bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of spatially distributed regional‐scale fields of air temperature and vapor pressure over mountain glaciers
Authors: Shea J. M. , Moore R. D.
Published: December 2010

Physically based models of glacier melt require fields of near‐surface air temperature (Tg) and vapor pressure (eg) for estimating turbulent heat exchanges. However, katabatic boundary layer (KBL) processes limit the effectiveness of standard interpolation or extrapolation routines for estimating Tg and eg from regional weather station networks. Climate data collected from nine automatic weather stations operated over three ablation seasons at three glaciers in the southern Coast Mountains of British Columbia are analyzed in this study. On‐glacier observations were compared to ambient values (Ta and ea) estimated from a regional network of off‐glacier weather stations. Piecewise regressions of Tg versus Ta at each AWS site reveal (1) a critical threshold temperature (T*) that denotes the onset of katabatic boundary layer (KBL) development and (2) a temperature damping that is consistent at each site, but variable between sites. Variations in near‐surface vapor pressure are related to processes of condensation or evaporation/sublimation at the glacier surface, which are controlled by the vapor pressure gradient between the surface and the ambient air. Statistical relations with flow path lengths calculated from glacier digital elevation models are used to predict the strength of KBL effects on Tg and eg, and examples of the approach for generating distributed fields of Tg and eg are given.
Effects of continental‐scale snow albedo anomalies on the wintertime Arctic oscillation
Authors: Allen R. J. , Zender C. S.
Published: December 2010

The NCAR CAM3 GCM with prescribed, satellite‐based snow albedo (SA) is used to investigate the remote effects of snow cover on Northern Hemisphere (NH) winter climate. A pair of 100 ensemble member experiments are integrated through the autumn‐winter season, with prescribed high and low SA over Eurasia (EA). Similar to other non‐CAM GCM studies using prescribed snow mass, anomalous EA snow albedo produces a wave activity pulse that propagates into the stratosphere, culminating in a negative phase Arctic Oscillation– (AO‐) like surface response. This occurs for idealized but representative SA anomalies, as well as for more realistic SA anomalies. Similar experiments over North America (NA) and the entire NH are also performed. Unlike prior studies, anomalous NA snow yields a significant AO signal. Here, the local NA surface cooling elicits a transient eddy response, which propagates downstream to Eurasia, resulting in significant but short‐lived cooling and upward propagating wave activity over Siberia. A negative AO‐like response develops, primarily confined to the stratosphere/upper troposphere, which eventually gives way to a tropospheric AO‐like response of the opposite phase, due to equatorward wave refraction and wave divergence. Reanalysis data support this NA snow‐positive AO response. Snow forcing experiments for the whole NH, however, yield a weakened AO signal. This is due to a muted wavenumber‐1 and ‐2 response caused by destructive interference between the background stationary wave and the corresponding Rossby wave response, which results in negligible wave activity reaching the stratosphere.
Radiative forcing over the conterminous United States due to contemporary land cover land use change and sensitivity to snow and interannual albedo variability
Authors: Barnes Christopher A. , Roy David P.
Published: December 2010

Satellite‐derived land cover land use (LCLU), snow and albedo data, and incoming surface solar radiation reanalysis data were used to study the impact of LCLU change from 1973 to 2000 on surface albedo and radiative forcing for 58 ecoregions covering 69% of the conterminous United States. A net positive surface radiative forcing (i.e., warming) of 0.029 Wm−2 due to LCLU albedo change from 1973 to 2000 was estimated. The forcings for individual ecoregions were similar in magnitude to current global forcing estimates, with the most negative forcing (as low as −0.367 Wm−2) due to the transition to forest and the most positive forcing (up to 0.337 Wm−2) due to the conversion to grass/shrub. Snow exacerbated both negative and positive forcing for LCLU transitions between snow‐hiding and snow‐revealing LCLU classes. The surface radiative forcing estimates were highly sensitive to snow‐free interannual albedo variability that had a percent average monthly variation from 1.6% to 4.3% across the ecoregions. The results described in this paper enhance our understanding of contemporary LCLU change on surface radiative forcing and suggest that future forcing estimates should model snow and interannual albedo variation.
Turbulent and advective momentum fluxes in streams
Authors: Noss C. , Salzmann T. , Storchenegger I.
Published: December 2010

The scope of the present paper is the evaluation of the exchange of momentum in natural streams to explore the contribution that turbulence and secondary currents have on the shear stress distributions within the flow, and hence evaluate the overall hydraulic resistance. Existing methods for the evaluation of shear stresses in rivers are examined with respect to their applicability to complex flow fields, and a new mathematical formulation for analyzing the shear stresses affecting the longitudinal velocity distribution is presented. This new method enables one to estimate the time‐averaged principal shear stress and its particular components due to turbulence and secondary currents directly from three‐dimensional velocity data. An acoustic Doppler velocimeter (ADV) was used to measure the currents and turbulence at five cross‐sections of two field sites over a wide range of discharges. The results of the cross‐sectional measurements reflect the nonuniformity of the river bed roughness, cross‐sectional form, and planform. Limited applicability was found for methods based on the theory of two‐dimensional boundary layer flows. Shear stresses estimated using the new method emphasize the dominance of secondary currents on the total momentum flux. Momentum fluxes caused by secondary currents were an order of magnitude larger than momentum fluxes due to turbulence.
Effects of model formulation and calibration data on uncertainty in dense nonaqueous phase liquids source dissolution predictions
Authors: Parker Jack C. , Kim Ungtae , Widdowson Mark , Kitanidis Peter , Gentry Randy
Published: December 2010

