bluuebunny/crossref_metadata_2025 huggingface dataset:
On the measurement of fracture toughness of soft biogel
Authors: Kwon H.J. , Rogalsky Allan D. , Kim Dong‐Woo
Published: March 2011

In this study, the rate dependent energy dissipation process and the fracture toughness of physical gels were investigated using agarose as a sample material. Both the J‐integral and Essential work of Fracture (EWF) methods were examined. To assess the quasi‐static fracture toughness of gels, linear regression was performed on critical J (Jc) values at different loading rates resulting in a quasi‐static Jc value of 6.5 J/m2. This is close to the quasi‐static EWF value of 5.3 J/m2 obtained by performing EWF tests at a quasi‐static loading rate (crosshead speed of less than 2 mm/min). Nearly constant crack propagation rates at low loading rates, regardless of crack length, suggest viscoplastic chain pull‐out is the fracture mechanism. At high loading rates failure was highly brittle, which is attributed to sufficient elastic energy accumulation to precipitate failure by chain scission. We conclude that in physical gels quasi‐static fracture toughness can be evaluated by both the J‐integral and EWF methods provided the effects of loading rate are investigated and accounted for. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Crystallization studies on a clay nanocomposite prepared from a degradable poly(ester amide) constituted by glycolic acid and 6‐aminohexanoic acid
Authors: Morales‐Gámez Laura , Franco Lourdes , Casas María Teresa , Puiggalí Jordi
Published: March 2011

An intercalated nanocomposite was prepared from an organomodified clay (Cloisite 25A) and a new biodegradable poly(ester amide) characterized by an alternating arrangement of glycolic acid and 6‐aminohexanoic acid units by the melt‐mixing technique. The influence of the final silicate layer morphology on hot and cold crystallization behavior was investigated by optical microscopy, differential scanning calorimetry, and synchrotron radiation. Primary nucleation increased significantly with the incorporation of nanoparticles, in contrast with the decrease previously observed when exfoliated structures were obtained. The secondary nucleation constant was higher for the nanocomposite sample, indicating that the growth mechanism was hampered by the presence of clay particles. However, the increase in primary nucleation had a greater effect, resulting in a faster overall crystallization rate for the nanocomposite. The addition of clay particles slightly reduced the degree of crystallinity attained after the hot and cold crystallization processes and favored a lamellar insertion mechanism. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Cocrystallization of ethylene/1‐octene copolymer blends during crystallization analysis fractionation and crystallization elution fractionation
Authors: Suriya Kanokpon , Anantawaraskul Siripon , Soares João B. P.
Published: March 2011

Blending of ethylene/1‐octene copolymers can be used to achieve a well‐controlled broad chemical composition distribution (CCD) required in several polyolefin applications. The CCD of copolymer blends can be estimated using crystallization analysis fractionation (CRYSTAF) or crystallization elution fractionation (CEF). Unfortunately, both techniques may be affected by the cocrystallization of chains with different compositions, leading to profiles that do not truly reflect the actual CCD of the polymer. Therefore, understanding how the polymer microstructure and the analytical conditions influence copolymer cocrystallization is critical for the proper interpretation of CRYSTAF and CEF curves. In this investigation, we studied the effect of chain crystallizabilities, blend compositions, and cooling rates on cocrystallization during CEF and CRYSTAF analysis. Cocrystallization is more prevalent when the copolymer blend has components with similar crystallizabilities, one of the components is present in much higher amount, and fast cooling rates are used. CEF was found to provide better CCD estimates than CRYSTAF in a much shorter analysis time. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Construal level, rumination, and psychological distress in palliative care
Authors: Galfin John M. , Watkins Edward R.
Published: March 2011

Background

Patients with a life‐limiting illness, such as cancer, and their carers experience elevated psychological distress. However, the psychological mechanisms underpinning distress in palliative care have been little studied. Recent theories predict that individuals who experience increased uncertainty in the context of ongoing difficulties, such as palliative patients and their carers, will (a) think more abstractly; (b) ruminate more; and (c) be more distressed.

Methods

Palliative patients (n = 36, 90% with cancer), their carers (n = 29), and age‐matched controls (n = 30) completed standardized questionnaires to assess anxiety, depression, and rumination, and open‐ended interviews to identify their concerns and idiosyncratic levels of rumination. Concerns were analyzed linguistically for level of abstraction.

Results

As predicted, (i) palliative patients and carers reported significantly more uncertainty, rumination, and abstract thinking than controls; (ii) uncertainty, abstractness, and rumination were associated with psychological distress.

Conclusions

Abstraction and rumination are psychological mechanism potentially involved in increased psychological distress in palliative care.

