bluuebunny/crossref_metadata_2025 huggingface dataset:
CARD8 gene encoding a protein of innate immunity is expressed in human atherosclerosis and associated with markers of inflammation
Authors: Paramel Geena Varghese , Folkersen Lasse , Strawbridge Rona J. , Elmabsout Ali Ateia , Särndahl Eva , Lundman Pia , Jansson Jan-Håkan , Hansson Göran K. , Sirsjö Allan , Fransén Karin
Published: April 2013

Inflammation is a key factor in the development of atherosclerotic coronary artery disease. It is promoted through the inflammasome, a molecular machine that produces IL (interleukin)-1β in response to cholesterol crystal accumulation in macrophages. The CARD8 (caspase recruitment domain 8) protein modulates this process by suppressing caspase 1 and the transcription factor NF-κB (nuclear factor κB). The expression of CARD8 mRNA was examined in atherosclerotic vascular tissue and the impact on MI (myocardial infarction) of a polymorphism in the CARD8 gene determined. CARD8 mRNA was analysed by microarray of human atherosclerotic tissue and compared with transplant donor arterial tissue. Microarray analysis was performed for proximal genes associated with the rs2043211 locus in plaque. The CARD8 rs2043211 polymorphism was analysed by genotyping of two Swedish MI cohorts, FIA (First Myocardial Infarction in Northern Sweden) and SCARF (Stockholm Coronary Atherosclerosis Risk Factor). The CRP (C-reactive protein) level was measured in both cohorts, but the levels of the pro-inflammatory cytokines IL-1β, IL-18, TNF (tumour necrosis factor) and MCP-1 (monocyte chemoattractant protein) were measured in sera available from the SCARF cohort. CARD8 mRNA was highly expressed in atherosclerotic plaques compared with the expression in transplant donor vessel (P<0.00001). The minor allele was associated with lower expression of CARD8 in the plaques, suggesting that CARD8 may promote inflammation. Carriers of the minor allele of the rs2043211 polymorphism also displayed lower circulating CRP and lower levels of the pro-atherosclerotic chemokine MCP-1. However, no significant association could be detected between this polymorphism and MI in the two cohorts. Genetic alterations in the CARD8 gene therefore seem to be of limited importance for the development of MI.
Thermopower and resistivity studies of Nd-Na-Mn-O manganites
Authors: Kalyana Lakshmi Y. , Raju K. , Venugopal Reddy P.
Published: April 2013

The electrical transport properties of the polycrystalline Nd1−xNaxMnO3 (0.05 ≤ x ≤ 0.25) were investigated. All the samples are found to exhibit insulating behavior down to the lowest measured temperature. However, on application of 4 T magnetic field, metal-insulator transitions along with a low temperature resistivity upturn are observed for the samples with x ≥ 0.15. Thermopower values of samples with x = 0.05, 0.10, and 0.20 are negative in the entire temperature range of investigation, while they changes from negative to positive with decreasing temperature in the case of samples with x = 0.15 and 0.25. The resistivity and thermopower data in the high temperature region are explained within the framework of variable range and small polaron hopping models, while the resistivity minima are explained using the combined effect of electron-electron and electron-phonon scattering is considered.
Trichloridothallium(III) Complexes with Bipyridine Derivatives: From Structure to Luminescence Properties.
Authors: Ghiasi Zahra , Amani Vahid , Mirzaei Peiman , Safari Nasser , Abedi Anita
Published: April 2013

Several new thallium(iii) complexes, [Tl(4,4′-dmbpy)Cl3(DMSO)]·H2O (1), [Tl(4,4′-dtbpy)Cl3(DMSO)] (2), [Tl(5,5′-dmbpy)Cl3(DMSO)]·(5,5′-dmbpy) (3), and [Tl(6-mbpy)Cl3(DMSO)] (4) (4,4′-dmbpy = 4,4′-dimethyl-2,2′-bipyridine, 4,4′-dtbpy = 4,4′-ditert-butyl-2,2′-bipyridine, 5,5′-dmbpy = 5,5′-dimethyl-2,2′-bipyridine, and 6-mbpy = 6-methyl-2,2′-bipyridine) were prepared from the reaction of TlCl3 with the mentioned ligands in DMSO. The four complexes were fully characterised and their structures were determined by X-ray diffraction. These complexes have a bidendate nitrogenous ligand, a DMSO molecule, and three chloride anions (in the facial position) attached to a TlIII metal centre in a distorted octahedral environment. The stability of the complexes in DMSO is evident by a 203,205Tl–1H spin–spin coupling, determined by 1H NMR spectroscopy. Interestingly, six bond hydrogen–thallium coupling was observed with a coupling constant of 6JTlH = 20 Hz. The absorption and emission spectra of the complexes were investigated. These studies revealed that upon coordination to TlIII, the luminescent intensity is increased in comparison with the related unbound ligands.
Halophyte anti-oxidant feedback seasonality in two salt marshes with different degrees of metal contamination: search for an efficient biomarker
Authors: Duarte Bernardo , Santos Dinis , Caçador Isabel
Published: April 2013

