bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tumour necrosis factor and lymphotoxin A polymorphisms and lung function in smokers
Authors: Tanaka G. , Sandford A. J. , Burkett K. , Connett J. E. , Anthonisen N. R. , Paré P. D. , He J-Q. 
Published: September 2006

Genetic variants in the tumour necrosis factor (TNF) gene have been investigated in chronic obstructive pulmonary disease (COPD). However, there are many instances of nonreplication of these associations due to insufficient power or other factors. In this study, a large number of subjects were examined to elucidate whether genetic variations ofTNFand/or lymphotoxin A (LTA), which is clustered withTNF, are associated with variations in lung function among smokers.The present authors designed two nested case–control studies in the National Heart, Lung, and Blood Institute Lung Health Study (LHS), which enrolled 5,887 smokers. The first design included continuous smokers who had the fastest (n = 279) and the slowest (n = 304) decline of lung function during the 5-yr follow-up period, and the second included the subjects who had the lowest (n = 533) and the highest (n = 532) post-bronchodilator % predicted forced expiratory volume in one second at the start of the LHS. Within theTNFandLTAregion, 10 tagging single-nucleotide polymorphisms were selected and genotyped.Unlike the previous associations betweenTNF-308 and COPD in Asians, the current study found no association between either of the two phenotypes and theLTAandTNFpolymorphisms.In conclusion, these results support the findings of previous studies in late-onset chronic obstructive pulmonary disease in Caucasian populations.
Sex differences in thoracic adaptation to pulmonary hyperinflation in cystic fibrosis
Authors: Bellemare F. , Jeanneret A. 
Published: September 2006

Sex differences in thoracic adaptation have been reported in patients with cystic fibrosis (CF). The interplay between the pattern of thoracic adaptation and the function of the respiratory muscles in male and female CF patients with pulmonary hyperinflation was investigated.Thoracic dimensions and diaphragm length were measured at residual volume, functional residual capacity and total lung capacity using chest radiography in 23 CF (12 males) and 18 normal (11 males) subjects. Respiratory muscle recruitment during resting breathing was assessed by recording intrathoracic and intra-abdominal pressures.In female CF patients, ribcage expansion was predominant, tending to preserve diaphragm length. In male CF patients, thoracic configuration was normal and diaphragm shortening consequently greater. Ribcage cross-sectional area for a given rib inclination was greater in CF patients, indicating a structural expansion of the ribcage 2.5 times greater in females than males. The contribution of inspiratory ribcage muscles to inspiratory pressure was also greater relative to the diaphragm in the CF group.In conclusion, a structural expansion of the ribcage occurs in cystic fibrosis patients with lung hyperinflation that is greater in females than males. This is associated with an apparent greater contribution of inspiratory ribcage muscles to inspiratory pressure.
Legionella pneumophila-induced NF-κB- and MAPK-dependent cytokine release by lung epithelial cells
Authors: Schmeck B. , N’Guessan P. D. , Ollomang M. , Lorenz J. , Zahlten J. , Opitz B. , Flieger A. , Suttorp N. , Hippenstiel S. 
Published: September 2006

