bluuebunny/crossref_metadata_2025 huggingface dataset:
La influencia de las creencias en la actuación formal en tareas con contenido étnico-racial
Authors: Corral Antonio , Enesco Ileana
Published: November 2002

Hemos pasado tres tareas de razonamiento lógico-formal a adultos de niveles socioculturales alto y bajo. Queríamos ver cómo influye el contenido de la tarea (racial, neutral o abstracto) en la actuación de los participantes. Todas las tareas “raciales” se diseñaron de modo que tuvieran una posible conclusión racista. Los resultados sugieren que los procesos de razonamiento se ven influidos por el contenido de la tarea. Sin embargo, tal influencia no es simple. En las tareas de tipo proporcional y probabilístico, donde hay un aspecto eminentemente aritmético, un significativo porcentaje de los participantes tienden a evitar una conclusión (aunque sea lógicamente correcta) si ésta puede interpretarse como una discriminación contra una determinada comunidad étnico-racial. Esta tendencia no se observa cuando la conclusión podría perjudicar a una comunidad no sometida a un prejuicio racial. Habría una activación, en el primer caso, de un cierto contrasesgo en contra del prejuicio dominante. En las tareas de carácter deductivo, donde no hay ningún componente numérico, este efecto no es tan appreciable.
Predictores emocionales y conductuales de la aceptación de los compaiñeros en la edad escolar
Authors: Fuentes Ma Jesús , López Félix , Eceiza Amaia , Aguirrezabala Edurne
Published: November 2002

El estudio analizóel poder predictivo de diversas variables emocionales y conductuales en la aceptación de los niños y niñas por sus compañeros, así como la relación de esta variable con el grado de satisfacción social del niño. La muestra estuvo constituida por 257 niños y niñas de 7 a 9 años. Entre las variables con má peso a la hora de discriminar a los niños aceptados y rechazados, destacaron, junto a variables conductuales como la conducta agresiva y la competencia social, diversas variables emocionales como las de confiado/ansioso, tolerante/irritable, ansiedad-depresión y regulación emocional. Estas uéltimas, por sí solas, mostraron un elevado poder predictivo. Sin embargo, tanto el conjunto de variables predictoras como las variables emocionales por sí solas mostraron gran poder predictivo en los varones, pero sílo modesto en las niñas. Ademiá, se encontró una correlación significativa entre la aceptació de los compañeros y el grado de satisfacció social del niño.
Influencia social y disociación: elaboración interna vs. externa de la amenaza de la identidad
Authors: Falomir Juan Manuel , Mugny Gabriel , Invernizzi Federica , Muñoz-Rojas Daniel
Published: November 2002

El presente estudio analiza qué mecanismo facilita la influencia de una información persuasiva que amenaza la identidad del individuo. Se tienen en cuenta dos modos de reaccionar a esta información en función de si el individuo describe previamente su identidad positiva o negativamente. También se consideran dos modos de elaborar la amenaza asociada a la información persuasiva: una elaboración externa, asociada a la fuente de influencia, y una elaboración interna, disociada de la fuente de influencia. Cincuenta y tres fumadores participaron en un estudio con un diseño experimental 2 (imagen de fumador: negativa o positiva) X 2 (elaboración de la amenaza: interna o externa). Las principales variables dependientes miden el cambio personal (actitud favorable al consumo de tabaco e intención de dejar de fumar). No se observa ningún cambio en aquellos fumadores que previamente se describieron positivamente. Aquellos fumadores que previamente se describieron negativamente cambian únicamente cuando la elaboración de la amenaza es interna. Finalmente se discute la importancia de los procesos de auto-persuasión cuando la información persuasiva o la relación de influencia introducen una amenazapara la identidaddel individuo.
El racismo del miedo y el miedo al racismo
Authors: Kauth Ángel Rodríguez
Published: November 2002

El mundo contemporáneo se mueve en sus relaciones entre grupos culturales diferentes, entre el racismo y el temor al racismo. el miedo es el denominador común de los habitantes locales como de los inmigrantes. No se nos escapa que el racismo es una forma encubierta de expresión del clasismo, aunque sin dudas que en algunas personas existe como tal, simplemente como una «cuestión de piel». Se relatan algunas de las expresiones más comunes de racismo, a la par que intenta demostrar que este no es producto de pequeños grupos aislados, sino más bien alentado desde las propias estructuras de Poder gubernamental y por los movimientos o partidos políticos xenófobos.
El perfil psicosocial del emprendedor: un estudio desde la perspectiva de los valores
Authors: Moriano Juan Antonio , Trejo Enrique , Palací Francisco J.
Published: November 2002

El objetivo general de este estudio es doble. Por una parte, realizamos una reflexión sobre las posibilidades que ofrece el marco teórico del Modelo de Schwartz (1992) al estudio de la conducta emprendedora y, por otra parte, exploramos de manera empírica los valores personales dentro de las dimensiones de Individualismo y Colectivismo que favorecen dicha conducta. Para ello, hemos realizado un estudio descriptivo comparando los diferentes tipos de valores y los valores específicos entre un grupo de sujetos emprendedores y otro grupo que no lo son. Los resultados muestran que existen diferencias significativas, tanto en el tipo de valores, como en los valores específicos de ambos grupos. Estas diferencias apuntan que los emprendedores están inspirados por unos tipos de valores más individualistas.
Avance profesional y género: variables personales, familiares y organizacionales
Authors: Osca Amparo , Martínez-Pérez Ma Dolores
Published: November 2002