Salt marshes can be affected by metal contamination when near a polluted area, and this excessive concentration of metals is a source of stress in plants. Production of proteins, flavonoids, phenolic compounds and anti-oxidant feedback can be used as biomarkers, as well to assess the suitability of halophytes to function as a biomonitors. Through monitoring the anti-oxidative feedback in Halimione portulacoides (L.) Aellen, Sarcocornia fruticosa (L.) A.J.Scott and Spartina maritima (Curtis) Fernald in a contaminated and non-contaminated marsh, S. maritima seems to have potential as a bioindicator species, showing different biochemical characteristics according to the degree of contamination to which it is exposed. The evident biochemical separation between individuals from contaminated and non-contaminated salt marshes is mostly due to differences in the activity of SOD as well APx and GPx. Without neglecting the need for further works, the present study suggests that S. maritima enzymatic defences as good candidates for efficient biomarkers for estuarine sediment quality assessment studies.
Queensland northern quolls are not immune to cane toad toxin
Authors: Ujvari Beata , Oakwood Meri , Madsen Thomas
Published: April 2013

Context The release of the highly toxic South American cane toad (Bufo marinus) to the toad-free Australian continent in 1935, and their subsequent rapid spread over large areas of tropical Australia, has resulted in a massive decline of predators such as yellow-spotted goannas (Varanus panoptes) and northern quolls (Dasyurus hallucatus). In spite of dramatic declines of northern quoll populations in the Northern Territory, a few populations still persist in areas of Queensland where northern quolls have co-existed with toads for several decades. Aims To determine whether the remaining quoll populations in Queensland have evolved resistance to cane toad toxins. Methods The extracellular H1–H2 domain of the α1 subunit of the sodium–potassium-ATPase gene was sequenced in four Queensland as well as four Northern Territory quolls. The transcribed sodium–potassium-ATPase enzyme from this gene is specifically targeted by toad toxins. Key results In all of the eight quolls, the sequences representing the 36 bp of the H1–H2 domain of the α1 subunit of the sodium–potassium-ATPase gene were identical. Conclusions Our results showed that Queensland quolls have not evolved an increased resistance to the toad toxins. We therefore suggest that the persistence of northern quolls in a few toad infested areas of Queensland could to be due to a combination of optimal habitat quality, and concomitant large quoll numbers, as well as an aversion to feeding on these highly toxic amphibians. Implications We suggest that a sample of northern quolls from the Queensland populations should be captured and their response, as well as that of their offspring and grand-offspring, to cane toads should be investigated to guide management of this declining species.
Assessment of radiative feedback in climate models using satellite observations of annual flux variation
Authors: Tsushima Yoko , Manabe Syukuro
Published: April 2013

In the climate system, two types of radiative feedback are in operation. The feedback of the first kind involves the radiative damping of the vertically uniform temperature perturbation of the troposphere and Earth’s surface that approximately follows the Stefan–Boltzmann law of blackbody radiation. The second kind involves the change in the vertical lapse rate of temperature, water vapor, and clouds in the troposphere and albedo of the Earth’s surface. Using satellite observations of the annual variation of the outgoing flux of longwave radiation and that of reflected solar radiation at the top of the atmosphere, this study estimates the so-called “gain factor,” which characterizes the strength of radiative feedback of the second kind that operates on the annually varying, global-scale perturbation of temperature at the Earth’s surface. The gain factor is computed not only for all sky but also for clear sky. The gain factor of so-called “cloud radiative forcing” is then computed as the difference between the two. The gain factors thus obtained are compared with those obtained from 35 models that were used for the fourth and fifth Intergovernmental Panel on Climate Change assessment. Here, we show that the gain factors obtained from satellite observations of cloud radiative forcing are effective for identifying systematic biases of the feedback processes that control the sensitivity of simulated climate, providing useful information for validating and improving a climate model.
The molecular basis for Mucosal-Associated Invariant T cell recognition of MR1 proteins
Authors: López-Sagaseta Jacinto , Dulberger Charles L. , Crooks James E. , Parks Chelsea D. , Luoma Adrienne M. , McFedries Amanda , Van Rhijn Ildiko , Saghatelian Alan , Adams Erin J.
Published: April 2013

Significance

Mucosal-associated invariant T (MAIT) cells are a highly conserved lineage of αβ T cells found in most mammals. These cells express a T-cell receptor of low diversity that recognizes vitamin metabolites presented by the MHC-related protein, MR1. Despite the evolutionary divergence of MR1 from other MHC proteins, we have found that MAIT T-cell receptors recognize MR1 using similar molecular strategies as that of the highly diverse, conventional αβ T cells, which recognize classical MHC molecules presenting peptide fragments. Our results also shed light onto how MR1-presented antigens can modulate the MAIT–T-cell receptor affinity and MAIT cell stimulation.
Ancestral amphibian
v2r
s are expressed in the main olfactory epithelium
Authors: Syed Adnan S. , Sansone Alfredo , Nadler Walter , Manzini Ivan , Korsching Sigrun I.
Published: April 2013

