bluuebunny/crossref_metadata_2025 huggingface dataset:
No correlation between body mass index and striatal dopamine transporter availability in healthy volunteers using SPECT and [123I]PE2I
Authors: Thomsen G. , Ziebell M. , Jensen P. S. , da Cuhna‐Bang S. , Knudsen G. M. , Pinborg L. H.
Published: May 2013

Objective

Dopamine plays an important role in both the rewarding and conditioning effects of food. These effects involve mesolimbic, mesocortical, and nigrostriatal pathways. In humans, the most consistent finding has been reduced striatal dopamine D2/3 receptor availability. In striatum, dopamine is inactivated by reuptake via the dopamine transporter (DAT). The aim of the study was to test the hypothesis of lower DAT availability in obese healthy subjects using a selective DAT radiotracer in a sample of subjects with a wide range of BMI values.

Design and Methods

Thirty‐three healthy subjects with a mean age of 48.4 ± 13.3 (range, 21‐71) years and a mean BMI of 29.6 ± 7.8 kg/m2 (range, 21.0‐49.5) were included in the study. We used [123I]PE2I and SPECT to measure DAT availability.

Results

Using multiple linear regression analyses with striatal DAT as the dependent variable and BMI, age and gender as predictors was performed. We found no correlation between BMI and striatal DAT availability in striatum (P = 0.99), caudate nucleus (P = 0.61), and putamen (P = 0.30). Furthermore, we found no group difference between obese/severely obese (BMI > 30 kg/m2) and normal weight controls (BMI ≤ 25 kg/m2).

Conclusions

We did not find any correlation between BMI and DAT availability in healthy volunteers.
The effect of leptin, caffeine/ephedrine, and their combination upon visceral fat mass and weight loss
Authors: Liu Ann G. , Smith Steven R. , Fujioka Ken , Greenway Frank L.
Published: May 2013

Objective

To evaluate the effects of combination caffeine/ephedrine and leptin A‐200 on visceral fat mass and weight loss over 24 weeks.

Design and Methods

In this randomized, double‐blind, parallel‐arm trial, 90 obese subjects received one of the three treatments for 24 weeks: 200 mg caffeine/20 mg ephedrine t.i.d. (CE), leptin A‐200 (recombinant methionyl human Fc‐leptin, 20 mg q.d.) (L), or combination leptin A‐200 and caffeine/ephedrine (LCE). Outcomes included change in weight, visceral fat mass by computed tomography, lean mass and fat mass by dual energy X‐ray absorptiometry.

Results

Groups treated with CE and LCE lost significant amounts of weight (−5.9 ± 1.2% and −6.5 ± 1.1%, P < 0.05) and whole body fat mass (−9.6 ± 2.4% and −12.4 ± 2.3%, P < 0.05) compared to leptin only group. Only treatment with LCE significantly reduced visceral fat mass (−11.0 ± 3.3%, P < 0.05). There were no differences in lean mass between treatment groups.

Conclusions

Our study provides evidence that CE is a modestly effective weight loss agent and produces significant reductions in fat mass. Leptin A‐200 was not effective in producing weight loss and did not have any significant additive or synergistic actions when combined with CE.
Minimizing control energy in a class of bounded‐control linear‐quadratic regulator problems
Authors: Costanza V. , Rivadeneira P. S. , González A. H.
Published: May 2013

Minimal‐control‐energy strategies are substantiated and illustrated for linear‐quadratic problems with penalized endpoints and no state‐trajectory cost, when bounds in control values are imposed. The optimal solution for a given process with restricted controls, starting at a known initial state, is shown to coincide with the saturated solution to the unrestricted problem that has the same coefficients but starts at a generally different initial state. This result reduces the searching span for the solution: from the infinite‐dimensional set of admissible control trajectories to the finite‐dimensional Euclidean space of initial conditions. An efficient real‐time scheme is proposed here to approximate (eventually to find) the optimal control strategy, based on the detection of the appropriate initial state while avoiding as much as possible the generation and evaluation of state and control trajectories. Numerical (including model predictive control) simulations are provided, compared, and checked against the analytical solution to ‘the cheapest stop of a train’ problem in its pure‐upper‐bounded brake, flexible‐endpoint setting. Copyright © 2013 John Wiley & Sons, Ltd.
Commercial landscape of noninvasive prenatal testing in the United States
Authors: Agarwal Ashwin , Sayres Lauren C. , Cho Mildred K. , Cook‐Deegan Robert , Chandrasekharan Subhashini
Published: May 2013

Cell‐free fetal DNA‐based noninvasive prenatal testing (NIPT) could significantly change the paradigm of prenatal testing and screening. Intellectual property (IP) and commercialization promise to be important components of the emerging debate about clinical implementation of these technologies. We have assembled information about types of testing, prices, turnaround times, and reimbursement of recently launched commercial tests in the United States from the trade press, news articles, and scientific, legal, and business publications. We also describe the patenting and licensing landscape of technologies underlying these tests and ongoing patent litigation in the United States. Finally, we discuss how IP issues may affect clinical translation of NIPT and their potential implications for stakeholders. Fetal medicine professionals (clinicians and researchers), genetic counselors, insurers, regulators, test developers, and patients may be able to use this information to make informed decisions about clinical implementation of current and emerging noninvasive prenatal tests. © 2013 John Wiley & Sons, Ltd.
Functional proteomics reveals the protective effects of saffron ethanolic extract on hepatic ischemia‐reperfusion injury
Authors: Pan Tai‐Long , Wu Tung‐Ho , Wang Pei‐Wen , Leu Yann‐Lii , Sintupisut Nardnisa , Huang Chun‐Hsun , Chang Fang‐Rong , Wu Yang‐Chang
Published: May 2013

