The study of ligand binding specificities of the lipid binding proteins : recombinant human a-tocopherol transport protein (a-ttp), supernatant protein factor (spf) and S. cerevisiae Sec 14p for vitamin e (rrr-a-tocopherol) and other hydrophobic ligands.

One of the various functions of proteins in biological systems is the transport of small molecules, for this purpose proteins have naturally evolved special mechanisms to allow both ligand binding and its subsequent release to a target site; a process fundamental to many biological processes. Transport of Vitamin E (a-tocopherol), a lipid soluble antioxidant, to membranes helps in the protection of polyunsaturated fatty acids against peroxidative damage. In this research, the ligand binding characteristics of several members of the CRALTRIO family of lipid binding proteins was examined; the recombinant human a-Tocopherol Transfer Protein (a-TIP), Supernatant Protein Factor (SPF)ffocopherol Associated Protein (TAP), Cellular Retinaldehyde Binding Protein (CRALBP) and the phosphatidylinositol transfer protein from S. cerevisiae Sec 14p. Recombinant Sec 14p was expressed and purified from E. coli for comparison of tocopherol binding to the two other recombinant proteins postulated to traffic a-tocopherol. Competitive binding assays using [3H]-a-tocopherol and Lipidex-l000 resin allowed determination of the dissociation constants ~) of the CRAL-TRIO proteins for a-tocopherol and - 20 hydrophobic ligands for evaluation of the possible biological relevance of the binding interactions observed. The KIs (nM) for RRR-a-tocopherol are: a-TIP: 25.0, Sec 14p: 373, CRALBP: 528 and SPFffAP: 615. This indicates that all proteins recognize tocopherol but not with the same affinity. Sec 14p bound its native ligand PI with a KI of381 whereas SPFffAP bound PI (216) and y-tocopherol (268) similarly in contrast to the preferential binding ofRRR-a-tocopherol by a-TIP. Efforts to adequately represent biologically active SPFff AP involved investigation of tocopherol binding for several different recombinant proteins derived from different constructs and in the presence of different potential modulators (Ca+2, Mg+2, GTP and GDP); none of these conditions enhanced or inhibited a-tocopherol binding to SPF. This work suggests that only aTTP serves as the physiological mediator of a-tocopherol, yet structural homology between proteins allows common recognition of similar ligand features. In addition, several photo-affmity analogs of a-tocopherol were evaluated for their potential utility in further elucidation of a-TTP function or identification of novel tocopherol binding proteins.

Resilience factors of university and college students with learning disabilities as revealed through retrospective interviews /

This qualitative study examined resilience factors of eight university and college students with learning disabilities as revealed through retrospective interviews. This study has added to the existing literature surrounding resilience especially as it relates to individuals with learning disabilities. This study may provide additional insight into the emotional impacts of repeated and chronic risks on students with learning disabilities. The major themes that emerged using the interpretive phenomenological analysis method (Smith & Osborn, 2003) were organized under these four major headings: Challenges and Obstacles, Surviving Challenges, Supportive Conditions, and A Journey of Discovery and Hope. An adaptation of the listening guide analytical method (Gilligan, Spencer, Weinberg, & Bertsch, 2003) was also utilized and offered a more personal depiction of the participants and an exploration of the unique contributions their stories made to this study. Specifically, a theme of feeling trapped/wanting to escape emerged as a reaction to adversity faced during elementary school years. Furthennore, this study has demonstrated that for several of the participants, the benefits of positive outlets extended beyond nurturing areas of strength and self-esteem to also include the provision of a short respite from their challenges and enhanced feelings of overall well-being. Additionally, this study may add to the existing literature surrounding character traits evident in resilient students, specifically highlighting the significance of optimism and selfacceptance.

Abrasion, transport and distribution of sediment in selected streams of Southern Ontario and Western New York /