La investigación muestra que, en general, existen diferencias a favor de los hombres en avance profesional. Este trabajo tiene dos objetivos: primero analizar las diferencias de género en tres indicadores de desarrollo de carrera (salario anual, el nivel profesionaly ascensos) en profesionales españoles (N=232); segundo, examinar la influencia de diversas variables personales, familiares y organizacionales sobre los indicadores de avance profesional según el sexo. Los resultados muestran que, aunque no hay diferencias de género en el nivel de estudios, las mujeres tienen menor salario y estatus profesional. Entre las variables que explican el avance profesional destacan las personales, fundamentalmenteel nivel de estudios. De las variables familiares el número de hijos predice el salario sólo en las mujeres. El sector profesional en el que se trabaja es la variable organizational que mejor explica el nivel alcanzado. El estudio muestra la conveniencia de considerar diferentes indicadores de avance profesionaly de realizar análisis separados para hombres y mujeres.
Determinantes sociales del prejuicio étnico
Authors: Echebarría Agustín , Fernández Emilia
Published: November 2002

Tres estudios analizaron la influencia de la información étnica y de clase social sobre los juicios y evaluaciones (estudio 1) y sobre la percepción social (estudios 2 y 3). Los resultados indican que la información de clase tuvo un impacto mayor en ambas medidas que la información étnica. Además, se encontró un “efecto invertido de la clase social” (evaluación más positiva de una persona pobre que una persona rica). Sin embargo, este efecto invertido se dio dentro del propio grupo étnico, pero no se generalizó a los miembros de otros grupos étnicos. Las implicaciones teóricas y prácticas son analizadas.
Implications of meta-stereotypes for intergroup behavior
Authors: Vorauer Jacquie D.
Published: November 2002

The present paper complements the analysis made by Gómez about meta-stereotyping processes considering the implications of meta-stereotypes (and evaluative concerns more generally) for individuals' behavior toward out-group members. Some studies and ideas are summarized respecting the interpersonal consequences of individuals' concerns about how their ingroup (White Canadians) is evaluated by a particular outgroup (Aboriginal Canadians). Specifically, the effects that evaluative concern and meta-stereotype activation have on low-and high-prejudice White Canadians on the treatment of outgroup members are analyzed.
¿Cómo perciben a sus superiores aquellos subordinados que experimentan su propia posición como injusta? Efectos de la (I)Legitimidad de la falta de poder sobre la percepción social
Authors: Rodríguez-Bailón Rosa , Moya Miguel
Published: November 2002

Investigaciones previas han mostrado que las diferentes posiciones de poder y subordinación en el orden social producen sesgos atencionales y evaluativos en los perceptores. En la presente investigación se estudia el efecto que la falta de poder y la percepción de (I)legitmidad tienen sobre los perceptores. Los participantes fueron asignados aleatoriamente a la condición legítima o ilegítima en el contexto de una tarea de resolución de problemas. A los participantes legítimos se les dijo que no contaban con las habilidades necesarias para ocupar la posición de superiores, por el contrario, a los subordinados ilegítimos se les indicó que la asignación a su condición de subordinados había sido totalmente aleatoria. El tiempo dedicado por ambos grupos de participantes a la información negativa o positiva estereotípica y a la negativa o positiva inconsistente con el estereotipo acerca de sus supuestos superiores constituyó la principal variable dependiente de la investigación. Los resultados mostraron que los participantes ilegítimos prefirieron la información negativa inconsistente con el estereotipo frente a la negativa consistente. Sin embargo, no aparecieron diferencias entre el tiempo dedicado por los subordinados ilegítimos a examinar la información estereotípica e inconsistente cuando ésta fue positiva. Tampoco aparecieron efectos significativos cuando los participantes fueron legítimos. En el presente artículo se discuten las implicaciones de nuestra manipulación sobre las motivaciones de los individuos y el mantenimiento o cambio de la estructura social.
Promoting AIDS-preventive behaviours: The role of message fear appeal and audience's characteristics
Authors: Manetti Lucia , Pierro Antonio
Published: November 2002

This study was conducted to assess the effects, in terms of cognitive elaboration and behavioural intentions, of television anti-AIDS public service announcements adopting different levels of fear appeal. At the same time, the influence of audience's characteristics, such as general orientation toward risk, perceived risk of contracting AIDS, and past sexual behaviours was analyzed. 114 Italian undergraduate non-psychology students participated in a pretest-treatment-posttest experiment on voluntary basis. Subjects were randomly allocated to the exposure of three messages adopting increasing levels of fear appeal. Results both from analyses of covariance and from structural equation modelling show that: a) extreme levels of fear appeal induce negative evaluations and reduced compliance with the message; b) future preventive intentions are much more affected by past preventive behaviours than by anti-AIDS messages; c) general orientation toward risk significantly affects both past and future preventive behaviours.
Diseño de un cuestionario para la medición de las creencias sobre las diferencias raciales
Authors: Torres Ramón Rodríguez , Pérez Armando Rodríguez
Published: November 2002

