Social Selling: An Examination of Strategic Efforts through Salesperson Activities and Their Networks

Kemp, April Field University of South Alabama ProQuest Dissertations 2020 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Information communications technology (ICT) resources, such as social networking sites and blogs, give salespeople access to increased information as well as the ability to connect and engage with current and potential customers. This interaction through social communities on ICT sites is often referred to as social selling. To date, there are limited studies examining the comprehensive nature of social selling. This study was the first to empirically test a framework including the intersection of ICT, self-efficacy, and social capital as part of strategic social selling. This mixed methods study drew on existing literature based on the technology acceptance model to expand the role ICT usage plays in helping salespeople achieve higher performance through increased confidence (self-efficacy) and the importance of their connections (social capital). This study advances the sales literature in understanding the role many levels play in a social selling strategy including the individual salesperson, the sales organization, and their connections. To this end, this study concludes with several recommendations for future social selling research.

Characterization of the in vitro Cellular Effects of Dihydroxyacetone

Smith, Kelly R University of South Alabama ProQuest Dissertations 2020 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Dihydroxyacetone is a small molecule, a simple achiral triose, which acts as the active ingredient in over-the-counter sunless tanning products (STPs) where it undergoes random, non-enzymatic interaction with amines in the upper layer of the skin. These glycation reactions result in a “browning” that is similar in appearance to the tanning effect generated in skin exposed to ultraviolet (UV) radiation, either from sunlight or from UV lamps used in indoor tanning. DHA may also arise as a by-product of the heating of the liquids used in e-cigarettes. Little is known about the effects of DHA in consumer use. In 1977, the FDA approved DHA use as a topical agent in STPs (at concentrations of up to 20%, with the typical value being approximately 5%), but has warned against inhalation which occurs in the use of e-cigarettes and when applied as an aerosolized STP in increasingly popular “spray tanning.”The carbohydrate nature of DHA means it can be incorporated into metabolic pathways and produce unwanted metabolites that induce DNA damage and protein damage. We hypothesize that exogenous DHA exposure alters 3-carbon metabolism via an increase in dihydroxyacetone phosphate, which results in destabilization of the cell’s redox state, disrupted glycolysis, and mitochondrial dysfunction. Evaluation of these effects is the focus of our work here.Using two cell line models, A375P (melanoma) and HEK293T (kidney), we have assessed cytotoxicity, genotoxicity, and examined changes in metabolic function. For both cell lines, we found cell death was induced at low millimolar doses (IC90 between 5–7 mM). Given the 5% (approximately 277 mM) concentration of DHA in STPs, our dosing regimens are very relevant to exposures encountered by users of these common products.We also observed cell cycle arrest, increases in reactive oxygen species, and metabolic changes in the two cell lines, supporting our overarching hypothesis. Interestingly, we saw differences in metabolism, reactive species generation, and cell death between the cell lines. A375P cells showed increased oxidative stress, rapid cell cycle arrest (within 24 hours), altered mitochondrial membrane potential, and cell death induced by apoptosis. The HEK293T cells showed no oxidative stress, delayed cell cycle arrest (72 hours), compromised mitochondrial function, loss of ATP and lactate production, and cell death induced by autophagy.This work in two different cell line models demonstrated that low millimolar, consumer-relevant doses of DHA are cytotoxic, genotoxic, and promote metabolic dysfunction. Metabolic incorporation of exogenous DHA into the three different cell lines appeared to differ, evidenced by altered ATP and mitochondrial functions, and likely drives the altered cell arrest and cell death pathways observed. Together these data support our hypothesis and suggest that DHA exposure through spray tanning and e-cigarette use require further evaluation to understand the health hazards they pose to consumers.

The duplicitous effects of fostering workplace social courage: How personal moral identity mitigates desire to perform unethical "courageous" actions

Holmes, Philip E University of South Alabama ProQuest Dissertations 2020 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Faculty Perceptions of the Impact of Active Classroom Design on Student Engagement, Attitudes toward Learning, and Preparation for Class