The rate of decrease in mean sediment size and weight per square metre along a 54 km reach of the Credit River was found to depend on variations in the channel geometry. The distribution of a specific sediment size consist of: (1) a transport zone; (2) an accumulation zone; and (3) a depletion zone. These zones shift downstream in response to downcurrent decreases in stream competence. Along a .285 km man-made pond, within the Credit River study area, the sediment is also characterized by downstream shifting accumulation zones for each finer clast size. The discharge required to initiate movement of 8 cm and 6 cm blocks in Cazenovia Creek is closely approximated by Baker and Ritter's equation. Incipient motion of blocks in Twenty Mile Creek is best predicted by Yalin's relation which is more efficient in deeper flows. The transport distance of blocks in both streams depends on channel roughness and geometry. Natural abrasion and distribution of clasts may depend on the size of the surrounding sediment and variations in flow competence. The cumulative percent weight loss with distance of laboratory abraded dolostone is defined by a power function. The decrease in weight of dolostone follows a negative exponential. In the abrasion mill, chipping causes the high initial weight loss of dolostone; crushing and grinding produce most of the subsequent weight loss. Clast size was found to have little effect on the abrasion of dolostone within the diameter range considered. Increasing the speed of the mill increased the initial amount of weight loss but decreased the rate of abrasion. The abrasion mill was found to produce more weight loss than stream action. The maximum percent weight loss determined from laboratory and field abrasion data is approximately 40 percent of the weight loss observed along the Credit River. Selective sorting of sediment explains the remaining percentage, not accounted for by abrasion.

Amino acid transport : the special case of a H/L-glutamate cotransport system in Asparagus sprengeri mesophyll cells /

The addition of L-Glutamate (L-GLU) and L-Hethionine ~ulfoximine (L-HSO) to mechanically isolated. photosynthetically competent, Asparagus sprengeri mesophyll cells ~u~pended in 1mM CaS04 cau~ed an immediate transient alkalinization of the cell su~pension medium in both the light and dark. The alkalinization response was specific and stereospecific as none of the L-isomers of the other 19 protein amino acids tested or D-GLU gave this response. Uptake of 14C-L-GLU was stimulated by the light. The addition of non-radioactive L-GLU. or L-GLU analogs together with 14C-L-GLU showed that only L-GLU and L-HSO stimulated alkalinization whilst inhibiting the uptake of 14C-L-GLU. Both the L-GLU dependent alkalinization and the upt~ke of 14C-L-GLU were stimulated when the external pH was decreased from 6.5 to 5.5. Increasing external K+ concentrations inhibited the uptake of 14C-L-GLU. Fusicoccin (FC) stimulated uptake. The L-GLU dependent alkalinization re~ponse exhibited monophasic saturation kinetics while the uptake of 14C-L-GLU exhibited biphasic saturation kinetics. In addition to a saturable component. the uptake kinetics also showed a linear component of uptake. Addition of L-GLU and L-MSO caused internal acidification of the cell as measured by a change in the distribution of 14C-DMO. There was no change in K+ efflux when L-GLU was added. A H+ to L-GLUinflux stoichiometry of 3:1 wa~ mea~ured at an external I.-GLU concentration of O.5mM and increased with increasing external 13 L-QLU concentration. Metabolism of L-GLU was detected manometrlcally by observing an increase in COa evolution upon the addition of L-QLU and by detection of i*C02 evolution upon the addition of »*C-L-GLU. »*C02 evolution was higher in the dark than in the light. The data are consistent with the operation of a H+/L-QLO cotransport system. The data also show that attempts to quantify the stoichlometry of the process were complicated by the metabolism of L-GLU.

Comparison of two measures of PSI electron transport in winter rye

The number of P700 (the reaction centre of Photosystem I) converted to P700+, in winter rye, was determined by measuring the absorbance change at 820nm . It was found, with a single turnover flash, that thylakoids isolated from cold grown plants have a 50% greater number of P700 oxidized than thylakoids isolated from warm grown plants. Incubation of thylakoids in the dark at 35 C did not change the number of P700 oxidized. The conversion of P700 to P700+ with a single flash can be compared to a steady state rate of electron transport using a Clark electrode. The results for P700 oxidation using the absorbance change at 820 nm measure effects within the PSI complex whereas the results obtained from a Clark electrode measures steady state electron transport between the cytochrome blf complex and the PSI complex. In contrast to the results for P700 oxidation it was shown, using a Clark electrode, that both thylakoids from cold grown plants and thylakoids incubated at in the dark 35 C exhibited 50% higher rates of electron transport than thylakoids from warm grown plants. The correlation between the higher rate of steady state PSI electron transport observed in thylakoids isolated from cold grown winter rye and number of active PSI reaction centres localizes the site of the increase to the PSI reaction centre. In contrast the lack of correlation after incubation at 35 C indicates the increase in the rate of light saturated electron transport in thylakoids isolated from cold grown plants and thylakoids incubated in the dark at 35 C occur by different mechanisms.

