bluuebunny/crossref_metadata_2025 huggingface dataset:
Arbitrary locations: in defence of the bounded field‐site
Authors: Candea Matei
Published: February 2007

The article offers a sympathetic critique of the original formulations of multi‐local/multi‐sited ethnography. The ‘multi‐sited imaginary’ values unboundedness and promotes methodological freedom, but it also implies a problematic reconfiguration of holism (on a grander scale). Whereas these formulations were extremely productive in straining against certain methodological rigidities, their very success in breaking down ‘boundaries’ has given rise to new problems in the doing and writing of ethnography. Written from the perspective of a recent Ph.D. graduate and first‐time fieldworker, the article suggests we reconsider the value of self‐imposed limitations, of boundedness as a methodological tool. What role did the bounded field‐site play for its so‐called ‘traditional’ practitioners in social/cultural anthropology? What role could it play for anthropologists who have taken on board the precepts of multi‐sitedness? Based on a case study from my own fieldwork in Corsica, I argue that we could think of boundedness (paradoxically) as a productive way of challenging holisms and deferring closure. The bounded field‐site, rethought as an ‘arbitrary location’, becomes an explicitly ‘partial’ and incomplete window onto complexity.
A Simple and Flexible Dynamic Approach to Foreign Direct Investment Growth: The Canada‐United States Relationship in the Context of Free Trade
Authors: Buckley Peter J. , Clegg Jeremy , Forsans Nicolas , Reilly Kevin T.
Published: February 2007

This paper asks a simple question: Did Wilfred Laurier's dream of free trade with the United States, when it came to fruition in 1989, also impact on foreign direct investment (FDI) into Canada by US multinationals? This paper argues that the customary static econometric approach found in the FDI literature, along with the assumption that policy changes influence only the intercept term, are inadequate to address the question. Instead we introduce an innovative dynamic framework to support the testing of hypotheses on behavioural changes in the variables using a structural break framework. A key conclusion is that prior to signing the free trade agreement US FDI responded only to current growth in the Canadian economy, in a unitary fashion, and current exchange rate shifts. This can be described as a static relationship. The implementation of the free trade agreements between Canada and the USA increased the responsiveness of US FDI to growth in the Canadian economy by a factor greater than two. Furthermore, dynamics are found in the form of a lagged effect for changes in the growth in the Canadian economy and interest rate differentials. These conclusions challenge the dominant view, including that in official policy circles, that the free trade agreement had no impact on US firms’ FDI decisions in Canada.
The Cultural Roots of Guanxi: An Exploratory Study
Authors: Dunning John H. , Kim Changsu
Published: February 2007

This paper first describes the cultural roots and characteristics of guanxi in Chinese society. It then goes on to test some propositions about the perceived relationship between these characteristics and (i) Hofstede's conceptualisation of collectivism and power distance and (ii) the content and quality of formal institutions. The sampling frame used consisted of three groups of students –viz. Chinese Singaporeans, Non‐Chinese Singaporeans and Mainland Chinese, studying in tertiary institutions in Singapore. Our findings suggest that, while the perceptions of guanxi were positively and significantly related to Hofstede's culturally related variables, this was not so in the case of formal institutions. This latter result suggests that, in East Asian countries, guanxi may well be regarded as, at least, a partial substitute for formal institutions.
Comparative Advantage and the Gains from Financial Trade: A Reappraisal
Authors: Morgan Wyn , Snowden Nicholas
Published: February 2007

Emerging market crises have suggested that a national benefit‐cost assessment of external financial liberalisation could well prove unfavourable. This paper re‐examines the principle of comparative advantage in its application to financial trade to seek guidance on measures that might permit a fuller realisation of the potential benefits involved. Drawing a parallel with Balasubramanyam's work on the gains from FDI and international migration we distinguish between those arising in financial trade from the net transfer of capital, and those deriving from the contemporaneous exchange of financial claims or services of equivalent value. In the first interpretation a country's comparative advantage is manifested by its role in ‘intertemporal’ trade (as a borrower or lender). Our alternative emphasis is on the contractual risk‐return characteristics of the financial claims exchanged. This perspective is applied firstly to portfolio diversification gains arising from further international stock market integration. Secondly, price risk management for developing countries in international primary commodity trade is discussed. Both applications imply the need for significant institutional development but could realise approximately contemporaneous gains reminiscent both of those involved in merchandise trade and in the skills and product (or service) flows that Balasubramanyam has emphasised in relation to FDI and international migration.
THE UNEQUALIZING EFFECTS OF ICT ON ECONOMIC GROWTH
Authors: Becchetti Leonardo , Giacomo Stefania Di
Published: February 2007

We analyse the effects of information and communication technology (ICT) on levels and growth of per capita GDP in two different ways: (1) by treating ICT as a specific type of physical capital and as a variable that helps to correct for quality existing physical capital measures, and (2) by considering that telephone lines, personal computers and internet hosts are ‘bottleneck‐reducing’ factors that increase the productivity of labour by making easier the diffusion and processing of (non‐rivalrous and almost non‐excludable) knowledge. We compare the relative significance of the two hypotheses in level and growth estimates and find that, when separately taken, both of them improve upon the classical Mankiw et al. (Quarterly Journal of Economics, Vol. 107 (1992), pp. 407–437)/Islam (Quarterly Journal of Economics, Vol. 110 (1995), pp. 1127–1169) framework. These findings show that our approach captures dimensions of time‐varying country‐specific technological progress that previous approaches in the literature did not take into account.
The Disparate Nature of Targeted Repurchases: Evidence from Long‐Run Performance
Authors: Chang Saeyoung , Sullivan Michael J.
Published: February 2007

