bluuebunny/crossref_metadata_2025 huggingface dataset:
Patterns and processes in complex landscapes: testing alternative biogeographical hypotheses through integrated analysis of phylogeography and community ecology in Hawai'i
Authors: Eldon Jon , Price Jonathan P. , Magnacca Karl , Price Donald K.
Published: May 2013

The Island of Hawai'i is a dynamic assemblage of five volcanoes with wet forest habitat currently existing in four distinct natural regions that vary in area, age and geographical isolation. In this complex landscape, alternative assumptions of the relative importance of specific habitat characteristics on evolutionary and ecological processes predict strikingly different general patterns of local diversity and regional similarity. In this study, we compare alternative a priori hypotheses against observed patterns within two distinct biological systems and scales: community composition of wet forest vascular plant species and mitochondrial and nuclear genes of Drosophila sproati, a wet‐forest‐restricted endemic. All observed patterns display strong and similar regional structuring, with the greatest local diversity found in Kohala and the windward side of Mauna Loa, the least in Ka'ū and Kona, and a distinctive pattern of regional similarity that probably reflects the historical development of this habitat on the island. These observations largely corroborate a biogeographical model that integrates multiple lines of evidence, including climatic reconstruction, over those relying on single measures, such as current habitat configuration or substrate age. This method of testing alternative hypotheses across biological systems and scales is an innovative approach for understanding complex landscapes and should prove valuable in diverse biogeographical systems.
The impact of paternity on male–infant association in a primate with low paternity certainty
Authors: Langos Doreen , Kulik Lars , Mundry Roger , Widdig Anja
Published: May 2013

In multimale groups where females mate promiscuously, male–infant associations have rarely been studied. However, recent studies have shown that males selectively support their offspring during agonistic conflicts with other juveniles and that father's presence accelerates offspring maturation. Furthermore, it was shown that males invest in unrelated infants to enhance future mating success with the infant's mother. Hence, infant care might provide fitness gain for males. Here, we investigate male–infant associations in rhesus macaques (Macaca mulatta), a primate with low paternity certainty as females mate with multiple partners and males ensure paternity less efficiently through mate‐guarding. We combined behavioural data with genetic paternity analyses of one cohort of the semi‐free‐ranging population of Cayo Santiago (Puerto Rico) and recorded affiliative and aggressive interactions between focal subjects and adult males from birth to sexual maturation (0–4 years) of focal subjects. Our results revealed that 9.6% of all interactions of focal subjects involved an adult male and 94% of all male–infant interactions were affiliative, indicating the rareness of male–infant aggression. Second and most interestingly, sires were more likely to affiliate with their offspring than nonsires with unrelated infants. This preference was independent of mother's proximity and emphasized during early infancy. Male–infant affiliation rose with infant age and was pronounced between adult males and male rather than female focal subjects. Overall, our results suggest that male–infant affiliation is also an important component in structuring primate societies and affiliation directed towards own offspring presumably represent low‐cost paternal care.
Pour some sugar on it: the expanding world of bacterial protein O‐linked glycosylation
Authors: Iwashkiw Jeremy A. , Vozza Nicolas F. , Kinsella Rachel L. , Feldman Mario F.
Published: May 2013

Protein glycosylation was once considered as an eccentricity of a few bacteria. However in the recent years multiple O‐glycosylation mechanisms have been identified in bacterial species from the most diverse genera, including various important human pathogens. This review focuses on summarizing the structural diversity, the various pathways and the physiological roles of this post‐translational protein modification. We propose a classification of O‐glycosylation based on the requirement of an oligosaccharyltransferase (OTase). OTase‐dependent glycosylation utilizes an oligosaccharide synthesized on a lipid carrier that is transferred to proteins en bloc by an OTase. Multiple proteins, including the pilins, are glycosylated using this mechanism. OTase‐independent glycosylation refers to the pathway in which glycosyltransferases sequentially add monosaccharides onto the target proteins. This pathway is employed for glycosylation of flagella and autotransporters. Both systems play key roles in pathogenesis. Exploiting glycosylation machineries it is now possible to generate glycoconjugates made of different proteins attached to polysaccharides derived from LPS or capsule biosynthesis. These recombinant glycoproteins can be exploited for vaccines and diagnostics of bacterial infections. Furthermore, O‐glycosylation systems are promising targets for antibiotic development. Technological advances in MS and NMR will facilitate the discovery of novel glycosylation systems. Likely, the O‐glycosylation pathways we currently know constitute just the tip of the iceberg of a still largely uncharacterized bacterial glycosylation world.
Peptidoglycan at its peaks: how chromatographic analyses can reveal bacterial cell wall structure and assembly
Authors: Desmarais Samantha M. , De Pedro Miguel A. , Cava Felipe , Huang Kerwyn Casey
Published: May 2013

