Identification and Control of Cladobotryum spp., Causal Agents of Cobeweb Disease of Cultivated Mushroom

OpenAIRE

Ivana Potočnik

2009-01-01

Cladobotryum spp. are causal agents of cobweb disease, one of the most serious diseases of cultivated mushroom (Agaricus bisporus (Lange) Imbach) in Serbia and worldwide, which affects product quality and yield. The disease symptoms are: cottony fluffy white or yellowish to pink colonies on mushroom casing, rapid colonization of casing surface, covering of host basidiomata by mycelia, and their decay. Prochloraz-Mn has been officially recommended for mushroom cultivation in EU countries. Howe...

Survival of Fusarium graminearum, the causal agent of Fusarium head blight. A review

OpenAIRE

Leplat , Johann; Friberg , Hanna; Abid , Muhammad; Steinberg , Christian

2012-01-01

International audience; Wheat is one of the most cultivated crops worldwide. In 2010, 20 % of wheat and durum wheat were cultivated in Europe, 17 % in China and 9 % in Russia and in North America. Wheat yield can be highly decreased by several factors. In particular Fusarium graminearum Schwabe is a worldwide fungal pest impacting wheat production. F. graminearum is the causal agent of Fusarium head blight, root and stem-base rot of cereals. Losses caused by Fusarium head blight in Northern a...

Estudios etiológicos de la marchitez del aguacate en Antioquia-Colombia

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Joaquín Guillermo Ramírez Gil

2014-02-01

Full Text Available El cultivo de aguacate en Colombia ha presentado un incremento en el área sembrada durante la última década, especialmente en clima frío moderado, entre 1.800 y 2.500 msnm. La variedad Hass se destaca por tener la mayor área sembrada en este clima, en el departamento de Antioquia-Colombia. Este cultivo presenta grandes retos tecnológicos para su expansión; entre ellos el manejo de enfermedades ocupa un lugar predominante por las implicaciones que tiene en costos, impacto en la salud, ambiente y restricciones para exportaciones. La marchitez, ocasiona la muerte de numerosos árboles en todas las etapas del cultivo y presenta la mayor incidencia y severidad de las enfermedades identificadas para este cultivo. El desconocimiento de los agentes causales de esta enfermedad, ha llevado a realizar prácticas de manejo encaminadas principalmente al control del oomycete Phytophthora cinnamomi Rands, como único agente causal. Esta investigación tuvo como objetivo identificar los distintos agentes causales de la marchitez del aguacate y la relación de su incidencia con las prácticas de manejo en lotes cultivados en el departamento de Antioquia-Colombia. Los resultados encontrados muestran que la marchitez es el principal problema del cultivo de aguacate. Los microorganismos P. cinnamomi, Phytophthora heveae Thompson, Phytophthora citrícola Sawada, Verticillium sp., y Cylindrocarpon destructans (Zinss Scholten fueron aislados y reprodujeron los síntomas asociados a marchitez. Las condiciones de bajo contenido de oxigeno el suelo también reprodujeron la sintomatología de marchitez, involucrando también un origen abiótico en la etiología.

Molecular Detection of Monilinia fructigena as Causal Agent of Brown Rot on Quince

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Jovana Hrustić

2012-01-01

Full Text Available Species of the genus Monilinia are important causal agents of fruit rot on pome and stone fruits in Serbia. The pathogen is very harmful, especially on small properties and cottage plantations where intensive control measures are not applied. Quince is importanthost for the pathogens of this genus. During spring 2010, intensive occurrence of mummified fruits overwintering on branches of the quince was observed. The pathogen was isolated using standard phytopathological methods. Pathogenicity of eight obtained isolates was tested by artificial inoculation of injured apple fruits. Identification was performed according to pathogenic, morphological and ecological properties, and was confirmed by Multiplex polimeraze chain reaction, PCR. All the isolates studied caused brown rot on inoculated apple fruits. The isolates form light yellow colonies with lobate margins,with single-celled, transparent, elliptical or oval conidia in chains, regardless temperature or light presence. Sclerotia are observed in 14 days old cultures. The highest growth rate of most of the isolates is at 27°C and in dark. Based on studied pathogenic, morphological and ecological characteristics, it was found that the Monilinia fructigena is causal agent of brown rot of quince. Using specific primers (MO368-5, MO368-8R, MO368-10R, Laxa-R2for detection of Monilinia species in Multiplex PCR reaction, the expected fragment 402 bp in size was amplified, which confirmed that the studied isolates belonged to the speciesM. fructigena.

A simple culture method inducing sexual reproduction by Fusarium graminearum, the primary causal agent of Fusarium head blight

Science.gov (United States)

The homothallic ascomycete fungus Fusarium graminearum is the primary causal agent of Fusarium head blight (FHB), a devastating disease of wheat and barley worldwide. The fungus undergoes both asexual and sexual stages in its life cycle. The asexual stage produces conidiospores, whereas the sexual s...

Causality in Classical Electrodynamics

Science.gov (United States)

Savage, Craig

2012-01-01

Causality in electrodynamics is a subject of some confusion, especially regarding the application of Faraday's law and the Ampere-Maxwell law. This has led to the suggestion that we should not teach students that electric and magnetic fields can cause each other, but rather focus on charges and currents as the causal agents. In this paper I argue…

Analysis of genetic diversity of Fusarium tupiense, the main causal agent of mango malformation disease in southern Spain

Science.gov (United States)

Mango malformation disease (MMD) has become an important global disease affecting this crop. The aim of this study was to identify the main causal agents of MMD in the Axarquía region of southern Spain and determine their genetic diversity. Fusarium mangiferae was previously described in the Axarquí...

Respuesta al glifosato de un aislamiento de Rhizoctonia solani agente causal del anublo de la vaina del arroz, y de cuatro aislamientos de Trichoderma, bajo condiciones in vitro In vitro response of one isolate of Rhizoctonia solani, the pathogen of the rice sheath blight and four isolates of Trichoderma to glyphosate

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Vargas de Álvarez Amparo

2002-08-01

Full Text Available El añublo de la vaina del arroz (Orysa saliva L., cuyo agente causal es Rhizoctonia solani Kuhn, es una de las enfermedades más importantes en el cultivo del arroz en Colombia. En los cultivos de arroz con frecuencia se aplica glifosato ((ácido N-(fosfonometil glicina para controlar las malezas, particularmente el arroz rojo (O. saliva, antes de la siembra del arroz. Observaciones de campo anteriores parecían indicar relación entre el uso intensivo del glifosato y el incremento en la incidencia del añublo de la vaina del arroz. Por tanto, se propuso el presente trabajo con el fin de dilucidar los posibles efectos del glifosato sobre R. solani y Trichoderma sp., conocido éste como antagonista de R. solani. Se determinó, bajo condiciones de laboratorio, el efecto del glifosato en el crecimiento, en medio líquido y sólido PDA, de R. solani y de Trichoderma. Se encontró que la dosis más alta de glifosato sin efecto detrimental sobre R. solani, fue de 300 mg/L y la dosis más baja del herbicida que
causó la mayor inhibición del crecimiento del hongo fue
de 2500 mg/L. Por otra parte, no se encontró que el glifosato
estimulara el crecimiento de R. solani. En teoría, en una aplicación comercial de glifosato de 1,5 Kg ia/ha y asperjando directamente al suelo sin vegetación, el glifosato en el suelo estaría a una concentración de 0,75 mg/Kg de suelo (suponiendo que la capa arable de una hectárea de suelo pesa 2.000.000 de Kg; por tanto, la concentración de glifosato después de una aplicación comercial, está muy por debajo de la concentración a la cual se inicia la reducción del crecimiento de R. solani. Por su parte, la respuesta de Trichoderma al glifosato fue similar a la de R. solani; además, se encontró que el glifosato no afecta la capacidad antagonista de Trichoderma sobre R. sotaní. Estos resultados no apoyan la hipótesis que el glifosato, bajo las condiciones de uso en cultivos de arroz para el control

ARTICULACIÓN ENTRE CONOCIMIENTO DEL MUNDO Y CONOCIMIENTO LINGÜÍSTICO EN LA COMPRENSIÓN DE RELACIONES CAUSALES Y CONTRACAUSALES: EL PAPEL DE LAS PARTÍCULAS CONECTIVAS

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Gabriela M. Zunino

2012-01-01

Full Text Available En este trabajo se intenta estudiar la intervención del conocimiento de mundo y del conocimiento lingüístico -semántico- durante el proceso de comprensión de relaciones causales y contracausales. Nuestra hipótesis inicial: las relaciones causales son más sencillas de procesar que las relaciones contracausales. Nuestro objetivo específico: verificar esta hipótesis en cuatro condiciones. Por un lado, se evaluó cómo se comprende una relación causal o contracausal entre dos eventos pertenecientes a un dominio de conocimiento “cotidiano” y a un dominio científico, sobre el cual los informantes no tienen conocimiento previo. Por el otro, se verificó qué rol cumplen las partículas conectivas con contenido semántico específico -causal y contracausal- en esos dos tipos de texto.

Draft Genome Sequences of Two Isolates of Colletotrichum lindemuthianum, the Causal Agent of Anthracnose in Common Beans.

Science.gov (United States)

de Queiroz, Casley Borges; Correia, Hilberty L Nunes; Menicucci, Renato Pedrozo; Vidigal, Pedro M Pereira; de Queiroz, Marisa Vieira

2017-05-04

Colletotrichum lindemuthianum is the causal agent of anthracnose in common beans, one of the main limiting factors of their culture. Here, we report for the first time, to our knowledge, a draft of the complete genome sequences of two isolates belonging to 83.501 and 89 A 2 2-3 of C. lindemutuianum . Copyright © 2017 de Queiroz et al.

El timerosal y las enfermedades del neurodesarrollo infantil

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Luis Maya

2006-09-01

Full Text Available Se evalúa la relación causal entre el timerosal (etilmercurio, como preservante en las vacunas pediátricas, y el incremento de casos de enfermedades del neurodesarrollo infantil, como consecuencia de la ampliación de los esquemas de inmunización. Se revisó la información científica, relacionando el timerosal y las evidencias que permitan evaluar una posible asociación causal, con estudios epidemiológicos, ecológicos, biomoleculares y toxicológicos, de bioseguridad, toxicológicos fetales y sobre salud reproductiva. Se encontró múltiples asociaciones entre la exposición a timerosal y las enfermedades del neurodesarrollo infantil. Tal neurotoxicidad ocurre en los infantes y fetos de gestantes vacunadas por dosis acumulativa de mercurio. Las diversas evidencias implican al timerosal como el agente causante, agravante o disparador de las enfermedades del neurodesarrollo infantil. La toxicidad del mercurio obligó al retiro progresivo del timerosal de los medicamentos. Lamentablemente, en las vacunas, ha habido una sustancial demora en la demostración de su impacto negativo. Actualmente, existen vacunas sin timerosal, cuyo uso está ocasionando la disminución de la incidencia de las enfermedades del neurodesarrollo infantil.

Integrated Management of Causal Agents of Postharvest Fruit Rot of Apple

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Mila Grahovac

2011-01-01

Full Text Available One of the major causes of poor quality and fruit loss (during storage and transportare diseases caused by phytopathogenic fungi. Economic losses which are the consequenceof the phytopathogenic fungus activity after harvest exceed the losses in the field.Themost important postharvest fungal pathogens of apple fruits are: Botrytis cinerea Pers. exFr., Penicillium expansum (Lk. Thom., Cryptosporiopsis curvispora (Peck. Grem., Colletotrichumgloeosporioides (Penz. Sacc., Monilinia sp., Gloeosporium album Osterw, Alternaria alternata(Fr. Keissler, Cladosporium herbarium Link., Cylindrocarpon mali (Alles. Wollenw., Stemphyliumbotryosum Wallr. The use of available protection technologies can significantly reducelosses caused by pathogens in storage. The concept of integrated pest management (IPMin apple fruits i.e. sustainable approach in control of causal agents of postharvest fruit rot,using cultural, physical, biological and chemical measures, to minimize economic, healthand risks to consumers and environment, is presented in the paper.

Causality in Europeanization Research

DEFF Research Database (Denmark)

Lynggaard, Kennet

2012-01-01

to develop discursive institutional analytical frameworks and something that comes close to the formulation of hypothesis on the effects of European Union (EU) policies and institutions on domestic change. Even if these efforts so far do not necessarily amount to substantive theories or claims of causality......Discourse analysis as a methodology is perhaps not readily associated with substantive causality claims. At the same time the study of discourses is very much the study of conceptions of causal relations among a set, or sets, of agents. Within Europeanization research we have seen endeavours......, it suggests that discourse analysis and the study of causality are by no means opposites. The study of Europeanization discourses may even be seen as an essential step in the move towards claims of causality in Europeanization research. This chapter deals with the question of how we may move from the study...

The causal structure of utility conditionals.

Science.gov (United States)

Bonnefon, Jean-François; Sloman, Steven A

2013-01-01

The psychology of reasoning is increasingly considering agents' values and preferences, achieving greater integration with judgment and decision making, social cognition, and moral reasoning. Some of this research investigates utility conditionals, ''if p then q'' statements where the realization of p or q or both is valued by some agents. Various approaches to utility conditionals share the assumption that reasoners make inferences from utility conditionals based on the comparison between the utility of p and the expected utility of q. This article introduces a new parameter in this analysis, the underlying causal structure of the conditional. Four experiments showed that causal structure moderated utility-informed conditional reasoning. These inferences were strongly invited when the underlying structure of the conditional was causal, and significantly less so when the underlying structure of the conditional was diagnostic. This asymmetry was only observed for conditionals in which the utility of q was clear, and disappeared when the utility of q was unclear. Thus, an adequate account of utility-informed inferences conditional reasoning requires three components: utility, probability, and causal structure. Copyright © 2012 Cognitive Science Society, Inc.

Las tesis de los filósofos del siglo XIII que afirmaron la existencia del intelecto agente

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Sellés, Juan Fernando

2008-06-01

Full Text Available In this article we review the statements of relevant philosophers of the XIII^eme century supporting the existence of the human agent intellect. Three groups can be distinguished: I The universal hylemorphism (Alexander of Hales, John de la Rochelle, Mathew of Acquasparta; II The synthesis between the augustinianism and the aristhotelism (Peter Hispanus, Saint Bonaventura, John Peckham; III The purified and advanced aristotelism (Albert the Great, Thomas Aquinas, Ramon Llull.

En este trabajo se revisan las tesis de relevantes filósofos del s. XIII que defendieron la existencia del intelecto agente en el hombre. En el trabajo se dividen en tres grupos a los pensadores: I Los que se suelen encuadrar dentro del llamado hilemorfismo universal (Alejandro de Hales, Juan de la Rochela y Mateo de Acquasparta. II La síntesis entre el agustinismo y el aristotelismo (Pedro Hispano, San Buenaventura, Juan Peckham. III El aristotelismo depurado y proseguido (San Alberto Magno, Sto. Tomás de Aquino, Ramón Llull.

Lesiones penetrantes y transfixiantes en los traumatismos abiertos del tórax

OpenAIRE

Sosa Delgado, Diego; González López, José; Hernández Varea, José; Conde Castells, Luis; González Martínez, Pablo

2001-01-01

La gravedad y el peligro para la vida que acompañan a las lesiones penetrantes y transfixiantes del tórax y la necesidad de una respuesta inmediata con un diagnóstico y tratamiento precoz, motivaron a profundizar en el estudio de estos traumatismos, evaluar la aplicación oportuna del tratamiento quirúrgico, determinar los agentes vulnerantes causales, los órganos más afectados y las complicaciones. Se realizó un estudio retrospectivo en 116 pacientes atendidos en el Hospital Militar Central "...

Isolation and characterization of the mating type locus of Mycosphaerella fijiensis, the causal agent of black leaf streak disease of banana

NARCIS (Netherlands)

Conde, L.; Waalwijk, C.; Canto-Canché, B.B.; Kema, G.H.J.; Crous, P.W.; James, A.C.; Abeln, E.C.A.

2007-01-01

Idiomorphs mat1-1 and mat1-2 from Mycosphaerella fijiensis, the causal agent of black leaf streak disease of banana, were isolated. Degenerate oligos were used to amplify the HMG box of the mat1-2 idiomorph from M. fijiensis, showing homology with the HMG box of Mycosphaerella graminicola. Using a

Control of Ralstonia Solanacearum The Causal Agent of Brown Rot in Potato Using Essential Oils

International Nuclear Information System (INIS)

Salem, E.A.

2011-01-01

Five essential oils, namely peppermint (Mentha piperita L.), caraway (Carium carvum L.), fennel (Foeniculum vulgare Mill.), lemongrass (Cymbopogon citratus Staph.) and thyme (Thymus vulgaris), were used separately against Ralstonia solanacearum; the causal agent of brown rot in potato. The most two effective oils (peppermint and thyme) were used in vitro and in vivo after testing their effects on potato tubers buds germination. Peppermint inhibited buds germination but thyme have no effects on buds germination. In vivo, the control of brown rot using thyme oil in glass house experiment reduced the percentage of brown rot infection to 30.6% and reduced the severity of disease from 5 to 3.

Identification and Control of Cladobotryum spp., Causal Agents of Cobeweb Disease of Cultivated Mushroom

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Ivana Potočnik

2009-01-01

Full Text Available Cladobotryum spp. are causal agents of cobweb disease, one of the most serious diseases of cultivated mushroom (Agaricus bisporus (Lange Imbach in Serbia and worldwide, which affects product quality and yield. The disease symptoms are: cottony fluffy white oryellowish to pink colonies on mushroom casing, rapid colonization of casing surface, covering of host basidiomata by mycelia, and their decay. Prochloraz-Mn has been officially recommended for mushroom cultivation in EU countries. However, inefficiency of prochloraz-Mn has been noted at a level of spotting symptoms of cobweb disease. With regard to cases of resistance evolution and a general threat to the environment and human health, special attention should be focused on good programmes of hygiene, and inventing and developing alternative methods of disease control.

Nueva clasificación de las fracturas de trazo unilateral del tercio medio facial

OpenAIRE

Francisco Avello; Allan Avello

2007-01-01

Las fracturas de trazo unilateral del tercio medio facial son las más frecuentes de las fracturas del macizo óseo-facial, en general. Dentro de estas, son las que afectan al maxilar superior y al malar las de mayor incidencia. Se producen como consecuencia de traumatismos severos, siendo la determinación de este tipo de fractura, por edad, sexo y agente causal importante para su manejo. Se pueden presentar en forma combinada con otro tipo de fractura facial. Tienen una mayor incidencia en el ...

Nueva clasificación de las fracturas de trazo unilateral del tercio medio facial

OpenAIRE

Avello, Francisco; Avello, Allan

2013-01-01

Las fracturas de trazo unilateral del tercio medio facial son las más frecuentes de las fracturas del macizo óseo-facial, en general. Dentro de estas, son las que afectan al maxilar superior y al malar las de mayor incidencia. Se producen como consecuencia de traumatismos severos, siendo la determinación de este tipo de fractura, por edad, sexo y agente causal importante para su manejo. Se pueden presentar en forma combinada con otro tipo de fractura facial. Tienen una mayor incidencia en el ...

Development of VNTR Markers to Assess Genetic Diversity of Mycosphaerella Fijiensis, the Causal Agent of Black Leaf Streak Disease in Bananas (Musa spp.)

Science.gov (United States)

Mycosphaerella fijiensis is the causal agent of black leaf streak (BLS) disease in bananas. This pathogen threatens global banana production as the main export cultivars are highly susceptible. As a consequence, commercial banana plantations must be protected chemically with fungicides; up to 40 app...

Causality and Information Dynamics in Networked Systems with Many Agents

Science.gov (United States)

2017-05-11

algorithms. 6 Future Perspectives Causal graph reconstruction from noisy data is a problem of central importance. In our research we have shown how the idea ...thrust of the research was to develop methods for GCG sparsification using ideas from Tikhonov regularization and ADMM based proximal algorithms...not vary with time. The notion of Granger-causality is captured in the following definition . Definition 2.1 If ξ̂[xi(t) |Ht] < ξ̂[xi(t) |H−jt ] , (2.2

TRATAMIENTO DEL CÁNCER CON AGENTES CITOSTÁTICOS: UN PROGRAMA REGRESIVO DE INVESTIGACIÓN

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Octavio Martínez Betancur

2007-10-01

Full Text Available La oncología ha llamado de regreso a la medicina mecanicista y a la causalidad determinista para orientar su quehacer investigativo en la terapia antineoplásica. A lo que ha llevado esta postura epistemológica, es a un cambio regresivo del programa de investigación terapéutica en cáncer, manifiesto por las modificaciones introducidas en los desenlaces de los ensayos clínicos con agentes citostáticos ante el fracaso del desenlace esperado de regresión tumoral y curación. Ya en estudios fase II con agentes citostáticos no se habla de tasas de remisión tumoral sino de mediciones subrogadas, muchas aún no validadas, del efecto citostático sobre el marcador molecular, y en los desenlaces de estudios fase III se incluye como criterio de respuesta la estabilización o no progresión tumoral. Todo un fracaso del prometido y anhelado “proyectil mágico” de la terapia orientada a blancos moleculares en cáncer.

Variable number of tandem repeat markers in the genome sequence of Mycosphaerella fijiensis, the causal agent of black leaf streak disease of banana (Musa spp)

NARCIS (Netherlands)

Garcia, S.A.L.; Lee, van der T.A.J.; Ferreira, C.F.; Lintel Hekkert, te B.; Zapater, M.F.; Goodwin, S.B.; Guzmán, M.; Kema, G.H.J.; Souza, M.T.

2010-01-01

ABSTRACT. We searched the genome of Mycosphaerella fijiensis for molecular markers that would allow population genetics analysis of this plant pathogen. M. fijiensis, the causal agent of banana leaf streak disease, also known as black Sigatoka, is the most devastating pathogen attacking bananas

Obesity and infection: reciprocal causality.

Science.gov (United States)

Hainer, V; Zamrazilová, H; Kunešová, M; Bendlová, B; Aldhoon-Hainerová, I

2015-01-01

Associations between different infectious agents and obesity have been reported in humans for over thirty years. In many cases, as in nosocomial infections, this relationship reflects the greater susceptibility of obese individuals to infection due to impaired immunity. In such cases, the infection is not related to obesity as a causal factor but represents a complication of obesity. In contrast, several infections have been suggested as potential causal factors in human obesity. However, evidence of a causal linkage to human obesity has only been provided for adenovirus 36 (Adv36). This virus activates lipogenic and proinflammatory pathways in adipose tissue, improves insulin sensitivity, lipid profile and hepatic steatosis. The E4orf1 gene of Adv36 exerts insulin senzitizing effects, but is devoid of its pro-inflammatory modalities. The development of a vaccine to prevent Adv36-induced obesity or the use of E4orf1 as a ligand for novel antidiabetic drugs could open new horizons in the prophylaxis and treatment of obesity and diabetes. More experimental and clinical studies are needed to elucidate the mutual relations between infection and obesity, identify additional infectious agents causing human obesity, as well as define the conditions that predispose obese individuals to specific infections.

Variable Number of Tandem Repeat Markers in the Genome Sequence of Mycosphaerella Fijiensis, the Causal Agent of Black Leaf Streak Disease of Banana (Musa spp.)

Science.gov (United States)

Mycosphaerella fijiensis, the causal agent of banana leaf streak disease (commonly known as black Sigatoka), is the most devastating pathogen attacking bananas (Musa spp). Recently the whole genome sequence of M. fijiensis became available. This sequence was screened for the presence of Variable Num...

Las causales exonerativas de la responsabilidad extracontractual. ¿Por qué y cómo impiden la declaratoria de responsabilidad? Aproximación a la jurisprudencia del Consejo de Estado

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Héctor Patiño

2011-07-01

Full Text Available El artículo, de la mano de la jurisprudencia del Consejo de Estado colombiano, y de alguna de la Corte Suprema de Justicia, señala el alcance general y la comprensión que se le debe dar a los conceptos de nexo causal, imputación y causales de exoneración y presenta los lineamientos actuales de la jurisprudencia colombiana sobre esas cuestiones.

Sartre's Contingency of Being and Asouzu's Principle of Causality ...

African Journals Online (AJOL)

The position of this work is that all contingent beings have a causal agent. This position is taken as a result of trying to delve into the issue of contingency and causality of being which has been discussed by many philosophers of diverse epochs of philosophy. This work tries to participate in the debate of whether contingent ...

ANTAGONISTIC EFFECT OF FOUR FUNGAL ISOLATES TO GANODERMA BONINENSE, THE CAUSAL AGENT OF BASAL STEM ROT OF OIL PALM

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OKKY SETYAWATI DHARMAPUTRA

1990-01-01

Full Text Available Four fungal isolates from soils obtained from three sites of the oil palm plantations in North Sumatra were found antagonistic to Ganoderma boninense, the causal agent of basal stem rot of oil palm. Penicillium citrinum inhibited the growth of the pathogen and formed a zone of inhibition on the agar media. Trichoderma harzianum BIO - 1 as well as BIO - 2 and T. viride not only repressed the growth of the pathogen but also caused lysis of the hyphae, and the colony was totally overgrown by the antagonists.

La justicia del accidente, variaciones sobre el síndrome del Síndrome del Aceite Tóxico Español

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Javier Izquierdo-martín

2003-01-01

Full Text Available El 1 de mayo de 2001 se celebró oficialmente en España el veinte aniversario del primer fallecimiento ocasionado por el llamado «Síndrome del Aceite Tóxico Español» (Spanish Toxic Oil Syndrome o STOS, una desconocida y mortal patología médica, asociada con un extraño episodio de intoxicación alimentaria a gran escala, cuyo agente causal, presumiblemente de origen industrial, sigue sin ser identificado. Con sus más de 1.100 muertos y 25.000 afectados, la catástrofe sanitaria del STOS está considerada el más grave envenenamiento masivo ocurrido en Europa durante el siglo XX. La carrera judicial del «caso» STOS, donde destacan dos importantes sentencias dictadas por la Audiencia Nacional (1989 y 1996 y sus correspondientes recursos de casación resueltos por el Tribunal Supremo (1992 y 1997, ofrece, por su parte, uno de los expedientes legales más complejos y controvertidos de la moderna historia jurídica española. La disputa sobre las causas materiales y las responsabilidades legales del caso se aborda aquí desde el punto de vista de los estudios culturales sobre el derecho. Para iluminar con otra luz los dilemas cognitivos y morales anudados en el expediente del STOS me serviré de la jurisprudencia narrativa extraída del filme Dulce Porvenir y de la novela homónima de la que fue adaptado.

Causal and causally separable processes

Science.gov (United States)

Oreshkov, Ognyan; Giarmatzi, Christina

2016-09-01

The idea that events are equipped with a partial causal order is central to our understanding of physics in the tested regimes: given two pointlike events A and B, either A is in the causal past of B, B is in the causal past of A, or A and B are space-like separated. Operationally, the meaning of these order relations corresponds to constraints on the possible correlations between experiments performed in the vicinities of the respective events: if A is in the causal past of B, an experimenter at A could signal to an experimenter at B but not the other way around, while if A and B are space-like separated, no signaling is possible in either direction. In the context of a concrete physical theory, the correlations compatible with a given causal configuration may obey further constraints. For instance, space-like correlations in quantum mechanics arise from local measurements on joint quantum states, while time-like correlations are established via quantum channels. Similarly to other variables, however, the causal order of a set of events could be random, and little is understood about the constraints that causality implies in this case. A main difficulty concerns the fact that the order of events can now generally depend on the operations performed at the locations of these events, since, for instance, an operation at A could influence the order in which B and C occur in A’s future. So far, no formal theory of causality compatible with such dynamical causal order has been developed. Apart from being of fundamental interest in the context of inferring causal relations, such a theory is imperative for understanding recent suggestions that the causal order of events in quantum mechanics can be indefinite. Here, we develop such a theory in the general multipartite case. Starting from a background-independent definition of causality, we derive an iteratively formulated canonical decomposition of multipartite causal correlations. For a fixed number of settings and

Causal and causally separable processes

International Nuclear Information System (INIS)

Oreshkov, Ognyan; Giarmatzi, Christina

2016-01-01

The idea that events are equipped with a partial causal order is central to our understanding of physics in the tested regimes: given two pointlike events A and B , either A is in the causal past of B , B is in the causal past of A , or A and B are space-like separated. Operationally, the meaning of these order relations corresponds to constraints on the possible correlations between experiments performed in the vicinities of the respective events: if A is in the causal past of B , an experimenter at A could signal to an experimenter at B but not the other way around, while if A and B are space-like separated, no signaling is possible in either direction. In the context of a concrete physical theory, the correlations compatible with a given causal configuration may obey further constraints. For instance, space-like correlations in quantum mechanics arise from local measurements on joint quantum states, while time-like correlations are established via quantum channels. Similarly to other variables, however, the causal order of a set of events could be random, and little is understood about the constraints that causality implies in this case. A main difficulty concerns the fact that the order of events can now generally depend on the operations performed at the locations of these events, since, for instance, an operation at A could influence the order in which B and C occur in A ’s future. So far, no formal theory of causality compatible with such dynamical causal order has been developed. Apart from being of fundamental interest in the context of inferring causal relations, such a theory is imperative for understanding recent suggestions that the causal order of events in quantum mechanics can be indefinite. Here, we develop such a theory in the general multipartite case. Starting from a background-independent definition of causality, we derive an iteratively formulated canonical decomposition of multipartite causal correlations. For a fixed number of settings and

Influencia de la concentración del precursor, catalizador y agente reductor en la síntesis de derivados del 2H-INDAZOL.

OpenAIRE

Ovalle Pérez, S.; Pérez Rodriguez, N.A.; Elizondo Martínez, P.; Velazoo Soto, M.A.

2011-01-01

La importancia de los derivados del2H-indazol es debida a la actividad biológica que han presentado, 10 que ha permitido aplicarlos en la industria farmacéutica, en el sector agrícola entre otros. En este trabajo, primeramente se estudió la influencia de la concentración del N,N'-bis(2-nitrobencil}-1,2-etanodiamina [PJ y diferentes cantidades tanto de agente reductor como de catalizador para favorecer la formación del 2,2' -(etano-I,2-

Agente adaptable y aprendizaje

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Arturo Angel Lara Rivero

2013-05-01

Full Text Available En este trabajo se contrasta el concepto de agente programado con el de agente complejo adaptable, se presenta una nueva visión ligada al aprendizaje y la estructura del agente. La imagen del agente se analiza considerando los modelos internos, la práctica, el concepto de rutina y la influencia en su comportamiento, y la importancia del aprendizaje ex ante y ex post. Por último se muestra que la resolución de problemas está sujeta a restricciones del agente y se describen las formas de explorar el espacio de soluciones mediante tres tipos de exploración: exhaustiva, aleatoria y selectiva.