Abstract:  We examine the announcement stock returns and long‐run performance of 352 targeted repurchases from 1979 to 1998. For those repurchases of blocks that are non‐control related we find a positive announcement stock price response and positive long‐run stock performance indicating that these repurchases are timed to occur when the company's shares are undervalued and that the market underreacts to this signal. In contrast, for those repurchases of blocks that are control related we find a negative announcement stock price response and insignificant long‐run stock performance indicating that these repurchases occur for a different reason. We conclude that control related repurchases are utilized solely to dismiss potential takeover bids and are not timed when the stock is undervalued.
The Market Quality of Dealer versus Hybrid Markets: The Case of Moderately Liquid Securities
Authors: Lai Hung‐Neng
Published: February 2007

Abstract:  Over the last decade, electronic limit‐order trading systems have been sweeping securities exchanges around the world. This paper studies a transitional case, namely, the commencement of trading of a group of moderately liquid stocks on SETS of the London Stock Exchange. The evidence reveals that the liquidity of those stocks dropped substantially after the introduction of the limit order book and the removal of the market makers' obligations. This transition provides an example that a hybrid market with a limit order book and voluntary dealers may not perform as well as a dealership market with obligatory market makers.
Missed opportunities? Reaching the ethnic consumer market
Authors: Emslie Lisa , Bent Richard , Seaman Claire
Published: February 2007

Changing population demographics within the UK have become a source of increased interest to marketers as companies have realized the importance of targeting their products and advertising efforts towards minority and ethnic groups. In addition, as the UK’s ethnic minorities grow in both numbers and in terms of prosperity, so does the commercial significance of this market. A clearer understanding of both the nature of changing markets and the relative importance of different minority ethnic groups as consumers is imperative to facilitate both consumer understanding and business development; marketers need to understand better how to target these people, what they have in common with the mainstream and where the differences lie. This paper seeks to describe current understanding of ethnic consumers and their impact on the marketplace while highlighting an area where future research is potentially of considerable benefit.
Duplex ultrasonography is an efficient diagnostic tool for the detection of moderate to severe internal carotid artery stenosis
Authors: Nowak Jacek , Jogestrand Tomas
Published: February 2007

Background The aim of this prospective national muliticentre study with 10 participating university and county hospitals was to establish the diagnostic accuracy of carotid duplex sonography in the identification of ≥70% internal carotid artery (ICA) stenosis defined according to European Carotid Surgery Trial (ECST) criteria.

Methods In 134 patients, aged 69 ± 9 years, ICA stenoses were identified by routine carotid duplex ultrasonography, confirmed angiographically within 2 months, and graded according to ESCT criteria. The accuracy of carotid duplex to detect ICA stenosis ≥70% was assessed using receiver operating characteristic (ROC) analysis with carotid angiography as a reference.

Results Measurement of peak systolic velocity in ICA (PSVICA) identified ICA stenosis ≥70% with high diagnostic accuracy that was Doppler angle dependent resulting in different optimal PSVICA cut points within the angle range 0°–49° (1·7 m s−1) and 50°–62° (2·3 m s−1). The diagnostic discrimination was significantly better when narrow Doppler angles (0°–49°) were used (P<0·01) providing the sensitivity of 98 ± 2% and specificity of 94 ± 4%.

Discussion Ultrasound duplex technique identifies moderate to severe (≥70%) ICA stenoses (ECST criteria) with high degree of accuracy that can be further improved by the use of Doppler angle specific optimal PSVICA cut points.
On the Move: International Migration in Southeast Asia since the 1980s
Authors: Kaur Amarjit
Published: February 2007

Migration has been a persistent theme in Southeast Asian labour history and migrants have been either permanent settlers or temporary residents. In the second half of the nineteenth‐century migration coincided with European expansion into the region and was linked to economic development and labour market needs. Borders were porous, there was an empire‐wide sourcing of labour, and migration regimes were relatively stable. Since the 1980s migration has predominantly comprised intra‐Southeast Asian labour flows, is mediated by institutions and involves formal and informal channels. It has resulted in risks for specific categories of migrants and more stringent border controls by the state. Increasing global interdependence nevertheless, has created the conditions for international governance, and consequently, national policies are being shaped by, and respond to, the expanding global governance regime. Crucially, major international organisations such as the United Nations and its ancillary bodies both inform and direct themes in research and directions for policy.
Writing the Biography of the Prophet Muhammad: Problems and Solutions
Authors: Hoyland Robert
Published: February 2007

This article looks at the different approaches that medieval and modern, Muslim and Western scholars have adopted when attempting to write on the life of Muhammad. It considers the sources for his life and the different methodologies that have been devised for assessing their authenticity. It examines the degree to which Muhammad and the ingredients of the religion that he started were a part of the Late Antique world that he lived in and the way in which religious trends of that era might have impacted upon the formation of Islam. Finally, some suggestions are given for how one might take the study of the biography of Muhammad in different directions in the future.
Low IgE monoclonal gammopathy level in serum highlights 20‐yr survival in a case of IgE multiple myeloma
Authors: Hayes Michael J. , Carey John L. , Krauss John C. , Hedstrom Deborah L. , Gulbranson Ronald L. , Keren David F.
Published: February 2007

