bluuebunny/crossref_metadata_2025 huggingface dataset:
The Utility of Situational Leadership Theory
Authors: Vecchio Robert P. , Bullis R. Craig , Brazil Donna M.
Published: August 2006

In a constructive replication of prior comprehensive tests of situational leadership theory, members of 86 squads of U.S. Military Academy cadets (total of 860 participants) provided data on leader consideration, leader structuring, follower readiness/maturity, follower satisfaction, follower performance, and leader-member exchange. Results of regression analyses and tests for mean differences within follower readiness/maturity level did not yield clear evidence of a predicted interaction among leader style and follower attributes. These results are in alignment with prior findings and suggest the theory may have little practical utility.
Group Ethos and the Communication of Social Action
Authors: Patrick Brian Anse
Published: August 2006

If an individual can possess or be possessed by some particular type of ethos, then why not a group? This article defines, and empirically supports with case studies, three modes of group ethos that are culturally available to work groups in modern organizational settings. Each mode is associated with a particular communication style. The three group ethos modes are (a) pluralistic, associated with a pragmatic style of communication; (b) social movement, which communicates via protest; and (c) administrative-technical, which manifests via a prescriptive communication style. Characteristic communication strengths, weaknesses, and management problems are associated with each mode. The ethos mode will explicitly inform group communication and rhetoric and hence can be reliably inferred by observers. Group effectiveness problems are often attributable to groups entrained by their own ethos or to clashes of groups of differing ethos. Hybridism of modes is possible and may offer advantages in effectiveness.
Effects of Process Feedback on Motivation, Satisfaction, and Performance in Virtual Teams
Authors: Geister Susanne , Konradt Udo , Hertel Guido
Published: August 2006

In virtual teams, the lack of feedback and information about team processes is a major problem. To encounter this challenge of virtual teamwork, team process feedback was provided by an Online-Feedback-System (OFS). It contained feedback regarding motivation, task-related aspects, and relationshiprelated aspects. A longitudinal study of 52 virtual teams with student participants was conducted. Teams that used the OFS showed an increase in performance compared with controls that did not use the OFS. Furthermore, results indicate initial motivation as a moderating variable on the improvement caused by the OFS. Positive OFS effects were found on motivation and satisfaction for the less motivated team members. Furthermore, for less motivated team members, effects of the OFS on performance were mediated by interpersonal trust. Overall, results imply that team process feedback has a positive effect on motivation, satisfaction, and performance in virtual teams.
Social and Cognitive Factors Driving Teamwork in Collaborative Learning Environments
Authors: Van den Bossche Piet , Gijselaers Wim H. , Segers Mien , Kirschner Paul A.
Published: August 2006

A team is more than a group of people in the same space, physical or virtual. In recent years, increasing attention has been devoted to the social bases of cognition, taking into consideration how social processes in groups and teams affect performance. This article investigates when and how teams in collaborative learning environments engage in building and maintaining mutually shared cognition, leading to increased perceived performance. In doing so, this research looks for discourse practices managing the co-construction of mutually shared cognition and reveals conditions in the interpersonal context that contribute to engagement in these knowledge-building practices. A comprehensive theoretical framework was developed and tested. The constructs in the model were measured with the Team Learning Beliefs & Behaviors Questionnaire and analyzed using regression and path analysis methodology. Results showed that both interpersonal and sociocognitive processes have to be taken into account to understand the formation of mutually shared cognition, resulting in higher perceived team performance.
Teamwork Behaviors
Authors: Rousseau Vincent , Aubé Caroline , Savoie André
Published: August 2006

The existing body of literature on teamwork behaviors is substantial and offers many different conceptualizations. However, there is a lack of consensus concerning the conceptual structure of teamwork behaviors. Many researchers pursue their own work without any attempt to build on and integrate the work of others. This article reviews the frameworks of teamwork behaviors in the literature on work teams and provides a way of integrating these frameworks. The behavioral dimensions included in this integrative framework are conceptually distinguished and arranged in a hierarchical conceptual structure based on theoretical approaches. Moreover, they are framed from the perspective of the timing of teamwork behaviors to clarify when these behaviors are most likely to have their intended effects. The proposed framework is then connected to the task conditions under which teamwork behaviors are most likely to facilitate collective task accomplishment. Finally, future directions for research regarding teamwork behaviors are discussed.
Management Are Aliens!
Authors: Bordia Prashant , Jones Elizabeth , Gallois Cindy , Callan Victor J. , DiFonzo Nicholas
Published: August 2006

Rumors collected from a large public hospital undergoing change were content analyzed, and a typology comprising the following five broad types of change-related rumors was developed: rumors about changes to job and working conditions, nature of organizational change, poor change management, consequences of the change for organizational performance, and gossiprumors. Rumors were also classified as positive or negative on the basis of their content. As predicted, negative rumors were more prevalent than positive rumors. Finally, employees reporting negative rumors also reported more change-related stress as compared to those who reported positive rumors and those who did not report any rumors. The authors propose that rumors be treated as verbal symbols and expressions of employee concerns during organizational change.
Avoiding the “Fallacy of the Wrong Level”
Authors: Dansereau Fred , Cho Jeewon , Yammarino Francis J.
Published: August 2006