The peptidoglycan (PG) cell wall is a unique macromolecule responsible for both shape determination and cellular integrity under osmotic stress in virtually all bacteria. A quantitative understanding of the relationships between PG architecture, morphogenesis, immune system activation and pathogenesis can provide molecular‐scale insights into the function of proteins involved in cell wall synthesis and cell growth. High‐performance liquid chromatography (HPLC) has played an important role in our understanding of the structural and chemical complexity of the cell wall by providing an analytical method to quantify differences in chemical composition. Here, we present a primer on the basic chemical features of wall structure that can be revealed through HPLC, along with a description of the applications of HPLC PG analyses for interpreting the effects of genetic and chemical perturbations to a variety of bacterial species in different environments. We describe the physical consequences of different PG compositions on cell shape, and review complementary experimental and computational methodologies for PG analysis. Finally, we present a partial list of future targets of development for HPLC and related techniques.
Vitamin D: beyond bone
Authors: Christakos Sylvia , Hewison Martin , Gardner David G. , Wagner Carol L. , Sergeev Igor N. , Rutten Erica , Pittas Anastassios G. , Boland Ricardo , Ferrucci Luigi , Bikle Daniel D.
Published: May 2013

In recent years, vitamin D has been received increased attention due to the resurgence of vitamin D deficiency and rickets in developed countries and the identification of extraskeletal effects of vitamin D, suggesting unexpected benefits of vitamin D in health and disease, beyond bone health. The possibility of extraskeletal effects of vitamin D was first noted with the discovery of the vitamin D receptor (VDR) in tissues and cells that are not involved in maintaining mineral homeostasis and bone health, including skin, placenta, pancreas, breast, prostate and colon cancer cells, and activated T cells. However, the biological significance of the expression of the VDR in different tissues is not fully understood, and the role of vitamin D in extraskeletal health has been a matter of debate. This report summarizes recent research on the roles for vitamin D in cancer, immunity and autoimmune diseases, cardiovascular and respiratory health, pregnancy, obesity, erythropoiesis, diabetes, muscle function, and aging.
‘Unlucky’ Gettier Cases
Authors: Stone Jim
Published: May 2013

This article argues that justified true beliefs in Gettier cases often are not true due to luck. I offer two ‘unlucky’ Gettier cases, and it's easy enough to generate more. Hence even attaching a broad ‘anti‐luck’ codicil to the tripartite account of knowledge leaves the Gettier problem intact. Also, two related questions are addressed. First, if epistemic luck isn't distinctive of Gettier cases, what is? Second, what do Gettier cases reveal about knowledge?
Acclimation to humidity modifies the link between leaf size and the density of veins and stomata
Authors: CARINS MURPHY MADELINE R. , JORDAN GREGORY J. , BRODRIBB TIMOTHY J.
Published: May 2013

The coordination of veins and stomata during leaf acclimation to sun and shade can be facilitated by differential epidermal cell expansion so large leaves with low vein and stomatal densities grow in shade, effectively balancing liquid‐ and vapour‐phase conductances. As the difference in vapour pressure between leaf and atmosphere (VPD) determines transpiration at any given stomatal density, we predict that plants grown under high VPD will modify the balance between veins and stomata to accommodate greater maximum transpiration. Thus, we examined the developmental responses of these traits to contrasting VPD in a woody angiosperm (Toona ciliata M. Roem.) and tested whether the relationship between them was altered. High VPD leaves were one‐third the size of low VPD leaves with only marginally greater vein and stomatal density. Transpirational homeostasis was thus maintained by reducing stomatal conductance. VPD acclimation changed leaf size by modifying cell number. Hence, plasticity in vein and stomatal density appears to be generated by plasticity in cell size rather than cell number. Thus, VPD affects cell number and leaf size without changing the relationship between liquid‐ and vapour‐phase conductances. This results in inefficient acclimation to VPD as stomata remain partially closed under high VPD.
Optimal Policies for Recovering the Value of Consumer Returns
Authors: Crocker Keith J. , Letizia Paolo
Published: May 2013

This study characterizes the class of Pareto optimal returns policies between a manufacturer and a retailer who receives consumer returns. The manufacturer may take a costly hidden action that reduces the expected number of products returned by consumers, which when realized is hidden information known only to the retailer. When faced with consumer returns, the retailer must decide whether to send the product back to the manufacturer, who harvests a low salvage value, or to engage in costly refurbishment that permits the returned product to be resold to consumers. We find that the optimal returns policies may be implemented through the payment by the manufacturer of a full refund to the retailer of the wholesale price for any returns as well as a bonus paid to the retailer that is decreasing in the number of returns to the manufacturer.
Diversity of Phytophthora infestans from Poland
Authors: Chmielarz M. , Sobkowiak S. , Dębski K. , Cooke D. E. L. , Brurberg M. B. , Śliwka J.
Published: May 2013

A collection of 96 Polish isolates of Phytophthora infestans sampled in the years 2006, 2008 and 2009 were analysed using phenotypic and genotypic markers. Mating type, virulence, resistance to metalaxyl, mitochondrial haplotype and polymorphism at 12 simple sequence repeat (SSR) loci were determined. The majority of isolates were of the A1 mating type, mitochondrial haplotype Ia and sensitive to metalaxyl. Virulence factors against potato R genes R1, R3, R4, R7, R10 and R11 were present in most isolates. Genotyping using SSR markers revealed high genetic diversity within the Polish P. infestans population. Amongst the 96 isolates 66 unique genotypes were identified, 49 of which were observed only in single isolates. Eight isolates of the genotype 13_A2 lineage that has been reported in other parts of Europe were also found in Poland. The implications of these results are discussed.
Influence of canopy structure on sheath blight epidemics in rice
Authors: Wu W. , Nie L. , Shah F. , Liao Y. , Cui K. , Jiang D. , Xie J. , Chen Y. , Huang J.
Published: May 2013