Simplified models have been proposed to describe dense nonaqueous phase liquids (DNAPL) source mass discharge versus time assuming that aqueous mass transfer is proportional to the DNAPL mass remaining raised to the power of a “source architecture” coefficient. Recent studies suggest that source discharge predictions may be improved using multiple functions for different architectures. However, multiple‐source functions require estimation of additional parameters, which can be difficult to do from available field data. A hypothetical problem was considered that involves a DNAPL source zone consisting of seven discrete trichloroethylene (TCE) sources within a roughly 120,000 m2 area, each having different release dates, masses, and rate parameters. A transport model was used to simulate dissolved TCE concentrations in 22 monitoring wells over a 23 year period. “Noise” representing conceptual model errors and sampling or measurement error was applied to produce synthetic monitoring data. Source mass and dissolution rates were computed for the total source and for various depth intervals for a 5 year period and were also overlaid with suitable “noise.” Data sets consisting of various subsets of the noisy monitoring and source data were employed to calibrate various model formulations. Results indicate that calibration using only near‐source discharge rates yield highly uncertain estimates of future mass discharge rates. Prediction accuracy is improved and uncertainty is reduced by calibrating to whole plume data in conjunction with source discharge estimates, especially if the latter are available for multiple depths. More complex models reduce prediction uncertainty up to a point beyond which added complexity was a liability unless additional or more accurate data are available.
Disentangling the relative influence of bacterioplankton phylogeny and metabolism on lysogeny in reservoirs and lagoons
Authors: Maurice Corinne F , Mouillot David , Bettarel Yvan , De Wit Rutger , Sarmento Hugo , Bouvier Thierry
Published: December 2010

Previous studies indicate that lysogeny is preponderant when environmental conditions are challenging for the bacterial communities and when their metabolism is reduced. Furthermore, it appears that lysogeny is more frequent within certain bacterial phylogenetic groups. In this comparative study from 10 freshwater reservoirs and 10 coastal lagoons, we aim to disentangle the influence of these different factors. In eight reservoirs and four lagoons, lysogeny was detected by induction assays with mitomycin C, and induction significantly modified the bacterial community composition (BCC), whereas community composition remained constant in ecosystems in which lysogeny was not observed. Among the phylogenetic groups studied, the most abundant ones were Bacteroidetes and α-proteobacteria in lagoons, and β-proteobacteria and Bacteroidetes in reservoirs. These dominant groups comprised the highest proportions of inducible lysogens. In order to unravel the effects of bacterial metabolism from phylogeny on lysogeny, we measured bacterial community physiology and the specific activities of selected phylogenetic groups. The proportion of inducible lysogens within the α- and the β-proteobacteria decreased with increasing group-specific metabolism in lagoons and reservoirs, respectively. In contrast, this relationship was not observed for the other lysogen-containing groups. Hence, both host physiology and phylogeny are critical for the establishment of lysogeny. This study illustrates the importance of lysogeny among the most abundant phylogenetic groups, and further suggests its strong structuring impact on BCC.
A novel clade of Prochlorococcus found in high nutrient low chlorophyll waters in the South and Equatorial Pacific Ocean
Authors: West Nyree J , Lebaron Philippe , Strutton Pete G , Suzuki Marcelino T
Published: December 2010

A novel high-light (HL)-adapted Prochlorococcus clade was discovered in high nutrient and low chlorophyll (HNLC) waters in the South Pacific Ocean by phylogenetic analyses of 16S ribosomal RNA (rRNA) and 16S–23S internal transcribed spacer (ITS) sequences. This clade, named HNLC fell within the HL-adapted Prochlorococcus clade with sequences above 99% similarity to one another, and was divided into two subclades, HNLC1 and HNLC2. The distribution of the whole HNLC clade in a northwest to southeast transect in the South Pacific (HNLC-to-gyre) and two 8°N to 8°S transects in the Equatorial Pacific was determined by quantitative PCR using specific primers targeting ITS regions. HNLC was the dominant HL Prochlorococcus clade (2–9% of bacterial 16S rRNA genes) at the three westernmost stations in the South Pacific but decreased to less than 0.1% at the other stations being replaced by the eMIT9312 ecotype in the hyperoligotrophic gyre. The highest contributions of HNLC Prochlorococcus in both Equatorial Pacific transects along the latitudinal lines of 170°W and 155°W were observed at the southernmost stations, reaching 16 and 6% of bacterial 16S rRNA genes, respectively, whereas eMIT9312 dominated near the Equator. Spearman Rank Order correlation analysis indicated that although both the HNLC clade and eMIT9312 were correlated with temperature, they showed different correlations with regard to nutrients. HNLC only showed significant correlations to ammonium uptake and regeneration rates, whereas eMIT9312 was negatively correlated with inorganic nutrients.
Evidence for gliadin antibodies as causative agents in schizophrenia.
Authors: Carter Chris
Published: December 2010

