bluuebunny/crossref_metadata_2025 huggingface dataset:
Look and turn: landmark-based goal navigation in honey bees
Authors: Fry S. N. , Wehner R.
Published: October 2005

This report describes the piloting mechanisms employed by honey bees during their final approach to a goal. Conceptually applying a bottom-up approach, we systematically varied the position, number and appearance landmarks associated with a rewarded target location within a large, homogenous flight tent. The flight behavior measured under various conditions is well explained with visuo-motor control loops that link perceived landmarks with appropriate turning responses. This view is consistent with the requirement of prolonged reinforcement learning for efficient goal navigation. A simple model is able to provide a comprehensive explanation for diverse flight patterns that range from convoluted searching behavior to highly idiosyncratic approaches,depending on the experimental context. Our results challenge the prevalent notion that honey bees employ image matching for visual guidance toward a goal site. Basic visuo-motor control loops may better meet the high demands for robust and fast flight control, which could serve as a powerful bio-mimetic design principle for micro-robotic aircraft.
Submerged swimming of the great cormorantPhalacrocorax carbo sinensisis a variant of the burst-and-glide gait
Authors: Ribak Gal , Weihs Daniel , Arad Zeev
Published: October 2005

Cormorants are water birds that forage by submerged swimming in search and pursuit of fish. Underwater they swim by paddling with both feet simultaneously in a gait that includes long glides between consecutive strokes. At shallow swimming depths the birds are highly buoyant as a consequence of their aerial lifestyle. To counter this buoyancy cormorants swim underwater with their body at an angle to the swimming direction. This mechanical solution for foraging at shallow depth is expected to increase the cost of swimming by increasing the drag of the birds. We used kinematic analysis of video sequences of cormorants swimming underwater at shallow depth in a controlled research setup to analyze the swimming gait and estimate the resultant drag of the birds during the entire paddling cycle. The gliding drag of the birds was estimated from swimming speed deceleration during the glide stage while the drag during active paddling was estimated using a mathematical`burst-and-glide' model. The model was originally developed to estimate the energetic saving from combining glides with burst swimming and we used this fact to test whether the paddling gait of cormorants has similar advantages.

We found that swimming speed was correlated with paddling frequency(r=0.56, P<0.001, N=95) where the increase in paddling frequency was achieved mainly by shortening the glide stage(r=–0.86, P<0.001, N=95). The drag coefficient of the birds during paddling was higher on average by two- to threefold than during gliding. However, the magnitude of the drag coefficient during the glide was positively correlated with the tilt of the body(r=0.5, P<0.003, N=35) and negatively correlated with swimming speed (r=–0.65, P<0.001, N=35), while the drag coefficient during the stroke was not correlated with tilt of the body (r=–0.11, P>0.5, N=35) and was positively correlated with swimming speed(r=0.41, P<0.015, N=35). Therefore, the difference between the drag coefficient during the glide and during propulsion diminished at lower speeds and larger tilt. The mean drag of the birds for a single paddling cycle at an average swimming speed of 1.5 m s–1 was 5.5±0.68 N. The burst-and-glide model predicts that energy saving from using burst-and-glide in the paddling cycle is limited to relatively fast swimming speeds (>1.5 m s–1), but that as the birds dive deeper (>1 m where buoyancy is reduced), the burst-and-glide gait may become beneficial even at lower speeds.
Electrical properties and fusion dynamics ofin vitromembrane vesicles derived from separate parts of the contractile vacuole complex ofParamecium multimicronucleatum
Authors: Sugino Kazuyuki , Tominaga Takashi , Allen Richard D. , Naitoh Yutaka
Published: October 2005

The contractile vacuole complex of Paramecium multimicronucleatumtransforms into membrane-bound vesicles on excision from the cell. The I–V relationship was linear in a voltage range of–80 to +80 mV in all vesicles, despite being derived from different parts of the contractile vacuole complex. No voltage-gated unit currents were observed in membrane patches from the vesicles. Vesicles derived from the radial arm showed a membrane potential of >10 mV, positive with reference to the cytosol, while those derived from the contractile vacuole showed a residual (<5 mV) membrane potential. The electrogenic V-ATPases in the decorated spongiome are responsible for the positive potential, and Cl– leakage channels are responsible for the residual potential. The specific resistance of the vesicle membrane (∼6 kΩcm2) increased, while the membrane potential shifted in a negative direction when the vesicle rounded. An increase in the membrane tension (to∼5×10–3 N m–1) is assumed to reduce the Cl– leakage conductance. It is concluded that neither voltage- nor mechano-sensitive ion channels are involved in the control of the fluid segregation and membrane dynamics that govern fluid discharge cycles in the contractile vacuole complex.

