bluuebunny/crossref_metadata_2025 huggingface dataset:
Age as a predictor of hyperphosphatemia after oral phosphosoda administration for colon preparation
Authors: GUMURDULU Y , SERIN E , OZER B , GOKCEL A , BOYACIOGLU S
Published: December 2003

Background and Aim:  It has been reported that oral phosphosoda (OPS), commonly used in bowel cleansing, may cause complications such as hyperphosphatemia and hypocalcemia. This has been observed in patients with normal kidney function and in those with renal insufficiency. Few controlled studies have been performed with respect to age on healthy subjects after OPS administration.

Methods:  Seventy patients (38 men and 32 women; mean age 47 ± 12 years, range 25–80 years) were enrolled in the present study. Half of the 90 mL total volume of OPS was ingested 18 h before colonoscopy, and the other half 6 h before the procedure. Creatinine clearance rate (CCR) and serum levels of sodium, potassium, calcium and phosphate were measured before and after OPS administration.

Results:  After OPS administration, serum calcium and potassium were significantly lower (P < 0.05), and serum phosphate and sodium were significantly higher than pretreatment levels (P ≤ 0.01). The statistically significant changes in serum sodium, potassium and calcium were within normal laboratory ranges. The mean change in serum phosphate was positively correlated with age (Pearson's r = 0.705; p < 0.001).

Conclusion:  Administration of OPS causes a significant rise in serum phosphate, even in patients with normal CCR. The elevation is significantly greater in elderly patients. Administration of OPS can be considered safe for young and middle‐aged patients with normal renal function; however, it should be used with caution in elderly patients, even in those with normal CCR and serum creatinine values.
Predictors for the onset of functional decline among initially non‐disabled older people living in a community during a 6‐year follow‐up
Authors: Shinkai Shoji , Kumagai Shu , Fujiwara Yoshinori , Amano Hidenori , Yoshida Yuko , Watanabe Shuichiro , Ishizaki Tatsuro , Suzuki Takao , Shibata Hiroshi
Published: December 2003

Background:  Predictors for functional decline in basic activities of daily living (BADL) among older people have been extensively studied. However, relatively little is known about predictors for decline in instrumental activities of daily living (IADL).

Objectives:  To identify predictors for functional decline in IADL as well as predictors for decline in BADL among initially non‐disabled older people living in a community by a longitudinal epidemiological study.

Methods:  Out of 748 older persons aged 65 years and over who participated in the interview survey and medical examination at baseline in 1992, 601 persons were identified as being independent in both BADL and IADL, and were followed‐up yearly for 6 years until 1998. Outcome events were the onset of IADL disability prior to the onset of BADL disability as well as the onset of BADL disability. A wide range of variables obtained in the baseline survey was entered into the model predicting functional decline in BADL and IADL during the follow‐up period.

Results:  Common predictors for BADL and IADL disability included: (1) advanced age; (2) lower levels in performance‐based measures; (3) a history of hospitalization in the past year; and (4) poor chewing ability. Longer sleep‐hours, poor intellectual activities, and poor self‐rated health were identified as significant predictors for only IADL disability. Not having an occupation, a history of heart disease, and higher blood β2‐microglobulin level were identified as a significant predictors of BADL disability.

Conclusions:  Good intellectual activities, good self‐rated health, good chewing ability, and good physical performance are closely associated with remaining independent in IADL for non‐disabled older people. Significance of blood β2‐microglobulin in predicting the onset of functional decline merits further study.
Trends and determinants of Australian managed fund transaction costs
Authors: Parwada Jerry T.
Published: December 2003

The present paper examines the often‐overlooked managed fund fee that is incurred when investors enter and exit managed fund products. The present paper documents that transaction costs for investors, measured by the application‐redemption spread, are above stock market brokerage rates although they have declined since 1995. The study analyses the relationship between this transaction fee and several variables. In summary, retail fund transaction costs are positively related to retail funds’ assets under management, whilst this relationship is negative for larger wholesale funds, consistent with economies of scale. Direct entry and exit fees and initial commissions are positively related to transaction costs which raises the possibility that the commissions are used to levy soft‐dollar payments. The paper also documents a relationship between transaction costs and fund flows which differs between retail and wholesale funds. Overall, the findings are consistent with the proposition that the various fees are used by managers as interchangeable and the different fee regimes reflect different products and markets.
Costs of adjustment to climate change
Authors: Quiggin John , Horowitz John
Published: December 2003

The present paper argues that the costs of climate change are primarily adjustment costs. The central result is that climate change will reduce welfare whenever it occurs more rapidly than the rate at which capital stocks (interpreted broadly to include natural resource stocks) would naturally adjust through market processes. The costs of climate change can be large even when lands are close to their climatic optimum, or evenly distributed both above and below that optimum.
An Integrated GIS Approach to Accessibility Analysis
Authors: Liu Suxia , Zhu Xuan
Published: December 2003

Accessibility is an important element in evaluating existing land‐use patterns and transportation services, predicting travel demands and programming transportation investments in urban transportation planning. This paper presents an integrated GIS approach to accessibility analysis, which provides a general framework for integrated use of GIS, travel impedance measurement tools and accessibility measures to support the accessibility analysis process, including formulating the concept of accessibility, selecting or developing accessibility measures, specifying the accessibility measures, deriving the accessibility values using the selected or developed accessibility measures, and presenting and interpreting the accessibility values. An integrated GIS tool, ACCESS, designed for implementing the integrated approach is also described and illustrated.
Quality Assessment of Cartographic Generalisation
Authors: Bard Sylvain
Published: December 2003