Copyright © 2011 John Wiley & Sons, Ltd.
Conformational changes induced by ATP‐hydrolysis in an ABC transporter: A molecular dynamics study of the Sav1866 exporter
Authors: Oliveira A. Sofia , Baptista António M. , Soares Cláudio M.
Published: March 2011

ATP‐Binding Cassette (ABC) transporters are ubiquitous membrane proteins that use energy from ATP binding or/and hydrolysis to actively transport allocrites across membranes. In this study, we identify ATP‐hydrolysis induced conformational changes in a complete ABC exporter (Sav1866) from Staphylococcus aureaus, using molecular dynamics (MD) simulations. By performing MD simulations on the ATP and ADP+IP bound states, we identify the conformational consequences of hydrolysis, showing that the major rearrangements are not restricted to the NBDs, but extend to the transmembrane domains (TMDs) external regions. For the first time, to our knowledge, we see, within the context of a complete transporter, NBD dimer opening in the ADP+IP state in contrast with all ATP‐bound states. This opening results from the dissociation of the ABC signature motif from the nucleotide. In addition, in both states, we observe the opening of a gate entrance in the intracellular loop region leading to the exposure of the TMDs internal cavity to the cytoplasm. To see if this opening was large enough to allow allocrite transport, the adiabatic energy profile for doxorubicin passage was determined. For both states, this profile, although an approximation, is overall downhill from the cytoplasmatic to the extracellular side, and the local energy barriers along the TMDs are relatively small, evidencing the exporter nature of Sav1866. The major difference between states is an energy barrier located in the cytoplasmic gate region, which becomes reduced upon hydrolysis, suggesting that allocrite passage is facilitated, and evidencing a possible molecular mechanism for the active transport in these proteins. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Optimizing the wavelength response in one‐dimensional p‐Si Schottky barrier optical PSDs
Authors: Henry Jasmine , Livingstone John
Published: March 2011

This paper reports on the varying wavelength response of optical position detectors made of different Schottky barrier metals, titanium, tantalum and aluminium. The best sensitivities came from the titanium devices, followed by the tantalum devices and finally the aluminium devices. The most linear devices were fabricated from tantalum followed by aluminium and the worst from titanium. The devices responded well under low intensity LED illumination indicating that common and cheap light sources are suitable for producing strong linear responses in these PSDs. Long wavelength illumination usually produced the highest sensitivities, though this depended on the Schottky metal used. Titanium devices averaged an increase of 250% between the responses for short (480 nm) and long wavelength (873 nm) light. The corresponding increase for tantalum devices was 125% while it was 116% for aluminium devices.
Hole distribution in nitrogen‐doped TiO2 anatase nanoparticles
Authors: Li Hui , Lei Yinkai , Tu Rui , Zheng Yongping , Pan Chunxu , Xiao Wei
Published: March 2011

Hole distributions introduced by a N doping atom in N‐doped TiO2 anatase nanoparticles are studied with first principles calculations. A nitrogen atom substitutes an oxygen atom in a TiO2 nanoparticle and introduces a hole in the particle. The empty state may be on the top of the valence band or inside the band gap as an impurity band. If the empty state is on the top of the valence band, the hole mainly distributes on the nitrogen atom and the two dangling atoms. The empty states on the dangling oxygen atoms introduced by the nitrogen doping atom can activate the dangling oxygen atoms and increase their oxidation ability. For example, the dangling oxygen atoms may oxidize absorbed small toxic molecules. The summation of the empty states on the nitrogen atom and the two dangling oxygen atoms is close to a constant and which is about one half of the total empty state of the particle for most of the substitutional configurations. Nitrogen atom can also generate an impurity band inside the band gap. This impurity band can make the N‐doped anatase particle absorb the visible lights. Eventually, the photo‐catalytic properties of anatase particles may be changed by the N‐doping processes. Most of the dopant formation energies in the particles are lower than that in the bulk. So, nitrogen doping process maybe easier in the small particle sample than in the bulk materials.
Effect of crystallisation on the magnetic properties of FeCuNbBSi amorphous thin films produced by sputtering
Authors: Celegato Federica , Coisson Marco , Tiberto Paola , Vinai Franco , Baricco Marcello
Published: March 2011

Soft magnetic thin films of FeCuNbSiB alloy having different thickness were deposited on a Si3N4 substrate by rf sputtering. The target was made of amorphous ribbons having nominal composition Fe73.5Cu1Nb3Si13.5B9. The amorphicity of as‐deposited films has been checked by X‐ray diffraction technique. Selected samples have been submitted to controlled annealing to induce the amorphous‐to‐crystalline transformation. The influence of thermal treatments on the hysteresis properties has been studied as a function of thickness and microstructure on as prepared and annealed samples. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adiabatic nucleation in devitrifying “fragile” oxide glasses
Authors: Meyer Erich , Soares Vitorvani
Published: March 2011

A simple adiabatic nucleation theory predicts nucleation rates in “fragile” oxide glasses (T00/Tg > 0.6, where T00 is the Fulcher temperature and Tg is the glass transition temperature) with an average deviation of only nine orders of magnitude (too high) and shows (within this uncertainty) correctly which glasses present devitrification and which ones do not, in experiments during “laboratory times.” The theory could not yet be extended to “strong” glasses because of the very low Fulcher temperatures of these glasses (T00/Tg < 0.6), where the Stokes‐Einstein relation loses its validity completely and where viscosity extrapolations from above Tg get very uncertain. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strong Influence of Polymer Architecture on the Microstructural Evolution of Hafnium‐Alkoxide‐Modified Silazanes upon Ceramization
Authors: Papendorf Benjamin , Nonnenmacher Katharina , Ionescu Emanuel , Kleebe Hans‐Joachim , Riedel Ralf
Published: March 2011