Sheath blight (caused by Rhizoctonia solani) is one of the most important constraints in achieving high grain yield in intensive rice production systems. Canopy structure can influence the development of sheath blight epidemics. The objective of this study was to determine the effect of canopy structure parameters such as shoot number, leaf area index, biomass production, contact frequency, light transmittance and plant height on the development of sheath blight epidemics in commercial fields. Field experiments were conducted in both early and late seasons of 2009 and 2010 in Wuxue, Hubei province, China. The effects of nitrogen (N) rate and hill density on structure and production parameters and sheath blight severity were investigated. Sheath blight severity was recorded as a sheath blight index or relative lesion height on inoculated and uninoculated plants in each crop. Lesion length was measured on inoculated plants in 2010. The results showed that the sheath blight index increased with an increase of N rate and hill density in uninoculated plots in each trial. Stepwise multiple regression analysis demonstrated that contact frequency was consistently related to sheath blight. Lesion length on inoculated plants was not correlated with canopy structure. These results indicate that canopy structure influences sheath blight epidemics. A ‘healthy’ canopy resulting from appropriate crop management practices can be used to suppress sheath blight epidemics in rice.
Transport Mode Selection for Toxic Gases: Rail or Road?
Authors: Bagheri Morteza , Verma Manish , Verter Vedat
Published: May 2013

A significant majority of hazardous materials (hazmat) shipments are moved via the highway and railroad networks, wherein the latter mode is generally preferred for long distances. Although the characteristics of highway transportation make trucks the most dominant surface transportation mode, should it be preferred for hazmat whose accidental release can cause catastrophic consequences? We answer this question by first developing a novel and comprehensive assessment methodology—which incorporates the sequence of events leading to hazmat release from the derailed railcars and the resulting consequence—to measure rail transport risk, and second making use of the proposed assessment methodology to analyze hazmat transport risk resulting from meeting the demand for chlorine and ammonia in six distinct corridors in North America. We demonstrate that rail transport will reduce risk, irrespective of the risk measure and the transport corridor, and that every attempt must be made to use railroads to transport these shipments.
Holistic Systems Biology Approaches to Molecular Mechanisms of Human Helper T Cell Differentiation to Functionally Distinct Subsets
Authors: Chen Z. , Lönnberg T. , Lahesmaa R.
Published: May 2013

Current knowledge of helper T cell differentiation largely relies on data generated from mouse studies. To develop therapeutical strategies combating human diseases, understanding the molecular mechanisms how human naïve T cells differentiate to functionally distinct T helper (Th) subsets as well as studies on human differentiated Th cell subsets is particularly valuable. Systems biology approaches provide a holistic view of the processes of T helper differentiation, enable discovery of new factors and pathways involved and generation of new hypotheses to be tested to improve our understanding of human Th cell differentiation and immune‐mediated diseases. Here, we summarize studies where high‐throughput systems biology approaches have been exploited to human primary T cells. These studies reveal new factors and signalling pathways influencing T cell differentiation towards distinct subsets, important for immune regulation. Such information provides new insights into T cell biology and into targeting immune system for therapeutic interventions.
The Antioxidative Effect of Heat‐Shock Protein 70 in Dendritic Cells
Authors: Je J. H. , Kim D. Y. , Roh H. J. , Pak C. , Kim D. H. , Byamba D. , Jee H. , Kim T.‐G. , Park J. M. , Lee S.‐K. , Lee M.‐G.
Published: May 2013

Reactive oxygen species (ROS) are produced by dendritic cells (DCs) during antigen presentation in contact hypersensitivity (CHS). ROS cause a number of non‐enzymatic protein modifications, such as carbonylation. Carbonylated proteins in DCs in response to hapten have not been fully identified yet. To identify the proteins carbonylated by ROS, murine epidermis‐derived DC line XS106 was challenged with a hapten, 2,4,6‐trinitrobenzene sulphonic acid (TNBS). MALDI‐TOF analysis revealed that heat‐shock protein 70 (HSP70) was one of the carbonylated proteins induced by TNBS. To verify the role of HSP70 in TNBS‐treated XS106 cell, we fused protein transduction domain (PTD) with HSP70 to facilitate protein delivery into the cell. The transfected fusion protein HSP70 within the cell caused transient increase of the cellular level of HSP70. Transient increase of HSP70 level in XS‐106 DCs resulted in inhibition of ROS production, carbonylation of HSP70, p38 MAPK activation and subsequently IL‐12 secretion. To investigate the effects of PTD–HSP70 in vivo, ear‐swelling experiments with 2,4,6‐trinitro‐1‐chlorobenzene (TNCB) were performed in BALB/c mice. Pretreatment of PTD–HSP70 reduced the CHS response to TNCB in vivo. We report here that carbonylation of HSP70 by ROS is associated with the pathogenesis of CHS, suggesting possibility of HSP70‐targeting therapy in CHS.
The Important Role of T Cells and Receptor Expression in Sjögren's Syndrome
Authors: Karabiyik A. , Peck A. B. , Nguyen C. Q.
Published: May 2013

