bluuebunny/crossref_metadata_2025 huggingface dataset:
Angiotensin II type 2 receptor gene polymorphisms in cardiovascular disease
Authors: Balmforth Anthony J
Published: October 2009

Considerable progress in our understanding of the role of the angiotensin II type 2 (AT2) receptor in the development of cardiac hypertrophy and coronary artery disease has been achieved using in vitro and in vivo animal models. Our understanding in humans, however, has been hindered by the lack of availability of specific AT2receptor agonists and antagonists suitable for human study. Nevertheless, an alternative approach involving genotyping humans for a functional polymorphism within the AT2receptor gene (—1332G/A) has been used in several association studies to elucidate the pathogenic role of the AT2receptor in cardiovascular disease. Both the A allele and the G allele have independently been associated with left ventricular remodelling. However, the methods of measuring left ventricular mass, sodium balance, age and degree of remodelling appear to influence the outcome. An association of carriers of the G allele and premature coronary artery disease has also been established, particularly in males presenting with stenotic atherosclerosis requiring revascularisation. At the molecular level, it remains unclear as to whether carriers of the G allele express more or fewer AT2receptors when compared to carriers of the A allele. Consequently, it is presently not possible to definitively interpret the role of the AT2receptor in human cardiovascular disease from these association studies.
The angiotensin II type 2 receptor in cardiovascular disease
Authors: Lemarié Catherine A , Schiffrin Ernesto L
Published: October 2009

Angiotensin II (Ang II) is considered the major final mediator of the renin-angiotensin system. The actions of Ang II have been implicated in many cardiovascular conditions, such as hypertension, atherosclerosis, coronary heart disease, restenosis, and heart failure. Ang II can act through two different receptors: Ang II type 1 (AT1) receptor and Ang II type 2 (AT2) receptor. The AT1receptor is ubiquitously expressed in the cardiovascular system and mediates most of the physiological and pathophysiological actions of Ang II. The AT2receptor is highly expressed in the developing foetus, but its expression is very low in the cardiovascular system of the normal adult. Expression of the AT2receptor can be modulated by pathological states associated with tissue remodelling or inflammation such as hypertension, atherosclerosis, and myocardial infarction. The precise role of the AT2receptor remains under debate. However, it appears that the AT2receptor plays a vasodilatory role, and may be enhanced as a countervailing mechanism in cardiac hypertrophy, and in presence of vascular injury in hypertension and atherosclerosis. Signalling pathways induced by the stimulation of the AT2receptor are poorly understood, but three main mechanisms have been described: (a) activation of protein phosphatases causing protein dephosphorylation; (b) activation of bradykinin/nitric oxide/cyclic guanosine 3’,5’-monophosphate pathway; and (c) stimulation of phospholipase A2and release of arachidonic acid. Vasodilatory effects of the AT2receptor, probably the only well-established role of the AT2receptor, have been attributed to the second of these mechanisms. The participation of the AT2receptor in cardiovascular remodelling and inflammation is more controversial. In vitro, AT2receptor stimulation clearly inhibits cardiac and vascular smooth muscle growth and proliferation, and stimulates apoptosis. In vivo, the situation is less clear, and depending on the studies, the AT2receptor appears to be required for cardiac hypertrophic growth or contrariwise, the AT2receptor has demonstrated no effects on cardiac hypertrophy. Similar controversial findings have been reported in atherosclerosis. Here we discuss the role of the AT2receptor on cardiovascular structure and disease, and the signalling pathways induced by its activation.
The angiotensin II type 2 receptor and the kidney
Authors: Siragy Helmy M
Published: October 2009

Recent knowledge demonstrated that the renin-angiotensin system (RAS) functions as a local renal paracrine system. All components of the RAS are present within the kidney and include angiotensinogen, renin, angiotensin I, angiotensin-converting enzymes, angiotensin II, the angiotensin II type 1 (AT1) receptor and the angiotensin II type 2 (AT2) receptor. Angiotensin II is the major effector hormone of the RAS and contributes to a variety of renal and cardiovascular physiologic and pathologic mechanisms through stimulation of AT1and AT2receptors. Angiotensin receptor blockers were developed based on the advanced knowledge of the AT1receptor contribution to development of a variety of kidney, vascular and cardiac diseases including but not limited to hypertension, diabetic nephropathy, heart failure, myocardial infarction and atherosclerosis. In contrast, knowledge concerning the role of the AT2receptor in health and disease is still emerging. The AT2receptor is believed to counterbalance the effects of the AT1receptor through influencing cellular differentiation, vasodilation, inhibition of cellular proliferation and hypertrophy, nitric oxide production and natriuresis. Thus, the pursuit of a specific AT2receptor agonist is a potentially fruitful area for combating renal and cardiovascular diseases. This review focuses on the role of the AT2receptor in the kidney.
The angiotensin II type 2 receptor and the gastrointestinal tract
Authors: Fändriks Lars
Published: October 2009

