bluuebunny/crossref_metadata_2025 huggingface dataset:
Hybrid Message-Passing and Shared-Memory Programming in a Molecular Dynamics Application On Multicore Clusters
Authors: Chorley Martin J. , Walker David W. , Guest Martyn F.
Published: June 2009

Hybrid programming, whereby shared-memory and message-passing programming techniques are combined within a single parallel application, has often been discussed as a method for increasing code performance on clusters of symmetric multiprocessors (SMPs). This paper examines whether the hybrid model brings any performance benefits for clusters based on multicore processors. A molecular dynamics application has been parallelized using both MPI and hybrid MPI/OpenMP programming models. The performance of this application has been examined on two high-end multicore clusters using both Infiniband and Gigabit Ethernet interconnects. The hybrid model has been found to perform well on the higher-latency Gigabit Ethernet connection, but offers no performance benefit on low-latency Infiniband interconnects. The changes in performance are attributed to the differing communication profiles of the hybrid and MPI codes.
Hierarchical Task-Based Programming With StarSs
Authors: Planas Judit , Badia Rosa M. , Ayguadé Eduard , Labarta Jesus
Published: June 2009

Programming models for multicore and many-core systems are listed as one of the main challenges in the near future for computing research. These programming models should be able to exploit the underlying platform, but also should have good programmability to enable programmer productivity. With respect to the heterogeneity and hierarchy of the underlying platforms, the programming models should take them into account but they should also enable the programmer to be unaware of the complexity of the hardware. In this paper we present an extension of the StarSs syntax to support task hierarchy. A motivation for such a hierarchical approach is presented through experimentation with CellSs. A prototype implementation of such a hierarchical task-based programming model that combines a first task level with SMPSs and a second task level with CellSs is presented. The preliminary results obtained when executing a matrix multiplication and a Cholesky factorization show the viability and potential of the approach and the current issues raised.
Gathering Points: Blood Donation and the Scenography of `National Integration' in India
Authors: Copeman Jacob
Published: June 2009

This article explores nationalist interpretations of blood donation activity, examining how some Indians read integrative messages into the practical procedures through which blood is donated and distributed. The first post-Independence Prime Minister of India, Jawaharlal Nehru, proclaimed the need for `national integration' as a bulwark against a myriad of linguistic, caste and ethnic agitations that threatened to disrupt the unity of the newly formed nation-state. This article shows that a striking manifestation of the Nehruvian ideology of national integration possesses a compelling presence in the Indian blood donation milieu. Scholars of India have long been preoccupied with documenting attempts by the Hindu right to redefine the nation in exclusively Hindu, anti-Nehruvian terms. Questioning the prevailing assumption that the only thing that counts politically in India today is the debunking or overriding of Nehruvian ideals of the secular inclusive nation, this article rehabilitates Nehruvianism as an important ethnographic subject. In so doing it demonstrates the roles of anonymity, enumeration and an array of technical and imaginative gathering points in the formation of the `difference-traversing gift'. The article also highlights ways in which technology may be employed for the imagining of social diversity.
`Please Give a Drop of Blood': Blood Donation, Conflict and the Haemato-Global Assemblage in Contemporary Sri Lanka
Authors: Simpson Bob
Published: June 2009

Blood is now essential for a widening repertoire of therapies and with this comes new forms of regulation and governmentality focused on the collection, use and storage of blood. Here blood begins to lose its `natural' underpinnings as it is drawn into the realms of the synthetic and the scientific. However, this change in theoretical lens obscures the ways that, in practice, constructing a `modern' blood compatible with the demands of the global biopolis is elided with prosaic uses of blood donation that convey powerful cultural and political messages at the local level. In a setting where, in recent decades, war, violence and the threat of social disintegration have been woven into the project of development and modernity, attempts at an alignment, or what might be characterized as the haemato-global assemblage, reveal significant tensions. The main one that I explore in this article is that between the aspiration to create an international blood donation service in which ideas of citizens and national solidarity are articulated through freely and altruistically gifted blood on the one hand and, on the other, the more potent and symbolically loaded ideas of blood, which come to the fore when connection and identity are threatened.
Vital Publics of Pure Blood
Authors: Strong Thomas
Published: June 2009

Blood supplies have become indexes of national security and the public good. While blood shortages can provoke anxiety, controversies continue to erupt in many countries over proper donor screening, especially with reference to HIV. This article sketches these dynamics in several global settings, focusing especially on activist efforts by gay men to reform exclusionary blood donor guidelines. The contours of the debate recall familiar conflicts between the putative demands of public health and the rights of individuals in the era of AIDS. However, if gay activists marshal a discourse of individual rights vis-a-vis forms of institutional exclusion, they also seek a broader shift in social and cultural understandings of gay identity. To capture this complex interplay of citizenship and sociality, risk and responsibility, the article introduces the notion of `vital publics' to refer to the peculiar associational form represented by blood supplies. Vital publics are kinds of embodied association elicited through the generalized exchange of body — in this case, blood. Hailed to `give life' by the jargon of the pervasive social marketing of varied blood service systems, activists seek to contribute to the life of the `vital public' that transfusion medicine calls into being.
Alleviative Bleeding: Bloodletting, Menstruation and the Politics of Ignorance in a Brazilian Blood Donation Centre
Authors: Sanabria Emilia
Published: June 2009

