Gender effect on the right-left discrimination task in a sample of heroin-dependent patients

Rationale: Discriminating right from left is an everyday cognitive ability. Repeated exposure to certain drugs, such as heroin, can produce poor performance on many cognitive tasks. However, it is yet unclear whether drug abuse impairs the ability of right-left discrimination. Objectives: The aim of the present study is to examine whether the spatial ability measured by the right-left discrimination task can be affected by heroin abuse and whether such drug effect, if it exists, is gender related. Methods: A paper-and-pen test was used. The test consists of line drawings of a person with no arm, one arm, or both arms crossing the vertical body axis of the figure. The line drawings are viewed from the back, from the front, or randomly alternating between the back and front drawings. The subjects task is to mark which is the right or left hand in the figure as fast as possible. Results: A main finding in this study was that the ability to discriminate between left and right in visual space was impaired in heroin-dependent patients. Especially, heroin-dependent females performed poorer than control females in all conditions but heroin-dependent males only performed poorly in part of conditions. Conclusions: Recent heroin abuse impairs the ability of right-left discrimination and such impairment is gender related: heroin-dependent females demonstrated greater performance deficits than males.

Ecological impacts of coastal aquaculture developments

The study presents the type and scale of any ecological change associated with coastal aquaculture development. These are enrichment, interaction with the food web, oxygen consumption, disturbance of wildlife and habitat destruction, interaction between escaped farmed stock and wild species, introduction and transfers, bioactive compounds (including pesticides and antibiotics), chemicals introduced via construction materials, and hormones and growth promoters.

Guidelines for the development of environmentally acceptable coastal aquaculture

The paper presents some recommendations for the development of the environmentally acceptable coastal aquaculture such as: 1) Formulate coastal aquaculture development and management plans, 2) Formulate integrated coastal zone management plans, 3) Apply the environmental impact assessment (EIA) process to all major aquaculture proposals, 4) Select suitable sites for coastal aquaculture, 5) Improve the management of aquaculture operations, 6) Assess the capacity of the ecosystem to sustain aquaculture development with minimal ecological change, 7) Establish guidelines governing the use of mangrove wetland for coastal aquaculture, 8) Establish guidelines for the use of bioactive compounds in aquaculture, 9) Assess and evaluate the true consequences of transfers and introductions of exotic organisms, 10) Regulate discharges from land-based aquaculture through the enforcement of effluent standards, 11) Establish control measures for aquaculture products, 12) Increase public awareness of the safety aspects of consuming seafood, 13) Apply incentives and deterrents to reduce environmental degradation from aquaculture activities, and 14) Monitor for ecological change.

Task-dependent coordination of rapid bimanual motor responses.

Optimal feedback control postulates that feedback responses depend on the task relevance of any perturbations. We test this prediction in a bimanual task, conceptually similar to balancing a laden tray, in which each hand could be perturbed up or down. Single-limb mechanical perturbations produced long-latency reflex responses ("rapid motor responses") in the contralateral limb of appropriate direction and magnitude to maintain the tray horizontal. During bimanual perturbations, rapid motor responses modulated appropriately depending on the extent to which perturbations affected tray orientation. Specifically, despite receiving the same mechanical perturbation causing muscle stretch, the strongest responses were produced when the contralateral arm was perturbed in the opposite direction (large tray tilt) rather than in the same direction or not perturbed at all. Rapid responses from shortening extensors depended on a nonlinear summation of the sensory information from the arms, with the response to a bimanual same-direction perturbation (orientation maintained) being less than the sum of the component unimanual perturbations (task relevant). We conclude that task-dependent tuning of reflexes can be modulated online within a single trial based on a complex interaction across the arms.

Buyer-supplier partnerships during product design and development in the global automotive sector: Who invests, in what and when?