Mammalian olfactory receptor families are segregated into different olfactory organs, with type 2 vomeronasal receptor (
v2r
) genes expressed in a basal layer of the vomeronasal epithelium. In contrast, teleost fish
v2r
genes are intermingled with all other olfactory receptor genes in a single sensory surface. We report here that, strikingly different from both lineages, the
v2r
gene family of the amphibian
Xenopus laevis
is expressed in the main olfactory as well as the vomeronasal epithelium. Interestingly, late diverging
v2r
genes are expressed exclusively in the vomeronasal epithelium, whereas “ancestral”
v2r
genes, including the single member of
v2r
family C, are restricted to the main olfactory epithelium. Moreover, within the main olfactory epithelium,
v2r
genes are expressed in a basal zone, partially overlapping, but clearly distinct from an apical zone of olfactory marker protein and odorant receptor-expressing cells. These zones are also apparent in the spatial distribution of odor responses, enabling a tentative assignment of odor responses to olfactory receptor gene families. Responses to alcohols, aldehydes, and ketones show an apical localization, consistent with being mediated by odorant receptors, whereas amino acid responses overlap extensively with the basal
v2r
-expressing zone. The unique bimodal
v2r
expression pattern in main and accessory olfactory system of amphibians presents an excellent opportunity to study the transition of
v2r
gene expression during evolution of higher vertebrates.
Imprinted expression of genes and small RNA is associated with localized hypomethylation of the maternal genome in rice endosperm
Authors: Rodrigues Jessica A. , Ruan Randy , Nishimura Toshiro , Sharma Manoj K. , Sharma Rita , Ronald Pamela C. , Fischer Robert L. , Zilberman Daniel
Published: April 2013

Arabidopsis thaliana
endosperm, a transient tissue that nourishes the embryo, exhibits extensive localized DNA demethylation on maternally inherited chromosomes. Demethylation mediates parent-of-origin–specific (imprinted) gene expression but is apparently unnecessary for the extensive accumulation of maternally biased small RNA (sRNA) molecules detected in seeds. Endosperm DNA in the distantly related monocots rice and maize is likewise locally hypomethylated, but whether this hypomethylation is generally parent-of-origin specific is unknown. Imprinted expression of sRNA also remains uninvestigated in monocot seeds. Here, we report high-coverage sequencing of the Kitaake rice cultivar that enabled us to show that localized hypomethylation in rice endosperm occurs solely on the maternal genome, preferring regions of high DNA accessibility. Maternally expressed imprinted genes are enriched for hypomethylation at putative promoter regions and transcriptional termini and paternally expressed genes at promoters and gene bodies, mirroring our recent results in
A. thaliana
. However, unlike in
A. thaliana
, rice endosperm sRNA populations are dominated by specific strong sRNA-producing loci, and imprinted 24-nt sRNAs are expressed from both parental genomes and correlate with hypomethylation. Overlaps between imprinted sRNA loci and imprinted genes expressed from opposite alleles suggest that sRNAs may regulate genomic imprinting. Whereas sRNAs in seedling tissues primarily originate from small class II (cut-and-paste) transposable elements, those in endosperm are more uniformly derived, including sequences from other transposon classes, as well as genic and intergenic regions. Our data indicate that the endosperm exhibits a unique pattern of sRNA expression and suggest that localized hypomethylation of maternal endosperm DNA is conserved in flowering plants.
Exploring the City in the Cinema of Bahram Beyzaie
Authors: Pak-Shiraz Nacim
Published: April 2013

This article explores five of Bahram Beyzaie's urban films over the last four decades to study their critique of the process of modernization and social changes that have taken place in Iran. These include The Journey (Safar, 1972), The Crow (Kalagh, 1977), Maybe Some Other Time (Shayad Vaqti Digar, 1987), Killing Mad Dogs (Sag Koshi, 2001) and When We Are All Asleep (Vaqti Hame Khabim, 2009). It examines the impact of modernization on the architecture and landscape of the city and consequently on the local community. It then studies the increasing complexity of ascertaining the real and unreal within the city. Finally, it looks at the changing values, the fears and threats within the city and the impact these have on its inhabitants, particularly women and their movement within the city.
Objects and Their Glassy Essence: Semiotics of Self in the Early Bronze Age Black Sea
Authors: Bauer Alexander A.
Published: April 2013

This article draws upon two concepts deployed by the American pragmatist philosopher Charles Sanders Peirce in his semiotic writings that have so far received little attention in studies of materiality and agency in archaeology, those of the “Interpretant” and “habit.” The emphasis of both of these concepts on the interpretive side of semiotic functioning suggests that some of the problems with current theories of material agency may be due to their focus on the production of meaning rather than the recursive nature of meaning-making that requires consideration of the consumption side of meaningful communication acts as well. Using an example of pottery-making practices from the Early Bronze Age Black Sea region, this article argues that we should instead rethink agency as an “archaeology of self” in which identity and meaning of signs—whether words, people, or things—are distributed across and emergent from social networks and communities of interpreters.
Perioperative Comparative Effectiveness of Anesthetic Technique in Orthopedic Patients
Authors: Memtsoudis Stavros G. , Sun Xuming , Chiu Ya-Lin , Stundner Ottokar , Liu Spencer S. , Banerjee Samprit , Mazumdar Madhu , Sharrock Nigel E.
Published: April 2013

Background

The impact of anesthetic technique on perioperative outcomes remains controversial. We studied a large national sample of primary joint arthroplasty recipients and hypothesized that neuraxial anesthesia favorably influences perioperative outcomes.