P3-10: Crossmodal Perceptual Grouping Modulates Subjective Causality between Action and Outcome

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Takahiro Kawabe

2012-10-01

Full Text Available Agents have to determine which external events their action has causally produced. A sensation of causal relation between action and outcome is called subjective causality. Subjective causality has been linked to the comparator model. This model assumes that the brain compares an internal prediction for action outcome with an actual sensory outcome, distinguishing between self and externally produced outcomes depending on spatiotemporal congruency. However, recent studies have expressed some doubt about the idea that subjective causality arises depending solely on the spatiotemporal congruency, suggesting instead that other perceptual/cognitive factors play a critical role in determining subjective causality. We hypothesized that crossmodal grouping between action and outcome contributed to subjective causality. Crossmodal temporal grouping is an essential factor for crossmodal simultaneity judgments with ungrouped crossmodal signals likely to be judged as non-simultaneous. We predicted that subjective causality would decrease when an agent's action was not temporally grouped with action outcome. In the experiment, observers were asked to press a key in order to trigger a display change with some temporal delay. To disrupt temporal grouping between action and outcome, a task-irrelevant visual flash or tone was sometimes presented synchronously with the button press and/or the display change. Subjective causality was decreased when the flash or the tone was coincided with the button press. This demonstrates that perceptual grouping has a key role in determination of subjective causality, a result that is not accounted for by the standard comparator model.

Lorenz, Gödel and Penrose: new perspectives on determinism and causality in fundamental physics

Science.gov (United States)

Palmer, T. N.

2014-07-01

Despite being known for his pioneering work on chaotic unpredictability, the key discovery at the core of meteorologist Ed Lorenz's work is the link between space-time calculus and state-space fractal geometry. Indeed, properties of Lorenz's fractal invariant set relate space-time calculus to deep areas of mathematics such as Gödel's Incompleteness Theorem. Could such properties also provide new perspectives on deep unsolved issues in fundamental physics? Recent developments in cosmology motivate what is referred to as the 'cosmological invariant set postulate': that the universe ? can be considered a deterministic dynamical system evolving on a causal measure-zero fractal invariant set ? in its state space. Symbolic representations of ? are constructed explicitly based on permutation representations of quaternions. The resulting 'invariant set theory' provides some new perspectives on determinism and causality in fundamental physics. For example, while the cosmological invariant set appears to have a rich enough structure to allow a description of (quantum) probability, its measure-zero character ensures it is sparse enough to prevent invariant set theory being constrained by the Bell inequality (consistent with a partial violation of the so-called measurement independence postulate). The primacy of geometry as embodied in the proposed theory extends the principles underpinning general relativity. As a result, the physical basis for contemporary programmes which apply standard field quantisation to some putative gravitational lagrangian is questioned. Consistent with Penrose's suggestion of a deterministic but non-computable theory of fundamental physics, an alternative 'gravitational theory of the quantum' is proposed based on the geometry of ?, with new perspectives on the problem of black-hole information loss and potential observational consequences for the dark universe.

Onicomicosis: epidemiología, agentes causales y evaluación de los métodos diagnósticos de laboratorio Onychomycoses: epidemiology, causative agents and assessment of diagnostic laboratory methods

OpenAIRE

Javier R Nazar; Paula E Gerosa; Osvaldo A Díaz

2012-01-01

Desde marzo de 2007 hasta marzo de 2011 se estudiaron prospectivamente 414 pacientes con onicodistrofias en un laboratorio privado de Esquel. La prevalencia de onicomicosis de pie fue del 78 %; la de mano, del 58 %. Los principales agentes etiológicos fueron Trichophyton rubrum, Candida spp. y Trichophyton mentagrophytes. El desarrollo de dermatofitos prevaleció en las onicopatías de pie y el de Candida spp. en las de uñas de mano (ambos, p < 0,05). En las onicomicosis candidiásicas predomina...

Causally nonseparable processes admitting a causal model

International Nuclear Information System (INIS)

Feix, Adrien; Araújo, Mateus; Brukner, Caslav

2016-01-01

A recent framework of quantum theory with no global causal order predicts the existence of ‘causally nonseparable’ processes. Some of these processes produce correlations incompatible with any causal order (they violate so-called ‘causal inequalities’ analogous to Bell inequalities ) while others do not (they admit a ‘causal model’ analogous to a local model ). Here we show for the first time that bipartite causally nonseparable processes with a causal model exist, and give evidence that they have no clear physical interpretation. We also provide an algorithm to generate processes of this kind and show that they have nonzero measure in the set of all processes. We demonstrate the existence of processes which stop violating causal inequalities but are still causally nonseparable when mixed with a certain amount of ‘white noise’. This is reminiscent of the behavior of Werner states in the context of entanglement and nonlocality. Finally, we provide numerical evidence for the existence of causally nonseparable processes which have a causal model even when extended with an entangled state shared among the parties. (paper)

Exceptionalist naturalism: Human agency and the causal order.

Science.gov (United States)

Turri, John

2018-02-01

This paper addresses a fundamental question in folk metaphysics: How do we ordinarily view human agency? According to the transcendence account, we view human agency as standing outside of the causal order and imbued with exceptional powers. According to a naturalistic account, we view human agency as subject to the same physical laws as other objects and completely open to scientific investigation. According to exceptionalist naturalism, the truth lies somewhere in between: We view human agency as fitting broadly within the causal order while still being exceptional in important respects. In this paper, I report seven experiments designed to decide between these three competing theories. Across a variety of contexts and types of action, participants agreed that human agents can resist outcomes described as inevitable, guaranteed, and causally determined. Participants viewed non-human animal agents similarly, whereas they viewed computers, robots, and simple inanimate objects differently. At the same time, participants judged that human actions are caused by many things, including psychological, neurological, and social events. Overall, in folk metaphysics, human and non-human animals are viewed as exceptional parts of the natural world.

Evaluación a nivel de laboratorio del efecto de 7 extractos vegetales para el control de Colletotrichum sp agente causal de la antracnosis en el cultivo de tomate de árbol - Evaluación a nivel de laboratorio del efecto de 7 extractos vegetales para el control de Colletotrichum sp agente causal de la antracnosis en el cultivo de tomate de árbol

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Christian Andrei Chacin Zambrano

2013-08-01

Full Text Available Was evaluated in the laboratory the effect of seven plant extracts of Neem leaves and fruit (Azadirachta indica leaves of lemon grass (Swinglea glutinosa, leaves of papaya (Carica papaya, Pringamosa leaves (Urtica dioica, eucalyptus leaves (Eucalyptus camaldulensis Dehn fruits of garlic (Allium sativum L. and fruits of pepper (Capsicum annuum in the control of the fungus Colletotrichum sp causal agent of anthracnose in tomato crop tree (Cyphomandra betacea. The pathogen was isolated on PDA medium from tomato fruit tree, the extracts were obtained taking into account the process by (Marin, et. Al 2007, which consists of chopping and blending plant material deposited in plastic bucket, add water ratio 2.5:1 (water: sample processed, vol.: w, subjecting to fermentation for 24 hours. The produto was filtered using sterile gauze and package them for further evaluation. The concentrations of the treatments that worked were 25, 50, 75 and 100% of the infectious agent, determining the degree of inhibition of the pathogen in Petri dishes. The best results were obtained with the application of eucalyptus leaves, since its effect was 100% at all concentrations, without neglecting the fruits of the Neem and garlic with inhibition percentages of 75 and 60% respectively, had a behavior directly proportional to the concentrations used, since the greater the amount of extract the inhibitory effect was better in this case 75% and 100%.

Agentes trombolíticos en el infarto agudo del miocardio

OpenAIRE

Manuel Cué Brugueras

1995-01-01

Se presenta un revisión bibliográfica sobre los agentes trombolíticos y su uso en el infarto agudo del miocardio con el objetivo de actualizar a los farmacéuticos y otros profesionales de la salud en la terapéutica de este importante problema de salud a nivel internacional. Se revisaron las bases de datos MEDLINE (1985-9/1994), Excerpta Medica (1985-1993), Internacional Pharmaceutical Abstracts (1970-9/1993) y Predicast (1992-11/1993). En la revisión se abordan los beneficios y riesgos de la ...

Factibilidad del uso del almidón de achira como agente controlador de fltrado en lodos de perforación base agua

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Emiliano Ariza León

2013-06-01

Full Text Available El almidón de achira es un polímero de glucosa natural proveniente de una variedad de plantas o semillas, compuesto principalmente por una fracción molecular lineal (amilosa y una ramificada (amilopectina, la relación de estos componentes y su organización física dentro de la estructura granular le confiere al almidón propiedades fisicoquímicas y funcionales características. La industria de los hidrocarburos desde el año de 1930, ha venido utilizando el almidón como agente aditivo en todo tipo de lodos, mostrando alta eficacia en funciones durante las actividades de perforación tales como la remoción de sólidos del fondo del hueco y en el control de filtrado hacia la formación. En este trabajo se evalúo la efectividad del almidón de achira o sagú sin modificar, como agente controlador de filtrado en lodos de perforación base agua, respecto a otros aditivos comercialmente utilizados por la industria, elaborados a base de celulosa polianiónica y polisacárido preservado. Se realizaron, al fluido de perforación y a condiciones de laboratorio, pruebas estándar de filtrado API, reología y pH.Los resultados de esta investigación muestran que el almidón de achira puede ser utilizado como agente controlador de filtrado en lodos de perforación base agua con un rendimiento superior comparado con los aditivos utilizados en este proyecto.

ITS-rDNA phylogeny of Colletotrichum spp. causal agent of apple Glomerella leaf spot Filogenia por ITS-rDNA de Colletotrichum spp., agente causal da mancha foliar da Gala em macieira

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Diorvania Ribeiro Giaretta

2010-04-01

Full Text Available Several diseases have affected apple production, among them there is Glomerella leaf spot (GLS caused by Colletotrichum spp. The first report of this disease in apple was in plants nearby citrus orchards in São Paulo State, Brazil. The origin of this disease is still not clear, and studies based on the molecular phylogeny could relate the organisms evolutionarily and characterize possible mechanisms of divergent evolution. The amplification of 5.8S-ITS (Internal Transcribed Spacer of rDNA of 51 pathogenic Colletotrichum spp. isolates from apples, pineapple guava and citrus produced one fragment of approximately 600 bases pairs (bp for all the isolates analyzed. The amplified fragments were cleaved with restriction enzymes, and fragments from 90 to 500bp were obtained. The sequencing of this region allowed the generation of a phylogenetic tree, regardless of their hosts, and 5 isolated groups were obtained. From the "in silico" comparison, it was possible to verify a variation from 93 to 100% of similarity between the sequences studied and the Genbank data base. The causal agent of GLS is nearly related (clustered to isolates of pineapple guava and to the citrus isolates used as control.A produção de maçã vem sendo comprometida pela ocorrência de muitas doenças, entre as quais se destaca a Mancha Foliar de Glomerella (MFG, causada por Colletotrichum spp. O primeiro relato dessa doença em maçã foi registrado em plantas próximas a pomares de citrus no Estado de São Paulo, Brasil. A origem da MFG ainda não está bem clara, e estudos baseados na filogenia permitirão relacionar o organismo evolutivamente, possibilitando caracterizar possíveis mecanismos divergentes de evolução. A amplificação da região 5.8S-ITS (espaçador interno transcrito do rDNA de 51 isolados de Colletotrichum patogênicos em de maçã, goiabeira serrana e citrus produziu um fragmento de aproximadamente 600 pares de bases (pb para todos os isolados analisados

Solución al Problema de Secuenciación de Trabajos mediante el Problema del Agente Viajero

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G.E. Anaya Fuentes

2016-10-01

Full Text Available Resumen: En este trabajo se estudia el Problema de Secuenciación de Trabajos codificado como un Problema de Agente Viajero y resuelto mediante Algoritmos Genéticos. Se propone un Algoritmo Genético en donde se comparan dos tipos de selección: por torneo y por ruleta. Se realizan diferentes pruebas para la solución del Problema del Agente Viajero con los dos tipos de selección bajo diferentes parámetros: número de individuos, número de iteraciones, probabilidad de cruce y probabilidad de mutación; a partir de estos se seleccionan los parámetros y el tipo de selección. Posteriormente se codifica al Problema de Secuenciación como un Problema del Agente Viajero. La propuesta se presenta mediante la aplicación a diferentes ejemplos del Problema de Secuenciación de Trabajos y la comparación con los resultados obtenidos en la literatura. Abstract: In this paper we proposed a solution to the Job-Shop Scheduling Problem using the Traveling Salesman Problem solved by Genetic Algorithms. We proposed a genetic algorithm where we compare two types of selection: tournament and roulette. Different tests are performed to solve the Traveling Salesman Problem with the two types of selection under different parameters: number of individuals, number of iterations, crossover probability and mutation probability. Then the best type of selection and the best parameters are used to solve the Job-Shop Scheduling Problem with Genetic Algorithms for the Traveling Salesman Problem. The proposal is presented solving different examples of Job Sequencing Problem and compare them with the results obtained in the literature. Palabras clave: algoritmos eficientes, sistemas industriales de producción, problemas de optimización, problema de agente viajero, Keywords: Efficient algorithms, industrial production systems, optimization problem, traveling salesman problem

Moniliophthora roreri, causal agent of cacao frosty pod rot.

Science.gov (United States)

Bailey, Bryan A; Evans, Harry C; Phillips-Mora, Wilbert; Ali, Shahin S; Meinhardt, Lyndel W

2017-12-01

Taxonomy: Moniliophthora roreri (Cif.) H.C. Evans et al. ; Phylum Basidiomycota; Class Agaricomycetes; Order Agaricales; Family Marasmiaceae; Genus Moniliophthora. Biology: Moniliophthora roreri attacks Theobroma and Herrania species causing frosty pod rot. Theobroma cacao (cacao) is the host of major economic concern. Moniliophthora roreri is a hemibiotroph with a long biotrophic phase (45-90 days). Spore masses, of apparent asexual origin, are produced on the pod surface after initiation of the necrotrophic phase. Spores are spread by wind, rain and human activity. Symptoms of the biotrophic phase can include necrotic flecks and, in some cases, pod malformation, but pods otherwise remain asymptomatic. Relationship to Moniliophthora perniciosa: Moniliophthora roreri and Moniliophthora perniciosa, causal agent of witches' broom disease of cacao, are closely related. Their genomes are similar, including many of the genes they carry which are considered to be important in the disease process. Moniliophthora perniciosa, also a hemibiotroph, has a typical basidiomycete lifestyle and morphology, forming clamp connections and producing mushrooms. Basidiospores infect meristematic tissues including flower cushions, stem tips and pods. Moniliophthora roreri does not form clamp connections or mushrooms and infects pods only. Both pathogens are limited to the Western Hemisphere and are a threat to cacao production around the world. Agronomic importance: Disease losses caused by frosty pod rot can reach 90% and result in field abandonment. Moniliophthora roreri remains in the invasive phase in the Western Hemisphere, not having reached Brazil, some islands within the Caribbean and a few specific regions within otherwise invaded countries. The disease can be managed by a combination of cultural (for example, maintenance of tree height and removal of infected pods) and chemical methods. These methods benefit from regional application, but can be cost prohibitive. Breeding for

ESQUEMA DE UNA TEORÍA DEL AGENTE CENTRADA EN LA CREATIVIDAD

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Javier Luis Cristiano

2016-01-01

Full Text Available Las diferentes tradiciones teóricas de la sociología han reconocido que la inventiva, la imaginación y la creatividad son rasgos inherentes a la acción humana. Sin embargo, han privilegiado en sus teorizaciones otros aspectos de la acción, como la racionalidad, el seguimiento de normas sociales, la espontaneidad de las prácticas cotidianas o las habilidades lingüísticas y comunicativas. La intención de este artículo es proponer un esquema amplio y flexible para el desarrollo de una concepción del agente centrada en la creatividad, cuyo interés para las ciencias sociales viene dado por el vínculo, intuitivamente obvio, pero extremadamente complejo, entre creatividad y emergencia de nuevas identidades y nuevas formas de organización social. El esquema parte de una concepción del agente como estratificación de niveles de consciencia y autoconocimiento, diferenciando un plano pulsional de la creatividad, un plano prereflexivo-práctico y un plano discursivo. En cada uno se identifican mecanismos específicos de la creatividad de la acción, para esbozar luego algunas hipótesis de articulación entre los tres y algunas líneas de investigación que podrían, a futuro, apuntalar la propuesta.

UMA TEORÍA CAUSAL PARA LOS CASOS FREGE

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ABEL WAJNERMAN PAZ

2015-06-01

Full Text Available Fodor ha argumentado a favor de un par de tesis que pueden caracterizarse como constituyendo un dilema: Por un lado, si adoptamos una teoría funcional para los conceptos explicamos semánticamente los casos Frege pero caemos en el holismo semántico. Por otro lado, si adoptamos una teoría causal/informacional evitamos el holismo pero no explicamos los casos Frege semánticamente. Fodor (por ej, 1994, 1998 y 2008 intenta evitar la segunda parte del dilema argumentando que los casos de Frege pueden tener una explicación sintáctica y no semántica. En este trabajo intentaré ofrecer una salida alternativa al dilema fodoriano. Propondré una explicación semántica de los casos Frege que incorpora tanto elementos de una teoría causal como de una de rol funcional. Afirmaré que el contenido cognitivo o estrecho de un concepto (el tipo de contenido aparentemente exigido por los casos Frege es el conjunto de contenidos causales/informacionales de las representaciones que figuran en su rol funcional. Considero que individuar a las representaciones en los roles por medio de sus contenidos causales permite evitar el holismo (evitando el proceso de ramsificación típicamente empleado para individuar a los roles y que identificar el contenido cognitivo con contenidos causales/informacionales de las representaciones en los roles permite evitar el referencialismo de las propuestas causales (podemos distinguir sentido de referencia en términos causales.

Gödel and Gödel-type universes in Brans–Dicke theory

Energy Technology Data Exchange (ETDEWEB)

Agudelo, J.A., E-mail: jaar@fisica.ufmt.br [Instituto de Física, Universidade Federal de Mato Grosso, 78060-900, Cuiabá, Mato Grosso (Brazil); Nascimento, J.R., E-mail: jroberto@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, 58051-970, João Pessoa, Paraíba (Brazil); Petrov, A.Yu., E-mail: petrov@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, 58051-970, João Pessoa, Paraíba (Brazil); Porfírio, P.J., E-mail: pporfirio@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, 58051-970, João Pessoa, Paraíba (Brazil); Santos, A.F., E-mail: alesandroferreira@fisica.ufmt.br [Instituto de Física, Universidade Federal de Mato Grosso, 78060-900, Cuiabá, Mato Grosso (Brazil); Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road Victoria, BC (Canada)

2016-11-10

In this paper, conditions for existence of Gödel and Gödel-type solutions in Brans–Dicke (BD) scalar–tensor theory and their main features are studied. The consistency of equations of motion, causality violation and existence of CTCs (closed time-like curves) are investigated. The role which cosmological constant and Mach principle play to achieve the consistency of this model is studied.

Indole-3-acetic acid biosynthesis in Fusarium delphinoides strain GPK, a causal agent of Wilt in Chickpea.

Science.gov (United States)

Kulkarni, Guruprasad B; Sanjeevkumar, S; Kirankumar, B; Santoshkumar, M; Karegoudar, T B

2013-02-01

Fusarium delphinoides (Ascomycota; Nectriaceae) is an indole-3-acetic acid (IAA) producing plant pathogen and a causal agent of wilt in chickpea. The IAA biosynthetic pathway in F. delphinoides strain GPK (FDG) was examined by analyzing metabolic intermediates and by feeding experiments. Gas chromatograph (GC) analysis of FDG culture filtrates showed the presence of metabolic intermediates of indole-3-pyruvic acid (IPyA), indole-3-acetamide (IAM), and tryptamine (TRA) pathways. The different IAA biosynthetic pathways were further confirmed by identifying the presence of different enzymes of these pathways. Substrate specificity study of aromatic amino acid aminotransferase revealed that the enzyme is highly specific for tryptophan (Trp) and α-ketoglutarate (α-kg) as amino group donor and acceptor, respectively. Furthermore, the concentration-dependent effect of exogenous IAA on fungal growth was established. Low concentration of exogenous IAA increases the fungal growth and at high concentration it decreases the growth of FDG.

Esquema de una teoría del agente centrada en la creatividad

Directory of Open Access Journals (Sweden)

Javier Luis Cristiano

2016-03-01

Full Text Available Las diferentes tradiciones teóricas de la sociología han reconocido que la inventiva, la imaginación y la creatividad son rasgos inherentes a la acción humana. Sin embargo, han privilegiado en sus teorizaciones otros aspectos de la acción, como la racionalidad, el seguimiento de normas sociales, la espontaneidad de las prácticas cotidianas o las habilidades lingüísticas y comunicativas. La intención de este artículo es proponer un esquema amplio y flexible para el desarrollo de una concepción del agente centrada en la creatividad, cuyo interés para las ciencias sociales viene dado por el vínculo, intuitivamente obvio, pero extremadamente complejo, entre creatividad y emergencia de nuevas identidades y nuevas formas de organización social. El esquema parte de una concepción del agente como estratificación de niveles de consciencia y autoconocimiento, diferenciando un plano pulsional de la creatividad, un plano prereflexivo-práctico y un plano discursivo. En cada uno se identifican mecanismos específicos de la creatividad de la acción, para esbozar luego algunas hipótesis de articulación entre los tres y algunas líneas de investigación que podrían, a futuro, apuntalar la propuesta.

The key role of causal explanation in the climate change issue

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Francesca Pongiglione

2012-06-01

Full Text Available The basis for adoption of pro-environment behaviour is the understanding of causal passages within climate dynamics. The understanding of the causes of climate change is necessary in order to be able to take mitigation actions  (the subject needs to be aware of his role as a causal agent. Conversely, the understanding of the consequences of climate change is essential in motivating action (the subject must be aware of the risks caused by it in order to prevent them. The case of ozone depletion confirms this view: the understanding of its causal dynamics played a determining role in people’s behavioural response.

La perspectiva de los agentes sanitarios sobre la incorporación programática de la autotoma del test de VPH

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Mariana Curotto

Full Text Available Resumen: El objetivo de este estudio fue analizar la percepción que poseen los agentes sanitarios sobre el ofrecimiento de la autotoma del test de VPH a las mujeres y el grado de acuerdo de los agentes para incorporarla a sus tareas diarias. Para ello, se aplicó una encuesta auto-administrada a 127/191 agentes sanitarios que participaron del Proyecto EMA (Proyecto Evaluación Modalidad Autotoma, llevado a cabo en la provincia de Jujuy (Argentina entre 2012-2013. Los agentes sanitarios que tuvieron y no la experiencia de ofrecer la autotoma manifestaron un alto grado de acuerdo para la adopción de la estrategia (78,7%, dado su potencial para prevenir el cáncer cervicouterino y los aportes que brinda al cuidado de la salud de las mujeres bajo su cobertura. Sin embargo, señalaron la sobrecarga de trabajo y los problemas de articulación con el sistema formal de salud, como los principales obstáculos para ofrecer esta modalidad en el futuro. Este estudio encontró que la autotoma es una práctica que puede ser adoptada por los agentes sanitarios de la provincia de Jujuy, pero debe ir acompañada de acciones de apoyo por parte del sistema de salud formal.

Historia del descubrimiento de la coccidioidomicosis History of the discovery of the coccidioidomycosis

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R Negroni

2011-09-01

Full Text Available La coccidioidomicosis es una micosis sistémica, endémica en las zonas áridas del continente americano, producida por los hongos dimorfos Coccidioides immitis y Coccidioides posadasii. El propósito de esta presentación es dar a conocer la forma en que esta enfermedad y sus agentes causales fueron descubiertos. La enfermedad fue descubierta en 1892, en Buenos Aires, por Posadas y Wernicke. Estos investigadores describieron prolijamente las manifestaciones clínicas de la enfermedad, la histopatología, la fase tisular del agente causal y lograron reproducir la afección en animales. Este estudio fue un modelo de investigación científica para su época. Pensaron que esta nueva enfermedad era debida a un protozoario del género Psorosperma y no consiguieron cultivarlo "in vitro". En1894, Rixford y Gilchrist, en San Francisco (California, observaron un caso similar y pensaron que era debido a un protozoario, al que llamaron Coccidioides immitis. En 1900, Ophüls y Moffit, consiguieron reproducir la enfermedad en cobayos inoculados con de un moho blanquecino, cultivado a partir de las lesiones de pacientes con coccidiodomicosis y comprobaron así la naturaleza fúngica de la infección. Después de este estudio de Ophüls, los investigadoresde California demostraron la existencia de infecciones autolimitadas, la importancia de las pruebas cutáneas y serológicas con coccidioidina, la vía de infección, los tratamientos eficaces y más recientemente las características genéticas de los agentes causales.Coccidioidomycosis is a systemic mycosis, endemic in arid regions of the American continent; it is due to the dimorphic fungi Coccidiodes immitis and Coccidiodes posadasii. The aim of this presentation is to relate the way in which this mycosis and its etiologic agents were discovered. The disease was reported for the first time in Buenos Aires in 1892, by Posadas and Wernicke. They performed a very skilful research, considered outstanding in

Molecular analysis of tooth enamel by Raman spectroscopy after treatment with bleaching agents at different concentrations; Analisis molecular del esmalte dental por medio de espectroscopia Raman despues del tratamiento con agentes blanqueadores a diferentes concentraciones

Energy Technology Data Exchange (ETDEWEB)

Duran Sedo, Randall; Obando Rosabal, Sofia; Saenz Bonilla, Paola; Soto Aguilar, Calendy; Vasquez Rodriguez, Amaya

2014-07-01

The changes in the concentration of the v1 phosphate molecule of the surface of dentin enamel are treated and researched with bleaching agents of chemical activation to basis of hydrogen peroxide than 9,5% and 14% and carbamide peroxide than 38%, for a period of 28 days. Raman spectroscopy was used and 30 dental pieces extracted, of which, were to be free of blemishes and pigmentations, without possessing fractures of the enamel, decay nor any other type of defect. The Raman spectrum was obtained of each dental piece prior to the application of bleaching agents. The specimens were separated into three experimental groups according to the concentration of whitening. The concentration of the v1 phosphate molecule was measured in the tooth enamel to the second and fourth week of treatment. In addition, ANOVA was performed for respective measurements (p≤0.05). A reduction of the v1 phosphate molecule were observed during and after the bleaching process in the experimental groups that have used of hydrogen peroxide to 14% and carbamide peroxide 38%. In the group of hydrogen peroxide to 9,5% has remained unproven a significant reduction. Within the limitations of this study is concluded that the bleaching agent causes a loss of v1 phosphate. This loss has been greater in the whitening of higher concentration. In spite, that the possible effect remineralizing of the saliva on a teeth whitening process has been unevaluated, it is recommended using during and after the treatment, toothpastes, mouthwashes, chewing gums, dental floss, among others, that contain ACP to help to cushion the potential loss of phosphate from tooth enamel. (author) [Spanish] Los cambios en la concentracion de la molecula de fosfato v1 de la superficie del esmalte dental son tratados e investigados con agentes blanqueadores de activacion quimica a base de peroxido de hidrogeno al 9,5% y 14% y peroxido de carbamida al 38%, por un periodo de 28 dias. Espectroscopia Raman fue utilizada y 30 piezas

Causal imprinting in causal structure learning.

Science.gov (United States)

Taylor, Eric G; Ahn, Woo-Kyoung

2012-11-01

Suppose one observes a correlation between two events, B and C, and infers that B causes C. Later one discovers that event A explains away the correlation between B and C. Normatively, one should now dismiss or weaken the belief that B causes C. Nonetheless, participants in the current study who observed a positive contingency between B and C followed by evidence that B and C were independent given A, persisted in believing that B causes C. The authors term this difficulty in revising initially learned causal structures "causal imprinting." Throughout four experiments, causal imprinting was obtained using multiple dependent measures and control conditions. A Bayesian analysis showed that causal imprinting may be normative under some conditions, but causal imprinting also occurred in the current study when it was clearly non-normative. It is suggested that causal imprinting occurs due to the influence of prior knowledge on how reasoners interpret later evidence. Consistent with this view, when participants first viewed the evidence showing that B and C are independent given A, later evidence with only B and C did not lead to the belief that B causes C. Copyright © 2012 Elsevier Inc. All rights reserved.

Monitoring the infective process of the downy mildew causal agent within micropropagated rose plants

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Sonia Yamile Gómez

2012-08-01

Full Text Available Downy mildew in the rose caused by a species of the Peronospora genus is a very restrictive disease for the Colombian greenhouse rose production. The damage observed in the susceptible varieties of commercial rose include symptoms affect young steams and tiny leaves causing reddish and brown spots and defoliation; leading to 10% production losses. The infective behavior of this pathogen was studied with the aim of increasing the knowledge about the biology of the rose downy mildew. The study of the infective process was performed on the Charlotte variety using micropropagated roses inoculated with suspensions of sporangia. A germinal tube was observed during the germination process, it came from a lateral papilla and reached up to 300 microns in length. During this study, the ability of the pathogen to use vascular sieves as communication systems within the plant was determined. Oogonia and antheridia were also observed inside the epidermal cells, and oospores inside the parenchymal tissue close to xylem vessels. To the best of our knowledge, these sexual structures have not been reported on in Colombia before. This study verifies the ability of the downy mildew causal agent to move through the xylem vessels and produce sexual structures, such as oogonia, antheridia and oospores within those tissues.

First Isolation and Molecular Characterization of Bacteriophages Infecting Acidovorax citrulli, the Causal Agent of Bacterial Fruit Blotch

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Aryan Rahimi-Midani

2018-02-01

Full Text Available Bacteriophages of Acidovorax citrulli, the causal agent of bacterial fruit blotch, were isolated from 39 watermelon, pumpkin, and cucumber leaf samples collected from various regions of Korea and tested against 18 A. citrulli strains. Among the six phages isolated, ACP17 forms the largest plaque, and exhibits the morphology of phages in the Myoviridae family with a head diameter of 100 ± 5 nm and tail length of 150 ± 5 nm. ACP17 has eclipse and latent periods of 25 ± 5 min and 50 ± 5 min, respectively, and a burst size of 120. The genome of ACP17 is 156,281 base pairs with a G + C content of 58.7%, 263 open reading frames, and 4 transfer RNA genes. Blast search and phylogenetic analysis of the major capsid protein showed that ACP17 has limited homology to two Stentrophomonas phages, suggesting that ACP17 is a new type of Myoviridae isolated from A. citrulli.

Causas y sobrevida en pacientes quemados en el centro de referencia del nororiente de Colombia

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Carlos E. Ramírez-Blanco

Full Text Available Introducción y Objetivo: En el mundo, las quemaduras son causa importante de morbilidad y responsables del fallecimiento de más de 300.000 personas al año. Más del 90% de estas muertes ocurren en países con ingresos bajos o medios. El objetivo de este estudio es caracterizar los pacientes quemados hospitalizados en el centro de referencia para el nororiente de Colombia, el Hospital Universitario de Santander, en Bucaramanga. Material y Método. Realizamos un estudio observacional, descriptivo y longitudinal, con información tomada de historias clínicas de pacientes quemados hospitalizados en el Hospital Universitario de Santander en un periodo de 12 meses. Obtuvimos información sociodemográfica y médica. Llevamos a cabo un análisis estadístico con medidas de tendencia central, proporciones, incidencia global y específica, además de densidad de incidencia global y específica. Resultados. Durante el 2014 se hospitalizaron en el centro de estudio 402 pacientes quemados provenientes de 12 departamentos del país, 234 (58.2% hombres y 168 (41.8% mujeres, con edades de entre 6 días y 83 años. Las quemaduras comprometían entre el 1-80% de superficie corporal; el 95.5% de los pacientes tenían vinculación con el Sistema General de Seguridad Social Nacional. Los agentes causales incluyeron líquidos calientes (52.5%, fuego (10.0%, gasolina (9.2%, electricidad (7.5% y químicos (3.7%, entre otros, y produjeron quemaduras de segundo y/o tercer grado. La mediana de la estancia hospitalaria fue de 14 días, con mortalidad acumulada del 1.5% que se relacionó con la profundidad y extensión de la quemadura. Consideramos que el tipo de agente compromete con mayor frecuencia a un grupo etario determinado por las actividades propias de la edad; que la profundidad de la quemadura puede tener relación con el agente causal debido a la temperatura que alcanza; y que la extensión de la quemadura es el único predictor de mortalidad y se relaciona

Morphological and molecular characterization of the causal agent of downy mildew on Quinoa (Chenopodium quinoa).

