bluuebunny/crossref_metadata_2025 huggingface dataset:
A preliminary prospective study of nutritional, psychological and combined therapies for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) in a private care setting
Authors: Arroll Megan Anne , Howard Alex
Published: November 2012

Background

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a condition characterised by severe and persistent fatigue, neurological disturbances, autonomic and endocrine dysfunctions and sleep difficulties that have a pronounced and significant impact on individuals’ lives. Current National Institute for Health and Clinical Excellence guidelines within the UK suggest that this condition should be treated with cognitive behavioural therapy and/or graded exercise therapy, where appropriate. There is currently a lack of an evidence base concerning alternative techniques that may be beneficial to those with ME/CFS.

Objectives

This study aimed to investigate whether three modalities of psychology, nutrition and combined treatment influenced symptom report measures in those with ME/CFS over a 3-month time period and whether there were significant differences in these changes between groups.

Design and setting

This is a preliminary prospective study with one follow-up point conducted at a private secondary healthcare facility in London, UK.

Participants

138 individuals (110 females, 79.7%; 42 participants in psychology, 44 in nutrition and 52 in combined) participated at baseline and 72 participants completed the battery of measures at follow-up (52.17% response rate; 14, 27 and 31 participants in each group, respectively).

Outcome measures

Self-reported measures of ME/CFS symptoms, functional ability, multidimensional fatigue and perceived control.

Results

Baseline comparisons showed those in the combined group had higher levels of fatigue. At follow-up, all groups saw improvements in fatigue, functional ability and symptomatology; those within the psychology group also experienced a shift in perceived control over time.

Conclusions

This study provides early evidence that psychological, nutritional and combined techniques for the treatment of ME/CFS may influence symptomatology, fatigue, function and perceived control. However, these results must be viewed with caution as the allocation to groups was not randomised, there was no control group and the study suffered from high drop-out rates.
Does mild cognitive impairment affect the occurrence of radiographic knee osteoarthritis? A 3-year follow-up in the ROAD study
Authors: Yoshimura Noriko , Muraki Shigeyuki , Oka Hiroyuki , Kawaguchi Hiroshi , Nakamura Kozo , Tanaka Sakae , Akune Toru
Published: November 2012

Objective

To determine whether mild cognitive impairment (MCI) increases the risk of occurrence or progression of radiographic knee osteoarthritis (KOA) in a general population.

Design

Population-based cohort study.

Setting

Residents in mountain and seaside areas of Wakayama Prefecture, Japan.

Participants

1690 participants (596 men, 1094 women; mean age 65.2 years old) were enrolled from the large-scale cohort for the Research on Osteoarthritis (OA)/osteoporosis Against Disability (ROAD) study initiated in 2005 to investigate epidemiological features of OA in Japan. Of these, 1384 individuals (81.9%; 466 men, 918 women) completed the second survey including knee radiography 3 years later.

Primary outcome measures

Radiographic KOA was defined as Kellgren-Lawrence (KL) grade ≥ 2 using paired x-ray films. Incidence of KOA during follow-up defined on radiographs as KL grade ≥2, progression of KOA defined as a higher KL grade (either knee) at follow-up compared with baseline. MCI defined as a summary mini-mental state examination (MMSE) score ≤23. Associations between MCI and incidence or progression of KOA were analysed.

Results

The annual cumulative incidence of KOA was 3.3%; for progression of OA it was 8.0%. On logistic regression analysis adjusted for age, gender, regional differences, body mass index, grip strength (worse side), smoking, alcohol consumption, regular exercise and history of knee injury, baseline MMSE summary score was significantly associated with the incidence of KOA (+1 MMSE score; OR 0.83, p=0.010). Baseline MCI was also significantly associated with the incidence of KOA (vs non-occurrence of KOA; OR 4.90, p=0.027). There was no significant association between MMSE scores, the presence of MCI and progression of KOA (+1 MMSE score; OR 0.96, p=0.232; vs non-progression of KOA; OR 1.38, p=0.416).

Conclusions

MCI significantly increases the risk of incident radiographic KOA, but not the progression of KOA.
Low income is associated with poor adherence to a Mediterranean diet and a higher prevalence of obesity: cross-sectional results from the Moli-sani study
Authors: Bonaccio Marialaura , Bonanni Americo Ettore , Di Castelnuovo Augusto , De Lucia Francesca , Donati Maria Benedetta , de Gaetano Giovanni , Iacoviello Licia ,   on behalf of the Moli-sani Project Investigators
Published: November 2012

Objectives

To examine cross-sectional associations of socioeconomic status (ie, income and education) with an adherence to a Mediterranean dietary pattern and obesity prevalence.

Design

Cross-sectional study on a sample of Italian subjects enrolled in the Moli-sani Project, a population-based cohort study. The Italian EPIC food frequency questionnaire was used to determine food intake. Adherence to a Mediterranean diet (MD) was appraised according to both the Mediterranean score elaborated by Trichopoulou (MDS) and the novel Italian Mediterranean Index (IMI) and to the a posteriori scores derived from principal component analysis. Four income categories were identified.

Setting

Molise region, Italy.

Participants

13 262 subjects (mean age 53±11, 50% men) out of 24 318 citizens (age ≥35) randomly enrolled in the Moli-sani Project.

