bluuebunny/crossref_metadata_2025 huggingface dataset:
It is Just Good Business: The Case for Supporting Reform in Divorce Court
Authors: Kourlis Rebecca Love
Published: September 2012

This article examines the ways in which divorce and child custody proceedings can impact employee productivity and suggests that it behooves businesses to become involved in supporting efforts to improve the process—both as a matter of community service and because it can impact their bottom line. This article further outlines some improvements that are being implemented or considered in various jurisdictions.

Key Points for the Family Court Community

Divorce does not just impact the parties and their children. It also impacts the work productivity of the individuals involved.

The population of individuals seeking court involvement in child custody issues has changed, and new processes must be developed to address their needs.

There are new ideas about how to restructure the divorce process in ways that could benefit both the individuals and their employers.
Biosonar, dive, and foraging activity of satellite tracked harbor porpoises (Phocoena phocoena)
Authors: Linnenschmidt Meike , Teilmann Jonas , Akamatsu Tomonari , Dietz Rune , Miller Lee A.
Published: September 2012

This study presents bioacoustic recordings in combination with movements and diving behavior of three free‐ranging harbor porpoises (a female and two males) in Danish waters. Each porpoise was equipped with an acoustic data logger (A‐tag), a time‐depth‐recorder, a VHF radio transmitter, and a satellite transmitter. The units were programmed to release after 24 or 72 h. Possible foraging occurred mostly near the surface or at the bottom of a dive. The porpoises showed individual diversity in biosonar activity (<100 to >50,000 clicks per hour) and in dive frequency (6–179 dives per hour). We confirm that wild harbor porpoises use more intense clicks than captive animals. A positive tendency between number of dives and clicks per hour was found for a subadult male, which stayed near shore. It showed a distinct day‐night cycle with low echolocation rates during the day, but five times higher rates and higher dive activity at night. A female traveling in open waters showed no diel rhythm, but its sonar activity was three times higher compared to the males'. Considerable individual differences in dive and echolocation activity could have been influenced by biological and physical factors, but also show behavioral adaptability necessary for survival in a complex coastal environment.
The outcomes of mycophenolate mofetil therapy combined with systemic corticosteroids in acute uveitis associated with Vogt–Koyanagi–Harada disease
Authors: Abu El‐Asrar Ahmed M. , Hemachandran Suhail , Al‐Mezaine Hani S. , Kangave Dustan , Al‐Muammar Abdulrahman M.
Published: September 2012

Purpose:  To study the effectiveness of mycophenolate mofetil (MMF) as first‐line therapy combined with systemic corticosteroids in acute uveitis associated with Vogt–Koyanagi–Harada (VKH) disease. The outcomes in this group were compared with those of another group of patients with VKH disease who were treated with corticosteroid monotherapy or with delayed addition of immunomodulatory therapy.

Methods:  This prospective study included 19 patients (38 eyes) diagnosed with acute uveitis associated with VKH disease.

Results:  The mean follow‐up period was 27.0 ± 11.1 months (range 16–54 months). Corticosteroid‐sparing effect was achieved in all patients. The mean interval between starting treatment and tapering prednisone to 10 mg or less daily was 5.1 ± 1.2 months (range 3–7 months). Ten (53%) patients discontinued treatment without relapse of inflammation. The mean time observed of treatment was 17.3 ± 11.9 months (range 3–41.5 months). Visual acuity of 20/20 was achieved by 38% of the eyes in the corticosteroid group and by 74% in the corticosteroid + MMF group (p < 0.001). Recurrent inflammation of ≥3 times was reduced significantly (p = 0.0383) in the corticosteroid + MMF group (3%) as compared to corticosteroid group (18%). Development of all complications was significantly higher in the corticosteroid group (43%) compared with the corticosteroid + MMF group (8%) (p < 0.001). None of the eyes in the corticosteroid + MMF group developed ‘sunset glow fundus’.

Conclusions:  Addition of MMF as first‐line therapy to corticosteroids in patients with acute uveitis associated with VKH disease leads to significant reduction in recurrences of uveitis and development of late complications and significantly improves visual outcome.
Immunogenicity of different hepatitis B virus vaccination schedules in liver transplant recipients
Authors: Feng Lijuan , Niu Yujian , Chen Hong , You Hong , Zang Yunjin , Li Li , Shan Shan , Tan Yule , Jia Jidong , Shen Zhongyang
Published: September 2012

Aim

To compare the immunogenicity of two modified hepatitis B virus (HBV) vaccination schedules in liver transplant recipients. Hepatitis B immunoglobulin (HBIG) in combination with nucleoside/nucleotide analogs (NUCs) is the recommended prophylaxis for preventing HBV recurrence following liver transplantation (LT). However, HBIG treatment is expensive. Active immunization with hepatitis B vaccine would be a preferable alternative prophylaxis to replace HBIG treatment. However, the overall response rate to standard vaccination (given at months 0, 1 and 6) is relatively low in immune‐compromised patients.

Methods

Two cohorts of 114 subjects were immunized with recombinant HBV vaccine containing S‐antigen. The patients in the rapid schedule group were immunized with 40 μg HBV vaccine at months 0, 1, 2 and 3, and with 20 μg at months 4, 5 and 6. The patients in the accelerated schedule group were immunized with 40 μg of HBV vaccine at days 0, 7, 14 and 28, and 20 μg at months 2, 3 and 4.

