bluuebunny/crossref_metadata_2025 huggingface dataset:
Solutions to the Navier‐Stokes equations with the large time energy concentration in the low frequencies
Authors: Skalák Z.
Published: February 2011

In this paper we study the large time behavior of the solutions to the Navier‐Stokes equations. We focus on the solutions exhibiting the large time energy concentration in the low frequencies and describe some classes of the initial conditions from Lσ2 such that if u0 belongs to such a class and u is a global weak solution with u(0) = u0 satisfying the strong energy inequality, then
\begin{eqnarray*}1 ‐ \frac {||E_\lambda u(t)||} {||u(t)||} \rightarrow 0, \text{ if } t \rightarrow \infty \end{eqnarray*}
for every λ > 0, where {Eλ λ > 0} is the resolution of the identity of the Stokes operator and ||·|| denotes the standard L2‐norm. We present some estimates of this concentration rate.
A variational approach to the decomposition of unstable viscous fluids and its consistent numerical approximation
Authors: Anders D. , Weinberg K.
Published: February 2011

The mixing and de‐mixing properties of highly viscous fluids can be described as a diffusive system driven by an external velocity field. In order to analyze the micro‐morphological evolution with a diffusion theory of heterogeneous mixtures we apply a Cahn‐Hilliard phase‐field model, which is here extended by a convective term. As the model is based on an energetic variational formulation, we state the underlying energy minimizing principles. For consistent finite element analysis we provide a piecewise smooth and globally C1‐continuous approximation by means of rational B‐spline basis functions. Numerical examples exhibit the physical properties of the model. Simulations of phase decomposition and coarsening controlled by diffusion and by convection show the robustness and the versatility of our approach.
Investigation of the stress‐strain state of the laminated shallow shells by R‐functions method combined with spline‐approximation
Authors: Awrejcewicz J. , Kurpa L. , Osetrov A.
Published: February 2011

The bending behavior of the laminated shallow shells under static loading has been studied using the R‐functions theory together with the spline‐approximation. Formulation is based on the first order shear deformation theory. Due to usage of the R‐functions theory the laminated shallow shells with complex shape and different types of the boundary conditions can be investigated. Application of the spline‐approximation allows getting reliable and validated results for non concave domains and domains with holes. The proposed method is implemented in the appropriate software in framework of the mathematical package MAPLE. The analysis of influence of certain factors (curvature, packing of layers, geometrical parameters, boundary conditions) on a stress‐strain state is carried out for shallow shells with cut‐outs. The comparison of obtained results with those already known from literature and results obtained by using ANSYS are also presented.
Existence theorems in the linear theory of micropolar shells
Authors: Eremeyev V.A. , Lebedev L.P.
Published: February 2011

Theorems regarding existence and uniqueness of weak solutions to mixed boundary value problems in the linear theory of micropolar shells in statics and dynamics are proved. Convergence of FEM for the static mixed problems is established. Eigenvalue problems for micropolar shells are studied and properties of the spectrum and eigenmodes are formulated.
Measuring Growth in a Longitudinal Large-Scale Assessment with a General Latent Variable Model
Authors: von Davier Matthias , Xu Xueli , Carstensen Claus H.
Published: February 2011

The aim of the research presented here is the use of extensions of longitudinal item response theory (IRT) models in the analysis and comparison of group-specific growth in large-scale assessments of educational outcomes.

A general discrete latent variable model was used to specify and compare two types of multidimensional item-response-theory (MIRT) models for longitudinal data: (a) a model that handles repeated measurements as multiple, correlated variables over time and (b) a model that assumes one common variable over time and additional variables that quantify the change. Using extensions of these MIRT models, we approach the issue of modeling and comparing group-specific growth in observed and unobserved subpopulations. The analyses presented in this paper aim at answering the question whether academic growth is homogeneous across types of schools defined by academic demands and curricular differences. In order to facilitate answering this research question, (a) a model with a single two-dimensional ability distribution was compared to (b) a model assuming multiple populations with potentially different two-dimensional ability distributions based on type of school and to (c) a model that assumes that the observations are sampled from a discrete mixture of (unobserved) populations, allowing for differences across schools with respect to mixing proportions. For this purpose, we specified a hierarchical-mixture distribution variant of the two MIRT models. The latter model, (c), is a growth-mixture MIRT model that allows for variation of the mixing proportions across clusters in a hierarchically organized sample. We applied the proposed models to the PISA-I-Plus data for assessing learning and change across multiple subpopulations. The results of this study support the hypothesis of differential growth.
Effect of Soybean Oil Fatty Acid Composition and Selenium Application on Biodiesel Properties
Authors: Fallen Benjamin D. , Pantalone Vincent R. , Sams Carl E. , Kopsell Dean A. , Vaughn Steven F. , Moser Bryan R.
Published: February 2011