Response rainbow trout (Salmon gairdneri) blood gas transport system to temperature, oxygen availability and photoperiod

Hematological status in rainbow trout, Salmo gairdneri, was examined in relation to eight combinations of three environmental fa ctors; temperature (5°, 20°C), oxygen availability «35%, >70% saturation) and photoperiod (16L:8D, 8L:16D) and evaluated by 3-factor analysis of variance. Hemog l obin and hematocrit , indicators of oxygenc arrying capacity increased significantly at the higher temperature, following exposure to hypoxia and in relation to reduced light period. Significant variations in mean corpuscular hemoglobin concentration were not detected. The effects of temperature and oxygen availability were more pronounced than that of photoperiod which was generally masked. Although oxygen availability and photoperiod did not interact with temperature, the interaction of the former fac tors was significant. Elec trophoresis revealed twelve hemoglobin isomorphs. Relative concentration changes were found in re lation to the factors c onsidered with temperature>hypoxia>photoperiod. Howeve r , in terms of absolute concentration, effects were hypoxia>temperature>photoperiod. Photoperiod effects were again masked by temperature and (or) hypoxia. Red cell +2 l eve ls of [CI ] and [Mg ], critical elements in the hemoglobin-oxygen affinity regulating system, were also significantly altered. Red cell CI +2 was influenced only by temperature ; Mg by temper ature and oxygen. No photoperiod influence on either ions was observed. Under nominal 'summer' conditions, these changes point to the likelihood of increases in oxygen-c arrying c apac ity coupled with low Hb-02 affinity adjustments which would be expected to increase oxygen delivery rates to their more rapidly metabolising tissues.

Thermoacclimatory variations in the activities of enzymes implicated in ion transport in the rainbow trout, salmo gairdneri

Two groups of rainbow trout were acclimated to 20 , 100 , and 18 o C. Plasma sodium, potassium, and chloride levels were determined for both. One group was employed in the estimation of branchial and renal (Na+-K+)-stimulated, (HC0 3-)-stimulated, and CMg++)-dependent ATPase activities, while the other was used in the measurement of carbonic anhydrase activity in the blood, gill and kidney. Assays were conducted using two incubation temperature schemes. One provided for incubation of all preparations at a common temperature of 2S oC, a value equivalent to the upper incipient lethal level for this species. In the other procedure the preparations were incubated at the appropriate acclimation temperature of the sampled fish. Trout were able to maintain plasma sodium and chloride levels essentially constant over the temperature range employed. The different incubation temperature protocols produced different levels of activity, and, in some cases, contrary trends with respect to acclimation temperature. This information was discussed in relation to previous work on gill and kidney. The standing-gradient flow hypothesis was discussed with reference to the structure of the chloride cell, known thermallyinduced changes in ion uptake, and the enzyme activities obtained in this study. Modifications of the model of gill lon uptake suggested by Maetz (1971) were proposed; high and low temperature models resulting. In short, ion transport at the gill at low temperatures appears to involve sodium and chloride 2 uptake by heteroionic exchange mechanisms working in association w.lth ca.rbonlc anhydrase. G.l ll ( Na + -K + ) -ATPase and erythrocyte carbonic anhydrase seem to provide the supplemental uptake required at higher temperatures. It appears that the kidney is prominent in ion transport at low temperatures while the gill is more important at high temperatures. 3 Linear regression analyses involving weight, plasma ion levels, and enzyme activities indicated several trends, the most significant being the interrelationship observed between plasma sodium and chloride. This, and other data obtained in the study was considered in light of the theory that a link exists between plasma sodium and chloride regulatory mechanisms.

Magnetic and transport properties of (Ba1-xKx)Fe2As2

Single crystals of (Bal - xKx)Fe2As2 were prepared using the Sn flux method. Two heating methods were used to prepare the single crystals: the slow heating and rapid heating methods. It was found that the single crystals grown using the slow heating method were not superconducting due to a significant loss of potassium. When the rapid heating method was used, the single crystals were observed to be superconducting with the desired potassium concentration. The energy dispersive X-ray spectroscopy analysis indicated the presence of multiple phases in the single crystals. Using single crystal X-ray diffraction, the crystal structure of the single crystals was found to be 14/mmm tetragonal at room temperature. The magnetic measurements on the single crystals indicated the presence of multiple phases and magnetic impurities.

