bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoelectric heat effect induce instability on the negative bias temperature illumination stress for InGaZnO thin film transistors
Authors: Huang Sheng-Yao , Chang Ting-Chang , Yang Man-Chun , Lin Li-Wei , Wu Ming-hsin , Yang Kai-Hsiang , Chen Min-Chen , Chiu Yi-Jen , Yeh Bo-Liang
Published: December 2012

This paper investigates the instability of negative bias temperature in the dark and the illumination stresses for the InGaZnO thin film transistors. During the negative bias temperature illumination stress, properties exhibit an obvious negative threshold voltage shift and a significant degradation of subthreshold swing. The photoelectric heat effect that combined the effects of electric field, illumination, and temperature induces the generation of dangling bonds in the interface, resulting in an apparent degradation. It is related to the presence of light energy. Finally, this work also employs the capacitance-voltage measurement and recovery behavior to further clarify the mechanism of degradation behaviors.
High frequency dynamic bending response of piezoresistive GaN microcantilevers
Authors: Talukdar Abdul , Qazi Muhammad , Koley Goutam
Published: December 2012

Static and dynamic ac responses of piezoresistive GaN microcantilevers, with integrated AlGaN/GaN heterostructure field effect transistors as highly sensitive deflection transducers, have been investigated. Very high gauge factor exceeding 3500 was exhibited by the microcantilevers, with quality factor determined from electronically transduced ac response exceeding 200 in air and 4500 at low pressure. The gauge factor reduced at resonance frequency of the cantilevers, possibly due to reduced charge exchange with surface donor and trap states. Ultrasonic waves generated in air by a piezochip, and in the Si substrate through photoacoustic effect, could be detected by the cantilevers with high sensitivity.
Spatially resolved study of quantum efficiency droop in InGaN light-emitting diodes
Authors: Lin Yue , Zhang Yong , Liu Zhiqiang , Su Liqin , Zhang Jihong , Wei Tongbo , Chen Zhong
Published: December 2012

We investigate the spatial variation of the external quantum efficiency (EQE) of InGaN light-emitting diodes. Two different types of EQE droop are examined in one single device, offering unambiguous analyses on the underlying material physics without the complications of the processing variation. The interplays of microscopic defects, extended defects, and energy fluctuation dictate the mechanisms of the droop, which represents a common theme in various optoelectronic devices. The two droop types correspond to the two extreme situations of energy fluctuation that affects the carrier diffusion and recombination. The finding suggests ways for improving the device performance, depending on operation conditions.
Effects of cutting and burning on regeneration of Alhagi sparsifolia Shap. on the southern fringe of the Taklamakan Desert, North-west China
Authors: Li Haifeng , Zeng Fanjiang , Gui Dongwei , Zhang Ligang , Song Cong , Luo Weicheng , Peng Shoulan
Published: December 2012

Indigenous vegetation such as Alhagi sparsifolia Shap. (Fabaceae) has been severely damaged in recent years because of the growing population and increasing land use on the southern margin of the Taklamakan Desert. Alhagi sparsifolia plays an important role in supporting the fragile ecosystem in the oasis foreland as it has multiple ecological and economic functions. Cele Oasis, located on the southern rim of the Taklamakan Desert, was used to investigate the impact of human disturbance on regeneration of A. sparsifolia in the oasis–desert ecotone. Observations of A. sparsifolia in response to cutting and burning were conducted in 2010 and 2011. The results showed that burning in spring significantly decreased height and biomass in comparison to cutting in the fall. Moreover, biomass was decreased by spring burning more than by spring cutting. Burning in spring is no advantage for the growth and survival of A. sparsifolia. Cutting in fall appears to be a useful treatment for increasing the production from and survival of A. sparsifolia that could facilitate the sustainable development of the Cele Oasis.
Changes in vegetation over nine years after rehabilitating a linear feature in Australia's arid zone
Authors: Low W. A. , McNally A. , Davies B. K. , Greenslade Penelope
Published: December 2012

A 36-km road built in 1961 between Ayers Rock (Uluru) and the Olgas (Kata Tjuta), Northern Territory, Australia had seriously deteriorated by the 1980s. A newly aligned road, which was ecologically located and avoided sensitive Aboriginal sites, was completed early in 1991. The old road was rehabilitated by deep ripping, filling with imported sand and topsoil and by grading logs and windrows1 over the new surface. This paper reports on the effectiveness of the rehabilitation technique used in reinstating vegetation over 8 years and considers whether this rehabilitation aim was met. Plant colonisation and succession were monitored on 15 paired plots, one in the rehabilitated road and the other in the adjacent undisturbed habitat (with four exceptions) and also on the windrows. Sites at eight creek crossings and those subject to fire and rabbit activity were also monitored. Different landscape units responded in different ways to the rehabilitation. Herbaceous species from imported sand plain fill and top soil eventually dominated the road where they were introduced and were likely to persist in most areas because of local recruitment. The revegetation of the road has stabilised the old road surface as observed by the reduced erosion although succession did not always approach the reference site communities because of a greater resemblance to the Simpson Land System. Over the 8 years of monitoring considerable changes in vegetation occurred and are probably continuing. Only the road sites in the Simpson Land System approached the condition of the adjacent undisturbed vegetation because the vegetation of the other two land systems became closer to that of the Simpson Land System rather than to that of the surrounding vegetation. It is recommended that the introduced Buffel grass, known to alter landscape-level processes by reducing native herbaceous species and increasing risk of high intensity wildfire, which is most evident at creek crossings, should be controlled. Recommendations are made for improved management.
Damage and control of major poisonous plants in the western grasslands of China – a review
Authors: Lu Hao , Wang Shan Shan , Zhou Qi Wu , Zhao Yi Nan , Zhao Bao Yu
Published: December 2012

