bluuebunny/crossref_metadata_2025 huggingface dataset:
Polycyclic aromatic hydrocarbons and black carbon in sediments of a remote alpine Lake (Lake Planina, northwest Slovenia)
Authors: Muri Gregor , Wakeham Stuart G. , Faganeli Jadran
Published: March 2010

Polycyclic aromatic hydrocarbons (PAH) and black carbon (BC) were measured in alpine Lake Planina (Slovenia) sediment. Lake Planina is a remote mountain lake with almost no direct anthropogenic influence. Long-distance atmospheric deposition is a major pathway for the loading of contaminants to the sediment. The PAH were analyzed by gas chromatography coupled to mass spectrometry, whereas the BC was determined by thermal oxidation method. A flux of PAH to surface sediments of approximately 1,100 μg m−2 year−1 was obtained and was higher than that in other alpine lakes of the central European Alps. However, surface sediment PAH concentration, normalized to organic carbon content (OC), amounted to 5 μg PAHpyr/g OC and showed that Lake Planina is relatively equally exposed to atmospheric pollution compared with other lakes in the region. The BC:OC ratios ranged from 3 to 8% (w/w). In addition, a huge forest fire occurred in 1948 in the lake's surrounding area, which is recorded in the sediment. Both PAH and BC distributions were affected by the fire in 1948 in the lake's watershed, because their concentration increased remarkably. The concentration of retene, a molecular marker of coniferous wood combustion, increased to 1,000 ng/g dry weight sediment at the sediment interval corresponding to approximately the year 1950.
Toxicity of chemicals to microalgae in river and in standard waters
Authors: Graff Lionel , Isnard Pascal , Cellier Pierre , Bastide Jean , Cambon Jean-Pierre , Narbonne Jean-Francois , Budzinski Helene , Vasseur Paule
Published: March 2010

The influence of the composition of natural waters on the toxicity of chemicals to microalgae was studied on samples representative of western European rivers. Effects of zinc, pentachlorophenol (PCP), 4-nonylphenol (4-NP), phosalone, and 2,4,5-trichloroaniline (TCA) on algal growth were tested in river waters without adding any nutrients or cosolvents, and in the International Standards Organization (ISO) medium for comparison. The mean values of effective concentrations reducing the algal growth by 50% (EC50s) after 72 h based on measured concentrations did not differ significantly in natural waters and in standard medium for 4-NP (0.5 mg/L) and phosalone (0.8–0.9 mg/L). These values were two or three times higher in rivers than in ISO medium for PCP (0.25 vs 0.1 mg/L), TCA (1.69 vs 0.73 mg/L), and zinc (0.20 vs 0.056 mg/L). Although the mean values were of the same order of magnitude, the distribution of the EC50 values ranged over 1.5 and 2 log concentrations in surface waters. Therefore, in view of a refined hazard assessment of a chemical on a local scale, it would be advisable to use the actual river water of the concerned aquatic environment in testing. Correlations between toxicity data and the physicochemical characteristics of the waters identified classic parameters such as water hardness or conductivity as factors that significantly influenced the toxicity of the ionizable compounds PCP and zinc. On the other hand, organic materials or suspended solids, but only at high levels, affected the toxicity of 4-NP, an organic chemical with high adsorption potential. No correlation could be drawn for phosalone and TCA.
Evaluation of biomarkers of exposure and effect in juvenile areolated grouper (Epinephelus areolatus) on foodborne exposure to benzo[a]pyrene
Authors: Wu Rudolf S. S. , Pollino Carmel A. , Au Doris W. T. , Zheng Gene J. , Yuen Bonnie B. H. , Lam Paul K. S.
Published: March 2010

Food-borne benzo[a]pyrene (B[a]P) was administered daily to juvenile grouper (Epinephelus areolatus) at two environmentally realistic concentrations (a low dose of 0.25 μg B[a]P/g body wt/d and a high dose of 12.5 μg B[a]P/g body wt/d) to investigate and relate temporal changes in body burden of B[a]P, hepatic ethoxyresorufin-O-deethylase (EROD) activities, growth, RNA:DNA ratio, estradiol, testosterone, and triiodothyronine (T3). After feeding with B[a]P diets for four weeks, fish were fed with normal diet for another four weeks to study recovery of the various biomarkers during the depuration period. After one week of exposure, both body muscle B[a]P burdens and hepatic EROD activities significantly increased. Body burdens were stable in tissues until the fourth week of exposure, when concentrations in the high-dose group increased markedly, at which time a concomitant decrease in EROD was found. During the depuration period, body burdens decreased in the second week, and EROD declined in the first week. Growth and RNA:DNA ratio were unaltered. Despite large variations found in sex steroid levels, elevation of testosterone was clearly evident in the fourth week, showing that B[a]P may disrupt the balance of sex steroids in fish. Significantly, increases in plasma-free T3 concentrations were found in the fourth week of exposure and the first week of depuration, suggesting that development and reproduction may potentially be at risk during chronic exposures. Our data also suggest that these hormonal disturbances are not persistent and that normal hormonal levels can be restored soon after contamination is abated.
Sanfte Gentrifizierung, Studentifizierung und Inseln ethnischer Konzentration in ostdeutschen Innenstadtrandgebieten?
Authors: Wiest Karin , Hill André
Published: March 2010

