Anolis lizards are the focus of most Caribbean lizard community ecology studies with few studies including other common species that might influence community structure. To study niche relationships and interspecific interactions in Antiguan lizard communities, we used five offshore islands with varying combinations of three diurnal lizards: Ameiva griswoldi, Anolis leachii, and Anolis wattsi. We collected data on perch height, substrate, thermal microhabitat, body size, head length, daily activity, and abundance to characterize the ecological niche of each species. Ameiva griswoldi was more similar to A. leachii in size and daily activity, but more similar to A. wattsi in perch height, and A. leachii and A. wattsi were more similar in thermal microhabitat. This pattern of niche differentiation was consistent with niche complementarity, where species are similar on some niche axes but differ on others. Using the same niche characteristics as in species comparisons, we tested for a niche shift among islands for A. wattsi. In the absence of A. griswoldi, A. wattsi used lower perches, sunnier microhabitats, and was found more often on the ground. In contrast, with A. leachii absent, A. wattsi perched higher, more often in the shade, and on trunks. Furthermore, A. wattsi was most abundant when with A. leachii only, but least abundant when alone with A. griswoldi. These results suggest interspecific interactions, most likely due to competition and intraguild predation, are important for structuring Antiguan lizard communities.

Introduction: The melatonin agonist LY 156735 (LY) is a new investigational drug under development to treat circadian rhythm disorders. The present study assessed the efficacy of LY to alleviate the symptoms of shift lag and to enhance readaptation of desynchronized circadian rhythms to a new time zone.Subjects and methods: Eight healthy male volunteers of age 25-35yr participated in three identical trials of 13d duration in a temporal isolation unit separated by washout intervals. A high dose (HD) of 5 mg and a low dose (LD) of 0.5 mg of LY and placebo (PL) were administered double-blinded in a three-period cross-over design. Each trial consisted of an adaptation period, a pre-shift period for baseline measurements, a simulated 9h phase-advance shift, and a post-shift period for follow-up. The time shift was performed at 23:00h of day 6 by advancing the laboratory time to 08:00h of day 7. Double-blind study medication was administered at 14:30h on day 6, and at 22:30h on days 7-10. Subjective ratings of jet lag, alertness, tenseness, and daytime fatigue were assessed using visual analog scales (VAS) and standardized questionnaires. The objective markers of readaptation included core body temperature, wrist actigraphy, cortisol and electrolyte excretion, and it battery of computerized performance tests.Results: HD but not LD enhanced the readaptation speed of all physiological rhythms investigated, as demonstrated by a significantly faster movement of acrophases towards the post-shift target time. HD (p = 0.05) significantly blunted the post-shift deterioration of performance in those tests that were sensitive to shift lag. Parameters of subjective well-being Were not significantly affected by either dose.Conclusion: This pilot study demonstrates the chronobiotic efticacy of LY when taken at a dose of 5 mg/d.

ADALI, TULAY, see Xuan, J. AN, GARY, and IRENE ANNE LEE, “Computer Simulation to Study Inflammatory Response,” 344. ANDERSON, ELIZABETH SCOTT, see Bacon, D. R. ANDERSON, JAMES H., see Li, Z. ARTZROUNI, MARC, and JEAN-PAUL GOUTEUX, “Population Dynamics of Sleeping Sickness: A Microsimulation,” 215. BACON, DONALD R., KIM A. STEWART, and ELIZABETH SCOTT ANDERSON, “Methods of Assigning Players to Teams: A Review and Novel Approach,” 6. BARACH, PAUL, see Christensen, U. J. BARACH, PAUL, see Satish, U. BARACH, PAUL, see Streufert, S. BARACH, PAUL, USHA SATISH, and SIEGFRIED STREUFERT, “Healthcare Assessment and Performance: Using Simulation,” 147. BARR, SHERRY L., see Lederman, L. C. BIDAUT, LUC, “Multisensor Imaging and Virtual Simulation for Assessment, Diagnosis, Therapy Planning, and Navigation,” 370. BLAKE, ELIZABETH L., see Starkey, B. A. BURNS, ALVIN C., see Fritzsche, D. J. CAI, YIYU, see Li, Z. CANNON, HUGH M., see Patz, A. L. CECCHINI, ARNALDO, and PAOLA RIZZI, “Is Urban Gaming Simulation Useful?” 507. CHEN, XUESONG, see Li, Z. CHRISTENSEN, ULRIK JUUL, DREW HEFFERNAN, and PAUL BARACH, “Microsimulators in Medical Education: An Overview,” 250. CHUI, CHEE-KONG, see Li, Z. CORBEIL, PIERRE, “BARAY, DEMENAGEMENT and STATION SPATIALE” [Simulation/Game Review], 435.