Biodiesel consisting principally of monounsaturated fatty acid methyl esters (FAME) has been reported to have the optimal balance between cold flow properties and oxidative stability, therefore producing a superior fuel. In addition, treating biodiesel with antioxidants such as selenium (Se) also increases oxidative stability. Fuel properties including acid value (AV), cloud point (CP), iodine value (IV), pour point (PP), peroxide value (PV), induction period (IP), onset temperature (OT), and kinematic viscosity (KV) were used to evaluate a newly developed Roundup Ready® soybean recombinant inbred line (RIL) and a commercial cultivar. The RIL had a fatty acid profile with elevated levels of monounsaturated FAME. TN07‐93RR was determined as the more desirable line for production of biodiesel, based on its fatty acid composition and subsequent fuel properties. The commercial cultivar AG3906 contained the highest abundance of polyunsaturated FAME and exhibited comparatively high IV and low oxidative stability. AG3906 was therefore not acceptable under the European biodiesel standard, EN 14214. However, TN07‐93RR and AG3906 both were considered satisfactory according to the American biodiesel standard, ASTM D6751. Foliar treatment of soybean plants with varying amounts of Se had no effect on subsequent biodiesel oxidative stabilities.
Perceived burden of illness in patients entering for treatment in a university hospital – is the threshold to secondary care higher for patients with depression than for those with somatic disorders?
Authors: Suominen K. , Karlsson H. , Rissanen A. , Valtonen H.M. , Räsänen P. , Sintonen H. , Roine R.P.
Published: February 2011

Background

The threshold to secondary health care should be similar for all patients independent of the underlying disease. This study compared, using a validated health-related quality of life (HRQoL)-instrument, whether the perceived burden of illness is similar in patients admitted for secondary care treatment into a university hospital because of one of six common conditions.

Methods

HRQoL, assessed by the generic 15D instrument before elective treatment, was compared in six groups: operative treatment of cataract (n = 219), operative treatment of cervical or lumbar radicular pain (n = 270), hysterectomy due to benign uterine conditions (n = 337), hip or knee replacement surgery (n = 223), coronary angiography due to suspected coronary artery disease (n = 261), and secondary care treatment of depression (n = 89).

Results

Mean (±SD) HRQoL score was clearly highest in patients with benign uterine conditions (0.908 ± 0.071) and lowest in patients with depression (0.729 ± 0.120) (P < 0.001 between the groups). Also all the other groups had a significantly (P < 0.001) higher baseline HRQoL score (ranging from 0.802 to 0.824) than patients with depression. Outcome of treatment, in terms of HRQoL improvement, was in depressive patients at least equal, and in some cases even better, than that in the other groups.

Discussion

Our results imply that, at least concerning perceived burden of illness, patients with depression are worse off when admitted to secondary care treatment than patients with many somatic conditions. That may be a consequence of poor motivation of depressive patients to seek treatment or that, contradictory to guidelines, the health care system does nor give priority to those worst off and sets a higher threshold for specialized care of patients with depression than of those with common somatic disorders.
Parental bonding and alexithymia: A meta-analysis
Authors: Thorberg F.A. , Young R.McD. , Sullivan K.A. , Lyvers M.
Published: February 2011

Aim

The primary purpose of this meta-analysis was to explore, clarify and report the strength of the relationship between alexithymia, as measured by the Toronto Alexithymia Scale (TAS-20), and parenting style as measured by the Parental Bonding Instrument (PBI).

Methods

Web of Science, PsycInfo, PubMed and ProQuest: Dissertations and Theses searches were undertaken, yielding nine samples with sufficient data to be included in the meta-analysis.

Results

Evidence indicated moderate to strong relationships between maternal care and alexithymia, and between maternal care and two of the three TAS-20 alexithymia facets (Difficulties Describing Feelings and Difficulties Identifying Feelings, but not Externally Oriented Thinking). Moderate relationships were observed for both maternal- and paternal-overprotection and alexithymia respectively, and for overprotection (both maternal and paternal) and Difficulties Describing Feelings.

Conclusion

This study is the first meta-analysis of the relationship between parenting styles and alexithymia, and findings confirm an especially strong association between maternal care and key elements of alexithymia. This review highlights the issues that still remain to be addressed in exploring the link between parenting style and alexithymia.
Quality of financial information and liquidity
Authors: Bardos Katsiaryna Salavei
Published: February 2011

This paper examines the relationship between liquidity and quality of financial information by analyzing long‐term trends in Amihud's (2002) illiquidity measure for firms that restate financial statements. I find that for most income decreasing restatements illiquidity increases several months before restatement announcement and remains at elevated levels one year after restatement. The result is most pronounced for firms listed on NASDAQ. Increase in illiquidity is greater upon restatements due to revenue recognition, those prompted by party other than auditor, those made by larger firms with high volatility of returns and low price levels. Income increasing restatements do not affect information asymmetry of the firm. Overall, my results indicate a positive relationship between quality of financial information and liquidity.
Micronutrient and anthropometric status indicators are associated with physical fitness in Colombian schoolchildren
Authors: Arsenault Joanne E. , Mora-Plazas Mercedes , Forero Yibby , Lopez-Arana Sandra , Jáuregui Germán , Baylin Ana , Gordon Paul M. , Villamor Eduardo
Published: February 2011

