bluuebunny/crossref_metadata_2025 huggingface dataset:
Construction of an sIgE:FLAG-mIgE:GFP Reporter Mouse Strain
Authors: Achatz-Straussberger Gertrude , Geisberger Roland , Oberndorfer Iris , Inführ Daniela , Luger Elke , Fallon Padraic , Lamers Marinus , Achatz Gernot
Published: May 2003

Like all other immunoglobulins, IgE can be secreted into the blood or expressed as a membrane receptor on the surface of B lymphocytes. Secreted immunoglobulins trace the antigen and contribute to its destruction. Membrane immunoglobulins accompany the B cell along its differentiation pathway, regulating processes like the induction and maintenance of immunological memory and differentiation of plasma cells. The regulation of the expression of IgE is very complex. A lot of positive and negative regulators influence the synthesis of IgE. In previous publications, we were able to show that the membrane IgE (mIgE) antigen receptor itself controls the quantity and quality of serum IgE produced. However, the knowledge about the regulatory function of the antigen receptor on these processes is at best limited. In the present paper, we present the construction of a reporter mouse strain, which will help us to follow an mIgE-bearing B cell during the immune response more precisely.
Involvement of Arachidonic Acid in Nonimmunologic Production of Superoxide in Mast Cells
Authors: Sakaguchi Masakiyo , Fukuishi Nobuyuki , Teramoto Kazuyo , Miyazaki Masahiro , Huh Nam-ho , Namba Masayoshi , Akagi Masaaki
Published: May 2003

Background: A number of different molecules are known to be involved in the signal pathway to release histamine from mast cells, among which arachidonic acid (AA) is one of the key mediators. On the other hand, we found that the application of compound 48/80, a typical histamine liberator, generated superoxide in mast cells. In the present study, we investigated the mechanism of superoxide production in mast cells with respect to AA signaling in conjunction with a fine structural analysis. Methods: Superoxide production was monitored by chemiluminescence in rat peritoneal mast cells and their subfractions after various treatments. For scanning electron micrography, the conditions for fixation and freeze-fracture were optimized to get natural fine images. Results: Compound 48/80 induced superoxide production in the isolated mast cells and some of their subfractions possibly through intracellular increase in Ca2+ concentration, activation of cytosolic phospholipase A2, and release of AA. Discussion: The present results indicate the critical role of AA in the signal pathway to generate superoxide from mast cells in response to compound 48/80.
Effect of Rapid Eye Movement Sleep Deprivation on Allergen-Induced Airway Responses in a Rat Model of Asthma
Authors: Irie Masahiro , Nagata Shoji , Endo Yutaka , Kobayashi Fumio
Published: May 2003

Background: Nocturnal airway narrowing is a common characteristic of asthma that remains poorly understood. Sleep itself or rapid eye movement (REM) sleep has been suspected to play a role in the etiology of nocturnal asthma; however, only inconsistent findings have so far been produced. The purpose of this study was to examine the effect of sleep deprivation, particularly REM sleep, using the classical platform (flowerpot) method on asthmatic responses in a rat model of asthma, in a situation of immobilization stress. Methods: After the rats had been randomly divided into three groups of 9 including (1) a caged control group, (2) a large (sham) platform group, and (3) a small platform group, we investigated the effect of REM sleep deprivation over a 72-hour period on both the antigen-induced immediate asthmatic response (IAR) and late asthmatic response (LAR) including the changes of stress hormones. Results: The small platform group showed significantly lower plasma histamine levels and higher plasma adrenaline levels during the IAR compared to the control group (p < 0.05). The number of eosinophils in either the bronchoalveolar lavage fluid or the bronchial lamina propria during the LAR in the small platform group was reliably suppressed compared to the other groups (p < 0.05). No significant differences were found in the plasma corticosterone and noradrenaline levels among the three groups, irrespective of the phase of the asthmatic response. Conclusions: Our results indicate that REM sleep contributes to nocturnal asthma, possibly due to an alteration of the sympathetic nervous function.
Antibody-Dependent Killing of Meningococci by Human Neutrophils in Serum of Late Complement Component-Deficient Patients
Authors: Platonov Alexander E. , Vershinina Irina V. , Käyhty Helena , Fijen Cees A.P. , Würzner Reinhard , Kuijper Edward J.
Published: May 2003

Background: Thirty-one Russian patients with late complement component deficiency (LCCD) who had experienced one to five meningococcal infections were immunized with meningococcal polysaccharide vaccine (A + C + W135 + Y) and were followed for 3–8 years. We investigated the potentially protective killing effect of human neutrophils (PMNL) on serogroup A and W135 meningococci. Methods: Meningococci were incubated in LCCD vaccinee sera in the absence or presence of PMNL, and the number of live bacteria (CFU) was determined by plating onto chocolate agar. Results: When meningococci were incubated in the LCCD sera alone, exponential growth of meningococci occurred despite the presence of meningococcal antibodies. After the addition of PMNL, meningococci were inhibited in their growth or even eliminated. Group A or W135 meningococci were killed effectively by PMNL in 80% of the sera which were collected 1 month to 1 year after vaccination compared to only 40% in the prevaccination LCCD sera (p < 0.05). Three years after vaccination 67% of the LCCD sera were still capable of promoting killing (and even 90% after revaccination). The rate of killing correlated with the concentration of serogroup-specific immunoglobulins. In 83% of the 72 LCCD sera with more than 5 µg/ml anti-group A immunoglobulins the killing of group A meningococci was promoted. By contrast, only 21% of 19 samples with lower specific antibody levels showed a PMNL-mediated meningococcal killing (p < 0.05). The same effect was observed for group W135 meningococci. Conclusion: PMNL kill meningococci during incubation in LCCD serum; this effect increases after vaccination and depends on both specific antibody and complement. Protection by vaccination may therefore be caused by an increased killing capacity of PMNL.
Fluoride, Beverages and Dental Caries in the Primary Dentition
Authors: Levy S.M. , Warren J.J. , Broffitt B. , Hillis S.L. , Kanellis M.J.
Published: May 2003