This article illustrates that any bivariate or multiple regression provides inadequate information about the levels of analysis in a data set collected in an organizational setting. As a result, individual-level effects may be incorrectly attributed to the group level, and group-level effects may be incorrectly viewed as being solely individual-level effects. Both of these situations are examples of the “fallacy of the wrong level.” Within and between analysis (WABA) allows levels of analysis to be tested in data. These WABA tests are useful in numerous analytical approaches, including structural equation modeling, hierarchical linear modeling, and various approaches to aggregation. This article provides a decision tree for use in performing tests for multiple alternative levels of analysis in a data set collected in organizations.
Sade, Masculinity, and Sexual Humiliation
Authors: Hekma Gert
Published: August 2006

During the eighteenth century, new ideals, theories, and practices of masculinity and sexuality developed in the countries of Northwestern Europe. This article discusses these ideals mainly using the example of the life and the works of the Marquis de Sade (1740-1814). While old ideals of Christian or noble masculinity demanded chastity or restraint and new Enlightened ones vigor and control, Sade's perspective that stressed sexual humiliation was in stark conflict with both the old and new ideas on male honor, masturbation, and same-sexual acts. The article discusses his life and some of his works before reviewing his philosophy and his views on masculinity and sexuality. It ends with the importance of Sade's work for his own times and for contemporary discussions.
Among the Dockhands
Authors: Gregory Chad
Published: August 2006

The following essay examines the congruence of American labor and social history scholarship with actualworking-classexperiences. Particularly, it compares an author's immersion in a masculine working-class environment with recent ideas in historical research about the interplay of gender and work. The author argues that the challenge of working on a fast-paced loading dock with male coworkers was made less onerous by the free expression of working-class male behaviors. Sexual kidding, physical posturing, and profanity, sometimes accentuated with crude but appreciable wit, made the demanding labor more bearable, a theme borne out by recent scholarship on masculinity and the workplace.
Collective Violence, Public Spaces, and the Unmaking of Men
Authors: Mehta Deepak
Published: August 2006

Drawing from fieldwork in a shantytown called Dharavi in Bombay, this article considers the effects of communal violence between Hindus and Muslims in December, 1993, and January, 1993. The effects of violence are charted through narrative accounts of residents of Dharavi. The article argues that collective violence brings together the nation, the neighborhood, and bodies of participants. The intersection of these three shows the procedures by which Muslim men are denuded of their masculinity.
The Stain of White
Authors: Abraham Janaki
Published: August 2006

During British colonial rule some matrilineal Thiyya women in North Kerala, India, had liaisons with British men. While the response of the caste (here, a Backward caste) to these liaisons shifted over time, in the late nineteenth and early twentieth century many women who had liaisons and their families were excommunicated. A “white connection” became a stain and kinship with the white man was denied or shrouded. This article looks at the ways in which both the liaisons and the denial of the white man as father or relative were located within practices of matrilineal kinship. Furthermore, this article seeks to understand how these liaisons are remembered today and how the presence of the white man as a relative is layered over by processes of forgetting and remembering.
Competing Masculinities in a Prison
Authors: Bandyopadhyay Mahuya
Published: August 2006

This article draws on fieldwork conducted in a central prison in Kolkata, India, which I experienced as an overwhelmingly male space. This ethnographic material demonstrates the nature of the male space and the practices through which male identities were made and defined within this space. I argue that the experience of the prison and incarceration is one in which the dominant norms of maleness are challenged. Through the processes of divestiture of rights implicit in imprisonment, the image of a man as an independent agent of his destiny, as protector of his family, as a worker and bread earner, or even as a strong and influential man in the neighborhood are displaced. I explore the ways male prisoners deal with this “less than a man” image within the prison. The gendered nature of the prison as an organization emerges when examining contexts in which male identities are enacted and made.
Academic Socialization Experiences of Latina Doctoral Students
Authors: González Juan Carlos
Published: August 2006

This article examines the experiences of academic socialization for Latina doctoral students. Thirteen 1- to 2-hour semistructured interviews were conducted with Latina doctoral students attending U.S. research institutions who had been in their programs for 3 or more years. Through production theory, a phenomenological analytic approach of Latina doctoral experiences was conducted. Findings include support systems, challenges, resistance methods, and issues with claiming their academic voice. The article concludes with policy implications and a discussion.
MAP-ping genomic organization and organ-specific expression profiles of poplar MAP kinases and MAP kinase kinases
Authors: Nicole Marie-Claude , Hamel Louis-Philippe , Morency Marie-Josée , Beaudoin Nathalie , Ellis Brian E , Séguin Armand
Published: August 2006

Background

As in other eukaryotes, plant mitogen-activated protein kinase (MAPK) cascades are composed of three classes of hierarchically organized protein kinases, namely MAPKKKs, MAPKKs, and MAPKs. These modules rapidly amplify and transduce extracellular signals into various appropriate intracellular responses. While extensive work has been conducted on the post-translational regulation of specific MAPKKs and MAPKs in various plant species, there has been no systematic investigation of the genomic organization and transcriptional regulation of these genes.

