4 resultados para immersion of manifold
em Brock University, Canada
Resumo:
3-alkyl-2-methoxypyrazines (MPs) are grape- and insect-derived odor-active compounds responsible for vegetative percepts that are detrimental to wine quality when elevated. This study tested both the effect of closure/packaging types and light/temperature storage conditions on MPs (isopropyl-, secbutyl-, and isobutyl-MP) in wine. An MP-emiched wine rapidly (after 140 hours) and significantly decreased in MP concentration after natural and synthetic cork contact (immersion of closures in wine). This decrease was greatest with synthetic closures (70% - 89% reduction) and secbutyl-MP. Subsequently storage trials tested the effects of commercial closure/packaging options (natural cork, agglomerate cork, synthetic corks, screwcaps and TetraPak® cartons) on MPs in MP-emiched Riesling and Cabernet Franc over 18 months. Regardless of packaging, isobutyl-MP was the most altered from bottling. Notably, all MP levels tended to decrease to the greatest extent in TetraPak® cartons (~34% for all MPs) and there was evidence of contribution ofisoproyl- and secbutyl-MP from cork-based closures (i.e. ~30% increase in secbutyl-MP after 6 months) or from an unidentified wine constituent. To test the effects of various light/temperature conditions (light exposed at ambient temperature in three different bottle hues, light excluded at ambient temperature and light excluded at a "cellar" temperature (14°C)), MP-emiched Riesling and Cabernet Franc were also analyzed for MP concentrations over 12 months. MPs did not vary consistently with light or temperature. Other odorants and physico-chemical properties were tested in all wines during storage trials and closely agree with previous literature. These results provide novel insights into MPs during ageing, interactions with packaging and storage conditions, and assist in the selection of storage conditions/packaging for optimal wine quality.
Resumo:
Basal body temperature (BBT) and thermoeffector thresholds increase following ovulation in
many women. This study investigated if solely central thermoregulatory alterations are responsible.
Seven females in a non-contraceptive group (NCG) were compared with 5 monophasic contraceptive
users (HCG) on separate accounts: pre-ovulation (Trial I; d 2-5) and post-ovulation (Trial 2; 4-8 d
post-positive ovulation) for NCG, and active phase for HCG (d 2-5, d 18-21). During immersion in
28°C water to the axilla, participants exercised for 20-30 min on an underwater ergometer. After
steadily sweating, immersion continued until metabolism increased two-fold due to shivering. Rectal
(Tre) BBT was not different between trials for neither NCG (1: 37.34±0.16°C; 2: 37.35±0.27°C) nor
HCG. At exercise termination, Tre forehead sweating cessation increased (P<0.05) in trial 2
irrespective of group (1: 37.55±0.39°C; 2: 37.90±0,46°C). Tre shivering onset did not increase
(P>0.05) in trial 2 (1: 36.91±0.50°C; 2: 37.07±0,45°C). The widths of the interthreshold zone
increased (P<0.05) in trial 2 (1: 0.64±0.22°C; 2: 0.82±0.37°C) due to the increased sweating threshold
only. HCG cooled quicker (1: -l.15±0,43°C; 2: -1.00±0.50°C) than NCG participants (1: -
0.58±0.22°C; 2: -0.52±O.29°C), and tympanic (Tty) sweat thresholds were significantly (P<0.05)
decreased (1: 34.76±0.54°C; 2: 35.39±0.61°C) versus NCG (l: 35.57±0.77°C; 2: 35.89±1.04°C).
Lastly, Tre and Tty thresholds were significantly different (P
Resumo:
The human neuromuscular system is susceptible to changes within the thermal environment. Cold extrinsic temperatures can significantly reduce muscle and nervous system function and communication, which can have consequences for motor performance. A repeated measures design protocol exposed participants to a 12°C cold water immersion (CWI) up to the ankle, knee, and hip to determine the effect that reduced skin and muscle temperature had on balance and strength task execution. Although a linear reduction in the ability to perform balance tasks was seen from the control condition through to the hip CWI, results from the study indicated a significant reduction in dynamic balance (Star Excursion Balance Test reach distance) performance from only the hip CWI (P<0.05). This reduced performance could have been due to an increase in joint stiffness, increased agonist-antagonist co-contraction, and/or reduced isokinetic muscular strength. Reduced physical performance due to cold temperature could negatively impact outdoor recreational athletics.
Resumo:
This project presents a primer for secondary French Immersion teachers that facilitates the use of French oral communicative activities in secondary Canadian and World Studies courses. The primer supports collaborative and inclusive teaching strategies that invite students to speak and develop their oral French communication skills. The primer is divided into 2 main components: (a) Rationale for the Primer, and (b) the Strategies themselves, comprising succinct descriptions as well as potential uses and suggestions. A critical content analysis of various Ontario Ministry of Education documents was undertaken in order to explore the importance of oral communication in second-language learning in Ontario secondary schools. Furthermore, holistic and invitational education perspectives were examined in order to define the advantages of collaborative learning. Moreover, research in the stream of French Immersion studies was also referenced to frame the relevance of second-language learning and the significant role the French Immersion teacher plays. The aforementioned research contributes to the advancement of theory and practice regarding the importance of opportunities for oral French communication in secondary Canadian and World Studies courses.