El objetivo de esta investigación es construir un instrumento que permita la medición de las distintas creencias con que las personas explican las diferencias entre razas. Para ello, partimos del marco conceptual y metodológico que proporciona el paradigma de las teorías implícitas. En las primerasfases de la investigación se realizó una revisión de distintos materiales documentales sobre las diferencias raciales, así como varios estudios exploratorios que permitieron construir el cuestionario final de teorías implícitas con una muestra de 348 personas. Los resultados del análisis factorial efectuado demuestran un agrupamiento de las creencias en torno a cinco teorías: Teoría de la Superioridad Biológica, Teoría de la Superioridad Sociológica, Teoría de las Diferencias Biológicas, Teoría de las Diferencias Sociológicas y Teoría Económica. Estas distintas teorías explican las diferencias raciales atendiendo a la superioridad de una raza sobre otra por motivos biológicos o sociales, o argumentando la igualdad sustancial entre las razas, aunque sin negar diferencias de índole biológica, sociológica e, incluso, económica. Finalmente, la comparación de estas teorías con la escala de racismo sutil vs. tradicional (Pettigrew y Meertens, 1995) permite concluir que bajo las distintas formas de racismo subyacen teorías explicativas sobre las diferencias entre razas.
Determinantes psicosociales de la experiencia de soledad
Authors: Isidro Ana Isabel , Vega María Teresa , Garrido Eugenio
Published: November 2002

El estilo de vida actual propicia que las personas se sientan cada vez más solas y vean mermada su calidad de vida. Habitualmente las investigaciones han destacado factores objetivos (cantidad de relaciones sociales, tiempo que duran, número de amigos…), subjetivos (calidad de la interacción) y autoevaluativos (sentimientos de felicidad, timidez, abandono…). Sin embargo, los aspectos psicosociales han sido menos relacionados con la soledad, especialmente la autoeficacia percibida ante situaciones de interacción social. Así, se estudia en una muestra de jóvenes la influencia de la autoeficaciapercibida en la autovaloración del sujeto al enfrentarse a experiencias afectivas y de tarea y cómo tales experiencias originan sentimientos de soledad y ausencia de conductas interactivas. Los resultados indican que la autoineficacia determina más significativamente el sentimiento de soledad que la autoevaluación. Igualmente, se constata la ausencia de relación entre índices objetivos y subjetivos de soledad. Es decir, una persona no se siente más sola cuando tiene pocas y cortas interacciones sociales, pocos amigos, etc., sino cuando no se cree capaz de abordar aquellas situaciones sociales que eviten la soledady mejoren así su calidad de vida.
Investigation of thin surface‐wetting films in two‐phase saturated porous media
Authors: Holmes William M. , Packer Ken J.
Published: November 2002

Strongly water‐wet porous solids were saturated with two immiscible phases, an aqueous and an hydrocarbon phase, in varying proportions. The porous solids studied were a sample of Fontainebleau sandstone and packs of monodisperse glass beads. The diffusive displacements of the aqueous phase (i.e. the wetting phase) were investigated using pulsed field gradient stimulated echo (PGSTE) NMR to measure the one‐dimensional displacement probability distribution PΔ(X). Measurements of PΔ(X) are presented for the whole accessible water saturation range. At lower water contents the displacement distributions PΔ(X) show a distinctive shape, which is attributed to the distribution of the aqueous phase in thin surface wetting films connecting pendular rings where the beads are in contact. The data are reproduced well by a random walk computer model based on such a geometry, the simulated propagators being very sensitive to the surface film thickness. The longitudinal relaxation times of the water phase were also measured and found to deviate from the fast diffusion model at low water saturations. Copyright © 2002 John Wiley & Sons, Ltd.
After‐hours trading of NYSE stocks on the regional stock exchanges
Authors: McInish Thomas H , Van Ness Bonnie F , Van Ness Robert A
Published: November 2002

A large number of New York Stock Exchange (NYSE)‐listed stocks are traded on the Chicago, Philadelphia, and Pacific exchanges, and these exchanges have extended their trading hours to permit trading in NYSE‐listed stocks after the close of trading on the NYSE. Demand for after‐hours trading on the regional exchanges is limited. The Pacific Stock Exchange, which transacts less than 40% of the combined regionals' trading volume during regular trading hours, captures more than 63% of the after‐hours trades. We find that there is very little price discovery during after‐hours trading. Almost all of the trades take place at either the NYSE closing ask, bid, or trade price. The most actively traded stocks intraday also tend to be the most actively traded stocks after hours. The percentage spreads and percentage half‐spreads are significantly higher during the after‐hours sessions on all three regional exchanges. Among the Chicago, Philadelphia, and Pacific exchanges, spreads are significantly lower after‐hours on the Pacific exchange at the .10 level. Depth declines significantly during after‐hours trading on the Chicago and Philadelphia exchanges and increases significantly on the Pacific exchange.
Synergetic effects of epidermal growth factor and estradiol on cytoplasmic maturation of porcine oocytes
Authors: Li Yong-Hai , Liu Rui-Hua , Jiao Li-Hong , Wang Wei-Hua
Published: November 2002

This study was conducted to examine the effect of epidermal growth factor (EGF) and 17β-estradiol (E2) on nuclear and cytoplasmic (male pronuclear formation and early embryo development) maturation of porcine oocytes. Oocytes were aspirated from antral follicles and cultured in modified TCM-199 medium supplemented with 0.57 mM cysteine, 10 IU/ml eCG, 10 IU/ml hCG, with or without EGF and/or E2. In vitro fertilisation of matured oocytes was performed in a modified Tris-buffered medium (mTBM) with frozen-thawed ejaculated spermatozoa. Oocytes were transferred to NCSU-23 supplemented with 0.4% bovine serum albumin at 6 h after in vitro fertilisation. Significantly higher (p < 0.05) rates of nuclear maturation, pronuclear formation and cleavage (91.7%, 65.2% and 37.3%, respectively) were observed when oocytes were cultured in the medium containing both EGF (10 ng/ml) and E2 (1 μg/ml) than in the medium supplemented with either EGF or E2 or without both. Intracellular glutathione concentration in the oocytes cultured in the medium containing both E2 and EGF was also significantly higher (12.1 pmol per oocyte) than that of oocytes cultured in the medium with E2 or EGF alone or without both. These findings suggested that EGF and E2 have a synergestic effect on both nuclear and cytoplasmic maturation of porcine oocytes.
Digital depth … or featureless surface?
Authors: Hill Richard
Published: November 2002