This paper explores the concept of partnerships between buyers and suppliers in the global automotive sector during product design and development. Partnerships are often the goal in a shift away from adversarial arms-length relationships. The objective of this research is to provide empirical evidence to explain the levels of mutual investment expected and achieved in partnerships from both buyer and supplier perspectives. During this research, 25 employees from 12 global supplier organisations who were in partnership with a specific vehicle manufacturer (VM) were interviewed. Twelve employees from this VM were also interviewed. The research showed the differences between partnerships and non-partnerships and the disparities in the expectations of investment from each partner. For suppliers and buyers to get the most out of partnerships, clear expectations and investments needed over time should be understood and agreed early in the relationship. © 2009 Elsevier B.V.All rights reserved.

The use of centrifuge tests in the study of arching

The horizontal arching mechanism transfers horizontal earth pressures acting on flexible retaining wall panels to stiffer neighbouring elements via soil shear stresses. In this research, the horizontal arching mechanism and lateral displacements of fixed cantilever walls in a model basement are investigated using centrifuge tests. A series of six tests was carried out at 45 gravities where the panel widths and thicknesses around the model basement were varied, so that the effects of panel geometry and stiffness on horizontal arching could be studied. It is shown that panel crest displacements and base bending moments of the most flexible, narrow panels can be an order of magnitude smaller than conventional active earth pressure calculations would allow. It is suggested that the reduction of earth pressure acting on a panel is directly correlated to the mobilized soil shear strength and hence, soil shear strain. Earth pressure coefficients K are plotted against panel displacements normalized by the panel width, u/B, to simulate the reduction of K with increasing soil strain.An idealized K-u/B curve is introduced, characterised by a reference distortion (u/B) ref beyond which fully plastic soil arching can be inferred, and which is related to the corresponding reference shear strain γ ref at which soil strength is fully mobilized in element tests. © 2006 Taylor & Francis Group, London.

Hybrid ventilation by revolving doors

The transfers of air driven by a revolving door connecting two rooms of initially different temperatures are investigated. The results of small-scale laboratory modelling show that a critical revolution rate exists for which transfers are maximal for a given combination of door geometry, revolution rate and temperature contrast. This critical revolution rate divides two possible transfer regimes for revolving doors. Potential implications of our findings to revolving door operation, to heat losses across the doorway and to ventilation driven by the door are discussed.

Numerical computation of laminar flow in a heated rotating cavity with an axial throughflow of air

A heated rotating cavity with an axial throughflow of cooling air is used as a model for the flow in the cylindrical cavities between adjacent discs of a high-pressure gas-turbine compressor. In an engine the flow is expected to be turbulent, the limitations of this laminar study are fully realised but it is considered an essential step to understand the fundamental nature of the flow. The three-dimensional, time-dependent governing equations are solved using a code based on the finite volume technique and a multigrid algorithm. The computed flow structure shows that flow enters the cavity in one or more radial arms and then forms regions of cyclonic and anticyclonic circulation. This basic flow structure is consistent with existing experimental evidence obtained from flow visualization. The flow structure also undergoes cyclic changes with time. For example, a single radial arm, and pair of recirculation regions can commute to two radial arms and two pairs of recirculation regions and then revert back to one. The flow structure inside the cavity is found to be heavily influenced by the radial distribution of surface temperature imposed on the discs. As the radial location of the maximum disc temperature moves radially outward, this appears to increase the number of radial arms and pairs of recirculation regions (from one to three for the distributions considered here). If the peripheral shroud is also heated there appear to be many radial arms which exchange fluid with a strong cyclonic flow adjacent to the shroud. One surface temperature distribution is studied in detail and profiles of the relative tangential and radial velocities are presented. The disc heat transfer is also found to be influenced by the disc surface temperature distribution. It is also found that the computed Nusselt numbers are in reasonable accord over most of the disc surface with a correlation found from previous experimental measurements. © 1994, MCB UP Limited.