Sjögren's syndrome (SjS), an autoimmune disease characterized by exocrine gland dysfunction leading to dry mouth and dry eye diseases, is typified by progressive leucocyte infiltrations of the salivary and lacrimal glands. Histologically, these leucocyte infiltrations generally establish periductal aggregates, referred to as lymphocytic foci (LF), which occasionally appear as germinal centre (GC)‐like structures. The formation and organization of these LF suggest an important and dynamic role for helper T cells (TH), specifically TH1, TH2 and the recently discovered TH17, in development and onset of clinical SjS, considered a B cell–mediated hypersensitivity type 2 disease. Despite an ever‐increasing focus on identifying the underlying aetiology of SjS, defining factors that initiate this autoimmune disease remain a mystery. Thus, determining interactions between infiltrating TH cells and exocrine gland tissue (auto‐)antigens represents a fertile research endeavour. This review discusses pathological functions of TH cells in SjS, the current status of TH cell receptor gene rearrangements associated with human and mouse models of SjS and potential future prospects for identifying receptor–autoantigen interactions.
A novel HLA‐A allele detected by sequence‐based typing: HLA‐A*24:223
Authors: Wang Daming , Xu Yunping , Zou Hongyan , Deng Zhihui
Published: May 2013

Compared with A*24:02:01:01, HLA‐A*24:223 shows one nucleotide difference at genomic nt 149 G>A (codon 26 GGC>GAC) in exon 2.
A Multi‐Grid Method of High Accuracy Surface Modeling and Its Validation
Authors: Yue Tian‐Xiang , Zhao Na , Yang Hai , Song Yin‐Jun , Du Zheng‐Ping , Fan Ze‐Meng , Song Dun‐Jiang
Published: May 2013

A method of high accuracy surface modeling (HASM) has been constructed to find a solution for error problems that had long troubled surface modeling in geographical information systems (GIS). It is found that when a preconditioned conjugate gradient (PCG) algorithm is used to solve the large sparse linear system, which HASM can be transferred into, HASM performs best in terms of simulation compared with all other algorithms. But its computing speed is not fast enough for all applications. A multi‐grid method is introduced into HASM to try to shorten its computing time. Both numerical and real‐world tests demonstrate that there is a range of stop error (SE). The multi‐grid method of HASM (HASM‐MG) greatly increases computing speed when SEs are within this range, compared with the PCG algorithm of HASM (HASM‐PCG). HASM‐MG is suitable for applications with a need for less accuracy and a shorter computing time. HASM‐PCG is appropriate for issues needing higher accuracy. HASM‐MG performs better than HASM‐PCG in flat areas, while HASM‐PCG does better in complex terrainm in terms of accuracy and computing time.
Advances in Fluid and Thermal Transport Property Analysis and Design of Sintered Porous Wick Microstructures
Authors: Bodla Karthik K. , Weibel Justin A. , Garimella Suresh V.
Published: May 2013

Sintered porous structures are ubiquitous as heat transport media for thermal management and other applications. In particular, low-porosity sintered packed beds are used as capillary-wicking and evaporation-enhancement structures in heat pipes. Accurate prediction and analysis of their transport characteristics for different microstructure geometries is important for improved design. Owing to the random nature and geometric complexity of these materials, development of predictive methods has been the subject of extensive prior research. The present work summarizes and builds upon past studies and recent advances in pore-scale modeling of fluid and thermal transport within such heterogeneous media. A brief review of various analytical and numerical models for simplified prediction of transport characteristics such as effective thermal conductivity, permeability, and interfacial heat transfer is presented. More recently, there has been a growing interest in direct numerical simulation of transport in realistic representations of the porous medium geometry; for example, by employing nondestructive 3D imaging techniques such as X-ray microtomography. Future research directions are identified, looking beyond techniques intended for material characterization alone, and focusing on those targeting the reverse engineering of wick structures via modeling of the physical sintering fabrication processes. This approach may eventually be employed to design intricate sintered porous structures with desired properties tailored to specific applications.
Thermal Processing of Biological Tissue at High Temperatures: Impact of Protein Denaturation and Water Loss on the Thermal Properties of Human and Porcine Liver in the Range 25–80 °C
Authors: Choi Jeunghwan , Morrissey Michael , Bischof John C.
Published: May 2013

Biothermal engineering applications impose thermal excursions on tissues with an ensuing biological outcome (i.e., life or death) that is tied to the molecular state of water and protein in the system. The accuracy of heat transfer models used to predict these important processes in turn depends on the kinetics and energy absorption of molecular transitions for both water and protein and the underlying temperature dependence of the tissue thermal properties. Unfortunately, a lack of tissue thermal property data in the literature results in an overreliance on property estimates. This work addresses these thermal property limitations in liver, a platform tissue upon which hyperthermic engineering applications are routinely performed and a test bed that will allow extension to further tissue property measurement in the future. Specifically, we report on the thermal properties of cadaveric human and porcine liver in the suprazero range between 25 °C to 80 °C for thermal conductivity and 25 °C to 85 °C for apparent specific heat. Denaturation and water vaporization are shown to reduce thermal conductivity and apparent specific heat within the samples by up to 20% during heating. These changes in thermal properties significantly altered thermal histories during heating compared to conditions when properties were assumed to remain constant. These differences are expected to alter the biological outcome from heating as well.
Fundamental Roles of Nonevaporating Film and Ultrahigh Heat Flux Associated With Nanoscale Meniscus Evaporation in Nucleate Boiling
Authors: Maroo Shalabh C. , Chung J. N.
Published: May 2013

