bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of food quality, distance and height on thoracic temperature in the stingless beeMelipona panamica
Authors: Nieh James C. , Sánchez Daniel
Published: October 2005

Stingless bees (Apidae, Meliponini) can recruit nestmates to good food sources. We present the first data showing that recruiting meliponine foragers at feeders and inside nests regulate their thoracic temperature according to net food profitability. Using infrared thermography, we found that Melipona panamica foragers elevated their thoracic temperature at profitable food sources (higher sucrose concentration, closer to the nest). At food sources, there is an increase of approximately 0.9°C in thoracic temperature (Tth) per 1 mol l–1 increase in sucrose concentration (at 20 m distance from nest: 1 mol l–1 sucrose concentration, Tth=36.6±0.8°C, Ta=31.3±0.5°C; 2.5 mol l–1sucrose concentration, Tth=36.9±0.6°C, Ta=29.9±0.2°C). Inside the nest, the difference between thoracic temperature Tth and ambient air temperature Ta (ΔTnest)decreases by 0.4°C with each 100 m increase in feeder-to-nest distance and increases by 0.1°C per 1 mol l–1 increase in sucrose concentration. The Tth of returning foragers was significantly higher at all tested sucrose concentrations (1.0–2.5 mol l–1 sucrose concentration) and distances (25–437 m) as compared to Ta (at 2.5 mol l–1 sucrose concentration: 25 m distance from nest, intranidal Tth=30.2±1.3°C, Ta=24.8±0.7°C; 437 m distance from nest,intranidal Tth=28.6±1.7°C, Tnest=25.4±1.4°C). For highly profitable food sources (2.5 mol l–1 sucrose concentration and ≤100 m from the nest), forager Tth was slightly higher than that of randomly chosen control bees inside the nest.
Encoding spatial information in the waggle dance
Authors: De Marco Rodrigo , Menzel Randolf
Published: October 2005

Apis mellifera bees execute waggle dances to recruit other bees to desirable food sources. Several components of the waggle dance are correlated with the direction of and the distance to food. Moreover, recruits use the spatial information encoded in the dance to locate the signalled food. However, although dance communication has been studied extensively, little is known about how the dancers combine the compass (direction) and the odometric(distance) information they acquire during the foraging flight. In the present study, we analysed the encoding of spatial information in the waggle dance by manipulating the navigational information provided to dancing bees. To this end, we took advantage of the bees' visually driven odometer. We found that the waggle dance basically encodes information on the distance gauged during the outbound (hive-to-food) flight. However, it does not necessarily refer to a global vector based on path integration of the outbound flight. Whenever the direction connecting the subjective food location and the hive does not match the direction of the global vector, dancers refer to a direction close to that of the shortcut connecting the actual food location and the hive. Moreover, in our experiments, this direction was close to that of the inbound(food-to-hive) flight, indicating that landmark-based information is computed during the inbound flight and that it may strongly affect the encoding of directional information in the waggle dance. Moreover, we found that the bees'experience of the terrain modulates the encoding of spatial information in the waggle dance, suggesting that interactions between path integration and visual landmarks are computed in the context of dance communication.
An updated catalogue of salivary gland transcripts in the adult female mosquito,Anopheles gambiae
Authors: Arcà Bruno , Lombardo Fabrizio , Valenzuela Jesus G. , Francischetti Ivo M. B. , Marinotti Osvaldo , Coluzzi Mario , Ribeiro José M. C.
Published: October 2005

Salivary glands of blood-sucking arthropods contain a variety of compounds that prevent platelet and clotting functions and modify inflammatory and immunological reactions in the vertebrate host. In mosquitoes, only the adult female takes blood meals, while both sexes take sugar meals. With the recent description of the Anopheles gambiae genome, and with a set of∼3000 expressed sequence tags from a salivary gland cDNA library from adult female mosquitoes, we attempted a comprehensive description of the salivary transcriptome of this most important vector of malaria transmission. In addition to many transcripts associated with housekeeping functions, we found an active transposable element, a set of Wolbachia-like proteins, several transcription factors, including Forkhead, Hairy and doublesex, extracellular matrix components and 71 genes coding for putative secreted proteins. Fourteen of these 71 proteins had matching Edman degradation sequences obtained from SDS-PAGE experiments. Overall, 33 transcripts are reported for the first time as coding for salivary proteins. The tissue and sex specificity of these protein-coding transcripts were analyzed by RT–PCR and microarray experiments for insight into their possible function. Notably, two gene products appeared to be differentially spliced in the adult female salivary glands, whereas 13 contigs matched predicted intronic regions and may include additional alternatively spliced transcripts. Most An. gambiae salivary proteins represent novel protein families of unknown function, potentially coding for pharmacologically or microbiologically active substances. Supplemental data to this work can be found at http://www.ncbi.nlm.nih.gov/projects/omes/index.html#Ag2.
Bioenergetics and diving activity of internesting leatherback turtlesDermochelys coriaceaat Parque Nacional Marino Las Baulas, Costa Rica
Authors: Wallace Bryan P. , Williams Cassondra L. , Paladino Frank V. , Morreale Stephen J. , Lindstrom R. Todd , Spotila James R.
Published: October 2005

