Showing papers by "Queen's University published in 1997"

Immigration, Acculturation, and Adaptation

Abstract: La psychologie interculturelle a montre qu'il existait des rapports etroits entre le contexte culturel et le developpement comportemental de l'individu. Cette relation etablie, l'effort des recherches interculturelles a de plus en plus porte sur ce qu'il advenait des individus quand ils tentaient de refaire leur vie dans une culture differente de leur culture d'origine. Les consequences psychologiques a long terme de ce processus d'acculturation sont tres variables, dependant de variables sociales et personnelles qui renvoient a la societe de depart, a la societe d'accueil et a des phenomenes qui existent avant, mais qui emergent pendant la periode d'acculturation. Cet article esquisse un schema conceptuel a partir duquel acculturation et adaptation peuvent ětre etudiees, puis presente quelques conclusions et resultats generaux tires d'un echantillon de travaux empiriques. On envisage des applications possibles a la politique et aux programmes d'insertion en prenant en consideration les couts et les benefices sociaux et psychologiques emanant de l'adoprion d'une orientation pluraliste et integrationniste. Cross-cultural psychology has demonstrated important links between cultural context and individual behavioural development. Given this relationship, cross-cultural research has increasingly investigated what happens to individuals who have developed in one cultural context when they attempt to re-establish their lives in another one. The long-term psychological consequences of this process of acculturation are highly variable, depending on social and personal variables that reside in the society of origin, the society of settlement. and phenomena that both exist prior to, and arise during, the course of acculturation. This article outlines a conceptual framework within which acculturation and adaptation can be investigated, and then presents some general findings and conclusions based on a sample of empirical studies. Applications to public policy and programmes are proposed. along with a consideration of the social and psychological costs and benefits of adopting a pluralist and integrationist orientation to these issues.

A Markov Model for the Term Structure of Credit Risk Spreads

Abstract: This article provides a Markov model for the term structure of credit risk spreads. The model is based on Jarrow and Turnbull (1995), with the bankruptcy process following a discrete state space Markov chain in credit ratings. The parameters of this process are easily estimated using observable data. This model is useful for pricing and hedging corporate debt with imbedded options, for pricing and hedging OTC derivatives with counterparty risk, for pricing and hedging (foreign) government bonds subject to default risk (e.g., municipal bonds), for pricing and hedging credit derivatives, and for risk management.

International Union of Pharmacology. XIII. Classification of Histamine Receptors

Abstract: The classification of histamine receptors has to date been based on rigorous classical pharmacological analysis, and as yet, the classification of the three histamine receptors that have been defined by this process, (i.e., the H1-, H2-, and H 3-receptors) have not been added to because of more

The Role of Internal Models in Motion Planning and Control: Evidence from Grip Force Adjustments during Movements of Hand-Held Loads

Abstract: We investigated the issue of whether or not the CNS makes use of an internal model of the motor apparatus in planning and controlling arm movements. In particular, we tested the ability of subjects to predict different hand-held loads by examining grip force adjustments used to stabilize the load in the hand during arm movements. Subjects grasped a manipulandum using a precision grip with the tips of the thumb and index finger on either side. The grip force (normal to the contact surfaces) and the load force (tangential to the surfaces) were measured, along with the trajectory of the hand. The manipulandum was attached to two servo-controlled linear motors used to create inertial and viscous loads as well as a composite load, including inertial, viscous, and elastic components. The form of the hand trajectory was independent of load for some subjects but varied systematically across load conditions in others. Nevertheless, under all load conditions and in all subjects, grip force was modulated in parallel with, and thus anticipated, fluctuations in load force despite the marked variation in the form of the load function. This indicates that the CNS is able to predict the load force and the kinematics of hand movement on which the load depends. We suggest this prediction is based on an internal model of the motor apparatus and external load and is used to determine the grip forces required to stabilize the load.

