bluuebunny/crossref_metadata_2025 huggingface dataset:
Pd–Co/MWCNTs Catalyst for Electrooxidation of Hydrazine in Alkaline Solution
Authors: Liu J. , Liu R. , Yuan C. L. , Wei X. P. , Yin J. L. , Wang G. L. , Cao D. X.
Published: August 2013

Multiwall carbon nanotubes supported Pd–Co electrocatalysts (Pd–Co/MWCNTs) for hydrazine electrooxidation in alkaline electrolytes were prepared. Their morphology and structure were characterized by scanning electron microscopy, transmission electron microscope, and X‐ray diffraction. The effect of the mass ratio of Pd to Co on the catalytic performance was examined via cyclic voltammetric and chronoamperometric measurements. The Pd–Co/MWCNTs with a mass ratio of 1:1 for Pd:Co shows higher catalytic performance than both Pd/MWCNTs and Co/MWCNTs and it has good stability for catalyzing the electrooxidation of hydrazine. The gas collection measurements indicated that hydrazine electrooxidation on Pd–Co/MWCNTs proceeded via a near 4‐electron pathway.
COST‐OFFSETS OF PRESCRIPTION DRUG EXPENDITURES: DATA ANALYSIS VIA A COPULA‐BASED BIVARIATE DYNAMIC HURDLE MODEL
Authors: Deb Partha , Trivedi Pravin K. , Zimmer David M.
Published: August 2013

In this paper, we estimate a copula‐based bivariate dynamic hurdle model of prescription drug and nondrug expenditures to test the cost‐offset hypothesis, which posits that increased expenditures on prescription drugs are offset by reductions in other nondrug expenditures. We apply the proposed methodology to data from the Medical Expenditure Panel Survey, which have the following features: (i) the observed bivariate outcomes are a mixture of zeros and continuously measured positives; (ii) both the zero and positive outcomes show state dependence and inter‐temporal interdependence; and (iii) the zeros and the positives display contemporaneous association. The point mass at zero is accommodated using a hurdle or a two‐part approach. The copula‐based approach to generating joint distributions is appealing because the contemporaneous association involves asymmetric dependence. The paper studies samples categorized by four health conditions: arthritis, diabetes, heart disease, and mental illness. There is evidence of greater than dollar‐for‐dollar cost‐offsets of expenditures on prescribed drugs for relatively low levels of spending on drugs and less than dollar‐for‐dollar cost‐offsets at higher levels of drug expenditures. Copyright © 2013 John Wiley & Sons, Ltd.
Long‐term hydrological response to reforestation in a large watershed in southeastern China
Authors: Li Shuo , Xu Ming , Sun Bo
Published: August 2013

The long‐term hydrological response to reforestation is critical to regional water management, especially in areas where large‐scale reforestation has been practiced. In this study, we investigated the long‐term hydrological response to reforestation in the 579 km2 basin in southeastern China through ground‐based monitoring of water yield, sedimentation, vegetation cover and climate in the basin. The vegetation dynamics were also examined by remote sensing data (MSS, Landsat and AVHRR NDVI). We found that forest cover increased 23% or 13 593 ha from 1975 to 2002. Meanwhile, annual water yield decreased 86–88 mm from 1971–1983 (i.e. pre‐reforestation) to 1984–2009 (i.e. post‐reforestation). These decreases were significant statistically according to both regression and double mass analyses. Time series analysis demonstrated that there was a clear decline in annual sediment yield and an increase in annual evapotranspiration (ET) over the period from 1971 to 2009. We concluded that reforestation could significantly reduce annual water yield and sediment yield in the basin because of the forest cover change and forest growth. This conclusion is consistent with findings from widely paired‐watershed studies and literatures published on the impact of reforestation in large watersheds. Our results also have important strategic implications and provide insight into more sustainable forest management practices for the future. Copyright © 2013 John Wiley & Sons, Ltd.
Seismic exploration‐scale velocities and structure from ambient seismic noise (>1 Hz)
Authors: Draganov Deyan , Campman Xander , Thorbecke Jan , Verdel Arie , Wapenaar Kees
Published: August 2013

The successful surface waves retrieval in solid‐Earth seismology using long‐time correlations and subsequent tomographic images of the crust have sparked interest in extraction of subsurface information from noise in the exploration seismology. Subsurface information in exploration seismology is usually derived from body‐wave reflections > 1 Hz, which is challenging for utilization of ambient noise. We use 11 h of noise recorded in the Sirte basin, Libya. First, we study the characteristics of the noise. We show that the bulk of the noise is composed of surface waves at frequencies below 6 Hz. Some noise panels contain nearly vertically traveling events. We further characterize these events using a beamforming algorithm. From the beamforming, we conclude that these events represent body‐wave arrivals with a fairly rich azimuthal distribution. Having body‐wave arrivals in the noise is a prerequisite for body‐wave reflections retrieval. We crosscorrelate and sum the recorded ambient‐noise panels to retrieve common‐source gathers, following two approaches—using all the noise and using only noise panels containing body‐wave arrivals likely to contribute to the reflections retrieval. Comparing the retrieved gathers with active seismic data, we show that the two‐way traveltimes at short offsets of several retrieved events coincide with those of reflections in the active data and thus correspond to apexes of reflections. We then compare retrieved stacked sections of the subsurface from both approaches with the active‐data stacked section and show that the reflectors are consistent along a line. The results from the second approach exhibit the reflectors better.
Experimental investigation of deformation mechanisms during shear‐enhanced compaction in poorly lithified sandstone and sand
Authors: Skurtveit Elin , Torabi Anita , Gabrielsen Roy H. , Zoback Mark D.
Published: August 2013