The three-phase moving contact line present at the base of a bubble in nucleate boiling has been a widely researched topic over the past few decades. It has been traditionally divided into three regions: nonevaporating film (order of nanometers), evaporating film (order of microns), and bulk meniscus (order of millimeters). This multiscale nature of the contact line has made it a challenging and complex problem, and led to an incomplete understanding of its dynamic behavior. The evaporating film and bulk meniscus regions have been investigated rigorously through analytical, numerical and experimental means; however, studies focused on the nonevaporating film region have been very sparse. The nanometer length scale and the fluidic nature of the nonevaporating film has limited the applicability of experimental techniques, while its numerical analysis has been questionable due to the presumed continuum behavior and lack of known input parameters, such as the Hamaker constant. Thus in order to gain fundamental insights and understanding, we have used molecular dynamics simulations to study the formation and characteristics of the nonevaporating film for the first time in published literature, and outlined a technique to obtain Hamaker constants from such simulations. Further, in this review, we have shown that the nonevaporating film can exist in a metastable state of reduced/negative liquid pressures. We have also performed molecular simulations of nanoscale meniscus evaporation, and shown that the associated ultrahigh heat flux is comparable to the maximum-achievable kinetic limit of evaporation. Thus, the nonevaporating film and its adjacent nanoscale regions have a significant impact on the overall macroscale dynamics and heat flux behavior of nucleate boiling, and hence should be included in greater details in nucleate boiling simulations and analysis.
Numerical Simulation of Pool Boiling: A Review
Authors: Dhir Vijay K. , Warrier Gopinath R. , Aktinol Eduardo
Published: May 2013

A review of numerical simulation of pool boiling is presented. Details of the numerical models and results obtained for single bubble, multiple bubbles, nucleate boiling, and film boiling are provided. The effect of such parameters such as wall superheat, liquid subcooling, contact angle, gravity level, noncondensables, and conjugate heat transfer are also included. The numerical simulation results have been validated with data from well designed experiments.
Wideband Tunable Omnidirectional Infrared Absorbers Based on Doped-Silicon Nanowire Arrays
Authors: Liu X. L. , Wang L. P. , Zhang Z. M.
Published: May 2013

The present study considers the directional and spectral radiative properties of vertically aligned, heavily doped silicon nanowires for applications as broadband infrared diffuse absorbers. The nanowire array is modeled as a uniaxial medium whose anisotropic dielectric function is based on an effective medium theory. The approximation model is verified by the finite-difference time-domain method. It is found that the radiative properties of this type of nanostructured material could be tailored by controlling the doping concentration, volume filling ratio, and length of the nanowires. Increasing the wire length yields a broadening of the absorption plateau, while increasing the doping concentration results in a shift of the plateau to shorter wavelengths. Moreover, two kinds of omnidirectional absorbers/emitters could be realized based on the doped-silicon nanowire arrays. The first one is a wavelength-tunable wideband absorber, which may be important for applications in thermal imaging and thermophotovoltaic devices. The second acts as a quasi-blackbody in the wavelength region from 3 to 17 μm and, therefore, is promising for use as an absorber in bolometers that measure infrared radiation and as an emitter in space cooling devices that dissipate heat into free space via thermal radiation.
Combined Microstructure and Heat Conduction Modeling of Heterogeneous Interfaces and Materials
Authors: Srivastava Ishan , Sadasivam Sridhar , Smith Kyle C. , Fisher Timothy S.
Published: May 2013

Heterogeneous materials are becoming more common in a wide range of functional devices, particularly those involving energy transport, conversion, and storage. Often, heterogeneous materials are crucial to the performance and economic scalability of such devices. Heterogeneous materials with inherently random structures exhibit a strong sensitivity of energy transport properties to processing and operating conditions. Therefore, improved predictive modeling capabilities are needed that quantify the detailed microstructure of such materials based on various manufacturing processes and correlate them with transport properties. In this work, we integrate high fidelity microstructural and transport models, which can aid in the development of high performance energy materials. Heterogeneous materials are generally comprised of nanometric or larger length scale domains of different materials or different phases of the same material. State-of-the-art structural optimization models demonstrate the predictability of the microstructure for heterogeneous materials manufactured via powder compaction of variously shaped and sized particles. The ability of existing diffusion models to incorporate the essential multiscale features in random microstructures is assessed. Lastly, a comprehensive approach is presented for the combined modeling of a high fidelity microstructure and heat transport therein. Exemplary results are given that reinforce the importance of developing predictive models with rich stochastic output that connect microstructural information with physical transport properties.
Tuning Phonon Transport: From Interfaces to Nanostructures
Authors: Norris Pamela M. , Le Nam Q. , Baker Christopher H.
Published: May 2013