Physiology, environment and life history demands interact to influence marine turtle bioenergetics and activity. However, metabolism and diving behavior of free-swimming marine turtles have not been measured simultaneously. Using doubly labeled water, we obtained the first field metabolic rates (FMRs; 0.20–0.74 W kg–1) and water fluxes (16–30% TBW day–1, where TBW=total body water)for free-ranging marine turtles and combined these data with dive information from electronic archival tags to investigate the bioenergetics and diving activity of reproductive adult female leatherback turtles Dermochelys coriacea. Mean dive durations (7.8±2.4 min (±1 s.d.), bottom times (2.7±0.8 min), and percentage of time spent in water temperatures (Tw) ≤24°C(9.5±5.7%) increased with increasing mean maximum dive depths(22.6±7.1 m; all P≤0.001). The FMRs increased with longer mean dive durations, bottom times and surface intervals and increased time spent in Tw≤24°C (all r2≥0.99). This suggests that low FMRs and activity levels, combined with shuttling between different water temperatures, could allow leatherbacks to avoid overheating while in warm tropical waters. Additionally, internesting leatherback dive durations were consistently shorter than aerobic dive limits calculated from our FMRs (11.7–44.3 min). Our results indicate that internesting female leatherbacks maintained low FMRs and activity levels, thereby spending relatively little energy while active at sea. Future studies should incorporate data on metabolic rate, dive patterns, water temperatures, and body temperatures to develop further the relationship between physiological and life history demands and marine turtle bioenergetics and activity.
The role of UV in crab spider signals: effects on perception by prey and predators
Authors: Heiling Astrid M. , Cheng Ken , Chittka Lars , Goeth Ann , Herberstein Marie E.
Published: October 2005

Australian crab spiders Thomisus spectabilis sit on the petals of flowers and ambush prey such as honeybees. White-coloured T. spectabilis reflect in the UV (UV+ spiders) and previous research has shown that their presence, curiously, attracts honeybees to daisies. We applied an UV-absorber (Parsol®) to create UV-absorbing(UV–) spiders that did not reflect any light below 395 nm wavelength. These physical changes of visual signals generated by crab spiders caused honeybees to avoid flowers with UV– spiders on their petals. They also affected the perception of UV– spiders by honeybees and a potential avian predator (blue tits). Compared to UV+ spiders, UV– spiders produced less excitation of the UV-photoreceptors in honeybees and blue tits,which translated into a reduced UV-receptor contrast and a reduced overall colour contrast between UV– spiders and daisy petals. Our results reveal that a clean physical elimination of reflection in the UV range affects perception in predators and prey and ultimately changes the behaviour of prey.
Residual-effected homogeneous charge compression ignition with delayed intake-valve closing at elevated compression ratio
Authors: Caton P A , Song H H , Kaahaaina N B , Edwards C F
Published: October 2005

Residual-effected homogeneous charge compression ignition (HCCI) was investigated using a single-cylinder research engine equipped with fully-flexible variable valve actuation. Operation at elevated compression ratios was explored to determine its effect on efficiency. Results showed that efficiency is decreased significantly by advanced phasing owing to increased thermal losses. However, if combustion phasing is held fixed, elevated compression ratio operation showed little effect on efficiency. Further experiments explored the use of IVC time as a control parameter at the elevated compression ratio. Tests were conducted to determine if an efficiency benefit could be realized from increasing the compression ratio and delaying IVC to increase the extent of expansion relative to compression. No significant change in efficiency was observed, although variation in IVC timing offered significant control authority. Delayed IVC was used in conjunction with variable IVO to control independently load and phasing of HCCI at the elevated compression ratio. Tests were also conducted to assess the significance of the measured exhaust temperature on HCCI phasing. EVO was introduced as a third control parameter, along with IVO and IVC, to control independently initial mixture composition, compression work, and exhaust temperature. Results indicated that the measured exhaust temperature was not a good indicator of HCCI phasing and suggested the stabilizing role of heat transfer to the reinducted exhaust gases. Results also suggested a set of control parameters that achieve the full range of HCCI operation with minimal degrees of freedom.
Attitudes and perceptions of registered nurses during and shortly after acute care restructuring in Newfoundland and Labrador
Authors: Way Christine , Gregory Deborah , Baker Norma , Lefort Sandra , Barrett Brendan , Parfrey Patrick
Published: October 2005

Objectives

To monitor changes in registered nurses' perceptions of the impact of seven years of health care restructuring in Newfoundland and Labrador (NL) and to measure the attitudinal and behavioural reactions over four years comparing the St John's region, where hospital aggregation occurred, to other regions of the province.