Antibodies to gliadin, a component of gluten, have frequently been reported in schizophrenia. Highly immunogenic B cell epitopes along its length are homologous to numerous proteins relevant to schizophrenia, including members of the DISC1 interactome, glutamate, dopamine and neuregulin signaling networks, and plasticity or myelination pathways. Antibodies to gliadin may cross react with these key proteins, as has already been observed with synapsin 1 and calreticulin. Gliadin may thus be a causative agent in schizophrenia, under certain genetic and immunological conditions, producing its effects via antibody mediated knockdown of multiple proteins relevant to the disease process. Because of such homology, an autoimmune response may be sustained by the human antigens that resemble gliadin itself, a scenario supported by many reports of immune activation both in the brain and in lymphocytes in schizophrenia. Gluten free diets and removal of such antibodies may be of therapeutic benefit in certain cases of schizophrenia.
Comparative theoretical investigation on the isomerization energies of long-chain perfluoroalkanes: A case study with perfluorooctane sulfonic acid congeners
Authors: Rayne Sierra , Forest Kaya
Published: December 2010

The gas and solution phase relative thermodynamic stabilities of the 89 perfluorooctane sulfonic acid (PFOS) congeners play an important role in assessing whether synthetic conditions for commercial mixtures are under thermodynamic or kinetic control, and in calculating various physico-chemical properties for these important industrial compounds and environmental contaminants. In the present study, 4,272 gas and solvent phase (water and n-octanol) calculations were conducted at various levels of semiempirical (PM6), density functional (B3LYP, B97D, PBE1PBE [PBE0], and M062X functionals with the 6-311++G(d,p) basis set), and second order Moller-Plesset perturbation (MP2/6-311++G(d,p)//B3LYP/6-311++G(d,p)) theory and the SMD, IEFPCM-UFF, and CPCM implicit solvation models on the 89 PFOS congeners in both their acid and anionic forms. The B3LYP functional consistently and incorrectly predicts substantially increasing thermodynamic stability of PFOS isomers with increasing linearity of the perfluoroalkyl chains. By comparison, PM6, M062X, and MP2 calculations more closely reflect the expected patterns of thermodynamic stability for branched versus linear PFOS congeners.
Insulin Sensitivity and Regional Fat Gain in Response to Overfeeding
Authors: Votruba Susanne B. , Jensen Michael D.
Published: December 2010

Although insulin resistance and type 2 diabetes (T2DM) are associated with upper body fat distribution, it is unknown whether insulin resistance predisposes to upper body fat gain or whether upper body fat gain causes insulin resistance. Our objective was to determine whether insulin sensitivity predicts abdominal (subcutaneous and/or visceral) fat gain in normal weight adults. Twenty‐eight (15 men) lean (BMI = 22.1 ± 2.5 kg/m2), healthy adults underwent ∼8 weeks of overfeeding to gain ∼4 kg fat. Body composition was assessed before and after overfeeding, using dual‐energy X‐ray absorptiometry (DXA) and abdominal computed tomography to measure total and regional (visceral, abdominal, and lower body subcutaneous) fat gain. We assessed insulin sensitivity with an intravenous glucose tolerance test (IVGTT) and the 24‐h insulin area under the curve (AUC). We found a wide range of insulin sensitivity and a relatively narrow range of body fat distribution in this normal weight cohort. Participants gained 3.8 ± 1.7 kg of body fat (4.6 ± 2.2 kg body weight). The baseline 24‐h AUC of insulin concentration was positively correlated with percent body fat (r = 0.43, P < 0.05). The contribution of leg fat gain to total fat gain ranged from 29 to 79%, whereas the contributions of abdominal subcutaneous fat and visceral fat gain to total fat gain ranged from 17 to 69% and −5 to 22%, respectively. Baseline insulin sensitivity, whether measured by an IVGTT (Si) or the 24‐h AUC insulin, did not predict upper body subcutaneous or visceral fat gain in response to overfeeding. We conclude that reduced insulin sensitivity is not an obligate precursor to upper body fat gain.
On the progressive enrichment of the oxygen isotopic composition of water along a leaf
Authors: FARQUHAR G. D. , GAN K. S.
Published: December 2010

A model has been derived for the enrichment of heavy isotopes of water in leaves, including progressive enrichment along the leaf. In the model, lighter water is preferentially transpired leaving heavier water to diffuse back into the xylem and be carried further along the leaf. For this pattern to be pronounced, the ratio of advection to diffusion (Péclet number) has to be large in the longitudinal direction, and small in the radial direction. The progressive enrichment along the xylem is less than that occurring at the sites of evaporation in the mesophyll, depending on the isolation afforded by the radial Péclet number. There is an upper bound on enrichment, and effects of ground tissue associated with major veins are included. When transpiration rate is spatially nonuniform, averaging of enrichment occurs more naturally with transpiration weighting than with area‐based weighting. This gives zero average enrichment of transpired water, the modified Craig–Gordon equation for average enrichment at the sites of evaporation and the Farquhar and Lloyd (In Stable Isotopes and Plant Carbon‐Water Relations, pp. 47–70. Academic Press, New York, USA, 1993) prediction for mesophyll water. Earlier results on the isotopic composition of evolved oxygen and of retro‐diffused carbon dioxide are preserved if these processes vary in parallel with transpiration rate. Parallel variation should be indicated approximately by uniform carbon isotope discrimination across the leaf.
Absorbance and fluorometric sensing with capillary wells microplates
Authors: Tan Han Yen , Cheong Brandon Huey-Ping , Neild Adrian , Liew Oi Wah , Wah Ng Tuck
Published: December 2010