Worldwide variations in prevalence of symptoms of allergic rhinoconjunctivitis in children: the International Study of Asthma and Allergies in Childhood (ISAAC)

Abstract: Background: As part of the International Study of Asthma and Allergies in Childhood (ISAAC), prevalence surveys were conducted among representative samples of school children from locations in Europe, Asia, Africa, Australasia, North and South America Subjects: 257,800 children aged 6-7 years from 91 centres in 38 countries, and 463,801 children aged 13-14 years from 155 centres in 56 countries Methods: Written symptom questionnaires were translated from English into the local language for self-completion by the 13-14-year-olds and completion by the parents of the 6-7-year-olds Rhinitis was described as a problem with sneezing, or a runny, or blocked nose when you (your child) DID NOT have a cold or the flu Additional questions were asked about rhinitis associated with itchy-watery eyes, interference with activities and a history of hay fever ever Results: The prevalence of rhinitis with itchy-watery eyes (“rhinoconjunctivitis”) in the past year varied across centres from 08%(to 149% in the 6-7-year-olds and from 14% to 397% in the 13-14-year-olds Within each age group, the global pattem was broadly consistent across each of the symptom categories In centres of higher prevalence there was great variability in the proportion of rhinoconjunctivitis labelled as hay fever The lowest prevalences of rhinoconjunctivitis were found in parts of eastern Europe south and central Asia High prevalences were reported from centres in several regions Conclusion: These results suggest substantial worldwide variations in the prevalence and labelling of symptoms of allergic rhinoconjunctivitis which require further study These differences, if real, may offer important clues to environmental influences on allergy

Neuronal Activity in Monkey Superior Colliculus Related to the Initiation of Saccadic Eye Movements

Abstract: The introduction of a temporal gap between the disappearance of an initially fixated target and the appearance of an eccentric saccadic target results in a general reduction of saccadic reaction times (SRTs)—the gap effect—and often in the production of express saccades, the latencies of which approach the conduction time of the shortest neural pathways from the retina to the eye muscles We investigated saccade initiation by recording neuronal activity in the superior colliculus in monkeys performing the gap paradigm Fixation-related neurons reduced their discharge rate during the gap period, regardless of the SRT This reduction in activity is consistent with the hypothesized release of ocular fixation that facilitates premotor processes and may contribute to the gap effect In addition to saccade-related discharges, many saccade-related neurons displayed phasic target-related responses and/or low-frequency preparatory activity during the gap period The level of this preparatory activity correlated with both SRT and express saccade occurrence when the saccade was made into the response field of the neuron Evidence indicates that advanced motor preparation is required for express saccade generation, which may be subserved by specific increases in the preparatory activity of saccade-related neurons Increased preparatory activity may allow the target-related responses to trigger short-latency express saccades directly This study provides insights into the functional mechanism of saccade initiation and may be relevant to the generation of all voluntary motor responses

A disk of scattered icy objects and the origin of Jupiter-family comets.

Abstract: Orbital integrations carried out for 4 billion years produced a disk of scattered objects beyond the orbit of Neptune. Objects in this disk can be distinguished from Kuiper belt objects by a greater range of eccentricities and inclinations. This disk was formed in the simulations by encounters with Neptune during the early evolution of the outer solar system. After particles first encountered Neptune, the simulations show that about 1 percent of the particles survive in this disk for the age of the solar system. A disk currently containing as few as ∼6 × 108 objects could supply all of the observed Jupiter-family comets. Two recently discovered objects, 1996 RQ20 and 1996 TL66, have orbital elements similar to those predicted for objects in this disk, suggesting that they are thus far the only members of this disk to be identified.

Effects of climate change on the freshwaters of arctic and subarctic north america