Results

The overall response rate was 16.7% (19/114) and all responders discontinued HBIG injection and only one patient developed HBV recurrence. The response rate was 24.6% (14/57) and 8.8% (5/57) in the rapid vaccination and the accelerated vaccination schedules, respectively (P = 0.024).

Conclusion

HBV vaccination may induce endogenous anti‐HBs to replace HBIG in selected patients. Vaccination schedules may influence vaccine response, and individual optimization may improve response rate to HBV vaccination.
Use of Exempt Wells As Natural Underground Storage and Recovery Systems
Authors: Embleton David G.
Published: September 2012

The water management practice of storing water underground for use during dry periods is a very effective technique that has been practiced for a long time. Another water management practice that has been around for a long time is collection of rainwater and storage of rainwater aboce ground. There have been significant advances more recently in our understanding of aquifer geology and technologies used for rainwater harvesting. This article combines our advance in knowledge of storing and recovery water from wells and new rainwater harvesting practices to recharge a low yielding exempt well with treated rainwater. The studies presented in this article demonstrate that exempt wells provide a valuable underground water storage option and may provide a new effective urban water management tool.
Compound‐specific carbon, nitrogen, and hydrogen isotopic ratios for amino acids in CM and CR chondrites and their use in evaluating potential formation pathways
Authors: ELSILA Jamie E. , CHARNLEY Steven B. , BURTON Aaron S. , GLAVIN Daniel P. , DWORKIN Jason P.
Published: September 2012

Abstract– Stable hydrogen, carbon, and nitrogen isotopic ratios (δD, δ13C, and δ15N) of organic compounds can reveal information about their origin and formation pathways. Several formation mechanisms and environments have been postulated for the amino acids detected in carbonaceous chondrites. As each proposed mechanism utilizes different precursor molecules, the isotopic signatures of the resulting amino acids may indicate the most likely of these pathways. We have applied gas chromatography with mass spectrometry and combustion isotope ratio mass spectrometry to measure the compound‐specific C, N, and H stable isotopic ratios of amino acids from seven CM and CR carbonaceous chondrites: CM1/2 Allan Hills (ALH) 83100, CM2 Murchison, CM2 Lewis Cliff (LEW) 90500, CM2 Lonewolf Nunataks (LON) 94101, CR2 Graves Nunataks (GRA) 95229, CR2 Elephant Moraine (EET) 92042, and CR3 Queen Alexandra Range (QUE) 99177. We compare the isotopic compositions of amino acids in these meteorites with predictions of expected isotopic enrichments from potential formation pathways. We observe trends of decreasing δ13C and increasing δD with increasing carbon number in the α‐H, α‐NH2 amino acids that correspond to predictions made for formation via Strecker‐cyanohydrin synthesis. We also observe light δ13C signatures for β‐alanine, which may indicate either formation via Michael addition or via a pathway that forms primarily small, straight‐chain, amine‐terminal amino acids (n‐ω‐amino acids). Higher deuterium enrichments are observed in α‐methyl amino acids, indicating formation of these amino acids or their precursors in cold interstellar or nebular environments. Finally, individual amino acids are more enriched in deuterium in CR chondrites than in CM chondrites, reflecting different parent‐body chemistry.
The Dilemma of Nocturnal Blood Pressure
Authors: Xu Tan , Zhang Yong‐Qing , Tan Xue‐Rui
Published: September 2012

J Clin Hypertens (Greenwich). 2012;14:787–791. ©2012 Wiley Periodicals, Inc.

During the past decades, blood pressure (BP) measurement technique has evolved rapidly from the traditionally manual measuring to fully automatic monitoring. In terms of management of BP, there have been tremendous changes from the controlling of daytime BP, nondipping pattern to nocturnal BP (NBP). Since the focus has turned to NBP, a number of dilemmas of NBP measurement have gradually emerged in clinical practice and research settings, including methods for monitoring NBP, different period definition of nocturnal time, different diagnostic thresholds of abnormal NBP, whether to control abnormal NBP, and how to manage abnormal NBP. Currently, these issues have hindered progress in the appropriate management of hypertensive patients. Therefore, the purpose of this review is to concisely discuss the dilemmas of NBP.
Mass spectrometry analysis of human P2X1 receptors; insight into phosphorylation, modelling and conformational changes
Authors: Roberts Jonathan A. , Bottrill Andrew R. , Mistry Sharad , Evans Richard J.
Published: September 2012

