fazel, Asghar M.; Fujimori, Shinichiro; Harfoot, Mike; Harhash, Khaled A.; Harrison, Paula A.; Hauck, Jennifer; Hendriks, Rob J.J.; Hernández, Gladys; Jetz, Walter; Karlsson-Vinkhuyzen, Sylvia I.; Kim, Hyejin; King, Nicholas; Kok, Marcel T.J.; Kolomytsev, Grygoriy O.; Lazarova, Tanya; Leadley, Paul; Lundquist, Carolyn J.; García Márquez, Jaime; Meyer, Carsten; Navarro, Laetitia M.; Nesshöver, Carsten; Ngo, Hien T.; Ninan, Karachepone N.; Palomo, Maria G.; Pereira, Laura M.; Peterson, Garry D.; Pichs, Ramon; Popp, Alexander; Purvis, Andy; Ravera, Federica; Rondinini, Carlo; Sathyapalan, Jyothis; Schipper, Aafke M.; Seppelt, Ralf; Settele, Josef; Sitas, Nadia; Van Vuuren, Detlef|info:eu-repo/dai/nl/11522016X

    2017-01-01

    Targets for human development are increasingly connected with targets for nature, however, existing scenarios do not explicitly address this relationship. Here, we outline a strategy to generate scenarios centred on our relationship with nature to inform decision-making at multiple scales.

  13. Alternative sources of natural rubber

    NARCIS (Netherlands)

    Mooibroek, H.; Cornish, K.

    2000-01-01

    Rubber (cis-1,4-polyisoprene) is one of the most important polymers naturally produced by plants because it is a strategic raw material used in more than 40,000 products, including more than 400 medical devices. The sole commercial source, at present, is natural rubber harvested from the Brazilian

  14. Natural Gas Energy Educational Kit.

    Science.gov (United States)

    American Gas Association, Arlington, VA. Educational Services.

    Prepared by energy experts and educators to introduce middle school and high school students to natural gas and its role in our society, this kit is designed to be incorporated into existing science and social studies curricula. The materials and activities focus on the origin, discovery, production, delivery, and use of natural gas. The role of…

  15. The Oscillator Principle of Nature

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2012-01-01

    Oscillators are found on all levels in Nature. The general oscillator concept is defined and investigated. Oscillators may synchronize into fractal patterns. Apparently oscillators are the basic principle in Nature. The concepts of zero and infinite are discussed. Electronic manmade oscillators...

  16. Natural disasters and human mobility

    NARCIS (Netherlands)

    Mbaye, L.; Zimmermann, K.

    2016-01-01

    This paper reviews the effect of natural disasters on human mobility or migration. Although there is an increase of natural disasters and migration recently and more patterns to observe, the relationship remains complex. While some authors find that disasters increase migration, others show that

  17. Fascinating Organic Molecules from Nature

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 18; Issue 5. Fascinating Organic Molecules from Nature - Using a Natural ... Road Banashankari 2nd Stage Bangalore 560 070, India. Department of Chemistry Sri Sathya Sai Institute of Higher Learning Brindavan Campus Bangalore 560 067, India.

  18. Natural selection promotes antigenic evolvability

    NARCIS (Netherlands)

    Graves, C.J.; Ros, V.I.D.; Stevenson, B.; Sniegowski, P.D.; Brisson, D.

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide

  19. A natural human hand model

    NARCIS (Netherlands)

    Van Nierop, O.A.; Van der Helm, A.; Overbeeke, K.J.; Djajadiningrat, T.J.P.

    2007-01-01

    We present a skeletal linked model of the human hand that has natural motion. We show how this can be achieved by introducing a new biology-based joint axis that simulates natural joint motion and a set of constraints that reduce an estimated 150 possible motions to twelve. The model is based on

  20. Natural radioactivity of the diet

    Energy Technology Data Exchange (ETDEWEB)

    Jeanmaire, L [CEA, CEN Fontenay-aux-Roses, Institut de Protection et de Surete Nucleaire, Departement de Protection Sanitaire, 92 (France)

    1985-01-01

    The so-called ''natural'' radionuclides are present in food in different proportions according to the nature and origin of the food products. After a summary of the principles allowing to understand environmental transfers, a study is made of the respective radionuclides to be found in food.

  1. Natur und Moderne um 1900

    DEFF Research Database (Denmark)

    , nordeuropäischen Vergleich widmen sich die Beiträge den medialen Repräsentationen von Natur (in Literatur, Philosophie, Film, Foto) ebenso wie der Kolonisierung des Raumes (in Tourismus, Reisen, Sport, Natur- und Heimatschutz). Der Band bietet damit auch Impulse für die neuen theoretisch-methodischen Ansätze der...

  2. Orlice Nature Park - environmental themes

    International Nuclear Information System (INIS)

    Hanus, L.

    2002-01-01

    The aim of this abstract is to outline the main characteristics of Orlice Nature Park and of the procedure of Environmental Impact Assessment (EIA), and to evaluate public interest in the nature park and in nature protection in general. Orlice Nature Park was instituted in 1996. The function of the park is to protect the character of the area of landscape around the River Orlice. Orlice Natural Park covers an area of 115 sq. km. The main environmental risks to the park are: intensive agriculture, forest mono-culture, industry, transport, channel improvement, the building of holiday cottages, sport, and recreation. Among the conflicts of interest in the park are: nature protection, water management, building constrictions, business, fishery, water sports and recreation. During the process of Environmental Impact Assessment in Hradec Kralove, the public voiced its opinion against the building of a supermarket within the grounds of of the nature park. In this case the public showed its interest in the value of nature and landscape, the value of human health and the value of plant species. In general, the public and the local media show an interest in the park only in exceptional circumstances. (author)

  3. The Case for Natural History

    DEFF Research Database (Denmark)

    King, Heather; Achiam, Marianne

    2017-01-01

    on the educational value afforded by understanding the epistemological bases of natural history and its particular forms of reasoning. We also briefly discuss the ways in which an education in natural history provides the foundation for environmental and social justice efforts that directly affect the lives of young...

  4. Egyptian Journal of Natural History

    African Journals Online (AJOL)

    The Egyptian Journal of Natural History publishes taxonomic and faunistic studies, or field-based research involving the natural history of the Egyptian fauna and flora. Both short and long papers are welcomed. We particularly encourage studies on Sinai.View the Instructions for authors All papers are reviewed by at least ...

  5. Natural gas monthly, December 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    This document highlights activities, events, and analysis of interest to the public and private sector associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also included.