Science.gov (United States)

Choi, Young-Joon; Danielsen, Solveig; Lübeck, Mette; Hong, Seung-Beom; Delhey, Rolf; Shin, Hyeon-Dong

2010-05-01

Downy mildew is an economically important and widespread disease in quinoa (Chenopodium quinoa) growing areas. Although in many studies Peronospora farinosa is most commonly regarded as the causal agent of the disease, identification and classification of the pathogen remain still uncertain due to its taxonomic confusion. Thirty-six Peronospora isolates from quinoa with different geographic origins including Argentina, Bolivia, Denmark, Ecuador, and Peru were morphologically and molecularly compared with Peronospora species from other Chenopodium species. The morphology of three herbarium specimens was similar to that of P. variabilis, which originated from C. album, characterized by flexuous to curved ultimate branchlets and pedicellated conidia. Phylogenetic analysis based on ITS rDNA sequences also placed the quinoa pathogen within the same clade as P. variabilis. Within the ITS rDNA sequences of the quinoa pathogens, two base substitutions were found, which separated the majority of the Danish isolates from isolates from South America, but no sequence difference was found among the isolates from different cultivars of quinoa. The present results indicate that the pathogen responsible for the quinoa downy mildew is identical to Peronospora variabilis and that it should not be lumped with P. farinosa as claimed previously by most studies.

Susceptibility of Haemophilus equigenitalis, the causal agent of contagious equine metritis, to 31 antimicrobial agents.

Science.gov (United States)

Sugimoto, C; Isayama, Y; Kashiwazaki, M; Mitani, K

1981-01-01

The minimal inhibitory concentrations of 31 antimicrobial agents were determined for 99 isolates of Haemophilus equigenitalis by the agar dilution method. All the isolates showed good susceptibility to 26 antimicrobial agents tests, minimal inhibitory concentrations of which were less than 3.13 micrograms/ml for more than 90% of the isolates. Of these agents, 4 macrolides (erythromycin, oleandomycin, kitasamycin, tylosin), 3 tetracyclines (tetracycline, chlortetracycline, oxytetracycline), 1 peptide (colistin), 1 penicillin (ampicillin) and 1 pleuromutilin (tiamulin) were the most active agents, showing a minimal inhibitory concentration of less than 0.39 micrograms/ml for more than 90% of the isolates. The growth of more than 90% of the isolates was not inhibited by 800 micrograms/ml of streptomycin.

Optimal causal inference: estimating stored information and approximating causal architecture.

Science.gov (United States)

Still, Susanne; Crutchfield, James P; Ellison, Christopher J

2010-09-01

We introduce an approach to inferring the causal architecture of stochastic dynamical systems that extends rate-distortion theory to use causal shielding--a natural principle of learning. We study two distinct cases of causal inference: optimal causal filtering and optimal causal estimation. Filtering corresponds to the ideal case in which the probability distribution of measurement sequences is known, giving a principled method to approximate a system's causal structure at a desired level of representation. We show that in the limit in which a model-complexity constraint is relaxed, filtering finds the exact causal architecture of a stochastic dynamical system, known as the causal-state partition. From this, one can estimate the amount of historical information the process stores. More generally, causal filtering finds a graded model-complexity hierarchy of approximations to the causal architecture. Abrupt changes in the hierarchy, as a function of approximation, capture distinct scales of structural organization. For nonideal cases with finite data, we show how the correct number of the underlying causal states can be found by optimal causal estimation. A previously derived model-complexity control term allows us to correct for the effect of statistical fluctuations in probability estimates and thereby avoid overfitting.

Comparación del efecto citotóxico de tres agentes quelantes sobre fibroblasto del ligamento periodontal humano. Estudio in vitro

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Edwin De la Cruz Rocha

2012-01-01

Full Text Available Objetivo: Comparar in vitro el efecto citotóxico de tres agentes quelantes sobre fibroblastos del ligamento periodontal humano. Materiales y métodos: Se utilizaron cultivos de fibroblastos de ligamento periodontal humano, los cuales fueron colocados en contacto con los agentes quelantes a evaluar (RCPrep, Glyde, EDTA al 17% a intervalos de 15, 30 y 60 minutos. Se midió la absorbancia para cada uno de los grupos, para determinar el grado de actividad enzimática, que es indicador de muerte celular. Previo a la cuantificación de la absorbancia se corroboró microscópicamente la formación de los cristales de formazán, los cuales se forman alrededor de los fibroblastos, y su presencia es indicador de integridad de la membrana y de la actividad metabólica. Por microscopia se verificó la formación de cristales de formazan, después de agregar azul de tripán. Resultados: El Glyde mostró mayor grado de citotoxicidad, con una diferencia estadísticamente significativa, al compararlo con EDTA 17% y el RC-PREP. El EDTA presentó mayor citotoxicidad que el RC-PREP a los 15minutos, evento que cambió a los 30 y 60 minutos. Conclusiones: Los agentes quelantes RC-Prep, Glyde y EDTA tienen un efecto citotóxico a nivel de los fibroblastos del ligamento periodontal, siendo el EDTA el de menor efecto citotóxico a los 30 y 60 minutos comparado con RC-Prep y Glyde.

"Variación sintáctica en las construcciones pasivas: las preposiciones introductoras del agente"

NARCIS (Netherlands)

Nieuwenhuijsen, Dorien

2015-01-01

El presente trabajo constituye un estudio diacrónico acerca de la pérdida de la preposición de como introductora del complemento agente y la subsiguiente propagación de la preposición por en construcciones pasivas perifrásticas con ser. Además de presentar datos cuantitativos acerca de la

Efectos de la inducción emocional en el Aprendizaje Causal

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Amparo Herrera

2006-01-01

Full Text Available Uno de los aspectos del aprendizaje causal menos estudiado es el papel que las emociones juegan en dicho aprendizaje. El principal objetivo de esta investigación fue estudiar el impacto que ejercen las emociones sobre una tarea de detección de relaciones causales de carácter afectivo neutral. La inducción de emociones negativas hizo que los participantes subestimaran la relación causal entre los sucesos presentados tanto cuando ésta era de tipo generativo (Experimento 1 – contingencia positiva – como cuando era de tipo preventivo (Experimento 2 – contingencia negativa –. Sin embargo, los participantes recordaban adecuadamente la frecuencia de ocurrencia de cada tipo de ensayo, y sus respuestas de predicción ensayo-a-ensayo no se vieron afectadas por la inducción de emociones. Estos datos parecen apoyar a las teorías que propugnan la existencia de procesos añadidos al mecanismo de cómputo de ocurrencias en la apreciación de relaciones causales entre sucesos, como serían los procesos de integración de la información derivada de las creencias causales previas.

Causality

Science.gov (United States)

Pearl, Judea

2000-03-01

Written by one of the pre-eminent researchers in the field, this book provides a comprehensive exposition of modern analysis of causation. It shows how causality has grown from a nebulous concept into a mathematical theory with significant applications in the fields of statistics, artificial intelligence, philosophy, cognitive science, and the health and social sciences. Pearl presents a unified account of the probabilistic, manipulative, counterfactual and structural approaches to causation, and devises simple mathematical tools for analyzing the relationships between causal connections, statistical associations, actions and observations. The book will open the way for including causal analysis in the standard curriculum of statistics, artifical intelligence, business, epidemiology, social science and economics. Students in these areas will find natural models, simple identification procedures, and precise mathematical definitions of causal concepts that traditional texts have tended to evade or make unduly complicated. This book will be of interest to professionals and students in a wide variety of fields. Anyone who wishes to elucidate meaningful relationships from data, predict effects of actions and policies, assess explanations of reported events, or form theories of causal understanding and causal speech will find this book stimulating and invaluable.

Causal events enter awareness faster than non-causal events

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Pieter Moors

2017-01-01

Full Text Available Philosophers have long argued that causality cannot be directly observed but requires a conscious inference (Hume, 1967. Albert Michotte however developed numerous visual phenomena in which people seemed to perceive causality akin to primary visual properties like colour or motion (Michotte, 1946. Michotte claimed that the perception of causality did not require a conscious, deliberate inference but, working over 70 years ago, he did not have access to the experimental methods to test this claim. Here we employ Continuous Flash Suppression (CFS—an interocular suppression technique to render stimuli invisible (Tsuchiya & Koch, 2005—to test whether causal events enter awareness faster than non-causal events. We presented observers with ‘causal’ and ‘non-causal’ events, and found consistent evidence that participants become aware of causal events more rapidly than non-causal events. Our results suggest that, whilst causality must be inferred from sensory evidence, this inference might be computed at low levels of perceptual processing, and does not depend on a deliberative conscious evaluation of the stimulus. This work therefore supports Michotte’s contention that, like colour or motion, causality is an immediate property of our perception of the world.

DISTRIBUCIÓN ESPACIAL DEL AMACHAMIENTO DEL FRIJOL (Aphelenchoides besseyi CHRISTIE EN CAMPO

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N\\u00E9stor Felipe Chaves-Barrantes

2014-01-01

Full Text Available El objetivo del presente trabajo fue determinar la distribución espacial del amachamiento en campo. La investigación se realizó entre mayo y julio del 2009 en las comunidades de Veracruz de Pérez Zeledón, San José y Concepción de Buenos Aires, Puntarenas, Costa Rica. Para ello se evaluó la incidencia de la enfermedad por punto de siembra en dos parcelas de frijol provenientes de distintas rotaciones (arroz/frijol y maíz/fri - jol, con lo cual, posteriormente se determinó la distribución espacial de la enfermedad en campo por medio de un análisis de corridas y los índices de varianza/media (V/M, Lloyd y Morisita. En el análisis de corridas se obtuvo un valor pro - medio de Z de -1,06 para la parcela sembrada previamente con arroz, y de -0,98 para la parcela sembrada previamente con maíz, lo que indica una tendencia a la agregación. Los índices de V/M, Lloyd y Morisita fueron mayores que 1 en ambas parcelas, por lo que se determinó que el amacha - miento presentó un patrón espacial agregado (en parches en condiciones de campo. El patrón espacial del amachamiento en campo tiende a enmascararse debido a la rotación con cultivos hospederos de Aphelenchoides besseyi , – su agente causal –, en especial la rotación maíz/frijol donde el produc - tor redistribuye el inóculo de la enfermedad cuando esparce las cañas de maíz sobre el terreno de cultivo

Concepts in causality: chemically induced human urinary bladder cancer

International Nuclear Information System (INIS)

Lower, G.M. Jr.

1982-01-01

A significant portion of the incidence of human urinary bladder cancer can be attributed to occupational and cultural (tobacco smoking) situations associated with exposures to various arylamines, many of which represent established human carcinogens. A brief historical overview of research in bladder cancer causality indicates that the identification of causal agents and causal mechanism has been approached and rests upon information gathered at the organismal (geographical/historical), cellular, and molecular levels of biologic organization. This viewpoint speaks of a natural evolution within the biomedical sciences; a natural evolution from descriptive approaches to mechanistic approaches; and a natural evolution from more or less independent discipline-oriented approaches to hierarchically organized multidisciplinary approaches. Available information relevant to bladder cancer causality can be readily integrated into general conceptual frameworks to yield a hierarchial view of the natural history of urinary bladder cancer, a view consistent with contemporary natural systems and information theory and perhaps relevant also to other chemically induced epithelial cancers. Such frameworks are useful in appreciating the spatial and temporal boundaries and interrelationships in causality and the conceptual interrelationships within the biomedical sciences. Recent approaches in molecular epidemiology and the assessment of relative individual susceptibility to bladder cancer indicate that such frameworks are useful in forming hypotheses

Atribuciones sobre el uso de la fuerza policial desde la perspectiva del agente

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Julián Martínez

2014-08-01

Full Text Available Se describen los contenidos de los procesos atribucionales asociados al uso de la fuerza en agentes de la Policía de la Provincia de Córdoba, Argentina. Los antecedentes indican que, además de los marcos legales, existen sistemas de creencias, valores, actitudes, definiciones morales, aspectos situacionales y una cultura institucional, que operan en los policías al momento de usar la fuerza. Mediante entrevistas en profundidad a 10 agentes policiales de la Provincia de Córdoba, hallamos dimensiones atributivas externas e internas, que a su vez guardan relación con el tipo de trabajo policial según éste sea bajo órdenes o sin ellas. También identificamos relaciones entre dichas dimensiones y diferentes niveles de fuerza que se aplican. Esta investigación cobra importancia por su abordaje psicosocial que prioriza la comprensión de las dimensiones subjetivas de los agentes, evitando explicar la práctica policial únicamente como un mecanismo para el control del orden social y político.

Theories of Causality

Science.gov (United States)

Jones, Robert

2010-03-01

There are a wide range of views on causality. To some (e.g. Karl Popper) causality is superfluous. Bertrand Russell said ``In advanced science the word cause never occurs. Causality is a relic of a bygone age.'' At the other extreme Rafael Sorkin and L. Bombelli suggest that space and time do not exist but are only an approximation to a reality that is simply a discrete ordered set, a ``causal set.'' For them causality IS reality. Others, like Judea Pearl and Nancy Cartwright are seaking to build a complex fundamental theory of causality (Causality, Cambridge Univ. Press, 2000) Or perhaps a theory of causality is simply the theory of functions. This is more or less my take on causality.

IDENTIFICACIÓN DEL AGENTE CAUSAL DE LA ANTRACNOSIS DE Sansevieria spp. EN COSTA RICA

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Gerardo Pérez-León

2013-01-01

Full Text Available Sansevieria spp. (Agavaceae es una ornamental de follaje originaria de África y Asia. S. trifasciata (St es la especie con mayor número de cultivares en el mercado de exportación de Costa Rica a Estados Unidos y Holanda. Muestras foliares de S. trifasciata var. “Hahnii” con lesiones circulares y acuosas (algunas alargadas y secas, fueron analizadas. El patógeno recuperado fue identificado como Colletotrichum sansevieriae Nakamura (CsN mediante pruebas de patogenicidad, morfología y técnicas moleculares. Los aislamientos mono-hifales presentaron coloración crema, crecimiento postrado y escasa producción de conidios. La patogenicidad de CsN se evaluó en 7 variedades de St; Sansevieriasp., var., jiboia; S. cylindrica y las ornamentalesCodiaeum variegatum, Cordelyne terminalis y Dracaena deremensis, mediante 2 sistemas deinoculación: plantas en maceta (invernaderoy hojas separadas (laboratorio; con ambos sereprodujeron los síntomas de la enfermedad. Cinco de las variedades de S. trifasciata desarrollaron síntomas, “Hahnii” la más susceptible. Ninguna de las otras ornamentales presentósíntomas. CsN fue re-aislado de hojas inoculadas (postulados de Koch. La amplificación mediante PCR de la región ITS con los iniciadores ITS5 e ITS4 produjo un fragmento de aproximadamente 600pb, cuya secuencia de nucleótidos fue idéntica para los aislamientos mono-hifales. En el Banco de Genes, la secuencia alineó con accesiones de CsN de Australia y USA, con un índice de simi laridad del 99 al 100%. El análisis filogenético, con base en la región ITS2, agrupó (99% valor debootstrap los aislamientos costarricenses con elaislamiento tipo CsN de Japón y los de Australia y USA. Hasta donde se conoce, éste es el primer informe de la antracnosis de Sansevieria en C. R.

Procesos de inferencia y aprendizaje de relaciones causales en el condicionamiento de segundo orden

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Javier Vila

2007-01-01

Full Text Available Los objetivos de este trabajo fueron en primer lugar, demostrar la fiabilidad y las condiciones necesarias del condicionamiento de segundo orden (CSO en tareas de aprendizaje causal (Experimento 1; en segundo lugar, mostrar que la extinción de la relación causal de primer orden, no produce el mismo efecto de extinción en la relación causal de segundo orden (Experimento 2. Las aportaciones de este estudio fueron por un lado, que durante la fase de extinción de la causa de primer orden, se conservó el nivel de excitación en la condición de control; y por otro, que en la fase de prueba se evaluaba el efecto de la extinción no sólo sobre las claves de segundo orden, sino también sobre todas las de primer orden, extinguidas o no. Los resultados comprobaron que la extinción y ruptura de la relación causal de primer orden, no genera la extinción de la relación de segundo orden (CSO una vez establecida, aunque sí produjo una atenuación de la fuerza de dicha relación causal. El conjunto de resultados es fácil de explicar desde los mismos modelos asociativos utilizados para explicar dicho efecto (CSO en condicionamiento animal, basados en el aprendizaje de relaciones independientes entre estímulos condicionados y estímulos incondicionados. De manera similar y desde una perspectiva cognitiva, los resultados sugieren que el individuo durante el proceso de aprendizaje del CSO no forma relaciones causales encadenadas, sino más bien relaciones relativamente independientes entre cada causa y sus efectos.

Leucemias y radiación: juicio causal según los criterios de SIR Austin Bradford Hill

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Octavio Martínez Betancur

2010-07-01

Full Text Available El cometido del presente trabajo es la lectura interpretativa con base en la propuesta de inferencia causal de Austin Bradford Hill, del documento Radiation-related leukemia in Hiroshima and Nagasaki, 1946-1964. I. Distribution, incidence and appearance time. El documento informado por el comité de las víctimas de la bomba atómica cumple con la totalidad de los nueve “criterios” propuesto por Hill, y entre las limitaciones se cuentan la presunciones de homogeneidad genética de los sujetos expuestos y linealidad de los efectos de las radiaciones en la leucemia, además del hecho de sólo considerar la edad como variable confusora. Por otra parte, el número de muertes por leucemia, patrón de oro de la sensibilidad y la especificidad del sistema de vigilancia del estudio de duración de la vida, fue 61 muertes por leucemia entre los supervivientes situados dentro de 1500 metros del epicentro de la explosión y 25 muertes en el grupo que recibió radiación estando entre 1501 y 10000 metros, lo que habla de posible subregistro de casos y de sobrediagnóstico por la sumatoria de criterios empleados. Los “criterios” de Hill no son reglas lógicas sino metodológicas, que ayudan en el proceso de decisión sobre la inferencia causal en epidemiología. Se apartan de la discusión de si las inferencias a partir de ellos se ajustan a la lógica inductiva o a la deductiva, y deben entenderse pragmáticamente como “inferencias de la mejor explicación” en el contexto de la abducción. La única conclusión permitida dentro del marco de la “inferencia de la mejor explicación”, es que se tienen buenas razones para considerar seriamente la hipótesis que la asociación estadística que se estudia, es una relación causal.

Resistencia bacteriana:sinergismo in vitro y eficacia clínica del tratamiento antimicrobiano en neonatos sépticos

OpenAIRE

Espino Hernández, María Hildelisa

2009-01-01

Este trabajo tuvo como objetivo determinar la etiología y susceptibilidad de los agentes causales de sepsis neonatal y la eficacia clínica del tratamiento antimicrobiano por pruebas de sinergismo in vitro, en el Hospital Ginecobstétrico Universitario "América Arias", durante el periodo comprendido desde enero de 1993 a diciembre 2000. Se definieron los patrones de resistencia de 533 cepas aisladas de los recién nacidos frente a los ß-lactámicos y aminoglucósidos, y se evaluó, por el método de...

Toxicology and Epidemiology: Improving the Science with a Framework for Combining Toxicological and Epidemiological Evidence to Establish Causal Inference

Science.gov (United States)

Adami, Hans-Olov; Berry, Sir Colin L.; Breckenridge, Charles B.; Smith, Lewis L.; Swenberg, James A.; Trichopoulos, Dimitrios; Weiss, Noel S.; Pastoor, Timothy P.

2011-01-01

Historically, toxicology has played a significant role in verifying conclusions drawn on the basis of epidemiological findings. Agents that were suggested to have a role in human diseases have been tested in animals to firmly establish a causative link. Bacterial pathogens are perhaps the oldest examples, and tobacco smoke and lung cancer and asbestos and mesothelioma provide two more recent examples. With the advent of toxicity testing guidelines and protocols, toxicology took on a role that was intended to anticipate or predict potential adverse effects in humans, and epidemiology, in many cases, served a role in verifying or negating these toxicological predictions. The coupled role of epidemiology and toxicology in discerning human health effects by environmental agents is obvious, but there is currently no systematic and transparent way to bring the data and analysis of the two disciplines together in a way that provides a unified view on an adverse causal relationship between an agent and a disease. In working to advance the interaction between the fields of toxicology and epidemiology, we propose here a five-step “Epid-Tox” process that would focus on: (1) collection of all relevant studies, (2) assessment of their quality, (3) evaluation of the weight of evidence, (4) assignment of a scalable conclusion, and (5) placement on a causal relationship grid. The causal relationship grid provides a clear view of how epidemiological and toxicological data intersect, permits straightforward conclusions with regard to a causal relationship between agent and effect, and can show how additional data can influence conclusions of causality. PMID:21561883

Quemaduras accidentales en niños y niñas remitidos del nivel primario de atención

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Raúl Ricardo Rizo González

2015-01-01

Full Text Available Se realizó un estudio descriptivo y transversal de 58 pacientes con quemaduras, ingresados en el Servicio de Caumatología del Hospital Infantil Norte Docente "Juan de la Cruz Martínez Maceira" de Santiago de Cuba, remitidos del nivel primario de atención, desde enero de 2009 hasta diciembre de 2010, con el objetivo de investigar los factores más frecuentes que ocasionaron estos accidentes. En la serie predominaron el sexo masculino, los líquidos hirvientes como agente causal más frecuente, además de la baja percepción del riesgo, las malas condiciones de vida y la procedencia rural como factores socioeconómicos desfavorables. La atención médica se consideró satisfactoria ya que más de 50 % de los pacientes ingresaron entre graves y críticos extremos y solo dos 2 fallecieron

Causal boundary for stably causal space-times

International Nuclear Information System (INIS)

Racz, I.

1987-12-01

The usual boundary constructions for space-times often yield an unsatisfactory boundary set. This problem is reviewed and a new solution is proposed. An explicit identification rule is given on the set of the ideal points of the space-time. This construction leads to a satisfactory boundary point set structure for stably causal space-times. The topological properties of the resulting causal boundary construction are examined. For the stably causal space-times each causal curve has a unique endpoint on the boundary set according to the extended Alexandrov topology. The extension of the space-time through the boundary is discussed. To describe the singularities the defined boundary sets have to be separated into two disjoint sets. (D.Gy.) 8 refs

Detección y cuantificación del Potato mop-top virus (PMTV) en Colombia mediante qRT-PCR

OpenAIRE

Nevar García Bastidas; Pablo Gutiérrez Sánchez; Mauricio Marín Montoya

2013-01-01

El Potato mop-top virus (PMTV) es uno de los virus re-emergentes en cultivos de papa en Colombia. Es transmitido por Spongospora subterranea, el agente causal de la sarna polvosa. La detección del PMTV presenta dificultades debido a su distribución irregular en las plantas, bajo título y movimiento sistémico como ARN desnudo. Con el fin de ampliar el rango de herramientas disponibles para detectar el PMTV en los programas de certificación de tubérculo-semilla, en este estudio se evaluó la pru...

Onicomicosis: epidemiología, agentes causales y evaluación de los métodos diagnósticos de laboratorio Onychomycoses: epidemiology, causative agents and assessment of diagnostic laboratory methods

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Javier R Nazar

2012-03-01

Full Text Available Desde marzo de 2007 hasta marzo de 2011 se estudiaron prospectivamente 414 pacientes con onicodistrofias en un laboratorio privado de Esquel. La prevalencia de onicomicosis de pie fue del 78 %; la de mano, del 58 %. Los principales agentes etiológicos fueron Trichophyton rubrum, Candida spp. y Trichophyton mentagrophytes. El desarrollo de dermatofitos prevaleció en las onicopatías de pie y el de Candida spp. en las de uñas de mano (ambos, p Since March 2007 to March 2011, 414 patients with onychopathies were prospectively analyzed. Prevalence of the toenail and fingernail mycoses was 78 % and 58 %, respectively. The major etiological agents were Trichophyton rubrum, Candida spp. and Trichophyton mentagrophytes. Dermatophytes were more frequently cultured from toenails, whereas Candida spp. from fingernails (both, p < 0.05. In candidal onychomycosis, species different from C. albicans were prevalent. A higher prevalence of toenail and fingernail mycoses, a predominance of T. rubrum in toenails (p < 0.05, and greater positivity in the direct examination (DE and in culture (both, p < 0.05 were more frequently observed in men than in women. The correlation between DE and culture was 68 %. DE and culture yields were associated with a greater size lesion. DE was more effective in onycodystrophies with duration of more than 5 years. Culture positivity was independent of nail affection chronicity.

Causal universe

CERN Document Server

Ellis, George FR; Pabjan, Tadeusz

2013-01-01

Written by philosophers, cosmologists, and physicists, this collection of essays deals with causality, which is a core issue for both science and philosophy. Readers will learn about different types of causality in complex systems and about new perspectives on this issue based on physical and cosmological considerations. In addition, the book includes essays pertaining to the problem of causality in ancient Greek philosophy, and to the problem of God's relation to the causal structures of nature viewed in the light of contemporary physics and cosmology.

Causal relationship: a new tool for the causal characterization of Lorentzian manifolds

International Nuclear Information System (INIS)

Garcia-Parrado, Alfonso; Senovilla, Jose M M

2003-01-01

We define and study a new kind of relation between two diffeomorphic Lorentzian manifolds called a causal relation, which is any diffeomorphism characterized by mapping every causal vector of the first manifold onto a causal vector of the second. We perform a thorough study of the mathematical properties of causal relations and prove in particular that two given Lorentzian manifolds (say V and W) may be causally related only in one direction (say from V to W, but not from W to V). This leads us to the concept of causally equivalent (or isocausal in short) Lorentzian manifolds as those mutually causally related and to a definition of causal structure over a differentiable manifold as the equivalence class formed by isocausal Lorentzian metrics upon it. Isocausality is a more general concept than the conformal relationship, because we prove the remarkable result that a conformal relation φ is characterized by the fact of being a causal relation of the particular kind in which both φ and φ -1 are causal relations. Isocausal Lorentzian manifolds are mutually causally compatible, they share some important causal properties, and there are one-to-one correspondences, which are sometimes non-trivial, between several classes of their respective future (and past) objects. A more important feature is that they satisfy the same standard causality constraints. We also introduce a partial order for the equivalence classes of isocausal Lorentzian manifolds providing a classification of all the causal structures that a given fixed manifold can have. By introducing the concept of causal extension we put forward a new definition of causal boundary for Lorentzian manifolds based on the concept of isocausality, and thereby we generalize the traditional Penrose constructions of conformal infinity, diagrams and embeddings. In particular, the concept of causal diagram is given. Many explicit clarifying examples are presented throughout the paper

Efecto de diferentes niveles de nitrógeno, potasio y Ph en el desarrollo de Fusarium oxysporum f.sp. dianthi, agente causal del marchitamiento vascular del clavel

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Orozco de Amézquita Martha

1993-06-01

Full Text Available Un balance de los diversos elementos nutricionales es indispensable para que un cultivo alcance su máximo potencial de crecimiento y desarrollo. Este balance implica un suministro equilibrado de nutrientes combinado con condiciones climáticas, edáficas y culturales adecuadas (Palti, 1981. El manejo de la nutrición de un cultivo se realiza a
través de la aplicación de fertilizantes o mediante la modificación del suelo y es uno de los componentes
importantes dentro del manejo de diversas enfermedades de las plantas (Huber, 1989. Aunque sólo muy pocas enfermedades pueden ser controladas totalmente por un régimen de fertilización, la severidad de muchas de ellas puede reducirse de una manera importante por la nutrición y con el uso; integrado de otras medidas de control genético,
biológico, qulmico y cultural (Huber, 1980.

Evasión molecular de la activación del macrófago bovino por Mycobacterium avium subespecie paratuberculosis

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René Ramírez G.

2013-11-01

Full Text Available El Mycobacterium avium subespecie paratuberculosis (MAP es el agente causal de una enfermedad granulomatosica crónica, que afecta el tracto gastrointestinal de rumiantes domesticos y salvajes, conocida como la enfermedad de Johne o paratuberculosis. MAP es un microorganismo de crecimiento lento en cultivo, no obstante sobrevive in vivo en células fagocíticas mononucleares de los rumiantes, bajo condiciones de susceptibilidad individual, virulencia de la cepa infectante y estado inmune del individuo afectado. Una vez MAP es fagocitado por el macrófago bovino, tanto el macrófago como MAP activan: el uno para tratar de destruir a MAP y luego sufrir apoptosis y el otro para evadir su destrucción dentro del fagolisosoma del macrófago. El balance de dicha confrontación molecular determina el curso inicial de la infección hacia la eliminación eficiente del microorganismo o hacia el establecimiento de la infección, que culminará en los estadios III (clínico intermitente y IV (clínica terminal de la enfermedad de Johne. En la presente revisión se discuten los diferentes mecanismos moleculares por los cuales MAP evade la respuesta inmune, con énfasis en su comportamiento dentro de la vacuola fagocítica y como el agente establece mecanismos de sobrevivencia intracelular y altera la activación de los macrófagos del hospedero y de la respuesta inmune específica.

Detection and characterization of mango malformation and its causal agent in Spain

OpenAIRE

Crespo Palomo, María

2014-01-01

El mango (Mangifera indica L.) es un árbol originario de la región indobirmana, laderas del Himalaya y Sri Lanka, donde aún existen poblaciones silvestres y ha sido cultivado desde la antigüedad en la India como atestiguan las sagradas escrituras hindúes, los libros de los Vedas, redactadas entre el 1500 y el 1000 a. C. (Galán-Saúco, 2009). La dispersión del mango fue muy rápida por el subcontinente de la India y el archipiélago malayo con la apertura del comercio entre Asia y Europa. El mang...

Caracterización de los mecanismos de defensa a sclerotinia sclerotiorum, agente causal de la podredumbre del estudio de perfiles metabólicos y transcripcionales

OpenAIRE

Peluffo, Lucila

2010-01-01

En Argentina, la podredumbre húmeda del capítulo, causada por el patógeno necrotrófico Sclerotinia sclerotiorum, es una enfermedad que provoca serias mermas en la producción y tiene una incidencia anual promedio sobre la producción de la pampa húmeda del 10-20%. Los síntomas de la enfermedad se manifiestan al final de la etapa de floración o durante el llenado de granos por lesiones en el receptáculo que pueden extenderse y afectar todo el capítulo, produciendo la caída del mismo. En estados ...

