bluuebunny/crossref_metadata_2025 huggingface dataset:
Visibility Analysis In Vision Metrology Network Design
Authors: Saadatseresht Mohammad , Fraser Clive S. , Samadzadegan Farhad , Azizi Ali
Published: August 2004

The aim of this paper is to present a method whereby accuracy enhancement of an existing photogrammetric network is achieved through the automatic selection of additional camera stations. The determination of the positions of these ‘‘accuracy fulfilment’’ camera stations is based upon what has been termed ‘‘visibility uncertainty prediction modelling’’ of visibility constraints derived from the existing network geometry. Following a review of vision constraints in network design, the concepts of visibility uncertainty prediction and visibility uncertainty spheres are introduced. These provide a mechanism to predict the visibility of current object target points for the new accuracy fulfilment images. This in turn aids in network design improvement. The visibility uncertainty modelling is then illustrated for two close range photogrammetric network configurations, for which the test results demonstrate that the proposed model can reliably predict target visibility with an overall certainty of 75%.
MARGINAL DETERRENCE THROUGH AMBIENT ENVIRONMENTAL INSPECTIONS
Authors: Franckx Laurent
Published: August 2004

We consider the enforcement of an environmental standard if the probabilities of inspection are determined by an inspection agency who permanently monitors ambient pollution. This monitoring creates strategic interactions between polluters, which imply that the probability of inspection is increasing in the transgression level. These interactions also imply that marginal deterrence is possible, even with penalties that are not increasing in the transgression levels.
Combination of micro suction cups and time‐domain reflectometry to measure osmotic potential gradients between bulk soil and rhizosphere at high resolution in time and space
Authors: Vetterlein D. , Jahn R.
Published: August 2004

A prerequisite to investigate the importance of osmotic potential (Ψo) in relation to matric potential (Ψm) in the soil for water uptake is the existence of a method that measures the temporal and spatial dynamics of Ψo in the vicinity of roots. One method for measuring Ψoin situ is the collection of soil solution with micro suction cups, the spatial resolution of which is suitable for rhizosphere studies. A major drawback of soil solution sampling is the disturbance of soil solution equilibrium, which makes frequent measurements impossible, so another method is required to provide information on the temporal dynamics of Ψo. The time‐domain reflectometry (TDR) technique might be suitable as the signal attenuation (σ) shows a close linear correlation with the salt concentration for a known soil water content. The temporal resolution of the TDR technique is high and the measurement has no impact on soil solution equilibrium. However, the spatial resolution of the TDR technique is too coarse to be used on its own in rhizosphere studies.

We used a combination of TDR (fine temporal resolution) and micro suction cups (fine spatial resolution) to measure Ψo in a model system with Zea mays grown in quartz substrates. Osmotic potential changed continuously with time, and a steep gradient between bulk soil and the root compartment developed during the 39‐day growing period. The steepest gradient measured over a distance of 6 mm across the nylon net, separating the bulk soil from the root compartment, was −365 kPa. The combination of both methods made it possible to extend the time interval between micro suction cup samplings and thus minimize the impact of sampling on soil solution equilibrium. Problems of separate calibration were avoided by calibrating the TDR measurements against the results obtained with the micro suction cups within the same experiment.
Fractionated extraction of polycyclic aromatic hydrocarbons (PAHs) from polluted soils: estimation of the PAH fraction degradable through bioremediation
Authors: Thiele‐Bruhn S. , Brümmer G.W.
Published: August 2004

Chemical extractions were tested to estimate the fraction of 15 polycyclic aromatic hydrocarbons (PAHs) in polluted soils degradable through bioremediation. Of 30 soil samples, differing in PAH concentrations, from 10 long‐term polluted sites, four were used in screening tests conducted with 14 different extractants. PAH extractability increased in the order salt solutions < surfactant solutions < organic solvents and organic solvent–water mixtures. Closest correlations (r = 0.73–0.91) and ratios of c. 1:1 of the extracted to the degradable PAH concentrations were found with aqueous solutions of two surfactants (Genapol UDD 88, Synperonic LF/RA 30).

The PAH extractability by surfactant solutions increased with surfactant concentration (0–50 mg ml−1) and with decreasing degree of PAH condensation (6–2 rings). Kinetic behaviour of PAH solubilization by surfactants resembled the kinetics of PAH degradation (r = 0.84–0.99). With repeated extractions, a finite fraction of PAHs was extracted, which is thought to be the mobile and mobilizable PAH fraction, the latter being controlled by back‐diffusion from intra‐ and inter‐particle sites.

