Temperature determinations of hot DA white dwarfs using IUE continuum fluxes

Effective temperatures of 15 DA white dwarfs hotter than 20,000 K were derived from low-dispersion far ultraviolet spectra obtained with IUE. The analysis was carried out by comparing the observed far ultraviolet fluxes with model fluxes scaled to the V-band flux. Accurate calibration of the IUE spectra is critical for this analysis. Observations at all epochs were corrected to the 1980 IUE calibration using the time-dependent corrections of Bohlin (1988). Taking advantage of the smooth and well-defined continuum fluxes provided by DA white dwarfs, seven white dwarfs for which accurate, independent temperature determinations were made from line profile analyses were used to improve the accuracy of the IUE flux calibration. The correction to the original calibration is as great as 20 percent in individual 5 A wavelength bins, while the average over the IUE wavelength range is 5 percent. The final calibration correction and the temperatures for the hot white dwarfs are presented

Differences among Nonresident Tourists Making Consumptive and Nonconsumptive Uses of Alaskan Wildlife

Tourism is an important sector of Alaska's economy; 23% of 4202 parties of tourists vacationing in Alaska from October 1982 to September 1983 indicated they hunted or fished. Tourists making consumptive use (hunting or fishing) of wildlife differed significantly from other visitors. Those who hunted or fished: (1) were in larger groups that contained a higher proportion of males; (2) tended to be younger; (3) were more involved in planning their vacation as indicated by starting the planning for their trip earlier and using more sources of information; (4) spent longer in the state and camped more often; (5) were more likely to charter aircraft within Alaska; (6) rated their experience highly, but thought they received a lower value for monies spent; (7) expended fewer total funds on their vacation; and (8) were more likely to return to Alaska than their counterparts who neither hunted nor fished. Visitors who used wildlife consumptively provided funds directly to the state for the conservation of these species through the purchase of hunting and fishing licenses and the subsequent receipt by the state of federal funds via the Pittman-Robertson and Dingell-Johnson acts. No formal mechanism exists for nonconsumptive users to aid wildlife conservation even though some nonconsumptive uses of resources are detrimental to wildlife. Although wildlife and their habitats are an important attractor for tourists, too little attention is given to the long-term benefits from the tourism industry in assessing the economic value of resource development and use that affects wildlife.

Comparative genomics of fungal allergens and epitopes shows widespread distribution of closely related allergen and epitope orthologues

BACKGROUND: Allergy is a common debilitating and occasionally life threatening condition. The fungal kingdom contains a number of species that produce a wide range of well defined protein allergens although the vast majority of fungal species have unknown allergenic potential. The recent genome sequencing of a variety of fungi provides the opportunity to assess the occurrence of allergen orthologues across the fungal kingdom. Here we use comparative genomics to survey the occurrence of allergen orthologues in fungi. RESULTS: A database of 82 allergen sequences was compiled and used to search 22 fungal genomes. Additionally we were able to model allergen structure for representative members of several highly homologous allergen orthologue classes. We found that some allergen orthologue classes that had predicted structural congruence to allergens and allergen epitopes were ubiquitous in all fungi. Other allergen orthologues classes were less well conserved and may not possess conserved allergen epitope orthologues in all fungi. A final group of allergen orthologues, including the major allergens Asp f 1 and Alt a 1, appear to be present in only a limited number of species. CONCLUSION: These results imply that most fungi may possess proteins that have potential to be allergens or to cross react with allergens. This, together with the observation that important allergens such as Asp f 1 are limited to genera or species, has significant implications for understating fungal sensitization, and interpreting diagnosis and management of fungal allergy

Conversation Effects on Driving: Neural Mechanisms Underlying Reaction Times to Visual Events

