bluuebunny/crossref_metadata_2025 huggingface dataset:
Instability and transition to turbulence in a free shear layer affected by a parallel magnetic field
Authors: VOROBEV A. , ZIKANOV O.
Published: February 2007

Instability and transition to turbulence in a temporally evolving free shear layer of an electrically conducting fluid affected by an imposed parallel magnetic field is investigated numerically. The case of low magnetic Reynolds number is considered. It has long been known that the neutral disturbances of the linear problem are three-dimensional at sufficiently strong magnetic fields. We analyse the details of this instability solving the generalized Orr–Sommerfeld equation to determine the wavenumbers, growth rates and spatial shapes of the eigenmodes. The three-dimensional perturbations are identified as oblique waves and their properties are described. In particular, we find that at high hydrodynamic Reynolds number, the effect of the strength of the magnetic field on the fastest growing perturbations is limited to an increase of their oblique angle. The dimensions and spatial shape of the waves remain unchanged. The transition to turbulence triggered by the growing oblique waves is investigated in direct numerical simulations. It is shown that initial perturbations in the form of superposition of two symmetric waves are particularly effective in inducing three-dimensionality and turbulence in the flow.
Boundary layer flow and bed shear stress under a solitary wave
Authors: LIU PHILIP L.-F. , PARK YONG SUNG , COWEN EDWIN A.
Published: February 2007

Liu & Orfila (J. Fluid Mech. vol. 520, 2004, p. 83) derived analytical solutions for viscous boundary layer flows under transient long waves. Their analytical solutions were obtained with the assumption that the nonlinear inertia force was negligible in the momentum equations. In this paper, using Liu & Orfila's solution and the solutions for the nonlinear boundary layer equations, we examine the boundary layer flow characteristics under a solitary wave. It is found that while the horizontal component of the free-stream velocity outside the boundary layer always moves in the direction of wave propagation, the fluid particle velocity near the bottom inside the boundary layer reverses direction as the wave decelerates. Consequently, the bed shear stress also changes sign during the deceleration phase. Laboratory measurements, including the free-surface displacement, particle image velocimetry (PIV) resolved velocity fields of the viscous boundary layer, and the calculated bed shear stress were also collected to check the theoretical results. Excellent agreement is observed.
Antioxidants promote establishment of trypanosome infections in tsetse
Authors: MacLEOD E. T. , MAUDLIN I. , DARBY A. C. , WELBURN S. C.
Published: February 2007

Efficient, cyclical transmission of trypanosomes through tsetse flies is central to maintenance of human sleeping sickness and nagana across sub-Saharan Africa. Infection rates in tsetse are normally very low as most parasites ingested with the fly bloodmeal die in the fly gut, displaying the characteristics of apoptotic cells. Here we show that a range of antioxidants (glutathione, cysteine, N-acetyl-cysteine, ascorbic acid and uric acid), when added to the insect bloodmeal, can dramatically inhibit cell death ofTrypanosoma brucei bruceiin tsetse. Both L- and D-cysteine invoked similar effects suggesting that inhibition of trypanosome death is not dependent on protein synthesis. The present work suggests that antioxidants reduce the midgut environment protecting trypanosomes from cell death induced by reactive oxygen species.
In vitro efficacy of nitro- and bromo-thiazolyl-salicylamide compounds (thiazolides) against Besnoitia besnoiti infection in Vero cells
Authors: CORTES H. C. E. , MUELLER N. , ESPOSITO M. , LEITÃO A. , NAGULESWARAN A. , HEMPHILL A.
Published: February 2007

Nitazoxanide (NTZ) and its deacetylated metabolite tizoxanide (TIZ) exhibit considerable in vitro activity against Besnoitia besnoiti tachyzoites grown in Vero cells. Real-time-PCR was used to assess B. besnoiti tachyzoite adhesion, invasion, and intracellular proliferation in vitro. A number of NTZ-derivatives, including Rm4822 and Rm4803, were generated, in which the thiazole-ring-associated nitro-group was replaced by a bromo-moiety. We here show that replacement of the nitro-group on the thiazole ring with a bromo (as it occurs in Rm4822) does not impair the efficacy of the drug, but methylation of the salicylate ring at the ortho-position in a bromo-derivative (Rm4803) results in complete abrogation of the antiparasitic activity. Treatment of extracellular B. besnoiti tachyzoites with NTZ has an inhibitory effect on host cell invasion, while treatments with TIZ, Rm4822 do not. TEM demonstrates that the effects of Rm4822 treatment upon the parasites are similar to the damage induced by NTZ. This includes increased vacuolization of the parasite cytoplasm, and loss of the structural integrity of the parasitophorous vacuole and its membrane. Thus, Rm4822, due to the absence of a potentially mutagenic nitro-group, may represent an important potential addition to the anti-parasitic arsenal for food animal production, especially in cattle.
The long-term course of depressive disorders in the Lundby Study
Authors: MATTISSON CECILIA , BOGREN MATS , HORSTMANN VIBEKE , MUNK-JÖRGENSEN POVL , NETTELBLADT PER
Published: February 2007

Background. The Lundby Study is a longitudinal cohort study on a geographically defined population consisting of 3563 subjects. Information about episodes of different disorders was collected during field investigations in 1947, 1957, 1972 and in 1997. Interviews were carried out about current health and past episodes since the last investigation; for all subjects information was also collected from registers, case-notes and key informants. This paper describes the course and outcome of 344 subjects who had their first onset of depression during the follow-up.