A wide range of modern technological devices utilize materials structured at the nanoscale to improve performance. The efficiencies of many of these devices depend on their thermal transport properties; whether a high or low conductivity is desirable, control over thermal transport is crucial to the continued development of device performance. Here we review recent experimental, computational, and theoretical studies that have highlighted potential methods for controlling phonon-mediated heat transfer. We discuss those parameters that affect thermal boundary conductance, such as interface morphology and material composition, as well as the emergent effects due to several interfaces in close proximity, as in a multilayered structure or superlattice. Furthermore, we explore future research directions as well as some of the challenges related to improving device thermal performance through the implementation of phonon engineering techniques.
Heat Transfer in Thermoelectric Materials and Devices
Authors: Tian Zhiting , Lee Sangyeop , Chen Gang
Published: May 2013

Solid-state thermoelectric devices are currently used in applications ranging from thermocouple sensors to power generators in space missions, to portable air-conditioners and refrigerators. With the ever-rising demand throughout the world for energy consumption and CO2 reduction, thermoelectric energy conversion has been receiving intensified attention as a potential candidate for waste-heat harvesting as well as for power generation from renewable sources. Efficient thermoelectric energy conversion critically depends on the performance of thermoelectric materials and devices. In this review, we discuss heat transfer in thermoelectric materials and devices, especially phonon engineering to reduce the lattice thermal conductivity of thermoelectric materials, which requires a fundamental understanding of nanoscale heat conduction physics.
The Treatment of Nongray Properties in Radiative Heat Transfer: From Past to Present
Authors: Modest Michael F.
Published: May 2013

Radiative heat transfer in high-temperature participating media displays very strong spectral, or “nongray,” behavior, which is both very difficult to characterize and to evaluate. This has led to very gradual development of nongray models, starting with primitive semigray and box models based on old experimental property data, to today's state-of-the-art k-distribution approaches with properties obtained from high-resolution spectroscopic databases. In this paper a brief review of the historical development of nongray models and property databases is given, culminating with a more detailed description of the most modern spectral tools.
Thermal Characteristics of Open and Contained Data Center Cold Aisle
Authors: Arghode Vaibhav K. , Sundaralingam Vikneshan , Joshi Yogendra , Phelps Wally
Published: May 2013

Cold aisle containment is used in raised floor, air cooled data centers to minimize direct mixing between the supplied cold air and the hot air exiting from the servers. The objective of such a system is to minimize the server inlet air temperatures. In this paper, large scale air temperature field measurements are performed to investigate the hot air entrainment characteristics in the cold aisle in both open and contained aisle conditions. Both under-provisioned and over-provisioned scenarios were examined. Thermal field measurements suggest significant improvement in the cold air delivery for the case with contained aisle as compared to open aisle. Even for an over-provisioned case with open aisle, hot air entrainment was observed from the aisle entrance; however, for the contained aisle condition, close to perfect cold air delivery to the racks was observed. For both under-provisioned and over-provisioned cases, the aisle containment tended to equalize the tile and rack air flow rates. Balance air is expected to be leaked into or out of the containment to makeup the flow rate difference for the contained aisle condition. The CFD modeling strategy at the aisle level is also discussed for open aisle condition. Our previous investigation for rack level modeling has shown that consideration of momentum rise above the tile surface improves the predictive capability as compared to the generally used porous jump model. The porous jump model only specifies a step pressure loss at the tile surface without any influence on flow field. The momentum rise above the tile surface was included using a modified body force model by artificially specifying a momentum source above the tile surface. The modified body force model suggested higher air entrainment and higher reach of cold air as compared to the porous jump model. The modified body force model was able to better capture hot air entrainment through aisle entrance and compared well with the experimental data for the end racks. The generally used porous jump model suggested lower hot air entrainment and under predicted the server inlet temperatures for end racks.
Terahertz Metamaterials for Linear Polarization Conversion and Anomalous Refraction
Authors: Grady Nathaniel K. , Heyes Jane E. , Chowdhury Dibakar Roy , Zeng Yong , Reiten Matthew T. , Azad Abul K. , Taylor Antoinette J. , Dalvit Diego A. R. , Chen Hou-Tong
Published: May 2013

Converting Polarization

The conversion of a light signal from one polarization direction to another plays an important role in communication and metrology. The components that are presently used for polarization conversion, however, tend to be relatively large, which is an issue that can make it difficult to integrate with chip-scale optoelectronic circuits.

Grady
et al.