Methods

Data from approximately 400 hospitals between 2006 and 2010 were accessed. Patients who underwent primary hip or knee arthroplasty were identified and subgrouped by anesthesia technique: general, neuraxial, and combined neuraxial–general. Demographics, postoperative complications, 30-day mortality, length of stay, and patient cost were analyzed and compared. Multivariable analyses were conducted to identify the independent impact of choice of anesthetic on outcomes.

Results

Of 528,495 entries of patients undergoing primary hip or knee arthroplasty, information on anesthesia type was available for 382,236 (71.4%) records. Eleven percent were performed under neuraxial, 14.2% under combined neuraxial–general, and 74.8% under general anesthesia. Average age and comorbidity burden differed modestly between groups. When neuraxial anesthesia was used, 30-day mortality was significantly lower (0.10, 0.10, and 0.18%; P < 0.001), as was the incidence of prolonged (>75th percentile) length of stay, increased cost, and in-hospital complications. In the multivariable regression, neuraxial anesthesia was associated with the most favorable complication risk profile. Thirty-day mortality remained significantly higher in the general compared with the neuraxial or neuraxial–general group for total knee arthroplasty (adjusted odds ratio [OR] of 1.83, 95% CI 1.08–3.1, P = 0.02; OR of 1.70, 95% CI 1.06–2.74, P = 0.02, respectively).

Conclusions

The utilization of neuraxial versus general anesthesia for primary joint arthroplasty is associated with superior perioperative outcomes. More research is needed to study potential mechanisms for these findings.
Lewis Edward John Roberts CBE. 31 January 1922 — 10 April 2012
Authors: Eyre Brian
Published: April 2013

Lewis Roberts was a distinguished nuclear chemist and outstanding leader in the development of science and technology. He read chemistry at Oxford, where he graduated with an honours BA and then conducted research for a DPhil on the separation of actinides. Actinide chemistry formed the central theme of his work for the next 20 years, during which he conducted pioneering research into the thermodynamic properties and structures of actinide oxides. In 1968 he underwent a major career change, moving into senior management at Harwell and eventually becoming Director in 1975. During this period he showed outstanding judgement and leadership first in developing the non-nuclear industrial programme at Harwell and then in leading the laboratory through a time of great change. In addition to his executive responsibilities as Director, Roberts played a major role in influencing the nuclear industry’s approach to the difficult issue of nuclear waste management, a particularly important achievement being the setting up of NIREX under his chairmanship. In his mid sixties Roberts made a further major career change in moving to the Chair of Environmental Risk Assessment at the University of East Anglia. This allowed him to widen his interest in risk and environmental issues and to apply this to areas outside the nuclear field.
Peter Henry Andrews Sneath. 17 November 1923 — 9 September 2011
Authors: Jones Dorothy , Grant William D.
Published: April 2013

Peter Sneath revolutionized the practice of bacterial taxonomy over a 30-year period. He was the first to apply Adansonian principles to bacterial taxonomy, arguing that a robust system required that bacteria should be subjected to many phenotypic (phenetic) tests, all given equal weight, with analysis of the subsequent binary test scores being used to derive groups that could be given taxonomic rank (taxa). The procedures came to be known collectively as ‘numerical taxonomy’. A further innovation was the realization that the then embryonic discipline of computing could be harnessed to derive taxa from these very large sets of data. Computer-aided numerical taxonomy became the method of choice for classifying bacteria by the early 1960s. Much of Peter’s effort as Director of a Medical Research Council (MRC) Research Unit in Leicester in the 1960s and early 1970s was to reassess the taxonomy of most of the medically important bacteria. This information was then interrogated to determine the minimum number of tests required to identify new isolates reliably. The tests available in commercial identification kits in use today directly reflect these original numerical analyses. Later, after appointment to the Foundation Chair of Medical Microbiology at the University of Leicester, he carried out, together with colleagues, the most important revision of bacterial nomenclature for more than a century, the 1980 ‘Approved lists of bacterial names’. He was also a member, Vice Chairman and then Chairman of Bergey’s Trust, the organization responsible for
Bergey’s manual of determinative bacteriology
(later
Bergey’s manual of systematic bacteriology
), the definitive account of bacterial taxonomy and properties. He continued to edit volumes and contribute sections right up to his death.
On a new class of electro-elastic bodies. II. Boundary value problems
Authors: Bustamante R. , Rajagopal K. R.
Published: April 2013