  6. The Problem of Naturalizing Semantics.

    Science.gov (United States)

    Sullivan, Arthur

    2000-01-01

    Investigates conceptual barriers prevalent in the works of both proponents and opponents of semantic naturalism. Searches for a tenable definition of naturalism according to which one can be a realist, a non-reductionist, and a naturalist about semantic content. (Author/VWL)

  7. Innovations for Natural Resource Management

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Improving input use efficiency and sustainable management of natural resource endowments - a continuous challenge. Improving input use efficiency and sustainable management of natural resource endowments - a continuous challenge. Innovations have focused on ...

  8. Measurement of natural background neutron

    CERN Document Server

    Li Jain, Ping; Tang Jin Hua; Tang, E S; Xie Yan Fong

    1982-01-01

    A high sensitive neutron monitor is described. It has an approximate counting rate of 20 cpm for natural background neutrons. The pulse amplitude resolution, sensitivity and direction dependence of the monitor were determined. This monitor has been used for natural background measurement in Beijing area. The yearly average dose is given and compared with the results of KEK and CERN.

  9. Bring money and natural gas

    International Nuclear Information System (INIS)

    Van Gelder, J.W.

    1993-01-01

    The budding natural gas markets in East Europe attract a great deal of interest from natural gas industries in the Western countries. Dutch companies, institutions and the government, too, are active in this market. So far the results have not been spectacular. An analysis is made of the present situation and the Dutch approach

  10. Combinatorial synthesis of natural products

    DEFF Research Database (Denmark)

    Nielsen, John

    2002-01-01

    Combinatorial syntheses allow production of compound libraries in an expeditious and organized manner immediately applicable for high-throughput screening. Natural products possess a pedigree to justify quality and appreciation in drug discovery and development. Currently, we are seeing a rapid...... increase in application of natural products in combinatorial chemistry and vice versa. The therapeutic areas of infectious disease and oncology still dominate but many new areas are emerging. Several complex natural products have now been synthesised by solid-phase methods and have created the foundation...... for preparation of combinatorial libraries. In other examples, natural products or intermediates have served as building blocks or scaffolds in the synthesis of complex natural products, bioactive analogues or designed hybrid molecules. Finally, structural motifs from the biologically active parent molecule have...

  11. Natural Disasters and Nontuberculous Mycobacteria

    Science.gov (United States)

    Bernhard, Jon N.; Chan, Edward D.

    2015-01-01

    Infectious diseases acquired by survivors of large-scale natural disasters complicate the recovery process. During events such as tsunamis, hurricanes, earthquakes, and tornados and well into the recovery period, victims often are exposed to water-soil mixtures that have relocated with indigenous microbes. Because nontuberculous mycobacteria (NTM) are ubiquitous in water and soil, there is potential for increased exposure to these organisms during natural disasters. In this hypothesis-driven commentary, we discuss the rise in NTM lung disease and natural disasters and examine the geographic overlap of NTM infections and disaster frequencies in the United States. Moreover, we show an increased number of positive NTM cultures from Louisiana residents in the years following three of the relatively recent epic hurricanes and posit that such natural disasters may help to drive the increased number of NTM infections. Finally, we advocate for increased environmental studies and surveillance of NTM infections before and after natural disasters. PMID:25644904

  12. Radiation stability of animate nature

    International Nuclear Information System (INIS)

    Romanov, G.N.; Spirin, D.A.

    1990-01-01

    The main principles of radiation safety for animate nature including provisions for biological species protection and main requirement for animate nature radiation protection, which is the guarantee of any ecosystem integrity, are discussed. Ecosystem should be taken as the objective unit for animate nature radiation protection. The maximum dose of biot irradiation may amount to 0.5 Gy/year, which is 20-fold lower than the main dose limit for animate nature and 40-fold lower than ecological dose limits for conifers as the weakest radiostable member in ecosystem, at environment radioactive contamination determined by radiation safety standards. The radiation protection of animate nature is guaranteed at such levels of environment radioactive contamination

  13. Mathematics in Nature Modeling Patterns in the Natural World

    CERN Document Server

    Adam, John A

    2011-01-01

    From rainbows, river meanders, and shadows to spider webs, honeycombs, and the markings on animal coats, the visible world is full of patterns that can be described mathematically. Examining such readily observable phenomena, this book introduces readers to the beauty of nature as revealed by mathematics and the beauty of mathematics as revealed in nature.Generously illustrated, written in an informal style, and replete with examples from everyday life, Mathematics in Nature is an excellent and undaunting introduction to the ideas and methods of mathematical modeling. It illustrates how mathem

  14. The Science of Middle Nature

    Science.gov (United States)

    Pataki, D. E.; Pincetl, S.

    2012-12-01

    In the field of biogeochemistry, urbanization is often considered as an "alteration" or "disturbance" to the earth's surface and its natural processes. This view is an outcome of the view of nature inherent in earth system science and ecology, in which nature is defined as separate from humans and society. However, other disciplines are based in alternative views of nature in which humans are more integral components of the landscape. Urban planning, landscape architecture, agriculture, and horticulture, for example, more fully integrate the role of landscape design and management in the functioning of human-dominated ecosystems. We suggest that the field of urban biogeochemistry has been somewhat limited by the predominant, disturbance-based view of the role of nature in cities, and that more deeply evaluating and broadening the concept of nature inherent in studies of urban processes can enhance our understanding of the role of urbanization in the earth system. A particularly useful concept is the "middle nature" proposed by Cosgrove (1993), which serves a purpose of "actively transforming nature into culture." It is this view of urban landscapes as middle nature, or transformation of urban space into human-dominated nature with a purpose, that is lacking from the current scientific discourse about the role of biogeochemistry in urban ecosystem services. A scientific evaluation of middle nature implies studying the performance of urban designs to meet intended cultural and environmental goals, including beauty, social equity, governance, and social capital as well as environmental quality. We describe our work in evaluating the transformed urban landscapes of Los Angeles from multiple perspectives that focus on urban livability, equity, and beauty as well as the physical impacts of plants and soils on the environment. The outcomes of this process do not necessary meet the traditional demands of biophysical ecology such as utilizing native species, maximizing

  15. Natural gas pipeline technology overview.

    Energy Technology Data Exchange (ETDEWEB)