Desertification and degradation of pastures has occurred over the last 50 years on the western grasslands of China due to human factors including overgrazing, unsuccessful reclamation of land, loss of soil through inappropriate cultivation, mining, population growth, and natural factors including drought. This has led to a decrease in herbage mass and a reduction in carrying capacity, leading to a reduction in the sustainability of livestock systems. One of the effects of desertification and degradation has been an increase in the area of poisonous plants over this period and these plants now cover 20.5 m ha and are now a contributing factor and symptom of the degeneration of the grasslands. The main poisonous plants that threaten livestock production are locoweeds (Oxytropis and Astragalus species), Stellera chamaejasme, Achnaterum inebrian, Cynanchum komarovii and Aconitum carmichaeli. Based on an analysis of previous and current data, this review describes the distribution of these poisonous plants and their impact on livestock production and assesses the state of poisonous plants in the western grasslands are having on the sustainability of livestock production, and addresses the issues of integrated control measures and the development of appropriate livestock management systems that could be implemented.
Response of woody and herbaceous fuel to repeated fires in Mediterranean gorse shrublands
Authors: Santana Victor M. , Baeza M. Jaime , Marrs Rob H.
Published: December 2012

Differences in both species flammability and post-fire regenerative abilities can be the key to understanding fire regimes and vegetation dynamics. We hypothesised that woody species that accumulate the greatest amount of dead fuel and also have fire-stimulated recruitment would benefit when fire occurrence is increased, thus establishing a positive fire–vegetation flammability feedback. To test this hypothesis, we compared successional change over a 25-year period in gorse shrublands that were burnt once and twice. We assessed change in life forms, species traits with respect to the kind of fuel (i.e. woody and herbaceous) and the abundance of standing dead fuel. We found that, at the community level, accumulation of dead fuel was unrelated to recurrent fires because a second fire in the period of maximum fire risk created a community with less dead fuel. This result implies a lack of positive fire–dead fuel accumulation feedback. In contrast, herbaceous species may establish a positive feedback with fire as they were increased by a second fire.
Nanostructured photovoltaics
Authors: Fu Lan , Hoe Tan H , Jagadish Chennupati
Published: December 2012

Energy and the environment are two of the most important global issues that we currently face. The development of clean and sustainable energy resources is essential to reduce greenhouse gas emission and meet our ever-increasing demand for energy. Over the last decade photovoltaics, as one of the leading technologies to meet these challenges, has seen a continuous increase in research, development and investment. Meanwhile, nanotechnology, which is considered to be the technology of the future, is gradually revolutionizing our everyday life through adaptation and incorporation into many traditional technologies, particularly energy-related technologies, such as photovoltaics.

While the record for the highest efficiency is firmly held by multijunction III–V solar cells, there has never been a shortage of new research effort put into improving the efficiencies of all types of solar cells and making them more cost effective. In particular, there have been extensive and exciting developments in employing nanostructures; features with different low dimensionalities, such as quantum wells, nanowires, nanotubes, nanoparticles and quantum dots, have been incorporated into existing photovoltaic technologies to enhance their performance and/or reduce their cost. Investigations into light trapping using plasmonic nanostructures to effectively increase light absorption in various solar cells are also being rigorously pursued. In addition, nanotechnology provides researchers with great opportunities to explore the new ideas and physics offered by nanostructures to implement advanced solar cell concepts such as hot carrier, multi-exciton and intermediate band solar cells.

This special issue of Journal of Physics D: Applied Physics contains selected papers on nanostructured photovoltaics written by researchers in their respective fields of expertise. These papers capture the current excitement, as well as addressing some open questions in the field, covering topics including the III–V quantum well superlattice and quantum dot solar cells, Si quantum dot tandem cells, nanostructure-enhanced dye-sensitized solar cells and nanopatterned organic solar cells.

We thank all the authors and reviewers for their contribution to this special issue. Special thanks are due to the journal's Publisher, Dr Olivia Roche and the editorial and publishing staff for their help and support.
A quantum-well superlattice solar cell for enhanced current output and minimized drop in open-circuit voltage under sunlight concentration
Authors: Sugiyama Masakazu , Wang Yunpeng , Fujii Hiromasa , Sodabanlu Hassanet , Watanabe Kentaroh , Nakano Yoshiaki
Published: December 2012

