One of the main goals of ecological research is to understand the factors that determine how communities are structured over both space and time. However, our understanding of any system is largely a function of the scale at which we make our observations. Thus, the mechanisms that determine patterns in community structure are likely to change depending on the scale of observation. This thesis explores how environmental variability affects community structure and species performance, and how the resulting patterns change as a function of scale. Specifically, I asses the role of variability in temperature, oxygen, pH, and chloride, on species richness, abundance, diversity, and species performance, at three observational scales: micro-spatial, local temporal, and landscape-temporal scales, in 49 natural erosional rock pool microcosms, located on the northern coast of Jamaica. I found that while environmental variability was not a primary determinant of species richness or abundance, it did play a role in determining species compositions in the pools. I also show that community patterns are strongly affected by the scale of observation. Recognizing scale-dependent changes in community patterns is a prerequisite for predicting the consequences of changes in ecological systems induced by variability in abiotic factors. / Thesis / Master of Science (MS)

The aim of behavior analysis has always been to apply technologies rooted in basic behavioral principles to problems of societal importance (e.g., Skinner, 1948; 1953; 1987). One such problem is the Tragedy of the Commons - a phenomenon arising from systemic failures among a community, leading to the total collapse of a critical resource (Hardin, 1968). Elinor Ostrom's Eight Design Principles were developed to provide a framework for the self-management of common pool resources (CPRs; Ostrom, 1990/2015). When applied as an independently manipulated variable, Ostrom's design principles have shown strong effects in the management of CPRs within the context of a tabletop board game Catan® (Smith & Becker, 2023). This preparation included both rewards (i.e., positive reinforcement) and sanctions (i.e., positive punishment) as a feature of the independent variable. However, it has been well documented that punishing and coercive contingencies can lead to problematic outcomes for individuals and societies (e.g., Sidman, 2001; Skinner, 1976). This study evaluated the effects of utilizing only rewarding consequences in lieu of sanctions in an effort to produce the previously observed control over self-management of a CPR, utilizing the previously adapted rules of the Catan® board game.

Geological processes define every place on earth. They tell us their story of formation, of shaping events that have long passed and about current conditions that continue to form the place. Each place therefore reveals its historical events and points towards its future. Man manipulates these processes and often ends the dialog between the past and the future. I wanted to explore an architecture related to this dialog, that occupies a site but also enters its existence and future. Erosion is the all-encompassing term for the processes that constantly sculpt and ultimately wear down the landscape of the earth. It accompanies weathering, the break up of material at the earth`s surface through chemical, physical and biological processes. Gravity plays a vital role in these processes. It is urging all of the erosional debris downhill. Most of the material is carried by running water, transported downstream often to the world`s oceans. / Master of Architecture

Master of Architecture / This thesis explores the transformative potential of designing spaces that prioritize healing, connection, and mindfulness, especially for those with post-traumatic stress disorder (PTSD). It uses intentional design choices like natural light, wood, water, and granite to create a relaxing and grounding environment. Geometric Islamic patterns are incorporated to enhance visual appeal and provide a sense of order. By prioritizing healing, connection, and mindfulness, we can create spaces that alleviate PTSD symptoms and empower individuals on their journey towards healing and well-being.

Hyporheic water is thought to infiltrate at the head of a riffle which in turn is complemented by upwelling back to the stream at the tail of the riffle in a pool-riffle-pool (PRP) sequence. Heat tracing is a potentially useful method to characterize these hyporheic flow paths and quantify associated fluxes. Temperature was monitored within a PRP sequence for several days. Temperature in the hyporheic zone reflected the diel temperature change in the river but not uniformly. The observed thermal pattern exhibited deeper penetration of thermal oscillations below the head pool and shallower penetration below the tail pool. This pattern is consistent with the conceptual model of hyporheic exchange over a PRP sequence. One-dimensional analytical heat transport models were used at different points below the PRP sequence to estimate distributed vertical fluid fluxes. The calculated fluxes exhibit a trend that follows the expected distribution for a PRP sequence but modified for a losing stream. Deviation of both magnitude and distribution of fluxes from the conceptual ‘downwelling-to-upwelling’ model is partly due to the dominantly losing conditions at the study site but the trends are consistent with a losing stream undergoing hyporheic exchange. Violation of the assumptions in the analytical models most likely adds error to flux estimates. For this study, flux estimation methods using a temperature time series amplitude analysis more closely matched field measurements than phase methods. / text

