bluuebunny/crossref_metadata_2025 huggingface dataset:
Angiogenesis and expression of PDGF‐C, VEGF, CD105 and HIF‐1α in human glioblastoma
Authors: Clara Carlos Afonso , Marie Suely K.N. , de Almeida José Reynaldo Walther , Wakamatsu Alda , Oba‐Shinjo Sueli Mieko , Uno Miyuki , Neville Munro , Rosemberg Sérgio
Published: February 2014

Glioblastoma (GBM), the most frequent and aggressive brain tumor, is characterized by marked angiogenesis directly related to invasiveness and poor prognosis. Hypoxia is considered to be an important stimulus for angiogenesis by inducing hypoxia‐inducible factor 1‐alpha (HIF‐1α) overexpression that activates platelet‐derived growth factor (PDGF) and VEGF. The aim of this study is to analyze the expression of PDGF‐C, VEGF in endothelial and tumor cells of GBM and their relation to HIF‐1α expression. Two hundred and eight GBM cases were studied by tissue microarray immunohistochemical preparation. Expression of HIF‐1α, VEGF and PDGF‐C was observed in 184 (88.5%), 131 (63%) and 160 (76.9%) tumor cases, respectively. The numbers of vessels were quantified by CD34, PDGF‐C, VEGF and CD105 staining, and were in median 20, 16, 5 and 6, respectively. The GBMs that showed positive or negative expression for HIF‐1α showed a median vascular density of 30 and 14, respectively, for CD34 (P < 0.015). Positive expression for HIF‐1α was correlated with VEGF and PDGF‐C expression in tumors (P < 0.001). There was a significant correlation between VEGF and PDGF‐C expression in the cytoplasm of GBM tumor cells (P < 0.0001). We showed that VEGF expression in tumor cells was correlated with its expression in blood vessels (P < 0.0001). Endothelial cells with PDGF‐C and VEGF positive expression were also positive for CD105 and their nuclei for Ki‐67, confirming the neoangiogenic and proliferative influence of VEGF and PDGF‐C. VEGF nuclear staining in tumor cells (P = 0.002) as well as nuclear staining for HIF‐1α and VEGF (P = 0.005) correlated with survival. In summary, our present findings of the concomitant upregulation of PDGF‐C with VEGF in GBM tumor cells and vessels further reinforce the benefit of using combined anti‐angiogenic approaches to potentially improve the therapeutic response for GBM.
PIFs get BRright: PHYTOCHROME INTERACTING FACTORs as integrators of light and hormonal signals
Authors: de Lucas Miguel , Prat Salomé
Published: February 2014

Light and temperature, in coordination with the endogenous clock and the hormones gibberellin (GA) and brassinosteroids (BRs), modulate plant growth and development by affecting the expression of multiple cell wall‐ and auxin‐related genes. PHYTOCHROME INTERACTING FACTORS (PIFs) play a central role in the activation of these genes, the activity of these factors being regulated by the circadian clock and phytochrome‐mediated protein destabilization. GA signaling is also integrated at the level of PIFs; the DELLA repressors are found to bind these factors and impair their DNA‐binding ability. The recent finding that PIFs are co‐activated by BES1 and BZR1 highlights a further role of these regulators in BR signal integration, and reveals that PIFs act in a concerted manner with the BR‐related BES1/BZR1 factors to activate auxin synthesis and transport at the gene expression level, and synergistically activate several genes with a role in cell expansion. Auxins feed back into this growth regulatory module by inducing GA biosynthesis and BES1/BZR1 gene expression, in addition to directly regulating several of these growth pathway gene targets. An exciting challenge in the future will be to understand how this growth program is dynamically regulated in time and space to orchestrate differential organ expansion and to provide plants with adaptation flexibility.

Contents

Summary
1126

I.
Introduction
1126

II.
Light and phytochrome signaling
1127

III.
Phytochrome regulation of PIF activity
1128

IV.
Developmental processes regulated by PIFs
1128

V.
PIFs and hormonal control of light signaling
1129

VI.
Role of PIFs in diurnal control of cell elongation
1132

VII.
Response to vegetational shade
1135

VIII.
PIF control of responses to elevated temperatures
1136

IX.
Concluding remarks and future perspectives
1136

Acknowledgements
1137

References
1137
Agriculture, nutrition, and health in global development: typology and metrics for integrated interventions and research
Authors: Masters William A. , Webb Patrick , Griffiths Jeffrey K. , Deckelbaum Richard J.
Published: February 2014

Despite rhetoric arguing that enhanced agriculture leads to improved nutrition and health, there is scant empirical evidence about potential synergies across sectors or about the mix of actions that best supports all three sectors. The geographic scale and socioeconomic nature of these interventions require integration of previously separate research methods. This paper proposes a typology of interventions and a metric of integration among them to help researchers build on each other's results, facilitating integration in methods to inform the design of multisector interventions. The typology recognizes the importance of regional effect modifiers that are not themselves subject to randomized assignment, and trade‐offs in how policies and programs are implemented, evaluated, and scaled. Using this typology could facilitate methodological pluralism, helping researchers in one field use knowledge generated elsewhere, each using the most appropriate method for their situation.
Précis of nutrition of children and women in Haiti: analyses of data from 1995 to 2012
Authors: Ayoya Mohamed Ag , Heidkamp Rebecca , Ngnie‐Teta Ismael , Mamadoultaibou Aissa , Daniel Eddy Felix , Durandisse Emmanuela Blain , Saint‐Fleur Jean Ernst , Beaulière Jean Max , Koita Youssouf , M'Mbakwa Bienfait Eca , Stoltzfus Rebecca J. , Pierre Joseline Marhone
Published: February 2014