This report describes the diagnosis, follow‐up, and problems measuring serum immunoglobulin E (IgE) levels in a case of IgE myeloma with 20‐yr survival. Serum and urine protein electrophoresis, immunofixation, and the N Latex IgE test were used to characterize the monoclonal proteins. The diagnosis of multiple myeloma in a 56‐yr‐old man was based on 5.4 g/24 h of monoclonal free lambda chain in urine and bone marrow findings of 23.5% plasma cells (19% mature and 4.5% atypical). IgE lambda monoclonal protein in serum measured 506 000 μg/L (210 833 IU/mL). The lack of other clinical findings of multiple myeloma places this case in the category of ‘smoldering or indolent myeloma’. Measurement of serum IgE levels was complicated by the need to predilute serum to avoid antigen excess. Following chemotherapy, the patient went into clinical remission, eventually dying of complications of emphysema. This case expands the recognized clinical spectrum of IgE multiple myeloma.
Outcomes in patients with an emergency department diagnosis of fever of unknown origin
Authors: Ingarfield Sharyn L , Celenza Antonio , Jacobs Ian G , Riley Thomas V
Published: February 2007

Objective:  To describe the outcomes in patients given an ED diagnosis of fever of unknown origin (FUO).

Methods:  A retrospective analysis of ED records linked to hospital morbidity, mortality and microbiology records of patients presenting to Western Australia’s teaching hospitals from July 2000 to July 2003.

Results:  There were 3218 presentations diagnosed with FUO, 2049 (63.7%) children (median age 1.8 years) and 1169 (36.3%) adults (median age 56.0 years). FUO accounted for 0.3% of adult and 1.5% of paediatric ED presentations. Overall, 1997 (62.1%, 95% confidence interval 60.4–63.8%) were admitted (82% adults vs 50.7% children; P < 0.001). Adults had a longer median length of stay than children (4 days vs 2 days; P < 0.001) and a higher proportion of positive blood cultures (admissions 15.1%vs 4.9%; P < 0.001) commonly with Escherichia coli. Streptococcus pneumoniae was the most common organism isolated from children. Of 3053 FUO index presentations, 338 (11.1%, 95% confidence interval 10.0–12.2%) re‐presented. Children were more likely to re‐present than adults (13.5% of 1959 vs 6.8% of 1094; P < 0.001).

Conclusions:  Fever of unknown origin is diagnosed less frequently in adults than in children. Adult patients are more likely to be admitted, have longer lengths of stay and have positive blood cultures. Although FUO is diagnosed infrequently in the ED, blood cultures remain useful in the evaluation of unexplained fever, particularly in adults as age increases.
Utility of urine drug screening: A Clinical audit
Authors: Murnion Bridin P , Granot Ron , Day Richard O
Published: February 2007

Objective:  To assess requesting patterns and clinical utility of urine drug screens (UDS).

Methods:  All UDS requests received between March 2002 and October 2002 were identified. Two trained assessors reviewed case histories and categorized the utility of the UDS and gave a utility score using a Visual Analogue Scale.

Results:  Of 171 UDS requested, 67.3% were men. Age range was 15–92 (mean 36) years. In total, 70.8% were received from accident and emergency centre (AEC). Clinical utility was identified in only 85 of 171 UDS. Sixty‐one per cent of requests from AEC were defined as having no clinical utility. Twenty‐four per cent of requests originating from other specialities were identified as having no clinical utility. Overall, a test was more likely to be of utility if it was requested from non‐AEC than from AEC (Pearson’s χ2 two‐sided t‐test, P < 0.0001). Indications for UDS were toxic ingestion (33.3%), psychosis (15.2%), impaired consciousness (13.5%), behavioural disturbance (4.1%), confusion with HIV infection (3.5%), alleged adulteration (3.5%), seizure (9.4%), cardiac arrest (1.8%) and miscellaneous (15.8%).

Conclusions:  Our data show excessive requesting for UDS in routine overdose, contrary to international guidelines. Requests for UDS originating from AEC are more likely to have no utility than those from other specialities. Availability of point of care UDS might increase use of UDS, but cost‐effectiveness and utility must be assessed.
Validation of emergency physician ultrasound in diagnosing hydronephrosis in ureteric colic
Authors: Watkins Stuart , Bowra Justin , Sharma Praneal , Holdgate Anna , Giles Alan , Campbell Lewis
Published: February 2007

Objective:  Patients presenting to the ED with obstructive nephropathies benefit from early detection of hydronephrosis. Out of hours radiological imaging is expensive and disruptive to arrange. Emergency physician ultrasound (EPU) could allow rapid diagnosis and disposition. If accurate it might avert the need for formal radiological imaging, exclude an obstruction and improve patient flow through the ED.

Methods:  This was a prospective study of a convenience sample of all adult non‐pregnant patients with presumed ureteric colic attending the ED with prior ethics committee approval. An emergency physician or registrar performed a focused ultrasound scan and were blinded to the patient’s other management. A computerized tomography scan was also performed for all patients while in the ED or within 24 h of the EPU. The accuracy of EPU detection of hydronephrosis was determined; using computerized tomography scans reported by a senior radiologist as the ‘gold‐standard’.

