bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and applications of a new neutron single-crystal diffractometer based on a two-dimensional large-area curved position-sensitive detector
Authors: Lee Chang-Hee , Noda Yukio , Ishikawa Yoshihisa , Kim Shin Ae , Moon Myungkook , Kimura Hiroyuki , Watanabe Masashi , Dohi Yuki
Published: May 2013

A new single-crystal neutron diffractometer based on a large-area curved two-dimensional position-sensitive detector (C-2DPSD) has been developed. The diffractometer commissioning is almost complete, together with development of the measurement methodology and the raw data processing software package, theReciprocal Analyzer, and the instrument is now ready to be launched for users. Position decoding of the C-2DPSD isviaa delay-line readout method with an effective angular range of 110 × 54° in the horizontal and vertical directions, respectively, with a nominal radius of curvature of 530 mm. The diffractometer is equipped with a Ge(311) mosaic monochromator and two supermirror vacuum guide paths, one before and one after the monochromator position. The commissioning incorporates corrections and calibration of the instrument using an NaCl crystal, various applications such as crystallographic and magnetic structure measurements, a crystallinity check on large crystals, and a study on the composition or dopant content of a mixed crystal of (TmxYb1−x)Mn2O5. The installation of the diffractometer and the measurement method, the calibration procedure and results, the raw data treatment and visualization, and several applications using the large C-2DPSD-based diffractometer are reported.
Low-temperature Debye–Scherrer powder diffraction on Beamline I11 at Diamond
Authors: Potter J. , Parker J. E. , Lennie A. R. , Thompson S. P. , Tang C. C.
Published: May 2013

A bespoke capillary sample holder is described that attaches to the cold head of a commercially manufactured (PheniX) closed-cycle helium cryostat originally intended for flat-plate geometry. The new holder allows high-resolution synchrotron powder diffraction data to be collected from samples in Debye–Scherrer geometry over the temperature range 11–295 K. To demonstrate that high-quality powder data can be obtained using this new sample holder, structural refinement (Rietveld) and thermal expansion results measured from reference samples (Si and Al) are presented.
Analytical model for neutron diffraction peak shifts due to the surface effect
Authors: Šaroun Jan , Kornmeier Joana Rebelo , Hofmann Michael , Mikula Pavol , Vrána Miroslav
Published: May 2013

Residual strains measured by neutron diffraction near sample boundaries can be biased by the surface effect as a result of incomplete filling of the instrumental gauge volume. This effect is manifested as anomalous shifts of diffraction lines, which can be falsely interpreted as a lattice strain unless appropriate data corrections are made. A new analytical model for the surface effect has been developed, which covers a broad variety of instrumental arrangements, including flat mosaic and bent perfect crystal monochromators, narrow slits, and Soller and radial collimators. This model permits the spurious peak shifts to be predicted quantitatively, and also allows the optimum configuration parameters, such as curvature of a focusing monochromator, which lead to suppression of the surface effect, to be calculated. The model has been thoroughly validated by comparisons with Monte Carlo simulations and experiments on a stress-free calibration sample. Predictions of the model proved to be very accurate, often within the interval of experimental errors, which makes it suitable for use in data analysis.
Sin2ψ-based residual stress gradient analysis by energy-dispersive synchrotron diffraction constrained by small gauge volumes. I. Theoretical concept
Authors: Meixner M. , Klaus M. , Genzel Ch.
Published: May 2013

The influence of the gauge volume size and shape on the analysis of steep near-surface residual stress gradients by means of energy-dispersive synchrotron diffraction is studied theoretically. Cases are considered where the irradiated sample volume is confined by narrow-slit systems, in both the primary and the diffracted beam, to dimensions comparable to the `natural' 1/einformation depth τ1/eof the X-rays. It is shown that the ratio between τ1/e, defined by the material's absorption, and the immersion depthhGVof the gauge volume into the sample is the crucial parameter that shapes thedψhklor ∊ψhklversussin2ψ distributions obtained in the Ψ mode of X-ray stress analysis. Since the actual information depth 〈z〉GVto which the measured X-ray signal has to be assigned is a superposition of geometrical and exponential weighting functions, ambiguities in the conventional plot of the Laplace stressesversus〈z〉GVmay occur for measurements performed using narrow-slit configurations. To avoid conflicts in data analysis in these cases, a modified formalism is proposed for the evaluation of the real space residual stress profiles σ||(z), which is based on a two-dimensional least-squares fit procedure.
Twiny: from morphology to twin element andvice versa
Authors: Nespolo Massimo , Iordache Cristian
Published: May 2013

Twinyis a small Fortran program for identification or confirmation of the twin element from the morphological analysis of twins. It takes as input the twin element and computes the angle between corresponding [uvw] directions in two individuals of the twin: the result can be used by the investigator to confirm or invalidate the supposed twin element.Twinyalso accepts as input the angle measured on the sample and computes all possible twin elements compatible with this angle: the result helps the investigator to identify the twin element before any attempt to unravel the diffraction pattern of a twin.
Resonant scattering and diffraction beamline P09 at PETRA III
Authors: Strempfer J. , Francoual S. , Reuther D. , Shukla D. K. , Skaugen A. , Schulte-Schrepping H. , Kracht T. , Franz H.
Published: May 2013

