bluuebunny/crossref_metadata_2025 huggingface dataset:
Helicity amplitudes for high-energy scattering
Authors: van Hameren A. , Kotko P. , Kutak K.
Published: January 2013

Abstract

We present a prescription to calculate manifestly gauge invariant tree-level helicity amplitudes for arbitrary scattering processes with off-shell initial-state gluons within the kinematics of high-energy scattering. We show that it is equivalent to Lipatov’s effective action approach, and show its computational potential through numerical calculations for scattering processes with several particles in the final state.
Intersections Between Nativity, Ethnic Density, and Neighborhood SES: Using an Ethnic Enclave Framework to Explore Variation in Puerto Ricans’ Physical Health
Authors: Roy Amanda Leigh , Hughes Diane , Yoshikawa Hirokazu
Published: January 2013

Although past research has demonstrated a “health disadvantage” for Puerto Rican adults, very little is known about correlates of health among this group. Given Puerto Ricans’ unique experiences of migration and settlement, an ethnic enclave framework that integrates nativity, ethnic density, and neighborhood SES may offer insight into factors influencing Puerto Ricans’ health. This study uses a sample of 449 adult mainland‐ and island‐born Puerto Ricans living in New York City and Chicago. The data, collected as a part of the MIDUS Survey of Minority Groups, are stratified by neighborhood ethnic density and neighborhood SES, allowing for the examination of the individual and joint influences of neighborhood characteristics on physical health. Results revealed that ethnic density and neighborhood SES were not independently or interactively related to physical health for mainland‐born Puerto Ricans. However, the interaction between ethnic density and neighborhood SES was related to self‐reported health, functional limitations, and health symptoms for island‐born Puerto Ricans. Island‐born Puerto Ricans living in ethnically dense, low SES neighborhoods reported worse health than island‐born Puerto Ricans living in other types of neighborhoods. This may be a result of isolation from resources both within and outside the neighborhood.
Transaldolase deficiency: report of 12 new cases and further delineation of the phenotype
Authors: Eyaid Wafaa , Al Harbi Talal , Anazi Shamsa , Wamelink Mirjam M. C. , Jakobs Cornelis , Al Salammah Mohammad , Al Balwi Mohammed , Alfadhel Majid , Alkuraya Fowzan S.
Published: January 2013

Purpose

Transaldolase deficiency is a recently described inborn error of pentose phosphate pathway. We conducted this study to further delineate the associated phenotype.

Methods and results

We report on 12 new cases representing six families with this metabolic defect that were observed over an 8 year span. None of these cases received the correct diagnosis initially because of significant overlap in the presenting symptoms (growth retardation, dysmorphic features, cutis laxa, congenital heart disease, hepatosplenomegaly, pancytopenia, and bleeding tendency) with a wide range of genetic disorders. However, the consanguineous nature of these families allowed us to pursue autozygome analysis, which highlighted TALDO as the likely candidate gene and sequencing confirmed segregation of a novel homozygous mutation with the disease in all the studied families. Biochemical analysis was also consistent with transaldolase deficiency.

Conclusion

This study expands the clinical definition of transaldolase deficiency, and adds to its allelic heterogeneity. In addition, we emphasize the diagnostic challenge posed by this rare and pleiotropic metabolic disorder.
Endurance training for cancer patients during and shortly after completion of the anti-cancer treatment
Authors: Knols Ruud H.
Published: January 2013

Cardiorespiratory fitness is one of the most important indicators of health and improves length of life. The attention and acceptance for endurance training in patients with several cancer diagnoses increased during the last decade. This review highlight’s the effect of endurance training in cancer patients by summarizing exemplary randomized clinical trials and systematic reviews both within the acute hospital treatment context, as in a rehabilitation setting. To date, most studies focus on endurance training in patient groups with moderate to good prognosis. The studies within these patient groups evaluate the endurance training in cancer patients using a moderate training intensity between 50 and 75 % of the VO2 peak with an exercise time varying from 20 min (five times per week) in hospital up to 45 min (two to three times per week) in an ambulatory setting. Recently, the American College of Sports Medicine indicated that cancer survivors should follow the Physical Activity Guidelines for Americans, which represents ≥150 min per week of moderate intensity, ≥75 min per week of vigorous intensity aerobic exercise, or an equivalent combination of moderate and vigorous intensity aerobic exercises. To date, fewer studies evaluate the effects of endurance training in a palliative setting to maintain physical function of the patient. Future studies should investigate the effect of endurance training by evaluating different types of intensity training (moderate vs. high intensity training), the use of high-tech devices to improve physical activity, and to evaluate the effect of endurance training in patients with a palliative intention.
Sources for skeletal muscle repair: from satellite cells to reprogramming
Authors: Sirabella Dario , De Angelis Luciana , Berghella Libera
Published: January 2013

