bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in caregiver burden and health‐related quality of life of informal caregivers of older people with Dementia: evidence from the European RightTimePlaceCare prospective cohort study
Authors: Bleijlevens Michel H.C. , Stolt Minna , Stephan Astrid , Zabalegui Adelaida , Saks Kai , Sutcliffe Caroline , Lethin Connie , Soto Maria E. , Zwakhalen Sandra M.G. ,   the RightTimePlaceCare Consortium
Published: November 2014

Aims

To describe differences in caregiver burden and health‐related quality of life of informal caregivers of people with dementia in eight European countries and assess changes after transition from home to institutional long‐term care.

Background

Country differences in the experience of burden and health‐related quality of life are rarely described.

Design

Prospective cohort study.

Methods

Data on burden and health‐related quality of life were collected at baseline (conducted between November 2010–April 2012) and follow‐up (after 3 months) using face‐to‐face interviews. Two groups of informal caregivers included those: (1) of people with dementia recently admitted to institutional long‐term care facilities; and those (2) of people with dementia receiving home care. Statistical analyses focused on descriptive comparisons between groups and countries.

Results

Informal caregivers of about 2014 were interviewed. Informal caregivers of people with dementia at home experienced more burden compared with informal caregivers of recently institutionalised people with dementia. Almost no differences in health‐related quality of life were found between groups. Large differences between countries on outcomes were found. Informal caregivers of people with dementia who made the transition to an institutional long‐term care facility experienced a statistically significant decrease in burden and psychological distress at follow‐up.

Conclusion

Cross‐country differences may be related to differences in health and social care systems. Taking this into account, informal caregiver interventions need to be tailored to (country specific) contexts and (individual) needs. Findings highlight the positive impact of admission to institutional long‐term care on informal caregiver well‐being.
Three‐Dimensional Optoacoustic Monitoring of Lesion Formation in Real Time During Radiofrequency Catheter Ablation
Authors: PANG GENNY A. , BAY ERWIN , DEÁN‐BEN X. LUÍS , RAZANSKY DANIEL
Published: November 2014

Real‐Time Optoacoustic Monitoring of RF Ablation

Introduction

Due to lack of reliable imaging contrast from catheter radiofrequency ablation (RFA) lesions, the vast majority of current procedures rely on indirect indicators of ablation activity, resulting in a significant number of arrhythmia reoccurrences after RFA procedures and the need for repeat surgeries. The objective of this work is to develop an accurate method for on‐the‐fly assessment of the durability and size of lesions formed during RFA procedures.

Method and Results

Radiofrequency catheter ablation on freshly excised porcine ventricular myocardial tissue was optoacoustically monitored by means of pulsed‐laser illumination in the near‐infrared spectrum. Lesion formation during ablation was captured at a rate of 10 Hz with a 256‐detector optoacoustic imaging probe. Postablated samples were imaged using multispectral excitation in the wavelength range 740–860 nm to determine the lesion contrast spectrum. Tomographic reconstruction was performed to generate 3‐dimensional images of the lesions, which were compared to photographs depicting the final ablated tissue samples. Video‐rate 3‐dimensional tomographic reconstructions depict formation of the lesion with high contrast and spatial resolution. The size and geometry of the lesion was shown to be in excellent agreement with the histological examinations. The wavelength dependence of the lesion contrast shows a contrast peak near 780 nm.

Conclusion

Deep‐tissue 3‐dimensional monitoring of RFA lesion generation in real time was demonstrated for the first time in this work. The results suggest the potential of optoacoustic monitoring for providing critical feedback on lesion position and size during radiofrequency catheter ablation, improving safety and efficacy of these treatments.
Stateless Euro: The Euro Crisis and the Revenge of the Chartalist Theory of Money
Authors: Otero‐Iglesias Miguel
Published: November 2014

This article argues that contemporary optimum currency area (OCA) theory is limited in its capacity to understand the euro crisis because it emanates from the commodity‐exchange theory of money and therefore under‐estimates the necessity of a (sovereign) political authority to underpin any given monetary space. An alternative conception of money, based on the chartalist approach, is more useful for grasping the fundamental weaknesses in European monetary union (EMU). Overall, the argument is that EMU will remain a fragile edifice as long as the eurozone does not create a centralized and legitimate political authority capable of taxing eurozone citizens at the European level. In order for this to be achieved, France and Germany need to resolve the ‘game of chicken’ in which they are entangled and strengthen their co‐operative efforts towards creating a European sovereign.
The foundations of next generation attention‐deficit/hyperactivity disorder neuropsychology: building on progress during the last 30 years
Authors: Sonuga‐Barke Edmund J.S. , Coghill David
Published: November 2014

