bluuebunny/crossref_metadata_2025 huggingface dataset:
Binge alcohol‐induced alterations in BDNF and GDNF expression in central extended amygdala and pyriform cortex on infant rats
Authors: Balaszczuk Verónica , Bender Crhistian , Pereno Germán , Beltramino Carlos A.
Published: April 2013

Mothers who consume alcohol during pregnancy may cause a neurotoxic syndrome termed fetal alcohol spectrum disorder (FASD) in the offspring, which includes cognitive deficits and emotional/social disturbances. These alterations are thought to be caused, at least in part, by alcohol‐induced imbalance in neurotrophic factor levels, which are critically involved in normal neurodevelopment. Our goal was to study whether brain‐derived neurotrophic factor (BDNF) and glial‐derived neurotrophic factor (GDNF) expression were affected by alcohol in central extended amygdala (CEXA) and pyriform cortex (Pyr), structures strongly involved in emotional/social behaviors. Further, we evaluated how these changes could be related to blood and brain alcohol concentrations. Postnatal day (PND) pups at 7, 15 and 20‐days old were administered alcohol (2.5 g/kg s.c. at 0 and 2 h) or saline. Immunohistochemistry was used to detect the expression of BDNF and GDNF at 2, 12 and 24 h after drug administration. Also, gas chromatography was bused to measure blood alcohol levels (BALs) and brain alcohol levels (BrALs) at each hour, from 2 to 8 h after the second alcohol administration. Results showed: (1) alcohol‐induced enhancement of BDNF positive cells on PND 7 and 20, a decrease on PND 15 in the CEXA, and no changes in the Pyr on PND 7 and 20, but a diminished on PND 15; (2) GDNF positive cells rise after alcohol administration for the three ages in the CEXA and Pyr except on PND 15, where there was a decline; and (3) pharmacokinetics analysis demonstrated age‐related differences showing equal BALs on PND 7 and 20 but higher BALs on PND 15. In contrast, BrALs were higher on PND 7 than 15 and 20. Hence, BALs may not be predictive of BrALs in postnatal rats. Furthermore, we did not find a relationship between age in pharmacokinetic differences and neurotrophins response. In conclusion, the CEXA and Pyr are brain structures sensitive to alcohol‐induced imbalance in neurotrophic factors expression; and BALs are not a mirror of BrALs.
Customer Attitude and Dispositions towards Customized Products: The Interaction between Customization Model and Brand
Authors: Miceli Gaetano “Nino” , Raimondo Maria Antonietta , Farace Stefania
Published: April 2013

Despite increasing interest in customization-related topics, little is known about the relation between customization and brand. The authors identify two main archetypes of product customization based on the degrees of freedom given to the customer in the design process: Combination-based Customization (CbC), which is the selection of product modules provided by the company, and Integration-based Customization (IbC), which is product customization by means of signs and symbols provided by the customer. The authors propose that customer attitude and dispositions towards CbC and IbC depend on the presence/absence of a mass brand logo upon the product. Results of three studies, based on web toolkits for t-shirt and trolley bag customization, demonstrate that in the presence of a mass brand logo CbC shows higher customer attitude and dispositions than IbC. In the absence of a mass brand logo, the opposite pattern holds. Additional findings show, however, that the advantage of CbC over IbC for branded products disappears when there is high congruence between the customer self and the brand, and when creative brands are considered.
Acquired Myopathy/Dystrophies
Authors: Chiodo Anthony
Published: April 2013

Diseases of muscle may be congenital or acquired. They cause muscle weakness without sensory loss. The onset, distribution, and clinical course help to differentiate the type of muscle disorder. The diagnostic workup may include laboratory examination, electrodiagnostic studies, and muscle biopsy. A definitive diagnosis leads to better decision making with regard to treatment, genetic education, prognosis, functional expectations, and the impact of exercise on muscle function.
External debt of post-communist countries
Authors: Yarashevich Viachaslau
Published: April 2013

On the background of continuous global economic instability and debt problems in the Eurozone, the significance of post-communist external debt goes without saying. The article will explore the scope and dynamics of external indebtedness in the post-communist world in a comparative and historical framework. Particular attention will be paid to a likelihood of a debt crisis in the region similar to the one in the developing world in the early 1980s. The debt crisis will be an ultimate price for reform mistakes and may have serious political economy implications by hampering or even reversing the process of the post-communist transformation.
Holocene vegetation history and fire regimes of Pseudotsuga menziesii forests in the Gulf Islands National Park Reserve, southwestern British Columbia, Canada
Authors: Lucas Jennifer D. , Lacourse Terri
Published: April 2013