Main outcomes

Dietary patterns and risk factors for cardiovascular disease.

Results

Household higher income were significantly associated with greater adherence to an MD (p<0.0001) and to Olive oil and Vegetables dietary pattern in a multivariable model including age, sex, daily energy intake, body mass index, physical activity, smoking, alcohol consumption, education and marital status. The odds of having the highest adherence to an MD clearly increased according to income levels. People having the highest income had 54% (95% CI 21% to 97%, MDS) or 72% (95% CI 34% to 121%, IMI) higher probability to stick to an MD-like eating pattern than those in the lowest-income group. Obesity prevalence was higher in the lowest-income group (36%) in comparison with the highest-income category (20%, p<0.0001). Income was associated with dietary patterns in all categories of education.

Conclusions

A higher income and education are independently associated with a greater adherence to MD-like eating patterns and a lower prevalence of obesity.
HIV incidence among men who have sex with men in Beijing: a prospective cohort study
Authors: Li Dongliang , Li Shuming , Liu Yingjie , Gao Yanjie , Yu Mingrun , Yang Xueying , Li Qingchun , Jiang Shulin , Zhou Zhenhai , Zhang Zheng , Yan Li , Jiang Guiyan , Xiao Dong , Pan Stephen W , Luo Fengji , Ruan Yuhua , Shao Yiming
Published: November 2012

Objectives

(1) To assess the HIV incidence rate among men who have sex with men (MSM) in a large cohort study in Beijing, China and (2) to identify sociodemographic and behavioural risk factors of HIV seroconversion among MSM in Beijing, China.

Design

A prospective cohort study.

Setting

Baseline and follow-up visits were conducted among MSM in Beijing, China.

Participants

A cohort of 797 HIV-seronegative MSM was recruited from August to December 2009, with follow-up occurring after 6 and 12 months.

Primary and secondary outcome measures

At baseline and follow-up visits, participants reported sociodemographic and sexual behaviour information, and were tested for HIV, herpes simplex virus-2 (HSV-2) and syphilis with whole blood specimens. Cox regression analysis was used to identify factors associated with HIV seroconversion.

Results

Most study participants (86.8%) were retained by the 12-month follow-up. The HIV, HSV-2 and syphilis incidence rates were 8.09 (95% CI 6.92 to 9.26), 5.92 (95% CI 5.44 to 6.40) and 8.06 (95% CI 7.56 to 8.56) cases per 100 person-years, respectively. HIV seroconversion was significantly associated with being <25 years old, having <12 years of education, having >1 male sex partner in the past 6 months, and being syphilis positive or HSV-2 positive.

Conclusions

The HIV incidence among MSM in Beijing is serious. Interventions and treatment of sexually transmitted diseases (STD) should be combined with HIV control and prevention measures among MSM.
Risk factors for stress fracture in female endurance athletes: a cross-sectional study
Authors: Duckham Rachel L , Peirce Nicholas , Meyer Caroline , Summers Gregory D , Cameron Noël , Brooke-Wavell Katherine
Published: November 2012

Objective

To identify psychological and physiological correlates of stress fracture in female endurance athletes.

Design

A cross-sectional design was used with a history of stress fractures and potential risk factors assessed at one visit.

Methods

Female-endurance athletes (58 runners and 12 triathletes) aged 26.0±7.4 years completed questionnaires on stress fracture history, menstrual history, athletic training, eating psychopathology and exercise cognitions. Bone mineral density, body fat content and lower leg lean tissue mass (LLLTM) were assessed using dual-x-ray absorptiometry. Variables were compared between athletes with a history of stress fracture (SF) and those without (controls; C) using χ², analysis of variance and Mann-Whitney U tests.

Results

Nineteen (27%) athletes had previously been clinically diagnosed with SFs. The prevalence of current a/oligomenorrhoea and past amenorrhoea was higher in SF than C (p=0.008 and p=0.035, respectively). SF recorded higher global scores on the eating disorder examination questionnaire (p=0.049) and compulsive exercise test (p=0.006) and had higher LLLTM (p=0.029) compared to C. These findings persisted with weight and height as covariates. In multivariate logistic regression, compulsive exercise, amenorrhoea and LLLTM were significant independent predictors of SF history (p=0.006, 0.009 and 0.035, respectively).

Conclusions

Eating psychopathology was associated with increased risk of SF in endurance athletes, but this may be mediated by menstrual dysfunction and compulsive exercise. Compulsive exercise, as well as amenorrhoea, is independently related to SF risk.
‘Are decisions about discharge of elderly hospital patients mainly about freeing blocked beds?’ A qualitative observational study
Authors: Ekdahl Anne Wissendorff , Linderholm Märit , Hellström I , Andersson Lars , Friedrichsen Maria
Published: November 2012

Objective

To explore the interactions concerning the frail and elderly patients having to do with discharge from acute hospital wards and their participation in medical decision-making. The views of the patients and the medical staff were both investigated.

Design

A qualitative observational and interview study using the grounded theory.

Setting and participants

The setting was three hospitals in rural and urban areas of two counties in Sweden of which one was a teaching hospital. The data comprised observations, healthcare staff interviews and patient interviews. The selected patients were all about to be informed that they were going to be discharged.