Hepatic ischemia‐reperfusion (IR) injury is a common clinical problem and ROS may be a contributing factor on IR injury. The current study evaluates the potential protective effect of saffron ethanol extract (SEE) in a rat model upon hepatic IR injury. Caspases 3 and terminal deoxynucleotidyl transferase‐mediated dUTP biotin nick end labeling (TUNEL) results showed increased cell death in the IR samples; reversely, minor apoptosis was detected in the SEE/IR group. Pretreatment with SEE significantly restored the content of antioxidant enzymes (SOD1 and catalase) and remarkably inhibited the intracellular ROS concentration in terms of reducing p47phox translocation. Proteome tools revealed that 20 proteins were significantly modulated in protein intensity between IR and SEE/IR groups. Particularly, SEE administration could attenuate the carbonylation level of several chaperone proteins. Network analysis suggested that saffron extract could alleviate IR‐induced ER stress and protein ubiquitination, which finally lead to cell apoptosis. Taken together, SEE could reduce hepatic IR injury through modulating protein oxidation and our results might help to develop novel therapeutic strategies against ROS‐caused diseases.
Global optimization of clusters using electronic structure methods
Authors: Heiles Sven , Johnston Roy L.
Published: May 2013

Over the past decade, there has been a significant growth in the development and application of methods for performing global optimization (GO) of cluster and nanoparticle structures using first‐principles electronic structure methods coupled to sophisticated search algorithms. This has in part been driven by the desire to avoid the use of empirical potentials (EPs), especially in cases where no reliable potentials exist to guide the search toward reasonable regions of configuration space. This has been facilitated by improvements in the reliability of the search algorithms, increased efficiency of the electronic structure methods, and the development of faster, multiprocessor high‐performance computing architectures. In this review, we give a brief overview of GO algorithms, though concentrating mainly on genetic algorithm and basin hopping techniques, first in combination with EPs. The major part of the review then deals with details of the implementation and application of these search methods to allow exploration for global minimum cluster structures directly using electronic structure methods and, in particular, density functional theory. Example applications are presented, ranging from isolated monometallic and bimetallic clusters to molecular clusters and ligated and surface supported metal clusters. Finally, some possible future developments are highlighted. © 2013 Wiley Periodicals, Inc.
Exact results in D = 2 supersymmetric gauge theories
Authors: Doroud Nima , Gomis Jaume , Le Floch Bruno , Lee Sungjay
Published: May 2013

Abstract

We compute exactly the partition function of two dimensional
$ \mathcal{N} $
= (2, 2) gauge theories on S
2 and show that it admits two dual descriptions: either as an integral over the Coulomb branch or as a sum over vortex and anti-vortex excitations on the Higgs branches of the theory. We further demonstrate that correlation functions in two dimensional Liouville/Toda CFT compute the S
2 partition function for a class of
$ \mathcal{N} $
= (2, 2) gauge theories, thereby uncovering novel modular properties in two dimensional gauge theories. Some of these gauge theories flow in the infrared to Calabi-Yau sigma models — such as the conifold — and the topology changing flop transition is realized as crossing symmetry in Liouville/Toda CFT. Evidence for Seiberg duality in two dimensions is exhibited by demonstrating that the partition function of conjectured Seiberg dual pairs are the same.
The Effect of Nativity, Ethnicity and Race on the Earnings of Cape Verdean Americans
Authors: Model Suzanne
Published: May 2013

This paper estimates the net effects of nativity, ethnicity and race on the earnings of Cape Verdean Americans, a small, Afro-European group who speak a Portuguese-based Creole. While in their homeland, most Cape Verdeans identify as mestiço, but in America they are usually perceived as black. The data come from the 2000 US Census and the American Community Survey (2000–2007); Native Born Non-Hispanic Whites and African Americans serve as benchmarks. The results show that, controlling for pre-migration education, foreign birth is not a handicap; indeed, for women it is an advantage. Ethnicity too is never a handicap and occasionally an advantage. Race, on the other hand, penalizes males. Native born Cape Verdean men who identify as “Other”, “Black Other” or “Black” earn significantly less than NBNH Whites. On the other hand, regardless of racial identity, Native born Cape Verdean women earn at least as much as NBNH Whites. Finally, one subgroup of native born Cape Verdean men and women, those who identify racially as “Black”, earn slightly more than African Americans.
Variation of Paleo-productivity and Terrigenous Input in the Eastern Arabian Sea during the Past 100 ka
Authors: Mir Ishfaq, Ahmad , Pattan J. N. , Matta V. M. , Banakar V. K.
Published: May 2013