The present study focuses on the synthesis and ceramization of novel hafnium‐alkoxide‐modified silazanes as well as on their microstructure evolution at high temperatures. The synthesis of hafnia‐modified polymer‐derived SiCN ceramic nanocomposites is performed via chemical modification of a polysilazane and of a cyclotrisilazane, followed by cross‐linking and pyrolysis in argon atmosphere. Spectroscopic investigation (i.e., NMR, FTIR, and Raman) shows that the hafnium alkoxide reacts with the N–H groups of the cyclotrisilazane; in the case of polysilazane, reactions of N–H as well as Si–H groups with the alkoxide are observed. Consequently, scanning and transmission electron microscopy studies reveal that the ceramic nanocomposites obtained from cyclotrisilazane and polysilazane exhibited markedly different microstructures, which is a result of the different reaction pathways of the hafnium alkoxide with cyclotrisilazane and with polysilazane. Furthermore, the two prepared ceramic nanocomposites are unexpectedly found to exhibit extremely different high‐temperature behavior with respect to decomposition and crystallization; this essential difference is found to be related to the different distribution of hafnium throughout the ceramic network in the two samples. Thus, the homogeneous distribution of hafnium observed in the polysilazane‐derived ceramic leads to an enhanced thermal stability with respect to decomposition, whereas the local enrichment of hafnium within the matrix of the cyclotrisilazane‐based sample induces a pronounced decomposition upon annealing at high temperatures. The results indicate that the chemistry and architecture of the precursor has a crucial effect on the microstructure of the resulting ceramic material and consequently on its high‐temperature behavior.
I‐Motif Nanospheres: Unusual Self‐Assembly of Long Cytosine Strands
Authors: Zikich Dragoslav , Liu Ke , Sagiv Lior , Porath Danny , Kotlyar Alexander
Published: March 2011

The synthesis and characterization of novel DNA structures based on tetraplex cytosine (C) arrangements, known as i‐motifs or i‐tetraplexes, is reported. Atomic force microscopy (AFM) investigation shows that long C‐strands in mild acidic conditions form compact spherically shaped nanostructures. The DNA nanospheres are characterized by a typical uniform shape and narrow height distribution. Electrostatic force microscopy (EFM) measurements performed on the i‐motif spheres clearly show their electrical polarizability. Further investigations by scanning tunneling microscopy (STM) at ultrahigh vacuum reveals that the structures exhibit an average voltage gap of 1.9 eV, which is narrower than the voltage gap previously measured for poly(dG)–poly(dC) molecules in similar conditions.
Survival After Liver Transplantation Using Hepatitis C Virus‐Positive Donor Allografts: Case‐Controlled Analysis of the UNOS Database
Authors: Burr Andrew T. , Li YouFu , Tseng Jennifer F. , Saidi Reza F. , Bozorgzadeh Adel , Shah Shimul A.
Published: March 2011

Background

Numerous reports have documented reduced graft and patient survival after use of hepatitis C (HCV) seropositive allografts in liver transplantation (OLT). We aimed to examine if the use of a HCV+ liver allograft affects patient and graft survivals compared to HCV− donor allografts in a case‐controlled analysis of the united network for organ sharing (UNOS) database.

Methods

We examined 63,149 liver transplants (61,905 donors HCV−; 1,244 donors HCV+) from the UNOS standard transplant analysis and research (STAR) file from 1987 to 2007. Donor and recipient demographics and outcomes were collected in which donor HCV serology was complete. A case‐controlled cohort from 11 donor and recipient variables comparing donor HCV− and HCV+ allografts (n = 540 in each group) was created using propensity scores with a matching algorithm. Graft and patient survival was estimated using Kaplan–Meier survival curves.

Results

Significant differences were evident in the unadjusted cohort between recipients who received HCV+ and HCV− allografts, including HCV+ recipients, donor and recipient age, and model for end‐stage liver disease (MELD) exception cases. Use of HCV+ allograft resulted in significantly lower graft survival (8.1 vs. 10.6 years; P = 0.001) and patient survival (10.2 vs. 12.3 years; P = 0.01) after OLT. In the matched cohort, HCV seropositivity had no detrimental effect on the graft (P = 0.57) or patient (P = 0.78) survival after OLT.

Conclusions

This is the first population‐based analysis to show that after adjusting for donor and recipient characteristics there was no difference in graft or patient survival with the use of HCV+ donor liver allografts compared to HCV− donor liver allografts.
Dynamic tuning of human withdrawal reflex receptive fields during cognitive attention and distraction tasks
Authors: Bjerre L. , Andersen A.T. , Hagelskjær M.T. , Ge N. , Mørch C.D. , Andersenl O.K.
Published: March 2011

Objectives: The aim of the present study was to investigate supraspinal modulation of human lower limb reflex receptive fields (RRFs) on the plantar side of the foot during cognitive tasks either distracting the subjects or actively directing their attention to the electrical stimuli directed to the sole of the foot.