The year 1997 marks a turning point in the development of east German inner-city fringe areas: many old residential quarters have registered clear increases in the number of inhabitants again after a phase of exodus. The time of the trend reversal coincides with the development of an excess supply of housing space and decreasing rents, which determine the situation of east German housing markets until today and allow a relatively large freedom of choice in the search for housing. Under these conditions the social contrasts between emptying areas and areas that receive immigrants are increasing. Simultaneously a cultural differentiation between individual urban sub-areas is emerging as a result of the development of characteristic milieus. The article aims to provide a deeper insight into the developments in old residential areas near the inner cities since the middle of the 1990's. Recent trends are considered by taking the social change in the inner-city fringe areas from the period of industrial expansion in Leipzig over a period eight years as a case in point.
Technische Ausbildungsstätten, Entwickler und ihr Beitrag zum Innovationssystem
Authors: Wilhelm Beate , Thierstein Alain
Published: March 2010

Within the process of innovation, technology and knowledge transfers between universities and other research institutes and private industry have a vital role to play. It is especially important that the various players involved should interact within a systematic context. All too f requently the weak link in this chain is the flow and exchange of information. What is the role within this process for developers and engineers? What part should training centres and research institutes play? The present article draws on a study of two industrial sectors to shed light on the networks and information exchange in place in Austria among these key players.
Ansatzpunkte zur Weiterentwicklung des Zentrale-Orte-Systems Schleswig-Holsteins
Authors: Hahne Ulf
Published: March 2010

The „central place” concept is employed in all of Germany’s federal states (apart from the city-states) as an instrument to steer state-level regional planning. By comparison with other states, the system in place in Schleswig-Holstein is very broadly recognised and taken into account both for spatial planning and in the context of budget allocations to local authorities. Empirical surveys of actual settlement development reveal that this system promotes future-orientated development in rural areas. There would appear to be a special need to develop the system further in areas characterised by the presence of close linkages between towns and cities and the areas surrounding them. A number of proposals are put forward which will place co-operation between cities and surrounding municipalities on a firmer footing.
Das „kreative Milieu” — nur theoretisches Konzept oder Instrument der Regionalentwicklung?
Authors: Fromhold-Eisebith M.A. Martina
Published: March 2010

Theories of successful regional development which, like the “creative milieu” concept, stress the importance of networks of personal contacts quite rightly attract the interest of those involved in the practice of regional development planning. This article presents some of the key ideas behind this concept and evaluates them with regard to the possibility of translating them into planning instruments. A selection of examples of “creative milieus” both in Germany and abroad serve to highlight the wealth of variety which exists, but also underline the unfeasibility of trying to plan for the regional development processes associated with this concept. The article concludes by advancing a number of ideas which demonstrate how — notwithstanding certain reservations — the milieu approach might still be applied to good effect in regional development.
Die Region
Authors: Becker-Marx Kurt
Published: March 2010

Discussion on the identification, construction and function of the region has broadened in scope and lost its focus. Although, since its optimistic beginnings in the 1960s, the concept of the region has advanced from local-authority level via the federal states to continental level, nowhere has it taken on contours which are in any way convincing. The lack of political control has become extremely striking. Indeed, those tendencies which are apparent tend to be destructive: examples of “regionalism” in Europe are discouraging. Nonetheless, the region does still have a future. Drawing together the principles of globalism and regionalism, which would allow step-by-step progression from continents — the “world regions” — to local authorities, could well provide the world with a new type of classification.
Schweden — ein Modell für Konsens und Rationalität?
Authors: Böhme Kai
Published: March 2010

Regional planning in Sweden is neither institutionalised in a manner comparable to the situation found in Germany, nor can it look back on a similarly long tradition. One reason for this is to be found in the near unassailable planning monopoly of local authorities. This case-study of regional planning in Stockholm shows that neither corporate pluralism nor the central importance attached to rational, consensus-based planning is being seriously called into question. What disharmony does exist is over the relationship between planning and politics. Although planning is informal and only vaguely defined, it is still important to ask whether there is anything for regional planning in Germany to learn from Sweden. Could Sweden provide a model?
Nutzung agrarstruktureller Informationen zur Strategiebildung in der räumlichen Planung
Authors: Haaren Christina von , Hein Angela , Makala Michael
Published: March 2010

Information on agrarian structure can make a valuable contribution to supplementing the strategies embodied in sectoral plans. Benefits can accrue for the process of selecting priorities for action and deciding on what locations are to be prioritised, for the preparation of plans, and equally for decisions on the approach to the implementation of planning measures. In two research projects a method has been developed which allows information on potential and availability for implementation — as well as on the scope for synergy effects between agriculture and nature conservation — to be integrated within strategies for greenfield protection at federal state level.
Regionale Ausgabeneffekte von Hochschulen
Authors: Blume Lorenz , Blume Lorenz , Fromm Oliver
Published: March 2010