Preamble

In the JCPP Virtual Issues series, editors are invited to look back over our catalogue and identify papers that illustrate the journal's influence on the emergence of specific fields within the broader domains of child psychology and psychiatry. This virtual issue1,2 focuses specifically on the last 30 years of attention‐deficit/hyperactivity disorder (ADHD) research. While the journal has published papers on nearly every aspect of this condition our initial scoping exercise highlighted a particular impact in two areas: neuropsychology and behavioural genetics. Here we address the JCPPs contribution to contemporary understanding of the neuropsychology of ADHD. We are planning to put together a further Virtual Issue on behavioural genetics in the near future.
Arctic skate Amblyraja hyperborea preys on remarkably large glacial eelpouts Lycodes frigidus
Authors: Byrkjedal I. , Christiansen J. S. , Karamushko O. V. , Langhelle G. , Lynghammar A.
Published: November 2014

During scientific surveys on the continental slopes north‐west of Spitsbergen and off north‐east Greenland (c. 600 and 1000 m depths), two female Arctic skates Amblyraja hyperborea were caught while swallowing extraordinary large individuals of glacial eelpout Lycodes frigidus. The total length (LT) of the prey constituted 50 and 80% of the LT of the skates, which reveal that A. hyperborea are capable predators of fishes of surprisingly large relative size.
Aesthetic dermatology and emotional well‐being questionnaire
Authors: Martínez‐González M. Covadonga , Martínez‐González Raquel‐Amaya , Guerra‐Tapia Aurora
Published: November 2014

Background

In recent years, there has been a great development of esthetic dermatology as a subspecialty of dermatology. It is important to know to which extent the general population regard this branch of medical surgical specialty as being of interest and contributing to emotional well‐being.

Objective

To analyze the technical features of a questionnaire which has been designed to reflect such perception of the general population about esthetic dermatology and its contribution to emotional well‐being.

Material and method

Production and psychometric analysis of a self‐filled in questionnaire in relation to esthetic dermatology and emotional well‐being (DEBIE). This questionnaire is made of 57 items and has been applied to a sample of 770 people within the general population. The drawing‐up process of the questionnaire is described to provide content validity. Items analysis was carried out together with exploratory and confirmatory factor analysis to assess the structure and construct validity of the tool. The extent of internal consistency (reliability) and concurrent validity has also been verified.

Results

DEBIE questionnaire (Spanish acronym for Aesthetic Dermatology and Emotional Well‐being) revolves around six factors explaining 53.91% of the variance; there is a high level of internal consistency (Cronbach's α 0.90) and reasonable criterion validity.

Conclusions

DEBIE questionnaire brings together adequate psychometric properties that can be applied to assess the perception that the general population have in relation to esthetic dermatology and its contribution to their emotional well‐being.
Assessment of the efficacy and tolerance of a new combination of retinoids and depigmenting agents in the treatment of melasma
Authors: Truchuelo Maria Teresa , Jiménez Natalia , Jaén Pedro
Published: November 2014

Background

Melasma is a dermatosis with significant repercussions on patients' quality of life, and there is currently no standard treatment. Hydroquinone is deemed the treatment of choice, but its safety has been questioned in certain cases.

Aims

To determine the efficacy and safety of a new combination of retinoids in the improvement of melasma.

Patients/Methods

Prospective, double‐blind, vehicle‐controlled, and randomized study in 30 patients with melasma. The product was applied on one side of the face and the vehicle on the other, twice daily during 3 months. Standardized photographs were taken using RBX technology on the three visits (basal, at one and a half months and at 3 months). The main variable to determine the efficacy was the improvement of the hemifacial Melasma Area Severity Index (MASI). Other variables were determined such as improvement perceived by the investigator, improvement perceived by the patient, impact on quality of life or side effects.

Results

The MASI improvement at 3 months of treatment was significant on the treated side vs. the vehicle side, reaching an improvement of 70%, which is comparable to the percentage of improvement described with hydroquinone. No notable side effects were detected, in spite of a significant percentage of patients included in the study citing a history that could be compatible with sensitive skin.

Conclusions

This new combination of retinoids and depigmenting agents proved to be effective and safe in the treatment of melasma.
Review of the safety profile for microfocused ultrasound with visualization
Authors: Hitchcock Thomas M , Dobke Marek K
Published: November 2014

The Safety of Microfocused Ultrasound with Visualization (MFU‐V) has been well established in both controlled clinical studies and in clinical use, showing only mild and transient anticipated side effects and only rare unanticipated adverse events (AEs). This publication discusses the safety profile of MFU‐V based on data from a variety of sources. Reports of side effects and AEs were obtained from published peer‐reviewed medical literature, clinical studies, in‐market use reports (AEs reported to the manufacturer), and retrospective chart reviews of patient treatments. Events that were typical included tenderness, redness, and slight edema. Rare events included bruising, welting, and nerve‐related effects (paresthesia and paresis). Rare incidence of surface thermal effects was seen in some cases where improper technique was used. In all cases where the device was uses properly, the safety events reported tended to be transient, mild in nature, and resolved without sequelae. In general, unexpected and rare AEs could be attributed to incorrect treatment technique or classified as unrelated to MFU‐V treatment. Side effects that do occur are generally mild and transient in nature. MFU‐V consistently allows for safe treatment when correct treatment technique is used.
Nail changes and disorders in elderly Egyptians
Authors: El‐Domyati Moetaz , Abdel‐Wahab Hossam , Abdel‐Azim Eman
Published: November 2014

Background

The nail unit is an important part of cosmetic appearance of an individual. Older people are at an increased risk of nail alterations, including normal age‐related changes and disorders that more commonly affect this specific population.