Methods: Twelve healthy volunteers participated. Nociceptive withdrawal reflexes (NWRs) were recorded in the ankle flexor tibialis anterior. The RRF was acquired by randomized activation of ten stimulation sites on the sole of the foot. The RRF was assessed during baseline, distraction, and attention in randomized order. Distraction was induced by the Stroop test, while attention was induced by requiring the subjects to localize the site of the stimulation and thereby forcing them to focus on the sole of the foot.

Results: The area of the RRF was significantly enlarged during the distraction task compared to baseline (P <0.05), whereas the RRF area was significantly reduced during the attention task compared to baseline (P <0.05).

Conclusion: The size of the RRF area was modulated by the cognitive state demonstrating a link between the cognitive activity and the descending control on spinal withdrawal reflex pathways.
Decision Quality Measures in Recommendation Agents Research
Authors: Aksoy Lerzan , Cooil Bruce , Lurie Nicholas H.
Published: March 2011

Electronic recommendation agents provide a way for online marketers to gather information about consumer preferences and assess the quality of consumer decisions. Much of the literature on recommendation agents, however, employs divergent measures to assess consumer decision quality. Moreover, decision quality measures are dictated by the type of agent employed. This article provides a review of the decision quality measures used in the recommendation agent research to date and proposes novel measures. We classify and examine the assumptions of–and relationships among–preference-dependent, preference-independent, and subjective measures of decision quality. The analysis of data from an experiment that simulates a broad spectrum of recommendation agents shows that the relative utility and the sum of attribute values of the chosen alternative capture the majority of variance in objective decision quality. Although subjective decision quality measures turn out to be poor proxies for objective measures, they provide important incremental information. Managerial implications for deploying electronic recommendation agents to gather information and measure consumer decision quality under different conditions are discussed.
Focus as emphasis: Conceptual and performance implications for hospitals
Authors: McDermott Christopher M. , Stock Gregory N.
Published: March 2011

Focus in hospitals has been heralded as the next frontier in improving its efficiency and efficacy (Herzlinger, 2004). However, there is scarce empirical work examining its effects in this setting. Focus in hospitals can take several different forms, ranging from standalone specialty centers to a hospital that chooses to emphasize in some operational way a particular specialty while still offering a full range of services. Although standalone facilities can be found in many locations, the vast majority of hospitals must follow the latter route to achieve focus. Current conceptualizations and measures of focus struggle to capture this construct in a way that does not assume a narrowing of range of offerings. In contrast to the traditional view of focus as narrowing, in this paper, we address the perspective of focus as emphasis. We select cardiology as the specialty and use secondary data for more than 264,000 patients in New York State to examine the relationship between focus as emphasis and hospital cost performance. Our results support the notion that such focus is associated with lower costs. Moreover, our results also show that focus in hospitals can be operationalized as a disproportionate emphasis on one line of service, without necessarily narrowing the overall range of services provided.
Effects of water quality and trophic status on helminth infections in the cyprinid fish,Schizothorax nigerHeckel, 1838 from three lakes in the Kashmir Himalayas
Authors: Zargar U.R. , Yousuf A.R. , Chishti M.Z. , Ahmed F. , Bashir H. , Ahmed F.
Published: March 2011

Water quality greatly influences the population density of aquatic biota, including parasites. In order to evaluate the relationship between fish parasites and water quality in Kashmir Himalayas, we assessed helminth parasite densities inSchizothorax nigerHeckel, 1838 (an endemic cyprinid fish of Kashmir) from three lakes, namely Anchar, Manasbal and Dal, which reflected the varied stages of eutrophication. The overall prevalence of helminth infections was higher in the hypertrophic Anchar Lake (prevalence = 18.6%) compared to Manasbal Lake, which was the least eutrophied (prevalence = 6.4%). Furthermore, mean prevalence of monoxenous and heteroxenous parasites was higher in lakes containing higher levels of water degradation (Anchar and Dal). The mean number of helminth species per fish host was the highest in the hypertrophic lake (1.3 ± 0.3) in comparison to the least eutrophic lake (0.2 ± 1.5). Variability of calculated infection indices (prevalence, mean intensity and mean abundance) revealed that helminth parasite composition in the fish was affected by the lakes' environmental stress (degraded water quality). Therefore, data on the density of helminth parasites in fish can provide supplementary information on the pollution status of a water body.
Age and growth of the snowy grouper,Epinephelus niveatus, off the Brazilian coast
Authors: Costa Paulo A.S. , Braga Adriana C. , Rubinich Juan P. , Ávila-da-Silva Antônio Olinto , Neto Cassiano M.
Published: March 2011