Pollen analysis of a 9.03-m-long lake sediment core from Pender Island on the south coast of British Columbia was used to reconstruct the island's vegetation history over the last 10,000 years. The early Holocene was characterized by open mixed woodlands with abundant Pseudotsuga menziesii and a diverse understory including Salix and Rosaceae shrubs and Pteridium aquilinum ferns. The establishment of Quercus garryana savanna-woodland with P. menziesii and Acer macrophyllum followed deposition of the Mazama tephra until ~ 5500 cal yr BP, when these communities gave way to modern mixed P. menziesii forest. Charcoal analyses of the uppermost sediments revealed low charcoal accumulation over the last 1300 years with a mean fire return interval (mFRI) of 88 years. Fires were more frequent (mFRI = 50 yr) during the Medieval Climate Anomaly (MCA) with warm, dry conditions facilitating a higher fire frequency than during the Little Ice Age, when fires were infrequent. Given the projected warming for the next 50–100 years, land managers considering the reintroduction of fire to the Gulf Islands National Park Reserve may want to consider using the mFRI of the MCA as a baseline reference in prescribed burning strategies.
Late Quaternary aeolian activity in Gonghe Basin, northeastern Qinghai-Tibetan Plateau, China
Authors: Qiang Mingrui , Chen Fahu , Song Lei , Liu Xingxing , Li Mingzhi , Wang Qin
Published: April 2013

Aeolian deposits at four sites in the Gonghe Basin were used to reconstruct the history of aeolian activity over the late Quaternary. These deposits include well-sorted aeolian sand, paleosols and/or loess. Aeolian sand represents dune-field expansion and/or dune buildup, whereas paleosols indicate stabilization of dunes, accompanying ameliorated vegetation cover. On the basis of 25 dates by optically stimulated luminescence (OSL), it appears that aeolian activities occurred episodically at 33.5, 20.3, 13.9, 11.8–11.0, 9.4, 7.8, and 5.7 (5.5) ka, which is largely consistent with the recent findings from the adjacent semi-arid areas. Aeolian sand mobility occurring during the early to mid Holocene conflicts with a climatic optimum inferred from lacustrine records in the northeastern Qinghai-Tibetan Plateau. This inconsistency may be resolved by interpreting aeolian activity as a response to decreased effective moisture due to enhanced evaporation, induced by higher summer insolation at that time, together with local terrain and its effects on moisture. Our results suggest that aeolian sand and paleosol cannot be simply ascribed to regional dry and wet climates, respectively, and they most likely reflect changes in effective moisture.
Analysis of hemlock pollen size in Holocene lake sediments from New England
Authors: Day Lindsay T. , Oswald W. Wyatt , Doughty Elaine D. , Foster David R.
Published: April 2013

We explored the middle-Holocene decline of Tsuga canadensis by measuring the diameters of pollen grains in two lake-sediment cores from New England. We hypothesized that a drop in pollen size at the time of the decline followed by an increase in pollen diameters as Tsuga recovered during the late Holocene might indicate reduced abundance of Tsuga in the vicinity of the lake during the decline, as smaller pollen grains travel farther than larger ones. To provide context for this hypothesis, we also measured the diameters of Tsuga pollen grains in the surface sediments of sites spanning the modern-day gradient of Tsuga in New England. Both fossil records exhibited a reduction in pollen size during the interval of the middle-Holocene decline, with diameters similar to those observed in the upper sediments of those sites, yet larger than Tsuga pollen grains in the surface sediments of coastal sites beyond the modern range of Tsuga. This pattern suggests that Tsuga persisted in scattered, low-density populations during the middle Holocene, as it has remained on the landscape since European settlement.
Rigidity and non-recurrence along sequences
Authors: BERGELSON V. , DEL JUNCO A. , LEMAŃCZYK M. , ROSENBLATT J.
Published: April 2013

We study two properties of a finite measure-preserving dynamical system and a given sequence$({n}_{m} )$of positive integers, namely rigidity and non-recurrence. Our goal is to find conditions on the sequence which ensure that it is, or is not, a rigid sequence or a non-recurrent sequence for some weakly mixing system or more generally for some ergodic system. The main focus is on weakly mixing systems. For example, we show that for any integer$a\geq 2$the sequence${n}_{m} = {a}^{m} $is a sequence of rigidity for some weakly mixing system. We show the same for the sequence of denominators of the convergents in the continued fraction expansion of any irrational$\alpha $. We also consider the stronger property of IP-rigidity. We show that if$({n}_{m} )$grows fast enough then there is a weakly mixing system which is IP-rigid along$({n}_{m} )$and non-recurrent along$({n}_{m} + 1)$.
Luminosity Bias: From Haloes to Galaxies
Authors: Baugh C. M.
Published: April 2013

Large surveys of the local Universe have shown that galaxies with different intrinsic properties such as colour, luminosity and morphological type display a range of clustering amplitudes. Galaxies are therefore not faithful tracers of the underlying matter distribution. This modulation of galaxy clustering, called bias, contains information about the physics behind galaxy formation. It is also a systematic to be overcome before the large-scale structure of the Universe can be used as a cosmological probe. Two types of approaches have been developed to model the clustering of galaxies. The first class is empirical and filters or weights the distribution of dark matter to reproduce the measured clustering. In the second approach, an attempt is made to model the physics which governs the fate of baryons in order to predict the number of galaxies in dark matter haloes. I will review the development of both approaches and summarise what we have learnt about galaxy bias.
Supplementation with a juice powder concentrate and exercise decrease oxidation and inflammation, and improve the microcirculation in obese women: randomised controlled trial data
Authors: Lamprecht Manfred , Obermayer Georg , Steinbauer Kurt , Cvirn Gerhard , Hofmann Lidija , Ledinski Gerhard , Greilberger Joachim F. , Hallstroem Seth
Published: April 2013