In part I of this two-part paper, a new theoretical framework was presented to describe the response of electro-elastic bodies. The constitutive theory that was developed consists of two implicit constitutive relations: one that relates the stress, stretch and the electric field, and the other that relates the stress, the electric field and the electric displacement field. In part II, several boundary value problems are studied within the context of such a construct. The governing equations allow for nonlinear coupling between the electric and stress fields. We consider boundary value problems wherein both homogeneous and inhomogeneous deformations are considered, with the body subject to an electric field. First, the extension and the shear of an electro-elastic slab subject to an electric field are studied. This is followed by a study of the problem of a thin circular plate and a long cylindrical tube, both subject to an inhomogeneous deformation and an electric field. In all the boundary value problems considered, the relationships between the stress and the linearized strain are nonlinear, in addition to the nonlinear relation to the electric field. It is emphasized that the theories that are currently available are incapable of modelling such nonlinear relations.
Power and temptation cause shifts between exploitation and cooperation in a cleaner wrasse mutualism
Authors: Gingins Simon , Werminghausen Johanna , Johnstone Rufus A. , Grutter Alexandra S. , Bshary Redouan
Published: April 2013

In many instances of cooperation, only one individual has both the potential and the incentive to ‘cheat’ and exploit its partner. Under these asymmetric conditions, a simple model predicts that variation in the temptation to cheat and in the potential victim's capacity for partner control leads to shifts between exploitation and cooperation. Here, we show that the threat of early termination of an interaction was sufficient to induce cleaner wrasseLabroides dimidiatusto feed selectively against their preference (which corresponds to cooperatively eating client fish ectoparasites), provided that their preference for alternative food was weak. Under opposite conditions, cleaners fed selectively according to their own preference (which corresponds to cheating by eating client mucus). By contrast, a non-cleaning fish species,Halichoeres melanurus, failed to adjust its foraging behaviour under these same conditions. Thus, cleaners appear to have evolved the power to strategically adjust their levels of cooperation according to the circumstances.
The Endoplasmic Reticulum Is a Reservoir for WAVE/SCAR Regulatory Complex Signaling in the Arabidopsis Leaf
Authors: Zhang Chunhua , Mallery Eileen , Reagan Sara , Boyko Vitaly P. , Kotchoni Simeon O. , Szymanski Daniel B.
Published: April 2013

During plant cell morphogenesis, signal transduction and cytoskeletal dynamics interact to locally organize the cytoplasm and define the geometry of cell expansion. The WAVE/SCAR (for WASP family verprolin homologous/suppressor of cyclic AMP receptor) regulatory complex (W/SRC) is an evolutionarily conserved heteromeric protein complex. Within the plant kingdom W/SRC is a broadly used effector that converts Rho-of-Plants (ROP)/Rac small GTPase signals into Actin-Related Protein2/3 and actin-dependent growth responses. Although the components and biochemistry of the W/SRC pathway are well understood, a basic understanding of how cells partition W/SRC into active and inactive pools is lacking. In this paper, we report that the endoplasmic reticulum (ER) is an important organelle for W/SRC regulation. We determined that a large intracellular pool of the core W/SRC subunit NAP1, like the known positive regulator of W/SRC, the DOCK family guanine nucleotide-exchange factor SPIKE1 (SPK1), localizes to the surface of the ER. The ER-associated NAP1 is inactive because it displays little colocalization with the actin network, and ER localization requires neither activating signals from SPK1 nor a physical association with its W/SRC-binding partner, SRA1. Our results indicate that in Arabidopsis (Arabidopsis thaliana) leaf pavement cells and trichomes, the ER is a reservoir for W/SRC signaling and may have a key role in the early steps of W/SRC assembly and/or activation.
Integration of Genome-Scale Modeling and Transcript Profiling Reveals Metabolic Pathways Underlying Light and Temperature Acclimation in Arabidopsis
Authors: Töpfer Nadine , Caldana Camila , Grimbs Sergio , Willmitzer Lothar , Fernie Alisdair R. , Nikoloski Zoran
Published: April 2013

Understanding metabolic acclimation of plants to challenging environmental conditions is essential for dissecting the role of metabolic pathways in growth and survival. As stresses involve simultaneous physiological alterations across all levels of cellular organization, a comprehensive characterization of the role of metabolic pathways in acclimation necessitates integration of genome-scale models with high-throughput data. Here, we present an integrative optimization-based approach, which, by coupling a plant metabolic network model and transcriptomics data, can predict the metabolic pathways affected in a single, carefully controlled experiment. Moreover, we propose three optimization-based indices that characterize different aspects of metabolic pathway behavior in the context of the entire metabolic network. We demonstrate that the proposed approach and indices facilitate quantitative comparisons and characterization of the plant metabolic response under eight different light and/or temperature conditions. The predictions of the metabolic functions involved in metabolic acclimation of Arabidopsis thaliana to the changing conditions are in line with experimental evidence and result in a hypothesis about the role of homocysteine-to-Cys interconversion and Asn biosynthesis. The approach can also be used to reveal the role of particular metabolic pathways in other scenarios, while taking into consideration the entirety of characterized plant metabolism.
Hedging late frost risk in viticulture with exotic options
Authors: Cortina Elsa , Sánchez Ignacio
Published: April 2013

Purpose

The purpose of this paper is to model and to value a temperature derivative to hedge late frost risk in viticulture.

