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Which memory representation creates the violation of encoding specificity?
Get PDFPast research has shown that object identification performance differs when people learn to recognize objects by sight or by touch, such that the representation of haptically presented objects seems to be richer than the representation of visually presented objects, resulting in a violation of encoding specificity. However, these studies were conducted using simple objects that were easy to describe verbally. In the present study, I used objects that were not easy to describe verbally. I examined how mental representations differ between simple shape objects and multi-feature objects, and whether they differ when individuals learn to recognize novel objects by sight or by touch. I planned to first conduct an online matching task to evaluate the effectiveness of specific distractors. In Experiment 2, participants would be asked to learn to recognize novel objects by sight or by touch, then to identify them using both modalities. One third of participants would experience the control condition, 1/3 would have completed a verbal distractor task, and 1/3 would have completed a visuospatial distractor task. It was expected that the multi-feature objects would be more difficult to learn than the simple shape set, and that a tapping distractor would restore encoding specificity in individuals learning to recognize novel objects by touch, since these participants make use of visuospatial cues during encoding. Additionally, this distractor was expected to interfere more with learning the multi-feature objects than the simple shape set. Due to unexpected circumstances, testing was not possible. In sum, the type of memory representations that we develop depend on our experiences with the world
Cloning, expression, purification, and characterization of novel initiating enzyme in Pseudo-nitzschia pungens dimethylsulfoniopropionate biosynthesis pathway
Get PDFDimethylsulfoniopropionate (DMSP) is a tertiary sulfonium compound synthesized by marine bacteria, algae, and some higher plants. This secondary metabolite functions as an osmolyte, a herbivore deterrent, an antioxidant, and a cryoprotectant. In algae, the biosynthesis of DMSP is catalyzed by a four-enzyme pathway, which begins with the conversion of methionine to methylthio-2-oxobutyrate. While it is known that Ulva macroalgae species requires a 2-oxoglutarate:methionine aminotransferase for the first step in the DMSP pathway, little research has been performed on other alga species. Genome searches by Dr. Waller identified an enzyme in diatom species of Pseudo-nitzschia, termed MetDA here, which based on strong genetic associations with known DMSP enzymes is believed to be a novel initiating enzyme for the DMSP pathway. Cloning the MetDA gene into three vectors was attempted. Two constructs of the recombinant MetDA protein were successfully expressed in E. coli cells and purified using affinity column chromatography. A 2,4-dinitrophenylhydrazine assay was developed to characterize the deamination activity of MetDA. A perhaps promising result shows MetDA acts as a methionine deaminase with a NAD+ prosthetic group with an activity rate of 18.3 pmol per min per μg protein, which is in a similar range of other DMSP enzymes. This newly discovered enzyme gives metabolic engineers another option for genetic engineering of plants or bacteria to enhance their osmotic and oxidative stress tolerance
Finding a path from idealized epistemology to our non-ideal epistemological landscape
Get PDFBefore you is one path that I have found to lead us from an idealized epistemology back to our current non-ideal epistemological landscape. I have chosen the metaphor of a path to point out that our theoretical paths are constantly changing and being made and remade by the people who walk them. Just as the path made by one lone traveler can disappear quickly, paths that are used by many can stay entrenched in our collective imagination without any other reason than that they are clear, and they have been widely used. The path that I have found is not new, and I am most certainly not the first to walk it; there are many footprints throughout it made by figures like Ludwig Wittgenstein, Stanley Cavell, Linda Martín Alcoff, José Medina, Kristie Dotson, Charles Mills and many more. With this being said, as we metaphorically walk along this path, what I want you to notice is how slippery it is at the beginning and how progressively we find our footing by the end
Does chronic hypoxia cause an increased reliance on lipid metabolism in freshwater fish?
Get PDFAquatic hypoxic zones around the world are increasing primarily due to eutrophication and climate change. The severity and duration of hypoxic exposures is also increasing, leading to major challenges for aquatic organisms. These organisms must find ways to survive these conditions, and many rely on a reduction in energy demands or metabolic reorganization. During an acute hypoxic exposure, there is a switch from aerobic ATP production to anaerobic glycolysis, which relies on adequate glycogen stores. We do know that glycogen stores can become depleted following chronic hypoxia, therefore, these organisms must rely on an alternative source of fuel. These may be lipids, amino acids, or ketone bodies, but it is currently unclear which is being used. There have been few studies on the potential use of lipids as a fuel source as there is evidence to suggest they are mobilized during chronic hypoxia. To understand if lipids are being used during chronic hypoxia, brook trout, a hypoxia sensitive species, were exposed to acute (24 hours) and chronic (9 days) hypoxia. Following the treatment, we examined the levels of glycogen in heart, liver, and muscle tissue and found it to be decreased in muscle and liver tissues. Seeing these declines in glycogen stores suggests that another fuel is being used. We examined plasma triglycerides and found decreases in the plasma suggesting that they are being taken up by the tissues or lipids are being circulated in another form during hypoxia. Finally, we examined lipid ß-oxidation in the tissues and found it to be increased in the liver where glycogen stores had been depleted. The results show some evidence for the use of lipids as an energy source during chronic hypoxia
Examining burnout and job satisfaction in a university context: Does self-compassion matter?