Experiments with all 30 soil samples and a priori testing with an additional 10 soil samples confirmed that single extractions with surfactant solutions (5 mg ml−1; soil:solution ratio 1:20) were suitable for estimating the degradable fraction of PAHs in soil. With separate linear regression equations for PAHs grouped according to their degree of condensation, the extracted concentrations described the degradable concentrations with correlation coefficients (r) ranging from 0.62 to 0.80 (P < 0.001). PAH extractions with the surfactant solutions can be used to assess the prospects of bioremediation of PAH‐polluted sites.
The impact of ivermectin treatment alone and when in parallel with Simulium neavei elimination on onchocerciasis in Uganda
Authors: Ndyomugyenyi Richard , Tukesiga Ephraim , Büttner Dietrich W. , Garms Rolf
Published: August 2004

The study was conducted in August 2002 in Kigoyera parish in Kyenjojo district, where ivermectin treatment had been the strategy to control onchocerciasis since 1991 and was later supplemented with Simulium neavei control in 1995 and subsequent elimination; and in July 2003 in Kicece parish in Kamwenge district, where ivermectin treatment alone had been the strategy used to control onchocerciasis since 1991. Our objective was to examine and compare the impact of ivermectin treatment alone and when in parallel with S. neavei elimination on nodule and microfilariae carrier rates and on onchocercal dermatitis to provide baseline data that could be used to monitor the trends of microfilariae carrier rates for decision‐making on when to discontinue ivermectin treatment. The combined interventions had significantly reduced onchocercal dermatitis from 34% pre‐control to 2.9% (P < 0.001), microfilariae carrier rate from 88 to 7.5% (P < 0.001) and nodule prevalence from 49 to 19.2% (P < 0.001). Ivermectin treatment alone had also reduced onchocercal dermatitis prevalence from 34.2% pre‐control to 9.5% (P < 0.001), the microfilariae carrier rate from 78 to 27.8% (P < 0.001) and nodule prevalence from 49.1 to 14.2% (P < 0.001). None of the children under 10 years were nodule or microfilariae carriers in both study areas. Histological examination of eight nodules extirpated from patients in Kigoyera identified five male and 12 female adult worms that were all old and alive. Five live and one dead female worms and one live male worm were identified from nodules extirpated from patients in Kicece. There was no female worm with embryogenesis from the nodules obtained from Kigoyera while two female worms from five nodules obtained from Kicece still showed a few embryos. Two female worms in each of the study area had sperms in uteri indicating that male worms were still active. Ivermectin treatment in parallel with vector elimination had a greater impact on onchocercal dermatitis and microfilariae carrier rates than ivermectin treatment alone. It would be worthwhile considering supplementation of ivermectin treatment with vector elimination in all isolated foci with S. neavei transmission to hasten the elimination of onchocerciasis as a public health and socio‐economic problem in those foci.
Rapid detection of human HLA transgenes in pigs by fluorescence in situ hybridization (FISH) for adjuvant study of human xenotransplantation
Authors: Wang Bao‐Tyan , Tu Ching‐Fu , Hsieh Lie‐Jiau , Tai Hao‐Chih , Chiu Ya‐Lan , Lee Jang‐Ming , Kuo Shou‐Jen , Tsuji Kimiyoshi , Lee Chun‐Jean
Published: August 2004

Abstract:  Objectives:  We have recently generated several lines of transgenic pigs for HLA‐DP and ‐DQ to elucidate the role of HLA‐II antigens in the modulation of cell‐mediated rejection of xenotransplantation. Using fluorescence in situ hybridization (FISH) analysis, the aim of this study was to determine integration sites and to test zygosity of these transgenes in the piglets after cross mating.

Methods:  Blood lymphocytes of transgenic pigs for HLA‐DP and ‐DQ were collected and cultured. Chromosome spreads were prepared by standard methodology. Gene constructs of HLA‐DP A1+B1, ‐DQ A1 & B1 were labeled with fluorescein isothiocyanate or Texas Red by nick‐translation. Hybridization was based on a standard FISH protocol.

Results:  FISH analysis revealed that the HLA‐DP probe hybridized to porcine chromosome 6, while both HLA‐DQ A1 and B1 probes hybridized to porcine chromosome 11 at the same site. There was no cross‐hybridization of HLA transgenes to the swine leukocyte antigen complex. Mosaic integration of HLA‐DQ transgenes in the genome of F0, but full penetrance in F1 after selective breeding was observed. Both HLA‐DP and HLA‐DQ lines were determined to be heterozygous at the integration site.

Conclusion:  By FISH, we have detected specific integration sites of the HLA‐DP and ‐DQ transgenes in pig genome and determined mosaic levels and zygosity types of these transgenes. We conclude that FISH is both sensitive and labor‐efficient in confirming and differentiating transgenic pigs for multiple rejection‐regulatory genes by visualizing individual integration sites in chromosomes or interphase nuclei.
Immunological rapid urease test using monoclonal antibody for Helicobacter pylori
Authors: NAKATA HIROYA , ITOH HIDEKAZU , ISHIGUCHI TADASHI , IWATA TAKUYA , SATO HIROAKI , HIGASHIMOTO YUJI , FUJIMOTO HISASHI , ICHINOSE MASAO
Published: August 2004

Background and Aim:  The current diagnostic methods for detecting Helicobacter pylori infection include rapid urease test (RUT), urea breath test (UBT), histology, culture, and serum antibody detection. The present study evaluated the efficacy of a novel highly specific test, an immunological RUT (IRUT), that uses a monoclonal antibody against H. pylori urease.

Methods:  The clinical evaluation of the IRUT was performed in 100 subjects. Each gastric mucus sample obtained during endoscopic examination was incubated for 15 min with a solid tip coated with monoclonal antibody for H. pylori urease, and then the tip was introduced into a pH‐monitoring cell containing urea solution. The change in pH of the solution after the enzymatic reaction (delta pH) was measured. The performance of the IRUT was compared with culture, histology, RUT, and UBT.