Recombinant FlagHis6 tagged Human P2X1 receptors expressed in HEK293 cells were purified, digested with trypsin and analysed by mass spectroscopy (96% coverage following de‐glycosylation and reduction). The receptor was basally phosphorylated at residues S387, S388 and T389 in the carboxyl terminus, a triple alanine mutant of these residues had a modest ~ 25% increase in current amplitude and recovery from desensitization. Chemical modification showed that intracellular lysine residues close to the transmembrane domains and the membrane stabilization motif are accessible to the aqueous environment. The membrane‐impermeant cross‐linking reagent 3,3′‐Dithiobis (sulfosuccinimidylpropionate) (DTSSP) reduced agonist binding and P2X1 receptor currents by > 90%, and modified lysine residues were identified by mass spectroscopy. Mutation to remove reactive lysine residues around the ATP‐binding pocket had no effect on inhibtion of agonist evoked currents following DTSSP. However, agonist evoked currents were ~ 10‐fold higher than for wild type following DTSSP treatment for mutants K199R, K221R and K199R‐K221R. These mutations remove reactive residues distant from the agonist binding pocket that are close enough to cross‐link adjacent subunits. These results suggest that conformational change in the P2X1 receptor is required for co‐ordination of ATP action.
Xenopus laevis RIC‐3 enhances the functional expression of the C. elegans homomeric nicotinic receptor, ACR‐16, in Xenopus oocytes
Authors: Bennett Hayley M. , Lees Kristin , Harper Kate M. , Jones Andrew K. , Sattelle David B. , Wonnacott Susan , Wolstenholme Adrian J.
Published: September 2012

RIC‐3 enhances the functional expression of certain nicotinic acetylcholine receptors (nAChRs) in vertebrates and invertebrates and increases the availability of functional receptors in cultured cells and Xenopus laevis oocytes. Maximal activity of RIC‐3 may be cell‐type dependent, so neither mammalian nor invertebrate proteins is optimal in amphibian oocytes. We cloned the X. laevis ric‐3 cDNA and tested the frog protein in oocyte expression studies. X. laevis RIC‐3 shares 52% amino acid identity with human RIC‐3 and only 17% with that of Caenorhabditis elegans. We used the C. elegans nicotinic receptor, ACR‐16, to compare the ability of RIC‐3 from three species to enhance receptor expression. In the absence of RIC‐3, the proportion of oocytes expressing detectable nAChRs was greatly reduced. Varying the ratio of acr‐16 to X. laevis ric‐3 cRNAs injected into oocytes had little impact on the total cell current. When X. laevis, human or C. elegans ric‐3 cRNAs were co‐injected with acr‐16 cRNA (1 : 1 ratio), 100 μM acetylcholine induced larger currents in oocytes expressing X. laevis RIC‐3 compared with its orthologues. This provides further evidence for a species‐specific component of RIC‐3 activity, and suggests that X. laevis RIC‐3 is useful for enhancing the expression of invertebrate nAChRs in X. laevis oocytes.
Periodontal health and serum, saliva matrix metalloproteinases in patients with mild chronic obstructive pulmonary disease
Authors: Yildirim E. , Kormi I. , Başoğlu Ö. K. , Gürgün A. , Kaval B. , Sorsa T. , Buduneli N.
Published: September 2012

Background and Objectives

The present case–control study aimed to evaluate comparatively the salivary and serum levels of matrix metalloproteinases (MMP)‐8 and‐ 13 and tissue inhibitor of matrix metalloproteinase‐1 (TIMP‐1) in patients with mild chronic obstructive pulmonary disease (COPD) and non‐COPD controls.

Material and Methods

Clinical periodontal measurements were recorded before any periodontal intervention in 36 patients with mild COPD and 20 non‐COPD controls admitted to Ege University Department of Chest Diseases COPD outpatient clinic (İzmir, Turkey). Salivary and serum levels of MMP‐8, MMP‐13, and TIMP‐1 were determined by immunofluorometric assay (IFMA) and enzyme‐linked immunosorbent assay (ELISA). Data were analyzed with non‐parametric statistical tests.

Results

Patients with COPD were significantly older than the control group (p < 0.05). The COPD group showed significantly higher serum levels of MMP‐8 IFMA, MMP‐8/TIMP‐1 IFMA than the control group (p < 0.005). By ELISA, serum MMP‐8, MMP‐8/TIMP‐1, TIMP‐1, and MMP‐13 levels were similar in both groups (p > 0.05). Salivary MMP‐8, MMP‐13, and TIMP‐1 levels were similar in both groups (p > 0.05).

Conclusions

The present findings suggest that immunodetection of MMP‐8 is dependent on the selected techniques and even with mild COPD some systemic inflammatory markers such as MMP‐8 tend to increase. However, the present clinical periodontal and biochemical findings do not provide support for the previously proposed interaction between COPD and periodontal diseases.
Does IL28B genotyping still have a role in the era of direct‐acting antiviral therapy for chronic hepatitis C infection?
Authors: Holmes J. A. , Desmond P. V. , Thompson A. J.
Published: September 2012

IL28B genotype has been shown to be the strongest pretreatment predictor of sustained virological response (SVR) in patients with genotype 1 chronic hepatitis C infection (CHC) treated with pegylated interferon (peg‐IFN) and ribavirin (RBV). Patients carrying the good response genotype have a two‐ to threefold higher chance of SVR than those with a poor response genotype, manifest as dramatically improved early viral kinetics. However, the treatment paradigm for CHC is changing with the introduction of potent direct‐acting antivirals (DAAs). IL28B genotype remains relevant to both telaprevir and boceprevir treatment regimens, although the strength of association with virological response is attenuated. The association between IL28B genotype and outcomes of treatment regimens that involve peg‐IFN plus combination DAA therapy, or IFN‐free regimens, is currently being evaluated. IL28B genotype may remain relevant to individualizing the choice of treatment regimen in the future.
Exploring the role of asexual multiplication in poplar rust epidemics: impact on diversity and genetic structure
Authors: Barrès Benoît , Dutech Cyril , Andrieux Axelle , Halkett Fabien , Frey Pascal
Published: September 2012