    Folga, S. M.; Decision and Information Sciences

    2007-11-01

    The United States relies on natural gas for one-quarter of its energy needs. In 2001 alone, the nation consumed 21.5 trillion cubic feet of natural gas. A large portion of natural gas pipeline capacity within the United States is directed from major production areas in Texas and Louisiana, Wyoming, and other states to markets in the western, eastern, and midwestern regions of the country. In the past 10 years, increasing levels of gas from Canada have also been brought into these markets (EIA 2007). The United States has several major natural gas production basins and an extensive natural gas pipeline network, with almost 95% of U.S. natural gas imports coming from Canada. At present, the gas pipeline infrastructure is more developed between Canada and the United States than between Mexico and the United States. Gas flows from Canada to the United States through several major pipelines feeding U.S. markets in the Midwest, Northeast, Pacific Northwest, and California. Some key examples are the Alliance Pipeline, the Northern Border Pipeline, the Maritimes & Northeast Pipeline, the TransCanada Pipeline System, and Westcoast Energy pipelines. Major connections join Texas and northeastern Mexico, with additional connections to Arizona and between California and Baja California, Mexico (INGAA 2007). Of the natural gas consumed in the United States, 85% is produced domestically. Figure 1.1-1 shows the complex North American natural gas network. The pipeline transmission system--the 'interstate highway' for natural gas--consists of 180,000 miles of high-strength steel pipe varying in diameter, normally between 30 and 36 inches in diameter. The primary function of the transmission pipeline company is to move huge amounts of natural gas thousands of miles from producing regions to local natural gas utility delivery points. These delivery points, called 'city gate stations', are usually owned by distribution companies, although some are owned by

  16. Natural Nanoparticles: A Particular Matter Inspired by Nature

    Directory of Open Access Journals (Sweden)

    Sharoon Griffin

    2017-12-01

    Full Text Available During the last couple of decades, the rapidly advancing field of nanotechnology has produced a wide palette of nanomaterials, most of which are considered as “synthetic” and, among the wider public, are often met with a certain suspicion. Despite the technological sophistication behind many of these materials, “nano” does not always equate with “artificial”. Indeed, nature itself is an excellent nanotechnologist. It provides us with a range of fine particles, from inorganic ash, soot, sulfur and mineral particles found in the air or in wells, to sulfur and selenium nanoparticles produced by many bacteria and yeasts. These nanomaterials are entirely natural, and, not surprisingly, there is a growing interest in the development of natural nanoproducts, for instance in the emerging fields of phyto- and phyco-nanotechnology. This review will highlight some of the most recent—and sometimes unexpected—advances in this exciting and diverse field of research and development. Naturally occurring nanomaterials, artificially produced nanomaterials of natural products as well as naturally occurring or produced nanomaterials of natural products all show their own, particular chemical and physical properties, biological activities and promise for applications, especially in the fields of medicine, nutrition, cosmetics and agriculture. In the future, such natural nanoparticles will not only stimulate research and add a greener outlook to a traditionally high-tech field, they will also provide solutions—pardon—suspensions for a range of problems. Here, we may anticipate specific biogenic factories, valuable new materials based on waste, the effective removal of contaminants as part of nano-bioremediation, and the conversion of poorly soluble substances and materials to biologically available forms for practical uses.

  17. New methods for assessing the fascinating nature of nature experiences.

    Science.gov (United States)

    Joye, Yannick; Pals, Roos; Steg, Linda; Evans, Ben Lewis

    2013-01-01

    In recent years, numerous environmental psychology studies have demonstrated that contact with nature as opposed to urban settings can improve an individual's mood, can lead to increased levels of vitality, and can offer an opportunity to recover from stress. According to Attention Restoration Theory (ART) the restorative potential of natural environments is situated in the fact that nature can replenish depleted attentional resources. This replenishment takes place, in part, because nature is deemed to be a source of fascination, with fascination being described as having an "attentional", an "affective" and an "effort" dimension. However, the claim that fascination with nature involves these three dimensions is to a large extent based on intuition or derived from introspection-based measurement methods, such as self-reports. In three studies, we aimed to more objectively assess whether these three dimensions indeed applied to experiences related to natural environments, before any (attentional) depletion has taken place. The instruments that were used were: (a) the affect misattribution procedure (Study 1), (b) the dot probe paradigm (Study 2) and (c) a cognitively effortful task (Study 3). These instrument were respectively aimed at verifying the affective, attentional and effort dimension of fascination. Overall, the results provide objective evidence for the claims made within the ART framework, that natural as opposed to urban settings are affectively positive (cfr., affective dimension) and that people have an attentional bias to natural (rather than urban) environments (cfr., attentional dimension). The results regarding the effort dimension are less straightforward, and suggest that this dimension only becomes important in sufficiently difficult cognitive tasks.

  18. New Methods for Assessing the Fascinating Nature of Nature Experiences

    Science.gov (United States)

    Joye, Yannick; Pals, Roos; Steg, Linda; Evans, Ben Lewis

    2013-01-01

    In recent years, numerous environmental psychology studies have demonstrated that contact with nature as opposed to urban settings can improve an individual’s mood, can lead to increased levels of vitality, and can offer an opportunity to recover from stress. According to Attention Restoration Theory (ART) the restorative potential of natural environments is situated in the fact that nature can replenish depleted attentional resources. This replenishment takes place, in part, because nature is deemed to be a source of fascination, with fascination being described as having an “attentional”, an “affective” and an “effort” dimension. However, the claim that fascination with nature involves these three dimensions is to a large extent based on intuition or derived from introspection-based measurement methods, such as self-reports. In three studies, we aimed to more objectively assess whether these three dimensions indeed applied to experiences related to natural environments, before any (attentional) depletion has taken place. The instruments that were used were: (a) the affect misattribution procedure (Study 1), (b) the dot probe paradigm (Study 2) and (c) a cognitively effortful task (Study 3). These instrument were respectively aimed at verifying the affective, attentional and effort dimension of fascination. Overall, the results provide objective evidence for the claims made within the ART framework, that natural as opposed to urban settings are affectively positive (cfr., affective dimension) and that people have an attentional bias to natural (rather than urban) environments (cfr., attentional dimension). The results regarding the effort dimension are less straightforward, and suggest that this dimension only becomes important in sufficiently difficult cognitive tasks. PMID:23922645

  19. Adsorptive storage of natural gas

    International Nuclear Information System (INIS)