Results:  Of the 47 H. pylori‐positive subjects, 43 were IRUT positive (sensitivity, 91.5%), and of the 53 H. pylori‐negative subjects, 52 were negative (specificity, 98.1%). Compared with the usual diagnostic methods, IRUT had high sensitivity and specificity for the detection of H. pylori and was no less efficient.

Conclusions:  IRUT is a sensitive, specific and very rapid (within 20 min) method of detecting H. pylori infection.
Effect of sex steroids on colonic distension‐induced delay of gastric emptying in rats
Authors: GÜNAL ÖMER , BOZKURT AYHAN , DENIZ MUSTAFA , SUNGUR MUSTAFA , YEǦ BERRAK Ç
Published: August 2004

Background and Aim:  The objective of the present study was to examine the effect of gonadal hormones on gastric motor response to non‐noxious and noxious stimuli of colonic distension.

Methods:  Male Wistar albino rats were used. Under ketamine anesthesia some rats underwent castration (n = 24), while the rest of the rats were sham‐operated (n = 67) and divided into different groups (n = 7–8 per group). On the 15th day of surgery, liquid gastric emptying studies were commenced.

Results:  Non‐noxious (P < 0.05) or noxious (P < 0.01) colonic distension inhibited gastric emptying rate. Estradiol pretreatment (20 µg/kg per day, for 5 days, s.c.) inhibited gastric motility, while estradiol pretreatment or castration of the rats prior to noxious distension prevented the delay in gastric emptying. In contrast, blockade of testosterone receptors had no effect on the delay in gastric emptying induced by either modes of distension.

Conclusions:  The results suggest that sex steroids have a modulatory role on the feedback control of gastric motility induced by noxious colonic distension.
Practical difficulties in the management of hepatitis B in the Asia–Pacific region
Authors: MOHAMED ROSMAWATI , DESMOND PAUL , SUH DONG‐JIN , AMARAPURKAR DEEPAK , GANE EDWARD , GUANGBI YAO , HOU JIN‐LIN , JAFRI WASIM , LAI CHING LUNG , LEE CHANG‐HONG , LEE SHOU‐DONG , LIM SENG GEE , GUAN RICHARD , PHIET PHAM HOANG , PIRATVISUTH TEERHA , SOLLANO JOSE , WU JAW‐CHING
Published: August 2004

The Asia–Pacific Expert Committee on Hepatitis B Management recently reviewed the impact of hepatitis B in the region and assessed the differences and similarities observed in the practical management of the disease in individual Asia–Pacific countries. Hepatitis B is a major health concern in the Asia–Pacific region, and of all chronically infected carriers worldwide, approximately 75% are found in Asia. The disease poses a considerable burden on healthcare systems, and is likely to remain a cause of substantial morbidity and mortality for several decades. Disease prevention activities, including screening and vaccination programs, have been implemented successfully in some Asia–Pacific countries and similar measures are being established in other parts of the region. The management of hepatitis B in the Asia–Pacific varies throughout the region, with each country confronting different issues related to treatment options, disease monitoring and duration of therapy. The influence of cost, availability of diagnostic equipment, and patient awareness and compliance are of additional concern. Although guidelines such as those developed by the Asian Pacific Association for the Study of the Liver have been created to address problems encountered in the management of hepatitis B, many physicians in the region still find it difficult to make satisfactory management decisions because of the treatment choices available. This article examines the different approaches to hepatitis B management in a number of Asia–Pacific countries, and highlights the difficulties that can arise when adhering to treatment guidelines and disease prevention solutions that have proved to be successful in the region.
Inquiry into the ideal function of the pharmacy in home care*
Authors: Onda Mitsuko
Published: August 2004

Background:  The aim of this study is to analyze why home‐care services provided by pharmacists have not been effectively utilized.

Method:  Questionnaires were submitted to home‐care service users, physicians, visiting nurses and home‐helpers and pharmacy directors. We studied whether gaps existed between users’ needs, physicians’ expectations of pharmacy services and pharmacists’ awareness of the importance of pharmacy services. We also investigated whether a failure to recognize the importance of cooperation with pharmacists in home‐care provision existed among physicians and nurses/home‐helpers.

Results:  Users and physicians expect pharmacists to be more involved in counseling about home care and welfare services than home‐visiting services. Pharmacists recognize home visiting services as being of greater importance than counseling about home care and welfare services. The results indicated that gaps existed between users’ needs, the physicians’ expectations and pharmacists’ awareness of the importance of pharmacy services. In terms of cooperation with pharmacists, study results implied that: (i) nurses/home‐helpers’ awareness of pharmacists’ home‐visiting service is lower than that of physicians; (ii) physicians’ expectations regarding pharmacists’ participation in home care services is lower than that of nurses/home‐helpers; (iii) over 70% of both groups recognize the necessity of pharmacists’ home‐visiting service.

Conclusions:  Pharmacists need to get more involved in counseling users about home care and welfare. Also, there should be a special focus on heightening nurses/home‐helpers’ awareness of pharmacists’ home‐visiting service and on raising physicians’ expectations for pharmacists’ participation in home care services to develop home‐care related pharmacy services in Japan.
Abdominal surgery in patients 90 years of age and older at a provincial general hospital
Authors: Ichikawa Hideyuki , Hayashi Shiro
Published: August 2004

Background:  It has been commonly accepted that age itself is never an absolute contraindication for surgical treatment in the elderly. Some of the many problems with the oldest old could be solved by surgical intervention. However, there are quite a few issues to be resolved for the surgical treatment of patients aged in their nineties. We therefore investigated cases of abdominal operations performed during the past decade, and wish to give our point of view on the indication, significance, merits and demerits of conducting surgical operations in this age‐group of patients.

