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1

RISCHIO AMBIENTALE E RESPONSABILITÀ AMBIENTALE  

Microsoft Academic Search

1. Introduzione Nel gennaio 2002 la Comunità Europea pubblicò la proposta di una Di- rettiva sulla Responsabilità Ambientale concernente la Prevenzione ed il Risanamento di Danni Ambientali. La Direttiva dovrebbe stabilire la responsabilità legale per danni all'ambiente derivanti dall'inquinamen- to del terreno e dell'acqua e per danni alla biodiversità in aree protette. Essa applicherà il principio «chi inquina paga» in

CHARLES PERRINGS

2

La valoraciòn econòmica de bienes y servicios ambientales como herramienta estrategica para la conservaciòn y uso sostenible de los ecosistemas  

Microsoft Academic Search

Resumen El trabajo corresponde a un estudio piloto hacia la implementación de una metodología que permita aproximar el valor monetario de los Bienes y Servicios Ambientales (BSA) ofertados por un ecosistema hídrico, caso “Ciénaga de la Caimanera, municipio de Coveñas, departamento de Sucre-Colombia”, como herramienta estratégica para incentivar la conservación y uso sostenible de los ecosistemas. Avanzar en procesos de

ADOLFO CARBAL HERRERA

2010-01-01

3

El problema de estabilidad de los sistemas Hamiltonianos multidimensionales  

NASA Astrophysics Data System (ADS)

Se revisarán los aspectos básicos del problema de estabilidad de sistemans Hamiltonianos N-dimensionales, haciendo especial énfasis en los posibles mecanismos que dan lugar a la aparición de ``caos": overlap de resonancias, difusión de Arnol'd y otros procesos difusivos alternativos. Se mencionarán los aspectos aún no resueltos sobre la estabilidad de los sistemas con N > 2. Finalmente, se discutirá cuáles de estos mecanismos podrían tener alguna relevancia en la dinámica de sistemas estelares y planetarios.

Cincotta, P. M.

4

Problema misto e soluzioni quasiperiodiche dell’equazione delle onde  

Microsoft Academic Search

\\u000a Sunto  Ricordate le principali proprietà delle funzioni quasi-periodiche a valori in uno spazio di Banach, si espongono alcuni recenti\\u000a risultati concernenti l’analisi del problema misto, secondo Hadamard, per l’equazione non omogenea delle onde. In particolare\\u000a si indicano i teoremi seguenti: I) tra tutte le soluzioni ad energia limitata, nel’intervallo — ? t < + ?, ne esiste una, e una sola,

Luigi Amerio

1960-01-01

5

Algunos problemas de la tintura de la lana y sus nuevas técnicas  

Microsoft Academic Search

La introducción de la Marca Lana en la industria lanera ha planteado algunos problemas a los tintoreros. Estos problemas son siempre los mismos. Algunos tintoreros los han resuelto con éxito, y otros están en camino de hallar la solución. No obstante, dado que estos problemas son prácticamente comunes a todos, expondré algunas posibilidades que permiten generalmente mejorar los procedimientos de

A Iancovici

1970-01-01

6

Ponencia MICROSISTEMAS MOTIVACIONALES Y ASIMILACION DE ESTRATEGIAS EN PROBLEMAS DE DESCUBRIMIENTO  

Microsoft Academic Search

* En la solución d e un p roblema, Davison, Deuser, & Sternberg (1994) señalan como procesos metacognitivos la identificación d el problema, la representación mental del problema, la planeación d e procedimientos y la evaluación del conocimiento a cerca del desempeño. Si en el ambiente de la tarea se le agregan activadores de juicios sobre valoraciones de dificultad, tiempo

DAVID MACÍAS; JAIME IBAÑEZ; NEREY ORTEGA

7

Aplicación del cálculo de las diferencias al problema del efecto de embalse  

Microsoft Academic Search

Resumen Presentamos una solución numérica del problema del efecto de embalse con ayuda de una ecuación lineal inhomogénea en diferencias finitas de primer orden, suponiendo una ley lineal del desagüe. Este método numérico es de maneje cómodo para un cálculo aproximado.

Hans Ertel

1962-01-01

8

Un Juego de Gravedad con Reconocimiento de Voz para Niños con Problemas de Lenguaje  

Microsoft Academic Search

En este trabajo presentamos un juego electrónico (Gravedad) con reconocimiento de voz para estimular a niños en edad escolar con problemas del lenguaje dislalia. Se presenta las características y elementos del juego electrónico, así como su integración con el sistema de reconocimiento de voz y los resultados de unas pruebas de usabilidad. El juego de Gravedad se desarrolló utilizando el

Carlos Miranda-Palm; Reyna Camal-U; José Cen-Magaña; Cinhtia Gonzalez-Segura; Sergio Gonzalez-Segura; Michel García; Lizzie Narvaez-Díaz

9

El desarrollo de la creatividad a través del proceso docente como problema social  

Microsoft Academic Search

El artículo tiene como propósito reflejar aspectos sobre el desarrollo de la creatividad en estudiantes de Educación Inicial del Programa Nacional de Formación de Educadores y Educadoras (PNFE). En tal sentido el Problema científico es ¿Cómo perfeccionar los modos de actuación en los estudiantes del PNFE? El Objetivo está dirigido a la Elaboración de una metodología para favorecer el desarrollo

Magaly Sarmiento Romero

2011-01-01

10

Gerenciamento de riscos na prática ortodôntica: como se proteger de eventuais problemas legais  

Microsoft Academic Search

Introdução: A relação profissional-paciente na área de Ortodontia e Ortopedia facial é bas- tante desgastante face à longa duração dos tratamentos e, por causa disso, muitas vezes essa relação pode se deteriorar trazendo prejuízos a ambas as partes. Objetivo: Este trabalho visa informar o leitor, em linguagem acessível, sobre os principais problemas jurídicos que podem envolver o ortodontista em sua

Ricardo Machado Cruz; Carla Pádua

2008-01-01

11

Habilidades Sociais e Problemas de Comportamento de Pré- Escolares: Comparando Avaliações de Mães e de Professoras Preschooler's Social Skills and Behavior Problems: Comparison between Mother and Teacher Assessments  

Microsoft Academic Search

Resumo Este estudo comparou avaliações de mães e professoras, sobre habilidades sociais e problemas de comportamento de crianças, identificadas pelas professoras, como tendo problemas de comportamento. Participaram mães e professoras de 24 crianças com problemas de comportamento e 24 crianças indicadas como sendo socialmente habilidosas. Foram utilizados o Questionário de Comportamentos Socialmente Adequados e a Escala Comportamental Infantil, versões para

Alessandra Turini Bolsoni-Silva; Edna Maria Marturano; Verônica Aparecida Pereira; Jair Wagner de Souza Manfrinato

12

STIMA DELLA VITA LCF E TMF DI ACCIAIO AUSTENITICO: CONFRONTO ANALITICO SPERIMENTALE DI MODELLI DI DANNEGGIAMENTO  

Microsoft Academic Search

Sommario La vita di un materiale metallico in presenza di so llecitazioni meccaniche e termiche variabili nel tempo in campo plastico può essere investigato mediante modelli di danneggiamento descritti dettagliatament e in letteratura. Per la calibrazione dei modelli costitutivi e di danneggia mento è necessario un numero di prove di caratterizzazione, standard e non, dipende nti dal livello di approfondimento

C. Delprete; R. Sesana; A. Vercelli

13

Caratterizzazione di materiali edili, con il metodo integrato termografico-ultrasonico-analitico  

Microsoft Academic Search

This study was focused on the use of Quantitative IR Thermography (QIRT) together with ultrasonic pulse velocity (UPV) for the determination of the thermal-mechanical properties of building materials as a non destructive testing (NDT) methods. The thermal diffusivity in Autoclaved Aerated Concrete (AAC), AKG Gazbeton ® , which is a highly porous and non-homogeneous material, was evaluated using a single

E. Grinzato; P. Bison; A. Tavukcuoglu

14

Resolución de problemas basada en el análisis. Hacer del análisis y del razonamiento el foco de la enseñanza de la física  

Microsoft Academic Search

Resumen. Usando los resultados provenientes de la investigación educativa en áreas tales como concepciones alternativas, diferencias entre expertos y novatos, adquisición de esquemas, sobrecarga cognitiva y análisis jerárquico, hemos desarrollado un marco para pensar sobre la organización del conocimiento y su uso para la comunicación, y sobre el razonamiento y la resolución de problemas. Basados en este marco y en

J. Leonard William; William J. Gerace; Robert J. Dufresne

2002-01-01

15

Il problema del litio.  

NASA Astrophysics Data System (ADS)

Contents: 1. Introduzione. 2. La nucleosintesi del Big Bang. 3. Il litio nelle stelle di popolazione II. 4. I modelli stellari standard. 5. Il litio negli ammassi aperti. 6. Meccanismi di distruzione "non standard". 7. I modelli non-standard applicati alla popolazione II. 8. L'evoluzione Galattica del litio. 9. Quali stelle producono litio? 10. Il litio come elemento chiave per dare un nome agli oggetti stellari più minuscoli. 11. Conclusioni.

D'Antona, F.

1995-03-01

16

EFFETTI DELLE VIBRAZIONI DI ORIGINE AMBIENTALE SULLE COSTRUZIONI CIVILI  

Microsoft Academic Search

A methodology for the assessment of civil engineering structures against vibration is outlined. Safety has to be checked both for ultimate limit states and for serviceability limit states, with reference to specific acceptability parameters. For this purpose the main features of the measurement systems are recalled, along with the regulations of some relevant Italian and international codes.

A. L. Materazzi

17

Comportamento Ambientale del Tecnezio (Environmental Behavior of Technetium).  

National Technical Information Service (NTIS)

A number of papers are presented within the framework of a study session organized by the Italian Association of Protection Against Radiation and by ENEA. The basic research orientation concerning the technology within the limits of experimental radiotech...

G. Queirazza A. A. Cigna

1984-01-01

18

Enfermedades neurológicas y problemas de atención  

Microsoft Academic Search

SUMMARY Attention is the capacity to select a particular stimulus of the set of an experience and in it to focus and to concentrate our interest. It is classified in passive and active. Their components are: selectivity, concentration, limit and facility to neglect. The upheavals of the attention are: distractibility, hipoprosexia, aprosexia, hiperprosexia and perseveration. The attention deficit disorder as

Sandra P. Mantilla

19

ESTADOS DE EXCEPCIÓN Y PROBLEMAS DE AGENCIA  

Microsoft Academic Search

In Venezuela in reflected the world tendency of inclu- ding to the human rights how an indispensable element for the consolidation of the State of Right. The present work to try to settle down as the declaration of excep- tion states exacerbates existent problems between the State and the citizens and between the government and the organs executioners, increased the

Úrsula Straka

20

The Prisoner Problem--A Generalization.  

ERIC Educational Resources Information Center

Presents a generalization to the classic prisoner problem, which is inherently interesting and has a solution within the reach of most high school mathematics students. Suggests the problem as a way to emphasize to students the final step in a problem-solver's tool kit, considering possible generalizations when a particular problem has been…

Gannon, Gerald E.; Martelli, Mario U.

2000-01-01

21

PROPUESTA DE UN MODELO DE GESTIÓN AMBIENTAL PARA LA SEDE UNIVERSITARIA MUNICIPAL LA PALMA  

Microsoft Academic Search

La gravedad de los problemas ambientales obliga a replantear el papel de la educación ante ella; reivindicando así sus aportes al respecto. En la Universidad recae una responsabilidad de primer orden en la socialización de los conocimientos y en la formación de una nueva cultura de respeto al entorno natural y social y sus valores. Se necesita, y es impostergable,

Yaima Gómez González; Diamelys Pimentel Rivera; Maray Martínez Sánchez

2012-01-01

22

Solucion numerica de la ecuacion de transporte de neutrones en geometria plana mediante esquemas analiticos empleando aceleracion por difusion sintetica. (Numerical solution of the equation of neutrons transport on plane geometry by analytical schemes using acceleration by synthetic diffusion).  

National Technical Information Service (NTIS)

A computer program has been developed which uses a technique of synthetic acceleration by diffusion by analytical schemes. Both in the diffusion equation as in that of transport, analytical schemes were used which allowed a substantial time saving in the ...

G. Alonso-Vargas

1991-01-01

23

Estudio comparativo de los metodos analitico-sintetico y global en el aprendizaje de la lectura (Comparative Study of the Analytical-Synthetical (Phonics) and Global (Sight) Reading Methods).  

ERIC Educational Resources Information Center

An investigation into the phonics and sight methods of reading instruction being taught in Uruguay schools seeks valid predictions in support of each approach. The study, written in Spanish, examines the progressive reading habits and abilities of 12 first-grade classes. Teachers assigned to teach each method uniformly had equivalent training and…

Carbonell de Grompone, Maria A.; And Others

24

Valoración de impactos socio- ambientales del arbolado urbano: una aplicación a la ciudad de Santiago, Chile  

Microsoft Academic Search

Santiago de Chile es tercero en la lista de ciudades más contaminadas de Latinoamérica, después de Ciudad de México y Sao Paulo, por lo cual la valoración ambiental y social del arbolado urbano en este contexto es de vital importancia. Los proyectos de arbolado urbano ya sea en calles, plazas, parques u otras áreas verdes tienen como propósito, por una

Carmen L. De la Maz; Claudia L. Cerd

2009-01-01

25

Da Bhopal a Porto Marghera: la responsabilità ambientale delle compagnie transnazionali  

Microsoft Academic Search

Sommario: La notte fra il 2 e il 3 dicembre 1984 quaranta tonnellate di una miscela di gas tossici fuoriuscirono dall'impianto di produzione di pesticidi della Union Carbide a Bhopal, in India. Questo incidente rappresenta il più grande disastro nella storia dell'industria chimica, per il quale oggi si contano almeno 20.000 vittime e circa mezzo milione di persone ne subiscono

Vittoria Polidori

26

Carbón versus viento. Los costos de generar electricidad incluyendo las externalidades ambientales  

Microsoft Academic Search

This paper compares the cost of electricity generation with a coal fired plant and a wind mill in Chile’s Central Interconnected System. To the standard costs of coal generation (capital investment and fuel) we add local and global environmental externalities. The environmental cost of generating with coal is US$17\\/MWh, and the total cost is US$78\\/MWh. Wind generation is considerable more

Alexander Galetovic; Cristián M. Muñoz

2011-01-01

27

La flora del litorale pescarese come indicatore biologico dello stato ambientale e delle sue trasformazioni  

Microsoft Academic Search

The littoral flora of Pescara as a biological indicator of the environmental status and its modifications.—The flora of the Pescara littoral, and the vegetation, limited now to restricted areas in the outskirts, mainly near the mouth of the Saline river, and to the dunes, have been studied.Three hundred and six entities have been recorded and the abundance, the distribution, the

Fernando Tammaro; Gianfranco Pirone

1979-01-01

28

Impacto de las regulaciones ambientales en las estrategias de comercialización del café costarricense  

Microsoft Academic Search

El uso de instrumentos de gestión ambiental se ha introducido paulatinamente en la forma de hacer negocios de las empresas. Sea por presión externa o por iniciativa local, la implementación de este tipo de prácticas ha venido en aumento y con ello más firmas han visualizado a través de estos esquemas importantes herramientas de apoyo y proyección de sus estrategias

Suyen Alonso Ubieta; Gerardo Jiménez

2009-01-01

29

Manual de Contabilidad para Cooperativas Agropecuarias de Mercadeo (Accounting Manual for Agriculture Cooperatives Dedicated to Marketing).  

National Technical Information Service (NTIS)

This is an accounting manual, geared to managers of agricultural marketing cooperatives. It contains the following chapters: Introduction to Accounting; Accounting Terminology; A System of Accounts; Daily Ledger ('Diario Mayor General Analitico); Other Bo...

G. Zurita

1971-01-01

30

PROBLEMAS ENTOMOLÓGICOS NA VITICULTURA DO VALE DO SÃO FRANCISCO  

Microsoft Academic Search

In the agricultural region of Petrolina- PE\\/Juazeiro-BA, located in the São Francisco River VaIIey, in the Brazilian Semi-Arid region, grape is one of the most technified and important crops. Social demands for better living quality have favored the use of new technologies, like Fruit lntegrated Production System (FIP), which assures a rational production, a great economy and environmental preservation. With

Francisca Nemaura; Pedrosa Haji

31

ALIMENTOS LIBRES DE GLUTEN: UN PROBLEMA AÚN SIN RESOLVER  

Microsoft Academic Search

RESUMEN: La celiaquía es una patología gastrointestinal causada por una intolerancia total y permanente a las proteínas del gluten. En medicina se están registrando importantes avances para anticipar el diagnóstico de nuevas formas de manifestación de esta patología engañosa y multifacé- tica. En varios países se desarrollan trabajos tendientes a lograr técnicas analíticas más eficientes para cuantificar gluten en alimentos

María Elisa García

2006-01-01

32

A Neutron Transport Problem UN Problema di Trasporto di Neutroni.  

National Technical Information Service (NTIS)

A method is given to determine the critical states of a nuclear reactor. Considering the Boltzman equation in integral form, it is shown that the eigenvalues of a special form of this equation provide the answer. The Ritz method is used to find an approxi...

G. Busoni G. Frosali L. Mangiarotti

1975-01-01

33

Colombia: Los problemas de competitividad de un país en conflicto  

Microsoft Academic Search

La persistencia del conflicto interno en Colombia inhibe todos los elementos principales que contribuyen a la determinación de la competitividad de la economía nacional, que son los siguientes: (i) el monto de sus recursos productivos; (ii) la calidad y productividad de los mismos; (iii) la eficiencia con que operan sus mercados; (iv) el estado de su infraestructura; (v) la capacidad

Alberto Melo

2003-01-01

34

Aedes albopictus in Italia: un problema sanitario sottovalutato  

Microsoft Academic Search

Summary (Aedes albopictus in Italy: an underestimated health problem). - Since 1990, Ae. albopictus has spread in 9 regions and 30 provinces of the country. This species was introduced in Italy in shipments of scrap tires form the USA. In Italy, Ae. albopictus is the major biting pest throughout much of its range and, although there is no evidence that

Roberto ROMI

35

El Ruido: Un Problema para la Salud (Noise: A Health Problem).  

ERIC Educational Resources Information Center

This booklet contains nine sections describing ways in which noise may endanger health and well-being. Sections are included on: (1) hearing loss; (2) heart disease; (3) other reactions by the body; (4) effects on the unborn; (5) special effects on children; (6) intrusion at home and work; (7) mental and social well-being; and (8) danger to life…

Environmental Protection Agency, Washington, DC. Office of Noise Abatement and Control.

36

ANSIEDAD Y DEPRESIÓN: EL PROBLEMA DE LA DIFERENCIACIÓN A TRAVÉS DE LOS SÍNTOMAS  

Microsoft Academic Search

SUMMARY The differentiation between the symptoms of anxiety and depres- sion is one of the most important problems in psychology as the dilemma profoundly affects the diagnosis and clinical intervention. According to the epidemiological data there is a strong comorbility between the two types of disorder. Nevertheless, it is not known which one of them precedes or predisposes to the

Diana Agudelo; Gualberto Buela-Casal; Charles Donald Spielberger

37

LAS CIUDADES ESPAÑOLAS Y EL RIESGO DE INUNDACIÓN: PERMANENCIA Y CAMBIO DE UN PROBLEMA CRÓNICO  

Microsoft Academic Search

Spanish cities and flood risk: permanency and change of a chronic problem. We study the incidence of flood risk in Spanish cities throughout the history. Through this analysis we can prove the role performed by physical and human factors in the spatial distribution and chronological evolution of this risk. Furthermore, its recent trends are explained in relation- ship to the

Juan Carlos; García Codron

38

Colonias: Problems and Promise. Desperate Situations, Local Innovations = Colonias: Problemas y Promesa. Situaciones Dificiles, Innovaciones Locales.  

ERIC Educational Resources Information Center

Colonias--unincorporated, low-income settlements endemic to the U.S. borderlands--have inadequate infrastructure and dismal living conditions, but also provide a creative solution to the housing dilemma faced by many border families. Colonias are most common in Texas and New Mexico, primarily as a result of weak rural planning laws, and are…

Borderlines, 1998

1998-01-01

39

MODELOS DE DURACIÓN Y GESTIÓN DEL RIESGO DE INTERÉS: ¿UN PROBLEMA DE DIMENSIÓN?  

Microsoft Academic Search

The group of duration models has grown rapidly during last years, offering manynew approaches for interest rate risk management in delta or delta-gamma frameworks.This paper attempts to make up for the lack of empirical evidence concerning theperformance of some of the most realistic duration models in interest rate riskmanagement by analyzing their effectiveness to immunize fixed income portfolios. Tothis end,

Gloria M. Soto Pacheco

2002-01-01

40

GEOFÍSICA APLICADA AL PROBLEMA DE LA INTRUSIÓN SALINA EN LOS ACUÍFEROS COSTEROS DE COSTA RICA  

Microsoft Academic Search

Geophysical prospection is a complement of hydro- geochemical methods, that allows a good delimitation of the saline intrusion in three pacific coastal aquifers of Costa Rica. The methodology includes: well logging (electrical resistivity and temperature), electrical soun- dings and pseudosections, slingram and transitory elec- tromagnetic soundings, profiles and maps, to delimit the extension of the intrusion brine. An hidrogeologic study

Mario E. Arias Salguero; Asdruval Vargas; Roger Guérin

41

MÉTODO DE SOLUCIÓN DE PROBLEMAS Y CREATIVIDAD EN LA ENSEÑANZA DE INGENIERÍA  

Microsoft Academic Search

This paper provides young professors with tools to learn how to teach engineering helping them to develop effectively and efficiently their task and their academic development. Engineering education focuses heavily i problem solving, but many professors teach content only and expect students to solve problems automatically. Ma, engineering schools teach routines and diagnosis; students are not proficient at strategy, interpretation

Edilberto Guevara Pérez

42

Um modelo para analisar o problema de filas em caixas de supermercados: um estudo de caso  

Microsoft Academic Search

In this study we applied queueing theory to analyze the problem of congestion in supermarket check- outs. We are particularly concerned with modeling the mean user waiting time in the queue, viewed as an important component of the user service, as a function of the capacity of the system (i.e., the number of cashiers in a given time period). Three

Reinaldo Morabito; Flavio C. R. de Lima

2000-01-01

43

A notação escrita na resolução de problemas por crianças pré-escolares  

Microsoft Academic Search

ABSTRACT - This study analyses how ,children from 4 to 6 years use written notation in subtraction ,problem ,solving. Thirty children from kindergarten to first levels were asked to solve ,four problems ,(two of the ,kind change ,and two of comparison), which involved numerical sets greater and smaller than 10. These problems were in a context which intented togive more

Ana Coêlho Vieira Selva; Ana Carolina Perrusi Brandão

2000-01-01

44

Autoconceito de crianças com dificuldades de aprendizagem e problemas de comportamento  

Microsoft Academic Search

The a im of this s tudy was to assess the self-concept of children with learning disability in comparison with children without learning disability. Fifty- eight school-age children were assessed, including: 32 Learning Disabled children, distinguished b y behavior problems, and 26 No Learning Disabled children. The c hild self-concept was assessed b y Piers Harris Self-Concept Scale and the

Indira Siqueira Stevanato; Sonia Regina Loureiro; Maria Beatriz Martins Linhares; Edna Maria Marturano

2003-01-01

45

Tod o conocimiento consiste en suscitar nuevos problemas a medida que resuelve los precedentes  

Microsoft Academic Search

In this paper I will present a revision of Piaget's equilibration theory in order to analyze its basic concepts through the epistemological framework depicted from non- monotonic logics. In particular I want to show that Piaget's equilibration model could be understood as a case of abductive reasoning. The paper's structure is in three main parts. The fi rst part presents

J. PIAGET

46

Sistema de Desafios Abertos Inteligentes: um incremento computacional lúdico para se trabalhar o problema da aprendizagem  

Microsoft Academic Search

The work contextually in general lines action of the Educational Technology applying techniques of Artificial Intelligence with the theory of Jean Piaget. Such research, still in implementation phase, has as hypothesis that from a playful increment, supported for IA, will be possible to reach learning situations and, consequently, of cognitive development for its user. This if gives by means of

Othon C. Bastos Filho; Margarete Axt; Sofiane Labidi; Paloma Dias Silveira

47

La incertidumbre estructural en el problema de la sostenibilidad. Una panorámica  

Microsoft Academic Search

Al incorporar el aspecto humano (junto con el económico y medio ambiental), a un sistema que pretende ser sostenible, éste se convierte en un sistema complejo, reflexivo y emergente. La propiedad de la reflexividad supone la existencia de una incertidumbre que no puede reducirse de ningún modo, pero que es necesario gestionar si se pretende la sostenibilidad del sistema. Este

Estrella Bernal Cuenca

2009-01-01

48

El embarazo en la adolescencia como problema público: una visión crítica  

Microsoft Academic Search

The present work is a review of the most commonly used arguments to define pregnancy during adolescence as a pub- lic problem: its supposed increase, contribution to acceler- ated population growth, adverse effects on maternal and child health and contribution to the persistence of poverty. Some elements are proposed for an alternative explanation with the intention of defining with more

CLAUDIO STERN

1997-01-01

49

Is overuse of sumatriptan a problem?A population-based study  

Microsoft Academic Search

Objective: Sumatriptan is highly efficacious in aborting acute attacks of migraine. Owing to recent reports of misuse of sumatriptan,\\u000a we performed a study of its use in a Danish population.\\u000a \\u000a Methods:\\u000a \\u000a \\u000a Data were retrieved from a prescription database covering a period of 27 months after release of the drug. Consumption was\\u000a described by the defined daily dose (DDD) unit and

D. Gaist; J. Hallas; S. H. Sindrup; L. F. Gram

1996-01-01

50

Expectativas, consumo de alcohol y problemas asociados en estudiantes universitarios de la ciudad de México  

Microsoft Academic Search

Objective. To assess the relationship between alcohol use expectancies, drinking patterns, and alcohol-related prob- lems, among college students in Mexico City. Material and methods. This cross-sectional study was conducted in October 1998. Study subjects were 678 male and female college students aged between 17 and 25 years, from pri- vate and public schools. Alcohol expectancies were meas- ured through the

Jazmín Mora-Ríos; Guillermina Natera

2001-01-01

51

Estado da Arte para Solução dos Problemas Vibroacústica por Métodos Numéricos  

Microsoft Academic Search

This paper presents the fundamentals of the numerical methods used in the acoustics and vibration fields as; Finite Elements Methods (FEM), Boundary Element Methods (BEM), Acoustic Rays, and Statistical Energy Analysis (SEA). State of arts and trend for future methods are presented. Some results are presented for practical study cases. RESUMO Neste trabalho serão apresentados os fundamentos dos métodos numéricos

Palestra Convidado; REFERÊNCIA PACS; Samir N. Y. Gerges

52

COOPERACIÓN Y CONFLICTOS AMBIENTALES LOCALES. ENTRE EMPRESAS, COMUNIDADES, NUEVOS MOVIMIENTOS SOCIALES Y EL PAPEL DEL GOBIERNO. EL CASO DE CERRO DE SAN PEDRO (MÉXICO)  

Microsoft Academic Search

El objetivo de este trabajo es analizar las relaciones de cooperación y conflicto entre una compañia minera y las comunidades, los Nuevos Movimientos Sociales y los tres niveles de gobierno involucrados. La compañia Minera inició operaciones para una mina a cielo abierto de oro y plata con el apoyo de oficiales de los gobiernos locales, estatales y federal. Los habitantes

José G. Vargas-Hernández

2007-01-01

53

BASES PARA EL MANEJO INTEGRADO DEL RECURSO LANGOSTA (Panulirus argus) EN LA ZONA COSTERA SUR DE PINAR DEL RÍO. I. FACTORES AMBIENTALES  

Microsoft Academic Search

A study of management of costal areas in the western gulf of Batabanó, southern coast of Pinar del Río province, is presented in three parts: environmental factors, socio economical factors and integrated management. Main characteristics of natural factors are analyzed, such as river supply of water to the coast, water temperature, salinity, dissolved oxygen, turbidity, ph, nutrients and organic nitrogen

Roberto Piñeiro; Rafael Puga; Gaspar González-Sansón

54

Rapporto annuale sulla radioattivita' ambientale in Italia: Reti nazionali 1990. (Environmental radioactivity in Italy: Annual report. Vol. 1 1990 national network).  

National Technical Information Service (NTIS)

This Annual Report on Environmental Radioactivity in Italy tables environmental radioactivity data collected in 1990 by the national monitoring network. It was prepared with the aim of gaining increased knowledge on environmental radioactivity transport d...

A. Ingarrica S. Mancioppi

1992-01-01

55

Il mesotelioma pleurico del cane come indicatore di esposizione ambientale ad amianto. (Canine pleural mesothelioma as an indicator of environmental exposure to asbestos).  

National Technical Information Service (NTIS)

Canine pleural mesothelioma represents a 'sentinel health event' because of the role of asbestos exposure in its etiology and pathogenesis. The observation of such event may thus trigger prevention-oriented remedial actions. This is especially due to the ...

P. De Nardo

1996-01-01

56

Towards a Solution of the Problem of Cercospora Beticola on Sugar Beet (Prilog Resavanju Problema Cercospora Beticola NA Secernoj Repi).  

National Technical Information Service (NTIS)

Results are given of field investigations to establish the efficacy of some chemical preparations in the control of Cercospora beticola, the optimal date for application, and which of the two above mentioned principles of chemical control better suits Yug...

A. Maric

1970-01-01

57

Contaminación por nitrógeno inorgánico en los ecosistemas acuáticos: problemas medioambientales, criterios de calidad del agua, e implicaciones del cambio climático  

Microsoft Academic Search

climate change. The major environmental problems related to inorganic nitrogen pollution in aquatic ecosystems are: (1) acidification of lakes and rivers with low or reduced alkalinity; (2) eutrophication of fresh and marine waters (with the additional problem of toxic algae); and (3) direct toxicity of nitrogenous compounds to aquatic animals. Additionally, inorganic nitrogen pollution could induce adverse effects on human

J. A. Camargo; A. Alonso

58

Delimitacion de las Zonas Dialectales de Mexico: Objetivos y Problemas (Delimitation of Dialect Zones in Mexico: Objectives and Problems)  

ERIC Educational Resources Information Center

Before creating a linguistic map of Mexican dialects, it is necessary to determine the dialect regions of the country. An extensive questionnaire must be written and distributed to collect data from a representative sample of the population for an accurate picture of the language. (CK) (Text in Spanish.)