Method. In this study individuals who had experienced their first episode of depression were followed up. Their course was studied with regard to recurrence of depression related to duration of follow-up, transition to other psychiatric disorders including alcohol disorders, as well as incidence and risk factors of suicide.

Results. Median age at first onset of depression was around 35 years for individuals followed up for 30–49 years. The recurrence rate was about 40% and varied from 17% to 76% depending on length of follow-up. Transition to diagnoses other than depression was registered in 21% of the total sample, alcohol disorders in 7% and bipolar disorder in 2%. Five per cent committed suicide; male gender and severity of depression were significant risk factors.

Conclusion. The low rates of recurrence and suicide suggest a better prognosis for community samples than for in- and out-patient samples.
Suicide in current psychiatric in-patients: a case-control study The National Confidential Inquiry into Suicide and Homicide
Authors: HUNT ISABELLE M. , KAPUR NAVNEET , WEBB ROGER , ROBINSON JO , BURNS JAMES , TURNBULL PAULINE , SHAW JENNY , APPLEBY LOUIS
Published: February 2007

Background. Few controlled studies have investigated factors associated with suicide in current in-patients. We aimed to identify psychosocial, behavioural and clinical risk factors, including variations in care, for in-patient suicide.

Method. We conducted a national population-based case-control study of people who died by suicide between 1 April 1999 and 31 December 2000 while in psychiatric in-patient care in England. Cases were 222 adult mental health in-patients who died by suicide matched on date of death with 222 living controls.

Results. Nearly a quarter of suicides took place within the first week of admission; most of these died on the ward or after absconding. After the first week, however, most suicides occurred away from the ward, the majority of patients having left the ward with staff agreement. Previous deliberate self-harm, recent adverse life events, symptoms of mental illness at last contact with staff and a co-morbid psychiatric disorder were associated with increased risk for suicide. Being off the ward without staff agreement was a particularly strong predictor. Those patients who were detained for compulsory treatment were less likely to die by suicide. Independent predictors of in-patient suicide were male sex, a primary diagnosis of affective disorder and a history of self-harm. Being unemployed or on long-term sick leave appeared to be independently protective.

Conclusion. Prevention of in-patient suicide should emphasize adequate treatment of affective disorder, vigilance in the first week of admission and regular risk assessments during recovery and prior to granting leave. Use of compulsory treatment may reduce risk.
Intersections of age and masculinities in the information technology industry
Authors: COMEAU TAMMY DUERDEN , KEMP CANDACE L.
Published: February 2007

This paper explores the intersections of age and masculinities in small information technology (IT) firms in Canada. The IT workforce, although demographically young, does not entirely comprise younger workers but is dominated by men and is ageing. Despite the infamous ‘nerd’ stereotype of IT workers and its associations with immature age and masculinity, perceptions of age and ageing in the industry have not been considered in the context of masculinities. To what extent are conceptualisations of IT work shaped by notions of age and masculinities? How do perceptions of age and masculinities correspond to occupational trajectories and responsibilities in IT work settings? To address these questions, this paper reports an analysis of qualitative semi-structured interviews with 76 employees of small IT firms in Canada. The findings indicate that the dominant frameworks for describing the nature of IT work are metaphors and analogies with sports, the military, entrepreneurial drive and craftsmanship. This paper focuses on the allusions to sport, war and ‘being driven’, and argues that the discursive ties to these masculine arenas normalise, or make ‘natural’, the affiliation of youthfulness and technical ability. The corresponding intersections between age and masculinity suggest that older workers are marginalised in small IT firms.
Influenza-attributable deaths, Canada 1990–1999
Authors: SCHANZER D. L. , TAM T. W. S. , LANGLEY J. M. , WINCHESTER B. T.
Published: February 2007

The number of deaths attributable to influenza is believed to be considerably higher than the number certified by vital statistics registration as due to influenza. Weekly mortality data for Canada from the 1989/1990 to the 1998/1999 influenza seasons were analysed by cause of death, age group, and place of death to estimate the impact of influenza on mortality. A Poisson regression model was found to accurately predict all-cause, as well as cause-specific mortality, as a function of influenza-certified deaths, after controlling for seasonality, and trend. Influenza-attributable deaths were calculated as predicted less baseline-predicted deaths. In summary, throughout the 1990s there were on average just under 4000 deaths attributable to influenza annually (for an influenza-attributable mortality rate of 13/100 000 persons), varying from no detectable excess mortality for the 1990/1991 influenza season, to 6000–8000 influenza-attributable deaths for the more severe influenza seasons of 1997/1998 and 1998/1999. On average, 8% (95% CI 7–10) of influenza-attributable deaths were certified as influenza, although this percentage varied from 4% to 12% from year to year. Only 15% of the influenza-attributable deaths were certified as pneumonia, and for all respiratory causes, 40%. Deaths were distributed over most causes. The weekly pattern of influenza-certified deaths was a good predictor of excess all-cause mortality.
Emerging fluoroquinolone and macrolide resistance ofCampylobacter jejuniandCampylobacter coliisolates and their serotypes in Thai children from 1991 to 2000
Authors: SERICHANTALERGS O. , DALSGAARD A. , BODHIDATTA L. , KRASAESUB S. , PITARANGSI C. , SRIJAN A. , MASON C. J.
Published: February 2007