Methods:  We studied perioperative status, postoperative morbidity/mortality, and short‐ and long‐term outcomes of abdominal surgery in patients 90 years of age and older who underwent abdominal surgical operation at a provincial general hospital.

Results:  Seven patients had elective operations and six patients underwent emergency operations. The postoperative morbidity was fairly high after both elective and emergency operations. Major complications occurred in one patient who died of multiple organ failure 20 days after the operation. One patient stayed in the hospital and died there 240 days after gastrectomy. Three patients survived more than 4 years after surgery. No definite relationship was revealed between the risk score and postoperative morbidity/mortality. No evident change was recognized in the performance status in patients who received abdominal surgical operations.

Conclusion:  The results indicate that more meticulous consideration as well as more precise decision about the indication for surgical intervention, and more intensive perioperative management will be necessary in order to secure more favorable outcomes of therapy and quality of life for high‐risk patients aged in their nineties.
Association of a single nucleotide polymorphism in the secreted frizzled‐related protein 4 (sFRP4) gene with bone mineral density
Authors: Fujita Masayo , Urano Tomohiko , Shiraki Masataka , Momoeda Mikio , Tsutsumi Osamu , Hosoi Takayuki , Orimo Hajime , Ouchi Yasuyoshi , Inoue Satoshi
Published: August 2004

Background:  Wnt‐β‐catenin signaling pathway is involved in the regulation of bone mineral density (BMD). Secreted frizzled‐related protein (sFRP) 4 that antagonize Wnt signals may modulate Wnt‐β‐catenin signaling pathway in the bone. Therefore, we analyzed expression of sFRP4 mRNA in primary osteoblasts and the association of a single nucleotide polymorphism (SNP) in the sFRP4 gene with BMD.

Methods:  Expression levels of sFRP4 mRNA were analyzed during the culture course of rat primary osteoblasts. Association of a SNP in the sFRP4 gene at Arg262 (CGC to CGT) with BMD was examined in 372 healthy post‐menopausal Japanese women.

Results:  sFRP4 mRNA was detected and increased during the differentiation of rat primary osteoblasts. As an association study of the SNP in the sFRP4 gene, the subjects without the T allele (CC; n = 129) had significantly higher lumbar BMD than the subjects bearing at least one T allele (TT + CT; n = 243) (Z score; 0.054 versus−0.324; P = 0.0188).

Conclusion:  sFRP4 mRNA was expressed and regulated in primary osteoblasts. A genetic variation at the sFRP4 gene locus is associated with BMD, suggesting an involvement of sFRP4 gene in the bone metabolism.
Risk factors for insomnia in community‐dwelling older persons
Authors: Kawamoto Ryuichi , Yoshida Osamu , Oka Yuichiro , Takagi Yaemi
Published: August 2004

Background:  Aging is associated with changes in both subjective sleep quality and objective sleep patterns. The objectives of this study were to clarify risk factors for sleeping habits and insomnia symptoms in the community‐dwelling older persons.

Methods:  Study subjects were 1270 (33.5%), of the 3786 community‐dwelling persons aged 65 and older who responded to questionnaires concerning sleep disorders between July and October 2001.

Results:  Out of 556 men (mean age 73 ± 6.6) and 714 women (75 ± 7.5), 416 persons (32.8%) experienced insomnia. Multiple regression analysis on insomnia showed that significantly independent explanatory variables included gender (female: odds ratio [OR], 1.94; 95% confidence interval [CI], 1.39–2.71), activity status (OR, 1.54; 95% CI, 1.04–2.28), prescription medication (OR, 1.66; 95% CI, 1.25–2.20), presence of visual impairment (OR, 1.85; 95% CI, 1.42–2.42), presence of hearing impairment (OR, 1.47; 95% CI, 1.12–1.95) and depressive symptoms (OR, 2.54; 95% CI, 1.93–3.34). Interaction between the activity status and the depressive symptoms (F = 4.231, P = 0.040) was a significant independent explanatory variable with other risk factors.

Conclusion:  These results indicate that the aging process per se is not responsible for the increase of insomnia, which is often reported in elderly, but that inactivity, depressive symptoms, and use of prescription medication, visual impairment and hearing impairment were the best predictors of insomnia, the age being insignificant.
International Differences in Student Achievement: An Economic Perspective
Authors: Jürges Hendrik , Schneider Kerstin
Published: August 2004

International comparisons reveal large cross-country differentials in average student performance. Although there is considerable public debate about these differences, their sources are hardly identified. Using school, teacher and student data from the Third International Mathematics and Science Study (TIMSS), the present paper attempts to explain what causes between-country gaps in mathematics test score distributions. Following a three-pronged strategy of microlevel and cross-country regressions as well as bilateral country comparisons, we show how these gaps are explained by differences in school, teacher and student characteristics, or financial resources devoted to the school system. Institutional characteristics, such as competition between schools and the composition of the faculty can also help to understand international differences in student achievement.
Negotiating ‘home’ and ‘national identity’: Chinese‐Malaysian transmigrants in Singapore
Authors: Lam Theodora , Yeoh Brenda S.A.
Published: August 2004