A 4.1m long sediment core from the Eastern Arabian Sea (EAS) is studied using multiple geochemical proxies to understand the variation of productivity and terrigenous matter supply during the past 100 ka. The temporal variation in element concentration and fluxes of CaCO3, organic carbon (Corg) and Barium excess (Baexc), together, in general indicate a higher productivity during the cold climate and highest during the Last Glacial Maximum (LGM) in particular. This cold climate-increased productivity coupling may be attributed to the shoaling of nutricline due to enhanced convective mixing resulting from the intensified winter monsoon. Increased linear sedimentation rates and fluxes of Al, Fe, Mg, Ti, Cr, Cu, Zn, and V during the cold period also suggest increased input of terrigenous matter supporting intensified winter winds. However, the presence of large abundance of structurally unsupported elemental content (e.g.: Mg-86%, Fe-82% and Al-53%) indicate increased input of terrigenous material which was probably enhanced due to intense winter monsoon.
Investigation of Quality of Life Determinants Among Mothers of Children with Pervasive Developmental Disorders in Iran
Authors: Mahani Mohammad Khayatzadeh , Rostami Hamid Reza , Nejad Seyfollah Jahantabi
Published: May 2013

Objective/Background

The objective of the study was to examine the association between socio-economic status (SES), marital satisfaction, and subtypes of pervasive developmental disorders (PDDs) with quality of life (QOL) in mothers of children with PDDs.

Methods

The study was conducted using a convenience sample of 210 mothers of children with PDDs. Data were collected using the World Health Organization QOL-BREF, Index of Marital Satisfaction, and SES Questionnaires. Data analysis was done by analysis of variance and multivariate analysis of variance tests.

Results

The findings of the study showed that SES is associated strongly with the environmental domain (p < .001, r2 = .421), marital satisfaction with the social domain (p < .001, r2 = .394), and PDDs’ subtype with the psychological domain (p < .001, r2 = .283). Mothers of children with autistic disorder subtype reported lower QOL in all domains compared with other subtypes (p < .05).

Conclusion

The determinants such as SES, marital satisfaction, and subtypes of PDDs have an important influence on QOL of mothers of children with PDDs. Further investigation in this regard is warranted.
Apolipoprotein E polymorphisms in frontotemporal lobar degeneration: A meta‐analysis
Authors: Rubino Elisa , Vacca Alessandro , Govone Flora , De Martino Paola , Pinessi Lorenzo , Rainero Innocenzo
Published: May 2013

Objective

Case–control studies have not been consistent in showing association between apolipoprotein E (APOE) polymorphisms and frontotemporal lobar degeneration (FTLD), producing contradictory findings. The study objective was to define and quantify further the disease risk associated with the carriage of different APOE alleles to determine whether APOE gene polymorphism is a risk factor for FTLD.

Methods

A systematic review of all case–control studies investigating the association between the APOE gene and FTLD up to December 2011 was conducted. Case–control studies using clinical or pathological criteria for FTLD and reporting APOE allelic or genotypic data were included. Pooled odds ratios (ORs) were estimated using a random effects model, and 95% confidence intervals (CIs) were calculated.

Results

Twenty‐eight case–control studies met the inclusion criteria. Carriage of the ε2 allele had no effect on disease risk. On the contrary, carriage of the ε4 allele was associated with a significantly increased disease risk (ε4 carriers vs non‐ε4 carriers: OR, 1.94; 95% CI, 1.43–2.64; ε4 vs ε3 allele: OR, 1.83; 95% CI, 1.34–2.52). Furthermore, a gene–dosage effect for the ε4 allele was found. There was no evidence of publication bias, but heterogeneity between the studies was high.

Conclusions

Our study provides evidence for an association between the APOE ε4 allele and frontotemporal lobar degeneration.
Unobtrusive measurement of daily computer use to detect mild cognitive impairment
Authors: Kaye Jeffrey , Mattek Nora , Dodge Hiroko H. , Campbell Ian , Hayes Tamara , Austin Daniel , Hatt William , Wild Katherine , Jimison Holly , Pavel Michael
Published: May 2013

Background

Mild disturbances of higher order activities of daily living are present in people diagnosed with mild cognitive impairment (MCI). These deficits may be difficult to detect among those still living independently. Unobtrusive continuous assessment of a complex activity such as home computer use may detect mild functional changes and identify MCI. We sought to determine whether long‐term changes in remotely monitored computer use differ in persons with MCI in comparison with cognitively intact volunteers.

Methods

Participants enrolled in a longitudinal cohort study of unobtrusive in‐home technologies to detect cognitive and motor decline in independently living seniors were assessed for computer use (number of days with use, mean daily use, and coefficient of variation of use) measured by remotely monitoring computer session start and end times.

Results

More than 230,000 computer sessions from 113 computer users (mean age, 85 years; 38 with MCI) were acquired during a mean of 36 months. In mixed‐effects models, there was no difference in computer use at baseline between MCI and intact participants controlling for age, sex, education, race, and computer experience. However, over time, between MCI and intact participants, there was a significant decrease in number of days with use (P = .01), mean daily use (∼1% greater decrease/month; P = .009), and an increase in day‐to‐day use variability (P = .002).

Conclusions

Computer use change can be monitored unobtrusively and indicates individuals with MCI. With 79% of those 55 to 64 years old now online, this may be an ecologically valid and efficient approach to track subtle, clinically meaningful change with aging.
Ideology, Realpolitik, and US Foreign Policy
Authors: Saunders Elizabeth
Published: May 2013

Explaining the Iraq War: Counterfactual Theory, Logic and Evidence. By Frank P. Harvey. New York: Cambridge University Press, 2011. 360p. $103.00 cloth, $29.99 paper.

