bluuebunny/crossref_metadata_2025 huggingface dataset:
Static electric field detection and behavioural avoidance in cockroaches
Authors: Newland Philip L. , Hunt Edmund , Sharkh Suleiman M. , Hama Noriyuki , Takahata Masakazu , Jackson Christopher W.
Published: November 2008

Electric fields are pervasively present in the environment and occur both as a result of man-made activities and through natural occurrence. We have analysed the behaviour of cockroaches to static electric fields and determined the physiological mechanisms that underlie their behavioural responses. The behaviour of animals in response to electric fields was tested using a Y-choice chamber with an electric field generated in one arm of the chamber. Locomotory behaviour and avoidance were affected by the magnitude of the electric fields with up to 85% of individuals avoiding the charged arm when the static electric field at the entrance to the arm was above 8–10 kV m–1. Electric fields were found to cause a deflection of the antennae but when the antennae were surgically ablated, the ability of cockroaches to avoid electric fields was abolished. Fixation of various joints of the antennae indicated that hair plate sensory receptors at the base of the scape were primarily responsible for the detection of electric fields, and when antennal movements about the head–scape joint were prevented cockroaches failed to avoid electric fields. To overcome the technical problem of not being able to carry out electrophysiological analysis in the presence of electric fields, we developed a procedure using magnetic fields combined with the application of iron particles to the antennae to deflect the antennae and analyse the role of thoracic interneurones in signalling this deflection. The avoidance of electric fields in the context of high voltage power lines is discussed.
Plasticity in a cerebellar-like structure: suppressing reafference during episodic behaviors
Authors: Zhang Zhi , Bodznick David
Published: November 2008

Detection of relevant sensory signals requires the filtering out of irrelevant noise, including noise created by the animal's own movements(reafference). This is accomplished in the electrosense of little skates(Raja erinacea) by an adaptive filter in the cerebellar-like electrosensory nucleus (dorsal nucleus) in the medulla. We have shown that electrosensory inputs reliably coupled to the regularly recurring movements of breathing over time are eliminated selectively in the principal neurons(ascending efferent neurons, AENs) by a cancellation signal that is a negative of the reafference and is supplied by a parallel fiber system. Similarly,electrosensory inputs repeatedly linked to passive fin movements are eliminated suggesting that the filter also functions in relation to other behaviors besides breathing. To determine whether this adaptive filter can eliminate reafference created by brief and infrequent episodic behaviors like swimming in skates, we initiated a series of coupling tests in which an external electrosensory stimulus was coupled to short bouts of either parallel fiber stimulation or passive fin movements, and then measured the ability of AENs to generate a cancellation signal. Following five brief coupling periods(30–60 s) separated by long rest periods (1–9 min), 38.5% of the AENs developed a cancellation signal when the coupling was to parallel fiber stimulation, and 73% when the coupling was to passive fin movement. We demonstrate that the cancellation signals can be developed incrementally,persist for at least a 3 h rest period without reinforcement, and are extinguished within minutes when the association of sensory stimulus and fin movement or parallel fiber stimulation no longer exists. The results indicate that the adaptive filter has the properties necessary to cancel reafference associated with even brief and infrequent behaviors.
Changes in pulmonary blood flow do not affect gas exchange during intermittent ventilation in resting turtles
Authors: Wang Tobias , Hicks James W.
Published: November 2008

The breathing pattern of many different air-breathing vertebrates,including lungfish, anuran amphibians, turtles, crocodiles and snakes, is characterized by brief periods of lung ventilation interspersed among apnoeas of variable duration. These intermittent ventilatory cycles are associated with characteristic increases in pulmonary blood flow and tachycardia. In animals with central vascular shunts, the rise in pulmonary blood flow during ventilation is associated with the development of left-to-right (L–R)cardiac shunt (pulmonary recirculation of oxygenated blood returning from the lungs). By contrast, a large net right-to-left (R–L) shunt (pulmonary bypass) normally prevails during apnoea. The cardio–respiratory interaction and the changes in cardiac shunting have been suggested to improve pulmonary gas exchange but the benefits of L–R shunting on pulmonary gas transport have not been studied experimentally. The present study measured pulmonary gas exchange in fully recovered, freely diving turtles, where changes in pulmonary blood flow were prevented by partial occlusion of the pulmonary artery. Prevention of L–R shunt during ventilation did not impair CO2 excretion and overall, oxygen uptake and CO2excretion did not correlate with changes in pulmonary blood flow. We conclude that increases in pulmonary blood flow associated with ventilation are not required to maintain resting rates of oxygen uptake and CO2excretion in resting animals.
Weight and nutrition affect pre-mRNA splicing of a muscle gene associated with performance, energetics and life history
Authors: Marden James H. , Fescemyer Howard W. , Saastamoinen Marjo , MacFarland Suzanne P. , Vera J. Cristobal , Frilander Mikko J. , Hanski Ilkka
Published: November 2008