This article focuses on blood donation as a form of bloodletting in a context where donation is commonly seen to alleviate the symptoms of `thick blood'. It deals with the gendered aspects of blood donation, and the parallels drawn between donating blood and menstruating. Women are seen not to need to donate blood as much as men, who, in the absence of menstruation, are more prone to thick blood and require a means to expunge the ensuing excess. While blood donation professionals strive to reconstruct donation as a selfless and ungendered act, counterposing the `facts' of arterial blood circulation to local blood-lore and beliefs, lay understandings challenge this construction in the use they make of blood donation centres or by reiterating the personalistic and gendered dimensions of donation. The article explores cases of patients who use hormonal contraceptives which suppress menstruation and express concerns over the resulting accumulation of blood in the body. It considers how blood donation is adopted by some women as a means of dispelling both the perceived inconveniences of menstrual bleeding and its swelling effects. Such literalized engagements with medical technologies reveal a conception of the body as a permeable, malleable and recipient-like enclosure. These views are often characterized as `ignorance' by medical practitioners, where ignorance is seen to derive not only from the absence of knowledge, but from the presence of the wrong kind of knowledge.
Sociodemographic variations in communication on sexuality and HIV/AIDS with parents, family members and teachers among in-school adolescents: A multi-site study in Tanzania and South Africa
Authors: Namisi Francis Sande , Flisher Alan J. , Overland Simon , Bastien Sheri , Onya Hans , Kaaya Sylvia , Aarø Leif Edvard
Published: June 2009

Aims: To identify with whom in-school adolescents preferred to communicate about sexuality, and to study adolescents' communication on HIV/AIDS, abstinence and condoms with parents/guardians, other adult family members, and teachers. Methods: Data were obtained from a baseline questionnaire survey carried out in South Africa (Cape Town and Mankweng) and Tanzania (Dar es Salaam) in early 2004. We analysed data for 14,944 adolescents from 80 randomly selected schools. The mean ages were as follows: Cape Town, 13.38 years (standard deviation (SD) 1.15); Mankweng, 13.94 years (SD 1.35); and Dar es Salaam, 12.94 years (SD 1.31). Results: Adolescent females preferred to receive sexuality information from their mothers, while among males there was a higher preference for fathers in two sites. Thirty-seven per cent, 41% and 29% reported never or hardly ever communicating about sexuality with parents, other adult family members, and teachers, respectively. ``Silence'' was more prevalent in Dar es Salaam than in the other two sites. The odds of ``never or hardly ever'' communicating with parents in Dar es Salaam were higher among girls than among boys (p < 0.01). For the two South African sites, boys had significantly higher odds of experiencing silence than did girls (both p < 0.001), and socioeconomic status was positively associated with parent—adolescent sexuality communication. In the logistic regression models, explained variation (Nagelkerke's R2) across sites ranged from 0.013 to 0.032. Conclusions: In all three sites, a substantial proportion of adolescents reported not communicating with their parents about HIV/AIDS, abstinence, or condoms. The low proportion of explained variation in sexuality communication implies that silence is common across sociodemographic subgroups.
Social outcome expectations regarding delayed sexual debut among adolescents in Mankweng, South Africa
Authors: Onya Hans , Aarø Leif Edvard , Madu Sylvester N.
Published: June 2009

Aims: To describe outcome expectations related to delayed sexual transition, to examine the dimensionality and internal consistency of such expectations, and to examine variations in social outcome expectations across subgroups defined by demographic variables, indicators of socioeconomic status and predictors related to school and educational ambitions. Methods: Data stem from a survey among school students (grades 8—12) in Mankweng, Limpopo, South Africa (n = 5,697). A five-item scale of outcome expectations was analysed with frequency and percentage distributions, principal components analysis, Cronbach's alpha, and general linear model procedures, while controlling for the cluster nature of the sample (school classes). Results: Four items formed a component on negative social outcome expectations (SOE) related to delayed sexual transition. The internal consistency of the SOE scale proved adequate. Negative SOEs increased with age, were higher among males than females, and decreased with father's education. Negative expectations were high among students who had repeated a school year due to failing exams, among those who did not expect to complete schooling up until grade 12, and among students who reported absence from school. Discussion: Negative social outcome expectations related to delayed sexual transition have elsewhere been shown to be important in predicting actual transition. The present study shows that there is considerable room for positive changes in such expectations. Negative SOEs may contribute to explaining demographic and socioeconomic variations in sexual transition. Conclusions: Social outcome expectations deserve more attention in programmes aimed at promoting sexual- and reproductive health.
The application of Intervention Mapping in developing and implementing school-based sexuality and HIV/AIDS education in a developing country context: The case of Tanzania
Authors: Mkumbo Kitila , Schaalma Herman , Kaaya Sylvia , Leerlooijer Joanne , Mbwambo Jessie , Kilonzo Gad
Published: June 2009