The age and growth of the snowy grouper,Epinephelus niveatus, from central and south-eastern Brazil were studied by otolith analysis from a sample of 341 specimens, ranging from 325 to 1216 mm in total length (TL) caught with bottom longlines between 1996 and 1998. Otolith length grew proportionally with the increasing TL of the fish. Marginal increment analysis indicated that a single opaque band forms each year during autumn–winter. The maximum estimated age was 54 years, which significantly extends the previously estimated life-span of 21–29 years for this species. The von Bertalanffy growth parameters for both sexes were estimated as L∞ = 1098.4 mm TL, K = 0.062 year−1and t0 = –2.68. The study revealed differences in mean length-at-age and size at recruitment, as well as in growth parameters between the central and the south-eastern Brazilian coast, which can be attributed mainly to different fishing pressures. The snowy grouper was found at depths of 82–492 m, and showed a positive relationship between age and depth, suggesting differential movements of older fish to deeper waters.
Evaluation of fixatives and autofluorescence reduction treatments for marine bivalve larvae
Authors: Heaney S.A. , Maloy A.P. , Slater J.W.
Published: March 2011

Improved understanding of the occurrence and spatio-temporal distribution of bivalve larvae holds significant benefits for ecological studies, shellfisheries management and aquaculture. Morphological methods for identification have proved difficult to develop because of the small size of these larvae and similarities in their shape and colour. Molecular methods based on DNA extraction can confirm the presence of a species in a plankton sample, but without sample sorting and individual larval analysis, provide no estimate of larval abundance and are incapable of providing an estimate of larval growth rate. Fluorescencein situhybridization (FISH) using species-specific DNA probes has the potential to resolve these issues. However, utilization of this technique is constrained by the strong autofluorescence, common in marine larvae. Here we evaluate the effect of eight different fixatives on the autofluorescence intensity of bivalve larvae using fluorescein isothiocyanate (FITC) and Cy3 filters. In addition, fifteen autofluorescence reduction treatments were evaluated and their compatibility with FISH assessed. Relative to fresh larvae, chemically fixed larvae had significantly higher autofluorescence in both filter sets. Larvae preserved by freezing at –80°C exhibited no significant increase in autofluorescence over a 3-year period. Autofluorescence levels were generally lower with the FITC filter set than the Cy3 filter set. For archived larvae preserved in modified saline ethanol and exhibiting fixative-induced autofluorescence, the autofluorescence intensity could be reduced to 20–30% with saturated Sudan Black B and to 30–40% with Chemicon™. Both of these autofluorescence reduction treatments were compatible with subsequent FISH protocols using a FITC-labelled probe.
Latent class analysis of co-morbidity in the Adult Psychiatric Morbidity Survey in England 2007: implications for DSM-5 and ICD-11
Authors: Weich S. , McBride O. , Hussey D. , Exeter D. , Brugha T. , McManus S.
Published: March 2011

Background

Psychiatric co-morbidity is complex and ubiquitous. Our aim was to describe the extent, nature and patterning of psychiatric co-morbidity within a representative sample of the adult population of England, using latent class analysis.

Method

Data were used from the 2007 Adult Psychiatric Morbidity Survey, a two-phase national household survey undertaken in 2007 comprising 7325 participants aged 16 years and older living in private households in England. The presence of 15 common mental health and behavioural problems was ascertained using standardized clinical and validated self-report measures, including three anxiety disorders, depressive episode, mixed anxiety depressive disorder, psychosis, antisocial and borderline personality disorders, eating disorders, post-traumatic stress disorder, attention deficit disorder, alcohol and drug dependencies, problem gambling and attempted suicide.

Results

A four-class model provided the most parsimonious and informative explanation of the data. Most participants (81.6%) were assigned to a non-symptomatic or ‘Unaffected’ class. The remainder were classified into three qualitatively different symptomatic classes: ‘Co-thymia’ (12.4%), ‘Highly Co-morbid’ (5.0%) and ‘Addictions’ (1.0%). Classes differed in mean numbers of conditions and impairments in social functioning, and these dimensions were correlated.

Conclusions

Our findings confirm that mental disorders typically co-occur and are concentrated in a relatively small number of individuals. Conditions associated with the highest levels of disability, mortality and cost – psychosis, suicidality and personality disorders – are often co-morbid with more common conditions. This needs to be recognized when planning services and when considering aetiology.
INFLATION AND GROWTH IN THE LONG RUN: A NEW KEYNESIAN THEORY AND FURTHER SEMIPARAMETRIC EVIDENCE
Authors: Vaona Andrea
Published: March 2011

This paper explores the influence of inflation on economic growth both theoretically and empirically. We propose to merge an endogenous growth model of learning by doing with a New Keynesian one with sticky wages. We show that the intertemporal elasticity of substitution of working time is a key parameter for the shape of the inflation–growth nexus. When it is set equal to zero, the inflation–growth nexus is weak and hump-shaped. When it is greater than zero, inflation has a sizable and negative effect on growth. Endogenizing the length of wage contracts does not lead to inflation superneutrality in the presence of a fixed cost of wage resetting. Adopting various semiparametric and instrumental-variable estimation approaches on a cross-country/time-series data set, we show that increasing inflation reduces real economic growth, consistent with our theoretical model with a positive intertemporal elasticity of substitution of working time.
A dominant connexin43 mutant does not have dominant effects on gap junction coupling in astrocytes
Authors: Wasseff Sameh , Abrams Charles K. , Scherer Steven S.
Published: March 2011