    Yan, Song; Lang, Liu; Licheng, Ling

    2001-01-01

    The Adsorbed Natural Gas (ANG) storage technology is reviewed. The present status, theoretical limits and operational problems are discussed. Natural gas (NG) has a considerable advantage over conventional fuels both from an environmental point of view and for its natural abundance. However, as well known, it has a two fold disadvantage compared with liquid fuels: it is relatively expensive to transport from the remote areas, and its energy density (heat of combustion/volume) is low. All these will restrict its use. Compressed natural gas (CNG) may be a solution, but high pressures are needed (up to 25 MPa) for use in natural-gas fueled vehicles, and the large cost of the cylinders for storage and the high-pressure facilities necessary limit the practical use of CNG. Alternatively, adsorbed natural gas (ANG) at 3 - 4 MPa offers a very high potential for exploitation in both transport and large-scale applications. At present, research about this technology mainly focuses on: to make adsorbents with high methane adsorption capacity; to make clear the effects of heat of adsorption and the effect of impurities in natural gas on adsorption and desorption capacity. This paper provides an overview of current technology and examines the relations between fundamentals of adsorption and ANG storage. (authors)

  20. Natural killer cells in psoriasis.

    LENUS (Irish Health Repository)

    Tobin, A M

    2012-02-01

    Psoriasis is one of the most common immune-mediated disorders. There is evidence that it is mediated by Th1 and, more recently, Th17 cells. The cytokine pattern, particularly the dominance of TNF-alpha, implicates the innate immune system in psoriasis pathogenesis. Of the many components of the innate immune system known to be involved in psoriatic lesions, natural killer and natural killer T cells appear to have a unique role. We review the evidence supporting a role for natural killer cells in psoriasis.

  1. Natural Fiber Composites: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Westman, Matthew P.; Fifield, Leonard S.; Simmons, Kevin L.; Laddha, Sachin; Kafentzis, Tyler A.

    2010-03-07

    The need for renewable fiber reinforced composites has never been as prevalent as it currently is. Natural fibers offer both cost savings and a reduction in density when compared to glass fibers. Though the strength of natural fibers is not as great as glass, the specific properties are comparable. Currently natural fiber composites have two issues that need to be addressed: resin compatibility and water absorption. The following preliminary research has investigated the use of Kenaf, Hibiscus cannabinus, as a possible glass replacement in fiber reinforced composites.

  2. Becquerel and natural origin radioactivity

    International Nuclear Information System (INIS)

    2011-01-01

    After a brief presentation of the Becquerel as radioactivity measurement unit, this document briefly explains the origin of natural radioactivity (Earth formation and cosmic rays), gives and comments the evolution of radioactivity of some radionuclides (U 238 and descendants, Th 232 and descendants, K 40 ) between 4.5 billions yeas ago and nowadays. It also gives assessments of natural radioactivity due to radon in the atmosphere and in the soil, of natural radioactivity in building materials, coals, ashes, seawater and food. Some remarkable figures are then given

  3. Natural Law and Mechanical Engineering

    Directory of Open Access Journals (Sweden)

    P. C. Haarhoff

    1984-03-01

    Full Text Available The first technological revolution, in the fourth millennium BC, was followed by immense social progress. The second revolution, which is now taking place, could lead to an even greater development in the human sciences, by setting men free from their daily struggle for existence while simultaneously exacting high social standards. Natural law - the “marriage between the ways of heaven and the ways of earth” of the Chinese - represents a route to such progress. In natural science and technology, natural law demands that conclusions be based on observation rather than speculation. The social sciences would do well to follow this example.

  4. Natural current profiles in tokamaks

    International Nuclear Information System (INIS)

    Biskamp, D.

    1986-01-01

    It is proposed that a certain class of equilibrium, which follow from an elementary variational principle, are the natural current profiles in tokamaks, to which actual discharge profiles tend to relax. (orig.)

  5. Natural disasters and the lung.

    Science.gov (United States)

    Robinson, Bruce; Alatas, Mohammad Fahmi; Robertson, Andrew; Steer, Henry

    2011-04-01

    As the world population expands, an increasing number of people are living in areas which may be threatened by natural disasters. Most of these major natural disasters occur in the Asian region. Pulmonary complications are common following natural disasters and can result from direct insults to the lung or may be indirect, secondary to overcrowding and the collapse in infrastructure and health-care systems which often occur in the aftermath of a disaster. Delivery of health care in disaster situations is challenging and anticipation of the types of clinical and public health problems faced in disaster situations is crucial when preparing disaster responses. In this article we review the pulmonary effects of natural disasters in the immediate setting and in the post-disaster aftermath and we discuss how this could inform planning for future disasters. © 2011 The Authors. Respirology © 2011 Asian Pacific Society of Respirology.

  6. Canadian natural gas price debate

    International Nuclear Information System (INIS)

    Wight, G.

    1998-01-01

    Sunoco Inc. is a subsidiary of Suncor Energy, one of Canada's largest integrated energy companies having total assets of $2.8 billion. As one of the major energy suppliers in the country, Sunoco Inc has a substantial stake in the emerging trends in the natural gas industry, including the Canadian natural gas price debate. Traditionally, natural gas prices have been determined by the number of pipeline expansions, weather, energy supply and demand, and storage levels. In addition to all these traditional factors which still apply today, the present day natural gas industry also has to deal with deregulation, open competition and the global energy situation, all of which also have an impact on prices. How to face up to these challenges is the subject of this discourse. tabs., figs

  7. Methane-bomb natural gas

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    About 50% of the so-called 'greenhouse-effect' is not caused by CO 2 , but by more dangerous gases, among them is methane. Natural gas consists to about 98% of methane. In Austria result about 15% of the methane emissions from offtake, storage, transport (pipelines) and distribution from natural gas. A research study of the Research Centre Seibersdorf points out that between 2.5% and 3.6% of the employed natural gas in Austria emits. The impact of this emitted methane is about 29 times worse than the impact of CO 2 (caused for examples by petroleum burning). Nevertheless the Austrian CO 2 -commission states that an increasing use of natural gas would decrease the CO 2 -emissions - but this statement is suspected to be based on wrong assumptions. (blahsl)

  8. Human economy and natural economy

    Directory of Open Access Journals (Sweden)

    Masullo Andrea

    2014-03-01

    Full Text Available The decline of economy is due to its dependency from a virtual value, the currency, the coin, that in the recent phase of consumerism is so far from real value: human capital and natural capital. If human economy wants to continue to produce wellbeing, it must accept to be a subset of natural economy, intercept flux of matter produced by its circular mechanisms, put constraints in it, i.e. machines and structures, to direct it temporarily for our advantage, and finally release it to the same original flux, in an still usable state. In this way it will assume a function no more parasitic but symbiotic. It will be connected to natural cycles without destroying it, recovering the co-evolutionary link between nature and culture, building an economic web suited to the ecological web; thus we will have a mosaic characterised by biodiversity, technological diversity, and cultural diversity, able to produce a durable prosperity.