Results:  Sixty‐three patients with suspected ureteric colic were enrolled of whom 57 completed both EPU and computerized tomography imaging. Forty‐nine had confirmed nephrolithiasis by computerized tomography with 39 having evidence of hydronephrosis. Overall prevalence of hydronephrosis was 68% (95% confidence interval [CI] 56–79%); compared with computerized tomography, EPU had a sensitivity of 80% (95% CI 65–89%); specificity of 83% (95% CI 61–94%); positive predictive value of 91% (95% CI 75–98%) and negative predictive value of 65% (95% CI 43–83%). The overall accuracy was 81% (95% CI 69–89%).

Conclusion:  Although the accuracy of detection of hydronephrosis after focused training in EPU is encouraging, further experience and training might improve the accuracy of EPU and allow its use as a screening tool.
Foraging Association between Coatis (Nasua nasua) and Birds of the Atlantic Forest, Brazil
Authors: Beisiegel Beatriz de Mello
Published: February 2007

Two bird species,Leucopternis polionotaandDendrocincla fuliginosa, frequently follow coatis (Nasua nasua)while they forage in the Atlantic forest of southeastern Brazil. Two other avian species,Trogon rufusandHabia rubica, have also been observed following coatis. This “following foraging behavior” is more frequent during the dry season when coatis forage in trees. For the birds, this can represent a coping strategy with the reduced resource availability during the drier season.
Fallen Branches as Part of Leaf‐Cutting Ant Trails: Their Role in Resource Discovery and Leaf Transport Rates inAtta cephalotes
Authors: Farji‐Brener Alejandro G. , Barrantes G. , Laverde O. , Fierro‐Calderón K. , Bascopé F. , López Adriana
Published: February 2007

Fallen branches, logs, and exposed roots (fallen branches hereafter) commonly form part of the trunk trail system of leaf‐cutting ants that inhabit the tropical rain forest. We studied the role of fallen branches on resource discovering and on leaf transport rates inAtta cephalotes. Fallen branches were common components of theA. cephalotestrail system; they were present in all the nests, and in the majority of the trunk trails examined (13/16). A field experiment revealed that, at the beginning of their foraging activity, ants discovered food sources located at the end of fallen branches earlier than those located on the leaf litter. Additionally, laden ants walked faster along a fallen branch than along soil tracks of the trunk trails. This increment in speed was higher in slow‐walking ants (e.g., with larger loads) than in fast‐walking ants (e.g., with smaller loads). These results suggest that the presence of fallen branches may direct the searching effort of leaf‐cutters and increase the foraging speed of laden ants when these structures are part of the trunk trail system. The advantages of using fallen branches as part of a trail system, and their potential consequences in the spatial foraging pattern of leaf‐cutting ants, are discussed.
Upland Soil Charcoal in the Wet Tropical Forests of Central Guyana
Authors: Hammond David S. , Steege Hans ter , Van Der Borg Klaas
Published: February 2007

A soil charcoal survey was undertaken across 60,000 ha of closed‐canopy tropical forest in central Guyana to determine the occurrence, ubiquity, and age of past forest fires across a range of terra firme soil types. Samples were clustered around six centers consisting of spatially nested sample stations. Most charcoal was found between 40 and 60 cm depth with fewest samples yielding material at 0–20 cm depth. The first core yielded charcoal at most stations. Charcoal ages of a random subsample ranged from less than 200 YBP to 9500 YBP with a noticeable peak between 1000 and 1250 YBP. Results reinforce a view that most closed‐canopy tropical forests in eastern Amazonia have been subject to palaeo‐fire events of unknown severity with a peak in charcoal age consistently appearing between 1000 and 2000 YBP. The two samples dated to the early Holocene represent some of the oldest indicators of paleo‐fire known from upland Neotropical forest soils. Ubiquitous soil charcoal in central Guyana further indicate both forest resilience to fire and the widespread propensity for regional forests to burn, particularly during anomalous periods of drought.
Explaining Leaf Herbivory Rates on Tree Seedlings in a Malaysian Rain Forest
Authors: Eichhorn Markus P. , Fagan K. C. , Compton Stephen G. , Dent Daisy H. , Hartley Sue E.
Published: February 2007

Seedlings of five species of dipterocarp trees were planted in experimental plots in rain forest gaps in Sabah, Malaysia, and the rates of herbivory on their mature leaves recorded over 6 mo. A novel method was used to estimate the feeding pressure exerted by the local insect herbivore community, derived from the relative abundances of the dominant generalist herbivores and their feeding preferences. Characteristics of the leaves related to their defense and nutritional value were measured—phenolic content, laminar fracture toughness, laminar thickness, and nitrogen content. Three main groups of herbivorous insects were present—coleopteran and lepidopteran herbivores, which were sampled by hand from the seedlings, and orthopteran herbivores, which were sampled by sweep netting. The feeding preferences of the main coleopteran and orthopteran herbivores were determined using laboratory feeding trials. Combining variables in a Principal Components Analysis, a clear separation was found between the five seedling species along the first extracted component. This correlated closely with herbivory rates between species. The first extracted component comprised a negative influence of phenolic content and positive effects of nitrogen content, laminar fracture toughness, abundances of coleopteran and lepidopteran herbivores, and estimated feeding pressure of the coleopteran community. Further studies are required to determine the potential applications of the latter measure of estimated herbivore community impact.
Cholesterol‐lowering management of stroke: Inconsistencies of evidence and practice
Authors: MOREY Belinda , ASH Susan , READ Stephen
Published: February 2007