Blanch, Juan M. Lope

1975-01-01

59

Problemas de alimentação em crianças com doença do refluxo gastroesofágico*** Feeding disorders in children with gastro-esophageal reflux disease  

Microsoft Academic Search

Background: feeding\\/eating disorders are frequent in pediatric patients and, in some cases, can be associated to an upper digestive motility disorder. Gastro-esophageal reflux is, nowadays, considered a risk factor for the development of feeding\\/eating disorders. Aim: to verify the occurrence of feeding\\/eating disorders in patients with Gastro-Esophageal Reflux Disease (GERD) determined by the 24-H esophageal pH monitoring evaluation. Method: an

Larissa Vieira Drent; Elizete Aparecida; Lomazi da Costa Pinto

2007-01-01

60

Aportes del Aprendizaje Basado en Problemas (ABP) en la ensenanza de la Fisiologia Animal en un programa de Zootecnia  

NASA Astrophysics Data System (ADS)

Based on difficulties observed on the subject of technical-scientific conceptualization and the integration of theory and practice in learning animal physiology for students in the Animal Science program at the National University of Colombia in Medellin, this research paper proposes a problem-based learning strategy founded on the method of Problem Based Learning (PBL), applied specifically to the issues of thermoregulation and physiological stress in domestic animals. In this case study, a sample size of eight students was presented with a pedagogical problem during the first session that would then be solved during the course. In order to evaluate the process, three surveys were conducted called Level Test Formulations (NF) performed at different times of the trial: one before beginning the topic (NF 1), one after three theoretical classes had been given and before beginning the fieldwork (NF 2), and another one after the end of the process (NF 3). Finally, individual interviews were conducted with each student to know the students' perceptions regarding the method. The information obtained was subjected to a qualitative analysis and categorization, using the QDA Miner program which reviewed and coded texts from the surveys and individual interviews, supplemented in turn, by field observation, analyzing the conceptual change, the theory-practice relationship and the correlation between the variables and categories established. Among the main results obtained, it should be noted that following the implementation of PBL in this Animal Physiology course, support for conceptual change was demonstrated and the formulated problem served as a connector between theory and practice. Moreover, there was a fusion of prior knowledge with newly acquired knowledge, meaningful learning, improvement in the level of conceptualization and an increase in the scientificness of definitions; it also led to problem-solving and overcoming epistemological obstacles such as multidisciplinarity and nonlinearity. As a result of this research, it is recommended that this method be evaluated in other topics related to Animal Physiology, in other sciences, in larger sample sizes, as well as to address the issue of evaluation applied directly to this method. Key words: Problem Based Learning (PBL), conceptual change, integration of theory and practice, significatif learning, animal physiology, thermoregulation, physiological stress.

Reinartz-Estrada, Monica

61

Temas y problemas del idioma espanol en la prensa (Spanish Language Topics and Problems in the Press).  

ERIC Educational Resources Information Center

This section consists of reprints on the following topics: (1) the misuse of "en"; (2) anglicisms; (3) widespread use of vulgar language; (4) an interview with Emilio Criado on Spanish language variation; (5) use of the feminine in professional titles; and (6) Spanish, the national language of Latin American countries. (AMH)

El Brocense; And Others

1980-01-01

62

La Biotecnología en los Cultivos: Problemas Potenciales para los Países en Desarrollo  

NSDL National Science Digital Library

Excerpts from an Oxfam report examine GM crops are an answer to world hunger for some. To others, these crops are a health risk and an environmental threat because some GM crops: have proven to be genetically unstable, do not do what they were designed to do, are a risk to human health, particularly children, cause animals who eat them to become immune to antibiotics, and spread and destroy natural crops.

Laura Spinney (Oxfam GB;)

1998-05-01

63

Digital color correlation for the recognition of Vibrio cholerae 01 in laboratory and environmental samples Correlación digital del color para el reconocimiento de Vibrio cholerae 01 en muestras ambientales y de laboratorio  

Microsoft Academic Search

In general, direct counts are more reflective of microbial abundance than plate counts. Microbiological techniques developed to recognize and count microorganisms in natural systems have had problems with reliability. Different methods frequently give different results for the enumeration of a specific organism. For direct microscopic examination of bacteria, automated digital systems represent a possible improvement in the identification and counting

Rosa R. Mouriño-Pérez; Josué Alvarez-Borrego; Cristián Gallardo-Escárate

2006-01-01

64

El problema de la barrera linguistica en el desarrollo cientifico y tecnologico (The Problem of the Language Barrier in Scientific and Technological Development).  

ERIC Educational Resources Information Center

This monograph discusses the problem of the language barrier in scientific and technological development in terms of several parameters describing the flow of scientific information from one language to another. The numerical values of the language barrier parameters of the model are calculated in the field of information on second language…

Zierer, Ernesto

65

Frozen Soil: A Material to Solve Problems in the Construction Industry (Suelo Congelado: Un Material para la So Lucion do Problemas en la Industria de la Construccion).  

National Technical Information Service (NTIS)

Digging a well, restoring the foundations of a building or digging a tunnel in the soils of big cities constitute difficult projects due to a large number of already existing pipelines and sewers. When the city has a clayey subsoil with some content of wa...

J. A. Careaga E. R. Mayer

1975-01-01

66

Solucoes Aproximadas para o Problema de Localizacao Simples. Algorithmo Simulated Annealing (Approximative Solutions for the Simple Plant Location Problem. Simulated Annealing Algorithm).  

National Technical Information Service (NTIS)

The Simple Plant Location (SPL) is a NP-hard problem that arises in a great variety of real world situations. Given a finite set of possible locations for establishing new facilities, SPL deals with the supply of a single commodity from a subset of these ...

M. Leonor de Almeida Gouveia Oliveira

1991-01-01

67

Temas y Problemas del idioma espanol en la prensa: El lenguaje, arma peligrosa (Themes and Problems of the Spanish Language in the Press: Language, a Dangerous Weapon).  

ERIC Educational Resources Information Center

Discusses the important role that language has in our society and compares human communication to animal group communication. Gives specific examples of corruption in the Spanish language today. (NCR)

de Senillosa, Antonio

1979-01-01

68

Problemas del Lenguaje Espanol en la Prensa: El Castellano, Esta Lengua Enferma (Problems of the Spanish Language in the Press: Castillian, That Closed-In Language)  

ERIC Educational Resources Information Center

Learned academies deplore the deterioration of Castillian Spanish due to foreign contamination. They ignore the real source of the problem within Spain itself where everyone speaks the language badly except those in the remote towns and a few intellectuals. A ray of hope comes from the Americans. (Text is in Spanish.) (AMH)

Quijada, Carlos Alonso

1977-01-01

69

Datirovka zvezdnogo kataloga Ptolemeya po sobstvennym dvizheniyam: tysyacheletnyaya problema reshena %t Dating Ptolemy's star catalogue based on proper motions: the thousand-year-old problem solved  

NASA Astrophysics Data System (ADS)

The thousand-year-old problem of the origin of the star catalogue included in Ptolemy's "Almagest" is considered. The dilemma whether stellar coordinates were based on Hipparchus' or Ptolemy's observations has arisen long ago, because the 1 degree error in ecliptic longitudes may be explained either by Ptolemy's error in the initial longitudes of the Sun, or by the fact that Ptolemy adopted the original Hipparchus' coordinates and transformed them to a 265-year later epoch using an erroneous constant for precession. In fact, only indirect evidence for the Hipparchan origin of most of the coordinates was available so far, and most specialists considered the issue still to be resolved. We have successfully applied a new approach based on stellar proper motions. The time-dependent mutual distances in the configurations including 8 fast stars yield an epoch of -53 ± 130 B.C., whereas the bulk method based on an analysis of the Almagest minus computed coordinate differences for 40 fastest stars yields an epoch of -90 ± 120 B.C. Standard errors in the ancient ecliptic longitudes and latitudes are found to be ?(?cos?) = 18' and ?? = 13', respectively. It is concluded that the stellar coordinates in the Almagest catalogue were observed during Hipparchus' lifetime and that Ptolemy's authorship claim can be rejected at a 94% significance level. Ptolemy's assertion that "we observed as many stars as we could sight down to the sixth magnitude" might simply imply that he found each star of the original catalogue to be near its position in the sky given by Hipparchus, and then adopted Hipparchus' coordinates as measured by a more skilled observer.

Dambis, A. K.; Efremov, Yu. N.

70

Use of Simulation Techniques in the Problem of Air Traffic Control l'USO Delle Tecniche di Simulazione Nel Problema Del Controllo Del Traffico Aereo.  

National Technical Information Service (NTIS)

The air-traffic control involves a series of necessarily interconnected problems, whose solution needs a charged system to work out the information and to plan the decisions with coordination. The use of simulation techniques with which the system is divi...

C. Bottiglieri A. Dicola

1976-01-01

71

`Why Can't They Do Anything for a Simple Back Problem?'A Qualitative Examination of Expectations for Low Back Pain Treatment and Outcome  

Microsoft Academic Search

In order to examine expectations for pain treatment and outcome and to determine whether they are influential in maintaining health service consumption 16 adults suffering from chronic pain were interviewed. Transcripts were subjected to thematic analysis. The six main themes to emerge were labelled: Unmet Expectations; Health Professionals; the Importance of Self; Getting Something Done; Back to Square One; and

Carol Campbell; Alison Guy

2007-01-01

72

Uncovering the Essence of the Climate Change Adaptation Problem—A Case Study of the Tourism Sector at Alpine Shire, Victoria, Australia  

Microsoft Academic Search

A problem-orientated and interdisciplinary approach was employed at Alpine Shire, in north-east Victoria, Australia, to explore the concept of contextual vulnerability and adaptability to stressors that include, but are not limited to climatic change. Using a policy sciences approach, the objective was to identify factors that influence existing vulnerabilities that might consequently act as barriers to effective adaptation for the

Carolina E. Roman; Amanda H. Lynch; Dale Dominey-Howes

2010-01-01

73

Evite los problemas de la diabetes: Mantenga sano el sistema nervioso (Prevent Diabetes Problems: Keep Your Nervous System Healthy, Number 6 in a Series of 7).  

National Technical Information Service (NTIS)

Too much glucose (sugar) in the blood for a long time can cause diabetes problems. This high blood glucose (also called blood sugar) can damage many parts of the body, such as the heart, blood vessels, eyes, and kidneys. Heart and blood vessel disease can...

2003-01-01

74

Hacia Una Pedagogia de Solucion de Problemas en La Educacion Ambiental. Serie Educacion Ambiental 15 (Pedagogy of Solutions and Problems in Environmental Education. Environmental Education Series 15.  

ERIC Educational Resources Information Center

This document discusses the teaching of problem solving in environmental education. From an interdisciplinary viewpoint, this study describes some strategies for teaching that can favor the practice of educational activities oriented toward solving the concrete problems of the surrounding environment. The volume is divided into seven chapters. The…

United Nations Educational, Scientific, and Cultural Organization, Santiago (Chile). Regional Office for Education in Latin America and the Caribbean.

75

Esquizofrenia y trastorno en el consumo de sustancias: prevalencia y character?sticas sociodemogr?ficas en la poblaci?n Latina  

PubMed Central

El interés por comprender la co-morbilidad de la esquizofrenia y el trastorno en el uso de sustancias, ha aumentado debido al incremento de este diagnóstico, a los efectos negativos observados en el sujeto y a los costos en los servicios de salud. Este trastorno dual puede tener efectos dramáticos en el curso clínico del trastorno psicótico tales como: mayores recaídas, re-hospitalizaciones, síntomas más severos, no adherencia al tratamiento antipsicótico, cambios marcados del humor, aumento en el grado de hostilidad e ideación suicida, así como alteraciones en otras áreas del funcionamiento incluyendo violencia, victimización, indigencia y problemas legales. La literatura proveniente en particular de Estados Unidos y Europa sugiere que el rango de prevalencia para este diagnóstico puede oscilar entre el 10% hasta el 70%. En este estudio, revisamos la prevalencia del diagnóstico dual de esquizofrenia y trastorno en el uso sustancias, así como sus características sociodemográficas, con base en la literatura disponible alrededor del mundo dando énfasis en la poblacion latina. A pesar de que este diagnóstico es ampliamente aceptado, se conoce poco sobre su prevalencia en la población latina, sobre los factores ambientales, demográficos, clínicos y otras características de estos individuos. Un mejor conocimiento sobre este diagnóstico permitiría mejorar los métodos para la detección y adecuada valoración del trastorno en el uso de sustancias en personas con trastornos metales severos como la esquizofrenia.

Jimenez-Castro, Lorena; Raventos-Vorst, Henriette; Escamilla, Michael

2012-01-01

76

USO DEL TERRITORIO, IMPATTO AMbIENTALE, bENESSERE DEGLI ANIMALI E SOSTENIbILITà ECONOMICA DEI SISTEMI DI ALLEvAMENTO DELLA vACCA DA LATTE PRESENTI IN MONTAGNA. IL CASO DI STUDIO DELL'ALTOPIANO DI ASIAGO  

Microsoft Academic Search

Dairy farming in the mountain regions has seen a deep transformation of the traditional production sys- tem based on the consumption of the local forage and the grazing entire herd of dual purpose animals on alpine pasture. Driven by a favourable milk price and by a convenient cost of the energy concentrates has seen a continuous growth of intensive systems

77

La Qualita Ambientale del Fosso Della Casaccia (Roma). Valutazione Dell'Impatto Ecologico Dello Scarico di Qcque Reflue Del Dentro Ricerche ENEA Casaccia (Environmental Quality of the Fosso Della Casaccia Stream (Rome, Italy). Evaluation of the Ecological Impact of Wastewaters from the ENEA Research Centre Casaccia).  

National Technical Information Service (NTIS)

The study concerned the evaluation of ENEA Research Centre wastewaters effect on the nearby stream 'Fosso della Casaccia'. These pollutants consist of black waters and low radioactivity substances. The effects on streams ecosystem were evaluated using mac...

G. Izzo J. G. Morgana L. Manccini P. Formichetti

2008-01-01

78

Using the PRECEDE-PROCEED Model to Assess Dietary Needs in the Hispanic Population in Northeastern Pennsylvania.  

PubMed

Research shows that as Hispanic immigrants spend more time in the United States and/or become more assimilated to the U.S. culture their diet begins to mimic that of a Western diet. A dietary needs assessment was conducted in the target population of low income, first-generation Hispanics in the greater Scranton, PA, area to identify nutrition problems and inform culturally appropriate nutrition intervention development. The PRECEDE-PROCEED model was used to guide the assessment. Interviews with key informants and a focus group as well as demographic and dietary-related questionnaires were completed with the target population to identify health and nutrition needs in the community and factors regarding dietary behaviors. Behavioral and environmental objectives were developed and led to a culturally tailored nutrition intervention. Las investigaciones muestran que a medida que los inmigrantes Hispanos pasan más tiempo en los EE. UU. Se vuelven más asimilados a la cultura y su dieta comienza a imitar la de la dieta occidental. Se llevó a cabo una evaluación dietética en la población Hispana de primera generación, de bajos recursos, la mayoría en el área de Scranton, PA para identificar los problemas de nutrición e informar sobre el desarrollo de una intervención de nutrición culturalmente apropiada. El modelo PRECEDE-PROCEDE fue utilizado para guiar la evaluación. Se realizaron entrevistas con informantes claves y un grupo de enfoque, así como cuestionarios demográficos y relacionados a la dieta con la población blanco para identificar las necesidades de salud y nutrición en la comunidad, así como los factores con relacionados a los hábitos alimenticios. Se desarrollaron objetivos conductuales y ambientales los cuales llevaron a una intervención nutricional culturalmente adaptada. PMID:24865439

Castellanos, Diana Cuy; Abrahamsen, Katie

2014-01-01

79

CUESTIONARIO BREVE DE TAMIZAJE Y DIAGNÓSTICO DE PROBLEMAS DE SALUD MENTAL EN NIÑOS Y ADOLESCEN- TES: ALGORITMOS PARA SÍNDROMES Y SU PREVALENCIA EN LA CIUDAD DE MÉXICO. SEGUNDA PARTE  

Microsoft Academic Search

and ICD-10 classifications. Based on these results, algorithms for probable psychiatric syndromes were created. Results Using the results from logistic regression analyses, algorithms were created considering different levels of severity for probable disor- ders: attention-deficit and hyperactivity distinguishing three subtypes, depressive with two definitions and two severity degrees, anxiety with two subtypes, oppositional behavior, conduct disorder, spe- cific language disorder,

Jorge Javier Caraveo

2007-01-01

80

A área de proteção ambiental 'Fazenda e Parque do Carmo': os problemas ambientais, as dificuldades de gestão e a influência na qualidade de vida da população The environmental protection area \\  

Microsoft Academic Search

RESUMO: A falta de planejamento urbano da Cidade de São Paulo contribuiu para a eliminação da maior parte da cobertura vegetal, dada à ocupação irregular, inclusive de áreas legalmente protegidas. Essas áreas verdes são reguladoras do equilíbrio ambiental e assim, interferem diretamente na qualidade de vida da população. Através de levantamento bibliográfico e documental e entrevista com o Conselho Consultivo

Mirtes Moreira Silva; José Luís Negrão Mucci; Maria Cecília Focesi Pelicioni

81

AS DOENÇAS SEXUALMENTE TRANSMISSÍVEIS SÃO PROBLEMAS ENTRE GESTANTES NO CEARÁ? ARE SEXUALLY TRANSMITTED DISEASES A PROBLEM TO PREGNANT WOMEN IN CEARÁ? MENÇÃO HONROSA - PRÊMIO MELHOR TRABALHO COMPLETO, CATEGORIA: EPIDEMIOLOGIA  

Microsoft Academic Search

Introduction: the complications of STD (Sexually Transmitted Diseases) include ectopic pregnancy, spontaneous abortions, stillbirth, prematurity, conge- nital perinatal and puerperal infection. In Brazil, studies in pregnant women are scarce, although STD have an important impact in pregnancy outcome. Objective: to estimate the prevalence of syphilis, gonorrhea, chlamydeous, and trichomoniasis in pregnant women in two municipalities of Ceará and to identify

Telma A Martins; Pierre Y-Bello; Martha D Bello; Lígia Regina; SK Pontes; Lúcia V Costa; Iracema S Miralles; Telma Régia

82

Memoria de calculo e simulacao do 2(sup 0) problema padrao da AIEA com o codigo Trac/PF1. (Input data preparation and simulation of the second standard problem of IAEA using the Trac/PF1 code).  

National Technical Information Service (NTIS)

The second Standard Problem sponsored by IAEA consists in the simulation of a small LOCA located in the downcomer of a PMK-NVH integral test facility, which models WWER/440 type reactor. This report presents input data preparation and comparison between T...

A. A. Madeira A. C. Pontedeiro M. R. Silva Galetti R. C. Borges

1989-01-01

83

EVP2D- um programa automatico para a analise elastovistoplastica e de dano de problemas bidimensionais e axissimetricos. (EVP2D- a computer code developed for the eslastoviscoplastic-damage analysis of axyssimetrical and two-dimensional problems).  

National Technical Information Service (NTIS)

This work aims to describe the computer code EVP2D developed for the elastoviscoplastic-damage analysis of metallic components, with particular emphasis dedicated to the problem of creep damage and rupture. After a brief introduction of the basic concepts...

O. J. A. Goncalves Filho

1987-01-01

84

Cooperazione Scientifica Italia (ISS) Ecuador (IFA). La Prevenzione Delle Patologie da Amianto: un Problema di Sanita Pubblica. (Scientific Cooperation Between Italy (ISS) and Ecuador (IFA). The Prevention of Asbestos-Related Diseases: a Public Health Concern.)  

National Technical Information Service (NTIS)

This report is aimed at discussing the health impact caused by asbestos exposure in the workplace as well as in the general environment. The report relies on a working hypothesis aimed at promoting contrast measures based on scientific evidence and intern...

D. Marsili P. Comba R. Harari

2009-01-01

85

Atención a la familia: otra forma de enfocar los problemas de salud en atención primaria. Instrumentos de abordaje familiar Taking account of the family: another form of focussing on health problems in primary care. Instruments of the family approach  

Microsoft Academic Search

On many occasions somatic symptoms that do not improve with conventional measures reflect hidden problems related to the patient's milieu, and this milieu is usually the family. But the family is not only what makes it possible to understand the problems, it is also a resource of incalculable value for attending to health problems in a global form, and for

I. Yurss

86

Estudo e aplicacao de codigos nucleares disponiveis no Ipen em problemas de fisica de reatores dependentes do tempo. (Study of reactor analysis code available at Ipen and their application to the time dependent problems).  

National Technical Information Service (NTIS)

Two computer codes available at IPEN are studied and applied to analyze time-dependent problems of nuclear reactors. The GAPOTKIN code can be used to analyze short-term transient behaviours and the CITATION code is applicable to long-term burnup analysis....

M. Yamaguchi

1989-01-01

87

Nine Tips To Help Faith Leaders and Their Communities Address Teen Pregnancy = Nueve consejos para ayudar a lideres espirituales y sus comunidades a hacerle frente al problema del embarazo en la adolescencia.  

ERIC Educational Resources Information Center

To support faith communities in protecting teenage boys and girls from too-early sexual activity and teen pregnancy, the National Campaign To Prevent Teen Pregnancy's Task Force on Religion and Public Values has compiled these nine tips which summarize a wealth of experience and advice from faith leaders around the country. The members of the Task…

National Campaign To Prevent Teen Pregnancy, Washington, DC.

88

A experiência da Universidade São Francisco com o internato médico de psiquiatria utilizando a metodologia da aprendizagem baseada em problemas The experience of Universidade São Francisco with the medical internship in psychiatry using the problem-based learning method  

Microsoft Academic Search

In the last few years, medical education has been going through curricular and pedagogical changes with the purpose of educating a new health professional. One of the pedagogical alternatives is the education based on problem-solving, which works essentially with the construction of knowledge using signifi cant experiences. Such learning model has enabled curricular changes, which, in the fi eld of

Fernando Ribeiro da Silva Paulin; Regina Caeli; Guerra Poças; Bragança Paulista

2009-01-01

89

Some Aspects of the Problems of the Average Life of Erythrocytes with the Use of Cr51 Radioactive Sodium Chromate; ALGUNS ASPECTOS DO PROBLEMA DA DETERMINACAO DA VIDA MEDIA DOS ERITROCITOS COM O EMPREGO DO Cr51 (RADIOCROMATO DE SODIO)  

Microsoft Academic Search

Analytical expressions were derived for the survival curves of Cr⁵¹; -labeled erythrocytes. Expressions are obtained for normal erythrocytes, ; normal erythrocytes transfused into receptors containing a lethal factor, ; erythrocytes subjected to a lethal factor after formation, and potentially ; immortal erythrocytes subjected to an exterior lethal factor which destroys them ; randomly, regardless of age. (J.S.R.);

Pieroni

1959-01-01

90

International meeting. Complexity in the Living: A Problem-Oriented Approach. Rome, September 28-30, 2004. (Convegno internazionale. La Complessita del Vivente: un Approccio Orientato al Problema. Roma, 28-30 Settembre 2004).  

National Technical Information Service (NTIS)

The scientific world has the clear perception that an interdisciplinary approach is urgently needed for attacking the many yet unsolved problems of today science. This attitude has several roots, including the search of biologists for quantitative foundat...

A. Colosimo A. Giuliani J. P. Zbilut P. Sirabella R. Benigni

2005-01-01

91

76 FR 6601 - Certain Pasta From Italy: Notice of Amended Final Results of the Thirteenth Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013

...ingredients such as chopped vegetables, vegetable purees, milk, gluten, diastasis, vitamins, coloring and flavorings, and up to...Certificazione Etica e Ambientale. Effective July 1, 2008, gluten free pasta is also excluded from this order. See Certain...

2011-02-07

92

75 FR 81212 - Certain Pasta From Italy: Notice of Final Results of the Thirteenth Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013

...ingredients such as chopped vegetables, vegetable purees, milk, gluten, diastasis, vitamins, coloring and flavorings, and up to...Certificazione Etica e Ambientale. Effective July 1, 2008, gluten free pasta is also excluded from this order. See Certain...

2010-12-27

93

77 FR 47816 - Certain Pasta from Italy: Notice of Initiation of Antidumping Duty Changed Circumstances Review  

Federal Register 2010, 2011, 2012, 2013

...ingredients such as chopped vegetables, vegetable purees, milk, gluten, diastasis, vitamins, coloring and flavorings, and up to...Certificazione Etica e Ambientale. Effective July 1, 2008, gluten free pasta is also excluded from this...

2012-08-10

94

76 FR 71311 - Certain Pasta From Italy: Notice of Partial Rescission of Antidumping Duty Administrative Review  

Federal Register 2010, 2011, 2012, 2013

...ingredients such as chopped vegetables, vegetable purees, milk, gluten, diastasis, vitamins, coloring and flavorings, and up to...Certificazione Etica e Ambientale. Effective July 1, 2008, gluten free pasta is also excluded from this order. See Certain...

2011-11-17

95

75 FR 49907 - Certain Pasta From Italy: Notice of Preliminary Results of Antidumping Duty Administrative Review  

Federal Register 2010, 2011, 2012, 2013

...ingredients such as chopped vegetables, vegetable purees, milk, gluten, diastasis, vitamins, coloring and flavorings, and up to...Certificazione Etica e Ambientale. Effective July 1, 2008, gluten free pasta is also excluded from this order. See Certain...

2010-08-16

96

75 FR 11116 - Certain Pasta from Italy: Notice of Amended Final Results of the Twelfth Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013

...ingredients such as chopped vegetables, vegetable purees, milk, gluten, diastasis, vitamins, coloring and flavorings, and up to...Certificazione Etica e Ambientale. Effective July 1, 2008, gluten free pasta is also excluded from this order. See Certain...

2010-03-10

97

76 FR 48125 - Certain Pasta From Italy: Notice of Preliminary Results of Antidumping Duty Administrative Review  

Federal Register 2010, 2011, 2012, 2013

...ingredients such as chopped vegetables, vegetable purees, milk, gluten, diastasis, vitamins, coloring and flavorings, and up to...Certificazione Etica e Ambientale. Effective July 1, 2008, gluten free pasta is also excluded from this order. See Certain...

2011-08-08

98

77 FR 46377 - Certain Pasta From Italy: Notice of Preliminary Results of Antidumping Duty Administrative Review...  

Federal Register 2010, 2011, 2012, 2013

...ingredients such as chopped vegetables, vegetable purees, milk, gluten, diastasis, vitamins, coloring and flavorings, and up to...Certificazione Etica e Ambientale. Effective July 1, 2008, gluten free pasta is also excluded from this order. See Certain...

2012-08-03

99

75 FR 10464 - Certain Pasta from Italy: Notice of Partial Rescission of Antidumping Duty Administrative Review...  

Federal Register 2010, 2011, 2012, 2013

...ingredients such as chopped vegetables, vegetable purees, milk, gluten, diastasis, vitamins, coloring and flavorings, and up to...Certificazione Etica e Ambientale. Effective July 1, 2008, gluten free pasta is also excluded from this order. See Certain...

2010-03-08

100

76 FR 76937 - Certain Pasta From Italy: Notice of Final Results of the Fourteenth Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013

...ingredients such as chopped vegetables, vegetable purees, milk, gluten, diastasis, vitamins, coloring and flavorings, and up to...Certificazione Etica e Ambientale. Effective July 1, 2008, gluten free pasta is also excluded from this order. See Certain...

2011-12-09

101

76 FR 23973 - Certain Pasta From Italy: Notice of Partial Rescission of Antidumping Duty Administrative Review  

Federal Register 2010, 2011, 2012, 2013

...ingredients such as chopped vegetables, vegetable purees, milk, gluten, diastasis, vitamins, coloring and flavorings, and up to...Certificazione Etica e Ambientale. Effective July 1, 2008, gluten free pasta is also excluded from this order. See Certain...

2011-04-29

102

Los Hispanos: Problemas y Oportunidades. Resumen de la Actual Situacion Demografica, Economica, Social y Politica de los Hispanos en los Estados Unidos y de las Iniciativas Tomadas por la Fundacion Ford Para Hacer Frente a las Necesidades de esta Poblacion en Aumento y Determinar sus Efectos Sobre la Sociedad Estadounidense. Documento de Trabajo de la Fundacion Ford, No. 436.  

ERIC Educational Resources Information Center

The Hispanic population's growing impact on American society has caused the Ford Foundation to explore new Foundation initiatives. The 1980 census revealed 14.6 million Hispanics: 60% Mexican American; 14% Puerto Rican; 6% Cuban, and 20% Other. The Hispanic population in the United States is growing and is characterized by diversity; rapid growth…

Ford Foundation, New York, NY.

103

Modelo de Petrov-Galerkin combinado com esquemas auto-adaptativos e sua aplicacao na resolucao numerica de problemas com camada limite. (Combined Petrov-Galerkin method with auto-adapting schemes and its applications in numerical resolution of problems with limit layer).  

National Technical Information Service (NTIS)

In this paper a new finite element model is constructed combining an r- refinement scheme with the CCAU method. The new formulation gives better approximation for boundary and internal layers compared to the standard CCAU, without increasing computer code...

R. S. Silva A. C. Galeao E. G. D. Carmo

1989-01-01

104

Metodo espectro-nodal para solucao das equacoes Sn em geometria x,y para problemas de penetracao profunda em meios altamente absorventes. (Spectral nodal method for the solution of the Sn equations in x,y geometry for highly absorbing deep penetration problems).  

National Technical Information Service (NTIS)

Presented here is an attempt to improve the accuracy of transport nodal methods applied to deep penetration transport problems in x, y-geometry. The resulting nodal method uses the Spectral Green's Function (SGF) scheme for solving the one-dimensional tra...

R. C. Barros

1991-01-01

105

La regulación de los órganos de gobierno de las cajas de ahorros: consideraciones electorales  

Microsoft Academic Search

El presente trabajo supone un avance en la resolución de los problemas de elección social y reparto proporcional de las cajas de ahorros españolas. La regulación estatal y regional relativa a estas instituciones no resuelve adecuadamente los problemas en las elecciones a representantes a los órganos rectores de dichas entidades financieras. La elección de un método para un problema de

Santiago Carbó Valverde; Antonio Palomares Bautista; Victoriano Ramírez González

2004-01-01

106

Los servicios hidrológicos y la conservación de los bosques de México  

Microsoft Academic Search

RESUMEN El manejo de los recursos hídricos es uno de los retos ambientales más importantes que los seres humanos tendrán que enfrentar en este nuevo siglo. En México, una crisis severa causada por el mal manejo del agua está siendo acentuada por las altas tasas de deforestación y la pérdida de los servicios hidrológicos proporcionados por los bosques y selvas

Robert H. Manson

107

Valoración De La Multifuncionalidad Agraria: Una Aplicación A Través Del Método De Los Experimentos De Elección\\/Agricultural Multifunctionality Valuation: A Case Study Using The Choice Experiment  

Microsoft Academic Search

La multifuncionalidad agraria es el reconocimiento del ejercicio conjunto por parte de este sector de funciones económicas, ambientales y sociales. Sin embargo, no todas estas aportaciones al conjunto de sociedad son valoradas en los mercados, sino que buena parte de ellas son bienes públicos. Por este motivo, para que este concepto de multifuncionalidad pueda utilizarse operativamente en el diseño de

Z. KALLAS; J. A. GÓMEZ-LIMÓN

2007-01-01

108

Plant bioregenerative life supports: The Italian CAB Project  

Microsoft Academic Search

The Bioregenerative Life Support program CAB (Controllo Ambientale Biorigenerativo) is a key element of the Italian Space Agency (ASI) Medicine & Biotechnology scientific program, set forth in the ASI Activity Plan 2006–2008. The CAB program started in October 2006, under the prime partnership of Thales Alenia Space Italia, with a feasibility study of a controlled biological system, allowing the regeneration

Cesare Lobascio; Matteo Lamantea; Vittorio Cotronei; Barbara Negri; Stefania De Pascale; Albino Maggio; Maria Foti; Sergio Palumberi

2007-01-01

109

Deforestation Impacts of Environmental Services Payments: Costa Rica’s PSA Program 2000–2005  

Microsoft Academic Search

Costa Rica’s environmental services payments program (Pagos por Servicios Ambientales, or PSA) started in 1997 and was the true pioneer in this area. It is broadly cited and has led to numerous calls for emulating its approach in various ways. It has itself evolved over time, with acknowledged shifts in focus. To measure the impacts of changed implementation, following earlier

Juan Robalino; Alexander Pfaff; G. Arturo Sanchez-Azofefia; Francisco Alpizar; Carlos Leon; Carlos Manuel Rodriguez

2008-01-01

110

Indicadores de sustentabilidad ambiental en la gestión de espacios verdes. Parque urbano Monte Calvario, Tandil, Argentina1  

Microsoft Academic Search

RESUMEN Los espacios verdes de las ciudades y particularmente los parques urbanos representan sistemas ambientales que cumplen con un doble rol, social y ecológico, en donde es posible evaluar las condiciones de sustentabilidad am- biental urbana. En tal sentido, proponemos un conjunto de indicadores destinados a evaluar en forma integral las condiciones de sustentabilidad del parque urbano Monte Calvario de

SUSANA GARCÍA; MARCELA GUERRERO

111

Indicadores de gestión urbana. Los observatorios urbano-territoriales para el desarrollo sostenible. Manizales, Colombia  

Microsoft Academic Search

Los Observatorios para el Desarrollo Sostenible del Municipio de Manizales en Colombia, hacen parte del Sistema de Monitoreo diseñado por el Municipio como apoyo a la gestión urbana local. A partir de los resultados de indicadores económicos, sociales y ambientales, los ciudadanos podrán evaluar de forma permanente el desempeño de programas y proyectos del Plan de Desarrollo Municipal y participar

Luz Stella Velásquez

2001-01-01

112

Proceso y métodos de evaluación integrada participativa de degradación en agroecosistemas semiáridos. Un caso de estudio en un área protegida en el trópico seco nicaragüense  

Microsoft Academic Search

Los procesos de evaluación integrada y participativa son un buen marco metodológico-operativo para la toma de decisiones frente a cuestiones ambientales complejas que conciernen a socio-agroecosistemas de alto dinamismo e impredecibilidad a cambios y con intereses conflictivos de los actores implicados en su gestión. La finalidad del artículo es mostrar el potencial de la aplicación de un enfoque interdisciplinar e

Federica Ravera; David Tarrasón; Pilar Andrés Pastor; Rafael Grasa

2009-01-01

113

APUNTES PARA INTRODUCIR EL SISTEMA DE ANÁLISIS DEL DÉFICIT DE CAPACIDAD INSTITUCIONAL EN LA GESTIÓN AMBIENTAL LOCAL  

Microsoft Academic Search

Las tendencias mundiales de afianzamiento de los sistemas democráticos, descentralización política y búsqueda de alternativas de desarrollo sustentable apuntan a los gobiernos locales como actores imprescindibles ¿Están en condiciones de subir a escena? La mayoría de los diagnósticos ambientales, se hacen a partir parámetros o indicadores de deterioro (efectos e impactos), aunque rara vez incluyen una evaluación de la gestión

Alberto E. Morán

2007-01-01

114

Auditoría al sistema de gestión ambiental de una cementera para determinar los porcentajes de adecuación a la norma venezolana covenin - iso 14001:2005  

Microsoft Academic Search

El presente trabajo consiste en la combinación de técnicas de evaluación propias de estudios ambientales con procedimientos de auditoría tradicionales, con el objetivo de auditar el Sistema de Gestión Ambiental (SGA) de una empresa cementera venezolana llamada Cementos Carora C. A. siguiendo los lineamientos de la norma venezolana COVENIN ISO 14001:2005 para determinar los porcentajes de adecuación a la norma.