Abstract:  Part of the globalisation phenomenon involves an increasing number of elite transmigrants traversing national boundaries in response to the global demand for skilled labour while maintaining multifaceted social ties astride political, geographic and cultural borders, linking home and host countries together. As transmigrants ‘live’ in several communities simultaneously, their identities, behaviour and values are often not limited by location. Thus, notions of ‘home’ and ‘national identity’ are also being reviewed given the discrepancies between these concepts and locality. In this context, this paper explores questions of ‘home’ and ‘national identity’ among skilled Chinese‐Malaysians working and residing in Singapore, portraying them as active participants of two (or more) countries. It focuses on their strategies and struggles in negotiating ideologies of ‘home’ and ‘national identities’ across borders in a setting of two neighbouring countries umbilically linked in a volatile political relationship. It further examines their degree of concern in the political affairs of both countries. Between ‘home’ and ‘host’, Chinese‐Malaysians redefine their practices of home(‐making) in relation to their national identity, drawing on the resources and resilience of familial ties, nostalgic memories and other practical lifecourse needs.
Aspects of Consumer Satisfaction With Brief Family Therapy
Authors: WOODWARD CHRISTEL A. , SANTA‐BARBARA JACK , LEVIN SOL , EPSTEIN N. B.
Published: August 2004

In an evaluative study of brief family therapy, 279 families were administered a Family Satisfaction Questionnaire in their own homes, six months after treatment terminated. This questionnaire was designed to assess several aspects of the families' satisfaction with services received. The identified patient in all families was a child with academic and/or behavioral problems at school. A variety of outcome measures were also obtained both at treatment termination and at the six‐month follow‐up. Families were generally satisfied with the overall services received but expressed widely varying degrees of satisfaction with various aspects of treatment. Very little dissatisfaction was expressed regarding the availability of services (less than 7 per cent), but a sizeable proportion of families (45 per cent) did not feel that the services provided were comprehensive and adequate. Despite concerns regarding comprehensiveness and adequacy of the service, the majority of families were functioning well at the time of follow‐up as assessed by a number of independent measures. Global satisfaction should not be regarded as the only index of treatment effectiveness, as many families who were dissatisfied experienced successful treatment outcomes.
Concurrent Grandparent Death and Birth of Schizophrenic Offspring: An Intriguing Finding
Authors: WALSH FROMA W.
Published: August 2004

The finding, in the following study, of grandparent death within ± two years of birth of 41 per cent of schizophrenics (N= 70), a rate significantly higher than that in psychiatric (N= 45) and normal (N= 25) control groups, raises the possibility that this family stress factor may contribute to the development of schizophrenia. The implications are considered regarding the likelihood that the concurrent stresses of the death and the birth, two major events in the family life cycle, could confound and impede mourning and parenting processes. Two hypotheses are suggested: (a) that a bereaved parent may be emotionally unavailable to spouse and infant, and (b) that attention to the child may block mourning and absorb painful feelings, with the child assuming a special replacement role. The dysfunctional potential is related to other interacting variables, including biological factors, mourning resolution, and the family system. Further study is called for.
Oral health status and change in handgrip strength over a 5‐year period in 80‐year‐old people
Authors: Hämäläinen Piia , Rantanen Taina , Keskinen Marja , Meurman Jukka H.
Published: August 2004

Objective: The number of remaining teeth may indicate the extent of life‐long exposure to inflammation, a known risk factor for muscle loss and consequent disability. The aim was to study dental health status as a risk factor for muscle strength loss in very old people.

Design: Cross‐sectional and prospective cohort study over a 5‐year follow‐up.

Setting: Research laboratory.

Participants: One hundred and ninety‐three 80‐year‐old people participated in the baseline examinations. Five years later, 79 survivors were retested.

Main outcome measures: Number of remaining teeth, presence of periodontitis and handgrip strength.

Results: At baseline, grip strength of men correlated positively with number of teeth but not with the presence of periodontitis. In women, the cross‐sectional associations were not statistically significant. In the prospective analyses, the presence of periodontitis at baseline showed a clear association with a steeper decline in handgrip over the 5‐year follow‐up in both sexes. The values adjusted for gender, height, weight, number of chronic conditions and physical activity were −28.3% (SE 5.7) among those with periodontitis vs. −11.9% (SE 3.1,p = 0.015) among those with healthy gingiva. No association between the number of teeth at baseline and change in grip strength over 5 years was observed.