Concentration dependence of the Er3+ visible and infrared luminescence in Y2-x Erx O3 thin films on Si

Y2-x Erx O3 thin films, with x varying between 0 and 0.72, have been successfully grown on crystalline silicon (c-Si) substrates by radio-frequency magnetron cosputtering of Y2 O 3 and Er2 O3 targets. As-deposited films are polycrystalline, showing the body-centered cubic structure of Y2 O3, and show only a slight lattice parameter contraction when x is increased, owing to the insertion of Er ions. All the films exhibit intense Er-related optical emission at room temperature both in the visible and infrared regions. By studying the optical properties for different excitation conditions and for different Er contents, all the mechanisms (i.e., cross relaxations, up-conversions, and energy transfers to impurities) responsible for the photoluminescence (PL) emission have been identified, and the existence of two different well-defined Er concentration regimes has been demonstrated. In the low concentration regime (x up to 0.05, Er-doped regime), the visible PL emission reaches its highest intensity, owing to the influence of up-conversions, thus giving the possibility of using Y2-x Er x O3 films as an up-converting layer in the rear of silicon solar cells. However, most of the excited Er ions populate the first two excited levels 4I11/2 and 4I13/2, and above a certain excitation flux a population inversion condition between the former and the latter is achieved, opening the route for the realization of amplifiers at 2.75 μm. Instead, in the high concentration regime (Er-compound regime), an increase in the nonradiative decay rates is observed, owing to the occurrence of cross relaxations or energy transfers to impurities. As a consequence, the PL emission at 1.54 μm becomes the most intense, thus determining possible applications for Y2-x Erx O 3 as an infrared emitting material. © 2009 American Institute of Physics.

The impact of government policy on technology transfer: An aircraft industry case study

This case study explores the interaction between domestic and foreign governmental policy on technology transfer with the goal of exploring the long-term impacts of technology transfer. Specifically, the impact of successive licensing of fighter aircraft manufacturing and design to Japan in the development of Japan's aircraft industry is reviewed. Results indicate Japan has built a domestic aircraft industry through sequential learning with foreign technology transfers from the United States, and design and production on domestic fighter aircraft. This process was facilitated by governmental policies in both Japan and the United States. Published by Elsevier B.V.

Control of bimanual rhythmic movements: Trading efficiency for robustness depending on the context

This paper investigates how the efficiency and robustness of a skilled rhythmic task compete against each other in the control of a bimanual movement. Human subjects juggled a puck in 2D through impacts with two metallic arms, requiring rhythmic bimanual actuation. The arms kinematics were only constrained by the position, velocity and time of impacts while the rest of the trajectory did not influence the movement of the puck. In order to expose the task robustness, we manipulated the task context in two distinct manners: the task tempo was assigned at four different values (hence manipulating the time available to plan and execute each impact movement individually); and vision was withdrawn during half of the trials (hence reducing the sensory inflows). We show that when the tempo was fast, the actuation was rhythmic (no pause in the trajectory) while at slow tempo, the actuation was discrete (with pause intervals between individual movements). Moreover, the withdrawal of visual information encouraged the rhythmic behavior at the four tested tempi. The discrete versus rhythmic behavior give different answers to the efficiency/robustness trade-off: discrete movements result in energy efficient movements, while rhythmic movements impact the puck with negative acceleration, a property preserving robustness. Moreover, we report that in all conditions the impact velocity of the arms was negatively correlated with the energy of the puck. This correlation tended to stabilize the task and was influenced by vision, revealing again different control strategies. In conclusion, this task involves different modes of control that balance efficiency and robustness, depending on the context. © 2008 Springer-Verlag.

Rhythmic feedback control of a blind planar juggler

The paper considers the feedback stabilization of periodic orbits in a planar juggler. The juggler is "blind," i.e, he has no other sensing capabilities than the detection of impact times. The robustness analysis of the proposed control suggests that the arms acceleration at impact is a crucial design parameter even though it plays no role in the stability analysis. Analytical results and convergence proofs are provided for a simplified model of the juggler. The control law is then adapted to a more accurate model and validated in an experimental setup. © 2007 IEEE.