The membrane vesicles shrank when the external osmolarity was increased,and swelled when the osmolarity was decreased, implying that the contractile vacuole complex membrane is water permeable. The water permeability of the membrane was 4–20×10–7 μm s–1Pa–1. The vesicles containing radial arm membrane swelled after initially shrinking when exposed to higher external osmolarity, implying that the V-ATPases energize osmolyte transport mechanisms that remain functional in the vesicle membrane. The vesicles showed an abrupt (<30 ms),slight, slackening after rounding to the maximum extent. Similar slackening was also observed in the contractile vacuoles in situ before the opening of the contractile vacuole pore. A slight membrane slackening seems to be an indispensable requirement for the contractile vacuole membrane to fuse with the plasma membrane at the pore. The contractile vacuole complex-derived membrane vesicle is a useful tool for understanding not only the biological significance of the contractile vacuole complex but also the molecular mechanisms of V-ATPase activity.
Expanding the operating range of homogeneous charge compression ignition-spark ignition dual-mode engines in the homogeneous charge compression ignition mode
Authors: Yang J
Published: October 2005

Vehicle fuel economy benefit through the use of homogeneous charge compression ignition (HCCI) engine technology depends on the range of HCCI operating conditions. The range of HCCI operating conditions also determines the frequency of combustion mode transition over vehicle drive cycles. Based on test data in a single-cylinder HCCI engine, the constraints on HCCI operating regimes were analysed, including combustion roughness and knock, combustion timing control, breathing, thermal energy for mixture autoignition, and combustion efficiency. The constraints due to inadequate thermal energy and insufficient breathing depend on the HCCI approaches employed. The operating ranges of alternative approaches to HCCI systems are quite different. For the other constraints, conventional control methods were tested and analysed to expand the range of HCCI operating conditions to higher loads, and to improve combustion efficiency at light loads.
Combustion control and operating range expansion in an homogeneous charge compression ignition engine with direct in-cylinder injection of reaction inhibitors
Authors: Ogawa H , Miyamoto N , Kaneko N , Ando H
Published: October 2005

Light naphtha, which exhibits two-stage ignition, was induced from the intake manifold and water or a low-ignitability fuel, which does not exhibit low temperature oxidation, was directly injected early in the compression stroke for ignition suppression in an homogeneous charge compression ignition (HCCI) engine. Their quantitative balance was flexibly controlled to optimize ignition timing according to operating conditions. Ultra-low NOx and smokeless combustion without knocking or misfiring was realized over a wide operating range with water or alcohol injection. The water injection significantly reduced the low-temperature oxidation, which suppressed the increase in charge temperature and the rapid combustion caused by the high-temperature oxidation. Rapid combustion was suppressed by reductions in the maximum in-cylinder gas temperature due to water injection while the combustion efficiency suffered. Therefore, the maximum charge temperature needs to be controlled within an extremely limited range to maintain a satisfactory compromise between mild combustion and high combustion efficiency. Alcohols inhibit low-temperature oxidation more strongly than other oxygenated or unoxygenated hydrocarbons, water, and hydrogen. Chemical kinetic modelling with methanol showed a reduction of OH radical before the onset of low-temperature oxidation, and this may be the main mechanism by which alcohols inhibit low-temperature oxidation.
A physics-based approach to the control of homogeneous charge compression ignition engines with variable valve actuation
Authors: Shaver G M , Roelle M J , Caton P A , Kaahaaina N B , Ravi N , Hathout J-P , Ahmed J , Kojic A , Park S , Edwards C F , Gerdes J C
Published: October 2005

Homogeneous charge compression ignition (HCCI) is a promising low-temperature combustion strategy for reducing NOx emissions and increasing efficiency in internal combustion engines. However, HCCI has no direct combustion initiator and, when achieved by reinducting or trapping residual exhaust gas with a variable valve actuation (VVA) system, becomes a dynamic process as the temperature of the residual gas couples one cycle to the next. These characteristics of residual-affected HCCI present a challenge for control engineers and a barrier to implementing HCCI in a production engine. In order to address these challenges, this paper outlines physics-based control strategies for both the VVA system and the HCCI combustion process. The results show that VVA system control can provide arbitrary valve timings on a cycle-to-cycle basis, enabling tight control of HCCI. By abstracting these valve timings further into an inducted gas composition and an effective compression ratio, model-based controllers can be developed to control simultaneously load and combustion timing in an HCCI engine.
Characterizing the thermal sensitivity of a gasoline homogeneous charge compression ignition engine with measurements of instantaneous wall temperature and heat flux
Authors: Chang J , Filipi Z , Assanis D , Kuo T-W , Najt P , Rask R
Published: October 2005

An experimental study was performed to provide qualitative and quantitative insight into the thermal effects on a gasoline-fuelled homogeneous charge compression ignition (HCCI) engine combustion. The single-cylinder engine utilized exhaust gas rebreathing to obtain large amounts of hot residual gas needed to promote ignition. In-cylinder pressure, heat release analysis, and exhaust emission measurement were employed for combustion diagnostics. Fast response thermocouples were embedded in the piston top and cylinder head surface to measure instantaneous wall temperature and heat flux, thus providing critical information about the thermal boundary conditions and a thorough understanding of the heat transfer process.