The Iraq War initiated by the Bush administration in 2003 was and perhaps continues to be an important episode in world politics, US politics, and the politics of the Middle East. The war also galvanized controversy among public intellectuals and broader publics, and generated strong opposition in many European and Middle Eastern countries. In Explaining the Iraq War, Frank P. Harvey offers an interesting analysis of the war and its causes, and does so in a way that raises broader questions about politics and about the scientific study of politics. We have thus invited a distinguished group of political scientists from a variety of subfields to review the book, both as an account of the Iraq War and as a contribution to political science more generally.—Jeffrey C. Isaac, Editor
The Puzzle of Extra-Lethal Violence
Authors: Fujii Lee Ann
Published: May 2013

This article proposes the concept “extra-lethal violence” to focus analytic attention on the acts of physical, face-to-face violence that transgress shared norms about the proper treatment of persons and bodies. Examples of extra-lethal violence include forcing victims to dance and sing before killing them, souvenir-taking and mutilation. The main puzzle of extra-lethal violence is why it occurs at all given the time and effort it takes to enact such brutalities and the potential repercussions perpetrators risk by doing so. Current approaches cannot account for this puzzle because extra-lethal violence seems to follow a different logic from strategic calculation. To investigate one alternative logic—the logic of display—the article proposes a performative analytic framework. A performative lens focuses attention on the process by which actors stage violence for graphic effect. It highlights the range of roles, participants, and activities that contribute to the production process as a whole. To demonstrate the value of a performative approach, the article applies this framework to three very different extra-lethal episodes: the massacre at My Lai during the Vietnam War, the rape and killing of two women during the Rwandan genocide, and a lynching that took place in rural Maryland. The article concludes by sketching a typology of performance processes and by considering the policy implications of this type of theorizing and knowledge.
Self-Harm and Homeless Adults
Authors: Pluck Graham , Lee Kwang-Hyuk , Parks Randolph W.
Published: May 2013

Background: Homelessness is associated with an increased incidence of mental illness and risk of self-harm, including suicide. Aims: To assess the prevalence of self-harm (including nonsuicidal self-injury and attempted suicide) among a UK sample of homeless adults and to compare demographic, clinical, and homeless-related variables to determine which are linked to self-harm in this population. Method: A sample of 80 homeless adults were interviewed regarding history of self-harm, mental health history, demographic, and homeless-related information. Results: Sixty-eight percent of the sample reported past acts of self-harm. Those with histories of self-harm started using significantly more substances since becoming homeless and were younger when they first became homeless. They were also significantly more likely to have a past psychiatric admission and thoughts of self-harm in the past year. Conclusion: Self-harm is common among homeless adults and linked to long-term and enduring social and mental health concerns.
The Relationship Between Prior Suicidal Behavior and Mortality Among Individuals in Community Corrections
Authors: Clark C. Brendan , Waesche Matthew C. , Hendricks Peter S. , McCullumsmith Cheryl B. , Redmond Nicole , Katiyar Nandan , Lawler Robert Marsh , Cropsey Karen L.
Published: May 2013

Background: Individuals under community corrections have multiple risk factors for mortality including exposure to a criminal environment, drug use, social stress, and a lack of medical care that predispose them to accidents, homicides, medical morbidities, and suicide. The literature suggests that prior suicidal behavior may be a particularly potent risk factor for mortality among individuals in the criminal justice system. Aims: This study looked to extend the link between history of a suicide attempt and future mortality in a community corrections population. Method: Using an archival dataset (N = 18,260) collected from 2002 to 2007 of individuals being monitored under community corrections supervision for an average of 217 days (SD = 268), we examined the association between past history of a suicide attempt and mortality. Results: A Cox Proportional Hazard Model controlling for age, race, gender, and substance dependence indicated that past history of a suicide attempt was independently associated with time to mortality, and demonstrated the second greatest effect after gender. Conclusion: These data suggest the need for a greater focus on screening and preventive services, particularly for individuals with a history of suicidal behavior, so as to reduce the risk of mortality in community corrections populations.
Pragmatic Language Assessment in Williams Syndrome: A Comparison of the Test of Pragmatic Language—2 and the Children's Communication Checklist—2
Authors: Hoffmann Anne , Martens Marilee A. , Fox Robert , Rabidoux Paula , Andridge Rebecca
Published: May 2013

Purpose

Individuals with Williams syndrome (WS) are recognized as having a strong desire for social relationships, yet many of them have difficulty forming and maintaining peer relationships. One cause may be impairments in pragmatic language. The current study compared the assessment of pragmatic language skills in individuals with WS using the Test of Pragmatic Language—Second Edition (TOPL–2; Phelps-Terasaki & Phelps-Gunn, 2007) and the Children's Communication Checklist—Second Edition (CCC–2; Bishop, 2003).

Method

Twenty children and adolescents diagnosed with WS were given the TOPL–2, and their parents completed the CCC–2.

