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The purpose of this study was to determine how comparable driving performance on a 'Low-Cost Desktop' single screen driving simulator and a 'Mid-level' fixed-base driving simulator (STISIM, Systems Technology Inc.) is. Fifty-two participants completed a 12 km virtual driving course on each simulator with at least 14 days separating both sessions. Driving performance was assessed using overall driving errors recorded by the simulator and through an observer-based demerit point scoring system. Speed and lane deviation parameters were used as local indicators of driving responses. Moderate to high correlations between the two platforms indicated that participants reacted similarly on both platforms. Our findings suggest that the two platforms yielded comparable data and that the 'Low-Cost Desktop' simulators could be used as a reliable replacement option to 'Mid-Level' driving simulators. [ABSTRACT FROM AUTHOR]

Global environmental change is altering natural and built systems in many regions of the world and such changes play a significant role in an emerging travel trend that has been labelled ‘last chance tourism’ (LCT). In LCT, tourism demand is based on the desire to see these vulnerable places and features before they disappear or are essentially and irrevocably changed. The paradox in this new form of travel lies in the fact that the tourists often travel long distances and, thus, are disproportionately responsible per capita for increased greenhouse gas emissions and various other stressors that have the potential to alter further the very attractions being visited. The emergence of LCT requires careful ethical consideration and adds a new twist to the debate about ‘loving a destination to death’. In this case, the relationship is indirect and intangible, and is complicated by spatial and temporal lags, as well as the complex system of biophysical interactions at the heart of climate change. LCT presents a situation that is considerably more difficult to manage and mitigate than those where tourism involves only direct and local impacts. Through a praxis/reflective approach, we discuss this complexity and the various ethical issues associated with marketing and managing LCT. In order to provide context and clarification of the LCT concept, we use one of the most evocative symbols of climate change, the polar bears of Churchill, Manitoba, Canada, as a source of empirical evidence and a foundation for exploring ethical considerations. [ABSTRACT FROM PUBLISHER]

Abstract: The tourism sector is one of the largest and fastest growing global industries and is a significant contributor to national and local economies around the world. The interface between climate and tourism is multifaceted and complex, as climate represents both a vital resource to be exploited and an important limiting factor that poses risks to be managed by the tourism industry and tourists alike. All tourism destinations and operators are climate-sensitive to a degree and climate is a key influence on travel planning and the travel experience. This chapter provides a synopsis of the capacities and needs for climate services in the tourism sector, including current and emerging applications of climate services by diverse tourism end-users, and a discussion of key knowledge gaps, research and capacity-building needs and partnerships that are required to accelerate the application of climate information to manage risks to climate variability and facilitate successful adaptation to climate change. [ABSTRACT FROM AUTHOR]

The dermorphin-derived tetrapeptide H-Dmt-d-Arg-Phe-Lys-NH2 (Dmt = 2′,6′-dimethyltyrosine) ([Dmt1]DALDA) is a highly potent and selectiveμ-opioid agonist capable of crossing the blood–brain barrier and producing a potent, centrally mediated analgesic effect when given systemically. For the purpose of biodistribution studies by fluorescence techniques, [Dmt1]DALDA analogues containing various fluorescent labels [dansyl, anthraniloyl (atn), fluorescein, or 6-dimethylamino-2′-naphthoyl] in several different locations of the peptide were synthesized and characterized in vitro in the guinea-pig ileum and mouse vas deferens assays, and inμ-,δ- andκ-opioid receptor-binding assays. The analogues showed various degrees ofμ receptor-binding selectivity, but all of them were lessμ-selective than the [Dmt1]DALDA parent peptide. Most analogues retained potent, fullμ-agonist activity, except for one with fluorescein attached at the C-terminus (3a) (partialμ-agonist) and one containingβ-(6′-dimethylamino-2′-naphthoyl)alanine (aladan) in place of Phe3 (4) (μ- andκ-antagonist). The obtained data indicate that the receptor-binding affinity, receptor selectivity and intrinsic efficacy of the prepared analogues vary very significantly, depending on the type of fluorescent label used and on its location in the peptide. The results suggest that the biological activity profile of fluorescence-labeled peptide analogues should always be carefully determined prior to their use in biodistribution studies or other studies. One of the analogues containing the atn group (2a) proved highly useful in a study of cellular uptake and intracellular distribution by confocal laser scanning microscopy. [ABSTRACT FROM AUTHOR]

