bluuebunny/crossref_metadata_2025 huggingface dataset:
Epidermal growth factor receptor (EGFR) expression in periocular and extraocular sebaceous carcinoma
Authors: Ivan Doina , Prieto Victor G. , Esmaeli Bita , Wistuba Ignacio I. , Tang Ximing , Lazar Alexander J. F.
Published: July 2009

Sebaceous carcinoma has a predominant periocular origin but can also be extraocular. These two groups have distinct clinical courses. Insight into the molecular determinants of tumorigenesis and metastasis is limited. There is no effective treatment for metastatic sebaceous carcinoma. Epidermal growth factor receptor (EGFR) is implicated in tumorigenesis and can be a therapeutic target in certain settings.

We evaluated EGFR levels by immunohistochemistry (IHC), comparing its expression between periocular and extraocular tumors and assessed EGFR mutation status. IHC was performed in 36 cases: 19 periocular and 17 extraocular (10 associated with Muir‐Torre syndrome—MTS). EGFR IHC was scored for percentage of positive cells (< 5%, 5–25%, 26–50%, > 50%) and intensity (+1 = low , +2 = moderate , +3 = high ). Extraocular carcinomas showed markedly increased levels of EGFR when compared to periocular carcinoma cases, both in terms of distribution (88% were > 25% of tumor cells vs. 16%) and intensity (77% were 2+ or 3+ vs. 21%) (p < 0.001). Among extraocular cases, there was significantly lower EGFR expression in MTS‐related cases (p < 0.05). No EGFR mutations were identified.

Our results underscore the divergent mechanisms underlying the tumorigenesis of periocular and extraocular sebaceous carcinoma and suggest an association between aggressive behavior and increased EGFR expression in extraocular sebaceous carcinoma.

Ivan D, Prieto VG, Esmaeli B, Wistuba II, Tang X, Lazar AJF. Epidermal growth factor receptor (EGFR) expression in periocular and extraocular sebaceous carcinomas.
Idiopathic Lymphoplasmacellular mucositis‐dermatitis
Authors: Brix William K. , Nassau Sarah R. , Patterson James W. , Cousar John B. , Wick Mark R.
Published: July 2009

Background: In 1952, Zoon described a series of patients with dense plasma‐cell infiltrates in the glans penis. Since then, similar Zoon‐like lesions (ZLL) have been described on the external female genitalia and in the airways, for which over 20 designations currently exist.

Methods: Twenty‐eight cases of ZLL, twenty‐two cases of lichen planus, eight cases of plasmacytoma and two cases of syphilis were evaluated from the surgical pathology archive at the University of Virginia. Twenty‐four histologic data points were tabulated in each case, including 12 epidermal and 12 dermal features.

Results: Histopathologic findings were similar in the majority of cases of ZLL, regardless of their location. They demonstrated superficial cutaneous erosions, basal vacuolar alteration and many showed lozenge‐shaped keratinocytes in the epiderms. The dermis contained a dense inflammatory infiltrate composed predominantly of plasma cells, with scattered neutrophils and lymphocytes. Dense fibrosis was seen in the upper dermis.

Conclusions: A uniform nomenclature for ZLL does not exist. Based on the results of this analysis, we suggest that the generic term idiopathic lymphoplasmacellular mucositis‐dermatitis be considered to encompass the lymphoplasmacellular infiltrates in the skin and mucosal surfaces considered herein. This designation is morphologically descriptive and can be applied regardless of anatomic location.

Brix WK, Nassau SR, Patterson JW, Cousar JB, Wick MR. Idiopathic lymphoplasmacellular mucositis‐dermatitis.
Microscopic inflammatory foci in burn scars: data from a porcine burn model
Authors: Wang Xue‐Qing , Phillips Gael E. , Wilkie Ian , Greer Ristan , Kimble Roy M.
Published: July 2009

Background: Hypertrophic scars in burn victims usually occur after delayed wound healing and the active phase of scar formation can persist substantially even after wound closure. Currently, the pathophysiology of the hypertrophic scar is not completely understood. This study investigated the inflammatory response in scar tissue at week 6 post‐burn injury.

Methods: A porcine deep dermal partial thickness burn model was used. At week 6 post‐burn, a total of 528 scar biopsies from 72 burn scars (7–8 biopsies from each scar) and 174 normal skin biopsies from 18 pigs were collected and examined histologically.

Results: Microscopic inflammatory foci were identified in 17% (89/528) of scar biopsies. These microscopic inflammatory foci do not contain any irritant materials, are composed largely of polymorphonuclear cells with other inflammatory cells including multinucleate giant cells and show acute on chronic inflammatory response that has not been described previously in burn scars. Importantly, they are present in a significantly lower number in burns surgically debrided than in burns which have not been debrided.

Conclusions: This study identifies microscopic inflammatory foci in the porcine scar tissue layer and recommends thorough cleaning/debriding of burned necrotic tissue in order to minimize the formation of these inflammatory foci in scar tissue.