Obesity and sedentary lifestyle are associated with increased oxidative stress, inflammation and vessel dysfunction. Previous research has shown that an encapsulated fruit/berry/vegetable juice powder (FBV) supplement or controlled exercise training improve the markers of redox biology, low-grade inflammation and circulation. The aim of the present study was to assess the effects of 8 weeks of supplementation with FBV or placebo, and a single bout of controlled walking on the markers of oxidation, inflammation and skin capillary microcirculation in forty-two obese pre-menopausal women (41 (sd 5) years, non-smokers and BMI 34·5 (sd 3·8) kg/m2) using a randomised, double-blind, placebo-controlled design. All assessments were made before and after 8 weeks of capsule supplementation, and pre- and post-30 min of controlled treadmill walking at 70 % of VO2max. Venous blood was collected for the determination of carbonyl proteins (CP), oxidised LDL (ox-LDL), total oxidation status (TOS) of lipids, malondialdehyde, TNF-α and IL-6. Capillary blood flow, O2 saturation of Hb (SO2Hb) and the relative concentration of Hb (rHb) were assessed at a 2 mm skin depth. Following 8 weeks of supplementation, compared with placebo, the FBV group had a significant (P< 0·05) reduction in CP, ox-LDL, TOS and TNF-α, and a significant increase in blood flow, SO2Hb and rHb. Independent of supplementation, moderate exercise significantly increased blood flow and rHb, with a trend towards increased SO2Hb. Compared with placebo, 8 weeks of supplementation with FBV decreased the markers of systemic oxidation and inflammation. Both FBV supplementation and a single walking bout improved the markers of the microcirculation in these obese women.
Wildlife predation on livestock and poultry: implications for predator conservation in the rainforest of south-east Mexico
Authors: Amador-Alcalá Saúl , Naranjo Eduardo J. , Jiménez-Ferrer Guillermo
Published: April 2013

We assessed wildlife predation on livestock and poultry and the implications for predator conservation in the most important rainforest areas of south-east Mexico. We estimated the economic impact of predation and identified variables correlated to predation frequency in four communities adjacent to Calakmul and Montes Azules Biosphere Reserves. We did participant observation and interviews with 161 residents during January–September 2010. We recorded 2,861 deaths of livestock and poultry from predation by wild carnivores over the previous 3 years. Opossums (n = 677 predation events), raptors (n = 676) and ocelots (n = 539) were responsible for the highest numbers of killings. Poultry constituted the main target of wild predators (n = 2,548 deaths). Sheep (n = 201 events) and cattle (167) were the most affected by large predators such as jaguarPanthera oncaand pumaPuma concolor. Economic losses from predation were estimated to be USD 55,600 over the 3 years in the four communities. Predation frequency was positively correlated with livestock numbers (r2 = 0.87, P < 0.05) but negatively associated with wild prey abundance (r2 = 0.96, P < 0.05). Better husbandry practices focused on the safety and location of livestock enclosures and on reducing overabundance of dogs and regulating hunting on wild prey in rural areas may help mitigating conflict between wild predators and residents in the rainforests of south-east Mexico.
Biological attributes and major threats as predictors of the vulnerability of species: a case study with Brazilian reef fishes
Authors: Bender M.G. , Floeter S.R. , Mayer F.P. , Vila-Nova D.A. , Longo G.O. , Hanazaki N. , Carvalho-Filho A. , Ferreira C.E.L.
Published: April 2013

Global biodiversity declines and increasing rates of extinction necessitate the assessment and prediction of the vulnerability of species to extinction. Here, we examine the relationships between conservation status and ecological traits of reef fish species of the Brazilian biogeographical province. We used binomial tests and a logistic regression to address two questions. Do biological attributes differ between threatened and non-threatened fishes? Which combination of traits and impacts exerts greater influence on species threat status? Of the 559 species, 36 are categorized as threatened (compiled from global, national and local Red Lists). Three species are categorized as Critically Endangered, seven as Endangered and 26 as Vulnerable. Our analyses revealed that Elasmobranchii, sex-changing bony fishes and endemic species are the most vulnerable reef fishes in Brazilian waters. Body size and trophic category were identified as good predictors of the vulnerability of a species to extinction. Small-bodied species that are exploited by the ornamental trade and have complex reproductive strategies are also of concern. Such combinations of attributes could be of value in predicting which reef fish species elsewhere have a high risk of extinction.
Estimating abundance of the Endangered onager Equus hemionus onager in Qatruiyeh National Park, Iran
Authors: Hemami Mahmoud-Reza , Momeni Moslem
Published: April 2013