Summarizing Simulation Results using Causally-relevant States

Science.gov (United States)

Parikh, Nidhi; Marathe, Madhav; Swarup, Samarth

2016-01-01

As increasingly large-scale multiagent simulations are being implemented, new methods are becoming necessary to make sense of the results of these simulations. Even concisely summarizing the results of a given simulation run is a challenge. Here we pose this as the problem of simulation summarization: how to extract the causally-relevant descriptions of the trajectories of the agents in the simulation. We present a simple algorithm to compress agent trajectories through state space by identifying the state transitions which are relevant to determining the distribution of outcomes at the end of the simulation. We present a toy-example to illustrate the working of the algorithm, and then apply it to a complex simulation of a major disaster in an urban area. PMID:28042620

Causal ubiquity in quantum physics. A superluminal and local-causal physical ontology

International Nuclear Information System (INIS)

Neelamkavil, Raphael

2014-01-01

A fixed highest criterial velocity (of light) in STR (special theory of relativity) is a convention for a layer of physical inquiry. QM (Quantum Mechanics) avoids action-at-a-distance using this concept, but accepts non-causality and action-at-a-distance in EPR (Einstein-Podolsky-Rosen-Paradox) entanglement experiments. Even in such allegedly [non-causal] processes, something exists processually in extension-motion, between the causal and the [non-causal]. If STR theoretically allows real-valued superluminal communication between EPR entangled particles, quantum processes become fully causal. That is, the QM world is sub-luminally, luminally and superluminally local-causal throughout, and the Law of Causality is ubiquitous in the micro-world. Thus, ''probabilistic causality'' is a merely epistemic term.

Causal ubiquity in quantum physics. A superluminal and local-causal physical ontology

Energy Technology Data Exchange (ETDEWEB)

Neelamkavil, Raphael

2014-07-01

A fixed highest criterial velocity (of light) in STR (special theory of relativity) is a convention for a layer of physical inquiry. QM (Quantum Mechanics) avoids action-at-a-distance using this concept, but accepts non-causality and action-at-a-distance in EPR (Einstein-Podolsky-Rosen-Paradox) entanglement experiments. Even in such allegedly [non-causal] processes, something exists processually in extension-motion, between the causal and the [non-causal]. If STR theoretically allows real-valued superluminal communication between EPR entangled particles, quantum processes become fully causal. That is, the QM world is sub-luminally, luminally and superluminally local-causal throughout, and the Law of Causality is ubiquitous in the micro-world. Thus, ''probabilistic causality'' is a merely epistemic term.

Causality in Science

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Cristina Puente Águeda

2011-10-01

Full Text Available Causality is a fundamental notion in every field of science. Since the times of Aristotle, causal relationships have been a matter of study as a way to generate knowledge and provide for explanations. In this paper I review the notion of causality through different scientific areas such as physics, biology, engineering, etc. In the scientific area, causality is usually seen as a precise relation: the same cause provokes always the same effect. But in the everyday world, the links between cause and effect are frequently imprecise or imperfect in nature. Fuzzy logic offers an adequate framework for dealing with imperfect causality, so a few notions of fuzzy causality are introduced.

Valoración de los agentes turísticos estratégicos del destino: el branding y marca en Hermosillo, Sonora

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Blanca Reyna Olguin Negrete

2015-01-01

Full Text Available Con la globalización los destinos turísticos tienden a ser más competitivos. El presente trabajo se realizó en la ciudad de Hermosillo, Sonora, México, con el fin de valorar las percepciones de los agentes turísticos en cuanto al branding y la marca Hermosillo. Se seleccionaron nueve agentes turísticos estratégicos de la ciudad, en el verano de 2014, y se les aplicó una entrevista. Se evaluaron los datos mediante una correlación lineal de Pearson con el método de mínimos cuadrados. Se encontró que los agentes estratégicos de la actividad turística tienen claras las ventajas de utilizar el branding para la marca Hermosillo. También se encontró consenso en la existencia de atributos que identifican a la ciudad de Hermosillo con la posibilidad de un destino turístico. Ellos están de acuerdo en promover más la marca Hermosillo, con la necesidad de posicionarla en el mercado nacional e internacional, utilizando la gestión del branding. Existe correlación positiva alta (r=0.81, p≤ 0.008 en las respuestas que los agentes estratégicos dan al cuestionamiento del objeto primordial de la marca Hermosillo, que es generar mayor número de visitantes; la cual es igualmente ponderada con la pregunta ¿los principales recursos de Hermosillo provienen del patrimonio cultural e histórico de la comunidad?.

A theory of causal learning in children: causal maps and Bayes nets.

Science.gov (United States)

Gopnik, Alison; Glymour, Clark; Sobel, David M; Schulz, Laura E; Kushnir, Tamar; Danks, David

2004-01-01

The authors outline a cognitive and computational account of causal learning in children. They propose that children use specialized cognitive systems that allow them to recover an accurate "causal map" of the world: an abstract, coherent, learned representation of the causal relations among events. This kind of knowledge can be perspicuously understood in terms of the formalism of directed graphical causal models, or Bayes nets. Children's causal learning and inference may involve computations similar to those for learning causal Bayes nets and for predicting with them. Experimental results suggest that 2- to 4-year-old children construct new causal maps and that their learning is consistent with the Bayes net formalism.

Dieback of rose caused by Acremonium sclerotigenum as a new causal agent of rose dieback in Iran

International Nuclear Information System (INIS)

Mirtalebi, M.; Banihashemi, Z.; Sabahi, F.; Mafakheri, H.

2016-01-01

Severe dieback of rose has been recently observed in several rose greenhouses in Fars province of Iran. During 2014 and 2015, stems of rose plants showing yellow to brown discoloration and dieback were collected from rose greenhouses. Coniothyrium fuckelii, Botrytis cinerea and Acremonium were subsequently isolated from the margin between healthy and symptomatic tissue. B. cinerea and C. fuckelii isolates were similar to those previously reported for dieback of rose worldwide. Morphological and cultural characters along with molecular analysis based on partial sequences of the internal transcribed spacer (ITS) region of the ribosomal RNA genome allowed confirming the affiliation of the Acremonium isolates, corresponding to A. sclerotigenum as a new causal agent of rose dieback. To determine its pathogenicity on rose, Koch's postulates were fulfilled by stem inoculation of nine rose cultivars under greenhouse conditions. While A. sclerotigenum is considered as a soil-born pathogen, and produces sclerotia that are resistant to adverse conditions enables the fungus to survive extended period in soil, propagule trapping in our study revealed that conidia can become airborn, imply that an aerial phase, forms an important component of the disease cycle.

Dieback of rose caused by Acremonium sclerotigenum as a new causal agent of rose dieback in Iran

Energy Technology Data Exchange (ETDEWEB)

Mirtalebi, M.; Banihashemi, Z.; Sabahi, F.; Mafakheri, H.

2016-07-01

Severe dieback of rose has been recently observed in several rose greenhouses in Fars province of Iran. During 2014 and 2015, stems of rose plants showing yellow to brown discoloration and dieback were collected from rose greenhouses. Coniothyrium fuckelii, Botrytis cinerea and Acremonium were subsequently isolated from the margin between healthy and symptomatic tissue. B. cinerea and C. fuckelii isolates were similar to those previously reported for dieback of rose worldwide. Morphological and cultural characters along with molecular analysis based on partial sequences of the internal transcribed spacer (ITS) region of the ribosomal RNA genome allowed confirming the affiliation of the Acremonium isolates, corresponding to A. sclerotigenum as a new causal agent of rose dieback. To determine its pathogenicity on rose, Koch's postulates were fulfilled by stem inoculation of nine rose cultivars under greenhouse conditions. While A. sclerotigenum is considered as a soil-born pathogen, and produces sclerotia that are resistant to adverse conditions enables the fungus to survive extended period in soil, propagule trapping in our study revealed that conidia can become airborn, imply that an aerial phase, forms an important component of the disease cycle.

The Reactive-Causal Architecture: Introducing an Emotion Model along with Theories of Needs

Science.gov (United States)

Aydin, Ali Orhan; Orgun, Mehmet Ali

In the entertainment application area, one of the major aims is to develop believable agents. To achieve this aim, agents should be highly autonomous, situated, flexible, and display affect. The Reactive-Causal Architecture (ReCau) is proposed to simulate these core attributes. In its current form, ReCau cannot explain the effects of emotions on intelligent behaviour. This study aims is to further improve the emotion model of ReCau to explain the effects of emotions on intelligent behaviour. This improvement allows ReCau to be emotional to support the development of believable agents.

Cutaneous Papillomaviruses and Non-melanoma Skin Cancer: Causal Agents or Innocent Bystanders?

Science.gov (United States)

Hasche, Daniel; Vinzón, Sabrina E; Rösl, Frank

2018-01-01

There is still controversy in the scientific field about whether certain types of cutaneous human papillomaviruses (HPVs) are causally involved in the development of non-melanoma skin cancer (NMSC). Deciphering the etiological role of cutaneous HPVs requires - besides tissue culture systems - appropriate preclinical models to match the obtained results with clinical data from affected patients. Clear scientific evidence about the etiology and underlying mechanisms involved in NMSC development is fundamental to provide reasonable arguments for public health institutions to classify at least certain cutaneous HPVs as group 1 carcinogens. This in turn would have implications on fundraising institutions and health care decision makers to force - similarly as for anogenital cancer - the implementation of a broad vaccination program against "high-risk" cutaneous HPVs to prevent NMSC as the most frequent cancer worldwide. Precise knowledge of the multi-step progression from normal cells to cancer is a prerequisite to understand the functional and clinical impact of cofactors that affect the individual outcome and the personalized treatment of a disease. This overview summarizes not only recent arguments that favor the acceptance of a viral etiology in NMSC development but also reflects aspects of causality in medicine, the use of empirically meaningful model systems and strategies for prevention.

Cutaneous Papillomaviruses and Non-melanoma Skin Cancer: Causal Agents or Innocent Bystanders?

Directory of Open Access Journals (Sweden)

Daniel Hasche

2018-05-01

Full Text Available There is still controversy in the scientific field about whether certain types of cutaneous human papillomaviruses (HPVs are causally involved in the development of non-melanoma skin cancer (NMSC. Deciphering the etiological role of cutaneous HPVs requires – besides tissue culture systems – appropriate preclinical models to match the obtained results with clinical data from affected patients. Clear scientific evidence about the etiology and underlying mechanisms involved in NMSC development is fundamental to provide reasonable arguments for public health institutions to classify at least certain cutaneous HPVs as group 1 carcinogens. This in turn would have implications on fundraising institutions and health care decision makers to force – similarly as for anogenital cancer – the implementation of a broad vaccination program against “high-risk” cutaneous HPVs to prevent NMSC as the most frequent cancer worldwide. Precise knowledge of the multi-step progression from normal cells to cancer is a prerequisite to understand the functional and clinical impact of cofactors that affect the individual outcome and the personalized treatment of a disease. This overview summarizes not only recent arguments that favor the acceptance of a viral etiology in NMSC development but also reflects aspects of causality in medicine, the use of empirically meaningful model systems and strategies for prevention.

Causal reasoning in physics

CERN Document Server

Frisch, Mathias

2014-01-01

Much has been written on the role of causal notions and causal reasoning in the so-called 'special sciences' and in common sense. But does causal reasoning also play a role in physics? Mathias Frisch argues that, contrary to what influential philosophical arguments purport to show, the answer is yes. Time-asymmetric causal structures are as integral a part of the representational toolkit of physics as a theory's dynamical equations. Frisch develops his argument partly through a critique of anti-causal arguments and partly through a detailed examination of actual examples of causal notions in physics, including causal principles invoked in linear response theory and in representations of radiation phenomena. Offering a new perspective on the nature of scientific theories and causal reasoning, this book will be of interest to professional philosophers, graduate students, and anyone interested in the role of causal thinking in science.

Los universitarios como agentes políticos en la construcción histórica del concepto de solidaridad

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Raquel García Bouzas

2010-07-01

Full Text Available Este trabajo tiene por objetivo la presentación del proceso histórico en que las cátedras jurídicas de la Facultad de Derecho difundieron en nuestro país la bibliografía crítica que reconoció al concepto de solidaridad como uno de los principios del reformismo.Nuestro método de trabajo sigue las orientaciones de la propuesta de Q.Skinner, rastreando el concepto en el contexto histórico y tomando a los intelectuales como agentes del enfrentamiento ideológico, buscando las intenciones que demuestran en sus discursos, intenciones políticas, más que intelectuales. Las acciones se orientaban, como sabemos, a la reforma del Estado y a las políticas distributivas, las teorías pueden ser englobadas bajo el término "pensamiento jurídico-critico".

A theory of causal learning in children: Causal maps and Bayes nets

OpenAIRE

Gopnik, A; Glymour, C; Sobel, D M; Schulz, L E; Kushnir, T; Danks, D

2004-01-01

The authors outline a cognitive and computational account of causal learning in children. They propose that children use specialized cognitive systems that allow them to recover an accurate "causal map" of the world: an abstract, coherent, learned representation of the causal relations among events. This kind of knowledge can be perspicuously understood in terms of the formalism of directed graphical causal models, or Bayes nets. Children's causal learning and inference may involve computatio...

First isolation of Mycoplasma capricolum subsp. capricolum, one of the causal agents of caprine contagious agalactia, on the island of Lanzarote (Spain).

Science.gov (United States)

De la Fe, C; Gutiérrez, A; Poveda, J B; Assunção, P; Ramírez, A S; Fabelo, F

2007-03-01

During an unusually long period of bad weather, several outbreaks of caprine contagious agalactia (CCA) were reported in a number of flocks on the island of Lanzarote (Canary Islands, Spain). Clinical and subclinical mastitis in lactating goats and some cases of arthritis and pneumonia in kids were observed in the affected flocks. Mycoplasma capricolum subsp. capricolum was isolated as the main causal agent of the outbreaks, associated with M. mycoides subsp. mycoides "large colony type" (Mmm LC) in two flocks. This is the first report of an isolation of M. capricolum subsp. capricolum on the island of Lanzarote. The finding is of epidemiological importance and could complicate plans to control the disease. The significance of this mycoplasma species in association with CCA must now be studied in detail.

Ação do óxido nitroso no sistema nervoso central: estudo eletrofisiológico como agente único e como agente coadjuvante Acción del óxido nitroso en el sistema nervioso central: estudio eletrofisiológico como agente único y como agente coadyuvante Nitrous oxide action on the central nervous system: electrophysiological study as a sole agent or a coadjuvant

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Verônica Vieira da Costa

2002-06-01

pode explicar o seu bom efeito analgésico.JUSTIFICATIVA Y OBJETIVOS: El óxido nitroso es el agente anestésico inhalatorio más utilizado en todo el mundo. Su mecanismo de acción es bastante discutido, con base en resultados experimentales y en evidencias clínicas. El objetivo de este estudio es evaluar la acción eletrofisiológica de este fármaco en el Sistema Nervioso Central a través de monitorización específica. MÉTODO: Fueron estudiados veinticinco pacientes de ambos sexos, con edades entre 6 y 25 años, sometidos a cirugía ortopédica o plástica reparadora, los cuales fueron monitorizados con índice bispectral del eletroencefalograma (BIS y potencial evocado somatosensitivo (PESS durante la anestesia. Fueron realizados registros basales del BIS y PESS, bien como después del uso del óxido nitroso en fraccionales alveolares (FA de 30%, 50% y 66%. En seguida el óxido nitroso era descontinuado y administrado aleatoriamente isoflurano o desflurano en 0,5 CAM y 1 CAM. Se mantenía 1 CAM del determinado agente y el óxido nitroso era nuevamente administrado en las mismas concentraciones anteriores. RESULTADOS: El óxido nitroso cuando utilizado como agente único, produce una reducción en el BIS que, aunque sea estadísticamente significante, no expresa un estado de hipnosis. Esta reducción también ocurre cuando utilizado como agente coadyuvante más sin importancia clínica. Como agente único, el óxido nitroso deprimió significantemente la amplitud de las ondas cerebrales, sin promover aumento en la latencia. El isoflurano y desflurano redujeron la amplitud y aumentaron la latencia de las ondas cerebrales. La asociación del óxido nitroso a estos agentes, intensificó aun más estos efectos en las ondas corticales. No hubo alteración significativa de las ondas periférica y medular del PESS. CONCLUSIONES: El óxido nitroso tiene una pequeña acción hipnótica, que no es captada completamente por el BIS. Tiene acción acentuada en las

Atribuición causal de las emociones en la formación inicial del docente de educación física

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Nelly Orellana Arduiz

2015-12-01

Full Text Available Estudio cualitativo de Investigación-Acción, que tiene por objetivo identificar la atribución causal de emociones en estudiantes de Pedagogía en Educación Física, durante la gestión de una clase en un ambiente educativo real. La población del estudio es de 60 estudiantes universitarios. Los datos fueron recopilados a través de informes afectivos y fueron analizados en el software Atlas.ti. 6.0. Los resultados más relevantes indican que los estudiantes atribuyen la tranquilidad y seguridad a la conformidad con la planificación, la preparación de material didáctico y al pensamiento optimista de su labor. El nerviosismo y la ansiedad son atribuidos a la incertidumbre y a las expectativas de logro. El bienestar, la felicidad, el amor y la satisfacción, se generan por la percepción de un buen resultado en la clase. Se concluye del estudio, que las atribuciones de emociones positivas y negativas, son en su mayoría externas y suceden en mayor proporción en momentos anteriores a la gestión de la clase de Educación Física.

Efectos del Estrés Laboral y los Mecanismos de Afrontamiento en el Personal de Salud del Área Quirúrgica del Hospital IESS Riobamba

OpenAIRE

Yuquilema Guachilema, Zoila del Rocio

2015-01-01

El presente trabajo se orientó a la determinación de los efectos del estrés laboral y los mecanismos de afrontamiento en el personal del área quirúrgica del Hospital IESS Riobamba. La población se conformó con 30 profesionales de la salud que laboran en el área quirúrgica: enfermeras, auxiliares de enfermería, asistentes de anestesiología y anestesiólogos. La información se obtuvo por medio de encuestas. Los resultados de la investigación demuestran que los causales de estrés laboral son: e...

Repeated causal decision making.

Science.gov (United States)

Hagmayer, York; Meder, Björn

2013-01-01

Many of our decisions refer to actions that have a causal impact on the external environment. Such actions may not only allow for the mere learning of expected values or utilities but also for acquiring knowledge about the causal structure of our world. We used a repeated decision-making paradigm to examine what kind of knowledge people acquire in such situations and how they use their knowledge to adapt to changes in the decision context. Our studies show that decision makers' behavior is strongly contingent on their causal beliefs and that people exploit their causal knowledge to assess the consequences of changes in the decision problem. A high consistency between hypotheses about causal structure, causally expected values, and actual choices was observed. The experiments show that (a) existing causal hypotheses guide the interpretation of decision feedback, (b) consequences of decisions are used to revise existing causal beliefs, and (c) decision makers use the experienced feedback to induce a causal model of the choice situation even when they have no initial causal hypotheses, which (d) enables them to adapt their choices to changes of the decision problem. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Identificación de una nueva área de infección por Rickettsias del grupo typhi: estudio de un brote de tifus en Huánuco

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Rosa Mostorino E

2003-03-01

Full Text Available Objetivos: Investigar un brote de síndrome febril en el distrito de Punchao mediante una evaluación clínica, laboratorial y entomológica para conocer los factores asociados a la aparición de dicho brote. Materiales y métodos: Debido al reporte de tres pacientes con cuadro clínico febril asociado a cefalea, mialgias y postración en la semana epidemiológica Nº41 del año 2000, procedentes del distrito de Punchao, Humalíes, Huánuco y ante la información de presentación inusual de pacientes febriles en la última semana en dicho lugar, se decidió investigar la naturaleza y características del brote. Se definió como caso a todo paciente con cuadro febril agudo y uno de estos síntomas: cefalea, mialgias o postración; procediéndose a la búsqueda activa de éstos y a la evaluación de presencia de anticuerpos para rickettsias en suero mediante inmunofluorescencia indirecta (IFI. Se capturaron roedores y se colectaron ectoparásitos en las viviendas (roedores, animales domésticos y humanos, a fin de identificar la presencia de Rickettsias en ellos mediante IFI, aislamiento o PCR. Resultados: No se logró el aislamiento del agente causal. Se evidenció circulación de la Rickettsia sp. (serología positiva tanto en humanos (en casos y en no casos como en roedores. Se evidenció mayor presencia de malos hábitos de aseo y condiciones inadecuadas de saneamiento básico en los casos (respecto a los no casos y una disminución de los casos luego del inicio de las medidas de control. Conclusiones: Las evidencias encontradas permitieron identificar un brote de tifus en Punchao, no pudiéndose determinar la especie involucrada debido a que no se aisló el agente causal.

Análisis proteómico de Plasmodium, el agente causal de la malaria Proteomic analysis of Plasmodium, the causal agent of Malaria

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Ivone Castro R

2009-01-01

Full Text Available Los plasmodios son protozoarios cuyo complejo ciclo de vida se lleva a cabo en dos hospederos, el vertebrado y el mosquito. La infección de los seres humanos produce la enfermedad conocida como malaria. La secuenciación del genoma de Plasmodium falciparum y el desarrollo de la proteómica han permitido un gran avance en el conocimiento de la biología de este letal parásito. La presente revisión se centra en describir los logros recientes en el estudio del proteoma de Plasmodium falciparum y algunas de las implicaciones en la búsqueda de nuevos fármacos antimaláricos, así como en la generación de vacunas para el control de la enfermedad.Plasmodia are protozoa whose complex life cycle takes place in two different hosts, the vertebrate and the mosquito. The human infection produces the malaria disease. The genome sequence of Plasmodium falciparum and the proteomic tools have enabled a huge advance in knowledge of the biology of this parasite. This review will focus on the recent advances in proteomic studies of Plasmodium falciparum and some implications for the search of new antimalarial drugs as well as vaccines for the control of the disease.

Causal ubiquity in quantum physics a superluminal and local-causal physical ontology

CERN Document Server

Neelamkavil, Raphael

2014-01-01

A fixed highest criterial velocity (of light) in STR (special theory of relativity) is a convention for a layer of physical inquiry. QM (Quantum Mechanics) avoids action-at-a-distance using this concept, but accepts non-causality and action-at-a-distance in EPR (Einstein-Podolsky-Rosen-Paradox) entanglement experiments. Even in such allegedly non-causal processes, something exists processually in extension-motion, between the causal and the non-causal. If STR theoretically allows real-valued superluminal communication between EPR entangled particles, quantum processes become fully causal. That

Determinantes de fidelidad en el servicio turístico un modelo de relaciones causales

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Silvina Etcheverría

2014-03-01

Full Text Available En el presente trabajo se analizan los factores que determinan la fidelidad del turista que visita la ciudad de Tandil (Argentina a partir de un modelo de relaciones causales; específicamente; Modelo de Ecuaciones Estructurales. A efectos de la estimación y evaluación del modelo se utilizó una encuesta estructurada a los turistas que visitaron la ciudad; a lo largo de un año calendario. Los resultados obtenidos muestran que la fidelidad del turista aparece como consecuencia tanto de su satisfacción como del potencial del destino percibido por el mismo. Mientras que la satisfacción depende tres constructos: cobertura de necesidades vivenciales; entendidas como el cúmulo de sensaciones que vive el turista producto de la visita y con las cuales finalmente asociará su viaje; cobertura de necesidades funcionales son aquellas ligadas a la logística del viaje y cobertura de necesidades simbólicas; en especial los aspectos vinculados al cuidado del medio ambiente.

Manipulating Morality: Third-Party Intentions Alter Moral Judgments by Changing Causal Reasoning.

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Phillips, Jonathan; Shaw, Alex

2015-08-01

The present studies investigate how the intentions of third parties influence judgments of moral responsibility for other agents who commit immoral acts. Using cases in which an agent acts under some situational constraint brought about by a third party, we ask whether the agent is blamed less for the immoral act when the third party intended for that act to occur. Study 1 demonstrates that third-party intentions do influence judgments of blame. Study 2 finds that third-party intentions only influence moral judgments when the agent's actions precisely match the third party's intention. Study 3 shows that this effect arises from changes in participants' causal perception that the third party was controlling the agent. Studies 4 and 5, respectively, show that the effect cannot be explained by changes in the distribution of blame or perceived differences in situational constraint faced by the agent. © 2014 Cognitive Science Society, Inc.

Non-Causal Computation

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Ämin Baumeler

2017-07-01

Full Text Available Computation models such as circuits describe sequences of computation steps that are carried out one after the other. In other words, algorithm design is traditionally subject to the restriction imposed by a fixed causal order. We address a novel computing paradigm beyond quantum computing, replacing this assumption by mere logical consistency: We study non-causal circuits, where a fixed time structure within a gate is locally assumed whilst the global causal structure between the gates is dropped. We present examples of logically consistent non-causal circuits outperforming all causal ones; they imply that suppressing loops entirely is more restrictive than just avoiding the contradictions they can give rise to. That fact is already known for correlations as well as for communication, and we here extend it to computation.

Nueva clasificación de las fracturas de trazo unilateral del tercio medio facial

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Francisco Avello

2007-03-01

Full Text Available Las fracturas de trazo unilateral del tercio medio facial son las más frecuentes de las fracturas del macizo óseo-facial, en general. Dentro de estas, son las que afectan al maxilar superior y al malar las de mayor incidencia. Se producen como consecuencia de traumatismos severos, siendo la determinación de este tipo de fractura, por edad, sexo y agente causal importante para su manejo. Se pueden presentar en forma combinada con otro tipo de fractura facial. Tienen una mayor incidencia en el sexo masculino, afectando mayormente a individuos entre 20 y 40 años de edad. Los accidentes de tránsito y las agresiones por robo son las principales causas. El tercio medio del macizo óseo-facial está conformado por un complejo de huesos unidos unos a otros, dentro de los que tenemos principalmente a los maxilares superiores, huesos propios nasales, malares y temporales. Razón por la que se ha querido elaborar una clasificación, que incluya las estructuras óseas mencionadas, que a la vez sea comprensible y de fácil aplicación.

Causality re-established.

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D'Ariano, Giacomo Mauro

2018-07-13

Causality has never gained the status of a 'law' or 'principle' in physics. Some recent literature has even popularized the false idea that causality is a notion that should be banned from theory. Such misconception relies on an alleged universality of the reversibility of the laws of physics, based either on the determinism of classical theory, or on the multiverse interpretation of quantum theory, in both cases motivated by mere interpretational requirements for realism of the theory. Here, I will show that a properly defined unambiguous notion of causality is a theorem of quantum theory, which is also a falsifiable proposition of the theory. Such a notion of causality appeared in the literature within the framework of operational probabilistic theories. It is a genuinely theoretical notion, corresponding to establishing a definite partial order among events, in the same way as we do by using the future causal cone on Minkowski space. The notion of causality is logically completely independent of the misidentified concept of 'determinism', and, being a consequence of quantum theory, is ubiquitous in physics. In addition, as classical theory can be regarded as a restriction of quantum theory, causality holds also in the classical case, although the determinism of the theory trivializes it. I then conclude by arguing that causality naturally establishes an arrow of time. This implies that the scenario of the 'block Universe' and the connected 'past hypothesis' are incompatible with causality, and thus with quantum theory: they are both doomed to remain mere interpretations and, as such, are not falsifiable, similar to the hypothesis of 'super-determinism'.This article is part of a discussion meeting issue 'Foundations of quantum mechanics and their impact on contemporary society'. © 2018 The Author(s).

Cladosporium cladosporioides and Cladosporium pseudocladosporioides as potential new fungal antagonists of Puccinia horiana Henn., the causal agent of chrysanthemum white rust.

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David Eduardo Torres

Full Text Available Puccinia horiana Hennings, the causal agent of chrysanthemum white rust, is a worldwide quarantine organism and one of the most important fungal pathogens of Chrysanthemum × morifolium cultivars, which are used for cut flowers and as potted plants in commercial production regions of the world. It was previously reported to be controlled by Lecanicillium lecanii, Cladosporium sphaerospermum, C. uredinicola and Aphanocladium album, due to their antagonistic and hyperparasitic effects. We report novel antagonist species on Puccinia horiana. Fungi isolated from rust pustules in a commercial greenhouse from Villa Guerrero, México, were identified as Cladosporium cladosporioides and Cladosporium pseudocladosporioides based upon molecular analysis and morphological characters. The antagonism of C. cladosporioides and C. pseudocladosporioides on chrysanthemum white rust was studied using light and electron microscopy in vitro at the host/parasite interface. Cladosporium cladosporioides and C. pseudocladosporioides grew towards the white rust teliospores and colonized the sporogenous cells, but no direct penetration of teliospores was observed; however, the structure and cytoplasm of teliospores were altered. The two Cladosporium spp. were able to grow on media containing laminarin, but not when chitin was used as the sole carbon source; these results suggest that they are able to produce glucanases. Results from the study indicate that both Cladosporium species had potential as biological control agents of chrysanthemum white rust.

Further properties of causal relationship: causal structure stability, new criteria for isocausality and counterexamples

International Nuclear Information System (INIS)

Garcia-Parrado, Alfonso; Sanchez, Miguel

2005-01-01

Recently (Garcia-Parrado and Senovilla 2003 Class. Quantum Grav. 20 625-64) the concept of causal mapping between spacetimes, essentially equivalent in this context to the chronological map defined in abstract chronological spaces, and the related notion of causal structure, have been introduced as new tools to study causality in Lorentzian geometry. In the present paper, these tools are further developed in several directions such as (i) causal mappings-and, thus, abstract chronological ones-do not preserve two levels of the standard hierarchy of causality conditions (however, they preserve the remaining levels as shown in the above reference), (ii) even though global hyperbolicity is a stable property (in the set of all time-oriented Lorentzian metrics on a fixed manifold), the causal structure of a globally hyperbolic spacetime can be unstable against perturbations; in fact, we show that the causal structures of Minkowski and Einstein static spacetimes remain stable, whereas that of de Sitter becomes unstable, (iii) general criteria allow us to discriminate different causal structures in some general spacetimes (e.g. globally hyperbolic, stationary standard); in particular, there are infinitely many different globally hyperbolic causal structures (and thus, different conformal ones) on R 2 (iv) plane waves with the same number of positive eigenvalues in the frequency matrix share the same causal structure and, thus, they have equal causal extensions and causal boundaries

A quantum causal discovery algorithm

Science.gov (United States)

Giarmatzi, Christina; Costa, Fabio

2018-03-01

Finding a causal model for a set of classical variables is now a well-established task—but what about the quantum equivalent? Even the notion of a quantum causal model is controversial. Here, we present a causal discovery algorithm for quantum systems. The input to the algorithm is a process matrix describing correlations between quantum events. Its output consists of different levels of information about the underlying causal model. Our algorithm determines whether the process is causally ordered by grouping the events into causally ordered non-signaling sets. It detects if all relevant common causes are included in the process, which we label Markovian, or alternatively if some causal relations are mediated through some external memory. For a Markovian process, it outputs a causal model, namely the causal relations and the corresponding mechanisms, represented as quantum states and channels. Our algorithm opens the route to more general quantum causal discovery methods.