Dominant mutations in GJA1, the gene encoding the gap junction protein connexin43 (Cx43), cause oculodentodigital dysplasia (ODDD), a syndrome affecting multiple tissues, including the central nervous system (CNS). We investigated the effects of the G60S mutant, which causes a similar, dominant phenotype in mice (Gja1Jrt/+). Astrocytes in acute brain slices from Gja1Jrt/+ mice transfer sulforhodamine-B comparably to that in their wild-type (WT) littermates. Further, astrocytes and cardiomyocytes cultured from Gja1Jrt/+ mice showed a comparable transfer of lucifer yellow to those from WT mice. In transfected cells, the G60S mutant formed gap junction (GJ) plaques but not functional channels. In co-transfected cells, the G60S mutant co-immunoprecipitated with WT Cx43, but did not diminish GJ coupling as measured by dual patch clamp. Thus, whereas G60S has dominant effects, it did not appreciably reduce GJ coupling.
Improving and Facilitating Research on Collapse Calderas
Authors: Aguirre‐Diaz Gerardo , Geyer Adelina , Martí Joan , Acocella Valerio
Published: March 2011

Roughly circular depressions known as calderas are distinctive features in volcanic areas (see Figure 1). Current views explain a caldera as the surface expression of a magma chamber's collapsed roof after magma drains elsewhere. Although not all calderas are associated with explosive activity, most major eruptions (i.e., those with a volcanic explosivity index of 5 or higher) develop such collapse calderas. Calderas are usually associated with magmatic systems that have endured for thousands of years at least. These systems undergo periods of unrest highlighted by ground displacement, seismicity, and gas emissions. As a consequence, calderas are some of the most studied volcanic features, particularly for their possible implications for hazard assessment and mitigation. In addition, calderas can be associated with geothermal and ore resources and can affect climate through the products they emit.
New High‐Resolution Images of Summer Arctic Sea Ice
Authors: Kwok Ronald , Untersteiner Norbert
Published: March 2011

In 1995 a group of government and academic scientists were appointed by the vice president of the United States to review and advise on acquisitions of imagery obtained by classified intelligence satellites (National Technical Means) and to recommend the declassification of certain data sets for the benefit of science. The group is called MEDEA and was first described by Richelson [1998]. MEDEA disbanded in 2000 but reassembled in 2008. On 15 June 2009, under the auspices of MEDEA, the U.S. Geological Survey (USGS) released to the public as Literal Image Derived Products (LIDPs) numerous images with 1‐meter resolution acquired since 1999 at six locations in the Arctic Basin (Beaufort Sea, Canadian Arctic, Fram Strait, East Siberian Sea, Chukchi Sea, and Point Barrow). These locations are named “fiducial sites” to suggest that the collected imagery establishes a baseline data set for understanding recent and future changes. Data in the Global Fiducials Library (GFL) can be accessed via http://gfl.usgs.gov/. This data repository is updated by USGS as additional data become available.
Otherworldly Earths: The Future of Deep Time Research
Authors: Jahren A. Hope , Bottjer David J. , Erwin Douglas H. , Smith Dena M. , Norris Richard D.
Published: March 2011

Once a week, Eos brings to the Earth and space science community new views of Earth, and often this message contains reports of a warming Arctic, rising sea level, organisms and ecosystems in flux, changing atmospheric composition, and other processes that are driving us to an increasingly foreign Earth system. However, as geoscientists we know that the Earth today—of the past few thousand years—is only one state of how the Earth works. Within rock, ice, and seafloor, the residua of long‐gone (and often very different) times serendipitously linger. The Deep Time Earth‐Life Observatory Network (DETELON) initiative, which aims to study these long‐gone times, defines deep time as the 99.94% of the Earth's history that preceded the current ice age (which began about 2.6 million years ago) and configured the climate and biota of the Earth before extensive human impacts. Within this time is the vast majority of what the Earth has been and what it can be, including not only novel Earth systems (e.g., tropical forests without flowers) but also analogs for anthropogenic climate change (e.g., rapid atmospheric carbon dioxide (CO2) rise) and extraterrestrial ecosystems (e.g., a planet inhabited only by microbes).
Students, Scientists, and Family Commemorate the Life and Diverse Works of Jack Eddy
Authors: Judge Philip
Published: March 2011

Eddy Cross‐Disciplinary Symposium on Sun‐Climate Research; Aspen, Colorado, 22–24 October 2010; In 1976, John Allen Eddy published a seminal article (see Science, 192(4245), 1189–1202) revealing a link between the Little Ice Age, which occurred during the sixteenth through nineteenth centuries, and a period of low sunspot activity, which Eddy called the “Maunder Minimum.” This work placed Sun‐climate research on a firm scientific footing. Eddy passed away on 10 June 2009. Following Eddy's passions for education and cross‐disciplinary research, a symposium was held to expose talented college students to the science and politics of Sun‐climate research. Funding from NASA's Living With a Star Targeted Research and Technology program and from the High Altitude Observatory, Advanced Study Program, and Integrated Science Program of the National Center for Atmospheric Research (NCAR) supported keynote speakers and provided scholarships for 30 students (junior year to Ph.D.) from diverse disciplines. Eddy's wife, Barbara, led a session devoted to personal recollections. Spencer Weart (American Institute of Physics) gave an after‐dinner tribute using recordings of Eddy from a 1999 interview.
Ill health unleashed? Cities and municipal services in Ghana
Authors: Obeng-Odoom Franklin
Published: March 2011