Knowledge concerning risk factors for primary dentition caries in young children is incomplete. Models are presented for caries development using longitudinally gathered fluoride exposure and dietary intake data in the Iowa Fluoride Study. Primary tooth caries examinations were conducted at age 5. Dietary (beverage) and fluoride exposure data were gathered longitudinally from age 6 weeks through 4 years (n = 291); 23% had decayed or filled surfaces. Logistic regression revealed that beverage components and toothbrushing made unique contributions to caries experience. Water consumption (36–48 months), milk consumption (24–36 months), and fluoridated toothpaste brushings (36–48 months) were negatively associated with caries; sugared beverages and milk (6 weeks to 12 months) were positively associated. Although fluoride exposure is important, sugared beverages contribute substantially to caries risk, while water and milk consumption and frequent toothbrushing early can have protective effects.
Effect of Fluoridated Milk on Progression of Root Surface Lesions in vitro under pH Cycling Conditions
Authors: Ivancakova R. , Hogan M.M. , Harless J.D. , Wefel J.S.
Published: May 2003

The aim of this study was to assess the effect of milk with 0, 2.5 or 5 ppm F on progression and remineralization of caries-like root surface lesions using a pH cycling model. The root surface lesions were created utilizing a partially saturated lactic acid buffer at pH 4.6. Longitudinal sections were cut through the lesion and analyzed using polarized light microscopy (PLM) and microradiography (MRG). The sections were then coated with an acid resistant varnish, except the outer natural surface that would be exposed to water, milk or fluoridated milk and cycled in a de- and remineralizing system for 2 weeks. The lesions were characterized again by PLM and MRG after treatment. A significant reduction in lesion progression was found by PLM and MRG after treatment with either non-fluoridated or fluoridated milk when compared to the control group. Using quantitative MRG, mineral change and distribution in the lesions were recorded. A possible protective effect of fluoridated milk on root surface caries was supported by a reduction in the progression of the lesions and an increase in the mineral within the lesion.
Effect of the Routine Professional Application of Topical Fluoride on Caries and Treatment Experience in Adolescents of Low Socio-Economic Status in The Netherlands
Authors: Schuller A.A. , Kalsbeek H.
Published: May 2003

The purpose of this study was to study the effect of professionally applied topical fluoride on oral health status at the population level in adolescents with low socio-economic status. Adolescents attending dental clinics where professional fluoride application was a routine procedure (high-fluoride group) were compared to adolescents from other clinics (low-fluoride group). The study consisted of a questionnaire, a clinical examination and two bitewing radiographs. X-rays showed no statistically significant differences in the number of DS, FS or DFS. Clinically, there were no statistically significant differences in the number of FS or in the number of DFS. The low-fluoride group had a statistically significant higher number of DS than the high-fluoride group. The results indicate that professionally applied fluoride has no effect on caries and treatment experience in a population. These results justify a randomized clinical trial on a population level to study the effectiveness of professionally applied topical fluorides.
The Effect of pH, Temperature and Plaque Thickness on the Hydrolysis of Monofluorophosphate in Experimental Dental Plaque
Authors: Pearce E.I.F. , Dibdin G.H.
Published: May 2003

Monofluorophosphate (MFP), an anti-caries agent commonly used in toothpaste, is known to be degraded to fluoride and orthophosphate by bacterial phosphatases in dental plaque. We have examined the effect of pH, temperature, plaque thickness and some ions on this process. Both natural plaque and artificial microcosm plaque incubated with purified MFP at pH 4–10 showed an optimum pH of ∼8 for hydrolysis. Diffusion and concomitant hydrolysis were examined in an apparatus in which artificial plaque was held between rigid membranes separating two chambers. When MFP diffused through a plaque of 0.51-mm thickness over 4 h it was almost completely hydrolysed at pH 8, but hydrolysis on diffusion decreased as the pH deviated from 8. MFP in toothpaste extract showed a similar pH susceptibility to hydrolysis, according to the inherent pH of the toothpaste. Hydrolysis of MFP in the toothpaste was reduced by no more than 10% when compared with a matched-pH control, suggesting that other toothpaste ingredients had no major influence on hydrolysis. Transport was slower and hydrolysis at pH 6 more complete the thicker the plaque, but hydrolysis was not significantly slower at 23°C than at 37°C. The addition of various potential activating or inhibiting ions at 0.1 and 1.0 mmol/l had small and non-significant effects on hydrolysis. The results suggest that MFP toothpaste should be formulated and used to maximise enzymic hydrolysis of this complex anion, and that plaque pH control is probably the most important factor.
Effect of a Varnish Containing Chlorhexidine and Thymol (Cervitec®) on Approximal Caries in 13- to 16-Year-Old Schoolchildren in a Low Caries Area
Authors: Haukali G. , Poulsen S.
Published: May 2003