Results

The patients were seldom invited to participate in the decision-making regarding discharge. Generally, most communications regarding discharge were between the doctor and the nurse, after which the patient was simply informed about the decision. It was observed that the discharge information was often given in an indirect way as if other, albeit absent, people were responsible for the decision. Interviews with the healthcare staff revealed their preoccupation with the need to free up beds: ‘thinking about discharge planning all the time’ was the core category. This focus not only failed to fulfil the complex needs of elderly patients, it also generated feelings of frustration and guilt in the staff, and made the patients feel unwelcome.

Conclusions

Frail elderly patients often did not participate in the medical decision-making regarding their discharge from hospital. The staff was highly focused on patients getting rapidly discharged, which made it difficult to fulfil the complex needs of these patients.
Identifying and quantifying misclassified and under-reported AIDS deaths in Brazil: a retrospective analysis from 1985 to 2009
Authors: Fazito Erika , Cuchi Paloma , Ma Fat Doris , Ghys Peter Denis , Pereira Mauricio G , Vasconcelos Ana Maria Nogales , Pascom Ana Roberta Pati
Published: November 2012

Background

A retrospective analysis of deaths registered in the Brazilian Mortality System was conducted to quantify the under-reporting of HIV/AIDS deaths and those misclassified to AIDS-related conditions in the 15–49 years old population in Brazil.

Methods

Death rates for AIDS-related diseases were calculated by age and sex for 1985–2009. Changes in the age-sex-specific death rates over time were used to identify conditions likely to be misclassified AIDS deaths and to quantify the corresponding number of misclassified deaths. Deaths due to ill-defined causes were redistributed across all other natural causes of death. The resulting total number of AIDS deaths was further adjusted for incompleteness of the mortality reporting system.

Results

Out of the 28 potential causes of death investigated, five increased in the same distinct age pattern as AIDS: pneumonia, Kaposi's sarcoma, other immunodeficiencies, other septicaemia and toxoplasmosis. 18 490 deaths due to these five causes were recoded to HIV/AIDS from 1985 to 2009. 38 145 deaths due to ill-defined causes were redistributed to AIDS and 15 485 were added to the number of AIDS deaths to correct for completeness of the mortality system in Brazil. Altogether, 72 120 deaths were recoded to AIDS between 1985 and 2009 and added to the reported 194 445 AIDS related deaths in the country, representing 27% misclassification of AIDS deaths in Brazil.

Conclusions

This study demonstrated that AIDS mortality is underestimated by the official mortality information system in Brazil. Efforts need to be made to reduce misclassification of causes of death in the future and identify ways in which the confidentiality of information regarding cause of death can be maintained.
Analysis of duration of risk behaviour for key populations: a literature review
Authors: Fazito Erika , Cuchi Paloma , Mahy Mary , Brown Tim
Published: November 2012

Background

The objective of this paper is to review literature in order to calculate regional estimates of the average duration of time individuals maintain a specific high-risk behaviour.

Methods

The review targeted the key populations of female sex workers (FSW), male clients of female sex workers (MCFSW), people who inject drugs (injecting drug users (IDU)) and high-risk men who have sex with men (MSM). To be included in the review the study had to provide information on (1) the time a person spent at risk until death or cessation of the risk behaviour, (2) the percentage of the sample who initiated the risk behaviour in less than a year or (3) the mean or median duration of the behaviour from a representative sample.

Results

49 papers were found for the FSW population describing the period of time FSW stay in sex work to be between 2.9 years (Asia) and 12 years (Latin America). Eight papers were found for MCFSW showing the duration of the risk behaviour in this category varying from 4.6 years in Africa to 32 years in Asia. 86 papers were reviewed for the population of IDU showing that the average time a person injects illegal drugs varies from 5.6 years (Africa) to 21 years (South America). No information was found for duration of high-risk behaviour among MSM; instead, the definitions found in the literature for high- and low-risk behaviour among MSM were described.

Conclusions

There is high variability of estimates of duration of high-risk behaviours at regional level. More research is needed to inform models and prevention programmes on the average duration of time individuals maintain a specific high-risk behaviour.
Estimates of peripartum and postnatal mother-to-child transmission probabilities of HIV for use in Spectrum and other population-based models
Authors: Rollins Nigel , Mahy Mary , Becquet Renaud , Kuhn Louise , Creek Tracy , Mofenson Lynne
Published: November 2012

Background

The Global Plan Towards the Elimination of New HIV Infections among Children and Keeping Their Mothers Alive aims to reduce by 2015 the number of new infections in children, in 22 priority countries, by at least 90% from 2009 levels. Mathematical models, such as Spectrum, are used to estimate national and global trends of the number of infants infected through mother-to-child transmission (MTCT). However, other modelling exercises have also examined MTCT under different settings. MTCT probabilities applied in models to populations that are assumed to receive antiretroviral interventions need to reflect the most current risk estimates.

Methods

The UNAIDS Reference Group on Estimates, Modelling and Projections held a consultation to review data on MTCT probabilities. Published literature, recent conferences and data from personal communications with principle investigators were reviewed. Based on available data, peripartum and postnatal transmission probabilities were estimated for different antiretroviral drug regimens and maternal CD4 levels including for women with incident infection.