This study investigated fluoroquinolone, macrolide resistances and serotype distributions amongCampylobacter jejuniandCampylobacter coliisolated from children in Bangkok and rural settings during 1991–2000. Phenotypic identification, serotyping, and susceptibility testing were performed by standard microbiological procedures. The predominant serotypes ofC. jejuniwere Lior 36, 2 and 4 and ofC. coliwere Lior 8, 29 and 55. Resistance to nalidixic acid increased significantly during 1991–2000 and the frequency of isolates resistant to both nalidixic acid and ciprofloxacin in Bangkok was significantly greater than in rural settings. In 1996–2000, a significant trend was observed inC. jejuniisolates resistant to ciprofloxacin from Bangkok but not for macrolide resistance from both settings. In summary, fluoroquinolone resistance amongC. jejuniandC. coliisolates became widespread in both Bangkok and rural settings in Thailand in the 1990s while widespread resistance to macrolides was undetected.
Industry Watch: Is 2007 the Year of Question-Answering?
Authors: DALE ROBERT
Published: February 2007

Back at the beginning of 2000, I was a member of a working group tasked to come up with some guidelines for revamping my University's website.During one of our meetings, someone made the suggestion thatdecisions about howto structure and present information on the website should be driven by the kinds of questions that users come to the site with.Suddenly a light went on, and there appeared an idea for data gathering that might provide us withsome useful information. To find out what people really wanted to know whenthey visited the website, we would replace the University's searchengine by a page that invited the user to type in his or her query as a full natural language question. Appropriately chosen examples would be given todemonstrate that using real questions delivered better pages as a result. The data gathered would tell us what people were really looking for, more than could be gleaned from conventional search queries, and would therefore help usto better structure the information available on the website.
Obesity and related risk factors among low socio-economic status minority students in Chicago
Authors: Wang Youfa , Liang Huifang , Tussing Lisa , Braunschweig Carol , Caballero Benjamin , Flay Brian
Published: February 2007

Objectives

To assess overweight and related risk factors among urban low socio-economic status (SES) African-American adolescents in an attempt to study the underlying causes of ethnicity and gender disparities in overweight.

Methods

Cross-sectional data collected on anthropometric measures, diet, physical activity and family characteristics from 498 students in grades 5–7 in four Chicago public schools were analysed to study the risk factors for overweight using stepwise regression analysis.

Results

Only 37.2% of the students lived with two parents. Nearly 90% had a television (TV) in their bedroom, and had cable TV and a video game system at home. Overall. 21.8% (17.7% boys versus 25.1% girls) were overweight (body mass index (BMI) ≥ 95th percentile); and 39.8% had a BMI ≥ 85th percentile. Compared with national recommendations, they had inadequate physical activity and less than desirable eating patterns. Only 66.1% reported having at least 20 min vigorous exercise or 30 min of light exercise in ≥ 5 days over the past 7 days; 62.1% spent >3 h days− 1 watching TV/playing video games/computer, while 33.1% spent ≥ 5 h days− 1. Their vegetable and fruit consumption was low, and they consumed too many fried foods and soft drinks: 55.1% consumed fried food twice or more daily and 19.5% four times or more daily; 70.3% consumed soft drinks twice or more daily and 22.0% four times or more daily on average. Gender, physical activity and pocket money were significant predictors of overweight (P < 0.05).

Conclusions

Several factors in the students' behaviours, school and family environments may increase overweight risk among this population. There is a great need for health promotion programmes with a focus on healthy weight and lifestyle, and targeting urban low-SES minority communities.
Habitual physical activity and body composition of black township adolescents residing in the North West Province, South Africa
Authors: Mamabolo RL , Kruger HS , Lennox A , Monyeki MA , Pienaar AE , Underhay C , Czlapka-Matyasik M
Published: February 2007

Objective

It is known that stunting and obesity affect a large proportion of children in the world, and these can be affected by the physical activity levels of the children. In the present study, we evaluated the association between physical activity, physical development and body composition in black adolescent children.

Design

Cross-sectional study.

Setting

Black township schools in the North West Province, South Africa.

Methods

Three-hundred and thirteen grade 8 children were included in the Physical Activity in Youth study. Anthropometric measurements, body composition measures and maturity level as assessed by Tanner stages were determined in these children. In addition, Previous Day Physical Activity Recall questionnaires were administered on the children to record the various activities they undertake daily.

Results

The demographic characteristics of the children showed a high level of homogeneity. A high prevalence of stunting (16.3%) was observed in the children, which was higher in boys than in girls (21.6 vs. 12.3%). Also prevalent was overweight/obesity (8.6%), but this was higher in girls than in boys (13.4 vs. 1.6%). The children also showed a reduction in levels of physical activity with advancement in maturity; furthermore, boys showed a more central form of fat deposition whilst girls showed more gynoid deposition.