Wang X‐Q, Phillips GE, Wilkie I, Greer R, Kimble RM. Microscopic inflammatory foci in burn scars: data from a porcine burn model.
Expanding the clinicopathologic spectrum of palisaded encapsulated neuroma
Authors: Jokinen Chris H. , Ragsdale Bruce D. , Argenyi Zsolt B.
Published: July 2009

Palisaded encapsulated neuroma (PEN; solitary circumscribed neuroma) is a benign, morphologically characteristic cutaneous or mucosal neuroma. Most are solitary lesions on the face, neck or oral mucosa. Histologically, the majority appears as dermal nodules of Schwann cell‐rich fascicles, with or without distinctive encapsulation. To further expand on the existing literature regarding this neuroma, we herein describe three PENs with unique clinical and histopathologic features. All occurred on the acral skin, a rarely described site. Furthermore, one exceptional patient presented with multiple PEN on the bilateral hands, biopsies of which showed a prominent plexiform architecture. Awareness that PEN may occur on acral skin, may rarely present as multiple lesions, and recognition of the plexiform variant is important because PEN may histologically mimic other peripheral nerve sheath tumors. Additionally, misdiagnosis may have significant clinical implications.
Is the OSCE more stressful? Examination anxiety and its consequences in different assessment methods in dental education
Authors: Brand H. S. , Schoonheim‐Klein M.
Published: July 2009

Objective: To measure the levels of anxiety, self‐perception of preparation and expectation for success induced by an objective structured clinical examination (OSCE), a written examination and a preclinical preparation test, and to examine the effects of the three predictive variables on the outcome of the assessments.

Materials and methods: Test anxiety was measured with Spielberger’s state anxiety inventory. Preparation for the assessment and expectation to succeed were quantified with 4‐point Likert scales. The questionnaire was completed during an OSCE, a written examination, a preclinical crown and bridge preparation test and a non‐examination situation.

Results: The OSCE was a most anxiety‐provoking assessment method and students prepared more for the OSCE than for the other examinations. The expectation to succeed was also higher for the OSCE. State anxiety during the OSCE was associated with the level of preparation but not with scores obtained. The state anxiety during a written examination showed a positive relation with the scores obtained, but not with preparation or expectation to succeed. During the preclinical test, state anxiety showed a positive association with the preparation and expectation to succeed, but not with the scores for this test.

No significant gender effects were observed for the state anxiety, level of preparation or the expectation to pass the examination. In the written examination female students scored significantly higher than male students. Such a gender effect was not found for the scores of the OSCE or the preclinical test.

Conclusion: State anxiety was elevated during all three assessment methods. However, anxiety was not predictive of performance outcome in the OSCE, written examination or preclinical preparation test.
The impact of undergraduate geriatric dental education on the attitudes of recently graduated dentists towards institutionalised elderly people
Authors: De Visschere L. , Van Der Putten G.‐J. , De Baat C. , Schols J. , Vanobbergen J.
Published: July 2009

Objective:  The aim of the study was to assess the impact of undergraduate geriatric dentistry education on knowledge of ageing and on attitudes towards institutionalised elderly people, as perceived by recently graduated dentists.

Methods:  A validated questionnaire was sent by mail to all dentists of the study group (n = 357). The questionnaire collected socio‐demographic data, motives for pursuing a dental career, knowledge of ageing, attitude towards institutionalised elderly people using the Aging Semantic Differential (ASD), and aspects of geriatric dentistry education.

Results:  Great variability between the six dental schools involved was observed in respect of the undergraduate education received in geriatric dentistry. Dentists’ knowledge of ageing was also low. The mean value of ASD‐total indicated that in this study there was a negative attitude towards the institutionalised elderly. The covariate ‘financial motive for pursuing a dental career’ was the only item that seemed to have any significant influence on the ASD. Age was the only significant variable for knowledge. All other covariates were found not to have any influence.

Conclusions:  From this study it would appear that the attitude of recently graduated dentists in Belgium towards the institutionalised elderly is rather negative and their knowledge of ageing is poor. The actual level of geriatric dentistry education in the undergraduate curriculum did not appear to influence this attitude, but Belgian dental schools are challenged to reorientate their provision of geriatric dentistry education to include activities that help to develop positive perceptions towards the elderly, with an empathic positive and caring attitude.
Who will pass the dental OSCE? Comparison of the Angoff and the borderline regression standard setting methods
Authors: Schoonheim‐Klein M. , Muijtjens A. , Habets L. , Manogue M. , Van Der Vleuten C. , Van Der Velden U.
Published: July 2009

Aim:  Aim of this study is to elucidate which standard setting method is optimal to prevent incompetent students to pass and competent students to fail a dental Objective Structured Clinical Examination (OSCE).

Material and methods:  An OSCE with 14 test stations was used to assess the performance of 119 third year dental students in a training group practice. To establish the pass/fail standard per station, three standard setting methods were applied: the Angoff I method, the modified Angoff II with reality check and the Borderline Regression (BR) method. For the final decision about passing or failing the complete OSCE, three methods were compared: total compensatory (TC), a partial compensatory (PC) within clusters of competence and a non‐compensatory (NC) model. The reliability of the pass/fail standard of the three methods was indicated by the root mean square error (RMSE). As a criterion measure, a sample of the students (n = 89) was rated in the clinic by their instructors and accordingly these students were divided into two groups: competent and incompetent students. The students’ clinical rating (considered for this study as ‘true qualification’) was compared with the pass‐fail classification resulting from the OSCE. Undeserved passing of an incompetent student was considered as more damaging than failing a competent student.