Results

Ten putative poplar MAPKK genes (PtMKKs) and 21 putative poplar MAPK genes (PtMPKs) have been identified and located within the poplar (Populus trichocarpa) genome. Analysis of exon-intron junctions and of intron phase inside the predicted coding region of each candidate gene has revealed high levels of conservation within and between phylogenetic groups. Expression profiles of all members of these two gene families were also analyzed in 17 different poplar organs, using gene-specific primers directed at the 3'-untranslated region of each candidate gene and real-time quantitative PCR. Most PtMKKs and PtMPKs were differentially expressed across this developmental series.

Conclusion

This analysis provides a complete survey of MAPKK and MAPK gene expression profiles in poplar, a large woody perennial plant, and thus complements the extensive expression profiling data available for the herbaceous annual Arabidopsis thaliana. The poplar genome is marked by extensive segmental and chromosomal duplications, and within both kinase families, some recently duplicated paralogous gene pairs often display markedly different patterns of expression, consistent with the rapid evolution of specialized protein functions in this highly adaptive species.
Optimization of a large-scale gene disruption protocol in Dictyostelium and analysis of conserved genes of unknown function
Authors: Torija Patricia , Robles Alicia , Escalante Ricardo
Published: August 2006

Background

Development of the post-genomic age in Dictyostelium will require the existence of rapid and reliable methods to disrupt genes that would allow the analysis of entire gene families and perhaps the possibility to undertake the complete knock-out analysis of all the protein-coding genes present in Dictyostelium genome.

Results

Here we present an optimized protocol based on the previously described construction of gene disruption vectors by in vitro transposition. Our method allows a rapid selection of the construct by a simple PCR approach and subsequent sequencing. Disruption constructs were amplified by PCR and the products were directly transformed in Dictyostelium cells. The selection of homologous recombination events was also performed by PCR. We have constructed 41 disruption vectors to target genes of unknown function, highly conserved between Dictyostelium and human, but absent from the genomes of S. cerevisiae and S. pombe. 28 genes were successfully disrupted.

Conclusion

This is the first step towards the understanding of the function of these conserved genes and exemplifies the easiness to undertake large-scale disruption analysis in Dictyostelium.
Heritability and major gene effects on left ventricular mass in the Chinese population: a family study
Authors: Chien Kuo-Liong , Hsu Hsiu-Ching , Su Ta-Chen , Chen Ming-Fong , Lee Yuan-Teh
Published: August 2006

Background

Genetic components controlling for echocardiographically determined left ventricular (LV) mass are still unclear in the Chinese population.

Methods

We conducted a family study from the Chin-San community, Taiwan, and a total of 368 families, 1145 subjects, were recruited to undergo echocardiography to measure LV mass. Commingling analysis, familial correlation, and complex segregation analysis were applied to detect component distributions and the mode of inheritance.

Results

The two-component distribution model was the best-fitting model to describe the distribution of LV mass. The highest familial correlation coefficients were mother-son (0.379,P< .0001) and father-son (0.356,P< .0001). Genetic heritability (h2) of LV mass was estimated as 0.268 ± 0.061 (P< .0001); it decreased to 0.153 ± 0.052 (P= .0009) after systolic blood pressure adjustment. Major gene effects with polygenic components were the best-fitting model to explain the inheritance mode of LV mass. The estimated allele frequency of the gene was 0.089.

Conclusion

There were significant familial correlations, heritability and a major gene effect on LV mass in the population-based families.
Syndecan-1 mediates internalization of apoE-VLDL through a low density lipoprotein receptor-related protein (LRP)-independent, non-clathrin-mediated pathway
Authors: Wilsie Larissa C , Gonzales Amanda M , Orlando Robert A
Published: August 2006

Background

Triacylglyerol-rich very low density lipoprotein (VLDL) particles are the primary carriers of fatty acids in the circulation and as such serve as a rich energy source for peripheral tissues. Receptor-mediated uptake of these particles is dependent upon prior association with apolipoprotein E (apoE-VLDL) and is brought about by cell surface heparan sulfate proteoglycans (HSPG) in some cell types and by the low density lipoprotein receptor-related protein (LRP) in others. Although LRP's role in apoE-VLDL uptake has been well studied, the identity of the HSPG family member that mediates apoE-VLDL uptake has not been established. We investigated if syndecan-1 (Syn-1), a transmembrane cell surface HSPG, is able to mediate the internalization of apoE-VLDL and examined the relationship between Syn-1 and LRP toward apoE-VLDL uptake. For this study, we used a human fibroblast cell line (GM00701) that expresses large amounts of LRP, but possesses no LDL receptor activity to eliminate its contributions toward apoE-VLDL uptake.