Background: Previous studies on the effect of the chlorhexidine and thymol-containing varnish (Cervitec®) have consistently shown a reduction in Streptococcus mutans, while the data on the caries-inhibiting effect are conflicting. Aim: To measure the effect of a chlorhexidine- and thymol-containing varnish (Cervitec) on approximal caries in a low caries population. Material: Eighty-five schoolchildren, 13 years of age, entered the study after being selected on the basis of bitewing radiographs. Children with at least one approximal lesion were included after informed consent. Methods: The study was carried out as a double-blind, randomized controlled trial according to a split-mouth design using Cervitec on one side and a placebo varnish on the other side. All approximal surfaces between molars and premolars were treated every 3rd month. After 2 years new bitewing radiographs were taken. A total of 73 children completed the 2-year study. Results: Neither the difference in number of new lesions between the Cervitec-treated and the placebo-treated side (d: –0.21; 95% CI: –0.57; 0.16) nor the mean difference in number of already existing lesions that progressed (d: –0.01; 95% CI: –0.33; 0.30) were statistically significant (pairedt test; p > 0.05). Conclusion: The results of our study do not indicate an effect of Cervitec on initiation or progression of approximal caries in a population with a low DMFS.
The Effect of Variable Energy Input from a Novel Light Source on the Photoactivated Bactericidal Action of Toluidine Blue O on Streptococcus mutans
Authors: Williams J.A. , Pearson G.J. , Colles M.J. , Wilson M.
Published: May 2003

Although the combination of toluidine blue O (TBO) dye and laser light at a wavelength of 633 nm has a bactericidal effect, light from laboratory lasers can only be directed externally at a bacterial colony or suspension. In this study a novel delivery system guided the laser light to an 800-µm diameter spherical tip (an isotropic tip) from which light radiated producing a uniform sphere of light within the colony or suspension. The system was highly effective in killing TBO-treated Streptococcus mutans NCTC 10449 in stirred planktonic suspension, killing at least 109 cfu/ml. Antibacterial action increased as the delivered energy dose increased. Energy doses of 1.8 J or more produced 100% kills and log reductions of 8–10 cfu/ml. Neither TBO dye nor light alone had a significant antibacterial effect under the experimental conditions used. The existence of a threshold energy, i.e. a minimum energy required before bactericidal action occurred, could not be demonstrated.
Influence of Number of Surfaces and Observers on Statistical Power in a Multiobserver ROC Radiographic Caries Detection Study
Authors: Hintze Hanne , Frydenberg Morten , Wenzel Ann
Published: May 2003

The aim of the study was to evaluate the influence of the number of surfaces (Nsurf) and the number of observers (Nobs) on the statistical power of a study comparing the diagnostic accuracies of radiographic systems used for approximal caries lesion detection. A data set consisting of 338 surfaces examined by 10 independent observers using four radiographic systems was available. The presence of a caries lesion was assessed from a 5-point confidence scale. The true lesion diagnosis was established by histological validation. ROC curve areas (Azs) were used to express the diagnostic accuracy of the observers with the radiographic systems. Assuming that the Azs were tested by a two-way analysis of variance, we performed a simulation study in order to evaluate how the power of this statistical analysis depended on Nsurf and Nobs. As a measure of the statistical power we used the standard error of the difference between the expected Azs of two systems. The simulations were made with Nsurf in the range from 25 to 338 and Nobsfrom 2 to 10. The simulations showed that the power increased as a function of the total number of evaluations per system (Nsurf× Nobs), but how this number was attained in relation to the number of surfaces and observers had only marginal influence on the power. Thus, from a statistical point of view it may be concluded, provided that data are analyzed by a two-way analysis of variance, that study designs for comparing the accuracy of several systems can be composed freely in relation to the number of surfaces and observers as long as the total number of evaluations per system are identical.
Cultivatable Bacteria in Dentine after Caries Excavation Using Rose-Bur or Carisolv
Authors: Lager Anders , Thornqvist Elisabeth , Ericson Dan
Published: May 2003