As regional policy considerations have frequently had a role to play in decisions on the creation of new universities, studies have also been carried out for a number of university locations in Germany to investigate the impacts of university spending on regional economies. In terms of methodology, however, these studies differ significantly in a number of areas. The present contribution describes methodological problems associated with attempts to quantify regional effects of university spending, illustrated by reference to Kassel. In considering differences in method — and notwithstanding the variety of approaches adopted — analysis of these studies reveals that they all record regional effects of university spending of a similar order of magnitude, with just a few isolated cases of exceptions to the pattern.
Ein revolvierendes Gewerbeflächensystem in interkommunaler Zusammenarbeit als Weg zu einem haushälterischen Umgang mit gewerblich-industriellen Flächenressourcen
Authors: Greiving Stefan , Neumeyer Hans-Peter , Sondermann Christina
Published: March 2010

This article discusses the question of the possible contribution towards the reduction of land consumption which might be achieved through intermunicipal co-operation in the acquisition, designation (for planning purposes) and in the marketing of commercial sites. By way of an example, the authors take as the basis for their study a status quo analysis of local-authority policy on commercial sites and land-use designation in the Märkischer Kreis. In their findings they are able to identify considerable inefficiencies in both the designation and the utilisation of sites. These findings can be seen as largely representative of other regions exhibiting similar structures. On this argumentational basis, the authors develop an instrument based upon a jointly-managed land pool; here sites are „booked in”, earmarked for planning purposes, and serviced for subsequent development. This pool also includes brown fields. The aim is to minimise the amount of open space being redesignated for commercial use, and to enable access to the most suitable locations at an intermunicipal level, which can then be put to efficient utilisation.
Zur Steuerung der Flächeninanspruchnahme durch handelbare Flächenausweisungsrechte
Authors: Hansjürgens Bernd , Schröter Christoph
Published: March 2010

The present article considers the idea to stop urban sprawl by introducing a tradable allowance system for the dedication of building land by the municipalities. It is suggested that the allowances should be created at the level of the central state and be distributed to the federal states, regions and municipalities. In this way the allowance system can benefit from the advantages of the well-established planning concepts at the regional and municipal level. The allocation effects of the tradable allowance system depend on the type of primary allocation, the economic strength of the trading municipalities, the use of auction proceeds and the development of regionally and functionally separated markets. It is recommended that the tradable allowance system should be integrated into an instrumental mix with an ecologically enhanced financial equalisation mechanism at the municipal level and an ecologically reformed real-estate tax.
Wie Siedlungsentwicklung steuern?
Authors: Droß Michael
Published: March 2010

Because of the finance problems of the civil sector and the needs of securing the services of public interest we need a consequent control of settlement development. But are the required instruments available? This paper focuses on the regional planning and the housing support. Their contribution to the control of the housing settlement development is analysed by case studies in North Rhine-Westphalia. The intention of the paper is to find ways for improving the control of the settlement development.
Auf dem Weg zu einer Euro päischen Laufenden Raumbeobachtung — die ESPON-Datenbank
Authors: Heidbrink Ingo , Schmidt-Seiwert Volker
Published: March 2010

Policy and practice perspective
Dilemmas of Practice: Challenges to Program Quality Encountered by Youth Program Leaders
Authors: Larson Reed W. , Walker Kathrin C.
Published: March 2010

To create and sustain high quality youth development programs it is important to understand the challenging situations and dilemmas that emerge in program leaders’ daily work with youth. In this research the experiences of leaders in 12 programs were followed over a 2–9 month period, which led to the identification of 250 dilemma situations. Qualitative analyses identified 5 categories and 12 subcategories of dilemmas that reflected distinct types of considerations (e.g., youth’s personalities, relationships with the community). The analyses also found that the experienced leaders in the study typically responded to these dilemmas in ways that were youth‐centered and that balanced multiple considerations. It is argued that researchers need to go beyond identifying features of high quality programs, and more fully examine how effective leaders create and sustain high quality in response to the challenging situations of practice.
Fatal cerebral edema associated with serine deficiency in CSF
Authors: Keularts Irene M. L. W. , Leroy Piet L. J. M. , Rubio‐Gozalbo Estela M. , Spaapen Leo J. M. , Weber Biene , Dorland Bert , de Koning Tom J. , Verhoeven‐Duif Nanda M.
Published: March 2010

Two young girls without a notable medical history except for asthma presented with an acute toxic encephalopathy with very low serine concentrations both in plasma and cerebrospinal fluid (CSF) comparable to patients with 3‐phosphoglycerate dehydrogenase (3‐PGDH) deficiency. Clinical symptoms and enzyme measurement (in one patient) excluded 3‐PGDH deficiency. Deficiencies in other serine biosynthesis enzymes were highly unlikely on clinical grounds. On basis of the fasting state, ketone bodies and lactate in plasma, urine and CSF, we speculate that reduced serine levels were due to its use as gluconeogenic substrate, conversion to pyruvate by brain serine racemase or decreased L‐serine production because of a lack of glucose. These are the first strikingly similar cases of patients with a clear secondary serine deficiency associated with a toxic encephalopathy.
Large neutral amino acids in daily practice
Authors: Ahring Kirsten Kiær
Published: March 2010