Autogestión en la red de agentes comunitarios en salud mental en las instituciones educativas del municipio de San Lorenzo (Nariño

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Christian Alexander Zambrano Guerrero

2015-07-01

Full Text Available El presente artículo de investigación tuvo como objetivo sistematizar el proceso de autogestión de la red de agentes comunitarios en salud mental en las instituciones educativas del municipio de San Lorenzo (Nariño, a través de un estudio cualitativo y desde el enfoque histórico-hermenéutico. Inicialmente, se recopiló la experiencia de autogestión durante una serie de encuentrosy se describieron las estrategias emergentes del proceso de autogestión. Luego se valoraron, interpretaron y clarificaron los resultados generados desde la autogestión de la red de agentes comunitarios en salud mental mediante encuentros participativos en las instituciones educativas del municipio, con una propuesta política, sostenible y sustentable. Abstract This research paper aimed to systematize the self-management process by the community mental health team in educational institutions from San Lorenzo (Nariño, conducted through a qualitative study based on the historical-hermeneutic approach. Several self-management experience meetings were held and emerging strategies of the self-management process were described. Later, the results, based on the community of mental health agents, were assessed, interpreted and clarified, suggesting a political, sustainable, and viable proposal.

Epidemiological causality.

Science.gov (United States)

Morabia, Alfredo

2005-01-01

Epidemiological methods, which combine population thinking and group comparisons, can primarily identify causes of disease in populations. There is therefore a tension between our intuitive notion of a cause, which we want to be deterministic and invariant at the individual level, and the epidemiological notion of causes, which are invariant only at the population level. Epidemiologists have given heretofore a pragmatic solution to this tension. Causal inference in epidemiology consists in checking the logical coherence of a causality statement and determining whether what has been found grossly contradicts what we think we already know: how strong is the association? Is there a dose-response relationship? Does the cause precede the effect? Is the effect biologically plausible? Etc. This approach to causal inference can be traced back to the English philosophers David Hume and John Stuart Mill. On the other hand, the mode of establishing causality, devised by Jakob Henle and Robert Koch, which has been fruitful in bacteriology, requires that in every instance the effect invariably follows the cause (e.g., inoculation of Koch bacillus and tuberculosis). This is incompatible with epidemiological causality which has to deal with probabilistic effects (e.g., smoking and lung cancer), and is therefore invariant only for the population.

Phytophthora palmivora, agente da podridão de raiz e frutos de mamoeiro no Estado de Alagoas Phytophthora palmivora, causal agent of root and fruit rots of papaya in the State of Alagoas, Brazil

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Juliana Paiva Carnaúba

2006-04-01

Full Text Available O mamoeiro (Carica papaya é uma das mais importantes fruteiras tropicais, e seus frutos contribuem com uma produção de 1,65 milhão de toneladas por ano para o Brasil. Um isolado de Phytophthora sp. obtido de frutos de mamoeiro da cultivar Havaí, em Alagoas, foi caracterizado morfologicamente e sua patogenicidade foi confirmada em frutos e mudas deste hospedeiro. Em meio suco V-8, os esporangióforos apresentaram-se delgados, simples ou pouco ramificados, enquanto os esporângios se apresentaram ovóides a elipsóides, proeminentemente papilados e um pedicelo curto na porção basal, medindo em média 37,68 x 27,52 mm. Através das características apresentadas pelo isolado e os sintomas induzidos, o agente causal foi identificado como Phytophthora palmivora. Apesar de essa doença já ocorrer em outros estados, como Bahia, Espírito Santo, São Paulo, Pernambuco e Pará, este é o primeiro relato de Phytophthora palmivora em mamoeiro no Estado de Alagoas.The papaya (Carica papaya is one of the most important tropical fruit crops and its fruit contribute with a production of 1.65 millions tons/year in Brazil. An isolated of Phytophthora sp. gotten from papaya fruits cv. Hawaii, in the state of Alagoas, was characterized morphologically and its pathogenicity to this fruits and seedling was confirmed. In a V-8 medium, the sporangiophores presented to be slim, simple or little ramified, while the sporangia presented ovoid to ellipsoid, prominently papillae and one short pedicel in the basal portion, measuring in average 37,68 x 27,52 (m. Through the characteristics presented by the isolated and the induced symptoms, the causal agent was identified as Phytophthora palmivora. Despite of this disease already occurring in other states like in Bahia, Espirito Santo, São Paulo, Pernambuco and Pará, this is the first report of Phytophthora palmivora on papaya in the state of Alagoas, Brazil.

El problema del agente viajero: un algoritmo determinístico usando búsqueda tabú

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Erasmo López

2014-04-01

Full Text Available Se implementa un algoritmo correspondiente al método Búsqueda Tabú, llamado EraDeterminístico, experimentado con el algoritmo básico que explora el espacio de búsqueda e incorporando la diversificación como estrategia para explorar nuevas regiones. El algoritmo se desarrolla en el ambiente de programación Visual Basic 6.0 y la implementación se orienta a encontrar soluciones cercanas a la óptima del problema NP−Completo del Agente Viajero Simétrico (AVS. Para probar la funcionalidad, el modelo se compara con algunas instancias de la Travel Salesman Problem Li- brary (TSPLIB, algunas instancias aleatorias y se aplica a tres situaciones reales. Finalmente, se presenta una sección donde se exponen recomendaciones y conclusiones, las cuales orientan posibles desarrollos futuros de ésta teoría y donde se pone en evidencian las bondades y la eficiencia de la implementación.

Structure and Connectivity Analysis of Financial Complex System Based on G-Causality Network

Science.gov (United States)

Xu, Chuan-Ming; Yan, Yan; Zhu, Xiao-Wu; Li, Xiao-Teng; Chen, Xiao-Song

2013-11-01

The recent financial crisis highlights the inherent weaknesses of the financial market. To explore the mechanism that maintains the financial market as a system, we study the interactions of U.S. financial market from the network perspective. Applied with conditional Granger causality network analysis, network density, in-degree and out-degree rankings are important indicators to analyze the conditional causal relationships among financial agents, and further to assess the stability of U.S. financial systems. It is found that the topological structure of G-causality network in U.S. financial market changed in different stages over the last decade, especially during the recent global financial crisis. Network density of the G-causality model is much higher during the period of 2007-2009 crisis stage, and it reaches the peak value in 2008, the most turbulent time in the crisis. Ranked by in-degrees and out-degrees, insurance companies are listed in the top of 68 financial institutions during the crisis. They act as the hubs which are more easily influenced by other financial institutions and simultaneously influence others during the global financial disturbance.

Discrete causal theory emergent spacetime and the causal metric hypothesis

CERN Document Server

Dribus, Benjamin F

2017-01-01

This book evaluates and suggests potentially critical improvements to causal set theory, one of the best-motivated approaches to the outstanding problems of fundamental physics. Spacetime structure is of central importance to physics beyond general relativity and the standard model. The causal metric hypothesis treats causal relations as the basis of this structure. The book develops the consequences of this hypothesis under the assumption of a fundamental scale, with smooth spacetime geometry viewed as emergent. This approach resembles causal set theory, but differs in important ways; for example, the relative viewpoint, emphasizing relations between pairs of events, and relationships between pairs of histories, is central. The book culminates in a dynamical law for quantum spacetime, derived via generalized path summation.

Causal Analysis After Haavelmo

Science.gov (United States)

Heckman, James; Pinto, Rodrigo

2014-01-01

Haavelmo's seminal 1943 and 1944 papers are the first rigorous treatment of causality. In them, he distinguished the definition of causal parameters from their identification. He showed that causal parameters are defined using hypothetical models that assign variation to some of the inputs determining outcomes while holding all other inputs fixed. He thus formalized and made operational Marshall's (1890) ceteris paribus analysis. We embed Haavelmo's framework into the recursive framework of Directed Acyclic Graphs (DAGs) used in one influential recent approach to causality (Pearl, 2000) and in the related literature on Bayesian nets (Lauritzen, 1996). We compare the simplicity of an analysis of causality based on Haavelmo's methodology with the complex and nonintuitive approach used in the causal literature of DAGs—the “do-calculus” of Pearl (2009). We discuss the severe limitations of DAGs and in particular of the do-calculus of Pearl in securing identification of economic models. We extend our framework to consider models for simultaneous causality, a central contribution of Haavelmo. In general cases, DAGs cannot be used to analyze models for simultaneous causality, but Haavelmo's approach naturally generalizes to cover them. PMID:25729123

Rickettsia typhi IN RODENTS AND R. felis IN FLEAS IN YUCATÁN AS A POSSIBLE CAUSAL AGENT OF UNDEFINED FEBRILE CASES

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Gaspar PENICHE-LARA

2015-04-01

Full Text Available Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chain reaction technique and sequencing. The study only identified the presence of Rickettsia typhi in blood samples obtained from Rattus rattus and it reported, for the first time, the presence of R. felis in the flea Polygenis odiosus collected from Ototylomys phyllotis rodent. Additionally, Rickettsia felis was detected in the ectoparasite Ctenocephalides felis fleas parasitizing the wild rodent Peromyscus yucatanicus. This study’s results contributed to a better knowledge of Rickettsia epidemiology in Yucatán.

Domain-specific perceptual causality in children depends on the spatio-temporal configuration, not motion onset

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Anne eSchlottmann

2013-07-01

Full Text Available Humans, even babies, perceive causality when one shape moves briefly and linearly after another. Motion timing is crucial in this and causal impressions disappear with short delays between motions. However, the role of temporal information is more complex: It is both a cue to causality and a factor that constrains processing. It affects ability to distinguish causality from non-causality, and social from mechanical causality. Here we study both issues with 3- to 7-year-olds and adults who saw two computer-animated squares and chose if a picture of mechanical, social or non-causality fit each event best. Prior work fit with the standard view that early in development, the distinction between the social and physical domains depends mainly on whether or not the agents make contact, and that this reflects concern with domain-specific motion onset, in particular, whether the motion is self-initiated or not. The present experiments challenge both parts of this position. In Experiments 1 and 2, we showed that not just spatial, but also animacy and temporal information affect how children distinguish between physical and social causality. In Experiments 3 and 4 we showed that children do not seem to use spatio-temporal information in perceptual causality to make inferences about self- or other-initiated motion onset. Overall, spatial contact may be developmentally primary in domain-specific perceptual causality in that it is processed easily and is dominant over competing cues, but it is not the only cue used early on and it is not used to infer motion onset. Instead, domain-specific causal impressions may be automatic reactions to specific perceptual configurations, with a complex role for temporal information.

La responsabilidad social corporativa de las marcas globales y sus efectos en la conducta del consumidor: un estudio del sector moda rápida.

OpenAIRE

Rivera Alcamí, José Javier

2015-01-01

La Responsabilidad Social Corporativa de las Marcas Globales y sus Efectos en la Conducta del Consumidor: un Estudio del Sector Moda Rápida. Esta tesis doctoral tiene por objetivo principal, diseñar y contrastar empíricamente un modelo de relaciones causales, que analiza los efectos en la conducta del consumidor de la Responsabilidad Social Corporativa (RSC), de las marcas globales. Los efectos, en la conducta del consumidor, se analizan a partir de la percepción de marca global, y a trav...

Molecular characterization and pathogenicity assays of Colletotrichum acutatum, causal agent for lime anthracnose in Texas

Science.gov (United States)

Several distorted Mexican lime [Citrus aurantiifolia (Christm). Swingle] fruit, leaf, and twig samples with lime anthracnose symptoms were collected from three trees in residential areas of Brownsville, Texas. The causal fungal organism, Colletotrichum acutatum J. H. Simmonds was isolated from leave...

Conceptos básicos sobre la interacción del sistema inmune y los hongos causales de micosis sistémicas The immune system and fungal pathogenesis

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Mary I. Gil Bustamante

1997-04-01

Full Text Available El curso de las infecciones micóticas lo determina principalmente la interacción del agente con los diferentes mecanismos de defensa naturales y específicos del hospedero. Las defensas naturales pueden ser físicas, químicas y celulares. Los factores que predisponen a la invasión micótica se reconocen tanto en los hongos como en el hospedero y les corresponde enfrentar la primera línea de defensa; de ello resulta que se establezca o no el proceso infeccioso; en algunas ocasiones esta primera respuesta es suficiente para limitar la infección pero existen hongos cuyo poder patógeno activa la producción de sustancias que dañan los tejidos o de componentes que inhiben las funciones de la fagocitosis, por lo cual el sistema inmune cuenta con una segunda línea de defensa: La inmunidad mediada por células. En la actualidad los estudios experimentales de la respuesta inmune a la infección micótica utilizan las citoquinas como herramienta para el diagnóstico y control de algunas micosis por considerarlas como las principales sustancias reguladoras del proceso inmune. Natural host resistance mechanisms against most mycotic agents act in a coordinated manner to prevent the proliferation of agents. The cooperative process betwen first line defenses and cell mediated immunity elicits production of substances that can increase the activity of phagocytic cells or mechanisms for killing fungi. Immunological factors that prevent establishement of fungal infections include: physical, mechanical and chemical barriers, cellular resistance mechanisms, humoral immunity and cell mediated immunity.

A Theory of Causal Learning in Children: Causal Maps and Bayes Nets

Science.gov (United States)

Gopnik, Alison; Glymour, Clark; Sobel, David M.; Schulz, Laura E.; Kushnir, Tamar; Danks, David

2004-01-01

The authors outline a cognitive and computational account of causal learning in children. They propose that children use specialized cognitive systems that allow them to recover an accurate "causal map" of the world: an abstract, coherent, learned representation of the causal relations among events. This kind of knowledge can be perspicuously…

Effect of Two Biological Formulations Based on Bacillus subtilis and Pseudomonas fluorescens on Control of Didymella applanata, the Causal Agent of Red Raspberry Cane Spur Blight

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Margarita Shternshis

2016-01-01

Full Text Available In vitro and in vivo studies were conducted to estimate the efficacy of the two microbial formulations based on Bacillus subtilis Cohn. and Pseudomonas fluorescens Mig. on the fungus Didymella applanata (Niessl. Sacc., the causal agent of red raspberry (Rubus idaeus L. spur blight. In vitro, both bacteria reduced the growth of D. applanata. In inoculation experiments with raspberry canes in two cultivars with different susceptibility to D. applanata, these antagonistic bacteria suppressed fungal development by reducing the lesions area and the number of D. applanata fruiting bodies. Field trials of two biological formulations under natural conditions showed a significant suppression of the disease. B. subtilis and P. fluorescens included in the formulations revealed antagonistic activity towards D. applanata that depended on the red raspberry cultivar and weather conditions. In all cases, B. subtilis showed better results than P. fluorescens in biocontrol of the raspberry spur blight. This study demonstrated for the first time the ability of the biocontrol agents B. subtilis and P. fluorescens to suppress red raspberry cane spur blight, a serious worldwide disease.

Energy power forward prices. Are forward prices rationally determined by agents in the Colombian market? Los precios forward sobre electricidad. ¿Determinados racionalmente por los agentes del mercado colombiano?

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Gloria Stella Salazar Marín

2011-06-01

Full Text Available This article considers fixed-terms transactions made by agents, in diverse segments of the Colombian energy power market, using forward contracts in order to secure buying/selling prices. The random behavior of prices and quantities, which is handled in the energy power flux, implies the sacrifice of agents according to the transaction segment (regulated, non-regulated or intermediary. In addition to this, the premium, which is paid in the commercial exchange with forwards, is defined by the agents’ expectations and is a reflection of their risk aversion level. This involves financial rationality in the establishment of the premium in order to secure a price on uncertain energy power quantity in the future. Thus, the measurement of such expectation becomes useful, as it is defined by the type of market in which the transaction is being made.El artículo considera las transacciones a plazo sobre electricidad que los agentes del mercado eléctrico en Colombia, en sus diferentes segmentos, hacen por medio de contratos forward, con el fin de asegurar el precio de compra/venta. El comportamiento aleatorio de los precios y las cantidades que se manejan de flujo eléctrico implican el sacrificio de alguno de los agentes, dependiendo del segmento —regulado, no-regulado o intermediación— en el que se realice la operación. Además, la prima que se paga en los intercambios comerciales con forwards está definida por las expectativas de los agentes y es un reflejo de su grado de aversión al riesgo, lo que involucra racionalidad financiera en el establecimiento de la misma, con el propósito de asegurar un precio sobre una cantidad incierta de electricidad a futuro. Así, resulta de mucha utilidad tener una medición de dicha expectativa, definida por el tipo de mercado en el cual se realiza el negocio.

EL CLIMA LABORAL COMO UN ELEMENTO DEL COMPROMISO ORGANIZACIONAL

OpenAIRE

DOMÍNGUEZ AGUIRRE, LUIS ROBERTO; RAMÍREZ CAMPOS, ÁLVARO FABRICIO; GARCÍA MÉNDEZ, ANDRÉS

2014-01-01

El compromiso y el clima organizacional son actitudes que reflejan un estado psicológico relacionado con los valores y objetivos de una organización. Existe un conjunto de causales para que una persona o un conjunto de personas sostengan un compromiso en las organizaciones, teóricamente la percepción favorable del clima laboral que les rodea incrementa el compromiso. El estudio muestra las relaciones observadas en las dimensiones del clima organizacional y las del compromiso. Los hallazgos se...

Acción inhibitoria de una cepa de Zymomonas mobilis mobilis aislada de caña de azúcar sobre Xanthomonas citri subsp. citri, agente causal de la cancrosis de los cítricos Inhibition of Xanthomonas citri subsp. citri, causal agent of citrus canker, by a strain of Zymomonas mobilis mobilis isolated from sugarcane

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María E. Romero

2008-06-01

Full Text Available Zymomonas mobilis mobilis (Zm produce factores antimicrobianos que actúan sobre un amplio espectro de microorganismos patógenos para el hombre, animales y plantas. Un problema importante a resolver en los tratamientos con antimicrobianos, es el desarrollo de resistencia a compuestos empleados actualmente, no siendo las bacterias fitopatógenas una excepción. En el presente trabajo se realizaron ensayos de antagonismo con células (pruebas de estrías cruzadas y sobrenadantes concentrados (Sc (por difusión en agar preparados a partir de cultivos de Zm (aislada de jugo de caña de azúcar producido en Tucumán, frente a la bacteria causal de la cancrosis: Xanthomonas citri subsp. citri. Se evaluaron aislamientos de Xcc sensibles (Xc y resistentes (Xcr a compuestos a base de cobre. Los resultados obtenidos mostraron que la bacteria testigo fue inhibida totalmente por las células de Zm, ejerciendo un efecto bactericida. En los ensayos de difusión en el agar se observó que tanto Xc, como Xcr fueron sensibles al Sc de Zm. Se sabe, por estudios anteriores, que los metabolitos de Zymomonas tienen un efecto deletéreo en la membrana celular de E. coli AB1133, inhibiéndose la respiración de la bacteria inmediatamente de agregado Sc (60 UA. En el presente trabajo se observó el mismo efecto, inhibición total de la respiración en Xc, luego del agregado del Sc (60 UA. Por lo observado, se deduce que el blanco de acción de los metabolitos antimicrobianos de Sc en Xc, sería el mismo que el de E. coli AB1133. Con los resultados obtenidos se considera de interés encarar el estudio de los compuestos de Zm para ser empleados en el control de enfermedades que afectan los cultivos de valor económico de la región, como es el caso de la cancrosis, como así también profundizar acerca de la acción de dichos metabolitos en la membrana de Xanthomonas citri subsp. citri.Zymomonas mobilis mobilis (Zm produces antimicrobial factors, which have an effect on

Neural Correlates of Causal Power Judgments

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Denise Dellarosa Cummins

2014-12-01

Full Text Available Causal inference is a fundamental component of cognition and perception. Probabilistic theories of causal judgment (most notably causal Bayes networks derive causal judgments using metrics that integrate contingency information. But human estimates typically diverge from these normative predictions. This is because human causal power judgments are typically strongly influenced by beliefs concerning underlying causal mechanisms, and because of the way knowledge is retrieved from human memory during the judgment process. Neuroimaging studies indicate that the brain distinguishes causal events from mere covariation, and between perceived and inferred causality. Areas involved in error prediction are also activated, implying automatic activation of possible exception cases during causal decision-making.

Primary health care lessons from the Northeast of Brazil: the Agentes de Saúde Program Lecciones del Nordeste de Brasil sobre la atención primaria de salud: el Programa de Agentes de Salud

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Ennio Cufino Svitone

2000-05-01

more achievable model for other countries, where, like Brazil, income, educational levels, and land tenure equity are limited.Generalmente se considera que las reformas económicas dirigidas por el mercado entran en conflicto con el desarrollo socioeconómico de los grupos desfavorecidos dirigido desde el gobierno. No obstante, desde 1987, Ceará, un estado pobre del Nordeste brasileño, ha seguido simultaneamente estas dos estrategias. Parte de este abordaje ha sido un programa de auxiliares sanitarios, dirigido por personal de enfermería, que cubre cerca de 5 millones de personas: casi todas las que habitan fuera de la capital y la mitad de las residentes en la capital. El programa requiere que esos auxiliares, llamados agentes de salud, vivan en las comunidades que sirven. Los agentes de salud visitan cada domicilio una vez al mes para llevar a cabo un pequeño número de actividades sanitarias prioritarias. Aunque hay una gran demanda de empleo como agentes de salud, el salario que reciben representa tan solo una pequeña fracióin del presupuesto estatal. Un aspecto clave del sistema es la provisión de información integral y oportuna, basada en las visitas de los agentes y gestionada por enfermeros entrenados. Desde que se implantó el sistema de los agentes de salud ha habido una rápida disminución de la mortalidad infantil y un rápido aumento de las inmunizaciones, se han identificado obstáculos que limitan la utilización de otros recursos médicos y ha habido intervenciones oportunas en momentos de crisis. El sistema de los agentes de salud ha combinado la descentralización administrativa con la centralización financiera en un período de democratización electoral. El sistema ha fortalecido el compromiso del estado de Ceará con la atención primaria, a pesar de los cambios dirigidos por el mercado que han reducido el papel global del gobierno. El programa de Ceará está siendo copiado en todo el Nordeste y en otras regiones de Brasil. El papel

Agency, time and causality

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Thomas eWidlok

2014-11-01

Full Text Available Cognitive Scientists interested in causal cognition increasingly search for evidence from non-WEIRD people but find only very few cross-cultural studies that specifically target causal cognition. This article suggests how information about causality can be retrieved from ethnographic monographs, specifically from ethnographies that discuss agency and concepts of time. Many apparent cultural differences with regard to causal cognition dissolve when cultural extensions of agency and personhood to non-humans are taken into account. At the same time considerable variability remains when we include notions of time, linearity and sequence. The article focuses on ethnographic case studies from Africa but provides a more general perspective on the role of ethnography in research on the diversity and universality of causal cognition.

Causal boundary for strongly causal spacetimes: Pt. 1

International Nuclear Information System (INIS)

Szabados, L.B.

1989-01-01

In a previous paper an analysis of the general structure of the causal boundary constructions and a new explicit identification rule, built up from elementary TIP-TIF gluings, were presented. In the present paper we complete our identification by incorporating TIP-TIP and TIF-TIF gluings as well. An asymptotic causality condition is found which, for physically important cases, ensures the uniqueness of the endpoints of the non-spacelike curves in the completed spacetime. (author)

Structural Equations and Causal Explanations: Some Challenges for Causal SEM

Science.gov (United States)

Markus, Keith A.

2010-01-01

One common application of structural equation modeling (SEM) involves expressing and empirically investigating causal explanations. Nonetheless, several aspects of causal explanation that have an impact on behavioral science methodology remain poorly understood. It remains unclear whether applications of SEM should attempt to provide complete…

Competencias TIC del profesorado participante en los planes de formación gestionados por los Agentes Sociales: el Sindicato FETE-UGT

OpenAIRE

Casal Otero, Lorena

2016-01-01

La Competencia en TIC se ha convertido en una competencia básica de los trabajadores de la sociedad del conocimiento. También, como no puede ser de otra forma, del profesorado. Esto implica la necesidad de formación en TIC. Esta formación llega a al profesorado a través de diferentes vías: formación inicial en la Universidad y la formación permanente a través de diferentes agentes de formación, el autoaprendizaje y el aprendizaje con otros. Nuestro trabajo indaga los usos de la...

Rickettsia typhi in rodents and R. felis in fleas in Yucatán as a possible causal agent of undefined febrile cases.

Science.gov (United States)

Peniche-Lara, Gaspar; Dzul-Rosado, Karla; Pérez-Osorio, Carlos; Zavala-Castro, Jorge

2015-01-01

Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chain reaction technique and sequencing. The study only identified the presence of Rickettsia typhi in blood samples obtained from Rattus rattus and it reported, for the first time, the presence of R. felis in the flea Polygenis odiosus collected from Ototylomys phyllotis rodent. Additionally, Rickettsia felis was detected in the ectoparasite Ctenocephalides felis fleas parasitizing the wild rodent Peromyscus yucatanicus. This study's results contributed to a better knowledge of Rickettsia epidemiology in Yucatán.

Aprendizajes significativos desde el juego, el arte y la literatura, “una experiencia estética del agente educativo de primera infancia”

OpenAIRE

Upegui Monsalve, Giovanni Alexander; Díaz Marín, Hugo ALexander

2015-01-01

Tesis de grado (Maestría en Educación y Desarrollo Humano). Universidad de Manizales. Facultad de Ciencias Sociales y Humanas, 2015 Este proyecto de investigación se inscribe en la línea de ambientes educativos del CINDE, cohorte UMZ20, a partir del proceso de cualificación dado en el municipio de Bello (Antioquia), mediante el diplomado de Expresolandia “lugares para crear, expresar y compartir”, cualificación dada a 240 agentes educativos de primera infancia y, que culminó con el diseño ...

Structure and Connectivity Analysis of Financial Complex System Based on G-Causality Network

International Nuclear Information System (INIS)

Xu Chuan-Ming; Yan Yan; Zhu Xiao-Wu; Li Xiao-Teng; Chen Xiao-Song

2013-01-01

The recent financial crisis highlights the inherent weaknesses of the financial market. To explore the mechanism that maintains the financial market as a system, we study the interactions of U.S. financial market from the network perspective. Applied with conditional Granger causality network analysis, network density, in-degree and out-degree rankings are important indicators to analyze the conditional causal relationships among financial agents, and further to assess the stability of U.S. financial systems. It is found that the topological structure of G-causality network in U.S. financial market changed in different stages over the last decade, especially during the recent global financial crisis. Network density of the G-causality model is much higher during the period of 2007–2009 crisis stage, and it reaches the peak value in 2008, the most turbulent time in the crisis. Ranked by in-degrees and out-degrees, insurance companies are listed in the top of 68 financial institutions during the crisis. They act as the hubs which are more easily influenced by other financial institutions and simultaneously influence others during the global financial disturbance. (interdisciplinary physics and related areas of science and technology)

Estudios sobre el Marchitamiento Bacterial de la Arracacha (Arracacciaxanthoriza Causado por Erwiniasp.

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Zapata G. Mario A.

1974-04-01

Full Text Available Durante el segundo semestre de 1973 se efectuó una investigación tendiente a determinar la naturaleza de un marchitamiento que afecta desde hace algunos años los cultivos de arracacha (Arracacciaxantboriza en el Oriente antioqueño. Tanto los aislamientos hechos a partir de las plantas afectadas, como los reaislamientos hechos a partir de las plantas inoculadas, así como las pruebas fisiológicas para la caracterización del agente causal, se realizaron en el laboratorio de Fitopatología de la Facultad de Ciencias Agrícolas de la Universidad Nacional en Medellín. Las inoculaciones y observaciones de patogenicidad se realizaron en el invernadero de Fitopatología del C.N.I.A. Tulio Ospina del Instituto Colombiano Agropecuario, ICA. Mediante la aplicación de los postulados de Koch se determinó como agente causal de la enfermedad a una bacteria del género Erwinia. Los métodos de inoculación empleados permitieron concluir que la bacteria penetra en el susceptivo a través del sistema radicular en condiciones naturales. /Abstract. During the second semester of 1973 a research was carried out in order to determine the nature of a wilting which has been observed for several years on arracacha crops (Arracacciazantboriza in East Antioquia. lsolations from the affected plants, reisolations from the plants inoculated, and physiological tests to characterize the causal agent were carried out in the Plant Pathology Laboratory, Facultad de CienciasAgrícolas, Universidad Nacional, Medellín. lnoculations and observations on pathogenicity were carried out in a greenhouse of the TulioOspina Experiment Station, I.C.A.. Medellin. By applying the Koch's postulates it was determined the bacterium Erwinia as the causal agent of the disease. The inoculation methods used made possible to conclude that the pathogen penetrates through the root system of the susceptive plant under natural conditions.

Seguimiento del paciente asmático: qué debe saber el farmacéutico comunitario

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Plaza Zamora J

2013-03-01

Full Text Available El asma tiene una prevalencia de entre un 1 y un 18% dependiendo del país. En el proceso de atención al paciente, y a través de los síntomas que presenta (disnea, tos, sibilancias, opresión torácica, el farmacéutico comunitario puede hacer educación sanitaria para evitar los agentes causales del asma, sobre cómo usar el dispositivo de inhalación prescrito por el médico, explicar al paciente su medicación, cómo es su tratamiento para conocer mejor su enfermedad, qué signos y síntomas denotan una falta de control de la misma, qué métodos se pueden usar para monitorizar la evolución del asma, detectar una posible falta de efectividad del tratamiento por tener sintomatología a pesar de estar usando adecuadamente el dispositivo de inhalación, sospechar que exista algún medicamento causante del asma, repasar el resto de medicación que usa por si existieran interacciones que afectaran tanto a la efectividad como a la seguridad del tratamiento. Existe un importante infradiagnóstico del asma, un 57,5% según el ECRHS (siglas del inglés European Community Respiratory Health Survey. En la farmacia comunitaria se puede hacer cribado de la enfermedad con la ayuda de cuestionarios validados en niños y no validados en adultos. Mediante la presente revisión se pretende ofrecer al farmacéutico comunitario una herramienta práctica para su labor diaria de atención al paciente asmático.

Combining human and machine intelligence to derive agents' behavioral rules for groundwater irrigation

Science.gov (United States)

Hu, Yao; Quinn, Christopher J.; Cai, Ximing; Garfinkle, Noah W.

2017-11-01

For agent-based modeling, the major challenges in deriving agents' behavioral rules arise from agents' bounded rationality and data scarcity. This study proposes a "gray box" approach to address the challenge by incorporating expert domain knowledge (i.e., human intelligence) with machine learning techniques (i.e., machine intelligence). Specifically, we propose using directed information graph (DIG), boosted regression trees (BRT), and domain knowledge to infer causal factors and identify behavioral rules from data. A case study is conducted to investigate farmers' pumping behavior in the Midwest, U.S.A. Results show that four factors identified by the DIG algorithm- corn price, underlying groundwater level, monthly mean temperature and precipitation- have main causal influences on agents' decisions on monthly groundwater irrigation depth. The agent-based model is then developed based on the behavioral rules represented by three DIGs and modeled by BRTs, and coupled with a physically-based groundwater model to investigate the impacts of agents' pumping behavior on the underlying groundwater system in the context of coupled human and environmental systems.

Causality discovery technology

Science.gov (United States)

Chen, M.; Ertl, T.; Jirotka, M.; Trefethen, A.; Schmidt, A.; Coecke, B.; Bañares-Alcántara, R.

