Measuring Outcome Expectations in Academic Persistence

Academic persistence, or a student’s decision to leave an institution of higher education, has remained an inveterate puzzle to researchers, theoreticians, institutions, and counselors. Despite a large body of theoretical and empirical literature, the rate at which students leave institutions of higher education has remained stable over the past 50 years. The discipline of counseling psychology has a long tradition of investigating academic persistence from a psychological perspective. Earlier investigations in counseling psychology focused on identifying psychopathological traits, cognitive abilities, and contextual factors associated with a student’s decision to leave. These investigations were met with a sociological reaction that has dominated the question of persistence for the past forty years. Though useful in describing the institution’s role in persistence, these models lack substantial empirical support and are fraught with conceptual problems. Meta-analytic studies investigating non-cognitive factors in academic persistence have revealed that social cognitive constructs namely academic self-efficacy and goals are predictive of student retention when traditional predictors are accounted for (Robbins et al., 2004). However, outcome expectations, an integral theoretical component of social cognitive theory, remain almost completely unexamined in the domain of academic persistence. This study sought to develop a theoretically derived scale to measure outcome expectations in the domain of academic persistence. An initial item pool was developed and sent to a sample of college students (N = 216). A second, confirmatory sample of undergraduate students was collected via an online crowdsourcing format known as Prolific Academic (N = 301). Results suggested the presence of a two-factor structure was the most parsimonious solution that fit the data rather than the hypothesized three-factor structure. The two factors retained across both samples anticipated rewards and punishments that students perceived about remaining in college for the year. This was contrary to Bandura’s (1977, 1997) hypothesis that outcome expectations conformed to three classes. Limitations and implications are discussed

Mechanics of periodic elastomeric structures with varying void volume fraction and thin-film coating

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008."June 2008."Includes bibliographical references (leaves 44-45).Super-elastic periodic structures possess special mechanical, photonic, phononic, and topological properties, making them particularly relevant for application at the micro and nano length scales. This study examines the behavior of such materials in two and three dimensions when void volume fraction is varied and a thin-film coating is incorporated. Computer modeling was used to predict and understand the mechanics of the transformation behavior; results showed that three-dimensional specimens behaved like their 2D counterparts and that addition of the film influenced structural transformation. Specifically, increasing volume fraction brought pattern transformation at lower values of stress and strain. Conversely, film presence postponed transformation and made it a gradual process. The film also showed considerable out-of-plane displacement and created a channel which spanned the structure. Out-of-plane motion and pattern transformation were verified experimentally by loading a 90 x 110 mm specimen to a strain of about 13% using a testing fixture. Although conducted in the macroscopic domain, experimental behavior can be expected at smaller length scales. The transformations and the surface topology alterations are reversible upon unloading, giving the ability to use deformation as a means of tuning or switching wave propagation properties that depend on periodicity, and surface properties that depend on topology.by Michael C. Kozlowski.S.B

Blue light-induced retinal damage: A brief review and a proposal for examining the hypothetical causal link between person digital device use and retinal injury

Background: There is growing concern that the increased use of personal digital devices, which emit a high proportion of their light in the blue wavelengths, may have harmful effects on the retina. Extensive historical as well as current research demonstrates that exposure to high energy visible light (blue light) can damage the retina under certain circumstances. There are, however, no studies that directly address whether blue light at the intensities emitted by digital devices can potentially cause such harm. The present review aimed to examine whether blue light exposure from computers, tablets, and cell phones can, when used habitually over a prolonged period of time, be harmful to the retinal. Methods: A search of the literature on blue light-induced retinal damage was performed using a number of scientific search engines, including BioOne Completeâ„¢, Google Scholarâ„¢, Paperityâ„¢, PubMedâ„¢, and ScienceOpenâ„¢. Studies most significant for addressing the question of possible harmful effects of blue light emitted by personal digital devices were selected from this search and reviewed. Results: The data from the selected studies were summarized and their limitations in addressing the question of whether the blue light from personal digital devices is capable of producing retinal damage were addressed. Based on these limitations, a practical experimental protocol for collecting the additional data needed was proposed. Data from pilot experiments are presented that indicate the practicality of this approach. Conclusions: The currently available data on the effects of blue light on the retina are not sufficient to refute the hypothesis that the use of personal digital devices could, over a lifetime, produce retinal damage. Additional studies, such as those proposed in this article, are needed to resolve this issue

Association of metformin use with age-related macular degeneration risk

Background: The association between metformin use and reduced age-related macular degeneration (AMD) risk has been explored. Studies have shown a positive association, no association, or ambiguous results. The aim of this narrative review is to compile these divergent findings, and thereby, better assess the potential of metformin use in reducing the AMD risk. Methods: Studies were extracted in two ways. First, a standard Google Scholar™ search was performed using the keywords “metformin” AND “macular degeneration” without language or time restrictions. The full texts of relevant articles identified in this search were retrieved and assessed, and articles of peer-reviewed original studies and meta-analyses were included. Second, the reference lists of the included articles were used to identify additional articles that satisfied the search algorithm and included in this review. Results: Of the 12 studies included in this review, eight showed a positive correlation between metformin use and a reduced AMD risk, while one showed no association. Of the eight positive studies, seven were retrospective. Apart from the design, the studies were also diverse. The number of participants in each study ranged from over 300 to 30 million person-years. The study populations included those with type 2 diabetes mellitus, those with AMD, and those without either. The study locations were the United States, Europe, and Asia. The ambiguous or negative results from four studies could largely be rationalized based on the confounding factor of study design. Conclusions: Most studies examined in this review demonstrated a positive association between metformin use and a reduced AMD risk. Studies not reporting such an association did not definitively demonstrate its absence. Overall, the studies reviewed herein support further clinical investigation of metformin as a prophylactic and potential treatment modality for AMD. Further randomized clinical trials with reasonably longer follow-up periods are necessary to determine the generalizability of the findings of studies reporting positive results