To measure the amount of viable bacteria after excavation using conventional rose-bur or the chemo-mechanical Carisolv method, a total of 22 lesions were analyzed (one vital tooth per patient) in this open, controlled and randomized study. Two samples per lesion were taken under aseptic conditions using a rose-bur, one superficially in the caries lesion and one after completed excavation. In in vitro tests more material was collected from the hard caries free dentine as compared to the carious dentine. The samples were incubated on blood agar (aerobically and anaerobically), Rogosa (SL) agar and mitis salivarius (MS) agar. For blood agar (aerobic) both methods resulted in a significant decrease in CFU, for blood agar (anaerobic) and MS agar only the Carisolv method resulted in a significant decrease in CFU and for SL agar neither method resulted in a significant decrease in CFU. Comparing CFU before and after excavation, a considerable reduction of CFU was seen ranging from 101 to 104. Comparing the excavation methods, there were no significant differences, except in the case of blood agar (aerobic), which showed that Carisolv excavation was more effective in reducing CFU. This study indicated that bacterial sampling collected more material from hard dentine as compared from soft. Remaining bacteria after excavation were low in both groups. The Carisolv method seemed to remove bacteria at least up to and possibly beyond the extent of conventional drilling.
A New Selective Medium for Streptococcus mutans and the Distribution of S. mutans and S. sobrinus and Their Serotypes in Dental Plaque
Authors: Hirasawa M. , Takada K.
Published: May 2003

A new selective medium (MS-MUT) was developed for the isolation of Streptococcus mutans from clinical specimens. The average growth recovery of S. mutans on MS-MUT medium was 72.4% of that on MS medium. Growth of Streptococcus sobrinus was significantly inhibited on the medium with an average recovery of 0.034%. In 103 subjects, S. mutans was detected at 58.3, 75.0 and 95.7% in the dental plaque of caries-free (CF), caries-inactive (CI) and caries-active (CA) subjects, respectively. S. sobrinus was detected in 8.3, 13.6 and 38.3% of CF, CI and CA subjects, respectively. S. sobrinus alone was detected in only 4.3% of CA subjects. The subjects in whom neither S. mutans nor S. sobrinus were detected were 41.6% in CF and 25.0% in CI. The most predominant serotype was c with a 67% detection rate. S. sobrinus, serotypes d or g were usually found together with S. mutans.
Endothelium-Dependent Effects of Statins
Authors: Wolfrum Sebastian , Jensen Kristin S. , Liao James K.
Published: May 2003

The vascular endothelium is a dynamic endocrine organ that regulates contractile, secretory, and mitogenic activities in the vessel wall and hemostatic processes within the vascular lumen. Risk factors for cardiovascular disease, such as cigarette smoking, hypertension, and elevated serum lipid levels, impair endothelial function and lead to the development of atherosclerotic vessels. Recent studies suggest that statins reduce cardiovascular events in part by improving endothelial function. Statins reduce plasma cholesterol levels, thereby decreasing the uptake of modified lipoproteins by vascular wall cells. There is increasing evidence, however, that statins may also exert effects beyond cholesterol lowering. Indeed, many of these cholesterol-independent or “pleiotropic” vascular effects of statins appear to involve restoring or improving endothelial function through increasing the bioavailability of nitric oxide, promoting re-endothelialization, reducing oxidative stress, and inhibiting inflammatory responses. Thus, the endothelium-dependent effects of statins are thought to contribute to many of the beneficial effects of statin therapy in cardiovascular disease.
Role of JNK, p38, and ERK in Platelet-Derived Growth Factor–Induced Vascular Proliferation, Migration, and Gene Expression
Authors: Zhan Yumei , Kim Shokei , Izumi Yasukatsu , Izumiya Yasuhiro , Nakao Takafumi , Miyazaki Hitoshi , Iwao Hiroshi
Published: May 2003

Objective—

We investigated the comparative roles of mitogen-activated protein (MAP) kinases, including c-Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38, in vascular smooth muscle cell (VSMC) proliferation, migration, and gene expression.

Methods and Results—

VSMCs were infected with recombinant adenovirus containing dominant-negative mutants of ERK, p38, and JNK (Ad-DN-ERK, Ad-DN-p38, and Ad-DN-JNK, respectively) to specifically inhibit the respective MAP kinases and then stimulated with platelet-derived growth factor (PDGF)-BB. Ad-DN-ERK attenuated PDGF-BB–induced VSMC proliferation more potently than Ad-DN-p38 or Ad-DN-JNK, indicating the dominant role of ERK in VSMC proliferation. Ad-DN-ERK, Ad-DN-p38, and Ad-DN-JNK similarly inhibited PDGF-induced VSMC migration. Ad-DN-ERK and Ad-DN-JNK suppressed PDGF-BB–induced downregulation of cyclin-dependent kinase inhibitor p27
Kip1
, whereas Ad-DN-p38 decreased PDGF-BB–induced upregulation of p21
Cip1
. Ad-DN-ERK inhibited PDGF-BB–induced plasminogen activator inhibitor type-1 (PAI-1), monocyte chemoattractant protein-1, and transforming growth factor-β
1
expressions, Ad-DN-p38 blocked monocyte chemoattractant protein-1 and transforming growth factor-β
1
expression but not PAI-1, whereas Ad-DN-JNK suppressed only PAI-1 expression. Moreover, in vivo gene transfer of Ad-DN-p38 to rat carotid artery caused the inhibition of intimal hyperplasia by balloon injury, indicating the involvement of p38 in vascular remodeling in vivo.