The resonant scattering and diffraction beamline P09 at PETRA III is designed for X-ray experiments requiring small beams, energy tunability, variable polarization and high photon flux. It is highly flexible in terms of beam size and offers full higher harmonic suppression. A state-of-the-art double phase-retarder set-up provides variable linear or circular polarization. A high-precision Psi-diffractometer and a heavy-load diffractometer in horizontal Psi-geometry allow the accommodation of a wide variety of sample environments. A 14 T cryo-magnet is available for scattering experiments in magnetic fields.
Investigation of non-corrin cobalt(II)-containing sites in protein structures of the Protein Data Bank
Authors: Abriata Luciano Andres
Published: May 2013

Protein X-ray structures with non-corrin cobalt(II)-containing sites, either natural or substituting another native ion, were downloaded from the Protein Data Bank and explored to (i) describe which amino acids are involved in their first ligand shells and (ii) analyze cobalt(II)–donor bond lengths in comparison with previously reported target distances, CSD data and EXAFS data. The set of amino acids involved in CoIIbinding is similar to that observed for catalytic ZnIIsites,i.e.with a large fraction of carboxylate O atoms from aspartate and glutamate and aromatic N atoms from histidine. The computed CoII–donor bond lengths were found to depend strongly on structure resolution, an artifact previously detected for other metal–donor distances. Small corrections are suggested for the target bond lengths to the aromatic N atoms of histidines and the O atoms of water and hydroxide. The available target distance for cysteine (Scys) is confirmed; those for backbone O and other donors remain uncertain and should be handled with caution in refinement and modeling protocols. Finally, a relationship between both CoII—O bond lengths in bidentate carboxylates is quantified.
The importance of proper crystal-chemical and geometrical reasoning demonstrated using layered single and double hydroxides
Authors: Richardson Ian G.
Published: May 2013

Atomistic modelling techniques and Rietveld refinement of X-ray powder diffraction data are widely used but often result in crystal structures that are not realistic, presumably because the authors neglect to check the crystal-chemical plausibility of their structure. The purpose of this paper is to reinforce the importance and utility of proper crystal-chemical and geometrical reasoning in structural studies. It is achieved by using such reasoning to generate new yet fundamental information about layered double hydroxides (LDH), a large, much-studied family of compounds. LDH phases are derived from layered single hydroxides by the substitution of a fraction (x) of the divalent cations by trivalent. Equations are derived that enable calculation ofxfrom theaparameter of the unit cell andvice versa, which can be expected to be of widespread utility as a sanity test for extant and future structure determinations and computer simulation studies. The phase atx= 0 is shown to be an α form of divalent metal hydroxide rather than the β polymorph. Crystal-chemically sensible model structures are provided for β-Zn(OH)2and Ni- and Mg-based carbonate LDH phases that have any trivalent cation and any value ofx, includingx= 0 [i.e.for α-M(OH)2·mH2O phases].
Learning through work: emerging perspectives and new challenges
Authors: Billett Stephen , Choy Sarojni
Published: May 2013

Purpose

This paper aims to consider and appraise current developments and emerging perspectives on learning in the circumstances of work, to propose how some of the challenges for securing effective workplace learning may be redressed.

Design/methodology/approach

First, new challenges and perspectives on learning in the circumstances of work are summarised. Then, three key emerging concepts are reviewed. These are: changes in requirements of work; conceptual understandings about the processes of learning; and more elaborated views about the relations between the social and personal attributes. The procedural contributions of learning to improve learning for occupations, and employability and working life are also appraised.

Findings

The authors suggest that current conceptual and procedural understandings of learning in the workplace, informed by fields of cognitive science, and learning and development are limited because learning in the workplace is multimodal and complex, considering the socio‐cultural nature and boundaries that influence learning in multiple ways.

Research limitations/implications

The appraisal here draws knowledge from the education discipline, yet there is a need to reach out to other fields to extend understandings and develop appropriate responses to emerging perspectives and new challenges.

Practical implications

A broader understanding of the workplace learning environment will assist those responsible for organising learning in the workplace and worker‐ learners to facilitate and engage in learning for transformations in work practices and meet changing performance requirements.

Originality/value

The authors advocate an extension to different disciplines such as anthropology and neurological science to broaden understandings about the potential of the workplace as a learning environment for novice as well as experienced workers.
Development of Streptococcus gordonii‐specific quantitative real‐time polymerase chain reaction primers based on the nucleotide sequence of rpoB
Authors: Park Soon‐Nang , Kook Joong‐Ki
Published: May 2013

In this study, Streptococcus gordonii‐specific quantitative real‐time polymerase chain reaction (qPCR) primers, RTSgo‐F2/RTSgo‐R2, were developed based on the nucleotide sequences of RNA polymerase β‐subunit gene (rpoB). The specificity of the RTSgo‐F2/RTSgo‐R2 primers was assessed by conventional PCR on 99 strains comprising 63 oral bacterial species, including the type strain and eight clinical isolates of S. gordonii. PCR products were amplified from the genomic DNAs of only S. gordonii strains. The qPCR primers were able to detect as little as 40 fg of S. gordonii genomic DNA at a cycle threshold value of 33. These findings suggest that these qPCR primers detect S. gordonii with high specificity and sensitivity.
‘We're here to get you sorted’: parental perceptions of the purpose, progression and outcomes of family therapy
Authors: O'Reilly Michelle
Published: May 2013

This article reports research on family therapy interactions. The research uses discourse analysis to explore the ways in which parents construct their reasons for requiring family therapy, the outcomes they desire from it and orientations to their progress. The analysis suggests that parents often position their child as the problem and this is something that is rarely challenged or questioned by the child. Parents express a desired outcome of ‘fixing’ the child and highlight this as what they believe the purpose of family therapy to be. During therapy they emphasize their progression and consider improvements in family functioning. By understanding parental perceptions we can move research forward in understanding engagement in therapy and attrition, and integrate guidelines on service improvements with what parents feel is beneficial.

