bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigations on Flow Pattern and Pressure inside SEN below Stopper Rod
Authors: Javurek M. , Thumfart M. , Wincor R.
Published: August 2010

In continuous casting of steel, the casting rate is often controlled by a stopper rod placed in the tundish outlet where the submerged entry nozzle (SEN) tube begins. The flow pattern inside the SEN plays an important role for the bubble formation at the argon injection nozzle at the stopper rod tip. High flow velocities are reached in the small gap between stopper rod and the surrounding SEN walls, and a flow separation has to be expected after the gap due to the fast expansion of the cross section. According to theoretical considerations and to the simulations, the absolute pressure in the gap becomes very low for liquid steel, which can cause cavitation‐like effects. PIV‐flow measurements in a 1:1 scaled water model of the caster show a highly oscillating and asymmetric flow pattern with rapidly changing separation regions. The low pressure effects expected in liquid steel cannot be investigated on the water‐model due to the lower density of water. In numerical simulations of the water‐model, the choice of the turbulence model and the usage or the non‐usage of geometrical symmetries for the bound of the computational domain have a great impact on the resulting flow pattern and the accuracy of the predicted pressure drop. The results of various turbulence models are compared with results from measurements on a water‐model. It turns out that only a 3D model using advanced turbulence models (SST k‐ω or Large Eddy) produce acceptable results, while 2D simulations completely fail and the standard turbulence models (e.g. k‐ε) significantly underestimate the pressure drop even in a 3D simulation.
Taking the appearances seriously: architectural experience and the phenomenological case for religious belief
Authors: WYNN MARK
Published: August 2010

This paper explores some implications of the idea that religious thoughts can enter into the sensory appearances of things. I begin by clarifying this idea, using some examples drawn from Roger Scruton's discussion of the phenomenology of architectural experience. Then I consider the bearing of the idea on the case for religious belief in pragmatic and epistemic terms. More exactly, I explore how the idea of an internal relation between religious thought and the sensory appearances of things can be used (1) to state William James's case in ‘The will to believe’ with new nuance, and (2) to set out an epistemic case for religious belief whose central claims seem quite commonly to weigh with believers, but which has not been much discussed by philosophers.
On Malleable and Immalleable Subtypes
Authors: Hugenberg Kurt , Blusiewicz Robin L. , Sacco Donald F.
Published: August 2010

Although relatively brief encounters with counterstereotypic targets can change automatic stereotypes, the capacity to subtype such counterstereotypic targets can also protect stereotypes against change. In a novel combination of these findings, the current research hypothesized that malleability in one subtype of a category engendered by mental imagery ( Blair, Ma, & Lenton, 2001 ) would not bleed over easily into other prominent subtypes of a category. Supporting this hypothesis, imagining a strong businesswoman elicited a reversal of the “women-as-weak” stereotype – but only for women presented in business contexts (i.e., businesswomen). When women were presented in domestic contexts (i.e., homemakers), the mental imagery had no effect on the stereotype of women as weak. Thus, these data suggest that stereotype malleability elicited by mental imagery can be subtype-specific, with changes in one subtype not bleeding over easily to other subtypes of the category.
Automatic Stereotype Activation Is Context Dependent
Authors: Casper Catharina , Rothermund Klaus , Wentura Dirk
Published: August 2010

Processes involving an automatic activation of stereotypes in different contexts were investigated using a priming paradigm with the lexical decision task. The names of social categories were combined with background pictures of specific situations to yield a compound prime comprising category and context information. Significant category priming effects for stereotypic attributes (e.g., Bavarians – beer) emerged for fitting contexts (e.g., in combination with a picture of a marquee) but not for nonfitting contexts (e.g., in combination with a picture of a shop). Findings indicate that social stereotypes are organized as specific mental schemas that are triggered by a combination of category and context information.
The Surprisingly Limited Malleability of Implicit Racial Evaluations
Authors: Joy-Gaba Jennifer A. , Nosek Brian A.
Published: August 2010

Implicit preferences for Whites compared to Blacks can be reduced via exposure to admired Black and disliked White individuals ( Dasgupta & Greenwald, 2001 ). In four studies (total N = 4,628), while attempting to clarify the mechanism, we found that implicit preferences for Whites were weaker in the “positive Blacks” exposure condition compared to a control condition (weighted average d = .08). This effect was substantially smaller than the original demonstration ( Dasgupta & Greenwald, 2001 ; d = .82). Factors beyond exposure to admired Blacks may be necessary for the effect, such as making race accessible during exemplar exposure and including negative White exemplars. Our evidence suggests that exposure to known-group members shifts implicit race bias reliably, but weakly.
Is Obama’s Win a Gain for Blacks?
Authors: Bernstein Michael J. , Young Steven G. , Claypool Heather M.
Published: August 2010

Many have questioned what Barack Obama’s victory in the 2008 presidential election means for prejudice and intergroup relations in the United States. In this study, we examined both explicit and implicit prejudice toward African Americans prior to and immediately following the election of the first African American to the nation’s highest office. Results indicated that implicit prejudice (as measured by an IAT) decreased following Obama’s victory, though explicit prejudice remained unchanged. The results are discussed in terms of the malleability of implicit attitudes, race relations, and the impact an Obama presidency and other positive exemplars may have on intergroup relations.
Social Dominance Orientation Attenuates Stereotype Change in the Face of Disconfirming Information
Authors: Tausch Nicole , Hewstone Miles
Published: August 2010