Alexis Colmenárez; Anoushka Colménarez

2008-01-01

115

Percolazione di nutrienti e di fitofarmaci, consumo della risorsa idrica: l'agro- meteorologia può esprimere in modo compiuto la relazione suolo-pianta-atmosfera. Con il bilancio idrico e altri strumenti, soprattutto di carattere modellistico; è in grado di dare un supporto fondamentale alla tutela dell'ambiente e del territorio  

Microsoft Academic Search

sari al calcolo della domanda irrigua a diversa scala territoriale, dall'a- zienda alla regione, e permettono di valutare l'impatto ambientale delle tecniche agronomiche, deter- minando il rischio di contamina- zione delle acque di falda. La stima della percolazione pro- fonda e del ruscellamento superfi- ciale consente di calcolare il bilan- cio sia degli elementi nutritivi, quali azoto e fosforo, sia

L. Botarelli; Servizio IdroMeteo; Arpa Emilia-Romagna

2005-01-01

116

LA NECESIDAD DE UNA CORRECTA GESTIÓN AMBIENTAL URBANA PARA LA LOCALIDAD  

Microsoft Academic Search

La consideración de la temática ambiental en el espacio urbano, desde una perspectiva global es un fenómeno nuevo, al menos, en América Latina. Desde hace varias décadas, los esfuerzos por mejorar las condiciones ambientales en nuestras ciudades se limitaron a la construcción progresiva de sistema de captación de agua y transporte de aguas servidas, sistemas de recolección de basura, entre

Eduardo López Bastidas; Tania Goicochea Borrell

2009-01-01

117

Determining the Appropriate Levels of Exchange Rates for Developing Economies: Some Methods and Issues (Comment déterminer le taux de change approprié pour un pays en développement: quelques méthodes et problèmes d'analyse) (Determinación del nivel apropiado para los tipos de cambio de las economías en desarrollo: Algunos métodos y problemas)  

Microsoft Academic Search

The paper reviews a number of approaches that are available for determining an appropriate exchange rate that yields a sustainable balance on the external current account for a developing economy, given appropriate monetary, fiscal, and income policies. The study focuses on two aspects of the exchange rate issue--assessing the appropriateness of the prevailing exchange rate, and, if the exchange rate

Ahsan H. Mansur

1983-01-01

118

Complicaciones gastrointestinales (PDQ®)  

Cancer.gov

Resumen de información revisada por expertos acerca del estreñimiento, impacción, obstrucción intestinal y diarrea como complicaciones del cáncer o su tratamiento. Se discute el manejo de estos problemas.

119

Computacao Algebrica no Calculo das Variacoes: Determinacao de Simetrias e Leis de Conservacao  

Microsoft Academic Search

Resumo. Os problemas de optimizacao dinamica (em espacos de funcoes) trata- dos pelo calculo das variacoes, sao normalmente resolvidos por recursoas condicoes necessarias de Euler-Lagrange, que sao equacoes diferenciais de segunda ordem (ou de ordem superior, quando os problemas variacionais envolvem derivadas de ordem superior a um). Estas equacoes sao, em geral, nao lineares e de dif´õcil resolucao. Uma forma

Paulo D. F. Gouveia; Delfim F. M. Torres

2004-01-01

120

Luz, cámara, acción: el cine y la matemática  

Microsoft Academic Search

1 sostiene que al evaluar un problema siempre se tiende a seguir un patrón natural o habitual de pensamiento (las sillas son para sentarse, el piso para caminar, un vaso para ser llenado con un líquido, etc.), lo cual nos limita. Este tipo de pensamiento es el llamado vertical, se caracteriza por encontrar una única solución al problema. Mientras tanto,

CLAUDIA MINNAARD; VIVIANA JULIA CONDESSE; Edward de Bono

121

Desnutrición a Nivel Municipal en Colombia, Censo 2005  

Microsoft Academic Search

Este trabajo va encaminado a resolver el problema de localización y cuantificación de la desnutrición en Colombia, para pequeñas áreas (municipios y localidades para Bogotá). Aquí se presentan los mapas de desnutrición para pequeñas áreas en Colombia, pues con el objetivo de reducir los niveles de desnutrición las entidades gubernamentales requieren herramientas para identificar los problemas a nivel regional y

Hermes Fernando Martínez

2010-01-01

122

Detección de huevos helmintos mediante plantillas dinámicas  

Microsoft Academic Search

La detección de micro-organismos es un problema abierto, donde diferentes técnicas deben ser utilizadas dependiendo del dominio de imágenes en el que se trabaje. El problema que nuestro grupo viene atacando es el referido a la detección de huevos de helmintos en micrografías adquiridas a partir de muestras biológicas. Una característica de estas muestras es la referida a la presencia

J. Chuctaya; J. P. Mena-Chalco; G. Humpire; A. Rodriguez; C. Beltrán; R. Patiño

2010-01-01

123

Inventario mundial de la calidad del carbon mineral (WoCQI) [The world coal quality inventory (WoCQI)  

USGS Publications Warehouse

Los oficiales encargados de la politica comercial de cada pais requieren informacion clara y precisa sobre el recurso del carbon mineral, particularmente sobre sus propiedades y caracteristicas, para tomar decisiones bien fundamentadas con respecto al mejor uso de los recursos naturales, necesidades de importacion y oportunidades de exportacion, objetivos de politica interna y externa, oportunidades de transferencia tecnologica, posibilidades de inversion externa, estudios ambientales y de salud, y asuntos relacionados con el uso de productos secundarios y su disposicion.

Finkelman, R. B.; Lovern, V. S.

2001-01-01

124

On the expansion-contraction rhythm of the sea anemone, Actinia equina L  

Microsoft Academic Search

Riassunto È stato studiato il ritmo di espansione-contrazione di esemplari diActinia equina L. della zona interoctidale del Mar Tirreno, sottoposti a condizioni differenti di illuminazione e di livello d'acqua. Gli autori ritengono che il ritmo sia direttamente dipendente dall'illuminazione ambientale e dallo stato di copertura o scopertura conseguente alle maree. Una luce di intensità pari a quella lunare non esercita

A. Milia; L. Geppetti

1964-01-01

125

La problematica de la demarcacion entre ciencia y pseudociencia y sus implicaciones en la educacion cientifica  

NASA Astrophysics Data System (ADS)

En la sociedad prevalece una tendencia generalizada hacia la inclusion de creencias y practicas pseudocientificas. Esta investigacion responde a la necesidad de analizar como la proliferacion de las pseudociencias afecta la vision que tienen los estudiantes universitarios sobre las ciencias naturales. A tales efectos, la investigadora describe las concepciones epistemologicas que tienen los estudiantes sobre las ciencias y las pseudociencias e identifica los criterios de demarcacion, entre un area y otra, que se derivan de estas concepciones. De igual modo, esta identifica las creencias y practicas pseudocientificas de mayor arraigo entre los estudiantes, destacando, a su vez, la razon de ser de las mismas. Por ultimo, la investigadora analiza las implicaciones educativas de la problematica de la demarcacion entre ciencia y pseudociencia. La investigacion es de naturaleza mixta, enmarcada en los paradigmas empirico- analitico y cualitativo. El proceso investigativo se llevo a cabo mediante la administracion del cuestionario Criterios para la demarcacion entre ciencia y pseudociencia. La parte cualitativa estuvo enmarcada en el diseno de estudio de caso, recopilando informacion mediante entrevistas semiestructuradas en dos grupos focales. La poblacion de estudio estuvo constituida por estudiantes universitarios del nivel subgraduado de la Universidad Central de Bayamon. Los resultados del estudio reflejaron las concepciones erroneas de los estudiantes sobre la naturaleza de las ciencias y las pseudociencias. Con respecto a la demarcacion entre ciencia y pseudociencia, el criterio imperante entre los universitarios es el de la verificabilidad, considerando la aplicacion del metodo cientifico como el metodo para demostrar la veracidad de las teorias cientificas. Las creencias y practicas pseudocientificas no son muy frecuentes entre los universitarios. Estos atribuyen las mismas a la prevalencia de elementos supersticiosos y al engano a que es sometida la poblacion por quienes promueven estas practicas. A partir de los resultados, la investigadora concluye que la problematica sobre la demarcacion entre ciencia y pseudociencia esta influenciada por unos procesos de ensenanza enfocados en una vision distorsionada de la ciencia, producto de la no integracion de los aspectos filosoficos, historicos y sociales de la misma.

Jimenez Tolentino, Dinorah

126

Risoluzione analitica delle equazioni algebriche generali  

Microsoft Academic Search

\\u000a Sunto  L’A. richiama la attenzione dei matematici sul secolare problema della risoluzione delle equazioni algebriche e ricorda che,\\u000a intorno al 1920, questo problema ha avuto una esauriente e generale soluzione mediante le funzioni ipergeometriche di più\\u000a variabili.\\u000a \\u000a L’A. indica che la soluzione di questo problema è stata data da due punti di vista differenti e mostra che, mediante i risultati\\u000a dell’A.,

G. Belaedinelli

1959-01-01

127

Intellectual Disability  

MedlinePLUS

... enfermedad o un problema en el cerebro. En muchos niños no se conoce la causa del discapacidad ... los niños más tarde en la vida. Hay muchos síntomas de discapacidad intelectual. Por ejemplo, los niños ...

128

Complicaciones gastrointestinales (PDQ®)  

Cancer.gov

Resumen de información revisada por expertos acerca del estreñimiento, la retención fecal, la obstrucción intestinal y la diarrea como complicaciones del cáncer o su tratamiento. Se discute el manejo de estos problemas.

129

Ordinary Duality Vis-A-Vis Geometric Duality.  

National Technical Information Service (NTIS)

The ordinary dual problem is characterized as an orthogonal projection of the corresponding geometric dual problem--a projection that can be obtained via a suboptimization. This characterization endows geometric duality with certain strong advantages over...

E. L. Peterson

1976-01-01

130

Utilização de hardware reconfigurável para acelerar a satisfação booleana  

Microsoft Academic Search

* Trabalho financiado com a bolsa da FCT-PRAXIS XXI\\/BD\\/21353\\/99 Resumo - Este artigo apresenta um estudo de possibilidade de aceleração da satisfação booleana com a ajuda do hardware reconfigurável. A satisfação booleana (SAT) é um problema importante que tem muitas aplicações em CAD e outras áreas. Neste artigo propomos uma técnica de desenvolvimento orientada a problema em geral para acelerar

Iouliia Skliarova; António B. Ferrari

2001-01-01

131

Análisis de sensibilidad en elasticidad mediante el método de los elementos de contorno  

Microsoft Academic Search

Se presenta en este artículo una revisión completa del análisis de sensibilidad para los funcionales más\\u000ahabituales en Elasticidad, en base al enfoque continuo del problema, teniendo en cuenta los conceptos de\\u000aderivada material y problema adjunto. La precisión en el cálculo de las sensibilidades depende en gran\\u000amedida de la precisión en el cálculo de las tensiones y deformaciones

Elena Calvo; Luis Gracia

1970-01-01

132

Optimización basada en confiabilidad por medio de redes neuronales y algoritmos evolutivos  

Microsoft Academic Search

A diferencia de la optimización usual, la optimización estocástica consiste en una minimización de una\\u000afunción de coste sujeta a condiciones expresadas en forma de probabilidades en lugar de funciones deterministas,\\u000alo que la convierte en un problema mucho más complejo. En esta clase de optimización son comunes\\u000alos problemas donde la función o funciones objetivo y sus condiciones son

J. E. Hurtado; Diego Álvarez

1970-01-01

133

Status of TJ-II project  

SciTech Connect

The flexible Heliac TJ-II is a medium six device (R=1.5m, [a]=0.2 m, B(0)=1.0 T) in an advanced stage of construction at Centro de Investigaciones Energeticas Medio Ambientales y Tecnologicas (CIEMAT), Madrid. The problems encountered during manufacturing so far have been solved satisfactorily. Nevertheless the narrow tolerances, which result from the compact machine design, create real challenges for all the component manufacturers. In this paper we present the present status of the project with a particular emphasis on the construction situation of the main components. 1 ref., 2 figs., 1 tab.

Alejaldre, C.; Blaumoser, M.; Almoguera, L. [Asociacion EURATOM-CIEMAT para Fusion, Madrid (Spain)] [and others

1995-04-01

134

Como Lo Hago Yo: Anomal?as del Tubo Neural en Guatemala -- Mielomeningocele Unidad de Espina B?fida e Hidrocefalia  

PubMed Central

En Guatemala nacen por añ 786 niños con defectos de tubo neural. Operamos 65 a 70 niños con mielomenigocele por año. Tenemos equipo multidisciplinario. Recomendamos parto por cesárea. Infección antes de la cirugía es un problema mayor. Derivación tardía es un problema. Disecamos la plaqueta con la técnica clásica. Suturamos la plaqueta para restituir la forma de la médula. Corpectomía en casos de cifósis. Hidrocefalía: Operamos el 80% de los niños. Chiari II: Operamos basados en los síntomas, primero nos aseguramos que la válvula funciona bien. Médula anclada: Operamos basados en los síntomas.

Manucci, Graciela; von Quednow, Enzo

2014-01-01

135

Detecci?n de huevos helmintos mediante plantillas din?micas  

Microsoft Academic Search

La detecci?n de micro-organismos es un problema abierto, donde\\u000adiferentes t?cnicas deben ser utilizadas dependiendo del dominio de im?genes en\\u000ael que se trabaje. El problema que nuestro grupo viene atacando es el referido\\u000aa la detecci?n de huevos de helmintos en micrograf?as adquiridas a partir de\\u000amuestras biol?gicas. Una caracter?stica de estas muestras es la referida a la\\u000apresencia

J. Chuctaya; J. P. Mena-Chalco; G. Humpire; A. Rodriguez; C. Beltrn; R. Patio

2010-01-01

136

ESTUDO GEOAMBIENTAL DO CURSO MÉDIO DA BACIA HIDROGRÁFICA DO RIO VERDE - CAMPO LARGO\\/PR  

Microsoft Academic Search

Resumo: A preocupação com questões ambientais tem crescido nos últimos anos motivada, principalmente, pela busca da sociedade por conhecimentos que apontem amenização e soluções de problemas tanto em áreas urbanas como rurais. Diante desta preocupação e utilizando como base teórico-metodológica a Geomorfologia Ambiental, este trabalho apresenta um estudo geoambiental do curso médio da bacia hidrográfica do rio Verde, localizado no

Maristela Moresco Mezzomo; Andreia Quintão Soares

137

El Balneario Marítimo como Espacio Utópico: los casos de Portmeirion (Gales), Thorpeness (Inglate rra), Pedernales (España) y Piriápolis (Uruguay)  

Microsoft Academic Search

(Estados Unidos). 1 Esta ponencia dirige la mirada a otro tipo de balneario marítimo, la pequeña colonia de vacaciones establecida por un empresario por motivos utópicos, tratando de construir un espacio de placer para llevar a habitantes y visitantes hacia un estado de perfecta tranquilidad y de aislamiento de los problemas del mundo exterior. Propongo un análisis comparativo de cuatro

Reino Unido

138

Lexical Connection: Semiterm Grammatical Patterns in Spanish  

ERIC Educational Resources Information Center

The aim of this article is to describe the grammatical patterns of a set of nouns frequently used in Spanish specialized discourse: the so-called "semiterms". The following nouns were selected for the study: "problema" "problem", "resultado" "result", "motivo" "motive/reason", "razon" "reason", and "consecuencia" "consequence". Apart from…

Ferrero, Carmen Lopez

2012-01-01

139

Blanqueo de capitales y lavado de dinero: su concepto, historia y aspectos operativos  

Microsoft Academic Search

Hoy en día el lavado o reciclaje de dinero es percibido por la comunidad internacional como uno de los principales problemas, frente al cual la actividad criminal ocupa la atención de todas las autoridades relacionadas con el tema. Los países son conscientes de la difícil situación de establecer un criterio uniforme precisamente porque las realidades de cada nación son diversas

Bruno Tondini

140

Não ao sedentarismo, sim à saúde: contribuições da Educação Física escolar e dos esportes No to sedentarianism, yes to health: contributions of school physical education and sports No al sedentarismo, sí a la salud: contribuciones de la educación física en la escuela y de los deportes  

Microsoft Academic Search

RESUMO: Um dos grandes problemas enfrentados pelos povos no mundo se refere ao sedentarismo. Associado a ele, a obesidade, as cardiopatias, a diabetes e tantas outras doenças aparecem com índices muito preocupantes principalmente nas populações de jovens em idade escolar. A tecnologia parece agravar mais ainda este quadro. Entretanto, a prática da atividade física regular, com orientação, com vestimenta e

Ubiratan Silva Alves

141

EVALUACIÓN DE LA SOSTENIBILIDAD EN LOS CULTIVOS DE PALMA AFRICANA EN EL DEPARTAMENTO DEL META  

Microsoft Academic Search

Al cultivo de la palma de aceite se le acusa por los problemas inherentes a los monocultivos y porque a éste en particular se le asocia con violaciones de los derechos humanos. Adicionalmente, en las plantaciones se usan formas de contratación que descargan sobre los trabajadores parte de los costos de la competitividad que exige el comercio internacional. Sin embargo,

Juan Manuel Ochoa Amaya; Ernesto Leonel Chávez Hernández

2011-01-01

142

ESTADO LAICO, SOCIEDAD LAICA. UN DEBATE PENDIENTE 1  

Microsoft Academic Search

El hablar sobre la necesidad de secularizar el estado y la sociedad abre normalmente un gran conjunto de interrogantes. Al igual que cuando hablamos de sexualidad, se encienden los debates, se polarizan las opiniones, se comparan nuestros países y los concordatos que la mayoría de estados latinoamericanos mantienen bajo un ilusorio seculorómetro y como ante cualquier otro dilema o problema

Blanca Varela

2002-01-01

143

DEPRESIÓN EN NIÑOS Y ADOLESCENTES: INFORMACIÓN PARA PADRES Y EDUCADORES DEPRESSION IN CHILDREN AND ADOLESCENTS: A PRIMER FOR PARENTS AND EDUCATORS  

Microsoft Academic Search

La depresión es un problema serio de salud que puede afectar a personas de todas las edades, incluyendo a niños y adolescentes. Generalmente se define como una experiencia en la que persiste una disposición de ánimo triste o irritable, así como también anhedonia, una pérdida de la habilidad de experimentar placer en casi todas las actividades. Incluye también una gama

144

Determinación de la densidad de la fibra poliester por el método de columna gradiente de densidades  

Microsoft Academic Search

En la industria se presentan a veces problemas en las tinturas de fibras de poliester que son difíciles de resolver y producen lamentables pérdidas de tiempo. La causa de ello es, en algunos casos, la estructura cristalina de las fibras. Estas, cuando están excesivamente cristalizadas hacen que sea más lenta la difusión de los colorantes, y al mismo tiempo disminuye

Publio Puente Garrido

1970-01-01

145

ANALISI TERMO-MECCANICA CON TECNICHE COMBINATE STRUTTURALI E CFD DEL COMPORTAMENTO DI UN FANALE AUTOVEICOLISTICO IN CONDIZIONI DI PROVA E DI UTILIZZO  

Microsoft Academic Search

Sommario Il lavoro si occupa della definizione di una metodologia completa per l'analisi termo-meccanica di componenti ottici per autoveicoli, prendendo le mosse da un problema industriale di criticità nel superamento di test previsti da normativa su fanali di \\

F. Cimolin; A. Menotti; M. Rabito; R. Vadori

146

Education in the human bounderies  

Microsoft Academic Search

Resumo: Neste artigo, o autor traz reflexões sobre o papel da educação no processo de formação do homem nas fronteiras do humano. Analisa os problemas do homem na contemporaneidade, focalizando a problemática da penetração da racionalidade instrumental em âmbitos da interação social, substituindo a racionalidade comunicativa, como base de decisões que envolvem o homem em seu agir ético, moral e

Maria Augusta Salin Gonçalves

147

LOS DADOS CONCEPTUALES: UN JUEGO PARA APRENDER A CONSTRUIR PROPOSICIONES  

Microsoft Academic Search

Durante la elaboración de mapas conceptuales, en ocasiones los docentes y estudiantes tienen problemas al construir proposiciones. Frecuentemente nos encontramos con mapas en donde la secuencia de conceptos desde la raíz del mapa hasta uno de los conceptos terminales forman una larga oración. En algunos casos esto se debe a preconcepciones de parte de los maestros sobre lo que es

Ginnie Hughes; José del Carmen Barrios; Damaris Bernal; Adrián Chang; Alberto J. Cañas

148

DESINFICAÇÃO DE BIOMASSA FLORESTAL  

Microsoft Academic Search

1. INTRODUÇÃO Todas as industrias que utilizam a madeira como matéria-prima, têm ao final do processamento uma grande quantidade de resíduos, tanto na industria como na floresta. Na maioria das vezes esses resíduos industriais, constituem-se num grave problema, devido à quantidade, dispersão e dificuldade de manuseio que os mesmos apresentam. Por outro lado, exigem grandes áreas para armazenamento ou simplesmente

Antonio José Migliorini

149

Los cuatro entornos del procomún  

Microsoft Academic Search

Bastan unos minutos para entender la inmensa complejidad que tiene la noción de procomún. Disponemos de muchas definiciones aceptables, aunque las más frecuentes bordean de una u otra manera el problema de la propiedad y la teoría del valor. Cuando decimos que pertenece al procomún todo cuanto es de todos y de nadie a mismo tiempo estamos pensando en un

Antonio Lafuente

150

MEJORA DEL COMPORTAMIENTO A CORROSIÓN BAJO TENSIÓN DE LOS ALAMBRES DE PRETENSADO  

Microsoft Academic Search

Resumen. La corrosión bajo tensión de las armaduras activas está generando problemas de durabilidad en las estructuras pretensadas construidas en la proximidad de ambientes agresivos. En este trabajo se pone de manifiesto la influencia que tienen las tensiones residuales producidas por el proceso de conformado (trefilado) en la fragilización por hidrógeno de los alambres y se propone un tratamiento alternativo

J. M. Atienza; J. Ruiz-Hervías; L. Caballero; M. Elices

151

Idosos atendidos em serviço de emergência de saúde mental: características demográficas e clínicas Elderly treated in mental health emergency rooms: demographic and clinic characteristics  

Microsoft Academic Search

O envelhecimento populacional vem provocando um aumento contínuo no número de idosos que buscam atendimento para problemas de saúde mental. Este trabalho teve como objetivo investigar os transtornos mentais que mais freqüentemente levam o idoso a um serviço de emergência psiquiátrica. Todos os idosos atendidos entre 1 o de janeiro e 31 de dezembro de 1997 no pronto-socorro de saúde

Osvaldo P. Almeida

152

Desempleo y la estructura de los mercados laborales en Colombia  

Microsoft Academic Search

Los problemas de desempleo e ingresos bajos de un sector de la fuerza laboral empleada ha sido de gran interés, tanto en países desarrollados como en vías de desarrollo. Se usan comúnmente tres hipótesis para explicar el desempleo en países en vías de desarrollo; la de crecimiento insuficiente, la demográfica (a medida que se acelera el crecimiento de la población

Ramón E. López

153

La culpa es del Yankee: Correlaciones e ineficiencias en el mercado de dinero  

Microsoft Academic Search

Los cambios en las tasas de interés de los bonos globales colombianos -mecanismo de transmisión de las presiones de los mercados internacionales sobre el mercado localson los principales causantes de las fluctuaciones en el mercado de dinero doméstico. Este fenómeno parece haberse acentuado incluso después de que los problemas del mercado de TES de fin de 2002 indujeron la conformación

Santiago Gutiérrez V; Michel Formisano P

2003-01-01

154

Contratos de alta dirección en empresas familiares  

Microsoft Academic Search

La presencia de la empresa familiar en el panorama empresarial español configura la realidad empresarial de nuestro país y su importancia es capital para el desarrollo de la economía española. Uno de los problemas más recurrentes en la bibliografía sobre empresa familiar es el tipo de contrato que vincula la empresa familiar con los miembros familiares que trabajan en ella.

Ignacio Contreras; Sandalio Gomez; Josep Tapies

2007-01-01

155

La definición de dinero, los medios de pago y los cuasidineros en Colombia  

Microsoft Academic Search

De tiempo atrás, los escritores sobre temas monetarios se han ocupado del problema de cómo definir el dinero. Se ha tratado, en breve, de primero establecer un criterio que sirva de fundamento para identificar los activos constitutivos de dinero, y luego, de aplicar el criterio adoptado al caso empírico concreto que se desea analizar. De todas formas, en el discurso

Mauricio Carrizosa

1983-01-01

156

La restricción intertemporal del presupuesto. Una evaluación empírica para el Gobierno Nacional Central de Colombia, 1950-2010  

Microsoft Academic Search

En este documento se analiza la sostenibilidad fiscal del Gobierno Nacional Central en Colombia utilizando el enfoque de la Restricción Intertemporal de Presupuesto. Los resultados empíricos revelan que la estrategia fiscal actual es sostenible. No obstante, se vislumbran problemas de insolvencia en el largo plazo, lo que implica generar un mayor superávit primario en comparación con el actualmente programado. Lo

Álvaro Hernando Chaves

2003-01-01

157

Gobierno Corporativo y Administradoras de Fondos de Pensiones (AFP). El caso chileno  

Microsoft Academic Search

El buen funcionamiento de los gobiernos corporativos incide positivamente en la competitividad y crecimiento de una economia. Las caracteristicas de los mercados de capitales inciden en la estructura del problema de agencia que se establece en las companias, por lo que determinara distintos modelos y requerimientos a los gobiernos corporativos que se establezcan en estos mercados. El objetivo de este

2010-01-01

158

El Gobierno de las Entidades no Lucrativas. Evidencia emp¡rica para las Organizaciones no Gubernamentales de Cooperaci¢n al Desarrollo Espa¤olas  

Microsoft Academic Search

La ausencia de derechos residuales en las entidades no lucrativas (non profit) singulariza el problema de gobierno tradicionalmente estudiado. En este contexto, el objetivo de este trabajo es verificar la existencia y relevancia de los mecanismos de control para evitar la expropiaci¢n de recursos por parte de los directivos e incrementar la eficiencia en una muestra representativa de las Organizaciones

2003-01-01

159

Análisis de oferta y demanda de trabajo en la pequeña agricultura chilena  

Microsoft Academic Search

El empleo es una de las variables económicas que está siendo incorporada en forma cada vez más explícita en las discusiones sobre programas y políticas de desarrollo. La preocupación por los problemas de empleo en América Latina ya no está circunscrita solamente a los ambientes académicos, a organismos internacionales y a instituciones de gobierno. Una reciente declaración de un representante

Alfonso Monardes

160

Francis Bacon e as marés: a concepção da natureza e o mecanicismo  

Microsoft Academic Search

Esta breve introdução visa duas tarefas ao mesmo tempo: primeiro, informar sobre a época provável de composição e o lugar ocupado, no conjunto da obra de Francis Bacon (1561-1626), pelo pequeno tratado intitulado De fluxu et refluxu maris (Do fluxo e refluxo do mar); segundo, expor a solução que nele se apresenta para o problema das marés, mostrando tratar-se de

Pablo Rubén Mariconda

2007-01-01

161

MODELADO Y SIMULACION DEL SISTEMA CARDIOVASCULAR FETAL  

Microsoft Academic Search

Resumen: En el modelado fisiológico, el propósito es comprender las funciones del cuerpo humano. Con este propósito, se abordan problemas del embarazo y el parto para minimizar las cesáreas innecesarias en mujeres propensas a cursar con Sufrimiento Fetal Agudo (SFA). En el presente estudio se realizó: el Modelado Matemático del Sistema Cardiovascular Fetal (SCVF), la Simulación y Validación del SCVF.