Aims: Effective sexuality and HIV/AIDS education programmes are needed to protect young people against HIV/AIDS and teenage pregnancy in Tanzania and other Sub-Saharan African countries. Using a theory- and evidence-based approach and adapting the programmes to local contexts, increases the effectiveness of these programmes. This paper describes and discusses the challenges and opportunities concerning the application of Intervention Mapping (IM) in the development and implementation of a sexuality and HIV/AIDS education programme targeting young people aged 12—14 in Tanzania. Methods: The sexuality and HIV/AIDS programme was designed in a participatory manner, involving researchers, curriculum developers and teachers' and students' panels. The programme comprised five lessons, organized around 23 sessions with the aim of delaying the onset of sexual intercourse and increase correct and consistent condom use among young people. The programme was delivered by trained teachers as an extracurricular lesson. Conclusions: The IM protocol facilitated the development of a comprehensive sexuality and HIV/AIDS education programme relevant and appropriate to the social cultural context and the needs of learners in Tanzania. The paper has demonstrated that, although the IM was developed in the Western context, it can be used in a flexible manner to adapt to local contexts such as those in Sub-Saharan Africa.
Development and test—retest reliability of a research instrument designed to evaluate school-based HIV/AIDS interventions in South Africa and Tanzania
Authors: Mũkoma Wanjirũ , Flisher Alan J. , Helleve Arnfinn , Aarø Leif Edvard , Mathews Catherine , Kaaya Sylvia , Klepp Knut-Inge
Published: June 2009

Aims: This article reports on the development and psychometric properties of an instrument to evaluate school-based HIV/ AIDS interventions aimed at adolescents in three African sites. Methods: The instrument was developed in a series of steps that involved a review of existing instruments; use of empirical data and secondary literature supporting an association between the variables of interest and sexual intercourse or condom use; operationalizing the constructs of the theoretical model employed; and using the objectives of the intervention. Test—retest reliability studies were conducted at each site. Results: The questionnaire demonstrated good internal consistency and adequate test—retest reliability. Cronbach's alpha was higher than 0.50 for all the 10 psychosocial scales, while Cohen's kappa showed poor to substantial test—retest reliability on the sexual behaviour items (κ = 0.14 to 0.69). Conclusions: We conclude that the instrument had sufficient test—retest reliability and internal consistency.
Impact and Implications of Word-Finding Difficulties in Adolescents on Listening Comprehension Assessment
Authors: Newman Diana B.
Published: June 2009

This investigation examined the listening comprehension (LC) performance of two groups of adolescent struggling readers, one group with word-finding difficulties (WFD) and one with no word-finding difficulties (NWFD). Of interest was whether the expressive language difficulties of the WFD group would interfere with their success on a LC assessment that requires oral responses to complete. Findings indicated that whereas the performance of the WFD group was comparable with the NWFD group when LC was measured using a multiple-choice response format, their performance was significantly poorer when LC was measured using an open-ended verbal response format, suggesting that learners’ WFD could interfere with their success on such assessments. Practical implications of these findings for the assessment of LC as part of adolescents’ reading evaluations are discussed.
The Short-Term Effects of Different Cueing Modalities on Turn Speed in People with Parkinson’s Disease
Authors: Nieuwboer Alice , Baker Katherine , Willems Anne-Marie , Jones Diana , Spildooren Joke , Lim Inge , Kwakkel Gert , Van Wegen Erwin , Rochester Lynn
Published: June 2009

Background. Turning has been associated with instability, falls, and freezing in people with Parkinson’s disease (PD). Objective. To investigate the effect of different modalities of rhythmic cueing on the duration of a functional turn in freezers and nonfreezers. Methods. A total of 133 patients with idiopathic PD while in the on phase of the medication cycle participated in this study as part of a subanalysis from the RESCUE trial. The effect of 3 different cue modalities on functional turning performance was investigated, involving a 180° turn while picking up a tray. Time to perform this task was measured using an activity monitor. Tests were performed without cues and with auditory, visual, and somatosensory cues delivered in a randomized order at preferred straight-line stepping frequency. Results. Cueing (all types) increased the speed of the turn in all subjects. There was no difference between turn performance of freezers and nonfreezers in cued and noncued conditions. Auditory cues made turning significantly faster than visual cues ( P < .01) but not compared with somatosensory cues, except in nonfreezers. There was a short-term carryover in the final noncued trial. Conclusions. Rhythmical cueing yielded faster performance of a functional turn in both freezers and nonfreezers. This may be explained by enhancing attentional mechanisms during turning. Although no harmful effects were recorded, the safety of cueing for turning as a therapeutic strategy needs further study.
Line and Colour in The Band Concert
Authors: Cubitt Sean
Published: June 2009

This article addresses the techniques and materials used in the production of The Band Concert (1935), a seven-minute Technicolor Mickey Mouse cartoon. An investigation of the standardization of drawing and line in the context of the histories of technical drawing and the industrialization of animation is followed by a description of the use of colour, particularly of the relation between the inks used on the cels and the dyes used in film prints at the time. The author asks whether it is possible to articulate a materialist theory of the aesthetic, ethical and political meanings of technique and technology without losing sight of the techniques and technologies themselves.
Technologies of Perception: Miyazaki in Theory and Practice
Authors: Bigelow Susan J.
Published: June 2009