A fundamental feature of gene expression in multicellular organisms is the production of distinct transcripts from single genes by alternative splicing(AS), which amplifies protein and functional diversity. In spite of the likely consequences for organismal biology, little is known about how AS varies among individuals or responds to body condition, environmental variation or extracellular signals in general. Here we show that evolutionarily conserved AS of troponin-t in flight muscle of adult moths responds in a quantitative fashion to experimental manipulation of larval nutrition and adult body weight. Troponin-t (Tnt) isoform composition is known to affect muscle force and power output in other animals, and is shown here to be associated with the thorax mass-specific rate of energy consumption during flight. Loading of adults with external weights for 5 days caused an AS response nearly identical to equal increases in actual body weight. In addition, there were effects of larval feeding history on adult Tntisoform composition that were independent of body weight, with moths from poorer larval feeding regimes producing isoform profiles associated with reduced muscle performance and energy consumption rate. Thus, Tntisoform composition in striated muscle is responsive to both weight-sensing and nutrition-sensing mechanisms, with consequent effects on function. In free-living butterflies, Tnt isoform composition was also associated with activity level and very strongly with the rate of egg production. Overall, these results show that AS of a muscle gene responds in a quantitative fashion to whole-organism variables, which apparently serves to coordinate muscle strength and energy expenditure with body condition and life history.
Damage monitoring of refractory wall in a generic entrained-bed slagging gasification system
Authors: Chakraborty S , Sarkar S , Gupta S , Ray A
Published: November 2008

The main cause of performance degradation in entrained-bed slagging gasification systems is attributed to evolution of structural damage in the refractory walls. Early detection of such damage is necessary to avert unscheduled shutdown of a gasification plant. This paper develops an integrated computer simulation model of a generic entrained-bed slagging gasifier for formulation of a damage prediction algorithm with the objective of real-time degradation monitoring and condition-based maintenance of refractory walls. The integrated simulation model yields: (a) quasi-steady-state spatial temperature profiles at any cross-section of the gasification system, and (b) dynamic response of the refractory wall temperature that is measured by an array of sensors installed at specified locations on the external surface of the gasifier wall. The key idea for early detection of refractory-wall damage is built upon the fact that a local anomaly (i.e. deviation from the nominal condition) is likely to influence the temperature gradient in the refractory wall due to changes in the thermal impedance. The information from dynamic response of refractory temperature is extracted in a compressed form as statistical patterns of evolving anomaly through usage of a recently reported data-driven pattern identification tool called symbolic dynamic filtering (SDF). The results of this model-based investigation show that the proposed anomaly detection and damage prediction method is potentially capable of characterizing the health status of refractory walls in particular and the entire gasification system in general. The SDF algorithms in this paper are implemented on the MATLAB platform and are interfaced with the gasification plant simulation model for emulation of real-time degradation monitoring.
Exergy analysis of a combined engine-organic Rankine cycle configuration
Authors: Mago P J , Chamra L M
Published: November 2008

This article presents an exergy analysis of a combined engine-organic Rankine cycle configuration (E-ORC) using the exergy topological method. A detailed roadmap of exergy flow is presented using an exergy destruction chart to clearly depict the exergy accounting associated with each thermodynamic process. The analysis indicates that an ORC combined with an engine not only improves the engine thermal efficiency but also increases the exergy efficiency. Different organic fluids are evaluated in this article. Depending on the organic fluid employed, the thermal and exergy efficiencies could be increased by approximately 10 per cent. Parameters such as the thermodynamic influence coefficient and degree of thermodynamic perfection are identified as useful design metrics to assist exergy-based design of devices. This article also examines the effect of the pinch-point temperature difference (PPTD) on the E-ORC performance. Results show that the lower the PPTD the higher the thermal and exergy efficiencies.
Numerical prediction of aerodynamic tonal noise radiated from a centrifugal fan
Authors: Mao Y , Qi D , Liu X , Tang H
Published: November 2008

The aerodynamic tonal noise radiated from a centrifugal fan is calculated using a hybrid computational aeroacoustics approach that couples numerical flow with an implementation of the acoustic analogy. The turbulent near field is computed by solving the two-dimensional unsteady Reynolds-averaged Navier—Stokes equations, with k—ɛ turbulence model. The second-order spatial and temporal discretization schemes with multi-domain structural grids in the computational domain and a small time step are used to capture the unsteady flow physics and pressure fluctuation on the wall of volute casing. The solution to the inhomogeneous wave equation is expressed in the frequency domain by making use of the fast Fourier transform and the acoustic far field, taking into account the scattering effect of volute casing, is computed using an acoustic thin-body boundary-element method. The calculated tonal sound pressure levels (SPLs) are compared with the experimental data. The calculated results accord well with the experimental data at blade-passing frequency (BPF) and its second harmonic, but are unsatisfactory at the higher frequency components. Finally, the free, scattering, and total acoustic fields in the volute casing are compared at BPF, and its fifth and tenth harmonic. The result shows that the scattering of the volute casing has an obvious effect on sound propagation with the increase in sound frequency.
Adaptive sliding mode control with sliding mode observer for a microelectromechanical vibratory gyroscope
Authors: Fei J , Batur C
Published: November 2008