At the Kennedy Centre for Phenylketonuria, Denmark, large neutral amino acids (LNAAs) are being used to treat adult and adolescent patients who are nonadherent to dietary treatment for phenylketonuria (PKU). At the start of treatment, a patient must undergo dietary analysis and regular blood sampling to measure plasma amino acid (AA) concentrations. The aim of this analysis and treatment is that the patient receives 25–30% of the daily protein requirement from LNAA supplementation and the remaining 70–75% from natural, low‐phenylalanine proteins (although some patients have difficulties in maintaining this level of protein intake). Patients are therefore able to follow a more “normal” diet than those adhering to a PKU diet with AA supplementation (in which only 20% of the daily protein requirement is provided from the diet and 80% from AA supplementation). LNAAs have also been used to treat older patients with untreated/late‐diagnosed PKU who show profound intellectual, psychological, and behavioral impairments. Treatment with LNAAs has been shown to improve measures of concentration and awareness of external stimuli in some of these patients and thus enhance their socialization, emotionality, frustration tolerance, and mood.
Lateral mass screw fixation in children
Authors: Hedequist Daniel , Proctor Mark , Hresko Timothy
Published: March 2010

Purpose

The safety and feasibility of posterior screw fixation of the cervical spine in children has not been well documented in the orthopedic literature. We performed a retrospective review of our experience using posterior cervical screw fixation in children.

Methods

The medical records and radiologic records of 36 children at a mean age of 10 years (range 3–16 years) were reviewed. Diagnoses included: ten instability, 11 deformity, seven trauma, five tumor, and three congenital abnormalities. Operative reports and postoperative computed tomography (CT) scans were reviewed to determine the technical feasibility of screw placement, any screw-related complications, and to assess for correct screw position. In this series, there were no neurologic complications, no vertebral artery injuries, and no screw-related complications.

Results

Thirty patients (141 screws) had screws evaluated postoperatively and were shown to be completely contained on postoperative CT scans. There were no revisions due to screw failure or dislodgement. There were no vascular or neurologic complications.

Conclusions

Posterior screw fixation in the pediatric population may be done safely and greatly enhances fixation strength for a variety of disorders requiring instrumentation and fusion.
A Conceptual Exploration of the Strategic Factors Driving New Brand Entry Decisions and Their Success
Authors: Chmielewski Danielle A.
Published: March 2010

New brand entry strategies, such as brand extensions and new-name brands, are increasingly being used by firms to facilitate strategic growth. Whilst the issue of new brand entry is of great strategic importance, particularly to marketing practitioners, most new brand entry research has taken a strong consumer behavior stance, with much less research being directed towards the strategic, firm-specific and market-specific drivers of new brand entry decisions and their performance. This paper takes an exploratory first step in providing a strategic management view of new brand entry by developing and introducing a conceptual framework of firm- and market-specific antecedents and moderators of two key new brand entry strategies, brand extensions and new-name brands. Specifically, this paper first explores the direct effect of a firm's resources and strategic orientation on the choice of a brand extension or a new-name brand strategy, before going onto investigate the effect of the two new brand entry strategies on performance under different environmental conditions, namely dynamism, complexity, and hostility. The paper puts forth a number of propositions and finishes off with a discussion of future research avenues.
Understanding Consumer Intention to Use Mobile Services
Authors: Revels Janeaya , Tojib Dewi , Tsarenko Yelena
Published: March 2010

Given the fast growth of mobile technology services in some countries and the relatively slow growth in others, it is important to understand the factors that contribute to the adoption of these applications in Australia. Drawing from the Technology Acceptance Model, Domestication Research, and Uses and Gratification Research, this study develops a model for consumers’ intentions to use mobile services (m-services). The main drivers of consumers’ intentions to use m-services are satisfaction along with perceived usefulness. In addition, this study shows that perceived ease of use is a strong predictor of perceived usefulness. This study found that perceived usefulness, perceived ease of use, and perceived enjoyment positively affect satisfaction with m-services while perceived cost has a negative effect. On a different note, it was proven that perceived image does not have a significant impact on customers’ satisfaction with m-services. Overall findings of this study provide some contribution to the growing body of research in the area of m-services and provide some assistance to practitioners in formulating better strategies to retain current m-service users.
Confocal microscopy of giant vesicles supports the absence of HIV‐1 neutralizing 2F5 antibody reactivity to plasma membrane phospholipids
Authors: Apellaniz Beatriz , García-Sáez Ana J. , Huarte Nerea , Kunert Renate , Vorauer-Uhl Karola , Katinger Hermann , Schwille Petra , Nieva José L.
Published: March 2010

The broadly neutralizing anti‐HIV‐1 2F5 monoclonal antibody recognizes a gp41 epitope proximal to the viral membrane. Potential phospholipid autoreactivity at cell surfaces has raised concerns about the use of this antibody for development of vaccines or immunotherapy. In this study, confocal microscopy of giant unilamellar vesicles (GUVs) was used to assess 2F5 reactivity with phospholipids assembled into bilayers with surface charge and curvature stress approximating those of the eukaryotic plasma membranes. Antibody partitioning into lipid bilayers required the specific recognition of membrane‐inserted epitope, indicating that 2F5 was unable to directly react with GUV phospholipids, even under fluid phase segregation conditions. Our results thus support the feasibility of raising 2F5‐like neutralizing responses through vaccination, and the medical safety of mAb infusions.
Personality and Political Attitudes: Relationships across Issue Domains and Political Contexts
Authors: GERBER ALAN S. , HUBER GREGORY A. , DOHERTY DAVID , DOWLING CONOR M. , HA SHANG E.
Published: March 2010