Insertion of quantum wells (QWs) extends the absorption edge to a longer wavelength than the value of a p-i-n cell without the QWs, which is preferable for the improved current matching of a InGaP/GaAs/Ge multijunction cell. The QWs, however, reduce the open-circuit voltage (V
oc) and degrade the fill factor; the latter is significant for a large number of QWs that are mandatory for sufficient light absorption. As a structure to minimize these drawbacks, a QW superlattice, a strain-balanced In0.13Ga0.86As (4.7 nm)/GaAs0.57P0.43 (3.1 nm) stack, was implemented by metalorganic vapour-phase epitaxy. It brought about an enhancement in short-circuit current density (3.0 mA cm−2) with a minimal drop in V
oc(0.03 V) compared with a p-i-n cell without the superlattice. The collection efficiency of photocarriers from the wells to an external circuit was evaluated: the efficiency was above 0.95 for the superlattice, while it was below 0.8 at a large forward bias for a conventional QW cell with thicker barriers. With the fast electron–hole separation in the superlattice owing to tunnelling transport, the superlattice cell exhibited a steeper increase in V
oc as a function of the sunlight concentration ratio than the conventional QW cell: at the concentration ratio of 50, the value of V
oc for the superlattice cell was almost equivalent to the value of the GaAs p-i-n cell without QWs. As a possible mechanism behind such an enhancement in V
oc, photocurrent generation by two-step photon absorption was observed, using the electron ground state of the superlattice as an intermediate state.
Sputter-grown Si quantum dot nanostructures for tandem solar cells
Authors: Huang Shujuan , Conibeer Gavin
Published: December 2012

Silicon quantum dot (QD)-based ‘all-silicon’ tandem solar cells have emerged as a promising third generation photovoltaic approach to realize high-efficiency and cost effective solar cells. This approach exploits the quantum confinement effect of silicon QDs embedded in a dielectric matrix to engineer the effective electronic bandgap of a solar cell material. Research work in our group has shown that such a Si QD solar cell can be fabricated by co-sputtering of thin layers of Si-rich dielectric sandwiched between stoichiometric dielectric layers which crystallize to form Si QDs of uniform size on annealing. The Si-richness in the Si-rich layer plays an important role in formation of uniform size and shape. The matrix and barrier layer materials also affect the formation of Si QDs. The bandgap tunability of such Si QD superlattice structures has been clearly demonstrated by photoluminescence and electroluminescence measurements. Doping of Si QD layers has been achieved by impurity incorporation of P, Sb or B in the Si-rich layers. Strong evidence of effective doping has been demonstrated from the enhanced conductivity, from the dopant concentrations extracted from MOS structures and from the formation of rectifying p–n junctions which give an open circuit voltage (V
oc) of 492 mV. The doping mechanism is more likely to be modified interface doping rather than direct doping to the Si QDs.
Simulations of ITER in the presence of ITB using the NTV intrinsic toroidal rotation model
Authors: Chatthong B. , Onjun T.
Published: December 2012

Simulations of a standard H-mode International Thermonuclear Experimental Reactor (ITER) scenario in the presence of internal transport barrier (ITB) are carried out using the 1.5D BALDUR integrated predictive modelling code. The intrinsic offset toroidal rotation, which can play an essential role in turbulent transport suppression that results in the ITB formation, is theoretically calculated using a model based on the neoclassical toroidal viscosity (NTV) concept. The core transport in this simulation is a combination of a mixed Bohm/gyro-Bohm anomalous transport model and an NCLASS neoclassical transport model. The boundary condition of the simulations is taken to be at the top of the pedestal where the pedestal value is calculated using the pedestal model based on a combination of pedestal width scaling determined by magnetic/flow shear stabilization and an infinite-n ballooning pressure gradient model. It is found that the predicted intrinsic rotation can result in the formation of ITB, locating mostly between r/a = 0.6 and 0.8 and having a strong impact on the plasma performance in ITER. It is also found that the variations of plasma density and heating power result in a minimal change in toroidal rotation; whereas the increase in plasma effective charge can considerably reduce the toroidal velocity peaking.
Stellarator optimization under several criteria using metaheuristics
Authors: Castejón F , Gómez-Iglesias A , Vega-Rodríguez M A , Jiménez J A , Velasco J L , Romero J A
Published: December 2012

A new algorithm based on metaheuristics has been developed to perform stellarator optimization. This algorithm, which is inspired by the behaviour of bees and is called distributed asynchronous bees, has been used for the optimization under three criteria: minimization ofB × grad(B) drift, Mercier and ballooning stability. This algorithm is tested by partially optimizing TJ-II and, afterwards, a three-period optimized configuration is found by performing a full optimization that starts from a three-period heliac.
Domestic Violence and Abuse
Authors: Sohal Alex , Feder Gene , Johnson Medina
Published: December 2012

Domestic violence and abuse (DVA) is a violation of human rights, a major public health issue and a clinical problem that is increasingly recognised as a health care issue. It has been estimated that its cost to the UK is at least £5.7 billion a year. This article aims to cover the knowledge that GPs require about DVA, as described in the Royal College of General Practitioners curriculum. It is focused on women's health and also considers the care of children and young people, and sexual health. We shall define DVA and consider its causes, prevalence and health impact. The ideal primary health care response to DVA is described, alongside practical information about how GPs should respond to early presentation of sexual assault, including rape.
Microbiota Separation and C‐reactive Protein Elevation in Treatment‐naïve Pediatric Granulomatous Crohn Disease
Authors: Kellermayer Richard , Mir Sabina A.V. , Nagy‐Szakal Dorottya , Cox Stephen B. , Dowd Scot E. , Kaplan Jess L. , Sun Yan , Reddy Sahna , Bronsky Jiri , Winter Harland S.
Published: December 2012

Objectives:

In patients with inflammatory bowel diseases (IBDs), the presence of noncaseating mucosal granuloma is sufficient for diagnosing Crohn disease (CD) and may represent a specific immune response or microbial‐host interaction. The cause of granulomas in CD is unknown and their association with the intestinal microbiota has not been addressed with high‐throughput methodologies.