Design/methodology/approach

Starting from 11 years of historical temperature data collected in Mendoza, Argentina, the authors reconstruct the missing data using principal component analysis. The frequency content of time series is examined by the periodogram method; ordinary least squares are used to estimate the trends of minimum, maximum and average temperatures, and hypothesis tests of univariate and bivariate normality are performed on deseasonalized and filtered temperature returns. The authors express the temperature dynamics by correlated Ornstein‐Uhlenbeck processes and historical data were fitted into the model to obtain parameters estimates. An Asian‐type option on a temperature index is constructed and its price and sensitivities are computed by Monte Carlo method.

Findings

The authors define an index in terms of minimum and average temperatures that, under some simplifying hypotheses, quantifies the damage produced by a late frost. To hedge the late frost risk, an Asian‐type option on the index is constructed. Together with the results concerning the design and pricing of the option, the analysis of historical data reveals non‐negligible linear trends, negative in minimum temperature and positive in maximum and average temperatures. These findings may be consistent with the hypothesis of global warming or with the presence of out‐of‐phase very low frequency components.

Originality/value

The authors have not found in the literature a similar option to hedge the risk of spring frosts faced by fruit producers.
Assessment and optimization of an airplane's environmental impact
Authors: Agarwal Ramesh , Zhang Zheming
Published: April 2013

Purpose

The ratio of the energy liberated during a flight to the revenue work done (ETRW) of an airplane can be employed as a key indicator to assess its environmental impact. It remains constant during the life cycle of the aircraft and is fixed by its designers. The goal of an environmentally optimum airplane is to minimize the ETRW. This paper seeks to address these issues.

Design/methodology/approach

For an existing airplane, there are two major parameters that can greatly affect the ETRW, which are the ratio of actual payload to maximum possible payload “c” and the flight range R. The goal of this paper is to study the effect of c and R on ETRW and minimize it by using a genetic algorithm (GA). The study is performed on a Boeing 737‐800 and a Boeing 747‐400 aircraft as well as recently proposed aircraft designs, namely the Boeing second generation Blended‐Wing‐Body (BWB) and MIT Double‐Bubble D8.2.

Findings

It turns out that the maximum possible values of payload and range do not necessarily lead to a flight with minimal environmental impact. For new aircraft designs, the minimization of ETRW should account for advances in materials, alternative fuels, structures, aerodynamics and propulsion technologies which can be taken into consideration at the design stage.

Research limitations/implications

It should be noted that other factors which also affect the emissions, namely the aircraft operations and air traffic management, are not included in the ETRW.

Originality/value

The optimization study is valuable in determining the payload and range of an existing aircraft or a new aircraft configuration for minimal environmental impact.
Inclusion effects of J2‐perturbed motion over Melton's problem
Authors: Soleymani Ahmad , Toloei Alireza
Published: April 2013

Purpose

The purpose of this paper is to analyze the inclusion effects of the linearized time‐varying J2‐perturbed terms for relative accuracy increase significantly over Melton's problem.

Design/methodology/approach

The methodology is based on the previous studies provided by Ross's paper. He gives a set of equations based on the C‐W equations which incorporates the J2 gravitational perturbations and states in his introduction that this method can be expanded for the elliptical reference orbits as described by Melton.

Findings

One challenge in implementing the relative motions is maintaining the relations as it experiences gravitational perturbations, most notably due to non‐spherical Earth. Simulation results show that the inclusion of time‐varying J2 perturbation terms in the derived linear equations increased the accuracy of the solution significantly in the out‐of‐orbit‐plane direction, while the accuracy within the orbit plane remained roughly unchanged.

Practical implications

By reason of replacing approximate terms (e, M) in this solution, for continues accuracy increase of time‐varying parameters containing θ(t) and RO(t), this solution could be useful in the element‐errors evaluation and analysis of orbital multiple rendezvous missions, that are involved to the limited orbit periods.

Originality/value

The originality of this paper is to develop Melton's researches. He provided a method for generalizing the linear equations of motion to an elliptical orbit which enabled the determination of a time‐explicit, approximate solution. In this regard, there is no paper which has evaluated the inclusion effects of the linearized time‐varying J2 perturbation terms over Melton's equations with such an approach.
Microcredit position in micro and small enterprise performance: the Malaysian case
Authors: Mahmood Rosman , Mohd Rosli M.
Published: April 2013

Purpose

This paper aims to evaluate the microcredit position in the performance of micro and small enterprises (MSEs). In the case of Malaysian MSEs, the paper also aims to examine other relevant factors, especially entrepreneur‐specific factors, which may be equally important for improving firm performance.