Objectives

To identify and evaluate the age‐related nail changes and disorders in Egyptian elderly people both clinically and histopathologically.

Patients/Methods

A total of 400 adult subjects, not complaining from any dermatological disease, were included in the present study; half of them were elderly of 60 years and above (elderly group). Meanwhile, the other half served as a control group with younger ages. Full history taking, general and local examinations as well as nail biopsies were performed from selected cases with age‐related nail changes and disorders.

Results

Nail changes were significantly (P < 0.05) more common in old age group (88%) compared to control subjects (39%). The commonest age‐related nail changes noticed were pale, dull, opaque, and lusterless nails (73%); brittle nails (67.5%); decreased lunula visibility (49%); and onychorrhexis (45.5%). They showed highly significant increase (P < 0.001) when compared with control group.

Conclusions

The prevalence of nail changes and disorders has increased among elderly patients although they are frequently overlooked by health care providers. Dermatologist should be aware about various nail changes related to aging and those associated with other dermatoses or systemic diseases. Histopathologic picture can enhance the accuracy of clinical diagnosis of various nail changes and disorders.
STABILISATION POLICY, RATIONAL EXPECTATIONS AND PRICE‐LEVEL VERSUS INFLATION TARGETING: A SURVEY
Authors: Hatcher Michael , Minford Patrick
Published: November 2014

We survey literature comparing inflation targeting (IT) and price‐level targeting (PT) as macroeconomic stabilisation policies. Our focus is on New Keynesian models and areas that have seen significant developments since Ambler's (2009, Price‐level targeting and stabilisation policy: a survey. Journal of Economic Surveys 23(5): 974–997) survey: optimal monetary policy; the zero lower bound; financial frictions and transition costs of adopting a PT regime. Ambler's conclusion that PT improves social welfare in New Keynesian models is fairly robust, but we note an interesting split in the literature: PT consistently outperforms IT in models where policymakers commit to simple Taylor‐type rules, but results in favour of PT when policymakers minimise loss functions are overturned with small deviations from the baseline model. Since the beneficial effects of PT appear to hang on the joint assumption that agents are rational and the economy New Keynesian, we discuss survey and experimental evidence on rational expectations and the applied macro literature on the empirical performance of New Keynesian models. Overall, the evidence is not clear‐cut, but we note that New Keynesian models can pass formal statistical tests against macro data and that models with rational expectations outperform those with behavioural expectations (i.e. heuristics) in direct statistical tests. We therefore argue that policymakers should continue to pay attention to PT.
GLOBAL VALUE CHAINS: A SURVEY OF DRIVERS AND MEASURES
Authors: Amador João , Cabral Sónia
Published: November 2014

Global value chains (GVCs) emerged as the paradigm for the international organization of production. For most goods and services production is nowadays vertically fragmented across different countries and this reality gave rise to a significant new strand of research in international trade. This article starts by discussing the major driving forces of GVCs in recent decades. Next, it surveys the main measures of GVCs, accounting for their different scopes and required data sets. The article highlights the timing of the contributions to the literature, signalling their sequential nature and the trend toward more accurate and data‐demanding indicators.
Technological Performance and Alliances Over the Industry Life Cycle: Evidence from the ASIC Industry
Authors: Vanhaverbeke Wim , Belderbos Réne , Duysters Geert , Beerkens Bonnie
Published: November 2014

Technology development in firms is frequently based on a combination of internal and external technological learning. Consequently, firms need to develop both technological capital (a patent portfolio) and alliance capital (a portfolio of technology alliances). This paper examines the relationship between technological capital, alliance capital, and their joint impact on the technological performance of firms, with an application to the application‐specific integrated circuit industry. We find that positive marginal returns to alliance capital are decreasing at higher levels of alliance capital. Technological capital and alliance capital can either augment or reduce each others' influence on innovation performance depending on the stage of the technology life cycle in the industry. A reinforcing relationship related to absorptive capacity requirements and technological uncertainty is present in early stages, while technology leakage and market competition effects render the combination of high levels of technological and alliance capital counterproductive in later stages of the technology life cycle.
Implementation of renal key performance indicators: Promoting improved clinical practice
Authors: Toussaint Nigel D , McMahon Lawrence P , Dowling Gregory , Soding Jenny , Safe Maria , Knight Richard , Fair Kathleen , Linehan Leanne , Walker Rowan G , Power David A
Published: November 2014

Aim

In the Australian state of Victoria, the Renal Health Clinical Network (RHCN) of the Department of Health Victoria established a Renal Key Performance Indicator (KPI) Working Group in 2011. The group developed four KPIs related to chronic kidney disease and dialysis. A transplant working group of the RHCN developed two additional KPIs. The aim was to develop clinical indicators to measure performance of renal services to drive service improvement.