The current Western fascination with Japanese animation can be understood in relation to the experience of the digital in cultural production that opens new avenues of understanding about the self-as-subject. Visualization to engage with the image in interactive, virtual environments involves relinquishing control to recognize the individual as emerging through the unique pattern of their relationships, both human and non-human. This reality is articulated in Eastern philosophical notions of interrelatedness and pre-reflective thinking, what Marshall McLuhan called `comprehensive awareness'. The Japanese animator Miyazaki Hayao draws on a Zen-Shinto religious imaginary to empower the individual to relinquish the self. As an alternative politics to the moral confusion of the post-modern age, his practice demonstrates that Walter Benjamin's gamble with cinema is in play.
The Spiritual—Functional Loop: Animation Redefined in the Digital Age
Authors: Chow Ka-nin Kenny
Published: June 2009

Can animation bring life to the computer? Can the computer take animation to a new horizon extending from cinema and visual art? This article starts with a scrutiny of the conventional definition of animation and its connection to the continuum of liveliness, followed by an examination of the two furthest points on that scale: lively movement, which is spiritual; and inorganic movement, which is functional. The author shows that, in the digital age, movement of various degrees of liveliness can be significant and meaningful through a wide array of motor—sensory functions. This brings about a new notion of materiality, which constructs an innovative meaning of animation. The author then argues that, when combined with the unique functions of the computer, animation can find a shortcut between the two extremes of liveliness: spirituality and functionality. Therefore, the field of animation could benefit from an expansion of its digital attributes. Finally, the author discusses a corpus of artefacts created in different historical periods and different media that exemplify the spiritual—functional loop.
Smoking cessation pharmacotherapy
Authors: Frishman William H.
Published: June 2009

Cigarette smoking remains an important risk factor for premature cardiovascular disease and its many complications. There are clear benefits from treating tobacco dependence on the rate of clinical outcomes. In addition to behavioral therapies, various pharmacologic strategies have been developed to help achieve this goal. First-line therapies include nicotine replacement, bupropion and varenicline, a partial nicotine antagonist. Second-line treatments include clonidine and nortriptyline. Additional treatment strategies with less proven efficacy include monoamine oxidase inhibitors, selective serotonin reuptake inhibitors, opioid receptor antagonists, bromocriptine, anti-anxiety drugs, nicotinic receptor antagonists (e.g. mecamylamine) and glucose tablets. Various approaches under investigation include inhibitors of the hepatic P450 enzyme (e.g. methoxsalen), cannabinoid-1 receptor antagonists (e.g. rimonabant), and nicotine vaccines.
Long-term daclizumab therapy in relapsing-remitting multiple sclerosis
Authors: Rojas Monica A. , Carlson Noel G. , Miller Thomas L. , Rose John W.
Published: June 2009

We performed a retrospective review of side effects and clinical outcomes in relapsing-remitting (RR) multiple sclerosis (MS) patients receiving long-term treatment with daclizumab. Twelve patients with RR MS were initially treated with daclizumab at 1 mg/kg IV, again 14 days later and then monthly treatments (average duration 42.1 months). Daclizumab dose (0.85 mg/kg to 1.5 mg/kg) was adjusted based on clinical response. Daclizumab was generally well tolerated. There was a significant reduction in relapse rate and improvement in Expanded Disability Status Scores (EDSSs) (p < 0.0001). Long-term treatment with daclizumab in RR MS patients has apparent benefit that will require formal confirmation.
Rediscovering the Arisaid
Authors: Quye Anita , Cheape Hugh
Published: June 2009

The stereotype of 'traditional' Highland dress is the kilted male figure. The National Museums Scotland (NMS) and other museums have long included a category 'Arisaids' in their collections; research reveals that this was a female version of 'traditional' Highland dress, a finely-made and high status garment which was going out of fashion in the eighteenth century, though leaving some material evidence. This essay looks at evidence within the textiles themselves, using results from dye analysis, and places the results against sparse but telling historical and literary evidence to rediscover a 'lost' fashion. In the Highlands and Islands of Scotland, this was high colour, high quality and high fashion.
Sir William Heathcote's Livery
Authors: Chappell Dawn
Published: June 2009

This paper focuses on livery purchased for Sir William Heathcote's menservants during the first half of the eighteenth century. Sir William, who resided in London and Hursley Park, Winchester, left documented evidence of his menservants' clothing allowances and, by comparing this data with his expenses and other extant archival sources, such as textile swatches, the author builds up an image of what the Heathcote livery might have consisted of and looked like. Consideration is also given to the cost of the livery, and who purchased it. In order to explore what it could have meant during the eighteenth century, some of the theoretical models of consumption are used, and an appendix of livery allowances supports the paper.
Japonisme and Femininity: A Study of Japanese Dress in British and French Art and Society, c. 1860–c. 1899
Authors: Kirk Anna Marie
Published: June 2009