Detection and readout from small volume assays in microplates are a challenge. The capillary wells microplate approach [Ng et al., Appl. Phys. Lett. 93, 174105 (2008)] offers strong advantages in small liquid volume management. An adapted design is described and shown here to be able to detect, in a nonimaging manner, fluorescence and absorbance assays minus the error often associated with meniscus forming at the air-liquid interface. The presence of bubbles in liquid samples residing in microplate wells can cause inaccuracies. Pipetting errors, if not adequately managed, can result in misleading data and wrong interpretations of assay results; particularly in the context of high throughput screening. We show that the adapted design is also able to detect for bubbles and pipetting errors during actual assay runs to ensure accuracy in screening.
Wedge mode of spoof surface plasmon polaritons at terahertz frequencies
Authors: Gao Zhen , Zhang Xufeng , Shen Linfang
Published: December 2010

Surface plasmon polaritons (SPPs) propagating along a structure consisting of a single row of metallic wedges periodically protruding out of a planar metallic surface are investigated theoretically. It is shown that such a structure can sustain a mode of spoof SPPs in the terahertz region, whose fields are highly confined in the transverse plane. The guiding mode in the structure possesses excellent properties such as good modal shape, large propagation length, and low bending loss, making it a promising candidate for routing terahertz radiation in highly integrated circuits.
Anomalous Hall mobility kink observed in Mg-doped InN: Demonstration of p-type conduction
Authors: Ma N. , Wang X. Q. , Xu F. J. , Tang N. , Shen B. , Ishitani Y. , Yoshikawa A.
Published: December 2010

The p-type conduction in Mg-doped InN film is identified by an anomalous Hall mobility kink observed at ∼600 K in temperature-dependent Hall-effect measurements. The good agreement between experimental results and ensemble Monte Carlo simulation confirms the p-type bulk conduction under the surface electron accumulation layer. Furthermore, it is found that there is an exponential relationship between the hole concentration in the p-type bulk layer and the reciprocal kink temperature, which provides an effective way to evaluate the hole concentration in Mg-doped InN bulk layer through Hall-effect measurements.
Commoditising Learning: Cultural Economy and the Growth of for-Profit Business Education Service Firms in London
Authors: Hall Sarah , Appleyard Lindsay
Published: December 2010

Individuals working in graduate labour markets are increasingly expected to enhance their employability and career progression by undertaking lifelong education and learning within the workplace. Research has examined how graduates navigate this dynamic educational landscape, but the changing nature of educational providers has been comparatively neglected. In response, in this paper we examine the growth of for-profit business education service firms that have grown to meet the increased demand for lifelong learning and education by focusing on the financial business education sector in London. We develop cultural economy approaches to market making in order to understand how these educational service firms have developed by ‘stabilising’ new educational services and products that compete with, and seek to ‘destabilise’, more established forms of business education, particularly MBA degrees. In so doing, we position educational service firms as an important, yet hitherto neglected set of business services within economic geography. Moreover, by focusing on a relatively mature for-profit educational sector, the research presented in the paper has important implications for the development of educational landscapes beyond the case of financial business education as they become increasingly beholden to the activities of for-profit education service firms and wider discourses of markets in educational services.
An integrated care facilitation model improves quality of life and reduces use of hospital resources by patients with chronic obstructive pulmonary disease and chronic heart failure
Authors: Bird Stephen , Noronha Michelle , Sinnott Helen
Published: December 2010