Methods

A data collection and benchmarking programme was established, with data provided monthly to the Department using a purpose‐designed website portal. The KPI Working Group is responsible for analysing data each quarter and ensuring indicators remain accurate and relevant. Each indicator has clear definitions and targets, and assess (i) patient education, (ii) timely creation of vascular access for haemodialysis, (iii) proportion of patients dialysing at home, (iv) incidence of dialysis‐related peritonitis, (v) incidence of pre‐emptive renal transplantation, and (vi) timely listing of patients for deceased donor transplantation.

Results

Most KPIs have demonstrated improved performance over time with limited gains notably in two: the proportion of patients dialysing at home (KPI 3) and timely listing patients for transplantation (KPI 6).

Conclusion

KPI implementation has been established in Victoria for 2 years, providing performance data without additional funding. The six Victorian KPIs are measurable, relevant and modifiable, and implementation relies on enthusiasm and goodwill of physicians and nurses involved in collecting data. The KPIs require further evaluation, but adoption of a similar programme by other jurisdictions could lead to improved national outcomes.
Changes in photo‐thermal sensitivity of widely grown Chinese soybean cultivars due to a century of genetic improvement
Authors: Wang Caijie , Wu Tingting , Wu Cunxiang , Jiang Bingjun , Sun Shi , Hou Wensheng , Han Tianfu
Published: November 2014

Photo‐thermal sensitivity is a crucial factor that determines the phenology, adaptation and yield production of soybean. However, the change of photo‐thermal sensitivity due to a long process of soybean breeding remains unknown. To better understand this unique characteristic of soybean, we sought to evaluate the genetic improvement in photo‐thermal sensitivity of 63 widely grown soybean cultivars, spanning 83 years of breeding (1923–2006), from four main subregions in China. Days to the first flower was measured, and photo‐thermal sensitivity was calculated. We found that photo‐thermal sensitivity of cultivars in the northern Heilongjiang (NH) region showed a quadratic relationship with year of release. However, photo‐thermal sensitivity was negatively correlated with year of release in the Huang‐Huai‐Hai Valley (HH) region. There were no significant trends of change found in the mid‐southern Heilongjiang (MSH) and Jilin and Liaoning (JL) regions. The changing trend of photo‐thermal sensitivity was relatively consistent across different environments, particularly in the NH and HH regions (photoperiod, temperature or planting year). The insensitivity to photo‐thermal condition provided an advantage for modern cultivars to achieve broad adaptation.
Variability and selection of verticillium wilt resistant genotypes in cultivated olive and in the Olea genus
Authors: Trapero C. , Rallo L. , López‐Escudero F. J. , Barranco D. , Díez C. M.
Published: November 2014

Developing verticillium wilt resistant genotypes is currently a major objective in olive breeding. In this study, 6017 genotypes derived from 48 crosses obtained by open pollination and crosses between olive cultivars, wild olive genotypes and other Olea species and Olea europaea subspecies were individually evaluated for verticillium wilt resistance. More than 800 genotypes were identified as resistant to the disease based on the absence of symptoms. High genetic variability and wide segregation in resistance were observed. The inheritance of resistance was studied, and the best parents and crosses to breed resistant genotypes were identified. According to the results, verticillium wilt resistance in olive appears to be a quantitative trait. The results obtained by comparing the level of resistance between different crosses as well as by estimating heritability suggest that it is possible to breed for verticillium wilt resistance in olive.
Modeling Users' Behavior for Testing the Performance of a Web Map Tile Service
Authors: Guan Xuefeng , Cheng Bo , Song Aihong , Wu Huayi
Published: November 2014

Web Map Tile Services (WMTS) are widely used in many fields to quickly and efficiently visualize geospatial data for public use. To ensure that a WMTS can successfully fulfill users' expectations and requirements, the performance of a service must be measured to track latencies and bottlenecks that may downgrade the overall quality of service (QoS). Traditional synthetic workloads used to evaluate WMTS applications are usually generated by repeated static URLs, through randomized requests, or by an access log replay. These three methods do not take request characteristics and users' behaviors into consideration, while access logs are not available for systems still under development. Thus, the evaluation outcomes obtained by these methods cannot represent the real performance of online WMTS applications.

In this article a new workload model named HELP (Hotspot/think‐timE/Length/Path) is proposed to measure the performance of a prototype WMTS. This model describes how users browse a WMTS map and statistically characterizes complete map navigation behaviors. Then, the HELP model is implemented in HP LoadRunner and used to generate a synthetic workload to evaluate the target WMTS. Experimental results illustrate that the performance representation of the HELP workload is more accurate than that of the other two models, and how a bottleneck in the target system was identified. Additional statistical analysis of request logs and “hotspots” visualizations further validate the proposed HELP workload.
Spatial Information Divergence: Using Global and Local Indices to Compare Geographical Masks Applied to Crime Data
Authors: Kounadi Ourania , Leitner Michael
Published: November 2014