(p.
1304
, published online 16 May) used a metasurfaces approach involving a designed array of cut wires to manipulate the polarization state of the propagating terahertz signals. Proper design of the device structure allowed for the control of the polarization conversion state for both reflected and transmitted light over a broad frequency range.
Genome Sequences of Two Emerging Non-O157 Shiga Toxin-Producing Escherichia coli Strains
Authors: Cao Guojie , Ju Wenting , Rump Lydia , Zhao Shaohua , Zou Likou , Wang Charles , Strain Errol , Luo Yan , Timme Ruth , Allard Marc , Brown Eric , Meng Jianghong
Published: May 2013

Shiga toxin-producing
Escherichia coli
(STEC) causes severe illness in humans, including hemorrhagic colitis and hemolytic uremic syndrome. A parallel evolutionary model was proposed in which
E. coli
strains of distinct phylogenies independently integrate Shiga toxin-encoding genes and evolve into STEC. We report the draft genomes of two emerging non-O157 STEC strains.
Draft Genome Sequences of Two Pairs of Human Intestinal Bifidobacterium longum subsp.
longum
Strains, 44B and 1-6B and 35B and 2-2B, Consecutively Isolated from Two Children after a 5-Year Time Period
Authors: Shkoporov A. N. , Efimov B. A. , Khokhlova E. V. , Chaplin A. V. , Kafarskaya L. I. , Durkin A. S. , McCorrison J. , Torralba M. , Gillis M. , Sutton G. , Weibel D. B. , Nelson K. E. , Smeianov V. V.
Published: May 2013

We report the genome sequences of four isolates of a human gut symbiont,
Bifidobacterium longum
. Strains 44B and 35B were isolated from two 1-year-old infants, while 1-6B and 2-2B were isolated from the same children 5 years later. The sequences permit investigations of factors enabling long-term colonization of bifidobacteria.
Complete Genome Sequence of the γ-Hexachlorocyclohexane-Degrading Bacterium
Sphingomonas
sp. Strain MM-1
Authors: Tabata M. , Ohtsubo Y. , Ohhata S. , Tsuda M. , Nagata Y.
Published: May 2013

γ-Hexachlorocyclohexane (γ-HCH) is a man-made chlorinated insecticide that has caused serious environmental problems. Here, we report the complete genome sequence of the γ-HCH-degrading bacterium
Sphingomonas
sp. strain MM-1, which consists of one chromosome and five plasmids. All the specific
lin
genes that are almost identical to those of
Sphingobium japonicum
UT26 for the conversion of γ-HCH to β-ketoadipate are dispersed on four out of the five plasmids.
Draft Genome Sequence of the Serratia marcescens Strain VGH107, a Taiwanese Clinical Isolate
Authors: Liu Po-Yu , Huang Yao-Ting , Lin Sheng-Yi , Chang Gee-Cheng , Chen Jian-Wei
Published: May 2013

Serratia marcescens
, a member of the family
Enterobacteriaceae
, is the causative agent of various types of wound infections. We report a high-quality draft genome sequence of
S. marcescens
strain VGH107, which was isolated from a patient with an infection from a snakebite wound.
Genome Sequences of Two Morphologically Distinct and Thermophilic Bacillus coagulans Strains, H-1 and XZL9
Authors: Xu Ke , Su Fei , Tao Fei , Li Chao , Ni Jun , Xu Ping
Published: May 2013

Two thermophilicBacillus coagulansstrains, H-1 and XZL9, both of which were isolated from soils, have different morphological properties. Strain XZL9 but not H-1 is an efficient pentose-utilizing producer of important platform compounds, such asl-lactic acid and 2,3-butanediol. Here we announce the 2.86- and 3.43-Mb sequences of their genomes.
Draft Genome Sequence of the Tyramine Producer Enterococcus durans Strain IPLA 655
Authors: Ladero Victor , Linares Daniel M. , del Rio Beatriz , Fernandez Maria , Martin M. Cruz , Alvarez Miguel A.
Published: May 2013

We here report a 3.059-Mbp draft assembly for the genome of
Enterococcus durans
strain IPLA 655. This dairy isolate provides a model for studying the regulation of the biosynthesis of tyramine (a toxic compound). These results should aid our understanding of tyramine production and allow tyramine accumulation in food to be reduced.
Benefits of combining inspiratory muscle with ‘whole muscle’ training in children with cystic fibrosis: a randomised controlled trial
Authors: Santana-Sosa Elena , Gonzalez-Saiz Laura , Groeneveld Iris F , Villa-Asensi José R , Barrio Gómez de Aguero María I , Fleck Steven J , López-Mojares Luis M , Pérez Margarita , Lucia Alejandro
Published: May 2013

Background

The purpose of this study (randomised controlled trial) was to assess the effects of an 8-week combined ‘whole muscle’ (resistance+aerobic) and inspiratory muscle training (IMT) on lung volume, inspiratory muscle strength (PImax) and cardiorespiratory fitness (VO2peak) (primary outcomes), and dynamic muscle strength, body composition and quality of life in paediatric outpatients with CF (cystic fibrosis, secondary outcomes). We also determined the effects of a detraining period.

Methods

Participants were randomly allocated with a block on gender to a control (standard therapy) or intervention group (initial n=10 (6 boys) in each group; age 10±1 and 11±1 years). The latter group performed a combined programme (IMT (2 sessions/day) and aerobic+strength exercises (3 days/week, in-hospital)) that was followed by a 4-week detraining period. All participants were evaluated at baseline, post-training and detraining.

Results

Adherence to the training programme averaged 97.5%±1.7%. There was a significant interaction (group×time) effect for PImax, VO2peakand five-repetition maximum strength (leg-press, bench-press, seated-row) (all (p<0.001), and also for %fat (p<0.023) and %fat-free mass (p=0.001), with training exerting a significant beneficial effect only in the intervention group, which was maintained after detraining for PImaxand leg-press.