Practitioner points

Parents manage their presence in family therapy in many ways and typically position the child as the reason for their attendance.

Offering the child some time alone with the therapist has potential to uncover the child's perspectives on goals and outcomes which may be inhibited by parental presence.

Anticipating that the child may be described in derogatory or negative ways at the start can help the therapist to reframe the problem in more helpful ways.
Repeated Cycles of Binge‐Like Ethanol (EtOH)‐Drinking in Male C57BL/6J Mice Augments Subsequent Voluntary EtOH Intake But Not Other Dependence‐Like Phenotypes
Authors: Cox Benjamin R. , Olney Jeffrey J. , Lowery‐Gionta Emily G. , Sprow Gretchen M. , Rinker Jennifer A. , Navarro Montserrat , Kash Thomas L. , Thiele Todd E.
Published: May 2013

Background

Recently, procedures have been developed to model specific facets of human alcohol abuse disorders, including those that model excessive binge‐like drinking (i.e., “drinking‐in‐the‐dark,” or DID procedures) and excessive dependence‐like drinking (i.e., intermittent ethanol [EtOH] vapor exposure). Similar neuropeptide systems modulate excessive EtOH drinking stemming from both procedures, raising the possibility that both paradigms are actually modeling the same phenotypes and triggering the same central neuroplasticity. Therefore, the goal of this present project was to study the effects of a history of binge‐like EtOH drinking, using DID procedures, on phenotypes that have previously been described with procedures to model dependence‐like drinking.

Methods

Male C57BL/6J mice first experienced 0 to 10 four‐day binge‐like drinking episodes (3 days of rest between episodes). Beginning 24 hours after the final binge‐like drinking session, mice were tested for anxiety‐like behaviors (with elevated plus maze [EPM] and open‐field locomotor activity tests), ataxia with the rotarod test, and sensitivity to handling‐induced convulsions (HICs). One week later, mice began a 40‐day 2‐bottle (water vs. EtOH) voluntary consumption test with concentration ranging from 10 to 20% (v/v) EtOH.

Results

A prior history of binge‐like EtOH drinking significantly increased subsequent voluntary EtOH consumption and preference, effects most robust in groups that initially experienced 6 or 10 binge‐like drinking episodes and completely absent in mice that experienced 1 binge‐like drinking episode. Conversely, a history of binge‐like EtOH drinking did not influence anxiety‐like behaviors, ataxia, or HICs.

Conclusions

Excessive EtOH drinking stemming from DID procedures does not initially induce phenotypes consistent with a dependence‐like state. However, the subsequent increases in voluntary EtOH consumption and preference that become more robust following repeated episodes of binge‐like EtOH drinking may reflect the early stages of EtOH dependence, suggesting that DID procedures may be ideal for studying the transition to EtOH dependence.
Name Recognition and Candidate Support
Authors: Kam Cindy D. , Zechmeister Elizabeth J.
Published: May 2013

The mass media devote a great deal of attention to high‐profile elections, but in American political life such elections are the exception, not the rule. The majority of electoral contests feature candidates who are relative unknowns. In such situations, does name recognition breed contempt, indifference, or affection? Existing work presents modest theory and mixed evidence. Using three laboratory experiments, we provide conclusive evidence that name recognition can affect candidate support, and we offer strong evidence that a key mechanism underlying this relationship is inferences about candidate viability. We further show that the name‐recognition effect dissipates in the face of a more germane cue, incumbency. We conclude with a field study that demonstrates the robustness of the name‐recognition effect to a real‐world political context, that of yard signs and a county election.
Package Deals in EU Legislative Politics
Authors: Kardasheva Raya
Published: May 2013

This is an article about package deals in EU legislative politics and their effects on policy outcomes. It analyzes interchamber exchange between the Council of Ministers and the European Parliament. The main argument is that package deals allow Member States control over the financial aspects of legislation and ensure its timely adoption. In exchange, the Parliament gains access to some of the EU's most expensive policy areas. Intercameral logrolling is analyzed across all EU legislation completed in the period 1 May 1999–30 April 2007, including 2,369 issues, 1,465 legislative proposals, and 19 policy areas. The results indicate that package deals in the EU are conditional on the distributive nature of proposals and their urgency. In turn, through logrolling, the Parliament extends its influence in distributive policies.
Effect of L‐carnitine on maturation, cryo‐tolerance and embryo developmental competence of bovine oocytes
Authors: Phongnimitr Teewara , Liang Yuanyuan , Srirattana Kanokwan , Panyawai Kanchana , Sripunya Nucharin , Treetampinich Chatchai , Parnpai Rangsun
Published: May 2013