Cholesterol‐lowering treatment by statins is an important and costly issue; however, its role in stroke has not been well documented. The aim of the present study was to review literature and current practice regarding cholesterol‐lowering treatment for stroke patients. A literature review was conducted on lipids in stroke and their management with both statins and diet, including the cost‐effectiveness of medical nutrition therapy. Qualifying criteria and prescription procedures of the Pharmaceutical Benefits Scheme (PBS) were also reviewed. Data on lipid levels and statin prescriptions were analysed for 468 patients admitted to a stroke unit. The literature shows that management with both medication and diet can be effective, especially when combined; however, 60% of patients with an ischaemic event had fasting total cholesterol measures ≥4 mmol/L (n = 231), with only 52% prescribed statins on discharge (n = 120). Hypercholesterolaemia is an underdiagnosed and undertreated risk factor within the stroke population. It appears that the PBS has not kept pace with advances in the evidence in terms of statin use in the stroke population, and review is needed. The present review should address the qualifying criteria for the stroke population and recommendations on referral to dietitians for dietary advice. Cholesterol‐lowering treatment for both stroke patients and the wider population is an area that needs awareness raising and review by the PBS, medical practitioners and dietitians. The role of dietary and pharmacological treatments needs to be clearly defined, including adjunct therapy, and the cost‐effectiveness of medical nutrition therapy realised.
Semiconductor Crystal Growth by the Vertical Bridgman Process With Transverse Rotating Magnetic Fields
Authors: Wang X. , Ma N.
Published: February 2007

During the vertical Bridgman process, a single semiconductor crystal is grown by the solidification of an initially molten semiconductor contained in an ampoule. The motion of the electrically conducting molten semiconductor can be controlled with an externally applied magnetic field. This paper treats the flow of a molten semiconductor and the dopant transport during the vertical Bridgman process with a periodic transverse or rotating magnetic field. The frequency of the externally applied magnetic field is sufficiently low that this field penetrates throughout the molten semiconductor. Dopant distributions in the crystal are presented.
Localized Heat Transfer in Buoyancy Driven Convection in Open Cavities
Authors: Terrell Wilson , Newell Ty A.
Published: February 2007

Background. An experimental study of buoyancy driven convection heat transfer in an open cavity was conducted. Method of Approach. Test cavities were constructed with calorimeter plates bonded to Styrofoam insulation. The inside of the cavities was heated and then exposed to ambient air for approximately thirty minutes. Different size cavities were examined at inclination angles of 0, 45, and 90deg. The heat transfer coefficient was determined from an energy balance on each calorimeter plate. The cavity’s plate temperatures varied spatially due to the transient nature of the tests. A parameter describing the nonisothermal cavity wall temperature variation was defined in order to compare with isothermal cavity heat transfer results. Results. Results showed that the cavity Nusselt number, based on a cavity averaged temperature, was insensitive to the transient development of nonisothermal conditions within the cavity. Comparison of cavity-average Nusselt number for the current study, where the Rayleigh number ranged from 5×106 to 2×108, to data from the literature showed good agreement. Cavity-average Nusselt number relations for inclination angles of 0, 45, and 90deg in the form of NuH,cav=CRa1∕3 resulted in coefficients of 0.091, 0.105, 0.093, respectively. The 45deg inclination angle orientation yielded the largest Nusselt numbers, which was similar to previous literature results. Trends in the local plate Nusselt numbers were examined and found similar to data from the literature.
An Efficient Localized Radial Basis Function Meshless Method for Fluid Flow and Conjugate Heat Transfer
Authors: Divo Eduardo , Kassab Alain J.
Published: February 2007

A localized radial basis function (RBF) meshless method is developed for coupled viscous fluid flow and convective heat transfer problems. The method is based on new localized radial-basis function (RBF) expansions using Hardy Multiquadrics for the sought-after unknowns. An efficient set of formulae are derived to compute the RBF interpolation in terms of vector products thus providing a substantial computational savings over traditional meshless methods. Moreover, the approach developed in this paper is applicable to explicit or implicit time marching schemes as well as steady-state iterative methods. We apply the method to viscous fluid flow and conjugate heat transfer (CHT) modeling. The incompressible Navier–Stokes are time marched using a Helmholtz potential decomposition for the velocity field. When CHT is considered, the same RBF expansion is used to solve the heat conduction problem in the solid regions enforcing temperature and heat flux continuity of the solid/fluid interfaces. The computation is accelerated by distributing the load over several processors via a domain decomposition along with an interface interpolation tailored to pass information through each of the domain interfaces to ensure conservation of field variables and derivatives. Numerical results are presented for several cases including channel flow, flow in a channel with a square step obstruction, and a jet flow into a square cavity. Results are compared with commercial computational fluid dynamics code predictions. The proposed localized meshless method approach is shown to produce accurate results while requiring a much-reduced effort in problem preparation in comparison to other traditional numerical methods.
Small Phytoplankton and Carbon Export from the Surface Ocean
Authors: Richardson Tammi L. , Jackson George A.
Published: February 2007

Autotrophic picoplankton dominate primary production over large oceanic regions but are believed to contribute relatively little to carbon export from surface layers. Using analyses of data from the equatorial Pacific Ocean and Arabian Sea, we show that the relative direct and indirect contribution of picoplankton to export is proportional to their total net primary production, despite their small size. We suggest that all primary producers, not just the large cells, can contribute to export from the surface layer of the ocean at rates proportional to their production rates.
Comment on "Obestatin, a Peptide Encoded by the Ghrelin Gene, Opposes Ghrelin's Effects on Food Intake"
Authors: Chartrel N. , Alvear-Perez R. , Leprince J. , Iturrioz X. , Goazigo A. Reaux-Le , Audinot V. , Chomarat P. , Coge F. , Nosjean O. , Rodriguez M. , Galizzi J. P. , Boutin J. A. , Vaudry H. , Llorens-Cortes C.
Published: February 2007