Shear‐enhanced compaction in shallow sandstone reservoirs has been investigated in laboratory experiments using high‐pressure triaxial testing of poorly lithified sandstone and sand. We have studied the deformation mechanism involved during shear‐enhanced compaction and controlling parameters for yield stress at varying confining pressures for sandstone/sand with different grain sizes, porosities, and packing. Experimental testing provides insights into the deformation mechanism during hydrostatic and axial compression of coarse‐ and fine‐grained sands with different packing including (1) natural coarse‐grained sandstone, (2) densely packed fine‐grained sand, and (3) loosely packed fine‐grained sand. Monitoring of deformation and ultrasonic velocity during deformation indicates porosity loss, compaction, and strain hardening for most of the samples. Visualization of deformation using pretest and posttest X‐ray imaging and thin sections demonstrates localized deformation fabrics and grain damage. The results show grain rearrangement as the controlling deformation mechanism for material at low stress and high porosity, whereas for lower porosity and higher stress, grain fracturing controlled the deformation. The most pronounced localization of deformation was observed for the coarse‐grained, low‐porosity material. A Cam‐Clay cap model was used to describe the porosity loss during compaction and shear‐enhanced compaction, demonstrating large inelastic compaction with increasing confining pressure. Yield stress and end caps for poorly lithified sandstone are observed for various porosities and stress conditions and found to be lower than predicted using empirical relationships for sandstone.
Volcanic sulfur dioxide plume forecasts based on UV satellite retrievals for the 2011 Grímsvötn and the 2010 Eyjafjallajökull eruption
Authors: Flemming Johannes , Inness Antje
Published: August 2013

The sulfur dioxide plumes released by the eruptions of the Icelandic volcanoes Eyjafjallajökull in May 2010 and Grímsvötn in May 2011 were studied using satellite observations from the Second Global Ozone Monitoring Experiment (GOME‐2), Ozone Monitoring Instrument (OMI), and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography and modeled with the Integrated Forecasting System of the European Centre for Medium‐Range Weather Forecasts (ECMWF). The retrievals of SO2 total columns (TCSO2) were (i) used to estimate emission rate and injection height of the two eruptions and (ii) assimilated with ECMWF's four‐dimensional variational data assimilation algorithm to obtain initial conditions for subsequent forecasts. The OMI retrievals provided the highest plume observation values, and GOME‐2 had the best coverage. The emission parameters were estimated by comparing TCSO2 observations with an ensemble of test tracers injected at different heights. The applied methodology led to emission estimates of 0.25 Tg over 20 days in May 2010 and 0.32 Tg over 2 days in May 2011. The SO2 analyses produced by assimilating GOME‐2 TCSO2 retrievals captured the plume maxima well but exaggerated the plume area. The injection height estimate was used during the assimilation to determine the height of the assimilated plume. Plume forecasts were evaluated by means of hit‐rate and plume‐size statistics for different TCSO2 thresholds. Plume forecasts using either the emission parameters or the SO2 analyses as initial conditions agreed reasonably with the observations, but using both led to the best forecast performance. The initialization with SO2 analysis fields improved, in particular, the forecast of the Grímsvötn plume after the end of the eruption. The developed forecast and assimilation system can be applied for near–real‐time forecasting of volcanic SO2 plumes.
Delirium superimposed on dementia is associated with prolonged length of stay and poor outcomes in hospitalized older adults
Authors: Fick Donna M. , Steis Melinda R. , Waller Jennifer L. , Inouye Sharon K.
Published: August 2013

BACKGROUND

Current literature does not identify the significance of underlying cognitive impairment and delirium in older adults during and 30 days following acute care hospitalization.

OBJECTIVE

Describe the incidence, risk factors, and outcomes associated with incident delirium superimposed on dementia.

DESIGN

A 24‐month prospective cohort study.

SETTING

Community hospital.

PATIENTS

A total of 139 older adults (>65 years) with dementia.

METHODS

This prospective study followed patients daily during hospitalization and 1 month posthospital. Main measures included dementia (Modified Blessed Dementia Rating score, Informant Questionnaire on Cognitive Decline in the Elderly), daily mental status change, dementia stage/severity (Clinical Dementia Rating, Global Deterioration Scale), delirium (Confusion Assessment Method), and delirium severity (Delirium Rating Scale‐Revised‐98). All statistical analysis was performed using SAS 9.3, and significance was an α level of 0.05. Logistic regression, analysis of covariance, or linear regression was performed controlling for age, gender, and dementia stage.

RESULTS

The overall incidence of new delirium was 32% (44/139). Those with delirium had a 25% short‐term mortality rate, increased length of stay, and poorer function at discharge. At 1 month follow‐up, subjects with delirium had greater functional decline. Males were more likely to develop delirium, and for every 1 unit increase in dementia severity (Global Deterioration Scale), subjects were 1.5 times more likely to develop delirium.