This study examined whether social dominance orientation (SDO) affects the malleability of group stereotypes in the face of disconfirmation. Data were collected at two time points: At Time 1, baseline stereotypes and SDO were assessed, and at Time 2, either moderately or extremely stereotype-inconsistent information was presented and stereotyping measures were repeated. Consistent with previous research, exposure to moderately inconsistent information resulted in greater stereotype change than exposure to extremely inconsistent information. As expected, SDO was negatively related to stereotype change, in particular after presentation of moderately inconsistent information. The judged typicality of the target exemplar mediated the effects of the manipulation but did not mediate the effects of SDO. Implications for future research and interventions to reduce stereotyping are discussed.
Enhanced Mediterranean‐Atlantic exchange during Atlantic freshening phases
Authors: Rogerson M. , Colmenero‐Hidalgo E. , Levine R. C. , Rohling E. J. , Voelker A. H. L. , Bigg G. R. , Schönfeld J. , Cacho I. , Sierro F. J. , Löwemark L. , Reguera M. I. , de Abreu L. , Garrick K.
Published: August 2010

The Atlantic‐Mediterranean exchange of water at Gibraltar represents a significant heat and freshwater sink for the North Atlantic and is a major control on the heat, salt and freshwater budgets of the Mediterranean Sea. Consequently, an understanding of the response of the exchange system to external changes is vital to a full comprehension of the hydrographic responses in both ocean basins. Here, we use a synthesis of empirical (oxygen isotope, planktonic foraminiferal assemblage) and modeling (analytical and general circulation) approaches to investigate the response of the Gibraltar Exchange system to Atlantic freshening during Heinrich Stadials (HSs). HSs display relatively flat W–E surface hydrographic gradients more comparable to the Late Holocene than the Last Glacial Maximum. This is significant, as it implies a similar state of surface circulation during these periods and a different state during the Last Glacial Maximum. During HS1, the gradient may have collapsed altogether, implying very strong water column stratification and a single thermal and δ18Owater condition in surface water extending from southern Portugal to the eastern Alboran Sea. Together, these observations imply that inflow of Atlantic water into the Mediterranean was significantly increased during HS periods compared to background glacial conditions. Modeling efforts confirm that this is a predictable consequence of freshening North Atlantic surface water with iceberg meltwater and indicate that the enhanced exchange condition would last until the cessation of anomalous freshwater supply into to the northern North Atlantic. The close coupling of dynamics at Gibraltar Exchange with the Atlantic freshwater system provides an explanation for observations of increased Mediterranean Outflow activity during HS periods and also during the last deglaciation. This coupling is also significant to global ocean dynamics, as it causes density enhancement of the Atlantic water column via the Gibraltar Exchange to be inversely related to North Atlantic surface salinity. Consequently, Mediterranean enhancement of the Atlantic Meridional Overturning Circulation will be greatest when the overturning itself is at its weakest, a potentially critical negative feedback to Atlantic buoyancy change during times of ice sheet collapse.
High‐latitude reconnection effect observed at the dayside dip equator as a precursor of a sudden impulse
Authors: Han D.‐S. , Yang H.‐G. , Liang J. , Iyemori T. , Cowley S. W. H. , Araki T.
Published: August 2010

Geomagnetic sudden impulses (SI) observed at the dayside dip equator normally show a decrease and then an increase in the H magnetic field component, i.e., a preliminary reverse impulse (PRI) followed by a main impulse. Using global geomagnetic field measurements, we examine an unusual SI event observed at the dayside dip equator, which shows a clear precursor ∼1 min before the PRI onset. The precursor was observed simultaneously at both the dayside dip equator and in the southern polar region but was not observed at all in the northern polar region. The global ground variations after the PRI onset were, however, consistent with a conventional SI model of the magnetospheric response to a sudden enhancement of the solar wind dynamic pressure. Considering that the interplanetary magnetic field Bx, By, and Bz components were positive with the By component dominant for this event, we suggest that the SI precursor was caused by high‐latitude magnetic reconnection that occurred only (or first) in the dawn quadrant of the southern hemisphere, the effect of which has for the first time been clearly identified at the dayside dip equator. This implies that electric field effects occurring in the polar ionosphere due to magnetopause reconnection may be rapidly monitored at the dayside dip equator. In addition, we argue that the quasi‐simultaneous (time difference is less than 10 s) appearance of the disturbance fields both in the polar region and at the dip equator confirmed in this study is extremely important for theoretically explaining the transmission of the polar electric field to the dayside dip equator, because different theories give different travel times for a disturbance field propagating from polar region to the dip equator. Our observations lend strong evidence for validity of the waveguide model.
Atmospheric inverse modeling to constrain regional‐scale CO2 budgets at high spatial and temporal resolution
Authors: Göckede Mathias , Michalak Anna M. , Vickers Dean , Turner David P. , Law Beverly E.
Published: August 2010