Previous research on personality traits and political attitudes has largely focused on the direct relationships between traits and ideological self-placement. There are theoretical reasons, however, to suspect that the relationships between personality traits and political attitudes (1) vary across issue domains and (2) depend on contextual factors that affect the meaning of political stimuli. In this study, we provide an explicit theoretical framework for formulating hypotheses about these differential effects. We then leverage the power of an unusually large national survey of registered voters to examine how the relationships between Big Five personality traits and political attitudes differ across issue domains and social contexts (as defined by racial groups). We confirm some important previous findings regarding personality and political ideology, find clear evidence that Big Five traits affect economic and social attitudes differently, show that the effect of Big Five traits is often as large as that of education or income in predicting ideology, and demonstrate that the relationships between Big Five traits and ideology vary substantially between white and black respondents.
UK Food Standards Agency Workshop Report: carbohydrate and cardiovascular risk
Authors: Peacock Emma , Stanley John , Calder Philip C. , Jebb Susan A. , Thies Frank , Seal Chris J. , Woodside Jayne V. , Sanders Tom A. B.
Published: March 2010

This report summarises a workshop convened by the UK Food Standards Agency (FSA) on 14 October 2008 to discuss current FSA-funded research on carbohydrates and cardiovascular health. The objective of this workshop was to discuss the results of recent research and to identify any areas which could inform future FSA research calls. This workshop highlighted that the FSA is currently funding some of the largest, well-powered intervention trials investigating the type of fat and carbohydrate, whole grains and fruit and vegetables, on various CVD risk factors. Results of these trials will make a substantive contribution to the evidence on diet and cardiovascular risk.
Spin-coating of vertically stratified thin liquid films
Authors: McINTYRE A. , BRUSH L. N.
Published: March 2010

Spin-coating is a process used to fabricate thin films for device applications. In this paper, lubrication theory is used to derive an axisymmetric model for the spin-coating of two immiscible vertically stratified Newtonian thin films. The model includes gravitational, van der Waals, capillary and viscous forces, differences in liquid layer properties and evaporation/condensation effects. Thinning calculations focus on the effects of viscosity and condensation/evaporation. In this case, for layers of uniform thickness, the lower layer thins monotonically yet never reaches zero thickness. With evaporation mass loss the upper layer disappears in finite time, whereas with condensation effects the upper layer approaches a steady-state thickness. Fully nonlinear calculations are carried out for films with non-uniform thickness and the deviation of the interfaces from the flat state is monitored. In general, disturbances to the lower layer have a greater effect on the upper layer than those of disturbances of the upper layer on the lower layer. Disturbances along the upper gas–liquid free surface propagate outward more rapidly than those along the lower liquid–liquid interface and disturbances that decrease the film thickness tend to dissipate more slowly.
Aerodynamic sound generation by global modes in hot jets
Authors: LESSHAFFT LUTZ , HUERRE PATRICK , SAGAUT PIERRE
Published: March 2010

The acoustic field generated by the synchronized vortex street in self-excited hot subsonic jets is investigated via direct numerical simulation of the compressible equations of motion in an axisymmetric geometry. The simulation simultaneously resolves both the aerodynamic near field and the acoustic far field. Self-sustained near-field oscillations in the present flow configurations have been described as nonlinear global modes in an earlier study. The associated acoustic far field is found to be that of a compact dipole, emanating from the location of vortex roll-up. A far-field solution of the axisymmetric Lighthill equation is derived, on the basis of the source term formulation of Lilley (AGARD-CP, vol. 131, 1974, pp. 13.1–13.12). With the near-field source distributions obtained from the direct numerical simulations, the Lighthill solution is in good agreement with the far-field simulation results. Fluctuations of the enthalpy flux within the jet are identified as the dominant aeroacoustic source. Superdirective effects are found to be negligible.
Intrusive gravity currents between two stably stratified fluids
Authors: MAURER BENJAMIN D. , BOLSTER DIOGO T. , LINDEN P. F.
Published: March 2010

We present an experimental and numerical study of one stratified fluid propagating into another. The two fluids are initially at rest in a horizontal channel and are separated by a vertical gate which is removed to start the flow. We consider the case in which the two fluids have the same mean densities but have different, constant, non-zero buoyancy frequencies. In this case the fluid with the smaller buoyancy frequency flows into the other fluid along the mid-depth of the channel in the form of an intrusion and two counter-flowing gravity currents of the fluid with the larger buoyancy frequency flow along the top and bottom boundaries of the channel. Working from the available potential energy of the system and measurements of the intrusion thickness, we develop an energy model to describe the speed of the intrusion in terms of the ratio of the two buoyancy frequencies. We examine the role of the stratification within the intrusion and the two gravity currents, and show that this stratification plays an important role in the internal structure of the flow, but has only a secondary effect on the speeds of the exchange flows.
Tear film dynamics on an eye-shaped domain. Part 2. Flux boundary conditions
Authors: MAKI K. L. , BRAUN R. J. , UCCIFERRO P. , HENSHAW W. D. , KING-SMITH P. E.
Published: March 2010