Results

Incident infections occurring during pregnancy are estimated to be associated with a 30% probability of MTCT; incident infections during breast feeding lead to a 28% probability of postnatal MTCT. The 2010 WHO recommended regimens (Options A or B) are estimated to be associated with a 2% peripartum transmission probability and 0.2% transmission probability per month of breast feeding. Peripartum and postnatal transmission probabilities were lowest for women who were taking antiretroviral therapy before the pregnancy namely 0.5% peripartum and 0.16% per month of breast feeding, respectively.

Discussion

These updated probabilities of HIV transmission (applied to Spectrum in April 2011) will be used to estimate new child HIV infections and track progress towards the 2015 targets of the Global Plan.
Phytoplankton food quality effects on gammarids: benthic–pelagic coupling mediated by an invasive freshwater clam
Authors: Basen Timo , Gergs Rene , Rothhaupt Karl-Otto , Martin-Creuzburg Dominik
Published: November 2012

Benthic–pelagic coupling mediated by bivalves has been shown to increase the flow of energy towards the benthos. To assess the capability of clams to process and therewith modify the quality of pelagic food sources for subsequent use by benthic invertebrates, we conducted a growth experiment in which juvenile Gammarus roeselii were raised either directly on sedimented pelagic autotrophs (algae, cyanobacteria) or on the same autotrophs biodeposited by the invasive freshwater clam Corbicula fluminea either as feces or pseudofeces. We show that growth and survival of G. roeselii are significantly improved when autotrophs are offered as biodeposition material and suggest that this clam-mediated upgrading of food quality is due to both an increased bioavailability of pelagic food particles, which are packed in mucus during clam processing, and an increased dietary provisioning with essential lipids (sterols and (or) polyunsaturated fatty acids) originating from the clams. Hence, filter-feeding bivalves provide a crucial link between the pelagic and benthic food web not only by deflecting energy fluxes, but also by processing and upgrading pelagic food (increased bioavailability, improved biochemical composition) for benthic invertebrates.
(NON-)ALIGNED GAUGES AND GLOBAL GAUGE SYMMETRY BREAKING
Authors: MAAS AXEL
Published: November 2012

The concept of (global) gauge symmetry breaking plays an important role in many areas of physics. Since the corresponding symmetry is a gauge symmetry, its breaking is actually gauge-dependent. Thus, it is possible to design gauges which restore the symmetry as good as possible. Such gauge constructions will be detailed here, illustrated with the use of lattice gauge theory. Their use will be discussed for the cases of the Higgs effect, high-baryon density color superconductors, and BRST symmetry.
MULTISCALE ENTROPY ANALYSIS OF FINANCIAL TIME SERIES
Authors: XIA JIANAN , SHANG PENGJIAN
Published: November 2012

The paper mainly applies the multiscale entropy (MSE) to analyze the financial time series. The MSE is used to examine the complexity of a quantified system. Based on MSE, we propose multiscale cross-sample entropy (MSCE) to analyze the complexity and correlation of two time series. By comparing with the results, we find that both results present remarkable scaling characterization and the value of each log return of financial time series decreases with a increasing scale factor. From the results of MSE, we also find that the entropy of the Europe markets is lower than that of the Asia, but higher than that of the Americas. It means the MSE can distinguish different areas markets. The results of MSCE show that financial plate have high synchrony with the plate of Electron, IT and Realty. The MSCE can distinguish the highly synchronous plates.
Porphyrin-embedded organosilicate materials for ammonia adsorption
Authors: Johnson Brandy J. , Peterson Gregory W. , Jones Paulette , Melde Brian J. , Taft Jenna R. , Schindler Bryan J.
Published: November 2012

This study describes the application of porphyrin-embedded porous organosilicate materials to the adsorption of ammonia gas. Organosilicate scaffolds were synthesized through a surfactant-templating process combined with a phase separation technique. The structure offers a macro-textured scaffold to facilitate flow through the sorbent material and provide enhanced access to the available surface area provided by a combination of micro- and mesopores distributed over a range of sizes. The materials were grafted post-synthesis to provide sites for covalent immobilization of porphyrins. These porphyrins were utilized for incorporation of metal sites into the organosilicate materials. The removal of ammonia was evaluated for a number of materials incorporating copper metalloporphyrins of varied structure at varied loading levels. Results have been compared to removal of ammonia by a carbon material. Copper deuteroporphyrin IX bis-ethylene glycol provided the strongest interactions with ammonia. High loading levels of this porphyrin within the sorbent structure showed increasing evidence of stacking and did not improve the performance of the material.
A Low-Voltage and High Uniformity Nano-Electro-Mechanical System Tunable Color Filter Based on Subwavelength Grating
Authors: Honma Hiroaki , Takahashi Kazuhiro , Ishida Makoto , Sawada Kazuaki
Published: November 2012

This paper reports on the construction of a nano-electro-mechanical system (NEMS) tunable color filter based on a subwavelength grating with high color uniformity and a low drive voltage. We recently proposed a ground-voltage-ground (GVG)-type tunable color filter with a parallel-plate actuator with three pairs of electrodes to decrease the crosstalk due to the electrostatic attractive force between each pair of actuators. Our finite element method (FEM) simulation results indicate that the drive voltage is decreased by 10 V, as compared to that of the previously reported GV type. The proposed structure was fabricated using a silicon-on-insulator (SOI) wafer. The color tuning capability of the device was demonstrated by applying a drive voltage of 6.7 V. The reflected light intensity was decreased by 34% at a wavelength of 680 nm. Color uniformity was also obtained in the filter area by reducing the variation of the displacement on the one-dimensional actuator arrays.
Fatigue Testing of Polycrystalline Silicon Thin-Film Membrane Using Out-of-Plane Bending Vibration
Authors: Tanemura Tomoki , Yamashita Shuichi , Wado Hiroyuki , Takeuchi Yukihiro , Tsuchiya Toshiyuki , Tabata Osamu
Published: November 2012