In this study, the effects of the addition of L‐carnitine in in vitro maturation (IVM) medium for bovine oocytes on their nuclear maturation and cryopreservation were investigated; they were matured in IVM medium supplemented with 0.0, 0.3, 0.6 and 1.2 mg/mL of L‐carnitine (control, 0.3, 0.6 and 1.2 groups, respectively) and some of them were vitrified by Cryotop. Moreover, the effects of L‐carnitine during in vitro fertilization (IVF) and in vitro culture (IVC) on the developmental potential and quality of IVF embryos were also examined. A significantly higher maturation rate of oocytes was obtained for 0.3 and 0.6 mg/mL groups compared with the control (P < 0.05). The blastocyst formation rate in the 0.6 group was significantly improved, whereas the rate in the 1.2 group was significantly decreased when compared with the control group (P < 0.05). No significant difference was found in embryo development between the control and the L‐carnitine group after oocyte vitrification. Supplementation of IVF and IVC media with L‐carnitine had no effect on development to the blastocyst stage of IVM oocytes treated with 0.6 mg/mL L‐carnitine. In conclusion, the supplementation of L‐carnitine during IVM of bovine oocytes improved their nuclear maturation and subsequent embryo development after IVF, but when they were vitrified the improving effects were neutralized.
Efficacy and ligand bias at the μ‐opioid receptor
Authors: Kelly E
Published: May 2013

In order to describe drug action at a GPCR, a full understanding of the pharmacological terms affinity, efficacy and potency is necessary. This is true whether comparing the ability of different agonists to produce a measurable response in a cell or tissue, or determining the relative ability of an agonist to activate a single receptor subtype and produce multiple responses. There is a great deal of interest in the μ‐opioid receptor (MOP receptor) and the ligands that act at this GPCR not only because of the clinically important analgesic effects produced by MOP agonists but also because of their liability to induce adverse effects such as respiratory depression and dependence. Our understanding of the mechanisms underlying these effects, as well as the ability to develop new, more effective MOP receptor drugs, depends upon the accurate determination of the efficacy with which these ligands induce coupling of MOP receptors to downstream signalling events. In this review, which is written with the minimum of mathematical content, the basic meaning of terms including efficacy, intrinsic activity and intrinsic efficacy is discussed, along with their relevance to the field of MOP receptor pharmacology, and in particular in relation to biased agonism at this important GPCR.

Linked Articles

Recent reviews on aspects of efficacy can be found at:

Kenakin, T (2013). New concepts in pharmacological efficacy at 7TM receptors: IUPHAR Review 2. British Journal of Pharmacology 168: 554–575. doi: 10.1111/j.1476‐5381.2012.02223.x

Roche D, Gil D and Giraldo J (2013). Mechanistic analysis of the function of agonists and allosteric modulators: reconciling two‐state and operational models. British Journal of Pharmacology 169: 1189–1202. doi: 10.1111/bph.12231
Ca2+ signals evoked by histamine H1 receptors are attenuated by activation of prostaglandin EP2 and EP4 receptors in human aortic smooth muscle cells
Authors: Pantazaka Evangelia , Taylor Emily J A , Bernard William G , Taylor Colin W
Published: May 2013

Background and Purpose

Histamine and prostaglandin E2 (PGE2), directly and via their effects on other cells, regulate the behaviour of vascular smooth muscle (VSM), but their effects on human VSM are incompletely resolved.

Experimental Approach

The effects of PGE2 on histamine‐evoked changes in intracellular free Ca2+ concentration ([Ca2+]i) and adenylyl cyclase activity were measured in populations of cultured human aortic smooth muscle cells (ASMCs). Selective ligands of histamine and EP receptors were used to identify the receptors that mediate the responses.

Key Results

Histamine, via H1 receptors, stimulates an increase in [Ca2+]i that is entirely mediated by activation of inositol 1,4,5‐trisphosphate receptors. Selective stimulation of EP2 or EP4 receptors attenuates histamine‐evoked Ca2+ signals, but the effects of PGE2 on both Ca2+ signals and AC activity are largely mediated by EP2 receptors.

Conclusions and Implications

Two important inflammatory mediators, histamine via H1 receptors and PGE2 acting largely via EP2 receptors, exert opposing effects on [Ca2+]i in human ASMCs.
Postural Influences on the Development of Infant Lateralized and Symmetric Hand‐Use
Authors: Babik Iryna , Campbell Julie M. , Michel George F.
Published: May 2013

Within‐individual variability is such an apparent characteristic of infant handedness that handedness is believed to consolidate only in childhood. Research showed that manifest handedness is influenced by emerging postural skills (sitting, crawling, and walking). In this investigation, it was proposed that symmetric hand‐use (tendency to acquire objects bimanually), rather than lateralized hand‐use (the use of one hand more than the other), may be influenced by postural changes. Trajectories of lateralized and symmetric hand‐use for object acquisition were examined in 275 infants tested monthly from 6 to 14 months. Multilevel modeling revealed that change in lateralized hand‐use is unrelated to developmental transitions in infant posture, whereas the trajectory of symmetric hand‐use changes significantly with the development of postural skills.
Trends and associated factors in prevalence of dental trauma in Latin America and Caribbean: a systematic review and meta‐analysis
Authors: Aldrigui Janaina Merli , Jabbar Nadia Salem , Bonecker Marcelo , Braga Mariana Minatel , Wanderley Marcia Turolla
Published: May 2013

Objectives

This study aimed to perform a systematic review on the prevalence of, and trends in, dental trauma in permanent teeth in ‘Latin America and Caribbean’ region and possible factors associated with this injury.