Results

The TOPL–2 identified 8 of the 14 older children (ages 8–16 years) as having pragmatic language impairment and all of the 6 younger children (ages 6–7 years) as having such. In comparison, the CCC–2 identified 6 of the 14 older children and 2 of the 6 younger children as having pragmatic language impairment. The older group also had a higher composite score than the younger group on the CCC–2.

Conclusion

The TOPL–2 identified significantly more participants as having pragmatic language impairment than did the CCC–2. The TOPL–2 may be more useful in assessing pragmatic language in older children than younger children. The results offer important preliminary clinical implications of language measures that may be beneficial in the assessment of individuals with WS.
Semantic Feature Analysis: Incorporating Typicality Treatment and Mediating Strategy Training to Promote Generalization
Authors: Wambaugh Julie L. , Mauszycki Shannon , Cameron Rosalea , Wright Sandra , Nessler Christina
Published: May 2013

Purpose

This investigation was designed to examine the generalization effects of semantic treatment for word retrieval deficits in people with aphasia. Semantic feature analysis (SFA; Boyle & Coelho, 1995), typicality treatment (Kiran & Thompson, 2003), and mediating strategy training were combined to maximize potential generalization effects.

Method

Treatment, which included SFA and a semantic feature judgment task, was conducted with 9 participants with chronic aphasia in the context of multiple baseline designs across behaviors. Typical and atypical exemplars were trained across animate and inanimate categories. Treatment was sequentially modified to overtly train the use of SFA as a mediating strategy.

Results

Eight of the 9 participants demonstrated improvements in naming of trained stimuli. Positive generalization effects were limited overall; possible response generalization was evident for 5 participants. Instruction in the use of a mediating strategy resulted in improved naming of treated words for all participants; however, generalization to untreated words did not occur.

Conclusion

Treatment using SFA resulted in improved naming of treated typical and atypical exemplars in both animate and inanimate categories for 8 of 9 participants. Training in a mediating strategy also resulted in improved retrieval of experimental words. Regardless of intervention approach, generalization to untreated items was limited.
Rehabilitation in Bilingual Aphasia: Evidence for Within- and Between-Language Generalization
Authors: Kiran Swathi , Sandberg Chaleece , Gray Teresa , Ascenso Elsa , Kester Ellen
Published: May 2013

Purpose

The goal of this study was to examine if there was a principled way to understand the nature of rehabilitation in bilingual aphasia such that patterns of acquisition and generalization are predictable and logical.

Method

Seventeen Spanish–English bilingual individuals with aphasia participated in the experiment. For each participant, three sets of stimuli were developed for each language: (a) English Set 1, (b) English Set 2 (semantically related to each item in English Set 1), (c) English Set 3 (unrelated control items), (d) Spanish Set 1 (translations of English Set 1), (e) Spanish Set 2 (translations of English Set 2; semantically related to each item in Spanish Set 1), and (f) Spanish Set 3 (translations of English Set 3; unrelated control items). A single-subject experimental multiple baseline design across participants was implemented. Treatment was conducted in 1 language, but generalization to within- and between-language untrained items was examined.

Results

Treatment for naming on Set 1 items resulted in significant improvement (i.e., effect size >4.0) on the trained items in 14/17 participants. Of the 14 participants who showed improvement, within-language generalization to semantically related items was observed in 10 participants. Between-language generalization to the translations of trained items was observed in 5 participants, and between-language generalization to the translations of the untrained semantically related items was observed in 6 participants.

Conclusion

The results of this study demonstrated within- and between-language patterns that were variable across participants. These differences are indicative of the interplay between facilitation (generalization) and inhibition.
Sensorless control of high‐power interior permanent‐magnet synchronous motor drives at very low speed
Authors: Yuan Lei , Xiao Fei , Shen Jian‐qing , Chen Ming‐liang , Shi Qiao‐ming , Quan‐feng Li
Published: May 2013

A novel sensorless control scheme is proposed for an interior permanent‐magnet synchronous motor drives at very low speed based on sliding‐mode observer (SMO) in this study, which substitutes a sigmoid function for the sign or saturation function with a variable boundary layer, overcomes the time delay caused by the low‐pass filter and the chattering problem used in the conventional SMO. In this study, an adaptive SMO is employed to estimate the rotor speed and extended electromotive force, a three‐phase soft phase‐locked loop technology is used to estimate rotor position because of its strong robustness since under voltage phase unbalance or polluted and variable‐frequency environment. The global asymptotic stability of the proposed adaptive SMO is verified using Lyapunov stability analysis with considering motor parameter variations. Experimental results are presented to verify the principles and to demonstrate the effectiveness of the proposed method at very low speed from 2 to 17 r/min.
Two‐dimensional finite element magnetostatic model of a permanent magnet synchronous generator for predicting its steady‐state performance under different loading conditions
Authors: Gonzalez Adolfo , Hernandez Concepcion , Arjona Marco Antonio
Published: May 2013

A new two‐dimensional magnetostatic finite element (FE) model for predicting the steady‐state performance of a permanent magnet synchronous generator (PMSG) is proposed. A PMSG can be found in wind farms and emergency electrical power plants. A FE model to predict the PMSG steady‐state operation is valuable for initialisation of transient studies and for PMSG design evaluation. In the proposed FE model, the unknowns to be determined are the magnetic vector potential, load angle, stator phase currents and terminal voltage. The model formulation allows the simultaneous computation of the magnetic field, load angle and terminal current of the PMSG. Frequency and load are considered as the model input data. The FE model is validated against experimental tests and a good agreement is obtained.
Travelling-wave similarity solutions for a steadily translating slender dry patch in a thin fluid film
Authors: Yatim Y. M. , Duffy B. R. , Wilson S. K.
Published: May 2013