Advances in Geographic Information Science (GISc) and the increasing availability of location data have facilitated the dissemination of crime data and the abundance of crime mapping websites. However, data holders acknowledge that when releasing sensitive crime data there is a risk of compromising the victims' privacy. Hence, protection methodologies are primarily applied to the data to ensure that individual privacy is not violated. This article addresses one group of location protection methodologies, namely geographical masks that are applicable for crime data representations. The purpose is to identify which mask is the most appropriate for crime incident visualizations. A global divergence index (GDi) and a local divergence index (LDi) are developed to compare the effects that these masks have on the original crime point pattern. The indices calculate how dissimilar the spatial information of the masked data is from the spatial information of the original data in regards to the information obtained via spatial crime analysis. The results of the analysis show that the variable radius mask and the donut geomask should be primarily used for crime representations as they produce less spatial information divergence of the original crime point pattern than the alternative local random rotation mask and circular mask.
Antibiotic failure in a renal transplant patient with Rhodococcus equi infection: an indication for surgical lobectomy
Authors: Ursales A. , Klein J.A. , Beal S.G. , Koch M. , Clement‐Kruzel S. , Melton L.B. , Spak C.W.
Published: November 2014

Rhodococcus equi is an animal pathogen that causes infrequent but challenging infections in immunocompromised individuals, few of which have been described in solid organ transplant recipients. Common clinical presentations include indolent cough, fever, and dyspnea, with necrotizing pneumonia and cavitation. We report a case of a dense right upper lung pneumonia with resultant R. equi bacteremia in a renal transplant recipient. Our patient initially responded to antibiotic treatment with resolution of bacteremia and clinical recovery, followed by interval progression in her right upper lobe consolidation on follow‐up computed tomography scans. She underwent lobectomy for definitive therapy with resolution of symptoms. Lobectomy can be utilized in isolated infection after antibiotic failure with excellent clinical outcomes.
Clinical, histopathological and immunohistochemical characterization of a novel equine ocular disorder: heterochromic iridocyclitis with secondary keratitis in adult horses
Authors: Pinto Nelson I. , McMullen Richard J. , Linder Keith E. , Cullen John M. , Gilger Brian C.
Published: November 2014

Objective

To describe the clinical, histopathologic and immunohistochemical characteristics of an equine ocular inflammatory disease resulting in anterior uveitis and corneal endothelial inflammation associated with iris pigment dispersion and retrocorneal fibrous membrane (RFM) formation.

Design

Retrospective study.

Animals studied

Sixteen horses with evidence of pigmented keratic precipitates (KPs), corneal edema, and/or iris depigmentation. Information collected from the medical records included signalment, clinical signs, prereferral treatment duration and response to therapy, ophthalmic examination findings, postreferral treatment, response to therapy, and outcome.

Results

Twenty‐one eyes from 16 horses were affected. Age ranged between 9 and 25 years (Average 16.1 years). Blepharospasm, epiphora, and/or corneal opacification were the first clinical signs noted. At the time of referral pigmented KPs, corneal edema, iridal depigmentation, and retrocorneal membranes were commonly seen. Treatment included topical and/or systemic anti‐inflammatories and antibiotics with variable response. Reduction or cessation of anti‐inflammatory therapy resulted in worsening of clinical signs and disease progression. Eight eyes ultimately required enucleation. Histopathology changes include iridal pigment loss and dispersion,RFMformation, and keratitis. Variable degrees of lymphoplasmacytic inflammation were dominated by T‐cells within the corneal stroma,RFM, iris, and ciliary body with occasional multinucleated giant cells.

Conclusions

Heterochromic iridocyclitis with secondary keratitis (HIK) is characterized by uveal inflammation with pigment dispersion and suspected corneal endothelial dysfunction. Horses being treated forHIKrequire diligent and frequent follow‐up examinations in combination with aggressive local immune suppression to control the disease. However,HIKmay not respond to therapy and enucleation may ultimately be required to ensure the horse's comfort.
Realization of quantum group Poisson boundaries as crossed products
Authors: Kalantar Mehrdad , Neufang Matthias , Ruan Zhong‐Jin
Published: November 2014

For a locally compact quantum group , consider the convolution action of a quantum probability measure on . As shown by Junge–Neufang–Ruan, this action has a natural extension to a Markov map on . We prove that the Poisson boundary of the latter can be realized concretely as the von Neumann crossed product of the Poisson boundary associated with under the action of induced by the coproduct. This yields an affirmative answer, for general locally compact quantum groups, to a problem raised by Izumi in the commutative situation, in which he settled the discrete case, and unifies earlier results of Jaworski, Neufang and Runde.
A Thermal Stress Mitigation Technique for Local Postweld Heat Treatment of Welds in Pressure Vessels
Authors: Nie Chunge , Dong Pingsha
Published: November 2014

This paper introduces a novel method for effectively mitigating high thermal stresses caused during local postweld heat treatment (PWHT) of welds in pressure vessels on which traditional heating method such as bull's eye heating arrangement has been proven difficult in meeting Code requirements for avoiding “harmful” temperature gradients. The method involves the use of a secondary heat band (SHB) that strategically positioned at some distance away from primary PWHT heat band (HB) in terms of vessel characteristic length parameter Rt, where R is vessel radius and t wall thickness. The basic principles associated with the SHB based technique are first demonstrated on a simple straight pipe girth weld configuration. Then, applications for treating nozzle welds in more complex spherical vessel, cylindrical vessel, and at end of cylindrical vessel are presented. Finally, a set of recommended guidelines are provided for defining both the SHB size and location for performing local PWHT on welds in three major nozzle/vessel weld configurations.
Unsteady Investigation on Tip Flow Field and Rotating Stall in Counter-Rotating Axial Compressor
Authors: Gao Limin , Li Ruiyu , Miao Fang , Cai Yutong
Published: November 2014