Skeletal muscle regeneration is the process that ensures tissue repair after damage by injury or in degenerative diseases such as muscular dystrophy. Satellite cells, the adult skeletal muscle progenitor cells, are commonly considered to be the main cell type involved in skeletal muscle regeneration. Their mechanism of action in this process is extensively characterized. However, evidence accumulated in the last decade suggests that other cell types may participate in skeletal muscle regeneration. Although their actual contribution to muscle formation and regeneration is still not clear; if properly manipulated, these cells may become new suitable and powerful sources for cell therapy of skeletal muscle degenerative diseases. Mesoangioblasts, vessel associated stem/progenitor cells with high proliferative, migratory and myogenic potential, are very good candidates for clinical applications and are already in clinical experimentation. In addition, pluripotent stem cells are very promising sources for regeneration of most tissues, including skeletal muscle. Conditions such as muscle cachexia or aging that severely alter homeostasis may be counteracted by transplantation of donor and/or recruitment and activation of resident muscle stem/progenitor cells. Advantages and limitations of different cell therapy approaches will be discussed.
Protein dynamics in living cells studied by in‐cell NMR spectroscopy
Authors: Li Conggang , Liu Maili
Published: January 2013

Most proteins function in cells where protein concentrations can reach 400 g/l. However, most quantitative studies of protein properties are performed in idealized, dilute conditions. Recently developed in‐cell NMR techniques can provide protein structure and other biophysical properties inside living cells at atomic resolution. Here we review how protein dynamics, including global and internal motions have been characterized by in‐cell NMR, and then discuss the remaining challenges and future directions.
Molecular machines directly observed by high‐speed atomic force microscopy
Authors: Ando Toshio
Published: January 2013

Molecular machines made of proteins are highly dynamic and carry out sophisticated biological functions. The direct and dynamic high‐resolution visualization of molecular machines in action is considered to be the most straightforward approach to understanding how they function but this has long been infeasible until recently. High‐speed atomic force microscopy has recently been realized, making such visualization possible. The captured images of myosin V, F1‐ATPase, and bacteriorhodopsin have enabled their dynamic processes and structure dynamics to be revealed in great detail, giving unique and deep insights into their functional mechanisms.
Comparative Analysis of MicroRNA Promoters in Arabidopsis and Rice
Authors: Zhao Xin , Li Lei
Published: January 2013

Endogenously-encoded microRNAs (miRNAs) are a class of small regulatory RNAs that modulate gene expression at the post-transcriptional level. In plants, miRNAs have increasingly been identified by experiments based on next-generation sequencing (NGS). However, promoter organization is currently unknown for most plant miRNAs, which are transcribed by RNA polymerase II. This deficiency prevents a comprehensive understanding of miRNA-mediated gene networks. In this study, by analyzing full-length cDNA sequences related to miRNAs, we mapped transcription start sites (TSSs) for 62 and 55 miRNAs in Arabidopsis and rice, respectively. The average free energy (AFE) profiles in the vicinity of TSSs were studied for both species. By employing position weight matrices (PWM) for 99 plant cis-elements, we discovered that three cis-elements were over-represented in the miRNA promoters of both species, while four and ten cis-elements were over-represented in Arabidopsis only and in rice only. Thus, comparison of miRNA promoters between Arabidopsis and rice provides a new perspective for studying miRNA regulation in plants.
Environmental isotopes and noble gases in the deep aquifer system of Kazan Trona Ore Field, Ankara, central Turkey and links to paleoclimate
Authors: Arslan Sebnem , Yazicigil Hasan , Stute Martin , Schlosser Peter
Published: January 2013

Environmental isotopes and noble gases in groundwater samples from the Kazan Trona Ore Field are studied to establish the temperature change between the Holocene and the late Pleistocene. Noble gas temperatures (NGTs) presented in this study add an important facet to the global paleotemperature map in the region between Europe and North Africa. The groundwater system under investigation consists of three different aquifers named shallow, middle and deep in which δ18O and δ2H vary from − 8.10‰ to − 12.80‰ and from − 60.89‰ to − 92.60‰ VSMOW, respectively. The average isotopic depletion between unconfined and confined parts of the system is − 2.5‰ in δ18O and − 20‰ in δ2H. It is not possible to explain this depletion solely with the elevation effect. Recharge temperatures derived from dissolved atmospheric noble gases reflect the current average yearly ground temperatures (13°C) for samples collected near the recharge area but are 3 to 8°C lower than today's temperatures in the deep aquifer system. Low 14C activities and high He excesses in the confined parts of the aquifer system suggest that the water in the deep aquifer was recharged during the last Pleistocene under considerably cooler climatic conditions.
Closed subgroups generated by generic measure automorphisms
Authors: SOLECKI SŁAWOMIR
Published: January 2013

We prove that for a generic measure-preserving transformation $T$, the closed group generated by $T$ is a continuous homomorphic image of a closed linear subspace of $L_0(\lambda , {\mathbb R})$, where $\lambda $ is the Lebesgue measure, and that the closed group generated by $T$contains an increasing sequence of finite-dimensional tori whose union is dense.
EFFICIENT TILLAGE AND NUTRIENT MANAGEMENT PRACTICES FOR SUSTAINABLE YIELDS, PROFITABILITY AND ENERGY USE EFFICIENCY FOR RICE-BASED CROPPING SYSTEM IN DIFFERENT SOILS AND AGRO-CLIMATIC CONDITIONS
Authors: SANKAR G. R. MARUTHI , SHARMA K. L. , REDDY K. SRINIVAS , PRATIBHA G. , SHINDE RESHMA , SINGH S. R. , NEMA A. K. , SINGH R. P. , RATH B. S. , MISHRA A. , BEHERA B. D. , SUBUDHI C. R. , SINGH BHAGWAN , SINGH H. C. , SINGH ASHOK KUMAR , RUSIA D. K. , YADAVA M. S. , THYAGARAJ C. R. , MISHRA P. K. , CHANDRIKA M. SUMA , VENKATESWARLU B.
Published: January 2013