Get PDFGiven that one-third of our adult lives are spent at work (Statistics Canada, 2011), being satisfied with one’s job has a profound impact on both institutions and individuals.
Research highlights that stress and burnout (i.e., emotional exhaustion) are robust predictors of decreased job satisfaction. The purpose of the present study was to
examine the role of self-compassion with these constructs. In the present study, 102 university personnel ranging in age from 23 to 65 years (M = 45.66, SD = 11.68)
completed an online survey to indicate their degree of stress, burnout, job satisfaction, and self-compassion. Using multiple regression analyses, I first replicated past research
and showed that increased stress was related to lower job satisfaction, in part because of its relationship with burnout. Building on past research, results also showed that selfcompassion was associated with low stress which, in turn, was associated with lower burnout. Although self-compassion was not directly related to job satisfaction, the
results highlight the need for researchers to examine the role of self-compassion in populations beyond the healthcare sector. In addition to replicating the present findings,
future research should use a longitudinal approach, potentially involving selfcompassion interventions, to further support the relationships uncovered here
To blink or not to blink? The potential for recovery in performance through the attentional boost effect
Get PDFThe purpose of this study was to investigate whether a common attentional deficit, the attentional blink effect, could be reduced through the use of auditory signals to cue the reorienting of attention. In Experiment 1, participants completed a two-target attentional blink task, half of whom heard an auditory tone presented simultaneously with the second of the two target words, whereas the other half did not. The participants had difficulty recalling the second of the two targets, and the presentation of the tone did not reduce this deficit. In Experiment 2, all participants heard tones presented simultaneously with the second target, but half of these participants had the additional task of providing a verbal response when they heard a rare tone frequency. In this case, the additional task of responding to some of the tones did not have the re-orienting effect as expected. Instead, the additional task caused more difficulty recalling the two target words. These findings are evidence of the limitations of the attentional system. overwhelming the attentional system with too many tasks leads to deficits in attention that then has an adverse impact on memory
Differences in use of Northumberland Strait habitat and fattening rates among migratory shorebird species
Get PDFMigratory shorebirds rely on stopover sites to rebuild fat stores during migration. The habitat used within each stopover site, and the strategies used to build fat, can vary between species and stopover. In the Canadian Maritimes, the Bay of Fundy has been the focus of migratory shorebird research given the large population of shorebirds it supports. Though less used, other sites on the New Brunswick and Nova Scotia coast, including the Northumberland Strait, also host a diverse shorebird assemblage. A variety of shorebird species use the mudflats, sandflats, and saltmarshes along the Northumberland Strait coast during their fall migration. It is unknown whether species in this region are using the available habitat on a mudflat-by-mudflat basis in this region, and how much fat they are building. We predicted that due to the different pressures associated with long- and short-distance migrations, short-distance migrant species will adhere to a slowly fattening, short stay, many movement strategy, while long-distance migrant species will build fat quickly over a longer period of time with few movements. We investigated duration of stay, habitat use and plasma metabolites of Least Sandpipers (Calidris minutilla Vieillot), Semipalmated Sandpipers (Calidris pusilla L.), White-rumped Sandpipers (Calidris fuscicollis Vieillot), and Semipalmated Plovers (Charadrius semipalmatus Bonaparte) to characterize their use of the Northumberland Strait, and to compare said use between species. Usage of habitat and length of stay were determined through radio telemetry, and plasma metabolites were investigated by measuring plasma triglyceride and B-hydroxybutyrate concentrations. Least Sandpipers had the lowest plasma triglyceride and highest B-hydroxybutyrate concentrations suggesting that they were fattening the slowest. Semipalmated Sandpipers and Semipalmated Plovers both had high triglyceride and low B-hydroxybutyrate, while White-rumped Sandpipers occupied an intermediate position with low triglyceride and B-hydroxybutyrate. All sandpiper species in this study had similar mean minimum stopover durations, between 14-19 days, while the plovers stay for up to a week longer. The species also exhibited differences in the habitat they used. Semipalmated Sandpipers ranged more widely than did the other species, though there was a universal preference for habitat nearest to our catching site. These findings provide evidence that shorebirds using the Northumberland Strait are not adhering to the predictions associated with expected stopover behaviour in short- and long-distance migrants. Instead, each species is using unique and variable strategies to build fat stores during their stopover. We also highlight the need for continued research of multiple species stopover strategies and the use of the Northumberland Strait as migratory shorebird habitat as limited movements between sites suggest region wide protection may be needed to conserve shorebirds
Murdochian moral privacy
Get PDFMuch 20th century philosophy in the analytic tradition can be characterized by a lack of concern for understanding moral claims. In the looming context of a world war, demonstrating that the
human species is not necessarily progressing towards being more ethical, the rise of logical positivism meant that ethics were no longer considered to be an important part of philosophical