  9. Computing nature turing centenary perspective

    CERN Document Server

    Giovagnoli, Raffaela

    2013-01-01

    This book is about nature considered as the totality of physical existence, the universe, and our present day attempts to understand it. If we see the universe as a network of networks of computational processes at many different levels of organization, what can we learn about physics, biology, cognition, social systems, and ecology expressed through interacting networks of elementary particles, atoms, molecules, cells, (and especially neurons when it comes to understanding of cognition and intelligence), organs, organisms and their ecologies? Regarding our computational models of natural phenomena Feynman famously wondered: “Why should it take an infinite amount of logic to figure out what one tiny piece of space/time is going to do?” Phenomena themselves occur so quickly and automatically in nature. Can we learn how to harness nature’s computational power as we harness its energy and materials? This volume includes a selection of contributions from the Symposium on Natural Computing/Unconventional Com...

  10. Natural hazard and disaster tourism

    Directory of Open Access Journals (Sweden)

    Rucińska Dorota

    2014-03-01

    Full Text Available An observed trend, which can be defined as tourist interest in natural hazards and disasters, has persuaded the authors to attempt to research several issues, including tourist motivations and specific tourism properties and functions of this form of activity. The objective also covered the allocation of this social and natural process in the general structure of tourism. This interest has a long history, and a new stage is currently forming, which partly results from factors affecting society, such as information and education, which provoke antagonistic reactions. Extreme natural phenomena entail a common reduction of tourist interest in the destination which hosted the event; however, it never drops to zero. Differences are visible depending on the type of phenomenon. On the other hand, natural hazards and disasters are considered to hold a specific tourism value. This article discusses the allocation of this human activity in the tourism forms known to scientists, accounting for its diversity and relating to ethics.

  11. Natural gas and the environment

    International Nuclear Information System (INIS)

    DeCarufel, A.

    1991-01-01

    The role of various atmospheric pollutants in environmental changes and the global water cycle, carbon cycle, and energy balance is explained. The role of sulfur dioxide and nitrogen oxides in acid deposition is also outlined. The pollutants that contribute to environmental problems include nitrogen oxides and volatile organic compounds, carbon dioxide, and other greenhouse gases. The potential for natural gas utilization to mitigate some of these pollution problems is explored. Natural gas combustion emits less carbon dioxide and nitrogen oxides than combustion of other fossil fuel, and also does not produce sulfur dioxide, particulates, or volatile organics. Other pollution controlling opportunities offered by natural gas include the use of low-polluting burners, natural gas vehicles, and cogeneration systems. 18 figs., 4 tabs

  12. Natural resources and control processes

    CERN Document Server

    Wang, Mu-Hao; Hung, Yung-Tse; Shammas, Nazih

    2016-01-01

    This edited book has been designed to serve as a natural resources engineering reference book as well as a supplemental textbook. This volume is part of the Handbook of Environmental Engineering series, an incredible collection of methodologies that study the effects of pollution and waste in their three basic forms: gas, solid, and liquid. It complements two other books in the series including Environmental and Natural Resources Engineering and Integrated Natural Resources Management that serve as a basis for advanced study or specialized investigation of the theory and analysis of various natural resources systems. This book covers the management of many waste sources including those from agricultural livestock, deep-wells, industries manufacturing dyes, and municipal solid waste incinerators. The purpose of this book is to thoroughly prepare the reader for understanding the sources, treatment and control methods of toxic wastes shown to have harmful effects on the environment. Chapters provide information ...

  13. The reactivity of natural phenols

    Energy Technology Data Exchange (ETDEWEB)

    Denisov, Evgenii T; Denisova, Taisa G [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation)

    2009-11-30

    This review surveys physicochemical data of natural phenols published in recent years. The structures of some compounds of this class are given. A complete set of the dissociation energies of the O-H bonds for 71 natural phenols is presented. Kinetic characteristics of the reactions of peroxyl, alkyl and thiyl radicals with natural phenols, exchange reactions of phenoxyl radicals with phenols and reactions of phenoxyl radicals with lipids, hydroperoxides, cysteine and ascorbic acid are compiled and described systematically. The reactivity of phenols in radical reactions and the factors that determine the reactivity (the enthalpy of reaction, triplet repulsion, the electronegativities of atoms at the reaction centre, the presence of pi-electrons adjacent to the reaction centre, the radii of atoms at the reaction centre, steric hindrance, the force constants of the reacting bonds) are discussed. An important role of hydrogen bonding between surrounding molecules and the OH groups of natural phenols in decreasing their reactivities is noted.

  14. Natural Heritage Inventory Element Occurrence

    Data.gov (United States)

    Kansas Data Access and Support Center — The database consists of three state-wide coverages representing location records for plant and animal species and natural community types contained in the Kansas...

  15. Two criticisms of natural theology

    Directory of Open Access Journals (Sweden)

    Błażej Gębura

    2014-01-01

    Full Text Available The article aims at considering two general criticisms often formulated against the natural theology. First criticism is based on the thesis that the conclusions of the natural theology are not adequate with the religious beliefs of non-philosophers. It is widely known as opposition between God of Religion and God of Philosophers. One can find that argument in the writings of Blaise Pascal. I’m arguing for the thesis, that the natural theologian cannot fulfill the criteria given by the proponents of this argument. This is because the argument of the natural theology cannot contains the premises taken from the Revelation. If the argument of the natural theology would contain the premises taken from the Revelation, then it would be the argument of religion. But philosopher of religion (natural theologian can’t do this, if he wants to formulate an philosophical argument. The second criticism is based on the notion of a rational person. In the light of this argument, the natural theology is successful only, if every rational person will accept the conclusion “God exist”. I’m trying to show that there is no philosophical argument that can guarantee it’s acceptance by some rational persons. The acceptance of the conclusion of the argument of the natural theology is a matter of personal decision. There is no logical argument, which can “force” rational persons (rational subjects to accept it’s conclusion. But if this is true, the arguments for the existence of God are no worse than other philosophical arguments.

  16. Nature tourism and Irish film

    OpenAIRE

    Brereton, Pat

    2006-01-01

    This article provides a historical overview and reading of seminal Irish film from the perspective of nature tourism. Within Irish cultural studies, tourism is frequently equated with an overly romantic image of the island, which has been used to sell the country abroad. However, using notions like the tourist gaze and taking on board influential debates around space/place, one can posit a more progressive environmental vision of nature and landscape in our readings of film.