Historically, the onager or Persian wild ass Equus hemionus onager, endemic to Iran, was widespread on the arid and semi-arid central steppes but only two natural populations remain. We estimated the population density of the onager in Qatruiyeh National Park using line transect distance sampling. Transects were surveyed on three plains in the Park and the results compared with total counts conducted by the Department of Environment. Our estimate (109 onagers per 100 km2; 95% confidence interval 67–179) is similar to that obtained by the total counts (137 onagers per 100 km2). Distance sampling is therefore a promising method for estimating the abundance of the onager. Using the annual censuses performed by the Department of Environment over the last 13 years we estimated that the population has a growth rate of 0.09. During the same period the onager population in the Touran Protected Complex has experienced a severe decline. The high density of onagers within the National Park indicates the unsuitability of adjacent habitats, including Bahram-e-Goor Protected Area, for this species. Lack of sufficient security and poorly distributed water sources appear to be the main reasons discouraging onagers from entering the Bahram-e-Goor Protected Area. We recommend and describe management interventions that could potentially assist in maintaining the last surviving onager populations in Iran.
Detecting an increase in an Endangered huemulHippocamelus bisulcuspopulation following removal of cattle and cessation of poaching in coastal Patagonia, Chile
Authors: Briceño Cristóbal , Knapp Leslie A. , Silva Alejandra , Paredes José , Avendaño Iván , Vargas Aliro , Sotomayor Juan , Vila Alejandro R.
Published: April 2013

The conservation of threatened species poses many challenges but through cooperation and pooling of resources, individuals and organizations can work together to achieve better results. Here we describe our experience, working through a governmental and private alliance, studying one of the most threatened mammals in the Southern Cone. The huemul deerHippocamelus bisulcus, one of two members of theHippocamelusgenus of South America, is endemic to Argentina and Chile and currently inhabits only a small fraction of its former range. Little is known about the huemul because it generally lives in remote areas with a harsh climate and rugged terrain. Using drive counts and fixed width transects over 5 consecutive years (2004–2008) we estimated density and abundance, and examined population changes and social structure, in three coastal huemul populations in the area of the Témpanos and Bernardo fjords of Bernardo O'Higgins National Park, Chile. Our results suggest that synergistic conservation actions, such as cattle removal and poaching control, can lead to the recovery of threatened huemul. The baseline information obtained from our surveys and the lessons learned through this governmental and private alliance will be useful for future monitoring of the huemul in the Patagonian fjords of Chile.
Demand and proximity: drivers of illegal forest resource extraction
Authors: Mackenzie Catrina A. , Hartter Joel
Published: April 2013

Illegal extraction from protected areas is often shaped by the surrounding socio-economic landscape. We coupled village-scale socio-economic parameters collected using household surveys with measured levels of illegal resource extraction proximate to study villages to investigate the socio-economic drivers of illegal extraction from Kibale National Park, Uganda. The level of illegal tree harvesting and the number of illegal entry trails into the Park were driven by subsistence demand from villages adjacent to the Park and by for-profit extraction to supply local urban markets, whereas grazing in the Park was linked to high livestock ownership. Capital asset wealth, excluding livestock, was found to mitigate illegal resource extraction from the Park. We also found high human population density to coincide spatially with park-based tourism, research and carbon sequestration employment opportunities. Conservation strategies should be integrated with national policy to meet the needs of local communities and to manage urban demand to reduce illegal extraction from protected areas.
Cognitive science of religion and theism: how can they be compatible?
Authors: NÄREAHO LEO
Published: April 2013

In this article, I examine the compatibility thesis, according to which the assumptions and results of cognitive (and other bio-psychological) theories of religion are compatible with the theistic world-view. In particular, I analyse the conception of world-view neutrality concerning scientific theories of religion. I also investigate the nature of pro-theistic argumentation; one aspect of this is the role that various forms of naturalism have in theistic compatibility claims. I point out that the version of theism guiding the argumentation of the proponents of the compatibility thesis is seldom explicated. A commitment to classical theism is problematic because of the ultimate metaphysical separation of God and the world. Instead, I support the compatibility view with a notion of God construed as the structuring cause of the world.
A study of teacher formative influence upon and student experience of social–emotional learning climate in secondary school music settings
Authors: Carlisle Katie
Published: April 2013

Conceiving the construct ‘social-emotional learning climate’ as an embodiment of Illeris’ contemporary learning theory, this paper serves dual purposes. First, it examines recent music education literature, which identifies issues of competence and institutionalised pedagogic practice in secondary school music settings that result in adolescents’ inability to target and develop personal locus of control over learning, and the subsequent rejection of the learning environment. Second, it details findings, discussion and pedagogic implications from the author's dissertation study exploring music teacher formative influence upon and student experience of Illeris’ theory of learning process within three Canadian secondary school learning settings integrating informal learning practices.
Quick X-ray reflectivity of spherical samples
Authors: Stoev Krassimir , Sakurai Kenji
Published: April 2013

Recently, a new experimental setup for quick X-ray reflectivity (q-XRR) measurements was proposed, which is based on simultaneous recording of an X-ray reflectivity curve over all angles of interest. This new setup for q-XRR allows measurements to be done within seconds, thus permitting studies of the time evolution of chemical, thermal, and mechanical changes at the surfaces and interfaces of different materials. Since the q-XRR measurement setup utilizes an extended X-ray source and detector, it is important to develop models and to account for the following two effects: (i) diffuse scattering associated with different points of the source and (ii) sample curvature. Models accounting for both effects are presented, and their influences on interpretation of the q-XRR measurement results are discussed.
Synthesis and crystallographic study of cation substituted NZP materials: Na1+xZr2−xMxP3O12(M = Sb, Al, Cr andx = 0.1)
Authors: Chourasia Rashmi , Shrivastava O. P.
Published: April 2013