Conclusions

The study revealed that physical activity plays a role in determining body composition, and further indicated that physical activity is associated with favourable body composition measures. Children who were more active were likely to have less fat deposits.
Introduction: law and neuroscience
Authors: Freeman Michael
Published: February 2007

The articles in this Special Issue of the journal explore diverse issues, but all in different ways are stimulated by developments in our understanding of the brain. It is coming to be understood that developments in neuroscience can help those who make the law and those who study it use the insights of scientific knowledge to assist in the understanding of human behaviour. Developments in cognitive neuroscience offer new insights into the nature of normative judgement. As Casebeer and Churchland (2003, p. 170) have noted, ‘the neurobiology of moral cognition is a justifiably hot topic’. As Goodenough and Prehn (2004, p. 1713) note, ‘the great advantage of the cognitive neuroscience approach is that we can now bring together psychological models of cognitive and affective process, experimental paradigms, various behavioural and psychophysiological measurements and functional brain imaging techniques’. Greene and Cohen have argued (2004, p. 1775) that neuroscience will probably have a transformative effect on the law, even though existing legal doctrine can, in principle, accommodate its findings. They foresee, and indeed recommend, a shift away from punishment rooted in retribution towards one adopting a consequentialist approach to the criminal law. That the US Supreme Court in 2005 (see Roper v. Simmons) eventually came to view the death penalty as unconstitutional for offenders who committed their offences when under 18 is in part the product of this shift in thinking. Steinberg and Scott (2003) had shown that adolescents did not meet the law’s requirements for rationality and so were unsuitable candidates for the death penalty.
Determinism, neuroscience and responsibility
Authors: Grant James
Published: February 2007

Fears that new scientific advances on the mind and the brain which establish that behaviour is determined by causes in one’s mind/brain and/or various past and present internal and external environments will undermine the attribution of legal responsibility are misplaced. Taking responsibility to inhere where conduct reflects upon an individual and where, properly understood, the individual could have done otherwise, determinism, operating in the right sort of way, should be embraced as a condition for responsibility.
Reflections on reading: words and pictures and law
Authors: Spiesel Christina
Published: February 2007

The practice of law today is awash with pictures of all kinds – from those that begin conceptually like graphs, diagrams or flow charts to those that originate in perception, like photographs, or those that emerge from the actions of technology, like animations and fMRI. Pictures are used as evidence, demonstratives, and for argument. The legal academy has yet seriously to come to grips with the changes that this infusion of the visual means for legal thinking and rhetoric. This article explores the intellectual implications of picturing in a discipline that has thought of itself as preeminently about the use of words and their linear logics. To do this, the author has sought out eye movement research, asking the question: Do we read pictures differently from words? If so, what are the implications of this as understood both in cognitive terms and in cultural terms? That is, can the differences in perceptual behaviour be seen as offering clues to differences in cognitive behaviour? Existing knowledge seems to answer these questions in the affirmative, which means that the deeply held cultural bias that maintains that only words containing thought needs revision. This article concludes with reflections on some benefits that adjustments to our understanding might give to legal thinkers.
Arbeitseinstellungen, Wohlbefinden und Leistung
Authors: Schmidt Klaus-Helmut , Neubach Barbara , Heuer Herbert
Published: February 2007

Zusammenfassung. Die meisten Untersuchungen der Beziehung zwischen Arbeitszufriedenheit, anderen arbeitsbezogenen Einstellungen und der Arbeitsleistung wurden auf der Ebene von Individuen als Einheiten der Analyse durchgeführt. In den letzten Jahren ist eine Verlagerung der Analyse dieser Beziehung auf die Ebene von Organisationen bzw. organisatorischen Teilstrukturen zu beobachten. Die vorliegende Studie untersucht Zusammenhänge zwischen Arbeitszufriedenheit, Organisationsbindung, Wohlbefinden und der Leistung in jeweils zwei getrennten Organisationseinheiten aus 111 Dienststellen einer großen Landesverwaltung. An der Untersuchung waren 5 261 Personen beteiligt. Ergebnisse von Korrelations- und Regressionsanalysen bestätigen die Existenz der erwarteten Beziehungen auf Organisationsebene. Die durch die Einstellungs-/Befindensmaße aufgeklärten Varianzanteile der Leistung variierten zwischen 13 % und 32 %. Zusätzlich durchgeführte Extremgruppenanalysen belegen auch die praktische Bedeutsamkeit der gefundenen Zusammenhänge.
AIST-R - Allgemeiner Interessen-Struktur-Test mit Umwelt-Struktur-Test (UST-R) - Revision
Authors: Muck Peter M.
Published: February 2007

Zusammenfassung. Mit dem AIST-R liegt eine revidierte Version des Allgemeinen Interessen-Struktur-Tests (1. Auflage von Bergmann & Eder, 1992 ) zur Erfassung des Hexagon-Modells beruflicher Interessen (z. B. Holland, 1997 ) vor. Sowohl eine Neu- bzw. Umformulierung einer großen Anzahl von Items als auch eine Neunormierung wurden vorgenommen. Die Modernisierung wird als gut begründet angesehen. Die Abbildung des theoretischen Strukturmodells gelingt eher bei weiblichen Personen sowie bei Personen mit höherer Schulbildung. Erste Reliabilitäts- und Validitätsbefunde sprechen für eine gelungene Überarbeitung des Verfahrens. Sein Einsatz ist vor allem in der schulischen, der Berufs- und der Laufbahnberatung zu empfehlen.
A Multitrait-Multimethod Validation of the Implicit Association Test
Authors: Nosek Brian A. , Smyth Frederick L.
Published: February 2007