This paper describes a new fatigue testing method for polycrystalline-silicon (polysilicon) thin-film membrane to evaluate its mechanical reliability not affected by surface roughness of etched sidewalls. The test specimen is a thin membrane consisting of polysilicon, silicon dioxide, and silicon nitride films with a circular weight at the center, and its outer edge is supported by a square frame. Stress on polysilicon for fatigue test is applied by deformation of the membrane generated by oscillating the weight in the out-of-plane direction near the resonant frequency. The polysilicon film fractured by fatigue damage accumulated by the cyclic stress. Stress and number of cycles to fracture (S–N) plots were well formulated on the basis of Weibull statistics and Paris' law. Weibull modulus and fatigue index of the 250-nm-thick polysilicon film were 19.2 and 21.8, respectively. These parameters make it possible to predict the lifetime of polysilicon thin-film membrane under arbitrary cyclic stress.
Morphological Effect of Doping Environment on Silicon Nanowires Grown by Plasma-Assisted Chemical Vapor Deposition
Authors: Lohn Andrew J. , Cormia Robert D. , Fryauf David M. , Zhang Junce , Norris Kate J. , Kobayashi Nobuhiko P.
Published: November 2012

Physical properties of semiconductor nanowires are tied intimately to their specific morphologies such as length and diameter. We studied the growth of silicon nanowires and found their lengths and diameters to vary over orders of magnitude in different doping environments. In all cases we examined, doping resulted in increased diameters. In addition, boron doping was found to accelerate volume growth rate while arsenic and antimony both appeared to slow it down. We further studied the formation of the native oxides that cover the nanowires. X-ray photoelectron spectroscopy indicated that properties of the native oxides are also dependent on doping environment and correlated to doping-dependent shifts in apparent binding energy of the Si 2p3/2peak illustrating that the electronic contribution is the dominant mechanism for the oxide growth.
Characterization of Highly Concentrated Bi Donors Wire-δ-Doped in Si
Authors: Murata Koichi , Neumann Péter Lajos , Koyano Tamotsu , Yasutake Yuhsuke , Nittoh Koh-ichi , Sakamoto Kunihiro , Fukatsu Susumu , Miki Kazushi
Published: November 2012

We studied the Bi wire-δ-doping process to achieve a high concentration of Bi donors in Si. Our process has two steps: (i) burial of Bi nanowires in Si by molecular beam epitaxy, and (ii) activation of Bi atoms in the δ-doped layer by laser annealing. The peak concentration of Bi atoms in the δ-doped layer is controlled by two parameters: the coverage of surfactant layer, and the growth temperature during the Si cap-layer growth, whose maximum concentration is larger than 1020 cm-3. Photoluminescence and electrical carrier transport measurements reveal that dense Bi atoms are activated upon heating the area at close to the melting point of Si. As a result, our doping process results in Bi donors in the wire-δ-doped layer with concentration of >1018 cm-3. This will be useful for establishing next-generation, quantum information processing platform.
Light Absorption in Semiconductor Nanowire Arrays with Multijunction Cell Structures
Authors: Motohisa Junichi , Hiruma Kenji
Published: November 2012

The light absorption of various types of semiconductor nanowire (NW) arrays for photovoltaic applications was calculated. The electromagnetic field in multilayer structures containing NW arrays was calculated by the scattering-matrix treatment developed by Whittaker and Culshaw [Phys. Rev. B 60 (1999) 2610], and the absorptance spectraA(λ) of the NW arrays were obtained from the transmittance and reflectivity of the structures. The ultimate efficiency η and weighted average absorptanceAavrof the NW array solar cells were evaluated fromA(λ). A general tendency of the light absorption in NW arrays in relation to their structural parameters, such as the pitchaof an NW array and the sizedof an NW, was identified, and the differences between the optimum structural parameters of NW arrays in terms of light absorption in the cases of InP, GaAs, Si, and Ge were determined. The maximum η was obtained fora= 375, 350, 700, and 400 nm, for InP, GaAs, Si, and Ge NW arrays withd/a=0.5, respectively. Moreover,Aavrfor multijunction structures consisting of GaAs and Ge NWs and GaAs NWs on a germaninum substrate was also calculated and showed that both of these structures exhibited good light trapping capabilities for photovoltaic applications. It is shown that the photogeneration profiles of carriers in two types of multijunction structures are different.
Vertical Silicon Nanowire Diode with Nickel Silicide Induced Dopant Segregation
Authors: Lu Weijie , Pey Kin Leong , Wang Xinpeng , Li Xiang , Chen Zhixian , Navab Singh , Leong Kam Chew , Gan Chee Lip , Tan Chuan Seng
Published: November 2012