The renin-angiotensin system (RAS) is well known for its vital involvement in body fluid homeostasis and circulation. However, very little research has been devoted to the impact of this regulatory system on the gastrointestinal (GI) system. This is surprising because the GI tract is fundamental for the intake and excretion of fluid and electrolytes (and nutrients), and it accommodates a large proportion of bodily haemodynamics and host defence systems. The RAS is well expressed and active in the GI tract, although the exact roles for the key mediator angiotensin II (Ang II) and its receptors in general, and the type 2 (AT2) receptor in particular, are not completely settled. There are several reports showing Ang II regulation of intestinal fluid and electrolyte transport. For example, mucosaprotective duodenal bicarbonate-rich secretion is inhibited by Ang II via type 1 (AT1) receptor-mediated facilitation of sympathoadrenergic activity, but this secretory process can also be stimulated by Ang II via AT2receptors. Novel data from human oesophagus and jejunum suggest that the AT1receptor mediates muscular contractions and that the AT2receptor regulates epithelial functions. Data are accumulating suggesting involvement of AT1and AT2receptors in GI inflammation and carcinogenesis. The picture of the RAS and AT2receptor in the GI tract is, however, far from complete. Much more basic research is needed with regard to GI pathophysiology before concluding clinical significance and potential applicability of pharmacological interferences with the RAS.
Does Provision of Extrinsic Feedback Result in Improved Motor Learning in the Upper Limb Poststroke? A Systematic Review of the Evidence
Authors: Subramanian Sandeep K. , Massie Crystal L. , Malcolm Matthew P. , Levin Mindy F.
Published: October 2009

Background. Recovery of the upper limb (UL) after a stroke occurs well into the chronic stage. Stroke survivors can benefit from adaptive plasticity to improve UL movement through motor relearning. The provision of feedback has been shown to decrease the use of compensatory UL movement patterns. However, the effectiveness of feedback in improving UL motor recovery after a stroke has not yet been systematically reviewed. Objective.The objective of this review was to systematically examine the role of extrinsic feedback on implicit motor learning after stroke, focusing on UL movement and functional recovery. Results. The authors retrieved 9 studies that examined the role of feedback on UL motor recovery. Of these, 6 were randomized controlled trials (RCTs), 1 was a single-subject design, 1 was a pre—post design, and 1 was a cohort study. The studies were rated on the basis of Sackett’s levels of evidence and PEDro (Physiotherapy Evidence Database) scores for RCTs. Levels of evidence were limited (level 2b) for UL motor learning of the less-affected extremity and strong (level 1a) for the more-affected extremity. Discussion and conclusions. The results suggest that people with stroke may be capable of using extrinsic feedback for implicit motor learning and improving UL motor recovery. Emergent questions regarding the advantages of using different media for feedback delivery and the optimal type and schedule of feedback to enhance motor learning in patient populations still need to be addressed.
The Politicization of Private Persona: Exceptional Leaders or the New Rule? The Case of the United Kingdom and the Blair Effect
Authors: Langer Ana Inés
Published: October 2009

This article investigates the extent and nature of the press coverage of the personal lives and personal qualities of contemporary British political leaders. In particular, it explores the legacy of the politicization of Blair’s private persona, or the Blair effect. Was Blair’s era a temporary anomaly, or did it have a transformative effect on the way that parties, politicians, and journalists conceive the role of the personal in public discourse and in the construction of a leader’s public persona? This research demonstrates that the degree of politicization of private persona still depends, to an important extent, on the personality of the leader and on the leader’s communication strategies, and that it is still possible to have a prime minister such as Gordon Brown, who tries to keep his personal life mostly private. But this is only part of the story. Blair’s era altered expectations about the role that the personal plays, and ought to play, in public discourse, and how much significance is given to it as a criterion of leadership evaluation.
Loss-of-function Additional sex combs like 1 mutations disrupt hematopoiesis but do not cause severe myelodysplasia or leukemia
Authors: Fisher Cynthia L. , Pineault Nicolas , Brookes Christy , Helgason Cheryl D. , Ohta Hideaki , Bodner Caroline , Hess Jay L. , Humphries R. Keith , Brock Hugh W.
Published: October 2009

The Additional sex combs like 1 (Asxl1) gene is 1 of 3 mammalian homologs of the Additional sex combs (Asx) gene of Drosophila. Asx is unusual because it is required to maintain both activation and silencing of Hox genes in flies and mice. Asxl proteins are characterized by an amino terminal homology domain, by interaction domains for nuclear receptors, and by a C-terminal plant homeodomain protein-protein interaction domain. A recent study of patients with myelodysplastic syndrome (MDS) and chronic myelomonocytic leukemia (CMML) revealed a high incidence of truncation mutations that would delete the PHD domain of ASXL1. Here, we show that Asxl1 is expressed in all hematopoietic cell fractions analyzed. Asxl1 knockout mice exhibit defects in frequency of differentiation of lymphoid and myeloid progenitors, but not in multipotent progenitors. We do not detect effects on hematopoietic stem cells, or in peripheral blood. Notably, we do not detect severe myelodysplastic phenotypes or leukemia in this loss-of-function model. We conclude that Asxl1 is needed for normal hematopoiesis. The mild phenotypes observed may be because other Asxl genes have redundant function with Asxl1, or alternatively, MDS or oncogenic phenotypes may result from gain-of-function Asxl mutations caused by genomic amplification, gene fusion, or truncation of Asxl1.
Gene ARMADA: an integrated multi-analysis platform for microarray data implemented in MATLAB
Authors: Chatziioannou Aristotelis , Moulos Panagiotis , Kolisis Fragiskos N
Published: October 2009