As part of the Department of Human Services Hospital Admissions Risk Program (HARP), a group of acute and community based health care providers located in the western suburbs of Melbourne formed a consortium to reduce the demand on hospital emergency services and improve health outcomes for patients with chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF). The model of care was designed by a team of multidisciplinary specialists and medical consultants. In addition to receiving normal care, patients recruited to the project were assessed by ‘Care Facilitators’, who identified unmet health care needs and provided information, advice and education for the patient concerning their condition and self-management. Patients declining recruitment received all normal care services. The patients’ rates of emergency department (ED) presentations, inpatient admissions and hospital inpatient bed-days before and after their recruitment were calculated from the Western Health patient activity records, and pre- versus post-recruitment rates were compared using ANOVA. Changes relative to the ongoing use by those who declined recruitment were compared using the group-by-time interaction. Patient health outcomes were assessed using established disease-specific tools, and pre- versus post-recruitment values were compared using paired t-tests. Patients recruited to the COPD project reduced (P < 0.05) their emergency presentations, admissions and hospital inpatient bed-days by 10, 25 and 18%, respectively, whereas those declining recruitment increased their usage by 45, 41 and 51% respectively. Recruited CHF patients also displayed reductions in emergency presentations (39%), admissions (36%) and hospital inpatient bed-days (33%), whereas those who declined recruitment displayed lesser reductions for ED presentations (26%) and admissions (20%), and increased their use of hospital inpatient bed-days (15%). The recruited COPD patients reported a significant reduction in their symptoms (P < 0.005) and the CHF patients reported an improvement in their overall health and quality of life scores (P < 0.001). The outcome measures used in this evaluation suggest that an integrated care facilitation model that is patient focussed, provides an education component to promote greater self-management compliance and delivers a continuum of care through the acute and community health sectors, may reduce the utilisation of acute health care facilities and benefit the patient.
Video force microscopy reveals the mechanics of ventral furrow invagination in Drosophila
Authors: Brodland G. Wayne , Conte Vito , Cranston P. Graham , Veldhuis Jim , Narasimhan Sriram , Hutson M. Shane , Jacinto Antonio , Ulrich Florian , Baum Buzz , Miodownik Mark
Published: December 2010

The absence of tools for mapping the forces that drive morphogenetic movements in embryos has impeded our understanding of animal development. Here we describe a unique approach, video force microscopy (VFM), that allows detailed, dynamic force maps to be produced from time-lapse images. The forces at work in an embryo are considered to be decomposed into active and passive elements, where active forces originate from contributions (e.g., actomyosin contraction) that do mechanical work to the system and passive ones (e.g., viscous cytoplasm) that dissipate energy. In the present analysis, the effects of all passive components are considered to be subsumed by an effective cytoplasmic viscosity, and the driving forces are resolved into equivalent forces along the edges of the polygonal boundaries into which the region of interest is divided. Advanced mathematical inverse methods are used to determine these driving forces. When applied to multiphoton sections of wild-type and mutant
Drosophila melanogaster
embryos, VFM is able to calculate the equivalent driving forces acting along individual cell edges and to do so with subminute temporal resolution. In the wild type, forces along the apical surface of the presumptive mesoderm are found to be large and to vary parabolically with time and angular position, whereas forces along the basal surface of the ectoderm, for example, are found to be smaller and nearly uniform with position. VFM shows that in mutants with reduced junction integrity and myosin II activity, the driving forces are reduced, thus accounting for ventral furrow failure.
Strongly bound citrate stabilizes the apatite nanocrystals in bone
Authors: Hu Y.-Y. , Rawal A. , Schmidt-Rohr K.
Published: December 2010

Nanocrystals of apatitic calcium phosphate impart the organic-inorganic nanocomposite in bone with favorable mechanical properties. So far, the factors preventing crystal growth beyond the favorable thickness of
ca
. 3 nm have not been identified. Here we show that the apatite surfaces are studded with strongly bound citrate molecules, whose signals have been identified unambiguously by multinuclear magnetic resonance (NMR) analysis. NMR reveals that bound citrate accounts for 5.5 wt% of the organic matter in bone and covers apatite at a density of about 1 molecule per (2 nm)
2
, with its three carboxylate groups at distances of 0.3 to 0.45 nm from the apatite surface. Bound citrate is highly conserved, being found in fish, avian, and mammalian bone, which indicates its critical role in interfering with crystal thickening and stabilizing the apatite nanocrystals in bone.
Astrocyte elevated gene-1 induces protective autophagy
Authors: Bhutia Sujit K. , Kegelman Timothy P. , Das Swadesh K. , Azab Belal , Su Zhao-zhong , Lee Seok-Geun , Sarkar Devanand , Fisher Paul B.
Published: December 2010

Astrocyte-elevated gene-1 (AEG-1) expression increases in multiple cancers and plays a crucial role in oncogenic transformation and angiogenesis, which are essential components in tumor cell development, growth, and progression to metastasis. Moreover, AEG-1 directly contributes to resistance to chemotherapeutic drugs, another important hallmark of aggressive cancers. In the present study, we document that AEG-1 mediates protective autophagy, an important regulator of cancer survival under metabolic stress and resistance to apoptosis, which may underlie its significant cancer-promoting properties. AEG-1 induces noncanonical autophagy involving an increase in expression of ATG5. AEG-1 decreases the ATP/AMP ratio, resulting in diminished cellular metabolism and activation of AMP kinase, which induces AMPK/mammalian target of rapamycin-dependent autophagy. Inhibition of AMPK by siAMPK or compound C decreases expression of ATG5, ultimately attenuating AEG-1–induced autophagy. AEG-1 protects normal cells from serum starvation-induced death through protective autophagy, and inhibition of AEG-1–induced autophagy results in serum starvation-induced cell death. We also show that AEG-1–mediated chemoresistance is because of protective autophagy and inhibition of AEG-1 results in a decrease in protective autophagy and chemosensitization of cancer cells. In summary, the present study reveals a previously unknown aspect of AEG-1 function by identifying it as a potential regulator of protective autophagy, an important feature of AEG-1 that may contribute to its tumor-promoting properties.
Timing and dynamics of Late Pleistocene mammal extinctions in southwestern Australia
Authors: Prideaux Gavin J. , Gully Grant A. , Couzens Aidan M. C. , Ayliffe Linda K. , Jankowski Nathan R. , Jacobs Zenobia , Roberts Richard G. , Hellstrom John C. , Gagan Michael K. , Hatcher Lindsay M.
Published: December 2010