Rubén Moreno

162

Una Metodología para Ajustar y Compensar las Diferencias de Riesgo entre el Sistema Público y Privado de Salud en Chile  

Microsoft Academic Search

En el marco conceptual de seguros de salud y ajuste de riesgo y a la luz de la experiencia internacional en Fondos de Compensación de Riesgos, este documento explora el problema del «descreme» que afecta al sistema de seguros Chileno. Se presenta una metodología para estimar diferencias de riesgo entre el sector público y privado de salud en Chile y

Verónica Vargas; Camilo Cid; Mauricio Matus; Iris Delgado; José Miguel Sánchez; Beatriz Heyermann; José Angulo

163

DESENVOLVIMENTO DE INSTRUMENTO DE COLETA DE DADOS DE ENFERMAGEM PARA PACIENTES COM CÂNCER DE PULMÃO EM QUIMIOTERAPIA AMBULATORIAL Developing a Nursing Data Colleting Instrument to Patients with Lung Cancer Treated by Chemotherapy in Ambulatory Desarrollo de Instrumento de Recogida de Datos de Enfermería para Pacientes con Cáncer de Pulmón en Quimioterapia Ambulatoria  

Microsoft Academic Search

Resumen O câncer é um grave problema de saúde pública, e, dentre suas variedades, há o câncer de pulmão, que vem crescendo na população brasileira e mundial. A principal causa do câncer de pulmão é o tabagismo. Há três formas de tratamento: cirurgia, radioterapia e quimioterapia; para essa patologia a mais utilizada é a terceira. A enfermeira deve estar apta

Salvadori AM; Lamas JLT; Anita Moda Salvadori; José Luiz Tatagiba Lamas; Cláudia Zanon

164

Probabilistic prediction of the next large earthquake in the Michoacán fault-segment of the Mexican subduction zone  

Microsoft Academic Search

RESUMEN La estimación del intervalo de tiempo ?t hasta el siguiente sismo fuerte, que es esperado en una región sísmica, es un problema difícil. Dentro del método más convencional de predicciones basadas en el intervalo de tiempo (?t), dada una distribu- ción probabilística de los intervalos de tiempo observados y el tiempo transcurrido (t) desde el último sismo fuerte, podemos

Sergio G. Ferráes

2003-01-01

165

SENSIBILIDAD IN VITRO DE AISLADOS DEL HONGO PHYTOPHTHORA CAPSICI A FUNGUICID AS  

Microsoft Academic Search

RESUMEN En el cultivo de chile, la incidencia de la enfermedad marchitez del chile causada por el hongo oomyceto Phytophthora capsici Leo., constituye a nivel nacional, uno de los principales problemas que afectan la productividad del cultivo. El presente estudio tuvo como objetivo: conocer la respuesta de 14 aislados de Phytophthora capsici a diferentes fungicidas. Los fungicidas utilizados fueron azoxystrobin,

Luis Pérez-Moreno; Luisa Josefina Durán-Ortiz; Rafael Ramírez-Malagón; Jesús Ricardo Sánchez-Pale; Víctor Olalde-Portugal

166

Vinhoto e cama de frango como coadjuvantes na compostagem de bagaço de cana de açúcar  

Microsoft Academic Search

Resumo: Atualmente, a agricultura está passando por um proc esso de modernização, trazendo com isso inúmeros fatores negativos que influenciam na degradação do meio ambiente. Dejetos estão sendo jogados em lugares impróprios trazendo danos ao ar, solo e águas. Percebendo a gravidade deste problema, este trabalho foi realiza do visando contribuir para o melhoramento das condições ambientais e propor renda

Fernando Lira; Renato Cassol de Oliveira

2008-01-01

167

Shock structure in an ultrarelativistic gas  

Microsoft Academic Search

Sommario Si tratta il problema della struttura dell'urto nello schema della teoria di Eckart della termodinamica irreversibile nel limite ultrarelativistico. In questo ambito si considerano un gas di neutrini ed un gas nell'approssimazione del modello di sfere rigide.

A. Majorana; O. Muscato

1990-01-01

168

IL PROGRAMMA DI AZIONE LOCALE DI LOTTA ALLA SICCITÀ E DESERTIFICAZIONE IN EMILIA-ROMAGNA  

Microsoft Academic Search

Il Programma di Azione Locale di lotta alla siccità e desertificazione (PAL) per la Regione Emilia-Romagna intende affrontare il problema del rapporto tra irrigazione e squilibrio del bilancio idrico di bacino, valutando la sostenibilità delle scelte colturali, anche alla luce degli attuali e dei prossimi scenari climatici. La struttura concettuale proposta per il PAL Emilia-Romagna si rifà al sistema degli

Lucio Botarelli; Vittorio Marletto; William Pratizzoli; Andrea Spisni

169

Biodiversità, miglioramento genetico partecipativo e diritto al cibo. (Chi decide cosa mangerai stasera per cena?)  

Microsoft Academic Search

Questo lavoro affronta il problema del controllo del seme e di conseguenza della sicurezza alimentare nel mondo. Man mano che il miglioramento genetico è passato dalle mani degli agricoltori che lo hanno praticato per migliaia di anni a quelle di privati, si è anche passati da una grande agro-biodiversità, dovuta al fatto che gli agricoltori miglioravano ciascuno per il proprio

Salvatore Ceccarelli

2009-01-01

170

Consideraciones para el desarrollo de la creatividad y la enseñanza problémica en el aula  

Microsoft Academic Search

La “Metodología para estimular y desarrollar la creatividad técnica a través de la enseñanza del dibujo básico” ofrece un material docente contentivo con un conjunto de orientaciones e indicaciones que contribuya a estimular la creatividad técnica en la solución de problemas técnicos para los estudiantes que cursan carreras técnicas y como vía para la capacitación de los docentes. La misma

Angel Carvajal Castillo; María Elena Sierra Sandoval

2011-01-01

171

TECNOLOGÍA Y CREATIVIDAD, RETOS EN EL PROCESO DE LA UNIVERSALIZACIÓN  

Microsoft Academic Search

En el nuevo milenio, las avanzadas tecnologías pueden ser analizadas y estudiadas desde perspectivas comprensivas e interpretativas, ofrecen oportunas soluciones a algunos de los graves problemas que enfrenta la sociedad de hoy, adquiriendo un papel importante en la educación superior, donde de forma general encuentran una proyección óptima dentro del proceso de enseñanza – aprendizaje, mediante iniciativas que impliquen una

Soleima Beatriz Enríquez Roche

2011-01-01

172

Peace Power for Adolescents: Strategies for a Culture of Nonviolence.  

ERIC Educational Resources Information Center

Recent school shootings are only one symptom of a greater problem--a toxic social environment that breeds isolation and rage among children. This book looks at the wide range of risk factors and indicators for violence and translates the findings into an effective prevention and intervention system. The Peace Power strategy is based on four core…

Mattaini, Mark A.

173

Ponencia MicrAS : UNA EXPERIENCIA DE CAMBIO DE PARADIGMAS EN ECONOMÍA CON MICROMUNDOS DESARROLLADOS CON DINÁMICA DE SISTEMAS  

Microsoft Academic Search

RESUMEN La crisis generalizada a que nos vemos abocados parece obedecer en g ran parte a las múltiples deficiencias que presenta por un lado el sistema educativo y por otro la teoría económica, esto se refleja en el comportamiento del sistema económico sometido a la aplicación de políticas que pretenden dar solución a problemas de una gran complejidad. Una alternativa

HUGO H. ANDRADE; ADRIANA R. LIZCANO; ELIÉCER PINEDA

174

A feature-interaction benchmark for IN and beyond  

Microsoft Academic Search

It is argued that the goal of the intelligent network (IN) is to accelerate the introduction of new telecommunications features in a multisupplier competitive environment. One major roadblock to fulfilling such requirements is the feature interaction problem-a new feature may interact with existing features in some undesirable ways, resulting in adverse behavior. Feature interaction examples are categorized by their causes,

E. Jane Cameron; Nancy Griffeth; Yow-Jian Lin; Margaret E. Nilson; W. K. Schnure; H. Velthuijsen

1993-01-01

175

Solução Paralela em Agregado de PCs de um Código de Elementos Finitos Aplicado à Elasticidade Linear  

Microsoft Academic Search

Resumo. Este trabalho apresenta os resultados comparativos de desempenho de códigos paralelos, baseados no método dos elementos finitos aplicado à elasticidade linear para problemas estruturais, que utilizam o método dos gradientes conjugados para solução do sistema de equações. Os programas foram executados em um agregado de PCs, por ser uma opção economicamente viável, já que utiliza tecnologia depurada de alta

Flávia R. Villa Verde; Roberta R. Ferreira; Gerson H. Pfitscher

176

Formas Plurais no Franchising de Alimentos: Evid?ncias de Estudos de Caso na França e no Brasil  

Microsoft Academic Search

O problema de formas plurais é importante tema de interesse na literatura dedicada ao franchising. A coexistência de lojas próprias e unidades franqueadas em uma mesma rede é fato bem conhecido, merecendo a grande atenção que vem recebendo dos pesquisadores. Acontece, porém, que formas organizacionais no franchising são mais diferenciadas do que sugere a literatura. De fato, informações oriundas de

Vivian Lara; S. Silva; Paulo Furquim de Azevedo

177

A Novel for High School Seniors: Hal Borland's "When the Legends Die."  

ERIC Educational Resources Information Center

Hal Borland's "When the Legends Die" is especially appropriate for high school seniors because its central problem--a Ute Indian boy's search for his identity and expected role in society--is exactly that faced by these students. The novel is divided into four sections, each concerned with a specific stage in the development of the protagonist.…

Adkins, Carl A.

1968-01-01

178

Salud, salarios y educación  

Microsoft Academic Search

El objetivo de este trabajo es ampliar la evidencia sobre el efecto de la educación en la salud y los salarios. Se estima un índice sintético del estado de salud para paliar el problema de subjetividad de los indicadores de autoevaluación. Para tener en cuenta la endogeneidad entre los salarios y la salud se estima simultáneamente una ecuación de salud

Cecilia Albert; María A. Davia

2004-01-01

179

El Lenguaje de los Chicanos (The Language of Chicanos). Regional and Social Characteristics of Language Used by Mexican Americans.  

ERIC Educational Resources Information Center

The following articles are included in this anthology on Chicano speech: (1) "Mexican Spanish," D.N. Cardenas; (2) "The Archaic and the Modern in the Spanish of New Mexico," J. Ornstein; (3) "Problemas Lexicograficos del Espanol del Sudoeste," A.M. Espinosa, Jr.; (4) "Associative Interference in New Mexican Spanish," J.B. Rael; (5) "Some Aspects…

Hernandez-Chavez, Eduardo, Ed.; And Others

180

PROGRAMAÇÃO DE TRANSFERÊNCIA DE DERIVADOS DE PETRÓLEO EM REDE DUTOVIÁRIA USANDO ALGORITMO GENÉTICO  

Microsoft Academic Search

O modal dutoviário é reconhecido como o meio mais eficaz de se transportar grandes volumes de petróleo e seus derivados por longas distâncias, mas que também exige um grande controle operacional. Isto torna a otimização do transporte de produtos neste sistema dutoviário, um problema de alta relevância do ponto de vista econômico, já que o preço final destes produtos depende

Rennó Frota; Moraes Alves

181

Nivelación interterritorial e ineficiencia de las decisiones presupuestarias: reflexiones para el caso español  

Microsoft Academic Search

En este trabajo se estudian los efectos negativos de los esquemas de nivelación horizontal sobre la eficiencia en las elecciones fiscales de los gobiernos regionales. Partiendo de unos resultados teóricos básicos, se examinan los aspectos dinámicos del problema, se ofrece alguna evidencia empírica para el caso español y se presenta una solución que combina los criterios de eficiencia y equidad.

Santiago Lago Peñas

2002-01-01

182

El sector rural y el plan de desarrollo  

Microsoft Academic Search

El diagnóstico del plan de desarrollo sobre los problemas rurales desconoce los avances logrados por la Misión Rural durante 1996-1997 en la precisión de la problemática y en las propuestas para resolverla. El diagnóstico es muy parcial y de corte economicista y sus propuestas son imprecisas e insuficientes. No profundiza el análisis de las causas de las causas de las

Absalón Machado

1999-01-01

183

VIABILIDADE FINANCEIRA DA PRODUÇÃO DE FRUTAS NA REGIÃO SUDESTE DA BAHIA  

Microsoft Academic Search

RESUMO - A região cacaueira da Bahia vem enfrentando uma crise sem precedente em sua história com a redução continuada da renda e emprego em virtude de problemas enfrentados pela cultura do cacau. O crescimento do parque agroindustrial de polpa de frutas na região poderá contribuir na diversificação da economia regional ao criar uma opção de mercado para a produção

Antônio Carlos de Araújo; Lúcia Maria Ramos Silva; Ahmad Saeed Khan; José B. V. Leite; Aurélio F. Macedo

184

LOS CONCEPTOS RELEVANTES EN EL APRENDIZAJE DE LA GRAFICACIÓN  

Microsoft Academic Search

Resumen: Diversos estudios muestran que los estudiantes tienen dificultades para entender conceptos específicos del cálculo diferencial. Algunos señalan los obstáculos que les representa la integración de los diferentes conceptos en la solución de proble- mas específicos, incluidos los de graficación de funciones. En este estudio se ana- lizan las respuestas de un grupo de estudiantes cuando resuelven estos problemas utilizando

MARÍA TRIGUEROS

2008-01-01

185

Notarios y agricultores: Crecimiento y atraso en el campo mexicano, 1780–1920  

Microsoft Academic Search

In 1909, with Mexico on the verge of revolution, a public notary from the central-plateau town of Jilotepec published a book that would deeply influence the tenor and tone of national resource policy in the twentieth century. Andres Molina Enriquez's Los Grandes Problemas Nacionales set forth a scathing critique of the hacienda system, faulting its feudalistic tendencies, venal landlords, and

Jeff M. Banister

2009-01-01

186

Mortalidade materna: um estudo dos níveis e das causas de óbitos no México e no Brasil entre 2000 e 2004  

Microsoft Academic Search

A mortalidade materna se apresenta como um grave problema social e de saúde pública, representando um importante indicador para avaliar as condições de assistência à saúde feminina. A preocupação com as mortes maternas está relacionada principalmente às repercussões sociais e econômicas que a morte de uma mulher acarreta para as famílias. Isto porque as mulheres assumem atribuições centrais na organização

Ana Paula Belon

187

Mulheres \\  

Microsoft Academic Search

Na virada do século XIX para o XX, o problema dos crimes sexuais transformou-se numa das maiores preocupações das autoridades públicas brasileiras. Vistos como uma das faces negativas do estágio de evolução da civilização ocidental, explicados enfaticamente como produtos da dissolução dos costumes resultante de \\

Carlos Martins Júnior

188

Outsourcing en servicios de tecnología informática  

Microsoft Academic Search

Históricamente las organizaciones han venido soportando totalmente la infraestructura de tecnología, pero actualmente ha surgido la herramienta gerencial de subcontratar (en inglés Outsourcing) la gestión tecnológica que no sea parte integral del negocio. Pero el problema de esta situación radica en que las organizaciones han llevado a sus departamentos de sistemas a utilizar esta herramienta desde criterios muy subjetivos y

Luís Merchán Paredes

1998-01-01

189

LA GESTIÓN DE RESIDUOS EN LA EMPRESA: MOTIVACIONES PARA SU IMPLANTACIÓN Y MEJORAS ASOCIADAS \\/ FIRMS’ WASTE MANAGEMENT IN THE COMPANY: MOTIVATIONS FOR THEIR IMPLEMENTATION AND ASSOCIATED IMPROVEMENTS  

Microsoft Academic Search

Entre los problemas medioambientales actuales, la reducción o eliminación de los residuos se ha convertido en una de las principales preocupaciones en los países industrializados y en una prioridad para las empresas. En el presente trabajo se realiza una revisión de los postulados del modelo económico clásico, vigente hasta hace escasas fechas, en relación con la variable medio ambiente y

Unai Tamayo Orbegozo; María Azucena Vicente Molina; Julen Izaguirre Olaizola

2012-01-01

190

“Esto no es un castigo de Dios”. Gestión local del agua en Guatemala: el caso de los municipios de Chiantla y Huehuetenango  

Microsoft Academic Search

En Guatemala coexisten muchos y variados sistemas de gestión del agua basados en tradiciones comunitarias, los cuales han nacido mayoritariamente debido a la ausencia de servicios públicos estatales. Sin embargo, una gran proporción de la población aún tiene problemas de acceso al agua, y los conflictos sociales son frecuentes. El objetivo de este artículo es la caracterización de los sistemas

Gonzalo Gamboa; Rocío García; Juan Mendoza; Fernando Recancoj; Juan Diego González; Geisselle Sánchez

2007-01-01

191

PROYECTO ESTRATÉGICO PARA UN SISTEMA DE INFORMACIÓN MEDIOAMBIENTAL  

Microsoft Academic Search

Este documento muestra algunos de los problemas reales en la Empresa Constructora de Obras de Arquitectura 44 de la provincia de Villa Clara, la cual a pesar de tener una política, visión y misión medioambiental no cumple con las exigencias de los actuales momentos al no contar con un sistema de gestión de la información, se buscan alternativas y un

Ramón Fernández Paret

2011-01-01

192

PERFIL FARMACOTERAPÊUTICO DE PACIENTES EM USO DE ANTIMICROBIANOS EM HOSPITAL PRIVADO, EM FORTALEZA - CE Pharmacotherapeutic profile of patients in use of antimicrobials at a private hospital, in Fortaleza - CE  

Microsoft Academic Search

RESUMO Apesar da disponibilidade de antimicrobianos eficazes, os germes continuam ganhando a batalha nas doenças infecciosas, acarretando mortes e morbidade. Uma das causas desta situação consiste no surgimento e disseminação de resistência microbiana, que tende a aumentar com o uso indiscriminado de antimicrobianos. Este sério problema afeta a saúde individual e coletiva. O presente trabalho propôs-se a conhecer o perfil

Fernanda Borges França

193

ANALISI SPERIMENTALE DEL CONTATTO PIANO-PIANO CON INDENTATORE CILINDRICO RACCORDATO  

Microsoft Academic Search

Sommario Nel presente studio è proposta l'analisi sperimentale, mediante ultrasuoni, del contatto tra un indentatore cilindrico piano a bordi raccordati ed un piano, problema per il quale è stata recentemente proposta una soluzione analitica mai validata sperimentalmente. Per ciascun accoppiamento è stata valutata la riflessione dall'interfaccia, che è noto essere in relazione con lo stato di contatto. I risultati sperimentali

B. Leban; M. Pau; A. Baldi; F. Ginesu

194

Isictometrics * : toward an alternative vision and process  

Microsoft Academic Search

Resumo A medição de bens e de fenômenos intangíveis traz dificuldades materiais e conceituais. Como a informação e as tecnologias da informação e da comunicação - TICS se estendem por grande parte da sociedade, a disponibilidade de indicadores válidos é um problema sério. As primeiras tentativas da escola de economia da informação trataram de adaptar as medidas socio-econômicas que existiam

Michel J. Menou

2001-01-01

195

Lo que usted necesita saber sobre? el cáncer  

Cancer.gov

La serie de folletos Lo que usted necesita saber sobre? está diseñada para pacientes con cáncer y proporciona información sobre muchos tipos de cáncer. Cada folleto incluye información acerca de los síntomas, diagnóstico y tratamiento del cáncer. En todos los títulos de la serie, se ofrece también información adicional acerca de los problemas emocionales y preguntas para hacer al doctor.

196

Automated Forensic DNA Purification Optimized for FTA Card Punches and Identifiler STR-based PCR Analysis  

Microsoft Academic Search

Forensic labs globally face the same problem—a growing need to process a greater number and wider variety of samples for DNA analysis. The same forensic lab can be tasked all at once with processing mixed casework samples from crime scenes, convicted offender samples for database entry, and tissue from tsunami victims for identification. Besides flexibility in the robotic system chosen

Lois C. Tack; Michelle Thomas; Karl Reich

2005-01-01

197

Algunos Resumenes  

NASA Astrophysics Data System (ADS)

La agenda comienza con un resumen de parte dei Director General: estado de los proyectos de telescopios mas importantes, instrumentaci6n futura y otros asuntos. Luego el Director en Chile y el Jefe de TRS describen las condiciones presentes en que se encuentran los instrumentos, los problemas que han surgido y aquellos que se esperan. Luego estos puntos son disculidos por el Comite.

1982-09-01

198

Diarrea intratable causada por anomalías congénitas de los enterocitos  

Microsoft Academic Search

ExtractoFundamento: La diarrea intratable de la lactancia representa un problema grave que conlleva un grado elevado de morbilidad y mortalidad. Estos casos requieren una asistencia dedicada tanto por parte de los padres como del personal médico, dado que no se dispone de remedios fáciles. La escasez de pacientes indica que para progresar en el conocimiento de estos trastornos son necesarios

Alan D. Phillips

2006-01-01

199

O CLIMATÉRIO E SUA RELAÇÃO COM A SAÚDE E O AMBIENTE DE TRABALHO The Climacterium and its relation to health and work environment  

Microsoft Academic Search

RESUMO O período do climatério é caracterizado por sinais e sintomas que podem repercutir de algum modo na vida de mulheres, tanto do ponto de vista familiar como profissional. Este estudo teve como objetivo analisar as interferências dos problemas vivenciados pela mulher no climatério e suas relações com a saúde e o ambiente de trabalho. Tratou-se de uma pesquisa exploratória-descritiva

Sandra Mar; Brasil Soares; Ana Maria Fontenelle Catri; Raimunda Magalhães da Silva; Mirna Albuquerque Frota

200

Desarrollo de un framework básico para la construcción de aplicaciones basadas en Internet utilizando el protocolo XMPP  

Microsoft Academic Search

El desarrollo de aplicaciones que se ejecutan a través de Internet ha crecido exponencialmente durante los últimos años. Sin embargo, la construcción de aplicaciones Web que se ejecutan sobre el protocolo HTTP y se visualizan en los navegadores Web, generan problemas de usabilidad, ya que estos interpretan de manera diferente algunas etiquetas, y la propia naturaleza de la actualización de

L I Herman; Geovany Ayala Zúñiga; MSIA Juan Francisco; Algara Norzagaray; Ángel Flores; Juan de Dios Batiz

201

Simulaciones hidrodinámicas de flujos complejos  

NASA Astrophysics Data System (ADS)

Son muchos los escenarios astrofísicos en que los procesos hidrodinámicos juegan un papel clave. En la complejidad que encierra la descripción de dichos procesos destaca el de la correcta simulación de flujos complejos donde la presencia de ondas de choque fuertes que, eventualmente, interaccionan entre ellas o también la presencia de inestabilidades (Kelvin-Helmholtz, Rayleigh-Taylor, etc.) suponen un verdadero desafío numérico. Los códigos hidrodinámicos basados en la solución de un problema de valores iniciales discontinuo (problema de Riemann) son, en la actualidad, los más robustos en el campo de la dinámica de fluidos computacional. En esta charla se dará un resumen de los fundamentos de dichas técnicas numéricas (esquemas de alta resolución de captura de choques) y se ilustrará su potencialidad mostrando una amplia gama de resultados en diferentes aplicaciones astrofísicas.

María Ibáñez Cabanell, José

202

Social And Economic Correlates Of Induced Abortion In Santiago, Chile  

Microsoft Academic Search

\\u000a Resumen  Desde 1962, se ha estado desarrollando un proyecto de investigación para estudiar el problema del aborto inducido y la planificación\\u000a de la familia en una de las cinco Areas en las cuales el Servicio Nacional de Salud divide la ciudad de Santiago. El proyecto\\u000a se dividió en un Estudio Piloto, que tenia por objetivoobtenerinformación sobre la incidencia del aborto inducido,

Requena B. Mariano

1965-01-01

203

Formación y evolución de planetas gigantes  

NASA Astrophysics Data System (ADS)

Presentamos el estado actual del trabajo que estamos realizando en el estudio de la formación de planetas gigantes. Detallamos los algoritmos numéricos necesarios para realizar este tipo de cálculo. Presentamos algunos resultados de la formación de objetos con masas de hasta una docena de veces la del planeta Júpiter, resaltando las principales caracteríticas. Finalmente detallamos los problemas que pensamos abordar en un futuro cercano en este tema de investigación.

Benvenuto, O. G.; Brunini, A.

204

Código árbol paralelizado para simulaciones astrofísicas. Experimentos de encuentros de galaxias compuestas  

NASA Astrophysics Data System (ADS)

Se describe la implementación de un código árbol octal paralelizado desarrollado por los autores. Este código permite la integración del problema de N--cuerpos simultáneamente en varias computadoras (``cluster''), lo que permite desarrollar altas velocidades de cálculo. Se muestran los resultados de algunas integraciones de encuentros entre galaxias de disco con bulbo y halo, generadas mediante algoritmos no utilizados hasta el momento en este campo.

Viturro, H. R.; Carpintero, D. D.

205

Juegos estocasticos continuos: Valor y estrategias optimas  

Microsoft Academic Search

Resumen  El objeto de este trabajo es analizar los juegos estocásticos cuyo espacio de estados y de acciones son métricos compactos,\\u000a con adecuadas condiciones de continuidad acerca de las funciones de pago y de transición. Tras describir el modelo e introducir\\u000a las hipótesis de continuidad, se trata el problema con horizonte finito, a fin de probar que existe valor y estrategias

M. Angeles Muruaga; R. Vélez Uned

1992-01-01

206

Multi-class Classification in Image Analysis via Error-Correcting Output Codes  

Microsoft Academic Search

\\u000a A common way to model multi-class classification problems is by means of Error-Correcting Output Codes (ECOC). Given a multi-class\\u000a problem, the ECOC technique designs a codeword for each class, where each position of the code identifies the membership of\\u000a the class for a given binary problem.A classification decision is obtained by assigning the label of the class with the closest

Sergio Escalera; David M. J. Tax; Oriol Pujol; Petia Radeva; Robert P. W. Duin

207

A fi social ?i nesocial online. Explorarea comportamentului agresiv online al copiilor ?i adolescen?ilor (cyber-bullying) 1  

Microsoft Academic Search

Acest studiu î?i propune s? exploreze problema incipient? a agresivit??ii online (cyber- bullying) în rândul adolescen?ilor români,cu accent pe diferen?ierea tipurilor de agresivitate în rela?ie cu utilizarea instrumentelor de socializare (mesagerie instant ?i re?ele sociale), monitorizare parental? ?i anumi?i factori psihosociali. Rezultatele sugereaz? leg?turi moderate cu utilizarea instrumentelor de socializare (SNS ?i IM) ?i cu monitorizarea parental? offline. Nu s-au

Monica Barbovschi

208

LA RIQUALIFICAZIONE DI COMPLESSI ARCHITETTONICI AD ALTA VALENZA STORICO-ARTISTICA DI PROPRIETÀ' DELLE AZIENDE USL: INDIVIDUAZIONE DI STRATEGIE METODOLOGICHE PER NUOVE IPOTESI DI IMPIEGO ALL'INTERNO DEL QUADRO NORMATIVO NAZIONALE  

Microsoft Academic Search

La presente memoria affronta il problema dell'applicazione ad una Azienda Sanitaria del Decreto Ministeriale del 6 febbraio 2004, emanato dalla Direzione Generale per i Beni Architettonici ed il Paesaggio di concerto con l'Agenzia del Demanio, che obbliga le pubbliche Amministrazioni a sottoporre alla verifica dell'interesse culturale i propri beni immobili. Il riconoscimento di interesse storico-artistico, secondo l'Art.12 del D. Lgs

L. Alberani; G. Cervato; M. Speciale; S. Mazzacane

209

IL PROGETTO DELL' OMS \\  

Microsoft Academic Search

Che effetto hanno i problemi di abuso d'alcol e droga sui membri delle famiglie:genitori, figli, mariti mogli, fratelli e famiglie allargate? Da quindici anni ci occupiamo del problema attraverso un ampio raggio di culture: Sud Est dell'Inghilterra, slum di Mexico city,comunità (rurali e urbane) di aborigeni nei territori del nord dell' Australia del Nord, ed ora in Italia (Napoli, Roma,

Richard Velleman; Caterina Arcidiacono

210

Satisfação booleana: algoritmos, aplicações, implementações  

Microsoft Academic Search

* Trabalho financiado com a bolsa da FCT-PRAXIS XXI\\/BD\\/21353\\/99 Resumo - Neste artigo considera-se em detalhe o problema de satisfação booleana (SAT) e descrevem-se os algoritmos discretos completos que são normalmente utilizados para a sua solução. É mostrado que SAT tem inúmeras aplicações práticas. Portanto, o desenvolvimento e a implementação de algoritmos eficientes assumem actualmente grande importância. Finalmente, são analizadas

Iouliia Skliarova; António B. Ferrari

2002-01-01

211

Dermatite atopica: dalla storia alle cure di oggi  

Microsoft Academic Search

La dermatite atopica (DA) è una malattia infiammatoria cronica della pelle, caratterizzata da cicli alternati di esacerbazioni\\u000a e stati clinici silenti. È stata definita come un problema di sanità pubblica a livello mondiale. Dati epidemiologici rilevano\\u000a una prevalenza compresa tra il 10% ed il 20% dei bambini, con variabilità in funzione dell’area geografica e dell’età. La\\u000a variabilità sarebbe legata non

Carlo Gelmetti

212

Propiedades de Calidad de Servicio en el Descubrimiento de Recursos Grid  

Microsoft Academic Search

Uno de los problemas abiertos en el contexto de las Arquitecturas Orientadas a Servicios es del descubrimiento de recursos y\\/o servicios adecuados para llevar a cabo una tarea determinada. Los proveedores de informaci?n Grid b?sicamente ofrecen informaci?n funcional sobre los recursos Grid que monitorizan, por lo que los modelos de informaci?n Grid b?sicamente representan esta informaci?n sint?ctica, y los consumidores

D. Buj'an-Carballal; 'Oscar Corcho; J. D'iaz-Labrador

2008-01-01

213

La gestione perioperatoria e intensivistica delle emorragie: il parere dell’ematologo  

Microsoft Academic Search

\\u000a Perché parlare di emorragie, e perché farne parlare un ematologo? La risposta è che l’emorragia massiva è ancor oggi un rilevante\\u000a problema clinico in molti ambiti. L’emorragia incontrollabile è responsabile del 40% delle morti per trauma, delle quali almeno\\u000a il 60% si verifica dopo il ricovero ospedaliero [1–5], ma può complicare anche gli interventi di chirurgia maggiore quali\\u000a i trapianti

Marco Marietta

214

Comportamiento social emergente - Formacion de Reglas y Simbolos a traves de la Dinamica de Sistemas  

Microsoft Academic Search

Abstract—Este articulo trata de mostrar,algunos de los conceptos principales en el campo,de vida artificial a fin de enfocarse en el concepto de emergencia, el cual es uno de los mas importantes en este campo,y en el cual se presentan,varios tipos de problemas interesantes a estudiar. La emergencia,presenta,distintos tipos de mecanismos,a partir de los cuales se establecen etapas claramente diferenciadas,en las

Jean Paul Manjarres Correal

215

Dessalar la Mediterrània? De quimera, negocis i béns comuns  

Microsoft Academic Search

La pressió per augmentar la producció d’aigua dessalada a la Mediterrània no para de créixer. A redós de la pobresa del bioma i de l’extraordinària expansió demogràfica, la indústria de la dessalació pretén facilitar la “solució” definitiva del problema de l’aigua en forma de garantia de subministrament il·limitat i assequible. La inexistència d’estàndards públics sobre la qualitat i de participació

Joan Buades Beltran

2008-01-01

216

Soundness of Symbolic Equivalence for Modular Exponentiation  

Microsoft Academic Search

In this paper, we study the Dynamic Decisional Diffie-Hellman (3DH) problem,a powerfulgeneralizationoftheDecisionalDiffie-Hellman(DDH)prob- lem. Our main result is that DDH implies 3DH. This result leads to significantly simpler proofs for protocols by relying directly on the more general problem. Our second contribution is a computationally sound symbolic technique for reasoning about protocols that use symmetric encryption and modular exponentiation. We show

Yassine Lakhnech; Laurent Mazare; Bogdan Warinschi

217

Patologies d'Ornamentals Associades a una Gestió i Pràctiques Incorrectes de Jardineria  

Microsoft Academic Search

Molt sovint, les patologies que pateixen la vegetació ornamental no es deuen a la casuística i a la mala sort. En un elevat percentatge, l'adopció d'una gestió inadequada i la pràctica d'activitats incorrectes, bé des d'un principi, com al llarg del temps, són la causa i l'inici del problema. Llavors, tant la vegetació arbrada, com l'arbustiva, palmeres, gespes i planta

Josep M Riba

2005-01-01

218

Provisioning Data-Aggregation Sessions in Lambda Grids?  