Long-term tillage and fertilizer experiments were conducted in rice in kharif followed by lentil in dry subhumid Inceptisols at Varanasi and Faizabad; horse gram at Phulbani and linseed at Ranchi in moist subhumid Alfisols in rabi during 2001 to 2010. The study was conducted to assess the effect of conventional tillage (CT), low tillage + interculture (LT1) and low tillage + herbicide (LT2) together with 100% N (organic) (F1), 50% N (organic) + 50% N (inorganic) (F2) and 100% N (inorganic) (F3) on productivity, profitability, rainwater and energy use efficiencies. The results at Varanasi revealed that CT was superior with mean yield of 2389 kg ha−1, while F1 was superior with 2378 kg ha−1 in rice. At Faizabad, CT was superior with mean rice yield of 1851 kg ha−1 and lentil yield of 977 kg ha−1, while F1 was superior with 1704 and 993 kg ha−1 of rice and lentil, respectively. At Phulbani, F2 was superior with rice yield of 1170 kg ha−1. At Ranchi, F2 with rice yield of 986 kg ha−1 and F3 with linseed yield of 224 kg ha−1 were superior. The regression model of crop seasonal rainfall and yield deviations indicated an increasing trend in rice yield over mean (positive deviation) with increase in rainfall at all locations; while a decreasing trend (negative deviation) was found for lentil at Faizabad, horse gram at Phulbani and linseed at Ranchi. Based on economic analysis, CTF1 at Varanasi and Faizabad, CTF2 at Phulbani and LT2F2 at Ranchi were superior.
Liquidity Risk, Return Predictability, and Hedge Funds’ Performance: An Empirical Study
Authors: Brandon Rajna Gibson , Wang Songtao
Published: January 2013

This article analyzes the effect of liquidity risk on the performance of equity hedge fund portfolios. Similarly to Avramov, Kosowski, Naik, and Teo (2007), (2011), we observe that, before accounting for the effect of liquidity risk, hedge fund portfolios that incorporate predictability in managerial skills generate superior performance. This outperformance disappears or weakens substantially for most emerging markets, event-driven, and long/short hedge fund portfolios once we account for liquidity risk. Moreover, we show that the equity market-neutral and long/short hedge fund portfolios’ “alphas” also entail rents for their service as liquidity providers. These results hold under various robustness tests.
Response ofEvernia prunastrito urban environmental conditions in Central Europe after the decrease of air pollution
Authors: LACKOVIČOVÁ Anna , GUTTOVÁ Anna , BAČKOR Martin , PIŠÚT Peter , PIŠÚT Ivan
Published: January 2013

The epiphytic lichenEvernia prunastriis sensitive to air pollution and reacted by total retreat to the worsening of air quality during the peak of SO2pollution in Central Europe (1950s–1990). Since 1990, after a significant decrease in air pollution, epiphytic lichens recolonized previously polluted areas, includingE. prunastri. We investigated the physiological status ofE. prunastri, transplanted for six months in 34 sites in the urban area of Bratislava (Slovakia) under current conditions. The content of chlorophylls, cortical and medullar secondary metabolites and soluble proteins were explored. We then examined the relationship of these parameters with the environmental quality status, reflected by the diversity of epiphytic lichens. The results showed that the physiological status ofE. prunastridid not change significantly after exposure. Positive correlations were found between lichen diversity in the sampling sites and physiological parameters (photosynthetic pigments and phaeophytinization quotient) in the transplants. Transplants from sampling sites with a greater proportion of nitrophilous lichens displayed a decrease in photosynthetic pigments. Sites whereE. prunastrinaturally occurred had a lower proportion of nitrophilous species in comparison to sites whereE. prunastriwas not present. This suggests that the indicator speciesE. prunastrimay also recolonize sites with low eutrophication in urban environments under decreased air pollution, and the information on its presence can help to assess the pressure caused by nitrogen excess.
Hydrogen sulphide inhibits PSII of lichen photobionts
Authors: BERTUZZI Stefano , TRETIACH Mauro
Published: January 2013

The effects of hydrogen sulphide (H2S) on five lichens with different photobionts, ecology, and tolerance to the pollutant were studied by means of samples exposed in closed chambers containing two known H2S solutions. The H2S concentration in the void volume at equilibrium with the liquid phase was measured by gas chromatography-mass spectrometry, combined with the use of solid phase micro extraction (GC/MS SPME). It was determined as 8 and 28 ppm H2S in the absence of lichen material, andc. 2 and 10 ppm H2S respectively with living lichen material inserted for 8 hours in the exposure chambers. Significant differences in the species-specific emission of chlorophyllafluorescence (ChlaF) were observed, with a pronounced depression ofFv/Fmalready detectable after 2 h exposure at 28 ppm H2S in all the species. The decreased intensity was positively correlated to sample surface and, to a lesser extent, to the species-specific pre-exposureFv/Fmvalue. Dark-exposed samples were less affected than light-exposed ones. All four chlorolichens could recover the pre-exposure ChlaF emission after two days in the absence of H2S, both in the light and in the dark, whereas the cyanolichen did not recover when kept in the dark. The results are thoroughly discussed on the basis of the known action mechanisms of H2S on the photosynthetic apparatus of vascular plants and cyanobacteria.
The feasibility of the north-eastern USA supporting the return of the cougar Puma concolor
Authors: Laundré John W.
Published: January 2013