Conclusions—

We propose that these 3 MAP kinases participate in vascular diseases via differential molecular mechanisms and are new therapeutic targets for treatment of vascular diseases.
Gyeongju VR Theater: A Journey into the Breath of Sorabol
Authors: Park Changhoon , Ahn Sang Chul , Kwon Yong-Moo , Kim Hyoung-Gon , Ko Heedong , Kim Taiyun
Published: May 2003

We have built the world's largest virtual reality (VR) theater for the Gyeongju World Culture EXPO 2000. The VR theater is characterized by a huge shared VR space with tightly coupled user inputs from 651 audience members in real time. The shared 3D virtual environment is augmenting the physical audience space in harmony. Large computer-generated passive stereo images on a huge cylindrical screen provide the sensation of visual immersion. The theater also provides 3D audio, vibration, and olfactory display as well as the keypads for each of the audience members to interactively control the virtual environment. This paper introduces the issues raised and addressed during the design of a versatile VR theater, the production process, and the presentation techniques using the versatile display and interaction capability of the future theater.
Levels of Control During a Collaborative Carrying Task
Authors: Ruddle Roy A. , Savage Justin C. D. , Jones Dylan M.
Published: May 2003

Three experiments investigated the effect of implementing low-level aspects of motor control for a collaborative carrying task within a VE interface, leaving participants free to devote their cognitive resources to the higher-level components of the task. In the task, participants collaborated with an autonomous virtual human in an immersive virtual environment (VE) to carry an object along a predefined path. In experiment 1, participants took up to three times longer to perform the task with a conventional VE interface, in which they had to explicitly coordinate their hand and body movements, than with an interface that controlled the low-level tasks of grasping and holding onto the virtual object. Experiments 2 and 3 extended the study to include the task of carrying an object along a path that contained obstacles to movement. By allowing participants' virtual arms to stretch slightly, the interface software was able to take over some aspects of obstacle avoidance (another low-level task), and this led to further significant reductions in the time that participants took to perform the carrying task. Improvements in performance also occurred when participants used a tethered viewpoint to control their movements because they could see their immediate surroundings in the VEs. This latter finding demonstrates the superiority of a tethered view perspective to a conventional, human'seye perspective for this type of task.
Psychophysical Characterization and Testbed Validation of a Wearable Vibrotactile Glove for Telemanipulation
Authors: Murray Anne M. , Klatzky Roberta L. , Khosla Pradeep K.
Published: May 2003

This paper describes and evaluates a high-fidelity, low-cost haptic interface for tele-operation. The interface is a wearable vibrotactile glove containing miniature voice coils that provides continuous, proportional force information to the user's finger-tips. In psychophysical experiments, correlated variations in the frequency and amplitude of the stimulators extended the user's perceptual response range compared to varying amplitude or frequency alone. In an adaptive, force-limited, pick-and-place manipulation task, the interface allowed users to control the grip forces more effectively than no feedback or binary feedback, which produced equivalent performance. A sorting experiment established that proportional tactile feedback enhances the user's ability to discriminate the relative properties of objects, such as weight. We conclude that correlated amplitude and frequency signals, simulating force in a remote environment, substantially improve teleoperation.
Social Inhibition in Immersive Virtual Environments
Authors: Hoyt Crystal L. , Blascovich Jim , Swinth Kimberly R.
Published: May 2003

We assessed the utility of using immersive virtual environment (IVE) technology for social psychological research by attempting to replicate two classic social influence effects. Specifically, we sought to replicate the classic social facilitation/inhibition effects wherein individuals' performance on a task is affected by the presence of others. Within an IVE, participants mastered one of two tasks and subsequently performed the mastered or nonmastered task either alone or in the presence of a virtual human audience whom they were led to believe were either computer-controlled agents or human-controlled avatars. Those performing in the presence of avatars demonstrated classic social inhibition performance impairment effects relative to those performing alone or in the presence of agents. We discuss important elements involved in the experience of social influence within immersive virtual environments.
Objective Metrics for the Evaluation of Simple Surgical Skills in Real and Virtual Domains
Authors: Moody Louise , Baber Chris , Arvanitis Theodoros N. , Elliott Martin
Published: May 2003

Surgical skills are traditionally assessed through subjective evaluation with experienced surgeons observing and rating trainee activity. However, this process can be expensive, particularly in terms of the time required of expert surgeons. Subjective assessment may also suffer from problems of intersubject variation in the application of evaluation criteria. Computer-based training, in particular systems combining virtual reality interfaces with haptic displays, offers a means of providing both automated and objective assessment of performance. In this paper we propose that, prior to the development of such systems, there is a need to determine measures that can adequately differentiate levels of performance. The paper therefore discusses the evaluation of surgical technique using objective metrics. Two main questions are addressed. How can surgical technique be assessed? What metrics prove useful in defining and modifying surgical skills and techniques?
Efectos del anonimato y el género sobre el nivel de consenso, cohesión y satisfacción en grupos con apoyo de sistemas informáticos
Authors: Martínez Isabel Ma , Mejías Roberto J.
Published: May 2003

Los sistemas de apoyo informático han dado lugar a nuevas formas de trabajo en grupo permitiendo la interacción en situaciones en las que los componentes del grupo están física, temporal y funcionalmente separados. El objetivo del presente trabajo es analizar los efectos del anonimato y el género sobre el nivel de consenso, la cohesión y la satisfacción de los individuos, en una situación de trabajo en grupo asistido por sistemas informáticos.