A novel family of three-dimensional travelling-wave similarity solutions describing a steadily translating slender dry patch in an infinitely wide thin fluid film on an inclined planar substrate when surface-tension effects are negligible is obtained, the flow being driven by gravity and/or a prescribed constant shear stress on the free surface of the film. For both driving mechanisms, the dry patch has a parabolic shape (which may be concave up or concave down the substrate), and the film thickness increases monotonically away from the contact lines to its uniform far-field value. The two most practically important cases of purely gravity-driven flow and of purely surface-shear-stress-driven flow are analysed separately.
Collisional radiative coarse-grain model for ionization in air
Authors: Panesi Marco , Lani Andrea
Published: May 2013

We present a reduced kinetic mechanism for the modeling of the behavior of the electronic states of the atomic species in air mixtures. The model is built by lumping the electronically excited states of the atomic species and by performing Maxwell-Boltzmann averages of the rate constants describing the elementary kinetic processes of the individual states within each group. The necessary reaction rate coefficients are taken from the model compiled by Bultel et al. [“Collisional-radiative model in air for earth re-entry problems,” Phys. Plasmas 13, 043502 (2006)10.1063/1.2194827]. The reduced number of pseudo-states considered leads to a significant reduction of the computational cost, thus enabling the application of the state of the art collisional radiative models to bi-dimensional and three-dimensional problems. The internal states of the molecular species are assumed to be in equilibrium. The rotational energy mode is assumed to quickly equilibrate with the translational energy mode at the kinetic temperature of the heavy species as opposed to the electronic and the vibrational modes, assumed to be in Maxwell-Boltzmann equilibrium at a common temperature TV. In a first step we validate the model by using simple zero- and one-dimensional test cases for which the full kinetic mechanism can be run efficiently. Finally, the reduced kinetic model is used to analyze the strong non-equilibrium flow surrounding the FIRE II flight experiment during the early part of its re-entry trajectory. It is found that the reduced kinetic mechanism is capable of reproducing the ionizational non-equilibrium phenomena, responsible for the drastic reduction of the radiative heat loads on the space capsules during the re-entry phase.
In-situ X-ray diffraction combined with scanning AC nanocalorimetry applied to a Fe0.84Ni0.16 thin-film sample
Authors: Gregoire John M. , Xiao Kechao , McCluskey Patrick J. , Dale Darren , Cuddalorepatta Gayatri , Vlassak Joost J.
Published: May 2013

We combine the characterization techniques of scanning AC nanocalorimetry and x-ray diffraction to study phase transformations in complex materials system. Micromachined nanocalorimeters have excellent performance for high-temperature and high-scanning-rate calorimetry measurements. Time-resolved X-ray diffraction measurements during in-situ operation of these devices using synchrotron radiation provide unprecedented characterization of thermal and structural material properties. We apply this technique to a Fe0.84Ni0.16 thin-film sample that exhibits a martensitic transformation with over 350 K hysteresis, using an average heating rate of 85 K/s and cooling rate of 275 K/s. The apparatus includes an array of nanocalorimeters in an architecture designed for combinatorial studies.
Development of a fast scintillator based beam phase measurement system for compact superconducting cyclotrons
Authors: Bhattacharjee Tanushyam , Kanti Dey Malay , Dhara Partha , Roy Suvodeep , Debnath Jayanta , Balakrishna Bhole Rajendra , Dutta Atanu , Pradhan Jedidiah , Pal Sarbajit , Pal Gautam , Roy Amitava , Chakrabarti Alok
Published: May 2013

In an isochronous cyclotron, measurements of central phase of the ion beam with respect to rf and the phase width provide a way to tune the cyclotron for maximum energy gain per turn and efficient extraction. We report here the development of a phase measurement system and the measurements carried out at the Variable Energy Cyclotron Centre's (VECC’s) K = 500 superconducting cyclotron. The technique comprises detecting prompt γ-rays resulting from the interaction of cyclotron ion beam with an aluminium target mounted on a radial probe in coincidence with cyclotron rf. An assembly comprising a fast scintillator and a liquid light-guide inserted inside the cyclotron was used to detect the γ-rays and to transfer the light signal outside the cyclotron where a matching photo-multiplier tube was used for light to electrical signal conversion. The typical beam intensity for this measurement was a few times 1011 pps.
Laser triggered Z-pinch broadband extreme ultraviolet source for metrology
Authors: Tobin I. , Juschkin L. , Sidelnikov Y. , O’Reilly F. , Sheridan P. , Sokell E. , Lunney J. G.
Published: May 2013

