Insights from coherence in students' scientific reasoning skills.

Improving scientific reasoning enables students to navigate the challenges of learning science. Teachers use Lawson's classroom test of scientific reasoning (LCTSR) to measure scientific reasoning. The LCTSR is a two-tiered assessment that uses content-based questions and explanation statements.

Impaired Knowledge of Social Norms in Dementia and Psychiatric Disorders: Validation of the Social Norms Questionnaire-Dutch Version (SNQ-NL).

The Social Norms Questionnaire-Dutch version (SNQ-NL) measures the ability to understand and identify social boundaries. We examined the psychometric characteristics of the SNQ-NL and its ability to differentiate between patients with behavioral variant frontotemporal dementia (bvFTD; = 23), Alzheimer's dementia (AD; = 26), chronic psychiatric disorders ( = 27), and control participants ( = 92). Between-group differences in the Total score, Break errors, and Overadhere errors were examined and associations with demographic variables and other cognitive functions were explored.

High human papillomavirus (HPV) prevalence in South African adolescents and young women encourages expanded HPV vaccination campaigns.

The objectives of the study were to investigate prevalence of cervical human papillomavirus (HPV) genotypes to inform HPV vaccination strategy in South Africa and to study factors associated with HPV prevalence. Sexually active, HIV-negative women, aged 16-22 years recruited from Soweto (n = 143) and Cape Town (n = 148) were tested for cervical HPV and other genital infections. Overall HPV prevalence was 66.

Comparison of sampling methods to measure HIV RNA viral load in female genital tract secretions.

Problem: How does menstrual cup (MC) compare to other genital sampling methods for HIV RNA recovery?

Method Of Study: We compared HIV RNA levels between MC, endocervical swab (ECS), and ECS-enriched cervicovaginal lavage (eCVL) specimens in 51 HIV-positive, antiretroviral therapy-naive women at enrollment, 3 and 6 months, with order rotated by visit. Paired comparisons were analyzed with McNemar's exact tests, signed-rank tests, and an extension of Somer's D for pooled analyses across visits.

Results: MC specimens had the highest proportion of quantifiable HIV VL at enrollment and month 3, but more MC specimens (n=12.

Comparing high-throughput methods to measure NK cell-mediated antibody dependent cellular cytotoxicity during HIV-infection.

HIV-specific binding antibody responses, including those mediating antibody-dependent cellular cytotoxicity (ADCC), provided the best functional correlate of lower risk of infection in the RV144 HIV-1 vaccine clinical trial. The aim of this study was to compare two high-throughput flow cytometry based methods to measure HIV-specific ADCC responses, the GranToxilux and PanToxilux assays. Plasma from nine HIV-1 seropositive individuals was screened for binding antibody titres against HIV-1 subtype C gp120 by ELISA and western blot.

Female genital tract inflammation, HIV co-infection and persistent mucosal Human Papillomavirus (HPV) infections.

Background: Persistent genital infections with high-risk HPV types increase risk of cervical disease and cancer. Since genital inflammation increases HIV acquisition risk and cancer progression, we evaluated whether HPV infection induces cytokine expression in the reproductive tract.

Methods: Genital cytokines concentrations were measured in 93 HIV-infected and 72 uninfected women.

Altered phenotype and function of NK cells infiltrating human papillomavirus (HPV)-associated genital warts during HIV infection.

HIV-infected individuals experience more persistent HPV infections and are less likely to resolve genital warts. This study compared phenotype and functions of NK and T cells from genital warts and blood from 67 women. We compared in vitro functional responses of NK and T cells by multiparametric flow cytometry.

Phosphorylation of PRAS40 on Thr246 by PKB/AKT facilitates efficient phosphorylation of Ser183 by mTORC1.

Type 2 diabetes is associated with alterations in protein kinase B (PKB/Akt) and mammalian target of rapamycin complex 1 (mTORC1) signalling. The proline-rich Akt substrate of 40-kDa (PRAS40) is a component of mTORC1, which has a regulatory function at the intersection of the PKB/Akt and mTORC1 signalling pathway. Phosphorylation of PRAS40-Thr246 by PKB/Akt, and PRAS40-Ser183 and PRAS40-Ser221 by mTORC1 results in dissociation from mTORC1, and its binding to 14-3-3 proteins.

AO-classification of thoracic and lumbar fractures--reproducibility utilizing radiographs and clinical information.

This study was designed to assess the inter-observer reliability and intra-observer reproducibility of standard radiographic evaluation of 150 thoraco-lumbar fractures using the AO-classification. The influence of clinical information on agreement levels was also evaluated. Six observers (two junior and four senior residents) evaluated the radiographic images.

Effects of a prudent diet containing either lean beef and mutton or fish and skinless chicken on the plasma lipoproteins and fatty acid composition of triacylglycerol and cholesteryl ester of hypercholesterolemic subjects.

In this two-phase crossover study, 39 hypercholesterolemic subjects followed a prudent diet with either lean red meat or fish and skinless chicken (treatment groups), and 13 subjects (reference group) followed their habitual diet. Fasting blood samples were analyzed for plasma total cholesterol, triacylglycerol (TAG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein one- and two-cholesterol, apolipoprotein-B, very low density lipoprotein cholesterol, and very low density lipoprotein TAG, and fatty acid composition of plasma TAG and cholesteryl ester (CE). Body mass and blood pressure were determined.

Solution structure of the 162 residue C-terminal domain of human elongation factor 1Bgamma.