Results:  The BR method showed more acceptable results than the two Angoff methods. In terms of pass rate the BR method showed the highest pass rates: for the TC model the Angoff method I and II and the BR showed pass rates of 86.6%, 86.6% and 97.5% respectively. For the PC model the pass rates were 30.3%, 34.5% and 61.3%, and for the NC model the pass rates were 0.8%, 1.7% and 7.6%. The BR method showed lower RMSEs (higher reliability): for the TC model the RMSEs were 1.3%, 1.0% and 0.3% for the Angoff I, Angoff II and BR method respectively, and for the PC model the RMSE of the clusters of competence range was 2.0—3.7% for Angoffs I; 1.8—2.2% for Angoff II and 0.6—0.7% for the BR method. In terms of incorrect decisions, the BR method had a higher loss due to incorrect decisions for the TC model than for the PC model which is in accordance with the results of other studies in medical education.

Conclusions:  Therefore we conclude that the BR method in a PC model provides defensible pass/fail standards and seems to be the optimal choice for OSCEs in health education.
In Vitro Protective Effect of Hypericum androsaemum Extract Against Oxygen and Nitrogen Reactive Species
Authors: Almeida Isabel F. , Fernandes Eduarda , Lima José L.F.C. , Costa Paulo Cardoso , Bahia Maria Fernanda
Published: July 2009

Abstract:  Hypericum androsaemum L. (Gutiferae) is a medicinal plant growing in Western Europe that has been used in traditional medicine in the prevention or treatment of liver diseases. Oxidative stress and nitrosative stress are common pathogenetic mechanisms contributing to initiation and progression of hepatic damage in several liver disorders. In the present study, an ethanol:water (4:6) extract from H. androsaemum branches and leaves were evaluated for its putative in vitro scavenging effects on 1,1‐diphenyl‐2‐picrylhydrazil radical, on reactive oxygen species, namely HO•, O2•−, ROO•, 1O2 and H2O2 and on reactive nitrogen species, namely •NO and ONOO−. The hypericum extract presented a remarkable capacity to scavenge all the tested reactive species, all the IC50 values being found at the μg/ml level. IC50 values for 1,1‐diphenyl‐2‐picrylhydrazil, and for the reactive oxygen species O2•−, H2O2, HO• and 1O2 were 11.3 ± 0.7, 32.7 ± 3.4, 944 ± 47, 595 ± 82, 28.3 ± 1.2 μg/ml respectively. The oxygen radical absorbance capacity value obtained for ROO• was 1.5 ± 0.1 μmol Trolox equivalents/mg extract. The IC50 values for •NO and ONOO− were 2.2 ± 0.2 and 1.2 ± 0.1 μg/ml respectively. The content of total phenolics was 281 ± 2 mg of gallic acid equivalents/g of lyophilized extract. The observed antioxidant activity provides scientific support for the reported therapeutic use of H. androsaemum, though further in vitro and in vivo studies are required to ascertain the risk/benefit score at therapeutic concentrations.
Beyond the “Model Minority” Stereotype: Trends in Health Risk Behaviors Among Asian/Pacific Islander High School Students
Authors: Lee Sung‐Jae , Rotheram‐Borus Mary Jane
Published: July 2009

BACKGROUND: Asian/Pacific Islander (API) students have been stereotyped as the “model minority.” The objective of this study was to examine the trends in health risk behaviors among API students who participated in the San Diego City Schools Youth Risk Behavior Survey (YRBS) between 1993 and 2005.

METHODS: High school students from the San Diego City School District completed the self‐administered YRBS between 1993 and 2005. Among sexually active students, logistic regression for survey data was used to examine trends in health risk behaviors.

RESULTS: From 1993 to 2005, condom use at last sexual intercourse was consistently lower among API students than their cross‐ethnic peers. We observed a significant increasing trend in lifetime smoking, drinking, and marijuana use. Parental communications regarding human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) were significantly less frequent and decreased over time.

CONCLUSIONS: Our findings challenge the notion of API youth being the “model minority.” API students face unique challenges, including barriers to good communication about sex and lower rates of condom use. School‐based prevention programs are needed for API students, including a focus on HIV communication with parents.
Influence of Funding Cuts on Texas School Tobacco Programs*
Authors: Gingiss Phyllis M. , Boerm Melynda
Published: July 2009

BACKGROUND: Following the Master Settlement Agreement, state tobacco prevention spending peaked in 2002, but has subsequently been diminishing annually. This study compared the influence of 2004 Texas tobacco program budget cuts on school practices a year after funding loss.

METHODS: Three school groups were compared: continuously funded for a 2‐year minimum (n = 109), funded but discontinued (n = 123), and never funded (n = 70). Among the 123 schools with discontinued funding, differences were examined based on funding cut decision level (state or local). Written responses to surveys based on the Centers for Disease Control and Prevention (CDC) School Health Education Profile Tobacco Module were received from 49% of health coordinators and 58% of principals.