This March, the University of Bath
Department of Architecture and Civil
Engineering held a conference on the
ways that computing can be used to
generate architecture and
engineering. Sponsored by RIBA
Future Studies, Buro Happold and Ove
Arup, and bringing together lecturers
from a variety of disciplines, it
considered both practical and
philosophical aspects. A publication is
planned, edited by the organizers, Neil
Leach, Chris Williams and David
Turnbull.
Platform: explorations of an architectural idea
Authors: Weston Richard , Pardey John
Published: November 2002

Establishing a horizontal plane is basic to architecture. Jørn Utzon's use
of the platform inspired the authors' entry to the recent international
competition for the design of a new theatre in Copenhagen.
Differential peristaltic motor effects of prostanoid (DP, EP, IP, TP) and leukotriene receptor agonists in the guinea‐pig isolated small intestine
Authors: Shahbazian Anaid , Heinemann Akos , Peskar Bernhard A , Holzer Peter
Published: November 2002

Since the role of prostanoid receptors in intestinal peristalsis is largely unknown, the peristaltic motor effects of some prostaglandin (DP, EP, IP), thromboxane (TP) and leukotriene (LT) receptor agonists and antagonists were investigated.

Propulsive peristalsis in fluid‐perfused segments from the guinea‐pig small intestine was triggered by a rise of the intraluminal pressure and recorded via the intraluminal pressure changes associated with the peristaltic waves. Alterations of distension sensitivity were deduced from alterations of the peristaltic pressure threshold and modifications of peristaltic performance were reflected by modifications of the amplitude, maximal acceleration and residual baseline pressure of the peristaltic waves.

Four categories of peristaltic motor effects became apparent: a decrease in distension sensitivity and peristaltic performance as induced by the EP1/EP3 receptor agonist sulprostone and the TP receptor agonist U‐46,619 (1–1000 nM); a decrease in distension sensitivity without a major change in peristaltic performance as induced by PGD2 (3–300 nM) and LTD4 (10–100 nM); a decrease in peristaltic performance without a major change in distension sensitivity as induced by PGE1, PGE2 (1–1000 nM) and the EP1/IP receptor agonist iloprost (1–100 nM); and a decrease in peristaltic performance associated with an increase in distension sensitivity as induced by the EP2 receptor agonist butaprost (1–1000 nM). The DP receptor agonist BW‐245C (1–1000 nM) was without effect.

The peristaltic motor action of sulprostone remained unchanged by the EP1 receptor antagonist SC‐51,089 (1 μM) and the DP/EP1/EP2 receptor antagonist AH‐6809 (30 μM), whereas that of U‐46,619 and LTD4 was prevented by the TP receptor antagonist SQ‐29,548 (10 μM) and the cysteinyl‐leukotriene1 (cysLT1) receptor antagonist tomelukast (10 μM), respectively.

These observations and their pharmacological analysis indicate that activation of EP2, EP3, IP, TP and cysLT1 receptors, but not DP receptors, modulate intestinal peristalsis in a receptor‐selective manner, whereas activation of EP1 seems to be without influence on propulsive peristalsis. In a wider perspective it appears as if the effect of prostanoid receptor agonists to induce diarrhoea is due to their prosecretory but not peristaltic motor action.

British Journal of Pharmacology (2002) 137, 1047–1054. doi:10.1038/sj.bjp.0704958
Atypical Antipsychotics: Impact on Overall Health and Quality of Life
Authors: Boyd Mary Ann
Published: November 2002

The use of antipsychotic medications for the treatment of schizophrenia requires a detailed assessment of patient history, including comorbidities and concomitant medications. Because all antipsychotics may produce a complex array of adverse effects, the patient’s drug therapy may lead to exacerbation of pre-existent health problems and impaired quality of life. The occurrence of drug-related side effects such as cardiac disturbances, diabetes, and obesity is important to document for these patients, especially if they are already at increased risk because of underlying disease, substance abuse, or smoking. Antipsychotics may also cause anticholinergic effects, gait disturbances, and excessive sedation, which are particularly important reactions to monitor in elderly patients. Psychiatric nurses need to be aware of the risk for these side effects in relation to patients’ new or ongoing medication so that potentially serious events can be recognized and corrected. Appropriate patient education about medication is also an important component in helping patients to recognize and manage side effects and to gain the most from their drug therapy.
The Agitated Psychotic Patient: Guidelines to Ensure Staff and Patient Safety
Authors: Murphy Mary C.
Published: November 2002