The cyclic enkephalin analog H-Tyr-c[d-Cys-Gly-Phe(pNO2)-d-Cys]NH2 is a highly potent opioid agonist with IC50s of 35 pmand 19 pmin the guinea-pig ileum (GPI) and mouse vas deferens (MVD) assays, respectively. The Phe1-analog of this peptide showed 370-fold and 6790-fold lower agonist potency in the GPI and MVD assays, respectively, indicating the importance of the Tyr1 hydroxyl-group in the interaction withμ andδ opioid receptors. In the present study, the effect of various substituents (-NH2, -NO2, -CN, -CH3, -COOH, -COCH3, -CONH2) introduced in thepara-position of the Phe1-residue of H-Phe-c[d-Cys-Gly-Phe(pNO2)-d-Cys]NH2 on the in vitro opioid activity profile was examined. Most analogs showed enhancedμ andδ agonist potencies in the two bioassays, except for the Phe(pCOOH)1-analog, which was weakly active, probably as a consequence of the negative charge. The most potent compounds were the Phe(pCOH3)1- and the Phe(pCONH2)1-analogs. The latter compound showed subnanomolarμ andδ agonist potencies and represents the most potent enkephalin analog lacking the Tyr1 hydroxyl-group reported to date. Taken together, these results indicate that various substituents introduced in thepara-position of Phe1 enhance opioid activity via hydrogen bonding or hydrophobic interactions with the receptor. Comparison with existingstructure-activity relationship on phenolic hydroxyl replacements in morphinans indicates that these nonpeptide opiates and some of the cyclic enkephalin analogs described here may have different modes of binding to the receptor. [ABSTRACT FROM AUTHOR]

Summary This work was initiated to integrate an image analysis system and a prediction equation to support decisions for post-emergence herbicide applications under field conditions. Data were collected from 1999 to 2001 in 32 commercial fields to obtain weed cover data at the three to four leaf stage of maize (Zea mays L.), and crop yield at maturity. Relative crop yield was predicted using a non-linear sigmoidal equation with relative weed cover as the predictor variable (P < 0.0001; R [sup 2] = 0.39). The decision procedure consists of using the equation within the limits of a yield loss threshold that represents the loss one is willing to tolerate. The tolerance threshold (TT) allows determination of a weed threshold (WT). The procedure considers the variability around the prediction equation by setting the WT at the intersection between the lower 95% confidence interval of the prediction line and the TT. It also considers the variability around the weed cover estimate. For a given field, the decision is made by comparing the average weed cover corrected for sampling error, to the WT. We tested the performance of the decision procedure and found it could lead to a saving of 25% of herbicide use. We also computed a probability table showing the chances of getting relative yield above or below the TT. We suggest using the probability table in combination with the decision procedure to manage risks. The proposed approach does not offer a set ‘yes’ or ‘no’ answer but rather provides a framework to support decisions by producers who ultimately must manage the risks. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The effects of topiramate (TPM) on components of energy balance were tested in male and female rats that were (i) left intact, (ii) castrated or (iii) castrated with replacement therapies consisting of testosterone administration in orchidectomized (OCX) rats and of estradiol or progesterone treatments in ovariectomized (OVX) rats. METHODS: TPM was mixed into the diet and administered at a dose of 60 mg per kg of body weight. Male and female rats were treated for 28 and 35 days, respectively. At the end of the treatment period, variables of energy balance and determinants of lipid and glucose metabolism were assessed. RESULTS: TPM reduced energy and fat gains in both male and female rats either in the absence or in the presence of hormone replacement therapies. In male rats, it also decreased food intake, protein gain and energetic efficiency. In female animals, TPM reduced energetic efficiency while it stimulated lipoprotein lipase activity in brown adipose tissue. TPM also reduced plasma glucose and plasma leptin levels in female rats as well as plasma insulin and liver triglycerides in male animals. As expected, castration and sex hormones also strongly influenced energy balance. In male rats, OCX led to a decrease in energy and protein gains that was blocked by treatment with testosterone. In female rats, OVX caused increases in energy, fat and protein gains that were prevented by treatment with estradiol. CONCLUSION: In female rats, the effects of TPM on fat and energy gains were clearly not influenced by the sex hormone status of the rats. In male animals, there was also no interaction of TPM and the status of sex hormones on energy balance, suggesting that OCX and testosterone minimally interfere with the action of TPM on energy balance. The effects of TPM on energy balance were accounted for by a decrease in energetic efficiency, resulting from an effect exerted by the drug on both energy intake and thermogenesis. The present results also... [ABSTRACT FROM AUTHOR]

