METABOLIC DIVERSITY AMONG FIBROBLASTS FROM REGENERATING AND NON-REGENERATING MAMMALS

Regeneration is a wound repair process that terminates in the restoration of tissue function and structure. Fibroblasts play pivotal roles in regenerative and fibrotic wound repair. Reports of extensive regenerative ability in mammals have been historically rare, but more recently spiny mice (Acomys) have emerged as a bona fide model of complex tissue regeneration. Recent work has indicated that fibroblasts from regenerators (Acomys and Oryctolagus) are more resistant to reactive oxygen species (ROS)-induced senescence compared to non-regenerating species, suggesting the influence of intrinsic cellular states on the fate of wound repair. Determining the basal metabolic signature of fibroblasts in the wound microenvironment, which experiences drastic changes in pH, cytokine bursts, hypoxia, damage associated molecular patterns (DAMPs), ROS bursts, as well as an innate and adaptive immune response, is key to understanding the dichotomy in wound repair outcomes between regenerating and non-regenerating species. I made use of fibroblasts isolated from the ear pinna of sexually mature spiny mice (Acomys cahirinus) and laboratory mice (Mus musculus), since extensive tissue repair had been reported in the former and not in the latter. I hypothesized that the underlying metabolic signatures between the two species would differ significantly with respect to glycolytic flux: oxidative phosphorylation (OxPHOS) rate ratios, with Mus exhibiting higher OxPHOS flux and Acomys being comparably glycolytic. In this study we show that under basal conditions in vitro, fibroblasts from Acomys possess a glycolytic bias compared to fibroblasts from Mus. In response to chronic glucose starvation, Acomys fibroblasts show no significant changes in glycolytic or OxPHOS rates, whereas Mus fibroblasts respond with significant increases in glycolytic and OxPHOS rates under similar conditions. In a bid to determine if glutamine metabolism played a pivotal role in maintaining this metabolic state in Acomys, we observed that treatment with BPTES (a glutamine metabolism inhibitor) caused mostly insignificant reductions in OxPHOS and glycolytic flux rates in both species, while DMSO exposure caused Acomys fibroblasts to switch their metabolic signature in response to glucose starvation, to one identical to Mus

A study of parent-child separation in Accra

Aspects of family welfare and plannin

Listening to the voices of women living with HIV/AIDS: A qualitative study of psychosocial impact and quality of life issues

In spite of the increasing number of women infected with HIV around the world, little is known about the psychosocial experiences of these women. In the mid-1990s, medical advances dramatically altered the experiences of living with HIV/AIDS. The shifting medical climate raised new social and psychological questions such as coping strategies and the possibility of gaining access to resources and services in the community. In this qualitative study, I examined how 5 women living with HIV/AIDS in Southern Ontario deal with their daily psychosocial needs and challenges. Based on a life history methodology, responses of participants were coded and analyzed in relation to the ecological framework of community psychology. The thematic analysis indicated that despite the existing medical, governmental, and community support provided in a Canadian context for women living with HIV/AIDS participants nevertheless faced numerous daily challenges. Psychosocial challenges that were identified included: stigma and social exclusion fear of death, suicidal ideation, as well as lack of adequate or appropriate support from healthcare professionals and psychologists. In addition participants also noted frequent experiences of loneliness, housing problems, poverty and unemployment as part of their every day challenges. Although the women reported adequate levels of support, it was also noted that there is an urgent need for various directions for enhanced services for HIV/AIDS women. The findings of the study are discussed in relation to the development of holistic, psychosocial strategies to address the daily needs and challenges of women living with HIV/AIDS. Findings have conceptual and methodological implications for future psychosocial research on the quality of life issues on women living with HIV/AIDS