Poor physical fitness is associated with increased health-related risks in children. The association of nutritional status indicators and physical fitness in children residing in developing countries is not well characterised. We conducted a cross-sectional study among 1945 children of age 5–12 years in Bogotá, Colombia, to assess whether anthropometric and micronutrient status indicators were associated with performance in the shuttle run and standing long jump tests. Stunted children scored significantly lower in the run (0·4 s;P = 0·0002) and jump (6 cm; boys only;P = 0·003) tests than non-stunted children, after adjustment for age and other factors. Children who were thin, overweight or obese ran slower than normal-weight children (P < 0·01). Lower jump scores were associated with overweight or obesity and greater arm fat area in boys only (P < 0·0001). Girls with low ferritin concentrations ran 0·6 s slower than girls with normal ferritin concentrations (P = 0·02). Erythrocyte folate concentrations were linearly related to higher run (P < 0·0001) and long jump scores (P = 0·0001). Boys with marginal or low vitamin B12status had 4 cm lower long jump scores than children with normal status (P = 0·01). Suboptimal anthropometric and micronutrient status are related to poorer performance in fitness tests. The effects of improving nutritional status on physical fitness of children warrant investigation.
Atwood ratio dependence of Richtmyer–Meshkov flows under reshock conditions using large-eddy simulations
Authors: LOMBARDINI M. , HILL D. J. , PULLIN D. I. , MEIRON D. I.
Published: February 2011

We study the shock-driven turbulent mixing that occurs when a perturbed planar density interface is impacted by a planar shock wave of moderate strength and subsequently reshocked. The present work is a systematic study of the influence of the relative molecular weights of the gases in the form of the initial Atwood ratio A. We investigate the cases A = ± 0.21, ±0.67 and ±0.87 that correspond to the realistic gas combinations air–CO2, air–SF6 and H2–air. A canonical, three-dimensional numerical experiment, using the large-eddy simulation technique with an explicit subgrid model, reproduces the interaction within a shock tube with an endwall where the incident shock Mach number is ~1.5 and the initial interface perturbation has a fixed dominant wavelength and a fixed amplitude-to-wavelength ratio ~0.1. For positive Atwood configurations, the reshock is followed by secondary waves in the form of alternate expansion and compression waves travelling between the endwall and the mixing zone. These reverberations are shown to intensify turbulent kinetic energy and dissipation across the mixing zone. In contrast, negative Atwood number configurations produce multiple secondary reshocks following the primary reshock, and their effect on the mixing region is less pronounced. As the magnitude of A is increased, the mixing zone tends to evolve less symmetrically. The mixing zone growth rate following the primary reshock approaches a linear evolution prior to the secondary wave interactions. When considering the full range of examined Atwood numbers, measurements of this growth rate do not agree well with predictions of existing analytic reshock models such as the model by Mikaelian (Physica D, vol. 36, 1989, p. 343). Accordingly, we propose an empirical formula and also a semi-analytical, impulsive model based on a diffuse-interface approach to describe the A-dependence of the post-reshock growth rate.
Stirring by squirmers
Authors: LIN ZHI , THIFFEAULT JEAN-LUC , CHILDRESS STEPHEN
Published: February 2011

We analyse a simple ‘Stokesian squirmer’ model for the enhanced mixing due to swimming micro-organisms. The model is based on a calculation of Thiffeault & Childress (Phys. Lett. A, vol. 374, 2010, p. 3487), where fluid particle displacements due to inviscid swimmers are added to produce an effective diffusivity. Here we show that, for the viscous case, the swimmers cannot be assumed to swim an infinite distance, even though their total mass displacement is finite. Instead, the largest contributions to particle displacement, and hence to mixing, arise from random changes of direction of swimming and are dominated by the far-field stresslet term in our simple model. We validate the results by numerical simulation. We also calculate non-zero Reynolds number corrections to the effective diffusivity. Finally, we show that displacements due to randomly swimming squirmers exhibit probability distribution functions with exponential tails and a short-time superdiffusive regime, as found previously by several authors. In our case, the exponential tails are due to ‘sticking’ near the stagnation points on the squirmer's surface.
Effects of salinity stress on cellular location of elements and photosynthesis in Ramalina canariensis Steiner
Authors: MATOS Paula , CARDOSO-VILHENA João , FIGUEIRA Rui , SOUSA A. Jorge
Published: February 2011

The impact of incubation in saline solutions of different concentrations on the uptake and cellular location of essential elements (Na+, K+, Mg2+ and Ca2+), and its effects on membrane integrity and on the photosynthetic apparatus, were investigated in the lichen Ramalina canariensis Steiner. Saline incubation resulted in a rapid uptake of Na+ and Mg2+ in the cell wall fraction, whereas in the intracellular fraction the accumulation of Na+ was slower. No changes were observed for intracellular Mg2+, suggesting that no generalized membrane damage occurred. Concomitantly with the increase in intracellular Na+, there was a specific loss of K+ from the cell interior, indicating that membrane permeability may have been compromised. Incubation in a 100% artificial sea water solution reduced the maximum photochemical efficiency of Photosystem II (Fv/Fm) by 17% after 5 min, and this inhibition increased with incubation time. In samples incubated in 100% artificial sea water solution for 2 h followed by 2 h incubation in deionized water, ion distribution and Fv/Fm did not recover to control values. The present findings show the importance of determining the cellular location of elements when assessing their physiological impact. Results indicate that saline stress may irreversibly impair photosynthesis, thus compromising lichen vitality.
Caloplaca aequata is a synonym of C. cinnabarina (Teloschistaceae)
Authors: JOSHI Yogesh , THÜS Holger , HUR Jae-Seoun
Published: February 2011