  17. Strong demand for natural uranium

    International Nuclear Information System (INIS)

    Kalinowski, P.

    1975-01-01

    The Deutsches Atomforum and the task group 'fuel elements' of the Kerntechnische Gesellschaft had organized an international two-day symposium in Mainz on natural uranium supply which was attended by 250 experts from 20 countries. The four main themes were: Demand for natural uranium, uranium deposits and uranium production, attitude of the uranium producing countries, and energy policy of the industrial nations. (orig./AK) [de

  18. Nature-inspired optimization algorithms

    CERN Document Server

    Yang, Xin-She

    2014-01-01

    Nature-Inspired Optimization Algorithms provides a systematic introduction to all major nature-inspired algorithms for optimization. The book's unified approach, balancing algorithm introduction, theoretical background and practical implementation, complements extensive literature with well-chosen case studies to illustrate how these algorithms work. Topics include particle swarm optimization, ant and bee algorithms, simulated annealing, cuckoo search, firefly algorithm, bat algorithm, flower algorithm, harmony search, algorithm analysis, constraint handling, hybrid methods, parameter tuning

  19. Chemical and natural stressors combined:

    DEFF Research Database (Denmark)

    Gergs, André; Zenker, Armin; Grimm, Volker

    2013-01-01

    In addition to natural stressors, populations are increasingly exposed to chemical pollutants released into the environment. We experimentally demonstrate the loss of resilience for Daphnia magna populations that are exposed to a combination of natural and chemical stressors even though effects...... demonstrates that population size can be a poor endpoint for risk assessments of chemicals and that ignoring disturbance interactions can lead to severe underestimation of extinction risk...

  20. Radiation processing of natural polymer

    International Nuclear Information System (INIS)

    Khairul Zaman; Kamaruddin Hashim; Zulkafli Ghazali; Mohd Hilmi Mahmood; Jamaliah Sharif

    2006-01-01

    Radiation processing of natural polymer has been the subject of interest of countries in this region in the past 5 ∼ 7 years. Although some of the output of the research have been commercialized in particular for the applications in the agriculture and healthcare sectors, the potential applications of radiation processing of natural polymers in the medical sector are yet to be fully understood and developed. (author)

  1. Unity behind diversity in nature

    International Nuclear Information System (INIS)

    Pati, J.C.

    1980-03-01

    This is a lecture delivered to general audiences of physicists as well as non-physicists at institutions in India, which are listed at the end. The central theme of the lecture is unity behind diversity in Nature. The main topic of the lecture concerns the unity of the basic forces of Nature and the unity of all basic matter, which are used to illustrate the central theme. (author)

  2. Synthesised standards in natural matrices

    International Nuclear Information System (INIS)

    Olsen, D.G.

    1980-01-01

    The problem of securing the most reliable standards for the accurate analysis of radionuclides is discussed in the paper and in the comment on the paper. It is contended in the paper that the best standards can be created by quantitative addition of accurately known spiking solutions into carefully selected natural matrices. On the other hand it is argued that many natural materials can be successfully standardized for numerous trace constituents. Both points of view are supported with examples. (U.K.)

  3. The emergent natural gas markets

    International Nuclear Information System (INIS)

    Dewert, F.; Meeder, J.

    1998-01-01

    A 30% increase of natural gas consumption worldwide is expected to occur since the year 2010. This development will concern countries located outside the traditional markets, in particular in central and eastern Europe, Asia, Africa and south America. This paper summarizes the talks given by the different representatives of these regions who explain the expected evolutions of the natural gas market in these areas: reserves, production, consumption, demand, competition with other energy sources, financial aspects.. (J.S.)

  4. SuperNatural: a searchable database of available natural compounds.

    Science.gov (United States)

    Dunkel, Mathias; Fullbeck, Melanie; Neumann, Stefanie; Preissner, Robert

    2006-01-01

    Although tremendous effort has been put into synthetic libraries, most drugs on the market are still natural compounds or derivatives thereof. There are encyclopaedias of natural compounds, but the availability of these compounds is often unclear and catalogues from numerous suppliers have to be checked. To overcome these problems we have compiled a database of approximately 50,000 natural compounds from different suppliers. To enable efficient identification of the desired compounds, we have implemented substructure searches with typical templates. Starting points for in silico screenings are about 2500 well-known and classified natural compounds from a compendium that we have added. Possible medical applications can be ascertained via automatic searches for similar drugs in a free conformational drug database containing WHO indications. Furthermore, we have computed about three million conformers, which are deployed to account for the flexibilities of the compounds when the 3D superposition algorithm that we have developed is used. The SuperNatural Database is publicly available at http://bioinformatics.charite.de/supernatural. Viewing requires the free Chime-plugin from MDL (Chime) or Java2 Runtime Environment (MView), which is also necessary for using Marvin application for chemical drawing.

  5. Naturally Efficient Emitters: Luminescent Organometallic Complexes Derived from Natural Products

    Science.gov (United States)

    Zhang, Wen-Hua; Young, David J.

    2013-08-01

    Naturally occurring molecules offer intricate structures and functionality that are the basis of modern medicinal chemistry, but are under-represented in materials science. Herein, we review recent literature describing the use of abundant and relatively inexpensive, natural products for the synthesis of ligands for luminescent organometallic complexes used for organic light emitting diodes (OLEDs) and related technologies. These ligands are prepared from the renewable starting materials caffeine, camphor, pinene and cinchonine and, with the exception of caffeine, impart performance improvements to the emissive metal complexes and resulting OLED devices, with emission wavelengths that span the visible spectrum from blue to red. The advantages of these biologically-derived molecules include improved solution processibility and phase homogeneity, brighter luminescence, higher quantum efficiencies and lower turn-on voltages. While nature has evolved these carbon-skeletons for specific purposes, they also offer some intriguing benefits in materials science and technology.

  6. Natural selection promotes antigenic evolvability.

    Science.gov (United States)

    Graves, Christopher J; Ros, Vera I D; Stevenson, Brian; Sniegowski, Paul D; Brisson, Dustin

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed 'cassettes' that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections.