Contra-rotating axial compressor/fan (CRAC) is a promising technology to meet the future goals aircraft industry. Massive time accurate simulations are performed to investigate rotating stall in CRAC containing two counter-rotating rotors. Particularly, the back pressure increasing with a very small step to avoid missing flow field transition from stability to instability. Due to the canceling of the stator, the instability of downstream rotor is more stronger. The present studies mostly focus on the downstream rotor. The tip leakage flow field is analyzed in detail under near stall condition, which indicates that a secondary leakage flow plays an important role in the unsteadiness of CRAC's unsteady flow field. The frequency analysis in the tip clearance of downstream rotor under multiple near stall conditions captured the transition of the second harmonic frequency which can be used as stall inception signal. Moreover, the rotating stall onset process in real CRAC is simulated on the numerical stall.
Model Analysis of Syngas Combustion and Emissions for a Micro Gas Turbine
Authors: Liu Chi-Rong , Shih Hsin-Yi
Published: November 2014

The purpose of this study is to investigate the combustion and emission characteristics of syngas fuels applied in a micro gas turbine, which is originally designed for a natural gas fired engine. The computation results were conducted by a numerical model, which consists of the three-dimension compressible k–ε model for turbulent flow and PPDF (presumed probability density function) model for combustion process. As the syngas is substituted for methane, the fuel flow rate and the total heat input to the combustor from the methane/syngas blended fuels are varied with syngas compositions and syngas substitution percentages. The computed results presented the syngas substitution effects on the combustion and emission characteristics at different syngas percentages (up to 90%) for three typical syngas compositions and the conditions where syngas applied at fixed fuel flow rate and at fixed heat input were examined. Results showed the flame structures varied with different syngas substitution percentages. The high temperature regions were dense and concentrated on the core of the primary zone for H2-rich syngas, and then shifted to the sides of the combustor when syngas percentages were high. The NOx emissions decreased with increasing syngas percentages, but NOx emissions are higher at higher hydrogen content at the same syngas percentage. The CO2 emissions decreased for 10% syngas substitution, but then increased as syngas percentage increased. Only using H2-rich syngas could produce less carbon dioxide. The detailed flame structures, temperature distributions, and gas emissions of the combustor were presented and compared. The exit temperature distributions and pattern factor (PF) were also discussed. Before syngas fuels are utilized as an alternative fuel for the micro gas turbine, further experimental testing is needed as the modeling results provide a guidance for the improved designs of the combustor.
Geometry Effects on Flow Instabilities of Different Three-Bladed Inducers
Authors: Pace Giovanni , Valentini Dario , Pasini Angelo , Torre Lucio , Fu Yanxia , d'Agostino Luca
Published: November 2014

The paper presents the results of an activity carried out on a three-bladed inducer and compares the experimental data from other similar inducers. All the inducers considered in the present study have been designed by means of the simplified analytical model recently developed by some of the authors. The main effects of different geometrical solutions on hydraulic performance and flow instabilities of the pumps under noncavitating and cavitating conditions are presented in the paper.
Reflections on a Bouncing Ball
Authors: Rohr Jim , Lopez Veronica , Rohr Tyler
Published: November 2014

While observing the bounce heights of various kinds of sports balls dropped from different heights onto a variety of surfaces, we thought of the following question: Could measurements of drop and bounce heights of balls of different diameters, but of the same material, falling from different heights, but on the same surface, be expressed by a simple mathematical formula? Our objective was to provide a simple classroom ball-drop experiment that produced robust and interesting data sets from which students could address this question. With a suitable choice of variables, all the ball drop data could be collapsed to a single curve, so that given the mass and drop height of the ball, the bounce height could be reasonably estimated (±10% of measured values).
Backyard Infrared Trapping
Authors: Gibbons Thomas C.
Published: November 2014

In this time of concern over climate change due to the atmospheric greenhouse effect,1 teachers often choose to extend relevant classroom work by the use of physical models to test statements. Here we describe an activity in which inexpensive backyard models made from cardboard boxes covered with various household transparent materials allow students to explore how transmission of visible and infrared light can affect the temperature.2 Our basic setup is shown schematically in Fig. 1, in which a black-lined box with a thermometer in contact with the bottom is covered with transparent (to visible light) household materials.
Number of bachelor's degrees doubled since 1999
Authors: White Susan C.
Published: November 2014