Abstract: Region 2 comprises arctic and subarctic North America and is underlain by continuous or discontinuous permafrost. Its freshwater systems are dominated by a low energy environment and cold region processes. Central northern areas are almost totally influenced by arctic air masses while Pacific air becomes more prominent in the west, Atlantic air in the east and southern air masses at the lower latitudes. Air mass changes will play an important role in precipitation changes associated with climate warming. The snow season in the region is prolonged resulting in long-term storage of water so that the spring flood is often the major hydrological event of the year, even though, annual rainfall usually exceeds annual snowfall. The unique character of ponds and lakes is a result of the long frozen period, which affects nutrient status and gas exchange during the cold season and during thaw. GCM models are in close agreement for this region and predict temperature increases as large as 4°C in summer and 9°C in winter for a 2 × CO2 scenario. Palaeoclimate indicators support the probability that substantial temperature increases have occurred previously during the Holocene. The historical record indicates a temperature increase of > 1°C in parts of the region during the last century. GCM predictions of precipitation change indicate an increase, but there is little agreement amongst the various models on regional disposition or magnitude. Precipitation change is as important as temperature change in determining the water balance. The water balance is critical to every aspect of hydrology and limnology in the far north. Permafrost close to the surface plays a major role in freshwater systems because it often maintains lakes and wetlands above an impermeable frost table, which limits the water storage capabilities of the subsurface. Thawing associated with climate change would, particularly in areas of massive ice, stimulate landscape changes, which can affect every aspect of the environment. The normal spring flooding of ice-jammed north-flowing rivers, such as the Mackenzie, is a major event, which renews the water supply of lakes in delta regions and which determines the availability of habitat for aquatic organisms. Climate warming or river damming and diversion would probably lead to the complete drying of many delta lakes. Climate warming would also change the characteristics of ponds that presently freeze to the bottom and result in fundamental changes in their limnological characteristics. At present, the food chain is rather simple usually culminating in lake trout or arctic char. A lengthening of the growing season and warmer water temperature would affect the chemical, mineral and nutrient status of lakes and most likely have deleterious effects on the food chain. Peatlands are extensive in region 2. They would move northwards at their southern boundaries, and, with sustained drying, many would change form or become inactive. Extensive wetlands and peatlands are an important component of the global carbon budget, and warmer and drier conditions would most likely change them from a sink to a source for atmospheric carbon. There is some evidence that this may be occurring already. Region 2 is very vulnerable to global warming. Its freshwater systems are probably the least studied and most poorly understood in North America. There are clear needs to improve our current knowledge of temperature and precipitation patterns; to model the thermal behaviour of wetlands, lakes and rivers; to understand better the interrelationships of cold region rivers with their basins; to begin studies on the very large lakes in the region; to obtain a firm grasp of the role of northern peatlands in the global carbon cycle; and to link the terrestrial water balance to the thermal and hydrological regime of the polar sea. Overall, there is a strong need for basic research and long-term monitoring. © 1997 John Wiley & Sons, Ltd.

Dynamical Lifetimes of Objects Injected into Asteroid Belt Resonances

Abstract: Numerical simulations of particles placed in orbital resonances in the main asteroid belt show that the typical dynamical lifetimes of objects that could become near-Earth asteroids or meteorites are only a few million years, with the majority destroyed by being transferred to Jupiter-crossing orbits or being driven into the sun. Particles that fortuitously migrate to the terrestrial planet region may be pushed to high-inclination orbits by resonances but are still dynamically eliminated on time scales of ∼10 million years. These shorter lifetimes may require a reassessment of our qualitative understanding about near-Earth asteroids and meteorite delivery.

Qualitative aspects of exertional breathlessness in chronic airflow limitation: pathophysiologic mechanisms.

Abstract: We compared qualitative aspects of the sensory experience of exertional breathlessness in normal subjects and in patients with chronic airflow limitation (CAL) and sought a physiologic rationale for these. Twelve patients (66 +/- 2 yr of age, mean +/- SEM) with severe CAL (FEV1 = 37 +/- 5% predicted) and 12 age-matched normal subjects (FEV1 = 103 +/- 5% predicted) were studied. Perceived inspiratory difficulty (BorgIN), inspiratory effort (esophageal pressure expressed as a fraction of maximal esophageal pressure at isovolume [Pes/PImax]), breathing pattern, and operational lung volumes (end-expiratory/inspiratory lung volumes [EELV/EILV]) were measured during symptom-limited incremental cycle exercise testing and compared at a standard VO2 of 50% predicted maximum in normal subjects and in patients with CAL. Qualitative descriptors of breathlessness were selected immediately after exercise. Breathlessness was qualitatively different between normal subjects and patients with CAL. Both normal subjects and patients with CAL chose descriptors of increased "work/effort" and "heaviness" of breathing; however, only patients with CAL consistently chose descriptors denoting "increased inspiratory difficulty" (75%), "unsatisfied inspiratory effort" (75%), and "shallow breathing" (50%). Stepwise regression analysis identified the ratio of Pes/PImax to VT/predicted VC as the strongest correlate of standardized BorgIN (n = 24, r = 0.86, p < 0.001). This latter measurement, which reflects the relationship between effort and ventilatory output, correlated strongly with dynamic EELV/TLC at isotime (r = 0.78, p < 0.001). In conclusion, the qualitatively discrete respiratory sensations of exertional inspiratory difficulty peculiar to patients with CAL may have their origins in thoracic hyperinflation and the resultant disparity between inspiratory effort and ventilatory output.