Mediante un diseño experimental de laboratorio se consideran dos condiciones experimentales: Grupos con apoyo de sistemas informáticos (GSS) y grupos cara a cara y dos situaciones: de anónimo e identificados. Los resultados, no muestran diferencias en los niveles de acuerdo pre-discusión y post-discusión, en función del anonimato, del género ni del uso de la tecnología. Sin embargo, a nivel individual, se advierten diferencias significativas en la cohesión grupal y satisfacción con el proceso y la decisión final, considerando la situación de anonimato y la variable género.
Inmigración y turismo: diferencias en percepciones y actitudes hacia los extranjeros en una muestra de niños-as almerienses
Authors: Cuadrado Isabel , Molero Fernando , Navas Marisol , García Ma Carmen
Published: May 2003

El objetivo de la presente investigación es conocer la percepción que una muestra de niños-as almerienses tiene de los inmigrantes africanos—un exogrupo especialmente significativo en la provincial—, en comparación con la que tienen del endogrupoy de otro exogrupo relevante en la zona (turistas europeos). La muestra estaba formada por 495 estudiantes (49.6% niñas y 50.4% niños) cuyas edades oscilaban entre 9–14 años (media=11.57; dt=1.02). Respondieron a varias preguntas abiertas sobre ambos exogrupos y a tres escalas tipo diferencial semántico sobre los tres grupos objeto de estudio. Los resultados muestran un claro favoritismo endogrupal, apoyando las predicciones de la teoría de la Identidad Social, pero también confirman la idea de que los niños-as, desde edades muy tempranas, son capaces de distinguir entre exogrupos con características diferenciales y sus percepciones dependen, igual que las de los adultos, de las distintas posiciones sociales que ocupan dichos grupos. Así, aunque la percepción que se tiene de los inmigrantes no es negativa en términos absolutos, sí lo es cuando se la compara con la de los turistas, un grupo probablemente con un estatus más alto. Los análisis de regresión muestran que cuando se percibe a los inmigrantes más parecidos al propio grupo, más trabajadores y con más dinero, más positiva es la evaluación que se hace de ellos. Se discuten las principales implicaciones de estos resultados y se tratan de relacionar con el diseño de intervencionespara mejorar las relaciones intergrupales.
El autoconcepto y la autoestima en la adolescencia media: análisis diferencial por curso y género
Authors: Pastor Yolanda , Balaguer Isabel , García-Merita María Luisa
Published: May 2003

El objetivo de este trabajo consiste en estudiar las características diferenciales del autoconcepto y la autoestima en la adolescencia media por edad y por género en una muestra representativa de la Comunidad Valenciana (N = 1.038, M edad = 16.31, Rango = 15–18 años). El instrumento utilizado ha sido una adaptación del Perfil de Autopercepciones para Adolescentes de Harter (1988) validado con adolescentes valencianos (Pastor, Balaguer, Atienza y García-Merita, 2001). Se realizan análisis descriptivos y diferenciales. Los resultados muestran que los chicos obtienen puntuacionespor encima de la media teórica en todas las dimensiones del autoconcepto, mientras que las chicas presentan puntuaciones por debajo de la media en Apariencia Física, Competencia Deportiva y Competencia Académica, y por encima de la media en el resto de subescalas. No se observan diferencias por curso, pero sí por género. Los chicos presentan puntuaciones más altas que las chicas en las subescalas de Apariencia Física, Competencia Académica, Competencia Deportiva y Autovalía Globaly más bajas que éstas en la subescala de Amistad Íntima.
Comportamiento colectivo y movimientos sociales: un reto para la Psicología Social
Authors: Javaloy Federico
Published: May 2003

La presente exposición pretende condensar los aspectos que pueden resultar más sugestivos para el psicólogo social que se hallan contenidos en el manual Comportamiento colectivo y movimientos sociales. Un enfoque psicosocial (Javaloy, Rodríguez y Espelt, 2001). El libro pretende of recer una visión global del comportamiento colectivo y de los movimientos sociales, tarea que había sido emprendida anteriormente en el marco de la sociología pero había quedado ampliamente desatendidapor la psicología social académica, especialmente en lengua española. El trabajo guarda correspondencia con las tres partes en que se halla estructurado el libro, centrando su análisis en la primera parte (fundamentación científica del campo estudiado) y en la tercera, referente a los movimientos sociales. De la segunda parte, sólo se mencionan aquí algunas aportaciones psicosociales provenientes de la investigación grupal que pueden ser consideradas la más importante contribución de la psicología social experimental al estudio del comportamiento colectivo y de los movimientos sociales. Se enfatiza también la relevancia socialdel campo estudiado, tratándose de ofrecer el reflejo de una sociedad en proceso de globalización en algunos de sus aspectos más problemáticos, como la crisis ecológica, el sexismo, el terrorismo y las desigualdades socials.
El reencuentro de la Psicologia Social con la conducta colectiva y los movimientos socials
Authors: Johnston Hank
Published: May 2003