Methods:

The mucosal microbiota from 3 different pediatric centers was studied with 454 pyrosequencing of the bacterial 16S rRNA gene and the fungal small subunit (SSU) ribosomal region in transverse colonic biopsy specimens from 26 controls and 15 treatment‐naïve pediatric CD cases. Mycobacterium avium subspecies paratuberculosis (MAP) was tested with real‐time polymerase chain reaction. The correlation of granulomatous inflammation with C‐reactive protein was expanded to 86 treatment‐naïve CD cases.

Results:

The CD microbiota separated from controls by distance‐based redundancy analysis (P = 0.035). Mucosal granulomata found in any portion of the intestinal tract associated with an augmented colonic bacterial microbiota divergence (P = 0.013). The granuloma‐based microbiota separation persisted even when research center bias was eliminated (P = 0.04). Decreased Roseburia and Ruminococcus in granulomatous CD were important in this separation; however, principal coordinates analysis did not reveal partitioning of the groups. CRP levels >1 mg/dL predicted the presence of mucosal granulomata (odds ratio 28 [6–134.32]; 73% sensitivity, 91% specificity).

Conclusions:

Granulomatous CD associates with microbiota separation and C‐reactive protein elevation in treatment‐naïve children; however, overall dysbiosis in pediatric CD appears rather limited. Geographical/center bias should be accounted for in future multicenter microbiota studies.
Upper Gastrointestinal Histopathological Findings in Children and Adolescents With Nonulcer Dyspepsia With Helicobacter pylori Infection
Authors: Carvalho Mary Assis , Machado Nilton Carlos , Ortolan Erika Veruska Paiva , Rodrigues Maria Aparecida Marchesan
Published: December 2012

Objectives:

The aim of the study was to investigate the histopathological lesions in the upper gastrointestinal mucosa associated with Helicobacter pylori infection in children with nonulcer dyspepsia.

Methods:

A cross‐sectional case‐control study was performed on 185 Brazilian children and adolescents (4–17 years, mean 9.5 ± 2.7 years), 63.2% girls, submitted to upper gastrointestinal endoscopy. The histopathological lesions of the esophageal and gastric mucosa were analyzed in biopsy samples.

Results:

H pylori infection was identified in 96 children (51.8%). Moderate to severe chronic active gastritis was present in antrum (70.5%) and corpus (45.2%), with higher grading in antrum than in corpus (P < 0.05). The topographic distribution of inflammation was pangastritis (61.9%), followed by antral (32.1%) and corpus (5.9%). H pylori density was higher in antrum than in corpus. Intestinal metaplasia was not found in the H pylori–infected group, nor was significant gastric atrophy. The scores for esophagitis were significantly higher (P < 0.05) in the noninfected group (1.4 ± 0.8) than in the H pylori–infected group (1.07 ± 0.9), with significant negative correlation (r = 0.29; P < 0.05) with the scores of gastric inflammation.

Conclusions:

The prevalence of H pylori infection was high among children with dyspepsia and associated with moderate/severe degrees of gastric inflammation. The high scores of esophagitis in the noninfected group point to 2 distinct groups of pathological conditions sharing similar clinical patterns.
Evaluation of the Presence of Hereditary and Acquired Thrombophilias in Brazilian Children and Adolescents With Diagnoses of Portal Vein Thrombosis
Authors: Menezes Ferri Priscila , Rodrigues Ferreira Alexandre , Tavares Fagundes Eleonora Druve , Guerra Xavier Sandra , Dias Ribeiro Daniel , Fernandes Ana Paula , Gomes Borges Karina Braga , Liu Shinfay Maximilian , de Melo Maria do Carmo Barros , Roquete Mariza Leitão Valadares , Penna Francisco José
Published: December 2012

Objective:

The aim of this study was to describe the prevalence of main hereditary thrombophilias, Janus kinase 2 (JAK2) V617F mutation, antiphospholipid antibody syndrome (APS), and hyperhomocysteinemia in Brazilian children and adolescents diagnosed with portal vein thrombosis (PVT) without associated hepatic disease.

Methods:

A cross‐sectional study was carried out with 32 children with PVT in accompaniment at Hospital das Clínicas of the Universidade Federal de Minas Gerais from January 1990 to July 2011. Laboratory evaluation of thrombophilias was performed from September 2010 to July 2011.

Results:

Thirty‐two patients were evaluated; 59% were boys. Median age at diagnosis was 2.4 years. Mean time of patients' accompaniment was between 4.7 and 5.2 years. The presence of hereditary and acquired thrombophilias occurred in 34.4% of patients, and 9 of them also showed other risk factors in the previous history evaluation. Risk factors were absent in the previous history of 18 patients (56.3%). Two patients showed persistent high titres of anticardiolipin antibodies. Hyperhomocysteinemia was not observed. One patient was heterozygous for factor V Leiden and prothrombin G20210A mutation (3.1%). Eleven patients (34.4%) showed heterozygous methylenetetrahydrofolate reductase (MTHFR) C677T, and no patient had the JAK2V617F mutation.