Patient-perpetrated violence is a serious problem that affects large numbers of nursing and healthcare staff. Incidents of assaultive behavior can lead to patient and staff injury, loss of productivity, and increased stress and burnout among healthcare professionals. The use of restraints for aggressive or assaultive behavior is governed by guidelines of the Joint Commission on Accreditation of Healthcare Organizations and the Centers for Medicare and Medicaid Services. Guidelines for dealing with the acutely agitated patient have recently been published by an expert consensus panel. All three sources agree that the use of nonphysical forms of behavior management (e.g., verbal intervention or show of force) is the appropriate first-line strategy. If medication is required, the current recommendation is the use of oral forms rather than intramuscular (IM) preparations, such as haloperidol and lorazepam, which have been the standard of care for many years. The primary disadvantages of injectables are the potential for injury and trauma to the patient, which is of special relevance for patients with paranoia, confusion, or previous assaults. Recent results suggest that oral formulations of atypical antipsychotics (e.g., risperidone) in combination with oral benzodiazepines (e.g., lorazepam) are as effective as similar IM treatments (e.g., haloperidol) in reducing psychotic agitation. Although additional large-scale studies are needed, early findings suggest that these oral formulations offer a less traumatic form of treatment than conventional IM drugs. For patients who will not accept oral medication, IM formulations of newer drugs are under investigation. These drugs (e.g., olanzapine, ziprasidone) may offer lower risk of side effects compared with older medications like haloperidol.
Female investment is retarded pending reception of allosperm in a hermaphroditic colonial invertebrate
Authors: Hughes Roger N. , Manríquez Patricio H. , Bishop John D. D.
Published: November 2002

Young colonies of the bryozoan
Celleporella hyalina
are capable of acquiring water-borne allosperm and of using it to fertilize ova for a period of 3–6 weeks after reaching female sexual maturity. In these simultaneous hermaphrodites, early allocation to female modules, but not male, is greatly enhanced by the acquisition of allosperm. The degree of enhancement is inversely proportional to coancestry of the recipient and donor colonies, thus promoting outcrossing. This apparently novel mechanism of adjusting operational sex ratio depends on the uptake and storage of sperm by nonreproductive (somatic) modules and subsequent translocation to females.
Finding genetic contributions to sporadic disease: A recessive locus at 12q24 commonly contributes to patent ductus arteriosus
Authors: Mani Arya , Meraji Seyed-Mahmoud , Houshyar Roozbeh , Radhakrishnan Jayaram , Mani Alaleh , Ahangar Mehrabeh , Rezaie Tayebeh M. , Taghavinejad Mohammad-Ali , Broumand Behrooz , Zhao Hongyu , Nelson-Williams Carol , Lifton Richard P.
Published: November 2002

The causes of many sporadic diseases are unexplained; the contribution of recessive loci with reduced penetrance is one possibility that has been difficult to explore. We describe an approach to this problem by first searching for diseases with higher prevalence in populations with high rates of consanguinity, then determining whether disease cases are more commonly the product of consanguinous union than controls in such populations, followed by analysis of genetic linkage in consanguinous cases. We demonstrate the utility of this approach by investigation of congenital heart disease in Iran. We found that patent ductus arteriosus (PDA), a common congenital heart disease, accounts for a higher fraction of congenital heart disease in Iran (15%) than in the United States (2–7%). Moreover, Iranian PDA cases demonstrated a marked increase of parental consanguinity (63%), compared with the general Iranian population (25%) or control cases with tetralogy of Fallot (30%). The recurrence of PDA among siblings was 5%. A genomewide analysis of linkage in 21 unrelated consanguinous PDA cases demonstrated a multipoint logarithm of odds score of 6.27 in favor of linkage of PDA to a 3-centimorgan interval of chromosome 12q24, with 53% of kindreds linked. These findings together establish a recessive component to PDA and implicate a single locus,
PDA1
, in one third or more of all PDA cases in Iran; they further suggest a role for this locus in PDA worldwide. Finally, these results suggest a general approach to the identification of recessive contributions to sporadic diseases.
Suppression of bone resorption by madindoline A, a novel nonpeptide antagonist to gp130
Authors: Hayashi Masahiko , Rho Mun-Chual , Enomoto Akiko , Fukami Akiko , Kim Yong-Pil , Kikuchi Yuji , Sunazuka Toshiaki , Hirose Tomoyasu , Komiyama Kanki , Omura Satoshi
Published: November 2002

IL-6 is a multifunctional cytokine involved in regulation of differentiation, antibody production, and growth of certain types of tumor cells. Its excessive production plays a major role in pathogenesis of multiple myeloma and postmenopausal osteoporosis. In the course of a screening program aimed at IL-6 inhibitor from microbial products, we found madindoline A (MDL-A) and madindoline B, which have a fuloindoline structure with diketocyclopentene bound to the methyl group. MDL-A has no cytotoxic activities. It inhibited only activities of both IL-6 and IL-11 without affecting the IL-6-specific signal transduction cascade, JAK2/STAT3. In a dose-dependent manner [3H]MDL-A binds to gp130, which is a signal transducing 130-kDa glycoprotein, but formation of the trimeric complex IL-6/IL-6 receptor/gp130 was not inhibited, suggesting that MDL-A suppresses dimerization of trimeric complexes. Not only did MDL-A markedly inhibit IL-6- and IL-11-induced osteoclastogenesisin vitro, but it also inhibited IL-6-stimulated serum amyloid A production and bone resorption in an experimental model of postmenopausal osteoporosisin vivoby a different mechanism from that of 17β-estradiol. Here we show that MDL-A has a highly selective inhibitory effect on IL-6 and IL-11 activities by inhibiting a gp130 activity while suppressing bone loss in ovariectomized mice. MDL-A is anticipated as a lead compound for treatment of hormone-dependent postmenopausal osteoporosis, which has no serious side effects, and as a new mechanism of action, gp130 blocking.
Posttranslational modifications in the CP43 subunit of photosystem II
Authors: Anderson Lorraine B. , Maderia Melissa , Ouellette Anthony J. A. , Putnam-Evans Cindy , Higgins LeeAnn , Krick Thomas , MacCoss Michael J. , Lim Hanjo , Yates John R. , Barry Bridgette A.
Published: November 2002