Methods

Data were collected on acute care nurses' personal characteristics and perceptions of the importance of reform and its impact on workplace conditions and health care quality in 1995, 1999, 2000 and 2002. Nurses' attitudes and intentions were monitored across three time periods (i.e.1999, 2000 and 2002).

Results

Perceived workplace conditions and health care quality, as well as attitudes and behaviours were generally negative. However, there was some improvement over time. The temporal sequence of scores suggests that restructuring had an adverse impact on nurses' attitudes. Few significant regional differences were observed.

Conclusions

Although health services restructuring had an adverse impact on nurses'attitudes, aggregation of hospitals in St John's region was achieved without further deterioration. Provincial wide initiatives are needed to promote more positive work environments and increase the organizational effectiveness.
Health care provider outcomes during and shortly after acute care restructuring in Newfoundland and Labrador
Authors: Way Christine , Gregory Deborah , Doyle Michael , Twells Laurie , Barrett Brendan , Parfrey Patrick
Published: October 2005

Objectives

To monitor changes in human resource indicators during six years of restructuring in Newfoundland and Labrador, and to measure providers’ perceptions of reform impact and attitudinal and behavioural reactions comparing changes in the St John's region, where hospital aggregation occurred, to other regions.

Methods

Data on human resource indicators from 1995/96 to 2001/02 were obtained and analysed. The Employee Attitude Survey was sent to acute care staff (n=5353) to assess perceptions of reform impact on workplace conditions, work-related attitudes, turnover intentions and personal characteristics. The response rate for 2000 and 2002 was approximately 42% (n=1222 and 1034, respectively). Only respondents to both surveys (n=589) were used in the analysis.

Results

Increases in average employee and full-time equivalent numbers occurred in the St John's region, despite hospital closure and aggregation. Increases in staff dislocation and turnover were observed, but paid sick hours decreased. Sick leave and overtime costs increased. Although perceived workplace conditions, and attitudes and behaviours were generally negative, there was evidence of improvement over time, especially in St John's. Few significant regional or provider group differences were observed on most study variables.

Conclusions

Aggregation of hospitals in StJohn's did not lead to a decrease in employee counts, or deterioration in human resource indicators or attitudes. However, province-wide initiatives are needed to promote more positive work environments and increase organizational effectiveness.
Hospital utilization, efficiency and access to care during and shortly after restructuring acute care in Newfoundland and Labrador
Authors: Barrett Brendan , Way Christine , McDonald Jackie , Parfrey Patrick
Published: October 2005

Objectives

Since the 1990s restructuring, including regionalization and downsizing, has largely been driven by a desire for cost containment. Regionalization, hospital closure and changes in management processes occurred in Newfoundland and Labrador (NL), Canada between 1995 and 2000. The objectives of the current study were: to describe trends in the utilization of acute care hospital services by residents of NL during and shortly after restructuring; to examine trends in the efficiency of utilization of acute care beds in the province during the same time frame; and to compare the trends in St John's with the rest of the province, taking account of confounding events, in an attempt to understand the impact of aggregation of hospitals in this region.

Methods

Hospital discharge and day surgical data were analysed for all facilities in NL from 1995/96 to 2000/01. Analyses were by facility of service and also by region of residence directly standardized to the provincial population for 1996. Efficiency of bed utilization was examined on three occasions by concurrent utilization review using a modified version of the Appropriateness Evaluation Protocol. Trends in the St John's region (where most tertiary services are located and greater aggregation of hospitals occurred) were compared with the rest of the province.

Results

Admissions declined by 14% in St John's facilities and by 17% elsewhere. Inpatient days fell by 9% in St John's and by 12% elsewhere. Average length of stay and Resource Intensity Weight changed little, apart from a rise in the final study year, with the largest change in St John's. Standardized hospital admission rates declined by 10% and inpatient days by 5.6% for residents of St John's region, and by 16% and 14% respectively for residents of other regions. There was no change over time in the use of day surgery. Efficiency of acute care bed use improved in 2002 in St John's, but was unchanged in other regions. Use of acute care beds by elderly patients for extended stay, or when an alternate level of care would have been appropriate, was greater in St John's with the disparity persisting over time. Waiting time for continuing care in the StJohn's region was unchanged comparing 1995/96 and 1999/00.

