Does the extent of Cortical Myelination at the age of onset of Second Language Acquisition (Sla) affect students’ academic performance? A University of Papua New Guinea case study

@#The influence of Age of Onset (AO) of Second Language Acquisition (SLA) on learners‟ Ultimate Attainment (UA) potential is well documented. The issue of Second Language Acquisition (SLA) potential enters a qualitatively different, pragmatic dimension in most multilingual developing nations (including Papua New Guinea), where English, a second language for most children, is also the language of education, and where, consequently, students‟ English proficiency necessarily affects their academic potential and the quality of their education. This study investigates whether the academic performance of students in the School of Humanities and Social Sciences (SHSS) University of Papua New Guinea (UPNG) is affected by their linguistic backgrounds. Specifically, we examined the effect of three factors in the students‟ Early Language Education – their Age of Onset of learning English (AO), their Age at Literacy (AGELIT), and their Early Learning Language (ELL) – on their Semester 1, 2017 Grade Points Average (GPA). A purposive cross-sectional sampling method was used for the selection of students. All full-time registered students in the SHSS during the 2017 academic session were eligible to participate in the study. A self-designed pretested questionnaire consisting of nine short questions was used to collect data on SHSS students‟ language education backgrounds, including their AO, AGELIT and ELL. Our results show a strong and statistically significant inverse correlation between students‟ AO/AGELIT and their GPAs, as well as a strong positive link between ELL English and students‟ GPAs, which contrasts sharply with a significant decrease in GPAs in the presence of ELL Tok Pisin. The ELL Vernacular category was too small (sample size N=34) to yield statistically significant results. Our current results corroborate the findings of our earlier studies which established a highly significant inverse correlation between students‟ AO and their academic performance in the National High Schools, as well as in the University of Papua New Guinea.

Increased rate of positive biopsies using a combination of MR-tomography, spectroscopy and diffusion-weighted magnetic resonance imaging prior to prostate biopsies in patients with persistent elevated prostate-specific antigen values: a retrospective analysis

Persistently elevated prostate-specific antigen [PSA] values following negative biopsies result in a diagnostic dilemma. In order to improve detection rates in patients with former negative biopsies and persistently elevated PSA values, magnetic resonance tomography [MRT], magnetic resonance spectroscopy [MRS], and diffusion-weighted magnetic resonance imaging [DW-MRI] were performed prior to prostate rebiopsies. Over a 14-month period, 67 patients [mean age of 66 years] with a history of 1-5 negative biopsies underwent endorectal magnetic resonance imaging [MRI] using T2-weighted MRT MRS and DW-MRI before an additional prostate biopsy was performed. Subsequently, 5 contrast-enhanced transrectal ultrasound-guided biopsies were performed according to a 10-core systematic scheme. Out of the 67 men, 25 patients had positive biopsies and opted for radical prostatectomy. Histological evaluation of cancer localization, PSA, diameters of primary tumors, numbers and diameters of satellite tumors, prostate volume, and staging pathology was performed. These findings were compared with MRI and MRS results. Serum PSA levels ranged from 3.1 to 19.5 g/ml [median level of 7.96 ng/ml]. After the 25 patients underwent radical prostatectomy, analysis of 20 whole-mount sections of 25 radical retropubic prostatectomy [RPE] specimens presented results agreeing with the tumor location from MRI and MRS data. The aim of image-guided diagnostics should be to provide more critical information prior to biopsy. Furthermore, the acquisition of such data is important for better risk stratification in therapeutic decisions

Pharmacological applications of a novel neoepitope antibody to a modified amyloid precursor protein-derived beta-secretase product

We have previously described a novel artificial NFEV β-secretase (BACE1) cleavage site, which when introduced into the amyloid-β precursor protein (APP), significantly enhances APP cleavage by BACE1 in in vitro and cellular assays. In this study, we describe the identification and characterization of a single chain fragment of variable region (scFv), specific to the EV neo-epitope derived from BACE1 cleavage of the NFEV-containing peptide, and its conversion to IgG1. Both the scFv displayed on phage and EV-IgG1 show exquisite specificity for binding to the EV neoepitope without cross-reactivity to other NFEV containing peptides or WT-APP KMDA cleavage products. EV-IgG1 can detect as little as 0.3 nmol/L of the EV peptide. EV-IgG1 antibody was purified, conjugated with alkaline phosphatase and utilized in various biological assays. In the BACE1 enzymatic assay using NFEV substrate, a BACE1 inhibitor MRK-3 inhibited cleavage with an IC(50) of 2.4 nmol/L with excellent reproducibility. In an APP_NFEV stable SH-SY5Y cellular assay, the EC(50) for inhibition of EV-Aβ peptide secretion with MRK-3 was 236 nmol/L, consistent with values derived using an EV polyclonal antibody. In an APP_NFEV knock-in mouse model, both Aβ_EV40 and Aβ_EV42 peptides in brain homogenate showed excellent gene dosage dependence. In conclusion, the EV neoepitope specific monoclonal antibody is a novel reagent for BACE1 inhibitor discovery for both in vitro, cellular screening assays and in vivo biochemical studies. The methods described herein are generally applicable to novel synthetic substrates and enzyme targets to enable robust screening platforms for enzyme inhibitors.