Methods

Literature search was carried out, in PubMed database up to 07 July 2011, for articles written in Portuguese, Spanish, or English reporting on dental trauma prevalence in the Latin American and Caribbean countries. Meta‐analyses were undertaken by using random effects modeling to satisfy the purposes of this review. Pooled estimates were calculated with a confidence interval of 95% (95% CI) both for prevalence and odds ratios (OR).

Results

This online searching strategy collected and listed 2436 articles on this topic. After evaluating their titles and abstracts, only 24 were finally selected for complete review and data collection. All studies had been performed during adolescence, mostly in 12‐year‐old adolescents. The pooled prevalence of dental trauma in permanent teeth was 18.6%. Positive summary association of dental trauma with boys (pooled OR = 1.72; 95% CI: 1.57–1.89), inadequate lip coverage (pooled OR = 2.26; 95% CI: 1.45–3.52), and increased overjet (>5 mm) (pooled OR = 1.98; 95% CI: 1.61–2.44) were observed across all meta‐analysis models. Differences in estimation could be observed when different criteria were used for evaluating dental trauma. On the other hand, prevalence of dental trauma did not tend to show sudden changes over time, despite criteria used. Prevalence of dental trauma after 2000s tended to decrease over time.

Conclusions

Approximately 15–20% of the adolescents in Latin American and Caribbean countries have shown some type of dental trauma in permanent teeth, and it seems there is a trend of decreasing prevalence of dental trauma in the studied areas of this region. Boys, adolescents presenting inadequate lip coverage, or an increased overjet greater than 5 mm are more likely to have traumatic dental injuries.
Discourses Underpinning Parenting Training Programmes: Positioning and Power
Authors: Cottam Susan , Espie Jonathan
Published: May 2013

Parenting training programmes (PTPs) aim to improve parenting skills and are widely offered in the UK. Despite evidence of efficacy, this paper hypothesises that PTPs may risk disempowering parents, children and even facilitators by prioritising professional expertise over lay knowledge. A Foucauldian discourse analysis examined six PTP manuals and identified discourses including victimhood, institutional salvation, scientism and collaboration. Power relations favouring government and professionals, and impacting outcomes and parental engagement were suggested to result from some of these discourses. Research into PTP engagement in terms of power relations and acknowledgement by policy‐makers of the impact of discourse was recommended.
Leptin induces secretion of pro‐inflammatory cytokines by human keratinocytes in vitro – a possible reason for increased severity of psoriasis in patients with a high body mass index
Authors: Xue Ke , Liu Haiyan , Jian Qiang , Liu Boqiang , Zhu Dongning , Zhang Min , Gao Lin , Li Chengxin
Published: May 2013

Investigations about prevalence of obesity in psoriasis patients are increased nowadays. Higher serum levels of leptin in patients with psoriasis who are overweight or obese suggest that leptin may serve as a molecular link between psoriasis and metabolic comorbidities. However, the pathological functions of leptin in psoriasis are not clearly understood. We investigated the influence of being overweight or obese on the risk of psoriasis, and the relationship between serum leptin levels and the severity of psoriasis in Chinese Han patients. We also investigated biological effects of leptin on the proliferation and secretion of pro‐inflammatory cytokines by human keratinocytes in vitro. Obesity was a significant risk factor for psoriasis in the Chinese Han population; however, we did not observe a significant correlation between Psoriasis Area and Severity Index (PASI) and body mass index (BMI). We observed a positive correlation between the serum leptin level and PASI in overweight and obese male patients with psoriasis. Strong leptin immunoreactivity was detected in the epidermis of psoriatic lesions, particularly in keratinocytes. Leptin significantly increased the proliferation and secretion of pro‐inflammatory cytokines by keratinocytes in vitro. In conclusion, this study suggests leptin as a novel molecular link between psoriasis and obesity, which may help to explain the more server conditions of psoriasis in patients with obesity.
Roles, regulation and inhibitors of sphingosine kinase 2
Authors: Neubauer Heidi A. , Pitson Stuart M.
Published: May 2013

The bioactive sphingolipids ceramide, sphingosine and sphingosine‐1‐phosphate (S1P) are important signalling molecules that regulate a diverse array of cellular processes. Most notably, the balance of the levels of these three sphingolipids in cells, termed the ‘sphingolipid rheostat’, can dictate cell fate, where ceramide and sphingosine enhance apoptosis and S1P promotes cell survival and proliferation. The sphingosine kinases (SKs) catalyse the production of S1P from sphingosine and are therefore central regulators of the sphingolipid rheostat and attractive targets for cancer therapy. Two SKs exist in humans: SK1 and SK2. SK1 has been extensively studied and there is a large body of evidence to demonstrate its role in promoting cell survival, proliferation and neoplastic transformation. SK1 is also elevated in many human cancers which appears to contribute to carcinogenesis, chemotherapeutic resistance and poor patient outcome. SK2, however, has not been as well characterized, and there are contradictions in the key physiological functions that have been proposed for this isoform. Despite this, many studies are now emerging that implicate SK2 in key roles in a variety of diseases, including the development of a range of solid tumours. Here, we review the literature examining SK2, its physiological and pathophysiological functions, the current knowledge of its regulation, and recent developments in targeting this complex enzyme.
Fatigue behaviour of aluminium foam sandwiches
Authors: Palano F. , Nobile R. , Dattoma V. , Panella F.W.
Published: May 2013

Aluminium foam sandwiches are subjected to four‐point bending fatigue test considering the effect of geometric parameters of panels, such as core and plate thickness, and loading mode, such as arm distance.