The cougar Puma concolor was part of the pre-European fauna of the north-eastern USA. It was extirpated in the late 1800s and since the late 1900s there have been discussions concerning its reintroduction to the region. One site considered is Adirondack State Park in northern New York. In 1981 an assessment of the feasibility of returning cougars concluded that the Park had adequate prey and forest cover to support a small population of cougars but that conflicts with humans would cause the demise of this population within 10 years. Thus reintroduction at that time was not advised. Since then knowledge of cougar ecology and how cougars interact with humans has increased substantially. Based on information compiled since the 1980s I conducted a landscape-scale analysis to assess whether cougars could live in the Park. The results indicate that cougars could occupy 15,300–17,000 km2 (61–69%) of the Park, with minimal contact with human habitation. Based on reported cougar densities the Park could support a population of 150–350 cougars. These cougars would consume < 10% of the adult deer population annually and fawn production would be sufficient to replace these losses. Human and road densities in the Park are similar to those of the Black Hills, South Dakota and southern Florida, both of which have viable populations of cougars. I concluded that Adirondack State Park could support a population of cougars. What is now required is the will to bring them back.
The Geographic Context of Political Attitudes among Migrant-Origin Individuals in Europe
Authors: Maxwell Rahsaan
Published: January 2013

This article examines political trust and government satisfaction among migrant-origin individuals in Europe. While much of the current literature on migrant political attitudes focuses on the positive or negative ramifications of individual-level integration outcomes, the author takes a different approach. He claims that the best way to understand political trust and government satisfaction among migrant-origin individuals is through the strong positive correlation with trust and satisfaction among native-origin individuals in the same subnational region. One implication of this argument is that migrant-origin individuals' trust and satisfaction are closer to native-origin individuals living in the same subnational region than to migrants living elsewhere in Europe. The research provides a new perspective for understanding the broad contours of migrant integration and shifts the debate away from whether or not migrants have positive attitudes about European society. The fact that migrant- and native-origin individuals have similar levels of trust and satisfaction is suggestive of successful attitudinal integration, irrespective of whether those attitudes are positive or negative.
COST-UTILITY OF WAITING TIME IN TOTAL JOINT REPLACEMENTS: A RANDOMIZED CLINICAL TRIAL
Authors: Tuominen Ulla , Sintonen Harri , Aronen Pasi , Hirvonen Johanna , Seitsalo Seppo , Lehto Matti , Hietaniemi Kalevi , Blom Maria
Published: January 2013

In many Western countries, long waiting times for elective surgery are a concern. Major joint replacement is an example of a type of surgery with a high volume of demand and relatively long waiting periods for patients. As populations get older, the prevalence of slowly progressive diseases, such as osteoarthritis (OA) in hip and knee joints, is increasing. Over three-quarters of a million total hip and knee replacement surgeries are done in the United States annually (1). Furthermore, according to March et al. (1997), the costs of OA have been estimated to account for up to 1–2.5 percent of the Gross National Product (GNP) in several developed countries (2). In Finland, a total of 11,104 total joint replacements (TJRs) were performed in 2004 (hip 6,600 and knee 5,905), with the median waiting time of 181 days for the surgery (hip 153 and knee 209 days). Until 2007, the number of TJRs was 17,334 (hip 7,698 and knee 9,636), with a median waiting time of 120 and 142 days, respectively (3;4). The mean waiting time for elective surgical procedures is approximately 3 months in several countries and the maximum waiting times can stretch into years.
ECONOMIC EVALUATIONS AND DIAGNOSTIC TESTING: AN ILLUSTRATIVE CASE STUDY APPROACH
Authors: Sanghera Sabina , Orlando Rosanna , Roberts Tracy
Published: January 2013

Objective:The aim of this study was to present a clear process of synthesizing test accuracy data when conducting economic evaluations of diagnostic tests for health technology assessment (HTA) assessors and health economists.

Methods:We appraised the methods advocated for using diagnostic test accuracy data in economic evaluations. We used a case study of fetal anemia in which data from a screening test are used in combination with a confirmatory test.

Results:We developed a step-by-step guide and consider two scenarios: when data on test accuracy from several studies are based on (i) thesametest threshold for positivity and (ii)differenttest thresholds.

Conclusions:We conclude that each approach has its strengths and limitations. We show that the optimal operating point of the test should be identified to determine the true cost-effectiveness of the test. We advocate that these issues require a multidisciplinary team of health economists, decision modelers and statisticians.
Miscellany and Collegiality in the British Periodical Press: TheHarmonicon(1823–1833)
Authors: Johnson-Hill Erin
Published: January 2013

The Harmonicon was, in its day, London's premiere music periodical, gaining a wide and loyal readership at home and abroad. Perhaps the most the distinctive feature of the journal was its deliberate imperative to raise what it considered to be the ‘lamentable’ level of musical knowledge held by the British reading public. The journal's editor, William Ayrton, was deeply concerned that there was a lack of a national school of music in his own country that could ever match that which his rival French and German critics called their own. In this light, I argue that the journal's appeal and economic success was due to a didactic philosophy of ‘collegiality’ and ‘miscellany’ – to borrow William Weber's terms – as a means of disseminating musical knowledge to the broadest readership possible. Through reviewing, critiquing and publishing a remarkably assorted array of national styles and genres of music, the Harmonicon attempted to create a very general type of musical knowledge in Britain in the early nineteenth century, one which looked necessarily beyond national borders in an effort to build up a shared knowledge of music. Data drawn from musical examples spanning all 11 years of the journal's print run is analysed, assessing in particular the high number of international composers featured in the journal. The many miscellaneous strands interwoven throughout the Harmonicon reflect a mode of thinking about music that was integral to a valiant effort to raise the status and awareness of music in early nineteenth-century British culture.
An Overview of Multidisciplinary Research Resources at the Osaka University Center for Twin Research
Authors: Hayakawa Kazuo , Iwatani Yoshinori ,   the Osaka Twin Research Group
Published: January 2013