  7. Natural selection promotes antigenic evolvability.

    Directory of Open Access Journals (Sweden)

    Christopher J Graves

    Full Text Available The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed 'cassettes' that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish

  8. Technology, society and nature. Technik, Gesellschaft und Natur

    Energy Technology Data Exchange (ETDEWEB)

    Kraemer, S

    1982-01-01

    This paper intends to counter with a demand for systematics the boom of ecological oriented criticism passed on technical science and engineering and on the fact that individual sciences make a subject of engineering. It deals with the theoretical foundations of relationships between technology, society and nature. An interdisciplinary approach attempts to do justice to the multi-dimensionality of engineering and ''technology''. This approach includes the formulation of questions and the findings of social sciences, philosophy, and technology. The object is to determine technology as a form of social practice - a practice which includes the vital adjustment of man to his natural environment as well as the organisation of his social behaviour.

  9. Environmentalism and natural aggregate mining

    Science.gov (United States)

    Drew, L.J.; Langer, W.H.; Sachs, J.S.

    2002-01-01

    Sustaining a developed economy and expanding a developing one require the use of large volumes of natural aggregate. Almost all human activity (commercial, recreational, or leisure) is transacted in or on facilities constructed from natural aggregate. In our urban and suburban worlds, we are almost totally dependent on supplies of water collected behind dams and transported through aqueducts made from concrete. Natural aggregate is essential to the facilities that produce energy-hydroelectric dams and coal-fired powerplants. Ironically, the utility created for mankind by the use of natural aggregate is rarely compared favorably with the environmental impacts of mining it. Instead, the empty quarries and pits are seen as large negative environmental consequences. At the root of this disassociation is the philosophy of environmentalism, which flavors our perceptions of the excavation, processing, and distribution of natural aggregate. The two end-member ideas in this philosophy are ecocentrism and anthropocentrism. Ecocentrism takes the position that the natural world is a organism whose arteries are the rivers-their flow must not be altered. The soil is another vital organ and must not be covered with concrete and asphalt. The motto of the ecocentrist is "man must live more lightly on the land." The anthropocentrist wants clean water and air and an uncluttered landscape for human use. Mining is allowed and even encouraged, but dust and noise from quarry and pit operations must be minimized. The large volume of truck traffic is viewed as a real menace to human life and should be regulated and isolated. The environmental problems that the producers of natural aggregate (crushed stone and sand and gravel) face today are mostly difficult social and political concerns associated with the large holes dug in the ground and the large volume of heavy truck traffic associated with quarry and pit operations. These concerns have increased in recent years as society's demand for

  10. Natural pigments and sacred art

    Science.gov (United States)

    Kelekian, Lena, ,, Lady

    2010-05-01

    Since the dawn of mankind, cavemen has expressed himself through art. The earliest known cave paintings date to some 32,000 years ago and used 4 colours derived from the earth. These pigments were iron oxides and known as ochres, blacks and whites. All pigments known by the Egyptians, the Greeks, the Romans and Renaissance man were natural and it was not until the 18th century that synthetic pigments were made and widely used. Until that time all art, be it sacred or secular used only natural pigments, of which the preparation of many have been lost or rarely used because of their tedious preparation. As a geologist, a mineralogist and an artist specializing in iconography, I have been able to rediscover 89 natural pigments extracted from minerals. I use these pigments to paint my icons in the traditional Byzantine manner and also to restore old icons, bringing back their glamour and conserving them for years to come. The use of the natural pigments in its proper way also helps to preserve the traditional skills of the iconographer. In the ancient past, pigments were extremely precious. Many took an exceedingly long journey to reach the artists, and came from remote countries. Research into these pigments is the work of history, geography and anthropology. It is an interesting journey in itself to discover that the blue aquamarines came from Afghanistan, the reds from Spain, the greens Africa, and so on. In this contribution I will be describing the origins, preparation and use of some natural pigments, together with their history and provenance. Additionally, I will show how the natural pigments are used in the creation of an icon. Being a geologist iconographer, for me, is a sacrement that transforms that which is earthly, material and natural into a thing of beauty that is sacred. As bread and wine in the Eucharist, water during baptism and oil in Holy Union transmit sanctification to the beholder, natural pigments do the same when one considers an icon. The

  11. Wind Extraction for Natural Ventilation

    Science.gov (United States)

    Fagundes, Tadeu; Yaghoobian, Neda; Kumar, Rajan; Ordonez, Juan

    2017-11-01

    Due to the depletion of energy resources and the environmental impact of pollution and unsustainable energy resources, energy consumption has become one of the main concerns in our rapidly growing world. Natural ventilation, a traditional method to remove anthropogenic and solar heat gains, proved to be a cost-effective, alternative method to mechanical ventilation. However, while natural ventilation is simple in theory, its detailed design can be a challenge, particularly for wind-driven ventilation, which its performance highly involves the buildings' form, surrounding topography, turbulent flow characteristics, and climate. One of the main challenges with wind-driven natural ventilation schemes is due to the turbulent and unpredictable nature of the wind around the building that impose complex pressure loads on the structure. In practice, these challenges have resulted in founding the natural ventilation mainly on buoyancy (rather than the wind), as the primary force. This study is the initial step for investigating the physical principals of wind extraction over building walls and investigating strategies to reduce the dependence of the wind extraction on the incoming flow characteristics and the target building form.

  12. Natural pedagogy as evolutionary adaptation.

    Science.gov (United States)

    Csibra, Gergely; Gergely, György

    2011-04-12

    We propose that the cognitive mechanisms that enable the transmission of cultural knowledge by communication between individuals constitute a system of 'natural pedagogy' in humans, and represent an evolutionary adaptation along the hominin lineage. We discuss three kinds of arguments that support this hypothesis. First, natural pedagogy is likely to be human-specific: while social learning and communication are both widespread in non-human animals, we know of no example of social learning by communication in any other species apart from humans. Second, natural pedagogy is universal: despite the huge variability in child-rearing practices, all human cultures rely on communication to transmit to novices a variety of different types of cultural knowledge, including information about artefact kinds, conventional behaviours, arbitrary referential symbols, cognitively opaque skills and know-how embedded in means-end actions. Third, the data available on early hominin technological culture are more compatible with the assumption that natural pedagogy was an independently selected adaptive cognitive system than considering it as a by-product of some other human-specific adaptation, such as language. By providing a qualitatively new type of social learning mechanism, natural pedagogy is not only the product but also one of the sources of the rich cultural heritage of our species.