Microsoft Academic Search

Abstract—Many,large-scale scientific applications need to ag- gregate large amounts,of data from,multiple distributed sites to a centralized facility. We call such a request as a Data-Aggregation Request (DAR). In this study, we investigate the novel problem of on-demand,DAR provisioning over a wavelength-division mul- tiplexing (WDM) backbone,network. We provide a mathematical formulation,for our problem,as a Mixed Integer Linear Program (MILP). To solve

Dragos Andrei; Massimo Tornatore; Dipak Ghosal; Charles U. Martel; Biswanath Mukherjee

219

Como Lo Hago Yo: Defectos Del Cierre Del Tubo Neural En Nicaragua  

PubMed Central

En Nicaragua no hay un plan de forltificación de alimentos con ácido fólico. Las madres son muy jóvenes. En La Mascota operamos mas de cuarenta niños por año. Derivación tardía es un problema. La infección preoperatoria tiene que ser descartada. Vancomicina y Ceftriaxone estan indicadas. Estricta regla de asepsia operatoria. Suturamos la plaqueta para asemejar su forma al cilindro normal de la médula. No ceramos la capa de músculo.

Gonzalez, Juan Bosco

2014-01-01

220

Semi-supervised Learning by Entropy Minimization  

Microsoft Academic Search

Abstract We consider the semi-supervised learning problem, where a decision rule is to be learned from labeled and unlabeled data. In this framework, we motivate minimum entropy regularization, which enables to incorporate unlabeled data in the standard supervised learning. Our approach includes other approaches to the semi-supervised problem,as particular or limiting cases. A series of experiments illustrates that th e

Yves Grandvalet; Yoshua Bengio

2005-01-01

221

Estudio de los hábitos alimentarios de niños de 4-6 años de Reynosa, Tamaulipas (México)  

Microsoft Academic Search

Se estudiaron los hábitos alimentarios de niños de 4 a 6 años en Reynosa, Tamaulipas (México) para determinar el riesgo de problemas nutricionales derivados del sobrepeso y obesidad. Se estudiaron las dietas de 999 niños. La ingesta de calorías en los niños (1457,10 ± 22,30 kcal) fue significativamente mayor que en las niñas (1345,69 ± 20,58 kcal). Un comportamiento similar se observó para la mayoría

O. Castillo-Ruiz; G. Velazquez; R. M. Uresti-Marín; N. Mier; M. Vázquez; J. A. Ramírez de León

2012-01-01

222

Recent Developments in Neutrino Science: A Whole Lot About Almost Nothing  

Microsoft Academic Search

Results from Super-K, SNO, and KamLAND provide strong evidence that neutrinos undergo flavor-changing oscillations and therefore have non-zero mass. The ν-disappearance observations by KamLAND, assuming CPT conservation, point to matter enhanced (MSW) oscillations with large mixing angles as the solution to the solar neutrino problem--a result consistent with the MSW parameters recently defined by these experiments. This requires that the

2005-01-01

223

La Transpiración - Movimiento del Agua a Través de las Plantas  

NSDL National Science Digital Library

La transpiración es la pérdida de agua en forma de vapor por las plantas. El agua es absorbida del suelo por las raíces y transportada en forma líquida por el xilema hacia las hojas. En las hojas, unos pequeños poros permiten que el agua (H2O) escape a la atmósfera en forma de vapor, al tiempo que se permite la entrada de bióxido de carbono (CO2) para la fotosíntesis. De toda el agua absorbida por las plantas, menos del 5% es retenida y utilizada para crecimiento y almacenamiento. En esta lección se explicará porque las plantas pierden tanta agua, la ruta que ésta sigue dentro de la planta, como pudieran las plantas controlar la pérdida excesiva de agua y como las condiciones ambientales influyen en la pérdida de agua por las plantas.

224

Modern Radar Techniques for Geophysical Applications: Two Examples  

NASA Technical Reports Server (NTRS)

The last decade of the evolution of radar was heavily influenced by the rapid increase in the information processing capabilities. Advances in solid state radio HF devices, digital technology, computing architectures and software offered the designers to develop very efficient radars. In designing modern radars the emphasis goes towards the simplification of the system hardware, reduction of overall power, which is compensated by coding and real time signal processing techniques. Radars are commonly employed in geophysical radio soundings like probing the ionosphere; stratosphere-mesosphere measurement, weather forecast, GPR and radio-glaciology etc. In the laboratorio di Geofisica Ambientale of the Istituto Nazionale di Geofisica e Vulcanologia (INGV), Rome, Italy, we developed two pulse compression radars. The first is a HF radar called AIS-INGV; Advanced Ionospheric Sounder designed both for the purpose of research and for routine service of the HF radio wave propagation forecast. The second is a VHF radar called GLACIORADAR, which will be substituting the high power envelope radar used by the Italian Glaciological group. This will be employed in studying the sub glacial structures of Antarctica, giving information about layering, the bed rock and sub glacial lakes if present. These are low power radars, which heavily rely on advanced hardware and powerful real time signal processing. Additional information is included in the original extended abstract.

Arokiasamy, B. J.; Bianchi, C.; Sciacca, U.; Tutone, G.; Zirizzotti, A.; Zuccheretti, E.

2005-01-01

225

Descripción de la zona de alta difusión en un modelo bidimensional para hojas de corriente  

NASA Astrophysics Data System (ADS)

Los modelos bidimensionales para describir hojas de corriente de alta simetría no suministran una descripción detallada de las regiones donde la difusión es considerablemente importante. Tal es el caso de los modelos desarrollados en la década del '60 por Sweet, Parker, Petschek y Sonnerup. En esta comunicación presentamos una solución de las ecuaciones MHD en el entorno del origen, construyendo series bidimensionales para todas las magnitudes físicas involucradas. Valiéndonos de la alta simetría y de las características del problema, logramos reducir el número de coeficientes a calcular. Utilizamos un programa autoconsistente para extender el cálculo a regiones vecinas con difusión moderada o despreciable.

Montero, M. F.; Paola, C. A.; Platzeck, A. M.

226

La gestione perioperatoria del paziente diabetico  

Microsoft Academic Search

\\u000a Il continuo aumento dei pazienti diabetici che giungono all’osservazione degli anestesisti rende sempre più importante la\\u000a conoscenza delle patologie comunemente associate al diabete e delle strategie da attuare per mantenere un equilibrio glicemico\\u000a ottimale nel periodo perioperatorio.\\u000a \\u000a \\u000a Per questa ragione, dopo aver sinteticamente descritto il metabolismo del glucosio, verrà trattato in questo capitolo il problema\\u000a del corretto trattamento insulinico del

Biagio Allaria

227

Fast, automated,N-dimensional phase-unwrapping algorithm  

Microsoft Academic Search

Abstract This reportinvestigates the generalproblemofphase,unwrapping,forarbitraryn-dimensional,phase maps. A cost function-based,approach,is outlined,which,leads to an integer programming,problem.,To solve this problem,a best-pair-first region merging,approach,is adopted,as the optimisation,method.,The algorithm,has been implemented and tested with 3D MRI medical data for fMRI applications in EPI unwarping and rapid, automated,shimming. Keywords: phase unwrapping;,echo planar imaging,(EPI); field mapping.

Mark Jenkinson

2003-01-01

228

On the free boundary problem in the wen-langmuir shrinking core model for noncatalytic gas-solid reactions  

Microsoft Academic Search

Sommario Si dimostra un risultato locale di esistenza e unicitá della soluzione di un problema con frontiera libera per il modello del nucleo in contrazione in reazioni gas-solido non catalitiche. Le condizioni sulla frontiera libera sono del tipo\\u000a$$\\\\begin{gathered} u_x (s(t),t) = g(u(s(t),t)),0< t \\\\leqslant T, \\\\hfill \\\\\\\\ \\\\dot s(t) = f(u(s(t),t)),0< t \\\\leqslant T, \\\\hfill \\\\\\\\ \\\\end{gathered} $$\\u000a con

Domingo A. Tarzia; Luis T. Villa

1989-01-01

229

A multidisciplinary environmental integrated approach to better understand the Tegnue Reefs formation, offshore Chioggia, Northern Adriatic Sea.  

NASA Astrophysics Data System (ADS)

Several hard substrata cover the northwestern Adriatic shelf around 20 m depth as patchy reefs called 'Tegnue'. These submerged reefs form many discrete sets from offshore Grado south to the Po river delta with a large field located off Chioggia. Even if the outer part of the reef is constituted by a thick biogenic formation the underlying structure, mainly buried, is made by cemented sand and this seems to be correlated with its origin not yet fully understood. Different genetic interpretations have been proposed thus far, contemplating among other cementation due to beach-rock like processes (e.g., Stefanon, 1969, Bonardi and Tosi, 2002, Bonardi et al., 2006) or the action of ascending fluids enriched in hydrocarbons (e.g., Gabbianelli et al., 1997, Casellato and Stefanon, 2008). An on-going project, mainly a multidisciplinary integrated approach, combining physical, biological, geological, geomorphological, hydrogeological and geochemical data, supported by a detailed bathymetric mapping, an overall general circulation modeling at high resolution, a robust geophysical evidence, and detailed underwater surveys performed by a team of scuba-diver scientists, aims to better understand the genetic processes backing the distribution, early genesis and evolution of such relevant habitats. Actually, using all the new available data, our plan is to verify which previous interpretations on the origin of the Tegnue core better match with the diagenetic processes that led to the cementation of the sand layers lying at the base of the organic reefs. Preliminary results suggest that the Tegnue reefs formed along paleochannels features related to the former alluvial plain and submerged by the Holocene transgression. Whatever their genesis, once exposed such rocky substrata are then quickly colonized by living organisms, which contribute to the growth and expansion of the reef. Calcareous algae and in general the organic concretion could have a role during the reef accretion, and benthic invertebrates like bryozoans, mollusks, serpulids and corals also contribute to the final building of the status of Tegnue's environment, but we want to demonstrate that the in first stage of consolidation abiotic phenomena could have played a major role. In order to prove our thesis a series of ground water sampling as well as rock sampling and sediment cores were carried out. The poster illustrates the overall ongoing program as well as some work in progress and first results from field cruise. Acknowledgments This work was supported by the Municipality of Chioggia through the Tegnue Project and partially by the Flagship Project RITMARE - The Italian Research for the Sea - coordinated by the Italian National Research Council and funded by the Italian Ministry of Education, University and Research within the National Research Program 2011-2013, and by the Scientific Cooperation Agreement between the CONICET (Argentina) - CNR (Italy), Program 2013-2014, Project 'Fresh-saltwaters in high-value coastlands: from the hydrogeophysical/geochemical characterization of the present interactions to the modeling quantification of the expected effects of climate changes'. References - Bonardi, M., Tosi, L. 2000. Indagini preliminari su alcune formazioni di sabbie cementate nella laguna di Venezia. In: La Ricerca Scientifica Per Venezia. Il Progetto Sistema Lagunare Veneziano, Modellistica del Sistema Lagunare Studio di Impatto Ambientale. Istituto Veneto di Scienze, Lettere ed Arti, Vol. II, Tomo II, p. 967-974, Venezia, ISBN: 88-86166-82-6. - Bonardi, M., Tosi, L., Rizzetto, F., Brancolini, G., Baradello, L. 2006. Effects of climate changes on the late Pleistocene and Holocene sediments of the Venice Lagoon, Italy. Journal of Coastal Research, SI 39, 279-284. - Casellato S., Stefanon A. 2008. Coralligenous habitat in the northern Adriatic Sea: an overview. Marine Ecology, 29: 321-341. - Gabbianelli, G., Colantoni, P., Degetto, S., Dinelli, E., Lucchini, F. 1997. Contributi sedimentologici, geochimici ed isotopici per una caratterizzazione ambientale dell'Adriat

Bergamasco, Andrea; Donnici, Sandra; Tosi, Luigi; Tagliapietra, Davide; Zaggia, Luca; Bonaldo, Davide; Braga, Federica; Da Lio, Cristina; Keppel, Erica; Lorenzetti, Giuliano; Manfè, Giorgia; Franceschini, Gianluca; Giovanardi, Otello; Carol, Eleonora; Fornaro, Elena; Grant, Carley

2014-05-01

230

Teorí­as de primer y segundo orden sobre el potencial de ciertas figuras de equilibrio de cuerpos celestes  

NASA Astrophysics Data System (ADS)

Uno de los problemas que aborda la Mecánica Celeste es la determinación de las figuras de equilibrio de los cuerpos celestes. Para investigar su solución mediante métodos directos, se precisa evaluar el potencial generado por su autogravitación, el generado por su fuerza centrí­fuga y el generado por la fuerza de atracción entre los cuerpos. Los métodos clásicos de Finlay y Kopal que afrontan estos problemas, para determinar el potencial autogravitatorio en las configuraciones de equilibrio, emplean desarrollos en serie de los potenciales interior y exterior del potencial autogravitatorio. Estos métodos incurren en el error de suponer la convergencia en capas donde resulta cuestionable dicha convergencia para estos desarrollos en serie. En este trabajo se han elaborado unos algoritmos que contemplan toda la casuí&stica y que permiten una manipulación efic iente del producto de polinomios de Legendre, del producto de funciones asociada s de Legendre y del producto de armónicos esféricos como combinacióon lineal de ellos mismos, respectivamente. Se han obtenido, para primer y segundo orden en las amplitudes, los desarrollos correctos para los potencial es interior y exterior del potencial autogravitatorio para configuraciones de equilibrio aisladas, y , en primer orden de amplitudes, los mismos potenciales para los sistemas binarios próximos. Se ha elaborado un método analítico, en primer orden respecto de las amplitudes, para la determinación del potencial de marea en sistemas binarios próximos en el cual se manifiesta la forma de la componente secundaria del sistema

Gumbau, Manuel Forner

2010-11-01

231

Captura de satélites durante a formação de Júpiter  

NASA Astrophysics Data System (ADS)

O planeta Jupiter apresenta um grande número de satélites irregulares. As características das órbitas destes objetos indicam que os mesmos não teriam se formado ao redor do planeta que se encontram. As teorias existentes são de que estes objetos teriam se formado em uma região distante do planeta e sua evolução dinâmica os teria levado a uma captura gravitacional pelo planeta. Tendo em vista que o processo de captura gravitacional sem efeitos dissipativos não produz uma captura permanente, estudamos o processo de captura durante o estágio de formação do planeta. Realizamos simulações numéricas para os casos de satélites prógrados e retrógrados que inicialmente se encontram ao redor de Jupiter com sua massa atual e então, evoluimos a integração voltando no tempo de modo que o planeta sofra uma redução em sua massa (de 100% para 10% de sua massa atual) e verificamos o instante em que o satélites escapa do planeta (quando sua energia do problema de dois corpos se torna positiva). Assim, analisando o problema inverso no tempo, obtivemos em qual estágio de formação de Jupiter aquele hipotético satélite teria sido capturado. Os resultados mostram que os satélites retrógrados são capturados assim que entram na região delimitada pela esfera de Hill do planeta, enquanto que os satélites prógrados só são capturados quando entram numa região bem mais próxima ao planeta, uma fração da esfera de Hill.

Winter, O. C.; Vieira Neto, E.; Yokoyama, T.

2003-08-01

232

Medicina integrativa en Am?rica: De qu? forma se est? practicando la medicina integrativa en los centros cl?nicos en los Estados Unidos  

PubMed Central

RESUMEN EJECUTIVO El impulso para desarrollar e implementar estrategias de medicina integrativa está enraizado en el deseo de mejorar la atención al paciente. The Bravewell Collaborative, una organización sin ánimo de lucro dedicada a la mejora de la atención sanitaria, define la medicina integrativa como “un enfoque de la medicina que coloca al paciente en el centro y se dirige al conjunto completo de influencias físicas, emocionales, mentales, sociales, espirituales y ambientales que afectan a la salud de la persona. Con una estrategia personalizada que considera las condiciones, necesidades y circunstancias únicas del paciente, utiliza las intervenciones más apropiadas de una variedad de disciplinas científicas para curar la afección y la enfermedad y ayudar a las personas a recobrar y mantener una salud óptima”. En las pasadas dos décadas, se ha documentado un número creciente de centros clínicos que proporcionan medicina integrativa, el número de facultades y escuelas médicas que enseñan estrategias integrativas, el número de investigadores que estudian intervenciones integrativas, y el número de pacientes que solicitan cuidados integrativos. Pero se desconocía si la medicina integrativa se estaba ofreciendo de manera igual, similar, o dispar. Además, mientras que los estudios anteriores se centraban en la prevalencia y el uso de la medicina complementaria o alternativa (MCA) por parte de los pacientes1,2 o de los médicos en hospitales3, enumerando la utilización de terapias MCA individuales, se había recogido muy poca información con respecto a la práctica real de la medicina integrativa que, por definición, trata a la persona en su conjunto. En 2011, The Bravewell Collaborative encargó una encuesta para determinar la forma en que la medicina integrativa se estaba practicando en los Estados Unidos: (1) describiendo las poblaciones de pacientes y las afecciones sanitarias tratadas más habitualmente; (2) definiendo las prácticas y modelos fundamentales de atención; (3) determinando cómo se reembolsaban los servicios; (4) identificando los valores y los principios subyacentes a la atención; y (5) determinando los factores principales que impulsan una implementación satisfactoria.

Horrigan, Bonnie; Lewis, Sheldon; Abrams, Donald I.; Pechura, Constance

2012-01-01

233

Como Lo Hago Yo: Lipomas Medulares  

PubMed Central

Basados en la experiencia de 82 casos; en 5% se observaron anomalías pélvicas asociadas. En los menores de 3 años el motivo de consulta (85%) fue la tumoración. En los mayores de 3 años (42%) tenía problemas neurológicos. Solo el 24% preocupados por la tumoración. El objetivo de la cirugía es desanclar la médula y no remover la totalidad del lipoma. El lipoma de filum es el que es mas simple para operar. Aún cuando la escuela francesa propone operar solamente cuando hay síntomas favorezco cirugía preventiva. Favorezco una segunda cirugía si hay signos de anclaje postoperatorio, aún cuando observamos empeoramiento postoperatorio motor en 2.5% de los operados y urológico a largo plazo en 6% de los operados.

Portillo, Santiago

2014-01-01

234

La Mancha Negra: Substance Abuse, Violence, and Sexual Risks Among Hispanic Males  

PubMed Central

Hispanics are disproportionately affected by substance abuse, intimate partner violence, and HIV. Although the relationship between these conditions has been documented in the literature, few studies have explored the intersection of these health problems and their culture-related risk factors in an integrative manner. The purpose of this study is to explore the experiences that Hispanic heterosexual males in South Florida have with substance abuse, violence, and risky sexual behaviors. Three focus groups with a total of 25 Hispanic adult men are completed and analyzed using grounded theory. Three core categories emerge from the data. These include la cuna de problemas sociales (the cradle of social problems), ramas de una sola mata (branches from one same tree), and la mancha negra (the black stain). This study suggests that substance abuse, violence, and risky sexual behaviors are linked conditions with common cultural and socioenvironmental risk factors and consequences.

Gonzalez-Guarda, Rosa Maria; Ortega, Johis; Vasquez, Elias P.; De Santis, Joseph

2011-01-01

235

On efeito do achatamento nos pontos de equilíbrio e na dinâmica de sistemas coorbitais  

NASA Astrophysics Data System (ADS)

Neste trabalho analisamos o efeito do achatamento do corpo principal nos pontos de equilíbrio lagrangianos e na configuração de órbitas girino-ferradura. Enfatizamos os sistemas coorbitais de satélites de Saturno, pois se encontram em relativa proximidade com o planeta, em que o efeito do achatamento se torna mais evidente. O estudo é dividido em três etapas independentes. Na primeira fase analisamos as equações de movimento do problema restrito de três corpos considerando o efeito do achatamento, e através do balanceamento de forças buscamos a nova configuração dos pontos de equilíbrio lagrangianos. Concluímos, nesta etapa, que os pontos de equilíbrio estáveis apresentam um pequeno deslocamento definido pelo parâmetro de achatamento, não podendo ser mais representados por triângulos eqüiláteros. Aplicamos este resultado aos satélites coorbitais de Tetis e Dione, encontrando as posições de equilíbrio levemente deslocadas em relação ao caso sem achatamento. Na segunda fase visamos o sistema Saturno-Jano-Epimeteu, que por se tratar de um sistema de massas comparáveis, optamos por desenvolver as equações de Yoder et al (Icarus 53, pág 431-443, 1983), que permitem determinar os pontos de equilíbrio e a amplitude de oscilação angular das órbitas girino-ferradura para o problema não-restrito de três corpos, porém, no nosso estudo consideramos o efeito do achatamento do corpo principal nestas equações. Encontramos que a distância angular entre satélites, quando em posição de equilíbrio estável, diminui quanto maior for o parâmetro de achatamento do corpo principal. Além disso, a órbita de transição girino-ferradura possui largura angular menor em relação ao caso sem achatamento. Por fim, realizamos integrações numéricas para os casos reais de coorbitais de Saturno comparando com os resultados analíticos. Nestas integrações simulamos diversas órbitas girino-ferradura com diferentes parâmetros de achatamento, utilizando condições iniciais corrigidas para a presença do achatamento.

Mourão, D. C.; Winter, O. C.; Yokoyama, T.

2003-08-01

236

Determinação de regiões de órbitas diretas estáveis ao redor da Lua  

NASA Astrophysics Data System (ADS)

Neste Trabalho estamos investigando regiões do sistema Terra-Lua que contêm órbitas diretas estáveis ao redor da Lua visando a utilização destas órbitas em futuras missões de veículos espaciais como alternativas de trajetórias com baixo custo de manutenção. Adotando-se o problema restrito de três corpos, Terra-Lua-partícula, a localização e a extensão destas regiões de estabilidade foram investigadas numericamente considerando como estável toda órbita que permanece ao redor a Lua por, no mínimo, 1000 dias com energia de dois corpos da partícula em relação à Lua negativa. A estabilidade de tais regiões está associada a duas famílias de órbitas periódicas simples H1 e H2 e a órbitas quase-periódicas associadas a elas. Uma vez identificadas as regiões de estabilidade passamos a analisá-las introduzindo, paulatinamente, outras interações relevantes ao sistema como as perturbações do Sol (via problema restrito de quatro corpos), das marés, da pressão de radiação e do achatamento terrestre. Os resultados encontrados até o momento mostram que a perturbação do Sol é a única que reduz significativamente o tamanho das regiões de estabilidade. Também estamos investigando o comportamento de tais regiões quando características intrínsecas do sistema como as excentricidades das órbitas da Terra e da Lua e a inclinação da órbita Lua são consideradas. Com este estudo estamos reunindo informações que nos permitirão compreender a evolução das regiões de estabilidade no sistema Terra-Lua, bem como estabelecer parâmetros adequados para a utilização das trajetórias estáveis em futuras missões espaciais. Agradecimentos: Este projeto conta com o apoio do CNPq, da Capes e da Fapesp.

de Melo, C. F.; Winter, O. C.; Vieira Neto, E.

2003-08-01

237

Role of vegetation on erosion processes: experimental investigation  

NASA Astrophysics Data System (ADS)

Investigations on soil-system ecology are ever more oriented toward quantitative information based on the study of the linkages between physical processes and ecological response in rivers. As it is known, in presence of vegetation, the hydrodynamics characteristics of flow are principally determined by the mutual interrelation between the flow velocity field and the hydraulic behavior (completely submerged or emergent) of the vegetation elements. Much effort has been made toward identifying the theoretical law to interpret the vertical profile of flow longitudinal velocity in vegetated channels. Many theoretical and experimental studies in laboratory channels have been carried out and especially the case of submerged flexible vegetation has been examined (Termini, 2012). The effects of vegetation on flow velocity are significant and of crucial importance for stabilizing sediments and reducing erosion. Vegetation has a complex effect on walls roughness and the study of the hydrodynamic conditions of flow is difficult. Although most studies based on the "boundary layer" scheme so that the hydrodynamic conditions inside and above the vegetated layer are considered separately, some authors (Ghisalberti and Nepft, 2002; Carollo et al., 2008) claim that the "mixing layer" scheme is more appropriate to define the velocity profile both inside and outside the vegetated layer. Experimental program has been recently carried out in two laboratory flumes constructed at the laboratory of Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali - University of Palermo (Italy) with real and flexible vegetation on the bed. In this paper, attention is paid to the influence of vegetation on the erosion processes both on the bed and on the channel banks. The structure of the detailed flow velocity field is analyzed and compared with that obtained in absence of vegetation. Attention is then devoted to the analysis of soil erosion mechanism. Carollo F.G., Ferro V., Termini D. (2008). Flow velocity profile and turbulence characteristics in a vegetated straight flume. International Congress Riverflow 2008- Cesnme - Izmir (Turkey) 3-5 September Ghisalberti, M. & Nepf, H. M. 2002. Mixing layer and coherent structures in vegetated acquatic flows. Journal of Geophysical Reseach 107(2). Termini D. (2012). Experimental investigation on the role of vegetation on sediment transport mechanism: review of recent results - 9th ISE - International Symposium on Ecohydraulics - 2012, ISSN 0945-358X Vienna - CD proceedings-

Termini, Donatella

2014-05-01

238

Characterization of fire regime in Sardinia (Italy)  

NASA Astrophysics Data System (ADS)

In the last decades, a number of Authors highlighted the crucial role of forest fires within Mediterranean ecosystems, with impacts both negative and positive on all biosphere components and with reverberations on different scales. Fire determines the landscape structure and plant composition, but it is also the cause of enormous economic and ecological damages, beside the loss of human life. In Sardinia (Italy), the second largest island of the Mediterranean Basin, forest fires are perceived as one of the main environmental and social problems, and data are showing that the situation is worsening especially within the rural-urban peripheries and the increasing number of very large forest fires. The need for information concerning forest fire regime has been pointed out by several Authors (e.g. Rollins et al., 2002), who also emphasized the importance of understanding the factors (such as weather/climate, socio-economic, and land use) that determine spatial and temporal fire patterns. These would be used not only as a baseline to predict the climate change effect on forest fires, but also as a fire management and mitigation strategy. The main aim of this paper is, thus, to analyze the temporal and spatial patterns of fire occurrence in Sardinia (Italy) during the last three decades (1980-2010). For the analyzed period, fire statistics were provided by the Sardinian Forest Service (CFVA - Corpo Forestale e di Vigilanza Ambientale), while weather data for eight weather stations were obtained from the web site www.tutiempo.it. For each station, daily series of precipitation, mean, maximum and minimum temperature, relative humidity and wind speed were available. The present study firstly analyzed fire statistics (burned area and number of fires) according to the main fire regime characteristics (seasonality, fire return interval, fire incidence, fire size distribution). Then, fire and weather daily values were averaged to obtain monthly, seasonal and annual values, and a set of parametric and not parametric statistical tests were used to analyze the fire-weather relationships. Results showed a high inter- and intra-annual variability, also considering the different type of affected vegetation. As for other Mediterranean areas, a smaller number of large fires caused a high proportion of burned area. Land cover greatly influenced fire occurrence and fire size distribution across the landscape. Furthermore, fire activity (number of fires and area burned) showed significant correlations with weather variables, especially summer precipitation and wind, which seemed to drive the fire seasons and the fire propagation, respectively.

Bacciu, V. M.; Salis, M.; Mastinu, S.; Masala, F.; Sirca, C.; Spano, D.

2012-12-01

239

Water vapour profiling in cloudy conditions integrating Raman lidar and passive microwave observations  

NASA Astrophysics Data System (ADS)

At the Istituto di Metodologie per l'Analisi Ambientale of the Italian National Research Council (CNR-IMAA) an advanced observatory for the ground-based remote sensing of the atmosphere is operative. This facility is equipped with several instruments including two multi-wavelength Raman lidars, one of which mobile, a microwave profiler, a 36 GHz Doppler polarimetric radar, two laser ceilometers, a sun photometer, a surface radiation station and three radiosounding stations. CNR-IMAA atmospheric observatory (CIAO) is located in Southern Italy on the Apennine mountains (40.60N, 15.72E, 760 m a.s.l.), less than 150 km from the West, South and East coasts. The site is in a valley surrounded by low mountains (<1100 m a.s.l.) and this location offers an optimal opportunity to study different kinds of weather and climate regimes. CIAO represents an optimal site where testing possible synergies between active and passive techniques for improving the profiling capabilities of several atmospheric key variables, such as aerosol, water vapour and clouds, and for the development of an integration strategy for their long-term monitoring. CIAO strategy aims at the combination of observations provided by active and passive sensors for providing advanced retrievals of atmospheric parameters exploiting both the high vertical resolution of active techniques and the typical operational capabilities of passive sensors. This combination offers a high potential for profiling atmospheric parameters in an enlarged vertical range nearly independently on the atmospheric conditions. In this work, we describe two different integration approaches for the improvement of water vapour profiling during cloudy condition through the combination of Raman lidar and microwave profiler measurements. These approaches are based on the use of Kalman filtering and Tikhonov regularization methods for the solution of the radiative transfer equation in the microwave region. The accuracy of the retrieved water vapour profiles during cloudy conditions is improved by the use of the water vapour Raman lidar profiles, retrieved up to a maximum height level located around the cloud base region (depending on their optical thickness), as a constraint to the obtained solution set. The presented integration approaches allow us to provide physically consistent solution to the inverse problem in the microwave region retrieving water vapour vertical profiles also in presence of thick clouds. The integration of Raman lidar and microwave measurements also provides a continuous high-resolution estimation of the water vapour content in the full troposphere and, therefore, a useful tool for the evaluation of model capability to capture mean aspects of the water vapour field in nearly all weather conditions as well as for the identification of possible discrepancies between observations and models.