A novel concept of immobilization of light water nuclear reactor fuel reprocessing waste effluent through interaction with sodium zirconium phosphate (NZP) has been established. It was found that a large number of hazardous cations could be loaded in the NZP-based matrix without significant change of three-dimensional framework structure. Starting from the raw powder diffraction data of polycrystalline solid phases, crystal structure of substituted NZP phases has been investigated using the General Structure Analysis System (GSAS) package. Cation(s) substituted NZP phases crystallize in rhombohedral symmetry (space groupR-3candZ = 6). Powder diffraction data have been subjected to Rietveld refinement to reach satisfactory structural convergence ofR-factors. Unit cell parameters, inter atomic distances, bond angles, reflecting planes (h,k,l), structure factors, polyhedral (ZrO6and PO4) distortion, and particle size have been reported. PO4stretching and bending vibrations in the Infra red (IR) region have been assigned. SEM and EDAX analysis provide analytical evidence of fixation of cations in the matrix.
Analytical method for observed powder diffraction intensity data based on maximum likelihood estimation
Authors: Ida Takashi , Izumi Fujio
Published: April 2013

A new methodology based on maximum likelihood estimation for structure refinement using powder diffraction data is proposed. The method can not only optimize the parameters adjusted in Rietveld refinement but also parameters to specify errors in a model for statistical properties of the observed intensity. The results of structure refinements with relation to fluorapatite Ca5(PO4)3F, anglesite PbSO4, and barite BaSO4 are demonstrated. The structure parameters of fluorapatite and barite optimized by the new method are closer to single-crystal data than those optimized by the Rietveld method, while the structure parameters of anglesite, whose values optimized by the Rietveld method are already in good agreement with the single-crystal data, are almost unchanged by the application of the new method.
Application of micro-XRF for nuclear materials characterization and problem solving
Authors: Worley Christopher G. , Tandon Lav , Martinez Patrick T. , Decker Diana L.
Published: April 2013

A number of spatially resolved elemental imaging techniques are commonly employed to examine plutonium and other nuclear materials (e.g., scanning electron microscopy). Up until the past 10–15 years, micro-X-ray fluorescence (MXRF) instrumentation had been relatively uncommon, and even currently, it is underutilized for spatially resolved nuclear materials analysis and imaging. In the current study, a number of plutonium materials problem solving applications are presented to demonstrate the power and utility of MXRF for providing unique, spatially resolved elemental composition information. Applications discussed include identification of multiple insoluble fractions in plutonium and neptunium mixed oxide, spatially resolved imaging of plutonium residue and other elements on surface swipes, and spatial mapping of impurities in plutonium metal. The mixed oxide particle analysis demonstrated the ability to non-destructively identify particles of interest for potential extraction and analysis by other methods. The surface swipes study demonstrated the unique ability of MXRF to non-destructively image large multiple cm2 sized, non-conducting, radiologically contaminated samples. The plutonium metal investigation showed the capability of MXRF to non-destructively map elemental heterogeneity directly in an actinide matrix. Such information is extremely valuable prior to using destructive analysis (DA) trace elemental analytical chemistry techniques. If a metal is found to contain significant elemental impurity heterogeneity by MXRF, time consuming destructive sample preparation and analysis do not need to be repeated to confirm that the sample is indeed heterogeneous.
The effect of iodine-deficiency disorders on academic achievement of schoolchildren in Southern Ethiopia
Authors: Wolka Eskinder , Shiferaw Solomon , Biadgilign Sibhatu
Published: April 2013

Objective

The present study aimed to assess the effect of iodine deficiency on academic achievement of schoolchildren in Wolaita Sodo town, Southern Ethiopia.

Design

School-based comparative cross-sectional study.

Settings

Primary school in Sodo town, Southern Ethiopia.

Subjects

A sample population of 270 children with goitre and 264 without goitre. All students in each class were examined for the presence of goitre and classified based on WHO recommendations.

Results

Among children with goitre, a higher proportion (54·8 %) was female and the proportion increased with age. The odds of scoring low on school performance was higher among children whose fathers were illiterate (adjusted OR = 1·9; 95 % CI 1·1, 3·5) and those who were absent for more than 5 d in the last academic year (adjusted OR = 1·5; 95 % CI 1·1, 2·3). Goitre was significantly associated with low academic achievement (adjusted OR = 1·8; 95 % CI 1·2, 2·5).

Conclusions

The study showed that the presence of goitre has a negative effect on academic achievement even after accounting for parental education and absenteeism from school. Awareness of endemic goitre and its impact on school performance, and an emphasis on prevention and control by concerned bodies, are recommended to alleviate the problem.
Selenium levels and hypertension: a systematic review of the literature
Authors: Kuruppu Dulanji , Hendrie Hugh C , Yang Lili , Gao Sujuan
Published: April 2013

Objective

Se is an antioxidant micronutrient and has been studied for its potential role in CVD prevention. The purpose of the present study was to conduct a systematic review of the literature on the relationship between Se and hypertension.

Design

We conducted a systematic literature search in PubMed and OVID of studies on Se levels and hypertension or blood pressure published in English up to June 2011. Articles meeting inclusion criteria were reviewed and the following information was gathered from each publication: study setting, participant demographics, exclusion criteria, intervention if applicable, medium of Se measure, mean level of Se, outcome definition, relationship between Se and the outcome variable, significance of this relationship, and covariates. In studies that also reported glutathione peroxidase levels, we extracted results on the relationship between glutathione peroxidase and hypertension.