Artworks of the second half of the nineteenth century offer substantial evidence of the differing ways in which the 'Japanese craze' of this period was disseminated in dress. A discussion of the availability of garments in Paris and London, and the evidence for ownership of garments, takes place in this article. This study shows that Whistler was reflecting and informing the usage of Japanese attire by aesthetic women such as Ellen Terry. These garments offered a freer, looser, artistic style. The immense popularity of Japanese accessories is explored, as is the kimono's adaptation as a dressing gown. Alfred Stevens' artworks reflect this usage in France during the 1870s and 1880s. An examination of fancy dress books provides evidence of a growing familiarity with Japanese dress towards the end of the nineteenth century. This article is informed by nineteenth-century writings on Japan, fancy dress books, Liberty's catalogues, photographs and surviving garments.
John Redfern and Sons, 1847 to 1892
Authors: North Susan
Published: June 2009

John Redfern's name appears frequently in the history of couture and late nineteenth- and early twentieth-century fashion, but information on his business is limited. The following is based on research done for the author's MA in the history of dress at the Courtauld Institute in 1993. It examines John Redfern's early years as a draper and how by 1892, he had become the leading ladies' tailor in Britain and France.
New Zealand School Uniforms in the Era of Democracy: 1965 to 1975
Authors: Webster Elaine
Published: June 2009

School uniforms are dynamic cultural forms and as such have meanings specific to the cultures in which they are worn. In New Zealand the history of their development is also a history of changing meanings specific to the New Zealand culture, connected to the status of children and the changing educational and social objectives of the education system. After a relatively slow development in New Zealand, school uniforms came into their own during the 1950s only to undergo radical change and diversification in the 1960s. During the 1970s school uniform as a practice reached a new extreme, allowing expressions of individualism and pluralism, values associated with a democratic ideal. Although such expressions threatened to overturn the sustaining principles of uniforms and uniformity, instead they reinforced uniforms as carriers and protectors of a powerful democratic ideal embedded in the New Zealand education system.
The Role of Veilcloths Among the Rabaris of Kutch, Gujarat, Western India
Authors: Edwards Eiluned
Published: June 2009

This article gives a brief introduction to the Rabaris of Kutch district, Gujarat, in western India. It then follows the biographical strands of the veilcloth worn by Rabari women (who are known as Rabaran) through its making, use and circulation, exploring the basis of their values and beliefs. Analysis of its trajectory reveals the impact of change on the Rabaris' way of life following the development of agricultural industries in Kutch in the past three to four decades. Previously secure in the pious nature of their vocation as herders, the decline of their form of animal husbandry in the post-colonial era has compelled Rabaris to review their calling; as they renegotiate their identity at individual and group level, in common with the nationalists of the early twentieth century, dress has become a site in which that identity is contested and reconfigured.
The Quintessential Englishman? Henry Temple's Town and Country Dress
Authors: Clatworthy Lee
Published: June 2009

This article examines some of the purchases of personal clothing by Henry Temple, first Viscount Palmerston (1676–1757) recorded in his surviving account books, and goes on to discuss whether he could be said to have had separate town and country wardrobes. A version of this paper was presented at the Costume Society Symposium: Town and Country Style in 2007 and is based on the author's research for a doctoral thesis on the subject of Henry Temple's personal papers at the Broadlands Estate.
Redfern Limited, 1892 to 1940
Authors: North Susan
Published: June 2009

This is the second of two articles on the history of Redfern, based on research for the author's M.A. in the history of dress at the Courtauld Institute in 1993 (Part I, 'John Redfern and Sons, 1847 to 1892', appeared in Costume, 42 (2008), 145–68). This article examines the company's history after incorporation in 1892, Redfern's influence on fashion, particularly during the period 1895–1908, and its survival under various names until 1940.
Complement promotes the development of inflammatory T-helper 17 cells through synergistic interaction with Toll-like receptor signaling and interleukin-6 production
Authors: Fang Chongyun , Zhang Xinhua , Miwa Takashi , Song Wen-Chao
Published: June 2009

Toll-like receptors (TLRs) and complement are 2 major components of innate immunity that provide a first-line host defense and shape the adaptive immune responses. We show here that coincidental activation of complement and several TLRs in mice led to the synergistic production of serum factors that promoted T-helper cell 17 (Th17) differentiation from anti-CD3/CD28 or antigen-stimulated T cells. Although multiple TLR-triggered cytokines were regulated by complement, Th17 cell–promoting activity in the serum was correlated with interleukin (IL)–6 induction, and antibody neutralization of IL-6 abrogated the complement effect. By using both in vitro and in vivo approaches, we examined in more detail the mechanism and physiologic implication of complement/TLR4 interaction on Th17-cell differentiation. We found that the complement effect required C5a receptor, was evident at physiologically relevant levels of C5a, and could be demonstrated in cultured peritoneal macrophages as well as in the setting of antigen immunization. Importantly, despite an inhibitory effect of complement on IL-23 production, complement-promoted Th17 cells were functionally competent in causing autoimmunity in an adoptive transfer model of experimental autoimmune encephalomyelitis. Collectively, these data establish a link between complement/TLR interaction and Th17-cell differentiation and provide new insight into the mechanism of action of complement in autoimmunity.
Graded repression of PU.1/Sfpi1 gene transcription by GATA factors regulates hematopoietic cell fate
Authors: Chou Stella T. , Khandros Eugene , Bailey L. Charles , Nichols Kim E. , Vakoc Christopher R. , Yao Yu , Huang Zan , Crispino John D. , Hardison Ross C. , Blobel Gerd A. , Weiss Mitchell J.
Published: June 2009