Legionella pneumophilacauses community-acquired pneumonia with high mortality, but little is known about its interaction with the alveolar epithelium. The aim of this study was to investigate whetherL. pneumophilainfection of lung epithelial cells (A549) resulted in pro-inflammatory activation.L. pneumophilainfection induced liberation of interleukin (IL)-2, -4, -6, -8 and -17, monocyte chemoattractant protein-1, tumour necrosis factor-α, IL-1β, interferon-γ and granulocyte colony-stimulating factor, but not of IL-5, -7, -10, -12 (p70) or -13 or granulocyte-macrophage colony-stimulating factor. The present study focused on IL-8 and found induction byL. pneumophilastrains 130b, Philadelphia 1, Corby and, to a lesser extent, JR32. Knockout ofdotA, a central gene involved in type IVB secretion, did not alter IL-8 induction, whereas lack of flagellin significantly reduced IL-8 release by Legionella. Moreover, p38 mitogen-activated protein kinase (MAPK) was activated and kinase inhibition reduced secretion of induced cytokines, with the exception of IL-2 and granulocyte colony-stimulating factor. In contrast, inhibition of the MAPK kinase 1/extracellular signal-regulated kinase pathway only reduced the expression of a few cytokines.L. pneumophilaalso induced binding of nuclear factor-κB subunit RelA/p65 and RNA polymerase II to theil8promoter, and a specific inhibitor of the inhibitor of nuclear factor-κB complex dose-dependently lowered IL-8 expression.Taken together,Legionella pneumophilaactivated p38 mitogen-activated protein kinase- and nuclear factor-κB/RelA pathway-dependent expression of a complex pattern of cytokines by human alveolar epithelial cells, presumably contributing to the immune response in legionellosis.
Acute symptoms related to air pollution in urban areas: a study protocol
Authors: Yunesian Masud , Asghari Fariba , Vash Javad Homayoun , Forouzanfar Mohammad Hossein , Farhud Dariush 
Published: September 2006

Abstract

Background
The harmful effects of urban air pollution on general population in terms of annoying symptoms are not adequately evaluated. This is in contrast to the hospital admissions and short term mortality. The present study protocol is designed to assess the association between the level of exposure to certain ambient air pollutants and a wide range of relevant symptoms. Awareness of the impact of pollution on the population at large will make our estimates of the pertinent covert burden imposed on the society more accurate.

Methods/design
A cross sectional study with spatial analysis for the addresses of the participants was conducted. Data were collected via telephone interviews administered to a representative sample of civilians over age four in the city. Households were selected using random digit dialling procedures and randomization within each household was also performed to select the person to be interviewed. Levels of exposure are quantified by extrapolating the addresses of the study population over the air pollution matrix of the city at the time of the interview and also for different lag times. This information system uses the data from multiple air pollution monitoring stations in conjunction with meteorological data. General linear models are applied for statistical analysis.

Discussion
The important limitations of cross-sectional studies on acute effects of air pollution are personal confounders and measurement error for exposure. A wide range of confounders in this study are controlled for in the statistical analysis. Exposure error may be minimised by employing a validated geographical information system that provides accurate estimates and getting detailed information on locations of individual participants during the day. The widespread operation of open air conditioning systems in the target urban area which brings about excellent mixing of the outdoor and indoor air increases the validity of outdoor pollutants levels that are taken as exposure levels.
Transcriptional analysis of the recA gene of Streptococcus thermophilus
Authors: Giliberti Gabriele , Baccigalupi Loredana , Cordone Angelina , Ricca Ezio , De Felice Maurilio 
Published: September 2006

Abstract

Background
RecA is a highly conserved prokaryotic protein that not only plays several important roles connected to DNA metabolism but also affects the cell response to various stress conditions. While RecA is highly conserved, the mechanism of transcriptional regulation of its structural gene is less conserved. In Escherichia coli the LexA protein acts as a recA repressor and is able, in response to DNA damage, of RecA-promoted self-cleavage, thus allowing recA transcription. The LexA paradigm, although confirmed in a wide number of cases, is not universally valid. In some cases LexA does not control recA transcription while in other RecA-containing bacteria a LexA homologue is not present.

Results
We have studied the recA transcriptional regulation in S. thermophilus, a bacterium that does not contain a LexA homologue. We have characterized the promoter region of the gene and observed that its expression is strongly induced by DNA damage. The analysis of deletion mutants and of translational gene fusions showed that a DNA region of 83 base pairs, containg the recA promoter and the transcriptional start site, is sufficient to ensure normal expression of the gene. Unlike LexA of E. coli, the factor controlling recA expression in S. thermophilus acts in a RecA-independent way since recA induction was observed in a strain carrying a recA null mutation.