The gut microbiota and its relationship with obese children

Background: It’s decelerated that childhood obesity is a global epidemic since 21st century. General obesity has doubled since 1980 and comes with a distinct increase of mobility and mortality. Obesity also correlate with future consequences in form of different diseases such as metabolic syndrome, cancer and increased risk of chronic diseases and not to mention the increased cost for the society. The condition is undoubtable multifactored and the precise mechanism behind are still incomplete. Previous studies have suggested an indirect pathogenicity of methanogens, favouring other microbes’ growth and in that way correlate in obesity. In this work the aim was to further investigate this possible correlation by analysing levels of methanogens in obsese and lean children. The analysis was made directly in faecal samples and after incubation of feaces in a nutrient solution. The hypothesis was that a small but important difference in methanogenic levels between lean and obese children exist but might be too low to be statistically proven and that an incubation allowing growth of the methanogens would ease the detection and result in a stronger signal. Methods: The participants in the study was assigned to lean- or obese group depending on S-BMI, a total of 29 participants. Faecal samples and anthropometrical data were collected from the two groups. Levels of methanogens in feaces, non-incubated and after 48h anaerobic incubation in a nutrient solution, was determined by quantitative PCR targeting the 16S-ribosomal RNA. Methanogen groups included in the analysis was Methanobacteriales (MBT), Methanosaetaceae (MST), Methanosarcinaceae (MSC) and Methanomicrobiales (MMB). Results and conclusion: The results showed a general low abundance of methanogen quantification in the different groups, except for the MBT group. The abundance of MSC, MMB and MST were at the point for detection, making the results quite uncertain. MBT however, were well detected and specific for its selected primers. Furthermore, a correlation between BMI and MBT was significantly lower in the obese group compared to the lean group in the non-incubated samples, and an even greater significance was seen in the incubated samples. The incubation aspect is unique for this study and according to hypothesis highlighted a significant correlation between levels of MBT and BMI. Further studies are needed to understand the importance of methanogens and their activity on effects of diet and obesity in childhood.Mag-tarmkanalens mående speglar ofta människans hälsa i stort. Koppling mellan tarmflorans komposition och övervikt har i djur- och humana studier visat sig ha en korrelation och forskning pågår just nu avsevärt för att försöka kartlägga sjukdomssamband, maghälsa och tarmflorans inflytande i människans liv. Övervikt är något som ökar runt om i värden och har lett till ett folkhälsoproblem. I denna studie undersöks specifikt övervikt i ung ålder då detta leder till en markant ökad risk för övervikt även i vuxen ålder. Detta indirekt ökar risken till följdsjukdomar som till exempel kroniska tillstånd och metabola syndromet (övervikt och diabetes). Det metalbolasyndromet har bland annat visat sig öka risken för hjärtinfarkt fem gånger jämfört med normalindividen, varför övervikt i unga år är av stor vikt att bekämpa. Övervikt och vem som drabbas har flera orsaker och kartläggningen till dessa mekanismer är fortfarande inte helt klart. Som tidigare nämnt fokuseras mycket forskning inom området på kopplingen mellan övervikt och tarmfloras sammansättning och aktivitet, där bland annat metanogener, olika bakterier samt kortkedjade fettsyror (mikrobiella nedbrytningsprodukter) visat sig ha en korrelation till övervikt. Metanogener producerar metan ifrån väte som frigörs tillsammans med kortkedjade fettsyrorna när olika bakterier fermenterar (bryter ner) kolhydrater. I två tidigare associerade studier gjorda på samma deltagare fann man en ökad nivå av propionat i överviktiga jämfört med normalviktiga barn men ingen tydlig koppling till sammansättningen av olika bakterier. I denna studie kompletteras dessa studier men en analys av metanogener, för att undersöka dessa mikroorganismers potentiella korrelation till övervikt hos barn. Insamling av material i from av avföringsprover och kroppsmätningar ifrån deltagarna samlades in. Där det olika metanogena grupperna sedan mättes i avföringsproverna. En av de metanogena grupperna, som fanns i högst nivå, undersöktes också efter det att mikroorganismerna i avföringsproverna fått växa till sig i en i näringslösning, detta för att få ett mått på individuell potentiell tillväxt av metanogener och för att tydligare kunna identifiera eventuella kopplingar mellan dessa, nivåer och fettsyror och övervikt. Resultaten visade en signifikant skillnad i nivåerna av en specifik metanogen grupp, Methanobacteriales (MBT) hos överviktiga jämfört med normalviktiga barn, men en lägre nivå in de förra. En positiv korrelation fanns också mellan nivåerna av fettsyror och samma metanogen. Denna studie var unik då den studerade tarmflorans sammansättning efter tillväxt i näringslösning, som visade sig ge en större åtskillnad mellan den överviktiga och normalviktiga gruppen. Dock krävs det mer forskning för att slutgiltigt bevisa att halten av metanogener är en riskfaktor för övervikt