This paper proposes a methodology to assess the quality of cartographic generalisa‐tion, which consists of representing geographic space in a simplified way according to the scale and the objectives of the intended map. The automation of this process makes the derivation of data easier, but the quality of the results is often not evaluated. This paper proposes an assessment model based on: (1) characterisation of the data in their initial and final states at different levels of analysis; (2) a data quality assessment by comparison of the two characterisations; and (3) aggregation of the various assessment results to summarise data quality. The assessment algorithm has been implemented and the method has been tested to assess the generalisation of a small urban area. A visualisation tool for assessment of the results has been developed to validate the generalisation evaluation. The results of the research are presented and discussed at the end of the paper.
The Effect of DEM Raster Resolution on First Order, Second Order and Compound Terrain Derivatives
Authors: Kienzle Stefan
Published: December 2003

It is well known that the grid cell size of a raster digital elevation model has significant effects on derived terrain variables such as slope, aspect, plan and profile curvature or the wetness index. In this paper the quality of DEMs derived from the interpolation of photogrammetrically derived elevation points in Alberta, Canada, is tested. DEMs with grid cell sizes ranging from 100 to 5 m were interpolated from 100 m regularly spaced elevation points and numerous surface‐specific point elevations using the ANUDEM interpolation method. In order to identify the grid resolution that matches the information content of the source data, three approaches were applied: density analysis of point elevations, an analysis of cumulative frequency distributions using the Kolmogorov‐Smirnov test and the root mean square slope measure. Results reveal that the optimum grid cell size is between 5 and 20 m, depending on terrain com‐plexity and terrain derivative. Terrain variables based on 100 m regularly sampled elevation points are compared to an independent high‐resolution DEM used as a benchmark. Subsequent correlation analysis reveals that only elevation and local slope have a strong positive relationship while all other terrain derivatives are not represented realistically when derived from a coarse DEM. Calculations of root mean square errors and relative root mean square errors further quantify the quality of terrain derivatives.
Speaking Softly Without Big Sticks: Meta‐Regulation and Public Sector Audit
Authors: Scott Colin
Published: December 2003

Australian government has undergone an “audit explosion” in the last twenty years. This article observes, first, that the constitutional function of public sector audit institutions (AIs) gives them a strong cultural commitment to the assessment of the regularity and legality of public expenditure. New functions connected with performance audit and evaluation of nonfinancial performance indicators are liable to be interpreted through the lens of these more traditional concerns. The second observation is that, if we think in terms of “regimes” of financial control, we find that AIs form only part of the overall regulatory regime. This calls into question the coherence and potential for effectiveness of regimes of financial control. However, AIs could also be conceived as “meta‐regulators” with the capacity to steer the self‐regulatory capacities of public sector organizations in respect of financial controls. Auditors may be effective as meta‐regulators through speaking softly, even though they demonstrably lack big sticks.
The Market for Financial Report Audits: Regulation of and Competition for Auditor Independence
Authors: Houghton Keith A. , Jubb Christine A.
Published: December 2003

The independence of auditors and the quality of financial report audits generally are rarely tested except in circumstances of corporate failure when alleged sub‐optimality is present. Often auditors have good defences as to their expertise or competency, but rarely do they have equally convincing defences for the independence of their audit. A major issue for the regulation of auditor independence is that the threats to independence are often subtle and difficult to measure. This paper argues that firms undertaking financial report audits need to be transparent and competitive in respect of auditor independence. Two models that adopt this premise are proposed.
Chisholm's Grand Move
Authors: Kaplan Mark
Published: December 2003

Abstract: Roderick Chisholm famously held that our knowledge of the world is supported entirely by a foundation of self‐justifying statements, none of which logically implies the existence of any physical object in that world. The only contingent statements to be found in the foundation, he maintained, are those that are “about our own psychological states and the ways we are ‘appeared to’.” It is a view that, as Chisholm was well aware, tallies poorly with our ordinary practice of justifying statements. We are typically happy to justify statements by ultimate appeal to what we have seen or heard; that is, by ultimate appeal to statements that logically imply that certain things in the world are as we take them to be. This essay examines how Chisholm sought to explain away this apparent disconfirmation of foundationalism by ordinary practice—in effect, how Chisholm responded to one of the chief criticisms of foundationalism launched by J. L. Austin. My suggestion will be that, when the dust clears, it is Austin who comes out ahead.
Roderick Chisholm and The Shaping of American Epistemology
Authors: Kornblith Hilary
Published: December 2003

Abstract: Roderick Chisholm had a profound effect on the shape of American epistemology. In this article, I not only give an account of the large‐scale structure of Chisholm's views but also say something about the place of Chisholmian themes in contemporary work. I thus present an understanding and an appreciation of Chisholm's contribution to epistemology by exhibiting a number of alternative developments of Chisholmian ideas that are currently under discussion.
Chisholm's Internalism and Its Consequences
Authors: Feldman Richard
Published: December 2003