Between 1995 and 2012, many surveys including child and maternal nutrition indicators were conducted in Haiti. While many questions emerged from the results of those surveys, they have remained unanswered, in particular as they pertain to the determinants of poor children's and women's nutrition in Haiti. The purpose of this paper is to fill that gap and provide policymakers, program managers, and readers interested in nutrition issues in Haiti with information on (1) the trends and determinants of infant and young child feeding and food practices; (2) micronutrient deficiencies among children and women; (3) the status of severe acute malnutrition in children; (4) associations among women's empowerment, access to health care, water, and sanitation and child nutrition; (5) the current community‐based early child care and nutrition initiatives; and (6) the status of nutrition governance in the country. By looking at many sources of data, including previously published and new data, we provide insight into major predictors of child malnutrition and associations among child feeding practices, maternal nutrition, and child growth outcomes. We also show that important progress has been made recently in the governance of nutrition programs and in child and maternal nutrition indicators, a result of effective evidence‐based advocacy, partnerships, and design, implementation, and scale‐up of nutrition‐specific and sensitive interventions.
Probiotics and prebiotics: prospects for public health and nutritional recommendations
Authors: Sanders Mary Ellen , Lenoir‐Wijnkoop Irene , Salminen Seppo , Merenstein Daniel J. , Gibson Glenn R. , Petschow Bryon W. , Nieuwdorp Max , Tancredi Daniel J. , Cifelli Christopher J. , Jacques Paul , Pot Bruno
Published: February 2014

Probiotics and prebiotics are useful interventions for improving human health through direct or indirect effects on the colonizing microbiota. However, translation of these research findings into nutritional recommendations and public health policy endorsements has not been achieved in a manner consistent with the strength of the evidence. More progress has been made with clinical recommendations. Conclusions include that beneficial cultures, including probiotics and live cultures in fermented foods, can contribute towards the health of the general population; prebiotics, in part due to their function as a special type of soluble fiber, can contribute to the health of the general population; and a number of challenges must be addressed in order to fully realize probiotic and prebiotic benefits, including the need for greater awareness of the accumulated evidence on probiotics and prebiotics among policy makers, strategies to cope with regulatory roadblocks to research, and high‐quality human trials that address outstanding research questions in the field.
Application of toxicogenomic profiling to evaluate effects of benzene and formaldehyde: from yeast to human
Authors: McHale Cliona M. , Smith Martyn T. , Zhang Luoping
Published: February 2014

Genetic variation underlies a significant proportion of the individual variation in human susceptibility to toxicants. The primary current approaches to identify gene–environment (GxE) associations, genome‐wide association studies and candidate gene association studies, require large exposed and control populations and an understanding of toxicity genes and pathways, respectively. This limits their application in the study of GxE associations for the leukemogens benzene and formaldehyde, whose toxicity has long been a focus of our research. As an alternative approach, our published work has applied innovative in vitro functional genomics testing systems, including unbiased functional screening assays in yeast and a near‐haploid human bone marrow cell line. Through comparative genomic and computational analyses of the resulting data, human genes and pathways that may modulate susceptibility to benzene and formaldehyde were identified, and the roles of several genes in mammalian cell models were validated. In populations occupationally exposed to low levels of benzene, we applied peripheral blood mononuclear cell transcriptomics and chromosome‐wide aneuploidy studies in lymphocytes. In this review, we describe our comprehensive toxicogenomic approach and the potential mechanisms of toxicity and susceptibility genes identified for benzene and formaldehyde, as well as related studies conducted by other researchers.
Peripheral targets in obesity treatment: a comprehensive update
Authors: Chatzigeorgiou A. , Kandaraki E. , Papavassiliou A. G. , Koutsilieris M.
Published: February 2014

Obesity is a major epidemic of our time and is associated with diseases such as metabolic syndrome, type 2 diabetes mellitus and atherosclerotic cardiovascular disease. Although weight loss drugs, when accompanied by diet and exercise, could be a very helpful medical tool in treating obese or overweight patients, their usefulness has been questioned due to the complexity of this type of medication, which regards a plethora of issues such as efficacy and safety of the drug and also risks and benefits among different patients. In general, obesity drugs that target peripheral pathophysiological mechanisms can be divided into two main categories. The first category includes anti‐obesity agents able to reduce or limit energy absorption, such as pancreatic lipase and microsomal triglyceride transfer protein inhibitors. The second category consists of a heterogeneous group of compounds aiming to decrease fat mass by increasing energy expenditure or by redistributing adipose tissue. Angiogenesis inhibitors, beta‐3 receptor agonists, sirtuin‐Iactivators, diazoxide and other molecules belong to this group. The glucagon‐like peptide‐1 receptor agonists consist the third category of peripheral anti‐obesity agents discussed therein.