Madonna, Fabio; Boselli, Antonella; Amodeo, Aldo; Cornacchia, Carmela; D'Amico, Giuseppe; Giunta, Aldo; Mona, Lucia; Pappalardo, Gelsomina

2010-10-01

240

Achieving Conservation Science that Bridges the Knowledge-Action Boundary  

PubMed Central

There are many barriers to using science to inform conservation policy and practice. Conservation scientists wishing to produce management-relevant science must balance this goal with the imperative of demonstrating novelty and rigor in their science. Decision makers seeking to make evidence-based decisions must balance a desire for knowledge with the need to act despite uncertainty. Generating science that will effectively inform management decisions requires that the production of information (the components of knowledge) be salient (relevant and timely), credible (authoritative, believable, and trusted), and legitimate (developed via a process that considers the values and perspectives of all relevant actors) in the eyes of both researchers and decision makers. We perceive 3 key challenges for those hoping to generate conservation science that achieves all 3 of these information characteristics. First, scientific and management audiences can have contrasting perceptions about the salience of research. Second, the pursuit of scientific credibility can come at the cost of salience and legitimacy in the eyes of decision makers, and, third, different actors can have conflicting views about what constitutes legitimate information. We highlight 4 institutional frameworks that can facilitate science that will inform management: boundary organizations (environmental organizations that span the boundary between science and management), research scientists embedded in resource management agencies, formal links between decision makers and scientists at research-focused institutions, and training programs for conservation professionals. Although these are not the only approaches to generating boundary-spanning science, nor are they mutually exclusive, they provide mechanisms for promoting communication, translation, and mediation across the knowledge–action boundary. We believe that despite the challenges, conservation science should strive to be a boundary science, which both advances scientific understanding and contributes to decision making. Logrando que la Ciencia de la Conservación Trasponga la Frontera Conocimiento-Acción Resumen Hay muchas barreras para utilizar ciencia para informar a la política y práctica de la conservación. Los científicos de la conservación que desean producir ciencia relevante para el manejo deben equilibrar esta meta con el imperativo de demostrar novedad y rigor en su ciencia. Los tomadores de decisiones que buscan que sus decisiones se basen en evidencias deben equilibrar el deseo de conocimientos con la necesidad de actuar a pesar de la incertidumbre. La generación de ciencia que informe efectivamente a las decisiones de manejo requiere que la producción de información (los componentes del conocimiento) sea sobresaliente (relevante y oportuna), creíble (autoritativa, verosímil y confiable) y legítima (desarrollada mediante un proceso que considera los valores y perspectivas de todos los actores relevantes) a la vista tanto de investigadores como de tomadores de decisiones. Percibimos tres retos clave para quienes desean generar ciencia de la conservación que logre estas tres características de la información. Primero, las audiencias científicas y de manejo pueden tener percepciones contrastantes sobre la relevancia de la investigación. Segundo, la credibilidad se puede lograr a costa de la relevancia y legitimidad a la vista de los tomadores de decisiones y tercero, los diferentes actores pueden tener percepciones conflictivas sobre los que constituye información legítima. Resaltamos cuatro marcos institucionales que pueden facilitar que la ciencia informe al manejo: organizaciones de frontera (organizaciones ambientales que trasponen la frontera entre la ciencia y el manejo), investigadores científicos insertados en agencias de manejo de recursos, vínculos formales entre tomadores de decisiones y científicos en instituciones enfocadas a la investigación, y programas de

Cook, Carly N; Mascia, Michael B; Schwartz, Mark W; Possingham, Hugh P; Fuller, Richard A

2013-01-01

241

Geological and geophysical activities at Spallanzani Science Department (Liceo Scientifico Statale "Lazzaro Spallanzani" - Tivoli, Italy)  

NASA Astrophysics Data System (ADS)

The high school Liceo Scientifico "Lazzaro Spallanzani" at Tivoli (Rome) has been fully involved in the study of geological and geophysical features of the town of Tivoli and the surrounding area in the last twelve years. Objective of this activity is to promote the knowledge of the local territory from the geological point of view. Main activities: • School year 2001-2002: Setting up inside the school building of a Geological Museum focusing on "Geological Evolution of Latium, Central Italy" (in collaboration with colleagues M. Mancini, and A. Pierangeli). • March, 15, 2001: Conference of Environmental Geology. Lecturer: Prof. Raniero Massoli Novelli, L'Aquila University and Società Italiana di Geologia Ambientale. • School years 2001-2002 and 2002-2003: Earth Sciences course for students "Brittle deformation and tectonic stress in Tivoli area". • November, 2003: Conference of Geology, GIS and Remote Sensing. Lecturers: Prof. Maurizio Parotto and Dr Alessandro Cecili (Roma Tre University, Rome), and Dr Stefano Pignotti (Istituto Nazionale per la Ricerca sulla Montagna, Rome). • November, 2003, 2004 and 2005: GIS DAY, organized in collaboration with ESRI Italia. • School year 2006-2007: Earth Sciences course for students "Acque Albule basin and the Travertine of Tivoli, Latium, Central Italy" (focus on travertine formation). • School year 2010-2011: Earth Sciences course for students "Acque Albule basin and the Travertine of Tivoli. Geology, Hydrogeology and Microbiology of the basin, Latium, Central Italy" (focus on thermal springs and spa). In the period 2009-2010 a seismic station with three channels, currently working, was designed and built in our school by the science teachers Felice De Angelis and Tomaso Favale. Our seismic station (code name LTTV) is part of Italian Experimental Seismic Network (IESN) with identification code IZ (international database IRIS-ISC). The three drums are online in real time on websites http://www.spallanzanitivoli.it/stazionesismica/ and http://www.iesn.it. Furthermore, until the end of January 2012 a semi-professional seismograph will work with educational aims. These activities allowed the school to receive the first prize in the 2002 contest held by the italian scientific magazine Quark "Giornalisti Scientifici si diventa" (How to become a scientific journalist), with an article co-authored with three students titled "Una TAC per il Vesuvio" (CT scan for Vesuvius). The article was published in the n. 15 issue of Quark magazine, May 2002. The school also runs a Science and Chemistry Laboratory, equipped with: (a) 1 mobile seismograph with six geophones for seismic invesitgation (rifraction, reflection, REMI, MASW, and HVSR), (b) 1 polarized microscope for mineralogy and petrography, (c) various geochemical instruments for water analysis (pH, Eh, T, etc.), (d) 1 Geiger counter to detect ?- particles and ? rays, and (e) 2 calcimeters to calculate the percentage of calcium carbonate in calcareous rocks. Two meteorological stations managed by Physics Laboratory, both online with data processing in real time, are hosted inside school building. Finally, we are planning a new scientific project for the next school year, involving students and science teachers, probably named "Gas hazard in volcanic and geothermal areas of the eastern Rome province".

Favale, T.; De Angelis, F.; De Filippis, L.

2012-04-01

242

Analysis of weather condition influencing fire regime in Italy  

NASA Astrophysics Data System (ADS)

Fires have a crucial role within Mediterranean ecosystems, with both negative and positive impacts on all biosphere components and with reverberations on different scales. Fire determines the landscape structure and plant composition, but it is also the cause of enormous economic and ecological damages, beside the loss of human life. In addition, several authors are in agreement suggesting that, during the past decades, changes on fire patterns have occurred, especially in terms of fire-prone areas expansion and fire season lengthening. Climate and weather are two of the main controlling agents, directly and indirectly, of fire regime influencing vegetation productivity, causing water stress, igniting fires through lightning, or modulating fire behavior through wind. On the other hand, these relationships could be not warranted in areas where most ignitions are caused by people (Moreno et al. 2009). Specific analyses of the driving forces of fire regime across countries and scales are thus still required in order to better anticipate fire seasons and also to advance our knowledge of future fire regimes. The objective of this work was to improve our knowledge of the relative effects of several weather variables on forest fires in Italy for the period 1985-2008. Meteorological data were obtained through the MARS (Monitoring Agricultural Resources) database, interpolated at 25x25 km scale. Fire data were provided by the JRC (Join Research Center) and the CFVA (Corpo Forestale e di Vigilanza Ambientale, Sardinia). A hierarchical cluster analysis, based on fire and weather data, allowed the identification of six homogeneous areas in terms of fire occurrence and climate (pyro-climatic areas). Two statistical techniques (linear and non-parametric models) were applied in order to assess if inter-annual variability in weather pattern and fire events had a significant trend. Then, through correlation analysis and multi-linear regression modeling, we investigated the influence of weather variables on fire activity across a range of time- and spatial-scales. The analysis revealed a general decrease of both number of fires and burned area, although not everywhere with the same magnitude. Overall, regression models where highly significant (p<0.001), and the explained variance ranged from 36% to 80% for fire number and from 37% to 76% for burned area, depending on pyro-climatic area. Moreover, our results contributed in determining the relative importance of climate variables acting at different timescales as control on intrinsic (i.e. flammability and moisture) and extrinsic (i.e. fuel amount and structure) characteristics of vegetation, thus strongly influencing fire occurrence. The good performance of our models, especially in the most fire affected pyro-climatic areas of Italy, and the better understanding of the main driver of fire variability gained through this work could be of great help for fire management among the different pyro-climatic areas.

Bacciu, Valentina; Masala, Francesco; Salis, Michele; Sirca, Costantino; Spano, Donatella

2014-05-01

243

The SunCloud project: An initiative for a development of a worldwide sunshine duration and cloudiness observations dataset  

NASA Astrophysics Data System (ADS)

One problem encountered when establishing the causes of global dimming and brightening is the limited number of long-term solar radiation series with accurate and calibrated measurements. For this reason, the analysis is often supported and extended with the use of other climatic variables such as sunshine duration and cloud cover. Specifically, sunshine duration is defined as the amount of time usually expressed in hours that direct solar radiation exceeds a certain threshold (usually taken at 120 W m-2). Consequently, this variable can be considered as an excellent proxy measure of solar radiation at interannual and decadal time scales, with the advantage that measurements of this variable were initiated in the late 19th century in different, worldwide, main meteorological stations. Nevertheless, detailed and up-to-date analysis of sunshine duration behavior on global or hemispheric scales are still missing. Thus, starting on September 2010 in the framework of different research projects, we will engage a worldwide compilation of the longest daily or monthly sunshine duration series from the late 19th century until present. Several quality control checks and homogenization methods will be applied to the generated sunshine dataset. The relationship between the more precise downward solar radiation series from the Global Energy Balance Archive (GEBA) and the homogenized sunshine series will be studied in order to reconstruct global and regional solar irradiance at the Earth's surface since the late 19th century. Since clouds are the main cause of interannual and decadal variability of radiation reaching the Earth's surface, as a complement to the long-term sunshine series we will also compile worldwide surface cloudiness observations. With this presentation we seek to encourage the climate community to contribute with their own local datasets to the SunCloud project. The SunCloud Team: M. Wild, Institute for Atmospheric and Climate Science, ETH Zurich, Switzerland (martin.wild@env.ethz.ch) E. Pallé, Institute of Astrophysics of the Canary Islands, Spain (epalle@iac.es) J. Calbó, Group of Environmental Physics, University of Girona, Spain (josep.calbo@udg.edu) M. Brunetti, Institute of Atmospheric Sciences and Climate, Italian National Research Council, Italy (m.brunetti@isac.cnr.it) G. Stanhill, Department of Environmental Physics and Irrigation, The Volcani Center, Israel (gerald@volcani.agri.gov.il) R. Brázdil, Institute of Geography, Masaryk University, Czech Republic (brazdil@sci.muni.cz) M. Barriendos, Department of Modern History, University of Barcelona, Spain (mbarriendos@ub.edu) C. Deser, National Center for Atmospheric Research, USA (cdeser@ucar.edu) P. Pereira, Department of Environmental Protection, Vilnius Gediminas Technical University, Lithuania (pereiraub@gmail.com) C. Azorin-Molina, The CEAM Foundation (Fundación Centro de Estudios Ambientales del Mediterráneo), Spain (cazorin@ceam.es) Q. You, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China (yqingl@126.com)

Sanchez-Lorenzo, A.

2010-09-01

244

Weather modeling for hazard and consequence assessment operations during the 2006 Winter Olympic Games  

NASA Astrophysics Data System (ADS)

Consequence assessment (CA) operations are those processes that attempt to mitigate negative impacts of incidents involving hazardous materials such as chemical, biological, radiological, nuclear, and high explosive (CBRNE) agents, facilities, weapons, or transportation. Incident types range from accidental spillage of chemicals at/en route to/from a manufacturing plant, to the deliberate use of radiological or chemical material as a weapon in a crowded city. The impacts of these incidents are highly variable, from little or no impact to catastrophic loss of life and property. Local and regional scale atmospheric conditions strongly influence atmospheric transport and dispersion processes in the boundary layer, and the extent and scope of the spread of dangerous materials in the lower levels of the atmosphere. Therefore, CA personnel charged with managing the consequences of CBRNE incidents must have detailed knowledge of current and future weather conditions to accurately model potential effects. A meteorology team was established at the U.S. Defense Threat Reduction Agency (DTRA) to provide weather support to CA personnel operating DTRA's CA tools, such as the Hazard Prediction and Assessment Capability (HPAC) tool. The meteorology team performs three main functions: 1) regular provision of meteorological data for use by personnel using HPAC, 2) determination of the best performing medium-range model forecast for the 12 - 48 hour timeframe and 3) provision of real-time help-desk support to users regarding acquisition and use of weather in HPAC CA applications. The normal meteorology team operations were expanded during a recent modeling project which took place during the 2006 Winter Olympic Games. The meteorology team took advantage of special weather observation datasets available in the domain of the Winter Olympic venues and undertook a project to improve weather modeling at high resolution. The varied and complex terrain provided a special challenge to the modelers on the meteorology team. Some of the Olympic venues were located in the mountains to the west of Torino, while the rest were located on the relatively flat plain in and around the cities of Pinerolo and Torino to the east. DTRA partners at Pennsylvania State University (PSU) and the U.S. National Center for Atmospheric Research (NCAR) established data collection and assimilation, and forecast modeling processes that used special weather station observations provided by the Area Previsione e Monitoraggio Ambientale of Italy's ARPA Piemonte. At PSU a version of the MM5 was especially prepared to use observation data to forecast weather in a four-nest configuration. Two other DTRA partners provided independent weather forecast models against which the PSU model data were compared. The U.S. Air Force Weather Agency provided its MM5 forecast model data and the U.S. National Oceanic and Atmospheric Administration's National Centers for Environmental Prediction provided data from a special version of their WRF model. The project produced many opportunities to improve the modeling and forecasting capability at DTRA. DTRA and its partners plan to expand upon this experience during upcoming field tests, and to further improve and expand the capability to provide accurate high-resolution weather forecast information to hazard and consequence assessment operations.

Hayes, P.; Trigg, J. L.; Stauffer, D.; Hunter, G.; McQueen, J.

2006-05-01

245

Introducing CAT (Centro di Allerta Tsunami), the Italian candidate Tsunami Watch Provider (It-cTWP) for the Mediterranean  

NASA Astrophysics Data System (ADS)

The recently established CAT (Centro di Allerta Tsunami) at Istituto Nazionale di Geofisica e Vulcanologia (INGV) will be part of the Italian National Tsunami Warning Center (It-NTWC) and it is a candidate Tsunami Watch Provider (cTWP) for the Mediterranean Sea in the framework of the Tsunami Early Warning and Mitigation System in the North-eastern Atlantic, the Mediterranean and connected seas (NEAMTWS). It-NTWC is a partnership of three Italian institutions: INGV, the Italian Department of Civil Protection (Dipartimento di Protezione Civile, DPC) and the Institute for Environmental Protection and Research (Istituto Superiore per la Protezione e la Ricerca Ambientale, ISPRA) which provides the sea-level data of the Italian mareographic network (Rete Mareografica Nazionale, RMN) in quasi-real-time. CAT is the operational part of the It-NTWC based at the INGV 24/7 seismic monitoring centre in Rome. CAT will be committed to deliver tsunami warning messages to DPC and, when it will enter its operational cTWP phase, to any IOC/UNESCO member state that will subscribe for the service. The current implementation of CAT is based on the NEAMTWS Decision Matrix (DM). Earthquake parameters are determined automatically by the Early-Est (EE) software, and used as an input to DM and tsunami travel times calculation to provide warning messages, including earthquake parameters, plus level of alert and estimated tsunami arrival time at pre-defined forecast points along threatened coasts. Basing on updated automatic EE solutions, seismologist's revision, and sea-level readings subsequent messages can be delivered until warning status ends. The use of the DM allows a rapid implementation of a tsunami warning system, but it does not consider some important features to better characterize a tsunami forecast, such as the earthquake's focal mechanism, the directivity of tsunami propagation and the morphology of the coast. More sophisticated procedures are currently under development: a database of pre-calculated, or calculated on the fly on GPU cards, tsunami scenarios, and rapid moment tensor calculation. The deployment of deep-sea tsunami (pressure) sensors is envisaged as well subject to budgetary constraints. A Decision Support System (DSS) is under development in order to integrate the different sources of information (earthquake parameters estimates and prior knowledge of the tectonic setting, numerical tsunami forecast, sea-level readings), and assist decision making during the first minutes after an event. CAT participated successfully in several NEAM communication tests within its function of National Tsunami Warning Focal Point (NTWFP) and the delivery of messages to DPC, ISPRA, and local authorities has also been tested. Preliminary CAT procedures have been tested internally, that is without delivering messages, also for two recent Mediterranean earthquakes: the M=6.6 occurred the 12th October 2013 offshore Crete and the M=5.9 occurred the 28th December 2013 offshore between Turkey and Cyprus. Here, we will present the current CAT implementation and describe its future developments.

Michelini, Alberto; Amato, Alessandro; Badiali, Lucio; Basili, Roberto; Bernardi, Fabrizio; Govoni, Aladino; Lauciani, Valentino; Lomax, Anthony; Lorito, Stefano; Mele, Francesco; Melini, Daniele; Molinari, Irene; Piatanesi, Alessio; Romano, Fabrizio; Selva, Jacopo; Selvaggi, Giulio; Sensale, Giampaolo; Tonini, Roberto; Vazzoler, Stefano; Zanolin, Francesco

2014-05-01

246

Direct simulation of groundwater transit-time distributions using the reservoir theory  

NASA Astrophysics Data System (ADS)

Groundwater transit times are of interest for the management of water resources, assessment of pollution from non-point sources, and quantitative dating of groundwaters by the use of environmental isotopes. The age of water is the time water has spent in an aquifer since it has entered the system, whereas the transit time is the age of water as it exits the system. Water at the outlet of an aquifer is a mixture of water elements with different transit times, as a consequence of the different flow-line lengths. In this paper, transit-time distributions are calculated by coupling two existing methods, the reservoir theory and a recent age-simulation method. Based on the derivation of the cumulative age distribution over the whole domain, the approach accounts for the whole hydrogeological framework. The method is tested using an analytical example and its applicability illustrated for a regional layered aquifer. Results show the asymmetry and multimodality of the transit-time distribution even in advection-only conditions, due to the aquifer geometry and to the velocity-field heterogeneity. Résumé Les temps de transit des eaux souterraines sont intéressants à connaître pour gérer l'évaluation des ressources en eau dans le cas de pollution à partir de sources non ponctuelles, et aussi pour dater quantitativement les eaux souterraines au moyen des isotopes du milieu. L'âge de l'eau est le temps qu'elle a passé dans un aquifère depuis qu'elle est entrée dans le système, alors que le temps de transit est l'âge de l'eau au moment où elle quitte le système. L'eau à la sortie d'un aquifère est un mélange d'eaux possédant différents temps de transit, du fait des longueurs différentes des lignes de courant suivies. Dans ce papier, les distributions des temps de transit sont calculées en couplant deux méthodes, la théorie du réservoir et une méthode récente de simulation des âges. Basée sur la dérivation de la distribution cumulées des âges sur tout le domaine, l'approche prend en compte le cadre hydrogéologique dans son ensemble. La méthode est testée sur un exemple analytique et son applicabilité est illustrée pour un aquifère stratifié régional. Les résultats montrent l'asymétrie et la plurimodalité de la distribution des temps de transit même dans des conditions uniquement d'advection, à cause de la géométrie de l'aquifère et de l'hétérogénéité du champ des vitesses. Resumen El estudio de los tiempos de tránsito del agua subterránea es muy útil para (1) la gestión de los recursos de agua frente a la contaminación por focos no puntuales, y (2) la datación de aguas mediante isótopos ambientales. La edad de un agua subterránea es el tiempo que ésta ha permanecido en el acuífero contada desde el momento de su entrada, mientras que el tiempo de tránsito corresponde a la edad del agua en el momento en que abandona el sistema. En el punto de descarga en realidad se encuentra una mezcla de aguas con distintos tiempos de tránsito, debido a la yuxtaposición de líneas de flujo con diferentes recorridos. En este artículo se calculan las distribuciones de tiempos de tránsito mediante el acoplamiento de dos métodos ya existentes: la teoría de embalse y un método reciente de simulación de edades. El método se basa en la derivación de la distribución acumulada de edades, y es aplicable en todo el dominio hidrogeológico. El método se ha probado en un ejemplo analítico, y su aplicabilidad se muestra para un acuífero estratificado. Como resultado se obtiene que, aun en el caso de flujo exclusivamente advectivo, la distribución de tiempos de tránsito es asimétrica y multimodal debido a la geometría del acuífero y a la heterogeneidad del campo de velocidades.

Etcheverry, David; Perrochet, Pierre

247

Sexual competitiveness and compatibility between mass-reared sterile flies and wild populations of Anastrepha Ludens (Diptera: Tephritidae) from different regions in Mexico  

SciTech Connect

The mass-reared colony of Anastrepha ludens (Loew) currently used in Mexico for suppression of the Mexican fruit fly has been in use for over 10 years. Sterile flies are released into a wide range of environmental conditions as part of an integrated area-wide approach to suppress diverse populations of this pest in the Mexican Republic. This paper assesses the performance of the sterile flies interacting with wild populations from the different environments. We investigated the sexual compatibility and competitiveness of the sterile flies when competing with wild populations from 6 representatives Mexican states: Nuevo Leon, Tamaulipas, Sinaloa, Nayarit, Michoacan, and Chiapas. Results show that the males of the wild populations differed in the time to the onset and peak of sexual activity. Nevertheless, the index of sexual isolation (ISI) reflected sexual compatibility between the populations and the mass-reared strain, indicating that the sterile individuals mate satisfactorily with the wild populations from the 6 states. The male relative performance index (MRPI) showed that the sterile male is as effective in copulating as the wild males. The female relative performance index (FRPI) reflected a general tendency for wild females to copulate in greater proportion than the sterile females, except for the strains from Tamaulipas and Chiapas. In general, the lower participation of the sterile females in copulation increases the possibilities of sterile males to mate with wild females. The relative sterility index (RSI) showed that the acceptance by wild females of the sterile males (25-55%) was similar to that of wild males. Females of the Chiapas strain showed the lowest acceptance of sterile males. Finally, the results obtained in the Fried test (which measures induced sterility in eggs) showed a competitiveness coefficient ranging from 0.2 to 0.5. This suggests that sterile males successfully compete and are compatible with flies from different geographic origins. (author) [Spanish] La colonia actualmente usada para controlar la mosca mexicana de la fruta, Anastrepha ludens (Loew), en Mexico tiene mas de 10 anos en cria masiva. Los insectos esteriles son liberados en una gran variedad de condiciones ambientales como parte de un control integrado para suprimir diversas poblaciones de esta plaga dentro de la Republica Mexicana. El objetivo de este documento esta dirigido a revisar el desempeno de las moscas esteriles frente a poblaciones silvestres procedentes de diferentes ambientes y para esto se realizaron comparaciones de compatibilidad y competitividad sexual de las moscas esteriles contra poblaciones silvestres de seis estados representativos de la Republica Mexicana: Nuevo Leon, Tamaulipas, Sinaloa, Nayarit, Michoacan y Chiapas. Los resultados obtenidos manifiestan diferencias en el horario de inicio de llamado y mayor actividad sexual del macho entre las moscas provenientes de cada estado. Sin embargo el indice de aislamiento (ISI) reflejo compatibilidad sexual entre la cepa de laboratorio y todas las poblaciones analizadas, indicando que los individuos esteriles pueden aparearse satisfactoriamente con las poblaciones silvestres de los seis estados. El indice de efectividad de apareamiento del macho (MRPI) reflejo de manera global que los machos esteriles son tan efectivos para copular como los silvestres. El indice de efectividad de apareamiento de la hembra (FRPI) reflejo que en la mayoria de los estados las hembras silvestres copularon en mayor proporcion que las hembras esteriles, excepto para las poblaciones de Tamaulipas y Chiapas. En general, la baja participacion de las hembras esteriles en el campo permitio al macho esteril ampliar su probabilidad de apareamiento con las hembras silvestres. En cuanto al indice de esterilidad relativa (RSI), observamos que la aceptacion de las hembras silvestres al macho esteril (25-55%) fue similar a la de los machos silvestres. Las hembras de la poblacion de Chiapas registro la menor aceptacion. Finalmente, los resultados obtenidos en la prueba de Fried, la cual determi

Orozco-Davila, D.; Hernandez, R.; Meza, S.; Dominguez, J. [Programa Moscamed Moscafrut-Desarrollo de Metodos, Central Poniente No. 14 altos-Esq. 2a Avenida Sur. CP 30700 Tapachula, Chiapas (Mexico)

2007-03-15

248

Influence of plant productivity over variability of soil respiration: a multi-scale approach  

NASA Astrophysics Data System (ADS)

To investigate the role of plant photosynthetic activity on the variations in soil respiration (SR), SR data obtained from manual sampling and automatic soil respiration chambers placed on eddy flux towers sites were used. Plant photosynthetic activity was represented as Gross Primary Production (GPP), calculated from the half hourly continuous measurements of Net Ecosystem Exchange (NEE). The role of plant photosynthetic activity over the variation in SR was investigated at different time-scales: data averaged hourly, daily and weekly were used to study the photosynthetic effect on SR dial variations (Hourly data), 15 days variations (Daily averages), monthly variations (daily and weekly averages) and seasonal variations (weekly data). Our results confirm the important role of plant photosynthetic activity on the variations of SR at each of the mentioned time-scales. The effect of photosynthetic activity on SR was high on hourly time-scale (dial variations of SR). At half of the studied ecosystems GPP was the best single predictor of dial variations of SR. However at most of the studied sites the combination of soil temperature and GPP was the best predictor of dial variations in SR. The effect of aboveground productivity over dial variations of SR lagged on the range of 5 to 15 hours, depending on the ecosystem. At daily to monthly time scale variations of SR were in general better explained with the combination of temperature and moisture variations. However, ‘jumps' in average weekly SR during the growing season yielded anomaly high values of Q10, in some cases above 1000, which probably reflects synoptic changes in photosynthates translocation from plant activity. Finally, although seasonal changes of SR were in general very well explained by temperature and soil moisture, seasonality of SR was better correlated to seasonality of GPP than to seasonality of soil temperature and/or soil moisture. Therefore the magnitude of the seasonal variation in SR was in general controlled by the seasonality of substrate supply by plants (via photosynthates translocation and/or litter) to soil. Although soil temperature and soil moisture exert a strong influence over the variation in SR, our results indicates that substrate supply by plant activity could exert a more important than previously expected role in the variability of soil respiration. 1. CREAF (Centre de Recerca Ecológica i Aplicacions Forestals), Unitat d'Ecofisiologia i Canvi Global CREAF-CEAB-CSIC, BELLATERRA (Barcelona), Spain (j.curiel@creaf.uab.es) 2. University of Antwerp (UA), Antwerp, Belgium (ivan.janssens@ua.ac.be) 3. Institute of Ecology, University of Innsbruck, Innsbruck, Austria (michael.bahn@uibk.ac.at) 4. UMR Ecologie et Ecophysiologie Forestières, Centre INRA de Nancy, France (longdoz@nancy.inra.fr) 5. ESPM, University of Calicornia at Berkeley, Berkeley, CA, US (baldocchi@nature.berkeley.edu) 6. The Woods Hole Research Center, Falmouth, USA (edavidson@whrc.org) 7. Max-Planck-Institute for Biogeochemistry, Jena, Germany (markus.reichstein@bgc-jena.mpg.de) 8. Institute of Systems Biology and Ecology, Academy of Sciences of the Czech Republic, Czech Republic (manuel@brno.cas.cz) 9. Università degli studi della Tuscia, Viterbo, Italy (arriga@unitus.it) 10. Laurence Berkeley lab, Berkeley, CA, USA (mstorn@lbl.gov) 11. Gembloux Agricultural University, Gembloux, Belgium (aubinet.m@fsagx.ac.be) 12. Fundacion CEAM(Centro de Estudios Ambientales del Mediterráneo), Valencia, Spain (arnaud@ceam.es) 13. Institute of Hydrology and Meteorology, Technische Universität Dresden, Pienner, Germany (gruenwald@forst.tu-dresden.de) 14. Department of Environmental Sciences, Second University of Naples, Caserta, Italy (ilaria.inglima@unina2.it) 15. CNRS-CEFE Montpellier, France (Laurent.MISSON@cefe.cnrs.fr) 16. Agenzia Provinciale per l'Ambiente, Bolzano, Italy (leonar@inwind.it) 17. University of Helsinki Department of Forest Ecology, Helsinki, Finland (jukka.pumpanen@helsinki.fi) 18. Institute for the Study of Earth, Oceans and Space, University of New Hampshire Dur

Curiel Yuste, J.

2009-04-01

249

Breakfast of champions or kiss of death? Survival and sexual performance of protein-fed, sterile Mediterranean fruit flies (Diptera: Tephritidae)  

SciTech Connect

The sterile insect technique (SIT) is increasingly being used around the world to control Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), the Mediterranean fruit fly as part of an area-wide integrated approach. One option that may improve the effectiveness of the SIT, by increasing the sexual competitiveness of released sterile males, consists of feeding males protein during the post-teneral stage, a diet that increases sexual performance of wild males. We examine the effects of diet on the successive hurdles males must overcome in order to inseminate females, i.e., joining leks, copulating females, having their sperm stored and inhibition of female remating. In addition, we address the effects of diet on post-release foraging success, longevity, and the ability to withstand starvation. While protein feeding universally increases the sexual success of wild males, its effect on sterile males varies with strain, experimental settings, and environmental conditions. In some cases, treatments that resulted in the best sexual performance were significantly associated with increased vulnerability to starvation. However, no particular diet affected the ability of sterile males to find nutrients in the field when these where available. We suggest it may be better to release relatively short-lived flies that are highly competitive, rather than long-lived, sexually ineffective ones. (author) [Spanish] El uso de la tecnica de insecto esteril (TIE) esta aumentando alrededor del mundo para el control de Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), la mosca mediterranea de la fruta como parte de un enfoque integrado por toda el area. Una opcion que puede mejorar la eficiencia de TIE, por medio del aumento de la capacidad de los machos esteriles liberados para competir, consiste en la alimentacion de los machos con proteina durante la etapa de pos-teneral, una dieta que aumenta el desempeno sexual de los machos naturales. Nosotros examinamos los efectos de la dieta sobre los obstaculos sucesivos que los machos tienen que superar para inseminar las hembras, i.e., unir con otros machos en areas para el apareamiento, copula de las hembras, almacenar esperma e inhibir el re-apareamiento de hembras. Ademas discutimos los efectos de la dieta sobre el exito de su actividad forrajera despues de ser liberados, la longevidad y la habilidad para aguantar la inanicion. Mientras que la alimentacion con proteina universalmente aumentan el exito sexual de los machos naturales, su efecto sobre los machos esteriles varia segun la raza, el lugar de los experimentos y las condiciones ambientales. En algunos casos, los tratamientos que resultaron con mejor desempeno sexual fueron asociados significativamente con el aumento de la vulnerabilidad a la inanicion. Sin embargo, ninguna dieta en particular afecto la habilidad de los machos esteriles para encontrar nutrientes en el campo cuando fueron disponibles. Nosotros sugerimos que puede ser mejor el liberar moscas que tienen una vida relativamente corta y que son mas competidoras, en vez de moscas que tienen una vida larga y sexualmente inefectiva. (author)

Yuval, B.; Maor, M.; Levy, K. [Dept. of Entomology, Hebrew University, PO 12, Rehovot, 76100 (Israel); Kaspi, R. [Dept. of Entomology, University of California, Davis CA 95616 (United States); Taylor, P. [Dept. of Psychology, Macquarie University, NSW 2109 (Australia); Shelly, T. [USDA-APHIS, 41-650 Ahiki Street, Waimanalo, HI 96795 (United States)

2007-03-15

250

Assessment of terrain slope influence in SWAT modeling of Andean watersheds  

NASA Astrophysics Data System (ADS)

Hydrological processes in the Andean Region are difficult to model. Large range of altitudes involved (from over 4000 meters above sea level, masl, to zero) indicates the high variability of rainfall, temperature and other climate variables. Strong runoff and extreme events as landslides and floods are the consequence of high slopes of terrain, especially in the upper part of the basins. Strong seasonality of rain and complex ecosystems (vulnerable to climate changes and anthropogenic activities) helps these processes. Present study focuses in a particular watershed from Peruvian Andes, the Jequetepeque River. The distributed watershed simulation model, Soil and Water Assessment Tool (SWAT) is applied to model run-off and sediments transport through the basin with data from 1997 to 2006. Specifically, the study focuses in the assessment of the influence of considering terrain slope variation in the definition of Hydrographical Response Units within SWAT. The Jequetepeque watershed (4 372.5 km2) is located in the north part of Peru. River flows east to west, to the Pacific Ocean. Annual average precipitation ranges from 0 to 1100 mm and altitude from 0 to 4188 masl. The "Gallito Ciego" reservoir (400 masl) separates upper-middle part from lower part of the watershed. It stores water for supplying the people from the big cities on the coast and for extensive agriculture uses. Upper-middle part of the watershed covers 3564.8 km2. It ranges from 400 to 4188 masl in no more that 80 km, with slopes up to 20%. Main activities are agricultural and livestock and mining and about 80% of the population are rural. Annual mean temperature drops from 25.4 °C at the reservoir to less than 4 °C in the upper part. Also the highest rainfall variability is found in the upper-middle part of the watershed. Erosion produced by extreme events like 1997/98 "el Niño" Phenomenon is silting the reservoir faster than expected. Moreover, anthropogenic activities like agriculture and extensive mining in the upper part may be contributing to it. For this reason, the Jequetepeque watershed was the object of several studies from the government and NGOs. In particular, the "CESAH" study (WWF, CARE and IIED 2007) constitutes the first serious effort to model hydrological basin behavior. It includes a compilation of the data needed to run the SWAT model and an analysis of the first results. In this study, model is calibrated. Model version "ArcSWAT 2005" is used. A sensitivity analysis of terrain slope influence in HRU definition and model results is included. Results confirm the relevance of an accurate calibration process as well as the pertinence of including a fine description of slope variation in the modeling of Andean watersheds. Reference: WWF, CARE and IIED 2007. Compensación Equitativa por Servicios Ambientales Hidrológicos, "CESAH". Análisis biofísico (modelo SWAT). Cajamarca, Perú.