discourse. As a result, moral discussions were dismissed as nonsense. Four female philosophers in particular—Iris Murdoch, Mary Midgley, Philippa Foot, and Elizabeth Anscombe—
understood the dangers of this philosophical climate and shared a concern for objective, moral meaning. They wanted to respond to the loss of ethical concepts they experienced and they each argued (in their own way) that ethical statements can be grounded and objective. As Midgley writes in her memoir:
In varying ways, we all attacked what may be crudely called the boo-hurray view of
ethics—more politely, the idea that facts are split off from values by a logical gap that
makes it impossible to think rationally at all about moral topics. […] ‘Values’ were
treated as a kind of arbitrary opinions [sic], and it was widely held—not only by analytic
philosophers—that, since all people are entitled to their own opinions, argument about
them made no sense.2
Murdoch was particularly concerned about the loss of ethical concepts in understanding one’s own moral stance, and much of her philosophical work focuses on developing or strengthening
our accounts of the moral person. Her work can be characterized as a search for a moral vocabulary that supports the ethical standard of living that she thinks is necessary to live a good
life. In the aftermath of logical positivism, along with the ever-diminishing depth and social importance of the concept of God, Murdoch was searching for a language and collection of ideas that could support her moral convictions.3 Murdoch (and many others) could no longer turn to religious or theological language as a foundational discourse for ethics. In addition to this, the
fact-value distinction that pervades much of analytic philosophy removes value from the sphere of things that can be empirically or objectively known. Here too, ethics loses its grounding in
reality and is left to be a matter of preference. Hence, Murdoch’s work is a search for a new vocabulary, set of concepts, or framework for understanding the world that can ground ethical
ideas.
Cardiac taurine deficiency impairs physiological performance and mitochondrial function in brook trout (Salvelinus fontinalis)
Get PDFTaurine is a nonessential amino acid abundant in skeletal and cardiac muscle tissues. Taurine plays a critical role in many physiological processes, such as osmoregulation, cardioprotection, and oxidative stress mediation. Studies in other animal models have shown that taurine deficiency is associated with the progression of cardiovascular and mitochondrial diseases, as well as interruptions in energy metabolism. This study evaluated the effects of taurine on the physiological performance and mitochondrial function in brook trout, Salvelinus fontinalis. Dietary supplementation of -alanine, a competitive inhibitor of the taurine transporter, was administered over a minimum time frame of four weeks to decrease intracellular taurine concentrations. Two treatment groups were used in this study, a group of fish fed a control diet and a taurine-deficient (TD) group fed the same diet infused with 5% -alanine. The physiological impacts of taurine deficiency were assessed through evaluating the critical thermal maximum (CTmax) and tolerance to acute hypoxia through time-to-loss of equilibrium (LOE) tests. CTmax was evaluated by increasing tank water temperature at a set ramp rate until fish could no longer maintain equilibrium. CTmax was found to be significantly higher in (p=0.017), while tolerance to acute hypoxia was observed to be significantly lower (p=0.015) in TD trout than in the control group. FluoRespirometry evaluated mitochondrial efficiency at different points along the electron transport chain. Increased mitochondrial leak rates were observed in TD trout, indicating a greater degree of proton leak into the intermembrane space (p=0.0056). Activities of mitochondrial complexes I and II were not affected by TD. The average respiratory control ratio (RCR) of the TD trout was significantly decreased in comparison to the control group, indicating that a greater portion of oxygen consumption in TD mitochondria is not coupled with ADP phosphorylation and is instead dissipated as heat energy (p=0.0051). Respirometry also revealed that maximum oxygen consumption of complex IV of the electron transport chain was significantly decreased by TD (p=0.0216). Expression of complex IV protein COX3 was significantly downregulated in TD cardiac muscle tissue, indicating potential defects in protein synthesis correlated with TD (p=0.007). Our findings provide further insight into the roles of taurine, and pathology of taurine deficiency in the cardiovascular system of fish. This understanding can enable us to further gauge the effects of environmental fluctuations on this species
Factors influencing pharmacy technicians' perceptions and choice of work setting
Get PDFIn recent years, hospital pharmacies have struggled to fill vacant technician positions. The current study investigated factors influencing pharmacy technician students’ perceptions and choice of work setting via a mixed-methods design. Surveys were administered to pharmacy technician students across Canada (N = 221, M = 28.56 years, SD = 8.52) and one focus group was conducted with six hospital pharmacy technicians working with the Horizon Health Network. Analysis of the survey found that group differences in program year, knowledge about hospital pharmacy, and expected hospital job satisfaction emerged between students pursuing community and hospital pharmacy. However, logistic regressions failed to yield a significant model. Thematic analysis of the focus groups identified four major themes organized in temporal (past, present and future) order: (a) Education, (b) Intrinsic Job Factors, (c) Extrinsic Job Factors and (d) Transitions. Overall, the results suggest that there are actionable factors hospitals and educators alike can capitalize on to increase recruitment and retention of hospital pharmacy technicians