Fungal plant pathogens, especially rust fungi (Pucciniales), are well known for their complex life cycles, which include phases of sexual and asexual reproduction. The effect of asexual multiplication on population genetic diversity has been investigated in the poplar rust fungusMelampsora larici‐populinausing a nested hierarchical sampling scheme. Four hierarchical levels were considered: leaf, twig, tree and site. Both cultivated and wild poplar stands were sampled at two time points at the start and end of rust epidemics. A total of 641 fungal isolates was analysed using nine microsatellite markers. This study revealed that the genetic signature of asexual multiplication in the wild poplar stand was seen only at lower hierarchical levels (leaf and twig). Moreover, we observed an erosion of clonal structure through time, with an increase in both gene and genotypic diversity. New genotypes contributed to host infection over time, which demonstrates the importance of allo‐infection in the epidemic process in this host‐pathogen system. Compared with the wild stands, the nearly lack of detection of clonal structure in the cultivated stands reflects the higher infection level on cultivated poplars. More generally, this genetic analysis illustrates the utility of population genetics approach for elucidating the proportion of asexual reproduction in the multiplication of isolates during an epidemic, and for proper quantification of asexual dispersal in plant pathogens.
Developing a pediatric pain service
Authors: Kost‐Byerly Sabine , Chalkiadis George
Published: September 2012

Pediatric pain services were first established in larger pediatric centers over two decades ago. Children's acute pain was poorly managed at the time owing to misconceptions, safety concerns, and variability in practice. While many larger pediatric centers now have acute pain services, there remains a need for better pain management in facilities and geographic locations with fewer resources. Institutional acknowledgement and desire to change, appropriate staffing, and funding are major obstacles. Better recognition and assessment as well safer and more efficacious treatment of pain are the principal objectives when establishing a pain service. It is important to determine whether the proposed service intends to treat acute, chronic, procedural, and/or cancer and palliative pain as each requires different skills and resources. An ideal and comprehensive pediatric pain service should be equipped to diagnose and treat acute, persistent (chronic), procedural, and cancer/palliative pain. It is not feasible or necessary for every hospital to manage all. Establishing the scope of practice (based on case mix and caseload) in any given hospital will determine which resources are desired. Country‐specific standards, local staffing, and fiscal constraints will influence which resources are available.
New technologies in pediatric anesthesia
Authors: Holtby Helen , Skowno Justin J. , Kor Daryl J. , Flick Randall P. , Uezono Shoichi
Published: September 2012

This article reviews potential pediatric applications of 3 new technologies. (1) Pulse oximetry‐based hemoglobin determination: Hemoglobin determination using spectrophotometric methods recently has been introduced in adults with varied success. This non‐invasive and continuous technology may avoid venipuncture and unnecessary transfusion in children undergoing surgery with major blood loss, premature infants undergoing unexpected and complicated emergency surgery, and children with chronic illness. (2) Continuous cardiac output monitoring: In adults, advanced hemodynamic monitoring such as continuous cardiac output monitoring has been associated with better surgical outcomes. Although it remains unknown whether similar results are applicable to children, current technology enables the monitoring of cardiac output non‐invasively and continuously in pediatric patients. It may be important to integrate the data about cardiac output with other information to facilitate therapeutic interventions. (3) Anesthesia information management systems: Although perioperative electronic anesthesia information management systems are gaining popularity in operating rooms, their potential functions may not be fully appreciated. With advances in information technology, anesthesia information management systems may facilitate bedside clinical decisions, administrative needs, and research in the perioperative setting.
International advocacy for education and safety
Authors: McQueen Kelly A. , Malviya Shobha , Gathuya Zipporah N. , Tyler Donald C.
Published: September 2012

Surgical safety has emerged as a significant global public health concern with reported mortality rates varying tremendously between developing and industrialized countries. This manuscript reviews some of the challenges encountered in providing safe anesthesia care in the humanitarian space; identifies the difficulties with providing high‐quality education in developing countries; and describes how audits and quality improvement databases enhance our understanding of the nature and causes of harm to patients to inform the development of strategies for improvement.
Implementing checklists in the operating room
Authors: Low Daniel , Walker Isabeau , Heitmiller Eugenie S.
Published: September 2012

Checklists have established themselves as a key safety process in the operating room environment. This paper describes the background and context of how checklists have evolved in medicine. It also highlights ongoing challenges with particular attention to the importance of nontechnical skills or human factors training with relation to checklist design, testing and implementation and ongoing coaching.
Compression garments do not alter cerebrovascular responses to orthostatic stress after mild passive heating
Authors: Morrison S. A. , Ainslie P. N. , Lucas R. A. I. , Cheung S. S. , Cotter J. D.
Published: September 2012