Results

Twenty-five articles were included. Approximately half of the studies reported no significant relationship between Se and hypertension. Of the remaining studies, about half found that higher Se levels were associated with lower blood pressure and the other half found the opposite relationship. The studies varied greatly in terms of study population, study design and Se levels measured in participants.

Conclusions

Based on the present systematic review, there is no conclusive evidence supporting an association between Se and hypertension. Randomized controlled trials and prospective studies with sufficient sample size in populations with different Se levels are needed to fully investigate the relationship between Se and hypertension.
ON THE EXPONENT OF A VERBAL SUBGROUP IN A FINITE GROUP
Authors: SHUMYATSKY PAVEL
Published: April 2013

Let $w$ be a multilinear commutator word. We prove that if $e$ is a positive integer and $G$ is a finite group in which any nilpotent subgroup generated by $w$-values has exponent dividing $e$, then the exponent of the corresponding verbal subgroup $w(G)$ is bounded in terms of $e$ and $w$only.
COMPLEX NUMBERS WITH BOUNDED PARTIAL QUOTIENTS
Authors: BOSMA WIEB , GRUENEWALD DAVID
Published: April 2013

Conjecturally, the only real algebraic numbers with bounded partial quotients in their regular continued fraction expansion are rationals and quadratic irrationals. We show that the corresponding statement is not true for complex algebraic numbers in a very strong sense, by constructing, for every even degree $d$, algebraic numbers of degree $d$ that have bounded complex partial quotients in their Hurwitz continued fraction expansion. The Hurwitz expansion is the complex generalization of the nearest integer continued fraction for real numbers. In the case of real numbers the boundedness of regular and nearest integer partial quotients is equivalent.
Use of advanced imaging to generate novel insights in inflammation and adaptive immunity
Authors: Hickey Michael J
Published: April 2013

In the April 2013 issue of Immunology and Cell Biology, we present an important special feature on in vivo imaging. Recent technological advances in imaging infrastructure and systems are leading to the discovery of previously hidden features and phenomena. Key exponents of in vivo imaging describe the use of state‐of‐the‐art imaging in their respective fields and illustrate the impact this technique has had on the understanding of inflammation and immunology. Together, the articles illustrate the range of advanced imaging methodologies available today, and detail their use in the investigation of a wide variety of immune responses. Further background information on this important topic is available through the accompanying web focus which links to related articles from across Nature Publishing Group.
Increasing population growth by asymmetric segregation of a limiting resource during cell division
Authors: Avraham Nurit , Soifer Ilya , Carmi Miri , Barkai Naama
Published: April 2013

We report that when budding yeast are transferred to low‐metal environment, they adopt a proliferation pattern in which division is restricted to the subpopulation of mother cells which were born in rich conditions, before the shift. Mother cells continue to divide multiple times following the shift, generating at each division a single daughter cell, which arrests in G1. The transition to a mother‐restricted proliferation pattern is characterized by asymmetric segregation of the vacuole to the mother cell and requires the transcription repressor Whi5. Notably, while deletion of WHI5 alleviates daughter cell division arrest in low‐zinc conditions, it results in a lower final population size, as cell division rate becomes progressively slower. Our data suggest a new stress‐response strategy, in which the dilution of a limiting cellular resource is prevented by maintaining it within a subset of dividing cells, thereby increasing population growth.
Advancing the defensive explanation for anxiety disorders: lorazepam effects on human defense are systematically modulated by personality and threat-type
Authors: Perkins A M , Ettinger U , Weaver K , Schmechtig A , Schrantee A , Morrison P D , Sapara A , Kumari V , Williams S C R , Corr P J
Published: April 2013

Clinically effective drugs against human anxiety and fear systematically alter the innate defensive behavior of rodents, suggesting that in humans these emotions reflect defensive adaptations. Compelling experimental human evidence for this theory is yet to be obtained. We report the clearest test to date by investigating the effects of 1 and 2 mg of the anti-anxiety drug lorazepam on the intensity of threat-avoidance behavior in 40 healthy adult volunteers (20 females). We found lorazepam modulated the intensity of participants’ threat-avoidance behavior in a dose-dependent manner. However, the pattern of effects depended upon two factors: type of threat-avoidance behavior and theoretically relevant measures of personality. In the case of flight behavior (one-way active avoidance), lorazepam increased intensity in low scorers on the Fear Survey Schedule tissue-damage fear but reduced it in high scorers. Conversely, in the case of risk-assessment behavior (two-way active avoidance), lorazepam reduced intensity in low scorers on the Spielberger trait anxiety but increased it in high scorers. Anti-anxiety drugs do not systematically affect rodent flight behavior; therefore, we interpret this new finding as suggesting that lorazepam has a broader effect on defense in humans than in rodents, perhaps by modulating general perceptions of threat intensity. The different patterning of lorazepam effects on the two behaviors implies that human perceptions of threat intensity are nevertheless distributed across two different neural streams, which influence effects observed on one-way or two-way active avoidance demanded by the situation.
Epithelial–mesenchymal transition and cancer stemness: the Twist1–Bmi1 connection
Authors: Wu Kou-Juey , Yang Muh-Hwa
Published: April 2013