Conclusions:

Even after investigation of main hereditary and acquired thrombophilia, PVT remains without apparent cause in most patients. Nevertheless, association of local and systemic risk factors seems to be important also in the pediatric age group. Therefore, despite the low prevalence, a complete investigation, which includes both hereditary and acquired thrombophilias, may be necessary.
Predictors of Proctocolectomy in Children With Ulcerative Colitis
Authors: Kelley‐Quon Lorraine I. , Jen Howard C. , Ziring David A. , Gupta Neera , Kirschner Barbara S. , Ferry George D. , Cohen Stanley A. , Winter Harland S. , Heyman Melvin B. , Gold Benjamin D. , Shew Stephen B.
Published: December 2012

Objectives:

Few clinical predictors are associated with definitive proctocolectomy in children with ulcerative colitis (UC). The purpose of the present study was to identify clinical predictors associated with surgery in children with UC using a disease‐specific database.

Methods:

Children diagnosed with UC at age <18 years were identified using the Pediatric Inflammatory Bowel Disease Consortium (PediIBDC) database. Demographic and clinical variables from January 1999 to November 2003 were extracted alongside incidence and surgical staging.

Results:

Review of the PediIBDC database identified 406 children with UC. Approximately half were girls (51%) with an average age at diagnosis of 10.6 ± 4.4 years in both boys and girls. Average follow‐up was 6.8 (±4.0) years. Of the 57 (14%) who underwent surgery, median time to surgery was 3.8 (interquartile range 4.9) years after initial diagnosis. Children presenting with weight loss (hazard ratio [HR] 2.55, 99% confidence interval [CI] 1.21–5.35) or serum albumin <3.5 g/dL (HR 6.05, 99% CI 2.15–17.04) at time of diagnosis and children with a first‐degree relative with UC (HR 1.81, 99% CI 1.25–2.61) required earlier surgical intervention. Furthermore, children treated with cyclosporine (HR 6.11, 99% CI 3.90–9.57) or tacrolimus (HR 3.66, 99% CI 1.60–8.39) also required earlier surgical management. Other symptoms, laboratory tests, and medical therapies were not predictive for need of surgery.

Conclusion:

Children with UC presenting with hypoalbuminemia, weight loss, a family history of UC, and those treated with calcineurin inhibitors frequently require restorative proctocolectomy for definitive treatment. Early identification and recognition of these factors should be used to shape treatment goals and initiate multidisciplinary care at the time of diagnosis.
Immunodiagnostic Methods: What Is Their Role in Areas of Low Endemicity?
Authors: Grenfell Rafaella Fortini Queiroz , Silva-Moraes Vanessa , Taboada Diana , de Mattos Ana Carolina Alves , de Castro Ana Karine Sarvel , Coelho Paulo Marcos Zech
Published: December 2012

WorldwideSchistosomiasis mansonicontinues to be a serious public health problem. Over the past decades, control programmes have made remarkable progress in reducingS. mansoniinfections to a relatively low level in Brazil and African countries. Endemic regions are currently circumscribed in certain core areas where reinfection and repeated chemotherapy are frequent and, consequently, are related to residents with low parasite load. At present, diagnosis is predominately a key step for final disease control although low endemicity area residents are hardly detected by most of the available assays. In this paper, we review the current status and efforts made aiming at the improvement of diagnostic tools forS. mansoniin low endemicity infections. The establishment of diagnostic assays—simple, affordable, sensitive, and specific for field diagnosis ofS. mansoni—is essential and should be given high priority.
Comparison of Infection and Urosepsis Rates of Ciprofloxacin and Ceftriaxone Prophylaxis before Percutaneous Nephrolithotomy: A Prospective and Randomised Study
Authors: Demirtas Abdullah , Yildirim Yunus Emre , Sofikerim Mustafa , Kaya Esma Gunduz , Akinsal Emre Can , Tombul Sevket Tolga , Ekmekcioglu Oguz , Gulmez Ibrahim
Published: December 2012

This study aimed at determining the choice and administration duration of ideal antibiotic prophylaxis before percutaneous nephrolithotomy (PNL) operation, a treatment modality for nephrolithiasis. The study included 90 patients who had no internal problem, yet had a negative urine culture and underwent a PNL operation. We compared infection rates between ciprofloxacin and ceftriaxone groups and their subgroups. The results showed no statistical difference between ciprofloxacin and ceftriaxone groups in terms of systemic inflammatory response syndrome (SIRS) (CIPP=0.306, CTX P=0.334. As a result of this study no statistical difference was observed between ciprofloxacin and ceftriaxone in terms of SIRS. It seems, however, reasonable to choose ceftriaxone, considering antibiotic sensitivity of microorganisms and detection of three cases accepted as urosepsis in the ciprofloxacin group. As there is no difference between short, and long-term prophylactic use of these antibiotics, preference of short-term prophylaxis for patients with no risk of infection will be important to avoid inappropriate antibiotic usage.
Enantiomerically pure and racemic dimethyl{N-[(2-oxidonaphthalen-1-yl-κO)methylidene]valinato-κ2N,O}tin(IV)
Authors: Böhme Uwe , Fels Sabine
Published: December 2012

The title compound, [Sn(CH3)2(C16H15NO3)], crystallized from one reaction batch with high enantiomeric excess as both a pure enantiomer and a racemate. TheSenantiomer crystallizes in the chiral space groupP32. The racemate crystallizes in the space groupP\overline{1} withRandSenantiomers in the crystal lattice; these form dimers about a crystallographic inversion centre.
A new polymorph of bis[2,6-bis(1H-benzimidazol-2-yl-κN3)pyridinido-κN]zinc(II)
Authors: Harvey Miguel Angel , Suarez Sebastián , Doctorovich Fabio , Baggio Ricardo
Published: December 2012