Results

Although LRP in these cells is fully active as established by substantial α2macroglobulin binding and internalization, uptake of apoE-VLDL is absent. Expression of human Syn-1 cDNA restored apoE-VLDL binding and uptake by these cells. Competition for this uptake with an LRP ligand-binding antagonist had little or no effect, whereas co-incubation with heparin abolished apoE-VLDL internalization. Depleting Syn-1 expressing cells of K+, to block clathrin-mediated endocytosis, showed no inhibition of Syn-1 internalization of apoE-VLDL. By contrast, treatment of cells with nystatin to inhibit lipid raft function, prevented the uptake of apoE-VLDL by Syn-1.

Conclusion

These data demonstrate that Syn-1 is able to mediate apoE-VLDL uptake in human fibroblasts with little or no contribution from LRP and that the endocytic path taken by Syn-1 is clathrin-independent and relies upon lipid raft function. These data are consistent with previous studies demonstrating Syn-1 association with lipid raft domains.
Learning to perform a new movement with robotic assistance: comparison of haptic guidance and visual demonstration
Authors: Liu J , Cramer S C , Reinkensmeyer DJ
Published: August 2006

Background

Mechanical guidance with a robotic device is a candidate technique for teaching people desired movement patterns during motor rehabilitation, surgery, and sports training, but it is unclear how effective this approach is as compared to visual demonstration alone. Further, little is known about motor learning and retention involved with either robot-mediated mechanical guidance or visual demonstration alone.

Methods

Healthy subjects (n = 20) attempted to reproduce a novel three-dimensional path after practicing it with mechanical guidance from a robot. Subjects viewed their arm as the robot guided it, so this "haptic guidance" training condition provided both somatosensory and visual input. Learning was compared to reproducing the movement following only visual observation of the robot moving along the path, with the hand in the lap (the "visual demonstration" training condition). Retention was assessed periodically by instructing the subjects to reproduce the path without robotic demonstration.

Results

Subjects improved in ability to reproduce the path following practice in the haptic guidance or visual demonstration training conditions, as evidenced by a 30–40% decrease in spatial error across 126 movement attempts in each condition. Performance gains were not significantly different between the two techniques, but there was a nearly significant trend for the visual demonstration condition to be better than the haptic guidance condition (p = 0.09). The 95% confidence interval of the mean difference between the techniques was at most 25% of the absolute error in the last cycle. When asked to reproduce the path repeatedly following either training condition, the subjects' performance degraded significantly over the course of a few trials. The tracing errors were not random, but instead were consistent with a systematic evolution toward another path, as if being drawn to an "attractor path".

Conclusion

These results indicate that both forms of robotic demonstration can improve short-term performance of a novel desired path. The availability of both haptic and visual input during the haptic guidance condition did not significantly improve performance compared to visual input alone in the visual demonstration condition. Further, the motor system is inclined to repeat its previous mistakes following just a few movements without robotic demonstration, but these systematic errors can be reduced with periodic training.
Analysis of vaccinia virus temperature-sensitive I7L mutants reveals two potential functional domains
Authors: Moerdyk Megan J , Byrd Chelsea M , Hruby Dennis E
Published: August 2006

As an approach to initiating a structure-function analysis of the vaccinia virus I7L core protein proteinase, a collection of conditional-lethal mutants in which the mutation had been mapped to the I7L locus were subjected to genomic sequencing and phenotypic analyses. Mutations in six vaccinia virus I7L temperature sensitive mutants fall into two groups: changes at three positions at the N-terminal end between amino acids 29 and 37 and two different substitutions at amino acid 344, near the catalytic domain. Regardless of the position of the mutation, mutants at the non-permissive temperature failed to cleave core protein precursors and had their development arrested prior to core condensation. Thus it appears that the two clusters of mutations may affect two different functional domains required for proteinase activity.
Human nasal rhinosporidiosis: an Italian case report
Authors: Morelli Luca , Polce Mario , Piscioli Francesco , Del Nonno Franca , Covello Renato , Brenna Alessia , Cione Antonio , Licci Stefano
Published: August 2006

Background

Rhinosporidiosis is a disease affecting primarily the mucosa of nose, conjunctiva and urethra. It is endemic in some Asiatic regions, affecting people of any age and sex. Its manifestation is a polypoid mass growing inside the affected cavity and the only treatment is surgical excision.Rhinosporidium seeberiis the aetiological agent. Many discussions arouse regarding the taxonomic classification of the microorganism, recent studies established it is an aquatic protistan parasite. The lesion may recur and sometimes cause osteolytic bone lesions. In endemic areas it is not easy to establish if recurrent lesions are due to relapse or reinfection.

Case presentation

A 26-year-old male patient from India, resident in Italy since 2005, presented in March 2006 with a history of nasal obstruction of three months duration. Physical examination showed an erythematous, papillomatous mass, 3 cm in diameter, obstructing the right nasal cavity. A microscopic diagnosis of rhinosporidiosis was made. Few Italian human cases of this disease have been previously reported in the literature.