Conclusion
In S. thermophilus, as in many other bacteria,recA expression is strongly induced by DNA damage, however, in this organism expression of the gene is controlled by a factor different from those well characterized in other bacteria. A small DNA region extending from 62 base pairs upstream of the recA transcriptional start site to 21 base pairs downstream of it carries all the information needed for normal regulation of the S. thermophilus recA gene.
Use of pre-packaged chloroquine for the home management of presumed malaria in Malagasy children
Authors: Ratsimbasoa Arsène , Randrianarivelojosia Milijaona , Millet Pascal , Soarès Jean Louis , Rabarijaona Leon , Rakotoson Benjamin , Malvy Denis , Ménard Didier 
Published: September 2006

Abstract

Objective
The main objective of this study was to assess the quality of home malaria management with pre-packaged chloroquine in two areas in the Moramanga district of Madagascar. The knowledge, attitude and practices of care providers in terms of home treatment options were evaluated and compared. The availability of treatment options by studying retailers and community-based service providers was also investigated.

Methods
A cross-sectional investigation in two communities, in the hamlets and villages located close to carers, retailers, community-based service providers and primary health centres was carried out.

Results
Carers in the two districts were equally well aware of the use of pre-packaged chloroquine. Their first response to the onset of fever was to treat children with this antimalarial drug at home. The dose administered and treatment compliance were entirely satisfactory (100%) with pre-packaged chloroquine and rarely satisfactory (1.6% to 4.5%) with non pre-packaged chloroquine. In cases of treatment failure, the carers took patients to health centres. Chloroquine was supplied principally by private pharmacies and travelling salesmen selling unpackaged chloroquine tablets. Non pre-packaged chloroquine was the most common drug used at health centres. The frequency of positive rapid malaria tests (P = 0.01) was significantly higher in children treated with non pre-packaged chloroquine (38%) than in children treated with pre-packaged chloroquine (1.3%).

Conclusion
Home malaria management should be improved in Madagascar. Efforts should focus on communication, the training of community-based service providers, access to pre-packaged drugs and the gradual withdrawal of pre-packaged chloroquine and its replacement by pre-packaged artemisinin-based combination therapies.
IFN-γ-activated monocytes weakly produce HIV-1 but induce the recruitment of HIV-sensitive T cells and enhance the viral production by these recruited T cells
Authors: Saïdi Héla , Magri Giuliana , Carbonneil Cedric , Nasreddine Nadine , Réquena Mary , Bélec Laurent 
Published: September 2006

AbstractThe ability of macrophages to adapt to changing cytokine environments results in the dominance of a particular functional phenotype of macrophages, which would play a significant role in HIV pathogenesis. In comparison with untreated macrophages (M0), we examined the role of macrophages derived from IFN-γ-activated monocytes (M1) in the HIV spread. We show that M0 and M1 bind with the same efficiency HIV-1 with a predominant role of C-type lectins in the R5-HIV attachment and of the heparan sulfate proteoglycans in the X4-HIV attachment. Despite similar levels of R5- and X4-HIV DNA, M1 replicates and weakly transmits the virus to activated T cells by releasing CXCR4- and CCR5-interacting chemokines. The blockade of dendritic cell-specific ICAM-3-grabbing nonintegrin expressed on M1 by mAb does not interfere with the viral transfer. Uninfected M1 recruits HIV-sensitive T cells efficiently and releases soluble factors, enhancing the viral production by these recruited cells. This study highlights the role of IFN-γ to induce a population of macrophages that archive HIV-1 within a latent stage and cause the persistence of the virus by favoring the recruitment of T cells or enhancing the viral replication in infected CD4+ T cells.
Children's autobiographies of learning to write
Authors: Scheuer Nora , de la Cruz Montserrat , Pozo Juan Ignacio , Neira Silvina 
Published: September 2006