Peterson, Karen Whiddon University of South Alabama ProQuest Dissertations 2020 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Peterson, Karen Whiddon. PhD. University of South Alabama, May 2020. Faculty Perceptions of the Impact of Active Classroom Design on Student Engagement, Attitudes Toward Learning, and Preparation for Class. Chair of Committee: R. Burke Johnson, PhD. Institutions of higher learning are investing in renovation of existing classrooms as well as constructing new classrooms in order to use new technology and pedagogical approaches like team-based and problem-based learning. Active learning classrooms and collaborative learning spaces are the latest trend in higher education learning design. The purpose of this study was to determine faculty perceptions of physical classroom layout (traditional, scale-up, and flexible) on student engagement, attitudes toward learning, and preparation for class. College and University faculty from 32 states across the United States and four other countries including Australia, the United Kingdom, Singapore, and Canada were surveyed that allowed respondents to answer using a five-point scale. The primary hypothesis was that active classroom design (scale-up and flexibility design) would have a positive impact on faculty perceptions of student engagement, attitudes toward learning, and preparation for class. Statistical results showed faculty respondents believed that the active classroom design positively impacted student engagement, attitudes toward learning, and preparation. The scale-up and flexible classroom designs showed statistically significant higher means than the traditional classroom design in all measures except student eye contact. These findings indicate that the participants perceived the active classroom design (scale up and flexible designs) as having the greatest impact (compared to traditional classroom design) on measures of student success. The qualitative results supported this general finding and identified many benefits of active classroom design.

Extracellular Vesicles as Mediators of the Adaptive Survival Response to Hypoxia in Pancreatic Cancer Cells

Patton, Mary Catherine University of South Alabama ProQuest Dissertations 2020 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Pancreatic cancer is a highly lethal malignancy and molecular mechanisms underlying its pathobiology are not yet well understood. Pancreatic tumors are characterized by a poor vasculature and fibrous stromal tissue network that creates an extensively hypoxic tumor microenvironment (TME). This unique histopathology requires that tumor cells develop adaptive mechanisms to sustain their growth under extremely hypoxic TME. Extracellular vesicles (EV) are released by all eukaryotic cell types and play important roles in normal physiology and disease pathobiology including that of pancreatic cancer. EV carry active biomaterial within them and transfer it from the donor to recipient cells to exert biological consequences. EV are broadly classified into three subtypes that differ in size distribution and marker profiles suggestive of their distinctive biogenesis. Small EV (SEV; 20 – 150 nm) mostly contain exosomes (Exos) originating through endosomal pathway. Medium-sized EV (MEV; 150 nm – 1 µm) are enriched for microvesicles (MVs) originating by pinching off of the plasma membrane. Large EV (LEV; 1 - 3 µm) are usually apoptotic bodies (ABs) derived from fragmentation of the dying cells. In our studies, we tested the hypotheses that hypoxic stress affects the release kinetics, size distribution and marker profiles of EV in pancreatic cancer cells, and EV play important roles in adaptive hypoxic survival of pancreatic cancer cells via transfer of active biomaterial from the cells that had been subjected to hypoxia. Our data demonstrate that under hypoxic conditions, pancreatic cancer cells (MiaPaCa-2 and AsPC-1) shed greater amount of EV with most noticeable changes recorded for the SEV. Moreover, all EV show a shift towards reduced size depending upon the extent of hypoxia. We also observe all size-based sub-fractions have a mixed profile of expression of subtype-specific markers. Thrombospondin-1 and ARF6 are exclusively detected in large and moderate size fractions, respectively, under both normoxia and hypoxia. However, CD9 is detected in both small and moderate size EV under hypoxia and CD63 is detected in all EV under both normoxia and hypoxia. Furthermore, in release kinetics study, we observe increases in accumulation of EV subtypes under hypoxic condition. In addition, our data demonstrate that EV from the hypoxic cancer cells promote survival of cancer cells under hypoxia and SEV is the most active sub-fraction. We also find that SEV from hypoxic pancreatic cancer cells confer alterations in tumor cell glucose metabolism and ROS accumulation. The data demonstrate hypoxic SEV treatment significantly reduces ROS accumulation and enhances glucose uptake and lactate production in pancreatic cancer cells under severe hypoxia as compared to that provided by normoxic SEV treatment. Mechanistically, we demonstrate that the enhanced release and survival-enhancing potency of SEV is dependent on HIF-1α stabilization. Further, EV analysis identifies differential presence of transcripts of key genes associated with glycolytic metabolism and oxidative stress neutralization suggesting a lateral transfer of biological information. Altogether, our findings establish that hypoxia alters the shedding of EV to support adaptive survival of pancreatic cancer cells, and associated differences could possibly be exploited for effective cancer management.