CONCLUSIONS

Delirium prolongs hospitalization for persons with dementia. Thus, interventions to increase early detection of delirium have the potential to decrease the severity and duration of delirium and to prevent unnecessary suffering and costs from the complications of delirium and unnecessary readmissions to the hospital. Journal of Hospital Medicine 2013;8:500–505. © 2013 Society of Hospital Medicine
High level of HIV‐2 false positivity in KwaZulu‐Natal province: A region of South Africa with a very high HIV‐1 subtype C prevalence
Authors: Singh Lavanya , Parboosing Raveen , Manasa Justen , Moodley Pravi , de Oliveira Tulio
Published: August 2013

Human immunodeficiency virus 2 (HIV‐2) is found predominantly in West Africa. It is not unlikely, however, that HIV‐2 may also be found in South Africa, due to the influx of immigrants into this country. It is important to distinguish between HIV‐1 and HIV‐2 since the clinical courses and treatment responses of these viruses are different. Routine serological methods for diagnosing HIV do not differentiate between HIV‐1 and ‐2 infections, while rapid tests, viral load quantification and PCR are HIV‐type—specific. The objective of this study was to describe the seroprevalence and molecular epidemiology of HIV‐2 in KwaZulu‐Natal, one of the regions with the highest HIV prevalence in the world and home of the two largest harbors in South Africa. HIV‐1 positive samples were screened for antibodies against HIV‐2, using a rapid test. The confirmation of HIV‐2 positive samples was done by PCR. Of the 2,123 samples screened, 319 (15%) were identified as positive by the rapid test. None of these samples were confirmed positive by PCR. To explore this discrepancy in the results, a subset (n = 52) of the rapid HIV‐2 positive samples was subjected to Western blotting. Thirty‐seven (71%) of these were positive, yielding an overall HIV‐2 seroprevalence of 10.6%. Three out of 28 (10.7%) Western blot positive samples were positive by a Pepti‐LAV assay. This discrepancy between serological and molecular confirmation may be attributed to non‐specific or cross‐reacting antibodies. The use of rapid tests and Western blots for HIV‐2 diagnosis in South Africa should be interpreted with caution. J. Med. Virol. 85:2065–2071, 2013. © 2013 The Authors. Journal of Medical Virology published by Wiley Periodicals, Inc.
Effects of local, synoptic and large‐scale climate conditions on daily nitrogen dioxide concentrations in Auckland, New Zealand
Authors: Jiang Ningbo , Dirks Kim N. , Luo Kehui
Published: August 2013

As with many urban centres around the world, nitrogen dioxide (NO2) is of concern in Auckland, New Zealand because of its possible link to respiratory and heart disease. It has also been associated with the frequent occurrence of brown haze in the region. This article examines quantitatively the differential effects of the local‐, synoptic‐ and large‐scale (El Niño‐Southern Oscillation—ENSO, Southern Annular Mode—SAM) climate conditions on daily NO2 concentrations in urban Auckland under the framework of generalized linear models. The local meteorology is found to be the most important driver of the daily NO2 concentrations in Auckland, primarily through the coupling of local‐scale atmospheric flow and stability conditions with local emissions and chemical processes. Both the synoptic circulation and large‐scale climate modes play significant roles in determining the local air pollution. Synoptic circulations, even after controlling for the local meteorological conditions, modulate the daily NO2 at a regional level via two main mechanisms: (1) blocking types facilitate the transport of clean oceanic air over the Auckland landmass, leading to generally low NO2 concentrations; (2) westerly cyclonic types contribute to region‐wide increases in NO2 concentrations due to the enhanced mixing‐in and/or downward transport of ozone (O3) from the upper troposphere or stratosphere. The large‐scale climate modes, ENSO and SAM, modulate the regional air quality through changing the frequency of occurrence and air‐mass characteristics of synoptic systems over New Zealand. Overall, this study demonstrates a holistic approach to understand how atmospheric circulations of different scales affect local air quality and thus provides useful information for the formulation of effective public health management and planning strategies in response to future climate variability and change.
Live and death of streptomyces in soil—what happens to the biomass?
Authors: Schütze Eileen , Miltner Anja , Nietzsche Sandor , Achtenhagen Jan , Klose Michael , Merten Dirk , Greyer Matthias , Roth Martin , Kästner Matthias , Kothe Erika
Published: August 2013

The formation of soil organic matter (SOM) has been proposed to depend on fragmentation of biomass after cell death. However, this is hard to mimic in laboratory experiments showing the process directly. We used heavy metal contamination in order to provide an environment in which one Streptomyces strain, the heavy metal resistant S. mirabilis P16B‐1, could survive while the sensitive strain S. lividans TK24 was expected to die and disintegrate; the necromass fragments would then contribute to SOM formation. Both strains were grown for 30 d in sterile mesocosms containing either highly metal‐contaminated soil from a former uranium‐mining site in Ronneburg, Germany, or control soil from a municipal park, Jena, Germany. The fate and morphology of living and dead bacterial biomass (necromass) was observed using scanning electron microscopy. Attachment of soil particles to the intact mycelium as well as decay of dead biomass was observed. Dead bacterial biomass was identified in form of patchy fragments while the superordinate filamentous structure of the hyphae was still visible and obviously stabilized in soil. The fate of cytosolic compounds was followed using the example of a nickel‐containing superoxide dismutase (NiSOD) which was found to be released after death of cells grown in liquid soil‐extract medium. Activity of the enzyme was proven for concentrated media supernatant by a gel‐based qualitative activity assay. This indicates that NiSOD remains active in soil after cell death. Hence, bacterial cell death results in the release of cytosolic compounds, e.g., intact proteins, as well as the formation of residual cell‐envelope fragments contributing to SOM formation.
Calcification of aortic human valves studied in situ by Raman microimaging: following mineralization from small grains to big deposits
Authors: Pilarczyk Marta , Czamara Krzysztof , Baranska Malgorzata , Natorska Joanna , Kapusta Przemysław , Undas Anetta , Kaczor Agnieszka
Published: August 2013