RESULTS: Principals and health coordinators from continuously funded schools reported more 1) tobacco instrunctional activities; 2) teacher training; 3) student cessation support; 4) program leadership; 5) a district advocate; 6) interest in tobacco use prevention education; 7) use of evidence‐based programs and CDC‐recommended teaching methods; 8) involvement of school staff; 9) student tobacco cessation programs at school and community; 10) family involvement; and 11) staff development funding. Previously funded schools approached profiles of those never funded. Few differences were noted among schools with funding loss due to state or local decisions.

CONCLUSION: The continuously funded schools consistently were better positioned to positively reach their students with effective tobacco programs. Funding reductions were associated with rapid reductions in programming. Results emphasize the need for early programmatic initiation of capacity building skill development to ensure implementation and retention of health programs during fiscally challenging circumstances.
Mountain Dew®or Mountain Don't?: A Pilot Investigation of Caffeine Use Parameters and Relations to Depression and Anxiety Symptoms in 5th‐ and 10th‐Grade Students
Authors: Luebbe Aaron M. , Bell Debora J.
Published: July 2009

BACKGROUND:Caffeine, the only licit psychoactive drug available to minors, may have a harmful impact on students' health and adjustment, yet little is known about its use or effects on students, especially from a developmental perspective. Caffeine use in 5th‐ and 10th‐grade students was examined in a cross‐sectional design, and relations and potential mediators of caffeine use to depression and anxiety symptoms were investigated.

METHODS:Children (n= 135) and adolescents (n= 79) completed a measure of naturalistic use of caffeinated and noncaffeinated beverages. Furthermore, daily availability, perceived benefits, and stimulating, psychological, and withdrawal effects of caffeinated and noncaffeinated beverages were assessed. Measures of depression and anxiety were also administered.

RESULTS:Fifth and 10th graders used caffeine frequently. Depression was positively related to caffeine use for both cohorts, though mediated by caffeine withdrawal effects. Surprisingly, anxiety was unrelated to use. Fifth graders reported less daily access to caffeine, but more psychological and stimulating effects of caffeine than 10th graders.

CONCLUSIONS:Although both children and adolescents experience negative caffeine‐related outcomes, intake is seemingly not greatly limited in either cohort. In particular, youth appear vulnerable to increased depressive symptoms with increasing caffeine consumption. Implications for school policy regarding students' caffeine use are discussed.
How Prosody Influences Sentence Comprehension
Authors: Carlson Katy
Published: July 2009

Prosody, or the tune and rhythm of speech, affects the interpretation and comprehension of sentences. This article first summarizes the prosodic system of English and then reviews research on how prosodic boundaries and pitch accents affect sentence processing. In general, prosodic boundaries usually influence attachment decisions, as they are seen to reflect syntactic structure, while pitch accents relate to the focus and information structure of a sentence. However, neither mapping is simple, because multiple prosodic contours are possible for any particular sentence. Prosody tends to be influential rather than decisive in resolving syntactic ambiguity.
Long‐term Hydrological Forecasting in Cold Regions: Retrospect, Current Status and Prospect
Authors: Gelfan Alexander N. , Motovilov Yury G.
Published: July 2009

The influence of long‐term snow accumulation on the runoff conditions several months afterwards is a distinct hydrological characteristic of cold regions, which creates opportunities for long‐term (seasonal and subseasonal) hydrological forecasting in these regions. We consider evolution of the long‐term forecasting approaches from the deterministic data‐based index methods to the hydrological model‐based ensemble approaches. Of key interest in this review are the methods developed and used in operational practice in Russia and in the USA, with the emphasis being placed on the methods used in Russia, which may be less familiar to international hydrological society. Following a description of the historical context, we review recent developments that place emphasis on problems relating to the uncertainty of the weather conditions for the lead time of the forecast. We conclude with a personal view of the prospects for the future development of long‐term hydrological forecasting techniques.
Effect of Beef Product Physical Structure on Salmonella Thermal Inactivation
Authors: Mogollón María Avelina , Marks Bradley P. , Booren Alden M. , Orta‐Ramirez Alicia , Ryser Elliot T.
Published: July 2009

ABSTRACT:  Numerous studies have assessed thermal inactivation of Salmonella in beef. However, the impact of muscle structure has been considered only recently, with several studies reporting enhanced thermal resistance in whole‐muscle as compared to ground meat. The functional relationship between meat product physical structure and Salmonella thermal resistance has not been reported; therefore, it is not known whether thermal resistance is affected by the degree of grinding (that is, size of resulting particles). The objective of this study was to evaluate the relationship between thermal resistance of Salmonella and degree of grinding (whole‐muscle, coarsely ground, finely ground, and beef puree). Each of the 4 product types was irradiated to sterility and inoculated with a marinade containing an 8‐serovar Salmonella cocktail to achieve approximately 107.8 CFU/g. Samples (5 g each) were packed into sterile brass tubes, which were sealed, held at 60 °C in a water bath, and removed at 30 s intervals. Samples were then serially diluted and plated on Petrifilm™ aerobic count plates to enumerate surviving salmonellae. All samples had the same composition, thermal history, and initial Salmonella counts; therefore, differences in thermal resistance were due entirely to the degree of grinding. Overall, thermal resistance of Salmonella was highest (P < 0.0001) in whole‐muscle (D = 2.7 min), but there were no differences among the 3 ground products (Dmean= 1.2 min). Therefore, it would be prudent for Salmonella thermal inactivation models to consider whether a product is whole‐muscle or ground, but not necessarily the degree of grinding.