Photosystem II (PSII) catalyzes the light-driven oxidation of water and the reduction of plastoquinone; the oxidation of water occurs at a cluster of four manganese. The PSII CP43 subunit functions in light harvesting, and mutations in the fifth luminal loop (E) of CP43 have established its importance in PSII structure and/or assembly [Kuhn, M. G. & Vermaas, V. F. J. (1993)
Plant Mol. Biol.
23, 123–133]. The sequence A
350
PWLEPLR
357
in luminal loop E is conserved in CP43 genes from 50 organisms. To map important posttranslational modifications in this sequence, tandem mass spectrometry (MS/MS) was used. These data show that the indole side chain of Trp-352 is posttranslationally modified to give mass shifts of +4, +16, and +18 daltons. The masses of the modifications suggest that the tryptophan is modified to kynurenine (+4), a keto-/amino-/hydroxy- (+16) derivative, and a dihydro-hydroxy- (+18) derivative of the indole side chain. Peptide synthesis and MS/MS confirmed the kynurenine assignment. The +16 and +18 tryptophan modifications may be intermediates formed during the oxidative cleavage of the indole ring to give kynurenine. The site-directed mutations, W352C, W352L, and W352A, exhibit an increased rate of photoinhibition relative to wild type. We hypothesize that Trp-352 oxidative modifications are a byproduct of PSII water-splitting or electron transfer reactions and that these modifications target PSII for turnover. As a step toward understanding the tertiary structure of this CP43 peptide, structural modeling was performed by using molecular dynamics.
Microtubule Flux and Sliding in Mitotic Spindles ofDrosophilaEmbryos
Authors: Brust-Mascher Ingrid , Scholey Jonathan M.
Published: November 2002

We proposed that spindle morphogenesis in Drosophilaembryos involves progression through four transient isometric structures in which a constant spacing of the spindle poles is maintained by a balance of forces generated by multiple microtubule (MT) motors and that tipping this balance drives pole-pole separation. Here we used fluorescent speckle microscopy to evaluate the influence of MT dynamics on the isometric state that persists through metaphase and anaphase A and on pole-pole separation in anaphase B. During metaphase and anaphase A, fluorescent punctae on kinetochore and interpolar MTs flux toward the poles at 0.03 μm/s, too slow to drive chromatid-to-pole motion at 0.11 μm/s, and during anaphase B, fluorescent punctae on interpolar MTs move away from the spindle equator at the same rate as the poles, consistent with MT-MT sliding. Loss of Ncd, a candidate flux motor or brake, did not affect flux in the metaphase/anaphase A isometric state or MT sliding in anaphase B but decreased the duration of the isometric state. Our results suggest that, throughout this isometric state, an outward force exerted on the spindle poles by MT sliding motors is balanced by flux, and that suppression of flux could tip the balance of forces at the onset of anaphase B, allowing MT sliding and polymerization to push the poles apart.
Clint: A Novel Clathrin-binding ENTH-Domain Protein at the Golgi
Authors: Kalthoff Christoph , Groos Stephanie , Kohl Rüdiger , Mahrhold Stefan , Ungewickell Ernst J.
Published: November 2002

We have characterized a novel clathrin-binding 68-kDa epsin N-terminal homology domain (ENTH-domain) protein that we name clathrin interacting protein localized in the trans-Golgi region (Clint). It localizes predominantly to the Golgi region of epithelial cells as well as to more peripheral vesicular structures. Clint colocalizes with AP-1 and clathrin only in the perinuclear area. Recombinantly expressed Clint interacts directly with the γ-appendage domain of AP-1, with the clathrin N-terminal domain through the peptide motif423LFDLM, with the γ-adaptin ear homology domain of Golgi-localizing, γ-adaptin ear homology domain 2, with the appendage domain of β2-adaptin and to a lesser extent with the appendage domain of α-adaptin. Moreover, the Clint ENTH-domain asssociates with phosphoinositide-containing liposomes. A significant amount of Clint copurifies with rat liver clathrin-coated vesicles. In rat kidney it is preferentially expressed in the apical region of epithelial cells that line the collecting duct. Clathrin and Clint also colocalize in the apical region of enterocytes along the villi of the small intestine. Apart from the ENTH-domain Clint has no similarities with the epsins AP180/CALM or Hip1/1R. A notable feature of Clint is a carboxyl-terminal methionine-rich domain (Met427-Met605), which contains >17% methionine. Our results suggest that Clint might participate in the formation of clathrin-coated vesicles at the level of thetrans-Golgi network and remains associated with the vesicles longer than clathrin and adaptors.
Regulation of CDC6, Geminin, and CDT1 in Human Cells that Undergo Polyploidization
Authors: Bermejo Rodrigo , Vilaboa Nuria , Calés Carmela
Published: November 2002