2012-11-01

Causality is the fabric of our dynamic world. We all make frequent attempts to reason causation relationships of everyday events (e.g., what was the cause of my headache, or what has upset Alice?). We attempt to manage causality all the time through planning and scheduling. The greatest scientific discoveries are usually about causality (e.g., Newton found the cause for an apple to fall, and Darwin discovered natural selection). Meanwhile, we continue to seek a comprehensive understanding about the causes of numerous complex phenomena, such as social divisions, economic crisis, global warming, home-grown terrorism, etc. Humans analyse and reason causality based on observation, experimentation and acquired a priori knowledge. Today's technologies enable us to make observations and carry out experiments in an unprecedented scale that has created data mountains everywhere. Whereas there are exciting opportunities to discover new causation relationships, there are also unparalleled challenges to benefit from such data mountains. In this article, we present a case for developing a new piece of ICT, called Causality Discovery Technology. We reason about the necessity, feasibility and potential impact of such a technology.

Uso de la evaluación en un contexto de múltiples agentes: el caso del plan de desarrollo rural del país vasco (en el marco de la UE

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María Ángeles Díez López

2011-05-01

Full Text Available Este artículo analiza la utilización de los resultados y del proceso seguido en la evaluación de un programa de desarrollo rural basada en un enfoque participativo. Para ello, se utiliza la experiencia de la Evaluación Intermedia del Plan de Desarrollo Rural Sostenible del País Vasco 2000-2006. La premisa fundamental del equipo evaluador es que la participación incrementa la utilización de la evaluación, favoreciendo su uso en el diseño y en la toma de decisiones. El artículo se estructura en dos partes fundamentales: la primera de ellas describe la adecuación del modelo de evaluación participativa a los intereses y propósitos de nuestra evaluación. La segunda parte examina el impacto que este modelo de evaluación tuvo sobre el uso de sus hallazgos y recomendaciones. Esta valoración permitió extraer lecciones que pueden ayudar a reforzar el uso de la evaluación en contextos donde participan múltiples agentes, favoreciendo así el desarrollo de la gobernanza.

Reasoning with Causal Cycles

Science.gov (United States)

Rehder, Bob

2017-01-01

This article assesses how people reason with categories whose features are related in causal cycles. Whereas models based on causal graphical models (CGMs) have enjoyed success modeling category-based judgments as well as a number of other cognitive phenomena, CGMs are only able to represent causal structures that are acyclic. A number of new…

Causal Factors for The Adoption Innovation Teacher’s Tv for Teachersand Educational Personnel

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Thanadol Phuseerit

2016-12-01

aire for the experts to examine the causal factors for the adoption innovation teacher’s TV for teachers and education personnel model by focus groups, 4 questionnaire to confirm the causal factors to an innovation teacher’s TV model for teachers and educational personnel Committee of the teacher’s TV, 5 the causal factor for the adoption innovation teacher’s TV for teachers and education personnel model, 6 evaluation form of the causal factor for the adoption of the innovation teacher’s TV for teachers and education personnel model from the specialists. The research results were: 1 The causal factors for the adoption innovation teacher’s TV for Teachers and educational personnel Model. Elements and factors are as follows: 1.1 Elements of the causes and factors of innovation teacher’s TV. Teachers and educational personnel The Review of literature and semi-structured questionnaire, interviewing Collecting quality data from in-depth interviews with a total 9 causal as fallow: (1 Characteristics of innovation, included: relative Advantage, Compatibility, Complexity, Trial ability, Observable (2 Communication Channels, included: interpersonal communication, the media as press, radio, television, communication specialized media (3 Innovation-Decision Process, included: Knowledge, Persuasion, Decision, Implementation, Confirmation (4 Economy and Social System, include: compensation and benefits. Social interaction, (5 Attitude, included: understanding the emotions, behavior (6 Motivation, included: Intrinsic motivation. External motivation (7 Support of Administrator, include: support for innovation, the budget support and materials, Academic support (8 Change agent, included: knowledge and ability, Skill-oriented capabilities Ability attitude (9 Opinion Leaders, included: access to others easily, Creative and 1element of the Adoption of the Innovation: TTV, included: the perceived ease of use, and Perceived benefits. The model’s validity of the consistency

Structure and Strength in Causal Induction

Science.gov (United States)

Griffiths, Thomas L.; Tenenbaum, Joshua B.

2005-01-01

We present a framework for the rational analysis of elemental causal induction--learning about the existence of a relationship between a single cause and effect--based upon causal graphical models. This framework makes precise the distinction between causal structure and causal strength: the difference between asking whether a causal relationship…

Regression to Causality : Regression-style presentation influences causal attribution

DEFF Research Database (Denmark)

Bordacconi, Mats Joe; Larsen, Martin Vinæs

2014-01-01

of equivalent results presented as either regression models or as a test of two sample means. Our experiment shows that the subjects who were presented with results as estimates from a regression model were more inclined to interpret these results causally. Our experiment implies that scholars using regression...... models – one of the primary vehicles for analyzing statistical results in political science – encourage causal interpretation. Specifically, we demonstrate that presenting observational results in a regression model, rather than as a simple comparison of means, makes causal interpretation of the results...... more likely. Our experiment drew on a sample of 235 university students from three different social science degree programs (political science, sociology and economics), all of whom had received substantial training in statistics. The subjects were asked to compare and evaluate the validity...

Factores causales en las complicaciones de estomas intestinales en cirugía de emergencia. Hospital Luis Vernaza, 2013.

OpenAIRE

Morán Mancero, María Cristina

2014-01-01

El estoma intestinal es una apertura del intestino en la superficie del abdomen. Las estadísticas según diversos autores indica que hay aproximadamente unas 32.000 personas ostomizadas, de las cuales el 75% presentan una colostomía y el 10% una ileostomía. Objetivo:Determinar los factores causales en las complicaciones tempranas y tardías de los estomas intestinales en la cirugía de emergencia.Metodología:Estudio de tipo Retrospectivo, Observacional, Transversal, de nivel Descriptivo y diseño...

Atribuições causais e nível educativo familiar na compreensão do desempenho escolar em alunos portugueses Atribuciones causales y nivel educativo familiar en la comprensión del desempeño escolar en alumnos portugueses Causal attributions and educational level of the family in understanding school performance in Portuguese students

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Lúcia C. Miranda

2012-04-01

Full Text Available Este artigo analisa o contributo específico do nível educativo familiar e das atribuições causais para o bom e fraco rendimento escolar dos alunos na explicação do seu desempenho nas disciplinas de Língua Portuguesa e de Matemática numa amostra de 2.082 alunos do ensino público de 11 escolas de Portugal, incluindo as Regiões Autónomas dos Açores e da Madeira. As atribuições causais foram avaliadas por meio do Questionário das Atribuições Causais para os Resultados Escolares (QARE. O nível educativo familiar foi estimado levando em conta o nível escolar do progenitor com maior habilitação escolar. As classificações obtidas pelos alunos nas disciplinas de língua portuguesa e matemática foram também examinadas. Os resultados apontam para correlações estatisticamente significativas, destacando as atribuições na capacidade para a explicação do rendimento escolar, situação que contrasta com a atribuição dos níveis de rendimento a variáveis externas ao aluno. A análise de regressão permite associar 34,5% da variância no rendimento conjunto em Língua Portuguesa e em Matemática no ensino básico, assim como 21,3% no ensino secundário, às dimensões atribucionais e ao nível educativo familiar. Implicações educacionais são derivadas a partir dos achados.Este artículo analiza la contribución específica del nivel educativo familiar y de las atribuciones causales para el buen y el flaco rendimiento escolar de los alumnos en la explicación de su desempeño en las disciplinas de Lengua Portuguesa y Matemáticas en una muestra de 2.082 alumnos de enseñanza pública de 11 escuelas de Portugal, incluyendo las Regiones Autónomas de Açores y Madeira. Las atribuciones causales fueron evaluadas por medio del "Questionário das Atribuições Causais para os Resultados Escolares" (QARE. El nivel educativo familiar fue estimado teniendo en cuenta el nivel escolar del progenitor con mayor habilitación escolar. Las

El timerosal y las enfermedades del neurodesarrollo infantil

OpenAIRE

Luis Maya; Flora Luna

2006-01-01

Se evalúa la relación causal entre el timerosal (etilmercurio), como preservante en las vacunas pediátricas, y el incremento de casos de enfermedades del neurodesarrollo infantil, como consecuencia de la ampliación de los esquemas de inmunización. Se revisó la información científica, relacionando el timerosal y las evidencias que permitan evaluar una posible asociación causal, con estudios epidemiológicos, ecológicos, biomoleculares y toxicológicos, de bioseguridad, toxicológicos fetales y so...

Development of Nested-PCR Assay to Detect Acidovorax citrulli, a Causal Agent of Bacterial Fruit Blotch at Cucurbitaceae

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Young-Tak Kim

2015-06-01

Full Text Available The specific and sensitive nested-PCR method to detect Acidovorax citrulli, a causal agent of bacterial fruit blotch on cucurbitaceae, was developed. PCR primers were designed from the draft genome sequence which was obtained with the Next Generation Sequencing of A. citrulli KACC10651, and the nested-PCR primer set (Ac-ORF 21F/Ac-ORF 21R were selected by checking of specificity to A. citrulli with PCR assays. The selected nested-PCR primer amplified the 140 bp DNA only from A. citrulli strains, and detection sensitivity of the nested PCR increased 10,000 times of 1st PCR detection limit (10 ng genomic DNA/PCR. The nested PCR detected A. citrulli from the all samples of seed surface wash (external seed detection of the artificially inoculated watermelon seeds with 101 cfu/ml and above population of A. citrulli while the nested PCR could not detected A. citrulli from the mashed seed suspension (internal seed detection of the all artificially inoculated watermelon seeds. When the naturally infested watermelon seeds (10% seed infested rate with grow-out test used, the nested PCR detected A. citrulli from 2 seed samples out of 10 replication samples externally and 5 seed samples out of 10 replication samples internally. We believe that the nested-PCR developed in this study will be useful method to detect A. citrulli from the Cucurbitaceae seeds.

Causality and headache triggers

Science.gov (United States)

Turner, Dana P.; Smitherman, Todd A.; Martin, Vincent T.; Penzien, Donald B.; Houle, Timothy T.

2013-01-01

Objective The objective of this study was to explore the conditions necessary to assign causal status to headache triggers. Background The term “headache trigger” is commonly used to label any stimulus that is assumed to cause headaches. However, the assumptions required for determining if a given stimulus in fact has a causal-type relationship in eliciting headaches have not been explicated. Methods A synthesis and application of Rubin’s Causal Model is applied to the context of headache causes. From this application the conditions necessary to infer that one event (trigger) causes another (headache) are outlined using basic assumptions and examples from relevant literature. Results Although many conditions must be satisfied for a causal attribution, three basic assumptions are identified for determining causality in headache triggers: 1) constancy of the sufferer; 2) constancy of the trigger effect; and 3) constancy of the trigger presentation. A valid evaluation of a potential trigger’s effect can only be undertaken once these three basic assumptions are satisfied during formal or informal studies of headache triggers. Conclusions Evaluating these assumptions is extremely difficult or infeasible in clinical practice, and satisfying them during natural experimentation is unlikely. Researchers, practitioners, and headache sufferers are encouraged to avoid natural experimentation to determine the causal effects of headache triggers. Instead, formal experimental designs or retrospective diary studies using advanced statistical modeling techniques provide the best approaches to satisfy the required assumptions and inform causal statements about headache triggers. PMID:23534872

Morphological and molecular identification of Fusarium tricinctum and Fusarium acuminatum as causal agents of garlic bulbs rot in Serbia

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Ignjatov Maja V.

2017-01-01

Full Text Available Garlic (Allium sativum L. is considered to be one of the oldest crops in the world. During 2016, infected garlic bulbs occurred in storages on several localities of the Province of Vojvodina. Symptomatic cloves showed typical rot symptoms such as softened and spongy areas covered with white fungal growth with deep lesions formed on the cloves which became dry over time. A total of 36 isolates of Fusarium species were obtained from diseased cloves of garlic. Colony morphology and microscopic properties of isolated Fusarium species were recorded from the cultures grown on PDA and CLA, respectively. Identification of two chosen isolates was performed by sequencing the EF-1α gene. The TEF sequence of isolate JBL12 showed 100% similarity with several F. tricinctum sequences and sequence of JBL539 showed 99% identity with several F. acuminatum sequences and they were deposited in the NCBI GenBank. Based on the results of the morphological and molecular identification, isolates JBL12 and JBL539 were identified as F. tricinctum and F. acuminatum, respectively, as new causal agents of garlic bulbs rot in Serbia. Specific primers were designed for the PCR identification of the F. tricinctum. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR31030

A Causal Model of Career Development and Quality of Life of College Students with Disabilities

Science.gov (United States)

Chun, Jina

2017-01-01

Researchers have assumed that social cognitive factors play significant roles in the career development of transition youth and young adults with disabilities and those without disabilities. However, research on the influence of the career decision-making process as a primary causal agent in one's psychosocial outcomes such as perceived level of…

Viscous causal cosmologies

International Nuclear Information System (INIS)

Novello, M.; Salim, J.M.; Torres, J.; Oliveira, H.P. de

1989-01-01

A set of spatially homogeneous and isotropic cosmological geometries generated by a class of non-perfect is investigated fluids. The irreversibility if this system is studied in the context of causal thermodynamics which provides a useful mechanism to conform to the non-violation of the causal principle. (author) [pt

Dynamics of Quantum Causal Structures

Science.gov (United States)

Castro-Ruiz, Esteban; Giacomini, Flaminia; Brukner, Časlav

2018-01-01

It was recently suggested that causal structures are both dynamical, because of general relativity, and indefinite, because of quantum theory. The process matrix formalism furnishes a framework for quantum mechanics on indefinite causal structures, where the order between operations of local laboratories is not definite (e.g., one cannot say whether operation in laboratory A occurs before or after operation in laboratory B ). Here, we develop a framework for "dynamics of causal structures," i.e., for transformations of process matrices into process matrices. We show that, under continuous and reversible transformations, the causal order between operations is always preserved. However, the causal order between a subset of operations can be changed under continuous yet nonreversible transformations. An explicit example is that of the quantum switch, where a party in the past affects the causal order of operations of future parties, leading to a transition from a channel from A to B , via superposition of causal orders, to a channel from B to A . We generalize our framework to construct a hierarchy of quantum maps based on transformations of process matrices and transformations thereof.

Causal inference based on counterfactuals

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Höfler M

2005-09-01

Full Text Available Abstract Background The counterfactual or potential outcome model has become increasingly standard for causal inference in epidemiological and medical studies. Discussion This paper provides an overview on the counterfactual and related approaches. A variety of conceptual as well as practical issues when estimating causal effects are reviewed. These include causal interactions, imperfect experiments, adjustment for confounding, time-varying exposures, competing risks and the probability of causation. It is argued that the counterfactual model of causal effects captures the main aspects of causality in health sciences and relates to many statistical procedures. Summary Counterfactuals are the basis of causal inference in medicine and epidemiology. Nevertheless, the estimation of counterfactual differences pose several difficulties, primarily in observational studies. These problems, however, reflect fundamental barriers only when learning from observations, and this does not invalidate the counterfactual concept.

The argumentative impact of causal relations

DEFF Research Database (Denmark)

Nielsen, Anne Ellerup

1996-01-01

such as causality, explanation and justification. In certain types of discourse, causal relations also imply an intentional element. This paper describes the way in which the semantic and pragmatic functions of causal markers can be accounted for in terms of linguistic and rhetorical theories of argumentation.......The semantic relations between and within utterances are marked by the use of connectors and adverbials. One type of semantic relations is causal relations expressed by causal markers such as because, therefore, so, for, etc. Some of these markers cover different types of causal relations...

Entropy for theories with indefinite causal structure

International Nuclear Information System (INIS)

Markes, Sonia; Hardy, Lucien

2011-01-01

Any theory with definite causal structure has a defined past and future, be it defined by light cones or an absolute time scale. Entropy is a concept that has traditionally been reliant on a definite notion of causality. However, without a definite notion of causality, the concept of entropy is not all lost. Indefinite causal structure results from combining probabilistic predictions and dynamical space-time. The causaloid framework lays the mathematical groundwork to be able to treat indefinite causal structure. In this paper, we build on the causaloid mathematics and define a causally-unbiased entropy for an indefinite causal structure. In defining a causally-unbiased entropy, there comes about an emergent idea of causality in the form of a measure of causal connectedness, termed the Q factor.

Dynamics of Quantum Causal Structures

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Esteban Castro-Ruiz

2018-03-01

Full Text Available It was recently suggested that causal structures are both dynamical, because of general relativity, and indefinite, because of quantum theory. The process matrix formalism furnishes a framework for quantum mechanics on indefinite causal structures, where the order between operations of local laboratories is not definite (e.g., one cannot say whether operation in laboratory A occurs before or after operation in laboratory B. Here, we develop a framework for “dynamics of causal structures,” i.e., for transformations of process matrices into process matrices. We show that, under continuous and reversible transformations, the causal order between operations is always preserved. However, the causal order between a subset of operations can be changed under continuous yet nonreversible transformations. An explicit example is that of the quantum switch, where a party in the past affects the causal order of operations of future parties, leading to a transition from a channel from A to B, via superposition of causal orders, to a channel from B to A. We generalize our framework to construct a hierarchy of quantum maps based on transformations of process matrices and transformations thereof.

Effect of Acacia raddiana extracts on Fusarium oxysporum f. sp. albedinis, the causal agent of Bayoud

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Noureddine BOULENOUAR

2016-07-01

Full Text Available In the present study, a medicinal plant from algerian Sahara (South-West of Algeria, Acacia raddiana has been used (leaves, bark to evaluate its extracts (reflux extraction with four solvents: methanol, ethyl acetate, dichloromethane, hexane on Fusarium oxysporum f. sp. albedinis (Foa. The Foa is the causal agent of the most dangerous disease of date palm (Phoenix dactylifera L.. The preliminary evaluation has been realized by agar diffusion technique and virulence test on potato tuber tissues. The extracts that present an inhibition or decrease the relative virulence (RV below 50% undergo phytochemical screening and direct bioautography. The bioautography has been used to localize the antifungal activity on the chromatogram and study the correlation with phytochemical screening data. Among eight extracts, five has been chosen for phytochemical screening and bioautography (2 leaves extracts and 3 bark extracts. Only six tests among 32 (22.58% present a detectable effect. The best effect is related to bark extract with ethyl acetate (inhibition diameter: 18mm, which is a moderate effect. Some extracts show an increase in RV. On the other hand, others decrease the RV. The best effect on RV is presented by hexanic extract of bark (RV=48%. The phytochemical screening highlighted the presence of flavonoids, tannins, coumarins and alkaloids in the studied plant. The direct bioautography has demonstrated no detectable effect. According to realized analyses, we can conclude that this species contains bioactive substances on Foa but need more precise analyses. The reason is simple, in addition to synergy principle in the crude extracts; the quantity of these metabolites is low compared to the detection level.

Infeccion urinaria temprana en trasplante renal: Factores de riesgo y efecto en la sobrevida del injerto Early urinary tract infection in kidney transplantation: Risk factors and impact on graft sur-vival

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Pablo A. Cepeda

2005-10-01

Full Text Available La infección urinariatemprana del injerto (IUTI, definida como infección urinaria sintomática en los primeros 3 meses del trasplante, su efecto sobre la sobrevida del injerto y los factores de riesgo han sido poco estudiados. Los objetivos del presente análisis fueron conocer factores de riesgo para IUTI, analizar agentes causantes e impacto en la sobrevida del injerto. En forma retrospectiva se analizaron pacientes que recibieron trasplante renal durante 1997-2000 en el Hospital Privado - Centro Médico de Córdoba. Se dividió en dos grupos de pacientes, según presencia (grupo IUTI o ausencia (grupo control de IUTI. Los factores de riesgo se analizaron con el modelo de riesgos proporcionales de Cox y la sobrevida del injerto con el método de Kaplan-Meier. Recibieron trasplante renal 226 pacientes consecutivos. La IUTI se presentó en 55 (24.3%. Factores de riesgo asociados con IUTI: antecedentes de maniobras urológicas invasivas (RR=4.34, IC 95% 1.42-13.21, diabetes mellitus (RR=3.79, IC 95% 1.42-10.14, infección por citomegalovirus (RR=2.9, IC 95% 1.02-8.24 y antecedente de trasplante previo (RR=2.83, IC 95% 1.08-7.45. El retardo en la función del injerto (RR=0.38, IC 95% 0.15-0.94 se asoció con menor incidencia de IUTI. Agentes más frecuentes: Klebsiella pneumoniae (36%, Pseudomonas aeruginosa (24% y Escherichia coli (9%. La sobrevida del injerto a los 2 años en el grupo IUTI (87.2% no fue diferente del control (81.2%, P = 0.32. En esta serie las maniobras urológicas invasivas fueron el principal factor de riesgo asociado a IUTI. No hubo disminución de la sobrevida del injerto asociada a IUTI. La alta prevalencia de uropatógenos no coli requiere mayor evaluación.The early urinary tract infection (EUTI in kidney transplant recipients is an infection develop during the first 3 months post transplant surgery. The effect of EUTI on graft survival and risk factors have been scarcely studied. Our objetives were the evaluation of

The Host-Agent-Environment Concept of Accidents.

Science.gov (United States)

Phillips, Don

Background information is presented to indicate that accidents are an environmental health problem. While accidents are seldom thought to be a disease process, in many ways there are remarkable similarities--not only in terms of causal relationships, but also in preventive aspects. These parallels are described in terms of host-agent-environment…

Causal inference in public health.

Science.gov (United States)

Glass, Thomas A; Goodman, Steven N; Hernán, Miguel A; Samet, Jonathan M

2013-01-01

Causal inference has a central role in public health; the determination that an association is causal indicates the possibility for intervention. We review and comment on the long-used guidelines for interpreting evidence as supporting a causal association and contrast them with the potential outcomes framework that encourages thinking in terms of causes that are interventions. We argue that in public health this framework is more suitable, providing an estimate of an action's consequences rather than the less precise notion of a risk factor's causal effect. A variety of modern statistical methods adopt this approach. When an intervention cannot be specified, causal relations can still exist, but how to intervene to change the outcome will be unclear. In application, the often-complex structure of causal processes needs to be acknowledged and appropriate data collected to study them. These newer approaches need to be brought to bear on the increasingly complex public health challenges of our globalized world.

Putting a cap on causality violations in causal dynamical triangulations

International Nuclear Information System (INIS)

Ambjoern, Jan; Loll, Renate; Westra, Willem; Zohren, Stefan

2007-01-01

The formalism of causal dynamical triangulations (CDT) provides us with a non-perturbatively defined model of quantum gravity, where the sum over histories includes only causal space-time histories. Path integrals of CDT and their continuum limits have been studied in two, three and four dimensions. Here we investigate a generalization of the two-dimensional CDT model, where the causality constraint is partially lifted by introducing branching points with a weight g s , and demonstrate that the system can be solved analytically in the genus-zero sector. The solution is analytic in a neighborhood around weight g s = 0 and cannot be analytically continued to g s = ∞, where the branching is entirely geometric and where one would formally recover standard Euclidean two-dimensional quantum gravity defined via dynamical triangulations or Liouville theory

HACIA UNA CONCEPTUALIZACIÓN DEL LEGADO DEL TRADUCTOR

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María Constanza Guzmán

2009-06-01

Full Text Available Este artículo se propone investigar el aporte de perspectivas traductológicas para el estudio de la figura del traductor y su legado. Se centra en enfoques teóricos contemporáneos, principalmente aquellos basados en perspectivas postestructuralistas, que consideran el papel del sujeto traductor como un aspecto crucial en la traducción y los estudios literarios, y proponen maneras interesantes de abordarlo. A lo largo del artículo se cuestionan nociones como la idea de un original sacralizado, la relación entre autoría y propiedad, el ideal del significado transparente, y la tensión entre la traducción y la escritura del "original". Se presta especial atención a la importancia de ubicar históricamente la práctica del traductor, reconocer su papel como agente visible, y conceptualizar la traducción como una forma de escritura que se desarrolla en medio de complejas interacciones y negociaciones.

HACIA UNA CONCEPTUALIZACIÓN DEL LEGADO DEL TRADUCTOR

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María Constanza Guzmán

2009-01-01

Full Text Available Este artículo se propone investigar el aporte de perspectivas traductológicas para el estudio de la figura del traductor y su legado. Se centra en enfoques teóricos contemporáneos, principalmente aquellos basados en perspectivas postestructuralistas, que consideran el papel del sujeto traductor como un aspecto crucial en la traducción y los estudios literarios, y proponen maneras interesantes de abordarlo. A lo largo del artículo se cuestionan nociones como la idea de un original sacralizado, la relación entre autoría y propiedad, el ideal del significado transparente, y la tensión entre la traducción y la escritura del "original". Se presta especial atención a la importancia de ubicar históricamente la práctica del traductor, reconocer su papel como agente visible, y conceptualizar la traducción como una forma de escritura que se desarrolla en medio de complejas interacciones y negociaciones.

Causality Statistical Perspectives and Applications

CERN Document Server

Berzuini, Carlo; Bernardinell, Luisa

2012-01-01

A state of the art volume on statistical causality Causality: Statistical Perspectives and Applications presents a wide-ranging collection of seminal contributions by renowned experts in the field, providing a thorough treatment of all aspects of statistical causality. It covers the various formalisms in current use, methods for applying them to specific problems, and the special requirements of a range of examples from medicine, biology and economics to political science. This book:Provides a clear account and comparison of formal languages, concepts and models for statistical causality. Addr

Resistencia inducida a la enfermedad del añublo de la panícula del arroz inoculando bacterias endofíticas

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Manuel José Peláez Pelaez

2017-09-01

Full Text Available Se evaluó el efecto antagónico de las bacterias endófitas aisladas de porciones de hojas, tallos y raíces de plantas de arroz completamente sanas, contra la bacteria patogénica Burkholderia glumae (Kurita & Tabei, 1967, agente causal   de la enfermedad del añublo bacterial de la panícula. Se obtuvieron 24 aislamientos en total de bacterias endófitas que fueron evaluadas mediante la técnica de enfrentamiento de cultivos duales, en condiciones de laboratorio, posteriormente se realizaron las inoculaciones de la solución bacteriana en condiciones de campo para evaluar el efecto antagónico. Los resultados obtenidos indican que sólo dos cepas bacterianas presentaron actividad antagónica contra B. glumae las cuales fueron identificadas mediante caracterización bioquímica, de los bioensayos realizados a nivel de laboratorio y en campo. Por tanto, hubo una mejor expresión de las bacterias antagónicas bajo condiciones controladas en el laboratorio comparado con los ensayos realizados en campo

A frequency domain subspace algorithm for mixed causal, anti-causal LTI systems

NARCIS (Netherlands)

Fraanje, Rufus; Verhaegen, Michel; Verdult, Vincent; Pintelon, Rik

2003-01-01

The paper extends the subspacc identification method to estimate state-space models from frequency response function (FRF) samples, proposed by McKelvey et al. (1996) for mixed causal/anti-causal systems, and shows that other frequency domain subspace algorithms can be extended similarly. The method

Aspectos moleculares del virus de la parvovirosis canina y sus implicaciones en la enfermedad

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César A. Díaz R.

2008-06-01

Full Text Available El parvovirus canino tipo 2 (CPV-2 es el agente causal de una enfermedad infecto-contagiosa que produce una gastroenteritis aguda hemorrágica que afecta a caninos jóvenes. El CPV-2 se adaptó a la especie canina por mutación del virus de la Panleucopenia felina (FPV luego de su paso por animales silvestres como el hurón y los zorros. La alta variabilidad de la proteína viral 2 (VP2 es la causa principal del amplio rango de hospedadores y de las reacciones cruzadas entre las variantes. En la actualidad, la secuenciación de esta proteína ha permitido identificar tres variantes del virus conocidas como 2a, 2b y 2c que conviven en el mundo con diferencias en tropismo celular, infecciocidad y patogenicidad. El virus ssADN ha presentado una gran variación génica en cortos períodos de tiempo lo que indica un alto grado de selección por evolución sólo comparable con virus RN, esta alta variabilidad no se ha aclarado totalmente. El empleo de las técnicas moleculares permitirá diferenciar entre cepas vacunales y de campo, tanto como contar con técnicas diagnósticas confiables y específicas.

Aislamiento, identificación y daños asociados al síndrome de la muerte súbita en el cultivo de soja en Argentina

OpenAIRE

Scandiani, María Mercedes; Carmona, Marcelo Aníbal; Luque, Alicia Graciela; Matos, Kedma da Silva; Lenzi, Lisandro; Formento, Ángela Norma; Martinez, Cristina Valeria; Ferri, Mónica Raquel; Lo Piccolo, Melina; Tartabini, Mirta; Alvarez, Diego; Sautua, Francisco

2012-01-01

Los objetivos de este trabajo fueron aislar e identificar los agentes causales del síndrome de la muerte súbita (SMS) en muestras provenientes de diferentes localidades de Argentina, y cuantificar la incidencia de la enfermedad y los daños causados a campo en el rendimiento. Se analizaron 215 raíces provenientes de plantas con síntoma foliares típicos de SMS para el aislamiento e identificación de los agentes causales. Para realizar las pruebas de patogenicidad se efectuaron dos bioensayos en...

The Functions of Danish Causal Conjunctions

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Rita Therkelsen

2004-01-01

Full Text Available In the article I propose an analysis of the Danish causal conjunctions fordi, siden and for based on the framework of Danish Functional Grammar. As conjunctions they relate two clauses, and their semantics have in common that it indicates a causal relationship between the clauses. The causal conjunctions are different as far as their distribution is concerned; siden conjoins a subordinate clause and a main clause, for conjoins two main clauses, and fordi is able to do both. Methodologically I have based my analysis on these distributional properties comparing siden and fordi conjoining a subordinate and a main clause, and comparing for and fordi conjoining two main clauses, following the thesis that they would establish a causal relationship between different kinds of content. My main findings are that fordi establishes a causal relationship between the events referred to by the two clauses, and the whole utterance functions as a statement of this causal relationship. Siden presupposes such a general causal relationship between the two events and puts forward the causing event as a reason for assuming or wishing or ordering the caused event, siden thus establishes a causal relationship between an event and a speech act. For equally presupposes a general causal relationship between two events and it establishes a causal relationship between speech acts, and fordi conjoining two main clauses is able to do this too, but in this position it also maintains its event-relating ability, the interpretation depending on contextual factors.

Space and time in perceptual causality

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Benjamin Straube

2010-04-01

Full Text Available Inferring causality is a fundamental feature of human cognition that allows us to theorize about and predict future states of the world. Michotte suggested that humans automatically perceive causality based on certain perceptual features of events. However, individual differences in judgments of perceptual causality cast doubt on Michotte’s view. To gain insights in the neural basis of individual difference in the perception of causality, our participants judged causal relationships in animations of a blue ball colliding with a red ball (a launching event while fMRI-data were acquired. Spatial continuity and temporal contiguity were varied parametrically in these stimuli. We did not find consistent brain activation differences between trials judged as caused and those judged as non-caused, making it unlikely that humans have universal instantiation of perceptual causality in the brain. However, participants were slower to respond to and showed greater neural activity for violations of causality, suggesting that humans are biased to expect causal relationships when moving objects appear to interact. Our participants demonstrated considerable individual differences in their sensitivity to spatial and temporal characteristics in perceiving causality. These qualitative differences in sensitivity to time or space in perceiving causality were instantiated in individual differences in activation of the left basal ganglia or right parietal lobe, respectively. Thus, the perception that the movement of one object causes the movement of another is triggered by elemental spatial and temporal sensitivities, which themselves are instantiated in specific distinct neural networks.

