THE PHENOTYPIC FLEXIBILITY OF THERMOGENIC CAPACITY: FROM PHYSIOLOGICAL MECHANISM TO EVOLUTIONARY IMPLICATIONS

Individuals face many selection pressures that change throughout their lives. Phenotypic flexibility, the ability to flexibly and reversibly modify a trait value, is one way an individual can optimally match its phenotype to the prevailing environmental conditions. In this dissertation, I used juncos as a lens to understand the causes of variation in flexibility within physiological systems and among individuals. In my first chapter, I investigated how Dark-eyed Juncos (Junco hyemalis) alter mechanisms of heat production and heat conservation to cope with variation in ambient conditions. My results demonstrate the ability of birds to adjust thermoregulatory strategies in response to thermal cues and reveal that birds may combine multiple responses to meet the specific demands of their environment. To further explore the thermoregulatory strategies available to juncos, in my second chapter, I assess their potential use of non-shivering thermogenesis. My results indicate that muscular non-shivering thermogenesis is not an important mechanism of avian thermoregulation, potentially as a consequence of a tradeoff between the many demands placed on avian muscles. In my third chapter, I measured 20 additional physiological traits to explore the mechanistic basis of flexibility in complex phenotypes. I show that the relationships among traits contributing to whole-organism performance varied with the environmental context. Moreover, whole-organism flexibility in thermogenic performance was correlated with only a handful of subordinate phenotypes. In my fourth chapter, I identified drivers of variation in flexibility among juncos. To do this, I integrated measures of population genetic variation with assays of thermogenic performance and indices of environmental heterogeneity for individuals across the genus Junco. I find that native temperature heterogeneity correlates both with population genetic variation and the degree of thermogenic flexibility exhibited by an individual. In my fifth chapter, I present a review that considers the evolutionary implications of phenotypic flexibility and contrast those with developmental plasticity. I hypothesize that because these two processes experience selection distinctly, confer stability to populations differentially, and will likely evolve at different rates. Collectively, this work helps us understand the role of flexibility in adaptation and species’ resilience to environmental change

Economics of Higher Education: Research Publications in English in Canada, 1971 to 1981

Research in the economics of education declined from the early 1970s to the end of the decade. American studies in the early 1960s had stimulated work on the contribution of education to economic growth and earnings differentials, but rapid expansion in post-secondary education led to declining relative earnings of graduates and a disillusionment with investment in higher education. In Canada, renegotiations of the Fiscal Arrangements Act in 1971-72 simply extended the 1967 provisions and dampened further interest in alternative financing arrange- ments. Topics researched in the 1970s in Canada were similar to those examined elsewhere: rates of return, institutional costs and efficiency, demand for educa- tion, income redistribution, alternative financing, manpower planning. Current work emphasizes enrolment flows. Future research should be directed to the demand for education and the relationship between education and earnings.La recherche dans le domaine de l'économie de l'éducation a subi un déclin dans les années 1970. Au début des années 60, plusieurs études américaines avaient stimulé les travaux démontrant la contribution de l'éducation à la croissance économique et aux différences de revenus, mais l'expansion rapide de l'éducation supérieure a mené au rétrécissement relatif des écarts de revenus et au désenchante-ment envers l'éducation postsecondaire comme investissement. Au Canada, les renégociations de l'arrangement fiscal entre les gouvernements fédéral et provin-ciaux conclues en 1971-72 ne firent que prolonger les ententes de 1967 et éteindre l'intérêt pour la recherche de d'autres alternatives fiscales. Les thèmes de recherche étudiés au Canada dans les années 70 furent essentiellement les mêmes que ceux examinés ailleurs: taux de rendement, coût-bénéfice, demande pour l'éducation, redistribution du revenu, alternatives de financement et main-d'oeuvre planifiée. Les thèmes courants portent principalement sur les modèles de flux et devraient dans le futur s'orienter vers la demande pour l'éducation et la relation entre le niveau de scolarité et le revenu

BOD and COD Loading Effects of Repeatedly Recycled Paper Fibers

BOD and COD are two very important and highly regulated aspects of the paper industry. The first is the biochemical oxygen demand, BOD, and it is simply the amount of oxygen that bacteria need to digest the nutrients in a wastestream. The second is the chemical oxygen demand, COD, and is the amount of oxygen required to fully oxidize all the material present in an effluent sample using hot concentrated chemicals. One aspect of recycling that has not been discerned is the effect of repeatedly recycling paper fibers on the BOD and COD of the effluent. This is important because the government, and the general public, are forcing higher and higher levels of recycle in a furnish. If a fiber exerts a higher BOD or COD as it is recycled than a virgin fiber, the resulting effluent will be naturally higher in BOD and COD. This in itself would not be very important of the EPA were not lowering the BOD and COD effluent limits as the years go by. Therefore, an effluent that may be naturally higher in BOD and COD will be regulated down to an even lower limit. This costs a significant amount of money to reach these new goals. Virgin Kraft Softwood was repeatedly recycled in a loop consisting of slurrying the pulp to a target freeness, draining the pulp on a screen and catching the effluent, testing the effluent for BOD and COD, pressing the fiber web, and drying the web. The dried fibers were· then run through the same loop. This process was completed six times. From this BOD and COD data was collected. Many problems occurred with the BOD and many of the data points were faulty. The COD fared better, and a discernible trend was observed. The BOD and COD went down as the number of recycles increased. This could be due to residual chemicals and the easy to break off fiber chunks getting washed away in the first few recycles. Many of the problems related to the DO meters. The first DO meter broke and was not able to be repaired. The second gave varied readings and was very difficult to calibrate. The last problem was contamination of starch from felt pressing pad. This caused a possible increase in the BOD and COD loading from that contaminant. Closing of the recycle loop would give a baseline reading for the BOD and COD due to keeping the chemicals and the fines in the loop. A good dependable DO meter would solve the dissolved oxygen problem

Paternalism in Academia

If a policy that is beneficial to most students nevertheless violates autonomy and harms even a minority of students in the process, then it should not be implemented. Banning laptops, requiring attendance, and other similar actions are beneficial to most students, but also violate autonomy and harm a least a minority of students to whom they are applied. Therefore, these policies, such as banning laptops and requiring attendance, should not be implemented