This review aims to provide a general overview of the molecules and substances that are already or could potentially be used as peripheral anti‐obesity drugs, the molecular mechanisms by which they act, as well as their current stage of development, production and/or availability.
Perforator Pedicled Propeller Flaps for Soft Tissue Coverage of Lower Leg and Foot Defects
Authors: Dong Kai‐xuan , Xu Yong‐qing , Fan Xin‐yu , Xu Long‐jiang , Su Xi‐xiong , Long Hai , Xu Li‐qi , He Xiao‐qing
Published: February 2014

Objective

To investigate the efficiency of perforator pedicled propeller flaps for soft tissue coverage of lower leg and foot defects.

Methods

Twenty patients (12 male, 8 females; mean age 28 years, range, 5–75) with soft tissue defects of the lower leg and foot were retrospectively reviewed. Their defects had been repaired with perforator pedicled propeller flaps from September 2011 to October 2013 and included five cases of injuries caused by spokes, four of infection with postoperative skin necrosis, two of dorsal skin defects caused by heavy objects and nine caused by car accidents. The areas of soft tissue defect were from 2 cm × 8 cm to 10 cm × 20 cm. Fifteen cases had terminal branch of the peroneal artery perforator flaps and five posterior tibia artery perforator flaps, flap size ranging from 5 cm × 11 cm to 12 cm × 28 cm. Color Doppler ultrasound was used to locate all perforator vessels, the calibers of which ranged from 0.8 mm to 1.0 mm.

Results

The intraoperative coincidence rate of the color Doppler ultrasound was 96.7%. The donor sites were sutured directly in 12 cases and skin grafted in 8. One case had a venous crisis within 24 h that was treated by removal some sutures and drainage. All cases were followed up for 1–18 months; all flaps survived well and pedicles had a satisfactory appearance. The patients were extremely satisfied with the results for repair.

Conclusion

Perforator pedicled propeller flaps have the advantages over other pedicle flap of being simple, safe, and effective and not involving vascular anastomosis.
New Cage for Posterior Minimally Invasive Lumbar Interbody Fusion: a Study in Vitro and in Vivo
Authors: Hong Xin , Wu Xiao‐tao , Zhuang Su‐yang , Bao Jun‐ping , Shi Rui
Published: February 2014

Objective

To design a new type of interbody fusion device made of nickel titanium NiTi shape memory alloy and to compare segmental stiffness after various posterior lumbar interbody fusion (PLIF) procedures in vitro and in vivo.

Methods

Twelve sheep lumbar functional spinal units were randomly allocated to four groups. One acted as controls (N); the other three were treated with autogenous iliac crest bone dowel graft (L), a threaded cylindrical titanium (KC) interbody fusion device (TFC) or a new type of interbody fusion device made of NiTi shape memory alloy (NT) containing autogenous iliac crest graft. In addition, 15 sheep were allocated to three groups; one served as controls and the other two underwent TFC (KC) or NiTi‐FC (NT). Nondestructive mechanical tests were performed in pure compression, extension, lateral bending and torsion. The operated spines were photographed regularly to assess changes in interbody height and degree of fusion. The animals were killed at 6 months for histologic testing.

Results

Biomechanical tests showed both the strength and axial stiffness of the NT and KC groups were significantly higher than those of the control group and L group (P < 0.05). When the mechanical performance in torque and torsion of each group were compared, the same results could be obtained. The maximal destructive load of the NiTi‐TFC was 11 200 N and the safety coefficient was above 1.2. Radiological observations revealed that the bone callus around the interbody fusion device were gradually increased postoperatively (2 months, no obvious; 4 months, poorly define; 6 months, dense). The KC and NT group had lost 16% and 16.5% of their postoperative height but remained well above normal disc height (P < 0.05). Histologic examination showed new trabeculation connected with that of the host.

Conclusion

The mechanical characteristics of the NiTi‐TFC are excellent and it is safe and reliable.
Lateral Patellar Translation Effects after Arthroscopic Partial Meniscectomy of Torn Discoid Lateral Meniscus
Authors: Fan Zhi‐ying , Wang Yi , Dong Qi‐rong , Chen Ming , Jin Zhi‐gao , Wang Yi‐gang
Published: February 2014

Objective

To investigate the effects of arthroscopic partial meniscectomy of torn discoid lateral meniscus on patellar tracking.

Methods

In all, 112 patients (112 knees) who underwent arthroscopic partial meniscectomy participated in the study. All subjects were examined with standing weight‐bearing magnetic resonance imaging (MRI) preoperatively and one month postoperation. Axial‐plane images through the maximum width of the patella and the maximum dorsal area of the femoral condyles were superimposed and the bisect offset index used to quantify patellar translation. Differences between pre‐ and postoperation in the bisect offset indexes were calculated and compared by Student's paired t‐test. P < 0.05 was considered statistically significant.

Results

Before surgery, the mean bisect offset index was 0.574 (0.437–0.692). One month postoperation, the mean bisect offset index was 0.622 (0.510–0.801). The postoperation bisect offset index increased by an average of 0.048 (−0.018 to 0.129) compared with the preoperation value; this difference is statistically significant result (t = 18.33, P < 0.01).