Conclusion

Rhinosporidiosis is a condition which both clinicians and pathologists should keep in mind when managing patients from endemic countries with nasal masses. Moreover, it is very interesting in such cases to follow the clinical course: an eventual recurrence of the lesion in our patient would mean a true relapse, excluding the possibility of a reinfection, more probable in the endemic areas.
Redundant and unique regulation of activated mouse B lymphocytes by IL-4 and IL-21
Authors: Jin Haoli , Malek Thomas R
Published: August 2006

IL-21 distinctively regulates B cell growth and death, and it redundantly functions with IL-4 for IgG production. B cells likely encounter IL-4 and IL-21 in vivo, as both are secreted by activated T cells. Therefore, the action of both these cytokines was investigated during activation of B cells. IL-21 or the combination of IL-4 and IL-21 inhibited proliferation by purified mouse B cells to LPS or CpG DNA, whereas these cytokines enhanced proliferation after engaging the BCR or CD40. Although B cell subsets expressed somewhat varied levels of the IL-21 receptor, LPS-stimulated follicular and marginal B cell subsets were also dominantly susceptible to IL-21-induced growth arrest and cell death. After activation of B cells with CD40 and LPS, IL-4 and IL-21 distinctively regulated the expression of CD23, CD44, and CD138, and they cooperatively promoted IgG1 class-switching and synthesis. These findings support a model in which the presence of IL-4 and IL-21 inhibits B cells activated by polyclonal innate signals, and they promote B cell expansion and differentiation during T cell-dependent antibody responses, although the individual responses to IL-4 and IL-21 do not always overlap.
Regulation of the tonsil cytokine milieu favors HIV susceptibility
Authors: Moutsopoulos Niki M , Vázquez Nancy , Greenwell-Wild Teresa , Ecevit Ismail , Horn Judith , Orenstein Jan , Wahl Sharon M
Published: August 2006

Mucosal associated lymphoid tissues are major targets of HIV during early infection and disease progression but can also provide a viral safe haven during highly active antiretroviral therapy. Among these tissues, the tonsils remain enigmatic regarding their status as primary and/or secondary sites of retroviral infection. To dissect the mechanisms underlying susceptibility to HIV in this compartment, isolated tonsil cells were studied for phenotypic and functional characteristics, which may account for their permissiveness to infection. For this, tonsil cells and PBMC were infected in parallel with HIV, and viral replication was monitored by p24 ELISA. Our results demonstrate that unstimulated tonsil cells were more readily infected than PBMC with HIV. Phenotypic characterization of the tonsil cells revealed heterogeneous lymphoid populations but with increased expression of early activation markers and the viral co-receptor CXCR4, relative to PBMC, all of which may contribute to viral susceptibility. Furthermore, the cytokine microenvironment appeared to be key in facilitating HIV infection and tonsil-secreted products enhanced HIV infection in PBMC. Of the cytokines detected in the tonsil supernatants, TH2 cytokines, particularly IL-4, promoted HIV infection and replication. Interestingly, this TH2 profile appeared to dominate, even in the presence of the TH1 cytokine IFNγ and the anti-viral factor IFNα, likely due to the enhanced expression of suppressor of cytokine signaling (SOCS) proteins, which may disengage IFN signaling. These and other local environmental factors may render tonsil cells increasingly susceptible to HIV infection.
Mycobacterium avium-induced SOCS contributes to resistance to IFN-γ mediated mycobactericidal activity in human macrophages
Authors: Vázquez Nancy , Greenwell-Wild Teresa , Rekka Sofia , Orenstein Jan M , Wahl Sharon M
Published: August 2006

Mycobacterium avium is an opportunistic pathogen that commonly infects individuals colonized with HIV-1, although it is less frequent in the post-HAART era. These microorganisms invade macrophages after interacting with TLR2 and/or CD14 co-receptors, but signaling pathways promoting survival in macrophages are not well defined. Although IFN-γ plays an important role in protective immunity against bacterial infections, IFN-γ responses are compromised in AIDS patients and evidence suggests that exogenous IFN-γ is inadequate to clear the mycobacteria. To determine the mechanism by which M. avium survives intracellularly, even in the presence of IFN-γ, we studied the effect of mycobacteria infection in macrophages during early IFN-γ signaling events. M. avium infected cells exhibited a reduced response to IFN-γ, with suppressed phosphorylation of STAT-1 compared with uninfected cells. Interaction of M. avium with macrophage receptors increased gene expression of the suppressors of cytokine signaling (SOCS) to diminish IFN responsiveness. Specifically, we observed an increase in mRNA for both SOCS-3 and SOCS-1, which correlates with elevated levels of SOCS protein and positive immunostaining in M. avium/HIV-1 co-infected tissues. We also linked the p38 MAPK signaling pathway to mycobacterial-induced SOCS gene transcription. The induction of SOCS may be part of the strategy that allows the invader to render the macrophages unresponsive to IFN-γ, which otherwise promotes clearance of the infection. Our data provide new insights into the manipulation of the host response by this opportunistic pathogen and the potential for modulating SOCS to influence the outcome of M. avium infection in immunocompromised hosts.
Escitalopram and paroxetine in the treatment of generalised
anxiety disorder
Authors: Baldwin David S. , Huusom Anna Karina Trap , Mæhlum Eli
Published: August 2006

Background

It is uncertain whether higher doses of selective serotonin reuptake
inhibitors have greater efficacy in generalised anxiety disorder.