Yacoub, C.; Pérez-Foguet, A.

2009-04-01

251

A preliminary attempt to determine the landslide hazard in Italy  

NASA Astrophysics Data System (ADS)

Determining landslide hazard at the national scale remains a difficult task. However, such a complex task needs to be accomplished to mitigate the landslide consequences, including loss of lives and economic and environmental damages. For administrative purposes, the Italian territory (303,000 km sq.) is subdivided in 20 regions that cover a large variety of natural environments, most of which are subject to landslide hazards. To determine landslide hazard in such a complex and diversified territory, the many natural and anthropogenic variables, and their variations, must be considered. In Italy, the Italian national Civil Protection Department (DPC), an office of the Prime Minister, is in charge of managing natural and human-made hazards, and the associated risk. For landslide (and flood) hazards, the DPC has subdivided the Italian territory into 134 "alert zones" (AZ), decided based on administrative and hydrological criteria. Here, we describe the results of a preliminary effort made by our research group - in the framework of a larger effort to forecast landslide hazard and risk in Italy - to describe landslide hazard in each AZ. For the purpose, we summarized in a specifically designed form the geographical, morphological, geological and landslide information available for each AZ. The form also contains general information on past landslide events and on the vulnerability to landslides of the AZ. We obtained the morphological information from the SRTM DEM with a grid resolution of 90 m × 90 m, and the geological and lithological information from the Geological Map of Italy, at the 1:500,000 scale, published by the Italian Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA). We used the morphological (terrain elevation and terrain gradient) and the lithological information to subdivide the Italian territory in three main morphological domains (plains, hills and mountains), and we computed the proportion of the three domains in each AZ. We determined the type, abundance and distribution of landslides in each AZ heuristically, based on our experience aided by the critical evaluation of existing official documents and maps, including: (i) the maps produced by the national Inventory of Landslide Phenomena in Italy (IFFI), (ii) the maps associated to the geo-hydrological (landslide and flood) hazard plans (PAI), and (iii) other landslide maps prepared by our Institute (CNR IRPI) for parts of Italy. We obtained information on the damage to the population caused by landslides in Italy from a catalogue of historical landslides (and floods) with human consequences compiled by Salvati et al. (2010), and information on sinkholes failures from a catalogue of natural and human-induced sinkhole failures in Italy recently compiled by Parise & Vennari (2013). For each AZ, the dates of the most damaging events were identified, and the number of landslide fatalities, casualties and evacuated people were calculated. These figures provide a quantitative measure of the intensity of the landslide consequences in each AZ. The ensemble of the information collected provides a comprehensive - albeit preliminary - evaluation of the hazard posed by landslides in the Italian territory, and the basic data for proceeding to determine the related vulnerability. References Parise M. & Vennari C. (2013) A chronological catalogue of sinkholes in Italy: the first step toward a real evaluation of the sinkhole hazard. Proceedings 8th Multidisciplinary Conference on Sinkholes & the Engineering and Environmental Impacts of Karst, Carlsbad, USA. Salvati P., Bianchi C., Rossi M. & Guzzetti F. (2010) Societal landslide and flood risk in Italy. Natural Hazards Earth System Sciences 10: 465-483.

Parise, Mario

2013-04-01

252

The function of 'functional': a mixed methods investigation  

PubMed Central

Objective The term ‘functional’ has a distinguished history, embodying a number of physiological concepts, but has increasingly come to mean ‘hysterical’. The DSM-V working group proposes to use ‘functional’ as the official diagnostic term for medically unexplained neurological symptoms (currently known as ‘conversion disorder’). This study aimed to explore the current neurological meanings of the term and to understand its resilience. Design Mixed methods were used, first interviewing the neurologists in a large UK region and then surveying all neurologists in the UK on their use of the term. Results The interviews revealed four dominant uses—‘not organic’, a physical disability, a brain disorder and a psychiatric problem—as well as considerable ambiguity. Although there was much dissatisfaction with the term, the ambiguity was also seen as useful when engaging with patients. The survey confirmed these findings, with a majority adhering to a strict interpretation of ‘functional’ to mean only ‘not organic’, but a minority employing it to mean different things in different contexts - and endorsing the view that ‘functional’ would one day be a neurological construct again. Conclusions ‘Functional’ embodies real divisions in neurologists' conceptualisation of unexplained symptoms and, perhaps, between those of patients and neurologists: its diversity of meanings allows it to be a common term while meaning different things to different people, or at different times, and thus conceal some of the conflict in a particularly contentious area. This flexibility may help explain the term's longevity.

Armstrong, David; Wessely, Simon C

2012-01-01

253

Controle orbital de satélites artificiais com propulsão e uso de gravidade lunar  

NASA Astrophysics Data System (ADS)

A redução do custo de combustível de uma manobra é atualmente a grande prioridade de todos os programas espaciais existentes no mundo. As manobras assistidas pela gravidade são uma ótima forma de se contornar o problema pois proporcionam economias com vasto impacto no custo final da missão. Neste trabalho é feito um estudo particular do controle orbital de um satélite artificial da Terra usando a gravidade da Lua. O objetivo é estudar uma técnica econômica para uma mudança de plano de um satélite que está em órbita em volta da Terra. A idéia principal desta abordagem é enviar primeiramente o veículo espacial em direção à Lua usando uma manobra mono-impulsiva para que assim o campo gravitacional da Lua possa fazer a mudança de plano desejada (sem custo de combustível) e só então retornar o veículo aos valores iniciais de semi-eixo e excentricidade usando uma manobra bi-impulsiva tipo Hohmann. Para tanto, é assumido que a espaçonave inicia em uma órbita circular coplanar à órbita da lua em torno da Terra e a meta é colocá-la em uma órbita similar que difere da órbita inicial somente pela inclinação. São usadas equações analíticas baseadas na abordagem Patched Conics para se calcular a variação na velocidade, momento angular, energia e inclinação do veículo espacial que realiza esta manobra. Várias simulações são feitas para se avaliar as economias de combustível envolvidas.

Torres, K. S.; de Almeida Prado, A. F. B.

2003-08-01

254

La salud en personas con discapacidad intelectual en Espa?a: estudio europeo POMONA-II  

PubMed Central

Introducción Estudios internacionales demuestran que existe un patrón diferenciado de salud y una disparidad en la atención sanitaria entre personas con discapacidad intelectual (DI) y población general. Objetivo Obtener datos sobre el estado de salud de las personas con DI y compararlos con datos de población general. Pacientes y métodos Se utilizó el conjunto de indicadores de salud P15 en una muestra de 111 sujetos con DI. Los datos de salud encontrados se compararon según el tipo de residencia de los sujetos y se utilizó la Encuesta Nacional de Salud 2006 para comparar estos datos con los de la población general. Resultados La muestra con DI presentó 25 veces más casos de epilepsia y el doble de obesidad. Un 20% presentó dolor bucal, y existió una alta presencia de problemas sensoriales, de movilidad y psicosis. Sin embargo, encontramos una baja presencia de patologías como la diabetes, la hipertensión, la osteoartritis y la osteoporosis. También presentaron una menor participación en programas de prevención y promoción de la salud, un mayor número de ingresos hospitalarios y un uso menor de los servicios de urgencia. Conclusiones El patrón de salud de las personas con DI difiere del de la población general, y éstas realizan un uso distinto de los servicios sanitarios. Es importante el desarrollo de programas de promoción de salud y de formación profesional específicamente diseñados para la atención de personas con DI, así como la implementación de encuestas de salud que incluyan datos sobre esta población.

Martinez-Leal, Rafael; Salvador-Carulla, Luis; Gutierrez-Colosia, Mencia Ruiz; Nadal, Margarida; Novell-Alsina, Ramon; Martorell, Almudena; Gonzalez-Gordon, Rodrigo G.; Merida-Gutierrez, M. Reyes; Angel, Silvia; Milagrosa-Tejonero, Luisa; Rodriguez, Alicia; Garcia-Gutierrez, Juan C.; Perez-Vicente, Amado; Garcia-Ibanez, Jose; Aguilera-Ines, Francisco

2011-01-01

255

Análise dos Conceitos Astronômicos Apresentados por Professores de Algumas Escolas Estaduais Brasileiras  

NASA Astrophysics Data System (ADS)

A razão para o desenvolvimento deste trabalho baseia-se no fato de que muitos professores da Educação Básica (EB) não lidam com conceitos relacionados à astronomia, e quando o fazem eles simplesmente seguem livros didáticos que podem conter erros conceituais. Como é de conhecimento geral a astronomia é um dos conteúdos a serem ensinados na EB fazendo parte dos Parâmetros Curriculares Nacionais e das Propostas Curriculares do Estado de São Paulo, mas é um fato, que vários pesquisadores apontam, a existência de muitos problemas no ensino da astronomia. Com o propósito de minimizar algumas dessas deficiências foi realizado um trabalho de pesquisa com a utilização de questionários pré e pós pesquisa, para tanto foi desenvolvido um Curso de Extensão Universitária para professores da Diretoria de Ensino Regional (DE) que abrange Mauá, Ribeirão Pires e Rio Grande da Serra (no Estado de São Paulo) com os seguintes objetivos: levantar concepções alternativas; subsidiar os professores por meio de palestras, debates e workshops, e verificar o sucesso da aprendizagem após o curso, adotando-se como referência, para a análise dos resultados, os dicionários de Língua Portuguesa (FERREIRA, 2004) e Enciclopédico de Astronomia e Astronáutica (MOUR?O, 1995). Portanto, dezesseis questões foram aplicadas antes e após o curso, assim pode-se verificar após a pesquisa que 100,0% dos professores sabiam os nomes das fases da Lua, 97,0% entenderam que o Sistema Solar é composto por oito planetas, 78,1% foram capazes de explicar como ocorre um eclipse lunar, um eclipse solar e um solstício, 72,7% sabiam como explicar a ocorrência das estações do ano; 64,5% explicaram corretamente a ocorrência do equinócio, 89,7% foram capazes de definir adequadamente o termo cometa; 63,6% definiram asteróide, 54,5% meteoro, 58,1% galáxia, e 42,4% planeta. Os resultados obtidos indicam uma aprendizagem significativa por parte dos participantes.

Voelzke, Marcos Rincon; Gonzaga, Edson Pereira

2011-12-01

256

Projeto do sistema anti-ressonante da fiação dos transdutores para o detector Mario Schenberg  

NASA Astrophysics Data System (ADS)

O detector de ondas gravitacionais Mario Schenberg está sendo projetado e construído pelo grupo Gráviton. Sua construção está ocorrendo no Laboratório de Estado Sólido e Baixas Temperaturas (LESBT) da Universidade de São Paulo, na cidade de São Paulo. Esse detector possui uma massa ressonante esférica de cobre-alumínio, com 65 cm de diâmetro, pesando aproximadamente 1150 Kg, suspensa por um sistema de isolamento vibracional, que se encontra em fase de testes preliminares. A real eficácia desse sistema, entretanto, só poderá ser comprovada quando o detector estiver aparelhado com, pelo menos, um transdutor eletromecânico de altíssima sensibilidade acoplado à massa ressonante. Neste momento, não só este sistema de isolamento vibracional será posto em teste, como o do projeto da fiação que transporta os sinais de microondas até os transdutores e destes para a pré-amplificação. Apesar dessa fiação ter sido projetada para não apresentar nenhum contato com a superfície esférica da antena, de maneira a não haver nenhuma transmissão de ruído vibracional do laboratório para esta, deve-se minimizar o ruído microfônico produzido nessa fiação por oscilações mecânicas, uma vez que ela não utiliza nenhum sistema de isolamento vibracional. Com o intuito de resolver este problema, projetamos uma estrutura, formada por pequenos cilindros conectados por barras, a qual não terá nenhuma ressonância mecânica na faixa de freqüências de interesse para detecção (3000 - 3400 Hz). Desta forma, as vibrações nessa faixa não serão amplificadas. O projeto foi feito usando iterativamente, de maneira a otimizar os resultados obtidos, o programa de elementos finitos Msc/Nastran. Através de simulações feitas neste programa, determinamos os parâmetros geométricos ideais a serem utilizados, os quais proporcionam a maior região espectral de interesse livre de ressonâncias.

Vieira, S. J.., Jr.; Melo, J. L.

2003-08-01

257

Composite endpoints in clinical trials.  

PubMed

Composite endpoints are often used in clinical trials, especially in the cardiovascular area. Decreases in sample size requirements, ability to assess the net effect of an intervention and to avoid bias in presence of competing risks are the most cited advantages for their use. However, there is a risk of misinterpretation when heterogeneity among components with respect to either importance, number of events, or magnitude of treatment effect exist. In the following review we present a conceptual discussion about the rationale and interpretation of such variables. Also, a user's friendly guide to interpret the results of clinical trials based on composite endpoints is presented. We also present an empirical study that provides evidence of the use of misleading composite endpoints in cardiovascular clinical trials. Las variables de resultado combinadas en los ensayos clinicos son un recurso metodologico usado con frecuencia, especialmente en los estudios cardiovasculares. Las motivaciones más importantes para su utilizacion son aumentar la potencia estadística del estudio, valorar el beneficio neto de una intervencion y evitar una interpretacion errónea del resultado en presencia de riesgos competitivos. Sin embargo, su interpretación puede ser problemática si hay heterogeneidad entre los componentes en cuanto a su importancia, la frecuencia de eventos o el efecto de la intervencion. En la discusión que sigue se presenta un revisión conceptual de los problemas del uso y la interpretación de las variables de resultado combinadas en ensayos clinicos, especialmente los cardiovasculares. Se presenta además una sencilla guia de interpretacion de los resultados de los estudios que utilizan variables de resultado combinadas a partir de la cual se puede valorar nuestra confianza en dichos resultados. Finalmente, se presenta un estudio empírico sobre cuál ha sido el uso real de variables de resultado combinadas potencialmente problemáticas en ensayos clinicos cardiovasculares. PMID:24775785

Ferreira-González, Ignacio; Alonso-Coello, Pablo; Solà, Ivan; Pacheco-Huergo, Valeria; Domingo-Salvany, Antónia; Alonso, Jordi; Montori, Víctor; Permanyer-Miralda, Gaietá

2008-01-01

258

Uvby-B Photometry of High Velocity Stars. Photometric Parallaxes and Preliminary Kinematic Results  

NASA Astrophysics Data System (ADS)

RESUMEN. Se han explorado dos metodos para la determinaci6n de paralajes fotometricos usando fotometrfa uv - . Estos metodos dependen de las relaciones estandar de Crawford (1975) y de Olsen (1984) y de colores y magnitudes sinteticas de VandenBerg y Bell (1985). Ambos metodos incluyen una correcci6n evolucionaria de forma f6c0. Se calculan las distancias para las 711 estrellas de alta velocidad y pobres en metales en el catalogo uvby-p de Schuster y Nissen (1988). Se comparan estas con las distancias de Sandage y Fouts (1987) y Laird, Carney y Latham (1988) para las estrellas en comtfin. Tambien son aplicables nuestros metodos a estrellas de paralaje. En general las comparaciones son satisfactorias y las sistematicas son despreciables o pequefias. Las distancias finales de nuestras 711 estrellas se aplican a un numero de problemas cinematicos. Se estudian algunos diagramas interesantes, tales como el diagrama de energia de Toomre y el diagrama V(rot) versus [Fe/H]. ABSTRACT Two methods for the determination of parallaxes using uvbyP photometry are being explored. These methods depend upon the standard relations of Crawford (1975) and of Olsen (1984) and upon synthetic colors and magnitudes of VandenBerg and Bell (1985). Both include an evolutionary correction of the form f6c0. Distances are calculated for the 711 high-velocity and metal-poor stars in the uvby-P catalogue of Schuster and Nissen (1988). These are compared to the distances of Sandage and Fouts (1987) and Laird, Carney, and Lathain (1988) for stars in common. Also our methods are applied to parallax stars. In general the comparisons are good with negligible or small systematic differences. The final distances of our 711 stars are applied to a number of kinematical problems. Several interesting diagrams are studied, sucl as Toomre energy diagram and the plot of V(rot) versus [Fe/H]. Key words: DISTANCES - PHOTOMETRY - STARS-POPULATION II

Schuster, W. J.

1990-11-01

259

Six Common Mistakes in Conservation Priority Setting  

PubMed Central

Abstract A vast number of prioritization schemes have been developed to help conservation navigate tough decisions about the allocation of finite resources. However, the application of quantitative approaches to setting priorities in conservation frequently includes mistakes that can undermine their authors’ intention to be more rigorous and scientific in the way priorities are established and resources allocated. Drawing on well-established principles of decision science, we highlight 6 mistakes commonly associated with setting priorities for conservation: not acknowledging conservation plans are prioritizations; trying to solve an ill-defined problem; not prioritizing actions; arbitrariness; hidden value judgments; and not acknowledging risk of failure. We explain these mistakes and offer a path to help conservation planners avoid making the same mistakes in future prioritizations. Seis Errores Comunes en la Definición de Prioridades de Conservación Resumen Se ha desarrollado un vasto número de esquemas de priorización para ayudar a que la conservación navegue entre decisiones difíciles en cuanto a la asignación de recursos finitos. Sin embargo, la aplicación de métodos cuantitativos para la definición de prioridades en la conservación frecuentemente incluye errores que pueden socavar la intención de sus autores de ser más rigurosos y científicos en la manera en que se establecen las prioridades y se asignan los recursos. Con base en los bien establecidos principios de la ciencia de la decisión, resaltamos seis errores comúnmente asociados con la definición de prioridades para la conservación: no reconocer que los planes de conservación son priorizaciones; tratar de resolver un problema mal definido; no priorizar acciones; arbitrariedad; juicios de valor ocultos y no reconocer el riesgo de fracasar. Explicamos estos errores y ofrecemos un camino para que planificadores de la conservación no cometan los mismos errores en priorizaciones futuras.

Game, Edward T; Kareiva, Peter; Possingham, Hugh P

2013-01-01

260

DIABETES MELLITUS COMO FACTOR DE RIESGO DE DEMENCIA EN LA POBLACI?N ADULTA MAYOR MEXICANA  

PubMed Central

Introduccion La diabetes mellitus y las demencias constituyen dos problemas crecientes de salud entre la población adulta mayor del mundo y en particular de los paises en desarrollo. Hacen falta estudios longitudinales sobre el papel de la diabetes como factor de riesgo para demencia. Objetivo Determinar el riesgo de demencia en sujetos Mexicanos con diabetes mellitus tipo 2. Materiales y Metodos Los sujetos diabéticos libres de demencia pertenecientes al Estudio Nacional de Salud y Envejecimiento en México fueron evaluados a los dos años de la línea de base. Se estudió el papel de los factores sociodemográficos, de otras comorbilidades y del tipo de tratamiento en la conversión a demencia. Resultados Durante la línea de base 749 sujetos (13.8%) tuvieron diabetes. El riesgo de desarrollar demencia en estos individuos fue el doble (RR, 2.08 IC 95%, 1.59–2.73). Se encontró un riesgo mayor en individuos de 80 años y más (RR 2.44 IC 95%, 1.46–4.08), en los hombres (RR, 2.25 IC 95%, 1.46–3.49) y en sujetos con nivel educativo menor de 7 años. El estar bajo tratamiento con insulina incrementó el riesgo de demencia (RR, 2.83, IC 95%, 1.58–5.06). Las otras comorbilidades que aumentaron el riesgo de demencia en los pacientes diabéticos fueron la hipertensión (RR, 2.75, IC 95%, 1.86–4.06) y la depresión (RR, 3.78, 95% IC 2.37–6.04). Conclusión Los sujetos con diabetes mellitus tienen un riesgo mayor de desarrollar demencia, La baja escolaridad y otras comorbilidades altamente prevalentes en la población Mexicana contribuyen a la asociación diabetes-demencia.

Silvia, Mejia-Arango; Clemente, y Zuniga-Gil

2012-01-01

261

Estudo espectral em raios-X duros de fontes do tipo Z com o HEXTE/RXTE  

NASA Astrophysics Data System (ADS)

Apresentam-se os resultados de um estudo espectral em raios-X de fontes do tipo Z. As fontes do tipo Z são binárias de raios-X de baixa massa (BXBM) com campo magnético intermediário (B~109G). Esta classe de fontes é composta por apenas 6 fontes Galácticas (a saber: ScoX-1, 9, 7, CygX-2, 5 e 0). A nossa análise se concentra na faixa de raios-X duros (E ~ 20keV), até cerca de 200keV, faixa ótima de operação do telescópio "High Energy X-ray Timing Experiment" (HEXTE), um dos três telescópios de raios-X à bordo do Rossi X-ray Timing Explorer (RXTE). Nossa motivação para tal estudo, uma busca de caudas em raios-X duros em fontes do tipo Z, foi o pouco conhecimento sobre a emissão nesta faixa de energia das referidas fontes quando comparadas, por exemplo, as fontes do tipo atoll (também BXBM). Apresentam-se a análise/redução de dados e explicita-se a maneira como o HEXTE mede o ru1do de fundo. Especial atenção é direcionada a este item devido a localização das fontes do tipo Z e também ao problema de contaminação por fontes próximas. Com exceção de ScoX-1, nenhuma cauda em raios-X duros foi encontrada para as outras fontes, a despeito de resultados de detecção dessas caudas em algumas fontes pelo satélite BeppoSAX. As interpretações deste resultado serão apresentadas. Do ponto de vista deste estudo, nós deduzimos que a produção de caudas de raios-X duros em fontes do tipo Z é um processo disparado quando, pelo menos, uma condição é satisfeita: o brilho da componente térmica do espectro precisa estar acima de um certo valor limiar de ~4´1036ergs-1.

D'Amico, F.; Heindl, W. A.; Rothschild, R. E.

2003-08-01

262

 

PubMed

O método Grade of Membership (GoM) tem sido cada vez mais utilizado por demógrafos brasileiros e tem a vantagem de possuir um parâmetro que mensura a heterogeneidade individual, com base nas correlações não-observáveis entre as categorias de resposta das variáveis de interesse, gerando um medida do grau de pertencimento de cada indivíduo a perfis extremos. Alguns autores, contudo, chamam atenção para questões importantes na calibragem dos modelos finais que utilizam o programa GoM versão 3.4, como o problema de identificabilidade - soluções múltiplas para parâmetros estimados. Neste artigo, é sugerido um procedimento capaz de identificar um modelo final com solução única que descreva os tipos puros mais fidedignos à base de dados, em uma tentativa de otimização. Para ilustrar esse processo, utilizou-se uma base de dados correspondente a um levantamento econômico e sociodemográfico de uma população de pequenos agricultores residentes ao longo da Rodovia Transamazônica, no Estado do Pará. Também identificou-se a existência de instabilidade nos parâmetros estimados pelo programa GoM 3.4, sendo proposto um método de estabilização de seus valores. Com esses procedimentos combinados, os usuários do programa GoM 3.4 poderão descrever sua base de dados de forma mais adequada e responder às críticas sobre questões de identificabilidade e estabilidade dos modelos resultantes. Essas soluções empíricas são relevantes por afetarem cálculos de prevalência e de incidência de eventos de interesse, além de trazerem consequências importantes sobre o ponto e o momento corretos para intervenções de políticas públicas ou de planejamento prospectivo em análises de projeção. PMID:21709732

Guedes, Gilvan Ramalho; Caetano, André Junqueira; Machado, Carla Jorge; Brondízio, Eduardo Sonewend

2010-01-01

263

Um supressor de fundo térmico para a câmara infravermelha CamIV  

NASA Astrophysics Data System (ADS)

O ângulo sólido subtendido pelos pixels na câmara infravermelha do NexGal (CamIV) que operamos no OPD/LNA contém contribuições provenientes do sistema de coleta de fluxo propriamente dito - sendo esta a parte que interessa para as medidas astronômicas - e contribuições da obstrução central, sistema de suporte do espelho secundário e região exterior à pupila de entrada do telescópio. Estas últimas contribuições são devi-das à emissão de corpo negro à temperatura ambiente e aumentam exponencialmente para comprimentos de onda maiores que 2 micra (banda K, no infravermelho próximo). Embora a resultante pode ser quantificada e subtraída dos sinais relevantes, sua variância se adiciona à variância do sinal, e pode ser facilmente a contribuição domi-nante para a incerteza final das medidas, tornando ineficiente o processo de extração de informação e degradando a sensibilidade da câmara. A maneira clássica de resolver esse problema em sistemas ópticos que operam no infravermelho, onde os efeitos da emissão térmica do ambiente são importantes, é restringir o ângulo sólido subtendido pelos pixels individuais exclusivamente aos raios provenientes do sistema óptico. Para tanto, projeta-se uma imagem real, bastante reduzida, da pupila de entrada do sistema óptico num anteparo que transmita para o sistema de imageamento só o que interessa, bloqueando as contribuições das bordas externas à pupila de entrada, obstrução central do telescópio e sistema de suporte. Como a projeção é realizada em ambiente criogênico, a contribuição térmica espúria é efetivamente eliminada. Nós optamos por um sistema do tipo Offner para implementar na prática esta função. Trata-se de um sistema baseado em espelhos esféricos, bastante compacto e ajustado por construção. A opção por espelhos do mesmo material que o sistema de suporte (Alumínio) minimiza a dilatação diferencial, crítica nesse tipo de aplicação. Apresentamos as soluções detalhadas do projeto óptico-mecânico, bem como uma análise de flexões e desempenho em termos de qualidade de imagem.

Jablonski, F.; Laporte, R.

2003-08-01

264

Using online database for landslide susceptibility assessment with an example from the Veneto Region (north-eastern Italy).  

NASA Astrophysics Data System (ADS)

Landslide susceptibility maps describe landslide-prone areas by the spatial correlation between landslides and related factors, derived from different kinds of datasets: geological, geotechnical and geomechanical maps, hydrogeological maps, landslides maps, vector and raster terrain data, real-time inclinometer and pore pressure data. In the last decade, thanks to the increasing use of web-based tools for management, sharing and communication of territorial information, many Web-based Geographical Information Systems (WebGIS) were created by local governments or nations, University and Research Centres. Nowadays there is a strong proliferation of geological WebGIS or GeoBrowser, allowing free download of spatial information. There are global Cartographical Portals that provide a free download of DTM and other vector data related to the whole planet (http://www.webgis.com). At major scale, there are WebGIS regarding entire nation (http://www.agiweb.org), or specific region of a country (http://www.mrt.tas.gov.au), or single municipality (http://sitn.ne.ch/). Moreover, portals managed by local government and academic government (http://turtle.ags.gov.ab.ca/Peace_River/Site/) or by a private agency (http://www.bbt-se.com) are noteworthy. In Italy, the first national projects for the creation of WebGIS and web-based databases begun during the 1980s, and evolved, through years, to the present number of different WebGIS, which have different territorial extensions: national (Italian National Cartographical Portal, http://www.pcn.minambiente.it; E-GEO Project, http://www.egeo.unisi.it), interregional (River Tiber Basin Authority, www.abtevere.it ), and regional (Veneto Region, www.regione.veneto.it). In this way we investigated most of the Italian WebGIS in order to verify their geographic range and the availability and quality of data useful for landslide hazard analyses. We noticed a large variability of the accessing information among the different browsers. In particular, the Trento and Bolzano Provinces Geobrowsers (http://www.provincia.bz.it; http://www.territorio.provincia.tn.it) provide a large availability of data respect to the other regional and interregional WebGIS, which generally allow only the download of topographic data. Recently, the Italian Institute for Environmental Protection and Research, ISPRA (Istituto Superiore per la Protezione e la ricerca Ambientale), makes available and free usable the Italian Inventory of Landslides (IFFI Project). The inventory contains information derived from the census of all the instability phenomena in Italy, offering a base-cognitive instrument for the landslide hazard evaluation. For the landslide hazard assessment it is essential to evaluate the real effectiveness of the available data. Hence, we test the effectiveness of the web databases to evaluate the landslides susceptibility in the Euganean Hill Regional Park (185.5 km2), located at SE of Padua (Veneto Region, Italy). We used data available from three online spatial databases: Veneto Region Cartographic Portal (http://www.regione.veneto.it), for vector terrain data at 1:5000 scale; the IFFI archive (http://www.sinanet.apat.it), for information concerning landslides; and the National Cartographic Portal of the Italian Ministry of Environment (http://www.pcn.minambiente.it), for the multi-temporal orthophotos. The landslide susceptibility was evaluated using a simple probabilistic analysis considering the relationships between landslides and DEM-derived factors, such as slope, curvature and aspect. For the validation of the analysis, we made a spatial test by subdividing the study area in two sectors: training area and test area. The obtained results show that the actual no-completeness of online available spatial databases related to the Veneto Region allows only regional and medium scale (>1:25,000) susceptibility analysis. Data about lithology, land use, groundwater and others relevant factors are absent. In addition, the lack of data on the temporal evolution of the landslides permits only a spatial analysis,

Floris, Mario; Squarzoni, Cristina; Zorzi, Luca; D'Alpaos, Andrea; Iafelice, Maria

2010-05-01

265

Modeling and efficient optimization for object-based scalability and some related problems.  