GATA-1 and PU.1 are essential hematopoietic transcription factors that control erythromegakaryocytic and myelolymphoid differentiation, respectively. These proteins antagonize each other through direct physical interaction to repress alternate lineage programs. We used immortalized Gata1− erythromegakaryocytic progenitor cells to study how PU.1/Sfpi1 expression is regulated by GATA-1 and GATA-2, a related factor that is normally expressed at earlier stages of hematopoiesis. Both GATA factors bind the PU.1/Sfpi1 gene at 2 highly conserved regions. In the absence of GATA-1, GATA-2 binding is associated with an undifferentiated state, intermediate level PU.1/Sfpi1 expression, and low-level expression of its downstream myeloid target genes. Restoration of GATA-1 function induces erythromegakaryocytic differentiation. Concomitantly, GATA-1 replaces GATA-2 at the PU.1/Sfpi1 locus and PU.1/Sfpi1 expression is extinguished. In contrast, when GATA-1 is not present, shRNA knockdown of GATA-2 increases PU.1/Sfpi1 expression by 3-fold and reprograms the cells to become macrophages. Our findings indicate that GATA factors act sequentially to regulate lineage determination during hematopoiesis, in part by exerting variable repressive effects at the PU.1/Sfpi1 locus.
Diagnosis of tuberculosis: principles and practice of using interferon-γ release assays (IGRAs)
Authors: Lalvani A. , Thillai M.
Published: June 2009

Educational aims

To provide an overview of T-cell interferon-γrelease assays (IGRAs) used for detection of tuberculosis (TB) infection.

To outline how these tests can be used in clinical practice for the assessment of latent TB infection (LTBI) and active TB.

One in three people worldwide are infected withMycobacterium tuberculosis; the vast majority have latent infection. Tracking this latent reservoir is the cornerstone of TB control and prevention in the developed world [1]. But standard tools for diagnosis and prevention are more than 100 years old and inadequate to control the global TB epidemic [2]. However, the last decade has witnessed a major advance in the diagnosis ofM. tuberculosisinfection [3–5]. T-cell IGRAs are the first practical output of a decade of reinvigorated basic science research into TB and are now revolutionising diagnosis and screening of LTBI.
The pathogenesis of acute infection in COPD
Authors: Anzueto A.
Published: June 2009

Educational aims

To give an overview of the types of infectious agents involved in causing acute exacerbations of chronic obstructive pulmonary disease (COPD).

To outline the mechanisms through which infectious agents drive exacerbations.

To introduce the concept that mixed infections may increase the severity of exacerbations.

A number of virulence factors have been associated with bacterial pathogens' propensity to cause exacerbations, and the genetic basis for these has begun to be examined. In addition, the acquisition of new strains of some bacteria has been associated with exacerbations. Viral nucleic acids are detected in about half of exacerbations, and several viruses are implicated, in particular rhinovirus. The manner in which these and other pathogens, individually and collectively, interact with the host merits further scrutiny if the prevention and treatment of acute COPD exacerbations are to be improved.
COPD guidelines in relation to infections: a critical analysis
Authors: Torres A.
Published: June 2009

Educational aims

To define the importance of exacerbations in COPD and chronic bronchitis.

To assess current guidelines for the treatment of COPD exacerbations.

To outline current antibiotic treatments and treatment periods for exacerbations.

Chronic obstructive pulmonary disease (COPD) exacerbations have been associated with an increased risk of mortality and currently available therapies for exacerbations show only limited beneficial effects. Bacterial infections caused by pathogens are the predominant cause of acute exacerbations in COPD and chronic bronchitis. Current guidelines suggest a correlation between forced expiratory volume in 1 s (FEV1) and the type of infecting pathogen and that purulence of sputum is one of the most important factors associated with the presence of a bacterial infection. Antibiotics are recommended for patients with exacerbations and sputum purulence. However, resistance to antibiotics is increasing, especially in southern Europe. To reduce the risk of resistance, shorter treatment periods can be implemented for patients with mild-to-moderate exacerbations.
Patient–ventilator interaction during noninvasive ventilation: practical assessment and theoretical basis
Authors: Nava S. , Carlucci A. , Ceriana P.
Published: June 2009

Synchrony refers to the agreement between the patient's own (neural) and the ventilator's (mechanical) inspiratory and expiratory time. Noninvasive ventilation (NIV) is a semi-open system, which means air leaks are common. This greatly affects patient synchrony. In addition to air leaks, there are other factors that affect patient–ventilator mismatching. This review will focus on NIV and on the main forms of asynchrony and mismatching, their causes and methods to eventually identify these problems from the flow and pressure signals.
Noninvasive ventilation as an adjunct to exercise training in patients with chronic respiratory disease
Authors: Piper A.J. , Menadue C.
Published: June 2009

Educational aims

To describe the potential benefits of noninvasive positive-pressure ventilation (NIV) as an adjunct to exercise training in selected patients with chronic obstructive pulmonary disease (COPD) or chest wall restriction.