Endomitosis is the process by which mammalian megakaryocytes become polyploid during terminal differentiation. As in other endoreplicating cells, cyclin-cdk complexes are distinctly regulated, probably to overcome the strict mechanisms that prevent rereplication in most somatic cells. We have asked whether key factors involved in the assembly and licensing of replication origins are equally regulated during endomitosis. Cdc6, cdt1, and geminin expression was analyzed during differentiation of two human megakaryoblastic cell lines, HEL and K562, which respectively do and do not establish endoreplication cycles. Geminin was downregulated, whereas cdt1 levels were maintained upon differentiation of both cell lines, independently of whether cells entered extra S-phases. In contrast, cdc6 was present and remained nuclear only in differentiated endoreplicating cells. Interestingly, cdc6 protein expression was reestablished in K562 cells that underwent endomitosis after transient or stable cyclin E overexpression. The high levels of cyclin E reached in these cells appeared to influence the stabilization of cdc6 protein rather than its RNA transcription rate. Finally, cdc6 overexpression drove HEL cells into endoreplication cycles in the absence of differentiation stimuli. Our results show that both cdt1 and cdc6 are differentially regulated during megakaryocytic differentiation and suggest an active role of cdc6 in endomitosis.
CASP, the Alternatively Spliced Product of the Gene Encoding the CCAAT-Displacement Protein Transcription Factor, Is a Golgi Membrane Protein Related to Giantin
Authors: Gillingham Alison K. , Pfeifer Andrea C. , Munro Sean
Published: November 2002

Large coiled-coil proteins are being found in increasing numbers on the membranes of the Golgi apparatus and have been proposed to function in tethering of transport vesicles and in the organization of the Golgi stack. Members of one class of Golgi coiled-coil protein, comprising giantin and golgin-84, are anchored to the bilayer by a single C-terminal transmembrane domain (TMD). In this article, we report the characterization of another mammalian coiled-coil protein, CASP, that was originally identified as an alternatively spliced product of the CUTL1 gene that encodes CCAAT-displacement protein (CDP), the human homologue of the Drosophila homeodomain protein Cut. We find that the Caenorhabditis elegans homologues of CDP and CASP are also generated from a single gene. CASP lacks the DNA binding motifs of CDP and was previously reported to be a nuclear protein. Herein, we show that it is in fact a Golgi protein with a C-terminal TMD and shares with giantin and golgin-84 a conserved histidine in its TMD. However, unlike these proteins, CASP has a homologue in Saccharomyces cerevisiae, which we callCOY1. Deletion of COY1 does not affect viability, but strikingly restores normal growth to cells lacking the Golgi soluble N-ethylmaleimide-sensitive factor attachment protein receptor Gos1p. The conserved histidine is necessary for Coy1p's activity in cells lacking Gos1p, suggesting that the TMD of these transmembrane Golgi coiled-coil proteins is directly involved in their function.
EFFECTIVE GEOMETRY IN NONLINEAR ELECTRODYNAMICS
Authors: NOVELLO M.
Published: November 2002

The electromagnetic force a photon undergoes in a nonlinear regime can be geometrized. This is a rather unexpected result and at the same time a beautiful consequence of the analysis of the behavior of the discontinuities of non-homogeneous nonlinear electromagnetic field. We show how such geometrization is possible.
WEYL-DIRAC QUINTESSENCE AND DARK MATTER
Authors: ISRAELIT MARK
Published: November 2002

In the Integrable Weyl-Dirac theory we consider a spatially closed universe undergoing at present accelerated expansion, having a non-vanishing cosmological constant, and filled with luminous- and dark matter. During the dust-dominated period, dark matter and the quintessence pressure, the latter giving rise to acceleration: both are created by the Dirac gauge function. The behavior of F-R-W models is considered in appropriate gauges, and plausible scenarios are obtained. The outcome of the present paper, together with results of a previous work, provide a geometrically based, classical, singularity-free model of the universe. This has originated from a pure geometric Weyl-Dirac entity, passed a prematter period, the radiation-dominated era, and continues its development in the present dust period.
AN OPEN SINGULARITY-FREE COSMOLOGICAL MODEL WITH INFLATION
Authors: KARACA KORAY , BAYIN SELÇUK
Published: November 2002

In the light of recent observations which point to an open universe (Ω0 < 1), we construct an open singularity-free cosmological model by reconsidering a model originally constructed for a closed universe. Our model starts from a nonsingular state called prematter, governed by an inflationary equation of state P = (γp - 1)ρ where γp (≃ 10-3) is a small positive parameter representing the initial vacuum dominance of the universe. Unlike the closed models universe cannot be initially static hence, starts with an initial expansion rate represented by the initial value of the Hubble constant H(0). Therefore, our model is a two-parameter universe model (γp,H(0)). Comparing the predictions of this model for the present properties of the universe with the recent observational results, we argue that the model constructed in this work could be used as a realistic universe model.
STRUCTURAL STUDIES OF ALUMINUM-DOPED LANTHANUM BORATES
Authors: SIMON S. , POP M. , BORODI GH. , DJURADO D.
Published: November 2002

Powder X-ray diffraction structural studies on aluminum-doped lanthanum borates La 4-y Al y B 4 O 12 were carried out on samples with y = 1, 2 starting compositions heat-treated at temperatures between 860°C and 1200°C. The samples were prepared by the sol-gel method. The structural data were obtained by the Rietveld refinement of the XRD patterns.
Clausura mental motivada: cerrando las puertas de nuestra alma
Authors: Kruglanski Arie W.
Published: November 2002