We model the dynamics of the human tear film during relaxation (after a blink) using lubrication theory and explore the effects of viscosity, surface tension, gravity and boundary conditions that specify the flux of tear fluid into or out of the domain. The governing nonlinear partial differential equation is solved on an overset grid by a method of lines using finite differences in space and an adaptive second-order backward difference formula solver in time. Our simulations in a two-dimensional domain are computed in the Overture computational framework. The flow around the boundary is sensitive to both our choice of flux boundary condition and the presence of gravity. The simulations recover features seen in one-dimensional simulations and capture some experimental observations of tear film dynamics around the lid margins. In some instances, the influx from the lacrimal gland splits with some fluid going along the upper lid towards the nasal canthus and some travelling around the temporal canthus and then along the lower lid. Tear supply can also push through some parts of the black line near the eyelid margins.
Onset of convection in two layers of a binary liquid
Authors: McFADDEN G. B. , CORIELL S. R. , LOTT P. A.
Published: March 2010

We perform linear stability calculations for horizontal bilayers of a two-component fluid that can undergo a phase transformation, taking into account both buoyancy effects and thermocapillary effects in the presence of a vertical temperature gradient. Critical values for the applied temperature difference across the system that is necessary to produce instability are obtained by a linear stability analysis, using both numerical computations and small wavenumber approximations. Thermophysical properties are taken from the aluminum–indium monotectic system, which includes a liquid–liquid miscibility gap. In addition to buoyant and thermocapillary modes of instability, we find an oscillatory phase-change instability due to the combined effects of solute diffusion and fluid flow that persists at small wavenumbers. This mode is sensitive to the ratio of the layer depths, and for certain layer depths can occur for heating from either above or below.
Instability of uniform micro-organism suspensions revisited
Authors: PEDLEY T. J.
Published: March 2010

Uniform suspensions of bottom-heavy, upswimming (gyrotactic) micro-organisms that are denser than water are unstable, through a gravitational mechanism first described by Pedley, Hill & Kessler (J. Fluid Mech., vol. 195, 1988, p. 223). Suspensions of downswimming, head-heavy cells do not experience this instability. In the absence of gravity, a uniform suspension of swimming micro-organisms may be unstable because of the ‘particle stresses’ generated by the swimming cells themselves, each of which acts as a force-dipole or stresslet (Simha & Ramaswamy,Phys. Rev. Lett., vol. 89, 2002, p. 058101). The stresslet strengthSis positive for ‘pullers’ such as algae and negative for ‘pushers’ such as bacteria or spermatozoa. In this paper, the combined problem is investigated, with attention being paid also to the effect of rotational diffusivity and to whether the probability density functionf(e) for the cells' swimming directionecan be approximated as quasi-steady in calculations of the mean swimming direction, which arises in the cell conservation equation, and the particle stress tensor, which appears in the momentum equation. The existence of both the previous instabilities is confirmed at long wavelength. However, the non-quasi-steadiness of the orientation distribution means that the particle-stress-driven instability no longer arises for arbitrarily small |S|, in the Stokes limit, but requires that the dimensionless stresslet strength (proportional to the product ofSand the basic state cell volume fractionno) exceed a critical value involving both viscosity and rotational diffusivity. In addition, a new mode of gravitational instability is found for ‘head-heavy’ cells, even when they exert no particle stresses (S= 0), in the form of weakly growing waves. This is a consequence of unsteadiness in the mean swimming direction, together with non-zero fluid inertia. For realistic parameter values, however, viscosity is expected to suppress this instability.
Frontostriatal activation in patients with obsessive–compulsive disorder before and after cognitive behavioral therapy
Authors: Freyer T. , Klöppel S. , Tüscher O. , Kordon A. , Zurowski B. , Kuelz A.-K. , Speck O. , Glauche V. , Voderholzer U.
Published: March 2010

Background

Cognitive behavioral therapy (CBT) with exposure and response prevention (ERP) is the psychotherapeutic treatment of choice for obsessive–compulsive disorder (OCD). However, little is known about the impact of CBT on frontostriatal dysfunctioning, known to be the neuronal correlate of OCD.

Method

A probabilistic reversal learning (RL) task probing adaptive strategy switching capabilities was used in 10 unmedicated patients with OCD and 10 healthy controls during an event-related functional magnetic resonance imaging (fMRI) experiment. Patients were scanned before and after intensive CBT, controls twice at comparable intervals.

Results

Strategy change within the RL task involved activity in a broad frontal network in patients and controls. No significant differences between the groups or in group by time interactions were detected in a whole-brain analysis corrected for multiple comparisons. However, a reanalysis with a more lenient threshold revealed decreased responsiveness of the orbitofrontal cortex and right putamen during strategy change before treatment in patients compared with healthy subjects. A group by time effect was found in the caudate nucleus, demonstrating increased activity for patients over the course of time. Patients with greater clinical improvement, reflected by greater reductions in Yale–Brown Obsessive Compulsive Scale (YBOCS) scores, showed more stable activation in the pallidum.