The title compound, [Zn(C19H12N5)2], crystallizes in the tetragonal space groupP43212, with the monomer residing on a twofold axis. The imidazole N-bound H atoms are disordered over the two positions, with refined occupancies of 0.59 (3) and 0.41 (3). The strong similarities to, and slight differences from, a reportedP42212 polymorph which has a 50% smaller unit-cell volume [Harvey, Baggio, Muñoz & Baggio (2003).Acta Cryst.C59, m283–m285], to which the present structure bears a group–subgroup relationship, are discussed.
Reduction of image noise in low tube current dynamic CT myocardial perfusion imaging using HYPR processing: A time‐attenuation curve analysis
Authors: Speidel Michael A. , Bateman Courtney L. , Tao Yinghua , Raval Amish N. , Hacker Timothy A. , Reeder Scott B. , Van Lysel Michael S.
Published: December 2012

Purpose:

This study describes a HighlY constrained backPRojection (HYPR) image processing method for the reduction of image noise in low tube current time‐resolved CT myocardial perfusion scans. The effect of this method on myocardial time‐attenuation curve noise and fidelity is evaluated in an animal model, using varying levels of tube current.

Methods:

CT perfusion scans of four healthy pigs (42–59 kg) were acquired at 500, 250, 100, 50, 25, and 10 mA on a 64‐slice scanner (4 cm axial coverage, 120 kV, 0.4 s/rotation, 50 s scan duration). For each scan a sequence of ECG‐gated images centered on 75% R‐R was reconstructed using short‐scan filtered back projection (FBP). HYPR processing was applied to the scans acquired at less than 500 mA using parameters designed to maintain the voxel noise level in the 500‐mA FBP images. The processing method generates a series of composite images by averaging over a sliding time window and then multiplies the composite images by weighting images to restore temporal fidelity to the image sequence. HYPR voxel noise relative to FBP noise was measured in AHA myocardial segment numbers 1, 5, 6, and 7 at each mA. To quantify the agreement between HYPR and FBP time‐attenuation curves (TACs), Bland‐Altman analysis was performed on TACs measured in full myocardial segments. The relative degree of TAC fluctuation in smaller subvolumes was quantified by calculating the root mean square deviation of a TAC about the gamma variate curve fit to the TAC data.

Results:

HYPR image sequences were produced using 2, 7, and 20 beat composite windows for the 250, 100, and 50 mA scans, respectively. At 25 and 10 mA, all available beats were used in the composite (41–60; average 50). A 7‐voxel‐wide 3D cubic filter kernel was used to form weighting images. The average ratio of HYPR voxel noise to 500‐mA FBP voxel noise was 1.06, 1.10, 0.97, 1.11, and 2.15 for HYPR scans at 250, 100, 50, 25, and 10 mA. The average limits‐of‐agreement between HYPR and FBP TAC values measured 0.02+/−0.91, 0.04+/−1.92, 0.19+/−1.59, 1.13+/−4.22, and 1.07+/−6.37 HU (mean difference +/−1.96 SD). The HYPR image subvolume that yielded a fixed level of TAC fluctuations was smaller, on average, than the FBP subvolume determined at the same mA.

Conclusions:

HYPR processing is a feasible method for generating low noise myocardial perfusion data from a low‐mA time‐resolved CT myocardial perfusion scan. The method is applicable to current clinical scanners and uses conventional image reconstructions as input data.
Prior listening exposure to a reverberant room improves open-set intelligibility of high-variability sentences
Authors: Srinivasan Nirmal Kumar , Zahorik Pavel
Published: December 2012

Previous studies have demonstrated that speech understanding in reverberant rooms improves when listeners are given prior exposure to the room. Results from these room-adaptation studies are limited, however, because they were conducted with materials that are not representative of the high acoustic variability observed in speech signals during everyday communication. Here, room adaptation effects were measured using an open-set speech corpus with high lexical and indexical variability and virtual auditory space techniques to simulate binaural listening in rooms. Room adaptation effects of comparable magnitude to previous studies were observed, suggesting general importance for facilitating speech intelligibility in reverberation.
Multivariate dissemination of species relationships for use in marine spatial planning
Authors: Jordaan Adrian , Frisk Michael G. , Incze Lewis S. , Wolff Nicholas H. , Hamlin Lindsay , Chen Yong
Published: December 2012

Employing ecological approaches to fisheries management or comprehensive marine spatial planning requires that species assemblage structure be accounted for. Fish and invertebrate spatial distributions from the National Marine Fisheries Service demersal trawl survey conducted in the Georges Bank – Gulf of Maine region were analyzed by bootstrapped principal component analysis (PCABtsp) and normal PCA (PCANrml). PCABtsp produced confidence limits for eigenvalue stopping rules and for eigenvectors to identify significantly correlated species. Stopping rules identified the first six principal components (PCs) as relevant. Initially, summer and fall survey data from 1963 to 2006 were analyzed, but high eigenvector variation led to reductions in the species and time series used. Confidence interval variation was achieved through removal of highly migratory species and restriction of the time series. PC scores were mapped using inverse distance weighted interpolation to reveal multispecies spatial arrangements. Core areas of species groupings and overlapping zones of higher diversity can be delineated and, even under high fishing pressure with large compositional changes, the assemblages maintained robust spatial organization. This spatial organization could be employed to protect appropriate species groups and minimize bycatch. Careful analysis of survey data can help ensure area-based management schemes are consistent with ecological scales.
Oxidative-stress-induced epigenetic changes in chronic diabetic complications
Authors: Feng Biao , Ruiz Michael Anthony , Chakrabarti Subrata
Published: December 2012