We present an inverse modeling framework designed to constrain CO2 budgets at regional scales. The approach captures atmospheric transport processes in high spatiotemporal resolution by coupling a mesoscale model with Lagrangian Stochastic backward trajectories. Terrestrial biosphere CO2 emissions are generated through a simple diagnostic flux model that splits the net ecosystem exchange into its major components of gross primary productivity and autotrophic and heterotrophic respirations. The modeling framework assimilates state‐of‐the‐art data sets for advected background CO2 and anthropogenic fossil fuel emissions as well as highly resolved remote sensing products. We introduce a Bayesian inversion setup, optimizing a posteriori flux base rates for surface types that are defined through remote sensing information. This strategy significantly reduces the number of parameters to be optimized compared with solving fluxes for each individual grid cell, thus permitting description of the surface in a very high resolution. The model is tested using CO2 concentrations measured in the fall and winter of 2006 at two AmeriFlux sites in Oregon. Because this database does not cover a full seasonal cycle, we focus on conducting model sensitivity tests rather than producing quantitative CO2 flux estimates. Sensitivity tests on the influence of spatial and temporal resolution indicate that optimum results can be obtained using 4 h time steps and grid sizes of 6 km or less. Further tests demonstrate the importance of dividing biome types by ecoregions to capture their different biogeochemical responses to external forcings across climatic gradients. Detailed stand age information was shown to have a positive effect on model performance.
Review of the formulation of present‐generation stratospheric chemistry‐climate models and associated external forcings
Authors: Morgenstern O. , Giorgetta M. A. , Shibata K. , Eyring V. , Waugh D. W. , Shepherd T. G. , Akiyoshi H. , Austin J. , Baumgaertner A. J. G. , Bekki S. , Braesicke P. , Brühl C. , Chipperfield M. P. , Cugnet D. , Dameris M. , Dhomse S. , Frith S. M. , Garny H. , Gettelman A. , Hardiman S. C. , Hegglin M. I. , Jöckel P. , Kinnison D. E. , Lamarque J.‐F. , Mancini E. , Manzini E. , Marchand M. , Michou M. , Nakamura T. , Nielsen J. E. , Olivié D. , Pitari G. , Plummer D. A. , Rozanov E. , Scinocca J. F. , Smale D. , Teyssèdre H. , Toohey M. , Tian W. , Yamashita Y.
Published: August 2010

The goal of the Chemistry‐Climate Model Validation (CCMVal) activity is to improve understanding of chemistry‐climate models (CCMs) through process‐oriented evaluation and to provide reliable projections of stratospheric ozone and its impact on climate. An appreciation of the details of model formulations is essential for understanding how models respond to the changing external forcings of greenhouse gases and ozone‐depleting substances, and hence for understanding the ozone and climate forecasts produced by the models participating in this activity. Here we introduce and review the models used for the second round (CCMVal‐2) of this intercomparison, regarding the implementation of chemical, transport, radiative, and dynamical processes in these models. In particular, we review the advantages and problems associated with approaches used to model processes of relevance to stratospheric dynamics and chemistry. Furthermore, we state the definitions of the reference simulations performed, and describe the forcing data used in these simulations. We identify some developments in chemistry‐climate modeling that make models more physically based or more comprehensive, including the introduction of an interactive ocean, online photolysis, troposphere‐stratosphere chemistry, and non‐orographic gravity‐wave deposition as linked to tropospheric convection. The relatively new developments indicate that stratospheric CCM modeling is becoming more consistent with our physically based understanding of the atmosphere.
Untangling complex shallow groundwater dynamics in the floodplain wetlands of a southeastern U.S. coastal river
Authors: Kaplan D. , Muñoz‐Carpena R. , Ritter A.
Published: August 2010

Understanding the hydrological functioning of tidally influenced floodplain forests is essential for advancing ecosystem protection and restoration goals in impacted systems. However, finding direct relationships between basic hydrological inputs and floodplain hydrology is hindered by complex interactions between surface water, groundwater, and atmospheric fluxes in a variably saturated matrix with heterogeneous soils, vegetation, and topography. Thus, an explanatory method for identifying common trends and causal factors is required. Dynamic factor analysis (DFA), a time series dimension reduction technique, models temporal variation in observed data as linear combinations of common trends, which represent unidentified common factors, and explanatory variables. In this work, DFA was applied to model water table elevation (WTE) in the floodplain of the Loxahatchee River (Florida, USA), where altered watershed hydrology has led to changing hydroperiod and salinity regimes and undesired vegetative changes in the floodplain forest. The technique proved to be a powerful tool for the study of interactions among 29 long‐term, nonstationary hydrological time series (12 WTE series and 17 candidate explanatory variables). Regional groundwater circulation, surface water elevations, and spatially variable net local recharge (cumulative rainfall – cumulative evapotranspiration) were found to be the main factors explaining groundwater profiles. The relative importance of these factors was spatially related to floodplain elevation, distance from the river channel, and distance upstream from the river mouth. The resulting dynamic factor model (DFM) simulated the WTE time series well (overall coefficient of efficiency,Ceff= 0.91) and is useful for assessing management scenarios for ecosystem restoration and predicted sea level rise.
Searching for Life Beyond Our Planet: Are We There Yet?
Authors: Schulze‐Makuch Dirk , Davila Alfonso F.
Published: August 2010

It has been 35 years since NASA undertook a bold journey, to search for life on another planet, by sending the Viking landers (Figure 1) to the surface of Mars. The general consensus was that both landers failed to find conclusive evidence of extant Martian organisms. NASA started the journey with the best car on the market, with the transmission in high gear, but after hitting a big bump in the road, it decided to downshift and take a closer look at the map.