This paper presents a novel adaptive sliding mode control with a sliding mode observer for a microelectromechanical system (MEMS) gyroscope. The proposed adaptive sliding mode controller with a sliding mode observer can estimate the unmeasured velocities, angular velocity, and damping and stiffness coefficients of the gyroscope in the presence of parameter variations and external disturbance. A novel adaptive sliding mode controller with a proportional and integral sliding surface is derived and the stability condition of the closed-loop feedback system is established. Simulation results demonstrate the effectiveness of the proposed adaptive sliding mode controller with sliding mode observer.
Tracking control for a synchronized dual parallel linear motor machine tool
Authors: Chen S-L , Lin W-M , Chang T-H
Published: November 2008

This paper analyses and compares several different synchronized controllers and motion command schemes, and implements them using a PC-based gantry-type machine tool. First, an integral-proportional (IP) controller and a proportional controller are applied to the velocity and position loop of a single-axis system respectively. The tracking control accuracy of the motor is advanced by the fastened response and improved lag. Next, for the dual-axis synchronized system, the equation of the cross-coupled controller (CCC) parameters can be acquired by analysing the tracking error and the synchronized error of the dual linear motors. The equation can be further applied to integrate the synchronized motion and reduce the synchronized error. The experiment results have proved these theories to be successful in reducing synchronized error and realizing the performance demand of tracking control.
Downcoiler surface fault prediction for a hot strip steel mill
Authors: Chuang W-L , Chen C-H , Yen J-Y , Hsu Y-L
Published: November 2008

This paper studies the means of detecting steel strip surface defects produced by a hot strip mill downcoiler. The analysis is based on the force feedback signals taken from the side-guide and the pinch-roll of the steel mill. The study compares the results from two approaches. One approach is to apply principal component analysis (PCA) on the autoregressive (AR) model spectrum, and the other is to apply PCA on the signal periodogram. The spectrum estimation processes help eliminate the noise effects, and the PCA then distinguishes the signals into different clusters. Some of these clusters will then represent the problematic strips. The analysis results on the data from China Steel Corporation (CSC) show that PCA in conjunction with the AR model is able to separate a major portion of the defective processes, and that PCA with the periodogram is not as effective. However, the two processes sometimes compensate for each other, and the combination of the methods may provide improved results.
Development of a direct pressure-sensing pressure-reducing valve for water hydraulics
Authors: Suzuki K , Urata E
Published: November 2008

This paper submits a new design for a pilot-operated pressure-reducing valve for water hydraulics. The developed valve operates with a primary pressure of up to 14 MPa, secondary pressure range of down to 3.5 MPa, and a flow range of 2.7 to 15 l/min. The major features of the designed valve are: the main valve has two serial throttles to prevent cavitation, the pilot valve detects the secondary pressure directly, seepage from inlet port to pilot chamber is removed, and a viscous damper stabilizes the motion of the valve. A valve was produced whose dimensions were determined according to dynamic and static analyses. Experimental studies were carried out on the produced valve. No cavitation noise was observed for primary pressure up to 14 MPa. The steady state characteristics of the produced valve agreed well with the prediction by simulation. The measured secondary pressure variation was about 0.2 MPa at the maximum for the primary pressure of up to 14 MPa, and about 0.5 MPa for the flowrate up to 15 l/min.
The Time-Series Link Prediction Problem with Applications in Communication Surveillance
Authors: Huang Zan , Lin Dennis K. J.
Published: November 2008

The ability to predict linkages among data objects is central to many data mining tasks, such as product recommendation and social network analysis. Substantial literature has been devoted to the link prediction problem either as an implicitly embedded problem in specific applications or as a generic data mining task. This literature has mostly adopted a static graph representation where a snapshot of the network is analyzed to predict hidden or future links. However, this representation is only appropriate to investigate whether a certain link will ever occur and does not apply to many applications for which the prediction of the repeated link occurrences are of primary interest (e.g., communication network surveillance). In this paper, we introduce the time-series link prediction problem, taking into consideration temporal evolutions of link occurrences to predict link occurrence probabilities at a particular time. Using Enron e-mail data and high-energy particle physics literature coauthorship data, we have demonstrated that time-series models of single-link occurrences achieve comparable link prediction performance with commonly used static graph link prediction algorithms. Furthermore, a combination of static graph link prediction algorithms and time-series models produced significantly better predictions over static graph link prediction methods, demonstrating the great potential of integrated methods that exploit both interlink structural dependencies and intralink temporal dependencies.
A Dynamic Programming Algorithm for the Generalized Minimum Filter Placement Problem on Tree Structures
Authors: Mofya E. Chisonge , Smith J. Cole
Published: November 2008