Multimode polymer waveguide components for complex on-board optical topologies

Multimode polymer waveguides are an attractive transmission medium for board-level optical links as they provide high bandwidth, relaxed alignment tolerances, and can be directly integrated onto conventional printed circuit boards. However, the performance of multimode waveguide components depends on the launch conditions at the component input, complicating their use in topologies that require the concatenation of multiple multimode components. This paper presents key polymer components for a multichannel optical bus and reports their performance under different launch conditions, enabling useful rules that can be used to design complex interconnection topologies to be derived. The components studied are multimode signal splitters and combiners, 90°-crossings, S-bends, and 90°-bends. By varying the width of the splitter arms, a splitting ratio between 1% and 95% is achieved from the 1 × 2 splitters, while low-loss signal combining is demonstrated with the waveguide combiners. It is shown that a 3 dB improvement in the combiner excess loss can be achieved by increasing the bus width by 50 μm. The worst-case insertion loss of 50 × 100 μm waveguide crossings is measured to be 0.1 dB/crossing. An empirical method is proposed and used to estimate the insertion losses of on-board optical paths of a polymeric four-channel optical bus module. Good agreement is achieved between the predicted and measured values. Although the components and empirical method have been tailored for use in a multichannel optical bus architecture, they can be used for any on-board optical interconnection topology. © 1983-2012 IEEE.

KHAWIA SAUROGOBII N. SP (CESTODA: CARYOPHYLLIDEA) FROM FRESHWATER FISH SAUROGOBIO SPP. (CYPRINIDAE) IN CHINA

Khawia saurogobii n. sp. is described from the intestine of the cyprinid fishes Saurogobio dabryi and Saurogobio dumerili in China. The new species belongs to the Lytocestidae and is placed in Khawia because of its afossate scolex, vitelline follicles in the cortical parenchyma, uterus not looping anterior to the cirrus sac, gonopores separate but close together in distinct genital atrium, external seminal vesicle absent, and postovarian follicles present. The new species differs from other congeneric species by the shape of the body markedly tapering posteriorly from the end of the anterior third, the shape of the scolex that is very short and markedly wider than the neck, spatulate without incisions, but shallow superficial grooves, vitelline follicles and testes starting immediately posterior to the scolex, and an ovary with long, posterior arms bent medially, thus giving the shape of an inverted A.

Population status, threats and conservation of the Yangtze finless porpoise

The Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis) is currently limited to the middle and lower reaches of the Yangtze River from Yichang to Shanghai, China, and the adjoining Poyang and Dongting Lakes. Its population size has decreased remarkably during the last several decades due to the heavy impact of human activities, including overfishing of prey species, water development projects that cause attendant habitat loss and degradation, water pollution, and accidental deaths caused by harmful fishing gear and collisions with motorized vessels. It was estimated that the number of remaining individuals was down to approximately 1800 in 2006, a number that is decreasing at a rate as high as 5% per year. Three conservation measures - in situ and ex situ conservation and captive breeding have been applied to the protection of this unique porpoise since the early 1990s. Seven natural and two "semi-natural" reserves have so far been established. Since 1996, a small group of finless porpoises has been successfully reared in a facility at the Institute of Hydrobiology of the Chinese Academy of Sciences; three babies were born in captivity on July 5, 2005, June 2, 2007 and July 5, 2008. These are the first freshwater cetaceans ever born in captivity in the world. Several groups of these porpoises caught in the main stream of the Yangtze River, or rescued, have been introduced into the Tian'e-Zhou Semi-natural Reserve since 1990. These efforts have proven that, not only can these animals survive in the area, they are also to reproduce naturally and successfully. More than 30 calves had been born in the reserve since then, with one to three born each year. Taking deaths and transfers into account, there were approximately 30 individuals living in the reserve as of the end of 2007. Among eight mature females captured in April 2008, five were confirmed pregnant. This effort represents the first successful attempt at off-site protection of a cetacean species in the world, and establishes a solid base for conservation of the Yangtze finless porpoise. A lesson must be drawn from the tragedy of Chinese River Dolphin (Lipotes vexillifer), which has already been declared likely extinct. Strong, effective and appropriate protective measures must be carried out quickly to prevent the Yangtze finless porpoise from becoming a second Chinese River Dolphin, and save the biodiversity of the Yangtze River as a whole.