Conclusions

Regionalization in Newfoundland and Labrador facilitated aggregation of hospitals, but did not control the number of front-line workers and, consequently, total acute care expenditure. Expenditure increased significantly between1995 and 2002, at a rate which exceeded the increase in government revenues. The government's ability to pay for acute care will not be achieved unless employee costs are controlled or provincial income increases.
A Study of the Philadelphia Knowledge Economy
Authors: Kimbrough Steven O. , Murphy Frederic H.
Published: October 2005

A local civic organization, Greater Philadelphia First, engaged us to study the knowledge economy of the Philadelphia, Pennsylvania region and make recommendations on ways to improve its rate of growth. To structure our thinking and the interviews with local entrepreneurs, civic leaders, and others, using soft operations research techniques, we developed a framework for collecting ideas through interviews, generating our own by reflecting on the interviews, and organizing the resulting ideas. We generated a large number of useful ideas for improving the local knowledge economy. The organization sifted through the collection of ideas and selected the ones it is now advocating.
Citibank Models Credit Risk on Hybrid Mortgage Loans in Taiwan
Authors: Smith L. Douglas , Bilir Canser , Huang Vega W. , Hung Kuo-yao , Kaplan Mark
Published: October 2005

A new type of hybrid loan in Taiwan consists of a traditional residential mortgage with an attached line of credit. Motivated by declines in Taiwanese property values and unexpected credit losses on all types of loans secured by residential real estate, we developed new statistical models for analyzing the credit risk on traditional mortgages, the hybrid loans, and pure equity lines of credit. Nonstationary Markovian models represent probabilities of transition among different financial states for the three credit instruments. We used logistic and regression models to estimate the losses on defaulted loans and the utilization of credit lines. We calibrated the models with account-level data and integrated them into comprehensive forecasting models that revealed differences in risk profiles among the three types of credit and among different segments of each portfolio.
Lying on the Web: Implications for Expert Systems Redesign
Authors: Jiang Zhengrui , Mookerjee Vijay S. , Sarkar Sumit
Published: October 2005

We consider a new variety of sequential information gathering problems that are applicable for Web-based applications in which data provided as input may be distorted by the system user, such as an applicant for a credit card. We propose two methods to compensate for input distortion. The first method, termed knowledge base modification, considers redesigning the knowledge base of an expert system to best account for distortion in the input provided by the user. The second method, termed input modification, modifies the input directly to account for distortion and uses the modified input in the existing (unmodified) knowledge base of the system. These methods are compared with an approach where input noise is ignored. Experimental results indicate that both types of modification substantially improve the accuracy of recommendations, with knowledge base modification outperforming input modification in most cases. Knowledge base modification is, however, more computationally intensive than input modification. Therefore, when computational resources are adequate, the knowledge base modification approach is preferred; when such resources are very limited, input modification may be the only viable alternative.
Toward Comprehensive Real-Time Bidder Support in Iterative Combinatorial Auctions
Authors: Adomavicius Gediminas , Gupta Alok
Published: October 2005

Many auctions involve selling several distinct items simultaneously, where bidders can bid on the whole or any part of the lot. Such auctions are referred to as combinatorial auctions. Examples of such auctions include truck delivery routes, industrial procurement, and FCC spectrum. Determining winners in such auctions is an NP-hard problem, and significant research is being conducted in this area. However, multiple-round (iterative) combinatorial auctions present significant challenges in bid formulations as well. Because the combinatorial dynamics in iterative auctions can make a given bid part of a winning and nonwinning set of bids without any changes in the bid, bidders are usually not able to evaluate whether they should revise their bid at a given point in time or not. Therefore, in this paper we address various computational problems that are relevant from the bidder's perspective. In particular, we introduce two bid evaluation metrics that can be used by bidders to determine whether any given bid can be a part of the winning allocation and explore their theoretical properties. Based on these metrics, we also develop efficient data structures and algorithms that provide comprehensive information about the current state of the auction at any time, which can help bidders in evaluating their bids and bidding strategies. Our approach uses exponential memory storage but provides fast incremental update for new bids, thereby facilitating bidder support for real-time iterative combinatorial auctions.
Reputation Mechanism Design in Online Trading Environments with Pure Moral Hazard
Authors: Dellarocas Chrysanthos
Published: October 2005

This paper offers a systematic exploration of reputation mechanism design in trading environments with opportunistic sellers of commonly known cost and ability parameters, imperfect monitoring of a seller's actions, and two possible seller effort levels, one of which has no value to buyers. The objective of reputation mechanisms in such pure moral hazard settings is to induce sellers to exert high effort as often as possible. I study the impact of various mechanism parameters (such as the granularity of solicited feedback, the format of the public reputation profile, the policy regarding missing feedback, and the rules for admitting new sellers) on the resulting market efficiency. I find that maximum efficiency is bounded away from the hypothetical first-best case where sellers can credibly precommit to full cooperation by a factor that is related to the probability that cooperating sellers may receive “unfair” bad ratings. Furthermore, maximum efficiency is independent of the length of past history summarized in a seller's public reputation profile. I apply my framework to a simplified model of eBay's feedback mechanism and conclude that, in pure moral hazard settings, eBay's simple mechanism is capable of inducing the maximum theoretical efficiency independently of the number of recent ratings that are being summarized in a seller's profile. I derive optimal policies for dealing with missing feedback and easy online identity changes. Finally, I show that if the number of buyers is large, the results obtained in the monopoly case are also approximately valid in settings where multiple sellers of different reputations simultaneously offer auctions for identical goods.
Collaborating on Multiparty Information Systems Development Projects: A Collective Reflection-in-Action View
Authors: Levina Natalia
Published: October 2005