Design/methodology/approach

Primary data were collected from 756 MSE samples in Kelantan, the state where a large majority of the microcredit recipients under AIM and TEKUN run their business. Descriptive and multiple regression analyses were used to analyze the data.

Findings

Microcredit is positively and significantly related to the performance of MSEs across all the microcredit programs under investigation. Other entrepreneur‐specific factors, especially entrepreneurial values and management practices are equally significant for enhancing firm performance.

Practical implications

This study reminds policy makers, support institutions and small entrepreneurs that the microcredit program alone is not enough for improving the performance of MSEs. Besides microcredit, entrepreneur‐specific factors are equally important for firm performance. Thus, readjustment to the existing microcredit programs, especially on entrepreneurial and managerial developments, should be made so that entrepreneurial values and management competencies of the entrepreneurs could be enhanced from time to time for superior performance of MSEs.

Originality/value

This paper proves that microcredit is important for firm performance. It also reminds theorists and practitioners that entrepreneur‐specific factors should not be neglected in their theoretical or practical consideration of micro and small firm performance.
Impact of information sharing and green information systems
Authors: Meacham Jeramy , Toms Lisa , Green Kenneth W. , Bhadauria Vikram S.
Published: April 2013

Purpose

This paper aims to theorize and assess a structural model that depicts the impact of an organization's capability to share information with supply chain partners through a focused green information system for the purpose of improving environmental performance.

Design/methodology/approach

Data were collected from 159 manufacturing managers and analyzed using a structural equation modeling methodology.

Findings

The general capability to share information with supply chain partners coupled with the specific capabilities of green information systems enhances environmental performance. Green information systems serve as a partial mediator to the relationship between supply chain information sharing and environmental performance.

Research limitations/implications

While environmental sustainability has implications for all categories of supply chain partners, the study sample focuses on the manufacturing sector only.

Practical implications

Evidence supports the need for manufacturers to develop information sharing and green information system capabilities to improve environmental performance.

Originality/value

This is one of the first studies to empirically assess the role of information systems in achieving environmental sustainability. The results of this investigation support the proposition that information sharing among supply chain partners is a key to achieving environmental sustainability.
Canadian public relations students' interest in government communication
Authors: Berry Jeremy
Published: April 2013

Purpose

The purpose of this paper is to determine Generation Y communicators' interest in government communications.

Design/methodology/approach

This paper outlines the results of a descriptive quantitative survey conducted with 39 students and recent public relations graduates at Calgary, Canada's Mount Royal University.

Findings

The results from the small, purposive sample confirm some assumptions employers have about Generation Y and challenge others. The results identify key themes requiring future research.

Research limitations/implications

The research is limited in its sample size, but is not meant to be representative. It is a purposive, exploratory study that provides valuable insight into future research.

Originality/value

The paper sheds further light on this important topic and fills a gap in the research specific to Generation Y government communicators, offering valuable insight into the recruitment and retention of Generation Y staff in Canadian governments.
Welfare participation by immigrants in the UK
Authors: Drinkwater Stephen , Robinson Catherine
Published: April 2013

Purpose

The purpose of this paper is to examine the welfare participation of immigrant groups in the UK, which has experienced a large growth in its immigrant flows and population levels in recent years, especially following EU enlargement in 2004. The analysis particularly focuses on the types of benefits that immigrants tend to claim, as well as examining differences by area of origin. It also examines the factors that determine social assistance benefit claims, including an investigation of the impact of education, ethnicity and years since migration.

Design/methodology/approach

A series of probit regression models are estimated using data from the UK Labour Force Survey collected between 2004 and 2009.

Findings

Social welfare claims vary considerably by immigrant group as well as by the type of benefit claimed in the UK. There are also differences by immigrant group in the factors determining social assistance claims.

Research limitations/implications

It is very difficult to generalise on the issue of welfare participation by immigrants in the UK. This is important, given policy changes towards migrants from non‐EU countries and in relation to welfare reforms.

Originality/value

The limited previous work in this area for the UK has tended to analyse all benefit claims made by immigrants as a whole, whereas this analysis splits immigrants into different groups and focuses on the types of benefits that are claimed. This has important implications, particularly given the recent increase in immigration to the UK.
Immigration and welfare state cash benefits: the Danish case
Authors: Pedersen Peder J.
Published: April 2013

Purpose

The purpose of this paper is to summarize existing evidence on welfare dependence among immigrants in Denmark and to produce new evidence with focus on the most recent years.

Design/methodology/approach

The paper combines a broad descriptive/analytical approach with multivariate estimation on the impact on welfare dependence from individual background factors.

Findings

The main finding is the importance of aggregate low unemployment for immigrants to assimilate out of welfare dependence. Fairly small effects are reported from policy changes intending to influence the economic incentives between welfare programs and jobs.

Research limitations/implications

While panel data as used in the paper have a great potential, still a number of policy changes are not identified at the individual level. In further work it would be relevant to broaden the coverage including also some small policy programs and to extend the analysis to cover the period including the financial crisis years.

Social implications

The paper has a potential to influence public attitudes in this area and to inform further public policy regarding benefit programs.