Subsequent studies focused on characterizing the physical, chemical, and geological environment on Mars today and in the past, before any more bold attempts were made to directly search for life. This led to an unanticipated but necessary detour that has provided us with some of the best highlights of the journey so far. Examples are the discovery of widespread secondary minerals that formed in the presence of liquid water, the detection of ground ice in the high latitudes of both hemispheres, including the polar caps, and the direct analysis of ground ice by the Phoenix mission in 2008. These research efforts have also allowed us to vastly improve the tools we now have at our disposal. But let there be no mistake: This detour was a necessary course of action, because it was futile to search for life on Mars without understanding the Martian environment.
Calculated rates of cosmic ray muon‐produced Ne in subsurface quartz
Authors: Fernandez‐Mosquera Daniel , Hahm Doshik , Marti Kurt
Published: August 2010

Interactions of cosmic ray secondaries with subsurface rocks produce both stable (3He, 21Ne, 22Ne) and radioactive (10Be, 26Al and 36Cl) cosmogenic nuclides. As the production rates by muons of 21Ne and 22Ne in quartz are not known, these can be estimated from published cross sections of analogous reactions, separately for fast and slow muon reactions. Our calculations show that subsurface 21Ne is affected mainly by fast muon interactions (P μf21Ne = 0.39 ± 0.15 at g−1a −1 vs Pμ−21Ne = 0.12 ± 0.03 at g−1a−1 sea level‐high latitude). We also infer that the resulting production rate ratio (P21Ne/P10Be) of 21Ne and 10Be changes with depth below the Earth's surface. This ratio in turn may provide supplemental erosion rate information in geological settings of varying erosion surface covers and for long time scales, when radionuclide data provide incomplete information. In environments with very low erosion rates, our calculations indicate noticeable differences in the production ratios P21Ne/P10Be, specifically for long time scales. However, calibrations are needed and may be carried out on a well documented quartz core.
Injection and loss of inner radiation belt protons during solar proton events and magnetic storms
Authors: Selesnick R. S. , Hudson M. K. , Kress B. T.
Published: August 2010

A survey of 27 to 45 MeV proton measurements from the HEO‐3 satellite during the years 1998 through 2005 has been taken to describe variability in the outer part of the inner radiation belt and slot region (L = 2 to 3). Rapid (∼1‐day) changes are described as injection or loss events, characterized respectively by Gaussian or exponential L dependencies. The radial extent of both event types is correlated to the minimum Dst of associated magnetic storms, while the injection magnitude is correlated to the flux of associated interplanetary solar proton events. Changes in the maximal L of observed trapped protons are consistent with trapping limits estimated from magnetic field line curvature. The inward extent and energy independence of the observed loss events are inconsistent with field line curvature induced scattering in a static magnetic field. However, time‐dependent geomagnetic cutoff suppression, observed during magnetic storms, may be the cause of significant losses. Drift resonance with electric field impulses caused by rapid magnetospheric compression is the likely cause of both solar proton injections and radial shifts of preexisting trapped protons.
A novel TMPRSS6 mutation that prevents protease auto-activation causes IRIDA
Authors: Altamura Sandro , D'Alessio Flavia , Selle Barbara , Muckenthaler Martina U.
Published: August 2010

IRIDA (iron-refractory iron-deficiency anaemia) is a rare autosomal-recessive disorder hallmarked by hypochromic microcytic anaemia, low transferrin saturation and high levels of the iron-regulated hormone hepcidin. The disease is caused by mutations in the transmembrane serine protease TMPRSS6 (transmembrane protease serine 6) that prevent inactivation of HJV (haemojuvelin), an activator of hepcidin transcription. In the present paper, we describe a patient with IRIDA who carries a novel mutation (Y141C) in the SEA domain of the TMPRSS6 gene. Functional characterization of the TMPRSS6(Y141C) mutant protein in cultured cells showed that it localizes to similar subcellular compartments as wild-type TMPRSS6 and binds HJV, but fails to auto-catalytically activate itself. As a consequence, hepcidin mRNA expression is increased, causing the clinical symptoms observed in this IRIDA patient. The present study provides important mechanistic insight into how TMPRSS6 is activated.
Survivin and IAP proteins in cell-death mechanisms
Authors: Altieri Dario C.
Published: August 2010

From the realization that cell number homoeostasis is fundamental to the biology of all metazoans, and that deregulation of this process leads to human diseases, enormous interest has been devoted over the last two decades to map the requirements of cell death and cell survival. This effort has led to tangible progress, and we can now chart with reasonable accuracy complex signalling circuitries controlling cell-fate decisions. Some of this knowledge has translated into novel therapeutics, and the outcome of these strategies, especially in cancer, is eagerly awaited. However, the function of cell-death modifiers have considerably broadened over the last few years, and these molecules are increasingly recognized as arbiters of cellular homoeostasis, from cell division, to intracellular signalling to cellular adaptation. This panoply of functions is best exemplified by members of the IAP (inhibitor of apoptosis) gene family, molecules originally narrowly defined as endogenous caspase inhibitors, but now firmly positioned at the crossroads of multiple normal and transformed cellular responses.
Adipose tissue inflammation and insulin resistance: all obese humans are not created equal
Authors: Gauthier Marie-Soleil , Ruderman Neil B.
Published: August 2010