Zhang
et al
. (Research Articles, 11 November 2005, p. 996) reported that obestatin, a peptide derived from the ghrelin precursor, activated the orphan G protein–coupled receptor GPR39. However, we found that I
125
-obestatin does not bind GPR39 and observed no effects of obestatin on GPR39-transfected cells in various functional assays (cyclic adenosine monophosphate production, calcium mobilization, and GPR39 internalization). Our results indicate that obestatin is not the cognate ligand for GPR39.
Structure of the Prefusion Form of the Vesicular Stomatitis Virus Glycoprotein G
Authors: Roche Stéphane , Rey Félix A. , Gaudin Yves , Bressanelli Stéphane
Published: February 2007

Glycoprotein G of the vesicular stomatitis virus triggers membrane fusion via a low pH–induced structural rearrangement. Despite the equilibrium between the pre- and postfusion states, the structure of the prefusion form, determined to 3.0 angstrom resolution, shows that the fusogenic transition entails an extensive structural reorganization of G. Comparison with the structure of the postfusion form suggests a pathway for the conformational change. In the prefusion form, G has the shape of a tripod with the fusion loops exposed, which point toward the viral membrane, and with the antigenic sites located at the distal end of the molecule. A large number of G glycoproteins, perhaps organized as in the crystals, act cooperatively to induce membrane merging.
Immunogenicity, Reactogenicity, and Immune Memory after Primary Vaccination with a Novel
Haemophilus influenzae
-
Neisseria meningitidis
Serogroup C Conjugate Vaccine
Authors: Schmitt Heinz-J. , Maechler Gudrun , Habermehl Pirmin , Knuf Markus , Saenger Roland , Begg Norman , Boutriau Dominique
Published: February 2007

We evaluated two formulations of a new combined
Haemophilus influenzae
type b (Hib)-meningococcal serogroup C (MenC)-tetanus toxoid (TT) conjugated vaccine and two formulations of a new MenC-TT vaccine (trials 711202/001 and 711202/008; clinical trial register numbers NCT00135486 and NCT00135564 [
www.ClinicalTrials.gov
]). A total of 520 healthy infants were randomized to receive primary vaccination (at 2, 3, and 4 months) with either MenC-TT plus diphtheria-tetanus-acellular pertussis (DTPa)-hepatitis B virus (HBV)-inactivated poliovirus (IPV)/Hib, Hib-MenC-TT plus DTPa-HBV-IPV, or MenC-CRM
197
plus DTPa-HBV-IPV/Hib (control). At 12 to 15 months, subjects received a polysaccharide challenge with meningococcal polysaccharide C plus a DTPa-HBV-IPV/Hib booster. Immune responses were assessed 1 month after dose 2, 1 month after dose 3, and prior to and 1 month after the booster. After primary vaccination, there was no difference between groups in seroprotection rates as measured by titers of serum bactericidal antibody (SBA) to MenC (≥1:8) or concentrations of anti-polyribosyl ribitol phosphate (PRP) antibody (≥0.15 μg/ml). Prior to the booster, there was no difference between groups in SBA seroprotection rates, whereas anti-PRP seroprotection rates were significantly higher after priming with Hib-MenC-TT. Booster doses induced large increases in SBA and anti-PRP antibodies in primed groups, indicating successful priming with induction of immune memory. Reactogenicity and safety were similar in all groups during the primary and booster phases. A novel combined Hib-MenC-TT conjugate vaccine induced MenC and Hib responses comparable to those induced by licensed monovalent vaccines. A Hib-MenC-TT conjugate vaccine provides vaccination against two major pathogens in a single injection and is a suitable candidate for use in primary or booster vaccination schedules.
Retrospective Species Identification of Microsporidian Spores in Diarrheic Fecal Samples from Human Immunodeficiency Virus/AIDS Patients by Multiplexed Fluorescence In Situ Hybridization
Authors: Graczyk Thaddeus K. , Johansson Michael A. , Tamang Leena , Visvesvara Govinda S. , Moura Laci S. , DaSilva Alexandre J. , Girouard Autumn S. , Matos Olga
Published: February 2007