To outline the mechanisms by which NIV may improve exercise performance in selected patients with COPD or chest wall restriction.

To identify characteristics of patients with chronic respiratory disease who are more likely to respond to NIV-assisted training.

To highlight major practical considerations for implementing NIV-assisted training in an individual with COPD or chest wall restriction.

Severe exertional dyspnoea is a major impediment to physical activity and adversely affects quality of life for many individuals with chronic respiratory disease. Although exercise can improve cardiorespiratory and peripheral muscle responses, training at sufficient intensity and duration may be difficult for the very breathless, deconditioned patient. Consequently, strategies to optimise training for such individuals are gaining interest. NIV is one such option and there is a growing body of evidence outlining its benefits in selected patients. However, the technique is not without its constraints and problems. An understanding of the mechanisms underlying improvements in exercise performance with NIV-assisted training is important in targeting appropriate candidates for intervention and identifying the best therapy to achieve the maximum benefit.
Cross-study analysis of genomic data defines the ciliate multigenic epiplasmin family: strategies for functional analysis in Paramecium tetraurelia
Authors: Damaj Raghida , Pomel Sébastien , Bricheux Geneviève , Coffe Gérard , Viguès Bernard , Ravet Viviane , Bouchard Philippe
Published: June 2009

Background

The sub-membranous skeleton of the ciliateParamecium, the epiplasm, is composed of hundreds of epiplasmic scales centered on basal bodies, and presents a complex set of proteins, epiplasmins, which belong to a multigenic family. The repeated duplications observed in theP. tetraureliagenome present an interesting model of the organization and evolution of a multigenic family within a single cell.

Results

To study this multigenic family, we used phylogenetic, structural, and analytical transcriptional approaches. The phylogenetic method defines 5 groups of epiplasmins in the multigenic family. A refined analysis by Hydrophobic Cluster Analysis (HCA) identifies structural characteristics of 51 epiplasmins, defining five separate groups, and three classes. Depending on the sequential arrangement of their structural domains, the epiplasmins are defined as symmetric, asymmetric or atypical. The EST data aid in this classification, in the identification of putative regulating sequences such as TATA or CAAT boxes. When specific RNAi experiments were conducted using sequences from either symmetric or asymmetric classes, phenotypes were drastic. Local effects show either disrupted or ill-shaped epiplasmic scales. In either case, this results in aborted cell division.

Using structural features, we show that 4 epiplasmins are also present in another ciliate,Tetrahymenathermophila. Their affiliation with the distinctive structural groups ofParameciumepiplasmins demonstrates an interspecific multigenic family.

Conclusion

The epiplasmin multigenic family illustrates the history of genomic duplication inParamecium. This study provides a framework which can guide functional analysis of epiplasmins, the major components of the membrane skeleton in ciliates. We show that this set of proteins handles an important developmental information inParameciumsince maintenance of epiplasm organization is crucial for cell morphogenesis.
Characterisation of atypical enteropathogenic E. coli strains of clinical origin
Authors: Tennant Sharon M , Tauschek Marija , Azzopardi Kristy , Bigham Andrea , Bennett-Wood Vicki , Hartland Elizabeth L , Qi Weihong , Whittam Thomas S , Robins-Browne Roy M
Published: June 2009

Background

Enteropathogenic E. coli (EPEC) is a prominent cause of diarrhoea, and is characterised in part by its carriage of a pathogenicity island: the locus for enterocyte effacement (LEE). EPEC is divided into two subtypes according to the presence of bundle-forming pili (BFP), a fimbrial adhesin that is a virulence determinant of typical EPEC (tEPEC), but is absent from atypical EPEC (aEPEC). Because aEPEC lack BFP, their virulence has been questioned, as they may represent LEE-positive Shiga toxin-producing E. coli (STEC) that have lost the toxin-encoding prophage, or tEPEC that have lost the genes for BFP. To determine if aEPEC isolated from humans in Australia or New Zealand fall into either of these categories, we undertook phylogenetic analysis of 75 aEPEC strains, and compared them with reference strains of EPEC and STEC. We also used PCR and DNA hybridisation to determine if aEPEC carry virulence determinants that could compensate for their lack of BFP.

Results

The results showed that aEPEC are highly heterogeneous. Multilocus sequence typing revealed that 61 of 75 aEPEC strains did not belong to known tEPEC or STEC clades, and of those that did, none expressed an O:H serotype that is frequent in tEPEC or STEC strains associated with disease. PCR for each of 18 known virulence-associated determinants of E. coli was positive in less than 15% of strains, apart from NleB which was detected in 30%. Type I fimbriae were expressed by all aEPEC strains, and 12 strains hybridised with DNA probes prepared from either bfpA or bfpB despite being negative in the PCR for bfpA.