In recent years, it has become widely accepted that obesity is characterized by a chronic low-grade inflammation of adipose tissue that predisposes affected individuals to insulin resistance, Type 2 diabetes and other disorders associated with the metabolic syndrome. On the other hand, a subset of obese individuals appears to be protected against insulin resistance and the disorders to which it predisposes. The comparison between such insulin-sensitive and insulin-resistant obese individuals offers a unique opportunity to identify key factors that either contribute to or prevent the development of insulin resistance in humans, without the confounding effect of a major difference in fat mass. In the previous issue of the Biochemical Journal, Barbarroja et al. reported that insulin-sensitive obese individuals show less inflammation in their visceral adipose tissue than a group of insulin-resistant subjects matched for BMI (body mass index). This finding reinforces the concept that inflammation in adipose tissue may be a cause of insulin resistance in most obese individuals, although it does not prove it. Further studies will be required for this purpose, as well as to identify the pathogenetic factors that determine whether or not adipose tissue of an obese individual becomes inflamed.
Explaining Lexical–Semantic Deficits in Specific Language Impairment: The Role of Phonological Similarity, Phonological Working Memory, and Lexical Competition
Authors: Mainela-Arnold Elina , Evans Julia L. , Coady Jeffry A.
Published: August 2010

Purpose

In this study, the authors investigated potential explanations for sparse lexical–semantic representations in children with specific language impairment (SLI) and typically developing peers. The role of auditory perception, phonological working memory, and lexical competition were investigated.

Method

Participants included 32 children (ages 8;5–12;3 [years;months]): Sixteen children with SLI and 16 typically developing age- and nonverbal IQ–matched peers (CA). Children’s word definitions were investigated. The words to be defined were manipulated for phonological neighborhood density. Nonword repetition and two lexical competition measures were tested as predictors of word definition abilities.

Results

Children with SLI gave word definitions with fewer content details than children in the CA group. Compared with the CA group, the definitions of children in the SLI group were not disproportionately impacted by phonological neighborhood density. Lexical competition was a significant unique predictor of children’s word definitions, but nonword repetition was not.

Conclusions

Individual differences in richness of lexical semantic representations as well as differences between children with SLI and typically developing peers may—at least, in part—be explained by processes of competition. However, difficulty with auditory perception or phonological working memory does not fully explain difficulties in lexical semantics.
Object and Action Naming in Children With Specific Language Impairment
Authors: Sheng Li , McGregor Karla K.
Published: August 2010

Purpose

In this study, the authors aimed to examine the accuracy, latency, and errors of noun (object) and verb (action) naming in children with and without specific language impairment (SLI) and to determine whether children with SLI have a particularly large noun–verb performance gap.

Method

Children with SLI, age-matched peers (AM), and expressive vocabulary–matched peers (VM) named 120 matched object and action pictures in a computerized confrontation naming task.

Results

The SLI and VM groups demonstrated comparable naming latency and accuracy; both were slower and less accurate than the AM group. Object naming was more accurate than action naming in the SLI and VM groups; their noun–verb performance gaps were comparable. Object naming was faster than action naming in all children. In comparison with the AM group, the SLI group made proportionally fewer taxonomic errors and more omission errors when naming objects, and fewer misperception errors when naming actions.

Conclusions

The naming abilities of children with SLI, although deficient given their chronological age, are commensurate with their vocabulary level. Their naming errors suggest immaturities in semantic representation. Action naming is significantly more difficult than object naming, but the noun–verb gap that characterizes the performance of children with SLI is appropriate for their vocabulary level.
A reappraisal of the incremental packing technique for light cured composite resins
Authors: Rees J. S. , Jagger D. C. , Williams D. R. , Brown G. , Duguid W.
Published: August 2010

summary  The cuspal flexure caused by a direct placement composite resin was measured using a technique that did not interfere with cuspal movement. Twenty upper premolar teeth with mesial‐occlusal‐distal (MOD) cavity preparations were restored using a posterior composite resin. Ten teeth were restored using a bulk packing technique and 10 were restored using three ‘U’ shaped bucco‐lingual increments. Total cuspal movement was measured 1 h following the initiation of curing. Bulk placement of the composite resin produced slightly more cuspal movement (12.5 μm) compared with the incremental placement of composite (11.3 μm). This difference was not statistically significant. The technique of incremental packing to reduce cuspal flexure is therefore questioned.
Laser Doppler flow investigation of fractured permanent maxillary incisors
Authors: Strobl H. , Emshoff I. , Bertram S. , Emshoff R.
Published: August 2010