Conclusion

After arthroscopic partial meniscectomy, the patella translates more lateral to the femoral trochlear groove. These results suggest that arthroscopic partial meniscectomy may result in patellar maltracking.
Does Spinal Alignment Influence Acetabular Orientation: a Study of Spinopelvic Variables and Sagittal Acetabular Version
Authors: Radcliff Kristen E , Kepler Christopher K , Hellman Michael , Restrepo Camilo , Jung Kwang Am , Vaccaro Alexander R , Albert Todd J , Parvizi Javad
Published: February 2014

Objective

Although hip alignment and spinal alignment have been studied individually, there is little information concerning the relationship between them. The questions addressed in this study are: (i) Is there a reproducible measure of sagittal plane acetabular orientation; (ii) Is sagittal plane acetabular orientation determined more by pelvic incidence (PI) or acetabular wall coverage?

Methods

Data on patients who had undergone screening by CT scan of the pelvis for non‐orthopedic indications from 2005–2010 were retrospectively studied. There were 164 patients of mean age 59 years (range, 27–87). Patients with pelvic trauma, hip arthroplasty or other hip pathology were excluded. Measurements of relevant acetabular and spinopelvic variables were made in the sagittal plane. The sacro‐acetabular angle (SA) was defined as the angle between a tangent line to the anterior and posterior walls of the acetabulum and the S1 endplate. Multiple regression analysis was used to determine which factors contribute to SA angle.

Results

The mean sacro‐acetabular angle was 72° (SD = 14.8°). Center edge angles (CEAs) were measured at the anterior and posterior walls of the acetabulum. Mean anterior CEA was 69° (SD = 8.3°) and posterior CEA 107° (SD = 16.4°). Regression analysis revealed the largest significant predictors of SA angle were PI and A‐CEA.

Conclusions

Sagittal acetabular orientation is related to spino‐pelvic balance and morphological characteristics. Increased PI or posterior wall coverage corresponds to a more vertical acetabular orientation. Sagittal plane acetabular alignment may be an important variable in achieving favorable results after reconstruction.
Finite element, occlusal, microwear and microstructural analyses indicate that conodont microstructure is adapted to dental function
Authors: Martínez‐Pérez Carlos , Rayfield Emily J. , Purnell Mark A. , Donoghue Philip C. J.
Published: February 2014

Conodonts constitute the earliest evidence of skeletal biomineralization in the vertebrate evolutionary lineage, manifest as a feeding apparatus of tooth‐like elements comprised of enamel‐ and dentine‐like tissues that evolved in parallel with these canonical tissues in other total‐group gnathostomes. As such, this remarkable example of evolutionary parallelism affords a natural experiment in which to explore the constraints on vertebrate skeletal evolution. Using finite element analysis, informed by occlusal and microwear analyses, we tested the hypothesis that coincidence of complex dental function and microstructural differentiation in the enamel‐like tissues of conodonts and other vertebrates is a consequence of functional adaptation. Our results show topological co‐variation in the patterns of stress distribution and crystallite orientation. In regions of high stress, such as the apex of the basal cavity and inner parts of the platform, the crown tissue comprises interwoven prisms, discontinuities between which would have acted to decussate cracks, preventing propagation. These results inform a general occlusal model for platform conodont elements and demonstrate that the complex microstructure of conodont crown tissue is an adaptation to the dental functions that the elements performed.
Activation of N‐methyl‐D‐aspartate receptor glycine site temporally ameliorates neuropsychiatric symptoms of Parkinson's disease with dementia
Authors: Tsai Chon‐Haw , Huang Hui‐Chun , Liu Bey‐Ling , Li Chia‐Ing , Lu Ming‐Kuei , Chen Xianxiu , Tsai Mu‐Chieh , Yang Yu‐Wan , Lane Hsien‐Yuan
Published: February 2014

Aim

We have previously found that sarcosine, a glycine transporter I inhibitor, can improve the psychiatric symptoms of schizophrenia. In this study, we aimed to investigate whether the agent can also ameliorate neuropsychiatric symptoms of Parkinson's disease (PD) patients with dementia.

Methods

An 8‐week, double‐blind, placebo‐controlled trial was conducted in patients who had PD with dementia (PD‐D). Neuropsychiatric manifestations were measured before and at week 2 (V1), week 4 (V2) and week 8 (V3) after treatment. Linear regression with the generalized estimating equations was applied for data analysis.

Results

Fifteen patients were randomized into a sarcosine group; the other 15 into a placebo group. The generalized estimating equations model revealed significant differences in Hamilton Depression Rating Scale score (P = 0.049) at V1 and Neuropsychiatry Inventory (P = 0.039) at V2 between the treatment and placebo groups. By excluding the advanced patients from analysis, there were significant differences in Unified Parkinson's Disease Rating Scale V2 (P = 0.004) and V3 (P = 0.040), Hamilton Depression Rating Scale V1 (P = 0.014) and V2 (P = 0.047), Neuropsychiatry Inventory V1 (P = 0.002) and V2 (P < 0.001) and Behavior Pathology in Alzheimer's Disease Rating Scale V2 (P = 0.025) in favor of sarcosine.