Practical Application: The results of this study suggest that thermal process validations for ready‐to‐eat meat products should also consider the structure of the product (which in this study was changed by the physical act of grinding). Salmonella was more resistant to heat in whole‐muscle beef than in ground products; however, the degree of grinding did not affect the resistance.
Effect of Osmotic Dehydration and Vacuum‐Frying Parameters to Produce High‐Quality Mango Chips
Authors: Nunes Yolanda , Moreira Rosana G.
Published: July 2009

ABSTRACT:  Mango (Mangifera indica L.) is a fruit rich in flavor and nutritional values, which is an excellent candidate for producing chips. The objective of this study was to develop high‐quality mango chips using vacuum frying. Mango (“Tommy Atkins”) slices were pretreated with different maltodextrin concentrations (40, 50, and 65, w/v), osmotic dehydration times (45, 60, and 70 min), and solution temperatures (22 and 40 °C). Pretreated slices were vacuum fried at 120, 130, and 138 °C and product quality attributes (oil content, texture, color, carotenoid content) determined. The effect of frying temperatures at optimum osmotic dehydration times (65 [w/v] at 40 °C) was assessed. All samples were acceptable (scores > 5) to consumer panelists. The best mango chips were those pretreated with 65 (w/v) concentration for 60 min and vacuum fried at 120 °C. Mango chips under atmospheric frying had less carotenoid retention (32%) than those under vacuum frying (up to 65%). These results may help further optimize vacuum‐frying processing of high‐quality fruit‐based snacks.
Probing Predispositions: The Pragmatism of a Process Perspective
Authors: Moore David S.
Published: July 2009

Abstract—AsJ. P. Spencer et al. (2009)argue, the theories of some developmental psychologists continue to be nativistic, even though nativism is an inherently nondevelopmental school of thought. Psychologists interested in development study the emergence of human characteristics—including predispositions—and are not content to simply catalogue competences that characterize human newborns; instead, they recognize that all human characteristics, including those present at birth, reflect the circumstances of development. A truly developmental science of behavior requires rejecting the nativism–empiricism debate outright, abandoning ideas such as “core knowledge” and psychological “endowments,” and adopting a process perspective that focuses onhowtraits emerge from the co‐actions of biological and experiential factors. Unlike nativism, the process perspective advocated byJ. P. Spencer et al.encourages research that can reveal the developmental origins of psychological characteristics of interest.
Research and Policy on Children’s Play
Authors: Pellegrini Anthony D.
Published: July 2009

Abstract— The role of play in human development is a source of controversy. Some view it as indispensable to children’s healthy development and education, whereas others marginalize it as a topic unworthy of study and of questionable functional significance. This article suggests that differences in how researchers define play and conceptualize function have led to this disagreement. It also makes educational policy and research recommendations about the role of play in children’s lives.
Privatizing Responsibility: Public Sector Reform under Neoliberal Government
Authors: ILCAN SUZAN
Published: July 2009

À la lumière des réformes du secteur public au Canada et ailleurs, l'auteure se concentre sur le déplacement des priorités des responsabilités sociales vers les responsabilités privées et soulève de nouvelles questions sur les forces de l'entreprise privée et des partenariats reposant sur les mécanismes du marché. D'après elle, dans les programmes néo‐libéraux du gouvernement, laresponsabilité de la privatisationest liée à trois principaux aménagements : la reconsidération des relations entre le public et le privé; la mobilisation de l'esprit de civisme; et la création d'une mentalité culturelle d'observance de la règle allant de pair avec ces transformations. La recherche qui a été effectuée pour cet article s'est fondée sur l'analyse à grande échelle de documents de politique et d'initiatives de réforme du secteur public, de même que sur des interviews de fonctionnaires fédéraux canadiens.

In light of public sector reforms in Canada and elsewhere, this paper focuses on the shift of emphasis from social to private responsibilities and raises new questions about the forces of private enterprise and market‐based partnerships. Under neoliberal governmental agendas,privatizing responsibilitylinks to three main developments: the reconsideration of the relations of public and private; the mobilization of responsible citizenship; and the formation of a cultural mentality of rule that works alongside these developments. The research for this article is based on extensive analysis of policy documents and public sector reform initiatives, as well as interviews with Canadian federal public service employees.
Application of Constrained Stochastic Simulation to Determine the Extreme Loads of Wind Turbines
Authors: Bierbooms Wim
Published: July 2009