AbstractAbstract The Critically Endangered Antiguan racerAlsophis antiguaeis confined to Great Bird Island, a 9.9 ha (24.5-acre) islet off the north-east coast of Antigua in the Lesser Antilles. This island represents well under 0.1 per cent of the species's historical distribution range. During the past 5 years, the total number of racers aged 1 year or more has fluctuated between 51 and 114, and currently stands at approximately 80. Since 1995, the Antiguan Racer Conservation Project (ARCP) has en-deavoured to save this harmless snake from extinction by using a combination of education, conservation breeding, habitat restoration, local capacity building and applied research. The Antiguan racer's ecology and population dynamics have become well understood after 5 years of intensive study, and the species has evidently benefited from the project's rat eradication programme. The snakes are still seriously threatened by other intrinsic and extrinsic factors, however, including inbreeding depression, frequent hurricanes, invasive predators and deliberate killing by tourists, as well as the problem that Great Bird Island is too small to support more than about 100 individuals. This paper describes the activities and impact of this project to date, and outlines a series of conservation activities to safeguard the long-term future of the species, which include reintroduction of the Antiguan racer to restored islands within its former distribution range.

Several gaps exist in the training of clinicians in health care domains, such as anesthesiology, that have the cognitive profile of complexity and dynamism. These features are shared with other industries such as com- mercial aviation. Training for cockpit crews on Crew Resource Management (CRM) emphasizes deci- sion-making and teamwork principles. The authors created a simulation-based curriculum (ACRM) for anesthesiology based on principles of CRM in aviation. The training philosophy adapted to health care is one of training single-discipline crews to work in teams. The ACRM curriculum involves highly realistic simulation scenarios requiring complex decision making and interaction with multiple personnel. Sce- narios are each followed by a detailed debriefing using videotapes of the simulation session. ACRM has been adopted at major health care institutions around the world. Special training for instructors is provided, especially concerning debriefing. The ACRM approach has been extended to a wide variety of other health care domains that involve complexity and dynamism, such as emergency and trauma medicine, intensive care, and cardiac arrest response teams. Simulation-based training based on CRM principles is expected to become routine in many health care settings in the coming decade.

Study Objectives: To measure the workload associated with specific airway management tasks. Setting and Intervention: Written survey instrument. Patients: 166 Stanford University and 75 University of California, San Diego, anesthesia providers. Measurements and Main Results: Subjects were asked to use a seven-point Likert-type scale to rate the level of perceived workload associated with different airway management tasks with respect to the physical effort, mental effort, and psychological stress they require to perform in the typical clinical setting. The 126 subjects completing questionnaires (overall 52% response rate) consisted of 43% faculty, 26% residents, 23% community practitioners, and 8% certified registered nurse-anesthetists (CRNAs). Faculty physicians generally scored lower workload measures than residents, whereas community practitioners had the highest workload scores. Overall, workload ratings were lowest for laryngeal mask airway (LMA) insertion and highest for awake fiberoptic intubation. Airway procedures performed on sleeping patients received lower workload ratings than comparable procedures performed on awake patients. Direct visualization procedures received lower workload ratings than fiberoptically guided procedures. Conclusions: These kinds of data may permit more objective consideration of the nonmonetary costs of technical anesthesia procedures. The potential clinical benefits of the use of more complex airway management techniques may be partially offset by the impact of increased workload on other clinical demands.