PubMed

MPEG-4 is the first visual coding standard that allows coding of scenes as a collection of individual audio-visual objects. We present mathematical formulations for modeling object-based scalability and some functionalities that it brings with it. Our goal is to study algorithms that aid in semi-automating the authoring and subsequent selective addition/dropping of objects from a scene to provide content scalability. We start with a simplistic model for object-based scalability using the "knapsack problem"--a problem for which the optimal object set can be found using known schemes such as dynamic programming, the branch and bound method and approximation algorithms. The above formulation is then generalized to model authoring or multiplexing of scalable objects (e.g., objects encoded at various target bit-rates) using the "multiple choice knapsack problem." We relate this model to several problems that arise in video coding, the most prominent of these being the bit allocation problem. Unlike previous approaches to solve the operational bit allocation problem using Lagrangean relaxation, we discuss an algorithm that solves linear programming (LP) relaxation of this problem. We show that for this problem the duality gap for Lagrange and LP relaxations is exactly the same. The LP relaxation is solved using strong duality with dual descent--a procedure that can be completed in "linear" time. We show that there can be at most two fractional variables in the optimal primal solution and therefore this relaxation can be justified for many practical applications. This work reduces problem complexity, guarantees similar performance, is slightly more generic, and provides an alternate LP-duality based proof for earlier work by Shoham and Gersho (1988). In addition, we show how additional constraints may be added to impose inter-dependencies among objects in a presentation and discuss how object aggregation can be exploited in reducing problem complexity. The marginal analysis approach of Fox (1966) is suggested as a method of re-allocation with incremental inputs. It helps in efficiently re-optimizing the allocation when a system has user interactivity, appearing or disappearing objects, time driven events, etc. Finally, we suggest that approximation algorithms for the multiple choice knapsack problem, which can be used to quantify complexity vs. quality tradeoff at the encoder in a tunable and universal way. PMID:18262907

Batra, P

2000-01-01

266

Quaternary Aquifer of the North China Plain-assessing and achieving groundwater resource sustainability  

NASA Astrophysics Data System (ADS)

The Quaternary Aquifer of the North China Plain is one of the world's largest aquifer systems and supports an enormous exploitation of groundwater, which has reaped large socio-economic benefits in terms of grain production, farming employment and rural poverty alleviation, together with urban and industrial water-supply provision. Both population and economic activity have grown markedly in the past 25 years. Much of this has been heavily dependent upon groundwater resource development, which has encountered increasing difficulties in recent years primarily as a result of aquifer depletion and related phenomena. This paper focuses upon the hydrogeologic and socio-economic diagnosis of these groundwater resource issues, and identifies strategies to improve groundwater resource sustainability. L'aquifère Quaternaire de la Plaine du Nord de la Chine est l'un des plus grands systèmes aquifères du monde; il permet une exploitation énorme d'eau souterraine, qui a permis des très importants bénéfices socio-économiques en terme de production de céréales, d'emplois ruraux et de réduction de la pauvreté rurale, en même temps que l'approvisionnement en eau potable et pour l'industrie. La population comme l'activité économique ont remarquablement augmenté au cours de ces 25 dernières années. Elles ont été sous la forte dépendance du développement de la ressource en eau souterraine, qui a rencontré des difficultés croissantes ces dernières années, du fait du rabattement de l'aquifère et des phénomènes associés. Cet article est consacré aux diagnostiques hydrogéologique et socio-économique des retombées de cette ressource en eau souterraine; il identifie les stratégies pour améliorer la pérennité des ressources en eau souterraine. El acuífero cuaternario de la Llanura Septentrional de China es uno de los mayores sistemas acuíferos del mundo y soporta una enorme explotación de su agua subterránea, las cuales han originado grandes beneficios socioeconómicos en términos de producción de grano, empleo en agricultura y mitigación de la pobreza rural, además de proveer agua para abastecimiento urbano e industria. Tanto la población como la actividad económica han crecido mucho en los últimos 25 años con una gran dependencia de las aguas subterráneas, que ha encontrado dificultades recientes por la explotación intensiva del acuífero y fenómenos relacionados. Este artículo se centra en la diagnosis hidrogeológica y socioeconómica de los problemas relacionados con las aguas subterráneas e identifica estrategias para mejorar la sustentabilidad de este recurco.

Foster, Stephen; Garduno, Hector; Evans, Richard; Olson, Doug; Tian, Yuan; Zhang, Weizhen; Han, Zaisheng

267

P-adic model of transport in porous disordered media  

NASA Astrophysics Data System (ADS)

The soil porosity and permeability are the most important quantitative indicators of soil dynamics under the land-use change. The main problema in the modeling of this dynamic is still poor correlation between the real measuring data and the mathematical and computer simulation models. In order to overpassed this deep divorce we have designed a new technique, able to compare the data arised from the multiscale image analices and time series of the basic physical properties dynamics in porous media studied in time and space. We present a model of the diffusion reaction type describing transport in disordered porous media, e.g., water or oil flow in a complex network of pores. Our model is based on p-adic representation of such networks. This is a kind of fractal representation. We explore advantages of p- adic representation, namely, the possibility to endow p-adic trees with an algebraic structure and ultrametric topology and, hence, to apply analysis which have (at least some) similarities with ordinary real analysis on the straight line. We present the system of two diffusion reaction equations describing propagation of particles in networks of pores in disordered media. As an application, one can consider water transport through the soil pore Networks, or oil flow through capillaries nets. Under some restrictions on potentials and rate coefficients we found the stationary regime corresponding to water content or concentration of oil in a cluster of capillaries. Usage of p-adic analysis (in particular, p-adic wavelets) gives a possibility to find the stationary solution in the analytic form which makes possible to present a clear pedological or geological picture of the process. The mathematical model elaborated in this paper (Khrennikov, 2013) can be applied to variety of problems from water concentration in aquifers to the problem of formation of oil reservoirs in disordered media with porous structures. Another possible application may have real practical output. In fact, our system of diffusion-reaction equations can be used to model the process of extraction of water or oil from an extended network of capillaries (Khrennikov et al., 2013). The accomplished analyses show that the time series of water content/pressure dynamics in saturated/unsaturated conditions reflect the fractal structure of pores separated by familias base don the seven geometric descriptors which we used for the soils multiscale images (Oleschko et al., 2012). The similar models were applied to the porous media behind the oil flow from wells. These results motivate usage of the fractal and, in particular, p-adic methods of modeling.

Khrennikov, Adrei Yu.; Oleschko, Klaudia

2014-05-01

268

A emissão em 8mm e as bandas de Merrill-Sanford em estrelas carbonadas  

NASA Astrophysics Data System (ADS)

Estrelas carbonadas possuem bandas moleculares em absorção no visível e, no infravermelho (IR) as principais características espectrais se devem a emissão de grãos. Recentemente foi detectada a presença de bandas de SiC2 (Merrill-Sanford, MS) em emissão sendo atribuída à presença de um disco rico em poeira. Neste trabalho analisamos uma amostra de 14 estrelas carbonadas, observadas no telescópio de 1.52 m do ESO em 4 regiões espectrais diferentes, a fim de detectar as bandas de MS em emissão. Nossa amostra é composta de estrelas que apresentam além da emissão em 11.3 mm, outra em 8 mm. Esta última emissão, não usual nestes objetos, tem sido atribuída ou a moléculas de C2H2, ou a um composto sólido ainda indefinido. A detecção de emissões de MS e aquelas no IR, simultaneamente, revelaria um cenário mais complexo que o habitualmente esperado para os ventos destes objetos. No entanto como primeiro resultado, verificamos que as bandas de Merrill-Sanford encontram-se em absorção, não revelando nenhuma conexão com a emissão a 8 mm. Assim, temos duas hipóteses: (a) a emissão a 8 mm se deve à molécula C2H2 ou (b) essa emissão é resultado da emissão térmica de grãos. Testamos a segunda hipótese modelando a amostra com grãos não-homogêneos de SiC e quartzo, o qual emite em aproximadamente 8mm. Este grão seria produzido em uma fase evolutiva anterior a das carbonadas (estrelas S) e por terem uma estrutura cristalina são destruídos apenas na presença de campos de radiação ultravioleta muito intensos. Os modelos para os envoltórios utilizam o método de Monte Carlo para descrever o problema do transporte da radiação. As conclusões deste trabalho são: (1) as bandas de Merrill-Sanford se encontram em absorção, sugerindo um cenário usual para os ventos das estrelas da amostra; (2) neste cenário, a emissão em 8 mm seria resultado de grãos de quartzo com mantos de SiC, indicando que o quartzo poderia sobreviver a fase evolutiva S.

de Mello, A. B.; Lorenz-Martins, S.

2003-08-01

269

Femtosecond magnetism and spin manipulation on a time-scale of the exchange interaction  

NASA Astrophysics Data System (ADS)

The dynamics of phase transformations on the time-scale pertinent to atomic, orbital and spin motion is a rather unexplored field in physics. This is also a particularly interesting problem of modern magnetism, a study of which may have tremendous consequences for future development of magnetic recording technology. However, generation of magnetic field pulses much shorter than 100 ps and strong enough to reverse magnetization (more than 1T) is an extremely challenging technical problem.As a result the dynamics of the magnetic phase transitions at the sub-100 ps time-scale remains to be one of the most intriguing areas of modern magnetism [1,2]. Recently it has been observed that a 40 fs laser pulse influences spins in a magnet as an equally short pulse of effective magnetic field with a strength up to 20 T [3,4]. In my talk I will discuss how these opto-magnetic pulses can be used to excite a magnet on a time-scale of the exchange interaction between the spins [5-7]. Novel insights into the physics of non-equilibrium magnetism will be provided, showing that two exchange-coupled magnetic sublattices of a ferrimagnet may have totally different spin dynamics [8]. As a result, ultrafast spin reversal of two antiferromagnetically coupled magnetic sub-lattices appears to proceed via a novel ferromagnet-like transient state. [4pt] [1] J. St"ohr and H. C. Siegmann, Magnetism: from fundamentals to nanoscale dynamics (Springer, Berlin, 2006). [0pt] [2] A. Kirilyuk, A. V. Kimel, Th. Rasing, Rev. Mod. Phys. 82 2731 (2010). [0pt] [3] A. V. Kimel et al, Nature 435 655 (2005) [0pt] [4] C. D. Stanciu et al, Phys. Rev. Lett. 99, 047601 (2007). [0pt] [5] K. Vahaplar et al Phys. Rev. Lett. 103, 117201 (2009). [0pt] [6] A.V. Kimel et al, Nature-Physics 5 727 (2009). [0pt] [7] A. H. M. Reid et al Phys. Rev. Lett.105 107402 (2010). [0pt] [8] I. Radu et al (submitted).

Kimel, Alexey

2011-03-01

270

On matrix diffusion: formulations, solution methods and qualitative effects  

NASA Astrophysics Data System (ADS)

Matrix diffusion has become widely recognized as an important transport mechanism. Unfortunately, accounting for matrix diffusion complicates solute-transport simulations. This problem has led to simplified formulations, partly motivated by the solution method. As a result, some confusion has been generated about how to properly pose the problem. One of the objectives of this work is to find some unity among existing formulations and solution methods. In doing so, some asymptotic properties of matrix diffusion are derived. Specifically, early-time behavior (short tests) depends only on ?m2RmDm / Lm2, whereas late-time behavior (long tracer tests) depends only on ?mRm, and not on matrix diffusion coefficient or block size and shape. The latter is always true for mean arrival time. These properties help in: (a) analyzing the qualitative behavior of matrix diffusion; (b) explaining one paradox of solute transport through fractured rocks (the apparent dependence of porosity on travel time); (c) discriminating between matrix diffusion and other problems (such as kinetic sorption or heterogeneity); and (d) describing identifiability problems and ways to overcome them. RésuméLa diffusion matricielle est un phénomène reconnu maintenant comme un mécanisme de transport important. Malheureusement, la prise en compte de la diffusion matricielle complique la simulation du transport de soluté. Ce problème a conduit à des formulations simplifiées, en partie à cause de la méthode de résolution. Il s'en est suivi une certaine confusion sur la façon de poser correctement le problème. L'un des objectifs de ce travail est de trouver une certaine unité parmi les formulations et les méthodes de résolution. C'est ainsi que certaines propriétés asymptotiques de la diffusion matricielle ont été dérivées. En particulier, le comportement à l'origine (expériences de traçage courtes) dépend uniquement du terme ?m2RmDm / Lm2, alors que le comportement à long terme (traçages de longue durée) ne dépend que de ?mRm, et non pas du coefficient de diffusion matricielle ou de la forme et de la taille des blocs. Ceci est toujours vrai pour le temps moyen d'arrivée. Ces propriétés permettent: (a) d'analyser le comportement de la diffusion matricielle; (b) d'expliquer un paradoxe du transport de soluté dans les roches fracturées (la dépendance apparente entre la porosité et le temps de transit); (c) de faire la distinction entre la diffusion matricielle et d'autres problèmes, tels que la sorption cinétique ou l'hétérogénéité et (d) de décrire les problèmes d'identification et les façons de les résoudre. Resumen La difusión en la matriz está reconocida en la actualidad como un importante mecanismo de transporte de solutos. Desgraciadamente, tener en cuenta este proceso complica las simulaciones de transporte. Esto ha llevado a una serie de formulaciones simplificadas, motivadas en parte por el propio método de solución. Como resultado, se ha producido cierta confusión respecto a cuál es la manera adecuada de formular el problema. Uno de los objetivos de este trabajo es encontrar una cierta unidad entre las formulaciones existentes y los métodos de solución, lo que conduce a algunas propiedades asintóticas de la difusión en la matriz; específicamente, se comprueba que el comportamiento para tiempos cortos depende únicamente del parámetro ?m2RmDm / Lm2, mientras que el de tiempos largos depende sólo de ?mRm, y no del coeficiente de difusión en la matriz o del tamaño o forma del bloque. Esto último también es cierto, en todos los casos, respecto al tiempo medio de llegada (definido como el valor esperado de la distribución de tiempos de llegada). Estas propiedades son útiles para: (a) analizar el comportamiento cualitativo de la difusión en la matriz; (b) explicar una de las paradojas del transporte de solutos en medios fracturados, la aparente dependencia entre porosidad y tiempo de llegada; (c) discriminar entre difusión en la matriz y otros problemas, como las reacciones con cinética

Carrera, Jesús; Sánchez-Vila, Xavier; Benet, Inmaculada; Medina, Agustín; Galarza, Germán; Guimerà, Jordi

271

Approaches to optimal aquifer management and intelligent control in a multiresolutional decision support system  

NASA Astrophysics Data System (ADS)

Despite remarkable new developments in stochastic hydrology and adaptations of advanced methods from operations research, stochastic control, and artificial intelligence, solutions of complex real-world problems in hydrogeology have been quite limited. The main reason is the ultimate reliance on first-principle models that lead to complex, distributed-parameter partial differential equations (PDE) on a given scale. While the addition of uncertainty, and hence, stochasticity or randomness has increased insight and highlighted important relationships between uncertainty, reliability, risk, and their effect on the cost function, it has also (a) introduced additional complexity that results in prohibitive computer power even for just a single uncertain/random parameter; and (b) led to the recognition in our inability to assess the full uncertainty even when including all uncertain parameters. A paradigm shift is introduced: an adaptation of new methods of intelligent control that will relax the dependency on rigid, computer-intensive, stochastic PDE, and will shift the emphasis to a goal-oriented, flexible, adaptive, multiresolutional decision support system (MRDS) with strong unsupervised learning (oriented towards anticipation rather than prediction) and highly efficient optimization capability, which could provide the needed solutions of real-world aquifer management problems. The article highlights the links between past developments and future optimization/planning/control of hydrogeologic systems. Malgré de remarquables nouveaux développements en hydrologie stochastique ainsi que de remarquables adaptations de méthodes avancées pour les opérations de recherche, le contrôle stochastique, et l'intelligence artificielle, solutions pour les problèmes complexes en hydrogéologie sont restées assez limitées. La principale raison est l'ultime confiance en les modèles qui conduisent à des équations partielles complexes aux paramètres distribués (PDE) à une échelle donnée. Alors que l'accumulation d'incertitudes et, par conséquent, la stockasticité ou l'aléat a augmenté la perspicacité et amis en lumière d'importantes relations entre l'incertitude, la fiabilité, le risque, et leur effet sur les coûts de fonctionnement, il a également (a) introduit une complexité additionnelle qui résulte dans un pouvoir prohibitif des moyens de calcul informatique même pour une simple estimation de l'incertitude; et (b) a conduita une reconnaissance de notre manque d'aptitude à maîtriser l'incertitude totale même en introduisant tous les paramètres connus de l'incertitude. La représentation du changement est introduit: une adaptation de nouvelles méthodes de contrôle intelligent qui va relâcher la dépendance à la rigidité des algorithmes, aux calculs informatiques intensifs, à la PDE stockastique, et qui modifiera l'emphase entre les MRDS—systèmes interactifs d'aide à la décision de multiresolutionelle (flexibles, adaptables et orientables selon les objectifs)—avec un fort apprentissage non (orienté vers l'anticipation plutôt que la prédiction), et une capacité d'optimisation efficiente très élevée, qui pourrait apporter le besoin de solutions pour la modélisation des problèmes de management des aquifères réalistes. Cet article met en lumière les liens entre les développements passés et les futurs moyens d'optimisation, de gestion et de contrôle des systèmes hydrogéologiques. A pesar de nuevos avances notables en hidrología estocástica y las adaptaciones de métodos avanzados de investigación de operaciones, control estocástico, e inteligencia artificial, las soluciones de problemas complejos del mundo real en hidrogeología han sido bastante limitadas. La principal razón es la dependencia definitiva en modelos de primer-principio que conducen a ecuaciones parciales diferencias de parámetro distribuido complejas (PDE) a una escala dada. Mientras que la adición de incertidumbre, y por lo tanto, estocasticidad o aleatoriedad ha incrementado la profundidad y resaltado relacion

Orr, Shlomo; Meystel, Alexander M.

2005-03-01

272

Production and quality assurance in the SIT Africa Mediterranean fruit fly (Diptera: Tephritidae) rearing facility in South Africa  

SciTech Connect

A mass-rearing facility for Mediterranean fruit fly Ceratitis capitata (Wiedemann) was commissioned in Stellenbosch in 1999 to produce sterile male fruit flies for a sterile insect technique (SIT) project in commercial fruit orchards and vineyards in the Western Cape province of South Africa. The mass-rearing procedure was largely based on systems developed by the FAO/IAEA Agriculture and Biotechnology Laboratory, Seibersdorf, Austria. A number of genetic sexing strains were used to produce only males for release. Initial cramped rearing and quality management conditions were alleviated in 2001 with the construction of a new adult rearing room and quality control laboratory. In 2002 a comprehensive Quality Management System was implemented, and in 2003 an improved genetic sexing strain, VIENNA 8, was supplied by the FAO/IAEA Laboratory in Seibersdorf. For most of the first 3 years the facility was unable to supply the required number of sterile male Mediterranean fruit flies for the SIT program without importing sterile male pupae from another facility. From mid-2002, after the quality management system was implemented, both production and quality improved but remained below optimum. After the introduction of the VIENNA 8 genetic sexing strain, and together with an improvement in the climate control equipment, production stability, and quality assurance parameters improved substantially. The critical factors influencing production and quality were an inadequate rearing infrastructure, problems with the quality of the larval diet, and the initial absence of a quality management system. The results highlight the importance of effective quality management, the value of a stable and productive genetic sexing strain, and the necessity for a sound funding base for the mass-rearing facility. (author) [Spanish] La facilidad para criar en masa la mosca mediterranea de la fruta, Ceratitis capitata (Wiedemann) fue comisionada en Stellenbosch en 1999 para producir machos esteriles de moscas para el proyecto de la tecnica del insecto esteril (TIE) en huertos de frutos y vinas comerciales en la provincia del Cabo Occidental del Sudafrica. El procedimiento de criar en masa fue en su mayor parte basado en los sistemas desarrollados por el Laboratorio de Agricultura y Biotecnologia de la FAO/IAEA, Seibersdorf, Austria. Un numero de razas que separara los sexos geneticamente fueron utilizadas para producir solo machos para la liberacion. La congestionada condicion inicial para criar las moscas y su manejo de calidad fueron aliviadas en 2001 con la construccion de un nuevo cuarto de cria para adultos y un laboratorio de control de calidad. En 2002, un Sistema de Manejo de Calidad comprensivo fue implementado, y en 2003 una raza mejorada que separa los sexos geneticamente, VIENNA 8, fue proveido por el Laboratorio de la FAO/IAEA en Seibersdorf. En la mayor parte de los primeros 3 anos la facilidad no pudo suplir el numero requerido de machos esteriles de la mosca mediterranea de la fruta para el programa de TIE sin la necesidad para importar machos esteriles de otra facilidad. Desde medio del ano de 2002, despues que el sistema de manejo de calidad fue implementado, la produccion y la calidad mejoraron pero aun quedaron por debajo del nivel optimo. Despues de la introduccion de la raza VIENNA 8 que separa los sexos geneticamente, y junto con el equipo mejorado de control de clima, la estabilidad y los parametros de seguridad de calidad mejoraron substancialmente. Los factores criticos que influyeron en la produccion y la calidad fueron la infraestructura inadecuada para criar las moscas, problemas con la calidad de la dieta para las larvas y la ausencia inicial de un sistema de manejo de calidad. Los resultados muestran claramente la importancia de un manejo efectivo de la calidad, el valor de una raza productiva que separa los sexos geneticamente y la necesidad de contar con una base solida de financimiento para la infraestructura de una cria en masa. (author)

Barnes, B. [Plant Protection Division, ARC Infruitec-Nietvoorbij Fruit, Vine and Wine Institute, Stellenbosch, 7599 (South Africa); Rosenberg, S.; Arnolds, L.; Johnson, J. [SIT Africa (Pty) Ltd., Stellenbosch, 7599 (South Africa)

2007-03-15

273

Physical activity and overweight among adolescents on the Texas-Mexico border  

PubMed Central

Objective To investigate differences in associations between physical activity and overweight for students in two adjacent areas on the border between Mexico and the United States of America: students in the city of Matamoros, Mexico, and Mexican-American students in the Lower Rio Grande Valley (LRGV) area of southern Texas. Since the extremely high prevalence of overweight among Mexican-American adolescents is well-recognized, we wanted to determine whether overweight has become a problem among Mexican adolescents. Methods Students from 6 schools (n = 669), representing 12% of the ninth-grade students in Matamoros during 2002-2003, and students from 13 high schools (n = 4 736), representing 22% of the ninth-grade students in the LRGV during 2000-2001, completed questionnaires. Polytomous logistic regression was performed to estimate the risk of being at risk of overweight (?85th percentile to <95th percentile of body mass index (BMI) for age and sex) and the risk of being overweight (?95th percentile of BMI-for-age and sex) versus normal weight associated with measures of physical activity. For simplicity normal weight includes underweight. Results A higher percentage of adolescents in the LRGV were at risk of overweight (17.2%) in comparison with adolescents from Matamoros (14.8%). The percentages of LRGV and Matamoros adolescents who were overweight were identical (16.9%). LRGV adolescent boys (OR = 0.87, 95% CI = 0.77-0.98) who participated in team sports were less likely to be at or above the 85th percentile of BMI-for-age and sex. Although of borderline significance, Matamoros and LRGV adolescent boys who participated in physical education classes were less likely to be at risk of overweight. Neither in Matamoros nor LRGV students were any of the various physical activity categories or levels associated with being at risk of overweight or being overweight. Conclusions Nearly one-third of the students in both Matamoros and the LRGV are at risk of overweight and are overweight. Implementation of interventions on healthful dietary choices and participation in physical education classes and sports teams are essential for reducing the extremely high prevalence of overweight among students on both sides of the Texas/Mexico border. ABSTRACT. Spanish. Objetivo: Investigar si hay diferencias en las asociaciones entre la actividad física y el sobrepeso observadas en estudiantes de dos zonas colindantes en la frontera mexicanoestadounidense: estudiantes de la ciudad de Matamoros, México, y estudiantes mexicanoestadounidenses del valle a lo largo de la desembocadura del Río Bravo (VRB) en la parte sur del estado de Texas. Dada la consabida prevalencia extremadamente alta de sobrepeso en adolescentes mexicanoestadounidenses, los autores queríamos determinar si el sobrepeso también se ha convertido en un problema entre adolescentes mexicanos. Métodos: Estudiantes de 6 escuelas (n = 653), que comprenden 11% de los estudiantes de noveno grado en Matamoros durante 2002–2003, y estudiantes de 13 bachilleratos (n = 4 736), que comprenden 22% de los estudiantes de noveno grado del VRB durante 2000–2001, contestaron cuestionarios. Se llevó a cabo una regresión logística politómica a fin de calcular el riesgo de estar en riesgo de tener sobrepeso (?85.° percentil a <95.° percentil de índice de masa corporal (IMC) para la edad y el sexo) y el riesgo de tener sobrepeso (?95.° percentil de índice de masa corporal (IMC) para la edad y el sexo), frente a un peso normal, que se asociaban con distintos grados de actividad física. En aras de la sencillez, en la clasificación del peso normal también se abarcó la insuficiencia de peso. Resultados: Un mayor porcentaje de adolescentes estaban en riesgo de sufrir sobrepeso en el VRB (17%) que en Matamoros (15%). Los porcentajes de adolescentes de VRB y de Matamoros que tenían sobrepeso fueron idénticos (17%). Los varones adolescentes en el VRB (raz&

Perez, Adriana; Reininger, Belinda M.; Flores, Maria Isabel Aguirre; Sanderson, Maureen; Roberts, Robert E.

2006-01-01

274

Hydrodynamic model of cells for designing systems of urban groundwater drainage  

NASA Astrophysics Data System (ADS)

An improved mathematical hydrodynamic quasi-two-dimensional model of cells, CELSUB3, is presented for simulating drainage systems that consist of pumping well fields or subsurface drains. The CELSUB3 model is composed of an assemblage of algorithms that have been developed and tested previously and that simulate saturated flow in porous media, closed conduit flow, and flow through pumping stations. A new type of link between aquifer cells and drainage conduits is proposed. This link is verified in simple problems with well known analytical solutions. The correlation between results from analytical and mathematical solutions was considered satisfactory in all cases. To simulate more complex situations, the new proposed version, CELSUB3, was applied in a project designed to control the water-table level within a sewer system in Chañar Ladeado Town, Santa Fe Province, Argentina. Alternative drainage designs, which were evaluated under conditions of dynamic recharge caused by rainfall in a critical year (wettest year for the period of record) and a typical year, are briefly described. After analyzing ten alternative designs, the best technical-economic solution is a subsurface drainage system of closed conduits with pumping stations and evacuation channels. Résumé. Un modèle hydrodynamique perfectionné de cellules en quasi 2D, CELSUB3, est présenté dans le but de simuler des systèmes de drainage qui consistent en des champs de puits de pompage ou de drains souterrains. Le modèle CELSUB3 est composé d'un assemblage d'algorithmes développés et testés précédemment et qui simulent des écoulements en milieu poreux saturé, en conduites et dans des stations de pompage. Un nouveau type de lien entre des cellules d'aquifères et des drains est proposé. Ce lien est vérifié dans des problèmes simples dont les solutions analytiques sont bien connues. La corrélation entre les résultats des solutions analytiques et des solutions mathématiques a été considérée comme satisfaisante dans tous les cas. Afin de simuler des situations plus complexes, la nouvelle version proposée, CELSUB3, a été mise en œuvre dans un projet destiné à contrôler le niveau de la nappe à l'intérieur d'un système d'égouts, dans la ville de Chaar Ladeado (province de Santa Fe, Argentine). Différentes organisations du projet de drainage, qui ont été testées pour des conditions de recharge dynamique causées par la pluie au cours d'une année critique (la plus humide de la chronique disponible) et une année typique, sont brièvement décrites. Après analyse de dix organisations différentes, la meilleure solution technico-économique retenue est un système de drainage souterrain de conduites avec des stations de pompage et des canaux d'évacuation. Resumen. Se presenta un modelo matemático hidrodinámico cuasi-bidimensional de celdas, CELSUB3, apto para la simulación integral de sistemas de drenaje subterráneo basados en campos de bombeo o drenes subsuperficiales. El modelo de simulación presenta un ensamble de algoritmos, previamente desarrollados y testeados, que representan al escurrimiento a través del medio poroso saturado, escurrimiento en conducciones cerradas, estaciones de bombeo, etc. En la estructura del modelo se propone un nuevo tipo de vinculación entre celdas acuíferas y conductos de drenaje, la cual es verificada en problemas simples con solución analítica conocida arrojando, en todos los casos, resultados satisfactorios. Abordando situaciones más complejas, la nueva versión propuesta fue aplicada en un proyecto de control de niveles freáticos que acompaña un sistema de conductos cloacales, en la localidad de Chañar Ladeado, Santa Fe, Argentina. Se describen las alternativas de drenaje consideradas las cuales fueron evaluadas bajo recargas dinámicas provocadas por años críticamente lluviosos y en situaciones típicas. Los resultados derivados permitieron definir, tras analizar una decena de proyectos alternativos, la mejor solución técnico-económica consistente en un sistema de drenes subte

Zimmermann, Eric; Riccardi, Gerardo

2000-08-01

275

EDITORIAL: A tribute to Zhores Ivanovitch Alferov, a pioneer who changed our way of daily life A tribute to Zhores Ivanovitch Alferov, a pioneer who changed our way of daily life  

NASA Astrophysics Data System (ADS)

Can you think of living without the World Wide Web, e-mail, DVDs, CD-ROMs, the bar code scanner, mobile phones or high-efficiency solar cells? I cannot. These systems are part of the backbone of our modern civilization. And they have something in common: they are all devices based on the double heterostructure. Zhores Alferov (and independently Herbert Krömer) proposed its concept and its usefulness for semiconductor lasers in 1962, two years after the first demonstration of the first (solid-state) laser. InP-based double heterostructure lasers are today, and have been for more than 20 years, the enabling light sources for optical fiber communication, sending their photonic bits around the globe at enormous and ever-increasing rates. In 2009, 61% of the 500+ billion world market for laser systems was based on semiconductor lasers. Obviously a straightforward success story? Not really at the beginning, rather the kind of survival story of somebody who was producing an enormous number of ideas and trying to make them reality; his production of ideas has not yet stopped after 60 years of professional life. Let's have a look back at how it started. Zhores Alferov was born 80 years ago on 15 March 1930 in Vitebsk in eastern Byelorussia, an area where 47 years before him the famous painter Marc Chagall had been born. His parents believed in socialism and named him after the French socialist Jean Jaurès, the author of J'accuse. The war came when he was an adolescent and his admired older and only brother was killed in 1944 at the battle of Stalingrad. Despite the turmoil of war and post-war times he finished school successfully on time, was admitted to the V I Uljanov Electrotechnical Institute in Leningrad, studied physics and graduated there in 1952. In 1953 he started work at the Physico-Technical Institute in Leningrad, founded by Abraham Ioffe, the first PhD student of Conrad Rèntgen in Munich. Ioffe had initiated systematic studies of semiconductors at this institute in the thirties, leading to many important discoveries such as the metal-semiconductor contact, work that Ioffe did together with Frenkel. Seven years later, in 1960, another completely different direction of research created excitement and interest across the world, including for Zhores Alferov. The first demonstration of laser action in ruby by Theodore Maiman, verifying Einstein's prediction of stimulated emission (1917), was followed within 18 months by the demonstration of gas lasers and semiconductor diode lasers based on GaAs homojunctions. Solid-state and gas lasers from the very beginning operated at room temperature (RT), but semiconductor lasers did not. They operated only at the temperature of liquid He, at 4 K. Gas and solid-state lasers very quickly found a wide range of applications. Not so semiconductor lasers, being judged at that time to be useless. The whole world however, recognized at once how important it would be to have RT semiconductor lasers. Teams at Bell Labs, IBM, RCA etc. entered the race, but failed for a long time. The problem—as we now know—was the p-n homojunction. In a forward-biased homojunction the charge carriers are widely spread in space at room temperature with low peak carrier density. In addition, there are enormous losses of the light emitted in the junction. At that time a new subject appeared in the life of Zhores Alferov: the heterojunctions. Heterojunctions had already appeared on the horizon in the early days of electronics, starting in 1951 with theoretical proposals for improved transistors by Shockley, Krömer and others. Single heterostructures were tried for laser action and the temperature limit was pushed up to 77 K, an enormous progression compared with 4 K, but still completely academic. In 1963, Zhores Alferov and Rudi Kazarinov in a patent application, and Herbert Krömer in a publication, proposed independently of each other to confine carriers in a double heterostructure, leading to an increase of carrier density by several orders of magnitude in the confinement layer. Alferov and Kazarinov

Bimberg, Dieter

2011-01-01