Explaining the Late Pleistocene demise of many of the world's larger terrestrial vertebrates is arguably the most enduring and debated topic in Quaternary science. Australia lost >90% of its larger species by around 40 thousand years (ka) ago, but the relative importance of human impacts and increased aridity remains unclear. Resolving the debate has been hampered by a lack of sites spanning the last glacial cycle. Here we report on an exceptional faunal succession from Tight Entrance Cave, southwestern Australia, which shows persistence of a diverse mammal community for at least 100 ka leading up to the earliest regional evidence of humans at 49 ka. Within 10 millennia, all larger mammals except the gray kangaroo and thylacine are lost from the regional record. Stable-isotope, charcoal, and small-mammal records reveal evidence of environmental change from 70 ka, but the extinctions occurred well in advance of the most extreme climatic phase. We conclude that the arrival of humans was probably decisive in the southwestern Australian extinctions, but that changes in climate and fire activity may have played facilitating roles. One-factor explanations for the Pleistocene extinctions in Australia are likely oversimplistic.
Old gene duplication facilitates origin and diversification of an innovative communication system—twice
Authors: Arnegard Matthew E. , Zwickl Derrick J. , Lu Ying , Zakon Harold H.
Published: December 2010

The genetic basis of parallel innovation remains poorly understood due to the rarity of independent origins of the same complex trait among model organisms. We focus on two groups of teleost fishes that independently gained myogenic electric organs underlying electrical communication. Earlier work suggested that a voltage-gated sodium channel gene (
Scn4aa
), which arose by whole-genome duplication, was neofunctionalized for expression in electric organ and subsequently experienced strong positive selection. However, it was not possible to determine if these changes were temporally linked to the independent origins of myogenic electric organs in both lineages. Here, we test predictions of such a relationship. We show that
Scn4aa
co-option and rapid sequence evolution were tightly coupled to the two origins of electric organ, providing strong evidence that
Scn4aa
contributed to parallel innovations underlying the evolutionary diversification of each electric fish group. Independent evolution of electric organs and
Scn4aa
co-option occurred more than 100 million years following the origin of
Scn4aa
by duplication. During subsequent diversification of the electrical communication channels, amino acid substitutions in both groups occurred in the same regions of the sodium channel that likely contribute to electric signal variation. Thus, the phenotypic similarities between independent electric fish groups are also associated with striking parallelism at genetic and molecular levels. Our results show that gene duplication can contribute to remarkably similar innovations in repeatable ways even after long waiting periods between gene duplication and the origins of novelty.
JOB PREFERENCES IN EUROPE
Authors: Gesthuizen Maurice , Verbakel Ellen
Published: December 2010

In this article we answered the research question to what extent variation in extrinsic and intrinsic job preference orientations can be attributed to and explained by differences between individuals and between countries. We argued that socialization in school, economic deprivation, and job quality influence job preferences, and formulated testable hypotheses on the individual and country level. After first testing for cross-national equivalence of the latent constructs and assuring that factor solutions were satisfactory, we employed multiple response multilevel models on a subset of 22 countries in the European Values Study 1999/2000. The findings indicate that higher educational attainment, a high income, working in managerial and higher professional jobs, and having autonomy in one's job stimulate intrinsic job preference orientations, while particularly educational attainment and autonomy temper extrinsic work values. Workers in semi- and unskilled manual jobs have the highest extrinsic job preferences. On top of individual characteristics, living in a nation that invests much in human capital or has a high quality labour market is associated with lower levels of extrinsic job preferences. Moreover, countries with socio-economic features that reduce the risk of economic deprivation have a more intrinsically motivated workforce.
‘IT IS NOT A MATTER OF TASTE … ’
Authors: Heikkilä Riie , Rahkonen Keijo
Published: December 2010

Upper classes and elites are usually exclusive circles which are hard to enter. In this paper we approach one such group using a focus group interview: a group from the Swedish-speaking upper class in officially bilingual Finland. Our paper addresses Bourdieu's idea of distinction by cultural or taste distinctions. In comparison to some international studies on elites and upper classes, our group was surprisingly keen on expressing disgust towards other tastes and lifestyles and therefore other classes and/or social groups. One might be surprised at how efficiently distinction works in the Swedish-speaking old upper class and how politically incorrect its outspokenness about cultural superiority is. In this specific group, there is a double-distinction: not only are Finnish speakers looked down upon regardless of their class position, almost any other group is, too. In this sense, this is more or less a case par excellence of Bourdieu's theory of distinction.
PUBLIC ATTITUDES TO SOCIAL PROTECTION AND POLITICAL ECONOMY TRADITIONS IN WESTERN EUROPE
Authors: Bonoli Giuliano
Published: December 2010