Osaka University Center for Twin Research is currently organizing a government-funded, multidisciplinary research project using a large registry of aged twins living in Japan. The purpose of the project is to collect various information as well as biological resources from registered twins, and to establish a biobank and databases for preserving and managing these data and resources. The Center is collecting data from twin pairs, both of whom have agreed to participate in a one-day comprehensive medical examination. The following data are being collected: physical data (e.g., height, body mass, blood pressure, theoretical visceral fat, pulse wave velocity, and bone density), data regarding epidemiology (e.g., medical history, lifestyle, quality of life, mood status, cognitive function, and nutrition), electrocardiogram, ultrasonography (carotid artery and thyroid), dentistry, plastic surgery, positron emission tomography, magnetoencephalogram, and magnetic resonance imaging of brain. These data are then aggregated and systematically stored in specific databases. In addition, peripheral blood is obtained from the participants, and then genomic DNA is purified and sera are stored. A wide variety of studies are ongoing, and more are in the planning stage.
CD134/CD137 dual costimulation‐elicited IFN‐γ maximizes effector T‐cell function but limits Treg expansion
Authors: St. Rose Marie‐Clare , Taylor Roslyn A , Bandyopadhyay Suman , Qui Harry Z , Hagymasi Adam T , Vella Anthony T , Adler Adam J
Published: January 2013

T‐cell tolerance to tumor antigens represents a major hurdle in generating tumor immunity. Combined administration of agonistic monoclonal antibodies (mAbs) to the costimulatory receptors CD134 plus CD137 can program T‐cells responding to tolerogenic antigen to undergo expansion, and effector T‐cell differentiation, and also elicits tumor immunity. Nevertheless, CD134 and CD137 agonists can also engage inhibitory immune components. To understand how immune stimulatory versus inhibitory components are regulated during CD134 plus CD137 dual costimulation (DCo), the current study utilized a model where DCo programs T‐cells encountering a highly tolerogenic self‐antigen to undergo effector differentiation. IFN‐γ was found to have a pivotal role in maximizing the function of effector T‐cells, while simultaneously limiting the expansion of CD4+CD25+Foxp3+ Tregs. In antigen‐responding effector T‐cells, IFN‐γ operates via a direct cell‐intrinsic mechanism to cooperate with IL‐2 to program maximal expression of granzyme B. Simultaneously, IFN‐γ limits expression of the IL‐2 receptor alpha chain (CD25) and IL‐2 signaling through a mechanism that does not involve T‐bet‐mediated repression of IL‐2. IFN‐γ also limited CD25 and Foxp3 expression on bystanding CD4+Foxp3+ Tregs, and limited the potential of these Tregs to expand. These effects could not be explained by the ability of IFN‐γ to limit IL‐2 availability. Taken together, during DCo IFN‐γ interacts with IL‐2 through distinct mechanisms to program maximal expression of effector molecules in antigen‐responding T‐cells, while simultaneously limiting Treg expansion.
Inhibition of human γ-glutamyl transpeptidase: development of more potent, physiologically relevant, uncompetitive inhibitors
Authors: Wickham Stephanie , Regan Nicholas , West Matthew B. , Thai Justin , Cook Paul F. , Terzyan Simon S. , Li Pui Kai , Hanigan Marie H.
Published: January 2013

GGT (γ-glutamyl transpeptidase) is an essential enzyme for maintaining cysteine homoeostasis, leukotriene synthesis, metabolism of glutathione conjugates and catabolism of extracellular glutathione. Overexpression of GGT has been implicated in many pathologies, and clinical inhibitors of GGT are under development for use in the treatment of asthma, cancer and other diseases. Inhibitors are generally characterized using synthetic GGT substrates. The present study of uncompetitive inhibitors of GGT, has revealed that the potency with which compounds inhibit GGT activity in the standard biochemical assay does not correlate with the potency with which they inhibit the physiological reaction catalysed by GGT. Kinetic studies provided insight into the mechanism of inhibition. Modifications to the sulfobenzene or distal benzene ring of the uncompetitive inhibitor OU749 affected activity. One of the most potent inhibitors was identified among a novel group of analogues with an amine group para on the benzosulfonamide ring. New more potent uncompetitive inhibitors of the physiological GGT reaction were found to be less toxic than the glutamine analogues that have been tested clinically. Development of non-toxic inhibitors is essential for exploiting GGT as a therapeutic target.
Concept for support and heating of plate-like samples in the ultra-high vacuum
Authors: Tröger L. , Pieper H. H. , Reichling M.
Published: January 2013