Growth of Web-based applications has drawn a great number of diverse stakeholders and specialists into the information systems development (ISD) practice. Marketing, strategy, and graphic design professionals have joined technical developers, business managers, and users in the development of Web-based applications. Often, these specialists work for different organizations with distinct histories and cultures. A longitudinal, qualitative field study of a Web-based application development project was undertaken to develop an in-depth understanding of the collaborative practices that unfold among diverse professionals on ISD projects. The paper proposes that multiparty collaborative practice can be understood as constituting a “collective reflection-in-action” cycle through which an information systems (IS) design emerges as a result of agents producing, sharing, and reflecting on explicit objects. Depending on their control over the various economic and cultural (intellectual) resources brought to the project and developed on the project, agents influence the design in distinctive ways. They use this control to either “add to,” “ignore,” or “challenge” the work produced by others. Which of these modes of collective reflection-in-action are enacted on the project influences whose expertise will be reflected in the final design. Implications for the study of boundary objects, multiparty collaboration, and organizational learning in contemporary ISD are drawn.
Rendezvous Search on the Labeled Line
Authors: Chester Elizabeth J. , Tütüncü Reha H.
Published: October 2005

The rendezvous search problem is the problem of finding optimal search strategies for two people who are placed randomly on a known search region and want to meet each other in minimal expected time. We focus on initial location distributions that are centrally symmetric and nonincreasing as one moves away from the center, including the discretized and/or truncated Gaussian densities. When the search region is a discrete or a continuous interval, and the interval is labeled so that the searchers know their own location at all times, we prove that the optimal strategy for both searchers is to go directly to the center and wait there. The same result also holds for rendezvous search on the infinite line.
The Optimality of Hedging Point Policies for Stochastic Two-Product Flexible Manufacturing Systems
Authors: Shaoxiang Chen
Published: October 2005

This paper studies the stochastic two-item, periodic review, single facility, flexible manufacturing systems, where stochasticity comes from random demands or/and unreliable production process. Based on a notion called μ-difference monotone introduced in this paper, we prove that the hedging point policy is optimal to the systems in general for both finite and infinite horizon cases of the problems. This result is (demand) distribution free and does not require strict convexity or even differentiability of the one-period expected cost function. A general characterization of the hedging point policy, together with monotone switching curves, is provided.
On Customer Contact Centers with a Call-Back Option: Customer Decisions, Routing Rules, and System Design
Authors: Armony Mor , Maglaras Constantinos
Published: October 2005

Organizations worldwide use contact centers as an important channel of communication and transaction with their customers. This paper describes a contact center with two channels, one for real-time telephone service, and another for a postponed call-back service offered with a guarantee on the maximum delay until a reply is received. Customers are sensitive to both real-time and call-back delay and their behavior is captured through a probabilistic choice model. The dynamics of the system are modeled as an M/M/N multiclass system. We rigorously justify that as the number of agents increases, the system's load approaches its maximum processing capacity. Based on this observation, we perform an asymptotic analysis in the many-server, heavy traffic regime to find an asymptotically optimal routing rule, characterize the unique equilibrium regime of the system, approximate the system performance, and finally, propose a staffing rule that picks the minimum number of agents that satisfies a set of operational constraints on the performance of the system.
Optimal Leadtime Differentiation via Diffusion Approximations
Authors: Plambeck Erica L.
Published: October 2005

This study illustrates how a manufacturer can use leadtime differentiation–selling the same product to different customers at different prices based on delivery leadtime–to simultaneously increase revenue and reduce capacity requirements. The manufacturer’s production facility is modeled as an exponential single-server queue with two classes of customers that differ in price sensitivity and delay sensitivity. The manufacturer chooses the service rate and a static price for each class of customer, and then dynamically quotes leadtimes to potential customers and decides the order in which customers are processed. The arrival rate for each class decreases linearly with price and leadtime. The manufacturer’s objective is to maximize profit, subject to the constraint that each customer must be processed within the promised leadtime. Assuming that some customers will tolerate a long delivery leadtime, we show that this problem has a simple near-optimal solution. Under our proposed policy, capacity utilization is near 100%. Impatient customers pay a premium for immediate delivery and receive priority in scheduling, whereas patient customers are quoted a leadtime proportional to the current queue length. Queue length and leadtime can be closely approximated by a reflected Ornstein-Uhlenbeck diffusion process. Hence, we have a closed form expression for profit, and choose prices and capacity to optimize this. In case customers may choose either the class 1 deal or the class 2 deal, the proposed policy is made incentive compatible by quoting a leadtime for the class 2 (patient) customers that is longer than the actual queueing delay.
A Strategic Flow Model of Traffic Assignment in Static Capacitated Networks
Authors: Marcotte Patrice , Nguyen Sang , Schoeb Alexandre
Published: October 2005