Aims

To assess the efficacy of different doses of escitalopram in generalised
anxiety disorder.

Method

Randomised, double-blind, placebo-controlled, fixed-dose, parallel-group,
12-week study, with 681 patients: placebo (n=139);
escitalopram, 5 mg/day, (n=134); 10 mg/day
(n=136); 20 mg/day (n=133);
paroxetine, 20 mg/day (n=139).

Results

Mean change in the primary efficacy measure was greater with escitalopram
10 and 20 mg than with placebo; 10 mg was more efficacious than
paroxetine. Paroxetine was superior to placebo on some secondary
measures, at sometime points. Compared with placebo, more patients
withdrew because of adverse events with escitalopram 20 mg and
paroxetine.

Conclusions

Escitalopram was efficacious in generalised anxiety disorder, 20 was not
significantly superior to 10 mg/day Escitalopram 10 mg was more
efficacious than paroxetine.
Attention to the eyes and fear-recognition deficits in child
psychopathy
Authors: Dadds Mark R. , Perry Yael , Hawes David J. , Merz Sabine , Riddell Alison C. , Haines Damien J. , Solak Emel , Abeygunawardane Amali I.
Published: August 2006

The ability to recognise fear is impaired in people with damage to the
amygdala and, interestingly, in adult psychopathy. Here we confirm that
deficits in recognising fear exist in children with psychopathic traits. We
show for the first time that, as with patients with amygdala damage, this
deficit can be temporarily corrected by simply asking them to focus on the
eyes of other people. These data support models of psychopathy that
emphasise specific dysfunction of the amygdala and suggest an innovative
approach for intervening early in the development of psychopathy.
Psychiatry at night: experience of the senior house officer
Authors: Mason Jules , Irani Tina , Fountoulaki Garyfallia , Warwick Sylvia , da Roza Davis Jane , Sudbury Peter
Published: August 2006

Aims and Method

We gathered detailed prospective data for first on-call activity of senior house officers (SHOs) in order to help plan changes in service provision so that SHOs in psychiatry complied with the Working Time Directive and to determine whether service changes affected training experience while on call. The incumbent SHOs designed a simple form to monitor on-call activity in West Berkshire.

Results

Admissions and assessments make up a quarter of calls but three-quarters of the work. An overnight crisis service reduced the number of assessments made by SHOs out of hours by 68%. Screening of calls by a senior nurse reduced the number of calls about in-patients by 60% on weekday nights. Between 73% and 100% of calls about in-patients after midnight were for assessment of patients in seclusion and rapid tranquillisation.

Clinical Implications

This survey helped to plan service delivery and to monitor the training of SHOs during on call. Screening of calls by a senior nurse, alternatives to seclusion and nurse-led prescribing for rapid tranquillisation would have the largest impact on the work generated by in-patients. The overnight crisis service reduced the number of assessments, but might have an adverse impact on training.
Man1, an inner nuclear membrane protein, regulates vascular remodeling by modulating transforming growth factor β signaling
Authors: Ishimura Akihiko , Ng Jennifer K. , Taira Masanori , Young Stephen G. , Osada Shin-Ichi
Published: August 2006

A growing number of integral inner nuclear membrane (INM) proteins have been implicated in diverse cellular functions. Man1, an INM protein, has recently been shown to regulate transforming growth factor (Tgf) βsuperfamily signaling by interacting with receptor-associated Smads. However,the in vivo roles of Man1 have not been fully characterized. Here, we show that Man1 regulates vascular remodeling by analyzing Man1-deficient embryos lacking the Smad interacting domain. Man1-deficient embryos die at midgestation because of defects in embryonic vasculature; the primary capillary plexus forms, but subsequent remodeling is perturbed. It has been proposed that the angiogenesis process is divided into two balanced phases,the activation and resolution/maturation phases, both of which are regulated by Tgfβ1. We have demonstrated, in Man1-deficient embryos, the expression of Tgfb1 is upregulated and Smad2/3 signaling is abnormally activated, resulting in increased extracellular matrix deposition,a hallmark of the resolution phase of angiogenesis. We have also showed that the recruitment of mural cells to the vascular wall is severely disturbed in mutants, which may lead to disruption of intercellular communication between endothelial and mural cells required for proper vascular remodeling. These results have revealed a novel role for Man1 in angiogenesis and provide the first evidence that vascular remodeling can be regulated at the INM through the interaction between Man1 and Smads.
Electron-Optical Study of Smectites
Authors: Mering J. , Oberlin A.
Published: August 2006