In 1915 Hue described Lecanora (sect. Placodium) aequata growing over quartzite rocks from Busan and the Kangwon Provinces of South Korea. Later Zahlbruckner (1931) transferred it to the genus Caloplaca. Careful examination of syntype material of L. aequata lodged at The Natural History Museum, UK (BM) demonstrates that the species is conspecific with C. cinnabarina (Ach.) Zahlbr. and we henceforth synonymize it with that species.
Morphological characterization of the haemocytes of the ivory snail,Babylonia areolata(Neogastropoda: Buccinidae)
Authors: Di G.L. , Zhang Z.X. , Ke C.H. , Guo J.R. , Xue M. , Ni J.B. , Wang D.X.
Published: February 2011

The nucleus diameter/cell diameter (N/C) ratio and morphological characteristics of the haemocytes of the snailBabylonia areolatawere studied using microscopy. Our results revealed two major types of haemocytes, namely granulocytes and hyalinocytes. In granulocytes, the cytoplasm was purplish red with Wright's staining, but it was blue in hyalinocytes. Hyalinocytes were smaller than granulocytes and had a higher N/C ratio. The granulocytes were sub-categorized into type I granulocytes and type II granulocytes based on the shape and the number of granules. Hyalinocytes were sub-categorized into large and small hyalinocytes based on the diameter and N/C ratio. Snails with a shell length from 2.7 to 3.3 cm showed no differences in the abundance of haemocytes.
Testing ecological and environmental changes during the last 6000 years: a multiproxy approach based on the bivalveTawera gayifrom southern South America
Authors: Gordillo Sandra , Martinelli Julieta , Cárdenas Javiera , Bayer M. Sol
Published: February 2011

This paper evaluates if the bivalveTawera gayifrom southern South America represents an opportunity to test ecological variability and environmental changes during the last 6000 years in southern South America. For this purpose, we analyse both modern and fossil (mid-to-late Holocene)T. gayishells from Tierra del Fuego using different techniques, including taphonomy, stable isotopes, cathodoluminiscence (CL) and linear morphometrics. Taphonomic analysis shows that differences between modern and fossil shells appear best related to local variations of physical factors such as current speed, wave action and freshwater input along the non-uniform Beagle Channel coast. However, slight changes of hydraulic energy regimes throughout the Holocene cannot be ruled out. The analysis of stable isotopes onT. gayishells indicates a mixing of oceanic waters with freshwater from precipitation, river runoff and glacier meltwater during the mid-to-late Holocene. The high depletion of δ18O at ~4400 years before present would be associated with a period of warmer temperatures, the so-called Hypsithermal. Under CL modern and fossilT. gayishells show a well defined pattern related to the growth dynamics of the shell, which can lead to a better understanding of its biology, adding details to further palaeoenvironmental analysis. Finally, conventional metrics shows that fossilT. gayishells are smaller and shorter than modern shells. These differences could be related to Holocene environmental changes, but here are best explained on the basis of a predator–prey relationship. This study shows thatT. gayimay be a good candidate for looking at evidences of environmental changes in southern South America, and multi-proxy data are necessary to better understand the driving mechanisms of ecological variability and changes over short geological time intervals of few thousands of years.
Comparison of fish assemblages between the Sea of Marmara and the Aegean Sea (north-eastern Mediterranean)
Authors: Keskin Cetin , Ordines Francesc , Guijarro Beatriz , Massutí Enric
Published: February 2011

The demersal fish assemblages of the south-western Sea of Marmara and the north-eastern Aegean Sea were examined in relation to their biogeographical and environmental conditions. Sampling was carried out during bottom trawl surveys conducted during five periods between June 2006 and August 2007. A total of 40 hauls were processed, including 16 in the Sea of Marmara (38–74 m deep) and 24 in the north-eastern Aegean Sea (63–401 m deep). A total of 47,940 individuals, from 91 species and 47 families were collected. Cluster analysis of catch data indicated that there were three assemblages, one in the shelf of the Sea of Marmara and two in the Aegean Sea (<100 and >200 m depth). The numerical abundance and biomass of fish, mean fish weight, mean species richness, diversity and evenness were compared between these assemblages. Multivariate analysis was used to test differences in environmental conditions between areas, and relationships between species and environmental variables were explored by using redundancy analysis. In addition to bathymetric differences, differences in both diversity and species composition were observed between shelf assemblages in the two nearby areas. The distinct biogeographical, environmental characteristics (depth, dissolved oxygen and temperature) and fishing pressure are discussed as the main factors which could explain the differences detected.
The larval development of the hermit crabAreopaguristes nigroapiculus(Decapoda: Anomura: Diogenidae) reared under laboratory conditions
Authors: Kornienko Elena S. , Korn Olga M.
Published: February 2011