OBJECTIVES The purpose of this study was to determine the behavioral and neural correlates of conversation effects on driving using the same visual event detection paradigm in brain imaging, behavioral testing, and closed-road driving experiments. METHODS The “load” paradigm (Young et al., 2005b) assessed the effects of conversation on visual event detection during simulated driving in behavioral labs, fMRI and MEG imaging centers, and actual driving on a closed road. Behavioral and imaging data were collected. The primary task was to depress a foot pedal in response to a small red light presented to the left or below the driving scene at unpredictable times. The secondary task was to engage in a conversation. The participant pressed a button to answer a ring tone, and then answered simple auditory questions such as “What is your birthdate?” fMRI and MEG data were analyzed to examine the neural substrates of driving with and without conversation. The correlation, reliability and repeatability across experimental settings were analyzed using statistical procedures such as random effect ANOVA and multivariate regression models with repeated measure adjustment. RESULTS The behavioral results from all sites demonstrated that conversation had a small but consistent increase in reaction time (about 70-200 ms) with no effect on miss rates compared to the “no conversation” baseline. The random effect ANOVA and adjusted regression models confirmed the conversation effect in all settings, with good reliability and repeatability. The fMRI results showed that conversation activated not only language-specific areas as expected, but also increased activation in fronto-parietal pathways engaged in sensory-motor integration, attention modulation, and decision execution (Young et al., 2005a). Results of MEG imaging showed that in the “no conversation” baseline, behavioral RT was inversely related to changes in MEG brain activity in the right superior parietal lobe: more modulation in brain activity in the 200-300 ms range after light onset resulted in shorter RTs, and less modulation in longer RTs. A similar relation to RT was also seen in brain activity in the visual cortex in the 85-90 ms interval after red light onset. Conversation again activated language-specific areas in the MEG study, and resulted in less modulation in the right parietal and visual regions (Bowyer et al., 2006). Accordingly, conversation tended to increase mean behavioral RT slightly (no conversation 926 ms; conversation 993 ms). Further experiments are required to determine if the reduction in modulation due to conversation arises from inhibition, interference, or a removal of facilitation from top-down attentional processes. CONCLUSIONS Conversation slightly increases visual event reaction times in laboratory and closed-road driving experiments compared to a no-conversation baseline, with little or no effect on miss rates. Common fMRI and MEG imaging findings revealed fronto-parietal and visual-auditory-motor networks associated with sensory-motor integration, decision-making, and attention modulation during a driving-like scenario. Conversation appears to contribute to increased reaction times by reducing brain modulation to visual events in the right superior parietal region and visual cortices. These experimental findings should not be interpreted as if conversation increases the rate of crashes in real-world driving when compared to baseline driving without real-world validation and comparison of reaction time effects from other in-vehicle tasks. REFERENCES Bowyer, S., Moran, J., Hsieh, L., Manoharan, A., Young R.A., Malladi, K., Yu, Y-J., Chiang, YR., Hersberger, R., Genik, R., & Tepley, N. (2006). MEG localization of neural mechanisms underlying reaction time to visual events while watching a driving video: Effects of conversation. International Congress Series: New Frontiers in Biomagnetism. Proceedings of the 15th International Conference on Biomagnetism. Vancouver, BC Canada, August 21-25. D. Cheyne, B. Ross, G. Stroink and H. Weinberg (Editors). Young, R.A., Hsieh, L., Graydon, F.X., Genik II, R., Benton, M.D., Green, C.C., Bowyer, S.M., Moran, J.E., & Tepley, N. (2005a). Mind-on-the-Drive: Real-time functional neuroimaging of cognitive brain mechanisms underlying driver performance and distraction. Human Factors in Driving, Telematics and Seating Comfort 2005, SP-1934. Society of Automotive Engineering, Warrendale, PA, April. Young, R.A., Aryal, B., Muresan, M., Ding, X., Oja, S., & Simpson, S. (2005b). Road-to-lab: Validation of the static load test for predicting on-road driving performance while using advanced in-vehicle information and communication devices. Proceedings of the Third International Driving Symposium on Human Factors in Driver Assessment, Training and Vehicle Design, Rockport, Maine, July

Genetic susceptibility to allergic bronchopulmonary aspergillosis in asthma: a genetic association study

Background: In patients with asthma, the fungus Aspergillus fumigatus can cause allergic bronchopulmonary aspergillosis (ABPA). Familial ABPA is reported, and some genetic factors have been associated with the disease, however, these are small studies (n ≤ 38) and do not explain all cases of ABPA.Methods: We analysed SNPs in 95 ABPA patients, comparing frequencies to 152 atopic asthmatic and 279 healthy controls. Twenty two genes were selected from literature, and 195 tagging SNPs were analysed for genetic association with ABPA using logistic regression corrected for multiple testing. We also analysed monocyte-derived macrophage gene expression before and during co-culture with A. fumigatus.Results: Seventeen ABPA-associated SNPs (ABPA v Atopic asthma) were identified. Three remained significant after correction for multiple testing; IL13 rs20541, IL4R rs3024656, TLR3 rs1879026. We also identified minor differences in macrophage gene expression responses in the ABPA group compared to the control groups.Conclusions: Multiple SNPs are now associated with ABPA. Some are novel associations. These associations implicate cytokine pathways and receptors in the aberrant response to A. fumigatus and susceptibility to ABPA, providing insights into the pathogenesis of ABPA and/or its complications. We hope these results will lead to increased understanding and improved treatment and diagnostics for ABPA

Exploring the effects of recursive conversations on participants’ interactional competence in a first-year EFL oral communication course

　 Recursive conversations (RCs) are described as a “return to a similar experience―but with a wider knowledge” (Kindt, 2004, p. 15). Focusing on RCs and their effects on learner beliefs and performance, including fluency, disfluency, and complexity, this paper describes the results of an Action Research study conducted over six weeks with 18 first-year English majors in a freshman oral communication program. Following a mixed methods approach, the researchers collected and analyzed both quantitized and qualitative data (Dornyei, 2007). Data included pre- and postquestionnaires, learner feedback forms, and conversation transcriptions. Analysis of the transcription data indicated up to a 20% increase in fluency markers attributable to the effect of RCs. Transcription analysis also showed a significant increase in sentence complexity, as indicated by increases in average sentence length of between 10% and 95%. Questionnaire and feedback data indicated that learners considered the RCs to be more interesting and less challenging than nonrecursive classroom conversations. Some students, however, considered the recursive conversations to be less useful than non-recursive ones, indicating a contradiction between learners’ experiences of the RCs and their perceptions of their usefulness in promoting L2 oral competence. The results of this research indicate that RCs can have a positive short-term impact on learners’ oral competency, but that educators should take steps to engage with learners regarding the impact of pedagogical tools in order for learners to become aware of potential benefits. Issues surrounding the long-term impact of RCs and appropriate methods for helping learners to see the benefits of such procedures are a promising area for future research