We compare the extreme ultraviolet emission characteristics of tin and galinstan (atomic %: Ga: 78.35, In: 14.93, Sn: 6.72) between 10 nm and 18 nm in a laser-triggered discharge between liquid metal-coated electrodes. Over this wavelength range, the energy conversion efficiency for galinstan is approximately half that of tin, but the spectrum is less strongly peaked in the 13–15 nm region. The extreme ultraviolet source dimensions were 110 ± 25 μm diameter and 500 ± 125 μm length. The flatter spectrum, and −19 °C melting point, makes this galinstan discharge a relatively simple high radiance extreme ultraviolet light source for metrology and scientific applications.
Excitation power dependence of the Purcell effect in photonic crystal microcavity lasers with quantum wires
Authors: Canet-Ferrer J. , Prieto I. , Muñoz-Matutano G. , Martínez L. J. , Muñoz-Camuniez L. E. , Llorens J. M. , Fuster D. , Alén B. , González Y. , González L. , Postigo P. A. , Martínez-Pastor J. P.
Published: May 2013

The Purcell effect dependence on the excitation power is studied in photonic crystal microcavity lasers embedding InAs/InP quantum wires. In the case of non-lasing modes, the Purcell effect has low dependence on the optical pumping, attributable to an exciton dynamics combining free and localized excitons. In the case of lasing modes, the influence of the stimulated emission makes ambiguous the determination of the Purcell factor. We have found that this ambiguity can be avoided by measuring the dependence of the decay time on the excitation power. These results provide insights in the determination of the Purcell factor in microcavity lasers.
Continuous flowing micro-reactor for aqueous reaction at temperature higher than 100 °C
Authors: Xie Fei , Wang Baojun , Wang Wei , Dong Tian , Tong Jianhua , Xia Shanhong , Wu Wengang , Li Zhihong
Published: May 2013

Some aqueous reactions in biological or chemical fields are accomplished at a high temperature. When the reaction temperature is higher than 100 °C, an autoclave reactor is usually required to elevate the boiling point of the water by creating a high-pressure environment in a closed system. This work presented an alternative continuous flowing microfluidic solution for aqueous reaction with a reaction temperature higher than 100 °C. The pressure regulating function was successfully fulfilled by a small microchannel based on a delicate hydrodynamic design. Combined with micro heater and temperature sensor that integrated in a single chip by utilizing silicon-based microfabrication techniques, this pressure regulating microchannel generated a high-pressure/high-temperature environment in the upstream reaction zone when the reagents continuously flow through the chip. As a preliminary demonstration, thermal digestion of aqueous total phosphorus sample was achieved in this continuous flowing micro-reactor at a working pressure of 990 kPa (under the working flow rate of 20 nl/s) along with a reaction temperature of 145 °C. This continuous flowing microfluidic solution for high-temperature reaction may find applications in various micro total analysis systems.
Conductive and transparent superhydrophobic films on various substrates by in situ deposition
Authors: Wang Guiyuan , Liang Weixin , Wang Ben , Zhang Yabin , Li Jing , Shi Lei , Guo Zhiguang
Published: May 2013

Conductive and transparent superhydrophobic coatings on poly (ethylene terephthalate), polystyrene (PS), glass slides were fabricated by a facile and low-cost in situ deposition method, forming a binary structure by nanocomposites. The results showed that the maximum transmittance of the coated PS substrates reached to as high as 62.6%, with the contact angle as high as 167° and the sliding angle as low as 4°. Importantly, the transparent superhydrophobic films are conductive, which is very vital for their promising applications in industry, such as auto-windshield glass, anti-corrosion materials, and microfluidic devices.
Enhancement of efficiency of a conducting polymer P3HT:CdSe/ZnS quantum dots hybrid solar cell by adding single walled carbon nanotube for transporting photogenerated electrons
Authors: Kumar Dixit Shiv , Madan Shikha , Kaur Amandeep , Madhwal Devinder , Singh Inderpreet , Bhatnagar P. K. , Mathur P. C. , Bhatia C. S.
Published: May 2013

Hybrid solar cells consisting of a composite of poly (3-hexylthiophene) (P3HT), single walled carbon nanotube (SWCNT), and cadmium selenide/zinc sulphide (CdSe/ZnS) coreshell quantum dots (QDs) have been fabricated in the present work. The bulk hetrojunction has been formed from the bilayer of P3HT:SWCNT composite and QDs using inter-diffusion process. Due to low percolation limit and high conductivity of SWCNT, the photo-generated electrons are collected at the electrode very fast (within few femto-seconds) enhancing the efficiency of the solar cell. The absorption measurements on the composite film show that the addition of SWCNT in the hybrid structure increases the absorption coefficient in the near infrared region and also makes the spectrum wider as compared to that of P3HT. The photoluminescence (PL) measurements show that the PL of hybrid P3HT, SWCNT, and QDs is quenched about ∼15 times as compared to that of P3HT film. This shows that a significant charge transfer of electrons occurs through SWCNT to the electrode. The morphology of P3HT:SWCNT:CdSe/ZnS was observed using atomic force microscopy. With this approach, we have been able to achieve power conversion efficiency of 5.4% using a standard solar simulator with an irradiance of 100 mW/cm2.
Catalyst size dependent growth of Pd-catalyzed one-dimensional InAs nanostructures
Authors: Xu Hong-Yi , Guo Ya-Nan , Liao Zhi-Ming , Sun Wen , Gao Qiang , Hoe Tan Hark , Jagadish Chennupati , Zou Jin
Published: May 2013