Whole‐body heating increases the likelihood of syncope, whereas utilizing lower‐body compression garments may reduce syncope risk. We hypothesized that graded compression garments would reduce the typically observed large postural reductions in arterial blood pressure and middle cerebral artery velocity, in normothermia and especially once passively heat stressed. Fifteen men (age: 27 ± 4 years, aerobic fitness range: 30–75 mL/kg/min) completed a supine‐to‐stand orthostatic challenge for 3 min at normothermia and after passive heating (esophageal temperature, +0.5 °C from baseline) on two occasions (> 7 days): once wearing commercially available compression trousers and once wearing low‐compression placebo trousers (randomized order). Blood flow velocity in the middle cerebral artery (transcranial Doppler), mean arterial blood pressure (mean BP: Finometer) and end‐tidal carbon dioxide pressure were measured continuously. During normothermia, compression, garments did not alter the magnitude of the postural changes in mean BP or middle cerebral artery velocity. After passive heating, although the magnitudes of these changes were exaggerated, they were not significantly affected by compression garments. Compression garments did not attenuate the initial or sustained orthostatic hypotension associated with posture change, either during normothermia or following passive heat stress.
Assessment of Various Turbulence Models in a High Pressure Ratio Centrifugal Compressor With an Object Oriented CFD Code
Authors: Mangani Luca , Casartelli Ernesto , Mauri Sebastiano
Published: September 2012

The flow field in a high pressure ratio centrifugal compressor with a vaneless diffuser has been investigated numerically. The main goal is to assess the influence of various turbulence models suitable for internal flows with an adverse pressure gradient. The numerical analysis is performed with a 3D RANS in-house modified solver based on an object-oriented open-source library. According to previous studies from varying authors, the turbulence model is believed to be the key parameter for the discrepancy between experimental and numerical results, especially at high pressure ratios and high mass-flow. Particular care has been taken at the wall, where a detailed integration of the boundary layer has been applied. The results present different comparisons between the models and experimental data, showing the influence of using advanced turbulence models. This is done in order to capture the boundary layer behavior, especially in large adverse pressure gradient single stage machinery.
Experimental and Computational Study of Heat/Mass Transfer and Flow Structure for Four Dimple Shapes in a Square Internal Passage
Authors: Acharya Sumanta , Zhou Fuguo
Published: September 2012

Mass/heat transfer measurements are made using the naphthalene sublimation method in a square internal passage where one wall has a single dimple. Four types of dimple shapes are studied: square, triangular, circular, and teardrop. Sherwood numbers are obtained both inside and around the dimples. Measurements are made at a Reynolds number of 21,000. In addition, computations are performed for the same dimple geometries, and with the same flow conditions as in the experiments. Flow patterns for the four dimples are identified and heat transfer distributions for each dimple are obtained. The computational results are compared with the experimental data and show satisfactory agreement. Both the experimental and numerical results suggest that the teardrop dimple has the highest heat /mass transfer among the four dimple shapes studied.
A Physical Interpretation of Stagnation Pressure and Enthalpy Changes in Unsteady Flow
Authors: Hodson H. P. , Hynes T. P. , Greitzer E. M. , Tan C. S.
Published: September 2012

This paper provides a physical interpretation of the mechanism of stagnation enthalpy and stagnation pressure changes in turbomachines due to unsteady flow, the agency for all work transfer between a turbomachine and an inviscid fluid. Examples are first given to illustrate the direct link between the time variation of static pressure seen by a given fluid particle and the rate of change of stagnation enthalpy for that particle. These include absolute stagnation temperature rises in turbine rotor tip leakage flow, wake transport through downstream blade rows, and effects of wake phasing on compressor work input. Fluid dynamic situations are then constructed to explain the effect of unsteadiness, including a physical interpretation of how stagnation pressure variations are created by temporal variations in static pressure; in this it is shown that the unsteady static pressure plays the role of a time-dependent body force potential. It is further shown that when the unsteadiness is due to a spatial nonuniformity translating at constant speed, as in a turbomachine, the unsteady pressure variation can be viewed as a local power input per unit mass from this body force to the fluid particle instantaneously at that point.
Effects of polarity and surface treatment on Ga- and N-polar bulk GaN
Authors: Foussekis Michael , Ferguson Josephus D. , McNamara Joy D. , Baski Alison A. , Reshchikov Michael A.
Published: September 2012

The effects of polarity and surface treatment on the morphological, electrical, and optical behaviors in bulk GaN have been investigated. Kelvin probe, atomic force microscopy (AFM), and photoluminescence (PL) techniques were utilized to examine a set of freestanding, bulk GaN samples, which were grown by halide vapor phase epitaxy. The Ga- and N-polar surfaces were treated with either a mechanical polish (MP) or chemical mechanical polish (CMP), which influences the morphology, surface photovoltage (SPV), and PL behaviors. Topography studies indicate that the CMP-treated, Ga-polar surface is the smoothest of the sample set, whereas the MP-treated, N-polar surface has the highest root mean square roughness. Local current–voltage spectra obtained with conducting AFM reveal a higher forward-bias, turn-on voltage for the N-polar versus Ga-polar surfaces. Using a Kelvin probe, intensity-dependent SPV measurements are performed on samples with CMP-treated, Ga- and N-polar surfaces, and provide band bending values of 0.83 and 0.70 eV, respectively. The restoration of the SPV from CMP-treated surfaces behaves as predicted by a thermionic model, whereas restoration from MP-treated surfaces has a faster rate than expected. This result is possibly due to enhanced electron conduction via hopping between defect states to the surface. The quantum efficiency of the PL from the CMP- and MP-treated surfaces at room temperature is ∼1% and 1 × 10−5%, respectively, suggesting high quenching of the PL for MP-treated surfaces by near-surface defects. Therefore, AFM, PL, and SPV data indicate that the MP-treated surfaces have a significantly higher density of surface defects.
Automatic assistance to Parkinsonˈs disease diagnosis in DaTSCAN SPECT imaging
Authors: Illán I. A. , Górriz J. M. , Ramírez J. , Segovia F. , Jiménez‐Hoyuela J. M. , Ortega Lozano S. J.
Published: September 2012