In the class of 2013, a record number of students earned bachelor's degrees in physics: 7,363. This is more than double the number of students doing so only 14 years earlier. Over the same time period, the total number of bachelor's degrees awarded in all disciplines was up also, but only by about 40%. The graph shows the number of students earning a bachelor's degree in physics since 1955. Between 1955 and the early 1960s, the number of undergraduates earning degrees in physics grew rapidly. After a brief downward turn in the middle of the decade, the number peaked at 5,975 in 1969. Thirty years later, it reached a low of 3,646 students in 1999. Every fall, the Statistical Research Center at the American Institute of Physics reaches out to all of the departments that award at least a bachelor's degree in physics. The departments graciously provide data on enrollments in introductory courses and the number of students earning degrees at the bachelor's, master's and doctoral level. In January, we will look at under-represented minorities among physics faculty members. If you have any questions or comments, please contact Susan White at the Statistical Research Center of the American Institute of Physics (swhite@aip.org).
What can we learn from PER: Physics Education Research?
Authors: Singh Chandralekha
Published: November 2014

Overview: Physics Education Research (PER) focuses on understanding how students learn physics at all levels and developing strategies to help students with diverse prior preparations learn physics more effectively. New physics instructors are encouraged to visit http://PhysPort.org, a website devoted to helping instructors find effective teaching resources based upon PER.1 The site has links to PER-based teaching approaches, hosts instructional materials sorted by pedagogy, and provides assessment tools and tips for troubleshooting if hurdles are encountered in the implementation of PER-based instructional strategies.
Metagenomes from Thawing Low-Soil-Organic-Carbon Mineral Cryosols and Permafrost of the Canadian High Arctic
Authors: Chauhan Archana , Layton Alice C. , Vishnivetskaya Tatiana A. , Williams Daniel , Pfiffner Susan M. , Rekepalli Bhanu , Stackhouse Brandon , Lau Maggie C. Y. , Phelps Tommy J. , Mykytczuk Nadia , Ronholm Jennifer , Whyte Lyle , Onstott Tullis C. , Sayler Gary S.
Published: November 2014

Microbial release of greenhouse gases from thawing permafrost is a global concern. Seventy-six metagenomes were generated from low-soil-organic-carbon mineral cryosols from Axel Heiberg Island, Nunavut, Canada, during a controlled thawing experiment. Permafrost thawing resulted in an increase in anaerobic fermenters and sulfate-reducing bacteria but not methanogens.
Characterization of Extreme Acidophile Bacteria (Acidithiobacillus ferrooxidans) Bioleaching Copper from Flexible PCB by ICP-AES
Authors: Gu Weihua , Bai Jianfeng , Dai Jue , Zhang Chenglong , Yuan Wenyi , Wang Jingwei , Wang Pengcheng , Zhao Xin
Published: November 2014

In order to improve copper leaching efficiency from the flexible printed circuit board (PCB) byAcidithiobacillus ferrooxidans, it is necessary to quantitatively measure the bacteria bioleaching copper under extreme acidic condition from flexible PCB. The inductively coupled plasma-atomic emission spectroscopy (ICP-AES) is a very accurate way to analyze metals in solution; this paper investigated the optimal conditions for copper bioleaching byAcidithiobacillus ferrooxidansfrom flexible PCB through ICP-AES. The conditions included particle size of flexible PCB powder, quantity of flexible PCB powder, initial pH of culture medium, bacteria inoculation, bacteria activation time, and quantity of FeSO4·7H2O. Prior to ICP-AES measurement, culture solution was digested by aqua regia. The experimental results demonstrated that flexible PCB contained one main metal (copper); this was associated with the structure of flexible PCB. The optimization conditions were in 50 mL medium, flexible PCB 10 g/L, particle size of flexible PCB 0.42~0.84 mm, culture medium initial pH 2.5, bacteria inoculation 5%, bacteria activation time 5 d, and quantity of FeSO4·7H2O 30 g/L. Under the optimization condition, the leaching rate of copper was 90.10%, which was 42.4% higher than the blank group. For the ICP-AES determination, it reached a conclusion that the best corresponding wavelength (nm) of copper will be 224.7 (nm).
A Portable Random Key Predistribution Scheme for Distributed Sensor Network
Authors: Zheng Shihui , Tian Yuan , Jin Lei , Yang Yu
Published: November 2014

A distributed sensor network (DSN) can be deployed to collect information for military or civilian applications. However, due to the characteristics of DSNs such as limited power, key distribution for a distributed sensor network is complex. In this paper, a neighbor-based path key establishing method and a seed-based algorithm are put forward to improve the original random key pre-distribution scheme. The new scheme is portable because it is independent of the routing protocol. Moreover, the connectivity of the entire network also approaches 1. In particular, the new scheme can keep high connectivity by setting a small amount of redundancy in parameter values when the number of neighbors drops because of the node dormancy or death. The resilience against node capture in our scheme is not lower than that in thel-path scheme and the basic schemes when the number of hops in a path is larger than 5, and the simulation result shows that the efficiency of our scheme is also slightly higher.
Earliest Results in the Use of Activated Composite Membranes for the Transport of Silver Ions from Aqueous Solutions
Authors: Mendoza-Tolentino Yucundo , Galán-Vidal Carlos Andrés , Álvarez-Romero Giaan Arturo , Ramírez-Silva M. T. , Páez-Hernández Ma. Elena
Published: November 2014