summary  Laser Doppler flowmetry (LDF) is a non‐invasive method to assess pulpal blood‐flow (PBF). Dental injury has been associated with losses of pulpal sensibility. The purpose of this study was to assess the outcome of splint therapy on tooth fracture type‐related PBF values. In 15 trauma patients, a single maxillary incisor treated by repositioning and splinting was investigated by LDF to assess local PBF values. Perfusion units were taken in four sessions, on the day of splint removel, and 12, 24 and 36 weeks after splint removal. Analysis of the tooth fracture type‐related PBF measurements revealed root fractures to be associated with a significant decrease (P < 0·05) and uncomplicated crown fractures to be associated with a significant increase in PBF values (P < 0·05), while complicated crown fractures showed no significant difference between the session‐related values (P > 0·05). The main findings of this study suggest splint therapy of root fractures of the central maxillary incisor to be associated with a short‐ and long‐term decrease in PBF values. The LDF may become useful in the detection of transient ischaemic episodes and the identification of teeth at risk for adverse sequelae such as avascular necrosis and tissue loss.
The influence of the accuracy of the intermaxillary relations on the use of complete dentures: a clinical evaluation
Authors: Dervis E.
Published: August 2010

summary  The aim of this study was to investigate possible associations between the accuracy of intermaxillary relations and complete denture usage 3 months and 3 years after their insertion. A total of 600 patients were provided with new complete dentures. Willis gauge and Woelfel's method were used to assess the quality of the existing complete dentures and the use of these dentures. Three years after insertion the remaining 250 patients took part in a follow‐up examination. Three months post‐insertion, significant relationships were found between adequate interocclusal rest space or quality of registration of centric relation and daily wearing of complete dentures and between quality of registration of centric relation and use of dentures for eating. Three years after insertion the adaptation to denture wearing was generally satisfactory. However, no significant relationship was observed between the accuracy of intermaxillary relations and complete denture usage.
Pattern of tooth loss in recipients of free dental treatment at the University Hospital of Amman, Jordan
Authors: Sayegh A. , Hilow H. , Bedi R.
Published: August 2010

summary  The aim of this study is to document reasons for tooth loss in disadvantaged Jordanians who seek free dental care at the University Hospital/Dental Clinics. A 4‐year (1998–2001) prospective study was undertaken involving 2200 randomly selected patients from this subpopulation. Of their 3069 lost teeth, 46·9% were lost due to caries and its sequel; 18% were lost because of periodontal disease; 8% were lost for a combination of caries and periodontal disease; 19·4% for pre‐prosthetic reasons; 4% for orthodontic reasons; 2·8% for eruption problems and 0·7% due to trauma. Logistic regression analysis for reasons of tooth loss in this sector revealed that caries and its sequel was the predominant cause of tooth loss in patients ≤40 years of age whereas periodontal extractions were predominant for the above 40‐year‐old group. In addition, the most frequently extracted teeth, due to caries, were lower first and second molars while lower incisors were most commonly extracted for periodontal disease. Premolars were extracted for orthodontic reasons, upper incisors for trauma, third molars for eruption problems and canines for pre‐prosthetic reasons. In conclusion, dental caries was the main reason for removal of teeth in adults attending the University of Jordan free dental casualty clinic. Therefore, in order to reduce the rate of dental extractions in this sector of the Jordanian population, efforts should focus on prevention and treatment of caries. Efforts should also be made to change the values and beliefs of this sector towards the importance of natural dentition.
A constitutive equation for droplet distribution in unidirectional flows of dilute emulsions for low capillary numbers
Authors: Ramachandran Arun , Loewenberg Michael , Leighton David T.
Published: August 2010

The concentration distribution of droplets in the unidirectional flow of an emulsion for small capillary numbers (Ca) can be written as a balance between the drift flux arising from droplet deformation and the flux due to shear induced migration. The droplet drift flux is modeled using the O(Ca) theoretical results of Chan and Leal [J. Fluid Mech. 92, 131 (1979)], while the flux due to shear-induced migration is modeled using the suspension balance approach of Nott and Brady [J. Fluid Mech. 275, 157 (1994)], whereby particle migration is ascribed to normal stress gradients in the flowing dilute emulsion. In the limit of vanishingly small capillary numbers, the leading order contribution of the normal stresses in dilute emulsions arises from droplet-droplet interaction and thus scales as ϕ2τ, where ϕ is the droplet volume fraction and τ is the local shear stress. In our model, the normal stress calculations of Zinchenko [Prikl. Mat. Mekh. 47, 56 (1984)] are connected to our gradient diffusivity data computed from droplet trajectories [M. Loewenberg and E. J. Hinch, J. Fluid Mech. 338, 299 (1997)] via a reduced droplet mobility to derive the droplet flux due to shear-induced migration. As an example, the model is applied to the tube Poiseuille flow of a dilute emulsion at small Ca. It is demonstrated that the unsteady concentration distribution of droplets resulting from arbitrary time-dependent average velocity obeys a self-similar solution, provided the thickness of the droplet-depleted region near the walls is always nonzero.
Response to “Comment on ‘Application of Kolmogorov entropy to the self-amplified spontaneous emission free-electron lasers’ ” [Phys. Plasmas 17, 084701 (2010)]
Authors: Zhang Shi-Chang , Elgin John
Published: August 2010