Fatigue strength curves are expressed in terms of different stress amplitude parameters calculated using an analytical model based on laminated plate classical theory and a solid finite element method model. Despite, the notable fatigue data scatter, originated by foam intrinsic inhomogeneity, experimental fatigue curves are coherent and allow obtaining unified fatigue curves.
Connectivity and complexity of floodplain habitats govern zooplankton dynamics in a large temperate river system
Authors: Górski Konrad , Collier Kevin J. , Duggan Ian C. , Taylor Claire M. , Hamilton David P.
Published: May 2013

Large river–floodplain systems are characterised by seasonal flow variability. High flows lead to hydrological connection between the main channel and inundated off‐channel lakes, wetlands and floodplains, which provide essential habitats for riverine biota. We tested the following hypotheses: (i) that crustacean zooplankton are more abundant in connected lentic habitats such as riverine lakes and wetlands and have a different community composition compared with the main channel and (ii) that vegetation structure will moderate abundances of crustacean zooplankton in the lower reaches of the Waikato River, New Zealand.

Zooplankton densities in main channel inflows and inundated floodplains showed clear seasonal changes, with cladoceran and copepod abundance peaks occurring in the majority of sites 2–3 weeks following the peak spring discharges (coinciding with the retreat of water from floodplains into the main channel).

Mean densities of zooplankton were highest in the inflows originating from riverine lakes (10–20 ind. L−1) where rotifers were dominant. We recorded significantly higher abundances of copepods in peat bog and swamp wetland inflows (c. 5 ind. L−1) relative to the main river channel and riverine lake inflows (0.1–1 ind. L−1). Some lake inflows also had high numbers of cladocerans (5–10 ind. L−1).

Inundated floodplains displayed heterogeneity in zooplankton community composition in relation to their structural complexity. Flooded forest accommodated higher numbers of copepods (c. 8 ind. L−1) and cladocerans (c. 17 ind. L−1) than flooded grassland, where zooplankton assemblages resembled those in the main river channel and were characterised by dominance of rotifers and low overall zooplankton densities (1–2 ind. L−1).

Our results suggest that seasonal flow and flood pulses, which determine the degree of connectivity of the main channel with the floodplain and off‐channel habitats, govern zooplankton densities and community structure in this large temperate river. Furthermore, the structural complexity of floodplain habitats may play an important role in enhancing riverine zooplankton diversity. We postulate that the post‐flood peak of large‐bodied cladocerans and copepods might have historically played an important role in the provision of food for juvenile fish such as migrating Galaxiidae.
Susceptibility to a metal under global warming is shaped by thermal adaptation along a latitudinal gradient
Authors: Dinh Van Khuong , Janssens Lizanne , Debecker Sara , De Jonge Maarten , Lambret Philippe , Nilsson‐Örtman Viktor , Bervoets Lieven , Stoks Robby
Published: May 2013

Global warming and contamination represent two major threats to biodiversity that have the potential to interact synergistically. There is the potential for gradual local thermal adaptation and dispersal to higher latitudes to mitigate the susceptibility of organisms to contaminants and global warming at high latitudes. Here, we applied a space‐for‐time substitution approach to study the thermal dependence of the susceptibility of Ischnura elegans damselfly larvae to zinc in a common garden warming experiment (20 and 24 °C) with replicated populations from three latitudes spanning >1500 km in Europe. We observed a striking latitude‐specific effect of temperature on the zinc‐induced mortality pattern; local thermal adaptation along the latitudinal gradient made Swedish, but not French, damselfly larvae more susceptible to zinc at 24 °C. Latitude‐ and temperature‐specific differences in zinc susceptibility may be related to the amount of energy available to defend against and repair damage since Swedish larvae showed a much stronger zinc‐induced reduction of food intake at 24 °C. The pattern of local thermal adaptation indicates that the predicted temperature increase of 4 °C by 2100 will strongly magnify the impact of a contaminant such as zinc at higher latitudes unless there is thermal evolution and/or migration of lower latitude genotypes. Our results underscore the critical importance of studying the susceptibility to contaminants under realistic warming scenarios taking into account local thermal adaptation across natural temperature gradients.
Characteristics of traditionally processed shea kernels and butter
Authors: Honfo Fernande G. , Linnemann Anita R. , Akissoe Noel , Soumanou Mohamed M. , van Boekel Martinus A. J. S.
Published: May 2013