An update on RPE cell senescence as a key contributor to age-related macular degeneration: support from current and experimental treatments

Background: Age-related macular degeneration (AMD) is a major cause of vision loss. Its prevalence has increased over the past decade. This increase is partly due to the scarcity of preventive and therapeutic interventions for this disorder, except when it is in its advanced neovascular form. Discovery of effective treatments for AMD is complicated by the multifactorial pathology of the disorder. Thus, it is difficult to determine which potential disease mechanism to target in order to achieve the greatest clinical benefit. Hypothesis: Over a decade ago, it was hypothesized that many of the pathologies observed in AMD stem from retinal pigment epithelial (RPE) cell senescence. This provided a potentially key mechanistic target. Supporting this hypothesis, many of the agents that were in development or clinical use for AMD at that time influenced RPE cell senescence, although they were not utilized for this specific effect. The present article re-evaluates this hypothesis by exploring the logical prediction that if RPE cell senescence is a key contributor to AMD, then inhibition of RPE cell senescence is important in the treatment of AMD. If this hypothesis holds true, the inhibition or reversal of RPE cell senescence or its effects should be a common characteristic of new treatments for AMD. Conclusions: Over the past decade, many agents have been investigated for the treatment of AMD. Although a few were designed to address cell senescence, the majority targeted other potential pathological mechanisms. In support of our original hypothesis, we now present evidence that many of the newer agents investigated for the treatment of AMD, even those that were not meant to reduce cell senescence or its effects, have this function as part of their activity profiles. Further experimental studies or clinical trials exploring the safety and efficacy of inhibiting RPE cell senescence or reversing its effects are needed to pave the way for improved AMD treatment

Competency-based assessment for the training of PhD students and early-career scientists.

The training of PhD students and early-career scientists is largely an apprenticeship in which the trainee associates with an expert to become an independent scientist. But when is a PhD student ready to graduate, a postdoctoral scholar ready for an independent position, or an early-career scientist ready for advanced responsibilities? Research training by apprenticeship does not uniformly include a framework to assess if the trainee is equipped with the complex knowledge, skills and attitudes required to be a successful scientist in the 21st century. To address this problem, we propose competency-based assessment throughout the continuum of training to evaluate more objectively the development of PhD students and early-career scientists. © 2018, Verderame et al

Financial distress, corporate takeovers and the distress anomaly

Purpose: This paper examines the relation between takeover likelihood and the documented underperformance of distressed company stocks while exploring two competing hypotheses. The failure risk explanation predicts lower returns to distressed firms with high probability of being acquired because the acquisition reduces risk and investors\u27 required return. Conversely, the agency conflicts explanation predicts lower returns when acquisition is unlikely. Design/methodology/approach: The likelihood of receiving a takeover bid is estimated, and portfolio tests explore the underperformance of distressed company stocks relative to non-distressed stocks across varying levels of takeover likelihood. Predictive regressions subsequently examine the relation between distress, takeover exposure and future firm operating performance including how the relation is affected by state anti-takeover laws. Findings: Distressed stocks underperform non-distressed company stocks by economically and statistically significant margins when takeover likelihood is low, yet there is no evidence of underperformance among distressed stocks with moderate or high takeover exposure. Consistent with agency conflicts playing a key role, distressed firms that are disciplined by takeover threats invest more, use more leverage and experience higher future profitability. State-level anti-takeover legislation limits this disciplinary effect, however. Originality/value: The results show that the well-documented distress anomaly is driven by a subset of distressed firms whose managers face limited pressure from the external takeover market. The evidence casts doubt on the failure risk explanation and suggests that agency conflicts play a key role

Anharmonicity due to Electron-Phonon Coupling in Magnetite

We present the results of inelastic x-ray scattering for magnetite and analyze the energies and spectral widths of the phonon modes with different symmetries in a broad range of temperature 125<T<293 K. The phonon modes with X_4 and Delta_5 symmetries broaden in a nonlinear way with decreasing temperature when the Verwey transition is approached. It is found that the maxima of phonon widths occur away from high-symmetry points which indicates the incommensurate character of critical fluctuations. Strong phonon anharmonicity induced by electron-phonon coupling is discovered within ab initio calculations which take into account local Coulomb interactions at Fe ions. It (i) explains observed anomalous phonon broadening, and (ii) demonstrates that the Verwey transition is a cooperative phenomenon which involves a wide spectrum of phonons coupled to charge fluctuations condensing in the low-symmetry phase.Comment: 5 pages, 5 figures, accepted in Physical Review Letter