Conclusions: The presence of oral inflammation may lead to loss in muscle strength increasing the risk of disability. Therefore, good dental care throughout the life span may decrease risk of disability in old age.
A three-parameter dispersion relationship for Biot’s fast compressional wave in a marine sediment
Authors: Buckingham Michael J.
Published: August 2004

When the bulk and shear moduli of the mineral frame are set to zero, the full Biot theory of wave propagation in a porous medium such as a marine sediment reduces to Williams’ “effective density fluid” (EDF) model [J. Acoust. Soc. Am. 110, 2276–2281 (2001)]. Although eight material variables appear in the EDF model, it is in fact tightly constrained, possessing just three degrees of freedom: the phase speeds in the limits of low and high frequency, c0 and c∞, respectively, and a transition frequency, fT, separating the low- and high-frequency regimes. In this paper, an algebraic approximation to the EDF model is formulated, which is termed the “modified viscous fluid” (MVF) model, involving only the three parameters (c0,c∞,fT). Expressions are developed for (c0,c∞,fT) in terms of the eight material properties; and a comparison of the MVF and EDF dispersion curves is performed, showing that they are essentially identical at all frequencies. Apart from its computational simplicity, the MVF model provides insight into the effect of each material parameter on the shape of the dispersion curves. For instance, the transition frequency scales as the ratio of the pore–fluid viscosity to the permeability, but neither the viscosity nor the permeability affects the limiting phase speeds c0 and c∞.
Broadband acoustic backscatter and high-resolution morphology of fish: Measurement and modeling
Authors: Reeder D. Benjamin , Jech J. Michael , Stanton Timothy K.
Published: August 2004

Broadband acoustic backscattering measurements, advanced high-resolution imaging of fish morphology using CT scans and phase-contrast x rays (in addition to traditional x rays), and associated scattering modeling using the images have been conducted involving alewife (Alosa pseudoharengus), a swimbladder-bearing fish. A greater-than-octave bandwidth (40–95 kHz) signal was used to insonify live, individual, adult alewife that were tethered while being rotated in 1-deg increments over all angles in two planes of rotation (lateral and dorsal/ventral). These data, in addition to providing the orientation dependence of the scattering over a continuous band of frequencies, were also used (after pulse compression) to identify dominant scattering features of the fish (including the skull and swimbladder). The x-ray and CT scan images of the swimbladder were digitized and incorporated into two scattering models: (1) Kirchhoff-ray mode (KRM) model [Clay and Horne, J. Acoust. Soc. Am. 96, 1661–1668 (1994)] and (2) conformal-mapping-based Fourier matching method (FMM), which has recently been extended to finite-length bodies [Reeder and Stanton, J. Acoust. Soc. Am. 116. 729–746 (2004)]. Comparisons between the scattering predictions and data demonstrate the utility of the CT scan imagery for use in scattering models, as it provided a means for rapidly and noninvasively measuring the fish morphology in three dimensions and at high resolution. In addition to further validation of the KRM model, the potential of the new FMM formulation was demonstrated, which is a versatile approach, valid over a wide range of shapes, all frequencies and all angles of orientation.
Acoustic scattering by axisymmetric finite-length bodies: An extension of a two-dimensional conformal mapping method
Authors: Reeder D. Benjamin , Stanton Timothy K.
Published: August 2004

A general scattering formulation is presented for predicting the far-field scattered pressure from irregular, axisymmetric, finite-length bodies for three boundary conditions—soft, rigid, and fluid. The formulation is an extension of a two-dimensional conformal mapping approach [D. T. DiPerna and T. K. Stanton, J. Acoust. Soc. Am. 96, 3064–3079 (1994)] to scattering by finite-length bodies. This extended formulation, which is inherently numerically efficient, involves conformally mapping the surface of an irregular, finite-length body to a new, orthogonal coordinate system in which the separation of variables method may be used to solve the Helmholtz equation and satisfy the boundary conditions. Extensive comparisons with previously published results using other formulations are presented. This formulation is shown to be accurate in the prediction of scattering from smooth, symmetric bodies for a wide range of frequencies (Rayleigh through geometric scattering region), scattering angles (monostatic and bistatic), aspect ratios, and for each of the three boundary conditions listed above. Reasonable agreement has also been demonstrated for irregular, realistic shapes with soft boundary conditions.
Performance bounds for passive sensor arrays operating in a turbulent medium: Spherical-wave analysis
Authors: Collier S. L. , Wilson D. K.
Published: August 2004

The Cramer–Rao lower bounds of the angle-of-arrival estimates for a spherical wave incident on a passive acoustic array are investigated for propagation through a turbulent medium with fluctuations described by a von Kármán spectrum. A single monochromatic source and a line-of-sight propagation path are assumed. The propagation distance, turbulence parameters (characteristic length scale and index-of-refraction variance), phase of the source, and signal-to-noise ratio are also included in the unknown parameter set. The Cramer–Rao lower bounds of the angle-of-arrival estimates are affected by the addition of the propagation distance and source phase as unknowns, and are not affected by the addition of the turbulence parameters and signal-to-noise ratio as unknowns.
Repetition patterns in Weddell seal (Leptonychotes weddellii) underwater multiple element calls
Authors: Moors Hilary B. , Terhune John M.
Published: August 2004

Many vocalizations produced by Weddell seals (Leptonychotes weddellii) are made up of repeated individual distinct sounds (elements). Patterning of multiple element calls was examined during the breeding season at Casey and Davis, Antarctica. Element and interval durations were measured from 405 calls all >3 elements in length. The duration of the calls (22±16.6 s) did not seem to vary with an increasing number of elements (F4,404=1.83,p=0.122) because element and interval durations decreased as the number of elements within a call increased. Underwater vocalizations showed seven distinct timing patterns of increasing, decreasing, or constant element and interval durations throughout the calls. One call type occurred with six rhythm patterns, although the majority exhibited only two rhythms. Some call types also displayed steady frequency changes as they progressed. Weddell seal multiple element calls are rhythmically repeated and thus the durations of the elements and intervals within a call occur in a regular manner. Rhythmical repetition used during vocal communication likely enhances the probability of a call being detected and has important implications for the extent to which the seals can successfully transmit information over long distances and during times of high level background noise.
Directional frequency and recording (DIFAR) sensors in seafloor recorders to locate calling bowhead whales during their fall migration
Authors: Greene Charles R. , McLennan Miles Wm. , Norman Robert G. , McDonald Trent L. , Jakubczak Ray S. , Richardson W. John
Published: August 2004