Conclusion

Sarcosine temporally improved depression and neuropsychiatric symptoms in PD‐D patients without exacerbating the motor or cognitive features; the beneficial effects were more prominent in patients with mild–moderate severity. Enhancement of N‐methyl‐D‐aspartate receptor–glycine cascade may lead to a novel path for the management of PD‐D.
Functional magnetic resonance imaging study of external source memory and its relation to cognitive insight in non‐clinical subjects
Authors: Buchy Lisa , Hawco Colin , Bodnar Michael , Izadi Sarah , Dell'Elce Jennifer , Messina Katrina , Lepage Martin
Published: February 2014

Aim

Previous research has linked cognitive insight (a measure of self‐reflectiveness and self‐certainty) in psychosis with neurocognitive and neuroanatomical disturbances in the fronto‐hippocampal neural network. The authors’ goal was to use functional magnetic resonance imaging (fMRI) to investigate the neural correlates of cognitive insight during an external source memory paradigm in non‐clinical subjects.

Methods

At encoding, 24 non‐clinical subjects travelled through a virtual city where they came across 20 separate people, each paired with a unique object in a distinct location. fMRI data were then acquired while participants viewed images of the city, and completed source recognition memory judgments of where and with whom objects were seen, which is known to involve prefrontal cortex. Cognitive insight was assessed with the Beck Cognitive Insight Scale.

Results

External source memory was associated with neural activity in a widespread network consisting of frontal cortex, including ventrolateral prefrontal cortex (VLPFC), temporal and occipital cortices. Activation in VLPFC correlated with higher self‐reflectiveness and activation in midbrain correlated with lower self‐certainty during source memory attributions. Neither self‐reflectiveness nor self‐certainty significantly correlated with source memory accuracy.

Conclusion

By means of virtual reality and in the context of an external source memory paradigm, the study identified a preliminary functional neural basis for cognitive insight in the VLPFC in healthy people that accords with our fronto‐hippocampal theoretical model as well as recent neuroimaging data in people with psychosis. The results may facilitate the understanding of the role of neural mechanisms in psychotic disorders associated with cognitive insight distortions.
Cutaneous Findings Mistaken for Physical Abuse: Present but Not Pervasive
Authors: Schwartz Kimberly A. , Metz James , Feldman Kenneth , Sidbury Robert , Lindberg Daniel M. ,   the ExSTRA Investigators
Published: February 2014

Incorrect diagnoses during child abuse evaluations are serious. Because skin lesions are common in abuse, it is important to consider cutaneous mimics of physical abuse. The current study prospectively identified cutaneous mimics in a cohort of children evaluated for possible physical abuse. This is a secondary analysis of data from the Examining Siblings To Recognize Abuse research network's prospective, observational, cross‐sectional study involving 20 U.S. child abuse teams. Subjects were younger than 10 years old and were evaluated by child abuse physicians (CAPs) for concerns of physical abuse. CAPs prospectively documented whether mimics were identified during their physical abuse evaluations. Details of each patient with cutaneous mimics were evaluated to determine the types of mimics, which part of the evaluations identified mimics, and the perceived abuse likelihood. Of 2,890 children evaluated for physical abuse, 137 had at least one mimic identified and 69 had some cutaneous mimic components. Although 985 of 2,753 (39%) subjects without mimics had high levels of abuse concern, only 9 of 137 (6%) children with mimics had high levels of abuse concern (p < 0.001). Of 69 children with cutaneous mimics, 56 (81%) were diagnosed by history and physical examination. Cutaneous abuse mimics were identified in 2.4% of children evaluated for physical abuse. Although it was eventually determined that there was little or no concern for abuse in 84% of children with cutaneous mimics, a small number were physically abused. CAP evaluation may be valuable in recognizing children with cutaneous mimics who also were abused.
A Mixed Methods Evaluation of an International Service Learning Program in the Dominican Republic
Authors: Curtin Alicia J. , Martins Diane C. , Schwartz‐Barcott Donna
Published: February 2014

Objective

To examine the impact of an international service learning experience (ISL) using a quantitative and qualitative approach.

Design and Sample

A descriptive study was used to explore the impact of an ISL experience on global awareness, professional and personal growth with 11 baccalaureate nursing students in the Dominican Republic.

Intervention

Students participated in a three credit ISL program in the Dominican Republic which included pre‐ and postexperience seminars and a 2‐week, on‐site immersion experience.

Measures

The International Education Survey (IES) was used as the quantitative measure. Content analysis of Critical Reflective Inquiry (CRI) narratives was used as the qualitative method.

Results

Students reported a high overall impact (M = 5.9) using the IES with high means for the Professional Student Nurse Role (M = 6.10, SD: 0.74), Personal Development (M = 6.08, SD: 0.76), International Perspectives (M = 6.03, SD: 0.71), and a lower mean for Intellectual Development (M = 5.40, SD: 0.69). CRI narratives revealed specific areas of impact, for example, increased empathy and ability to communicate effectively with patients from life situations very different from their own.