We present the concept for a sample holder designed for mounting and heating of plate-like samples that is based on a clamping mechanism for easy handling. The clamping mechanism consists of a U-shaped bracket encompassing the sample support plate from the rear. Two spring wires are fixed in the walls of the bracket spanning the sample to secure it with only two point contacts. This enables the sample to freely expand or contract during heating and cooling. To accommodate for a large variety in sample size, shape, and quality, we introduce two designs differing in the generation of the clamping force: One pressing the sample against the spring wires, the other one pulling the spring wires onto the sample. Both designs yield an automatically even alignment of the sample during the mounting process to achieve an even load distribution and reliable fixation specifically for brittle samples. For high temperature treatment, the sample holders are enhanced by a resistive heating plate. As only the sample and a small fraction of the sample holder are heated, temperatures of 1300 °C are reached with only 8 W heating power. The sample support and heating components are mounted on a 11 mm × 13 mm base plate with a handle that can be transferred between the sample entry stage, the preparation stage, and surface science experiments in the ultra-high vacuum system.
Gaussian basis sets for highly excited and resonance states of helium
Authors: Kaprálová-Žďánská Petra Ruth , Šmydke Jan
Published: January 2013

A consistent method for optimizing Gaussian primitives for Rydberg and multiply excited helium states is designed. A novel series for the “exponentially tempered Gaussians” is introduced, which is markedly more efficient than the commonly used series of even tempered Gaussians. The optimization is made computationally feasible due to an approximate calculation of excited states using the effective one-electron Hamiltonian that is defined as Fockian from which the redundant Coulomb and exchange terms are dropped. Finally, ExTG5G and ExTG7F Gaussian basis sets are proposed. They enable calculations of the helium spectrum all the way from the ground state up to the (5, 4)5 1Se and (6, 5)7 1Se doubly excited resonances, respectively, mostly in the spectroscopic accuracy of 1 cm−1.
Major and minor stress-magnetization loops in textured polycrystalline Fe81.6Ga18.4 Galfenol
Authors: Weng Ling , Walker Travis , Deng Zhangxian , Dapino M. J. , Wang Bowen
Published: January 2013

Major and minor magnetization versus stress loops under different bias magnetic fields from 0.8 kA/m to 8.0 kA/m in 0.8 kA/m steps were measured in research grade, ⟨100⟩ oriented, textured polycrystalline Fe81.6Ga18.4. Both compressive and tensile stresses were applied from −63 MPa to 63 MPa for major loop analysis. Minor loops were generated by superimposing a 4.0 Hz, 2.8 MPa amplitude sinusoidal stress on different dc compressive stresses ranging from −40.7 MPa to −5.6 MPa in 7.0 MPa increments. Bias magnetic fields were applied in two ways, constant field in the sample obtained using a controller and constant current to the excitation coils. An energy-averaged model and related optimization method are presented to compare the experiments with simulations. The slope of magnetic flux density versus stress, i.e., the material's sensitivity to stress, is quantified from major and minor loop measurements. The peak sensitivity at constant field is about 75 T/GPa for constant-field major loops, whereas it is 41 T/GPa for constant-current major loops. The sensitivity for minor loops is consistently lower than for major loops, whether at constant field or constant current.
Electromechanical instability and oscillating deformations in electroactive polymer films
Authors: De Tommasi D. , Puglisi G. , Zurlo G.
Published: January 2013

Based on an energetic approach, we analytically determine inhomogeneous equilibrium configurations of thin electroactive polymeric films of under assigned voltage. We show that our results are useful in the analysis of well known failure phenomena taking place in this type of devices. Moreover, we demonstrate that neglecting inhomogeneity effects may lead to a drastic overestimate of the activation performances.
Tunable spin reorientation transition and magnetocaloric effect in Sm0.7−xLaxSr0.3MnO3 series
Authors: Aparnadevi M. , Mahendiran R.
Published: January 2013

We report electrical resistivity, magnetic, and magnetocaloric properties in Sm0.7−xLaxSr0.3MnO3 series for x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.65, and 0.7. All the compounds show second order paramagnetic to ferromagnetic (FM) transition at T = Tc, which is tunable anywhere between 83 K and 373 K with a proper choice of the doping level (x). The insulating ferromagnet x = 0 transforms to a ferromagnetic metal below Tc for x = 0.1, and the insulator-metal transition temperature shifts up with increasing x. The magnetization (M) exhibits an interesting behavior as a function of temperature and doping level. The field-cooled M(T) of all but x = 0.7 compounds show a cusp at a temperature T* much below Tc. While the Tc increases monotonically with increasing x, T* increases gradually, attains a maximum value (T* = 137 K) for x = 0.6 and decreases rapidly thereafter. It is suggested that the decrease of M(T) below T* is due to ferrimagnetic interaction between Sm(4f) and Mn(3d) sublattices that promotes spin-reorientation transition of the Mn-sublattice. The observed anomalous feature in M(T) does not have impact on the dc resistivity. Magnetic entropy change (ΔSm) was estimated from magnetization isotherms. The sign of ΔSm is found to change from negative above T* to positive below T* indicating the coexistence of normal and inverse magnetocaloric effects. ΔSm is nearly composition independent (−ΔSm = 1.2 ± 0.2 J/Kg K for μ0ΔH = 1 Tesla) and refrigeration capacity lies between 40 and 50 J/kg K for 0.1 ≤ x ≤ 0.6. We show scaling of magnetic entropy change under different magnetic fields and analysis of critical exponents associated with the phase transition in x = 0.6 compound. The tunability of Curie temperature with nearly constant ΔSm value along with high refrigeration capacity makes this series of compounds interesting for magnetic refrigeration over a wide temperature range.
Extraordinary light circulation and concentration of s- and p-polarized phase resonances
Authors: Enemuo Amarachukwu , Nolan Martin , Uk Jung Young , Golovin Andrii B. , Crouse David T.
Published: January 2013

