Evaluation of a Conceptual Model of Student Retention at a Public Urban Commuter University

A new conceptual model of student retention was developed and evaluated for first-year retention and for second-year retention of students at an urban, mid-western commuter university. The model captured the joint effects of academic engagement and environmental factors on academic performance and persistence of commuter students in their first two years of college attendance. The academic engagement and environmental factors incorporated into the model included: pre-college academic achievement, Deep Learning, Study Time per Week, College Math Readiness, Major Selection, Hours of Employment, receiving (or not receiving) a Pell Grant Award and Financial Concerns. Structural equation modeling techniques were utilized to simultaneously assess the quality of the theoretical construct known as Deep Learning and to test the hypothesized causal paths linking the engagement and environmental factors to the college grades and student retention. Results indicated that when controlling for pre-college academic achievement, Deep Learning, Study Time per Week, and College Math Readiness had positive effects on First-year Grades. Working outside campus 21 or more hours per week negatively impacted First-year Grades. First-year Grades and Pell Grant Award were significantly related to First-year Retention, but Financial Concerns were found to have a negative effect on retention. When applied to second-year students, Deep Learning and Major Selection were found to have significant effects on Second-year Grades. Factors that positively influenced Second-year Retention were Grades, Major Selection and Pell Grant Award, while Financial Concerns lowered the likelihood of Second-year Retention. Based on these results I suggest that institutional efforts in engaging students in a deep learning-based curriculum, encouraging major and career exploration, and providing college-financing resources can create pathways to greater academic success and persistence among commuter students

Competition and firm performance: evidence from Vietnam

Purpose – This paper aims to examine the impact of competition on firm performance using a dataset of 352 firms listed on Vietnam's stock exchanges from 2015-2019. Design/methodology/approach – The two-step system Generalized Method of Moments is used to estimate this impact. Findings – The findings reveal an inverted U-shaped relationship between competition and firm performance. Competition improves firm performance if its intensity is moderate. However, if the competition intensity exceeds the optimal level, the performance deteriorates accordingly. Research limitations/implications – We have only studied Vietnamese firms due to our limited ability in data collection. It would be better to validate the findings using data from other transition economies. Practical implications – The non-linear relationship between competition and performance implies that government should pay more attention to retaining competition at an appropriate level. Social implications – Firms contribute a lot to the prosperity of Vietnam. Therefore, the findings have a meaningful implication for Vietnam's government to moderate competition to improve its firms' performance. Originality/value – This paper contributes to the extant literature by providing firsthand evidence of the impact of competition on firm performance in Vietnam – a transition economy

Additive biocomponents from catfish by-products enhance the growth of shrimp Litopenaeus vannamei

The rapid expansion of shrimp production requires a huge amount of protein sources from soybeans and wild-caught fishmeal; both are becoming a shortage. Meanwhile, catfish production and processing is a giant industry in Vietnam, which produce hundred thousand tonnes of protein- and lipid-rich by-products, annually. Using catfish by-products to gradually replace the traditional protein sources in shrimp aquaculture may bring triple benefits: 1) reducing pressure on wild fish exploitation for fishmeal, 2) reducing the environmental impacts of catfish by-products, and 3) increasing the value and sustainability of aquaculture production. In this study, we used catfish by-products to produce fish protein hydrolysate (FPH) and nano-hydroxyapatite (HA) as additives in feed for Pacific white shrimp (Litopenaeus vannamei). The supplement mixture of FPH and HA was added into the commercial diet (Charoen Pokphand Group [CP], 38% protein, and 6.5% lipid) to reach 38%, 38.5%, 40%, 43%, and 44% of the crude protein content. The survival and growth of shrimps were weekly assessed to day 55. The results showed that the shrimp growth was highest at 43% crude protein content in the feed as indicated by an increase of 124% and 112% in shrimp weight and length, respectively, compared to the commercial reference diet. No negative effects of adding the mixture of FPH and HA on the water quality were observed. Vibrio density was lower than 6.5 × 103 CFU/mL, which is the lowest Vibrio density negatively affecting the shrimp growth and development. These findings indicate that the mixture of FPH and HA are promising additive components in feed for post-larval shrimp L. vannamei diets

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

Multi band gap electronic structure in CH3NH3PbI3

Organo-lead halide perovskite solar cells represent a revolutionary shift in solar photovoltaics, introducing relatively soft defect containing semiconductors as materials with excellent charge collection for both electrons and holes. Although they are based on the nominally simple cubic perovskite structure, these compounds are in fact very complex. For example, in (CH3NH3)PbI3 the dynamics and ensuing structural fluctuations associated with the (CH3NH3)+ ions and the interplay with the electronic properties are still not fully understood, despite extensive study. Here, using ab-initio calculations, we show that at room and higher temperature, the rotation of CH3NH3 molecules can be viewed as effectively giving local structures that are cubic and tetragonal like from the point of view of the PbI3 framework, though in fact having lower symmetry. Both of these structures are locally polar, with sizable polarization, ~10 μC/cm2 due to the dipoles on the organic. They become energetically degenerate in the volume range, V ~ 250 Å3/f.u–265 Å3/f.u. We also find very significant dependence of the band gap on the local structure. This type of transition is analogous to a transition between two ferroelectric structures, where in-spite of strong electron phonon coupling, there is strong screening of charged defects which can lead to enhanced mobility and charge collection. The results provide insights into the enhanced light absorption near the band edge and good charge collection in this material.ASTAR (Agency for Sci., Tech. and Research, S’pore)MOE (Min. of Education, S’pore)Published versio

An adaptive model of health system organization and responses helped Vietnam to successfully halt the Covid-19 pandemic: What lessons can be learned from a resource-constrained country

Coping with the COVID-19 pandemic has been painful and no single model for such a purpose is perfect. However, sharing experiences is the best way for countries to learn real-time lessons and adapt to this rapidly changing pandemic. This commentary shares with the international community how an adaptive model of health system organization and responses helped Vietnam to break transmission of coronavirus. We find that an effective model is adaptive to time and context, and mobilizes and engages the wider society. We identify merging of different health system units into Center for Diseases Controls as a health system organization that saved massive resources. The early establishment of a formal committee responding to the pandemic helped unify every public health strategy. The mobilization of different stakeholders and communities added resources and facilitated a synchronous implementation of response strategies, even where those strategies involved significant personal or financial sacrifice. National training on Covid-19 treatment for healthcare professionals across the entire hospital system was useful to expand the health service availability. Quickly published response guidelines helped to activate every level of the health system and involve every sector of society. A strategy of keeping high alert and preemptive action is also essential for coping with the pandemic