Purpose:

In this work, an approach to computer aided diagnosis (CAD) system is proposed as a decision‐making aid in Parkinsonian syndrome (PS) detection. This tool, intended for physicians, entails fully automatic preprocessing, normalization, and classification procedures for brain single‐photon emission computed tomography images.

Methods:

Ioflupane[123I]FP‐CIT images are used to provide in vivo information of the dopamine transporter density. These images are preprocessed using an automated template‐based registration followed by two proposed approaches for intensity normalization. A support vector machine (SVM) is used and compared to other statistical classifiers in order to achieve an effective diagnosis using whole brain images in combination with voxel selection masks.

Results:

The CAD system is evaluated using a database consisting of 208 DaTSCAN images (100 controls, 108 PS). SVM‐based classification is the most efficient choice when masked brain images are used. The generalization performance is estimated to be 89.02 (90.41–87.62)% sensitivity and 93.21 (92.24–94.18)% specificity. The area under the curve can take values of 0.9681 (0.9641–0.9722) when the image intensity is normalized to a maximum value, as derived from the receiver operating characteristics curves.

Conclusions:

The present analysis allows to evaluate the impact of the design elements for the development of a CAD‐system when all the information encoded in the scans is considered. In this way, the proposed CAD‐system shows interesting properties for clinical use, such as being fast, automatic, and robust.
Grading Homework to Emphasize Problem-Solving Process Skills
Authors: Harper Kathleen A.
Published: September 2012

This article describes a grading approach that encourages students to employ particular problem-solving skills. Some strengths of this method, called “process- based grading,” are that it is easy to implement, requires minimal time to grade, and can be used in conjunction with either an online homework delivery system or paper-based homework.
Improving the Quality of Lab Reports by Using Them as Lab Instructions
Authors: Haagen-Schuetzenhoefer Claudia
Published: September 2012

Lab exercises are quite popular in teaching science. Teachers have numerous goals in mind when teaching science laboratories. Nevertheless, empirical research draws a heterogeneous picture of the benefits of lab work. Research has shown that it does not necessarily contribute to the enhancement of practical abilities or content knowledge.1 Lab activities are frequently based on recipe-like, step-by-step instructions (“cookbook style”), which do not motivate students to engage cognitively. Consequently, students put the emphasis on “task completion” or “manipulating equipment.”2
Noise suppression of a dipole source by tensioned membrane with side-branch cavities
Authors: Liu Y. , Choy Y. S. , Huang L. , Cheng L.
Published: September 2012

Reducing the ducted-fan noise at the low frequency range remains a big technical challenge. This study presents a passive approach to directly suppress the dipole sound radiation from an axial-flow fan housed by a tensioned membrane with cavity backing. The method aims at achieving control of low frequency noise with an appreciable bandwidth. The use of the membrane not only eliminates the aerodynamic loss of flow, but also provides flexibility in controlling the range of the stopband with high insertion loss by varying its tension and mass. A three-dimensional model is presented which allows the performance of the proposed device to be explored analytically. With the proper design, this device can achieve a noise reduction of 5 dB higher than the empty expansion cavity recently proposed by Huang et al. [J. Acoust. Soc. Am. 128, 152–163 (2010)]. Through the detailed modal analysis, even in vacuo modes of the membrane vibration are found to play an important role in the suppression of sound radiation from the dipole source. Experimental validation is conducted with a loudspeaker as the dipole source and good agreement between the predicted and measured insertion loss is achieved.
Traffic noise and blood pressure in low-socioeconomic status, African-American urban schoolchildren
Authors: Belojevic Goran , Evans Gary W.
Published: September 2012

The primary aim of this field study was to investigate the relationships among residential noise exposure at home and at school and blood pressure in low-socioeconomic status African-American children. Children were recruited from Boys and Girls Clubs in a mid-sized, Northeastern city. The sample consisted of 250 schoolchildren (128 boys and 122 girls) aged 6–14 years. Each child was interviewed prior to anthropometric and blood pressure measurement. An oscillometric monitor was used for measurement of resting blood pressure. Correlation analysis in the overall sample showed no significant relationship between noise exposure and children’s blood pressure. No interactions were found between noise at home and at schools as well as orientation of bedroom and/or living room and noise at home with blood pressure. A sub-sample of children was also examined by adding the orientation of bedroom and living room as inclusion criteria (n = 128), and there was an interaction between noise exposure and age on systolic blood pressure. In younger children aged 6–10 years, a significant positive relation was found between noise levels at homes and systolic blood pressure, controlling for Body Mass Index (B = 0.48, 95% C.I. = 0.07 –0.88, p = 0.02).
Cancellous bone fast and slow waves obtained with Bayesian probability theory correlate with porosity from computed tomography
Authors: Hoffman Joseph J. , Nelson Amber M. , Holland Mark R. , Miller James G.
Published: September 2012