Via so-called constrained stochastic simulation, gusts can be generated, which satisfy some specified constraint. In this paper, it is used in order to generate specific wind gusts, which will lead to local maxima in the response of wind turbines. The advantage of constrained simulation is that any gust amplitude (no matter how large) can be chosen. By performing simulations for different gust amplitudes and mean wind speeds, the distribution of the response is obtained. This probabilistic method is demonstrated on the basis of a generic 1 MW stall regulated wind turbine. By considering a linearized dynamic model of the reference turbine, the proposed probabilistic method could be validated. The determined 50 year response value indeed corresponds to the theoretical value (based on the work of Rice on random noise). Next, both constrained and (conventional) unconstrained simulations have been performed for the nonlinear wind turbine model. For all wind speed bins, constrained simulation results in 50 year estimates closer to the real value. Furthermore, via constrained simulation a lower uncertainty range of the estimate is obtained. The involved computational effort for both methods is about the same.
Prediction of Wind Farm Power Ramp Rates: A Data-Mining Approach
Authors: Zheng Haiyang , Kusiak Andrew
Published: July 2009

In this paper, multivariate time series models were built to predict the power ramp rates of a wind farm. The power changes were predicted at 10 min intervals. Multivariate time series models were built with data-mining algorithms. Five different data-mining algorithms were tested using data collected at a wind farm. The support vector machine regression algorithm performed best out of the five algorithms studied in this research. It provided predictions of the power ramp rate for a time horizon of 10–60 min. The boosting tree algorithm selects parameters for enhancement of the prediction accuracy of the power ramp rate. The data used in this research originated at a wind farm of 100 turbines. The test results of multivariate time series models were presented in this paper. Suggestions for future research were provided.
Tracking Speed Analysis for Heliostat Using Spinning-Elevation Tracking Mode
Authors: Li Li , Lim Chern Sing
Published: July 2009

This paper discusses the tracking speed for different types of sun tracking algorithms, particularly the latitude-oriented spinning-elevation tracking mode in the solar energy application. It is found that the tracking speed of the spinning axis of a latitude-oriented type of heliostat varies drastically during solar noon around days of equinox. We analyze the time intervals during which the heliostat requires faster tracking speed and discuss the causes and possible solutions.
Determination of power-law attenuation coefficient and dispersion spectra in multi-wall carbon nanotube composites using Kramers–Kronig relations
Authors: Mobley Joel , Mack Richard A. , Gladden Joseph R. , Mantena P. Raju
Published: July 2009

Using a broadband through-transmission technique, the attenuation coefficient and phase velocity spectra have been measured for a set of multi-wall carbon nanotube (MWCNT)-nylon composites (from pure nylon to 20% MWCNT by weight) in the ultrasonic frequency band from 4 to 14 MHz. The samples were found to be effectively homogeneous on spatial scales from the low end of ultrasonic wavelengths investigated and up (>0.2 mm). Using Kramers–Kronig relations, the attenuation and dispersion data were found to be consistent with a power-law attenuation model with a range of exponents from y=1.12 to y=1.19 over the measurement bandwidth. The attenuation coefficients of the respective samples are found to decrease with increasing MWCNT content and a similar trend holds also for the dispersion. In contrast, the mean phase velocities for the samples rise with increasing MWCNT content indicating an increase in the mechanical moduli.
Cross-language differences in cue use for speech segmentation
Authors: Tyler Michael D. , Cutler Anne
Published: July 2009

Two artificial-language learning experiments directly compared English, French, and Dutch listeners’ use of suprasegmental cues for continuous-speech segmentation. In both experiments, listeners heard unbroken sequences of consonant-vowel syllables, composed of recurring three- and four-syllable “words.” These words were demarcated by (a) no cue other than transitional probabilities induced by their recurrence, (b) a consistent left-edge cue, or (c) a consistent right-edge cue. Experiment 1 examined a vowel lengthening cue. All three listener groups benefited from this cue in right-edge position; none benefited from it in left-edge position. Experiment 2 examined a pitch-movement cue. English listeners used this cue in left-edge position, French listeners used it in right-edge position, and Dutch listeners used it in both positions. These findings are interpreted as evidence of both language-universal and language-specific effects. Final lengthening is a language-universal effect expressing a more general (non-linguistic) mechanism. Pitch movement expresses prominence which has characteristically different placements across languages: typically at right edges in French, but at left edges in English and Dutch. Finally, stress realization in English versus Dutch encourages greater attention to suprasegmental variation by Dutch than by English listeners, allowing Dutch listeners to benefit from an informative pitch-movement cue even in an uncharacteristic position.
Finite element modeling of sound transmission with perforations of tympanic membrane
Authors: Gan Rong Z. , Cheng Tao , Dai Chenkai , Yang Fan , Wood Mark W.
Published: July 2009

A three-dimensional finite element (FE) model of human ear with structures of the external ear canal, middle ear, and cochlea has been developed recently. In this paper, the FE model was used to predict the effect of tympanic membrane (TM) perforations on sound transmission through the middle ear. Two perforations were made in the posterior-inferior quadrant and inferior site of the TM in the model with areas of 1.33 and 0.82mm2, respectively. These perforations were also created in human temporal bones with the same size and location. The vibrations of the TM (umbo) and stapes footplate were calculated from the model and measured from the temporal bones using laser Doppler vibrometers. The sound pressure in the middle ear cavity was derived from the model and measured from the bones. The results demonstrate that the TM perforations can be simulated in the FE model with geometrical visualization. The FE model provides reasonable predictions on effects of perforation size and location on middle ear transfer function. The middle ear structure-function relationship can be revealed with multi-field coupled FE analysis.
Lamb wave characterization of corrosion-thinning in aircraft stringers: Experiment and three-dimensional simulation
Authors: Bingham Jill , Hinders Mark
Published: July 2009