BACKGROUND:Techniques are needed to assess anesthesiologists' performance when responding to critical events. Patient simulators allow presentation of similar crisis situations to different clinicians. This study evaluated ratings of performance, and the interrater variability of the ratings, made by multiple independent observers viewing videotapes of simulated crises.METHODS:Raters scored the videotapes of 14 different teams that were managing two scenarios: malignant hyperthermia (MH) and cardiac arrest. Technical performance and crisis management behaviors were rated. Technical ratings could range from 0.0 to 1.0 based on scenario-specific checklists of appropriate actions. Ratings of 12 crisis management behaviors were made using a five-point ordinal scale. Several statistical assessments of interrater variability were applied.RESULTS:Technical ratings were high for most teams in both scenarios (0.78 +/- 0.08 for MH, 0.83 +/- 0.06 for cardiac arrest). Ratings of crisis management behavior varied, with some teams rated as minimally acceptable or poor (28% for MH, 14% for cardiac arrest). The agreement between raters was fair to excellent, depending on the item rated and the statistical test used.CONCLUSIONS:Both technical and behavioral performance can be assessed from videotapes of simulations. The behavioral rating system can be improved; one particular difficulty was aggregating a single rating for a behavior that fluctuated over time. These performance assessment tools might be useful for educational research or for tracking a resident's progress. The rating system needs more refinement before it can be used to assess clinical competence for residency graduation or board certification.

This paper describes an informal but systematic method for how to test and verify a knowledge-based system in a large open-ended medical target domain. The system used is Guardian, an intelligent system for monitoring and diagnosis of post-cardiac surgery patients in an intensive-care unit. The knowledge base is tested and verified by running the system on a series of realistic test scenarios, both with an embedded simulator and with an external simulation system. The same scenarios are presented to human test subjects, making it possible to compare and analyze the performance of the knowledge-based system with that of human physicians. The use of simulators instead of clinical data also means that it is possible to test crucial scenarios which occur seldom in medical practice. Our results show that a system like Guardian might indeed be useful in medical care.

Simple linear relations between properties and composition are developed for jet and diesel fuels of different boiling ranges. Composition is defined in terms of two parameters readily determined by 13C n.m.r. spectroscopy, namely Cn, the fraction of n-alkyl carbon, and Car, the fraction of aromatic carbon. The boiling distribution of the fuels is defined, using gas chromatography, in terms of two parameters, T10 and T90, the temperatures at which 10 and 90 wt% of the fuel has vaporized. Relations of the form P = a1Cn + a2Car + Σ biTi + k, where P is the property value and a1, a2, biand k are constants determined by multiple linear regression, are valid for jet fuels with initial boiling points in the range 150–190°C and final boiling points in the range 230–250°C, and for diesel fuels with initial and final boiling point ranges of 190–230°C and 320–370°C respectively. Properties investigated include smoke point, aromatics content, hydrogen content, density and freezing point for jet fuels, and cloud point, pour point, aniline point, hydrogen content, density, cetane index and cetane number for diesel fuels. Except for the low-temperature properties (jet fuel freezing point and diesel fuel cloud and pour points), an even simpler model of the form previously developed for jet and diesel fuels of fixed boiling range, viz. P = a1Cn + a2Car + k are also adequate.

Green tree pythons, Chondropython viridis, are polymorphic for color as juveniles, commonly being primarily yellow or brown until becoming mostly green at about 1 year of age. We tested the hypothesis that the different morphs arose as a result of selection tor differential background matching, yellow morphs selecting light-colored backgrounds, and brown morphs selecting dark-colored backgrounds. Twelve yellow and eight brown morphs were placed repeatedly in individual testing enclosures and allowed to choose between black and white or yellow and brown halves of a t-perch. Trials showed that both color morphs preferred dark over light perches. We tentatively suggest that individuals chose dark-colored perches for purposes of concealment. (C) 1994 Wiley Liss, Inc.