Our objective was to compare the effect of 2 regimens for treatment of Mycobacterium avium complex (MAC) bacteraemia in an HIV-positive population on symptoms and health status outcomes using a substudy of an open-label randomized controlled trial. The study was conducted in 24 hospital-based human immunodeficiency virus (HIV) clinics in 16 Canadian cities. Patients had HIV infection and MAC bacteraemia and were given either rifampin 600 mg, ethambutol 15 mg/kg daily, clofazimine 100 mg daily and ciprofloxacin 750 mg twice daily (4-drug arm) or rifabutin 600 mg daily (amended to 300 mg daily in mid-trial), ethambutol 15 mg/kg daily and clarithromycin 1000 mg twice daily (3-drug arm). The primary health status outcome was the change on the 8-item symptom subscale of the Medical Outcome Study (MOS)-HIV Health Survey adapted for MAC. Changes on other MOS-HIV subscales and on the Karnofsky score were also evaluated. Patients on the 3-drug arm had better outcomes on the MOS-HIV symptom subscale at 16 weeks (P=0.06), with statistically significant differences restricted to night sweats and fever and chills (P < 0.001). The proportion of patients improving on the symptom subscale relative to baseline was 55% on the 3-drug arm and 40% on the 4-drug arm. Patients on the 3-drug arm also had better Karnofsky score at 16 weeks (P < 0.001) and better outcomes on the social function, mental health, energy/fatigue, health distress and cognitive function subscales of the MOS-HIV. The 3-drug arm is superior to the 4-drug arm in terms of impact on MAC-associated symptoms, functional status and other aspects of health status. [ABSTRACT FROM AUTHOR]

In a study of Grade 8 French immersion students (N=95), in six schools in southwestern Ontario, who were going on to high school, an attrition rate from the bilingual stream of 12.7% was noted. Those withdrawing were characterized first by an external locus of control —more likely to attribute their success and failure to luck. Next, on Gardner's (1985) Attitude/Motivation Test Battery (AMTB) these same students showed a more negative attitude to learning French. Interestingly, though, they did not differ from the more persistent with respect to (1) achievement in French or other academic areas, (2) effort and ability attributions, (3) self-esteem, (4) parental encouragement, (5) motivational intensity, (6) the desire to learn French, (7) an instrumental orientation, nor (8) in their interest in foreign languages. Somewhat paradoxically, however, and most likely a statistical anomaly, the less persistent did show a more positive attitude to the European French and more of an integrative orientation. Teachers and guidance counsellors dealing with attrition apparently need to address attributions related to LUCK, and attitudes related to learning French. Suggestions are offered. [ABSTRACT FROM AUTHOR]

Investigates the derivation of a flexible sigmoidal model pertaining to crop yield to relative leaf cover of weed. Conduction of maize competition field studies with weed infestation to validate the model; Calculation of model parameters via a non-linear regression approach; Presence of null hypothesis rejection of hyperbolic yield response.