Two parameters determining thermal conditions in the cylinder, i.e. intake charge temperature and wall temperature, were considered and their effect on ignition and burning rate in an HCCI engine was investigated through systematic experimentation. The approach allowed quantitative analysis, and separating qualitatively different effects on the core gas temperature from the effects of near-wall temperature stratification. The results show great sensitivity to changes in wall temperature and such like, but a somewhat weaker effect of intake charge temperature on HCCI combustion. Variations of combustion phasing and peak burn rates due to wall temperature changes can be compensated if the intake charge temperature is varied in the opposite direction and with a factor of 1.11. The combustion stability limit of the HCCI engine depends more on wall temperature than on intake charge temperature. Analysis of a large number of individual cycles indicates that decreasing intake temperature retards timing, and the burn rates change primarily as a function of ignition timing. In contrast, lowering the wall temperature led to greater reduction in the bulk burn rate and greater increase in cyclic variability than expected simply as a result of retarded ignition, thus indicating significance of the thermal stratification in the near-wall boundary layer.
Health care quality from the perspective of health care providers and patients during and shortly after acute care restructuring in Newfoundland and Labrador
Authors: Gregory Deborah , Way Christine , Barrett Brendan , Parfrey Patrick
Published: October 2005

Objectives

To monitor changes in providers' perceptions of health care quality and the importance of health reform, and in patients' satisfaction with services during and two years after restructuring, comparing the region of the province that was restructured (StJohn's) with those regions in which hospitals were not aggregated.

Methods

The Employee Attitude Survey questionnaire was sent to acute care providers (n=5353) to assess personal characteristics and perceptions of the impact of reform on workplace conditions, work-related attitudes and turnover intentions. The response rate for 2000 and 2002 was 42% (n=1222 and1034, respectively). Only respondents in both surveys (n=589) were used in the analysis because study results were the same for both the repeat sample and total samples. A Patient Satisfaction Survey questionnaire was administered to patients discharged from acute care facilities in 2000 (n=1741) and 2002 (n=704). Response rates were 82.5% and 90.2%, respectively.

Results

Most providers felt, at both time periods, that restructuring of the health care system was a positive step, but felt that health care quality was low. In the StJohn's region, perceptions of quality and standards of care improved over time. Patients were extremely satisfied with the admission process and hospital stay at both time periods in StJohn's. However, satisfaction declined in 2002 in regions outside StJohn's.

Conclusions

Aggregation of acute care hospitals is possible without adverse effects on providers' perceptions of health care quality or on patient satisfaction.
Acute care restructuring in Newfoundland and Labrador: the history and impact on expenditure
Authors: Twells Laurie , Doyle Michael , Gregory Deborah , Barrett Brendan , Parfrey Patrick
Published: October 2005

Objectives

To document the history of regionalization and its effects on the Newfoundland and Labrador acute care health system, and to describe changes in acute care expenditure in the St John's region where hospital redesign, closure and aggregation occurred in relation to other regions not exposed to aggregation.

Methods

Interviews were conducted with senior health officials. Transcripts and other reports were reviewed. Financial data were abstracted from audited general ledger statements received from the Ministry of Health.

Results

Regionalization achieved its objectives of hospital aggregation in St John's. The average number of full-time equivalent employees increased slightly by 2% (5304–5416). In some regions, integration of services was delayed because of conflict and resistance to change. There was some disparity between the Provincial Government's objectives for cost control and the CEOs’ perceptions of economies of scale. Between 1995/96 and 2002/03, total expenditures for the St John's region and the other five regional hospitals increased by 46% and 54%, respectively; total personal income of the population and government revenues increased by only 18% and 16%, respectively.

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.
The DSS LOGDIS Optimizes Delivery Routes for FRILAC’s Frozen Products
Authors: Faulin Javier , Sarobe Pablo , Simal Jorge
Published: October 2005

We designed a decision-support system for FRILAC Company in Navarre, Spain, to optimize its routes for delivering frozen products. FRILAC’s logistics department had been organizing deliveries based on vehicle runs, but FRILAC deemed this process inaccurate and expensive. We suggested simplifying this procedure by creating a decision-support system (DSS). We had a twofold aim: to design a route builder geared specifically to the road network of the area and to integrate the DSS into the global management of the company. We achieved both objectives by constructing the DSS LOGDIS in Microsoft Access. LOGDIS, using Clarke and Wright’s (1964) algorithm, designs routes that minimize distances traveled, shows final outcomes on screen, creates reports for vehicle drivers, and estimates route costs. FRILAC has successfully implemented the results, reaching an average cost saving of 10 percent.
America West Airlines Develops Efficient Boarding Strategies
Authors: van den Briel Menkes H. L. , Villalobos J. René , Hogg Gary L. , Lindemann Tim , Mulé Anthony V.
Published: October 2005