Conclusions

Further exploration of the usefulness of various evaluation tools and methodological designs is warranted to understand this type of pedagogy and its' impact on student learning outcomes short‐ and long‐term.
Probing the sensory effects of involuntary attention change by ERPs to auditory transients
Authors: Horváth János
Published: February 2014

An auditory selective attention set allows one to enhance the processing of goal‐relevant sound events, which is reflected by the enhancement of the N1 event‐related potential (ERP). The present study investigated whether the sensory consequences of distraction (i.e., involuntary attention changes triggered by infrequent sensory events) can be revealed as the removal of this attentional ERP enhancement. Continuous tones featuring occasional gaps were presented, and participants performed a gap‐detection task. Independently from gaps, abrupt pitch changes (glides) were introduced, either rarely or frequently, in separate conditions. Whereas rare glides preceding gaps by 150 ms strongly impacted gap‐detection performance and gap‐related N1 amplitudes, their impact on gaps following rare glides by 650 ms was significantly smaller in both measures. This result demonstrates the utility of N1 in probing the sensory impact of auditory distraction.
Event‐related potential N270 delayed and enhanced by the conjunction of relevant and irrelevant perceptual mismatch
Authors: Bennett Matthew A. , Duke Philip A. , Fuggetta Giorgio
Published: February 2014

Event‐related potential studies using delayed match‐to‐sample tasks have demonstrated the presence of two components, N270 and N400, possibly reflecting the sequential processing of multiple sources of endogenous mismatch. To date, studies have only investigated mismatch between a single cue and target. In this study, we used distractor stimuli to investigate the effect of a secondary source of mismatch distinct from the task‐relevant stimulus. Subjects performed two paradigms in which the cue and target could match or mismatch. In one paradigm, task‐irrelevant distractors were added—producing a source of task‐irrelevant perceptual mismatch. A mismatch‐triggered negativity was elicited in both paradigms, but was delayed and enhanced in magnitude in the distractors present paradigm. It is suggested that the distractors may differentially affect mismatch responses through the generation of a task‐irrelevant mismatch response.
Spatial conceptual associations between music and pictures as revealed byN400 effect
Authors: Zhou Linshu , Jiang Cunmei , Delogu Franco , Yang Yufang
Published: February 2014

The processing of extramusical meaning can be reflected inN400 effects of theERP. However, how conceptual representations can be activated in music still needs to be specified. We investigated the activation of iconic meaningful representations in music by using a cross‐modal semantic priming paradigm with an implicit task. Pictures of spatial scenes were semantically congruent or incongruent to preceding music in three stimulus onset asynchrony (SOA) conditions. The results revealed that the semantically incongruent target pictures elicited largerN400 amplitude than the congruent target pictures. Moreover, the semantic priming effect was modulated by theSOAs. TheN400 effect was observed in the 200‐ms and 800‐msSOAconditions, but not in the 1,200‐msSOAcondition. These results suggest that extramusical meaning purely due to iconic sign quality can be activated, and that the conceptual activation in music can be rapid and automatic.
Correlation of band gap position with composition in high-k films
Authors: Ding Li , Friedrich Marion , Fronk Michael , Gordan Ovidiu D. , Zahn Dietrich R. T. , Chen Lin , Wei Zhang David , Cobet Christoph , Esser Norbert
Published: February 2014

Two series of ultrathin high-k samples (mixed layers HfxAlyOz and bilayers HfO2 on Al2O3) prepared by atomic layer deposition were investigated using spectroscopic ellipsometry in the energy range of 0.7–10.0 eV. The (effective) optical gap of both mixed layer and bilayer structures can be tuned by the film composition. The optical gap of mixed layers is linearly dependent on the Hf fraction from 5.77 (±0.02) eV for pure HfO2 to 6.71 (±0.02) eV for pure Al2O3. The effective absorption gap of bilayers measured in reflection geometry is lower than that of mixed layers with a comparable Hf fraction due to the dominant effect of the top layer. An increase in film thickness as well as a decrease in refractive index and gap energy was observed after sample storage for two months in atmosphere. The aging effect is likely due to further oxidation of the oxygen deficient high-k films caused by the oxygen diffusion from air into the films.
Measurement of decay times in coupled spaces
Authors: Xiang Ning , Goggans Paul M. , Li Donghua
Published: February 2014

To achieve enough variability for different performances, a number of new concert halls with secondary hard chambers coupled to the main floor have recently received positive evaluations. As a result, the acoustics of coupled spaces is drawing growing attention in architectural acoustics. In these coupled spaces, the sound energy decays with different exponential constants under certain conditions. For better understanding and control of the acoustics in coupled spaces an efficient measurement technique of identifying multiple decay times is therefore of critical importance. A Bayesian parameter estimation approach is applied to an algorithmic evaluation of decay times using measured Schroeders decay functions. This work discusses Bayesian analysis of systematic measurements in scaled-down, coupled rooms and real coupled spaces.
Concert hall acoustics at Bass Hall
Authors: Knight Derrick , Kwon Young-Min , Kreiger John , Holcomb Brandon , Hemenway Jamin , Summers Jason , Shimizu Yasushi , Jaffe Christopher
Published: February 2014

Traditionally, multi-purpose halls are believed to have less than adequate symphonic acoustic listening characteristics compared to one room concert halls such as Boston Symphony Hall. Over the last two years, students and faculty of the Sonics Program at the Rensselaer Polytechnic Institute conducted a series of measurements at the multi-purpose Bass Performance Hall in Forth Worth, Texas. In this investigation, Bass Hall is shown to have excellent concert hall metrics when configured for that purpose. Measurements of reverberation time, early decay time, clarity (C80), and center time (Ts) were taken according to the ISO 3382 standard. This data was compared to data from the great one-room concert halls. This comparison demonstrates that Bass Hall can function as an equally excellent concert hall, in spite of being a multi-purpose hall. [Research supported by the Bass Foundation.]
Simple, nonoptimal, real-time classifiers for euphausiid and copepod numerical density estimation
Authors: Atkins Philip R. , Bongiovanni Claire , Francis David T. I. , Foote Kenneth G. , Knutsen Tor , Eriksen Peter K. , Torp Larsen Mette , Mortensen Tom
Published: February 2014