The multisubunit elongation factor 1 (eEF1) is required for the elongation step of eukaryotic protein synthesis. The eEF1 complex consists of four subunits: eEF1A, a G-protein that shuttles aminoacylated tRNAs to the ribosome; eEF1Balpha and eEF1Bbeta, two guanine nucleotide exchange factors, and eEF1Bgamma. Although its exact function remains unknown, this latter subunit is present in all eukaryotes.

Lipoprotein(a) determination and risk of cardiovascular disease in South African patients with familial hypercholesterolaemia.

Objective: A raised plasma level of lipoprotein(a) (Lp(a)) is an established genetic risk factor for coronary heart disease (CHD), particularly in patients with concomitant elevation of low-density lipoprotein (LDL) cholesterol. The current study focused on the comparison of two commercially available Lp(a) assay kits to determine whether differences observed in measured Lp(a) levels could be deemed negligible in CHD risk assessment in familial hypercholesterolaemic (FH) patients.

Design: To compare results obtained on duplicate plasma samples using two commercially available Lp(a) measuring kits, the immunoradiometric assay (RIA) and the enzyme-linked immunoabsorbent assay (ELISA).

The solution structure of the guanine nucleotide exchange domain of human elongation factor 1beta reveals a striking resemblance to that of EF-Ts from Escherichia coli.

Background: In eukaryotic protein synthesis, the multi-subunit elongation factor 1 (EF-1) plays an important role in ensuring the fidelity and regulating the rate of translation. EF-1alpha, which transports the aminoacyl tRNA to the ribosome, is a member of the G-protein superfamily. EF-1beta regulates the activity of EF-1alpha by catalyzing the exchange of GDP for GTP and thereby regenerating the active form of EF-1alpha.

Endemic goitre in the absence of iodine deficiency in schoolchildren of the Northern Cape Province of South Africa.

Objective: The study was undertaken to investigate whether endemic goitre still exists in the Northern Cape Province of South Africa more than 55 years after it was reported and, if so, whether iodine deficiency, or fluoride in the drinking water, is linked to the goitres.

Design: Cross-sectional study of children in three pairs of towns.

Subjects: The 6-, 12- and 15-year-old children (n = 671) who had been lifetime residents in two Northern Cape towns with low levels, two towns with near optimal levels and two towns with high levels of fluoride in the drinking water were recruited through the schools as study participants.

Expression, purification, and spectroscopic studies of the guanine nucleotide exchange domain of human elongation factor, EF-1beta.

Two guanine nucleotide exchange domains, corresponding to the C-terminal region of the human translational elongation factor EF-1beta (which consists of 225 amino acids), were produced by DNA recombinant overexpression techniques in Escherichia coli. We describe here a fast and efficient method for purifying these two protein fragments and for concentrating their solutions rapidly to a level as high as 25 mg/ml. This technique permitted the isolation of 20-30 mg of pure, native protein per liter of bacterial culture.

Nutritional status of rural children in the Lesotho Highlands.

A baseline cross-sectional study was done to evaluate the nutritional status of the population of the Mohale Dam catchment area before construction of the dam commenced. In this article we report on the anthropometric, clinical and dietary assessment of the children less than 15 years of age in the study population. A two stage stratified sampling technique was used to randomly select 29 of the 83 villages in the study area.

Iodine deficiency and endemic goitre in the Langkloof area of South Africa.

Objective: To quantify the prevalence of iodine deficiency and endemic goitre in the Langkloof area.

Design: A cross-sectional study.

Setting: Four primary schools in four communities in the Langkloof.

The subunit structure of elongation factor 1 from Artemia. Why two alpha-chains in this complex?

Elongation factor 1 (EF-1) regulates the specific interaction of aminoacyl-tRNA with the ribosome during the elongation phase of protein biosynthesis. Although individual functions of its separate chains have been well defined, to date there is hardly information about the structure and function of the whole complex. We describe here the complete subunit structure of elongation factor 1, and discuss its change during development of Artemia.

Phenotypic variation among familial hypercholesterolemics heterozygous for either one of two Afrikaner founder LDL receptor mutations.

Two common founder-related gene mutations that affect the low-density lipoprotein receptor (LDLR) are responsible for approximately 80% of familial hypercholesterolemia (FH) in South African Afrikaners. The FH Afrikaner-1 (FH1) mutation (Asp206-->Glu) in exon 4 results in defective receptors with approximately 20% of normal activity, whereas the FH Afrikaner-2 (FH2) mutation (Val408-->Met) in exon 9 completely abolishes LDLR activity (< 2% normal activity). We analyzed the contribution of these mutations and other factors on the variation of hypercholesterolemia and clinical features in Afrikaner FH heterozygotes.

Dietary patterns and nutritional status in free-living older white men with established vascular disease.

Thirty-nine white men aged 51-84 years with established vascular disease were studied to investigate the effect of fish oil capsules on the regression of these lesions. This article deals with the baseline data of the study. The subjects completed a 7-day dietary record, weight and height were measured and a fasting blood sample was analysed for proteins, haematological values and certain vitamins.

DNA screening of hyperlipidemic Afrikaners for familial hypercholesterolemia.

Three different point mutations of the low-density lipoprotein receptor (LDLR) gene are responsible for familial hypercholesterolemia (FH) in about 90% of Afrikaner patients. Screening of hyperlipidemic Afrikaner individuals for these founder-related mutations was performed to determine the distribution of the mutations in individuals with different lipid profiles, and to provide guidelines for screening of the mutations in hyperlipidemics. Rapid DNA methods, based on restriction enzyme analysis or allele-specific hybridisation of enzymatically-amplified genomic DNA, have been used to analyse the LDLR gene mutations in four groups of Afrikaner individuals.