Background

The microarray data analysis realm is ever growing through the development of various tools, open source and commercial. However there is absence of predefined rational algorithmic analysis workflows or batch standardized processing to incorporate all steps, from raw data import up to the derivation of significantly differentially expressed gene lists. This absence obfuscates the analytical procedure and obstructs the massive comparative processing of genomic microarray datasets. Moreover, the solutions provided, heavily depend on the programming skills of the user, whereas in the case of GUI embedded solutions, they do not provide direct support of various raw image analysis formats or a versatile and simultaneously flexible combination of signal processing methods.

Results

We describe here Gene ARMADA (Automated Robust MicroArray Data Analysis), a MATLAB implemented platform with a Graphical User Interface. This suite integrates all steps of microarray data analysis including automated data import, noise correction and filtering, normalization, statistical selection of differentially expressed genes, clustering, classification and annotation. In its current version, Gene ARMADA fully supports 2 coloured cDNA and Affymetrix oligonucleotide arrays, plus custom arrays for which experimental details are given in tabular form (Excel spreadsheet, comma separated values, tab-delimited text formats). It also supports the analysis of already processed results through its versatile import editor. Besides being fully automated, Gene ARMADA incorporates numerous functionalities of the Statistics and Bioinformatics Toolboxes of MATLAB. In addition, it provides numerous visualization and exploration tools plus customizable export data formats for seamless integration by other analysis tools or MATLAB, for further processing. Gene ARMADA requires MATLAB 7.4 (R2007a) or higher and is also distributed as a stand-alone application with MATLAB Component Runtime.

Conclusion

Gene ARMADA provides a highly adaptable, integrative, yet flexible tool which can be used for automated quality control, analysis, annotation and visualization of microarray data, constituting a starting point for further data interpretation and integration with numerous other tools.
Relatedness facilitates cooperation in the subsocial spider, Stegodyphus tentoriicola
Authors: Ruch Jasmin , Heinrich Lisa , Bilde Trine , Schneider Jutta M
Published: October 2009

Background

Cooperative hunting and foraging in spiders is rare and prone to cheating such that the actions of selfish individuals negatively affect the whole group. The resulting social dilemma may be mitigated by kin selection since related individuals lose indirect fitness benefits by acting selfishly. Indeed, cooperation with genetic kin reduces the disadvantages of within-group competition in the subsocial spider Stegodyphus lineatus, supporting the hypothesis that high relatedness is an important pre-adaptation in the transition to sociality in spiders. In this study we examined the consequences of group size and relatedness on cooperative feeding in the subsocial spider S. tentoriicola, a species suggested to be at the transition to permanent sociality.

Results

We formed groups of 3 and 6 spiders that were either siblings or non-siblings. We found that increasing group size negatively affected feeding efficiency but that these negative effects were reduced in sib-groups. Sib groups were more likely to feed cooperatively and all group members grew more homogenously than groups of unrelated spiders. The measured differences did not translate into differential growth or mortality during the experimental period of 8 weeks.

Conclusion

The combination of our results with those from previous studies indicates that the conflict between individual interests and group interests may be reduced by nepotism and that the latter promote the maintenance of the social community.
Time series analysis of dengue fever and weather in Guangzhou, China
Authors: Lu Liang , Lin Hualiang , Tian Linwei , Yang Weizhong , Sun Jimin , Liu Qiyong
Published: October 2009

Background

Monitoring and predicting dengue incidence facilitates early public health responses to minimize morbidity and mortality. Weather variables are potential predictors of dengue incidence. This study explored the impact of weather variability on the transmission of dengue fever in the subtropical city of Guangzhou, China.

Methods

Time series Poisson regression analysis was performed using data on monthly weather variables and monthly notified cases of dengue fever in Guangzhou, China for the period of 2001-2006. Estimates of the Poisson model parameters was implemented using the Generalized Estimating Equation (GEE) approach; the quasi-likelihood based information criterion (QICu) was used to select the most parsimonious model.

Results

Two best fitting models, with the smallest QICu values, are selected to characterize the relationship between monthly dengue incidence and weather variables. Minimum temperature and wind velocity are significant predictors of dengue incidence. Further inclusion of minimum humidity in the model provides a better fit.

Conclusion

Minimum temperature and minimum humidity, at a lag of one month, are positively associated with dengue incidence in the subtropical city of Guangzhou, China. Wind velocity is inversely associated with dengue incidence of the same month. These findings should be considered in the prediction of future patterns of dengue transmission.
Comparative functional analysis of Jembrana disease virus Tat protein on lentivirus long terminal repeat promoters: evidence for flexibility at its N-terminus
Authors: Su Yang , Deng Gang , Gai Yuanming , Li Yue , Gao Yang , Du Jiansen , Geng Yunqi , Chen Qimin , Qiao Wentao
Published: October 2009

Background

Jembrana disease virus (JDV) encodes a potent regulatory protein Tat that strongly stimulates viral expression by transactivating the long terminal repeat (LTR) promoter. JDV Tat (jTat) promotes the transcription from its own LTR as well as non-cognate LTRs, by recruiting host transcription factors and facilitating transcriptional elongation. Here, we compared the sequence requirements of jTat for transactivation of JDV, bovine immunodeficiency virus (BIV) and human immunodeficiency virus (HIV) LTRs.