College Students’ Persistence and Degree Completion In Science, Technology, Engineering, and Mathematics (STEM): The Role Of Non-Cognitive Attributes Of Self-Efficacy, Outcome Expectations, And Interest

The lack of students’ persistence (or student’s effort to continue their academic studies until degree completion) in Science, Technology, Engineering, and Mathematics (STEM) and the attrition of STEM students as well as the shortage of STEM workers have gathered much attention from policy makers, governmental agencies, higher education researchers and administrators in recent years. As a result, much research efforts have been directed towards identifying factors causing the leaks in the STEM pipeline and finding effectively antidotes to patch the leakage points along the pipe. In the past, most studies in the STEM disciplines have focused on individual cognitive capacities (or academic predictors) such as precollege performance indicators (e.g., high school GPA) and standardized achievement test scores (e.g., SAT and ACT) to explain the leading factors contributing to the high attrition rate among STEM college students. Yet these studies just address mainly one aspect of the key reasons why students failed to persist. We still lack evidence, both empirically and theoretically, on how “non-cognitive skills”—which are essential individual characteristics vital for success in any schooling, work, and other life-time outcomes— may influence STEM major persistence. Absent from most of the scholarly discussions are the many ways in which psychosocial factors (such as grit, tenacity, optimism, self-efficacy, perseverance, motivation, self-discipline, teamwork, reliability) influence the decision-making processes of students’ persistence. Rather than focusing on the traditional cognitive ability and academic achievement measures of academic preparation this study focused on psychosocial factors that influence the decision-making processes of students’ persistence and degree completion. The purpose of the study is to examine the extent to which non-cognitive factors (i.e., self-efficacy, outcome expectation, and interest) contribute to undergraduate students’ persistence and college degree completion in STEM with particular attention to students enrolled in 4-year colleges and universities in the United States. The analytical sample for this study was drawn from the Educational Longitudinal Study (ELS:2002-2012) dataset with the final sample used for analysis representing the 2002 cohort of 10th graders who declared STEM major in college by 2006 and participated in the final wave of ELS in 2012. As such, the result was reflective of this group of students, and not all STEM students in college in general. Result of the study revealed three general findings about the three noncognitive factors. First, students with strong interest in pursuing a STEM major, a high sense of self-efficacy, and a mid to high level of outcome expectations are more likely to persist and complete their college degree in their declared major in STEM field. Students who reported that they had no interest in pursuing a STEM major yet declared a STEM major in their postsecondary education, and who have moderate to high self-efficacy and high outcome expectations are more likely to switch to a non-STEM major and persist to complete a degree in a non-STEM field. Thirdly, irrespective of whether the student was interested in pursuing STEM, a student with low self-efficacy and low outcome expectations was more likely to not attain any degree or credential