Studies of public attitudes to the welfare state have generally failed to uncover consistent and clear country variations in relation to patterns of support for different social programmes. This finding contrasts with the important degree of cross-national variation that exists with regard to the institutional structure of welfare states. This article argues that in order to capture the extent of cross-national variation in public attitudes to social protection, the focus needs to be expanded to forms of protection other than income transfer programmes, to encompass labour law and collective bargaining. The article presents survey data that show cross-national variation in relation to these alternative forms of social protection to be significant, and suggests that such variation can be explained with reference to the political economy traditions that are typical of the different countries covered.
Multilayer As2Se3/GeS2 quarter wave structures for photonic applications
Authors: Todorov R , Tasseva J , Babeva Tz , Petkov K
Published: December 2010

The optical properties of single layers from As2Se3 and GeS2, double-layered stack and quarter-wave multilayer structure consisting of alternating layers from both materials are investigated. For modelling of multilayer coating the thickness dependence of the refractive index of single coatings from both materials is studied. The particularities and scope of application of different spectrophotometric methods for calculation of optical parameters of thin chalcogenide layers are discussed for film thickness, d, in the range λ/25–1.5λ (λ being the operating wavelength). Having acquired the knowledge of optical parameters (refractive index, n, and extinction coefficient, k) of the single layers, we designed and produced a one-dimensional photonic crystal with fundamental reflection band at λ = 850 nm. It was shown that the photoinduced changes of the refractive index of thin chalcogenide films can be used for enhancement of the optical contrast of both materials.
Reply to Comment on ‘On the origin dependence of multipole moments in electromagnetism’
Authors: De Visschere Patrick
Published: December 2010

In this reply, we emphasize that the goal of our original paper was to show that a straightforward application of standard multipole theory does not lead to unphysical results as claimed by Raab and de Lange. We stress once more that an origin shift for calculating the multipoles must be accompanied by a relocation of these multipoles, which compensates the effects of the origin dependence of the multipoles. We point out that the position of the macroscopic boundary is a relevant parameter. We agree that the transformation proposed by Raab and de Lange could still be useful supposing it only affects the phase of the reflected/trasmitted waves. We dispute that the transformation as derived by Raab and de Lange is unique.
Individual benefits of nestling begging: experimental evidence for an immediate effect, but no evidence for a delayed effect
Authors: Lessells C. (Kate) M. , Riebel Katharina , Draganoiu Tudor Ion
Published: December 2010

The evolutionary stability of honest signalling by offspring is thought to require that begging displays be costly, so the costs and benefits of begging—and whether they are experienced individually or by the whole brood—are crucial to understanding the evolution of begging behaviour. Begging is known to have immediate individual benefits (parents distribute more food to intensely begging individuals) and delayed brood benefits (parents increase provisioning rate to the brood), but the possibility of delayed individual benefits (previous begging affects the current distribution of food) has rarely, if ever, been researched. We did this using playback of great tit
Parus major
chick begging and a control sound from either side of the nest. Male parents fed chicks close to the speaker more when great tit chick begging, but not other stimuli, was played back. In contrast, there was no effect of playback at the previous visit on the chicks that male parents fed. We have thus demonstrated an immediate individual benefit to begging, but found no evidence of a delayed individual benefit in this species.
Altered pairing behaviour and reproductive success in white ibises exposed to environmentally relevant concentrations of methylmercury
Authors: Frederick Peter , Jayasena Nilmini
Published: December 2010

Methylmercury (MeHg) is the most biologically available and toxic form of mercury, and can act as a powerful teratogen, neurotoxin and endocrine disruptor in vertebrates. However, mechanisms of endocrine impairment and net effects on demography of biota are poorly understood. Here, we report that experimental exposure of an aquatic bird over 3 years to environmentally relevant dietary MeHg concentrations (0.05–0.3 ppm wet weight) resulted in dose-related increases in male–male pairing behaviour (to 55% of males), and decreases in egg productivity (to 30%). Dosed males showed decreased rates of key courtship behaviours, and were approached less by courting females in comparison to control males. Within dosed groups, homosexual males showed a similar reduction when compared with dosed heterosexual males. We found an average 35 per cent decrease in fledgling production in high-dose birds over the study duration. These results are of interest because (i) MeHg exposure is experimentally tied to demographically important reproductive deficits, (ii) these effects were found at low, chronic exposure levels commonly experienced by wildlife, and (iii) effects on reproductive behaviour and sexual preference mediated by endocrine disruption represent a novel and probably under-reported mechanism by which contaminants may influence wild populations of birds.
Inhibition of quorum sensing in Pseudomonas aeruginosa by azithromycin and its effectiveness in urinary tract infections
Authors: Bala Anju , Kumar Ravi , Harjai Kusum
Published: December 2010