Results

In this study, we identified the minimal protein sequence for LTR activation using jTat truncation mutants. We found that jTat N-terminal residues were indispensable for transactivating the HIV LTR. In contrast, transactivation of BIV and JDV LTRs depended largely on an arginine-rich motif and some flanking residues. Competitive inhibition assay and knockdown analysis showed that P-TEFb was required for jTat-mediated LTR transactivation, and a mammalian two-hybrid assay revealed the robust interaction of jTat with cyclin T1. In addition, HIV LTR transactivation was largely affected by fusion protein at the jTat N-terminus despite the fact that the cyclin T1-binding affinity was not altered. Furthermore, the jTat N-terminal sequence enabled HIV Tat to transactivate BIV and JDV LTRs, suggesting the flexibility at the jTat N-terminus.

Conclusion

This study showed the distinct sequence requirements of jTat for HIV, BIV and JDV LTR activation. Residues responsible for interaction with cyclin T1 and transactivation response element are the key determinants for transactivation of its cognate LTR. N-terminal residues in jTat may compensate for transactivation of the HIV LTR, based on the flexibility.
Management of renal nutcracker syndrome by retroperitoneal laparoscopic nephrectomy with ex vivo autograft repair and autotransplantation: a case report and review of the literature
Authors: Xu Danfeng , Liu Yushan , Gao Yi , Zhang Lei , Wang Junkai , Che Jiangping , Zhu Youhua
Published: October 2009

Introduction

Nutcracker syndrome (NCS) is caused by a compression of the left renal vein between the aorta and the superior mesenteric artery (SMA). It results in left renal venous hypertension, and the subsequent development of venous varicosities of the renal pelvis, ureter, and gonadal vein.

Case presentation

A 21-year-old Chinese woman was admitted with a seven-month history of unilateral severe hematuria. On admission, she was identified as having nutcracker syndrome. The patient was treated with retroperitoneal laparoscopic donor nephrectomy and renal autotransplantation. The patient underwent retroperitoneal laparoscopic donor nephrectomy using a retroperitoneal three-port technique with ex vitro autograft repair and subsequent renal autotransplantation into the iliac fossa. In order to shorten the hot ischemia time and improve the patient's cosmetic outcome, a minor oblique incision in the left, lower quadrant was prepared in advance of the laparoscopic donor nephrectomy for use as a site for the autograft to be procured through the retroperitoneal space and as a transplant site for the autograft. Two days after the operation, the patient's symptoms subsided. Serum creatinine before and after the operation were 53 mmol/L and 55 mmol/L, respectively. The patient had normal renal function during a follow-up three months after the operation.

Conclusion

The treatment of nutcracker syndrome by retroperitoneal laparoscopic nephrectomy with ex vitro repair and autotransplantation is a simpler and less invasive procedure than open surgery. Moreover, a minor incision on the left hypogastrium can shorten the autograft's hot ischemic time and improve patients' cosmetic outcomes, especially in young women.
“No Grave Cannot Hold My Body Down”: Rituals of Death and Burial in Postcolonial Jamaica
Authors: Paul Annie
Published: October 2009

In contemporary Jamaica, funerals increasingly revolve around fantasy coffins and designer caskets. This paper attempts to marshal visual and textual information describing recent developments in Jamaican funerals with a view to recording attempts by the Jamaican underclasses to produce prestige for themselves in the face of an ever-effacing violence.
Haitian Novels and Novels of Haiti: History, Haitian Writing, and Madison Smartt Bell's Trilogy
Authors: Munro Martin
Published: October 2009

This essay reads Madison Smartt Bell's Haitian trilogy in the context of contemporary Haitian literature, and considers why Haitian writers have tended not to evoke the revolution in their work, and why it is an American author has produced the most ambitious work of Haitian historical fiction of recent times.
Capturing Louverture
Authors: Dubois Laurent
Published: October 2009

This essay discusses the ways in which Madison Smartt Bell's novel The Stone That the Builder Refused represents the history of the Haitian Revolution, and particularly the figure of Toussaint Louverture. It argues that the novel engages usefully with the problem of how we can and should grasp this revolution and its political meaning.
Madison Smartt Bell's Toussaint at the Crossroads: The Haitian Revolutionary between History and Fiction
Authors: Forsdick Charles
Published: October 2009

Central to Madison Smartt Bell's trilogy of novels on the Haitian Revolution is the character of Toussaint Louverture. The article considers how Bell's Toussaint fits into two centuries of representations of the revolutionary leader, exploring in particular the ways in which his character is to be situated between historiography and fiction. It addresses the extensive documentary foundations of Bell's fictional account, while highlighting the imagined interpretations essential to this refiguring of the revolutionary.
Sa Nou Pa We Yo (The Invisible Ones): A Reply to Four Readers
Authors: Bell Madison Smartt
Published: October 2009