Both s-polarized and p-polarized phase resonances in one-dimensionally compound transmission gratings are analyzed, modeled, and measured. We demonstrate that s-polarized phase resonances occur with similar characteristics of p-polarized phase resonances, with narrow bandwidths, high Q values, and highly amplified fields. The phase difference of π radian between the fields in the coupled cavities produces light circulation and an inversion of the transmissivity/opacity of the structure. The dependencies of bandwidth and wavelength of the resonances on structural and material properties are described, as well as the way light flows in the structure when the phase resonances are excited.
Nonlinear optical absorption and stimulated Mie scattering in metallic nanoparticle suspensions
Authors: He Guang S. , Law Wing-Cheung , Baev Alexander , Liu Sha , Swihart Mark T. , Prasad Paras N.
Published: January 2013

The nonlinear optical properties of four metallic (Au-, Au/Ag-, Ag-, and Pt-) nanoparticle suspensions in toluene have been studied in both femtosecond and nanosecond regimes. Nonlinear transmission measurements in the femtosecond laser regime revealed two-photon absorption (2PA) induced nonlinear attenuation, while in the nanosecond laser regime a stronger nonlinear attenuation is due to both 2PA and 2PA-induced excited-state absorption. In the nanosecond regime, at input pump laser intensities above a certain threshold value, a new type of stimulated (Mie) scattering has been observed. Being essentially different from all other well known molecular (Raman, Brillouin) stimulated scattering effects, the newly observed stimulated Mie scattering from the metallic nanoparticles exhibits the features of no frequency shift and low pump threshold requirement. A physical model of induced Bragg grating initiated by the backward Mie scattering from metallic nanoparticles is proposed to explain the gain mechanism of the observed stimulated scattering effect.
Cooperativity in the annealing of DNA origamis
Authors: Arbona Jean-Michel , Aimé Jean-Pierre , Elezgaray Juan
Published: January 2013

DNA based nanostructures built on a long single stranded DNA scaffold, known as DNA origamis, offer the possibility to organize various molecules at the nanometer scale in one pot experiments. The folding of the scaffold is guaranteed by the presence of short, single stranded DNA sequences (staples), that hold together separate regions of the scaffold. In this paper, we modelize the annealing-melting properties of these DNA constructions. The model captures important features such as the hysteresis between melting and annealing, as well as the dependence upon the topology of the scaffold. We show that cooperativity between staples is critical to quantitatively explain the folding process of DNA origamis.
Conductive probe AFM study of Pt-thiol and Au-thiol contacts in metal-molecule-metal systems
Authors: Kim Chang Min , Bechhoefer John
Published: January 2013

The charge transport mechanism between 1,8-octanedithiol (ODT, C8H16S2H2) and platinum and gold electrodes is studied by breaking bonds between single ODT molecules and atomic metal junctions using conductive probe atomic force microscopy. Histograms of conductance values show peaks that are obscured by background processes that differ from the metal-molecule-metal conduction path of interest. We introduce a new method to reduce greatly such backgrounds by dividing by a 1-octanethiol (OMT, C8H17SH) reference histogram, without data selection. The method reveals three series of conductance values for both platinum and gold contacts, which we associate with geometrically different configurations between thiol and metal atoms. The ordering of conductance values, Pt-ODT-Pt > Pt-ODT-Au> Au-ODT-Au, is consistent with a relative dependence on both the number of electron channels and the density of states.
Theory of spatially non-symmetric kinetic equilibria for collisionless plasmas
Authors: Cremaschini Claudio , Tessarotto Massimo
Published: January 2013

The problem posed by the possible existence/non-existence of spatially non-symmetric kinetic equilibria has remained unsolved in plasma theory. For collisionless magnetized plasmas, this involves the construction of stationary solutions of the Vlasov-Maxwell equations. In this paper, the issue is addressed for non-relativistic plasmas both in astrophysical and laboratory contexts. The treatment is based on a Lagrangian variational description of single-particle dynamics. Starting point is a non-perturbative formulation of gyrokinetic theory, which allows one to construct “a posteriori” with prescribed order of accuracy an asymptotic representation for the magnetic moment. In terms of the relevant particle adiabatic invariants generalized bi-Maxwellian equilibria are proved to exist. These are shown to recover, under suitable assumptions, a Chapman-Enskog form which permits an analytical treatment of the corresponding fluid moments. In particular, the constrained posed by the Poisson and the Ampere equations are analyzed, both for quasi-neutral and non-neutral plasmas. The conditions of existence of the corresponding non-symmetric kinetic equilibria are investigated. As a notable feature, both astrophysical and laboratory plasmas are shown to exhibit, under suitable conditions, a kinetic dynamo, whereby the equilibrium magnetic field can be self-generated by the equilibrium plasma currents.
Effect of density stratification on vortex merger
Authors: Dixit Harish N. , Govindarajan Rama
Published: January 2013