Abstract: Among the important themes in Roderick Chisholm's epistemology are his commitment to internalism, his defense of the independence of epistemology from empirical science, and his assumption that we do know most of what we initially think we know. In “Roderick Chisholm and the Shaping of American Epistemology” Hilary Kornblith argues that Chisholm's views lead to a radical divorce between the factors that justify beliefs and the factors that cause beliefs, that Chisholm's views have the consequence that there is no connection between justification and truth, and that Chisholm's kind of epistemology is unable to give epistemic advice. I argue that Chisholm's views do not have these consequences.
Economic Integration and Convergence Processes in the EU Cohesion Countries
Authors: BARRY FRANK
Published: December 2003

This article compares the economic performance of the EU cohesion countries—Greece, Spain, Portugal and Ireland — from 1960 to the present, in order to identify the processes that have promoted or inhibited real convergence prospects at various points in time. The likely impacts of EMU in strengthening or weakening these processes are then analysed. Amongst the factors studied are labour‐market performance, macroeconomic stability and the efficacy of microeconomic policy‐making.
Greece and EMU: Between External Empowerment and Domestic Vulnerability
Authors: FEATHERSTONE KEVIN
Published: December 2003

EMU was an agenda determined outside Greece and it represents the importation of a radical new policy paradigm. In gaining entry into the ‘euro’ system, EMU has been the stimulus to profound change in Greek macroeconomic policy. However, the developing EU agenda on structural reform highlights the dilemmas of policy‐making in Athens: the uncertain political commitment; the domestic vetoes from rent‐seeking behaviour; and the imprecise external constraint. Threee central questions are raised here. What were the Greek priorities and expectations at the time of negotiating EMU? How did Greece qualify for entry into the euro system?. And how has Greece responded to the post‐Maastricht EU agenda on structural reform? These questions relate to fundamental issues of the contemporary Greek state: the capability to bring about reform; the political and cultural impediments to reform by consensus; and the challenges posed by deeper ‘Europeanization’. For the EU, the Greek case raises issues of relevance to the cohesion of the euro area and the management of the enlargement process.
A microbial survey of food service can openers, food and beverage can tops and cleaning methodology effectiveness
Authors: Michaels Barry , Gangar Vidhya , Schultz Ann , Curiale Michael S.
Published: December 2003

A can opener and food/beverage can top survey was undertaken to identify potential microbiological hazards. Results indicated the potential for high levels of bacterial and fungal contamination. Characterization of microorganisms from 10 can openers indicated the most common contaminants as Klebsiella pneumoniae and a variety of Staphylococcus and spore‐forming Bacillus species. In contrast to previous commercial food service surveys, no Escherichia coli or Salmonella species were found on the cans or can openers, however, low numbers of Bacillus cereus (22 of 25 cans) and Clostridium perfringens (15 of 25 cans) were identified. The effectiveness of various can‐cleaning methods was evaluated using marker bacteria (Serratia marcescens) suspended in soil consisting of tryptone soya broth, ground beef or vacuum cleaner dust. In addition to rinsing under running water, two paper towel types and a paper napkin product were used for wiping, moist wiping and wiping after rinsing. The most effective cleaning method was rinsing and wiping combined (P < 0.0003), while wiping alone was not as effective as moist wiping (P = 0.038) or rinsing with water (P = 0.061). Food cans were more easily cleaned than beverage cans because of the tab area. Soil type influenced the degree of effectiveness of the cleaning methods, with mean log10 reduction values for each type at 3.4 and 3.1 for food and beverage cans (tab area excluded), respectively. No significant difference was observed in the effectiveness of paper products (P = 0.433).
Coagulation profiles in 27 horses with large colon volvulus
Authors: Dallap Barbara L. , Dolente Brett , Boston Ray
Published: December 2003

Objective:The objective of this study was to evaluate coagulation profiles in horses with surgical treatment of large colon volvulus (LCV), and determine if an association exists between hemostatic dysfunction and outcome.

Design:Prospective clinical investigation from February to December 2000.

Setting:Large animal intensive care unit in a veterinary teaching hospital.

Interventions:Blood was collected from horses intra‐operatively, 24, and 48 hours following surgical treatment for LCV.

Measurements:Coagulation profiles, thrombin–antithrombin (TAT) levels, and D‐dimer concentrations were determined for each time point. The number of tests abnormal in the standard coagulation profile, defined as the degree of hemostatic dysfunction, was determined for each horse for the duration of the study period. The association between each test and outcome, as well as the degree of hemostatic dysfunction for each horse and outcome, was determined using univariate analysis and logistic regression. TAT levels and D‐dimer concentrations were compared to the results of the standard coagulation profile and to patient outcome using univariate analysis and logistic regression.

Main results:Seventy percent of horses evaluated with surgical treatment of LCV had evidence of hemostatic dysfunction (3/6 tests abnormal). Only 18% of those patients had clinical signs recognized by the attending clinician as a coagulopathy. There was an association between the development of a coagulopathy and outcome, with horses with 4/6 tests abnormal being more likely to be euthanized, and those with 3/6 tests abnormal having a prolonged hospital stay. Platelet count, prothrombin time, and TAT levels may be helpful in predicting outcome in horses with LCV.