This essay responds to four critics who discuss Bell's trilogy of novels about the Haitian Revolution—All Souls' Rising, Master of the Crossroads, The Stone That the Builder Refused. Particular attention is paid to the idea of a French royalist plot behind the slave insurrection of 1791 and the role of Vodou in the revolution.
From New World to Abeng: George Beckford and the Horn of Black Power in Jamaica, 1968-1970
Authors: Hill Robert A.
Published: October 2009

This essay examines the role played by George Beckford in grappling critically with the complicated legacy of the plantation system. It focuses on the transition from his role in the New World group to his participation in the Abeng newspaper group in Jamaica, in 1969. The essay argues that it was Beckford's participation in the Abeng group that helped to pave the way for his expanded concept of dispossession as well as his concept of the culture of dread. The essay examines how this twin set of concepts displaced the dominant New World theoretical model of dependency.
A Loving Freedom: A Caribbean Feminist Ethic
Authors: Robinson Tracy
Published: October 2009

This essay explores the expansion of Jacqui Alexander's earlier concept of erotic autonomy through the motif of the Sacred in her new book, and her articulation of what could be described as a Caribbean feminist ethic that demands radical self-determination exercised within self and community and a collectivized vision-making that is not circumscribed by feminist engagement with the state.
Crosses/Crossroads/Crossings
Authors: Smith Faith
Published: October 2009

This essay discusses Jacqui Alexander's Pedagogies of Crossing as framing an analysis of the curtailment of erotic autonomy in the United States and the Caribbean, the failures of liberal feminism and academia, and the propensity for military intervention, with an examination of the possibilities offered by the sacred.
Rethinking Interdisciplinarity: Meditations on the Sacred Possibilities of an Erotic Feminist Pedagogy
Authors: Rowley Michelle
Published: October 2009

In this paper I examine Jacqui Alexander's Pedagogies of Crossing in order to consider the interdisciplinary synergies that might be realized through a practice of knowledge production which bridges the metaphysical and the material. While the text encourages us to pursue the Sacred in our various academic and activist locations, I build on this deployment of the Sacred to argue for a feminist pedagogy of the erotic as a form of liberatory politics within Women's Studies.
Notes on the Age of Dis: Reading Kingston through Agamben
Authors: Edwards Nadi
Published: October 2009

This paper examines the representation of contemporary figures of “bare life” in the context of postcolonial Jamaican modernity. The representation of Kingston as a dystopia is one such trope of bare life, as evident in Kamau Brathwaite's 1994 prose poem, Trench Town Rock, and the selected lyrics of dancehall artistes such as Damian Marley and Super Cat, which are read in terms of Giorgio Agamben's concepts of homo sacer, the state of exception, and the biopolitical paradigm of the camp.
Solving Caribbean Mysteries: Art, Embodiment and an Eye for the Tropics
Authors: Wainwright Leon
Published: October 2009

This article discusses various perspectives on image-making in the Anglophone Caribbean with reference to the economy of relations between its visitors and inhabitants during the modern colonial period and its aftermath. It evaluates the framework of the “tropical picturesque” as a locus of embodied visual practices—with a significant, if often mysterious past—and debates Krista A. Thompson's notion of an “eye for the tropics” by reference to recent art historical insights drawn from fieldwork in Trinidad.
The Picturesque, Miss Nottage and the Caribbean Sublime
Authors: Powell Richard J.
Published: October 2009

In response to Krista A. Thompson's An Eye for the Tropics: Tourism, Photography, and Framing the Caribbean Picturesque (2006), this essay considers the notion of a tourism generated tropical image, but informed and colored as well by local self-conceptions. From probing the colonialist underpinnings of the picturesque subject, to surveying artistic and cultural forays into the particular landscapes, likenesses, and states of consciousness in the modern Caribbean, this essay spawns a view which claims for the region an aesthetic and conceptual insurgency in representational matters, manifested in human melodramas, public rituals, and social exegeses.
After Empire: Training Lawyers as a Postcolonial Enterprise
Authors: Lazarus-Black Mindie
Published: October 2009

The early history of legal education in the English-speaking Caribbean reflects a struggle for local identity and authenticity, while serving multiple states. Because schools are key locales for the making of docile bodies, West Indian lawyers experienced “subjection,” a process that names new categories of persons but also subjects them to an articulation of disciplinary powers not of their own making.
The Hills of Hebron: Sylvia Wynter's Disruption of the Narrative of the Nation
Authors: Toland-Dix Shirley
Published: October 2009

Sylvia Wynter's 1962 novel, The Hills of Hebron, is both a narrative of the nation and critique of the extant vision of the nation. Writing her novel from the perspective of a theorist, Wynter introduces insights and concepts that she has since developed in her extensive body of theoretical essays. This article looks particularly at the strategies she uses to incorporate gender issues into her novel.
Constructing a Nation: Jamaica Kincaid's A Small Place
Authors: McLeod Corinna
Published: October 2009