Parallel computation: models and methods

Abstract: 1. Introduction2. Models of Computation3. Combinational Circuits4. Parallel Prefix Computation5. Divide and Conquer6. Pointer-Based Data Structures7. Linear Arrays8. Meshes and Related Models9. Hypercubes and Stars10. Models Using Buses11. Broadcasting with Selective Reduction12. Parallel SynergyBibliographyIndex

Questions and Answers about BSP

Abstract: Bulk Synchronous Parallelism (BSP) is a parallel programming model that abstracts from low-level program structures in favour of supersteps. A superstep consists of a set of independent local computations, followed by a global communication phase and a barrier synchronisation. Structuring programs in this way enables their costs to be accurately determined from a few simple architectural parameters, namely the permeability of the communication network to uniformly-random traffic and the time to synchronise. Although permutation routing and barrier synch ronisations are widely regarded as inherently expensive, this is not the case. As a result, the structure imposed by BSP does not reduce performance, while bringing considerable benefits for application building. This paper answers the most common questions we are asked about BSP and justifies its claim to be a major step forward in parallel programming.

Quality of life among persons with multiple sclerosis and their caregivers.

Abstract: For those with a chronic illness, suffering may result not only from physical limitations, but also from the psychosocial consequences of having a chronic condition. Few studies have described the psychosocial characteristics of the physically disabled. Even more rare are population-based studies of quality of life (QOL) among persons with multiple sclerosis (MS) and their caregivers. We conducted a large survey of persons with MS and their caregivers in Ontario using self-completed mailed questionnaires. The objectives included describing satisfaction with QOL and determining relationships between QOL as a whole and several other factors, such as demographic characteristics and measures of physical disability. Response rates were 83% for those with MS and 72% for their caregivers. Based on 697 respondents with MS, mean age was 48 years, 70% were women, and 75% were married. While 24% experienced no mobility restrictions, the majority required some type of aid or a wheelchair for getting around. Health received the lowest satisfaction rating among the six components of QOL, while finances received a relatively low satisfaction rating from the 345 caregivers. Less satisfaction with several QOL components was evident for those with MS compared with the disabled in the Canadian general population, and for caregivers compared with the able-bodied general population. Poorer QOL as a whole among those with MS was associated with unemployment, MS symptoms of moderate or worse, fatigue, mobility limitations on stairs, a disease course other than stable, and was most strongly related to interference by MS in social activities. Among caregivers, poorer QOL as a whole was associated with being a spouse, longer duration of caregiving, moderate or worse MS symptoms in the care recipient, and most strongly related to a care recipient's current MS disease course of other than stable. Through an understanding of the satisfaction with QOL of persons with MS and caregivers, and the relationships with other important factors, autonomy and home care may be supported and prolonged, while preventing unnecessary institutionalization.

Corporate Disclosure of Environmental Liability Information: Theory and Evidence*