The development of automatic guided wave interpretation for detecting corrosion in aluminum aircraft structural stringers is described. The dynamic wavelet fingerprint technique (DWFT) is used to render the guided wave mode information in two-dimensional binary images. Automatic algorithms then extract DWFT features that correspond to the distorted arrival times of the guided wave modes of interest, which give insight into changes of the structure in the propagation path. To better understand how the guided wave modes propagate through real structures, parallel-processing elastic wave simulations using the finite integration technique (EFIT) has been performed. Three-dimensional (3D) simulations are used to examine models too complex for analytical solutions. They produce informative visualizations of the guided wave modes in the structures and mimic the output from sensors placed in the simulation space. Using the previously developed mode extraction algorithms, the 3D EFIT results are compared directly to their experimental counterparts.
Pile driving zone of responsiveness extends beyond 20 km for harbor porpoises (Phocoena phocoena (L.))
Authors: Tougaard Jakob , Carstensen Jacob , Teilmann Jonas , Skov Henrik , Rasmussen Per
Published: July 2009

Behavioral reactions of harbor porpoises (Phocoena phocoena) to underwater noise from pile driving were studied. Steel monopile foundations (4 m diameter) for offshore wind turbines were driven into hard sand in shallow water at Horns Reef, the North Sea. The impulsive sounds generated had high sound pressures [source level 235 dB re 1 μPapp at 1 m, transmission loss 18 log(distance)] with a strong low frequency emphasis but with significant energy up to 100 kHz. Reactions of porpoises were studied by passive acoustic loggers (T-PODs). Intervals between echolocation events (encounters) were analyzed, and a significant increase was found from average 5.9 h between encounters in the construction period as a whole to on average 7.5 h between first and second encounters after pile driving. The size of the zone of responsiveness could not be inferred as no grading in response was observed with distance from the pile driving site but must have exceeded 21 km (distance to most distant T-POD station).
Fundamental frequency influences the relationship between sound pressure level and spectral balance in female classically trained singers
Authors: Collyer Sally , Davis Pamela J. , Thorpe C. William , Callaghan Jean
Published: July 2009

The influence of fundamental frequency (F0) on the relationship between sound pressure level (SPL) and spectral balance (SB) has been largely unexplored in the female singing voice. Five classically trained females performed a messa di voce across their musical F0 range. Average maximum SB rose with F0 by 0.27 dB/semitone (ST) to B4 and then decreased, while average minimum SB fell by 0.5 dB/ST to E5 and then generally rose. Of 318 tokens, 208 showed a linear SPL:SB relationship (R2≥0.5), but F0 affected SPL:SB slope and intercept and their interaction above and below B4. The possibility that this reflects a change from subglottal inertance to compliance is discussed. Consistency of SB behavior change at B4 and E5 contrasted with variability in first-formant frequency. Nonlinear SPL:SB relationships did not arise from SB saturation. The presence of low-SPL “tails” may reflect the challenge in modifying vocal-fold adduction during crescendo and decrescendo. The results show that analysis of the SPL:SB relationship must take F0 into consideration.
A study of coupled flexural-longitudinal wave motion in a periodic dual-beam structure with transverse connection
Authors: Yun Yi , Mak Cheuk Ming
Published: July 2009

A theoretical study of the multi-coupling flexural and longitudinal waves that propagate in a periodic dual-beam-type waveguide with structural connection branches is conducted. The analytical equations of the transfer matrix method are derived for the wave transmission with consideration given to the fully flexural and longitudinal motions that are tri-coupled at each connection. Based on this transfer matrix method, numerical calculation is performed to investigate the characteristic wave-types that propagate in a semi-infinite periodic structure. The complex wave-coupling phenomena in the periodically connected dual-beam waveguide are then analyzed numerically. Remarkably, it is found that three symmetric and three antisymmetric types of characteristic coupled waves propagate in a periodic structure. The numerical results show that the energy contribution of the coupled waves with respect to the source excitation depends on the forbidden band of the wave-types and on the energy ratios and combination of wave-types. This study promotes the fundamental understanding and prediction of coupled acoustic waves in multi-layered frame structures. The long-term significance is that it may lead to a more effective control method for structure-borne sound transmission in a multi-layered coupling structure.
Factors affecting masking release in cochlear-implant vocoded speech
Authors: Li Ning , Loizou Philipos C.
Published: July 2009