Propulsion-induced aerodynamic interference effects are presented for a full-scale, powered, STOVL righter aircraft model. The ejector-lift/vectored thrust configuration, designated the E-7A, was tested at low speed in the 40- by 80- and 80- by 120-ft wind tunnels of the National Full-Scale Aerodynamics Complex located at NASA Ames Research Center. Aerodynamic effects on vehicle lift, drag, and pitching moment are presented over a range of effective velocities for simultaneous operation of all lifting jets. The jet/airframe interactions for separate operation of the lifting ejector system and vectorable ventral nozzle are also presented. Ejector and engine inlet momentum effects were fully simulated in these full-scale, powered tests. The jet thrust vector angle of the ventral nozzle was varied to simulate transition from hover to wingborne flight modes. When the lifting ejector system and ventral nozzle are operated simultaneously, the induced effects on lift decrease as the thrust vector angle of the ventral nozzle approaches the horizontal. A negative increment in drag is produced over a narrow portion of the transition speed range when the ejectors and ventral nozzle are operated together. Aerodynamic induced effects of the ejector system measured at full-scale compare well with the small-scale data. Changes in lift and pitching moment due to ventral nozzle operation are smaller at full scale.

Relationships between fuel composition and four secondary measures of diesel fuel ignition quality have been established. Composition has been defined in terms of the fractions of 13C n.m.r. intensity attributable to n-alkyl carbon (Cn) and aromatic carbon (Car). The indicators of diesel ignition quality are: a secondary engine test based on an Institute of Petroleum standard (IP41); an index calculated using boiling point and specific gravity data based on ASTM D976; a calculated index based on aniline point; and a diesel index (IP21) calculated from aniline point and specific gravity. It has been found that all four cetane quality indicators can be adequately described by a very simple property-composition relationship of the form, P = aCn + bCar + c, where P is the property in question and a, b and c are coefficients determined by multiple linear regression using a sample set deriving from a diverse range of petroleum and synthetic fuel sources. The cetane quality indicator based on ASTM D976 has been found to give a distinctly pessimistic view of ignition quality for highly naphthenic diesel fuels, such as are produced via coal liquefaction.

A simple, chemically explicit tool for guiding blending options has been tested and verified for jet and diesel fuels of fixed boiling range, deriving from Fischer-Tropsch synthesis, coal hydroliquefaction, and petroleum sources. The complementary nature of the properties of Fischer-Tropsch and coal hydroliquefaction fuels has been demonstrated. The approach described utilizes previously derived fuel composition-property relationships of the form P = a1[n] + a2[BC] + a3[Ar], where P is the property in question, [n], [BC], and [Ar] are the weight fractions of n-alkanes, branched plus cyclic saturates, and aromatics, respectively, and a1, a2, and a3 are coefficients of known value from previous studies of diverse fuels. The methodology has proven effective in identifying suitable blendstocks, estimating suitable blend ratios, and calculating blend properties. It has been applied to jet fuel smoke point, aromatics content, hydrogen content, heat of combustion, freezing point, and specific gravity, as well as to diesel fuel pour point, cloud point, hydrogen content, specific gravity, aniline point, diesel index, cetane index, and cetane number. The successful application of this methodology does not require that the properties of the blendstocks themselves are accurately predicted or that the blend properties are linear combinations of blendstock properties.

Desalting brackish ground water can be combined with ground water management in the San Joaquin Valley to partially alleviate environmental and economic problems caused by agricultural drainage water. Desalting subsurface drainage water produced from on—farm shallow drainage systems is costly due to high salinity and the potential for scaling and fouling of reverse osmosis (RO) membranes. When subsurface drainage water is transported in open canals, algal growth and accompanying organic transformations present pretreatment problems that have yet to be solved. Similar problems have been experienced at desalting facilities outside the San Joaquin Valley using comparable feed waters. The proposed pumping of usable ground water from the semiconfined aquifer on the Valley's west side to lower the shallow water table and thus eliminate waterlogging of crop root zones may result in degradation and mining of usable ground water and contamination of the confined aquifer below the Corcoran clay, the principal confining layer in the Valley. A combination of brackish ground water desalting and ground water management by pumping unusable shallow ground water from an interval between the crop root zones and the usable water body at the bottom of the semiconfined aquifer would result in (1) a lower salinity feed water that will reduce the cost of desalting, (2) a feed water that requires little, if any, filtration to protect RO membranes, and (3) the removal of the body of water containing high levels of salt and selenium that endanger usable water in both aquifers. The combination of brackish ground water desalting and ground water management would result in the production of usable quantities of fresh water for California's ever-increasing population and a reduction in the cost of reclaiming and managing drainage water by desalination.