Indicators of causal agency in physical interactions: the role of the prior context.

Science.gov (United States)

Mayrhofer, Ralf; Waldmann, Michael R

2014-09-01

The question how agent and patient roles are assigned to causal participants has largely been neglected in the psychological literature on force dynamics. Inspired by the linguistic theory of Dowty (1991), we propose that agency attributions are based on a prototype concept of human intervention. We predicted that the number of criteria a participant in a causal interaction shares with this prototype determines the strength of agency intuitions. We showed in two experiments using versions of Michotte's (1963) launching scenarios that agency intuitions were moderated by manipulations of the context prior to the launching event. Altering features, such as relative movement, sequence of visibility, and self-propelled motion, tended to increase agency attributions to the participant that is normally viewed as patient in the standard scenario. Copyright © 2014 Elsevier B.V. All rights reserved.

In vitro Antagonistic Mechanisms of Trichoderma spp. and Talaromyces flavus to Control Gaeumannomyces graminis var. tritici the Causal Agent of Wheat Take-all Disease

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Seddighe Mohammadi

2015-07-01

Full Text Available Wheat take-all disease caused by Gaeumannomyces graminis var. tritici has recently been detected in different regions of Iran. With respect to biocontrol effect of Trichoderma spp. on many pathogenic fungi, seven isolates of Trichoderma and four isolates of Talaromyces were in vitro evaluated in terms of their biological control against the disease causal agent. In dual culture test the five isolates showed efficient competition for colonization against pathogenic fungus and the highest percentages of inhibition belonging to Talaromyces flavus 60 and Talaromyces flavus 136 were 59.52 and 57.61%, respectively. Microscopic investigations showed that in regions where antagonistic isolates and Gaeumannomyces graminis var. tritici coincide, hyphal contact, penetration and fragmentation of Gaeumannomyces graminis var. tritici were observed. Investigating the effect of volatile and non-volatile compounds at 10 ml concentration showed that the highest inhibition percentage on mycelium growth of the pathogen caused by T. harzianum (44.76% and T. longibrachiatum (52.38% respectively.

Causal inference in nonlinear systems: Granger causality versus time-delayed mutual information

Science.gov (United States)

Li, Songting; Xiao, Yanyang; Zhou, Douglas; Cai, David

2018-05-01

The Granger causality (GC) analysis has been extensively applied to infer causal interactions in dynamical systems arising from economy and finance, physics, bioinformatics, neuroscience, social science, and many other fields. In the presence of potential nonlinearity in these systems, the validity of the GC analysis in general is questionable. To illustrate this, here we first construct minimal nonlinear systems and show that the GC analysis fails to infer causal relations in these systems—it gives rise to all types of incorrect causal directions. In contrast, we show that the time-delayed mutual information (TDMI) analysis is able to successfully identify the direction of interactions underlying these nonlinear systems. We then apply both methods to neuroscience data collected from experiments and demonstrate that the TDMI analysis but not the GC analysis can identify the direction of interactions among neuronal signals. Our work exemplifies inference hazards in the GC analysis in nonlinear systems and suggests that the TDMI analysis can be an appropriate tool in such a case.

Mantenimiento y conservación de edificios: agentes que intervienen en la gestión y explotación del parque inmobiliario

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García Navarro, Justo

1995-12-01

Full Text Available During the last two decades, and specially at the end of the eighties and the beginning of the nineties, the professional specialization in building maintenance, and also the concept of "Integral Maintenance", were both developed in Spain. There are not many new contributions in this field. In most cases, techniques and ideas implanted and used in countries with higher real estate culture and tradition were imported. This paper is based on the conclusions of a conference celebrated last year in the "Fundación Cultural COAM" of the Architects Association of Madrid, and it was included in a Course of Specialization in Building Maintenance. Different agents involved in building management were discussed as well as the basis of the "Integral Maintenance" It would be necessary to say that the structural, finishing materials and facilities aspects have not deep analyzed, because of they were separately studied in other conferences of the mentioned Course.

Durante las dos últimas décadas y especialmente en los últimos años ochenta y primeros de los noventa, la especialización profesional en el campo del mantenimiento y conservación de los edificios, así como la implantación del concepto de "mantenimiento integral " del inmueble, se han desarrollado en España de una manera clara y progresiva. No se han realizado muchas aportaciones originales, sino que en la mayoría de los casos se han extrapolado técnicas y planteamientos ya contrastados en otros países con una mayor cultura y tradición inmobiliarias. Este artículo -que surge como conclusiones de una conferencia impartida en el Curso de Especialización en Mantenimiento y Conservación de Edificios, celebrado por la Fundación Cultural COAM del Colegio Oficial de Arquitectos de Madrid el pasado año-, se abordan distintos agentes que intervienen en la gestión y explotación de un inmueble, y su tratamiento de manera conjunta, como base del "mantenimiento integral”. Conviene

Paradoxical Behavior of Granger Causality

Science.gov (United States)

Witt, Annette; Battaglia, Demian; Gail, Alexander

2013-03-01

Granger causality is a standard tool for the description of directed interaction of network components and is popular in many scientific fields including econometrics, neuroscience and climate science. For time series that can be modeled as bivariate auto-regressive processes we analytically derive an expression for spectrally decomposed Granger Causality (SDGC) and show that this quantity depends only on two out of four groups of model parameters. Then we present examples of such processes whose SDGC expose paradoxical behavior in the sense that causality is high for frequency ranges with low spectral power. For avoiding misinterpretations of Granger causality analysis we propose to complement it by partial spectral analysis. Our findings are illustrated by an example from brain electrophysiology. Finally, we draw implications for the conventional definition of Granger causality. Bernstein Center for Computational Neuroscience Goettingen

On causality of extreme events

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Massimiliano Zanin

2016-06-01

Full Text Available Multiple metrics have been developed to detect causality relations between data describing the elements constituting complex systems, all of them considering their evolution through time. Here we propose a metric able to detect causality within static data sets, by analysing how extreme events in one element correspond to the appearance of extreme events in a second one. The metric is able to detect non-linear causalities; to analyse both cross-sectional and longitudinal data sets; and to discriminate between real causalities and correlations caused by confounding factors. We validate the metric through synthetic data, dynamical and chaotic systems, and data representing the human brain activity in a cognitive task. We further show how the proposed metric is able to outperform classical causality metrics, provided non-linear relationships are present and large enough data sets are available.

Causal symmetric spaces

CERN Document Server

Olafsson, Gestur; Helgason, Sigurdur

1996-01-01

This book is intended to introduce researchers and graduate students to the concepts of causal symmetric spaces. To date, results of recent studies considered standard by specialists have not been widely published. This book seeks to bring this information to students and researchers in geometry and analysis on causal symmetric spaces.Includes the newest results in harmonic analysis including Spherical functions on ordered symmetric space and the holmorphic discrete series and Hardy spaces on compactly casual symmetric spacesDeals with the infinitesimal situation, coverings of symmetric spaces, classification of causal symmetric pairs and invariant cone fieldsPresents basic geometric properties of semi-simple symmetric spacesIncludes appendices on Lie algebras and Lie groups, Bounded symmetric domains (Cayley transforms), Antiholomorphic Involutions on Bounded Domains and Para-Hermitian Symmetric Spaces

Hacia una conceptualización del legado del traductor

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Guzmán María Constanza

2009-06-01

Full Text Available Este artículo se propone investigar el aporte de perspectivas traductológicas para el estudio de la figura del traductor y su legado. Se centra en enfoques teóricos contemporáneos, principalmente aquellos basados en perspectivas postestructuralistas, que consideran el papel del sujeto traductor como un aspecto crucial en la traducción y los estudios literarios, y proponen maneras interesantes de abordarlo. A lo largo del artículo se cuestionan nociones como la idea de un original sacralizado, la relación entre autoría y propiedad, el ideal del significado transparente, y la tensión entre la traducción y la escritura del "original". Se presta especial atención a la importancia de ubicar históricamente la práctica del traductor, reconocer su papel como agente visible, y conceptualizar la traducción como una forma de escritura que se desarrolla en medio de complejas interacciones y negociaciones.

Síntesis y caracterización del almidón oxidado para su posterior evaluación como agente aglutinante en tabletas

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Milena Díaz Molina

1999-08-01

Full Text Available Se realizó un estudio sobre la oxidación del almidón de maíz, con el objetivo de caracterizarlo y posteriormente evaluarlo para su posible uso en la industria farmacéutica. Se efectuó un diseño experimental donde se midió la influencia de 3 variables: concentración del agente oxidante (permanganato de potasio en medio ácido, concentración de almidón y tiempo de reacción; las 3 variables resultaron significativas. El almidón oxidado fue caracterizado mediante la determinación del contenido de grupos carbonilos y carboxilos, determinaciones físico-químicas y reológicas. En este sentido, se apreciaron variaciones de sus propiedades en comparación con las del almidón nativo. Estadísticamente, se logró correlacionar el número de grupos carbonilos en el almidón oxidado con la disminución de la viscosidad y de la temperatura de gelatinización, así como con el aumento de la capacidad de hinchamiento.The oxidation of corn starch was studied to characterize it and assess it for possible use in the drug industry. An esperimental design allowed us to measure the effect of 3 variables: exidizing agent concentration (sedium permanganate in acid medium; starch concentration and reaction time. The three variables were significant. The oxidized starch was characterized by the determination of carboxyl and carbonyl group content; physico -chemical and reologic properties. In this regard, there were changes in the oxidized properties as compared to those of the natural starch. The number of carboxyl groups was statistically correlation to a reduction in viscosity and gelatinization temperature, and to a rise in swelling capacity.

Predicting Causal Relationships from Biological Data: Applying Automated Causal Discovery on Mass Cytometry Data of Human Immune Cells

KAUST Repository

Triantafillou, Sofia; Lagani, Vincenzo; Heinze-Deml, Christina; Schmidt, Angelika; Tegner, Jesper; Tsamardinos, Ioannis

2017-01-01

Learning the causal relationships that define a molecular system allows us to predict how the system will respond to different interventions. Distinguishing causality from mere association typically requires randomized experiments. Methods for automated  causal discovery from limited experiments exist, but have so far rarely been tested in systems biology applications. In this work, we apply state-of-the art causal discovery methods on a large collection of public mass cytometry data sets, measuring intra-cellular signaling proteins of the human immune system and their response to several perturbations. We show how different experimental conditions can be used to facilitate causal discovery, and apply two fundamental methods that produce context-specific causal predictions. Causal predictions were reproducible across independent data sets from two different studies, but often disagree with the KEGG pathway databases. Within this context, we discuss the caveats we need to overcome for automated causal discovery to become a part of the routine data analysis in systems biology.

Predicting Causal Relationships from Biological Data: Applying Automated Causal Discovery on Mass Cytometry Data of Human Immune Cells

KAUST Repository

Triantafillou, Sofia

2017-09-29

Learning the causal relationships that define a molecular system allows us to predict how the system will respond to different interventions. Distinguishing causality from mere association typically requires randomized experiments. Methods for automated  causal discovery from limited experiments exist, but have so far rarely been tested in systems biology applications. In this work, we apply state-of-the art causal discovery methods on a large collection of public mass cytometry data sets, measuring intra-cellular signaling proteins of the human immune system and their response to several perturbations. We show how different experimental conditions can be used to facilitate causal discovery, and apply two fundamental methods that produce context-specific causal predictions. Causal predictions were reproducible across independent data sets from two different studies, but often disagree with the KEGG pathway databases. Within this context, we discuss the caveats we need to overcome for automated causal discovery to become a part of the routine data analysis in systems biology.

Nail and skin lesions caused by scytalidium dimidiatum in Medellín (Colombia, 1990-1999: report of 128 cases and review of the name of the agent Lesiones ungueales y cutáneas por Scytalidium dimidiatum en Medellín (Colombia, 1990-1999. Presentación de 128 casos y revisión del problema del nombre del agente

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Jaime Carmona Fonseca

2000-03-01

hyphae alone or with chlamydospores (21% and yeast cells alone or with pseudohyphae (5%. There was no significant difference between the results of nail and skin Objetivo:Revisar el problema de la denominación del agente y presentar los rasgos epidemiológicos de 128 casos de lesiones en uñas o en piel por Scytalidium dimidiatum. Diseño: Estudio descriptivo, en parte retrospectivo (1990-1996 y en parte prospectivo (1997-1999. Marco de referencia: hasta hace poco tiempo hubo problemas con la nomenclatura del agente, pero ahora existen los argumentos para despejar las dificultades y ese es el primer objetivo del trabajo: presentar esos argumentos e indicar la manera de usar bien uno u otro nombre. Por otra parte, la importancia del S. dimidiatum como causa de lesiones en humanos aumenta cada día. Este informe, restringido a lesiones en uñas y piel, recoge una cifra muy alta de pacientes (128 casos, correspondientes al lapso 1990-1999. Métodos: los autores revisaron cada uno de los registros de laboratorio y, aplicando criterios de consenso, resolvieron las dudas. Se utilizaron criterios estándar de identificación micológica. El análisis estadístico de los datos se hizo con el programa EpiInfo versión 6.04. y consistió, principalmente, en evaluar la asociación de variables con la chi cuadrada y en comparar posiciones de datos continuos y ordenados según su magnitud con la prueba H de Kruskal-Wallis. Resultados: los diferentes nombres del agente (Nattrassia mangiferae, Scytalidium dimidiatum, Scytalidium hialinum, Scytalidium lignicola, Hendersonula toruloidea deben usarse en situaciones precisas, que se describen aquí. Se estudiaron 128 muestras de las cuales se aisló por cultivo Scytalidium dimidiatum: 102 en uñas (92% en pies y 26 en lesiones extraungueales (73% interdigitales en pies. Las características epidemiológicas de un caso típico de lesión ungueal por S. dimidiatum indican que en el 41% de las veces es una mujer, de 21 a 49 años, que usa

Clinical bacterial isolates from hospital environment as agents of ...

African Journals Online (AJOL)

The relationship between bacteria isolated from the hospital environment and those from wounds of operated patients was investigated to determine the causal agents of surgical site nosocomial infections. The study was carried out on bacterial species isolated from the theatre, surgical ward and patients' surgical wounds ...

Investigating the multi-causal and complex nature of the accident causal influence of construction project features.

Science.gov (United States)

Manu, Patrick A; Ankrah, Nii A; Proverbs, David G; Suresh, Subashini

2012-09-01

Construction project features (CPFs) are organisational, physical and operational attributes that characterise construction projects. Although previous studies have examined the accident causal influence of CPFs, the multi-causal attribute of this causal phenomenon still remain elusive and thus requires further investigation. Aiming to shed light on this facet of the accident causal phenomenon of CPFs, this study examines relevant literature and crystallises the attained insight of the multi-causal attribute by a graphical model which is subsequently operationalised by a derived mathematical risk expression that offers a systematic approach for evaluating the potential of CPFs to cause harm and consequently their health and safety (H&S) risk implications. The graphical model and the risk expression put forth by the study thus advance current understanding of the accident causal phenomenon of CPFs and they present an opportunity for project participants to manage the H&S risk associated with CPFs from the early stages of project procurement. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Born Rule and Free Will: why Libertarian Agent-Causal Free Will is not "antiscientific"

Science.gov (United States)

Kastner, Ruth E.

In the libertarian "agent causation" view of free will, free choices are attributable only to the choosing agent, as opposed to a specific cause or causes outside the agent. An often-repeated claim in the philosophical literature on free will is that agent causation necessarily implies lawlessness, and is therefore "antiscientific." That claim is critiqued and it is argued, on the contrary, that the volitional powers of a free agent need not be viewed as anomic, specifically with regard to the quantum statistical law (the Born Rule). Assumptions about the role and nature of causation, taken as bearing on volitional agency, are examined and found inadequate to the task. Finally, it is suggested that quantum theory may constitute precisely the sort of theory required for a nomic grounding of libertarian free will.

Principal stratification in causal inference.

Science.gov (United States)

Frangakis, Constantine E; Rubin, Donald B

2002-03-01

Many scientific problems require that treatment comparisons be adjusted for posttreatment variables, but the estimands underlying standard methods are not causal effects. To address this deficiency, we propose a general framework for comparing treatments adjusting for posttreatment variables that yields principal effects based on principal stratification. Principal stratification with respect to a posttreatment variable is a cross-classification of subjects defined by the joint potential values of that posttreatment variable tinder each of the treatments being compared. Principal effects are causal effects within a principal stratum. The key property of principal strata is that they are not affected by treatment assignment and therefore can be used just as any pretreatment covariate. such as age category. As a result, the central property of our principal effects is that they are always causal effects and do not suffer from the complications of standard posttreatment-adjusted estimands. We discuss briefly that such principal causal effects are the link between three recent applications with adjustment for posttreatment variables: (i) treatment noncompliance, (ii) missing outcomes (dropout) following treatment noncompliance. and (iii) censoring by death. We then attack the problem of surrogate or biomarker endpoints, where we show, using principal causal effects, that all current definitions of surrogacy, even when perfectly true, do not generally have the desired interpretation as causal effects of treatment on outcome. We go on to forrmulate estimands based on principal stratification and principal causal effects and show their superiority.

Causal inference regarding infectious aetiology of chronic conditions: a systematic review.

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Sofia Orrskog

Full Text Available BACKGROUND: The global burden of disease has shifted from communicable diseases in children to chronic diseases in adults. This epidemiologic shift varies greatly by region, but in Europe, chronic conditions account for 86% of all deaths, 77% of the disease burden, and up to 80% of health care expenditures. A number of risk factors have been implicated in chronic diseases, such as exposure to infectious agents. A number of associations have been well established while others remain uncertain. METHODS AND FINDINGS: We assessed the body of evidence regarding the infectious aetiology of chronic diseases in the peer-reviewed literature over the last decade. Causality was assessed with three different criteria: First, the total number of associations documented in the literature between each infectious agent and chronic condition; second, the epidemiologic study design (quality of the study; third, evidence for the number of Hill's criteria and Koch's postulates that linked the pathogen with the chronic condition. We identified 3136 publications, of which 148 were included in the analysis. There were a total of 75 different infectious agents and 122 chronic conditions. The evidence was strong for five pathogens, based on study type, strength and number of associations; they accounted for 60% of the associations documented in the literature. They were human immunodeficiency virus, hepatitis C virus, Helicobacter pylori, hepatitis B virus, and Chlamydia pneumoniae and were collectively implicated in the aetiology of 37 different chronic conditions. Other pathogens examined were only associated with very few chronic conditions (≤ 3 and when applying the three different criteria of evidence the strength of the causality was weak. CONCLUSIONS: Prevention and treatment of these five pathogens lend themselves as effective public health intervention entry points. By concentrating research efforts on these promising areas, the human, economic, and societal

Causal Set Generator and Action Computer

OpenAIRE

Cunningham, William; Krioukov, Dmitri

2017-01-01

The causal set approach to quantum gravity has gained traction over the past three decades, but numerical experiments involving causal sets have been limited to relatively small scales. The software suite presented here provides a new framework for the generation and study of causal sets. Its efficiency surpasses previous implementations by several orders of magnitude. We highlight several important features of the code, including the compact data structures, the $O(N^2)$ causal set generatio...

Spectral dimension in causal set quantum gravity

International Nuclear Information System (INIS)

Eichhorn, Astrid; Mizera, Sebastian

2014-01-01

We evaluate the spectral dimension in causal set quantum gravity by simulating random walks on causal sets. In contrast to other approaches to quantum gravity, we find an increasing spectral dimension at small scales. This observation can be connected to the nonlocality of causal set theory that is deeply rooted in its fundamentally Lorentzian nature. Based on its large-scale behaviour, we conjecture that the spectral dimension can serve as a tool to distinguish causal sets that approximate manifolds from those that do not. As a new tool to probe quantum spacetime in different quantum gravity approaches, we introduce a novel dimensional estimator, the causal spectral dimension, based on the meeting probability of two random walkers, which respect the causal structure of the quantum spacetime. We discuss a causal-set example, where the spectral dimension and the causal spectral dimension differ, due to the existence of a preferred foliation. (paper)

The causal link between energy and output growth: Evidence from Markov switching Granger causality

International Nuclear Information System (INIS)

Kandemir Kocaaslan, Ozge

2013-01-01

In this paper we empirically investigate the causal link between energy consumption and economic growth employing a Markov switching Granger causality analysis. We carry out our investigation using annual U.S. real GDP, total final energy consumption and total primary energy consumption data which cover the period between 1968 and 2010. We find that there are significant changes in the causal relation between energy consumption and economic growth over the sample period under investigation. Our results show that total final energy consumption and total primary energy consumption have significant predictive content for real economic activity in the U.S. economy. Furthermore, the causality running from energy consumption to output growth seems to be strongly apparent particularly during the periods of economic downturn and energy crisis. We also document that output growth has predictive power in explaining total energy consumption. Furthermore, the power of output growth in predicting total energy consumption is found to diminish after the mid of 1980s. - Highlights: • Total energy consumption has predictive content for real economic activity. • The causality from energy to output growth is apparent in the periods of recession. • The causality from energy to output growth is strong in the periods of energy crisis. • Output growth has predictive power in explaining total energy consumption. • The power of output growth in explaining energy diminishes after the mid of 1980s

¿QUE SIGNIFICA VOTAR? DE LA INTENCIONALIDAD DEL AGENTE A LA CONSTRUCCIÓN PÚBLICA DEL SENTIDO DE LA ACCIÓN

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Federico Lorenc Valcarce

2010-12-01

Full Text Available Este ensayo intenta poner en cuestión un problema central de la política democrática – la naturaleza del acto electoral – a la luz de la teoría sociológica de la acción, recorriendo el trayecto que separa al sentido subjetivo que  el propio agente asigna a su acción en el momento de realizarla y las diversas descripciones “objetivas” que emergen a partir de las interpretaciones de la acción que realizan otros actores,  en nuestro caso descripciones que se realizan en la esfera pública y  cuyos autores son un conjunto de individuos socialmente reconocidos como enunciadores legítimos de esas interpretaciones.  Mi trabajo ofrece una reflexión sistemática sobre el modo en que se construye socialmente el significado de los comportamientos electorales. Partiendo de una serie de descripciones posibles de la acción de votar, intento mostrar las limitaciones de una teoría de la acción que reduzca el significado de ésta última al sentido que ella pueda tener para su autor o a la intención subjetiva  que podemos imputarle. Así, se muestran las diversas interpretaciones de que puede ser objeto un “hecho” supuestamente básico y elemental, restituyendo el lugar de los discursos sociales en la producción del significado (objetivo de una determinada acción individual.

¿CONFIEREN PODERES CAUSALES LOS UNIVERSALES TRASCENDENTES?

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José Tomás Alvarado Marambio

2013-11-01

Full Text Available This work discusses the so-called ‘Eleatic’ argument against the existence of transcendent universals, i. e. universals which does not require instantiation for its existence. The Eleatic Principle states that everything produces a difference in the causal powers of something. As transcendent universals seem not to produce such a difference, transcendent universals seem not to exist. The argument depends crucially on the justification and the interpretation of the Eleatic Principle. It is argued, first, that it is not very clear that the principle is justified, and, second, that there are several alternatives for its interpretation, in relation with the different theories one can endorse about modality or causality. Anti-realist theories of modality or causality are not very appropriate for the understanding of what should be a ‘causal power’. Neither does a realist theory of causality conjoined with a combinatorial theory of possible worlds. A ‘causal power’ seems to be better understood in connection with a realist –non-reductionist– theory of causality and a causal theory of modality. Taken in this way the Eleatic Principle, nonetheless, it is argued that transcendent universals do ‘produce’ a difference in causal powers, for every causal connection requires such universals for its existence.

Re-thinking local causality

NARCIS (Netherlands)

Friederich, Simon

There is widespread belief in a tension between quantum theory and special relativity, motivated by the idea that quantum theory violates J. S. Bell's criterion of local causality, which is meant to implement the causal structure of relativistic space-time. This paper argues that if one takes the

mediation: R package for causal mediation analysis

OpenAIRE

Tingley, Dustin; Yamamoto, Teppei; Hirose, Kentaro; Keele, Luke; Imai, Kosuke

2012-01-01

In this paper, we describe the R package mediation for conducting causal mediation analysis in applied empirical research. In many scientific disciplines, the goal of researchers is not only estimating causal effects of a treatment but also understanding the process in which the treatment causally affects the outcome. Causal mediation analysis is frequently used to assess potential causal mechanisms. The mediation package implements a comprehensive suite of statistical tools for conducting su...

The gut microbiota and obesity: from correlation to causality.

Science.gov (United States)

Zhao, Liping

2013-09-01

The gut microbiota has been linked with chronic diseases such as obesity in humans. However, the demonstration of causality between constituents of the microbiota and specific diseases remains an important challenge in the field. In this Opinion article, using Koch's postulates as a conceptual framework, I explore the chain of causation from alterations in the gut microbiota, particularly of the endotoxin-producing members, to the development of obesity in both rodents and humans. I then propose a strategy for identifying the causative agents of obesity in the human microbiota through a combination of microbiome-wide association studies, mechanistic analysis of host responses and the reproduction of diseases in gnotobiotic animals.

EVALUACIÓN DEL DESEMPEÑO EN REDES INALÁMBRICAS DE SENSORES MEJORADAS CON AGENTES MÓVILES AVALIAÇÃO DO DESEMPENHO EN REDES DE SENSORES SEM FIO MELHORADAS COM AGENTES MÓVEIS PERFORMANCE EVALUATION OF WIRELESS SENSOR NETWORKS IMPROVED WITH MOBILE AGENTS

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Alcides Montoya

2012-06-01

Full Text Available La reconfiguración, reprogramación y despliegue de nuevas tareas computacionales en redes inalámbricas de sensores es un problema no resuelto satisfactoriamente en la actualidad. Este artículo propone la evaluación del desempeño en redes inalámbricas de sensores mejoradas con agentes móviles inteligentes como mecanismo de reprogramación autónoma. El método utilizado para la evaluación del desempeño se fundamenta en la medida del consumo de energía durante el proceso de migración de los agentes móviles inteligentes entre los nodos sensores y en el cálculo del tiempo de convergencia de la red, definido como el tiempo que tarda la red en pasar de un estado a otro; en los experimentos se refiere al retardo durante el cambio del tiempo de muestreo para toda la red. La solución más eficiente, que fue probada y evaluada en una red inalámbrica formada por 40 nodos que detectan fugas de amoniaco en tiempo real, determinó que el punto clave consiste en disminuir el consumo de energía producto de las confirmaciones y retransmisiones innecesarias de datos y procedimientos, desde los nodos sensores hasta la estación base. Este hecho representa, además de la disminución en el consumo energético, un ahorro significativo en el tiempo de convergencia de la red.A reconfiguração, reprogramação e implantação de novas tarefas computacionais em redes de sensores sem fio é um problema não resolvido de modo satisfatório na atualidade. Este artigo propõe a avaliação do desempenho em redes de sensores sem fio melhoradas com agentes móveis inteligentes como mecanismo de reprogramação autônoma. O método utilizado para a avaliação do desempenho fundamenta-se na medida do consumo de energia durante o processo de migração dos agentes móveis inteligentes entre os nós sensores e no cálculo do tempo de convergência da rede, definido como o tempo que demora a rede de passar de um estado a outro; nos experimentos se refere ao

Causal knowledge and the development of inductive reasoning.

Science.gov (United States)

Bright, Aimée K; Feeney, Aidan

2014-06-01

We explored the development of sensitivity to causal relations in children's inductive reasoning. Children (5-, 8-, and 12-year-olds) and adults were given trials in which they decided whether a property known to be possessed by members of one category was also possessed by members of (a) a taxonomically related category or (b) a causally related category. The direction of the causal link was either predictive (prey→predator) or diagnostic (predator→prey), and the property that participants reasoned about established either a taxonomic or causal context. There was a causal asymmetry effect across all age groups, with more causal choices when the causal link was predictive than when it was diagnostic. Furthermore, context-sensitive causal reasoning showed a curvilinear development, with causal choices being most frequent for 8-year-olds regardless of context. Causal inductions decreased thereafter because 12-year-olds and adults made more taxonomic choices when reasoning in the taxonomic context. These findings suggest that simple causal relations may often be the default knowledge structure in young children's inductive reasoning, that sensitivity to causal direction is present early on, and that children over-generalize their causal knowledge when reasoning. Copyright © 2013 Elsevier Inc. All rights reserved.

Causal Diagrams for Empirical Research

OpenAIRE

Pearl, Judea

1994-01-01

The primary aim of this paper is to show how graphical models can be used as a mathematical language for integrating statistical and subject-matter information. In particular, the paper develops a principled, nonparametric framework for causal inference, in which diagrams are queried to determine if the assumptions available are sufficient for identifiying causal effects from non-experimental data. If so the diagrams can be queried to produce mathematical expressions for causal effects in ter...

CAUSAL ATTRIBUTIONS OF POVERTY IN LESS DEVELOPED COUNTRIES: COMPARING AMONG UNDERGRADUATES FROM NATIONS WITH DIFFERENT DEVELOPMENT LEVELS

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José Juan Vázquez

2017-01-01

Full Text Available El estudio analiza las atribuciones causales de la pobreza en los países menos desarrollados en una muestra de 1.092 estudiantes universitarios de Nicaragua, El Salvador, Chile y España. Los análisis estadísticos mostraron la existencia de tres componentes que inicialmente agrupaban las diferentes atribuciones causales de la pobreza en los estados menos desarrollados: "Por causa de la estructura económica mundial", "Por el destino, la naturaleza, los hábitos cultu rales, y la mala conducta de los políticos" y "Por causa de la población de los países en desarrollo". Posteriormente se identificaron cinco tipos de motivos en función de las atribuciones causales de la pobreza que realizaron los estudiantes y su país de origen, clase social percibida, situación económica, ideología política y creencias religiosas. Los resultados obtenidos muestran que las atribuciones causales de la pobreza en los países en desarrollo se ven influidas principalmente por el nivel de desarr ollo del país de origen de los entrevistados, su ideología política y su situación económica .

Sistemas de Costes: Importancia, Viabilidad y Utilidad en la Concepción de los Agentes Públicos del Estado de Paraná (Brasil

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Luciane Maria Gonçalves Franco

2013-06-01

Full Text Available Este estudio tiene por objetivo conocer el nivel de entendimiento y de adopción en relación a los sistemas de costes por parte de los municipios de Paraná. Se trata de estudio descriptivo, con abordaje cualitativo. La colecta de datos tuvo lugar mediante aplicación de un cuestionario en 67 municipios del Estado de Paraná. Se ejecutó un análisis descriptivo y se aplicó el test estadístico de correlación del coeficiente de Spearman para fines de atender al objetivo. De entre los resultados del estudio, se destaca: la insipiencia del conocimiento acerca de la importancia, viabilidad y utilidad de un sistema de costes; embasado por limitaciones en el conocimiento por parte de los agentes públicos, sobretodo, en los tópicos que tratan de viabilidad presupuestaria y financiera de la adopción de sistemas de costes; ambiente para el sistema de costes, sistemas de costes implantados y sistemas operacionales; aunque las respuestas obtenidas en las proposiciones sobre información y control de costes hayan sido significativamente coherentes.