In this response, we conceptually and quantitatively demonstrate that the criticism in the Comment by Maraghechi and Salehi [Phys. Plasmas 17, 084701 (2010)] is unacceptable and the following conclusions obtained in our previous paper do hold on: (1) the self-fields of the electron beam have an effect of stabilizing the electron’s dynamic behavior and (2) the adiabatic magnetic field of a linearly polarized one-dimensional planar wiggler has trivial influence to the stability of the electron’s dynamic behavior, although it is helpful to the electrons to enter the cavity smoothly.
Summer warming effects on biomass production and clonal growth of Leymus chinensis
Authors: Wang Jun-Feng , Gao Song , Lin Ji-Xiang , Mu Yong-Guang , Mu Chun-Sheng
Published: August 2010

Understanding how the biomass production and clone growth of perennial grasses respond to summer warming is crucial for understanding how grassland productivity responds to global warming. Here, we experimentally investigated the effects of summer warming on the biomass production and clonal growth of potted Leymus chinensis in a phytotron. Summer warming significantly decreased the biomass of both parent and daughter shoots, slightly increased the belowground biomass, and lead to a significant increase in root : shoot ratio. Warming significantly increased the total belowground bud number and decreased the daughter shoot number. Importantly, the proportions of each type of bud changed; vertical apical rhizome buds decreased, while horizontal rhizome buds increased in number. The change in proportions of each type of bud is closely related to the decrease in daughter shoot number, rhizome number and length, as well as the decrease in aboveground biomass and increase in belowground biomass. These results indicate that, as a rhizomatous, perennial grass, L. chinensis adopts a selective growth strategy that reduces the energy allocated to aboveground growth and emphasises the development of belowground organs. The implication is that continued summer warming, will further reduce the aboveground biomass production of temperate grasslands dominated by rhizomatous, perennial grasses. Inevitably, species that depend on these grasses for forage will suffer should global climate warming continue.
Variation for qualitative and quantitative traits and identification of trait-specific sources in new sorghum germplasm
Authors: Upadhyaya H. D. , Sharma Shivali , Ramulu B. , Bhattacharjee Ranjana , Gowda C. L. L. , Reddy V. Gopal , Singh Sube
Published: August 2010

Assembling, collecting and characterising the unique germplasm accessions for morphological and agronomic characteristics are essential activities of a dynamic genebank. The phenotypic diversity and agronomic performance of 667 newly acquired sorghum germplasm accessions, representing five basic races, eight intermediate races and two wild species, originating from 34 countries were assessed for seven qualitative and eight quantitative traits. Large variability was observed among these accessions for various qualitative and quantitative traits. Trait-specific accessions for early flowering (108), short plant height (8), medium panicle exsertion (34), and medium-sized seeds (78) have been identified. The diverse trait-specific promising accessions have the potential for their utilisation in future breeding programs for developing improved sorghum cultivars with a broad genetic base. The hierarchical cluster analysis grouped five races, six intermediate races, and two wild species into three clusters. The present study has played a significant role in filling up the gaps and has also identified region(s) to carry out future explorations, and in providing the trait-specific germplasm for use by the breeders.
Sequential floods drive 'booms' and wetland persistence in dryland rivers: a synthesis
Authors: Leigh Catherine , Sheldon Fran , Kingsford Richard T. , Arthington Angela H.
Published: August 2010

Flow is a key driver regulating processes and diversity in river systems across a range of temporal and spatial scales. In dryland rivers, variability in the timing and scale of floods has specific ecological significance, playing a major role in sustaining biotic diversity across the river-floodplain mosaic. However, longitudinal effects of floods are equally important, delivering water downstream through channels and wetland complexes. Interaction among spatially distributed wetlands, their connecting channel and floodplain geomorphology and the temporally variable flow events not only creates the spatial complexity in dryland rivers but also determines temporal persistence of wetlands. These act as hydrological ‘sponges’, absorbing water from upstream and needing to fill before releasing water downstream. Sequential high flow events are essential for the ecological persistence of riverine wetlands and the transmission of flows further downstream through the channel network. These flood sequences maintain aquatic refugia and drive booms in productivity sustaining aquatic and terrestrial biota over large spatial and temporal scales. Disrupting the sequence, with modified flow regimes and water removal for diversion (e.g. irrigation), significantly reduces the opportunity for wetland replenishment. As a result, the benefits of sequential flooding to the wetland ‘sponges’ and their biotic communities will be lost.
Influenza Vaccination and Intention to Receive the Pandemic H1N1 Influenza Vaccine among Healthcare Workers of British Columbia, Canada: A Cross-Sectional Study
Authors: Kaboli Fariba , Astrakianakis George , Li Guiyun , Guzman Jaime , Naus Monika , Donovan Tara
Published: August 2010

Objective.

To assess healthcare workers' attitudes and concerns regarding seasonal and pandemic influenza vaccines in order to improve vaccination campaign communications.

Design.

Cross-sectional survey.

Setting.

All 6 health authorities in British Columbia, Canada.

Methods.

An anonymous, self-administered online survey was conducted from August 30 through September 30, 2009. Question topics included demographic characteristics, factors influencing acceptance of seasonal influenza vaccine, factors influencing intentions to accept pandemic H1N1 influenza vaccine, and knowledge and concerns regarding the effect of the influenza pandemic.

Participants.

All 96,217 British Columbia healthcare workers were eligible to participate.

Results.