  13. Naturally-occurring alpha activity

    Energy Technology Data Exchange (ETDEWEB)

    Mayneord, W V

    1960-12-01

    In view of the difficulties of assessing the significance of man-made radioactivity it is important to study for comparison the background of natural radioactivity against which the human race has evolved and lives. It is also important to define the present levels of activity so that it will be possible to detect and study as quickly as possible any changes which may occur owing to the release into the environment of new radioactive materials. Moreover, by the study of the behaviour of natural radioactivity light may be shed upon that of the artificially produced isotopes and a number of analogies traced between the two groups. These concepts have led to studies of naturally-occurring radioactive materials alongside a programme of research into fission products in food, water and air, as well as studies of the metabolism of both sets of materials in the human body. Since the last report there has been a useful increase in our knowledge of natural radioactivity in the biosphere, and its levels relative to the new man-made activities. These studies have necessitated technical developments, particularly in the methods of measuring and identifying alpha-ray emitters, to which group many of the more important natural radioactive materials belong.

  14. Natural gas and crude oil

    International Nuclear Information System (INIS)

    Valais, M.R.

    1991-01-01

    Two main development could gradually modify these traditional features of natural gas markets and prices. First, environmental pressures and the tightening of emission standards and of the quality specifications for fuels should work in favor of natural gas. Second the increasing distance of resources in relation to the major consuming zones should bring about a considerable development of international natural gas trade. International expansion should mark the development of the gas industry in the coming decades. This evolution will give natural gas an importance and a role appreciably closer to those of oil on the world energy scene. But it is obvious that such a development can come about only at the cost of considerable investments for which the economic viability is and will remain dependent on the level of the prices of natural gas as the inlet to its consuming markets. This paper attempts to answer the questions: Will these markets accept a new scale of value for gas in relation to other fossil fuels, including oil, which will take into account new environmental constraints and which will be able to fulfill the formidable financial needs of the gas industry in the coming decades?

  15. Economics of natural gas upgrading

    International Nuclear Information System (INIS)

    Hackworth, J.H.; Koch, R.W.

    1995-01-01

    Natural gas could be an important alternative energy source in meeting some of the market demand presently met by liquid products from crude oil. This study was initiated to analyze three energy markets to determine if greater use could be made of natural gas or natural gas derived products and if those products could be provided on an economically competitive basis. The three markets targeted for possible increases in gas use were motor fuels, power generation, and the chemical feedstocks market. The economics of processes to convert natural gas to transportation fuels, chemical products, and power were analyzed. The economic analysis was accomplished by drawing on a variety of detailed economic studies, updating them and bringing the results to a common basis. The processes analyzed included production of methanol, MTBE, higher alcohols, gasoline, CNG, and LNG for the transportation market. Production and use of methanol and ammonia in the chemical feedstock market and use of natural gas for power generation were also assessed. Use of both high and low quality gas as a process feed stream was evaluated. The analysis also explored the impact of various gas price growth rates and process facility locations, including remote gas areas. In assessing the transportation fuels market the analysis examined production and use of both conventional and new alternative motor fuels

  16. Review of natural fiber composites

    Science.gov (United States)

    Rohan, T.; Tushar, B.; T, Mahesha G.

    2018-02-01

    Development of new alternative materials to the existing traditional metals, alloys and synthetic materials is the new buzz in recent research activities at the academic and industrial level taking place all over the world. Earning carbon credits by minimizing the atmospheric pollution is getting an increase in attention by industries. One small step to conserve the atmosphere around us is to use natural resources in making fully bio degradable or partially bio degradable composite materials. Such prepared alternative materials can find applications in interior housing, automotive, marine, domestic, and other applications. Composites made by using appropriate natural fibers as reinforcements is a possibility that ensures such a reality as they can be well received in multiple disciplines of engineering. Results published from various research activities illustrates that natural fiber composites can successfully be adapted for non-structural, moderate load bearing indoor applications. Further, the few deficiencies in the natural fibers can be overcome by subjecting them to morphological changes by various physical or chemical treatment methods. The overall objective of this paper is to provide a comprehensive overview of the property profiles of Natural Fiber Composites.

  17. Statistics of natural binaural sounds.

    Directory of Open Access Journals (Sweden)

    Wiktor Młynarski

    Full Text Available Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD and level (ILD disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA. Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction.

  18. Statistics of natural binaural sounds.

    Science.gov (United States)

    Młynarski, Wiktor; Jost, Jürgen

    2014-01-01

    Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD) and level (ILD) disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA). Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction.

  19. Natural pedagogy as evolutionary adaptation

    Science.gov (United States)

    Csibra, Gergely; Gergely, György

    2011-01-01

    We propose that the cognitive mechanisms that enable the transmission of cultural knowledge by communication between individuals constitute a system of ‘natural pedagogy’ in humans, and represent an evolutionary adaptation along the hominin lineage. We discuss three kinds of arguments that support this hypothesis. First, natural pedagogy is likely to be human-specific: while social learning and communication are both widespread in non-human animals, we know of no example of social learning by communication in any other species apart from humans. Second, natural pedagogy is universal: despite the huge variability in child-rearing practices, all human cultures rely on communication to transmit to novices a variety of different types of cultural knowledge, including information about artefact kinds, conventional behaviours, arbitrary referential symbols, cognitively opaque skills and know-how embedded in means-end actions. Third, the data available on early hominin technological culture are more compatible with the assumption that natural pedagogy was an independently selected adaptive cognitive system than considering it as a by-product of some other human-specific adaptation, such as language. By providing a qualitatively new type of social learning mechanism, natural pedagogy is not only the product but also one of the sources of the rich cultural heritage of our species. PMID:21357237

  20. Natural gas industry in Bulgaria

    International Nuclear Information System (INIS)

    Mashkin, L.

    1994-01-01

    An overview of the Bulgarian natural gas industry is presented. The starting point was the discovery of the indigenous Chiren gas-field in 1967. The first agreement with the ex-USSR for supply of natural gas and construction of main pipelines was signed in 1968. The state gas company BULGARGAZ is responsible for transportation, storage, distribution, processing and marketing of the gas to over 150 industrial companies in the country, as well as for the transportation services to gas importers in neighboring Turkey. The GAZSTROJMONTAZH company accomplish the construction of the local and transit pipelines to Turkey and Greece, as well as of some objects in Iran, Syria, Ukraine and Germany. In the past 20 years, 87890 million m 3 natural gas from Russia are supplied and 846 million m 3 - from domestic sources. The share of natural gas in the overall energy balance is 13.6% for 1992. The restructuring and further development of gas industry require to take into account some factors as: security in supply; investments for technical assurance; pricing policy for natural gas; development of private business. Some administrative problems are also mentioned. 2 tabs., 1 fig