The traditional production of shea butter requires a heat treatment of the nuts. This study compared the end products derived by two commonly used heat treatments, namely smoking and boiling followed by sun‐drying. Neither treatment influenced the moisture content of the kernels (8–10%), but the boiling treatment resulted in more free fatty acids (FFA) (6%) and a higher fat content (41%) of kernels. A sensory panel preferred shea butter from boiled kernels because of its soft texture and intense smell. This butter also had the highest values for moisture content (2%), unsaponifiable matter (7%), tocopherol compounds (125 mg g−1), peroxide value (8 meq O2 kg−1), iodine value (53 mg I2 100 g−1) and FFA (2%). Minor variations were noticed in the fatty acid profile. Aside from the use of butter from both boiled and smoked kernels in cosmetics, the butter from smoked kernels will be more suitable for food purposes.
Effects of postharvestUV‐Ctreatment on carotenoids and phenolic compounds of vine‐ripe tomatoes
Authors: Bravo Sergio , García‐Alonso Javier , Martín‐Pozuelo Gala , Gómez Victoria , García‐Valverde Verónica , Navarro‐González Inmaculada , Periago María Jesús
Published: May 2013

Light red tomatoes were exposed to different doses of ultraviolet C (UV‐C) irradiation (1.0, 3.0 and 12.2 kJ m−2). After treatment, the tomatoes were stored for 2 days at room temperature, and then analysed to determine the effect of irradiation on the main antioxidants, carotenoids and phenolic compounds and the results compared with the control samples. The lycopene content was found to have increased by 14% with respect to the control samples, while β‐carotene decreased.Cis‐isomers from lycopene also increased when the tomatoes were exposed to irradiation for more than 3 h.UV‐Cirradiation also had a positive effect on total phenolic compounds; however, the same effect was not observed in the individually analysed phenolic compounds. While chlorogenic and ferulic acids increased in content, naringenin and rutin contents decreased. These results suggest thatUV‐Cirradiation of tomatoes could improve the beneficial effect of red tomatoes for human health by increasing the levels of certain bioactive compounds; it could also be used to obtain higher content of bioavailability components, such ascis‐isomers from lycopene.
Botulinum toxin treatment for bladder dysfunction
Authors: Santos‐Silva André , da Silva Carlos Martins , Cruz Francisco
Published: May 2013

Botulinum toxin A is available under three different protein complexes that are not interchangeable until appropriate comparative studies are undertaken. The best studied for the treatment of urinary incontinence as a result of neurogenic detrusor overactivity and overactive bladder/idiopathic detrusor overactivity is onabotulinum toxin A. This brand is only approved for the treatment of urinary incontinence as a result of neurogenic detrusor overactivity at a dose of 200 U and idiopathic detrusor overactivity at a dose of 100 U. In patients with detrusor overactivity as a result of spinal cord injury or multiple sclerosis, 200 U of onabotulinum toxin A should be injected in 30 different sites above the trigone. It was shown to be highly effective in curing or decreasing urinary symptoms of incontinence, increasing quality of life, increasing bladder capacity and decreasing maximal detrusor pressure. This effect was independent of the concomitant use of oral anticholinergic drugs. Adverse events were mild, mainly urinary tract infections and high postvoid residual requiring clean intermittent catheterization. In patients with overactive bladder/idiopathic detrusor overactivity, 100 U of onabotulinum toxin A should be injected in 20 sites above the trigone. It markedly decreases urinary incontinence and improves quality of life. Frequency and urgency episodes are also decreased. Adverse events are mild, mainly urinary tract infections and urinary retention. The latter occurred in just 5% of the patients. Candidates for onabotulinum toxin A treatment should be warned that the effect of the toxin is transient and that repeated injections will be required to maintain the effect in the long term. There is no evidence that repeated injections will have a decreased efficacy.
Depending on the Sky: Environmental Distress, Migration, and Coping in Rural Cambodia
Authors: Bylander Maryann
Published: May 2013

Increasingly, research seeks to understand how environmental distress motivates migration, often focusing on the importance of singular events such as flood, drought or crop loss. This article explores the case of a Cambodian community where environmental shocks have been frequent over the past decade and international migration has increased. It shows that as a result of recurring and varied environmental shocks, households increasingly perceive agriculture‐based livelihood strategies as unwise and risky. This perception is widespread even among households not directly experiencing income loss. As a result, households use migration as a replacement for local livelihood strategies. These findings support two arguments relevant for future research and policy. First, that environmental shocks have importance beyond their immediate, direct impact. Second, that recurring shocks can influence preferences for and risk perceptions of local investments. Thus for policies to effectively address environmental vulnerability and/or rural development in precarious environments, they must incorporate local understandings of risk and possibility.
Third‐Degree Price Discrimination and Consumer Surplus
Authors: Cowan Simon
Published: May 2013

This paper considers the effects of monopoly third‐degree price discrimination on aggregate consumer surplus. Discrimination is likely to reduce surplus (relative to that obtained with a uniform price), but surplus can rise under reasonable conditions. If the ratio of the pass‐through coefficient to the price elasticity at the uniform price is higher in the market with the higher price elasticity then surplus is larger with discrimination (for a large set of demand functions). The relatively high pass‐through coefficient implies a large price reduction in this market. With logit demand functions surplus is higher with discrimination if pass‐through is above 0.5.
Vertical and Horizontal Scope Economies in the Regulated U.S. Electric Power Industry
Authors: Arocena Pablo , Saal David S. , Coelli Tim
Published: May 2013