We consider a network where nodes communicate by exchanging information packets whose fields include the address of the sending node and that of the destination node. In the absence of some verification mechanism, an attacking node can send packets to another node using a forged origin address. In this study, we consider an optimization problem of identifying a minimum cardinality subset of verification nodes on a tree such that the number of attacks from any forged origin to any destination is limited to a prescribed level. For the case in which communication is permitted between every node in the tree, we develop an optimal polynomial-time dynamic programming algorithm for this problem. We compare the performance of the dynamic programming algorithm against a mixed-integer programming model on randomly generated tree networks at varied levels of security.
Solving Beam-Angle Selection and Dose Optimization Simultaneously via High-Throughput Computing
Authors: Zhang Hao Howard , Shi Leyuan , Meyer Robert , Nazareth Daryl , D'Souza Warren
Published: November 2008

We provide a framework for integrating two stages of radiation treatment planning (RTP): beam-angle selection (BAS) and dose optimization (DO). The framework is applied to both classical three-dimensional conformal radiotherapy and advanced intensity-modulated radiation therapy. Automated BAS and improved dose distribution are achieved within the framework. A metaheuristic approach, nested partitions, is applied. Alternative BAS and DO algorithms or commercial RTP software and clinical experience can be embedded within the framework to provide new methods for warm starts and evaluations of the quality of beam-angle set samples. Computational efficiency is achieved by utilizing high-throughput computing via the Condor system. Computational results show that our framework has led to a significant improvement in terms of solution quality and delivery time compared with current clinical practice.
Embracing the challenge of bold theories of autism
Authors: Klin Ami
Published: November 2008

This article is a commentary on ‘Fetal testosterone and autistic traits’ (Auyeung et al., 2009).
Regionally Specified Human Neural Progenitor Cells Derived from the Mesencephalon and Forebrain Undergo Increased Neurogenesis Following Overexpression of ASCL1
Authors: Kim Hyun-Jung , McMillan Erin , Han Fabin , Svendsen Clive N.
Published: November 2008

Human neural progenitor cells (hNPC) derived from the developing brain can be expanded in culture and subsequently differentiated into neurons and glia. They provide an interesting source of tissue for both modeling brain development and developing future cellular replacement therapies. It is becoming clear that hNPC are regionally and temporally specified depending on which brain region they were isolated from and its developmental stage. We show here that hNPC derived from the developing cortex (hNPCCTX) and ventral midbrain (hNPCVM) have similar morphological characteristics and express the progenitor cell marker nestin. However, hNPCCTX cultures were highly proliferative and produced large numbers of neurons, whereas hNPCVM divided slowly and produced fewer neurons but more astrocytes. Microarray analysis revealed a similar expression pattern for some stemness markers between the two growing cultures, overlaid with a regionally specific profile that identified some important differentially expressed neurogenic transcription factors. By overexpressing one of these, the transcription factor ASCL1, we were able to regain neurogenesis from hNPCVM cultures, which produced larger neurons with more neurites than hNPCCTX but no fully mature dopamine neurons. Thus, hNPC are regionally specified and can be induced to undergo neurogenesis following genetic manipulation. Although this restores neuronal production with a region-specific phenotype, it does not restore full neurochemical maturation, which may require additional factors.
The effect of human GATA4 gene mutations on the activity of target gonadal promoters
Authors: Bouchard Marie France , Taniguchi Hiroaki , Viger Robert S
Published: November 2008

GATA transcription factors are crucial regulators of cell-specific gene expression in many tissues including the gonads. Although clinical cases of reproductive dysfunction have yet to be formally linked to GATA gene mutations, they have begun to be reported in other systems. Heterozygous GATA4 mutations have been associated with cases of congenital heart defects. Little is known, however, about the effect of these mutations on gonadal gene transcription. Since individuals carrying these mutations do not appear to suffer from gross reproductive defects, we hypothesized that this might be due to the differential transcriptional properties of the mutant proteins on heart versus gonadal target genes. Five mutations (S52F, E215D, G295S, V266M, and E359X) were recreated in the rat GATA4 protein. Several parameters were used to analyze the transcriptional properties of the mutants: activation of known gonadal target promoters (Star, Cyp19a1, and Inha), DNA binding, and interaction with GATA4 transcriptional partners. Three mutations (S52F, G295S, and E359X) reduced GATA4 transcriptional activity on the different gonadal promoters. With the exception of the G295S mutant, which showed a significant loss of DNA-binding affinity, the decrease in activity of the other GATA4 mutants was not associated with a change in DNA binding. All GATA4 mutants retained their ability to interact and cooperate with their major gonadal partners (NR5A1 and NR5A2) thereby compensating in part for the loss in intrinsic GATA4 transcriptional activity. Thus, unlike the heart, where the GATA4 mutations have deleterious effects, our data suggest that they would have a lesser impact on gonadal gene transcription and function.
Blockade of the V1b receptor reduces ACTH, but not corticosterone secretion induced by stress without affecting basal hypothalamic–pituitary–adrenal axis activity
Authors: Spiga Francesca , Harrison Louise R , Wood Susan , Knight David M , MacSweeney Cliona P , Thomson Fiona , Craighead Mark , Lightman Stafford L
Published: November 2008