A Spatial Assessment of the GO bg Transit Services in Bowling Green, Kentucky

The decision to live in a particular place, accept a job at a distant location, where to go shopping or purchase groceries, and many other similar decisions are all largely influenced by the availability of transportation. As such, it is important that everyone who requires transportation can have access. However, certain population segments, such as low income earners, are less likely to own cars due to the cost involved. There are others who may be impaired physically or have other difficulties that may prevent them from driving. Access to transportation is essential for people of all backgrounds and social statuses. Public transportation is therefore put in place by some cities to enhance the mobility and accessibility of commuters. This study assesses the services of the GO bg public transit service in Bowling Green, Kentucky, to determine how well its services meet the transportation needs of some population sub-groups in the city. A number of Geographic Information Systems (GIS) techniques, including service area analysis, intersect, areal proportion, and demand mapping, were employed in assessing the existing transit routes and stops, and the extent to which certain demographic groups, such as African Americans, Hispanics, seniors aged 65 and older, and low-income households, were served. The study also used spatial proximity to determine accessibility options from transit stops for transit riders. In this study, accessibility was determined based on the available destinations of some basic consumer necessities in the study area such as health, education, shopping, and recreation. The results of this study suggest that the GO bg transit service on the whole has a reasonable level of coverage, particularly within five-minute and seven-minute walking distances. It also provides acceptable accessibility to major activity centers such as health centers, higher educational institutions, grocery stores, and other places of basic needs, and most of these centers are within five-minute walking distance from the current bus stops. Findings from this study should help the management of public transit services in the study area and improve the provision of transit services to meet the transportation needs of vulnerable members of the community, such as transit dependent individuals. In addition, it could also contribute to the rather limited literature on studies of public transportation in small U.S. cities

Partnership or Neo-Colonialism? : the Role of the south in global resource governance

This thesis is about using nuclear magnetic resonance (NMR) spectroscopy for studying soft materials. Soft materials may be encountered everyday by most readers of this thesis, for example when taking a shower or watching TV. The usefulness of these materials originates from them being soft yet, at the same time, having some kind of a structure. The characteristic length scale of those structures is often on the order of nanometers (10-9 m) and the structure can respond to various external stimuli such as temperature, electric and magnetic fields, or the presence of interfaces. NMR spectroscopy excels when studying soft materials because it is a non-invasive technique with a large spectral resolution. Moreover, different NMR methods allow us to study local molecular dynamics or longer-range translational diffusion. Understanding those latter aspects is very important for the development of dynamic and responsive materials. Papers I-III present our work on assessing molecular adsorption on interfaces in colloidal dispersions. Here, carbon nanotubes (CNTs) or silica particles were the colloidal substrates to which proteins, polymers or surfactants adsorbed. Papers IV-VI concern ionic mobility in liquid crystals (LCs). The influence of material structure on, for example, the anisotropy of diffusion or on the association/dissociation of ions was studied in several LC phases.QC 2011022

College Students’ Persistence and Degree Completion In Science, Technology, Engineering, and Mathematics (STEM): The Role Of Non-Cognitive Attributes Of Self-Efficacy, Outcome Expectations, And Interest