El autor discute tres tendencias recientes que refuerzan la marea creciente de interés hacia los factores sociopsicológicos. Al hacerlo, el autor intenta situar la perspective psicosocial, la tesis central del artículo de Javaloy, 2003 (en este mismo número), justamente en el centro del progreso científico del estudio de la conducta colectiva y los movimientos sociales. Estas tendencias son las siguientes: 1) el interés en los procesos enmarcadores de la acción colectiva, 2) la renovación del interés en torno a las emociones y los movimientos sociales, y 3) la focalización en el espacio geográfico y las relaciones espaciales y su papel de moldeamiento de la conducta colectiva y los movimientos socials.
Psicología colectiva y compromiso
Authors: Ovejero Anastasio
Published: May 2003

El excesivo individualismo que a lo largo del siglo XX ha caracterizado a la Psicología Social le ha impedido desarrollar suficientemente uno de sus campos más propios y genuinos, el de la conducta colectiva y los movimientos sociales. Sin embargo, un mayor y más adecuado desarrollo de la Psicología Colectiva facilitaría a nuestra disciplina, en primer lugar, superar algunos de los aspectos más centrales de su crisis permanente; en segundo lugar, conectaría a los psicólogos sociales con la realidad social más actual, como son los nuevos movimientos sociales y particularmente el movimiento antiglobalizacin; y, en tercer lugar, la obligaría, al menos en cierta medida, a tomar posición frente a los problemas sociales y colectivos de nuestra época, lo que les empujaría a comprometerse con la problemática de los tiempos que corren. Es decir, que con todo ello, la Psicología Social adquiriría más relevancia social.
La venganza de Marx
Authors: Blanco Amalio
Published: May 2003

Si el objetivo primordial de los movimientos sociales reside en buscar una solución a los problemas que plantea el orden establecido, se hace necesario contemplar la incidencia que la dinámica del poder, una variable olvidada en la Psicología social, y a su vera el conflicto, un elemento perteneciente a la propia naturaleza de los movimientos sociales. El “giro psicosocial” en el estudio del comportamiento colectivo necesita de estos dos ingredientes para completarse. De otra manera no sabremos hacia dónde se dirige el cambio, ni cuál es elpropósito que lo guía.
System for Testing the Hygrothermal Performance of Multi-Layered Building Envelopes
Authors: Pavlik Zbysek , Pavlik Jaroslav , Jirickova Milena , Cerny Robert
Published: May 2003

A measuring system for determination of temperature, moisture, relative humidity, capillary pressure and salinity profiles in building envelopes is presented in the paper. The system makes it possible to analyze the hygrothermal performance of either particular materials or the whole building envelopes in the conditions of difference climate. Both the spatial dimensions of the specimens and the applied exterior and interior climatic data are chosen to be as close as possible to the conditions in the particular building site, so that the system can simulate the hygrothermal processes in the envelopes in quite a realistic way. A sophisticated technology for the determination of moisture, relative humidity, capillary pressure, temperature and salinity in the analyzed specimens based on the application of timedomain reflectometry, mini-tensiometry and mini-hygrometry is employed, which guarantees obtaining reliable data for validation of sophisticated computational models.
Performance Prediction for Masonry Walls with EIFS Using Calculation Procedures and Laboratory Testing
Authors: Hens H. , Carmeliet J.
Published: May 2003

This paper looks at masonry walls insulated outside with an EIFS system. It applies calculation procedures, laboratory testing and field experience to the selection of the materials and the details of the design. Special attention is given to the thermal and hygric response of the walls and to the durability of EIFS applications. The study shows that calculation procedures and measurements cannot only provide confidence in the prediction of the performances but can also give the fundamental information required for the improvement and optimisation of the design.
Modelling Settling of Loose-fill Insulation in Walls, Part II Determination of Coefficients
Authors: Rasmussen Torben ValdbjØrn
Published: May 2003

This paper presents material parameters for theoretically estimating the necessary density of granular loose-fill insulation in walls in order to ensure volume stability. Various parameters including the friction coefficient, the horizontal stress ratio, the elastic modulus, instantaneous plastic strain and instantaneous elastic strain together with strain–time behaviour and progressive strain caused by an alternating relative humidity are determined. Parametersrelated to strain are determined from creep tests where the insulation material is exposed to a constant load. These characteristics describing the material behaviour are combined with theories describing creep of the material, thus providing a better understanding of the material behaviour of granulated loose-fill materials used as thermal insulation in walls. The theory used is outlined in ‘‘Modelling Settling of Loose-fill Insulation in Walls, Part I’’.
Prediction of Mould Growth by Hygrothermal Calculation
Authors: Sedlbauer Klaus
Published: May 2003

In buildings growing conditions for mould fungi can occur and cause fungus infestation. The danger for the occupants of dwellings lies in the production and spreading of pathogens (disease causing agents). Therefore, consequent measures have to be taken to avoid health dangers that come from mould fungi in buildings. In order to avoid the mould fungus formation, a strategy has to be set up that focuses on the growth conditions for mould fungi and also considers the complex transient processes of building physics. The boundary conditions for the growth of fungi are temperature, humidity and substrate conditions which have to be simultaneously available over a certain period of time. In [15] a biohygrothermal procedure is developed, which allows the prediction of mould growth under transient boundary conditions. The assessment results from a comparison of the water content in a modelled mould spore determined by transient calculations, with the critical water content, above which the spore germinates and grows. This means that long-term humidity values exceeding this critical water content indicate mould growth. This new method is described in this article and the functions are shown within an example.
Protection of Foam Plastic Thermal Insulation in Low Sloped Roofing Systems
Authors: Booth Robert J. , Derushie Clinton , Liu Karen
Published: May 2003