Vasopressin (AVP), produced in parvocellular neurons of the hypothalamic paraventricular nucleus, regulates, together with CRH, pituitary ACTH secretion. The pituitary actions of AVP are mediated through the G protein receptor V1b (V1b|R). In man, hyperactivity of the hypothalamic–pituitary–adrenal axis has been associated with depression and other stress-related conditions. There are also clinical data suggesting a role for AVP in the dysfunctional HPA axis described in some depressed patients. In this study, we have investigated the effect of a recently synthesised selective antagonist of the V1bR both on exogenous AVP-induced ACTH and corticosterone secretion, and on basal and stress-induced pituitary–adrenal activity. Adult male Sprague-Dawley rats treated with the V1bR antagonist (Org, 30 mg/kg, s.c.) or vehicle (5% mulgofen in 0.9% saline, 2 ml/kg, s.c.). We found that blockade of the V1bR reduced the increase in both ACTH and corticosterone secretion induced by AVP (100 ng, i.v.). The same treatment had no effect either on basal ACTH and corticosterone levels or on the ultradian or diurnal rhythms of corticosterone secretion. Acute administration of the V1bR antagonist reduced ACTH secretion following both restraint and lipopolysaccharide, but did not antagonise the ACTH response to noise. The same treatment did not reduce corticosterone secretion in response to any of the three stressors used in this study. Our results confirm that this compound is an antagonist of the V1bR in the rat, and that its ability to reduce stress-induced ACTH responses is stressor dependent with differential modulation of pituitary and adrenal responses.
Differential involvement of estrogen receptorα and estrogen receptorβ in the healing promoting effect of estrogen in human keratinocytes
Authors: Merlo Sara , Frasca Giuseppina , Canonico Pier Luigi , Sortino Maria Angela
Published: November 2008

Estrogen affects proliferation and migration of different skin components, thus influencing wound healing processes. The human keratinocyte cell line NCTC 2544 has been used to examine the effects of estrogen, dissect its mechanism of action and characterize receptor subtypes involved. Western blot and immunocytochemical analyses confirmed the expression of estrogen receptors (ERs) α and β, with prevalence in the nuclear and extranuclear compartment, for ERα and ERβ respectively. Treatment with 10 nM 17β-estradiol (17β-E2) and the ERα and ERβ selective agonists, 1,3,5-tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT; 100 nM), and diarylpropionitrile (DPN; 1 nM) produced a slight but significant increase in cell proliferation, as by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and bromodeoxyuridine incorporation assays, only after a long-term treatment (96 h). Analysis of cell migration by a scratch wound assay showed that 17β-E2 (10 nM) accelerated migration between 5 and 24 h after scratching, an effect confirmed by the transwell migration assay. PPT and DPN elicited similar effects. Pre-treatment with the mitogen-activated protein kinase inhibitor, U0126 (1 μM), abolished the ability of 17β-E2 and DPN, but not of PPT, to accelerate wound closure. TGF-β1 (10 ng/ml) produced a similar positive effect on wound closure and the TGF-β1 receptor antagonist, SB431542 (10 μM), reduced the ability of 17β-E2 and PPT to accelerate cell migration, but did not modify DPN effect. It is suggested that estrogen positively affects in vitro wound healing by stimulating cell proliferation after long-term exposure but mainly by accelerating cell migration within a few hours from treatment. Selective activation of ERβ may result in favorable stimulation of wound healing without any increase of transforming growth factor-β1 production.
Briefing: Innovative design of semi-integral bridges on the new A428
Authors: Bhattacharya Saprava
Published: November 2008

Integral and semi-integral bridges of steel–concrete composite superstructure have become very common on highway projects in the UK because of their speed and ease of construction as well as low future maintenance costs. This briefing describes innovative solutions to some problems encountered late in the design stage of a design-and-build project. One provides a new robust detail for movement joints and the other gives an anchoring solution to contiguous bored piled abutments for semi-integral bridges.
Performance-based seismic design of a continuous bridge
Authors: Ghosh G. , Singh Y. , Thakkar S. K.
Published: November 2008

Performance-based design (PBD) provides an insight into the expected performance of a designed structure during an earthquake. Over recent decades, considerable development on the PBD of buildings has taken place, but studies regarding the PBD of bridges are limited. This paper examines the estimated performance of a three-span continuous bridge designed using a codal procedure for the site-specific design response spectrum. A three-dimensional model of the bridge was developed using non-linear modelling of the piers. The response of the bridge was estimated using non-linear static and dynamic procedures. The effect of loading patterns and the accuracy of different pushover analysis methods were examined, and Fema-356 performance levels compared with limit states defined by Kowalsky. The performance of the bridge was studied for different values of the response reduction factor used in the design. The paper also discusses the advantages of PBD and pushover analysis.
Sustainable bridge construction through innovative advances
Authors: Long A. E. , Basheer P. A. M. , Taylor S. E. , Rankin B. G. I. , Kirkpatrick J.
Published: November 2008