Cochlear-implant (CI) listeners generally perform better when listening to speech in steady-state noise than in fluctuating maskers, and the reasons for that are unclear. The present study presents a new hypothesis for the observed absence of release from masking. When listening to speech in fluctuating maskers (e.g., competing talkers), CI users cannot fuse the pieces of the message over temporal gaps because they are not able to perceive reliably the acoustic landmarks introduced by obstruent consonants (e.g., stops). These landmarks are evident in spectral discontinuities associated with consonant closures and releases and are posited to aid listeners determine word/syllable boundaries. To test this hypothesis, normal-hearing (NH) listeners were presented with vocoded (6–22 channels) sentences containing clean obstruent segments, but corrupted (by steady noise or fluctuating maskers) sonorant segments (e.g., vowels). Results indicated that NH listeners performed better with fluctuating maskers than with steady noise even when speech was vocoded into six channels. This outcome suggests that having access to the acoustic landmarks provided by the obstruent consonants enables listeners to integrate effectively pieces of the message glimpsed over temporal gaps into one coherent speech stream.
A Burton–Miller inverse boundary element method for near-field acoustic holography
Authors: Chappell D. J. , Harris P. J.
Published: July 2009

An inverse boundary element method based on the Burton–Miller integral equation is proposed for reconstructing the Neumann boundary data from pressure values on a conformal surface in the near-field of an arbitrary radiating object. The accuracy of the reconstruction is compared with that of a method based on the more commonly used Helmholtz integral equation. In particular, the behavior at characteristic frequencies, which are known to be problematic in the Helmholtz integral equation for the forward problem, is examined. The effect of regularization is considered, including the L-curve parameter selection method. Numerical computations are given for noisy data generated from an internal point source.
Underwater acoustic beam dynamics
Authors: Beron-Vera Francisco J. , Brown Michael G.
Published: July 2009

Ray- and mode-based theoretical predictions of the spreads of directionally narrow beams are presented and compared to parabolic-equation-based simulations in deep-ocean environments. Both the spatial and temporal spreads of beams are considered. The environments considered consist of a range-independent deep-ocean background sound channel on which a highly structured sound-speed perturbation, associated with either internal waves or homogeneous isotropic single-scale turbulence, is superimposed. The simulation results are shown to be in good agreement with simple theoretical expressions which predict that beam spreading, in both the unperturbed and perturbed environments, is largely controlled by a property of the background sound channel—the ray-based stability parameter α or the asymptotically equivalent mode-based waveguide invariant β. These results are consistent with earlier results showing that wavefield structure and stability are largely controlled by α (or β).
Construction of the temporal invariants of the time-reversal operator
Authors: Philippe Franck D. , Prada Claire , Clorennec Dominique , Fink Mathias , Folégot Thomas
Published: July 2009

This paper proposes a method to construct the temporal Green’s function from a scatterer to an array of transducers in a waveguide using free-space back propagation of the eigenvectors of the time-reversal operator (TRO). The monostatic Green’s function is obtained as an eigenvector of the TRO which is known with an arbitrary phase; thus the impulse response cannot be obtained by a simple inverse Fourier transform. Assuming that the monochromatic fields obtained by the back propagation of the eigenvectors are in phase at the focal point, the phase correction is determined. Simulations and laboratory experiments are presented.
Scaled model experiment of long-range across-slope pulse propagation in a penetrable wedge
Authors: Korakas Alexios , Sturm Frédéric , Sessarego Jean-Pierre , Ferrand Didier
Published: July 2009

In this paper, laboratory scale measurements of long-range across-slope propagation of broadband pulses in a shallow-water wedge-shaped environment with a sandy bottom are reported. The scaled model was designed to study the three-dimensional (3D) acoustic field in the presence of only a few propagating modes. The recorded time series exhibit prominent 3D effects such as mode shadow zones and multiple mode arrivals. Inspection of the spectral content of the time signals gives evidence of intra-mode interference and frequency dependence of the mode cut-off range in the across-slope direction.
Multiband product rule and consonant identification
Authors: Li Feipeng , Allen Jont B.
Published: July 2009

The multiband product rule, also known as band-independence, is a basic assumption of articulation index and its extension, the speech intelligibility index. Previously Fletcher showed its validity for a balanced mix of 20% consonant-vowel (CV), 20% vowel-consonant (VC), and 60% consonant-vowel-consonant (CVC) sounds. This study repeats Miller and Nicely’s version of the hi-/lo-pass experiment with minor changes to study band-independence for the 16 Miller–Nicely consonants. The cut-off frequencies are chosen such that the basilar membrane is evenly divided into 12 segments from 250 to 8000 Hz with the high-pass and low-pass filters sharing the same six cut-off frequencies in the middle. Results show that the multiband product rule is statistically valid for consonants on average. It also applies to subgroups of consonants, such as stops and fricatives, which are characterized by a flat distribution of speech cues along the frequency. It fails for individual consonants.
Sensitivity of acoustic microscopy for detecting three-dimensional nanometer gaps embedded in a silicon structure
Authors: Tohmyoh Hironori , Akanda M. A. Salam
Published: July 2009

The sensitivity of acoustic microscopy for detecting three-dimensional defects in a Si structure is reported. Circular, nanometer gaps with diameters ranging from 5 to 1000 μm were embedded in Si disks by a direct bonding technique, and these were visualized using acoustic microscopy. The limits of detection for the gap thickness and diameter were observed simultaneously in samples with gaps of 4 and 140 nm. The behavior of the sensitivity in detecting the gaps can be explained by a simple analytical model. It is shown experimentally and theoretically that the gap thickness and diameter are not independent variables as regards detection. The sensitivity of acoustic microscopy is governed by the three-dimensional features of the embedded defects.