Abstract. Recent theoretical and methodological innovations suggest a distinction between implicit and explicit evaluations. We applied Campbell and Fiske's (1959) classic multitrait-multimethod design precepts to test the construct validity of implicit attitudes as measured by the Implicit Association Test (IAT). Participants (N = 287) were measured on both self-report and IAT for up to seven attitude domains. Through a sequence of latent-variable structural models, systematic method variance was distinguished from attitude variance, and a correlated two-factors-per-attitude model (implicit and explicit factors) was superior to a single-factor-per-attitude specification. That is, despite sometimes strong relations between implicit and explicit attitude factors, collapsing their indicators into a single attitude factor resulted in relatively inferior model fit. We conclude that these implicit and explicit measures assess related but distinct attitude constructs. This provides a basis for, but does not distinguish between, dual-process and dual-representation theories that account for the distinctions between constructs.
Affective Priming of Nonaffective Semantic Categorization Responses
Authors: Spruyt Adriaan , De Houwer Jan , Hermans Dirk , Eelen Paul
Published: February 2007

Recent studies have shown that robust affective priming effects can be obtained when participants are required to categorize the targets on the basis of their valence, but not when participants are asked to categorize the targets on the basis of nonaffective features. On the basis of this pattern of results, it has been argued that affective priming is due to processes that operate at a response selection stage rather than to processes that operate at an encoding stage. We demonstrate (a) that affective priming of nonaffective semantic categorization responses can be obtained when participants assign attention to the affective stimulus dimension, and (b) that affective priming in the standard evaluative categorization task is strongly reduced when participants assign attention to nonaffective stimulus features. On the basis of these findings, we argue (a) that processes operating at an encoding stage do contribute to the affective priming effect, and (b) that automatic affective stimulus processing is reduced when participants selectively attend to nonaffective stimulus features.
Early evolution of Mars with mantle compositional stratification or hydrothermal crustal cooling
Authors: Parmentier E. M. , Zuber M. T.
Published: February 2007

Analysis of Martian gravity and topography implies that crustal thickness variations created in the earliest evolution of planet have persisted to the present day. Relaxation of crustal thickness variations due to lower crustal flow by thermally activated creep is strongly temperature‐dependent and so, for particular crustal rheology and thickness, provides a constraint on thermal evolution. Previous models have assumed that the heat flux from the mantle, which controls lower crustal temperatures, simply reflects radiogenic heat production. However, global thermal evolution models in which the mantle cools by solid‐state thermal convection indicate that the additional contribution to near‐surface heat flux due to secular cooling significant increases lower crustal temperatures. With, a 50‐km‐thick crust, and a wet diabase rheology, these higher temperatures allow crustal rock to flow fast enough to relax crustal thickness variations during the first ∼750 Myr of evolution. Previous studies have not considered the presence of an impact‐brecciated crustal layer that would almost certainly be present on early Mars and could have a significant influence on crustal temperatures. The presence of a dry brecciated crustal layer several kilometers thick would significantly increase the temperature of the lower crust resulting in more rapid relaxation of crustal thickness variations. If the porosity of a brecciated crust is water saturated, then the effect of such a layer is greatly reduced. However, if water is present, cooling of the upper crust by groundwater convection in a deeper impact‐fractured crustal layer with modest permeabilities could reduce lower crustal temperatures enough to explain the preservation of ancient crustal thickness variations. A cooler lower crust is also possible if solid‐state thermal convection in the mantle is inhibited by a stable compositional stratification resulting from the fractional solidification of an early magma ocean.
Dynamic models for mantle flow and seismic anisotropy in the North Atlantic region and comparison with observations
Authors: Marquart Gabriele , Schmeling Harro , Čadek Ondřej
Published: February 2007

Dynamic mantle flow and temperature models for the North Atlantic based on a regionalized P‐wave and a global S‐wave tomography model were derived under the constraint of a maximum fit to the observed gravity field. For the regional flow model Cartesian geometry, temperature‐ and depth‐dependent viscosity and a free slip surface were assumed, while the global model assumed a radially dependent viscosity and kinematic plate velocity boundary conditions. Both models show pronounced upwellings within the upper mantle beneath the Iceland area and the lower mantle beneath, the regional model containing a lateral shift associated with a horizontal flow near 660 km depth. The upper mantle temperature field of the regional model shows two distinct anomalies, one beneath Iceland and the westerly adjacent regions with a connection to a deep mantle root and an excess temperature of 200°C, and a second one below 300 km at the Kolbeinsey Ridge with an excess temperature of 120°C. These anomalies do not appear to be connected. An essentially radial flow pattern is found south of Iceland with ridge parallel flow along Reykjanes and divergent flow at the Kolbeinsey Ridge. The long‐wavelength global model does not show such details but is characterized by a NE‐SW elongated upwelling flow beneath Iceland and a ridge perpendicular flow within the upper mantle. From the modeled flow fields, lattice preferred orientations (LPO) of olivine are calculated. For the regional model, azimuthal seismic anisotropy is predicted with fast directions diverging away from Iceland and the Kolbeinsey ridge. The global model predicts roughly ridge perpendicular fast directions. Comparison of predicted with observed seismic anisotropy models shows regions of good agreement north, east, and SE of Iceland, as well as for Iceland. No agreement is found beneath the Reykjanes Ridge area, leading to the speculation that the fast directions are perpendicular to the flow due to a change in the LPO generating mechanism. Regarding geochemical findings, the regional flow model can explain plume‐related geochemical signatures observed on the Reykjanes Ridge and predicts a deep, hot melt zone beneath the Kolbeinsey Ridge without plume tracers.
REMAP: A reaction transport model for isotope ratio calculations in porous media
Authors: Chernyavsky Boris M. , Wortmann Ulrich G.
Published: February 2007