A working paper exploring the effects of recursive conversations on participants’ fluency development in a first-year EFL oral communication course

Recursive conversations (RCs) are described as a “return to a similar experience—but with a wider knowledge” (Kindt, 2004, p. 15). Focusing on RCs and their effects on learner beliefs and performance, including fluency, disfluency, and complexity, this paper describes the results of an Action Research study conducted over six weeks with 18 first-year English majors in a freshman oral communication program. Following a mixed methods approach, the researchers collected and analyzed both quantitized and qualitative data (Dörnyei, 2007). Data included pre- and post-questionnaires, learner feedback forms, and conversation transcriptions. Analysis of the transcription data indicated up to a 20% increase in fluency markers attributable to the effect of RCs. Transcription analysis also showed a significant increase in sentence complexity, as indicated by increases in average sentence length of between 10% and 95%. Questionnaire and feedback data indicated that learners considered the RCs to be more interesting and less challenging than non-recursive classroom conversations. Some students, however, considered the recursive conversations to be less useful than non-recursive ones, indicating a contradiction between learners’ experiences of the RCs and their perceptions of their usefulness in promoting L2 oral competence. The results of this research indicate that RCs can have a positive shortterm impact on learners’ oral competency, but that educators should take steps to engage with learners regarding the impact of pedagogical tools in order for learners to become aware of potential benefits. Issues surrounding the long-term impact of RCs and appropriate methods for helping learners to see the benefits of such procedures are a promising area for future research

EFFECTS OF BILATERAL AND UNILATERAL SEMI-RIGID ANKLE ORTHOSES ON ANKLE STABILITY AND GROUND CONTACT KINETICS

Injuries of the ankle complex are common in the sporting, civilian and military populations. The purpose of this study was to ascertain and compare the effects of unilateral and bilateral orthoses on the range of inversion and eversion at the ankle complex and on Ground Reaction Forces. Isokinetic goniometric measurement and the assessment of peak loads and timing parameters during the gait cycle were assessed in subjects with no history of ankle injury (n=31) and subjects recovering from ankle injury (n=24). There were differences in inversion angle between the braces (

Aspergillus fumigatus allergen expression is coordinately regulated in response to hydrogen peroxide and cyclic AMP

<p>Abstract</p> <p>Background</p> <p><it>A. fumigatus </it>has been associated with a wide spectrum of allergic disorders such as ABPA or SAFS. It is poorly understood what allergens in particular are being expressed during fungal invasion and which are responsible for stimulation of immune responses. Study of the dynamics of allergen production by fungi may lead to insights into how allergens are presented to the immune system.</p> <p>Methods</p> <p>Expression of 17 <it>A. fumigatus </it>allergen genes was examined in response to various culture conditions and stimuli as well as in the presence of macrophages in order to mimic conditions encountered in the lung.</p> <p>Results</p> <p>Expression of 14/17 allergen genes was strongly induced by oxidative stress caused by hydrogen peroxide (Asp f 1, -2, -4, -5, -6, -7, -8, -10, -13, -17 and -18, all >10-fold and Asp f 11, -12, and -22, 5-10-fold) and 16/17 allergen genes were repressed in the presence of cAMP. The 4 protease allergen genes (Asp f -5, -10, -13 and -18) were expressed at very low levels compared to the comparator (<it>β</it>-tubulin) under all other conditions examined. Mild heat shock, anoxia, lipid and presence of macrophages did not result in coordinated changes in allergen gene expression. Growth on lipid as sole carbon source contributed to the moderate induction of most of the allergen genes. Heat shock (37°C > 42°C) caused moderate repression in 11/17 genes (Asp f 1, -2, -4, -5, -6, -9, -10, -13, -17, -18 and -23) (2- to 9-fold), which was mostly evident for Asp f 1 and -9 (~9-fold). Anaerobic stress led to moderate induction of 13/17 genes (1.1 to 4-fold) with one, Asp f 8 induced over 10-fold when grown under mineral oil. Complex changes were seen in gene expression during co-culture of <it>A. fumigatus </it>with macrophages.</p> <p>Conclusions</p> <p>Remarkable coordination of allergen gene expression in response to a specific condition (oxidative stress or the presence of cAMP) has been observed, implying that a single biological stimulus may play a role in allergen gene regulation. Interdiction of a putative allergen expression induction signalling pathway might provide a novel therapy for treatment of fungal allergy.</p