Dopant segregated Schottky barrier (DSSB) and Schottky barrier (SB) vertical silicon nanowire (VSiNW) diodes were fabricated using industry complemetary metal oxide semiconductor field effect transistor (CMOS) processes to investigate the effects of segregated dopants at the silicide/silicon interface and different annealing steps on nickel silicide formation in the DSSB VSiNW diodes. With segregated dopants at the silicide/silicon interface, VSiNW diodes showed higher on-current, due to an enhanced carrier tunneling, and much lower off-current. This can be attributed to the altered energy bands caused by the accumulated Arsenic dopants at the interface. Moreover, DSSB VSiNW diodes also presented ideality factor much closer to unity and exhibited lower electron Schottky barrier height (ΦBn) than SB VSiNW diodes. This proved that interfacial accumulated dopants could impede the inhomogeneous nature of the Schottky diodes and simultaneously, minimize the effect of Fermi level pinning and ionization of surface defect states. Comparing the impact of different silicide formation annealing sequence using DSSB VSiNW diodes, the 2-step anneal process reduces the silicide intrusion length within the SiNW by ∼5× and the silicide interface was smooth along the (100) direction. Furthermore, the 2-step DSSB VSiNW diode also exhibited much lower leakage current and an ideality factor much closer to unity, as compared to the 1-step DSSB VSiNW diode.
Investigation of Gas Sensing Characteristics of TiO2 Nanotube Field-Effect Transistor
Authors: Ishii Masayuki , Terauchi Masahiro , Yoshimura Takeshi , Nakayama Tadachika , Fujimura Norifumi
Published: November 2012

Hydrothermal TiO2 nanotubes are focused on as a functional material owing to their large surface-to-bulk ratio. We have revealed that the electric conduction of a TiO2 nanotube field-effect transistor (FET) is dominated by a double Schottky barrier formed between the TiO2 nanotubes. In this study, the gas sensing characteristics of the FET for ethanol at room temperature were investigated. The decrease of the drain current was observed in atmosphere with an ethanol concentration of 30 ppm. From the detailed analysis of the barrier height and the threshold voltage using the model of a double Schottky barrier, it was found that the barrier decreases and the carrier densities decrease through the adsorption of ethanol, which works as an electron acceptor.
Mechanism of Growth of Cr2O3Thin Films on (11̄02), (112̄0), and (0001) Surfaces of Sapphire Substrates by Direct Current–Radio Frequency Magnetron Sputtering
Authors: Iwata Nobuyuki , Kuroda Takuji , Yamamoto Hiroshi
Published: November 2012

With the aim of directly controlling the magnetization in a ferromagnetic (FM) metal/Cr2O3multilayer by means of an electric field without field cooling, the mechanism of growth of magnetoelectric (ME) Cr2O3thin films onr-,a-, andc-cut sapphire substrates is investigated. In all the films, epitaxial growth is observed with a unit step on the film surface. The growth difference, which appears during the initial growth stage (at about 1 nm film thickness), is observed in the oriented films on each substrate surface. This growth difference arises from the different surface energies and the presence of twin grains due to the dislocation of Cr atoms. The twin-freer-oriented film contains coalesced grains with deep trenches at the grain boundaries, which release film stress and maintain flat grain surfaces because of the lowest surface energy. Thea-oriented film shows anisotropic grains with the unit step and no trenches because the film starts to grow in a three-dimensional mode. Thec-oriented film contains twin grains with the lowest full width at half-maximum of the rocking curve for the Bragg diffraction and a surface roughness of 0.17 nm. The twin grains in thec-oriented film contain a mixture of Cr atoms with up and down spins, which would simultaneously induce both an increase and a decrease in the exchange bias magnetic field (HEB) under an applied electric field through the ME effect. Therefore, the magnetization depends on the ratio of the twin grains. The Cr spins of the twin-freer-oriented film are expected to show FM ordering, indicating thatHEBcan be increased or decreased by an applied electric field. Thisr-oriented film is thus a promising surface for direct magnetization control using an electric field.
Creation of Nanoparticle–Nanotube Conjugates for Life-Science Application Using Gas–Liquid Interfacial Plasmas
Authors: Kaneko Toshiro , Hatakeyama Rikizo
Published: November 2012

Gold nanoparticles (AuNPs) conjugated with carbon nanotubes (CNTs) and/or biomolecules such as DNA are synthesized by a novel plasma technique combined with the introduction of ionic liquids or aqueous solutions for application to life sciences. We successfully generated the gas–liquid interfacial discharge plasma (GLIDP) using an ionic liquid, in which a large sheath electric field was formed on the ionic liquid and high-energy plasma ion irradiation to the ionic liquid was realized. Using this GLIDP, it is found that the high-energy ion irradiation to the ionic liquid is effective for the synthesis of AuNPs. Furthermore, controlled ion irradiation to the ionic liquid including functional groups can realize distance-controlled synthesis of AuNPs on CNTs by dissociation of the ionic liquid and the functionalization of CNTs by dissociated carboxyl and amino groups. On the other hand, DNA is used as the functional group that connects the AuNPs to the CNTs. Monodispersed and high-density AuNPs are synthesized on CNTs in the same way as the carboxyl and amino groups.
Influence of Chemical Bonding States on Electrical Properties of Amorphous Carbon Nitride Films
Authors: Tamura Naoyuki , Aono Masami , Kishimura Hiroaki , Kitazawa Nobuaki , Watanabe Yoshihisa
Published: November 2012