In this study, Pd was used as catalyst to grow one-dimensional InAs nanostructures on GaAs (111)B substrates in order to explore the growth mechanism and the effect of non-gold catalysts in growing epitaxial III-V nanostructures. With detailed morphological, structural, and chemical characterizations using electron microscopy, coupled with analysis of the Pd-In binary phase diagram, it was found that size of Pd nanoparticles plays a key role in determining the growth mechanism of one-dimensional InAs nanostructures.
THY1 is a surface marker of porcine gonocytes
Authors: Zheng Yi , He Ying , An Junhui , Qin Jinzhou , Wang Yihan , Zhang Yaqing , Tian Xiue , Zeng Wenxian
Published: May 2013

Gonocytes are important for the study of spermatogenesis. Identification and isolation of gonocytes has been reported in rodents but not in pigs due to a lack of molecular markers for gonocytes. The objective of this study was to identify THY1 expression in porcine testicular tissue and subsequently utilise THY1 as a marker to isolate and enrich porcine gonocytes from testes of newborn piglets. Immunohistochemical analysis showed that THY1 was expressed in gonocytes. Double-immunofluorescent analysis of THY1 and ZBTB16 indicated that THY1 and ZBTB16 were partially co-localised in gonocytes. Double-immunofluorescent analysis of both THY1 and GATA4 suggested that THY1+ cells were not Sertoli cells. Magnetic-activated cell sorting of THY1+ cells yielded a cell population with an enrichment of UCHL1+ gonocytes 3.4-fold of that of the unsorted testicular cell population. Western blot and quantitative reverse transcription–polymerase chain reaction analyses confirmed that the selected THY1+ fraction had a higher expression of UCHL1 than the unsorted cells. In conclusion, the study demonstrated that THY1 is a surface marker of gonocytes in testes of pre-pubertal boars and could be utilised to identify and isolate porcine gonocytes. The findings will also facilitate culture and manipulation of male germline stem cells.
Evaluation of net primary productivity and its spatial and temporal patterns in southern China’s grasslands
Authors: Sun Z. G. , Long X. H. , Sun C. M. , Zhou W. , Ju W. M. , Li J. L.
Published: May 2013

The net primary productivity (NPP) of grassland ecosystems is an important indicator of the capacity for carbon (C) absorption. The Global Production Efficiency Model was adopted to simulate NPP in southern China’s grasslands and to analyse the temporal and spatial dynamics from 1981 to 2000. There was a high correlation between measured and simulated values (R2 = 0.84). Based on the data from 1981 to 2000, the mean annual NPP was 1082 g C m–2 year–1, and the highest value (1798 g C m–2 year–1) was in Hainan province, and the lowest value (500 g C m–2 year–1) was in south-western Tibet. The highest mean NPP values were in the permanent wetlands (1193 g C m–2 year–1) and savannas (1137 g C m–2 year–1); woody savannas had an intermediate value (1087 g C m–2 year–1), and the lowest NPP occurred in typical grasslands and open shrubs, the mean values were 709 and 689 g C m–2 year–1, respectively. Temporally, the total NPP in southern China’s grasslands slightly increased in the 20-year period, especially from 1981 to 1990. The mean annual total of NPP in the 20 years was 0.758 Pg C. Inter-annual variation in total NPP was driven mainly by mean annual temperature rather than mean annual precipitation. The results suggest that grassland ecosystems in southern China have a large C sink.
Balancing trade-offs between biodiversity and production in the re-design of rangeland landscapes
Authors: Waters C. M. , Penman T. D. , Hacker R. B. , Law B. , Kavanagh R. P. , Lemckert F. , Alemseged Y.
Published: May 2013

The conflict that exists between the competing needs of biological conservation and pastoral production is well recognised but few studies have examined these conflicts due to their complexity and the uncertainty that surrounds these relationships. The development of a Bayesian network model that examines the trade-offs between the conservation value of the landscape for a range of taxa (flora, mammals, birds and herpetofauna) and its primary production value under alternative land uses is described. The model emphasises structural diversity of vegetation and ecosystem productivity as key drivers of both biodiversity and agricultural production. Simple scenarios, used to examine the influence of different land uses on multiple components of biodiversity and agricultural productivity, demonstrated the potential for the analysis of the trade-offs associated with alternative landscape designs. The potential of the model, as a planning or policy development tool for land management agencies or regional Natural Resource Management bodies, at multiple scales, is identified.
Building community–agency trust in fire-affected communities in Australia and the United States
Authors: Olsen Christine S. , Sharp Emily
Published: May 2013

As a result of the increasing environmental and social costs of wildfire, fire management agencies face ever-growing complexity in their management decisions and interactions with the public. The success of these interactions with community members may be facilitated through building community–agency trust in the process of providing public input opportunities and community engagement and education activities. Without trust, the public may become frustrated in their interactions with the agency and withhold support for management decisions. This study takes a comparative case approach using interview data from communities near the King Valley fires in Victoria, Australia, and the Bear & Booth Complex fires in Oregon, USA. Several themes emerge that are common to both sites, including components of trustworthiness and actions or activities that contribute to a trusting relationship or environment. Key findings suggest trust and trustworthiness can be addressed interpersonally and institutionally and that flexible policies are important for implementation of locally appropriate outreach and management plans.