In September 2003, America West Airlines implemented a new aircraft boarding strategy that reduces the airline’s average passenger boarding time by over two minutes, or approximately 20 percent, for full and nearly full flights. The strategy, developed by a team of Arizona State University and America West Airline’s personnel, is a hybrid between traditional back-to-front boarding and outside-inside boarding used by other airlines. Field observations, numerical results of analytical models, and simulation studies provided information that resulted in an improved aircraft-boarding strategy termed reverse pyramid. With the new boarding strategy, passengers still have personal seat assignments, but rather than boarding by rows from the back to the front of the airplane, they board in groups minimizing expected passenger interference in the airplane. The analytical, simulation, and implementation results obtained show that the method represents a significant improvement in terms of boarding time over traditional pure back-to-front, outside-inside boarding strategies.
The US Army Uses a Network Optimization Model to Designate Career Fields for Officers
Authors: Shrimpton Dan , Newman Alexandra M.
Published: October 2005

In 1999, the United States Army instituted a new career-progression pattern for its officers. This pattern assigns, or designates, Army officers to specialized roles in which they must serve. Such roles include, for example, foreign area officer and operations research analyst. Manually designating officers into these roles under the new system is impossible because the problem is very large. We developed a network-optimization model, the career-field designation model, that makes these designations in minutes on a personal computer. The US Army has used this system four times since June 2001 to designate a total of approximately 10,500 officers and expects to continue to use the model to designate about 1,500 officers each year.
The Economic Incentives for Sharing Security Information
Authors: Gal-Or Esther , Ghose Anindya
Published: October 2005

Given that information technology (IT) security has emerged as an important issue in the last few years, the subject of security information sharing among firms, as a tool to minimize security breaches, has gained the interest of practitioners and academics. To promote the disclosure and sharing of cyber security information among firms, the U.S. federal government has encouraged the establishment of many industry-based Information Sharing and Analysis Centers (ISACs) under Presidential Decision Directive (PDD) 63. Sharing security vulnerabilities and technological solutions related to methods for preventing, detecting, and correcting security breaches is the fundamental goal of the ISACs. However, there are a number of interesting economic issues that will affect the achievement of this goal. Using game theory, we develop an analytical framework to investigate the competitive implications of sharing security information and investments in security technologies. We find that security technology investments and security information sharing act as “strategic complements” in equilibrium. Our results suggest that information sharing is more valuable when product substitutability is higher, implying that such sharing alliances yield greater benefits in more competitive industries. We also highlight that the benefits from such information-sharing alliances increase with the size of the firm. We compare the levels of information sharing and technology investments obtained when firms behave independently (Bertrand-Nash) to those selected by an ISAC, which maximizes social welfare or joint industry profits. Our results help us predict the consequences of establishing organizations such as ISACs, Computer Emergency Response Team (CERT), or InfraGard by the federal government.
Editorial Notes
Authors: Sambamurthy Vallabh
Published: October 2005

The synergistic relationship between Information Systems Research and the Information Systems Society is an important element of the information systems academic community. A call is made for members of the community to strengthen this relationship. Further, the efforts of the “founding” generation of IS academics in establishing the IS community are acknowledged. Finally, a new senior editor is introduced.
Pricing American Options: A Duality Approach
Authors: Haugh Martin B. , Kogan Leonid
Published: October 2005

We develop a new method for pricing American options. The main practical contribution of this paper is a general algorithm for constructing upper and lower bounds on the true price of the option using any approximation to the option price. We show that our bounds are tight, so that if the initial approximation is close to the true price of the option, the bounds are also guaranteed to be close. We also explicitly characterize the worst-case performance of the pricing bounds. The computation of the lower bound is straightforward and relies on simulating the suboptimal exercise strategy implied by the approximate option price. The upper bound is also computed using Monte Carlo simulation. This is made feasible by the representation of the American option price as a solution of a properly defined dual minimization problem, which is the main theoretical result of this paper. Our algorithm proves to be accurate on a set of sample problems where we price call options on the maximum and the geometric mean of a collection of stocks. These numerical results suggest that our pricing method can be successfully applied to problems of practical interest.
Dynamic Scheduling of a Multiclass Queue in the Halfin-Whitt Heavy Traffic Regime
Authors: Harrison J. Michael , Zeevi Assaf
Published: October 2005

We consider a Markovian model of a multiclass queueing system in which a single large pool of servers attends to the various customer classes. Customers waiting to be served may abandon the queue, and there is a cost penalty associated with such abandonments. Service rates, abandonment rates, and abandonment penalties are generally different for the different classes. The problem studied is that of dynamically scheduling the various classes. We consider the Halfin-Whitt heavy traffic regime, where the total arrival rate and the number of servers both become large in such a way that the system's traffic intensity parameter approaches one. An approximating diffusion control problem is described and justified as a purely formal (that is, nonrigorous) heavy traffic limit. The Hamilton-Jacobi-Bellman equation associated with the limiting diffusion control problem is shown to have a smooth (classical) solution, and optimal controls are shown to have an extremal or “bang-bang” character. Several useful qualitative insights are derived from the mathematical analysis, including a “square-root rule” for sizing large systems and a sharp contrast between system behavior in the Halfin-Whitt regime versus that observed in the “conventional” heavy traffic regime. The latter phenomenon is illustrated by means of a numerical example having two customer classes.
Optimal Policies for Multi-Echelon Inventory Problems with Batch Ordering
Authors: Chen Fangruo
Published: October 2005