We study the effect of density stratification in the plane on the merging of two equal vortices. Direct numerical simulations are performed for a wide range of parameters. Boussinesq and non-Boussinesq effects are considered separately. With the Boussinesq approximation, moderate to high Prandtl number and Froude number close to unity, there is a monotonic drifting away of the vortices from each other, and merger is completely prevented. Among non-Boussinesq effects, the inertial effects of density stratification are highlighted. These give rise to a breaking of symmetry, and consequently, the vorticity centroid is found to drift significantly from its initial position. Using an idealized model, we explore the role of baroclinic vorticity in determining these features of the merger process.
Correlated driving and dissipation in two-dimensional spectroscopy
Authors: Xu Jian , Zhang Hou-Dao , Xu Rui-Xue , Yan YiJing
Published: January 2013

The correlation between coherent driving and non-Markovian dissipation plays a vital role in optical processes. To exhibit its effect on the simulation of optical spectroscopy, we explore the correlated driving-dissipation equation (CODDE) [R. X. Xu and Y. J. Yan, J. Chem. Phys. 116, 9196 (2002)]10.1063/1.1474579, which modifies the conventional Redfield theory with the inclusion of correlated driving-dissipation effect at the second-order system–bath coupling level. With an exciton model mimicking the Fenna–Matthews–Olson pigment-protein complex, we compare between the Redfield theory, CODDE, and exact hierarchical dynamics, for their results on linear absorption and coherent two-dimensional spectroscopy. We clarify that the failure of Redfield approach originates mainly from the neglect of driving–dissipation correlation, rather than its second-order nature. We further propose a dynamical inhomogeneity parameter to quantify the applicable range of CODDE. Our results indicate that CODDE is an efficient and quantifiable theory for many light-harvesting complexes of interest. To facilitate the evaluation of multi-dimensional spectroscopy, we also develop the mixed Heisenberg–Schrödinger picture scheme that is valid for any dynamics implementation on nonlinear response functions.
Localized surface plasmon resonances in graphene ribbon arrays for sensing of dielectric environment at infrared frequencies
Authors: Vasić Borislav , Isić Goran , Gajić Radoš
Published: January 2013

High confinement of surface plasmon polaritons in graphene at infrared frequencies enhances the light-matter interaction and can be used for the sensing of the environment. The considered sensing platform consists of parallel graphene ribbons which enables efficient coupling of an electromagnetic field into localized surface plasmons. Changes in the environment are then detected by measuring the resulting frequency shifts of the plasmonic resonances. It is shown that the graphene ribbons have the sensitivity comparable to the sensitivity of noble metal nanoparticles at visible frequencies, which enable sensing of only several nanometers thick films at wavelengths around ten microns. At the same time, the tunability of graphene plasmons enables a design of broadband substrates for surface enhanced infrared absorption of thin films. By changing the Fermi level in graphene, the plasmonic resonance of graphene ribbons can be adjusted to desired vibrational mode which facilitates detection of multiple absorption bands.
Resonantly overcoming metal opacity
Authors: Edmunds J. D. , Lockyear M. J. , Hibbins A. P. , Sambles J. R. , Youngs I. J.
Published: January 2013

The near-perfect response of electrons in metals to low-frequency electromagnetic fields makes even a sub-skin-depth film almost completely opaque to microwave radiation. Here, it is experimentally demonstrated that by surrounding a ∼60 nm aluminium film with an array of thin resonant cavities, over 35% of the microwave radiation incident can be transmitted over a discrete set of narrow bands. This represents an enhancement of ∼1000 times over an isolated film and allows for a frequency selective screen with a thickness less than 1/70th of the operating wavelength that may be tuned through choice of resonant geometry.
Influence of transparent coating hardness on laser-generated ultrasonic waves
Authors: Guo Yuning , Yang Dexing , Feng Wen , Chang Ying
Published: January 2013

Numerical models are established to investigate the influence of transparent coating hardness on the laser-generated thermoelastic force source and ultrasonic waves in coating-substrate systems by using finite element method. With the increase of coating hardness, the characteristic of longitudinal wave in substrate is more obvious due to the gradual increase of reactive force produced by coating constraint; the directivity patterns of longitudinal wave show that the energy concentration area transfers from bilateral area to the axial direction area gradually. Therefore, the directivity pattern can be regulated to obtain the better ultrasonic signals by coating different hardness materials. It is significant for further development of the experiment in composite evaluation and in extreme condition.
Design and development of 3 dB patch compensated tandem hybrid coupler
Authors: Yadav Rana Pratap , Kumar Sunil , Kulkarani S. V.
Published: January 2013

Design and development procedure of the strip line based 3 dB patch compensated tandem hybrid coupler at 91.2 ± 15 MHz and 2.5 kW is presented. The coupled strip-line structure is designed and electromagnetic analysis software is used for accurate modelling and optimization of parameters. Coupled strip lines are well known for poor impedance matching and poor isolation due to discontinuities, fabrication tolerance constraints, and theoretical approximations in design. These effects are realized and compensated or taken into consideration. The conventional methods of compensation like open stubs or lumped capacitors are useful in the low rf power applications only. In the present paper, patch compensation technique is explored, explained, applied, and incorporated in the development of a 3 dB tandem hybrid coupler. This newly explored patch compensation technique is found substantially effective in improving the overall performance in terms of return loss and isolation. A prototype tandem coupler rated for 2.5 kW at 91.2 ± 15 MHz, has been developed, fabricated, tested, and the effect of patch compensation technique is found to be quite effective.