A Raman microimaging‐based approach has been used in the current study to evaluate formation and progression of calcification in situ in human stenotic aortic valves obtained during surgical valve replacement. The capability of the method to visualize distribution of the calcified deposits resulted in structural characterization of deposits in the various phases of development. A high spatial resolution of the method along with the confocal depth profiling enabled to identify extremely small salt inclusions (of ca. 0.5 µm in diameter), formed probably at the very early stage of calcification. Structurally, these inclusions are built from an octacalcium phosphate‐like compound that during grains' growth transforms into tricalcium phosphate, mixed with the salt containing the acidic phosphate groups (HPO42−) and, finally, into stable B‐type hydroxyapatite that is the only salt present in large‐area calcium salt deposits. Copyright © 2013 John Wiley & Sons, Ltd.
Confocal Raman microspectroscopy discriminates live human metastatic melanoma and skin fibroblast cells
Authors: Terentis Andrew C. , Fox Sara A. , Friedman Samantha J. , Spencer Emily S.
Published: August 2013

Confocal Raman microspectroscopy (CRM) continues to develop as a promising technique with possible clinical applications for the diagnosis and treatment of skin cancers. CRM studies of single cells can provide information on the biochemical content of cancer cells in situ, potentially providing new biochemical signatures or markers of cancer cells. Here, we report a CRM study of single, living human metastatic melanoma cells (SK‐Mel‐2) and normal skin fibroblast cells (BJ) cultured and examined under identical experimental conditions. A total of almost 1200 Raman spectra were measured from more than 120 BJ and SK‐Mel‐2 cells using an inverted microscope with 647 nm laser excitation. Raman spectra were measured from within three distinct intracellular regions of the cells – cytoplasm, nucleoplasm, and nucleolus. When Raman spectra from each cell type were compared using principal components analysis (PCA) and linear discriminant analysis with leave‐one‐dish‐out cross‐validation (LDA‐CV), the two cell types were discriminated with 93% (cytoplasm), 98% (nucleolus), and 96% (nucleoplasm) accuracy. The main biochemical differences identified between the two cell types were higher RNA levels in the nucleoli of BJ cells and high amounts of lipid and collagen in the cytoplasm of SK‐Mel‐2 cells. For both cell types, higher levels of RNA were detected in the nucleoli versus the nucleoplasm. PCA with LDA‐CV was 98% (cytoplasm), 93% (nucleoplasm), and 73% (nucleolus) accurate in identifying the intracellular region based on the Raman spectra from both cell types. No significant trend was observed when the data were analyzed with respect to cell passage number. Thus, CRM with PCA and LDA‐CV successfully discriminated two skin cancer‐relevant cell lines while detecting different amounts of nucleic acids, lipids, and proteins in distinct intracellular regions, further underscoring its potential as a clinical diagnostic tool. Copyright © 2013 John Wiley & Sons, Ltd.
Enantioseparation of tartaric acid by ligand‐exchange capillary electrophoresis using contactless conductivity detection
Authors: Knob Radim , Petr Jan , Ševčík Juraj , Maier Vítězslav
Published: August 2013

A method for the determination of tartaric acid enantiomers using CE with contactless conductivity detection has been developed. Cu(II) as a central metal ion together with l‐hydroxyproline were used as a chiral selector, the BGE was composed of 7 mM CuCl2, 14 mM trans‐4‐hydroxy‐l‐proline, and 100 mM ε‐aminocaproic acid; the pH was adjusted to 5 by hydrochloric acid. Separation with a resolution of 1.9 was achieved in 9 min in a polyacrylamide‐coated capillary to suppress the EOF. Various counterions of the BGE were studied, and migration order reversal was achieved when switching from ε‐aminocaproic acid to l‐histidine. With detection limits of about 20 μM, the method was applied to the analysis of wine and grape samples; only l‐tartaric acid was found.
Patentability of Plants: At the Crossroads between Monopolizing Nature and Protecting Technological Innovation?
Authors: Bostyn Sven J. R.
Published: August 2013

This article provides an in‐depth critical analysis of pressing issues regarding the patentability of plants. There is no public interest overarching principle present in the European Patent Convention or any other convention for that matter which would exclude patent protection for plants. The expansionist behavior of some users of the patent system seeking to obtain patent protection for methods and products which are very akin to traditional breeding methods needs to be halted and patent applications in that context deserve very close scrutiny so as to avoid that the border is crossed. Patents for hybrid seeds ought not to be protected by patents, as they in effect protect plant varieties as such. If the patent system is not capable of keeping such innovations outside of the patent territory, the call for excluding all plant‐related innovations from patentability will become more influential. Products produced by essentially biological processes should not be patentable. However, in the absence of a statutory basis, the current legal framework does not allow the judiciary to come to such conclusion. The EPC needs to be amended in this respect. Finally, introducing a breeders' exemption in the patent system could jeopardize the internal and external architecture of the patent system and one should be wary of introducing it.
Calderón‐Zygmund operators with non‐diagonal singularity
Authors: Li Kangwei , Sun Wenchang
Published: August 2013