In many production/distribution systems, materials flow from one stage to another in fixed lot sizes. For example, a retailer orders a full truckload from a manufacturer to qualify for a quantity discount; a factory has a material handling system that moves full containers of parts from one production stage to the next. In this paper, we derive optimal policies for multi-stage serial and assembly systems where materials flow in fixed batches. The optimal policies have a simple structure, and their parameters can be easily determined. This research extends the multi-echelon inventory theory in several ways. It generalizes the Clark-Scarf model by allowing batch transfers of inventories. Rosling (1989) shows that assembly systems can be interpreted as serial systems under the assumption that there are no setup costs. We show that the series interpretation still holds when materials flow in fixed batches which satisfy a certain regularity condition. Finally, Veinott (1965) identifies an optimal policy for a single-location inventory system with batch ordering. This paper generalizes his result to multi-echelon settings.
Adaptive Ordering and Pricing for Perishable Products
Authors: Burnetas Apostolos N. , Smith Craig E.
Published: October 2005

We consider the combined problem of pricing and ordering for a perishable product with unknown demand distribution and censored demand observations resulting from lost sales, faced by a monopolistic retailer. We develop an adaptive pricing and ordering policy with the asymptotic property that the average realized profit per period converges with probability one to the optimal value under complete information on the distribution. The pricing mechanism is modeled as a multiarmed bandit problem, while the order quantity decision, made after the price level is established, is based on a stochastic approximation procedure with multiplicative updates.
A Lagrangian Heuristic Based Branch-and-Bound Approach for the Capacitated Network Design Problem
Authors: Holmberg Kaj , Yuan Di
Published: October 2005

The capacitated network design problem is a multicommodity minimal cost network flow problem with fixed charges on the arcs and is well known to be NP-hard. The problem type is very common in the context of transportation networks, telecommunication networks, etc. In this paper we propose an efficient method for this problem, based on a Lagrangian heuristic within a branch-and-bound framework. The Lagrangian heuristic uses a Lagrangian relaxation to obtain easily solved subproblems and solves the Lagrangian dual by subgradient optimization. It also includes techniques for finding primal feasible solutions. The Lagrangian heuristic is then embedded into a branch-and-bound scheme that yields further primal improvements. Special penalty tests and cutting criteria are developed. The branch-and-bound scheme can either be an exact method that guarantees the optimal solution of the problem or be a quicker heuristic. The method has been tested on networks of various structures and sizes. Computational comparisons between this method and a state-of-the-art mixed-integer code are presented. The method is found to be capable of generating good feasible solutions to large-scale problems within reasonable time and data storage limits.
Lawmakers, Law Lords and Legal Fault: Two Tales from the (Thames) River Bank: Sexual Offences Act 2003; R v G and Another
Authors: Davies Mitchell
Published: October 2005

This article examines the conflicting approaches of Parliament and the senior courts to the need for mens rea in relation to those offences which are seriously criminal in character. Prompted by the imminent enactment of the Sexual Offences Act 2003 and the recent decision of the House of Lords in R v G and Another, the conclusion is reached that whilst the senior courts have become ever more sensitive to the need for true mens rea to be insisted upon as a precursor to liability for any serious crime, Parliament, in enacting the Sexual Offences Act 2003, has shown itself, in this context at least, to have priorities of a very different order. In applying a purely subjective meaning to the term reckless it is argued however that their Lordships in G have gone too far and have made prosecutions under the Criminal Damage Act 1971 for unintentionally caused criminal damage potentially unwinnable as well as having thereby perpetuated the definitional plurality of this much litigated mens rea term. The reader is accordingly guided to the conclusion that G is far from being the last word on the meaning of recklessness in English criminal law.
‘A Jury of Peers’: A Comparative Analysis
Authors: Davies Colin , Edwards Christopher
Published: October 2005

The article considers the historical development of the concept of a jury of peers in the UK, which is contrasted with US development. It is argued that if the jury process is to continue as an element of the judicial process, then issues of jury selection need to be revisited. In outlining the historical development of what is meant by the concept of a trial by a person's peer, it is suggested that there are a number of parallels to contemporary issues of equality. The representation of peer/social groups on a jury panel is considered in the light of contemporary equality and human rights laws.
Monitoring Temporary Immunodepression by Flow Cytometric Measurement of Monocytic HLA-DR Expression: A Multicenter Standardized Study
Authors: Döcke Wolf-Dietrich , Höflich Conny , Davis Kenneth A , Röttgers Karsten , Meisel Christian , Kiefer Paul , Weber Stefan U , Hedwig-Geissing Monika , Kreuzfelder Ernst , Tschentscher Peter , Nebe Thomas , Engel Andrea , Monneret Guillaume , Spittler Andreas , Schmolke Kathrin , Reinke Petra , Volk Hans-Dieter , Kunz Dagmar
Published: October 2005

Background: Single-center trials have shown that monocytic HLA-DR is a good marker for monitoring the severity of temporary immunodepression after trauma, major surgery, or sepsis. A new test for measuring monocytic HLA-DR is now available.