The larval development of the hermit crabAreopaguristes nigroapiculus(Komai, 2009) (Decapoda: Anomura: Diogenidae) is described and illustrated from the material reared in the laboratory. The development included three zoeal and a single megalopal stages. At 22–25°C, megalop ofA. nigroapiculuswas attained 6–9 days after hatching. The present paper is the first description of the complete larval development in the genusAreopaguristes. Morphological characters of zoeas and megalop ofA. nigroapiculusare compared with those described for the closely relatedPaguristesspecies. The comparison on the zoeal characters revealed thatA. nigroapiculusis distinguished fromPaguristesspecies by the absence of anterolateral carapace spines and by the fused fourth telson process in zoea III. These two features are possible generic characters ofAreopaguristes. In the rest of larval characters,A. nigroapiculusagree well withPaguristesspecies having three zoeal stages. In the plankton of Peter the Great Bay, the larvae ofA. nigroapiculussporadically occurred only in July and August, at depths of 3–45 m and surface water temperatures of 18–22°C.
Development and use of FFQ among adults in diverse settings across the globe
Authors: Sharma Sangita
Published: February 2011

In nutritional epidemiology, development of valid dietary assessment instruments specific to populations in diverse settings is of paramount importance. Such instruments are essential when trying to characterise dietary patterns and intake, investigate diet–disease associations, inform and evaluate nutrition interventions, assess nutrient–gene interactions, conduct cross-country comparison studies and monitor nutrition transitions. The FFQ is a relatively inexpensive tool for measuring long-term dietary intake for large populations and for allowing researchers to track dietary changes over time. However, FFQ must be population specific to capture the local diet and available foods. Collecting 24-h dietary recalls and utilising community feedback to build the FFQ ensures that a culturally appropriate instrument is developed. This article presents several examples describing FFQ development and utilisation in different settings globally. In the Canadian Arctic, FFQ were developed and utilised to inform and evaluate a community-based intervention programme, characterise the diet and track dietary changes occurring among Inuit and Inuvialuit, populations experiencing rising rates of chronic disease and likely to be extremely vulnerable to the potential effects of climate change. Another example is an FFQ developed to assess sodium intake and evaluate a sodium reduction trial in a high-risk population in Barbados. An example is provided from Brazil, where an FFQ was developed to assess associations between diet, heterocyclic aromatic amines and colorectal adenoma among Japanese Brazilians and to conduct cross-country comparisons. These and other case studies highlight the diversity in dietary intake between populations and the need for FFQ to be developed to capture this diversity.
Animal grazing selectivity and plant chemistry issues impact on the potential of Rhagodia preissii as an anthelmintic shrub
Authors: KOTZE A. C. , ZADOW E. N. , VERCOE P. E. , PHILLIPS N. , TOOVEY A. , WILLIAMS A. , RUFFELL A. P. , DINSDALE A. , REVELL D. K.
Published: February 2011

As Rhagodia preissii had shown significant in vitro anthelmintic activity in a previous study, we examined the effect of including this shrub in the diet of sheep infected with Trichostrongylus colubriformis. Worm-infected merino wethers were grazed for 7 weeks on either R. preissii or annual pasture, and faecal egg counts (FECs) were conducted weekly. Plant material was collected weekly from eaten and uneaten plants, and analysed for levels of plant secondary metabolites (tannins, oxalates, saponins) and in vitro anthelmintic activity. While mean FECs were consistently lower in sheep grazing R. preissii compared to pasture (reductions of 20–74%), the differences were not significant. There was no relationship between grazing preference (eaten or uneaten) and in vitro anthelmintic activity of plant extracts. The levels of saponins and oxalates did not correlate with grazing preference or in vitro anthelmintic activity, while tannins were not responsible for the anthelmintic activity. While the identity of the grazing deterrent and in vitro anthelmintic compounds remain unknown, the presence of plants which were both highly preferred by the sheep and showed in vitro anthelmintic activity indicates a potential to develop the species as an anthelmintic shrub through selection of shrub populations dominated by such plants.
Salivary secretions from the honeybee mite,Varroa destructor:effects on insect haemocytes and preliminary biochemical characterization
Authors: RICHARDS E. H. , JONES BENJAMIN , BOWMAN ALAN
Published: February 2011

Introduction.The ectoparasitic honey bee miteVarroa destructorfeeds on the haemolymph of the honey bee,Apis mellifera, through a single puncture wound that does not heal but remains open for several days. It was hypothesized that factors in the varroa saliva are responsible for this aberrant wound healing.Methods.Anin vitroprocedure was developed for collecting salivary gland secretions fromV. destructor.Mites were incubated on balls of cotton wool soaked in a tissue culture medium (TC-100), and then induced to spit by topical application of an ethanolic pilocarpine solution.Results.Elution of secretions from balls of cotton wool, followed by electrophoretic analysis by SDS-PAGE and electroblotting indicated the presence of at least 15 distinct protein bands, with molecular weights ranging from 130 kDa to <17 kDa. Serial titration ofV. destructorsalivary secretions in TC-100 followed by an 18-h incubation with haemocytes from the caterpillar,Lacanobia oleracea, indicated that the secretions damage the haemocytes and suppresses their ability to extend pseudopods and form aggregates.Conclusion.We suggest that these secretions facilitate the ability ofV. destructorto feed repeatedly off their bee hosts by suppressing haemocyte-mediated wound healing and plugging responses in the host.
Need support and wellbeing during morning care activities: an observational study on resident–staff interaction in nursing homes
Authors: CUSTERS ANNETTE F. J. , KUIN YOLANDE , RIKSEN-WALRAVEN MARIANNE , WESTERHOF GERBEN J.
Published: February 2011