This paper investigates vertical economies between generation and distribution of electric power, and horizontal economies between different types of power generation in the U.S. electric utility industry. Our quadratic cost function model includes three generation output measures (hydro, nuclear and fossil fuels), which allows us to analyze the effect that generation mix has on vertical economies. Our results provide (sample mean) estimates of vertical economies of 8.1% and horizontal economies of 5.4%. An extensive sensitivity analysis is used to show how the scope measures vary across alternative model specifications and firm types.
Joining of Porous Alumina with a CaO–Al2O3–SiO2 Glass‐Ceramic
Authors: Zhu Weiwei , Chen Jichun , Jiang Chunhai , Hao Chuanyong , Zhang Jinsong
Published: May 2013

A CaO–Al2O3–SiO2 (CAS)‐based glass interlayer was developed for joining of porous alumina membrane tubes with dense alumina in this work. The results indicated that the interfacial microstructure of the joint was highly sensitive to the quench rate from the joining temperature, which rendered crystallization of CaTiSiO5 at a fast quench rate but CaAl2Si2O8 at a slow quench rate due to the interfacial reaction between the CAS glass interlayer and the substrate. An extra crystallization treatment during quench, i.e., dwelling at 800°C–900°C for 2 h, produced a multiphase interlayer consisting of LiAlSi2O6, CaTiSiO5, and CaAl2Si2O8. All joints were evaluated by the thermal shock test. The results showed that the LiAlSi2O6‐containing joint interlayer had much lower thermal shock resistance than those without LiAlSi2O6.
Microstructures and Microwave Dielectric Properties of Bi2O3‐Deficient Bi12SiO20 Ceramics
Authors: Jeong Byoung‐Jik , Joung Mi‐Ri , Kweon Sang‐Hyo , Kim Jin‐Seong , Nahm Sahn , Choi Ji‐Won , Hwang Seong‐Ju
Published: May 2013

The Microstructure and microwave dielectric properties of Bi2O3‐deficient Bi12SiO20 ceramics were investigated. A small amount of unreacted Bi2O3 phase melted during sintering at 825°C and assisted with densification and grain growth in all samples. The melted Bi2O3 reacted with remnant SiO2 during cooling to form a Bi4Si3O12 secondary phase. The nominal composition of Bi11.8SiO19.7 ceramics sintered at 825°C for 4 h had a high relative density of 97% of the theoretical density, and good microwave dielectric properties: εr = 39, Q × f = 74 000 GHz, and τf = −14.1 ppm/°C. Moreover, this ceramic did not react with Ag at 825°C.
Luminescence and Structural Properties of High Stable Si–N‐Doped BaMgAl10O17:Eu2+ Phosphors Synthesized by a Mechanochemical Activation Route
Authors: Wang Yi‐Fei , Wang Yi‐Fei , Zhu Qiang‐Qiang , Hao Lu‐Yuan , Xu Xin , Xie Rong‐Jun , Agathopoulos Simeon
Published: May 2013

Highly thermal stable Si–N‐doped BAM (BaMgAl10O17: Eu2+) phosphors have been successfully synthesized by a mechanochemically assisted solid‐state reaction method. Mechanical milling greatly improved the amount of Si–N pairs substituted for Al–O pairs in BAM lattice>. Si–N incorporation improves the photoluminescence (PL) properties and the color purity, reduces the thermal quenching, and most importantly, increases the thermal stability of the BAM phosphors significantly. The interpretation of the positive influence of Si–N doping was attributed to the local structure of the produced phosphors, which was analyzed with the aid of first‐principles density functional calculations. This analysis showed that the substitution of Al–O pairs with Si–N pairs should preferentially occur in the boundary between the spinel layer and the conduction layer of the BAM phosphor, leading to a compression of the conduction layer. Eu2+ ions prefer to substitute the N‐coordinated Ba2+ ions in the lattice of Si–N‐doped BAM phosphors, leading to a strong Eu–N bonding. The results of these calculations agree fairly well with the results recorded experimentally, specifically the electron paramagnetic resonance (EPR) spectra, the X‐ray absorption fine structure (XAFS), thermoluminescence spectra (TL), and decay behaviors.
Evolution of pleiotropic costs in experimental populations
Authors: Jasmin J.‐N. , Zeyl C.
Published: May 2013

The fitness of populations adapting to new environments is expected to decline in different environments, but empirical studies often do not lend support for such adaptation costs. We test the idea that the initial fitness of the selected populations in the environment where the cost is estimated is key for interpreting tests of ecological trade‐offs. We isolated single clones of the yeast Saccharomyces cerevisiae every ~250 generations from replicate experimental lineages that had been selected during 5000 generations in a glucose‐limited environment. We then selected these clones in a galactose‐limited environment for ~120 generations. Finally, we estimated single‐clone fitness in both environments, before and after selection on galactose. The pleiotropic effects on glucose of selection on galactose evolved from positive to negative as fitness in glucose increased, providing strong support for the importance of initial fitness for determining the sign and magnitude of pleiotropic effects. This demonstrates that the sign of pleiotropic effects for fitness following adaptation to a new environment can change during long‐term adaptation to an original environment. We also found no relationship between the size of the fitness changes in galactose and glucose, such that pleiotropic effects in glucose became relatively smaller as the sizes of direct effects on galactose increased.