Conclusions:Hemostatic function should be evaluated in horses with surgical treatment of LCV to detect subclinical coagulopathies and direct subsequent intervention.
Co‐expression of p53 and Ki67 and lack of EBV expression in oral squamous cell carcinoma
Authors: Iamaroon Anak , Khemaleelakul Udomrat , Pongsiriwet Surawut , Pintong Jarupan
Published: December 2003

Background:  The objectives of the study were to determine the association between Epstein‐Barr virus (EBV) and oral squamous cell carcinoma (OSCC), to compare the expression of p53 and Ki67 between normal oral mucosa, oral hyperkeratosis, oral pre‐malignant dysplasia, and OSCC, and to determine the correlation between the expression of p53 and Ki67 in OSCC.

Methods:  The expression of EBV mRNA was studied by in situ hybridization technique in 24 cases of OSCC, and the expression of p53 and Ki67 was investigated by immunohistochemical method in 19 cases of OSCC, 7 cases of oral pre‐malignant dysplasia, 6 cases of oral hyperkeratosis, and 5 cases of normal oral epithelium.

Results:  None of OSCC cases expressed EBV‐encoded RNA (EBER) transcripts. The labeling indices (LI) of p53‐ and Ki67‐positive cells were significantly higher in OSCC than in oral pre‐malignant dysplasia, oral hyperkeratosis, and normal oral mucosa (P < 0.05). A significant correlation between the LI of p53‐ and Ki67‐positive cells was observed in OSCC (r = 0.6; P = 0.01).

Conclusions:  These findings suggested that the co‐expression of p53 and Ki67 may play roles in carcinogenesis of OSCC and p53 overexpression may promote cell proliferation in OSCC. Furthermore, EBV does not appear to be a risk factor for OSCC particularly in the population of northern Thailand.
Prevalence of oral mucosal alterations in children from 0 to 12 years old
Authors: Bessa C. F. N. , Santos P. J. B. , Aguiar M. C. F. , Do Carmo M. A. V.
Published: December 2003

Background:  As the exact prevalence of oral alterations in children is still not known and the findings are controversial, other studies about this subject are necessary.

Methods:  A cross‐sectional survey was carried out on 1211 Brazilian children divided in two age groups: 0–4 and 5–12 years. The patients were economically classified and data of medical history were obtained from medical records.

Results:  The frequency of children presenting alterations was 27.0%, and it was higher in older children. The most common lesions were geographic tongue, cheek biting, and melanotic macule. Candidiasis was associated with antibiotic therapy and use of pacifiers. Fissured tongue was associated with congenital anomalies, allergy; age from 5 to 12 years. There was a lack of association of patient's economic status and prevalence of oral mucosal alterations.

Conclusions:  The frequency of mucosal alterations in children is high and increases with age, and some of them are associated with habits and medical history of the patients.
Expression of parathyroid hormone‐related protein (PTHrP), osteoclast differentiation factor (ODF)/receptor activator of nuclear factor‐κB ligand (RANKL) and osteoclastogenesis inhibitory factor (OCIF)/osteoprotegerin (OPG) in ameloblastomas
Authors: Kumamoto Hiroyuki , Ooya Kiyoshi
Published: December 2003

Background:  To clarify the roles of osteoclast regulatory factors in progression of odontogenic tumors, expression of parathyroid hormone‐related protein (PTHrP), osteoclast differentiation factor (ODF)/receptor activator of nuclear factor‐κB ligand (RANKL), and osteoclastogenesis inhibitory factor (OCIF)/osteoprotegerin (OPG) were analyzed in ameloblastomas as well as tooth germs.

Methods:  Tissue specimens of nine tooth germs and 36 benign and one malignant ameloblastomas were examined by reverse transcriptase‐polymerase chain reaction (RT‐PCR) and immunohistochemistry for the expression of PTHrP, ODF/RANKL, and OCIF/OPG.

Results:  Expression of PTHrP, ODF/RANKL, and OCIF/OPG mRNA was detected in all tooth germ and ameloblastoma samples. Immunohistochemical reactivity for PTHrP was recognized in both normal and neoplastic odontogenic epithelial cells. In ameloblastomas, PTHrP reactivity in peripheral columnar or cuboidal cells was stronger than that in central polyhedral cells, and keratinizing cells showed increased PTHrP reactivity. ODF/RANKL and OCIF/OPG were expressed predominantly in mesenchymal cells rather than in odontogenic epithelial cells in both tooth germs and ameloblastomas. Epithelial ODF/RANKL and OCIF/OPG expression was slightly lower in ameloblastomas than in tooth germs. Tumor cells in plexiform ameloblastomas showed slightly higher reactivity for PTHrP and ODF/RANKL than tumor cells in follicular ameloblastomas.