The electrical properties of amorphous carbon nitride (a-CN
x
) films have been investigated in terms of the nitrogen concentration (N/C) and chemical bonding states in the films. The films were deposited by the reactive rf magnetron sputtering method. Nitrogen concentration and chemical bonding states in the films were controlled by regulating the deposition temperature. C–C networks in the films changed to those having a graphite like structure with decreasing N/C, as deduced by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). In addition, the N–sp2C bonding state becomes more predominant. These results indicate the contributions of the N–sp2C component to the decrease in electrical resistivity and increase in photoconductivity.
Pressure Dependences of Gas Temperature and Electron Density in Microhollow Cathode Discharges in He and He+H2O Gases
Authors: Yamasaki Tsutomu , Namba Shinichi , Takiyama Ken , Nojima Hideo
Published: November 2012

Microplasmas were generated using a cylindrical hollow cathode with a diameter of 0.5 mm and a length of 3 mm in He and He+H2O gases at pressures in the range of 20 to 765 Torr. Spectral line profiles of He I (667.8 nm) and Hα(656.3 nm) were measured to determine the plasma parameters. Gas temperature and electron density were evaluated by the analysis of spectral line broadening. These parameters linearly increased with gas pressure in the range of 300 to 765 Torr. The gas temperatures and electron densities at atmospheric pressure were obtained to be 610 K and 5.0×1014cm-3for He and 820 K and 3.5×1014cm-3for He+H2O microplasmas, respectively. A comparison of these values with those obtained in a previous work [M. Micleaet al.: J. Phys. D 38 (2005) 1709] demonstrated that our device could generate high-density plasmas with a large volume and a high degree of nonequilibrium. The influences of an admixture of H2O on the discharge properties and plasma parameters were also discussed.
Calculations of Starting Currents and Frequencies in Frequency-Tunable Gyrotrons
Authors: Dumbrajs Olgierd , Idehara Toshitaka , Saito Teruo , Tatematsu Yoshinori
Published: November 2012

Cold cavity and self-consistent formalisms for starting current and frequency calculations in frequency-tunable gyrotrons are summarized. Numerical solution schemes of the corresponding equations are discussed. A specific case is analyzed in detail.
Bridging the gap
Authors: Taylor Simon J. E. , Turner Stephen J. , Strassburger Steffen , Mustafee Navonil
Published: November 2012

In Operations Research and Management Science (OR/MS), Discrete Event Simulation (DES) models are typically created using commercial off-the-shelf simulation packages (CSPs) such as AnyLogic™, Arena™, Flexsim™, Simul8™, SLX™, Witness™, and so on. A DES model represents the processes associated with a system of interest. Some models may be composed of submodels running in their own CSPs on different computers linked together over a communications network via distributed simulation software. The creation of a distributed simulation with CSPs is still complex and typically requires a partnership of problem owners, modelers, CSP vendors, and distributed simulation specialists. In an attempt to simplify this development and foster discussion between modelers and technologists, the SISO-STD-006-2010 Standard for COTS Simulation Package Interoperability Reference Models has been developed. The standard makes it possible to capture interoperability capabilities and requirements at a DES modeling level rather than a computing technical level. For example, it allows requirements for entity transfer between models to be clearly specified in DES terms (e.g. the relationship between departure and arrival simulation times and input element (queue, workstation, etc.), buffering rules, and entity priority, instead of using specialist technical terminology. This article explores the motivations for distributed simulation in this area, related work, and the rationale for the standard. The four Types of Interoperability Reference Model described in the standard are discussed and presented (A. Entity Transfer, B. Shared Resource, C. Shared Event, and D. Shared Data Structure). Case studies in healthcare and manufacturing are given to demonstrate how the standard is used in practice.
Transparent optimistic synchronization in the high-level architecture via time-management conversion
Authors: Santoro Andrea , Quaglia Francesco
Published: November 2012

Distributed simulation allows the treatment of large/complex models by having several interacting simulators running concurrently, each one in charge of a portion of the model. In order to effectively manage integration and interoperability aspects, the standard known as High Level Architecture (HLA) has been developed, which is based on a middleware component known as Run-Time-Infrastructure (RTI). One of the main issues faced by such a standard is synchronization, so that HLA supports both conservative and optimistic approaches. However, technical issues, combined with some peculiarities of the optimistic approach, force most simulators to use the conservative approach. In order to tackle these issues, we present the design and implementation of a Time Management Converter (TiMaC) for HLA based simulation systems. TiMaC is a state machine designed to be transparently interposed between the application layer and the underlying RTI, which performs mapping of the conservative HLA synchronization interface onto the optimistic one. Such a mapping allows transparent optimistic execution (and the related benefits) for simulators originally designed to rely on conservative synchronization. This is achieved without the need to modify the RTI services or alter the HLA standard. An experimental evaluation demonstrating the viability and effectiveness of our proposal is also reported, by integrating our TiMaC implementation with the Georgia Tech B-RTI package and running on it both (A) benchmarks relying on traces from simulated demonstration exercises collected using the Joint Semi-Automated Forces (JSAF) simulation program and (B) a self-federated Personal Communication System simulation application.
Perceived obsolescence, organizational embeddedness, and turnover of it workers
Authors: Zhang Xiaoni , Ryan Sherry D. , Prybutok Victor R. , Kappelman Leon
Published: November 2012