Methods: We evaluated a new test reagent set for monocytic HLA-DR expression (BD Quantibrite™ HLA-DR/Monocyte reagent; Becton Dickinson) in single-laboratory and interlaboratory experiments, assessing preanalytical handling, lyse-no-wash (LNW) vs lyse-wash (LW) values, reference values, and the effect of use of different flow cytometers and different instrument settings on test variance.

Results: For preanalytical handling, EDTA anticoagulation, storage on ice as soon as possible, and staining within 4 h after blood collection gave results comparable to values obtained for samples analyzed immediately after collection (mean increase of ∼4% in monocytic HLA-DR). Comparison of LNW and LW revealed slightly higher results for LNW (∼18% higher for LNW compared with LW; r = 0.982). Comparison of different flow cytometers and instrument settings gave CVs <4%, demonstrating the independence of the test from these variables and suggesting that this method qualifies as a standardized test. CV values from the interlaboratory comparison ranged from 15% (blood sample unprocessed before transport) to 25% (stained and fixed before transport).

Conclusions: For the BD Quantibrite HLA-DR/Monocyte test, preanalytical handling is standardized. Single-laboratory results demonstrated the independence of this test from flow cytometer and instrument settings. Interlaboratory results showed greater variance than single-laboratory values. This interlaboratory variance was partly attributable to the influence of transport and can be reduced by optimization of transport conditions.
Erythrocyte Folate Extraction and Quantitative Determination by Liquid Chromatography–Tandem Mass Spectrometry: Comparison of Results with Microbiologic Assay
Authors: Fazili Zia , Pfeiffer Christine M , Zhang Ming , Jain Ram
Published: October 2005

Background: Erythrocyte folate analysis is an important diagnostic tool to establish folate status or screen for folate deficiency.

Methods: We evaluated conditions that influence the complete hemolysis and deconjugation of folate polyglutamates to folate monoglutamates (FMGs) from whole blood (WB). WB samples were hemolyzed in 10 g/L ascorbic acid at various temperatures (room temperature, 30 °C, and 37 °C; n = 15) or hemolysate pH values (pH 4.0, 4.7, 5.2; n = 11) and incubated up to 6 h. FMGs and folate diglutamates (FDGs) were analyzed by liquid chromatography–tandem mass spectrometry (LC/MS/MS) and total folate (TF) by microbiologic assay. We investigated delaying hemolysis by freezing WB for 10 days (n = 20).

Results: Hemolysates frozen immediately after preparation contained 22%–27% FDGs, depending on hemolysate pH. The proportion of FDGs decreased to <3% after incubation at pH 4.7/37 °C for 3 h and did not significantly change on extended incubation up to 5 h. Short-term delayed hemolysis of WB produced results indistinguishable from those of immediate hemolysis. TF results obtained by the microbiologic assay were not different across incubation conditions and agreed with the sum of FMGs and FDGs by LC/MS/MS. The difference between the 2 methods was an insignificant 3% for pH 4.7/37 °C for 3 h.

Conclusions: Hemolysate incubation up to 2 h at 37 °C is not adequate for full polyglutamate deconjugation. We obtained the highest yield of FMGs with lowest FDG concentrations at pH 4.7/37 °C for 3 h. Delaying hemolysis of WB for several days had no negative effect on measurable folate for presumed MTHFR C/C genotype samples.
Evaluation of a Brief Child-focused Group-based Intervention for Anxiety-disordered Children
Authors: Cobham Vanessa E.
Published: October 2005

This paper presents a pilot study of a brief, group-based, cognitive-behavioural intervention for anxiety-disordered children. Five children (aged 7 to 13 years) diagnosed with a clinically significant anxiety disorder were treated with a recently developed 6-session, child-focused, cognitive-behavioural intervention that was evaluated using multiple measures (including structured diagnostic interview, self-report questionnaires and behaviour rating scales completed by parents) over four follow-up occasions (post-treatment, 3-month follow-up, 6-month follow-up and 12-month follow-up). This trial aimed to (a) evaluate the conclusion suggested by the research of Cobham, Dadds, and Spence (1998) that anxious children with non-anxious parents require a child-focused intervention only in order to demonstrate sustained clinical gains; and (b) to evaluate a new and more cost-effective child-focused cognitive-behavioural intervention. Unfortunately, the return rate of the questionnaires was poor, rendering this data source of questionable value. However, diagnostic interviews (traditionally the gold standard in terms of outcome in this research area) were completed for all children at all follow-up points. Changes in diagnostic status indicated that meaningful treatment-related gains had been achieved and were maintained over the full follow-up period. The results would thus seem to support the principle of participant-intervention matching proposed by Cobham et al. (1998), as well as the utility of the more brief intervention evaluated.
Specificity of Dysfunctional Thinking in Children with Symptoms of Social Anxiety, Separation Anxiety and Generalised Anxiety
Authors: Bögels Susan M. , Snieder Nienke , Kindt Merel
Published: October 2005