The combined use of electron microscopy and of selected area diffraction (SAD) has been applied to the study of montmorillonites from Wyoming and from Camp-Berteaux, of nontronite, and of hectorite. The study shows that only the elementary layers of the Wyoming montmorillonite and of the nontronite are single two-dimensional crystals. The elementary layers of the montmorillonite from Camp-Berteaux are formed by edge-to-edge associations of very small elements with mutual orientations of about 60° or multiples of 60°. The layers of hectorite are formed by edge-to-edge association of laths with fluctuations of orientation of the order of 10° rotation around adjoining edges. The SAD patterns of Wyoming montmorillonite show that the single layer plane symmetry group of this mineral is c1m1; nontronite layers belong to the symmetry group c2mm. The study of thick particles shows that in turbostratic smectites the layers are stacked with mutual rotations around the perpendicular to their plane. This mode of stacking explains the absence of hkl reflections. High resolution diffraction (HRD) patterns obtained with sample inclined to the electron beam show that only the structure of hectorite approaches the ideal model; nontronite and montmorillonite exhibit appreciable distortions with respect to the ideal model. HRD diagrams provide precise information for the refinement of the crystal structures of smectites
Electron Diffraction and Micrographic Study of the High-Temperature Changes in Illite and Montmorillonite Under Continuous Heating Conditions
Authors: Furlong Robert B.
Published: August 2006

Transmission and diffraction electron micrographs were made of illite and montmorillonite to study the changes that take place as the clays were heated continuously to 1200°C.

In both of the clay minerals studied, expulsion of a highly fluid material occurred subsequent to dehydroxylation and prior to the development of the first-formed high temperature phases. It was hypothesized that this material represented the expulsion of constituents in the clay in excess of those needed for the formation of the first high-temperature phase. Electron diffraction indicates that the high-temperature phases that formed all developed with some preferential orientation, and were strongly influenced in their development by the structure of the original clay.
Sorption of Water at High Temperatures on Certain Clay Mineral Surfaces. Correlation with Lattice Fluoride
Authors: Granquist W. T. , Kennedy J. V.
Published: August 2006

The sorption of water, at 490°C and ca. 23–24 torr, on clay mineral surfaces has been studied using thermogravimetry and infrared absorption spectroscopy. Results from a series of synthetic hectorites, with and without lattice fluoride (see Granquist and Pollack, 1960), point to the presence of F− in the clay lattice as an important condition for the sorption. Similar studies on natural hectorite and montmorillonite, synthetic interstratified montmorillonite/mica with and without fluoride, and Al2F6 support this interpretation of the role of the F− ion and show that dioctahedral 2:1 clays sorb more water at 490°C than do trioctahedral 2:1 clays. The infrared spectra demonstrate that the sorbed water is for the most part hydrogen-bonded to the surface.
Infrared Absorption Spectrometry in Clay Studies
Authors: Farmer V. C. , Russell J. D.
Published: August 2006

The relationships between spectrum and structure in layer-silicates are reviewed, and applied in the study of structural changes occurring during the heating of montmorillonites up to dehydroxylation, and their subsequent rehydroxylation. Information given by infrared spectroscopy on the binding of water in expanding layer silicates is presented, and the physical and chemical processes associated with entry of basic, neutral and acidic molecules into the interlayer space of these minerals are illustrated for ammonia, ethylamine, pyridine, nitrobenzene, and benzoic acid. Problems associated with the study of soil clays, which are often complex mixtures including poorly ordered and amorphous constituents, frequently firmly combined with organic matter, are discussed.

New evidence is presented concerning the environment of the two types of hydroxyl group in beidellite. The thermal stabilities of NH4+ and lattice OH in montmorillonite and beidellite, and the properties of their dehydroxylates, are contrasted. The nature of the collapsed phase formed in Li-, Mg-, and NH4-montmorillonite at 300–500°C is discussed. The presence of weak hydrogen bonds between lattice oxygens and interlayer water is established, although it is shown that the strength of hydrogen bonds formed between NH4+ and lattice oxygens is dependent on the sites of substitution in the layer lattice.
Influence of Exchange Ions on the b-Dimensions of Dioctahedral Vermiculite
Authors: Leonard R. A. , Weed S. B.
Published: August 2006

The 1–5 μ size fractions of different ground muscovites were treated for a 30-day period for K+ removal with a pH 7.5 solution containing sodium tetraphenylboron. The initial K+ contents ranged from 211 to 219 me/100 g. After the extraction period, the final K contents ranged from 21 to 37 me/100 g. The apparent structural charge on the expanded material decreased to values ranging from 156 to 184 me/100 g, which are within the charge range for natural vermiculites. The b-dimensions of these laboratory-produced vermiculites were found to vary with the exchange ion and with the hydration state of the ion. For hydrated samples, saturation with Cs+, Li+, and Mg2+ ions increased the observed b-dimension in comparison to that of the corresponding parent mica, whereas saturation with Sr2+ and La3+ ions had little effect on b. After dehydration at 350°C, only Cs+-saturated samples had a b-dimension greater than that of the parent mica. The observed b-dimension for the dehydrated samples was found to be a direct function of the crystal radius of the interlayer ion. Apparently, as the ion dehydrates, the surface oxygen triads rotate until some of the oxygens “lock” onto the ion, limiting the minimum b-dimension. Before dehydration, however, the water of hydration in the interlayer region is evidently held with sufficient energy to limit rotations of the oxygen triads that give rise to a decrease in b. When Li+ and Mg2+ ions occupy the interlayer region, their water network apparently even produces a slight increase in the observed b-dimension.
Clay Minerals and Oceanic Evolution
Authors: Harriss Robert C.
Published: August 2006