Conclusion:  Expression of PTHrP, ODF/RANKL and OCIF/OPG in tooth germs and ameloblastomas suggests that these factors might locally regulate bone metabolism and dynamics in tooth development as well as in progression of ameloblastomas. These factors might also be involved in tumor cell differentiation and/or tumor tissue structuring in ameloblastomas.
The acoustic impedance of a circular orifice in grazing mean flow: Comparison with theory
Authors: Peat Keith S. , Ih Jeong-Guon , Lee Seong-Hyun
Published: December 2003

It is well known that the presence of a grazing mean flow affects the acoustic impedance of an aperture, but the detailed nature and understanding of the influence is still unknown. In this paper, results from a recent theoretical analysis of the problem are compared with a new set of experimental results. The purpose is twofold. First, the experimental results are used to validate the theory. It is found that the theory predicts the resistance quite well, but not the reactance. Second, the theory is used to try and give some physical understanding to the experimental results. In particular, some scaling laws are confirmed, and it is also shown that measured negative resistance values are to be expected. They are not erroneous, as previously thought. Former sets of experimental data for this problem are notable for the amount of variation that they display. Thus, both the theory and the new experimental results are also compared with those earlier detailed results that most closely conform to the conditions assumed here, namely fully developed turbulent pipe flow of low Mach number past circular orifices. The main field of application is in flow ducts, in particular, flow through perforated tubes in exhaust mufflers.
Acoustic variability and distinguishability among mouse ultrasound vocalizations
Authors: Liu Robert C. , Miller Kenneth D. , Merzenich Michael M. , Schreiner Christoph E.
Published: December 2003

Auditory neurobiology has benefited significantly from ethological approaches using acoustic communication signals. Developing an ethological model in a genetically manipulable system such as the mouse would enhance the ability to investigate the processing, learning, and recognition of sounds. Characterizing the basic acoustic structure of mouse vocalizations would help lay a foundation for such a future study. Towards this goal, ultrasound vocalizations emitted by isolated mouse pups and pairs of adult males and females have been digitally recorded and examined. Previous work suggests that these calls may have communicative significance. An analysis of the natural variability in their spectral content, median frequency, duration, and repetition period reveals acoustic structure that could be used for recognizing the calls. Other parameters, like the rate of frequency modulation, may also be informative, but have not been examined. Pup isolation calls develop systematically between postnatal day 5 and 12 towards a more stereotyped vocalization—contracting from a wide range of values into narrower clusters of frequency and duration, and shifting from longer to shorter repetition periods. Most significantly, pup isolation and adult encounter calls fall into two distinct spectral and temporal categories, making it possible for a receiver to acoustically distinguish between them, and to potentially categorically perceive them along those dimensions.
Tone decay for hearing-impaired listeners with and without dead regions in the cochlea
Authors: Huss Martina , Moore Brian C. J.
Published: December 2003

For people with normal hearing, a sustained tone with a frequency within the standard audiometric range remains audible when presented at a level well above threshold. However, for a pure tone with frequency close to the upper limit of hearing (well above 8 kHz), the loudness may decrease within seconds and the tone may decay to inaudibility, even when presented at a level between 20 and 40 dB SL. Scharf [in Hearing Research and Theory, edited by J. V. Tobias and E. D. Schubert (Academic, New York, 1983), Vol. 2, pp. 1–53] suggested that marked loudness adaptation only occurs when the excitation pattern evoked by a tone is spatially limited. The upper limit of hearing may be comparable to the boundary of a “dead region,” which is a region with a complete loss of inner hair cell (IHC) and/or neural function. The present study investigated the perceived decay of pure tones for 9 normal-hearing subjects and 12 subjects with moderate to severe sensorineural hearing loss, using a wide range of frequencies (0.125–12 kHz). A dead region was diagnosed for 8 of the 12 subjects. No consistent association was found between the degree of tone decay and the presence of a dead region. Subjects with dead regions did not experience significantly more tone decay than subjects with comparable absolute thresholds but without a dead region, even when the frequency of the tone fell within or close to the edge of a dead region. For severely hearing-impaired subjects, spatial restriction of the excitation pattern was neither necessary nor sufficient to lead to tone decay. The prevalence of tone decay was not well predicted by the audiometric threshold at the test frequency. It is proposed that tone decay depends on the physiological condition of the place in the cochlea where the tone is detected, which, in a case involving a dead region, is the place adjacent to the dead region. The prevalence of tone decay increased when the audiometric threshold was above 50 dB HL in the frequency region where the tone was detected.
Bridging automatic speech recognition and psycholinguistics: Extending Shortlist to an end-to-end model of human speech recognition (L)
Authors: Scharenborg Odette , ten Bosch Louis , Boves Lou , Norris Dennis
Published: December 2003

This letter evaluates potential benefits of combining human speech recognition (HSR) and automatic speech recognition by building a joint model of an automatic phone recognizer (APR) and a computational model of HSR, viz., Shortlist [Norris, Cognition 52, 189–234 (1994)]. Experiments based on “real-life” speech highlight critical limitations posed by some of the simplifying assumptions made in models of human speech recognition. These limitations could be overcome by avoiding hard phone decisions at the output side of the APR, and by using a match between the input and the internal lexicon that flexibly copes with deviations from canonical phonemic representations.
Impedance measurements of ex vivo rat lung at different volumes of inflation
Authors: Oelze Michael L. , Miller Rita J. , Blue James P. , Zachary James F. , O’Brien William D.
Published: December 2003