Se presenta una teoría de la mentalidad cerrada en la que se asigna un papel clave a un constructo motivacional conocido como la necesidad de clausura cognitiva (Kruglanskiy Webster, 1996; Webster y Kruglanski, 1998). Se presupone que la mentalidad cerrada realiza una función epistémica fundamental al dar por finalizada la secuencia de búsqueda de información y de contrastación de hipótesis. En cuanto tal, la mentalidad cerrada puede subyacer a algún nivel a todos nuestros juicios y decisiones, dado que sin ella no seríamos nunca capaces de formarnos una idea clara acerca de lo que debemos pensar o hacer. Se presupone que la necesidad de clausura cognitiva constituye una base motivacional clave para la mentalidad cerrada y que es activada por un amplio conjunto de circunstancias situacionales entre las que cabe citar la presión temporal, el ruido, la fatiga, la intoxicación etílica o el aburrimiento. Se considera igualmente que la necesidad de clausura describe una dimensión de diferencias individuales y, en cuanto tal, se mide con la escala apropiada (Webstery Kruglanski, 1994). Las consecuencias de la necesidad de clausura son exactamente iguales cuando se activa situacionalmente y cuando se mide con una escala. Dichas consecuencias se canalizan por medio de dos grandes tendencias, la de la urgencia, que da lugar a la ‘captación’ de la información inicial, y la tendencia a la permanencia, que da lugar al ‘congelamiento’ de las hipótesis implicadas por la información inicial. Se describe una amplia variedad de resultados de investigación que exploran las implicaciones de la teoría de la necesidad de clausura para los fenómenos psicosociales en los niveles de análisis intrapersonal, interpersonal, grupal e intergrupal.
Identidad social, valoración política y movilización colectiva en un contexto supranacional
Authors: Sabucedo José Manuel , Klandermans Bert , Rodríguez Mauro , Fernández Concepción
Published: November 2002

En este estudio analizamos la influencia de diferentes variables relacionadas con la identidad social y valoración política sobre la intención de participar en acciones de protesta contra la normativa agrícola de la Unión Europea. De las diversas medidas de identificación utilizadas, la identificación grupal activa, expresada en la pertenencia a organizaciones agrarias, resultó ser la variable con una mayor capacidadpredictiva. Junto a ella también presentan una contribución significativa las condiciones estructurales del grupo, como el pesimismo sobre el futuro y la permeabilidad de las fronteras grupales, y la crítica al gobierno central por no defender los intereses de los agricultores.
La democracia a examen: creencias, actitudes y valores en el cooperativismo de trabajo asociado de Andalucía
Authors: Romero Antonio José
Published: November 2002

El fenómeno de la cooperación responde a una concepción holística del proceso productivo. Por ello, la calidad del sistema democrático de una organización cooperativa va a depender de la dinámica psicosocial y económica establecida. Entre esos condicionantes internos y externos a la cooperación, que actuarán determinando la forma, contenido y extensión de la participación, nos encontramos con la cultura organizacionaly las características psicosociales propias de los cooperativistas. En este estudio contrastamos, precisamente, la incidencia de estas variables sobre el sistema de participación de una muestra de cooperativas andaluzas de trabajo asociado.
Perfil de los niños con problemas de integración social en el aula
Authors: Cava María Jesús , Musitu Gonzalo
Published: November 2002

La relevancia que las relaciones entre compañeros tienen en el desarrollopsicosocial del niño, así como las consecuencias negativas de sus dificultades, han merecido una considerable atención de los investigadores (Parker y Asher, 1987). Sin embargo, es todavía necesaria una mayor clarificación de las diferencias existentes entre los niños con problemas de integración social y sus compañeros bien adaptados socialmente. Este es el objetivo principal de esta investigación. La muestra está configuradapor 537 alumnos, de ambos sexos y de edades comprendidas entre los 10 y 16 años. También, se contó con la colaboración de 21 profesores. Se utilizó un cuestionario sociométrico, medidas de autoestima y de percepción del clima escolar y una escala de percepción del alumno por el profesor. Los resultados indican la existencia de diferencias significativas entre ambos grupos de niños en la percepción que de ellos tiene el profesor, en autoestima social y académica, y en algunas dimensiones de la percepción del clima escolar.
Valoración del autobús como medio de transporte público urbano: un estudio de las diferencias entre segmentos de la población
Authors: Ferraces Ma José , Andrade Elena Ma , Arce Constantino
Published: November 2002

Las actitudes de la población hacia los medios de transporte público han sido evaluadas en una investigación previa a la que aquí se presenta (Arce et al., 1996). Una de las conclusiones más importante de dicha investigación era que las propiedades utilizadas por los ciudadanos para juzgar los medios de transporte público se agrupaban en tres dimensiones: Prestigio, Confortabilidady Seguridad. El objetivo del presente trabajo ha consistido en analizar las posibles diferencias existentes en las tres dimensiones mencionadas en función de las variables sexo, usuario y edad, tomando únicamente el autobús como medio de transporte público urbano. Los resultados reflejan diferencias significativas en el grado de prestigio, confortabilidady seguridad que los distintos colectivos estudiados conceden al autobús. Se ha observado, además, que las puntuaciones medias obtenidas en las dimensiones prestigio y confortabilidad eran muy bajas, y relativamente más altas en la dimensión seguridad.
Relaciones afectivas y satisfaccion sexual en la pareja
Authors: Fuertes Antonio
Published: November 2002

Con objeto de analizar la asociación entre las relaciones afectivas y la satisfacción sexual, setenta y una parejas completaron tres diferentes formatos adaptados de la Escala de Amor de Rubin (1970, 73), así como el Inventario de Interacción Sexual de LoPiccolo y Steger (1974).

Los resultados obtenidos indican que, mientras que en las parejas que no tienen hijos, los sentimientos de intimidad de la mujer (confianza, preocupación percibida en el otro), y la dependencia afectiva que el hombre percibe en su pareja, son las dimensiones que mayor asociación mantienen con la satisfacción sexual, en las parejas que tienen hijos, es la forma en que el hombre percibe y vivencia las relaciones afectivas lo que mantiene una relación más importante con la satisfacción sexual.