In this paper, we introduce a class of singular integral operators which generalize Calderón‐Zygmund operators to the more general case, where the set of singular points of the kernel need not to be the diagonal, but instead, it can be a general hyper curve. We show that such operators have similar properties as ordinary Calderón‐Zygmund operators. In particular, we prove that they are of weak‐type (1, 1) and strong type for .
Estimates of scattered electromagnetic fields
Authors: Wellander N. , Kristensson G.
Published: August 2013

We present some general estimates of the scattered electromagnetic fields for a general bounded scattering domain Ω in the anisotropic materials setting. In particular, it is shown that the ‐ norm and sup norm of the scattered field in an arbitrary finite exterior domain Ωs is bounded by the H(curl,Ω) norm of the incident field. Moreover, several estimates of the traces of the scattered field on the boundary are presented. These estimates have bearing on estimations on cloaking. Copyright © 2013 John Wiley & Sons, Ltd.
Use of antiepileptic drugs and risk of hypothyroidism
Authors: Lai Edward Chia‐Cheng , Yang Yea‐Huei Kao , Lin Swu‐Jane , Hsieh Cheng‐Yang
Published: August 2013

Purpose

This study aimed to investigate the risk of clinically significant hypothyroidism among all the currently available antiepileptic drugs (AED).

Methods

The Taiwan National Health Insurance Research Database (NHIRD) from 2004 to 2010 was analyzed using a prescription sequence symmetry analysis, and thyroxine treatment was used as a proxy to identify a hypothyroidism event. A cohort of patients who have been treated with both AED and thyroxine was selected, and the chronological order of AED and thyroxine use constituted the basis of the prescription sequence symmetry analysis. A causal relationship was suspected if there was a significantly higher proportion of patients who initiated thyroxine after AED than those who initiated thyroxine before AED. The ratio of the two proportions was described as a sequence ratio. To benchmark the effect size of AEDs on thyroid function, amiodarone was selected as the reference indicator.

Results

A total of 1,878,189 AED users was found in the database, with 16,200 of them also used thyroxine. The adjusted sequence ratio of thyroxine use after each AED was 1.75 (99% confidence interval, 1.58–1.94) for phenytoin, 1.34 (1.20–1.49) for valproate, 1.25 (1.15–1.36) for phenobarbital, 1.21 (1.08–1.34) for carbamazepine, and 1.22 (1.03–1.46) for oxcarbazepine. The risk of hypothyroidism from phenytoin use within a shorter time frame was similar that associated with amiodarone use. No association was shown in most of the new generation AEDs.

Conclusion

The results indicated an increased risk of hypothyroidism among patients using AEDs, especially phenytoin, valproate, phenobarbital, carbamazepine, and oxcarbazepine. The findings also provided strong grounds for further investigations on acute thyroid adverse effect induced by phenytoin. Copyright © 2013 John Wiley & Sons, Ltd.
3D features in the calendering of thermoplastics: A computational investigation
Authors: Polychronopoulos Nickolas D. , Sarris Ioannis E. , Papathanasiou T.D.
Published: August 2013

We present results of a fully three‐dimensional computational study of the calendering process of thermoplastics using the fluid dynamics software OpenFOAM. Our aim is to elucidate unique 3D features of the process, such as spreading and melt flow. We assume that the material is fed in the form of a sheet of finite thickness and detaches from the cylinders at a prescribed thickness. The rotational motion of the cylinders, the consequent pressure build‐up (both in the machine and the transverse directions) and the presence of the free surfaces (sides) of the calendered sheet—both deformable and at ambient pressure—forces the thermoplastic melt to spread in the transverse direction. A decoupled iterative procedure is used to predict the shape of the spreading side surfaces under different conditions. A spiraling transverse flow pattern in the melt feeding section is shown to exist, which determines the actual flow path of the calendered material in a nonintuitive way. We show that insofar as the material redistribution (from the fed sheet to the produced film) during the process is concerned, the results of the present analysis predict a 3D spiral flow pattern and a redistribution of the fed material from the central region of the fed sheet to the sides of the calendered product. POLYM. ENG. SCI., 54:1712–1722, 2014. © 2013 Society of Plastics Engineers
Basin Modelling of Temperature and Heat Flow Distributions and Permafrost Evolution, Urengoy and Kuyumbinskaya Areas, Siberia
Authors: Galushkin Yu. I. , Sitar K. А. , Frolov S. V.
Published: August 2013