An active sonar covering the frequency range 1.6–3.2 MHz was used to observe zooplankton at two sites along the Norwegian coast during the period 28 April–9 May 1999. The sonar transmitted LFM signals with an approximate bandwidth-time product of 100. The matched-filter envelope was computed within the receiver at a sampling rate of 10 M samples/s. Freshly caught, swimming specimens were insonified ex situ in a tank mounted on the stern of R/V Johan Hjort, and the envelope signal was classified by eye as belonging to the euphausiid Meganyctiphanes norvegica, or copepod Calanus finmarchicus. The separated signals were then averaged to produce templates corresponding to the two classes. All orientation information associated with the specimens was thus removed. A sliding-window-normalized covariance was calculated between the templates and the receiver output for a large number of ex situ and in situ pings, a technique capable of being implemented at the sampling rate of the receiver. Although simple, this multiple-hypothesis-testing procedure outperformed a conventional split-window (CFAR) normalizer and produced a rapid and apparently reliable method of distinguishing the two classes and estimating their numerical density. [Work supported by EU RTD Contract No. MAS3-CT95-0031.]
Use of multiple-beam echo-sounders for estimation of target strength in situ
Authors: Hampton Ian , Soule Michael A.
Published: February 2014

In principle, the average target strength of fish in a defined volume can be estimated in situ from the ratio between the volume backscattering strength and a count of the number of fish in the volume. The chief problems, which have precluded use of the method in practice, are the difficulty in obtaining reliable counts at common fish densities and in defining beam volume. It is suggested that both problems could be solved to a large extent by using a relatively modest high-frequency, multi-beam echo-sounder as a counter. This presentation outlines the underlying principle of the method, considers the design criteria, and describes a 48-element 420 kHz system, (code named abacus) which is being built to test the method. The system, which has been designed to operate to approximately 70 m, for target strengths in the range 40 to 55 dB, generates a single transmit beam and 32 receiving beams orthogonal to it, which intersect to give up to ten 1 deg × 1 deg resolution cells. Preliminary test-tank results are presented, and plans for further experimental work discussed. It is believed that the method should be capable of delivering in situ target strength estimates at densities well beyond the limit of current methods.
Rapid improvements on interaural-time-difference discrimination: Evidence for three types of learning
Authors: Ortiz Jeanette A. , Wright Beverly A. , Fitzgerald Matthew B. , Pillai Jagan
Published: February 2014

Listeners often show rapid improvements when first performing auditory discrimination tasks. This learning was explored by investigating how training 300–1500 trials on one of three conditions (all 2IFC) influenced interaural-time-difference (ITD) discrimination on a target ITD condition (lateralization, 0-μs ITD, 500 Hz). Listeners trained on ITD or interaural-level-difference (ILD) discrimination had equivalent ITD-discrimination thresholds that were significantly lower than those of naive listeners. However, listeners trained on duration discrimination had ITD-discrimination thresholds between those of naive and ITD-trained listeners. These data suggest that rapid decreases in ITD-discrimination threshold result partly from learning the general procedure (induced by the duration training) and partly from learning the lateralization task (induced by the ILD training). In contrast, compared to naive listeners, final within-subject standard deviations of the ITD-discrimination thresholds were significantly smaller for ITD-trained, somewhat smaller for ILD-trained, and no smaller for duration-trained listeners. These data suggest that rapid reductions in threshold variabiilty result partly from learning the lateralization task (induced by the ILD training) and partly from learning something provided, here, only by ITD training. Thus, at least three different types of learning can contribute to initial improvements in performance on auditory discrimination tasks. [Work supported by NIDCD.]
A method for studying variability in fricatives using time-dependent changes in spectral mean
Authors: Munson Benjamin
Published: February 2014

A large literature has examined variability in temporal, spectral, and kinematic measures as indices of speech motor control. While much of this literature has examined factors that influence within-speaker variability in temporal parameters, relatively little research has examined variability in acoustic parameters, and, in particular, variability in consonant acoustics. This paper presents a new method for studying within-speaker variability in fricative production by examining dynamic characteristics of the spectral mean. In this method, nonlinear regression is used to predict values of the first spectral moment of a 10-ms window of frication noise from its position in the fricative. The resulting measure of model fit, R2, is used as an index of within-speaker variability. This method was used on two corpora of archival data. In the first study, three English-speaking adults’ productions of /s/ in initial /sp/ and /sw/ clusters was examined. /s/ was found to be spectrally less variable when embedded in /sw/ sequences than when embedded in /sp/ sequences. The second study examined variability in the spectra of /f/, /s/ and /∫/ spoken at normal and slow rates of speech by adults and two groups of children. Age-group, rate and phonetic context affected fricative variability.
Vowel formant discrimination in quiet and noise for natural speech
Authors: Liu Chang , Kewley-Port Diane
Published: February 2014