Quality of life and wellbeing in nursing homes are becoming more important in research and practice. One of the main influences on residents' wellbeing is the interaction with their professional care-givers. The purpose of this study was to explore to what extent care-givers support the residents' needs of relatedness, autonomy and competence, and how this need support is related to wellbeing. Residents and their professional care-givers of four nursing homes in the Netherlands participated in an observational and questionnaire study. Three video-observations of each resident (with different care-givers) were made during morning care. Additional data were collected by means of questionnaires. The results show that the needs of residents were, on average, moderately fulfilled during care interactions. More need support by care-givers was related to higher resident wellbeing. Care-givers provided more need support to residents with stronger functional impairments. More need support was provided by higher-educated care-givers and care-givers in higher job functions. The results show the importance of need support for situational wellbeing, but the contribution to the general subjective wellbeing of residents remains unclear. Further (longitudinal) research is needed to investigate changes in wellbeing over time. Possible differences between subjective ratings and observations of need support and wellbeing should be taken into account.
Temporal dynamics of dry-season water-hole use by large African herbivores in two years of contrasting rainfall in Hwange National Park, Zimbabwe
Authors: Valeix Marion
Published: February 2011

As the dry season progresses in arid and semi-arid ecosystems, rain-fed surface water sources become depleted, forcing most animals to concentrate in the immediate vicinity of the few remaining permanent sources of drinking water. This study investigates the temporal dynamics of use of water-holes by nine African large-herbivore species in the dry season in the semi-arid savanna of Hwange National Park, Zimbabwe, and particularly how annual rainfall influences this temporal dynamics. Two contrasting years in terms of annual rainfall were compared: 2003 (a drought – 362.6 mm) and 2004 (average rainfall – 695.8 mm). In 2003, water-holes were used far more intensively and the level of aggregation of herbivores at water-holes was significantly higher. The temporal dynamics of water-hole use in the dry season differed between the two years: in 2003, the peak of water-hole use started much earlier and lasted 3 mo. Elephants and grazers showed the largest difference in use of water-holes between 2003 and 2004 supporting the suggestion that browsers are less water dependent. This study suggests that annual rainfall should be taken into account when predicting the peak of the dry season.
An aggregative response of the tropical Australian magpie goose (Anseranas semipalmata) to seasonal floodplains
Authors: Traill Lochran W. , Brook Barry W.
Published: February 2011

We describe the spatial aggregation of the magpie goose (Anseranas semipalmata) in relation to the dynamics of the ephemeral floodplains of northern Australia. Past broad-scale studies have linked geese to floodplains dominated by the sedge,Eleocharis dulcis, but the type of response has not been determined, nor the impact of predation on food plants. Moreover, departure thresholds are not known. We develop hypotheses on aggregation and departure and confront these with field data. Thus, from 2005–2007 we established two sites on the floodplains of Kakadu National Park (three 1-ha plots per site, six plots in total) and used for monthly, dry season bird counts. An airboat was used to collect data from each of the six plots, including sedge tubers and measures of water level and soil viscosity. Further, we built exclosures (three per site, six in total) to test the impact of herbivory onE. dulcis. Generalized linear models and information theory were used to test the strength of supporting evidence for alternate hypotheses. Geese showed a clear aggregative response toE. dulcistubers, were forced to depart following floodplain drying and had a marked impact onE. dulcistuber density. Despite this, there was no evidence of a negative-feedback mechanism between plant–herbivore populations, suggesting that the system is driven by extrinsic parameters (here rainfall).
Seasonal changes in species composition, resource use and reproductive patterns within a guild of nectar-feeding bats in a west Mexican dry forest
Authors: Sperr Ellen B. , Caballero-Martínez Luis Antonio , Medellin Rodrigo A. , Tschapka Marco
Published: February 2011

Seasonal changes in resource use and reproduction within a guild of nectar-feeding phyllostomid bats were studied between 2002 and 2004 in a west Mexican dry forest using mist-net captures and diet analysis over 82 nights during both dry and wet seasons. The local guild consisted of three resident species,Glossophaga soricina,Leptonycteris yerbabuenae,Musonycteris harrisoni, and ofAnoura geoffroyi, which was mostly captured during the wet season. The proportion ofL. yerbabuenaefemales more than doubled during the dry season. Diet was accessed by identifying the pollen collected from the bats' bodies and by analysis of faecal material. Bats used at least 28 different nectar plants over the year. In the dry season, 91.9% of all bats carried pollen while only 54.6% did so in the wet season. Bat individuals used the highest number of plant species during the dry season, mainly the cactusPachycereus pecten-aboriginum, various Bombacaceae and the CapparaceaeCleome spinosa. Niche overlap was higher in the dry season than in the wet season.Musonycteris harrisoniandLeptonycteris yerbabuenaeshowed the largest overlap and both relied heavily on cactus flowers, whereasG. soricinasupplemented its nectar diet with fruits. While reproductive females of most species were found only in the flower-rich dry season,G. soricinashowed a bimodal reproductive pattern.
Children with Specific Language Impairment in Finnish: the use of tense and agreement inflections
Authors: KUNNARI SARI , SAVINAINEN-MAKKONEN TUULA , LEONARD LAURENCE B. , MÄKINEN LEENA , TOLONEN ANNA-KAISA , LUOTONEN MIRJA , LEINONEN EEVA
Published: February 2011