Bowhead whales, Balaena mysticetus, migrate west during fall ∼10–75 km off the north coast of Alaska, passing the petroleum developments around Prudhoe Bay. Oil production operations on an artificial island 5 km offshore create sounds heard by some whales. As part of an effort to assess whether migrating whales deflect farther offshore at times with high industrial noise, an acoustical approach was selected for localizing calling whales. The technique incorporated DIFAR (directional frequency and recording) sonobuoy techniques. An array of 11 DASARs (directional autonomous seafloor acoustic recorders) was built and installed with unit-to-unit separation of 5 km. When two or more DASARs detected the same call, the whale location was determined from the bearing intersections. This article describes the acoustic methods used to determine the locations of the calling bowhead whales and shows the types and precision of the data acquired. Calibration transmissions at GPS-measured times and locations provided measures of the individual DASAR clock drift and directional orientation. The standard error of the bearing measurements at distances of 3–4 km was ∼1.35° after corrections for gain imbalance in the two directional sensors. During 23 days in 2002, 10 587 bowhead calls were detected and 8383 were localized.
A closed-form solution for reflection and transmission of transient waves in multilayers
Authors: Caviglia G. , Morro A.
Published: August 2004

The reflection–transmission problem for a multilayer is examined in the time domain. The layers are linearly elastic, possibly anisotropic, but homogeneous. The multilayer is sandwiched between two homogeneous half-spaces and the incident wave propagates along the normal to the layers. By applying repeatedly the continuity of displacement and traction, the outgoing waves at each interface are evaluated in terms of the incoming ones. As a result, a system of equations is established which eventually determines the reflected and transmitted waves and the waves inside the layers, in terms of the incident wave. A few simple cases are examined in detail to show, e.g., the distortion of a rectangular incident pulse, originated by multiple reflections, and the occurrence of resonance effects.
A linear least-squares version of the algorithm of mode isolation for identifying modal properties. Part I: Conceptual development
Authors: Ginsberg Jerry H. , Allen Matt
Published: August 2004

The Algorithm of Mode Isolation (AMI) is an iterative procedure for identifying the number of modes contributing to a frequency response function (FRF) concurrently with identifying the complex eigenvalues and eigenvectors of those modes. The latest modifications obtain these modal properties solely by using linear least squares fits of the FRF data to canonical forms. The algorithmic operations are explained in a detailed sequence of steps that are illustrated by some sample data. The computational efficiency of AMI relative to other modal identification algorithms that fit response data to multi-degree-of-freedom model equations is discussed.
Shock-induced borehole waves in porous formations: Theory and experiments
Authors: Chao G. , Smeulders D. M. J. , van Dongen M. E. H.
Published: August 2004

The characteristics of the pseudo-Stoneley wave along boreholes in porous formations are studied in a broad band of frequencies (100 Hz–200 kHz). Experiments are performed using a shock tube technique to excite the pseudo-Stoneley wave in a water saturated confined reservoir. The formation is a natural Berea sandstone. Frequency-dependent phase velocities and damping coefficients are measured using this technique. Quantitative agreement between the experimental results and the theoretical predictions is found for the phase velocity in the frequency range from 10 to 50 kHz. Theoretically, the influence of the permeability on the phase velocity, attenuation, radial displacement, and pore pressure is studied on the basis of the Biot theory and the contribution of the different bulk modes to the average radial displacement is analyzed in the frequency domain. The numerical results indicate that the permeability dependence at low frequencies is caused by the Biot slow wave.
Across-frequency interference effects in fundamental frequency discrimination: Questioning evidence for two pitch mechanisms
Authors: Gockel Hedwig , Carlyon Robert P. , Plack Christopher J.
Published: August 2004

Carlyon and Shackleton [J. Acoust. Soc. Am. 95, 3541–3554 (1994)] presented an influential study supporting the existence of two pitch mechanisms, one for complex tones containing resolved and one for complex tones containing only unresolved components. The current experiments provide an alternative explanation for their finding, namely the existence of across-frequency interference in fundamental frequency (F0) discrimination. Sensitivity (d′) was measured for F0 discrimination between two sequentially presented 400 ms complex (target) tones containing only unresolved components. In experiment 1, the target was filtered between 1375 and 15 000 Hz, had a nominal F0 of 88 Hz, and was presented either alone or with an additional complex tone (“interferer”). The interferer was filtered between 125–625 Hz, and its F0 varied between 88 and 114.4 Hz across blocks. Sensitivity was significantly reduced in the presence of the interferer, and this effect decreased as its F0 was moved progressively further from that of the target. Experiment 2 showed that increasing the level of a synchronously gated lowpass noise that spectrally overlapped with the interferer reduced this “pitch discrimination interference (PDI)”. In experiment 3A, the target was filtered between 3900 and 5400 Hz and had an F0 of either 88 or 250 Hz. It was presented either alone or with an interferer, filtered between 1375 and 1875 Hz with an F0 corresponding to the nominal target F0. PDI was larger in the presence of the resolved (250 Hz F0) than in the presence of the unresolved (88 Hz F0) interferer, presumably because the pitch of the former was more salient than that of the latter. Experiments 4A and 4B showed that PDI was reduced but not eliminated when the interferer was gated on 200 ms before and off 200 ms after the target, and that some PDI was observed with a continuous interferer. The current findings provide an alternative interpretation of a study supposedly providing strong evidence for the existence of two pitch mechanisms.
Impulsive sound reflection from an absorptive and dispersive planar boundary
Authors: Lam Chee-Heun , Kooij Bert Jan , De Hoop Adrianus T.
Published: August 2004