Reactive transport modeling has become an important tool in geochemistry and has recently been expanded to isotopic studies as well. However, there is currently no publicly available code specifically tailored to isotopic studies. We therefore present here a computer program for 1‐D reactive transport modeling of bacterially mediated isotope fractionation processes in porous media. Our numerical method allows the modeling of both stationary and time‐dependent processes and implements various boundary condition types, including floating boundaries. The model specifically handles cases where the substrate is fully consumed, either at the lower boundary or at any point within the model. We provide a detailed analysis of our implementation as well as some example cases. The program is designed to be run on Matlab or Octave, which are available for all major operating systems.
Possible eigenmode trapping in density enhancements in Saturn's inner magnetosphere
Authors: Menietti J. D. , Yoon P. H. , Gurnett D. A.
Published: February 2007

We report a re‐examination of observations of radio waves and banded fine structure observed by Cassini in the Saturn inner magnetosphere. These emissions have been identified in the past as Z‐mode emission from possible density cavities along the inner edge of the Saturn plasma torus. A careful examination of the emission fine structure in a region where the ratio of plasma to cyclotron frequency fp/fce < 1 suggests that the emission bands may be due to eigenmode trapping from density enhancement source regions. The observations are similar to those made at both the Earth and Jupiter and suggest that radio emission fine structure is a remote diagnostic of density fluctuations in planetary magnetospheres.
On the post‐sunset rise of the equatorial F layer and superposed upwellings and bubbles
Authors: Tsunoda Roland T. , Ecklund Warner L.
Published: February 2007

Usual practice has been to describe the post‐sunset rise (PSSR) of the equatorial F layer with the vertical drift velocity measured overhead, as a function of local time, by a ground‐based sensor. However, with the finding that large‐scale wave structure (LSWS) develops with its own eastward polarization electric field, during a PSSR, the measured upward velocity must now be thought of as containing two components, one associated with PSSR, and the other with LSWS. This distinction may hold the key to understanding the lack of correlation, on a day‐to‐day basis, between measured vertical drift and ensuing plasma structure in the form of plasma bubbles. Measurements of backscatter from the bottomside of the F layer, using a three‐beam radar at Pohnpei, are presented in this paper to further validate this interpretation.
Geometry of the high‐latitude magnetopause as observed by Cluster
Authors: Zhang H. , Dunlop M. W. , Zong Q.‐G. , Fritz T. A. , Balogh A. , Wang Y.
Published: February 2007

This investigation reveals the geometrical properties of the high‐latitude boundaries surrounding the high‐altitude cusp. These have been shown by recent studies to include the outer boundary between the magnetosheath and the cusp; the outer boundary between the magnetosheath and the high‐latitude, closed field‐line region of the dayside magnetosphere (which we call the high‐latitude trapping region (HLTR)); and the inner boundaries on the equatorward and tailward edges of the high‐altitude cusp region. We present a survey of the normal directions of the outer boundaries: between the magnetosheath and cusp in comparison to between the magnetosheath and the HLTR. This study is based on the magnetic field data set obtained by the Cluster quartet for a period during which the orbits passed through either the dayside cusp or the magnetopause on consecutive orbits. These initial results show some evidence of the control of cusp geometry by the IMF orientation and clear trends which are consistent with an indentation or at least a nonplanar geometry in the cusp‐magnetosheath boundary for those cases which are clearly identified. The detailed geometry of all surrounding cusp boundaries, deduced from selected crossings in the data set, case by case, is also shown to support these findings and to address the issue of the identification of relative spacecraft location with respect to this highly dynamic region.
Effects of adenosine on adhesion molecule expression and cytokine production in human PBMC depend on the receptor subtype activated
Authors: Takahashi H K , Iwagaki H , Hamano R , Wake H , Kanke T , Liu K , Yoshino T , Tanaka N , Nishibori M
Published: February 2007

Background and purpose:

Adenosine suppresses immune responses through adenosine2A(A2A) receptors, by raising intracellular cAMP. Interleukin (IL)‐18 up‐regulates the expression of intercellular adhesion molecule (ICAM)‐1 on monocytes, leading to production of pro‐inflammatory cytokines such as IL‐12, interferon (IFN)‐γand tumor necrosis factor (TNF)‐αby human peripheral blood mononuclear cells (PBMC). We have previously demonstrated that elevation of cAMP inhibits this IL‐18‐induced expression of adhesion molecules. In the present study, we examined the effect of adenosine on the IL‐18‐induced up‐regulation of ICAM‐1 on human monocytes and production of IL‐12, IFN‐γand TNF‐αby PBMC.