Everyday communication takes place in background noise. The purpose of this study is to investigate the effects of noise on formant discrimination for naturally spoken vowels. Our analysis of formant discrimination for synthetic vowels found that formant resolution could be accounted for by excitation pattern and specific loudness models [D. Kewley-Port and Y. Zheng, J. Acoust. Soc. Am. 103, 1654 (1998)]. It is expected that excitation pattern and specific loudness model can be extended to account for the formant discrimination in natural speech in both quiet and noise, even though natural speech has more variability than synthetic speech. The present study measured formant frequency discrimination in quiet and noise for normal-hearing listeners. Thresholds were measured as ΔF in natural speech for F1 and F2 for a set of vowels /I, ε, ʌ, æ/ spoken by a female talker. Noise conditions used a long-term averaged speech spectrum to shape the noise. The signal-to-noise ratio (SNR) was manipulated systematically from −6 to +6 dB. Results showed different masking patterns for F1 and F2 with performance approaching asymptote between 0 and +3 dB SNR. Results from an analysis of these data with a specific loudness pattern model will be presented. [Work supported by NIHDCD-02229.]
Wavelet detection and denoising of low-frequency chirp signals
Authors: Wheatley Joseph S. , Ioup Juliette W. , Ioup George E.
Published: February 2014

The detection and classification of underwater acoustic signals embedded in noise is a fundamental problem of interest to the Navy. The use of wavelet transforms is a recent development in digital signal processing that has been applied in many different areas. A particular type of wavelet is the chirplet, which includes frequency variation as well as time shift and scaling. The analysis of low-frequency signals containing multiple chirps using wavelet and chirplet techniques is demonstrated. Examples of low-frequency synthetic chirp signals are generated. Denoising and feature extraction of these signals using various wavelets with wavelet packet techniques are described.
Wavelet analysis of acoustic Green’s functions in a shallow ocean environment
Authors: Morgan Antonio M. , Ioup Juliette W. , Ioup George E. , Smith George B.
Published: February 2014

Knowledge of the properties of acoustic Green’s functions can assist in the development of effective blind deconvolution algorithms for enhancing the classification performance of active and passive sonar systems. Green’s functions have been produced representing the acoustic propagation of signals in a given shallow ocean multipath environment. Simulated noise-free received signals are the result of convolving the Green’s functions with representative source signals. Wavelet analysis is performed on the Green’s functions, the source signals, and the received signals. Forty different wavelets are tested. Comparison of the wavelet transform coefficients illustrates similarities and differences in signal properties. Significant differences can be exploited to separate the source from the Green’s functions in the multichannel received signals for blind deconvolution source recovery. [Work supported by ONR.]
Shape sensitivity calculations for exterior acoustics problems
Authors: Feijoo Gonzalo R. , Pinsky Peter M.
Published: February 2014

We present a method to calculate the derivative of a functional determined by the shape of an object. This functional depends on the solution of a linear acoustic problem posed in an unbounded domain. We rewrote this problem in terms of another one posed in a bounded domain using the Dirichlet-to-Neumann (DtN) map, or the modified DtN map. Using a classical method in shape sensitivity analysis, called the adjoint method, we are able to calculate the derivative of the functional using the solution of an auxiliary problem. This method is particularly efficient because the cost of calculating the derivatives is independent of the number of parameters used to approximate the shape of the domain. The resulting variational problems are discretized using the finite-element method and solved using an efficient Krylov-subspace iterative scheme. Numerical examples that illustrate the efficacy of our approach are presented.
Scattering measurements and interface model validation for a rocky bottom at 2–4 kHz
Authors: Soukup Raymond J.
Published: February 2014

Validation of interface scattering models for the ocean bottom, such as the small slope approximation model of Gragg and Wurmser [J. Acoust. Soc. Am. 109 (2001)] requires acoustic scattering data covering a wide range of grazing angles with minimal sub-bottom penetration. Such data measurements were performed in the frequency band 2–4 kHz over an exposed limestone bottom off the Carolina coast (120 to 310 m water depths) during the Littoral Warfare Advanced Development Focused Technology Experiment 96-2 (LWAD FTE 96-2). Direct-path bottom scattering strengths were obtained at grazing angles ranging from 8 to 75 degrees using data fusion from multiple experimental geometries coupled with careful signal processing. This data processing includes corrections for the surface-reflected and other hybrid paths, and the rapid reverberation decay observed over the length of the pulses at higher grazing angles. The resulting frequency and grazing-angle dependencies exhibit trends consistent with those predicted by the elastic small-slope approximation model of Gragg and Wurmser. [Work supported by ONR.]
A new strategy for applying the parabolic equation to a penetrable rough surface
Authors: Wurmser Daniel
Published: February 2014

The range-dependent parabolic equation (PE) propagates an auxiliary field that roughly corresponds to the square root of the downrange flux. At the ocean bottom, the interface is broken into stair steps, and this auxiliary field is conserved at the vertical interfaces. Because of its success in matching benchmark solutions, this method is widely used to model standard propagation problems in underwater acoustics. However, when the interface is rough at the wavelength scale, the physics of the problem changes, and the standard approach ceases to be practicable. This talk presents a new approach specifically designed to handle this important problem. The Foldy–Wouthuysen transformation generates the PE for this auxiliary field, complete with a full suite of boundary conditions. In the discrete problem, the boundary conditions are used to evaluate the Hamiltonian on the interface, and the result is used to perform the next downrange step. At lowest order, the new theory streamlines the stair step method, and frees it from ad hoc impositions such as those spawned by the density jump at the ocean bottom. The approach also systematically provides higher-order corrections. [Work supported by ONR.]