The thermal history and permafrost evolution in the Urengoy area of the West Siberian basin and in the Kuyumbinskaya area of the Siberian platform during the Pliocene‐Quaternary were reconstructed numerically in a forward model from 3.4 Ma using the software package FROST, part of the basin modelling system GALO. Calculations suggest that variations in rock composition with depth strongly influenced permafrost evolution. Rock temperatures decreased by 15–20°C within the upper 1500 m of the sedimentary sequence because of climate cooling in the Pliocene‐Holocene. The effect of cooling is greater in the Kuyumbinskaya area, which has a thinner sedimentary cover, than in the more northern Urengoy area. The model estimates permafrost depth and the stability zone of methane gas hydrate. An increase in salt content in porewater from 1 to 30 g/l lowers the melting temperature of ice by 2°С and decreases permafrost thickness by almost 100 m. The change in shape of the unfrozen water curve W(T), dependent upon the lithological composition of sedimentary rocks, strongly influences the numerical estimations of permafrost depth. The modelling demonstrates that permafrost thickness and temperature and heat flow distributions with depth in the basins calculated with climate variations of the last 50 ka differ significantly from the more accurate values obtained with climate variations during the last 200 ka, 1 Ma or 3.4 Ma. Copyright © 2013 John Wiley & Sons, Ltd.
Exploring the Visuospatial Challenge of Learning About Day and Night and the Sun's Path
Authors: HEYWOOD DAVID , PARKER JOAN , ROWLANDS MARK
Published: August 2013

The role of visualization and model‐based reasoning has become increasingly significant in science education across a range of contexts. It is generally recognized that supporting learning in developing causal explanations for observed astronomical events presents considerable pedagogic challenge. Understanding the Sun's apparent movement across the sky requires a sophisticated interpretation of visuospatial relations. This study explores how preservice teachers employ models in reasoning about this phenomenon. It adopts a research methodology that attempts to capture the fine detail of learning using a range of strategies to determine student teachers’ use of models in visuospatial reasoning. This included individual learners documenting their responses during taught sessions as part of the process of capturing their personal perceptions. Student reflections on their own learning were subsequently discussed during follow‐up audiotaped interviews. The findings revealed four different models of visuospatial reasoning used by the student teachers and highlighted subtle differences between individuals. The ways participants used these to make sense of the phenomenon and how this contributes to our understanding of model‐based reasoning in basic astronomy are discussed. © 2013 Wiley Periodicals, Inc. Sci Ed 97:772–796, 2013
Estimation of the wild‐type minimum inhibitory concentration value distribution
Authors: Jaspers Stijn , Aerts Marc , Verbeke Geert , Beloeil Pierre‐Alexandre
Published: August 2013

Antimicrobial resistance has become one of the main public health burdens of the last decades, and monitoring the development and spread of non‐wild‐type isolates has therefore gained increased interest. Monitoring is performed based on the minimum inhibitory concentration (MIC) values, which are collected through the application of dilution experiments. In order to account for the unobserved population heterogeneity of wild‐type and non‐wild‐type isolates, mixture models are extremely useful. Instead of estimating the entire mixture globally, it was our major aim to provide an estimate for the wild‐type first component only. The characteristics of this first component are not expected to change over time, once the wild‐type population has been confidently identified for a given antimicrobial. With this purpose, we developed a new method based on the multinomial distribution, and we carry out a simulation study to study the properties of the new estimator. Because the new approach fits within the likelihood framework, we can compare distinct distributional assumptions in order to determine the most suitable distribution for the wild‐type population. We determine the optimal parameters based on the AIC criterion, and attention is also paid to the model‐averaged approach using the Akaike weights. The latter is thought to be very suitable to derive specific characteristics of the wild‐type distribution and to determine limits for the wild‐type MIC range. In this way, the new method provides an elegant means to compare distinct distributional assumptions and to quantify the wild‐type MIC distribution of specific antibiotic–bacterium combinations. Copyright © 2013 John Wiley & Sons, Ltd.
One‐Step Formation of a Single Atomic‐Layer Transistor by the Selective Fluorination of a Graphene Film
Authors: Ho Kuan‐I , Liao Jia‐Hong , Huang Chi‐Hsien , Hsu Chang‐Lung , Zhang Wenjing , Lu Ang‐Yu , Li Lain‐Jong , Lai Chao‐Sung , Su Ching‐Yuan
Published: August 2013

In this study, the scalable and one‐step fabrication of single atomic‐layer transistors is demonstrated by the selective fluorination of graphene using a low‐damage CF4 plasma treatment, where the generated F‐radicals preferentially fluorinated the graphene at low temperature (<200 °C) while defect formation was suppressed by screening out the effect of ion damage. The chemical structure of the C–F bonds is well correlated with their optical and electrical properties in fluorinated graphene, as determined by X‐ray photoelectron spectroscopy, Raman spectroscopy, and optical and electrical characterizations. The electrical conductivity of the resultant fluorinated graphene (F‐graphene) was demonstrated to be in the range between 1.6 kΩ/sq and 1 MΩ/sq by adjusting the stoichiometric ratio of C/F in the range between 27.4 and 5.6, respectively. Moreover, a unique heterojunction structure of semi‐metal/semiconductor/insulator can be directly formed in a single layer of graphene using a one‐step fluorination process by introducing a Au thin‐film as a buffer layer. With this heterojunction structure, it would be possible to fabricate transistors in a single graphene film via a one‐step fluorination process, in which pristine graphene, partial F‐graphene, and highly F‐graphene serve as the source/drain contacts, the channel, and the channel isolation in a transistor, respectively. The demonstrated graphene transistor exhibits an on‐off ratio above 10, which is 3‐fold higher than that of devices made from pristine graphene. This efficient transistor fabrication method produces electrical heterojunctions of graphene over a large area and with selective patterning, providing the potential for the integration of electronics down to the single atomic‐layer scale.
Encouraging Entrepreneurship: Microfinance, Knowledge Support, and the Costs of Operating in Institutional Voids
Authors: Chakrabarty Subrata , Bass A. Erin
Published: August 2013