Abstract: . The decision to disclose information concerning a firm's environmental liabilities is modeled as a sequential game involving the firm, a capital market, and outside stakeholders who can impose proprietary (political) costs on the firm. A partial disclosure equilibrium is derived in which firms reveal information strategically, maximizing the share-value net of expected political costs. Inherent uncertainty regarding the existence and size of the liabilities creates a setting where outsiders are uncertain if management is informed about these liabilities, so firms can plausibly withhold “bad news”, that is, they do not disclose liabilities that exceed a threshold level. Three novel hypotheses are that a firm is more likely to disclose as (1) its pollution propensity increases, (2) outsiders' knowledge of its environmental liabilities increases, and (3) the risk of incurring proprietary costs decreases. Empirical support is found for the hypotheses, based on the accounting disclosures made by sample firms selected from the records of the Ontario Ministry of the Environment and Energy. Improved accounting and auditing standards for environmental disclosure would build on at least three implications of the study: 1 To the extent that inherent uncertainty leaves managers with discretion as to what to disclose, the partial disclosure equilibrium result suggests that not all firms will comply with disclosure standards. 2 Publishing broad environmental performance indicators for companies in nonaccounting outlets would increase public awareness of a manager's private information endowment, making voluntary accounting disclosures of the liabilities more likely. 3 If a significant decline in stakeholder tolerance of pollution occurs, the expected proprietary costs of disclosing increase, and companies become less likely to disclose.

Guidelines for the initial biopsy diagnosis of suspected chronic idiopathic inflammatory bowel disease. The British Society of Gastroenterology Initiative.

Abstract: Accepted for publication 12 August 1996 Introduction Unambiguous interpretation of colorectal biopsy specimens is important for clinical decisions in the investigation of suspected chronic idiopathic inflammatory bowel disease (IBD). Variability of reporting style and terms such as mild inflammatory change and nonspecific proctitis/colitis may hide pathologists' difficulties with diagnostic uncertainty and confuse clinical management. Four main problems underlie these difficulties: (1) lack of awareness of the range of normal colorectal histology and the minimal features which indicate clinically important inflammation; (2) wide overlap in the pathological changes of most large bowel inflammatory diseases; (3) lack of awareness of the accuracy and reproducibility of many changes used in diagnosis; and (4) absence of standard terminology for pathological description and diagnosis. On behalf ofthe British Society of Gastroenterology, we have used an evidence-based approach to compile guidelines for the biopsy diagnosis of suspected chronic idiopathic IBDt. The guidelines are aimed primarily at improved accuracy of diagnosis when colorectal biopsy is used in the initial investigation of patients with diarrhoea. The objectives are to assist: the recognition of normal colorectal mucosa; the detection of important minor inflammatory change needing further investigation; the early diagnosis of chronic idiopathic IBD; the distinction between ulcerative colitis and Crohn's disease; the recognition of infective type colitis; and the diagnosis of less frequent forms of colitis. The guidelines include recommendations for minimum clinical information, useful morphological features, standardised terminology, and a clinically relevant reporting format. The evidence is from Europe and North America, and the conclusions should not be applied uncritically where the prevalence and the nature of the diseases are very different.

A demonstration of gaze following in 3- to 6-month-olds

Abstract: An adult, with a puppet held at shoulder height on either side (within the infant's visual field), interacted with 3- to-6-month-olds, turning her head intermittently to talk to a puppet. Seventy- three percent of infants' first eye-turns were in the direction of the adult head-turn.

The criminal recidivism process

Abstract: List of illustrations and tables Preface 1. Introduction: the prediction of criminal behavior 2. The study 3. Recidivists: a general profile 4. Comparisons with nonrecidivists 5. Comparisons across offender groups 6. Comparisons within offender groups 7. Final considerations References Appendix: interview form Index.

Micromodular implants to provide electrical stimulation of paralyzed muscles and limbs

Abstract: Describes the design, fabrication, and output capabilities of a microminiature electrical stimulator that can be injected in or near nerves and muscles. Each single channel microstimulator consists of a cylindrical glass capsule with hermetically sealed electrodes in either end (2-mm diameter/spl times/13-mm overall length). Power and digital control data can be transmitted to multiple implants (256 unique addresses) via a 2-MHz RF field created by an external AM oscillator and inductive coil. In vitro testing demonstrated accurate control of output pulsewidth (3-258 /spl mu/s in 1-/spl mu/s steps) and current (0-30 mA in two linear ranges of 16 steps each, up to 8.5 V available compliance voltage). Microstimulators were used successfully for chronic stimulation in hindlimb muscles of cats. Design and fabrication issues affecting yield and reliability of the packaging and electronics are discussed.