This work pleads for the use of the concept of strategies, and their network-theoretic representation as hyperpaths, for modeling network assignment problems. While this concept describes adequately the behavior of users in transit systems, we show that it can apply as well to networks where arc capacities are rigid. This opens up a whole new field of research and raises several questions, from both the theoretical and computational points of view. These are investigated in the paper.
Operations Research at Bell Laboratories through the 1970s: Part II
Authors: Dawson Cree S. , McCallum Charles J. , Murphy R. Bradford , Wolman Eric
Published: October 2005

This historical account of operations research at Bell Laboratories was drafted in the late 1970s when the authors were part of the Operations Research Center within Bell Laboratories at AT&T; it has not previously appeared in the open literature. We have added a few references to later publications that describe particular aspects of the period covered. Discussions of technological practices and organizational arrangements expressed in the present tense represent a viewpoint of about 1980, before “divestiture” split up the Bell System. A comprehensive table of contents for parts I, II, and III can be found in the Online Collection of the Operations Research Home Page, at www.informs.org/pubs .

We describe the work done in the Bell System up to about 1980, mainly at Bell Labs, both in developing the techniques of operations research and in applying them to the telecommunications business. This account does not include military OR or direct support of other federal government activities. Part II covers capacity expansion and operations analysis.
Service Design and Price Competition in Business Information Services
Authors: Bashyam T. C. A.
Published: October 2005

We examine two competing technologies for delivering business information to professional subscribers: first, a package service that delivers information using physical media, such as CD-ROMs; second, an online service that allows subscribers to access information over online networks. We model the information services market as a duopoly, where each information service provider is equipped with either packaged or online information delivery technology. They compete for potential subscribers characterized by their usage volume. Subscribers may also choose “self-service,” wherein they collect and collate information directly from the source. Service design for information service providers must specify their information delivery technology and the size of the database they provide. Service providers first commit to a service design and then enter a price competition phase, where they choose the parameters of their feasible pricing strategies. Specifically, a package service provider chooses a fixed charge for subscription. An online provider chooses both a fixed charge and a marginal charge, because it is possible to meter usage in that technology. We show that the package provider serves high volume subscribers while the online provider serves low volume subscribers. We also derive bounds on equilibrium database sizes, prices, and market shares for each provider.
Pure Strategy Asymmetric Rendezvous on the Line with an Unknown Initial Distance
Authors: Alpern Steve , Beck Anatole
Published: October 2005

Suppose two blind agents with unit speed are placed a distance H apart on an infinite line, and faced in random directions. Their initial distance H is picked from a distribution F with finite mean μ. We present a pair of rendezvous strategies which do not depend on the distribution F and ensure a meeting in expected time less than 5:514μ. This improves the bound of 5:74μ given by Baston and Gal. Furthermore, the bound we give is best possible for strategies of our type.
Willingness, Confidence, and Knowledge to Work with Adolescent Sex Offenders: An Evaluation of Training Workshops
Authors: Dadds Mark R. , Smallbone Stephen , Nisbet Ian , Dombrowski Julie
Published: October 2005

Increasing attention is being paid to best practice in mental health sciences. One crucial aspect of this is the extent to which the mental health workforce has the knowledge and skills to implement state-of-the-art interventions. Recently, evidence has indicated that sexual offending often begins in adolescence, can be a persistent disorder when left untreated, and is associated with a range of other mental health problems in the perpetrator and subsequently in victims. A small number of evaluations of treatment programs are appearing but little work has appeared addressing the issue of how the workforce is equipped, or can be trained, to work with this challenging population. In this paper we present data on the effects of training on knowledge, skills, confidence, and willingness, to work with this client group. Trainees were 107 mental health workers who attended training workshops provided throughout Queensland, Australia by the Griffith Adolescent Forensic Assessment and Treatment Centre. Results showed that the measures developed for assessing training effects were change sensitive and valid. Training was associated with increases in self-rated skills, confidence, knowledge, and willingness to work with this population, and these changes were maintained for the follow-up sample.
A Descriptive Model of the Homicide Process
Authors: Cassar Emma , Ward Tony , Thakker Jo
Published: October 2005

Homicides are committed by a diverse array of individuals in all sectors of society for many different reasons. Any successful theory of homicide will have sufficient scope to encompass this diversity. Researchers in the fields of drunk driving and sexual offending have developed descriptive theories, using grounded theory approaches, which show promise in outlining the diversity of offence processes in these areas. This study uses a grounded theory approach to develop a descriptive multi-pathway model of the homicide process. The resulting model consists of three distinct phases and provides a fine grained description of the homicide process. A major finding is that individuals vary in terms of their goals, emotional states, degree of planning, and behaviour throughout the different phases of the model. Finally, the clinical and theoretical implications of the study are briefly discussed.
A Longitudinal Study of Developmental Differences in Universal Preventive Intervention for Child Anxiety
Authors: Lock Sally , Barrett Paula M.
Published: October 2005