This study focuses on the supplemented strategies of microfinance institutions (MFIs), in which the MFI offers nonfinancial services, such as entrepreneurship related knowledge, in addition to financial services to impoverished borrowers at the bottom of the pyramid (BoP). We examine two contextual factors–foreign direct investment (FDI) and loan defaults–to better understand the relationship between providing knowledge support to encourage entrepreneurship and costs of operating at the BoP for MFIs. In contexts where FDI is low and loan defaults are high, providing knowledge support to encourage entrepreneurship aggravates the MFI's costs of operating at the BoP. However, in contexts where FDI is high and loan defaults are low, providing knowledge support to encourage entrepreneurship among impoverished borrowers does not aggravate the MFI's costs of operating at the BoP. Hence, in emerging markets where governments welcome FDI and curb loan defaults, MFIs can viably support entrepreneurship among the poor. © 2013 Wiley Periodicals, Inc.
Molecular Structure and Real‐Space Bonding Descriptors (AIM, ELI‐D) of Phenyl(triphenylstannyl)telluride
Authors: Beckmann Jens , Heinrich Darina , Mebs Stefan
Published: August 2013

The previously known phenyl(triphenylstannyl)telluride, PhTeSnPh3, was prepared by the reaction of triphenyltin chloride, Ph3SnCl, with sodium phenyltellurolate, Na(TePh), in liquid ammonia. The molecular structure established by X‐ray crystallography and by geometry optimization at the DFT/B3PW91/TZ level of theory was used for calculations of real‐space bonding descriptors derived from an atoms‐in‐molecules (AIM) analysis of the theoretically calculated electron density. In addition, the electron localizability indicator (ELI‐D) was derived from the corresponding pair density and the Raub‐Jansen‐Index (RJI) was determined.
Living with an inborn error of metabolism detected by newborn screening—Parents’ perspectives on child development and impact on family life
Authors: Gramer Gwendolyn , Haege Gisela , Glahn Esther M. , Hoffmann Georg F. , Lindner Martin , Burgard Peter
Published: August 2013

Background

Newborn screening for inborn errors of metabolism is regarded as highly successful by health professionals. Little is known about parents’ perspectives on child development and social impact on families.

Methods

Parents of 187 patients with metabolic disorders detected by newborn screening rated child development, perceived burdens on child and family, and future expectations on a questionnaire with standardized answers. Parental ratings were compared with standardized psychometric test results. Regression analysis was performed to identify factors associated with extent of perceived burden.

Results

In 26.2 % of patients, parents perceived delays in global development and/or specific developmental domains (physical, social, intellectual, language). Parents expected normal future development in 95.7 %, and an independent adult life for their child in 94.6 %. Comparison with psychometric test results showed that parents of children with cognitive impairments tended to overrate their child's abilities. Mild/medium burden posed on the family (child) by the metabolic disorder was stated by 56.1 % (48.9 %) of parents, severe/very severe burden by 19.3 % (8.6 %). One third of families reported financial burden due to the metabolic disorder. Dietary treatment and diagnoses with risk for metabolic decompensation despite treatment were associated with higher perceived burden for the family. Disorders rated as potentially very burdensome by experts were not rated accordingly by parents, demonstrating different perspectives of professionals and parents.

Conclusion

Although newborn screening leads to favourable physical and cognitive outcome, living with a metabolic disorder may cause considerable stress on patients and families, emphasizing the need for comprehensive multidisciplinary care including psychological and social support.
Modern Vegetational Distribution and Pollen Dispersal Study within Gangotri Glacier Valley, Garhwal Himalaya
Authors: Ranhotra Parminder S. , Bhattacharyya Amalava
Published: August 2013

Modern pollen-vegetation relationship has been analyzed in respect to vegetational distribution and pollen dispersal from sub-alpine and alpine ecological regimes within the higher reaches of the Gangotri glacier valley. The results in general cope with the local ecological conditions of the sites within the valley. Above the tree line limits, the pollen frequency of arboreal taxa is found lower than those of non-arboreal taxa. In contrast the pine-birch forest area at Chirbasa represented the frequency of arboreal pollen (AP) more than that of non-arboreal pollen (NAP) due to over representation of Pinus wallichiana (conifer). Pollen grains of extra-local arboreal elements, mostly conifers have also been recorded here with fair amount of temperate broad-leaved arboreal taxa viz. Quercus, Alnus, Corylus, Carpinus, Ulmus, Juglans etc. that have been transported by the upthermic winds from their growing limits at lower altitudes to the study sites at higher altitudes. Non-arboreal taxa viz. marshy/aquatic, steppe and of other herbaceaous taxa, represents the existing ecological regimes of their respective sites within the valley. Differential pollen preservation has been observed between the moss cushion and sediment samples from the same site that may be due to the direct exposure of moss cushions to air, thus showing more concentration of wind pollinated pollen-spores as compared to surface sediments.
Usefulness of Adaptive Filtering for Improved Digital Elevation Model Generation
Authors: Bhattacharya Atanu , Arora Manoj K. , Sharma Mukat L.
Published: August 2013