Conclusions

Although these findings are preliminary and need to be replicated in larger samples, they indicate a possible influence of psychotherapy on brain activity in core regions that have been shown to be directly involved both in acquisition of behavioral rules and stereotypes and in the pathophysiology of OCD, the caudate nucleus and the pallidum.
The undue influence of shape and weight on self-evaluation in anorexia nervosa, bulimia nervosa and restrained eaters: a combined ERP and behavioral study
Authors: Blechert J. , Ansorge U. , Beckmann S. , Tuschen-Caffier B.
Published: March 2010

Background

Current theories and nosology assume that the self-evaluation (SE) of individuals with eating disorders (EDs) is unduly influenced by body shape and weight. However, experimental data supporting this link are scarce, and it is not specified which subdomains of SE might be affected.

Method

We studied patients with anorexia nervosa (AN), bulimia nervosa (BN) and healthy controls (HC) with an affective priming (AP) procedure (Study 1) to unveil explicit and implicit associations between shape/weight and SE. We used weight/shape-related prime sentences, complemented by affectively congruent and incongruent target words from two SE domains. AP effects were assessed by event-related potentials (ERPs), reaction times (RTs) and subjective ratings. The ratings were also assessed (Study 2) in undergraduate restrained (RES) and unrestrained eaters (UNRES).

Results

Study 1 demonstrated stronger AP effects in both ED groups compared to HC on RTs and subjective ratings. ERPs showed AP effects only in the BN group. Restrained eaters showed similar, albeit less pronounced, priming effects on subjective ratings.

Conclusions

ED patients associate shape/weight concerns with the non-appearance-related SE domains of interpersonal relationships and achievement/performance. These associations seem to be encoded deeper in BN patients relative to the other groups. Links between shape/weight and SE explain how body dissatisfaction impacts on self-esteem and mood in ED. The existence of similar associations in restrained eaters supports a continuum model according to which increasing associations between shape/weight and SE go along with increasing levels of ED symptoms.
THE N-NETWORK MODEL WITH UPGRADES
Authors: Down Douglas G. , Lewis Mark E.
Published: March 2010

In this article we introduce a new method of mitigating the problem of long wait times for low-priority customers in a two-class queuing system. To this end, we allow class 1 customers to be upgraded to class 2 after they have been in queue for some time. We assume that there are ci servers at station i, i=1, 2. The servers at station 1 are flexible in the sense that they can work at either station, whereas the servers at station 2 are dedicated. Holding costs at rate hi are accrued per customer per unit time at station i, i=1, 2. This study yields several surprising results. First, we show that stability analysis requires a condition on the order of the service rates. This is unexpected since no such condition is required when the system does not have upgrades. This condition continues to play a role when control is considered. We provide structural results that include a c-μ rule when an inequality holds and a threshold policy when the inequality is reversed. A numerical study verifies that the optimal control policy significantly reduces holding costs over the policy that assigns the flexible server to station 1. At the same time, in most cases the optimal control policy reduces waiting times of both customer classes.
USING EXCURSIONS TO ANALYZE SIMULATION OUTPUT
Authors: Calvin James M.
Published: March 2010

We consider the steady-state simulation output analysis problem for a process that satisfies a functional central limit theorem. We construct an estimator for the time-average variance constant that is based on excursions of a process above the minimum. The resulting estimator does not require a fixed run length, and the memory requirement can be dynamically bounded. Standardized time series methods based on excursions are also described.
AGING FUNCTIONS AND MULTIVARIATE NOTIONS OF NBU AND IFR
Authors: Durante Fabrizio , Foschi Rachele , Spizzichino Fabio
Published: March 2010

Ford≥2, letX=(X1, …,Xd) be a vector of exchangeable continuous lifetimes with joint survival function$\overline{F}$. For such models, we study some properties of multivariate aging of$\overline{F}$that are described by means of the multivariate aging function$B_{\overline{F}}$, which is a useful tool for describing the level curves of$\overline{F}$. Specifically, the attention is devoted to notions that generalize the univariate concepts of New Better than Used and Increasing Failure Rate. These multivariate notions are satisfied by random vectors whose components are conditionally independent and identically distributed having univariate conditional survival function that is New Better than Used (respectively, Increasing Failure Rate). Furthermore, they also have an interpretation in terms of comparisons among conditional survival functions of residual lifetimes, given a same history of observed survivals.
SUBEXPONENTIAL INTERVAL GRAPHS GENERATED BY IMMIGRATION–DEATH PROCESSES
Authors: Miyoshi Naoto , Ogura Mariko , Shigezumi Takeya , Uehara Ryuhei
Published: March 2010