Originality/value

The main new result is the finding, at a disaggregate level, of how changes in immigration policy and cyclical changes interact, influencing the assimilation into or out of dependence on cash benefit programs.
Social assistance among immigrants and natives in Sweden
Authors: Anders Gustafsson Björn
Published: April 2013

Purpose

The purpose of this paper is to provide an overview of the issue of social assistance receipt among immigrants to Sweden and compare to receipt by natives.

Design/methodology/approach

The paper describes the institutional background, reports statistical information and surveys the literature on the immigrant‐native disparity in social assistance receipt.

Findings

Most out‐payment for social assistance in Sweden refers to foreign‐born persons, a category comprising 14 percent of the population. Immigrants tend to assimilate out of social assistance receipt. However, receipt continues to be higher many years after immigration among immigrants from non‐rich countries than for natives with several identical characteristics. The elevated probabilities of social assistance receipt among immigrants from non‐rich countries are interpreted to be mainly due to failed integration into the labor market at the destination.

Practical implications

Policies for integrating immigrants into the labor market are also policies for reducing social assistance receipt among immigrants and reducing immigrant‐native social assistance disparity. However, other factors such as the structure of Swedish welfare policy play a role as well.

Originality/value

This is the first survey of the literature on disparities in social assistance receipt between immigrants and natives in Sweden.
The gender subtext of new public management‐based work practices in Swedish health care
Authors: Hedegaard Joel , Ahl Helene
Published: April 2013

Purpose

The purpose of this paper is to propose a theoretical framework for researching gender equality implications of Clinical Microsystems, a new public management‐based model for multi‐professional collaboration and improvement of health care delivery.

Design/methodology/approach

The paper draws on literature from gender in organizations, new public management, multi‐professional collaboration and organizational control to critically analyze the Clinical Microsystem model.

Findings

While on the surface an egalitarian and consensus‐based model, it nevertheless risks reinforcing a gendered hierarchical order. The explicit emphasis on social competencies, on being collaborative and amenable to change risks, paradoxically, disfavoring women. A major reason is that control becomes more opaque, which favors those already in power.

Practical implications

The paper calls for researchers as well as practitioners to incorporate concerns of equality in the work place when introducing new work practices in health care. For research, the authors propose a useful theoretical framework for empirical research. For practice, the paper calls for more transparent conditions for multi‐professional collaboration, such as formalized merit and advancement systems, precisely formulated performance expectations and selection of team members based strictly on formal merits.

Originality/value

A gender analysis of a seemingly anti‐hierarchical management model is an original contribution, adding to the literature on Clinical Microsystem in particular but also to critical studies on new public management. Moreover, the paper makes a valuable practical contribution in suggesting ways of avoiding the reproduction of gender inequalities otherwise implied in the model.
Economic recession and investment on human resource information systems (HRIS)
Authors: Iwu Chux , Benedict Henrie
Published: April 2013

Purpose

The purpose of this paper is to examine the impact of an economic recession on human resource information systems (HRIS) investment decisions by asking: Are there high levels of disinvestment in HRIS during a recession? Are there low levels of trust and confidence in HRIS during a recession? Could there be an absence of concerted commitment in leveraging technology, even in the face of an economic crunch?

Design/methodology/approach

An HRIS impact questionnaire was used, targeting human resource and financial managers. The data obtained were analyzed using Statistical Programme for Social Sciences (SPSS).

Findings

The findings suggest that while a recession is acknowledged, the continued use of HRIS is not considered a risk factor that warrants cost cutting.

Originality/value

This is an original study. It will add value by indicating to management the significance of strategic decision making. The study also points out the need for further research in order to make more sense of certain variables.
The analysis of demographic and work life variables which affect the occupational commitment of nurses
Authors: Benligiray Serap , Sonmez Harun
Published: April 2013

Purpose

It is very important for health institutions to develop the occupational commitment of their nurses. While the occupational commitments of the nurses develop during their education, they also change according to certain variables during their work life. In order to employ nurses who are more committed to their occupation, it is essential to know the effects of these variables on occupational commitment. The purpose of this paper is to exhibit and test a model that will display the correlation between demographic, work life and family life variables and occupational commitment.

Design/methodology/approach

The research was conducted with the participation of 355 nurses employed in seven state hospitals with 500 or more bed capacity and three medical faculties under the administration of Ankara Ministry of Health, using the proportional distribution method in stratified sampling. Structural equation modeling was used for analysis.

Findings

The results of the analysis suggest that there is a relationship between the nurses’ professional commitment and age, education, parental status, tenure and working hours scheme. Although the previous studies generally revealed a positive relationship between professional commitment and age and tenure, the relationship found out in this study is a negative one. Similarly, although a negative relationship was presented between professional commitment and parental status and working hours scheme, the relationship revealed in this study is a positive one. Further, unlike the previous studies, this study found out no relationship between the nurses’ professional commitment and weekly working time.

Originality/value

This study is an original study, having been applied to a different sample in a different cultural environment. The authors sincerely believe that the results of the study will be beneficial to the scientific world.