Children with specific language impairment (SLI) vary widely in their ability to use tense/agreement inflections depending on the type of language being acquired, a fact that current accounts of SLI have tried to explain. Finnish provides an important test case for these accounts because: (1) verbs in the first and second person permit null subjects whereas verbs in the third person do not; and (2) tense and agreement inflections are agglutinating and thus one type of inflection can appear without the other. Probes were used to compare the verb inflection use of Finnish-speaking children with SLI, and both age-matched and younger typically developing children. The children with SLI were less accurate, and the pattern of their errors did not match predictions based on current accounts of SLI. It appears that children with SLI have difficulty learning complex verb inflection paradigms apart from any problem specific to tense and agreement.
A geochemical record of late Holocene palaeoenvironmental changes at King George Island (maritime Antarctica)
Authors: Monien Patrick , Schnetger Bernhard , Brumsack Hans-Jürgen , Hass H. Christian , Kuhn Gerhard
Published: February 2011

During RV Polarstern cruise ANT-XXIII/4 in 2006, a gravity core (PS 69/335-2) and a giant box core (PS 69/335-1) were retrieved from Maxwell Bay off King George Island (KGI). Comprehensive geochemical (bulk parameters, quantitative XRF, Inductively Coupled Plasma Mass Spectrometry) and radiometric dating analyses (14C, 210Pb) were performed on both cores. A comparison with geochemical data from local bedrock demonstrates a mostly detrital origin for the sediments, but also points to an overprint from changing bioproductivity in the overlying water column in addition to early diagenetic processes. Furthermore, ten tephra layers that were most probably derived from volcanic activity on Deception Island were identified. Variations in the vertical distribution of selected elements in Maxwell Bay sediments further indicate a shift in source rock provenance as a result of changing glacier extents during the past c. 1750 years that may be linked to the Little Ice Age and the Medieval Warm Period. Whereas no evidence for a significant increase in chemical weathering rates was found, 210Pb data revealed that mass accumulation rates in Maxwell Bay have almost tripled since the 1940s (0.66 g cm-2 yr-1 in ad 2006), which is probably linked to rapid glacier retreat in this region due to recent warming.
Polynoid polychaetes living in the gut of irregular sea urchins: a first case of inquilinism in the Southern Ocean
Authors: Schiaparelli Stefano , Alvaro Maria Chiara , Barnich Ruth
Published: February 2011

Many different polychaete-echinoderm relationships have been described, from tropical to polar environments. Most of these associations have been generally defined as ‘commensal’, with polychaetes guests usually found on the oral surface of their hosts or, in a very few cases, even inside the host's body. Here we present an inquilinistic association involving two Antarctic species, the polychaeteGorekia crassicirris(Willey, 1902) (Polynoidae) and the irregular sea urchinAbatus nimrodi(Koheler, 1911) (Schizasteridae) found in the Ross Sea. This record is only the second worldwide for this kind of association, after that of the polychaeteBenthoscolex cubanuswhich lives in the gut of the spatangoidArcheopneustes hystrixin Caribbean waters.Gorekia crassicirrisseems to be a polyxenous species as it was also observed on another schizasterid,Brachysternaster chescheriLarrain, 1985 in the Weddell Sea. Considering thatA. nimrodiis absent from that area and that the two sea urchin species have a disjoint distribution, it is possible that a ‘host-switch’ phenomenon occurred at some stage. We review the available literature to compare the Antarctic pairing with the other known examples of similar associations.
The germination niches of grassland species targeted for restoration: effects of seed pre-treatments
Authors: Wagner Markus , Pywell Richard F. , Knopp Tatjana , Bullock James M. , Heard Matthew S.
Published: February 2011

Restoration of semi-natural grassland communities involves a combination of (1) sward disturbance to create a temporal window for establishment, and (2) target species introduction, the latter usually by seed sowing. With great regularity, particular species establish only poorly. More reliable establishment could improve outcome of restoration projects and increase cost-effectiveness. We investigated the abiotic germination niche of ten poorly establishing calcareous grassland species by simultaneously exploring the effects of moisture and light availability and temperature fluctuation on percentage germination and speed of germination. We also investigated the effects of three different pre-treatments used to enhance seed germination – cold-stratification, osmotic priming and priming in combination with gibberellic acid (GA3) – and how these affected abiotic germination niches. Species varied markedly in width of abiotic germination niche, ranging fromCarex flaccawith very strict abiotic requirements, to several species reliably germinating across the whole range of abiotic conditions. Our results suggest pronounced differences between species in gap requirements for establishment. Germination was improved in most species by at least one pre-treatment. Evidence for positive effects of adding GA3to seed priming solutions was limited. In several species, pre-treated seeds germinated under a wider range of abiotic conditions than untreated seeds. Improved knowledge of species-specific germination niches and the effects of seed pre-treatments may help to improve species establishment by sowing, and to identify species for which sowing at a later stage of restoration or introduction as small plants may represent a more viable strategy.
Amsterdam and London as financial centers in the eighteenth century
Authors: Carlos Ann M. , Neal Larry
Published: February 2011