Conclusion

Our findings indicate that clinical isolates of aEPEC obtained from patients in Australia or New Zealand are not derived from tEPEC or STEC, and suggest that functional equivalents of BFP and possibly type I fimbriae may contribute to the virulence of some aEPEC strains.
Growth and development of the placenta in the capybara (Hydrochaeris hydrochaeris)
Authors: Kanashiro Claudia , Santos Tatiana C , Miglino Maria Angelica , Mess Andrea M , Carter Anthony M
Published: June 2009

Background

The guinea pig is an attractive model for human pregnancy and placentation, mainly because of its haemomonochorial placental type, but is rather small in size. Therefore, to better understand the impact of body mass, we studied placental development in the capybara which has a body mass around 50 kg and a gestation period of around 150 days. We paid attention to the development of the lobulated arrangement of the placenta, the growth of the labyrinth in the course of gestation, the differentiation of the subplacenta, and the pattern of invasion by extraplacental trophoblast.

Methods

Material was collected from six animals at pregnancy stages ranging from the late limb bud stage to mid gestation. Methods included latex casts, standard histology, immunohistochemistry for cytokeratin, vimentin, alpha-smooth muscle actin, and proliferating cell nuclear antigen as well as transmission electron microscopy.

Results

At the limb bud stage, the placenta was a pad of trophoblast covered by a layer of mesoderm from which fetal vessels were beginning to penetrate at folds in the surface. By 70 days, the placenta comprised areas of labyrinth (lobes) separated by interlobular areas. Placental growth resulted predominantly from proliferation of cellular trophoblast situated in nests at the fetal side of the placenta and along internally directed projections on fetal mesenchyme. Additional proliferation was demonstrated for cellular trophoblast within the labyrinth.

Already at the limb bud stage, there was a prominent subplacenta comprising cellular and syncytial trophoblast with mesenchyme and associated blood vessels. At 90 days, differentiation was complete and similar to that seen in other hystricognath rodents. Overlap of fetal vessels and maternal blood lacunae was confirmed by latex injection of the vessels. At all stages extraplacental trophoblast was associated with the maternal arterial supply and consisted of cellular trophoblast and syncytial streamers derived from the subplacenta.

Conclusion

All important characteristics of placental development and organization in the capybara resembled those found in smaller hystricognath rodents including the guinea pig. These features apparently do not dependent on body size. Clearly, placentation in hystricognaths adheres to an extraordinarily stable pattern suggesting they can be used interchangeably as models of human placenta.
Multisegmental spondylitis due to Tropheryma whipplei: Case report
Authors: Spoerl David , Bär Diego , Cooper Julian , Vogt Thomas , Tyndall Alan , Walker Ulrich A
Published: June 2009

We report a patient who presented with inflammatory back pain due to multisegmental spondylitis. Following a vertebral biopsy which failed to detect an infectious organism, the patient was treated with etanercept, a tumor necrosis factor (TNF)-α inhibitor, for suspected undifferentiated spondyloarthritis. The back pain worsened and the spondylitic lesions increased. Only in a vertebral rebiopsy with polymerase chain reaction (PCR) amplification of Tropheryma whipplei, the causative agent of Whipple's disease was identified. Tropheryma whipplei should be considered as a cause of spondylitis even with multisegmental involvement and in the absence of gastrointestinal symptoms. In this clinical setting, routine PCR for Tropheryma whipplei from vertebral biopsies is recommended.
Impaired Glucose-Induced Glucagon Suppression after Partial Pancreatectomy
Authors: Schrader Henning , Menge Bjoern A. , Breuer Thomas G. K. , Ritter Peter R. , Uhl Waldemar , Schmidt Wolfgang E. , Holst Jens J. , Meier Juris J.
Published: June 2009

Introduction: The glucose-induced decline in glucagon levels is often lost in patients with type 2 diabetes. It is unclear whether this is due to an independent defect in α-cell function or secondary to the impairment in insulin secretion. We examined whether a partial pancreatectomy in humans would also impair postchallenge glucagon concentrations and, if so, whether this could be attributed to the reduction in insulin levels.

Patients and Methods: Thirty-six patients with pancreatic tumours or chronic pancreatitis were studied before and after approximately 50% pancreatectomy with a 240-min oral glucose challenge, and the plasma concentrations of glucose, insulin, C-peptide, and glucagon were determined.

Results: Fasting and postchallenge insulin and C-peptide levels were significantly lower after partial pancreatectomy (P < 0.0001). Likewise, fasting glucagon concentrations tended to be lower after the intervention (P = 0.11). Oral glucose ingestion elicited a decline in glucagon concentrations before surgery (P < 0.0001), but this was lost after partial pancreatectomy (P < 0.01 vs. preoperative values). The loss of glucose-induced glucagon suppression was found after both pancreatic head (P < 0.001) and tail (P < 0.05) resection. The glucose-induced changes in glucagon levels were closely correlated to the respective increments in insulin and C-peptide concentrations (P < 0.01).

Conclusions: The glucose-induced suppression in glucagon levels is lost after a 50% partial pancreatectomy in humans. This suggests that impaired α-cell function in patients with type 2 diabetes may also be secondary to reduced β-cell mass. Alterations in glucagon regulation should be considered as a potential side effect of partial pancreatectomies.