Background. Learning conceptions may be studied as specific implicit theories based on theory of mind. Previous studies suggest that a developmental shift from a direct implicit theory of learning to an interpretative one occurs during childhood. Here we explore the development of children's autobiographies of learning to write by adopting this framework.Aims. We aim to study children's autobiographical accounts of learning to write and whether these accounts change according to the mentioned developmental shift and sociocultural environment.Sample. Sixty children attending public schools in Argentina that were equally distributed according to school level (kindergarten, first grade, fourth grade) and sociocultural environment (middle and marginal).Methods. Children were interviewed individually at school and requested to write ‘as you used to when you were just beginning to write ’. This question was repeated for one‐year‐intervals until child's current age was reached; anticipation of writing next year was also requested. Children's responses were coded into descriptive categories. A multiple correspondence factorial analysis studied the relations among response categories, school grade and sociocultural environment. On the basis of these results, categories were ordered into a Guttman scale.Results. A developmental shift from a focus on isolated products to the integration of procedural and representational changes was evident. School grade and sociocultural environment were statistically significant.Conclusions. Children's writing autobiographies show developmental differences that suit the shift from a direct to an interpretative theory of learning on the basis of hierarchical integration rather than conceptual replacement.
Investigating the relationship between variations in students' perceptions of their academic environment and variations in study behaviour in distance education
Authors: Richardson John T. E. 
Published: September 2006

Background. Recent research on student learning in higher education has identified clear associations between variations in students' perceptions of their academic environment and variations in their study behaviour.Aims. This research investigated a general theoretical model linking students' demographic characteristics, perceptions and study behaviour with measures of outcome and in particular compared four accounts of the casual relationship between perceptions and study behaviour.Samples. Study 1 employed data from 1,123 students taking six courses by distance learning; Study 2 employed data from 2,049 students taking seven courses by distance learning.Methods. Path analysis was used to assess the causal relationships among the students' age, gender and prior qualifications, their scores on the Course Experience Questionnaire, their scores on a short version of the Approaches to Studying Inventory or the Revised Approaches to Studying Inventory, their overall marks and their ratings of general satisfaction.Results. Both studies yielded evidence for the causal efficacy of all the paths identified in the general theoretical model.Conclusions. There exists a bi‐directional causal relationship between variations in students' perceptions of their academic environment and variations in their study behaviour.
Academic self‐handicapping: The role of self‐concept clarity and students' learning strategies
Authors: Thomas Cathy R. , Gadbois Shannon A. 
Published: September 2006

Background. Self‐handicapping is linked to students' personal motivations, classroom goal structure, academic outcomes, global self‐esteem and certainty of self‐esteem. Academic self‐handicapping has yet to be studied with respect to students' consistency in self‐description and their description of themselves as learners.Aims. This study examined students' self‐esteem and self‐concept clarity as well as their tendencies to employ deep‐ or surface‐learning approaches and self‐regulate while learning in relation to their self‐handicapping tendencies and exam performance.Sample. Participants were 161 male and female Canadian, first‐year university students.Method. Participants completed a series of questionnaires that measured their self‐esteem, self‐concept clarity, approaches to learning, self‐regulation and reflections on performance prior to and following their exam.Results. Self‐handicapping was negatively correlated with self‐concept clarity, deep learning, self‐regulated learning and exam grades, and positively correlated with surface learning and test anxiety. Regression analyses showed that self‐concept clarity, self‐regulation, surface‐learning and test anxiety scores predicted self‐handicapping scores. Self‐concept clarity, test anxiety scores, academic self‐efficacy and self‐regulation were predictors of mid‐term exam grades.Conclusions. This study showed that students' self‐concept clarity and learning strategies are related to their tendencies to self‐handicap and their exam performance. The role of students' ways of learning and their self‐concept clarity in self‐handicapping and academic performance was explored.
Job stressors, personality and burnout in primary school teachers
Authors: Kokkinos Constantinos M. 
Published: September 2006