Resilience in environmental educators

Contemporary environmental issues (such as global warming) can present psychological stress, the effects of which are under-examined. The ability to "bounce back" from stress associated with increasing environmental adversity can be understood as resilience, and can be found in some environmental educators. The following paper examines how veteran environmental educators respond to psychological stress to increasing environmental adversity and describes the experience of resilience. Through in-depth interviews, this hermeneutical study sheds light on the environmental factors and internal competencies that contribute to resilience in seven environmental educators. Additionally, the interaction (known as the person/environment transactional process) between these factors and competencies is explored, providing insight into how the participants construct resilience. Kumpfer's (1999) Resilience Framework provided the organizational framework for the results of this study. Findings suggest ways in which resilience in environmental educators can be supported and offers directions for future research.

Educating for Community Resilience: How the Work of Thomas Homer-Dixon and JohnDewey's Pattern of Inquiry Can Help Us Prepare for the Ecological and Social Challenges of the 21st Century

Scientists have overwhelmingly concluded that global warming occurs as a consequence of human activities and that climate change, combined with the depletion of resources, could have catastrophic consequences for the human civilization later this century. However, in political circles and in the public sphere these conclusions are not taken seriously, or they are laid aside for future generations to deal with; at the same time, significant efforts are being deployed to discredit the scientific evidence. In this thesis I have studied the positions of climate scientists as well as those of climate change deniers, and I also examined how their points of view are likely to impact the interests and habits of corporations and citizens. The work of Thomas Homer-Dixon was used as an important source for analyzing the complex interaction between our natural, economic, and social systems, and John Dewey's pattern of inquiry provided the theoretical foundation for an analysis of the current crisis and its possible solutions. No concerted action to deal with climate change has yet been taken by the leaders of the Western world; I corroborated data from four reliable sources (Hansen, 2009; IPCC, 2007; Lynas, 2007; Steffen, 2011) regarding several development scenarios and their likely consequences on greenhouse gas emissions, and I concluded that a future temperature increase of more than 2°C appears now as unavoidable. In the light of this conclusion I argue that education for increasing the resilience of smaller communities is a realistic alternative that can offer some hope in dealing with the challenges ahead.

Resilience: An Annotated Bibliography

This annotated bibliography provides an account of the research that has been done on engineering resilience, ecological resilience, and social-ecological resilience. Undertaken as part of the WEPGN research project titled “Applying resilience analysis to a transboundary river system: Developing surrogates for institutions and governance”, this annotated bibliography investigates factors that lead to greater resilience, with a focus on institutions and governance. Citations for key scholarly publications related to three types of resilience – engineering, ecological, and social-ecological – are listed in the first three sections along with a brief summary of each work. The fourth and final section of the document provides additional resources on resilience.

Mindfulness Practices and Children’s Emotional and Mental Well-Being: Activities to Build and Strengthen Everyday Resilience Adapted for Primary School Teachers

This project reviewed current research on mental health and Canadian children, and then examined the practice of mindfulness as a means of supporting well-being and circumventing the potential detrimental effects of mental health problems. By contextualizing these findings within the recently released educational vision of the Ontario Ministry of Education (2014), which identifies well-being as one of the core principles of education in Ontario, this project investigated how mindfulness-based practices can be brought into the primary grade classroom. The ultimate purpose of this project is the development of a handbook for Ontario teachers of students in grades 1 to 3 (ages 6 to 8). This resource was developed from a comprehensive literature review and provides educators with easy-to-follow activities to use in the classroom to encourage the development of resilience and emotional well-being through mindfulness. The handbook also includes additional information and resources regarding both mindfulness and mental health that may be helpful to teachers, students, and parents.

Assessment of Stress During Handling and Transport

The article focuses on assessing the stress levels of animals when transported and handled. The paper was presented at a symposium titled Effects of Stress in Farm Animals at the American Society of Animal Science 87th annual meeting, July 1995.

The Welfare of pigs during Transport and Slaughter

The article researches "electric stunning, carbon dioxide stunning, pig behaviour during handling, return to sensibility, facility design, truck loading, density and transport stress".

Resilience in a Watershed Governance Context: A Primer

Watersheds are complex systems involving social, economic, and ecological dimensions that are constantly interacting and influencing each other, and governance of these systems involve a large and diverse cast of actors that add to the complexity and difficulty in deciding what is best for the watershed and people. Resilience thinking offers a way to understand and navigate the uncertainty, dynamics and complexity of watershed governance. This primer describes key ideas associated with resilience: more inclusive participation; building a shared understanding; inclusion of ecosystem services and functions in long-term planning; strong leadership; institutional and decision making flexibility; and, a decentralized system. This primer is an initial effort to translate the scholarly understanding of these key ideas and initiate a dialogue about their application in the context of watershed governance.