A Bayesian probability theory approach for separating overlapping ultrasonic fast and slow waves in cancellous bone has been previously introduced. The goals of this study were to investigate whether the fast and slow waves obtained from Bayesian separation of an apparently single mode signal individually correlate with porosity and to isolate the fast and slow waves from medial-lateral insonification of the calcaneus. The Bayesian technique was applied to trabecular bone data from eight human calcanei insonified in the medial-lateral direction. The phase velocity, slope of attenuation (nBUA), and amplitude were determined for both the fast and slow waves. The porosity was assessed by micro-computed tomography (microCT) and ranged from 78.7% to 94.1%. The method successfully separated the fast and slow waves from medial-lateral insonification of the calcaneus. The phase velocity for both the fast and slow wave modes showed an inverse correlation with porosity (R2 = 0.73 and R2 = 0.86, respectively). The slope of attenuation for both wave modes also had a negative correlation with porosity (fast wave: R2 = 0.73, slow wave: R2 = 0.53). The fast wave amplitude decreased with increasing porosity (R2 = 0.66). Conversely, the slow wave amplitude modestly increased with increasing porosity (R2 = 0.39).
Kalman-based autoregressive moving average modeling and inference for formant and antiformant tracking
Authors: Mehta Daryush D. , Rudoy Daniel , Wolfe Patrick J.
Published: September 2012

Vocal tract resonance characteristics in acoustic speech signals are classically tracked using frame-by-frame point estimates of formant frequencies followed by candidate selection and smoothing using dynamic programming methods that minimize ad hoc cost functions. The goal of the current work is to provide both point estimates and associated uncertainties of center frequencies and bandwidths in a statistically principled state-space framework. Extended Kalman (K) algorithms take advantage of a linearized mapping to infer formant and antiformant parameters from frame-based estimates of autoregressive moving average (ARMA) cepstral coefficients. Error analysis of KARMA, wavesurfer, and praat is accomplished in the all-pole case using a manually marked formant database and synthesized speech waveforms. KARMA formant tracks exhibit lower overall root-mean-square error relative to the two benchmark algorithms with the ability to modify parameters in a controlled manner to trade off bias and variance. Antiformant tracking performance of KARMA is illustrated using synthesized and spoken nasal phonemes. The simultaneous tracking of uncertainty levels enables practitioners to recognize time-varying confidence in parameters of interest and adjust algorithmic settings accordingly.
Listening level of music through headphones in train car noise environments
Authors: Shimokura Ryota , Soeta Yoshiharu
Published: September 2012

Although portable music devices are useful for passing time on trains, exposure to music using headphones for long periods carries the risk of damaging hearing acuity. The aim of this study is to examine the listening level of music through headphones in the noisy environment of a train car. Eight subjects adjusted the volume to an optimum level (Lmusic) in a simulated noisy train car environment. In Experiment I, the effects of noise level (Ltrain) and type of train noise (rolling, squealing, impact, and resonance) were examined. Spectral and temporal characteristics were found to be different according to the train noise type. In Experiment II, the effects of Ltrain and type of music (five vocal and five instrumental music) were examined. Each music type had a different pitch strength and spectral centroid, and each was evaluated by ϕ1 and Wϕ(0), respectively. These were classified as factors of the autocorrelation function (ACF) of the music. Results showed that Lmusic increased as Ltrain increased in both experiments, while the type of music greatly influenced Lmusic. The type of train noise, however, only slightly influenced Lmusic. Lmusic can be estimated using Ltrain and the ACF factors ϕ1 and Wϕ(0).
Effect of fundamental-frequency and sentence-onset differences on speech-identification performance of young and older adults in a competing-talker background
Authors: Hee Lee Jae , Humes Larry E.
Published: September 2012

This study investigated the benefits of differences between sentences in fundamental frequency (F0) and temporal onset for sentence pairs among listener groups differing in age and hearing sensitivity. Two experiments were completed with the primary difference between experiments being the way in which the stimuli were presented. Experiment 1 used blocked stimulus presentation, which ultimately provided redundant acoustic cues to mark the target sentence in each pair, whereas Experiment 2 sampled a slightly more restricted stimulus space, but in a completely randomized presentation order. For both experiments, listeners were required to detect a cue word (“Baron”) for the target sentence in each pair and to then identify the target words (color, number) that appeared later in the target sentence. Results of Experiment 1 showed that F0 or onset separation cues were beneficial to both cue-word detection and color-number identification performance. There were no significant differences across groups in the ability to detect the cue word, but groups differed in their ability to identify the correct color-number words. Elderly adults with impaired hearing had the greatest difficulty with the identification task despite the application of spectral shaping to restore the audibility of the speech stimuli. For the most part, the primary results of Experiment 1 were replicated in Experiment 2, although, in the latter experiment, all older adults, whether they had normal or impaired hearing, performed worse than young adults with normal hearing. From Experiment 2, the benefits received for a difference in F0 between talkers of 6 semitones were equivalent to those received for an onset asynchrony of 300 ms between sentences and, for such conditions, the combination of both sound-segregation cues resulted in an additive benefit.
Computational modeling of phonatory dynamics in a tubular three-dimensional model of the human larynx
Authors: Xue Q. , Mittal R. , Zheng X. , Bielamowicz S.
Published: September 2012