Sustainability is now recognised as a key issue that must be addressed in the design, construction and lifelong maintenance of civil engineering structures. This paper briefly discusses the generic aspects of sustainability, but the main focus is its application to bridges. Motorway bridges built in the 1960s and 1970s had design lives of 120 years; many, however, were showing signs of deterioration after only 20–40 years. This led to much (ongoing) debate on the issue of initial versus full life-cycle costing. In order to address the highly complex issue of the sustainability of bridges, this paper considers the following specific areas that impinge on this important subject: the impact on sustainability of different forms of bridge construction and maintenance/repair/replacement strategies; the utilisation of innovative in situ testing equipment for assessing the long-term durability of concrete; the development of innovative structural designs for bridges that inherently have greatly extended lives at minimal, if any, additional cost.
The 4000 tonne lift of Stonecutters Bridge steel back-spans, H.K.
Authors: Morgenthal G. , Sham R. , Schwarz A.
Published: November 2008

A heavy-lift scheme has been developed for the erection of the 88 m long steel deck sections around the towers of Stonecutters Bridge. With 4000 t lifted to a height of 80 m and subsequent sliding operations in two directions, this operation became one of the most substantial heavy lifts ever undertaken on a cable-stayed bridge project. The scheme utilised the concrete back-spans and the bridge towers as lifting points. This required detailed checking of the combined effects on the permanent works, design of substantial temporary works and partial strengthening of the permanent works. Implementation of the scheme effectively eliminated the need for self-contained vertical support structures for the deck erection. This paper describes the development of the erection procedures, the design of temporary and permanent works, aerodynamic analyses and geometry control methods. The actual implementation of the scheme is also outlined, along with load testing and typhoon measures.
Antecedents and consequences of TESOL student expectations
Authors: Bordia Sarbari , Wales Lynn , Gallois Cindy , Pittam Jeffery
Published: November 2008

Affective variables can help understand differences in student performance. This paper presents student expectations as an affective variable that has so far received little research attention. Students have expectations from educational providers, the fulfilment of which can create a positive learning environment leading to better performance. This study investigates students’ expectations from programs, the sources of these expectations and the outcomes of unmet expectations. A questionnaire was administered to learners of English as an additional language (n=65) in Brisbane, Australia. Factor analyses were conducted, and the results indicated that expectations are affected by levels of competitiveness, the educational and cultural gap between the home country and Australia, future orientation, and social value in the homeland. Unmet expectations affect performance, emotions, learning behaviour and cause rebelliousness. Followup interviews of teachers (n=10) at the same institutions were conducted to validate the results of the study. Students are likely to exhibit poorer performance and experience negative affective outcomes, thus hindering learning, if expectations are unmet. They may consider changing institutions and providing negative recommendations to prospective students. This research extends the understanding of affective variables in second language acquisition and has practical implications for educational providers.
Motivational and cultural correlates of second language acquisition
Authors: Yu Baohua , Watkins David A.
Published: November 2008

The present study investigates the relationships among motivational factors, cultural correlates and second language proficiency. The participants, from both Western and Asian backgrounds, were learning Chinese at university level in the People’s Republic of China. 115 students (35 Western students and 80 Asian students) ranging from beginning to advanced levels of proficiency were surveyed.

The results of the study indicated that the degree of integrativeness into Chinese culture and motivation was significantly and positively related to Chinese language proficiency, while language anxiety was significantly and negatively correlated to such proficiency. However instrumental orientation was found to have no statistically significant relationship with such proficiency. Multiple regression analysis indicated that integrativeness and gender were major variables predicting Chinese language proficiency. Significant differences between Western and Asian student groups were found in terms of motivational variables and Chinese language proficiency. Compared with the Asian student group, the Western student group tended to perform better in spoken Chinese proficiency as evaluated by their teachers and seemed to have higher levels of motivation and integrativeness but lower levels of instrumental orientation and language anxiety. Recommendations are made to enhance motivation and second language acquisition.
The Effects of Failing to Include Hard-to-Reach Respondents in Longitudinal Surveys
Authors: Odierna Donna H. , Schmidt Laura A.
Published: November 2008

Objectives. We sought to determine whether failure to locate hard-to-reach respondents in longitudinal studies causes biased and inaccurate study results.

Methods. We performed a nonresponse simulation in a survey of 498 low-income women who received cash aid in a California county. Our simulation was based on a previously published analysis that found that women without children who applied for General Assistance experienced more violence than did women with children who applied for Temporary Assistance to Needy Families. We compared hard-to-reach respondents whom we reinterviewed only after extended follow-up effort 12 months after baseline with other respondents. We then removed these hard-to-reach respondents from our analysis.