A review of mineralogical and geochemical studies on Recent sediments indicates that the clay fraction of marine sediments is not in isotopic or chemical equilibrium with the oceanic reservoir and will not reflect the chemical environment of deposition. Consideration of the sedimentary geochemistry of the alkali metals suggests that fractionation of these elements, which may be one of the major features of the chemical evolution of ocean water, occurs in the terrestrial weathering environment during the formation of clay minerals and in the subsurface environment during clay mineral diagenesis. It is proposed that during the initial stages of oceanic development the Na/K ratio of ocean water was adjusted to a value of forty to fifty by the extensive diagenesis of the existing natural water. With an increase in oceanic volume and a major change in the hydrologic cycling of natural waters the chemical evolution of alkali metals in ocean water has now become primarily controlled by mixing with continental drainage water.
Pressure Effects on Conductance of Frozen Montmorillonite Suspensions
Authors: Hoekstra P. , Keune R.
Published: August 2006

The influence of pressure on the conductance of frozen montmorillonite suspensions was measured in the temperature range from 0°C to − 12°C on Na- and Ca-saturated samples. Pressures invariably increase the conductance of frozen suspensions. The change in conductance with pressure is postulated to be due to pressure melting of the ice in the frozen suspension. From swelling pressure data the increase in unfrozen water with pressure at constant temperature is calculated and shown to be consistent with the effect of pressure on conductance.
Interlamellar Reactions of Tetracalcium Aluminate Hydrates with Water and Organic Compounds
Authors: Dosch Werner
Published: August 2006

Tetracalcium aluminate hydrates are the first example of layer-structured crystals containing neutral sheets, which are highly capable of interlamellar adsorption of water and neutral organic compounds. In this respect tetracalcium aluminate hydrates present new aspects of the phenomenon of swelling, and bring about the challenge of comparison with the frequently examined clay-organic compounds.

This report is concerned with the probable monolayer structure of tetracalcium aluminate hydrate which forms five hydration stages. A summary concerning configuration and properties of adsorption complexes with approximately 500 selected organic substances follows. As far as these substances are homologues of certain functional groups, the change of basal distances depends upon the number of C-atoms.

Aside from pure organic compounds, one can also form interlamellar complexes with a mixture of such compounds. Here again a rule of proportion between the number of C-atoms and the basal distance becomes evident. Another variant is the mixed interlamellar complexing of water with organic compounds and the re- and de-hydration reactions of these products.

The report discusses the bonding conditions of various functional organic groups to the inorganic lattice. Furthermore, a series of homopolar organic derivatives of the tetracalcium aluminate hydrates can be produced. As is known, the existence of such compounds of clay minerals is a subject of dispute.
The Influence of Alkaline Solutions on the Alteration of the Clay Minerals
Authors: Ferrell Ray E. , Grim Ralph E.
Published: August 2006

The influence of an alkaline environment on clay mineral alterations in the laboratory was studied by means of one-dimensional structural analyses. Samples of illite, illite-mixed-layered material, kaolinite, and two montmorillonites (smectites) were treated with NH4OH solutions of pH 8.5, 9.5, 10.5, 11.5, and 12.5 for 6, 12, 24, 48, 72, and 96 hr at 60°C.

One-dimensional structural analyses of the treated samples are quite demonstrative in determining the effects of laboratory-controlled degradation. These analyses show an oscillatory change in the population of the tetrahedral and octahedral structural sites which is consistent with a core-rind structural concept of the clay minerals. Leaching of clay minerals takes place by the alternate growth of the rind and destruction of this frayed edge by agitation. The extent to which the rind develops is controlled by particle size, variability of chemical composition, and the amount of agitation. The order of increasing development of the frayed edge is; kaolinite, illite, illite-mixed-layered material, and then the montmorillonite.
Surface Properties and Texture of Chrysotiles
Authors: Fripiat J. J. , della Faille M.
Published: August 2006

Nitrogen surface areas and pore-size distribution curves of various chrysotiles have been measured using a continuous flow method. A model founded on a hexagonal close packing of fibers has been adjusted to fit the frequency distribution curve of the fiber outside diameters obtained from electron micrographs. From this model, theoretical distribution functions of the surface area versus the pore diameter were computed and compared to the experimental data. For one fiber only (i.e. Coalinga chrysotile), the good agreement between the computed and experimental data allows one to conclude that the external pores (between the fibers) and the internal pores (within the fibers) are free from any amorphous material. For the other studied chrysotiles, the degree of filling of the pore system by amorphous materials was always higher than 50%. Under these conditions, hydration water cannot be removed unless the samples are pretreated in the 300°–400°C temperature range. On the contrary, water is driven off from the “clean” Coalinga fibers at temperatures lower than 100°C. Surface area measurements derived from water-adsorption isotherms correspond to those obtained with nitrogen after the hydration water has been removed.