Increasing urbanisation, wealth and ill health in cities necessitate careful study, especially in African cities whose development is widely regarded as rapid and chaotic. Using Ghanaian cities as a case study, this article analyses some of the important sources of ill health, identifies why they persist, and assesses how they impinge on economic growth, redistribution, and poverty reduction. It argues that, although there is considerable evidence that policy change is urgently needed, the tensions and contradictions between economic and social efficiency, intermeshed with vested political interests, are likely to impede significant changes to the status quo.
Giving students voice as a strategy for improving teacher practice
Authors: Ferguson Dianne L. , Hanreddy Amy , Draxton Shawna
Published: March 2011

This study used a semi-structured interview tool with elementary students in an inclusive charter school in a western state in the United States. Students with and without disabilities were asked to comment on their participation in their classroom and their perceptions of the classroom
climate in order to begin a dialogue with their teachers that would lead to more participation in decision-making. Compiled data from the interviews were shared with teachers who were then interviewed about their analysis and use of the data for making improvements to their classroom environment
and approach to pedagogy. Teacher responses were analysed for trends and actions taken following the feedback. Teachers concluded that the data were helpful and committed to use the tool regularly in the future to foster ongoing conversations with their students. They used the information
from their students to make changes in the classroom climate, in their own teaching practices, and in the content of what they were teaching. Implications for expanding upon the use of the tool in the future to promote greater dialogue between teachers and students are discussed.
The stability of social relations among adolescents with special educational needs (SEN) in regular schools in Norway
Authors: Frostad Per , Mjaavatn Per Egil , Pijl Sip Jan
Published: March 2011

The study focuses the stability of friendships of students with special educational needs in regular schools, compared to regular students. The sample consisted of 114 students (M age = 14,4); 22 students (19.3%) were identified by the school as SEN students. The results show that on
average, SEN students had fewer stable friendships than their peers. Further, a significantly lower proportion of SEN students were members of stable groups compared to regular students. Friendship stability was positively predicted by gender (boys more stable than girls) and perceived friend
support. Friendship stability was negatively predicted by special needs (special needs predicted lower friend stability) and peer acceptance.
Getting personal – what does it mean? A critical discussion of the personal dimension of thesis supervision in higher education
Authors: Bengtsen Søren S.E.
Published: March 2011

The argument of the article is that contemporary research into thesis supervision overlooks important didactical features of the supervisory dialogue because of its focus on general pedagogical categories. Entailing this argument I suggest that the personal dimension should be seen
not only as a means to enhanced communication between supervisor and supervisee but as a way of manifesting personalised subject knowledge. As its point of departure the article gives a treatment of different understandings of the personal dimension in thesis supervision in contemporary research
in Scandinavia and Britain. Subsequently these lines of research are contrasted with views on personality and professionalism found in prominent Danish and British research into the so-called ontological turn in higher education.
Kindness in the art classroom: kind thoughts on Stephen Rowland
Authors: Lampert Nancy
Published: March 2011

This article is a response to Stephen Rowland's article, Kindness, which appeared in London Review of Education, November 2009. Much to my amazement, Stephen Rowland's article was the only one I found when I did a global database search on 'kindness in education'. I had
thought that I would find reams of information in the databases on the topic that I had wanted to write about. So I am grateful for the depth of information provided in Kindness; it led the way for this, my own article on 'kindness in education'.
Fourier expansions for Apostol-Bernoulli, Apostol-Euler and Apostol-Genocchi polynomials
Authors: Bayad A.
Published: March 2011

We find Fourier expansions of Apostol-Bernoulli, Apostol-Euler and Apostol-Genocchi polynomials. We give a very simple proof of them.
Physics and control of wall turbulence for drag reduction
Authors: Kim John
Published: March 2011

Turbulence physics responsible for high skin-friction drag in turbulent boundary layers is first reviewed. A self-sustaining process of near-wall turbulence structures is then discussed from the perspective of controlling this process for the purpose of skin-friction drag reduction. After recognizing that key parts of this self-sustaining process are linear, a linear systems approach to boundary-layer control is discussed. It is shown that singular-value decomposition analysis of the linear system allows us to examine different approaches to boundary-layer control without carrying out the expensive nonlinear simulations. Results from the linear analysis are consistent with those observed in full nonlinear simulations, thus demonstrating the validity of the linear analysis. Finally, fundamental performance limit expected of optimal control input is discussed.
Active Learning via Multi-View and Local Proximity Co-Regularization for Hyperspectral Image Classification
Authors: Di Wei , Crawford Melba M.
Published: March 2011