EMT (epithelial–mesenchymal transition), a major mechanism of cancer metastasis, is a process that generates cells with stem-like properties. These stem-like cells in tumours are described as cancer stem cells. The link between EMT and cancer stemness is well documented without detailed mechanistic proof. Bmi1 belongs to the PRC1 (polycomb repressive complex 1) maintaining self-renewal and stemness together with EZH2 (enhancer of zeste homologue 2), which is a component of PRC2. Bmi1 is frequently overexpressed in different types of human cancers. Recent demonstration of an EMT regulator, Twist1, directly regulating the expression of Bmi1 provides a mechanistic explanation of the relationship between EMT and cancer stemness. The functional interdependence between Twist1 and Bmi1 provides a fresh insight into the common mechanism mediating EMT and cancer stemness. This observation is also confirmed using head and neck cancer patient samples. These results provide a critical mechanism of Twist1-induced EMT and cancer stemness in cancer cells through chromatin remodelling. The role of hypoxia and microRNAs in regulating EMT and cancer stemness is also discussed.
Single-molecule FRET study of SNARE-mediated membrane fusion
Authors: Diao Jiajie , Ishitsuka Yuji , Bae Woo-Ri
Published: April 2013

Membrane fusion is one of the most important cellular processes by which two initially distinct lipid bilayers merge their hydrophobic cores, resulting in one interconnected structure. Proteins, called SNARE (soluble N-ethylmaleimide-sensitive factor-attachment protein receptor), play a central role in the fusion process that is also regulated by several accessory proteins. In order to study the SNARE-mediated membrane fusion, the in vitro protein reconstitution assay involving ensemble FRET (fluorescence resonance energy transfer) has been used over a decade. In this mini-review, we describe several single-molecule-based FRET approaches that have been applied to this field to overcome the shortage of the bulk assay in terms of protein and fusion dynamics.
Piezoelectric Al1−xScxN thin films: A semiconductor compatible solution for mechanical energy harvesting and sensors
Authors: Matloub R. , Hadad M. , Mazzalai A. , Chidambaram N. , Moulard G. , Sandu C. S. , . Metzger Th , Muralt P.
Published: April 2013

The transverse piezoelectric coefficient e31,f of Al1-xScxN thin films was investigated as a function of composition. It increased nearly 50% from x = 0 to x = 0.17. As the increase of the dielectric constant was only moderate, these films are very suitable for energy harvesting, giving a 60% higher transformation yield (x = 0.17) as compared to pure AlN. A higher doping might even lead to a 100% augmentation. The thickness strain response (d33,f) was found to increase proportionally to the ionic part of the dielectric constant. The e-type coefficients (stress response), however, did not augment so much as the structure becomes softer. As a result, the transverse voltage/strain response (h31,f-coefficient) was raised only slightly with Sc doping. The low dielectric loss obtained at all compositions suggests also the use of Al1−xScxN thin films in sensors.
Diffusion transport coefficients for granular binary mixtures at low density: Thermal diffusion segregation
Authors: Garzó Vicente , Murray J. Aaron , Vega Reyes Francisco
Published: April 2013

The mass flux of a low-density granular binary mixture obtained previously by solving the Boltzmann equation by means of the Chapman-Enskog method is considered further. As in the elastic case, the associated transport coefficients D, Dp, and D′ are given in terms of the solutions of a set of coupled linear integral equations which are approximately solved by considering the first and second Sonine approximations. The diffusion coefficients are explicitly obtained as functions of the coefficients of restitution and the parameters of the mixture (masses, diameters, and concentration) and their expressions hold for an arbitrary number of dimensions. In order to check the accuracy of the second Sonine correction for highly inelastic collisions, the Boltzmann equation is also numerically solved by means of the direct simulation Monte Carlo (DSMC) method to determine the mutual diffusion coefficient D in some special situations (self-diffusion problem and tracer limit). The comparison with DSMC results reveals that the second Sonine approximation to D improves the predictions made from the first Sonine approximation. We also study the granular segregation driven by a uni-directional thermal gradient. The segregation criterion is obtained from the so-called thermal diffusion factor Λ, which measures the amount of segregation parallel to the temperature gradient. The factor Λ is determined here by considering the second-order Sonine forms of the diffusion coefficients and its dependence on the coefficients of restitution is widely analyzed across the parameter space of the system. The results obtained in this paper extend previous works carried out in the tracer limit (vanishing mole fraction of one of the species) by some of the authors of the present paper.
Inducing bistability with local electret technology in a microcantilever based non-linear vibration energy harvester
Authors: López-Suárez M. , Agustí J. , Torres F. , Rurali R. , Abadal G.
Published: April 2013

A micro-electro-mechanical system based vibration energy harvester is studied exploring the benefits of bistable non linear dynamics in terms of energy conversion. An electrostatic based approach to achieve bistability, which consists in the repulsive interaction between two electrets locally charged in both tip free ends of an atomic force microscope cantilever and a counter electrode, is experimentally demonstrated. A simple model allows the prediction of the measured dynamics of the system, which shows an optimal distance between the cantilever and the counter electrode in terms of the root mean square vibration response to a colored Gaussian excitation noise.
Simulations of laminar flow past a superhydrophobic sphere with drag reduction and separation delay
Authors: Gruncell Brian R. K. , Sandham Neil D. , McHale Glen
Published: April 2013