The present paper presents the results of a longitudinal study evaluating the effects of a universal school-based intervention for child anxiety at two developmental stages. The study involved a cohort of 733 children enrolled in grade 6 (n = 336, 45.6%) aged between 9 and 10 years, and grade 9 (n = 401, 54.4%) aged between 14 and 16 years. Participants were allocated to either a school-based cognitive-behavioural intervention or to a monitoring group, and completed standardised measures of anxiety, depression and coping style. Young people identified as “at risk” of an anxiety disorder were assessed for a clinical diagnosis with a structured diagnostic interview. Findings showed universal intervention as potentially successful in reducing symptoms of anxiety and increasing coping skills in children. Primary school children reported the greatest changes in anxiety symptoms, suggesting earlier preventive intervention was potentially more advantageous than later intervention. Developmental differences in anxiety, depression and coping strategies are discussed in addition to the implications and limitations of this study and directions for future research.
Contributions to Rehabilitation from Behavioural Psychology: Then and Now
Authors: Murphy Gregory C. , Young Amanda E. , Reid Katharine
Published: October 2005

This paper analyses the contribution of behaviourally-oriented psychologists to the field of rehabilitation. Following a brief description of the prominent contribution of behavioural psychology in the period 1950—1970, an analysis of the contents of four contemporary North American behaviour therapy and rehabilitation journals suggests that there is currently little behaviourally-oriented rehabilitation research being published, even though rehabilitation settings in North America have provided the most positions of employment for psychologists over the recent past. It is concluded that, locally, Australian behavioural psychologists could make a valuable contribution to the nation's public health effort by increasing their prominence as researchers and practitioners within the field of rehabilitation.
Internet Use in Adulthood: Loneliness, Computer Anxiety and Education
Authors: Matanda Maona , Jenvey Vickii B. , Phillips James G.
Published: October 2005

With the recent exponential increase in Internet use, there are concerns about obstacles to gaining access to this potentially beneficial technology. To understand the psychological factors that might be offering barriers to Internet use, the present study considered age, attitudes towards computers, gender, education and social isolation as potential predictors of Internet usage. A sample of 158 adults completed questionnaires about computer anxiety, loneliness and Internet use. Time spent in activities associated with entertainment, communication, information searches and commerce, and overall time spent on the Internet were analysed using multiple regression. It was difficult to predict overall Internet use, but possible to predict specific categories of use. Better-educated participants were more likely to use the Internet for communication. Men, the young, and the lonely used the Internet more for entertainment. Those with lower computer anxiety used the Internet for information searches, and men were more likely than women to use the Internet for commercial purposes. It is suggested that computer anxiety and education may constrain the use of specific applications but Internet use otherwise follows pre-existing tendencies or interests.
Danger Ideation Reduction Therapy (DIRT) for Atypical Obsessive—Compulsive Disorder: A Case Study
Authors: St Clare Tamsen
Published: October 2005

This paper describes the application of danger ideation reduction therapy (DIRT) to a case of atypical obsessive—compulsive disorder (OCD) with prominent magical ideation. Treatment consisted of eight weekly sessions. It was cognitive in nature, did not include any exposure or response prevention, and was aimed solely at reducing threat expectancy. The treatment components were adapted from the original DIRT package for compulsive washing, and comprised attentional focusing, corrective information, cognitive restructuring and the probability of catastrophe estimation task. At posttreatment, the subject demonstrated normal functioning on all assessment measures, and met Jacobson and Truax's criteria for ‘recovery’ on the MOCI, OCI-R, DASS depression scale and DASS stress scale. The findings provide preliminary support for the effectiveness of DIRT in individuals with atypical OCD symptoms characterised by magical ideation. Implications of these findings are discussed.
Evaluation of the Controlling Alcohol and Relationship Enhancement (CARE) Program With Hazardous Drinkers
Authors: Bouma Ruth , Halford W. Kim , Young Ross McD.
Published: October 2005

We assessed the effects of the Controlling Alcohol and Relationship Enhancement (CARE) program, an early intervention combining reduction of hazardous alcohol consumption and enhancement of couple relationships. Thirty-seven hazardous drinking couples were randomly allocated to either the CARE program or to a control condition. CARE couples improved their communication more than controls, but couples in both conditions reduced hazardous drinking to a similar extent. CARE is a potentially useful means of promoting positive relationship communication in hazardous drinking couples.
The Superiority of Danger Ideation Reduction Therapy (DIRT) Over Exposure and Response Prevention (ERP) in Treating Compulsive Washing
Authors: Krochmalik Annette , Jones Mairwen K. , Menzies Ross G. , Kirkby Ken
Published: October 2005