Jamaica Kincaid's A Small Place reveals the subalternity of Antigua as a tourist locale; an identity which undermines Antigua's position as a nation. Through the use of a metafictional discourse, Kincaid's narrator deconstructs colonial, postcolonial and neocolonial myths, thereby interrogating the tourists' perspective and unraveling the continuing colonizing construction of a place legitimized only by its visitors.
Seeing Darkly: Guyana, Black Power, and Walter Rodney's Expulsion from Jamaica
Authors: West Michael O.
Published: October 2009

Walter Rodney's expulsion from Jamaica in October 1968, and its consequences, had important implications elsewhere in the Caribbean, especially in Rodney's native Guyana. Recently discovered documents shed much light on the Guyanese reaction to those events, and more broadly on Guyana's reception of Black Power. An exposition of the new documents forms the background to a broader discussion of Rodney's subsequent life and work, up to the point of his assassination in 1980.
Venus in Two Acts
Authors: Hartman Saidiya
Published: October 2009

This essay examines the ubiquitous presence of Venus in the archive of Atlantic slavery and wrestles with the impossibility of discovering anything about her that hasn't already been stated. As an emblematic figure of the enslaved woman in the Atlantic world, Venus makes plain the convergence of terror and pleasure in the libidinal economy of slavery and, as well, the intimacy of history with the scandal and excess of literature. In writing at the limit of the unspeakable and the unknown, the essay mimes the violence of the archive and attempts to redress it by describing as fully as possible the conditions that determine the appearance of Venus and that dictate her silence.
Are They Mad? Nation and Narration in Tous les hommes sont fous
Authors: Daut Marlene , Richman Karen
Published: October 2009

All Men Are Mad, by Philippe Thoby-Marcelin and Pierre Marcelin, is set during the antisuperstition campaign in Haiti, which was led by the French Catholic Church during the 1940s. The Marcelin brothers' novel was not only a devastating critique of religious persecution but also a pithy commentary on the structure of the nation-state, meaning all nation-states, not only the polity of Haiti. The text was consequently misread by literary critics whose stereotype of Haitians and belief in nationalism influenced their mean-spirited dismissals of the novel. This paper rereads the Marcelins' prescient novel and addresses its critics in light of critical theory and ethnography.
Writing Caribbean Intellectual History
Authors: Bogues Anthony
Published: October 2009

Arguing that An Intellectual History of the Caribbean is an important text in the emerging field of Caribbean intellectual history, this essay suggests that missing from this important text is the working through of an intellectual history that grapples with black religious practices as modes of thought. It also argues that if Caribbean thought gets knotted up in the trope of Caliban, it will not decolonize itself and begin to wrestle with what Kamau Brathwaite has called the “inner plantation.”
Conversation Manqué: On Judging Someone Else's Book
Authors: Torres-Saillant Silvio
Published: October 2009

In this response to his critics, the author values the areas of missed opportunity observed by Braziel, Buscaglia-Salgado, and Bogues, while also endeavoring to “defend” his book from those objections that he ascribes more to the exigencies of the critic's particular reading practice than to the text's demonstrable failings. He uses the occasion to meditate on the psychopathology that informs the writing of a scholarly critique of a peer's work and the tension that such a task may entail.
Membrane type-1 matrix metalloproteinase activity is regulated by the endocytic collagen receptor Endo180
Authors: Messaritou Georgia , East Lucy , Roghi Christian , Isacke Clare M. , Yarwood Helen
Published: October 2009

The molecular interactions leading to organised, controlled extracellular matrix degradation are of central importance during growth, development and tissue repair, and when deregulated contribute to disease processes including cancer cell invasion. There are two major pathways for collagen degradation: one dependent on secreted and membrane-bound collagenases, the other on receptor-mediated collagen internalisation and intracellular processing. Despite the established importance of both pathways, the functional interaction between them is largely unknown. We demonstrate here, that the collagen internalisation receptor Endo180 (also known as CD280, uPARAP, MRC2) is a novel regulator of membrane-bound matrix metalloproteinase (MT1-MMP) activity, MT1-MMP-dependent MMP-2 activation and urokinase plasminogen activator (uPA) activity. We show close correlation between Endo180 expression, collagen accumulation and regulation of MT1-MMP cell-surface localisation and activity. We directly demonstrate, using collagen inhibition studies and non-collagen-binding mutants of Endo180, that the molecular mechanism underlying this regulation is the ability of Endo180 to bind and/or internalise collagens, rather than by acting as an interaction partner for pro-uPA and its receptor uPAR. These studies strongly support a functional interaction between two distinct collagen degradation pathways, define a novel mechanism regulating MT1-MMP activity and might have important implications for organised collagen clearance in the pericellular environment.
Increased sex chromosome expression and epigenetic abnormalities in spermatids from male mice with Y chromosome deletions
Authors: Reynard Louise N. , Turner James M. A.
Published: October 2009