Results. Other than having a greater prevalence of substance dependence (14% vs 6%), there were no significant differences between hard- and easy-to-reach respondents. However, excluding the hard to reach would have decreased response rates from 89% to 71% and nullified the findings, a result that did not stem primarily from reduced statistical power.

Conclusions. The effects of failure to retain hard-to-reach respondents are not predicable based on respondent characteristics. Retention of these respondents should be a priority in public health research.
Albert Sabin and the Coalition to Eliminate Polio From the Americas
Authors: Hampton Lee
Published: November 2008

Albert B. Sabin, MD, developer of the oral polio vaccine, was also a major proponent of its use in annual vaccination campaigns aimed at the elimination of polio. Sabin argued that administering his vaccine simultaneously to every child in a country would break polio's chains of transmission. Although he was already promoting mass vaccination by the 1960s, Sabin's efforts expanded considerably when he became an adviser to groups fighting polio in the Americas in the 1980s. Sabin's experiences provide a window into both the formation of the coalition that eliminated poliomyelitis from the Western Hemisphere and what can happen when biomedical researchers become public health policy advisers. Although the polio elimination coalition succeeded in part because member groups often accommodated each other's priorities, Sabin was often limited by his indifference to the interests of those he was advising and to the shortcomings of his vaccine.
Terrorism-Related Fear and Avoidance Behavior in a Multiethnic Urban Population
Authors: Eisenman David P. , Glik Deborah , Ong Michael , Zhou Qiong , Tseng Chi-Hong , Long Anna , Fielding Jonathan , Asch Steven
Published: November 2008

Objectives. We sought to determine whether groups traditionally most vulnerable to disasters would be more likely than would be others to perceive population-level risk as high (as measured by the estimated color-coded alert level) would worry more about terrorism, and would avoid activities because of terrorism concerns.

Methods. We conducted a random digit dial survey of the Los Angeles County population October 2004 through January 2005 in 6 languages. We asked respondents what color alert level the country was under, how often they worry about terrorist attacks, and how often they avoid activities because of terrorism. Multivariate regression modeled correlates of worry and avoidance, including mental illness, disability, demographic factors, and estimated color-coded alert level.

Results. Persons who are mentally ill, those who are disabled, African Americans, Latinos, Chinese Americans, Korean Americans, and non-US citizens were more likely to perceive population-level risk as high, as measured by the estimated color-coded alert level. These groups also reported more worry and avoidance behaviors because of concerns about terrorism.

Conclusions. Vulnerable populations experience a disproportionate burden of the psychosocial impact of terrorism threats and our national response. Further studies should investigate the specific behaviors affected and further elucidate disparities in the disaster burden associated with terrorism and terrorism policies.
Estimating the World Trade Center Tower Population on September 11, 2001: A Capture–Recapture Approach
Authors: Murphy Joe
Published: November 2008

I applied the capture–recapture method to estimate the World Trade Center tower population at the time of the September 11, 2001, terrorist attacks. Available lists helped identify 8965 survivors and 2152 confirmed casualties. The capture–recapture model suggested that an additional 4435 survivors were present, putting the total count of all present at 15 552 (95% confidence interval = 15 216, 15 897). An accurate estimate represents the potential number at risk for trauma as a result of direct exposure to the events of the day.
Community Influences on Young People's Sexual Behavior in 3 African Countries
Authors: Stephenson Rob
Published: November 2008

Objectives. I examined the role of community-level factors in the reporting of risky sexual behaviors among young people aged 15 to 24 years in 3 African countries with varying HIV prevalence rates.

Methods. I analyzed demographic and health survey data from Burkina Faso, Ghana, and Zambia during the period 2001 through 2003 to identify individual, household, and community factors associated with reports of risky sexual behaviors.

Results. The mechanisms through which the community environment shaped sexual behaviors varied among young men and young women. Community demographic profiles were not associated with reports of risky sexual behavior among young women but were influential in shaping the behavior of young men. Prevailing economic conditions and the behaviors and attitudes of adults in the community were strong influences on young people's sexual behaviors.

Conclusions. These results provide strong support for a focus on community-level influences as an intervention point for behavioral change. Such interventions, however, should recognize specific cultural settings and the different pathways through which the community can shape the sexual behaviors of young men and women.
The Interaction of Sexual Identity With Sexual Behavior and Its Influence on HIV Risk Among Latino Men: Results of a Community Survey in Northern San Diego County, California
Authors: Zellner Jennifer A. , Martínez-Donate Ana P. , Sañudo Fernando , Fernández-Cerdeño Araceli , Sipan Carol L. , Hovell Melbourne F. , Carrillo Héctor
Published: November 2008

Objectives. We examined the sexual behavior, sexual identities, and HIV risk factors of a community sample of Latino men to inform efforts to reduce Latinos' HIV risk.