A previous study [J. Acoust. Soc. Am. 111, 1102–1109 (2002)] showed that the occurrence of ultrasonically induced lung hemorrhage in rats was directly correlated to the level of lung inflation. In that study, it was hypothesized that the lung could be modeled as two components consisting of air and parenchyma (contiguous tissue [pleura and septa]). The speed of sound and lung impedance would then depend on the fractional volume of air in the lung. According to that model, an inflated lung should act like a pressure-release surface for sound incident from tissue onto a tissue-lung boundary. A deflated lung containing less air should allow more acoustic energy into the lung tissue because the impedance was more closely matched to the contiguous tissues. In the study reported herein, a measurement technique was devised to calculate the impedance of seven rat lungs, ex vivo, under deflation (atmospheric pressure) and three volumes of inflation pressure (7-cm H2O, 10-cm H2O, and 15-cm H2O). Lungs were dissected from rats and immediately scanned in a tank of degassed 37 °C water. The frequency-dependent acoustic pressure reflection coefficient was measured over a frequency range of 3.5 to 10 MHz. From the reflection coefficient, the frequency-dependent lung impedance was calculated with values ranging from an average of 1 Mrayls in deflated lungs to 0.2 Mrayls for fully inflated lungs. Lung impedance calculations showed that deflated lungs had an impedance closer to water (1.52 Mrayls) than inflated lungs. At all volumes of inflation, the lungs acted as pressure-release surfaces relative to the water. The average of the four lung impedance values (deflated, 7-cm H2O, 10-cm H2O, and 15-cm H2O) at each level of inflation was statistically different (p<0.0001).
Characterization of chaotic dynamics in the vocalization of Cervus elaphus corsicanus (L)
Authors: Facchini Angelo , Bastianoni Simone , Marchettini Nadia , Rustici Mauro
Published: December 2003

Chaos, oscillations, instabilities, and intermittency represent only some nonlinear examples apparent in the natural world. These phenomena appear in any field of study, and advances in complex and nonlinear dynamic techniques bring about opportunities to better understand animal signals. In this work an analysis method is suggested based on the characterization of the vocal-fold dynamics by means of the nonlinear time-series analysis, and by the computations of the parameters typical of chaotic oscillations: Attractor reconstruction, spectrum of Lyapunov exponents, and maximum Lyapunov exponent were used to reconstruct the dynamic of the vocal folds. Identifying a sort of vocal fingerprint can be useful in biodiversity monitoring and understanding the health status of a given animal. This method was applied to the vocalization of the Cervus elaphus corsicanus, the Sardinian red deer.
Characterizing computer cooling fan noise
Authors: Huang Lixi
Published: December 2003

Computer cooling fan noise is studied theoretically, focusing on the radiation from the interaction between rotor blades and motor struts. The source is decomposed into axial thrust, circumferential drag, and radial force. There is no sound-power coupling among the three components. The index of spatial spinning pressure mode plays the key role in noise radiation. The leading modes are the zeroth, or coincident, mode for thrust and the first mode for the drag and radial force. The effect of source noncompactness is quantified and found to be substantial only for higher-order radiation modes. The sound powers of the leading modes follow a sixth-power law, while the next high-order modes follow an eighth-power law. Quantitative analysis shows that the drag force can be equally noisy as the coincident thrust force. Based on an empirical aerodynamic model of rotor–strut interaction, it is found that the total sound power is more sensitive to the number of struts than rotor blades. Numerical examples are given to demonstrate how the struts can be optimized for typical cooling fan conditions.
Preceding phonetic context affects perception of nonspeech (L)
Authors: Stephens Joseph D. W. , Holt Lori L.
Published: December 2003

A discrimination paradigm was used to detect the influence of phonetic context on speech (experiment 1a) and nonspeech (experiment 1b) stimuli. Results of experiment 1a were consistent with the previously observed phonetic context effect of liquid consonants (/l/ and /r/) on subsequent stop consonant (/g/ and /d/) perception. Experiment 1b demonstrated a context effect of liquid consonants on subsequent nonspeech sounds that were spectrally similar to the stop consonants. The results are consistent with findings that implicate spectral contrast in phonetic context effects.
Sound focusing in rooms. II. The spatio-temporal inverse filter
Authors: Yon Sylvain , Tanter Mickaël , Fink Mathias
Published: December 2003

The potential of time reversal processing for room acoustics has been extensively investigated in the companion of this paper [J. Acoust. Soc. Am. 113(3), 1533–1543 (2003)]. In particular, a simple implementation of a loudspeaker time reversal antenna able to take advantage of the multiple reflections in reverberating rooms demonstrates its potential for audible range acoustics while improving focusing both in space and time. However, loss of information (e.g., sound absorption in walls or nonequalized bandwidths of the loudspeakers) during a time reversal experiment degrades the quality of time reversal focusing. In this paper, a more sophisticated technique called spatio-temporal inverse filtering is investigated that achieves time and space deconvolution of the propagation operator between the loudspeakers antenna and a set of microphones embedded inside the insonified volume. Theoretical and experimental comparisons between time reversal and inverse filter focusing are presented. Finally, advantages and limitations of both focusing approaches are highlighted.
Schlieren imaging of shock waves from a trumpet
Authors: Pandya Brian H. , Settles Gary S. , Miller James D.
Published: December 2003