Experimental approach:

The expression of ICAM‐1 was examined by flow cytometry. IL‐12, IFN‐γand TNF‐αwere determined by ELISA assay.

Key results:

Adenosine inhibited the IL‐18‐induced up‐regulation of ICAM‐1 on human monocytes and it abolished the IL‐18‐enhanced production of IL‐12, IFN‐γand TNF‐α. While an A2Areceptor antagonist reversed the action of adenosine, an A1or A3receptor antagonist enhanced them. An A2Areceptor agonist, CGS21680, mimicked the effects of adenosine and its effects were abolished not only by the A2Areceptor antagonist but also by A1or A3receptor agonists. Activation via A2Areceptors resulted in elevation of cAMP in monocytes, whereas the stimulation of A1or A3receptors inhibited it, suggesting that intracellular signal transduction following ligation of A2Areceptors might be blocked by activation of A1or A3receptors.

Conclusions and Implications:

Adenosine differentially regulates IL‐18‐induced adhesion molecule expression and cytokine production through several subtypes of its receptors.

British Journal of Pharmacology(2007)150, 816–822. doi:10.1038/sj.bjp.0707126
Escherichia coli minimum genome factory
Authors: Mizoguchi Hiroshi , Mori Hideo , Fujio Tatsuro
Published: February 2007

Research programmes for constructing a ‘cell factory’ have been funded in several countries. In Japan, the ‘Minimum genome factory’ (MGF) project was launched in 2001. In this project, several model microbes have been genetically reconstructed to obtain a cell with fewer genes on a chromosome of reduced size. A microbe with a ‘minimum genome’ is expected to exhibit less regulation and therefore to be an ideal platform for a cell‐factory system. The goal of this project is to construct such a minimum genome microbe for a cell factory. In this project, the 4.6 Mbp genome of Escherichia coli K‐12 has been successfully reduced to 3.6 Mbp. The constructed reduced‐genome strain, MGF‐01, shows better growth and higher threonine production compared with the wild‐type strain. Furthermore functional analyses of all E. coli genes have also been performed. CGH (comparative genomic hybridization) analysis revealed that about 2600 genes were commonly conserved in the 23 E. coli strains tested. This set of conserved genes was hypothesized as a core set for E. coli species. Phenotype array analysis of a nearly complete collection of single‐gene knockout mutants of E. coli provided insights into E. coli metabolic networks. The data sets from the functional genomics will be used to improve design of an E. coli MGF. The present minireview summarizes the progress of the E. coli MGF project and overviews related research.
Bacillus minimum genome factory: effective utilization of microbial genome information
Authors: Ara Katsutoshi , Ozaki Katsuya , Nakamura Kouji , Yamane Kunio , Sekiguchi Junichi , Ogasawara Naotake
Published: February 2007

In 1997, the complete genomic DNA sequence of Bacillus subtilis (4.2 Mbp) was determined and 4100 genes were identified [Kunst, Ogasawara, Moszer, Albertini, Alloni, Azevedo, Bertero, Bessieres, Bolotin, Borchert, S. et al. (1997) Nature 90, 249–256]. In addition, B. subtilis, which shows an excellent ability to secrete proteins (enzymes) and antibiotics in large quantities outside the cell, plays an important role in industrial and medical fields. It is necessary to clarify the genes involved in the production of compounds by understanding the network of these 4100 genes and the proceeding analysis of genes of unknown functions. In promoting such a study, it is expected that the regulatory system of B. subtilis can be simplified by the creation of a Bacillus strain with a reduced genome by discriminating genes unnecessary for the production of proteins from essential genes, and deleting as many of these unnecessary genes as possible, which may help to understand this complex network of genes. We have previously distinguished essential and non‐essential genes by evaluating the growth and enzyme‐producing properties of strains of B. subtilis in which about 3000 genes (except 271 essential genes) have been disrupted or deleted singly, and have successfully utilized the findings from these studies in creating the MG1M strain with an approx. 1 Mbp deletion by serially deleting 17 unnecessary regions from the genome. This strain showed slightly reduced growth in enzyme‐production medium, but no marked morphological changes. Moreover, we confirmed that the MG1M strain had cellulase and protease productivity comparable with that of the B. subtilis 168 strain, thus demonstrating that genome reduction does not contribute to a negative influence on enzyme productivity.
Acetaldehyde dissociates the PTP1B–E-cadherin–β-catenin complex in Caco-2 cell monolayers by a phosphorylation-dependent mechanism
Authors: Sheth Parimal , Seth Ankur , Atkinson Katherine J. , Gheyi Tarun , Kale Gautam , Giorgianni Francesco , Desiderio Dominic M. , Li Chunying , Naren Anjaparavanda , Rao Radhakrishna
Published: February 2007