Simulation of the phonatory flow-structure interaction has been conducted in a three-dimensional, tubular shaped laryngeal model that has been designed with a high level of realism with respect to the human laryngeal anatomy. A non-linear spring-based contact force model is also implemented for the purpose of representing contact in more general conditions, especially those associated with three-dimensional modeling of phonation in the presence of vocal fold pathologies. The model is used to study the effects of a moderate (20%) vocal-fold tension imbalance on the phonatory dynamics. The characteristic features of phonation for normal as well as tension-imbalanced vocal folds, such as glottal waveform, glottal jet evolution, mucosal wave-type vocal-fold motion, modal entrainment, and asymmetric glottal jet deflection have been discussed in detail and compared to established data. It is found that while a moderate level of tension asymmetry does not change the vibratory dynamics significantly, it can potentially lead to measurable deterioration in voice quality.
Acoustoelastic Lamb wave propagation in biaxially stressed plates
Authors: Gandhi Navneet , Michaels Jennifer E. , Lee Sang Jun
Published: September 2012

Acoustoelasticity, or the change in elastic wave speeds with stress, is a well-studied phenomenon for bulk waves. The effect of stress on Lamb waves is not as well understood, although it is clear that anisotropic stresses will produce anisotropy in the Lamb wave dispersion curves. Here the theory of acoustoelastic Lamb wave propagation is developed for isotropic media subjected to a biaxial, homogeneous stress field. It is shown that, as expected, dispersion curves change anisotropically for most stresses, modes, and frequencies. Interestingly, for some mode-frequency combinations, changes in phase velocity are isotropic even for a biaxial stress field. Theoretical predictions are compared to experimental results for several Lamb wave modes and frequencies for uniaxial loads applied to an aluminum plate, and the agreement is reasonably good.
Effects of reverberation and masker fluctuations on binaural unmasking of speech
Authors: George Erwin L. J. , Festen Joost M. , Theo Goverts S.
Published: September 2012

In daily life, listeners use two ears to understand speech in situations which typically include reverberation and non-stationary noise. In headphone experiments, the binaural benefit for speech in noise is often expressed as the difference in speech reception threshold between diotic (N0S0) and dichotic (N0Sπ) conditions. This binaural advantage (BA), arising from the use of inter-aural phase differences, is about 5–6 dB in stationary noise, but may be lower in everyday conditions. In the current study, BA was measured in various combinations of noise and artificially created diotic reverberation, for normal-hearing and hearing-impaired listeners. Speech-intelligibility models were applied to quantify the combined effects. Results showed that in stationary noise, diotic reverberation did not affect BA. BA was reduced in conditions where the masker fluctuated. With additional reverberation, however, it was restored. Results for both normal-hearing and hearing-impaired listeners were accounted for by assuming that binaural unmasking is only effectively realized at low instantaneous speech-to-noise ratios (SNRs). The observed BA was related to the distribution of SNRs resulting from fluctuations, reverberation, and peripheral processing. It appears that masker fluctuations and reverberation, both relevant for everyday communication, interact in their effects on binaural unmasking and need to be considered together.
The forced sound transmission of finite single leaf walls using a variational technique
Authors: Brunskog Jonas
Published: September 2012

The single wall is the simplest element of concern in building acoustics, but there still remain some open questions regarding the sound insulation of this simple case. The two main reasons for this are the effects on the excitation and sound radiation of the wall when it has a finite size, and the fact that the wave field in the wall is consisting of two types of waves, namely forced waves due to the exciting acoustic field, and free bending waves due to reflections in the boundary. The aim of the present paper is to derive simple analytical formulas for the forced part of the airborne sound insulation of a single homogeneous wall of finite size, using a variational technique based on the integral-differential equation of the fluid loaded wall. The so derived formulas are valid in the entire audible frequency range. The results are compared with full numerical calculations, measurements and alternative theory, with reasonable agreement.
Robust acoustic source localization based on modal beamforming and time–frequency processing using circular microphone arrays
Authors: Torres Ana M. , Cobos Maximo , Pueo Basilio , Lopez Jose J.
Published: September 2012

Uniform circular array processing has been shown to be a very useful tool for broadband acoustic source localization over 360°. Specifically, beamforming methods based on circular harmonics have attracted a lot of research attention in the last several years, as modal array signal processing is a very active research topic. On the other hand, due to the sparsity properties of speech, source localization methods in the time–frequency (T–F) domain have also demonstrated their capability to locate several simultaneous sources with high accuracy. In this paper, a localization framework based on circular harmonics beamforming and T–F processing that provides accurate localization performance under very adverse acoustic conditions is presented. Modal processing and sparsity-based localization are jointly addressed to estimate the direction-of-arrival of multiple concurrent speech sources. Experiments in real and simulated environments with different microphone setups are discussed, showing the validity of the proposed approach and comparing its performance with other state-of-the-art methods.