In order to assess the applicability of multiplexed fluorescence in situ hybridization (FISH) assay for the clinical setting, we conducted retrospective analysis of 110 formalin-stored diarrheic stool samples from human immunodeficiency virus (HIV)/AIDS patients with intestinal microsporidiosis collected between 1992 and 2003. The multiplexed FISH assay identified microsporidian spores in 94 of 110 (85.5%) samples: 49 (52.1%) were positive for
Enterocytozoon bieneusi
, 43 (45.8%) were positive for
Encephalitozoon intestinalis
, 2 (2.1%) were positive for
Encephalitozoon hellem
, and 9 samples (9.6%) contained both
E. bieneusi
and
E. intestinalis
spores. Quantitative spore counts per ml of stool yielded concentration values from 3.5 × 10
3
to 4.4 × 10
5
for
E. bieneusi
(mean, 8.8 × 10
4
/ml), 2.3 × 10
2
to 7.8 × 10
4
(mean, 1.5 × 10
4
/ml) for
E. intestinalis
, and 1.8 × 10
2
to 3.6 × 10
2
for
E. hellem
(mean, 2.7 × 10
2
/ml). Identification of microsporidian spores by multiplex FISH assay was more sensitive than both Chromotrope-2R and CalcoFluor White M2R stains; 85.5% versus 72.7 and 70.9%, respectively. The study demonstrated that microsporidian coinfection in HIV/AIDS patients with intestinal microsporidiosis is not uncommon and that formalin-stored fecal samples older than 10 years may not be suitable for retrospective analysis by techniques targeting rRNA. Multiplexed FISH assay is a reliable, quantitative fluorescence microscopy method for the simultaneous identification of
E. bieneusi
,
E. intestinalis
, and
E. hellem
, as well as
Encephalitozoon cuniculi
, spores in fecal samples and is a useful tool for assessing spore shedding intensity in intestinal microsporidiosis. The method can be used for epidemiological investigations and applied in clinical settings.
Use of Sequence Analysis of the NS5B Region for Routine Genotyping of Hepatitis C Virus with Reference to C/E1 and 5′ Untranslated Region Sequences
Authors: Murphy Donald G. , Willems Bernard , Deschênes Marc , Hilzenrat Nir , Mousseau Roger , Sabbah Sidney
Published: February 2007

Nucleotide sequence analysis of the NS5B region was performed to identify genotypes of 8,479 hepatitis C virus (HCV) RNA-positive patient samples collected in the Canadian province of Quebec. Genotypes could be determined for 97.3% of patients. Genotypes 1 to 6 were found in 59.4, 9.0, 25.7, 3.6, 0.6, and 1.8% of patients, respectively. Two isolates did not classify within the six genotypes. The subtype 1 distribution was 76.7% 1a, 22.6% 1b, and 0.7% others, while the subtype 2 distribution was 31.8% 2a, 47.6% 2b, 10.9% 2c, 4.1% 2i, and 5.6% others. Subtype 3a accounted for 99.1% of genotype 3 strains, while all genotype 5 samples were of subtype 5a. The subtype 4 distribution was 39.2% 4a, 15.4% 4k, 11.6% 4d, 10.2% 4r, and 23.6% others. The subtype 6 distribution was 40.4% 6e, 20.5% 6a, and 39.1% others. The 5′ untranslated region (5′UTR) sequences of subtype 6e were indistinguishable from those of genotype 1. All samples that did not classify within the established subtypes were also sequenced in C/E1 and 5′UTR. C/E1 phylogenetic reconstructions were analogous to those of NS5B. The sequences identified in this study allowed the provisional assignments of subtypes 1j, 1k, 2m, 2r, 3i, 4q, 6q, 6r, and 6s. Sixty-four (0.8%) isolates classifying within genotypes 1 to 6 could not be assigned to one of the recognized subtypes. Our results show that genotyping of HCV by nucleotide sequence analysis of NS5B is efficient, allows the accurate discrimination of subtypes, and is an effective tool for studying the molecular epidemiology of HCV.
The Adenovirus E4 ORF3 Protein Binds and Reorganizes the TRIM Family Member Transcriptional Intermediary Factor 1 Alpha
Authors: Yondola Mark A. , Hearing Patrick
Published: February 2007

One of the most interesting functions attributed to the adenovirus early region 4 open reading frame 3 (E4 ORF3) protein is its reorganization of promyelocytic leukemia (PML) protein nuclear bodies. These normally punctate structures are reorganized by E4 ORF3 into tracks that eventually surround viral replication centers. PML rearrangement is an evolutionarily conserved function of E4 ORF3, yet its cause and functional relevance remain mysteries. The E4 ORF3 protein coimmunoprecipitates with the PML protein, yet E4 ORF3 still forms tracks in cells that lack PML. The PML protein is a member of a larger protein family termed tripartite motif (TRIM) proteins. TRIM proteins contain a tripartite domain structure in proximity to their N termini that consists of a RING finger domain, followed by one or two B box domains and a C-terminal coiled-coil domain (collectively termed the RBCC domain). The order and spacing of these domains are evolutionarily conserved and thought to mediate protein-protein interactions and other functions. We implemented a proteomic approach to isolate cellular proteins that bind to E4 ORF3. We identified a novel interaction between E4 ORF3 and another TRIM family member, transcriptional intermediary factor 1 alpha (TIF1α). TIF1α functions by recruiting coactivators and/or corepressors to modulate transcription. The interaction between E4 ORF3 and TIF1α was validated by coimmunoprecipitation and binding of recombinant proteins. Indirect immunofluorescence assays demonstrated that TIF1α is reorganized into track structures that contain PML upon E4 ORF3 expression. The RBCC domain of TIF1α is sufficient for E4 ORF3-induced rearrangement, and TIF1α reorganization is conserved across adenovirus serotypes.
Phenotypic and Genotypic Comparisons of Human T-Cell Leukemia Virus Type 1 Reverse Transcriptases from Infected T-Cell Lines and Patient Samples
Authors: Mitchell Michael S. , Bodine Ellen T. , Hill Shawn , Princler Gerald , Lloyd Patricia , Mitsuya Hiroaki , Matsuoka Masao , Derse David
Published: February 2007