During male meiosis, the X and Y chromosomes are transcriptionally silenced, a process termed meiotic sex chromosome inactivation (MSCI). Recent studies have shown that the sex chromosomes remain substantially transcriptionally repressed after meiosis in round spermatids, but the mechanisms involved in this later repression are poorly understood. Mice with deletions of the Y chromosome long arm (MSYq–) have increased spermatid expression of multicopy X and Y genes, and so represent a model for studying post-meiotic sex chromosome repression. Here, we show that the increase in sex chromosome transcription in spermatids from MSYq– mice affects not only multicopy but also single-copy XY genes, as well as an X-linked reporter gene. This increase in transcription is accompanied by specific changes in the sex chromosome histone code, including almost complete loss of H4K8Ac and reduction of H3K9me3 and CBX1. Together, these data show that an MSYq gene regulates sex chromosome gene expression as well as chromatin remodelling in spermatids.
A role for the DNA-damage checkpoint kinase Chk1 in the virulence program of the fungusUstilago maydis
Authors: Mielnichuk Natalia , Sgarlata Cecilia , Pérez-Martín José
Published: October 2009

During induction of the virulence program in the phytopathogenic fungus Ustilago maydis, the cell cycle is arrested on the plant surface and it is not resumed until the fungus enters the plant. The mechanism of this cell cycle arrest is unknown, but it is thought that it is necessary for the correct implementation of the virulence program. Here, we show that this arrest takes place in the G2 phase, as a result of an increase in the inhibitory phosphorylation of the catalytic subunit of the mitotic cyclin-dependent kinase Cdk1. Sequestration in the cytoplasm of the Cdc25 phosphatase seems to be one of the reasons for the increase in inhibitory phosphorylation. Strikingly, we also report the DNA-damage checkpoint kinase Chk1 appears to be involved in this process. Our results support the emerging idea that checkpoint kinases have roles other than in the DNA-damage response, by virtue of their ability to interact with the cell cycle machinery.
Stat3 promotes directional cell migration by regulating Rac1 activity via its activator βPIX
Authors: Teng Terk Shin , Lin Baohong , Manser Ed , Ng Dominic Chi Hiung , Cao Xinmin
Published: October 2009

Stat3 is a member of the signal transducer and activator of transcription family, which is important for cytokine signaling as well as for a number of cellular processes including cell proliferation, anti-apoptosis and immune responses. In recent years, evidence has emerged suggesting that Stat3 also participates in cell invasion and motility. However, how Stat3 regulates these processes remains poorly understood. Here, we find that loss of Stat3 expression in mouse embryonic fibroblasts leads to an elevation of Rac1 activity, which promotes a random mode of migration by reducing directional persistence and formation of actin stress fibers. Through rescue experiments, we demonstrate that Stat3 can regulate the activation of Rac1 to mediate persistent directional migration and that this function is not dependent on Stat3 transcriptional activity. We find that Stat3 binds to βPIX, a Rac1 activator, and that this interaction could represent a mechanism by which cytoplasmic Stat3 regulates Rac1 activity to modulate the organization of actin cytoskeleton and directional migration.
Rapid endocytosis provides restricted somatic expression of a K+ channel in central neurons
Authors: Corrêa Sônia A. L. , Müller Jürgen , Collingridge Graham L. , Marrion Neil V.
Published: October 2009

Trafficking motifs present in the intracellular regions of ion channels affect their subcellular location within neurons. The mechanisms that control trafficking to dendrites of central neurons have been identified, but it is not fully understood how channels are localized to the soma. We have now identified a motif within the calcium-activated potassium channel KCa2.1 (SK1) that results in somatic localization. Transfection of hippocampal neurons with KCa2.1 subunits causes expression of functional channels in only the soma and proximal processes. By contrast, expressed KCa2.3 subunits are located throughout the processes of transfected neurons. Point mutation of KCa2.1 within this novel motif to mimic a sequence present in the C-terminus of KCa2.3 causes expression of KCa2.1 subunits throughout the processes. We also demonstrate that blocking of clathrin-mediated endocytosis causes KCa2.1 subunit expression to mimic that of the mutated subunit. The role of this novel motif is therefore not to directly target trafficking of the channel to subcellular compartments, but to regulate channel location by subjecting it to rapid clathrin-mediated endocytosis.
In vivo analysis of the functions of γ-tubulin-complex proteins
Authors: Xiong Yi , Oakley Berl R.
Published: October 2009

To enhance our understanding of the function(s) of γ-tubulin-complex proteins (GCPs), we identified and analyzed the functions of the Aspergillus nidulans homologs of GCP2-GCP6 (here designated GCPB-GCBF). The γ-tubulin small complex (γ-TuSC) components, γ-tubulin, GCPB and GCPC, are essential for viability and mitotic spindle formation, whereas GCPD-GCPF are not essential for viability, spindle formation or sexual reproduction. GCPD-GCPF function in reducing the frequency of chromosome mis-segregation and in the assembly of large γ-tubulin complexes. Deletion of any of the γ-TuSC components eliminates the localization of all GCPs to the spindle pole body (SPB), whereas deletion of GCPD-GCPF does not affect localization of γ-TuSC components. Thus, GCPD-GCPF do not tether the γ-TuSC to the SPB, but, rather, the γ-TuSC tethers them to the SPB. GCPD-GCPF exhibit a hierarchy of localization to the SPB. Deletion of GCPF eliminates GCPD-GCPE localization to the SPB, and deletion of GCPD eliminates GCPE (but not GCPF) localization. All GCPs localize normally in a GCPE deletion. We propose a model for the structure of the γ-tubulin complex and its attachment to polar microtubule organizing centers.
Mould cooling simulation for injection moulding using a fast boundary element method approach
Authors: Zhou H , Zhang Y , Wen J , Cui S
Published: October 2009