Oxidative stress plays an important role in the development and progression of chronic diabetic complications. Diabetes causes mitochondrial superoxide overproduction in the endothelial cells of both large and small vessels. This increased superoxide production causes the activation of several signal pathways involved in the pathogenesis of chronic complications. In particular, endothelial cells are major targets of glucose-induced oxidative damage in the target organs. Oxidative stress activates cellular signaling pathways and transcription factors in endothelial cells including protein kinase C (PKC), c-Jun-N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), forkhead box O (FOXO), and nuclear factor kappa-B (NF-κB). Oxidative stress also causes DNA damage and activates DNA nucleotide excision repair enzymes including the excision repair cross complimenting 1(ERCC1), ERCC4, and poly(ADP-ribose) polymerase (PARP). Augmented production of histone acetyltransferase p300, and alterations of histone deacetylases, including class III deacetylases sirtuins, are also involved in this process. Recent research has found that small noncoding RNAs, like microRNA, are a new kind of regulator associated with chronic diabetic complications. There are extensive and complicated interactions and among these molecules. The purpose of this review is to demonstrate the role of oxidative stress in the development of diabetic complications in relation to epigenetic changes such as acetylation and microRNA alterations.
COARSE-GRAINED CELLULAR AUTOMATON FOR TRAFFIC SYSTEMS
Authors: KRAWCZYK MAŁGORZATA J. , KUŁAKOWSKI KRZYSZTOF
Published: December 2012

A coarse-grained cellular automaton is proposed to simulate traffic systems. There, cells represent road sections. A cell can be in two states: jammed or passable. Numerical calculations are performed for a piece of square lattice with open boundary conditions, for the same piece with some cells removed and for a map of a small city. The results indicate the presence of a phase transition in the parameter space, between two macroscopic phases: passable and jammed. The results are supplemented by exact calculations of the stationary probabilities of states for the related Kripke structure constructed for the traffic system. There, the symmetry-based reduction of the state space allows to partially reduce the computational limitations of the numerical method.
COLLABORATIVE ENVIRONMENTAL MANAGEMENT: A REVIEW OF THE LITERATURE
Authors: BENCHEKROUN HASSAN , LONG NGO VAN
Published: December 2012

This paper reviews the game-theoretic literature on collaborative environmental management. It begins with a survey of static models of international environmental agreements (IEAs), comparing their underlying assumptions and their results. Extensions of the basic model to allow for both adaptation and mitigation, and for transfer payments are considered. We review the various concepts of coalitional stability, such as internal and external stability and far-sighted stability in the noncooperative strand, and the gamma core concept in the cooperative strand. The network approach to cooperation building is reviewed. We next survey extensions of IEA theory to dynamic models with stock pollutants, allowing membership status to change over time. Finally, dynamic cooperative games of pollution with transfer payments that take place over time are discussed.
LOCAL MICROSTRUCTURE EVOLUTION OF BISMUTH SODIUM TITANATE-BASED LEAD-FREE PIEZOELECTRIC SYSTEMS ACROSS THE MORPHOTROPIC PHASE BOUNDARY REGION
Authors: LIU YUN , WITHERS RAY L. , WANG JIAN , NORÉN LASSE , STUDER ANDREW J. , LI YONGXIANG
Published: December 2012

Morphotropic phase boundary (MPB) containing piezoelectric systems generally exhibit enhanced piezoelectric performance at compositions within, or close to, the MPB region. The mechanism/s underlying such enhancement, however, are still contentious due to complex micro/nanostructure and apparently inherent local structural variability associated with octahedral tilt disorder/platelet precipitates in such piezoelectric materials. This paper reviews some recent structural analysis results from Bi0.5Na0.5TiO3 (BNT) and other binary, lead-free, piezoelectric materials systems derived from it via electron diffraction and in situ neutron diffraction. The results suggest that intrinsically existing local microstructure (LMS) in BNT essentially continues across the MPB region. The LMS, originating from inherent octahedral tilt disorder, is strongly temperature-, electric field-, pressure- and chemical composition-dependent, and may help to explain a series of phenomena observed in BNT-based binary materials systems, including the enhanced piezoelectric effect in the region of the MPB.
DIELECTRIC AND PIEZOELECTRIC PROPERTIES OF LEAD-FREE (Bi0.5Na0.5)0.94Ba0.06TiO3 + x%Ce2O3 + y%La2O3 + z%Y2O3 COMPOUNDS SYNTHESIZED BY SOL–GEL TECHNIQUE
Authors: CHAOUCHI A. , SAIDI M. , D'ASTORG S. , RGUITI M. , COURTOIS C.
Published: December 2012