The present study investigated whether children with high symptom levels of either social phobia (SP), separation anxiety disorder (SAD), or generalised anxiety disorder (GAD) are characterised by a specific set of dysfunctional interpretations that are consistent with the cognitive model of their specific fear (“content-specificity of interpretations”). It was also examined whether such cognitive bias is predominantly activated in those ambiguous situations that are relevant for the pertinent fear (“content-specificity of situations”). Children high on symptoms of SP, SAD, and GAD and low-anxious control children were exposed to stories describing ambiguous situations and asked to give their interpretations and action plans. Results showed that high-anxious children displayed a negative cognitive bias compared to control children, but did not differ from controls with respect to the action plans given. Some evidence was found for the content-specificity of this cognitive bias. That is, consistent with the hypothesis of content-specificity of interpretations, children high on SAD reported more interpretations consistent with the content of their fear than children high on SP and GAD. Further, children high on SP and SAD predominantly displayed a negative cognitive bias in response to respectively social and separation situations. Children high on GAD did not show content-specificity for interpretations or situations. The theoretical implications of these findings are briefly discussed.
Investigating Safety Behaviours in Insomnia: The Development of the Sleep-related Behaviours Questionnaire (SRBQ)
Authors: Ree Melissa J. , Harvey Allison G.
Published: October 2005

A safety behaviour is an overt or covert strategy employed in order to prevent a feared outcome from occurring. These behaviours can, however, prevent the disconfirmation of unhelpful beliefs, and may make the feared outcome more likely to occur (Salkovskis, 1991). The current study extends Harvey's (2002a) investigation of safety behaviours in insomnia by developing a questionnaire measure designed to assess the use of safety behaviours that are employed to promote sleep and cope with tiredness. A development sample of 132 individuals with and without insomnia was employed to develop the 32-item Sleep-Related Behaviours Questionnaire (SRBQ). The SRBQ showed good internal consistency and was able to discriminate normal sleepers from those with insomnia. Interestingly, most safety behaviours were associated with impairment in both sleep and daytime functioning. This highlights that day- and night-time processes may be interlinked in insomnia, and stresses the importance of research and treatment focusing on both the day and night. Future research is needed to further investigate the psychometric properties of the SRBQ, and to explore the relationships between safety behaviours and dysfunctional beliefs about sleep.
Evaluation of a Puppet Interview to Measure Young Children's Self-Reports of Temperament
Authors: Roth Janet H. , Dadds Mark R. , McAloon John
Published: October 2005

This study developed and evaluated a puppet interview that allows children to self-report on temperamental constructs. Structured child self-report measures are rarely utilised in clinical assessment of young children under the age of 7—8 years. Given that clinical assessment is often characterised by low convergence between raters, such a measure may offer important contributions. The present study developed and evaluated a measure based on items from the Colorado Childhood Temperament Inventory and reports two studies with child participants aged 4 to 5 years. Independent observations of the children were also made. Results showed moderate levels of internal consistency and stability, and convergence between child self-report and teacher/parent raters was low, but similar levels of agreement were achieved between adult informants. The puppet interview thus showed some potential but highlighted the difficulties of self-report in young children within a multiple informant framework in clinical assessment.
Cyber-Flirting: An Examination of Men's and Women's Flirting Behaviour Both Offline and on the Internet
Authors: Whitty Monica T.
Published: October 2005

While flirting is a relatively underresearched area within psychology, even less is known about how people cyber-flirt. This paper explores how often individuals flirt offline compared to online. Moreover, it attempts to examine how men and women flirt within these different spaces. Five thousand, six hundred and ninety-seven individuals, of which 3554 (62%) were women and 2143 (38%) were men, completed a survey about their flirting behaviour both in face-to-face interactions and in chatrooms. The first hypothesis, which stated that the body would be used to flirt with as frequently online as offline, was partly supported. However, it was found that individuals downplayed the importance of physical attractiveness online. Women flirted by displaying nonverbal signals (offline) or substitutes for nonverbal cues (online), to a greater extent than men. In chatrooms men were more likely than women to initiate contact. It is concluded that cyber-flirting is more than simply a meeting of minds and that future research needs to consider the role of the body in online interactions.
Internet Relationships and Their Impact on Primary Relationships
Authors: Underwood Heather , Findlay Bruce
Published: October 2005