The existing cooling simulations for injection moulding are mostly based on the boundary element method (BEM). In this paper, a fast BEM approach for mould cooling analysis is developed. The actual problem is decoupled into a one-dimensional transient heat conduction problem within the thin part and a cycle-averaged steady state three-dimensional heat conduction problem of the mould. The BEM is formulated for the solution of the mould heat transfer problem. A dynamic allocation strategy of integral points is proposed when using the Gaussian integral formula to generate the BEM matrix. Considering that the full and unsymmetrical influence matrix of the BEM may lead to great storage space and solution time, this matrix is transformed into a sparse matrix by two methods: the direct rounding method or the combination method. This approximated sparsification approach can reduce the storage memory and solution time significantly. For validation, six typical cases with different element numbers are presented. The results show that the error of the direct rounding method is too large while that of the combination method is acceptable.
Interactive fixture and tool space design considering tool movement, machine, and inspection for five-axis grinding
Authors: Wang Y , Wang Z-J , Yilmaz O , Gindy N
Published: October 2009

This paper proposes a novel method of collision-free fixture and tool space design for five-axis grinding, considering tool movement, machine degrees of freedom, the machine envelope, inspection, and related features. The fixture space is designed in three steps. First, the fixture space is generated as the remaining space after cutting out the tooling space (i.e. the sweeping space of the grinding wheel along the profile of the machined features). In this way, the fixture space is naturally collision-free with respect to tool movement. Second, the fixture space is further modified based on the constraints imposed by the grinding machine centre, which include over-travel distance, the positions of coolant nozzle and wheel dresser, and so on. Third, the fixture space is modified again according to measurements conducted by coordinate measuring machines and in-cycle machine probes. Interactions of fixture space with tool space, machine, and inspection are considered.

The fixture space design for holding aerofoil blades on a five-axis machining centre Makino A55 for grinding operations is used as a case study, and the results of this study have been verified by computer-aided manufacture (CAM) simulation software Vericut and physical experiments using dummy wheels.
An empirical regressive model to improve the metrological performance of mobile spatial coordinate measuring systems
Authors: Maisano D , Mastrogiacomo L
Published: October 2009

The mobile spatial coordinate measuring system (MScMS) is a system to perform dimensional measurements of large-scale objects. It consists of a wireless measuring probe with ultrasonic (US) transceivers, the position of which is determined using a distributed constellation of analogous transceivers arranged around the measuring area. The principle is to measure the time-of-flight (TOF) of the US signals exchanged between pairs of transceivers and, consequently, to obtain an estimate of their distances. The accuracy of TOF measurements can be attributed to many factors; the most influential are those associated with US signal attenuation.

The purpose of this paper is to build an experimental correction model to reduce the MScMS’ error in TOF measurements. First, a two-way block design, which is based on exploratory experiments, is created to show that transmitter—receiver distance and relative orientation between US transceivers have significant effects on TOF measurement error. Next, an empirical regressive model is constructed on the basis of additional detailed experiments. After performing an extensive experimental validation, the model is automatically implemented by MScMS, with an iterative procedure. The most important benefit of such a model is an important reduction in the dispersion and an improved accuracy associated with TOF measurements.
Free vibration analysis of a rotating annular disc under uniform pressure loading
Authors: Das D , Sahoo P , Saha K
Published: October 2009

The out-of-plane free vibration behaviour of a rotating annular disc under the application of uniform transverse pressure is presented. The method of analysis is based on energy principles, and the governing equations are obtained by the application of variational principles. Both rotation and transverse pressures act as external loading on the disc, producing in-plane and out-of-plane displacements. The displacements are approximated through linear combinations of admissible orthogonal functions and unknown coefficients. The orthogonal functions are generated numerically and the entire analysis is performed on a numerically generated grid in the physical domain of interest. The results are validated successfully with the results available in the literature and also with the results generated by the commercial finite-element package ANSYS. The dynamic behaviour of the rotating disc is furnished in a non-dimensional plane for different combinations of rotational speed and uniform transverse pressure, up to the initiation of yielding.
Research applications and opportunities in power ultrasonics
Authors: Lucas M , Gachagan A , Cardoni A
Published: October 2009

The first applications in power ultrasonics were largely focused on ultrasonic cleaning baths, which rely on generating inertial cavitation, and the incorporation of ultrasonic excitation in manufacturing processes such as joining of plastics and metals. Since the early days of power ultrasonics there has been a rapid growth in the number of applications, and the diversified range of applications, from microwelding to ultrasonic osteotomy, has been made possible by a combination of advances in experimental techniques for characterizing low ultrasonic frequency vibrations and acoustics, and advances in computational modelling. This article highlights just some of the research in power ultrasonics that aims to exploit the benefits of low ultrasonic frequency high ultrasonic amplitude vibrations. This article reports current research and suggests future opportunities in three different application areas that have seen significant recent advances: joining and shaping of metals, surgical devices, and cavitation cells.