A sensitive, large-aperture schlieren optical instrument is applied to observe gas-dynamic phenomena at the exit of a trumpet. Shock waves are seen, especially for loud, high-pitched trumpet notes, and several illustrations are given. Microphone waveforms are given for representative examples. These shock waves arise from the shock-tube-like effect of the performer’s intermittent breath pressure driving the cylindrical duct of the trumpet, and are the result of cumulative nonlinear acoustic propagation inside the trumpet bore. They are, however, very weak, traveling only marginally above the acoustic speed. In the 118–124 peak dB(A) range, they are near the weak limit of shock wave visibility by schlieren optics. The schlieren evidence confirms that the frequency of the emitted shock waves corresponds to the frequency of the note being played. Ancillary laminar and turbulent jet phenomena associated with the performer’s breath are also visible in the images.
Evidence of Sexual Recombination among
Cryptococcus neoformans
Serotype A Isolates in Sub-Saharan Africa
Authors: Litvintseva Anastasia P. , Marra Robert E. , Nielsen Kirsten , Heitman Joseph , Vilgalys Rytas , Mitchell Thomas G.
Published: December 2003

The most common cause of fungal meningitis in humans,
Cryptococcus neoformans
serotype A, is a basidiomycetous yeast with a bipolar mating system. However, the vast majority (>99.9%) of
C. neoformans
serotype A isolates possess only one of the two mating type alleles (
MATα
). Isolates with the other allele (
MAT
a) were recently discovered and proven to mate in the laboratory. It has been a mystery whether and where
C. neoformans
strains undergo sexual reproduction. Here, we applied population genetic approaches to demonstrate that a population of
C. neoformans
serotype A clinical isolates from Botswana contains an unprecedented proportion of fertile
MAT
a isolates and exhibits evidence of both clonal expansion and recombination within two partially genetically isolated subgroups. Our findings provide evidence for sexual recombination among some populations of
C. neoformans
serotype A from sub-Saharan Africa, which may have a direct impact on their evolution.
Mating and Pathogenic Development of the Smut Fungus
Ustilago maydis
Are Regulated by One Mitogen-Activated Protein Kinase Cascade
Authors: Müller Philip , Weinzierl Gerhard , Brachmann Andreas , Feldbrügge Michael , Kahmann Regine
Published: December 2003

In the phytopathogenic fungus
Ustilago maydis
, pheromone-mediated cell fusion is a prerequisite for the generation of the infectious dikaryon. The pheromone signal elevates transcription of the pheromone genes and elicits formation of conjugation hyphae. Cyclic AMP and mitogen-activated protein kinase (MAPK) signaling are involved in this process. The MAPK cascade is presumed to be composed of Ubc4 (MAPK kinase kinase), Fuz7 (MAPK kinase), and Ubc3/Kpp2 (MAPK). We isolated the
kpp4
gene and found it to be allelic to
ubc4
. Epistasis analyses with constitutively active alleles of
kpp4
and
fuz7
substantiate that Kpp4, Fuz7, and Kpp2/Ubc3 are components of the same module. Moreover, we demonstrate that Fuz7 activates Kpp2 and shows interactions in vitro. Signaling via this cascade regulates expression of pheromone-responsive genes, presumably through acting on the transcription factor Prf1. Interestingly, the same cascade is needed for conjugation tube formation, and this process does not involve Prf1. In addition,
fuz7
as well as
kpp4
deletion strains are nonpathogenic, while
kpp2
deletion mutants are only attenuated in pathogenesis. Here we show that strains expressing the unphosphorylatable allele

kpp2
T182A/Y184F

are severely affected in tumor induction and display defects in early infection-related differentiation.
The Yeast Protein Kinase C Cell Integrity Pathway Mediates Tolerance to the Antifungal Drug Caspofungin through Activation of Slt2p Mitogen-Activated Protein Kinase Signaling
Authors: Reinoso-Martín Cristina , Schüller Christoph , Schuetzer-Muehlbauer Manuela , Kuchler Karl
Published: December 2003

The echinocandin caspofungin is a new antifungal drug that blocks cell wall synthesis through inhibition of β-(1-3)-glucan synthesis.
Saccharomyces cerevisiae
cells are able to tolerate rather high caspofungin concentrations, displaying high viability at low caspofungin doses. To identify yeast genes implicated in caspofungin tolerance, we performed a genome-wide microarray analysis. Strikingly, caspofungin treatment rapidly induces a set of genes from the protein kinase C (PKC) cell integrity signaling pathway, as well as those required for cell wall maintenance and architecture. The mitogen-activated protein kinase Slt2p is rapidly activated by phosphorylation, triggering signaling through the PKC pathway. Cells lacking genes such as
SLT2
,
BCK1
, and
PKC1
, as well as the caspofungin target gene,
FKS1
, display pronounced hypersensitivity, demonstrating that the PKC pathway is required for caspofungin tolerance. Notably, the cell surface integrity sensor Wsc1p, but not the sensors Wsc2-4p and Mid2p, is required for sensing caspofungin perturbations. The expression modulation of PKC target genes requires the transcription factor Rlm1p, which controls expression of several cell wall synthesis and maintenance genes. Thus, caspofungin-induced cell wall damage requires Wsc1p as a dedicated sensor to launch a protective response through the activated salvage pathway for de novo cell wall synthesis. Our results establish caspofungin as a specific activator of Slt2p stress signaling in baker's yeast.
Glycosyl Phosphatidylinositol-Anchored Proteins in Chemosensory Signaling: Antisense Manipulation of
Paramecium tetraurelia PIG-A
Gene Expression
Authors: Yano Junji , Rachochy Villa , Van Houten Judith L.
Published: December 2003