The Digital Elevation Models (DEMs), which represent the variation of elevation in a terrain at spatial level, are an important source of input to a variety of applications for deriving a number of terrain parameters such as relative relief, slope, aspect direction etc. In recent years, Synthetic Aperture Radar Interferometry has been viewed as a powerful approach to derive quality DEMs from a pair of SAR images. Despite the interferometric technique is often limited by several de-correlations several researchers demonstrate its effectiveness in topographic mapping. The DEM accuracy is strongly influenced by the effectiveness of the phase unwrapping technique. In this study an effective adaptive filtering approach has been used to reduce the phase noise due to de-correlation and in improving the accuracy of phase unwrapping. Two well known phase unwrapping approaches such as branch cut and minimum cost flow network have been used. Interferometric data from ASAR sensor onboard ENVISAT satellite have been used. A highly undulated terrain condition near Dehradun city situated in Uttarakhand state of India was selected to investigate the performance of this adaptive filtering approach. The RMS error between the InSAR derived elevations and the map derived elevations was obtained as 7.2 m using adaptive filter. However, elevation map of the study area could not be generated due to high de-correlation effect without the use of adaptive filter. This result clearly demonstrates the effectiveness of adaptive filtering approach for generation of DEM at meter level accuracy, which is sufficient for many engineering applications.
A western blot assay to measure cyclin dependent kinase activity in cells or in vitro without the use of radioisotopes
Authors: Lewis Cody W. , Taylor Ryan G. , Kubara Philip M. , Marshall Kris , Meijer Laurent , Golsteyn Roy M.
Published: August 2013

We developed a quantitative method to measure the activity of cyclin‐dependent kinases (Cdks) by western blotting, without radioisotopes. We prepared a recombinant protein substrate based upon the natural Cdk1 substrate, PP1Cα. By combining this substrate in a western blot method using fluorochrome based antibodies and phospho‐imager analysis, we measured the Km of ATP binding to Cdk1 to be 3.5 μM. We then measured Cdk1 activity in cell extracts from interphase or mitotic cells, and demonstrated that previously identified Cdk inhibitors could be detected by this assay. Our data show that we have a safe, reliable assay to identify Cdk1 inhibitors and measure Cdk1 activity.
Exploration of 100 commonly used drugs and supplements on cognition in older adults
Authors: Obermann Karen R. , Morris John C. , Roe Catherine M.
Published: August 2013

Background

There are conflicting reports and a lack of evidence‐based data regarding effects of medications on cognition in cognitively normal older adults. We explored whether use of 100 common medications taken by older adults is associated with longitudinal cognitive performance.

Methods

A longitudinal observational cohort was used with analysis of data collected from September 2005 through May 2011 and maintained in the National Alzheimer's Coordinating Center (NACC) Uniform Data Set. Participants were aged 50 years or older and cognitively normal (N = 4414). Composite scores were constructed from 10 psychometric tests. Scores for each participant reflecting change in the psychometric composite score from the baseline clinical assessment to the next assessment were calculated. General linear models were used to test whether the mean composite change score differed for participants who reported starting, stopping, continuing, or not taking each of the 100 most frequently used medications in the NACC sample.

Results

The average time between assessments was 1.2 years (SD = 0.42). Nine medications showed a difference (P < .05) across the four participant groups in mean psychometric change scores from the first to the second assessment. Medications associated with improved psychometric performance were naproxen, calcium‐vitamin D, ferrous sulfate, potassium chloride, flax, and sertraline. Medications associated with declining psychometric performance were bupropion, oxybutynin, and furosemide.

Conclusions

Reported use of common medications is associated with cognitive performance in older adults, but studies are needed to investigate the mechanisms underlying these effects.
Blood pressure variability and risk of dementia in an elderly cohort, the Three‐City Study
Authors: Alpérovitch Annick , Blachier Martin , Soumaré Aïcha , Ritchie Karen , Dartigues Jean‐François , Richard‐Harston Sandrine , Tzourio Christophe
Published: August 2013

Background

The relationship between blood pressure and dementia is incompletely understood in elderly individuals. Blood pressure variability may have a role in the risk of dementia.

Methods

This investigation was a cohort study of 6506 elderly individuals followed‐up for 8 years (1999–2001 through 2008) with assessments at years 2, 4, and 7–8. Blood pressure was measured by electronic devices at baseline and at 2‐ and 4‐year follow‐up examinations. Cox proportional hazard models adjusted for potential confounders were used to estimate the risk of incident dementia according to blood pressure (means and coefficients of variation of the three measures).

Results

During the 40,151 person‐years of follow‐up 474 participants developed dementia. We observed no association between mean blood pressure and risk of dementia. In contrast, an increase of 1 standard deviation in the coefficient of variation of blood pressure was associated with a 10% increased risk of dementia. Analysis by deciles of the coefficient of variation showed that the higher the variability, the higher the risk of dementia (P < .02 for trend). In the fully adjusted Cox model, the risk of dementia for those in the highest decile of the coefficient of variation of systolic blood pressure was 1.77 (1.17–2.69) compared with the lowest decile.

Conclusions

In this cohort study, variability of blood pressure during follow‐up was associated with an increased risk of incident dementia, whereas mean blood pressure was not. Limitation of blood pressure fluctuation may be an important target to preserve cognitive function in the elderly.