Conclusion

The relatively short-term (8-week) training programme used here induced significant benefits in important health phenotypes of paediatric patients with CF. IMT is an easily applicable intervention that could be included, together with supervised exercise training in the standard care of these patients.
The effects on student health of interventions modifying the school environment: systematic review
Authors: Bonell C , Wells H , Harden A , Jamal F , Fletcher A , Thomas J , Campbell R , Petticrew M , Whitehead M , Murphy S , Moore L
Published: May 2013

Background

Owing to the limited effectiveness of traditional health education curricula in schools, there is increasing interest in interventions aiming to promote young people's health by modifying the school environment. Existing systematic reviews cannot determine whether environmental intervention is effective because they examine interventions combining environmental modifications and traditional health education. This gap is significant because school-environment interventions are complex to implement and may be sidelined in underfunded and attainment-focused school systems without evidence to support such an approach. This systematic review examined the effectiveness of school-environment interventions without health-education components on student health and inequalities.

Methods

This was a systematic review of experimental/quasi-experimental studies of school-environment interventions. Sixteen databases were searched, eliciting 62 329 references which were screened, with included studies quality assessed, data extracted and narratively synthesised.

Results

Sixteen reports of 10 studies were included, all from the USA and the UK. Five evaluations of interventions aiming to develop a stronger sense of community and/or improve relationships between staff and students suggested potential benefits particularly regarding violence and aggression. Two trials of interventions enabling students to advocate for changes in school catering and physical activity reported benefits for physical activity but not diet. Three evaluations of improvements to school playgrounds offered weak evidence of effects on physical activity.

Conclusions

School environment interventions show the potential to improve young people's health particularly regarding violence, aggression and physical activity. Further trials are required to provide a stronger and more generalisable evidence base.
STRONGLY INTERACTING MATTER AT FINITE CHEMICAL POTENTIAL: HYBRID MODEL APPROACH
Authors: SRIVASTAVA P. K. , SINGH C. P.
Published: May 2013

Search for a proper and realistic equation of state (EOS) for strongly interacting matter used in the study of the QCD phase diagram still appears as a challenging problem. Recently, we constructed a hybrid model description for the quark–gluon plasma (QGP) as well as hadron gas (HG) phases where we used an excluded volume model for HG and a thermodynamically consistent quasiparticle model for the QGP phase. The hybrid model suitably describes the recent lattice results of various thermodynamical as well as transport properties of the QCD matter at zero baryon chemical potential (μB). In this paper, we extend our investigations further in obtaining the properties of QCD matter at finite value of μB and compare our results with the most recent results of lattice QCD calculation.
RAMAN STUDY OF BENZENE NEAR THE MELTING POINT
Authors: YURTSEVEN H. , ÇETINBAŞ İŞERI E.
Published: May 2013

We calculate here the Raman frequencies of some lattice modes as a function of pressure at constant temperatures for the solid and liquid phases of benzene. The observed data for the molar volume from literature is used to calculate the Raman frequencies through the mode Grüneisen parameter in benzene.

Our calculated frequencies are in good agreement with the observed data when the mode Grüneisen parameter is taken as a constant at one particular pressure in solid benzene.

It is shown here that the Raman frequencies can be calculated from the volume data, as demonstrated for benzene here.
2,2,3,3-Tetrafluoropropoxy substituted oxo-titanium phthalocyanines axially ligated with common MALDI matrix materials
Authors: Tarakci Deniz Kutlu , Gürol İlke , Ahsen Vefa
Published: May 2013

The synthesis of tetra and octa 2,2,3,3-tetrafluoropropoxy substituted oxo-titanium phthalocyanines (TiOPc) are reported. Using strongly chelating oxygen donor ligands, the reactions of TiOPc with catecholate (1a, 2a), 4-nitrocatecholate (1b, 2b) and caffeic acid (1c, 2c), ellagic acid (1d, 2d) and chlorogenic acid (1e, 2e) are described. The new compounds were characterized by mass, 1 H NMR, FT-IR, and UV-vis spectroscopic techniques as well as elemental analysis.
The solvation dynamics and rotational relaxation of protonated meso-tetrakis(4-sulfonatophenyl)porphyrin in imidazolium-based ionic liquids measured with a streak camera
Authors: Zhao Yun Fang , Gao Guang Yu , Wang Shu Feng , Jin Wei Jun
Published: May 2013

For the steady-state behavior of diprotonated tetrakis(4-sulfonatophenyl)porphyrin (H4TPPS2-) in five imidazolium ionic liquids (ILs), the absorption positions of H4TPPS2- primarily depend on the constituent ions of the ILs whereas the emission positions of H4TPPS2- strongly depend on the polarity of the ILs. The fluorescence spectra of H4TPPS2- with different excitation wavelengths show no red-edge effect in our system. The dynamics of H4TPPS2- in ILs is further studied with a streak camera, and the relaxation process of ILs occurs on two different time scales. The short lived component attributed to the local motion of the cations and the anions around the porphine core varies from 32 to 196 ps. The long lived one originated from the collective diffusive motions of the cations and anions varies from 460 to 1072 ps. The average solvation time depends on the viscosity of the ILs. The rotational relaxation times of H4TPPS2- decrease as the viscosity of the ILs decreases.