Pseudomonas aeruginosa, an opportunistic pathogen, is the third most common pathogen associated with nosocomial urinary tract infections (UTIs). The virulence of this organism is due to its ability to produce quorum-sensing (QS) signal molecules and form biofilms. These biofilms are usually resistant to conventional antibiotics and host immune responses. Recently, beneficial effects of macrolides, especially azithromycin (AZM), have been shown in patients suffering from chronic infections caused by P. aeruginosa. These were due to anti-inflammatory and modulatory effects of AZM on the expression of virulence factors of this pathogen. The present study was designed to evaluate the potential of AZM to inhibit QS signal molecules and its ability to attenuate the virulence of P. aeruginosa in an experimental UTI model. Sub-MIC concentrations of AZM significantly inhibited the production of QS signals, swimming, swarming and twitching motilities, and biofilm formation in vitro. The therapeutic evaluation of AZM in this experimental UTI model showed complete clearance of the organisms from the mouse kidneys. The results of this study highlight the potential effectiveness of AZM in attenuating the virulence of P. aeruginosa in a UTI model.
Maternal antenatal peanut consumption and peanut and rye sensitization in the offspring at adolescence
Authors: Kemp A. S. , Ponsonby A‐L , Dwyer T. , Cochrane J. A. , Pezic A. , Jones G.
Published: December 2010

Cite this as: A. S. Kemp, A‐L Ponsonby,T. Dwyer J. A. Cochrane, A. Pezic and G. Jones, Clinical & Experimental Allergy, 2011 (41) 224–231.

Background
There is considerable controversy whether maternal peanut ingestion during pregnancy might influence sensitization in later life.

Objective
To examine whether maternal peanut ingestion during pregnancy might increase sensitization in the offspring.

Methods
A population‐based longitudinal cohort study with 16 years follow‐up was conducted (N=373). Subjects were recruited at birth as part of an infant health study. Maternal antenatal peanut consumption was documented at birth and peanut and rye sensitization were determined by measurement of serum‐specific IgE at age 16.

Results
Peanut sensitization was common (14%). In the entire cohort (n=310), there was no association between antenatal peanut ingestion and peanut sensitization (P=0.17). However, there was a strong association between antenatal peanut ingestion and decreased risk of rye sensitization and peanut sensitization in those (n=201) without a family history (FH) of asthma (Rye OR 0.30, 95% CI 0.14–0.63, P=0.001 and Peanut OR 0.18, 95% CI 0.04–0.78, P=0.02). There was an increased risk of rye sensitization in those (n=108) with a FH of asthma and antenatal peanut ingestion (Rye OR 2.69, 95% CI 1.11–6.51 P=0.03). It was considered that these sensitizations were likely to be related to the presence of IgE antibodies to cross‐reacting carbohydrate epitopes common to rye and peanut allergens.

Conclusions and Clinical Relevance
Antenatal peanut ingestion may influence the development of IgE antibody to cross‐reacting carbohydrate epitopes in later life. Genetic factors may modify this association.
Carbon accumulation in paddy ecosystems in subtropical China: evidence from landscape studies
Authors: Wu J.
Published: December 2010

Carbon (C) sequestration in terrestrial ecosystems can play a role in counteracting the rapid increase in CO2 concentration in the atmosphere. In this study, soils were sampled from some 2700 sites under contrasting land uses in four selected landscape units as representatives of the lowland (LL), low hill (LH), high hill (HH) and karst mountain (KM) areas in subtropical China. The aim was to quantify the potential for C sequestration in paddy ecosystems in the region. The mean values of organic C stocks in paddy soils (0–20 cm) in the landscape units varied from 37.8 to 60.4 t ha−1, and were considerably larger than those for soils under arable cropping and orchard managements, and even under woodland except in the KM landscape unit. In the LH unit, the mean organic C concentration in paddy soils increased by 1.67 times (P < 0.05) during the period between 1979 and 2003. This increase was consistent with the prolonged increase (since the 1950s) in rice productivity in the region. It is concluded that paddy ecosystems in subtropical China have the ability to accumulate organic C faster than other ecosystems. Because these landscape units represent the real situation in paddy ecosystems under farmers' practices for rice production, the data confirm that prolonged organic C accumulation in paddy soils has occurred in subtropical China.
Oral mucosal lesions during orthodontic treatment
Authors: Baricevic Marinka , Mravak‐Stipetic Marinka , Majstorovic Martina , Baranovic Marijan , Baricevic Denis , Loncar Bozana
Published: December 2010

Background

Oral mucosal lesions can result from irritation caused by orthodontic appliances or malocclusion, but their frequency is not known.

Aim

To examine the frequency of oral mucosal lesions in wearers of orthodontic appliances in comparison to children with malocclusion.

Design

This study comprised 111 subjects: 60 wearers of orthodontic appliances and 51 controls (aged between 6 and 18 years). Type and severity of mucosal lesions, their topography, gingival inflammation, and oral hygiene status were determined by using clinical indices.

Results

Mucosal lesions were more present in wearers of orthodontic appliances than in children with malocclusion. Gingival inflammation, erosion, ulceration, and contusion were the most common findings in orthodontic patients. The severity of gingival inflammation was in correlation with oral hygiene status; the poorer oral hygiene, the more severe gingival inflammation was. Better oral hygiene status was found in children during orthodontic treatment than in children with malocclusion.

Conclusions

Orthodontic treatment carries a higher risk of mucosal lesions and implies greater awareness of better oral hygiene as shown by the results of this study. Oral hygiene instructions and early treatment of oral lesions are important considerations in better patient’s motivation, treatment planning, and successful outcome.