5 resultados para sweat
em Brock University, Canada
Resumo:
Sweat bees exhibit a range of social behaviours, from solitary nesting, in which no workers are produced, to strong eusociality, in which workers exhibit a high degree of altruism, behaviour that is measured by the degree of personal reproductive sacrifice. Field studies were carried out for seven weeks during May-June 2000 in southern Greece in order to investigate intraspecific social variation, and test the hypothesis of a north-south cline of decreasing eusociality in the obligately eusocial sweat bee L. (E.) malachurum. A comparative study, using principal components analysis, was performed to determine if patterns of intraspecific social variation in L. malachurum reflect the patterns of social variation within the subgenus, Evylaeus, as a whole. The results of the field study reveal that, in Greece, two worker broods were produced followed by a third brood consisting of gynes, males and some workers, indicating that there was an overlap in worker and gyne production. There was strong caste distinction between queens and workers. Workers actively foraged and participated in nest construction as most workers (58%, n=303) had a high degree of mandibular wear. Workers did not participate in the oviposition of Brood 3 gynes since only 0.7% (n=278) of workers were mated. Furthermore, queen survival until the end of Brood 3 and a substantial size differential of 10.6% between queens and workers suggested that queen domination over worker behaviour during the early to mid-part of the colony cycle was plausible. Male production in Brood 3 by some workers was likely, since the timing of worker ovarian development corresponded with the timing of male production. These findings suggest that workers of the first two broods were primarily altruistic, but some (28%) Brood 1 (9%) and Brood 2 (19%) workers produced males, indicating that the degree of altruistic behaviour declined during the lifetime of the colony. In comparison with other L. malachurum populations in Europe, the Greek population of L. malachurum had a weaker social level as a result of the higher proportion of workers potentially involved in male production, thus 3 supporting the hypothesis of a southerly cline of decreasing eusociality. Furthermore, intraspecific variation in social level across Europe appears to be due to longer breeding seasons in more southerly locations that would promote the production of larger colonies and provide opportunities for workers to evade queen control. The comparative study using principal components analysis on 20 solitary (of the subgenera Evylaeus and Lasioglossum), eusocial and socially polymorphic Evylaeus species and populations reveals that six traits are closely associated with stronger eusociality in Evylaeus. These traits are: (1) a reduction in the proportion of males in the early brood(s); (2) a reduction in the proportion of females that mate; (3) an increase in the mean number of first brood workers; (4) a reduction in the proportion of females with developed ovaries; (5) an increase in size dimorphism between castes, and (6) nest guarding. These are traits that most significantly define principal component one and therefore distinguish social type as indicated by a clear separation of the eusocial and the solitary populations, with a socially polymorphic species falling in between. Furthermore, most of these traits are under foundress control and may suggest that the evolutionary loss or gain of eusociality is based on selection pressures on a founding female. Colony size and female ovarian development are common factors distinguishing social variation in L. malachurum and within the subgenus as a whole. The principal components analysis excluding the solitary species and the socially aberrant L. marginatum populations show the L. malachurum populations separated based on an increasing proportion of workers with developed ovaries as populations are found more south, lending further support to the hypothesis of a north-south cline of decreasing eusociality.
Resumo:
Within the crime film tradition there is a plethora of sub-genres all of which relate to crime and its consequences. However, directors Joel and Ethan Coen, Quentin Tarantino and David Lynch, all of whom create plots around crime and criminality, have been difficult to pin down and attribute to any given sub-genre. This thesis demonstrates that an absurdist philosophy can be used to effectively examine the content of the previously mentioned filmmakers. Through an analysis of these filmmakers and their better known works compelling evidence is revealed suggesting that these filmmakers may all belong to the emerging crime film sub-genre known as absurdist crime films.
Resumo:
Teach, Lean Develop: Sweat, Breathe, Yoga is a Handbook for the Educator intended to be a practical took for educators to integrate yoga into their classrooms and for the betterment of students. The handbook offers teachers several activities and ideas to get them started using yoga in the classroom-these activities can be modified to suit different ages, abilities, and classroom levels. The project includes a look at the literature alongside my opinions and experience from what I have experiences while teaching yoga in the classroom. The handbook itself is intended to assist experiences and inexperienced educators by offering some ideas and activities that will encourage educators to explore using yoga in the classroom. After the completion of the handbook 2 educators reviewed it, and information was collected with regards to how they saw it fitting into their classrooms and the curriculum in general. They provided critiques, constructive feedback, and further recommendations for the handbook.
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:
Type 1 Diabetes Mellitus (T1DM) is an autoimmune disease that destroys pancreatic beta cells, affecting glucose homeostasis. In T1DM, glucoregulation and carbohydrate oxidation may be altered in different ambient temperatures; however, current literature has yet to explore these mechanisms. This study examines the effects of 30 minutes of exercise at 65% VO2max in 5ºC, 20ºC and 35ºC in individuals with T1DM. No significant differences were observed for blood glucose across the 3 conditions (p = 0.442), but significance was found for core temperature, heat storage, and sweat rate (p < 0.01). Blood glucose was also shown to vary greatly between individuals among conditions. The mechanisms behind the differences in blood glucose may be due to the lack of significant glucagon production among conditions. These findings suggest that T1DM individuals may exercise submaximally for 30 minutes in different ambient temperatures without significant differences in glucoregulation.