Methods. In 2005 and 2006, 680 Latino men in San Diego County, California, in randomly selected, targeted community venues, completed an anonymous, self-administered survey.

Results. Most (92.3%) respondents self-identified as heterosexual, with 2.2%, 4.9%, and 0.6% self-identifying as bisexual, gay, or other orientation, respectively. Overall, 4.8% of heterosexually identified men had a lifetime history of anal intercourse with other men. Compared with behaviorally heterosexual men, heterosexually identified men who had sex with both men and women were more likely to have had a sexually transmitted infection, to have unprotected sexual intercourse with female partners, and to report having sex while under the influence of alcohol or other drugs. Bisexually identified men who had sex with men and women did not differ from behaviorally heterosexual men in these risk factors.

Conclusions. Latino men who have a heterosexual identity and bisexual practices are at greater risk of HIV infection, and efforts to reduce HIV risk among Latinos should target this group.
The Scientific Basis for Law as a Public Health Tool
Authors: Moulton Anthony D. , Mercer Shawna L. , Popovic Tanja , Briss Peter A. , Goodman Richard A. , Thombley Melisa L. , Hahn Robert A. , Fox Daniel M.
Published: November 2008

Systematic reviews are generating valuable scientific knowledge about the impact of public health laws, but this knowledge is not readily accessible to policy makers. We identified 65 systematic reviews of studies on the effectiveness of 52 public health laws: 27 of those laws were found effective, 23 had insufficient evidence to judge effectiveness, 1 was harmful, and 1 was found to be ineffective. This is a valuable, scientific foundation—that uses the highest relevant standard of evidence—for the role of law as a public health tool.

Additional primary studies and systematic reviews are needed to address significant gaps in knowledge about the laws’ public health impact, as are energetic, sustained initiatives to make the findings available to public policy makers.
Tobacco Industry Efforts to Undermine Policy-Relevant Research
Authors: Landman Anne , Glantz Stanton A.
Published: November 2008

The tobacco industry, working through third parties to prevent policy-relevant research that adversely affected it between 1988 and 1998, used coordinated, well-funded strategies in repeated attempts to silence tobacco researcher Stanton A. Glantz. Tactics included advertising, litigation, and attempts to have the US Congress cut off the researcher's National Cancer Institute funding. Efforts like these can influence the policymaking process by silencing opposing voices and discouraging other scientists from doing work that may expose them to tobacco industry attacks. The support of highly credible public health organizations and of researchers’ employers is crucial to the continued advancement of public health.
Effects of Alcohol Tax Increases on Alcohol-Related Disease Mortality in Alaska: Time-Series Analyses From 1976 to 2004
Authors: Wagenaar Alexander C. , Maldonado-Molina Mildred M. , Wagenaar Bradley H.
Published: November 2008

Objective. We evaluated the effects of tax increases on alcoholic beverages in 1983 and 2002 on alcohol-related disease mortality in Alaska.

Methods. We used a quasi-experimental design with quarterly measures of mortality from 1976 though 2004, and we included other states for comparison. Our statistical approach combined an autoregressive integrated moving average model with structural parameters in interrupted time-series models.

Results. We observed statistically significant reductions in the numbers and rates of deaths caused by alcohol-related disease beginning immediately after the 1983 and 2002 alcohol tax increases in Alaska. In terms of effect size, the reductions were –29% (Cohen's d = –0.57) and –11% (Cohen's d = –0.52) for the 2 tax increases. Statistical tests of temporary-effect models versus long-term-effect models showed little dissipation of the effect over time.

Conclusions. Increases in alcohol excise tax rates were associated with immediate and sustained reductions in alcohol-related disease mortality in Alaska. Reductions in mortality occurred after 2 tax increases almost 20 years apart. Taxing alcoholic beverages is an effective public health strategy for reducing the burden of alcohol-related disease.
Gender as a Moderator in the Association of Body Weight to Smoking and Mental Health
Authors: Park Eunkyung
Published: November 2008

Objectives. I sought to examine gender's role as a moderator in the association of relative body weight to smoking and mental health.

Methods. Data came from the 2004–2005 Minnesota Survey on Adult Substance Use, a statewide telephone survey (N = 16 289). Current smoking and mental health problems were examined in relation to relative body weight across genders, with control for covariates.

Results. Relative to their healthy-weight counterparts, overweight or obese men were less likely to smoke, whereas overweight women were more likely to smoke. Mental health problems were not related to relative body weight among men. However, overweight or obese women were more likely than were their healthy-weight counterparts to have a negative self-assessment of mental health, and obese women were more likely to have a mental health problem. In addition, underweight women had increased odds of being a smoker and having mental health problems.

Conclusions. The results indicate that gender has a moderating role in the association between body weight and both smoking and mental health. Gender-specific analysis rather than adjustment for the impact of gender in analyses is a promising avenue for future research.