It is well established that cell-free infection with human T-cell leukemia virus type 1 (HTLV-1) is less efficient than that with other retroviruses, though the specific infectivities of only a limited number of HTLV-1 isolates have been quantified. Earlier work indicated that a postentry step in the infectious cycle accounted for the poor cell-free infectivity of HTLV-1. To determine whether variations in the
pol
gene sequence correlated with virus infectivity, we sequenced and phenotypically tested
pol
genes from a variety of HTLV-1 isolates derived from primary sources, transformed cell lines, and molecular clones. The
pol
genes and deduced amino acid sequences from 23 proviruses were sequenced and compared with 14 previously published sequences, revealing a limited number of amino acid variations among isolates. The variations appeared to be randomly dispersed among primary isolates and proviruses from cell lines and molecular clones. In addition, there was no correlation between reverse transcriptase sequence and the disease phenotype of the original source of the virus isolate. HTLV-1
pol
gene fragments encoding reverse transcriptase were amplified from a variety of isolates and were subcloned into HTLV-1 vectors for both single-cycle infection and spreading-infection assays. Vectors carrying
pol
genes that matched the consensus sequence had the highest titers, and those with the largest number of variations from the consensus had the lowest titers. The molecular clone from CS-1 cells had four amino acid differences from the consensus sequence and yielded infectious titers that were approximately eight times lower than those of vectors encoding a consensus reverse transcriptase.
Multiple Roles of Epstein-Barr Virus SM Protein in Lytic Replication
Authors: Han Zhao , Marendy Elessa , Wang Yong-Dong , Yuan Jing , Sample Jeffery T. , Swaminathan Sankar
Published: February 2007

The effect of Epstein-Barr virus (EBV) SM protein on EBV gene expression was examined using a recombinant EBV strain with the SM gene deleted and DNA microarrays representing all known EBV coding regions. Induction of lytic EBV replication in the absence of SM led to expression of approximately 40% of EBV genes, but a block in expression of over 50% of EBV genes. Contrary to previous findings, several early genes were SM dependent, and lytic EBV DNA replication did not occur in the absence of SM. Notably, two genes essential for lytic EBV DNA replication, BSLF1 and BALF5, encoding EBV DNA primase and polymerase, respectively, were SM dependent. Lytic DNA replication was partially rescued by ectopic expression of EBV primase and polymerase, but virion production was not. Rescue of DNA replication only enhanced expression of a subset of late genes, consistent with a direct requirement for SM for late gene expression in addition to its contribution to DNA replication. Therefore, while SM is essential for most late gene expression, the proximate block to virion production by the EBV SM deletion strain is an inability to replicate linear DNA. The block to DNA replication combined with the direct effect of SM on late gene expression leads to a global deficiency of late gene expression. SM also inhibited BHRF1 expression during productive replication in comparison to that of cells induced into lytic replication in the absence of SM. Thus, SM plays a role in multiple steps of lytic cycle EBV gene expression and that it is transcript-specific in both activation and repression functions.
SUBFACTORS AND 1+1-DIMENSIONAL TQFTs
Authors: KODIYALAM VIJAY , PATI VISHWAMBHAR , SUNDER V. S.
Published: February 2007

We construct a certain "cobordism category" [Formula: see text] whose morphisms are suitably decorated cobordism classes between similarly decorated closed oriented 1-manifolds, and show that there is essentially a bijection between (1+1-dimensional) unitary topological quantum field theories (TQFTs) defined on [Formula: see text], on the one hand, and Jones' subfactor planar algebras, on the other.
FACTORS GENERATED BY C*-FINITELY CORRELATED STATES
Authors: OHNO H.
Published: February 2007

We present several equivalent conditions for C*-finitely correlated states defined on the UHF algebras to be factor states and consider the types of factors generated by them. Subfactors generated by generalized quantum Markov chains defined on the gauge-invariant parts of the UHF algebras are also discussed.
A DISSIPATION-FREE TIME-DOMAIN DISCONTINUOUS GALERKIN METHOD APPLIED TO THREE-DIMENSIONAL LINEARIZED EULER EQUATIONS AROUND A STEADY-STATE NON-UNIFORM INVISCID FLOW
Authors: BERNACKI MARC , PIPERNO SERGE
Published: February 2007

We present in this paper a time-domain discontinuous Galerkin dissipation-free method for the transient solution of the three-dimensional linearized Euler equations around a steady-state solution. In the general context of a nonuniform supporting flow, we prove, using the well-known symmetrization of Euler equations, that some aeroacoustic energy satisfies a balance equation with source term at the continuous level, and that our numerical framework satisfies an equivalent balance equation at the discrete level and is genuinely dissipation-free. In the case of ℙ1 Lagrange basis functions and tetrahedral unstructured meshes, a parallel implementation of the method has been developed, based on message passing and mesh partitioning. Three-dimensional numerical results confirm the theoretical properties of the method. They include test-cases where Kelvin–Helmholtz instabilities appear.
Molecular Mechanisms of Magnetosome Formation
Authors: Komeili Arash
Published: February 2007

Magnetotactic bacteria are a diverse group of microorganisms with the ability to use geomagnetic fields for direction sensing. This unique feat is accomplished with the help of magnetosomes, nanometer-sized magnetic crystals surrounded by a lipid bilayer membrane and organized into chains via a dedicated cytoskeleton within the cell. Because of the special properties of these magnetic crystals, magnetotactic bacteria have been exploited for a variety of applications in diverse disciplines from geobiology to biotechnology. In addition, magnetosomes have served as a powerful model system for the study of biomineralization and cell biology in bacteria. This review focuses on recent advances in understanding the molecular mechanisms of magnetosome formation and magnetite biomineralization.