Background. Teaching is considered a highly stressful occupation. Burnout is a negative affective response occurring as a result of chronic work stress. While the early theories of burnout focused exclusively on work‐related stressors, recent research adopts a more integrative approach where both environmental and individual factors are studied. Nevertheless, such studies are scarce with teacher samples.Aims. The present cross‐sectional study sought to investigate the association between burnout, personality characteristics and job stressors in primary school teachers from Cyprus. The study also investigates the relative contribution of these variables on the three facets of burnout – emotional exhaustion, depersonalization and reduced personal accomplishment.Sample. A representative sample of 447 primary school teachers participated in the study.Method. Teachers completed measures of burnout, personality and job stressors along with demographic and professional data. Surveys were delivered by courier to schools, and were distributed at faculty meetings.Results. Results showed that both personality and work‐related stressors were associated with burnout dimensions. Neuroticism was a common predictor of all dimensions of burnout although in personal accomplishment had a different direction. Managing student misbehaviour and time constraints were found to systematically predict dimensions of burnout.Conclusions. Teachers' individual characteristics as well as job related stressors should be taken into consideration when studying the burnout phenomenon. The fact that each dimension of the syndrome is predicted by different variables should not remain unnoticed especially when designing and implementing intervention programmes to reduce burnout in teachers.
Classroom interactions: Exploring the practices of high‐ and low‐expectation teachers
Authors: Rubie‐Davies Christine M. 
Published: September 2006

Background. Early research exploring teacher expectations concentrated on the dyadic classroom interactions of teachers with individual students. More recent studies have shown whole class factors to have more significance in portraying teachers' expectations. Recently teachers having high or low expectations for all their students have been identified.Aims. The aim of the current investigation was to explore whether the classroom exchanges of high‐ and low‐expectation teachers differed substantially and might be considered a mechanism for teachers' expectations.Sample. The participants were 12 primary school teachers from eight schools who had been identified as having expectations for their students' learning that were either significantly above or below the children's achievement level. The teachers formed three groups called high‐expectation, low‐expectation and average‐progress teachers.Method. The participants were observed twice in the academic year during half‐hour reading lessons. Two people observed each lesson, one completing a structured observation protocol and the other a running record and audiotape.Results. In contrast to the average progress and low expectation teachers, the high‐expectation teachers spent more time providing a framework for students' learning, provided their students with more feedback, questioned their students using more higher‐order questions, and managed their students' behaviour more positively.Conclusions. There appear to be important differences in the classroom environments for the students of high‐expectation, average‐progress and low‐expectation teachers. The differences apply to both the instructional and socioemotional environments of the classroom. Such disparities may act as mechanisms for teacher expectation effects.
‘Ain't nothin' like the real thing’. Motivation and study processes on a work‐based project course in information systems design
Authors: Helle Laura , Tynjälä Päivi , Olkinuora Erkki , Lonka Kirsti 
Published: September 2006

Background. Advocates of the project method claim that project‐based learning inspires student learning. However, it has been claimed that project‐based learning environments demand quite a bit of self‐regulation on the part of the learner.Aims. Consequently, it was tested whether students scoring low in self‐regulation of learning experienced ‘friction’, an incompatibility between student self‐regulation and the demands posed by the learning environment. This would be manifest in cognitive processing and motivation.Samples. The target group consisted of 58 mainly third‐year Finnish university students taking a mandatory project course in information systems design. During the project course, student teams completed a commissioned assignment. The study also included a matched nonequivalent comparison group composed of computer science students attending study programmes without a project‐based component.Methods. Data were gathered by means of a questionnaire administered at the beginning and end of the project course and it was analysed by between‐groups repeated measures ANOVA. In addition, the students on the course were interviewed.Results. Results suggest that the work‐based project model in question may indeed have a substantial motivational impact, interestingly benefitting especially those students who scored low in self‐regulation.Conclusions. It is argued that we tend to view learning environments too simplistically. In particular, a basic distinction should be made between individual and collaborative learning contexts, since peer scaffolding, group grading and choice of group roles may explain why students scoring low in self‐regulation of learning did not encounter friction as expected.