The lack of students’ persistence (or student’s effort to continue their academic studies until degree completion) in Science, Technology, Engineering, and Mathematics (STEM) and the attrition of STEM students as well as the shortage of STEM workers have gathered much attention from policy makers, governmental agencies, higher education researchers and administrators in recent years. As a result, much research efforts have been directed towards identifying factors causing the leaks in the STEM pipeline and finding effectively antidotes to patch the leakage points along the pipe. In the past, most studies in the STEM disciplines have focused on individual cognitive capacities (or academic predictors) such as precollege performance indicators (e.g., high school GPA) and standardized achievement test scores (e.g., SAT and ACT) to explain the leading factors contributing to the high attrition rate among STEM college students. Yet these studies just address mainly one aspect of the key reasons why students failed to persist. We still lack evidence, both empirically and theoretically, on how “non-cognitive skills”—which are essential individual characteristics vital for success in any schooling, work, and other life-time outcomes— may influence STEM major persistence. Absent from most of the scholarly discussions are the many ways in which psychosocial factors (such as grit, tenacity, optimism, self-efficacy, perseverance, motivation, self-discipline, teamwork, reliability) influence the decision-making processes of students’ persistence. Rather than focusing on the traditional cognitive ability and academic achievement measures of academic preparation this study focused on psychosocial factors that influence the decision-making processes of students’ persistence and degree completion. The purpose of the study is to examine the extent to which non-cognitive factors (i.e., self-efficacy, outcome expectation, and interest) contribute to undergraduate students’ persistence and college degree completion in STEM with particular attention to students enrolled in 4-year colleges and universities in the United States. The analytical sample for this study was drawn from the Educational Longitudinal Study (ELS:2002-2012) dataset with the final sample used for analysis representing the 2002 cohort of 10th graders who declared STEM major in college by 2006 and participated in the final wave of ELS in 2012. As such, the result was reflective of this group of students, and not all STEM students in college in general. Result of the study revealed three general findings about the three noncognitive factors. First, students with strong interest in pursuing a STEM major, a high sense of self-efficacy, and a mid to high level of outcome expectations are more likely to persist and complete their college degree in their declared major in STEM field. Students who reported that they had no interest in pursuing a STEM major yet declared a STEM major in their postsecondary education, and who have moderate to high self-efficacy and high outcome expectations are more likely to switch to a non-STEM major and persist to complete a degree in a non-STEM field. Thirdly, irrespective of whether the student was interested in pursuing STEM, a student with low self-efficacy and low outcome expectations was more likely to not attain any degree or credential

Formation of Electrostatic Complexes within Admixtures of Lentil Protein Isolates and Anionic Polysaccharides (κ-Carrageenan, De-acyl Gellan Gum and Gum Arabic)

Proteins from plant sources are generally less soluble and have poorer functionality compared to animal proteins. The overall goal of this thesis was to better understand mechanisms associated with the formation of electrostatic complexes involving mixed systems of lentil protein isolates (LPI) and three different anionic polysaccharides (gum Arabic (GA), κ-carrageenan (κ-CG) and de-acyl gellan gum (GG)). A better understanding of mixed systems should lead to the development of formulated ingredients for targeted applications. Findings also may lead to enhanced utilization of lentil proteins as food and/or biomaterial ingredients with improved functionality over the protein alone. Maximum complexation occurred in the 1:1 LPI:GA mixed system (total biopolymer concentration (Cp) = 0.05%, w/w) at pH 3.50 with complexation following two pH-dependent structure forming events associated with the formation of soluble (pHc) and insoluble (pH1) complexes at pH 5.87 and 3.62, respectively. The addition of GA resulted in a shift of the LPI isoelectric point (pH 4.70) to a lower pH (3.17). The addition of sodium chloride (NaCl) disrupted coacervation, whereas the addition of urea caused a drop in the magnitude of the observed maximum optical density (O.D.). Increasing the temperature to 60°C resulted in a shift in turbidity curves towards more acidic pH and a decrease in maximum O.D. relative to the control (21-23°C). The addition of GG or κ-CG to LPI resulted in a suppression of LPI aggregation by electrostatic repulsion with a shift in net neutrality of the formed complexes to a lower pH (4.36) compared to LPI alone (pH 4.70) as measured by electrophoretic mobility of a 15:1 LPI:GG/κ-CG mixed system (Cp = 0.05%, w/w). The addition of salts resulted in disruption of formed LPI:GG/κ-CG complexes, and no polysaccharide-ion specific sensitivities were evident (i.e., Ca2+ to GG or K+ to κ-CG). Complexation was primarily driven by electrostatic attractive forces with secondary stabilization by hydrogen bonding. Hydrophobic interactions were thought to play a role in the stabilization of LPI-LPI aggregates. Removal of the lentil hull had a minor effect on complexation. Initial interactions occurred slightly above the pI of the LPI where biopolymers carried net negative charges with polysaccharide chains interacting with positive patches on the protein’s surface