The present study involved the random allocation of 22 obsessive-compulsive (OC) washer/cleaners to one of two treatment conditions: Danger Ideation Reduction Therapy (DIRT), or Exposure and Response Prevention (ERP). Participants received 12 1-hour individual clinical sessions and were assessed at pretreatment, posttreatment and at a 6-month follow-up with a battery of 17 measures assessing core obsessive-compulsive disorder (OCD) symptomatology, depression, stress, general anxiety, disease expectancy and perceived responsibility. DIRT subjects experienced significantly greater before to after-treatment reductions in symptomatology on six outcome measures. On 10 of the remaining 11 measures, posttreatment mean scores were lower in the DIRT condition than in the ERP condition, though differences between groups failed to reach significance. Of note, on 3 of the 17 measures, DIRT subjects experienced significantly greater posttreatment to follow-up symptom reduction. Finally, and most importantly, symptom change (regardless of treatment condition) was shown to significantly correlate with change in threat or disease expectancy across the trial. No relationships were found between improvements in perceived responsibility and any of the dependent variables. The findings suggest that DIRT and ERP may be working by reducing specific beliefs in threat; the former treatment being more effective in producing such change than the latter.
Performance-Related Beliefs in Social Phobia: Why Social Phobics Perceive Performance Requirements as Exceeding Their Abilities
Authors: Allen Karina L. , Page Andrew C.
Published: October 2005

This review evaluates five explanations for why social phobics perceive a discrepancy between performance requirements and their own abilities. There is little evidence to suggest that social phobia is associated with perfectionistic performance standards (possibility 1), perfectionistic standards in social situations (possibility 2), or perceptions of perfectionistic standards in others (possibility 3). Possibility 4, that social phobics set rigid performance standards, requires additional research. Support is provided for possibility 5, however, which proposes that social phobics perceive their own performance abilities negatively. Subsequently, it is concluded that low self-related beliefs account for the discrepancy between social phobics' perceptions of performance requirements, and their perceptions of their performance abilities. This conclusion is discussed in the context of contrasting models of social phobia, and implications for treatment are considered.
Home-Based Imaginal Desensitisation in Pathological Gambling: Short-Term Outcomes
Authors: Blaszczynski Alex , Drobny Juliette , Steel Zachary
Published: October 2005

Randomised controlled outcome studies have demonstrated the efficacy of imaginal desensitisation in inpatient settings. The purpose of this study was to evaluate the effects of a prerecorded audiocassette version of the imaginal desensitisation procedure that was designed for home-based use in reducing gambling urges and behaviours on a sample of diagnosed pathological gamblers who sought treatment at a university teaching hospital at 2-month follow-up. Pretreatment to 2-month follow-up repeated measures revealed a significant reduction in visual analogue scale ratings of urge, preoccupation and perceived self-control over gambling; indices of actual gambling behaviour; and psychometric measures of anxiety, depression and impulsivity. A prerecorded audiocassette version of imaginal desensitisation for home use represents a cost-effective approach in the management of pathological gambling.
Are Negative Cognitions Associated With Severe Acute Trauma Responses?
Authors: Nixon Reginald D.V. , Bryant Richard A.
Published: October 2005

Recent cognitive models of trauma response predict that negative trauma appraisals are central to the development of psychopathological stress reactions. Fifty-nine civilian survivors of motor vehicle accidents (MVA;n= 24) and nonsexual assaults (n= 35) were assessed within 4 weeks of their traumatic event for acute stress disorder (ASD), prior traumatic events and prior mental health contact, and were administered the Anxiety Sensitivity Index and the Posttraumatic Cognitions Inventory. Participants who were diagnosed with ASD displayed more maladaptive appraisals about their functioning following their trauma and reported higher levels of concern regarding anxiety symptoms than those who were not diagnosed with ASD. Negative beliefs were strongly associated with acute stress severity. These findings are discussed in the context of cognitive mechanisms that may influence maladaptive adjustment following trauma.
Facilitation of Memory for Events by Photographic Review for People With Traumatic Brain Injury
Authors: Rendle Valerie , McDonald Skye , Salmon Karen
Published: October 2005

People with severe traumatic brain injury (TBI) often have poor psychosocial outcomes. Poor memory may contribute to this because it impedes the ability to share experiences and reminisce about past experiences. This study was designed to determine whether photographic partial reminders would improve recall of incidentally learned complex events in people with severe TBI. Two groups of 10 people with severe TBI viewed videotapes of everyday events. One group was shown photographic reminders of half the events shown two days later on 3 occasions separated by 10 minutes. Twenty minutes after the last review (or control activity) both groups were tested for free recall and recognition of the videotape events. The reminder group recalled a greater percentage of reviewed events and objects per events recalled, but a similar number of actions per event recalled, compared to the control group. Photographic review did not decrease recall of nonreviewed events or affect recognition of reviewed or nonreviewed events.