In the seventeenth century, Amsterdam and London developed distinctive innovations in finance through both banks and markets that facilitated the growth of trade in each city. In the eighteenth century, a symbiotic relation developed that led to bank-oriented finance in Amsterdam cooperating with market-oriented finance in London. The relationship that emerged allowed each to rise to unprecedented dominance in Europe, while the respective financial innovations in each city provided the means for the continued expansion of European trade, both within Europe and with the rest of the world. The increasing strains of war finance for the competing European powers over the course of the eighteenth century stimulated fresh financial innovations in each city that initially reinforced the symbiosis of the two centers. The external shocks arising from revolutionary movements in America and France, however, interrupted the relationship long enough to leave London as the supreme financial center.
Does the technique of interventional closure of perimembranous ventricular septal defect reduce the incidence of heart block?
Authors: Bentham James R. , Gujral Arjun , Adwani Satish , Archer Nick , Wilson Neil
Published: February 2011

Objective

To describe the difficulties and differing techniques in the transcatheter placement of amplatz ventricular septal defect devices to close perimembranous ventricular septal defects and place these in the context of the expanding literature on ventricular septal defect catheter closure.

Background

Surgery remains the established first-line therapy for closure of haemodynamically significant perimembranous ventricular septal defects. Transcatheter techniques appeared to promise a possible alternative, obviating the need for cardiac surgery. However, significant technical and anatomical constraints coupled with ongoing reports of a high incidence of heart block have prevented these hopes from being realised to any significant extent. It is likely that there are important methodological reasons for the high complication rates observed. The potential advantages of transcatheter perimembranous ventricular septal defect closure over surgery warrant further exploration of differing transcatheter techniques.

Methods

Between August, 2004 and November, 2009, 21 patients had a perimembranous ventricular septal defect closed with transcatheter techniques. Of these, 14 were closed with a muscular amplatz ventricular septal defect device. The median age and weight at device placement were 8 years, ranging from 2 to 19 years, and 18.6 kilograms, ranging from 10 to 21 kilograms, respectively.

Results

There were 25 procedures performed on 23 patients using 21 amplatz ventricular septal defect devices. Median defect size on angiography was 7.8 millimetres, ranging from 4 to 14.3 millimetres, with a median device size of 8 millimetres, ranging from 4 to 18 millimetres, and a defect/device ratio of 1.1, with a range from 0.85 to 1.33. Median procedure time was 100 minutes, with a range from 38 to 235 minutes. Adverse events included device embolisation following haemolysis in one, and new aortic incompetence in another, but there were no cases of heart block. Median follow-up was 41.7 months, with a rangefrom 2 to 71 months.

Conclusions

Evaluating transcatheter closure of perimembranous ventricular septal defect using amplatz ventricular septal defect devices remains important, if a technically feasible method with low and acceptable complication rates is to be identified. Incidence of heart block may be minimised by avoiding oversized devices, using muscular devices, and accepting defeat if an appropriately selected device pulls through. Given the current transcatheter technologies, the closure of perimembranous ventricular septal defects should generally be performed in children when they weigh at least 10 kilograms.
Lead Pipe Scale Analysis Using Broad-Beam Argon Ion Milling to Elucidate Drinking Water Corrosion
Authors: Nadagouda Mallikarjuna N. , White Colin , Lytle Darren
Published: February 2011

Herein, we characterized lead pipe scale removed from a drinking water distribution system using argon ion beam etching and a variety of solids analysis approaches. Specifically, pipe scale cross sections and solids were analyzed using scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, and acid digestion followed by inductively coupled plasma mass spectrometry analyses. The pipe scale consisted of at least five layers that contained Pb(II) and Pb(IV) minerals, and magnesium, aluminum, manganese, iron, and silicon solids. The outer layer was enriched with crystalline amorphous manganese and iron, giving it a dark orange to red color. The middle layers consisted of hydrocerussite and plattnerite, and the bottom layer consisted primarily of litharge. Over the litharge layer, hydrocerussite crystals were grown vertically away from the pipe wall, which included formations of plattnerite. Significant amounts of trace contaminant vanadium, likely in the form of vanadinite, and copper accumulated in the scale as well.
Electron-Beam-Induced Growth of TiO2 Nanostructures
Authors: Chee See Wee , Sivaramakrishnan Shankar , Sharma Renu , Zuo Jian-Min
Published: February 2011

We report the evolution of titanium dioxide nanostructures when Au nanoparticles, supported on single crystal TiO2 substrates, were heated under ∼260 Pa of flowing O2 in an environmental transmission electron microscope. Nanostructures with different morphologies were first observed around 500°C. Our measurements show that temperature, oxygen pressure, and the electron beam control the nanostructure growth. We propose a reaction-controlled growth mechanism where mobile Ti atoms generated by the electron- beam-induced reduction of TiO2 are preferentially reoxidized at the Au-TiO2 interface.