Foam plastic thermal insulations have substantially replaced traditional insulations in low sloped roofing systems in North America. Foam plastic thermal insulations used in low sloped roofs are low density (typically 16–48 kg/m3) materials with low permeability to air and water vapour. In many roofs these materials have been directly substituted for traditional (wood and glass fibre) insulations without due attention to the different material characteristics. Moist air movement within roofs,condensation protection (air and vapour barriers),steel deck corrosion,roof membrane blistering and roof traffic damage are discussed. This paper discusses protection of foam plastic thermal insulations in roofing systems, why the protection is needed,and what consequences result if these materials are not protected. Case studies demonstrate the importance of condensation protection in reducing corrosion of galvanized steel in roofs containing closed cell phenolic foam roof insulation in Canada.
Evaluating the Air Pressure Response of Multizonal Buildings
Authors: Lstiburek Joseph , Pressnail Kim , Timusk John
Published: May 2003

Air flow in buildings is a complex flow and pressure distribution problem that makes quantification difficult. However, certain parameters have recently become easy to quantify – specifically the air pressure relationships within buildings.

The measured building air pressure field can be used with network analysis to solve the building flow and leakage regime creating an analytical macro model of the building flow and leakage regime. The response of the analytical model can be further tuned by perturbing both the building air pressure field and the analytical model.

Building analysis typically focuses on flows and requires that all flow paths into and out of a control volume be defined. The flow path resistances need to be characterized. Determining all air flow paths and determining the flow path resistances directly is difficult. As such, estimates of these flow path resistances are commonly used. These estimates are based on limited field data and laboratory measurements. The literature provides some component values that vary by orders of magnitude and their application is often unable to predict building flow fields (ASHRAE, 1997).

Standard building analysis develops the building pressure field from the flow field. This paper argues that developing the flow field from the building pressure field is more powerful. Determining the characteristics of the building pressure field directly is considerably easier than determining flow path resistances.

It allows closing of the gap between the mathematical sophistication of available multi-cell air flow models and the necessary input information defining the building boundary conditions. This approach allows the pressure response of the building to be used to ‘‘tune’’ the models extending the range of their applicability and accuracy.
The Influence of Soil Moisture in the Unsaturated Zone on the Heat Loss from Buildings via the Ground
Authors: Janssen Hans , Carmeliet Jan , Hens Hugo
Published: May 2003

In calculations of building heat loss via the ground, the coupling with soil moisture transfer is generally ignored, an important hypothesis which will be falsified in this paper. Results from coupled simulations – coupled soil heat and moisture transfer equations and complete surface heat and moisture balances – are compared to results from linear simulations. It is shown that the coupled calculations give notably higher heat losses. Surface temperature, the driving force for heat loss via the ground, is identified as a first important source for these deviations: it is shown that while the averages of the surface temperature are almost equal in coupled and linear calculations, the amplitude in the coupled simulation is considerably higher. A further study reveals that variation of the thermal properties with moisture content also contributes partially to the observed differences. Transfer and storage of sensible heat linked to moisture in the liquid phase was shown to be the last important influencing factor.
Measurements and Simulations of Natural and Forced Convection in Loose-Fill Attic Insulation
Authors: Wahlgren Paula
Published: May 2003

The influence of convection on the thermal performance of loose-fill attic insulation has been investigated using measurements and simulations. Thermal resistance measurements have been performed in a large-scale attic test model, with and without attic ventilation, and on loose-fill rock wool and fiberglass insulation. Measurements of natural convection have shown that the critical modified Rayleigh number for attic insulation in a conventional attic floor is approximately 22. The maximum decrease in measured thermal resistance due to natural convection was 25% compared to that obtained at the onset of convection. There was no indication of a decrease in the total thermal resistance of the attic floor due to attic ventilation.
Information Based Delivery System for Sprayed Polyurethane Foam in Roofing
Authors: Kashiwagi Dean T. , Tisthammer Thom
Published: May 2003

This paper describes the results of a three year research effort to reshape a Spray Polyurethane Foam (SPF) roofing manufacturer’s delivery system from a ‘‘low-bid,’’ marketing system, into an information based delivery system. The objective of this program is to develop a high-performance product sector that is based on performance information, parallel to the existing commoditysector that is based on low price.

This paper describes an SPF roofing deliverysy stem aiming at the following:

1. Use of Information Measurement Theoryto identifyperformance criteria.

2. Use the performance information to increase the ‘‘perceived’’ and actual value of the installed system.

3. Allow the facilityowner and their representatives to impact the contractor’s rating to motivate a higher level of performance.

4. Allow contractors to relate better to various requirements depending on the type of work, facilityowner preferences, and performance/price relationships.

5. Increase the market share for a high performance SPF roofing system.

6. Eliminate several business problems that affect performance of SPF systems.

This program infers that the performance information is the best wayto reduce liabilityrisk of the contractor and manufacturer. The participants also realized that using performance information is the best wayto maintain profit margins in a very competitive marketplace.