The relation of self-report pain scales to neuropsychological performance

Boettcher, Anneliese C University of South Alabama ProQuest Dissertations 2016 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Chronic pain constitutes a lifelong condition for numerous patients and presents a costly public health issue. The aim of this dissertation study was to examine the relation of self-report pain scales to neuropsychological test performance. Using exploratory factor analysis, two latent factor(s) of pain were identified: "pain distress" and "pain dysfunction." Using structural equation modeling, both factors were confirmed and examined in relation to an overall latent factor of cognition ("g"). Greater perceived pain distress and pain dysfunction significantly predicted worse cognition and accounted for 12% of the variance in g. History of sexual abuse moderated the path from pain distress to g, but not the path from pain dysfunction to g. After controlling for effort, the model was found to have slightly (not significantly), better fit. Word Memory Test (WMT) Delayed Recall and Consistency percent correct were found to significantly confound the relationship between pain distress and cognition. Greater perceived pain distress no longer significantly predicted worse cognition while greater perceived dysfunction still significantly predicted worse g. The model now accounted for nearly 50% of the variance seen in g. Multivariate analysis of variance was used to identify whether failure of a performance validity test resulted in reported symptoms of pain falling above established cutoffs. Results revealed a significant effect of type of WMT performance on the combined dependent variable of pain ratings. Separate examination of the dependent variables revealed that WMT performance groups significantly differed in their Pain Catastrophizing Scale scores, but not in other pain scales. Overall, this dissertation study found that latent factors of chronic pain, history of sexual abuse, and poor effort impact cognitive functioning. These findings have numerous implications for patients, the medical community, and resources allocated to provide support to individuals with chronic pain following surgical intervention. The more attempts made to understand exactly how these factors are affecting cognition and exactly who is being affected will only further help to bring the most appropriate aid and services to patients who are suffering from chronic pain.

The morphometric analysis of pulmonary arterial remodeling in relation to branching patterns in pulmonary hypertension

Oshima, Kaori University of South Alabama ProQuest Dissertations 2016 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

In the lung, it is generally assumed that the branching of pulmonary arteries parallels the airway branches, in such a way that they are mirror images. The typical branching pattern of pulmonary arteries is dichotomous, with 60-degree branching angles and gradual decreases in diameters, which promotes efficient blood flow. Curiously, pulmonary arteries have additional supernumerary branches without accompanying airway branches. Supernumerary arteries are characterized by acute, 90-degree branching angles and very small diameters. These structures appear to be under perfused, yet they are more numerous than conventional arteries in human lungs. There is evidence that hemodynamic stress plays a critical role in vascular remodeling in pulmonary hypertension. In severe pulmonary hypertension, extensive and irreversible remodeling comprising neointimal lesions contributes to the increase in pulmonary arterial resistance and pressure. These obstructive lesions exacerbate the hemodynamic stress and perpetuate a vicious cycle of remodeling and hypertension. Given these anatomical and structural differences between conventional and supernumerary arteries, which influence the hemodynamic stresses that these arteries experience, the hypothesis tested in this project was that the morphological changes are different in supernumerary and conventional arteries in moderate and severe pulmonary hypertension. Histological sections of normal and hypertensive rat lungs were examined and morphological changes were described. In chronic hypoxia-induced moderate pulmonary hypertension, which only develops medial and adventitial thickening without neointimal occlusions, supernumerary arteries did not develop wall thickening. Severe pulmonary hypertension, induced with a combination of the VEGFR blocker, Sugen 5416, and chronic hypoxia, causes a wide spectrum of arterial remodeling, including neointimal lesions. The supernumerary arteries in this model were more susceptible to pathological changes, with a majority (81%) of vessels occluded or closed, while only 42% of the conventional branches were occluded. Both types of arteries had various types of vascular remodeling, but supernumerary arteries exclusively had two types: aneurysm-type plexiform lesions with complex and disorganized appearance, and total lumenal closure. Our data suggest that intimal cells in supernumerary arteries are more proliferative than those in parent arteries, which may contribute to the genesis of occlusive lesions. The important implications are: (1) hemodynamic stress is critically involved in vascular remodeling in both moderate and severe pulmonary hypertension and may influence the morphology of occlusive lesions, and (2) occlusion of supernumerary arteries likely contributes to the development of severe pulmonary hypertension, considering their frequency and high percentage of occluded branches, as well as their potential function as collateral pathways. Furthermore, our data in moderate non-occlusive pulmonary hypertension that showed lack of wall thickening in supernumerary arteries highlights the importance of recognizing supernumerary arteries in histological evaluation, because of the possible misidentification of supernumerary arteries as pulmonary veins by pathologists.