We propose a simple model of random interval graphs generated by immigration–death processes (also known as M/G/∞ queuing processes), where the length of each interval follows a subexponential distribution, and provide a condition under which the stationary degree distribution is also subexponential. Furthermore, we consider the conditional expectation of the cluster coefficient of a vertex given the degree and show that it vanishes in the limit as the degree goes to infinity under the same condition as that for obtaining the tail asymptotics of the stationary degree distribution.
What is the evidence of a role for host genetics in susceptibility to influenza A/H5N1?
Authors: HORBY P. , SUDOYO H. , VIPRAKASIT V. , FOX A. , THAI P. Q. , YU H. , DAVILA S. , HIBBERD M. , DUNSTAN S. J. , MONTEERARAT Y. , FARRAR J. J. , MARZUKI S. , HIEN N. T.
Published: March 2010

The apparent family clustering of avian influenza A/H5N1 has led several groups to postulate the existence of a host genetic influence on susceptibility to A/H5N1, yet the role of host factors on the risk of A/H5N1 disease has received remarkably little attention compared to the efforts focused on viral factors. We examined the epidemiological patterns of human A/H5N1 cases, their possible explanations, and the plausibility of a host genetic effect on susceptibility to A/H5N1 infection. The preponderance of familial clustering of cases and the relative lack of non-familial clusters, the occurrence of related cases separated by time and place, and the paucity of cases in some highly exposed groups such as poultry cullers, are consistent with a host genetic effect. Animal models support the biological plausibility of genetic susceptibility to A/H5N1. Although the evidence is circumstantial, host genetic factors are a parsimonious explanation for the unusual epidemiology of human A/H5N1 cases and warrant further investigation.
Waist circumference and waist-to-height ratio in Han Chinese children living in Chongqing, south-west China
Authors: Xiong Feng , Garnett Sarah P , Cowell Chris T , Biesheuvel Cornelis , Zeng Yan , Long Chun-Li , Wang Qing , Wang Dong-Gang , Luo Yan-Hong , Luo Shun-Qing
Published: March 2010

Objective

To derive age- and sex-specific reference values for waist circumference (WC) and waist-to-height ratio (WHtR) for Han Chinese children and adolescents and to establish the prevalence of excess central adiposity in our study population.

Design

Cross-sectional study of schoolchildren attending randomly selected primary and secondary schools in south-west China in October 2003 and April 2004. Anthropometry was measured using standard procedures. The LMS method was used to construct smoothed WC and WHtR percentile curves. Overweight and obesity were defined by the International Obesity Task Force (IOTF) criteria and the Working Group on Obesity in Children. Excess central adiposity fat was defined by previously published WC cut-points and a WHtR ≥ 0·5.

Setting

Primary and secondary schools in Chongqing, south-west China.

Subjects

A total of 7326 (49·2 % boys) Han Chinese students at 5–17 years old.

Results

On the basis of the IOTF criteria, 26·4 % of boys were overweight or obese compared with 16·4 % of girls (P < 0·001). WC cut-points identified 31 % of boys and 28 % of girls as having excess central adiposity, whereas using the WHtR criterion, 14·8 % of boys and 5·6 % of girls were identified. Young boys (5–12 years) had a significantly (P < 0·001) higher WHtR than girls.

Conclusions

We have constructed WC and WHtR percentile curves for Han Chinese children and adolescents living in Chongqing. Our measurements were based on a student population with a relatively high rate of overweight and obesity. These data will provide a point of reference for future studies measuring the prevalence of overweight and obesity in China.
Self-reported physical activity in European adolescents: results from the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study
Authors: De Cocker Katrien , Ottevaere Charlene , Sjöström Michael , Moreno Luis A , Wärnberg Julia , Valtueña Jara , Manios Yannis , Dietrich Sabine , Mauro Beatrice , Artero Enrique G , Molnár Dénes , Hagströmer Maria , Ruiz Jonathan R , Sarri Katerina , Kafatos Anthony , Gottrand Frédéric , De Henauw Stefaan , Maes Lea , De Bourdeaudhuij Ilse
Published: March 2010

Objective

To describe self-reported physical activity (PA) patterns in the various domains (school, home, transport, leisure time) and intensity categories (walking, moderate PA, vigorous PA) in European adolescents. Furthermore, self-reported PA patterns were evaluated in relation to gender, age category, weight status category and socio-economic status (SES).

Design

Cross-sectional study.

Setting

Ten European cities.

Subjects

In total, 3051 adolescents (47·6 % boys, mean age 14·8 (sd1·2) years) completed an adolescent-adapted version of the validated International Physical Activity Questionnaire.

Results

The total sample reported most PA during leisure time (485 min/week) and least PA at home (140 min/week). Boys reported significantly more school-based PA (P< 0·001), leisure-time PA (P= 0·003), vigorous PA (P< 0·001) and total PA (P= 0·002) than girls, while girls reported more home-based PA (P< 0·001) and walking (P= 0·002) than boys. Self-reported PA at school (P< 0·001), moderate PA (P< 0·001), vigorous PA (P< 0·001) and total PA (P< 0·001) were significantly higher in younger age groups than in older groups. Groups based on weight status differed significantly only in leisure-time PA (P= 0·004) and total PA (P= 0·003), while groups based on SES differed in all PA domains and intensities except transport-related PA and total PA.

Conclusions

The total sample of adolescents reported different scores for the different PA domains and intensity categories. Furthermore, patterns were different according the adolescents’ gender, age, weight status and SES.