The impulsive sound reflection from a planar boundary with absorptive and dispersive properties is investigated. The acoustic properties of the boundary are modeled via a local impedance transfer function whose complex frequency domain representation is taken to be a Padé (2,2) expression. The coefficients in this representation are matched to frequency domain acoustic wave reflection measurements. With the aid of the Cagniard–De Hoop method, a closed-form space-time expression is derived for the acoustic pressure of the reflected wave arising from the incidence of a point-source monopole excited spherical pulse. Depending on the acoustic impedance properties of the boundary, large-amplitude oscillating surface effects can occur. These surface phenomena differ in nature from the true surface waves like the Rayleigh, Scholte, and Stoneley waves in elastodynamics. Illustrative numerical results are presented.
Response of force excited elastic solids with internal fluid loading
Authors: Hassan Scott E. , Stepanishen Peter R.
Published: August 2004

A general approach to solving for the velocity response and associated pressure field of elastic solids loaded internally by a fluid is formulated. An in vacuo eigenvector expansion is used to describe the time dependent velocity field of the fluid loaded solid resulting from an arbitrary force excitation. The pressure field in the fluid is expressed using a Green’s function and fluid loading on the structure is included via the use of the impulse responses of the modal acoustic radiation impedances. The time dependent modal velocity responses are obtained from the solution to a set of coupled convolution integral equations. A Fourier transform approach is used to develop the associated equations of motion for the harmonic response. The special case of a fluid filled axisymmetric elastic cylindrical shell with a base plate is considered. Transient and harmonic velocity and pressure responses due to a bandlimited axisymmetric point force excitation applied to the base plate are discussed and compared with experimental measurements.
The cochlear amplifier as a standing wave: “Squirting” waves between rows of outer hair cells?
Authors: Bell Andrew , Fletcher Neville H.
Published: August 2004

This paper draws attention to symmetric Lloyd–Redwood (SLR) waves—known in ultrasonics as “squirting” waves—and points out that their distinctive properties make them well-suited for carrying positive feedback between rows of outer hair cells. This could result in standing-wave resonance—in essence a narrow-band cochlear amplifier. Based on known physical properties of the cochlea, such an amplifier can be readily tuned to match the full 10-octave range of human hearing. SLR waves propagate in a thin liquid layer enclosed between two thin compliant plates or a single such plate and a rigid wall, conditions found in the subtectorial space of the cochlea, and rely on the mass of the inter-plate fluid interacting with the stiffness of the plates to provide low phase velocity and high dispersion. The first property means SLR wavelengths can be as short as the distance between rows of outer hair cells, allowing standing wave formation; the second permits wide-range tuning using only an order-of-magnitude variation in cochlear physical properties, most importantly the inter-row spacing. Viscous drag at the two surfaces potentially limits SLR wave propagation at low frequencies, but this can perhaps be overcome by invoking hydrophobic effects.
Relationship between exposure to multiple noise sources and noise annoyance
Authors: Miedema Henk M. E.
Published: August 2004

Relationships between exposure to noise [metric: day-night level (DNL) or day-evening-night level (DENL)] from a single source (aircraft, road traffic, or railways) and annoyance based on a large international dataset have been published earlier. Also for stationary sources relationships have been assessed. Here the annoyance equivalents model concerning noise annoyance from combined sources and the underlying assumptions are presented. The model first translates the noise from the individual sources into the equally annoying sound levels of a reference source, road traffic, and then sums these levels giving total level L. The annoyance from the combined sources is found by substituting exposure L in the road traffic exposure-annoyance relationship. The most important assumption, independence of the contributions of the sources, is discussed. It appears that independence will be violated substantially only due to the effect of the presence or absence of a quiet side of a building, which is not incorporated in the model. For use in practice, the application of the model is broken down in five steps. The step by step procedure can be used for the assessment of the total noise level and the associated total annoyance on the basis of the DNL or DENL values of the individual sources.
Acoustic Casimir pressure for arbitrary media
Authors: Bárcenas J. , Reyes L. , Esquivel-Sirvent R.
Published: August 2004

In this paper we derive a general expression for the acoustic Casimir pressure between two parallel slabs made of arbitrary materials and whose acoustic reflection coefficients are not equal. The formalism is based on the calculation of the local density of modes using a Green’s function approach. The results for the Casimir acoustic pressure are generalized to a sphere/plate configuration using the proximity theorem.