El daño y el nexo causal en la perdida de oportunidad

OpenAIRE

Herrera Montañez, Diego Alejandro

2016-01-01

El presente escrito se ocupa de estudiar el nexo de causalidad como elemento estructural de la responsabilidad cuando éste es difuso. Para ello, se pretende abordar la pérdida de la oportunidad como una teoría especial de causalidad que tiene lugar cuando el nexo causal no resulta claro, lo cual contradice la tesis preponderante de la doctrina y la jurisprudencia tradicional según la cual, la pérdida de la oportunidad es un criterio autónomo del daño. En su contenido se realiza una explic...

Construction and characterization of a bacterial artificial chromosome library of the causal agent of Black Sigatoka fungal leaf spot disease of banana and plantain, Mycosphaerella fijiensis.

Science.gov (United States)

Canto-Canché, Blondy; Guillén-Maldonado, Diana Karina; Peraza-Echeverría, Leticia; Conde-Ferráez, Laura; James-Kay, Andrew

2007-05-01

A bacterial artificial chromosome library of the causal agent of the Black Sigatoka leaf spot disease of banana and plantain, Mycosphaerella fijiensis, has been constructed using a non-sphaeroplasting technique and characterized using both homologous and heterologous probes. After first and a second size selection of PFGE-fractionated DNA, a ligation was obtained using a 1:4 molar ratio (insert:vector). One hundred random clones were analyzed, and the mean insert size was estimated to be 90 kb. The range of the insert sizes was between 40 and 160 kb. The highest percentage of inserts belonged to the range between 80 and 100 kb; 32% of the inserts had 2 or 3 internal NotI sites. This library consists of 1920 clones, if the genomic size is at least 35 Mb, then this represents 4.9 x genome equivalents, which was supported by hybridization results with homologous and heterologous probes.

Effect of bodily fluids from honey bee (Apis mellifera) larvae on growth and genome-wide transcriptional response of the causal agent of American Foulbrood disease (Paenibacillus larvae).

Science.gov (United States)

De Smet, Lina; De Koker, Dieter; Hawley, Alyse K; Foster, Leonard J; De Vos, Paul; de Graaf, Dirk C

2014-01-01

Paenibacillus larvae, the causal agent of American Foulbrood disease (AFB), affects honey bee health worldwide. The present study investigates the effect of bodily fluids from honey bee larvae on growth velocity and transcription for this Gram-positive, endospore-forming bacterium. It was observed that larval fluids accelerate the growth and lead to higher bacterial densities during stationary phase. The genome-wide transcriptional response of in vitro cultures of P. larvae to larval fluids was studied by microarray technology. Early responses of P. larvae to larval fluids are characterized by a general down-regulation of oligopeptide and sugar transporter genes, as well as by amino acid and carbohydrate metabolic genes, among others. Late responses are dominated by general down-regulation of sporulation genes and up-regulation of phage-related genes. A theoretical mechanism of carbon catabolite repression is discussed.

The selective power of causality on memory errors.

Science.gov (United States)

Marsh, Jessecae K; Kulkofsky, Sarah

2015-01-01

We tested the influence of causal links on the production of memory errors in a misinformation paradigm. Participants studied a set of statements about a person, which were presented as either individual statements or pairs of causally linked statements. Participants were then provided with causally plausible and causally implausible misinformation. We hypothesised that studying information connected with causal links would promote representing information in a more abstract manner. As such, we predicted that causal information would not provide an overall protection against memory errors, but rather would preferentially help in the rejection of misinformation that was causally implausible, given the learned causal links. In two experiments, we measured whether the causal linkage of information would be generally protective against all memory errors or only selectively protective against certain types of memory errors. Causal links helped participants reject implausible memory lures, but did not protect against plausible lures. Our results suggest that causal information may promote an abstract storage of information that helps prevent only specific types of memory errors.

Rate-Agnostic (Causal) Structure Learning.

Science.gov (United States)

Plis, Sergey; Danks, David; Freeman, Cynthia; Calhoun, Vince

2015-12-01

Causal structure learning from time series data is a major scientific challenge. Extant algorithms assume that measurements occur sufficiently quickly; more precisely, they assume approximately equal system and measurement timescales. In many domains, however, measurements occur at a significantly slower rate than the underlying system changes, but the size of the timescale mismatch is often unknown. This paper develops three causal structure learning algorithms, each of which discovers all dynamic causal graphs that explain the observed measurement data, perhaps given undersampling. That is, these algorithms all learn causal structure in a "rate-agnostic" manner: they do not assume any particular relation between the measurement and system timescales. We apply these algorithms to data from simulations to gain insight into the challenge of undersampling.

IMPLICACIONES JURÍDICAS DE LA EXPIRACIÓN DEL CONTRATO DE ARRENDAMIENTO DE VIVIENDA URBANA Y DE LOCAL COMERCIAL

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Sergio Alfredo Martínez Ramírez

2014-05-01

Full Text Available El contrato de arrendamiento de vivienda ha tenido amplio desarrollo normativo, su regulación se encuentra contenida en la ley 820 de 2003. Por su parte el contrato de arrendamiento comercial se encuentra regulado exiguamente en los artículos 518 a 524 del Código de Comercio; paralelamente a estas normatividades está el Decreto 3817 de 1982, el cual en su artículo 5 regula la situación del arrendador en los casos en que el arrendatario ha dado cumplimiento a las obligaciones dinerarias derivadas del contrato, sosteniendo que en dichos casos, el vencimiento del término inicial no es causal para dar por terminado el contrato, norma que va en contravía de los dispuesto en el artículo 2008, numeral 2 del Código Civil, que estipula que la expiración del término pactado en el contrato es causal para darlo por terminado. Dicha norma se encuentra vigente y tiene plena aplicabilidad tanto en los contratos de arrendamiento de vivienda, como en contratos comerciales. En consecuencia se plantea que el numeral 5 del artículo 3817 de 1982, implica una limitación al derecho de dominio del propietario y va en contra vía del principio que establece que el contrato es Ley para las partes.

Análisis de mapas causales de impactos del turismo residencial

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ANTONIO ALEDO

2010-01-01

El caso de estudio es el municipio de Dénia, situado en el norte de la provincia de Alicante. Los resultados muestran que las causas profundas de los impactos negativos inducidos por el turismo residencial están conectados con el déficit democrático en el proceso de gestión municipal del desarrollo turístico-residencial.

Causality and analyticity in optics

International Nuclear Information System (INIS)

Nussenzveig, H.M.

In order to provide an overall picture of the broad range of optical phenomena that are directly linked with the concepts of causality and analyticity, the following topics are briefly reviewed, emphasizing recent developments: 1) Derivation of dispersion relations for the optical constants of general linear media from causality. Application to the theory of natural optical activity. 2) Derivation of sum rules for the optical constants from causality and from the short-time response function (asymptotic high-frequency behavior). Average spectral behavior of optical media. Applications. 3) Role of spectral conditions. Analytic properties of coherence functions in quantum optics. Reconstruction theorem.4) Phase retrieval problems. 5) Inverse scattering problems. 6) Solution of nonlinear evolution equations in optics by inverse scattering methods. Application to self-induced transparency. Causality in nonlinear wave propagation. 7) Analytic continuation in frequency and angular momentum. Complex singularities. Resonances and natural-mode expansions. Regge poles. 8) Wigner's causal inequality. Time delay. Spatial displacements in total reflection. 9) Analyticity in diffraction theory. Complex angular momentum theory of Mie scattering. Diffraction as a barrier tunnelling effect. Complex trajectories in optics. (Author) [pt

mediation: R Package for Causal Mediation Analysis

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Dustin Tingley

2014-09-01

Full Text Available In this paper, we describe the R package mediation for conducting causal mediation analysis in applied empirical research. In many scientific disciplines, the goal of researchers is not only estimating causal effects of a treatment but also understanding the process in which the treatment causally affects the outcome. Causal mediation analysis is frequently used to assess potential causal mechanisms. The mediation package implements a comprehensive suite of statistical tools for conducting such an analysis. The package is organized into two distinct approaches. Using the model-based approach, researchers can estimate causal mediation effects and conduct sensitivity analysis under the standard research design. Furthermore, the design-based approach provides several analysis tools that are applicable under different experimental designs. This approach requires weaker assumptions than the model-based approach. We also implement a statistical method for dealing with multiple (causally dependent mediators, which are often encountered in practice. Finally, the package also offers a methodology for assessing causal mediation in the presence of treatment noncompliance, a common problem in randomized trials.

Los biocidas vegetales en el control del biodeterior o del patrimonio documental. Perspectivas e impacto

OpenAIRE

Sofía Borrego-Alonso

2015-01-01

Los procesos de biodeterioro afectan a los sistemas industriales de d istintos sectores productivos (industrias del petróleo, del papel, energética, etc.), a los biomateriales y al patrimonio cultural de cada nación. Los principales agentes que causan el biodeterioro del patrimonio documental son los microorganismos y los in sectos que utilizan el papel , como fuente nutritiva y junto a las condiciones ambientales inadecuadas, aceleran el deterioro de los diferentes soporte...

Causal asymmetry across cultures: Assigning causal roles in symmetric physical settings

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Andrea eBender

2011-09-01

Full Text Available In the cognitive sciences, causal cognition in the physical domain has featured as a core research topic, but the impact of culture has been rarely ever explored. One case in point for a topic on which this neglect is pronounced is the pervasive tendency of people to consider one of two (equally important entities as more important for bringing about an effect. In order to scrutinize how robust such tendencies are across cultures, we asked German and Tongan participants to assign prime causality in nine symmetric settings. For most settings, strong asymmetries in both cultures were found, but not always in the same direction, depending on the task content. This indicates that causal asymmetries, while indeed being a robust phenomenon across cultures, are also subject to culture-specific concepts. Moreover, the asymmetries were found to be modulated by figure-ground relations, but not by marking agency.

Entanglement, non-Markovianity, and causal non-separability

Science.gov (United States)

Milz, Simon; Pollock, Felix A.; Le, Thao P.; Chiribella, Giulio; Modi, Kavan

2018-03-01

Quantum mechanics, in principle, allows for processes with indefinite causal order. However, most of these causal anomalies have not yet been detected experimentally. We show that every such process can be simulated experimentally by means of non-Markovian dynamics with a measurement on additional degrees of freedom. In detail, we provide an explicit construction to implement arbitrary a causal processes. Furthermore, we give necessary and sufficient conditions for open system dynamics with measurement to yield processes that respect causality locally, and find that tripartite entanglement and nonlocal unitary transformations are crucial requirements for the simulation of causally indefinite processes. These results show a direct connection between three counter-intuitive concepts: entanglement, non-Markovianity, and causal non-separability.

Amodal causal capture in the tunnel effect.

Science.gov (United States)

Bae, Gi Yeul; Flombaum, Jonathan I

2011-01-01

In addition to identifying individual objects in the world, the visual system must also characterize the relationships between objects, for instance when objects occlude one another or cause one another to move. Here we explored the relationship between perceived causality and occlusion. Can one perceive causality in an occluded location? In several experiments, observers judged whether a centrally presented event involved a single object passing behind an occluder, or one object causally launching another (out of view and behind the occluder). With no additional context, the centrally presented event was typically judged as a non-causal pass, even when the occluding and disoccluding objects were different colors--an illusion known as the 'tunnel effect' that results from spatiotemporal continuity. However, when a synchronized context event involved an unambiguous causal launch, participants perceived a causal launch behind the occluder. This percept of an occluded causal interaction could also be driven by grouping and synchrony cues in the absence of any explicitly causal interaction. These results reinforce the hypothesis that causality is an aspect of perception. It is among the interpretations of the world that are independently available to vision when resolving ambiguity, and that the visual system can 'fill in' amodally.

Space-time as a causal set

International Nuclear Information System (INIS)

Bombelli, L.; Lee, J.; Meyer, D.; Sorkin, R.D.

1987-01-01

We propose that space-time at the smallest scales is in reality a causal set: a locally finite set of elements endowed with a partial order corresponding to the macroscopic relation that defines past and future. We explore how a Lorentzian manifold can approximate a causal set, noting in particular that the thereby defined effective dimensionality of a given causal set can vary with length scale. Finally, we speculate briefly on the quantum dynamics of causal sets, indicating why an appropriate choice of action can reproduce general relativity in the classical limit

Representing Personal Determinants in Causal Structures.

Science.gov (United States)

Bandura, Albert

1984-01-01

Responds to Staddon's critique of the author's earlier article and addresses issues raised by Staddon's (1984) alternative models of causality. The author argues that it is not the formalizability of causal processes that is the issue but whether cognitive determinants of behavior are reducible to past stimulus inputs in causal structures.…

Teoría de agencia: una revisión del origen biológico del delito

Directory of Open Access Journals (Sweden)

Iván Araya

2016-01-01

Full Text Available Este trabajo aborda la causa del conflicto entre principal y agente, buscando respuestas en las disciplinasde la biología, particularmente en las ciencias de la antropología criminal. Se ha realizado un ensambleentre los hallazgos de la teoría de agencia y la teoría de los delitos de cuello blanco, reinterpretando lasactuaciones del agente desde su configuración entre instinto, herencia y personalidad. Los resultadosen las ciencias biológicas podrían aportar nuevas interpretaciones y explicaciones en las ciencias de laadministración, avanzando hacia mejores conceptualizaciones del conflicto, mediante teorías con mayorcontenido empírico. En general, pese al conflicto permanente entre las partes, su dinámica potencia losresultados perseguidos por el principal.

[Causal analysis approaches in epidemiology].

Science.gov (United States)

Dumas, O; Siroux, V; Le Moual, N; Varraso, R

2014-02-01

Epidemiological research is mostly based on observational studies. Whether such studies can provide evidence of causation remains discussed. Several causal analysis methods have been developed in epidemiology. This paper aims at presenting an overview of these methods: graphical models, path analysis and its extensions, and models based on the counterfactual approach, with a special emphasis on marginal structural models. Graphical approaches have been developed to allow synthetic representations of supposed causal relationships in a given problem. They serve as qualitative support in the study of causal relationships. The sufficient-component cause model has been developed to deal with the issue of multicausality raised by the emergence of chronic multifactorial diseases. Directed acyclic graphs are mostly used as a visual tool to identify possible confounding sources in a study. Structural equations models, the main extension of path analysis, combine a system of equations and a path diagram, representing a set of possible causal relationships. They allow quantifying direct and indirect effects in a general model in which several relationships can be tested simultaneously. Dynamic path analysis further takes into account the role of time. The counterfactual approach defines causality by comparing the observed event and the counterfactual event (the event that would have been observed if, contrary to the fact, the subject had received a different exposure than the one he actually received). This theoretical approach has shown limits of traditional methods to address some causality questions. In particular, in longitudinal studies, when there is time-varying confounding, classical methods (regressions) may be biased. Marginal structural models have been developed to address this issue. In conclusion, "causal models", though they were developed partly independently, are based on equivalent logical foundations. A crucial step in the application of these models is the

Repeated Causal Decision Making

Science.gov (United States)

Hagmayer, York; Meder, Bjorn

2013-01-01

Many of our decisions refer to actions that have a causal impact on the external environment. Such actions may not only allow for the mere learning of expected values or utilities but also for acquiring knowledge about the causal structure of our world. We used a repeated decision-making paradigm to examine what kind of knowledge people acquire in…

Contribución a la histopatologia del distemper canino

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E. Encinas

1945-09-01

en efecto las unidades celulares o estructurales reaccionan en la medida y forma señaladas frente a cualquier otro agente alterativo. Posible es que en el caso particular de las lesiones aisladas de la lámina Vª juegue rol determinante la especial susceptibilidad de esta lámina a deficiencias en el aporte de oxígeno, ocasionadas por perturbaciones en el aprovisionamiento de sangre, portador de este gas cuestión que discutieron acertadamente BIELCHOWSKY y PALADINO, MARINESCO y otros; y como alteraciones pericapilares y endocapilares son hechos frecuentes en este proceso, no sería aventurado sostener que las lesiones aisladas de esta lámina se deban a aportes insuficientes de oxígeno por las anotadas alteraciones vasculares. Pero, y repitiendo lo que dijimos en líneas anteriores, factor este vascular, no explica el hecho anatómico del cambio celular aislado como el de las unidades mencionadas de la formación ammónica (Fig. 44. Alguna otra causal citoespecífica debe ser la sola causante de alteración tan particular. Y no es extraño que el virus del distemper, tan notable por la especificidad de las inclusiones citoplasmáticas y nucleares que provoca, sea ajeno a esta modificación. En lo fundamental, desearíamos que nuestros hallazgos sean verificados y que la autorizada opinión de los cultores del tema se pronuncien sobre ellos.

Kant on causal laws and powers.

Science.gov (United States)

Henschen, Tobias

2014-12-01

The aim of the paper is threefold. Its first aim is to defend Eric Watkins's claim that for Kant, a cause is not an event but a causal power: a power that is borne by a substance, and that, when active, brings about its effect, i.e. a change of the states of another substance, by generating a continuous flow of intermediate states of that substance. The second aim of the paper is to argue against Watkins that the Kantian concept of causal power is not the pre-critical concept of real ground but the category of causality, and that Kant holds with Hume that causal laws cannot be inferred non-inductively (that he accordingly has no intention to show in the Second analogy or elsewhere that events fall under causal laws). The third aim of the paper is to compare the Kantian position on causality with central tenets of contemporary powers ontology: it argues that unlike the variants endorsed by contemporary powers theorists, the Kantian variants of these tenets are resistant to objections that neo-Humeans raise to these tenets.

Histopatología de Ustilaginales (carbones) en Poaceas de los géneros Sorghum, Bromus y Glyceria

OpenAIRE

Astiz Gassó, Marta Mónica

2017-01-01

Sporisorium cruentum (Kühn.), es el agente causal de enfermedades en el género Sorghum incluyendo Sorghum halepense (L.) Pers.. El presente trabajo tuvo por objeto analizar el desarrollo y la evolución del patógeno en los tejidos del hospedante, y evaluar las implicancias de la enfermedad en el crecimiento vegetativo de los rizomas del sorgo de alepo. Para determinar la presencia del hongo se realizaron cortes histológicos del hospedante que se observaron por medio de microscopía óptica (MO) ...

An Evaluation of Active Learning Causal Discovery Methods for Reverse-Engineering Local Causal Pathways of Gene Regulation

Science.gov (United States)

Ma, Sisi; Kemmeren, Patrick; Aliferis, Constantin F.; Statnikov, Alexander

2016-01-01

Reverse-engineering of causal pathways that implicate diseases and vital cellular functions is a fundamental problem in biomedicine. Discovery of the local causal pathway of a target variable (that consists of its direct causes and direct effects) is essential for effective intervention and can facilitate accurate diagnosis and prognosis. Recent research has provided several active learning methods that can leverage passively observed high-throughput data to draft causal pathways and then refine the inferred relations with a limited number of experiments. The current study provides a comprehensive evaluation of the performance of active learning methods for local causal pathway discovery in real biological data. Specifically, 54 active learning methods/variants from 3 families of algorithms were applied for local causal pathways reconstruction of gene regulation for 5 transcription factors in S. cerevisiae. Four aspects of the methods’ performance were assessed, including adjacency discovery quality, edge orientation accuracy, complete pathway discovery quality, and experimental cost. The results of this study show that some methods provide significant performance benefits over others and therefore should be routinely used for local causal pathway discovery tasks. This study also demonstrates the feasibility of local causal pathway reconstruction in real biological systems with significant quality and low experimental cost. PMID:26939894

Las ciudades en la Web. Barcelona y Turín: el storytelling del turismo y del ocio

OpenAIRE

Soro, Elsa

2014-01-01

El presente trabajo parte de la necesidad de comprender y describir el funcionamiento del sistema mediático dentro del escenario urbano contemporáneo, en el cual los sectores productivos tradicionales se han visto progresivamente eclipsados, y los sectores recreativos y de la cultura han ido adquiriendo una importancia creciente, convirtiéndose así en agentes involucrados en la producción de imágenes y representaciones urbanas. La creciente relevancia dentro del sistema-ciudad del reino...

Cáncer cutáneo por exposición ocupacional a agentes químicos

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Santiago José Rocha Eiroa

2014-06-01

Full Text Available El cáncer cutáneo profesional integra un grupo de neoplasias malignas atribuibles a la exposición a factores cancerígenos en el medio laboral. Presenta dificultades en el diagnóstico debido a su etiología multifactorial, existencia de diferentes desencadenantes durante la vida laboral y no laboral, largos periodos de latencia y una clínica semejante a las no profesionales. Actualmente existen diferencias entre las sustancias químicas identificadas en el listado de enfermedades profesionales como cancerígenos cutáneos y las que señala la evidencia científica. Se ha realizado una revisión sistemática para actualizar el conocimiento existente entre la exposición a agentes químicos y el cáncer cutáneo en el medio laboral. Se utilizaron once bases de datos, estableciendo como límites: humanos y fecha publicación desde 1-1-2006 hasta 12-12-2012. Tras aplicar los criterios de inclusión/exclusión se analizaron finalmente 16 artículos, predominando el diseño epidemiológico de cohorte. El nivel de evidencia de la asociación entre exposición a determinados agentes químicos y el cáncer de piel de origen laboral que determinaron los estudios revisados fue de 2+, no existiendo controversia en la dirección de esta asociación, siendo los agentes causales más referenciados los plaguicidas con OR entre 1.7 IC 95% (1.1-2.5 y 2.4 IC 95% (1.2-4.9 y derivados del petróleo con RR de 1,99 IC 95% (1.00-3.96. En algunos artículos se analizó la exposición simultánea a un conjunto de agentes químicos sin definir una sustancia concreta. No se pudieron identificar factores de vulnerabilidad ni factores de especial sensibilidad ya que no se estudiaron, al igual que ningún factor protector. En varios se incluye población ya jubilada, destacando la importancia del seguimiento post-ocupacional debido a los largos periodos de latencia en determinados cánceres.

Repair of Partly Misspecified Causal Diagrams.

Science.gov (United States)

Oates, Chris J; Kasza, Jessica; Simpson, Julie A; Forbes, Andrew B

2017-07-01

Errors in causal diagrams elicited from experts can lead to the omission of important confounding variables from adjustment sets and render causal inferences invalid. In this report, a novel method is presented that repairs a misspecified causal diagram through the addition of edges. These edges are determined using a data-driven approach designed to provide improved statistical efficiency relative to de novo structure learning methods. Our main assumption is that the expert is "directionally informed," meaning that "false" edges provided by the expert would not create cycles if added to the "true" causal diagram. The overall procedure is cast as a preprocessing technique that is agnostic to subsequent causal inferences. Results based on simulated data and data derived from an observational cohort illustrate the potential for data-assisted elicitation in epidemiologic applications. See video abstract at, http://links.lww.com/EDE/B208.

Nutritional capability of and substrate suitability for Pseudogymnoascus destructans, the causal agent of bat white-nose syndrome.

Science.gov (United States)

Raudabaugh, Daniel B; Miller, Andrew N

2013-01-01

Pseudogymnoascus destructans, the causal agent of bat white-nose syndrome, has caused nearly six million deaths in North American bats since its introduction into the United States in 2006. Current research has shown that caves can harbor P. destructans even after the infected bats are removed and bats no longer visit or inhabit previously infected caves. Our research focuses on elucidating reservoir requirements by investigating the nutritional capabilities of and substrate suitability requirements for six different P. destructans isolates from various localities including Illinois, Indiana, New York (Type specimen), and Pennsylvania. Enzyme assays implicate that both urease and b-glucosidase appear to be constitutive, lipase and esterase activity were more rapid than proteinase activity on 6% gelatin, gelatin degradation was accompanied by medium alkalinization, the reduction of thiosulfate generated hydrogen sulfide gas, chitinase and manganese dependent peroxidase activity were not visually demonstrated within eight weeks, and keratinase activity was not evident at pH 8 within eight weeks. We demonstrate that all P. destructans isolates are capable of growth and sporulation on dead fish, insect, and mushroom tissues. Sole nitrogen source assays demonstrated that all P. destructans isolates exhibit Class 2 nitrogen utilization and that growth-dependent interactions occur among different pH and nitrogen sources. Substrate suitability assays demonstrated that all isolates could grow and sporulate on media ranging from pH 5-11 and tolerated media supplemented with 2000 mg/L of calcium and 700 mg/L of three separated sulfur compounds: thiosulfate L-cysteine, and sulfite. All isolates were intolerant to PEG-induced matric potential with delayed germination and growth at -2.5 MPa with no visible germination at -5 MPa. Interestingly, decreasing the surface tension with Tween 80 permitted germination and growth of P. destructans in -5 MPa PEG medium within 14 days

Murcha do manjericão (Ocimum basilicum no Brasil: agente causal, círculo de plantas hospedeiras e transmissão via semente Sweet basil (Ocimum basilicum wilt in Brazil: causal agent, host range and seed transmission

Directory of Open Access Journals (Sweden)

Ailton Reis

2007-06-01

Full Text Available O manjericão (Ocimum basilicum L. é uma hortaliça da família Lamiaceae, utilizada na culinária ou como matéria prima para a indústria de fármacos e óleos essenciais. Amostras de plantas de manjericão apresentando sintomas de murcha, seca de hastes e podridão de colo foram coletadas na área rural de Brazlândia (DF durante a estação chuvosa de 2005. Outras duas amostras foram coletadas em plantas cultivadas em campo aberto e casas de vegetação na região de Ponte Alta (DF. Isolados de um fungo, identificado como Fusarium oxysporum, foram obtidos em todas as amostras. Testes de patogenicidade foram conduzidos com mudas das cultivares O. basilicum 'Dark Opal' e 'Italian Large Leaf', e de acessos das espécies O. americanum L. (manjericão de folha miúda, O. campechianum Mill. (alfavaca, Origanum manjorana L. (manjerona, Origanum vulgare L. (orégano, Mentha arvensis L. (menta, Coleus blumei Benth. (tapete, Leonorus sibiricus L. (rubim e Leonotis nepetaefolia (L. W.T. Aiton (cordão-de-frade. Todos os isolados fúngicos mostraram-se altamente virulentos sobre as duas cultivares de manjericão. Em O. campechianum e O. americanum os isolados causaram apenas suave escurecimento vascular e leve redução de crescimento, sendo avirulentos sobre acessos das espécies O. manjorana, O. vulgare, M. arvensis, C. blumei, L. sibiricus e L. nepetaefolia. Este conjunto de dados indicou que o agente causal da doença é o fungo F. oxysporum f. sp. basilici, constituindo-se no primeiro registro formal deste patógeno no Brasil. Os lotes de sementes utilizados nas áreas de ocorrência da doença foram submetidos a um teste de sanidade visando verificar a presença do patógeno. O fungo F. oxysporum f. sp. basilici foi detectado em quatro dos seis lotes e os isolados obtidos das sementes contaminadas mostraram similar sintomatologia e um idêntico perfil de virulência aos verificados em campo e casa de vegetação, sugerindo que as sementes

Functional equations with causal operators

CERN Document Server

Corduneanu, C

2003-01-01

Functional equations encompass most of the equations used in applied science and engineering: ordinary differential equations, integral equations of the Volterra type, equations with delayed argument, and integro-differential equations of the Volterra type. The basic theory of functional equations includes functional differential equations with causal operators. Functional Equations with Causal Operators explains the connection between equations with causal operators and the classical types of functional equations encountered by mathematicians and engineers. It details the fundamentals of linear equations and stability theory and provides several applications and examples.

Classical planning and causal implicatures

DEFF Research Database (Denmark)

Blackburn, Patrick Rowan; Benotti, Luciana

In this paper we motivate and describe a dialogue manager (called Frolog) which uses classical planning to infer causal implicatures. A causal implicature is a type of Gricean relation implicature, a highly context dependent form of inference. As we shall see, causal implicatures are important...... to generate clarification requests"; as a result we can model task-oriented dialogue as an interactive process locally structured by negotiation of the underlying task. We give several examples of Frolog-human dialog, discuss the limitations imposed by the classical planning paradigm, and indicate...

Tipificación molecular del virus dengue 3 durante el brote epidémico de dengue clásico en Lima, Perú, 2005

Directory of Open Access Journals (Sweden)

Enrique Mamani Z

2005-07-01

Full Text Available Objetivos: Identificar mediante trascripción reversa-reacción en cadena de la polimerasa (RT-PCR y sitios específicos de restricción - reacción en cadena de la polimerasa (RSS-PCR al agente causal del brote epidémico presentado en el distrito de Comas, Lima en abril del año 2005. Materiales y métodos: veinte muestras de suero colectadas durante el brote de dengue fueron procesados por RT-PCR para determinar el serotipo, esta técnica se realizó en un solo paso. Luego se aplicó la técnica RSS-PCR para la identificación del genotipo circulante y se corroboraron los resultados posteriormente con aislamiento viral y secuenciamiento. Resultados: El análisis del RTPCR del ARN extraído de las muestras presentó un producto amplificado de 290pb que corresponden al dengue serotipo 3 (DEN 3. El análisis de los productos de RSS-PCR del ARN extraído a partir de aislamientos de DEN 3 correspondió al patrón C, incluido en el genotipo III. Los aislamientos de los virus dengue 3 en líneas celulares C6/36, tipificadas por IFI y el secuenciamiento genético confirmaron los resultados obtenidos por las pruebas previamente descritas. Conclusión: Durante el brote epidémico de dengue clásico en Lima, circuló el genotipo III del virus DEN 3.

Causal inference in economics and marketing.

Science.gov (United States)

Varian, Hal R

2016-07-05

This is an elementary introduction to causal inference in economics written for readers familiar with machine learning methods. The critical step in any causal analysis is estimating the counterfactual-a prediction of what would have happened in the absence of the treatment. The powerful techniques used in machine learning may be useful for developing better estimates of the counterfactual, potentially improving causal inference.

Acción intencional, Intención en acción y representaciones motoras: algunas puntualizaciones sobre la teoría causal revisada y su posible articulación con la neurociencia cognitiva de la acción

OpenAIRE

Ibarra, Romina Alejandra; Amoruso, Lucía

2017-01-01

La introducción del concepto de intención en acción llevada a cabo por John Searle ha permitido resolver algunas de las principales dificultades a las cuales se venía enfrentando la Teoría Causal de la Acción. No obstante, su teoría impone, simultáneamente, nuevos desafíos. Dado lo anterior, el objetivo del presente artículo consiste en revisar algunas de las principales problemáticas que presenta la versión searleana de la Teoría Causal a la luz de los avances recientes en neurociencia cogni...

Resúmenes de las tesis de grado en floricultura realizadas en la Facultad de Agronomía, Universidad Nacional de Colombia. Bogotá D.C., entre 1981 y 1993

OpenAIRE

Casas Eduardo; Arbeláez Germán; Saavedra Alejandro; Chaves José Fransico; Molina Juan Carlos; Rodríguez Arias Pedro

1992-01-01

Reconocimiento e identificación de Phialophora cinerescens y Fusarium oxysporum f. sp. dianthi en el cultivo del clavel en la sabana de Bogotá. / Estudio del poder patogénico de Botrytis cinerea pers. Sobre cinco especies de flores de exportación. / Botrytis cinerea Pers. / Agente causal de la pudrición de las flores y de la corona del estatice (Limonium sinuatum