Glutamate is the main excitatory neurotransmitter in the CNS and at the neuromuscular junctions (NMJs) of invertebrate. The characteristic similarities to CNS glutamatergic synapses in vertebrate and the anatomical simplicity of invertebrate NMJs favor the investigation of glutamatergic synaptic functions in this system. This dissertation mainly aimed to physiologically separate two functional vesicle groups, the reserve pool (RP) and readily releasable pool (RRP) within presynaptic nerve terminals of Procambarus Clarkii and Drosophila melanogaster. This was addressed in part by blocking the vesicular glutamate transporter (VGlut) with bafilomycin A1. Various frequencies of motor nerve stimulation, exposure time, and concentration of bafilomycin A1 were examined. The low-output tonic opener NMJs in crayfish exposed to 4μM bafilomycin A1 and 20Hz continuous stimulation decreased the EPSP amplitude to 50% in ∼30min with controls lasting 3h. After activity and bafilomycin A1-induced synaptic depression, the EPSPs were rapidly revitalized by serotonin (5-HT, 1μM) in the crayfish preparations. The 5-HT action can be blocked almost completely with a PLC inhibitor, but partially with a cAMP activator. The higher output synapses of the larval Drosophila NMJ when stimulated at 1Hz or 5Hz and exposed to 4μM of bafilomycin A1 showed a depression rate of 50% within ∼10min with controls lasting ∼40min. After low frequency depression and/or exposure to bafilomycin A1 a burst of higher frequency (10Hz) can recruit vesicles from the RP to the RRP. Physiological differences in low- (tonic like) and high-output (phasic like) synapses match many of the expected anatomical features of these terminals, part of this dissertation highlights physiological differences and differential modulation and/or extent of the vesicles in a RP for maintaining synaptic output during evoked depression of the RRP in crayfish abdomen extensor preparation. With the use of bafilomycin A1, the tonic terminal is fatigue resistant due to a large RRP, whereas the phasic depresses rapidly upon continuous stimulation. Upon depression of the tonic terminal, 5-HT has a large RP to act on to recruit vesicles to the RRP; whereas, the phasic terminal, 5-HT can recruit RP vesicles to the RRP prior to synaptic depression but not after depression.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Sitosterolemia (STSL) is a sterol storage disorder characterized by very high plasma plant sterol (PS) and 5α-stanol levels, and leads to premature atherosclerosis, xanthomas, macrothrombocytopenia and endocrine disruption. Ezetimibe (EZE), a sterol absorption inhibitor, reduces plasma PS levels in STSL but its effect on tissue pool of sterols has not been investigated yet. The research objectives were to assess if EZE reduces whole body sitosterol and cholesterol pool sizes, improves cholesterol homeostasis, enhance hematologic profile and reduce endocrine disruption in STSL. EZE effects on circulating levels of cholestanol and its precursors (cholesterol and bile acid derivative 7α-hydroxy-4-cholesten-3-one, 7α-H-C4) relative to exogenous stanols (sitostanol) were also studied. Eight STSL patients were taken off EZE for 14 wks. After 4 wks off EZE they received intravenous doses of D7-sitosterol and 18O-cholesterol for sterol pool sizes assessments, and oral doses of 13C-cholesterol and deuterium oxide to measure fractional cholesterol absorption and synthesis rates. EZE (10 mg/d) was resumed and stable isotopes testing repeated. Measurement parameters included isotopic sterol enrichments, blood cell count, plasma and red blood cell (RBC) PS, cholesterol and its precursor (lathosterol), 5α-stanols and plasma 7α-H-C4, and thyroid hormones levels. EZE reduced plasma levels of sitosterol and total cholesterol, whole body sitosterol and cholesterol pool sizes and fractional cholesterol absorption rate while increasing cholesterol synthesis, production and clearance rates. EZE increased platelet count and decreased platelet size without affecting RBC indices of size or mass. A substantial decrease in circulating sitostanol but moderate decrease of cholestanol was noted with EZE. EZE increased lathosterol but not 7α-H-C4, suggesting increases in cholesterol biosynthesis and thus precursor availability for synthesis of cholestanol. In summary, EZE reduces body stores of PS and cholesterol, and increases cholesterol turnover by reducing cholesterol absorption and enhancing its synthesis and clearance. EZE reduces circulating PS and 5α-stanol levels, and improves macrothrombocytopenia and thyroid disruption. Endogenous cholestanol in STSL is mainly derived from cholesterol but not bile acid synthesis pathway. These data suggest that EZE may reduce the risks of developing premature atherosclerosis, bleeding and hormone disruption, thereby reinforcing the rationale for the use of EZE in treatment of STSL. / February 2015

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

This report aims to investigate the economical possibilities of implementing mobility services, such as electrical carpool and electrical bicyclepool, in the upcoming mobility house Brandmästaren in Rosendal, Uppsala. A model based on a travel habit survey in Uppsala has been developed in order to calculate the need of vehicles. Thereafter the financial profits are calculated depending on the need of vehicles and according to different scenarios regarding how many people that potentially will join the mobility hub. The profits are then compared to the profits from a conventional parking house, in order to decide whether the mobility system is economically viable. The results concluded the following. The most suitable mobility system for Rosendal includes 104 bicycles, 36 cargo bicycles and 94 cars. For a supplement rent of 50 SEK per user connected to the mobility center, the break-even point for the business model where bicycles are rented is when 30.56% of the residents are connected to the system. For the business model where bicycles are bought the break-even point is 18.28%. A sensitivity analysis on the number of hours the service is assumed to be used showed that the profitability would not change to a significant extent. The highest break-even point after the sensitivity analysis was 34.40%. After comparison to other mobility services in Sweden, the conclusion was that the number of connected users needed was relatively low, hence the results shows that the mobility house has the potential of being more profitable than conventional parking house.