A volunteer sample of 4,046 healthcare workers returned the survey; 3,563 (88%) were women, 58% were under 50 years old (mean age ± standard deviation, 45.3 ± 10.9 years), 3,152 of 4,023 (79%) had 5 or more years of experience in their profession, 1,853 of 4,023 (46%) were nurses, and 2,833 (70%) had been vaccinated against seasonal influenza the previous year. Two thousand eight hundred (69%) respondents reported intending to receive the pandemic H1N1 vaccine. The most important predictor of this intention was having received the seasonal vaccine the previous year (odds ratio [OR], 6.25 [95% confidence interval {CI}, 5.39-7.26]). Worry about making loved ones ill was the only attitude associated with intention to receive the pandemic H1N1 vaccine (adjusted OR, 1.38 [95% CI, 1.27-1.50]). Concerns with vaccine safety (adjusted OR, 0.31 [95% CI, 0.25-0.39]) and belief “that H1N1 is not severe enough” (adjusted OR, 0.29 [95% CI, 0.26-0.32]) were independently associated with the intention to reject the pandemic H1N1 vaccine.

Conclusions.

Vaccination campaigns for pandemic H1N1 vaccine should use messages that emphasize the risk of illness among younger people and the opportunity to protect loved ones by getting the vaccine and should address concerns about the safety and effectiveness of the vaccine.
Gas density in a pulsed positive streamer measured using laser shadowgraph
Authors: Ono Ryo , Teramoto Yoshiyuki , Oda Tetsuji
Published: August 2010

Gas density in a pulsed positive streamer is quantitatively measured using a laser shadowgraph. The discharge occurs in a point–plane gap of 13 mm in humid air. After the onset of the streamer, the gas density decreases in two steps. The first step is a rapid decrease in gas density, which is caused by gas heating owing to electron impact onto molecules. This step is significant within 1 mm from the anode, although it occurs throughout the gap. The second step is a gradual decrease in gas density after the streamer pulse, which is caused by gas heating due to vibration-to-translation energy transfer. This step takes place mainly in the secondary streamer channel, not in the primary streamer channel. When the discharge voltage is 32 kV, the decrease in gas density reaches 30% of the ambient density. This large decrease in gas density affects the rate of various chemical reactions in the postdischarge period.
Mechanisms behind variation in the Clostridium difficile 16S–23S rRNA intergenic spacer region
Authors: Indra Alexander , Blaschitz Marion , Kernbichler Silvia , Reischl Udo , Wewalka Guenther , Allerberger Franz
Published: August 2010

Clostridium difficileinfection is an increasing problem in hospitals worldwide, mainly due to the recent emergence of a hypervirulentC. difficilestrain.C. difficilePCR ribotyping, based on size variation of the 16S–23S rRNA intergenic spacer region (16S–23S ISR), is widely used in Europe for molecular epidemiological investigation. The mechanism underlying the 16S–23S ISR size variations in the genome ofC. difficileis currently not completely understood. To elucidate this mechanism, isolates of six different PCR ribotypes were analysed by cloning and sequencing the 16S–23S ISR. A direct repeat, IB, of 9 bp was detected up to five times in the 16S–23S ISR in all 47 clones investigated. Thirty-five clones displayed differences either by ribotype or by nucleotide sequence. The sequences of the 16S–23S ISR ofC. difficileshowed a uniformly organized structure, composed of a tRNAAlagene and spacers of 33 and 53 bp separated by the 9 bp direct repeat IB. The results of the study support the hypothesis that this composition is responsible for the length variations seen in the 16S–23S ISR, and indicate that these length variations result from slipped-strand mispairing and intra- and possibly interchromosomal homologous recombination.
Chlamydophila psittaci in homing and feral pigeons and zoonotic transmission
Authors: Dickx V. , Beeckman D. S. A. , Dossche L. , Tavernier P. , Vanrompay D.
Published: August 2010

Chlamydiosis is a zoonotic disease in birds caused by Chlamydophila psittaci, an obligate intracellular bacterium. There are seven known avian outer-membrane protein A genotypes, A–F and E/B. The importance of genotyping lies in the fact that certain genotypes tend to be associated with certain hosts and a difference in virulence. Genotype B is the most prevalent in pigeons, but the more virulent genotypes A and D have also been discovered. The current study assessed the prevalence of C. psittaci in 32 Belgian homing-pigeon facilities and in 61 feral pigeons captured in the city of Ghent, Belgium. Additionally, zoonotic transmission of C. psittaci was investigated in the homing-pigeon facilities. Homing pigeons were often infected, as at least one of the lofts was positive in 13 of the 32 (40.6 %) pigeon breeding facilities. Genotypes B, C and D were detected. Zoonotic transmission was discovered in 4 of the 32 (12.5 %) pigeon fanciers, revealing genotype D in two of them, whilst genotyping was unsuccessful for the other two human pharyngeal swabs. This study clearly demonstrates the possible risk of C. psittaci zoonotic transmission from homing pigeons. Pigeon fanciers often (37.5 %) used antibiotics for prevention of respiratory disease. Because of the risk of developing drug-resistant strains, regular use of antimicrobial drugs must be avoided. This study is believed to be the first to detect C. psittaci in Belgian feral pigeons. The prevalence rate in the city of Ghent was extremely low, which is beneficial for public health.