Superhydrophobic surfaces have potential for reducing hydrodynamic drag by combining a structured surface and hydrophobicity to retain a lubricating air layer (plastron) at the surface. In the present contribution, numerical simulations of laminar flow past a superhydrophobic sphere are conducted using a two-phase flow representation. The results show drag reductions in Stokes flow of up to 19% for an air-water system, in agreement with previous analytic work, and demonstrate an increased effect as the Reynolds number is increased to 100. Drag reductions of up to 50% are achieved due to reduction in viscous drag and suppression of separation by the plastron, resulting in a narrower wake. To explore a less idealised model of the plastron, baffles have also been introduced to simulate the support of a plastron by roughness elements. The baffles lead to the attached vortex regime no longer being suppressed, but separation is delayed and drag reductions are evident in comparison to a solid sphere. Increasing the area solid fraction results in a diminished drag reduction due to the plastron, however drag reductions of up to 15% can still be achieved with solid fractions of 10%.
Obliquely propagating waves in the magnetized strongly coupled one-component plasma
Authors: Kählert Hanno , Ott Torben , Reynolds Alexi , Kalman Gabor J. , Bonitz Michael
Published: April 2013

The quasi-localized charge approximation is used to calculate the wave spectrum of the magnetized three-dimensional strongly coupled one-component plasma at arbitrary angles θ between the wave vector and the magnetic field axis. Three frequency branches are identified whose interplay is strongly determined by β=ωc/ωp, the ratio of the cyclotron frequency ωc, and the plasma frequency ωp. The frequency dispersion relations for the three principal modes along the magnetic field cross in the case β<1, which strongly affects the transition from parallel to perpendicular wave propagation. For β>1, the frequencies of the different branches are well separated, and the long-wavelength dispersion in the intermediate and upper branch changes sign as θ is varied from 0 to π/2. In addition to the frequencies, we also investigate the waves' polarization properties.
Stability and spacial trap state distribution of solution processed ZnO-thin film transistors
Authors: Ortel Marlis , Pittner Steve , Wagner Veit
Published: April 2013

Solution processed zinc oxide thin film transistors (TFTs) were investigated for spacial identification of instability inducing electronic trap states by utilizing surface-to-active-channel distance dependent analysis. It is shown that the performance and stability of zinc oxide TFTs deposited by spray pyrolysis strongly depend on the surface-to-channel distance and herewith on the film thickness in the investigated regime from 1 nm to 30 nm. In thin layers, the charge transport process is dominated by the number of percolation paths and near channel trapping processes due to coulomb interactions with surface charges. This leads to a high thickness of 3 nm for the percolation threshold. As soon as a closed layer is formed and the charge separation of 7 nm between surface and active channel is exceeded, bulk properties become more dominant. A maximum linear mobility of 11cm2 V−1 s−1 and an on-set voltage of 2 V were obtained for a film thickness of 30 nm. An increase of the film thickness from 10 nm to 30 nm leads to a reduction in the trap rate by one order of magnitude from 4.3 × 108 cm−2 s−1 to 3.7 × 107 cm−2 s−1. Due to this, the bias stress stability and the long term storage stability were found to improve significantly.
Formation of self-assembled large droplet-epitaxial GaAs islands for the application to reduced reflection
Authors: Lee E. H. , Song J. D. , Yoon J. J. , Bae M. H. , Han I. K. , Choi W. J. , Chang S. K. , Kim Y. D. , Kim J. S.
Published: April 2013

The structural and reflectance properties of large gallium (Ga) droplets and GaAs islands grown by droplet epitaxy (DE) were presented. The reflectance results of self-assembled large GaAs islands by DE suggest the possibility of a novel method for antireflective coating. The diameter, height, density, and aspect ratio of large Ga droplets were investigated up to the scale of optical size. After GaAs island growth, the reflectance of s-polarization at 70° on in-situ measurement was reduced up to approximately 2%–20% in the wavelength range of 350–900 nm. For large GaAs islands, reduction of reflectance for s-, p-polarization at 20°–80° and reduction of reflectance at normal incidence was presented. This result shows that a layer of self-assembled large GaAs islands by DE can be a good candidate for an antireflector for high-quality optoelectronic devices.
High power buried sampled grating distributed feedback quantum cascade lasers
Authors: Zhang J. C. , Liu F. Q. , Yao D. Y. , Zhuo N. , Wang L. J. , Liu J. Q. , Wang Z. G.
Published: April 2013

A novel index-coupled distributed feedback quantum cascade laser emitting at λ ∼ 4.8 μm is demonstrated by a sampled grating. The coupling coefficient can be almost controlled arbitrarily according to the duty cycle of sampled grating. The additional supermodes caused by the sampled grating can be strongly suppressed by choosing a small sampling period, so that the supermodes are shifted apart from the gain curve. Single-mode emission without any significant disadvantages compared with uniform grating is achieved. Especially, this powerful approach presented here can be applied to achieve the performance with high power and low threshold simultaneously.