The number of personal relationships occurring via the Internet is increasing as more people gain access to it. Many of these relationships are romantic in nature, and evidence is accumulating that they have the potential to have an adverse effect on existing face-to-face relationships. This study explored the formation of romantic relationships on their Internet, their nature, and their possible impact on existing marital or de facto relationships in a sample of 75 adults (mean age 42 years, SD = 11.1 years) who responded to an online survey of individuals involved in extradyadic relationships on the Internet. Respondents reported a variety of means of contacting their online partner. More females than males communicated with them daily. Most respondents knew what their partner looked like, most had contacted them by telephone, and a third had met them. Most reported more satisfaction with their online relationship than with their face-to-face one, though few said that it was more important to them than their primary relationship. Although only a quarter of the sample admitted that their online relationship had affected their primary one, those participants reported concealing the truth about the time or nature of their activities, that everyday tasks did not get done, and that levels of sexual intimacy with their primary partner had dropped. The nature of these and other problems suggests that therapists should be aware of the potential for Internet relationships to seriously affect face-to-face relationships.
Psychological Sense of Community in Groups on the Internet
Authors: Forster Peter M.
Published: October 2005

Psychological sense of community (PSOC) was studied within two types of virtual community and one type of community of place. Fifty-six members of these community groups completed the Sense of Community Index (SCI). An analysis of variance found partial support for the initial hypotheses with the intentional-community-of-place group scoring significantly higher on the SCI than the location-oriented virtual community. The results were discussed in the context of 3 PSOC correlates of depth of disclosure, reciprocity and shared interests/experience. It was concluded that virtual communities may contribute to overall PSOC.
Computer-Delivered Behavioural Avoidance Tests for Spider Phobia
Authors: Meng Charles Teng Tat , Kirkby Kenneth C. , Martin Frances , Gilroy Lisa J. , Daniels Brett A.
Published: October 2005

Behavioural avoidance tests (BATs) are a cornerstone of objective assessment of phobias. However, live BATs have several disadvantages. They are practically difficult and time-consuming to set up and are not standardised. This study examined two computer-delivered BATs (using slide and video presentations of phobic stimuli respectively): first, in respect to their ability to discriminate fearfuls from nonfearfuls, and second, in terms of convergent validity with a live BAT and the Spider Phobia Questionnaire (SPQ). Sixty-four low (n = 32) and high (n = 32) spider-fearful undergraduate participants were administered the three BATs in counterbalanced order. Results showed that subjective anxiety on all BATs was highly discriminative of low and high spider-fearfuls. The number of steps completed did not discriminate between phobics and nonphobics on the computer BATs. However, there was good convergent validity between the live BAT, the SPQ and both computer-delivered BATs on subjective anxiety. Overall, the live BAT gives a clearer indication of avoidance behaviour while the video BAT assesses subjective anxiety across a wider range of steps. The development of computer-delivered BATs that reliably measure avoidance is necessary before contemplating them as an alternative to a live BAT.
Effectiveness of CBT Versus Standard Treatment for Childhood Anxiety Disorders in a Community Clinic Setting
Authors: Barrington Julie , Prior Margot , Richardson Margaret , Allen Kathleen
Published: October 2005

The efficacy of cognitive—behavioural therapy (CBT) for the treatment of childhood anxiety has mainly been demonstrated in university-clinic settings. This study aimed to evaluate the effectiveness of CBT for the treatment of childhood anxiety in a community mental health service, compared with standard treatments (‘Treatment as Usual’ [TAU]) 'child psychotherapy, family therapy and eclectic treatments. Fifty-four children with anxiety disorders, aged from 7 to 14 years, were randomly assigned to either a CBT or TAU group. CBT and the standard treatments were provided by 18 experienced therapists, and the mean number of treatment sessions was 12. Baseline and follow-up measures at 3, 6 and 12 months included an interview based on criteria in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) that was conducted by a clinical psychologist who was blind to the treatment conditions, and standardised anxiety measures (parent, child and teacher reports). Significant improvements were found on all anxiety measures over time, but no significant differences were found between CBT and TAU. The challenge of conducting such research in community settings is discussed.
The Starship Post-Traumatic Amnesia Scale: Does It Predict Outcome After Mild to Moderate Traumatic Brain Injury in Children Aged 3 to 7 Years?
Authors: Thickpenny-Davis Kirsten L. , Ogden Jenni A. , Fernando Kris
Published: October 2005

This study assesses whether the Starship Post-Traumatic Amnesia scale, developed for children aged 3 to 7 years, can predict neuropsychological impairment and behavioural outcome following mild to moderate traumatic brain injury. Participants are 19 children aged from 3 to 7 years with a GCS score of >13, and a PTA of 0–3 days. Neuropsychological outcome is measured by the NEPSY, and behavioural outcome by the Child Behaviour Checklist (CBCL) two months after the TBI. The duration of PTA contributed to the prediction of scores on the NEPSY memory and learning domain. In all cases the longer the duration of PTA, the poorer the memory scores were. The duration of PTA did not contribute to the prediction of NEPSY visuospatial processing or attention and executive functions domain scores, or to any of the CBCL scores. This preliminary study suggests that the Starship PTA scale has good sensitivity for this very young age group, even when the TBI is mild.