A novel co-regularization framework for active learning is proposed for hyperspectral image classification. The first regularizer explores the intrinsic multi-view information embedded in the hyperspectral data. By adaptively and quantitatively measuring the disagreement level, it focuses only on samples with high uncertainty and builds a contention pool which is a small subset of the overall unlabeled data pool, thereby mitigating the computational cost. The second regularizer is based on the “consistency assumption” and designed on a spatial or the spectral based manifold space. It serves to further focus on the most informative samples within the contention pool by penalizing rapid changes in the classification function evaluated on proximally close samples in a local region. Such changes may be due to the lack of capability of the current learner to describe the unlabeled data. Incorporating manifold learning into the active learning process enforces the clustering assumption and avoids the degradation of the distance measure associated with the original high-dimensional spectral features. One spatial and two local spectral embedding methods are considered in this study, in conjunction with the support vector machine (SVM) classifier implemented with a radial basis function (RBF) kernel. Experiments show excellent performance on AVIRIS and Hyperion hyperspectral data as compared to random sampling and the state-of-the-art SVMSIMPLE.
Does readiness to change predict in‐session motivational language? Correspondence between two conceptualizations of client motivation
Authors: Hallgren Kevin A. , Moyers Theresa B.
Published: March 2011

Aims  Client language reflecting motivation for changing substance use (i.e. change talk) has been shown to predict outcomes in motivational interviewing. While previous work has shown that change talk may be elicited by clinician behaviors, little is known about intrapersonal factors that may elicit change talk, including clients' baseline motivation for change. The present study tested whether in‐session change talk differs between clients based on their readiness for change.

Design and setting  First‐session audio recordings from Project MATCH, a large multi‐site clinical trial of alcohol treatments.

Participants  Project MATCH out‐patients (n = 69) and aftercare patients (n = 48) receiving motivational enhancement therapy (MET).

Measurements  Client language from first‐session MET was coded using the Sequential Code for Observing Process Exchanges. Readiness and stages of change were assessed using both categorical and dimensional variables derived from the University of Rhode Island Change Assessment and the Stages of Change Readiness and Treatment Eagerness Scale, administered prior to first treatment sessions.

Findings  Stage of change scales followed some of the expected correspondence with change talk, although the associations were generally small in magnitude and inconsistent across measures and treatment arms. Higher overall readiness did not predict more overall change talk, contemplation had mixed associations with preparatory change talk, and preparation/action did not predict commitment language.

Conclusions  Motivational language used in initial sessions by people receiving counselling for excessive alcohol consumption does not appear to be associated with readiness to change as construed by the Transtheoretical Model.
Histone H4 acetylation by immunohistochemistry and prognosis in relapsed acute lymphocytic leukaemia (ALL)
Authors: Advani Anjali S. , Gibson Sarah , Douglas Elizabeth , Diacovo Julia , Elson Paul , Kalaycio Matt , Copelan Ed , Sekeres Mikkael , Sobecks Ronald , Sungren Shawnda , Lagoo Anand , Rizzieri David , Hsi Eric
Published: March 2011

Histone H4 acetylation was examined by immunohistochemistry in patients with acute lymphocytic leukaemia (ALL) in first relapse. Univariate and multivariate models identified correlates of complete remission (CR) and overall survival (OS). No variables were associated with achievement of CR. In multivariate analysis, weak histone H4 acetylation [Hazard Ratio (HR) 2·20, 95% confidence interval (CI) 0·93–5·23, P = 0·07], shorter interval from diagnosis to relapse (<9 vs. 9–24 vs. >24 months) (HR 1·82, 95% CI 1·20–2·75, P = 0·005), and central nervous system involvement (HR 3·43, 95% CI 1·31–8·99, P = 0·01) were independent poor prognostic factors for OS. These data provide a rationale for the use of histone deacetylase inhibitors in the treatment of relapsed ALL.
Fairy tales: a compass for children's healthy development – a qualitative study in a Greek island
Authors: Tsitsani P. , Psyllidou S. , Batzios S. P. , Livas S. , Ouranos M. , Cassimos D.
Published: March 2011

Background  Fairy tales have always been an integrated part of children's everyday life. In our days, they still represent important ways of helping the children share their desires and express their agonies and inner conflicts. The present descriptive qualitative study aims to describe parents' opinions and children's preferences regarding storytelling.

Methods  Four hundred and seventy parents took part in the study and were interviewed following a semi‐structured guide with open‐ended trigger questions. Data were processed via content analysis methods.

Results  Three main themes were constructed. The vast majority of interviewees acknowledged their strong belief in the power of fairy tales and stated that their children listen to stories at least once a week. Most of them use storytelling as an instructive tool, in order to soothe their children's anxieties or set examples for them. Concerning children's preferences, the majority of them choose classic fairy tales over modern ones with Little Red Riding Hood taking precedence over other famous stories. All participants acknowledged the fact that their children are amused and positively affected by storytelling, while young readers share their enthusiasm for fairy tales in many ways, mostly by talking about their favourite character. Finally, in relation to the villains, children seem to be satisfied or relieved when they are punished and only a small number of participants stated that the cruel punishment of bad characters creates feelings of fear to their kids.

Conclusions  The findings of this study emphasize the crucial role that storytelling plays in children's life and normal development.