Interactions between E-cadherin, β-catenin and PTP1B (protein tyrosine phosphatase 1B) are crucial for the organization of AJs (adherens junctions) and epithelial cell–cell adhesion. In the present study, the effect of acetaldehyde on the AJs and on the interactions between E-cadherin, β-catenin and PTP1B was determined in Caco-2 cell monolayers. Treatment of cell monolayers with acetaldehyde induced redistribution of E-cadherin and β-catenin from the intercellular junctions by a tyrosine phosphorylation-dependent mechanism. The PTPase activity associated with E-cadherin and β-catenin was significantly reduced and the interaction of PTP1B with E-cadherin and β-catenin was attenuated by acetaldehyde. Acetaldehyde treatment resulted in phosphorylation of β-catenin on tyrosine residues, and abolished the interaction of β-catenin with E-cadherin by a tyrosine kinase-dependent mechanism. Protein binding studies showed that the treatment of cells with acetaldehyde reduced the binding of β-catenin to the C-terminal region of E-cadherin. Pairwise binding studies using purified proteins indicated that the direct interaction between E-cadherin and β-catenin was reduced by tyrosine phosphorylation of β-catenin, but was unaffected by tyrosine phosphorylation of E-cadherin-C. Treatment of cells with acetaldehyde also reduced the binding of E-cadherin to GST (glutathione S-transferase)–PTP1B. The pairwise binding study showed that GST–E-cadherin-C binds to recombinant PTP1B, but this binding was significantly reduced by tyrosine phosphorylation of E-cadherin. Acetaldehyde increased the phosphorylation of β-catenin on Tyr-331, Tyr-333, Tyr-654 and Tyr-670. These results show that acetaldehyde induces disruption of interactions between E-cadherin, β-catenin and PTP1B by a phosphorylation-dependent mechanism.
Immediate early gene-X1 interferes with 26 S proteasome activity by attenuating expression of the 19 S proteasomal components S5a/Rpn10 and S1/Rpn2
Authors: Arlt Alexander , Minkenberg Jörg , Kruse Marie-Luise , Grohmann Frauke , Fölsch Ulrich R. , Schäfer Heiner
Published: February 2007

The stress response gene IEX-1 (immediate early gene-X-1) is involved in the regulation of cell growth and cellular viability. To some extent, these effects include an interference with the proteasomal turnover of certain regulatory proteins. Here, we show that IEX-1 directly attenuates the activity and formation of the 26 S proteasome in HEK-293 cells (human embryonic kidney cells). We further demonstrate that IEX-1 reduces the overall expression levels of certain protein components of the 19 S proteasomal subunit such as S5a/Rpn10 and S1/Rpn2, whereas the expression of other proteasomal proteins was less or not affected. In contrast with direct apoptotic stimuli, such as the anti-cancer drug etoposide, leading to caspase-dependent degradation of S1 and S5a, the effect of IEX-1 is independent of proteolytic cleavage of these proteins. Furthermore, the decreasing effect of IEX-1 on S5a and S1 expression is still seen in the presence of cycloheximide, but not in the presence of actinomycin D, and quantitative real-time PCR revealed lower mRNA levels of S5a and S1 in IEX-1-overexpressing cells, suggesting an interference of IEX-1 with the gene transcription of S5a and S1. Additionally, luciferase assays confirmed an interference of IEX-1 with the activity of the S5a promoter. These findings indicate a role of IEX-1 in the maintenance and assembly of the 26 S proteasome, obviously involving an altered gene expression of certain proteasomal proteins. Thereby, IEX-1 may essentially modulate signalling pathways related to 26 S proteasome activity and involved in cellular growth control and apoptosis.
A novel role for Oct-2 in the lipopolysaccharide-mediated induction of resistin gene expression in RAW264.7 cells
Authors: Lu Shao-Chun , Chang Shwu-Fen , Chen Hui-Ling , Chou Yuan-Yi , Lan Ya-Hsin , Chuang Chia-Ying , Yu Wei-Hsuan , Chen Chia-Lin
Published: February 2007

Although resistin was first suggested as a possible link between obesity and diabetes, we have demonstrated previously that expression of resistin is induced by LPS (lipopolysaccharide). In the present study, we showed that LPS increased levels of resistin mRNA and promoter activity in murine RAW264.7 macrophages. Investigation of cis-regulatory elements in the mouse resistin promoter required for LPS-mediated induction showed that an Octamer (ATTTGCAT) element, located at −914 to −907, was required for maximal promoter activity in response to LPS stimulation. Co-transfection of RAW264.7 cells with a resistin promoter–luciferase construct and an Oct-1 or Oct-2 expression plasmid (pCG-Oct-1 or pCG-Oct-2) showed that Oct-2, but not Oct-1, activated the resistin promoter upon LPS treatment. Binding of Oct-2 to the Octamer element was demonstrated by supershift DNA-affinity precipitation and chromatin immunoprecipitation assays. Reverse transcription–PCR and Western blot results showed that levels of Oct-2 mRNA and protein were both up-regulated by LPS in RAW264.7 cells. The LPS-induced increase in Oct-2 protein was inhibited by LY294002 (a phosphoinositide 3-kinase inhibitor) post-transcriptionally, and the inhibition also resulted in a lower response of both resistin mRNA and promoter activity to LPS treatment. Moreover, specific knockdown of Oct-2 by RNA interference impaired the LPS-induced increase in resistin mRNA and promoter activity. Together, these results indicate that Oct-2 is involved in the LPS-mediated induction of resistin gene expression in macrophages and suggest that activation of Oct-2 is a part of LPS signalling pathways in macrophages.