Technical skill currency is especially important to IT professionals, yet past research has not integrated perceived obsolescence into the nomological net with organizational embeddedness when investigating IT workers' turnover intentions. Responding to a call for additional research on IT worker turnover we utilize a sample of 1,777 IT workers in a very large and complex IT organization and find that organizational embeddedness explains significant incremental variance beyond the traditional turnover model. The findings presented here show that organizational embeddedness is an essential mediator between perceived skill obsolescence and IT voluntary turnover. Our data also show that the effect of perceived obsolescence on embeddedness is moderated by age. This work provides organizations with insights on why employees choose to stay in an organization, or leave it. We find that both fit and sacrifice dimensions of embeddedness mediate the relationship between perceived skill obsolescence and turnover intention, but that only the sacrifice dimension is a full mediator. These findings suggest that turnover intention is a multivariate issue and that future IT turnover research needs to include other variables such as perceived obsolescence and age. Furthermore there is a need for future research on the role of the specific dimensions of embeddedness. We suggest strategies to reduce voluntary turnover based on the predictive variables in the research model.
Verified heap theorem prover by paramodulation
Authors: Stewart Gordon , Beringer Lennart , Appel Andrew W.
Published: November 2012

We present
VeriStar
, a verified theorem prover for a decidable subset of separation logic. Together with VeriSmall [3], a proved-sound Smallfoot-style program analysis for C minor, VeriStar demonstrates that fully machine-checked static analyses equipped with efficient theorem provers are now within the reach of formal methods. As a pair, VeriStar and VeriSmall represent the first application of the
Verified Software Toolchain
[4], a tightly integrated collection of machine-verified program logics and compilers giving foundational correctness guarantees.

VeriStar is (1)
purely functional
, (2)
machine-checked
, (3)
end-to-end
, (4)
efficient
and (5)
modular
. By purely functional, we mean it is implemented in Gallina, the pure functional programming language embedded in the Coq theorem prover. By machine-checked, we mean it has a proof in Coq that when the prover says "valid", the checked entailment holds in a proved-sound separation logic for C minor. By end-to-end, we mean that when the static analysis+theorem prover says a C minor program is safe, the program will be compiled to a semantically equivalent assembly program that runs on real hardware. By efficient, we mean that the prover implements a state-of-the-art algorithm for deciding heap entailments and uses highly tuned verified functional data structures. By modular, we mean that VeriStar can be retrofitted to other static analyses as a plug-compatible entailment checker and its soundness proof can easily be ported to other separation logics.
An error-tolerant type system for variational lambda calculus
Authors: Chen Sheng , Erwig Martin , Walkingshaw Eric
Published: November 2012

Conditional compilation and software product line technologies make it possible to generate a huge number of different programs from a single software project. Typing each of these programs individually is usually impossible due to the sheer number of possible variants. Our previous work has addressed this problem with a type system for variational lambda calculus (VLC), an extension of lambda calculus with basic constructs for introducing and organizing variation. Although our type inference algorithm is more efficient than the brute-force strategy of inferring the types of each variant individually, it is less robust since type inference will fail for the entire variational expression if any one variant contains a type error. In this work, we extend our type system to operate on VLC expressions containing type errors. This extension directly supports locating ill-typed variants and the incremental development of variational programs. It also has many subtle implications for the unification of variational types. We show that our extended type system possesses a principal typing property and that the underlying unification problem is unitary. Our unification algorithm computes partial unifiers that lead to result types that (1) contain errors in as few variants as possible and (2) are most general. Finally, we perform an empirical evaluation to determine the overhead of this extension compared to our previous work, to demonstrate the improvements over the brute-force approach, and to explore the effects of various error distributions on the inference process.
Shake before building
Authors: Mitchell Neil
Published: November 2012

Most complex software projects are compiled using a build tool (e.g. make), which runs commands in an order satisfying user-defined dependencies. Unfortunately, most build tools require all dependencies to be specified
before
the build starts. This restriction makes many dependency patterns difficult to express, especially those involving files generated at build time. We show how to eliminate this restriction, allowing additional dependencies to be specified while building. We have implemented our ideas in the Haskell library Shake, and have used Shake to write a complex build system which compiles millions of lines of code.
On the complexity of equivalence of specifications of infinite objects
Authors: Endrullis Jörg , Hendriks Dimitri , Bakhshi Rena
Published: November 2012

We study the complexity of deciding the equality of infinite objects specified by systems of equations, and of infinite objects specified by λ-terms. For equational specifications there are several natural notions of equality: equality in all models, equality of the sets of solutions, and equality of normal forms for productive specifications. For λ-terms we investigate Böhm-tree equality and various notions of observational equality. We pinpoint the complexity of each of these notions in the arithmetical or analytical hierarchy.

We show that the complexity of deciding equality in all models subsumes the entire analytical hierarchy. This holds already for the most simple infinite objects, viz. streams over {0,1}, and stands in sharp contrast to the low arithmetical ϖ
0
2
-completeness of equality of equationally specified streams derived in [17] employing a different notion of equality.