This paper presents the results concerning the first use of activated composite membranes (ACMs) for the facilitated transport of silver ions containing di-(2-ethylhexyl)-dithiophosphoric acid (DTPA) as the carrier. DTPA was immobilized by interfacial polymerization in a dense layer that was deposited in a porous layer, which was prepared on a nonwoven fabric support by phase inversion. The influence of fundamental parameters affecting the transport of silver ion as the carrier concentration in the membrane phase and stripping agent variation of the stripping solution have been studied. In the optimal conditions, the amount of silver transported across the ACMs was greater than 50%, whereas if the content of the carrier is modified, more than the 90% of the initial silver is removed from the feed phase.
The Influence of Climate Factors, Meteorological Conditions, and Boundary-Layer Structure on Severe Haze Pollution in the Beijing-Tianjin-Hebei Region during January 2013
Authors: Wang Lili , Zhang Nan , Liu Zirui , Sun Yang , Ji Dongsheng , Wang Yuesi
Published: November 2014

The air-pollution episodes in China in January 2013 were the most hazardous in the Beijing-Tianjin-Hebei (BTH) region. PM2.5, AOD, and long-term visibility data, along with various climate and meteorological factors and the boundary-layer structure, were used to investigate the cause of the heavy-haze pollution events in January 2013. The result suggests that unfavorable diffusion conditions (weak surface winds and high humidity) and high primary-pollutant emissions have induced heavy-haze pollution in the BTH region over the past two decades. A sudden stratospheric warming (SSW), weak East Asian winter monsoon, a weak Siberian High, weak meridional circulation, southerly wind anomalies in the lower troposphere, and abnormally weak surface winds and high humidity were responsible for the severe haze pollution events, rather than an abrupt increase in emissions. Heavy/severe haze pollution is associated with orographic wind convergence zones along the Taihang and Yanshan Mountains, slight winds (1.7∼2.1 m/s), and high humidity (70%∼90%), which limits the diffusion of pollutants and facilitates the hygroscopic growth of aerosols. Recirculation and regional transport, along with the poorest diffusion conditions and favorable conditions for hygroscopic growth of aerosols and secondary transformation under the high emission, led to explosive growth and the record high hourly average concentration of PM2.5in Beijing.
Outcome of Adolescents with Acute Lymphoblastic Leukemia Treated by Pediatrics versus Adults Protocols
Authors: Ibrahim Abeer , Ali Amany , Mohammed Mahmoud M.
Published: November 2014

Objective.Several studies showed better outcome in adolescents and young adults with acute lymphoblastic leukemia (ALL) treated with pediatrics protocols than similarly aged patients treated with adults protocols, while other studies showed similar outcome of both protocols. We conducted this study to compare the outcome of our pediatrics and adults therapeutic protocols in treatment of adolescents ALL.Patients and Methods.We retrospectively reviewed files of 86 consecutive adolescent ALL patients aged 15–18 years who attended to outpatients clinic from January 2003 to January 2010. 32 out of 86 were treated with pediatrics adopted BFM 90 high risk protocol while 54 were treated with adults adopted BFM protocol. We analyzed the effect of different treatment protocols on achieving complete remission (CR), disease-free survival (DFS), and overall survival (OS).Results.The 2 patients groups have almost similar characteristics. The CR was significantly higher in pediatrics protocol 96% versus 89%(P=0.001). Despite the fact that the toxicity profiles were higher in pediatrics protocol, they were tolerable. Moreover, the pediatrics protocol resulted in superior outcome in EFS 67% versus 39% (P=0.001), DFS 65% versus 41%(P=0.000), and OS 67% versus 45%(P=0.000).Conclusion.Our study’s findings recommend using intensified pediatrics inspired protocol to treat adolescents with acute lymphoblastic leukemia.
External Ventricular Drain Infections: Risk Factors and Outcome
Authors: Hagel S. , Bruns T. , Pletz M. W. , Engel C. , Kalff R. , Ewald C.
Published: November 2014

External ventricular drainage (EVD) is frequently used in neurosurgery to drain cerebrospinal fluid in patients with raised intracranial pressure. We performed a retrospective single center study in order to evaluate the incidence of EVD-related infections and to identify underlying risk factors. 246 EVDs were placed in 218 patients over a 30-month period. EVD was continued in median for 7 days (range 1–44). The cumulative incidence of EVD-related infections was 8.3% (95% CI, 5.3–12.7) with a device-associated infection rate of 10.4 per 1000 drainage days (95% CI, 6.2–16.5). The pathogens most commonly identified were coagulase-negativeStaphylococcus(62%) followed byEnterococcusspp. (19%). Patients with an EVD-related infection had a significantly longer ICU (11 versus 21 days,P<0.01) and hospital stay (20 versus 28.5 days,P<0.01) than patients without. Median total duration of external drainage was twice as long in patients with EVD-related infection (6 versus 12 days,P<0.01). However, there was no significant difference in the duration between first EVD placement and the occurrence of EVD-related infection and EVD removal in patients without EVD-related infection (6 versus 7 days,P=0.87), respectively. Interestingly no risk factor for EVD-related infection could be identified in our cohort of patients.