( Bi 0.5 Na 0.5)0.94 Ba 0.06 TiO 3 + x% Ce 2 O 3 + y% La 2 O 3 + z% Y 2 O 3 compounds (named BNT–BT– x/y/z) were synthesized by a sol–gel technique, for (x,y,z) = (0,0,0), (0.25, 0.25, 0.25), (0.25, 0.5, 0.5), (0.5, 0.25, 0.25) and (0.5, 0.5, 0.25). The structural variation according to the different system compositions is investigated by X-ray diffraction analyses. The results shows that the addition of Ce2O3 , La2O3 or Y2O3 in BNT–BT system, do not modify the crystalline structure, and a rhombohedral–tetragonal morphotropic phase boundary is maintained for different dopant addition. The BNT–BT–x/y/z-based ceramics sintered at relatively low temperature (1100°C) exhibit a good densification ratio. The optimum dielectric and piezoelectric properties are obtained with the BNT–BT–0.5/0.25/0.25 composition. High dielectric properties at room temperature (εr > 1000) and low dielectric losses (tan δ < 4 × 10-2) are obtained for this composition. This compound exhibits a piezoelectric constant d33 of 95 pC/N, a good polarization behavior is observed with high remanent polarization Pr of 9.21 μC/cm2 and low value coercitive field Ec of 2.66 kV/mm.
Designing and developing an open source medical informatics module
Authors: Kasthurirathne Suranga Nath
Published: December 2012

Lessons learned in planning and managing a development sprint to build a flexible, open source HL7 query service while successfully collaborating with diverse stakeholders and volunteers.
Online education for developing contexts
Authors: Younos Arjumand
Published: December 2012

A personal experience with academia in Pakistan leads to using online education initiatives as an opportunity for massive improvement.
ICTD at the University of California Berkeley
Authors: Sambasivan Nithya
Published: December 2012

Several leading researchers from UC Berkeley share their personal research stories, opinions about the field, and advice for students interested in ICTD.
A social scientist sits among ICTD workers
Authors: Nair Sumitra
Published: December 2012

Reflections on the place of qualitative methods in ICTD work.
Lessons and opportunities in ICT4D
Authors: Merritt Samantha
Published: December 2012

If ICT4D aims to effectively answer the grand challenges it faces, young researchers, in both design and computer science, must be aware of the consequences of how terminology frames this field, be willing to critique and adjust research methods and attend to neglected, challenging concepts.
Exploiting and Maintaining Materialized Views for XML Keyword Queries
Authors: Liu Ziyang , Chen Yi
Published: December 2012

Keyword query is a user-friendly mechanism for retrieving useful information from XML data in Web and scientific applications. Inspired by the performance benefits of exploiting materialized views when processing structured queries, we investigate the feasibility and present a general framework for answering XML keyword queries using materialized views. Then we develop an XML keyword search engine that leverages materialized views for query evaluation and maintains materialized views incrementally upon XML data update. Experimental evaluation demonstrates the significance and efficiency of our approach.
POWER-MODES
Authors: Krieg Armin , Grinschgl Johannes , Steger Christian , Weiss Reinhold , Bock Holger , Haid Josef
Published: December 2012

Innovation cycles have been shortening significantly during the last years. This process puts tremendous pressure on designers of embedded systems for security-or reliability-critical applications. Eventual design problems not detected during design time can lead to lost money, confidentiality, or even loss of life in extreme cases. Therefore it is of vital importance to evaluate a new system for its robustness against intentionally and random induced operational faults. Currently this is generally done using extensive simulation runs using gate-level models or direct measurements on the finished silicon product. These approaches either need a significant amount of time and computational power for these simulations or rely on existing product samples.

This article presents a novel system evaluation platform using
power emulation
and
fault injection
techniques to provide an additional tool for developers of embedded systems in security-and reliability-critical fields. Faults are emulated using state-of-the-art fault injection methods and a flexible pattern representation approach. The resulting effects of these faults on the power consumption profile are estimated using state-of-the-art power emulation hardware. A modular system augmentation approach provides emulation flexibility similar to fault simulation implementations. The platform enables the efficient evaluation of new hardware or software implementations of critical security or reliability solutions at an early development phase.
The Equine Endometrial Cup Reaction: A Fetomaternal Signal of Significance
Authors: Antczak D.F. , de Mestre Amanda M. , Wilsher Sandra , Allen W.R.
Published: December 2012

A remarkable feature of equine pregnancy is the development of the invasive trophoblast of the chorionic girdle and its formation of the gonadotrophin-secreting endometrial cup cells in early gestation. The details of this process have been revealed only slowly over the past century, since the first description of the endometrial cups in 1912. This centennial presents an opportunity to review the characteristics of the cells and molecules involved in this early, critical phase of placentation in the mare. The invasiveness of the chorionic girdle trophoblast appears to represent an atavistic attribute more commonly associated with the hemochorial placentae of primates and rodents but not with the more recently derived epitheliochorial placentae of the odd-toed ungulates. The nature of and raison d’être for the strong fetal signals transmitted to the mare by the endometrial cup reaction, and her responses to these messages, are the subject of the present review.
Evidence-Based Psychological Treatments: An Update and a Way Forward
Authors: Barlow David H. , Bullis Jacqueline R. , Comer Jonathan S. , Ametaj Amantia A.
Published: December 2012

Enormous progress in the field of clinical science has been made over the past 50 years, with advances in our understanding of psychopathology and more sophisticated research methodology leading to the development of more efficacious psychological treatments for a variety of behavioral disorders. Despite these advances, the public health impact of well-established psychological treatments is less than it should be. After an overview of the current status of the field, we identify barriers that must be overcome to maximize the public health impact and propose that to breach these barriers we must (a) augment the efficacy of treatments, (b) broaden the impact of treatments across diagnoses to include temperamental variables, (c) attend more closely to mechanisms of action of treatments, and (d) learn the best methods for disseminating and implementing psychological interventions. We conclude by proposing new directions in both research and clinical practice to accomplish these goals.