Glycosyl phosphatidylinositol (GPI)-anchored proteins are peripheral membrane proteins tethered to the cell through a lipid anchor. GPI-anchored proteins serve many functions in cellular physiology and cell signaling. The
PIG-A
gene codes for one of the enzymes of a complex that catalyzes the first step in anchor synthesis, and we have cloned the
Paramecium tetraurelia pPIG-A
gene using homology PCR. To understand the function of
pPIG-A
and the significance of GPI-anchored proteins in
Paramecium
, we reduced the mRNA for
pPIG-A
in transformed cells using an expression vector that transcribed antisense mRNA. The amount of transcript is reduced to ∼0.3% of the mRNA in control-transformed cells. Compared to control cells, cells transformed with the antisense pPIG-A vector show reduced synthesis of GPI anchor intermediates catalyzed in their endoplasmic reticula and a very few GPI-anchored proteins among the peripheral proteins that can be recovered from their surfaces. They also show specific defects in chemoresponse to glutamate and folate. Other cellular functions, such as growth and mating, seem to be normal.
Molecular Identification of a Calcium-Inhibited Catalytic Subunit of Casein Kinase Type 2 from
Paramecium tetraurelia
Authors: Vetter Daniel , Kissmehl Roland , Treptau Tilman , Hauser Karin , Kellermann Josef , Plattner Helmut
Published: December 2003

We have previously described the occurrence in
Paramecium
of a casein kinase (CK) activity (EC 2.7.1.37) with some unusual properties, including inhibition by Ca
2+
(R. Kissmehl, T. Treptau, K. Hauser, and H. Plattner, FEBS Lett. 402:227-235, 1995). We now have cloned four genes,
PtCK2α1
to
PtCK2α4
, all of which encode the catalytic α subunit of type 2 CK (CK2) with calculated molecular masses ranging from 38.9 to 39.4 kDa and pI values ranging from 8.8 to 9.0. They can be classified into two groups, which differ from each other by 28% on the nucleotide level and by 18% on the derived amino acid level. One of them,
PtCK2α3
, has been expressed in
Escherichia coli
and characterized in vitro. As we also have observed with the isolated CK, the recombinant protein preferentially phosphorylates casein but also phosphorylates some
Paramecium
-specific substrates, including the exocytosis-sensitive phosphoprotein pp63/parafusin. Characteristically, Ca
2+
inhibits the phosphorylation at elevated concentrations occurring during stimulation of a cell. Reconstitution with a recombinant form of the regulatory subunit from
Xenopus laevis
, XlCK2β, confirms Ca
2+
sensitivity also under conditions of autophosphorylation. This is unusual for CK2 but correlates with the presence of two EF-hand calcium-binding motifs, one of which is located in the N-terminal segment essential for constitutive activity, as well as with an aberrant composition of normally basic domains recognizing acidic substrate domains. Immunogold localization reveals a considerable enrichment in the outermost cell cortex layers, excluding cilia. We discuss a potential role of this Ca
2+
-inhibited PtCK2α species in a late step of signal transduction.
Sla1, aSchizosaccharomyces pombeHomolog of the Human La Protein, Induces Ectopic Meiosis when Its C Terminus Is Truncated
Authors: Tanabe Kaori , Ito Noriko , Wakuri Tomomi , Ozoe Fumiyo , Umeda Makoto , Katayama Satoshi , Tanaka Katsunori , Matsuda Hideyuki , Kawamukai Makoto
Published: December 2003

Sla1 is aSchizosaccharomyces pombehomolog of the human La protein. La proteins are known to be RNA-binding proteins that bear conserved RNA recognition motifs (La and RRMs), but their biological functions still have not been fully resolved. In this study, we show that theS. pombeLa homolog (Sla1) is involved in regulating sexual development. Sla1 truncated in the C terminus (Sla1ΔC) induced ectopic sporulation in theras1Δ strain and several other sporulation-deficient mutants. The C terminus contains a nuclear localization signal. While full-length Sla1 localizes in the nucleus, Sla1ΔC is found throughout the cell, suggesting the cytoplasmic localization of Sla1ΔC is involved in its sporulation-inducing activity. Further deletion analysis of Sla1 indicated that a small region (35 amino acids) that includes a portion of RRM2 is sufficient to induce sporulation. The La motif (RRM1) is not involved in this activity. Strikingly, Sla1ΔC induced haploid meiosis in a heterothallic strain, similar to thepat1-114ormei2-SATAmutation. Sla1ΔC induced sporulation in amei3disruptant but not in amei2disruptant, indicating that Sla1ΔC requires Mei2 to induce haploid meiosis. Deletion of the chromosomalsla1gene lowered the temperature sensitivity of thepat1-114mutant. Two-hybrid analysis indicated that Pat1 interacts with Sla1ΔC but not full-length Sla1. Thus, Sla1ΔC may block Pat1 activity. This block would remove the inhibition on Mei2, which would then drive the cell into haploid meiosis. Finally, Sla1 was degraded prior to the start of meiosis when we monitored Sla1 in cells in which meiosis was synchronously induced. The ability of truncated Sla1 to induce ectopic meiosis represents a very novel function that has hitherto not been suspected for the La family of proteins.