Assessing How Pre-requisite Skills Affect Learning of Advanced Concepts

Students often struggle with advanced computing courses, and comparatively few studies have looked into the reasons for this. It seems that learners do not master the most basic concepts, or forget them between courses. If so, remedial practice could improve learning, but instructors rightly will not use scarce time for this without strong evidence. Based on personal observation, program tracing seems to be an important pre-requisite skill, but there is yet little research that provides evidence for this observation. To investigate this, our group will create theory-based assessments on how tracing knowledge affects learning of advanced topics, such as data structures, algorithms, and concurrency. This working group will identify relevant concepts in advanced courses, then conceptually analyze their pre-requisites and where an imagined student with some tracing difficulties would encounter barriers. The group will use this theory to create instructor-usable assessments for advanced topics that also identify issues caused by poor pre-requisite knowledge. These assessments may then be used at the start and end of advanced courses to evaluate to what extent students\u2019 difficulties with the advanced course originate from poor pre-requisite knowledge

Constructionist Attempts at Supporting the Learning of Computer Programming: A Survey

Although programming is often seen as a key element of constructionist approaches, the research on learning to program through a constructionist strategy is somewhat limited, mostly focusing on how to bring the abstract and formal nature of programming languages into \u201cconcrete\u201d, possibly tangible objects, graspable even by children with limited abstraction power. We survey the literature in programming education and analyse some programming languages designed to help novices from a constructionist perspective

Ataxia with oculomotor apraxia type 2: clinical, biological and genotype/phenotype correlation study of a cohort of 90 patients

Ataxia with oculomotor apraxia type 2 (AOA2) is an autosomal recessive disease due to mutations in the senataxin gene, causing progressive cerebellar ataxia with peripheral neuropathy, cerebellar atrophy, occasional oculomotor apraxia and elevated alpha-feto-protein (AFP) serum level. We compiled a series of 67 previously reported and 58 novel ataxic patients who underwent senataxin gene sequencing because of suspected AOA2. An AOA2 diagnosis was established for 90 patients, originating from 15 countries worldwide, and 25 new senataxin gene mutations were found. In patients with AOA2, median AFP serum level was 31.0 mu g/l at diagnosis, which was higher than the median AFP level of AOA2 negative patients: 13.8 mu g/l, P = 0.0004; itself higher than the normal level (3.4 mu g/l, range from 0.5 to 17.2 mu g/l) because elevated AFP was one of the possible selection criteria. Polyneuropathy was found in 97.5% of AOA2 patients, cerebellar atrophy in 96%, occasional oculomotor apraxia in 51%, pyramidal signs in 20.5%, head tremor in 14%, dystonia in 13.5%, strabismus in 12.3% and chorea in 9.5%. No patient was lacking both peripheral neuropathy and cerebellar atrophy. The age at onset and presence of occasional oculomotor apraxia were negatively correlated to the progression rate of the disease (P = 0.03 and P = 0.009, respectively), whereas strabismus was positively correlated to the progression rate (P = 0.03). An increased AFP level as well as cerebellar atrophy seem to be stable in the course of the disease and to occur mostly at or before the onset of the disease. One of the two patients with a normal AFP level at diagnosis had high AFP levels 4 years later, while the other had borderline levels. The probability of missing AOA2 diagnosis, in case of sequencing senataxin gene only in non-Friedreich ataxia non-ataxia-telangiectasia ataxic patients with AFP level >= 7 mu g/l, is 0.23% and the probability for a non-Friedreich ataxia non-ataxia-telangiectasia ataxic patient to be affected with AOA2 with AFP levels >= 7 mu g/l is 46%. Therefore, selection of patients with an AFP level above 7 mu g/l for senataxin gene sequencing is a good strategy for AOA2 diagnosis. Pyramidal signs and dystonia were more frequent and disease was less severe with missense mutations in the helicase domain of senataxin gene than with missense mutations out of helicase domain and deletion and nonsense mutations (P = 0.001, P = 0.008 and P = 0.01, respectively). The lack of pyramidal signs in most patients may be explained by masking due to severe motor neuropathy

Role of leukocyte cell-derived chemotaxin 2 as a biomarker in hepatocellular carcinoma

We sought to identify a secreted biomarker for β-catenin activation commonly seen in hepatocellular carcinoma (HCC). By examination of our previously published genearray of hepatocyte-specific β-catenin knockout (KO) livers, we identified secreted factors whose expression may be β-catenin-dependent. We verified expression and secretion of the leading factor in HCC cells transfected with mutated (Hep3BS33Y)-β- catenin. Serum levels of biomarker were next investigated in a mouse model of HCC with β-catenin gene (Ctnnb1) mutations and eventually in HCC patients. Leukocyte cell-derived chemotaxin-2 (LECT2) expression was decreased in KO livers. Hep3BS33Y expressed and secreted more LECT2 in media as compared to Hep3BWT. Mice developing HCC with Ctnnb1 mutations showed significantly higher serum LECT2 levels. However patients with CTNNB1 mutations showed LECT2 levels of 54.28±22.32 ng/mL (Mean ± SD; n = 8) that were insignificantly different from patients with non-neoplastic chronic liver disease (32.8±21.1 ng/mL; n = 15) or healthy volunteers (33.2±7.2 ng/mL; n = 11). Intriguingly, patients without β-catenin mutations showed significantly higher serum LECT2 levels (54.26 ± 22.25 ng/mL; n = 46). While β-catenin activation was evident in a subset of non-mutant β-catenin HCC group with high LECT2 expression, serum LECT2 was unequivocally similar between β-catenin-active and -normal group. Further analysis showed that LECT2 levels greater than 50 ng/ml diagnosed HCC in patients irrespective of β-catenin mutations with specificity of 96.1% and positive predictive value of 97.0%. Thus, LECT2 is regulated by β-catenin in HCC in both mice and men, but serum LECT2 reflects β-catenin activity only in mice. Serum LECT2 could be a potential biomarker of HCC in patients. © 2014 Okabe et al

β-Catenin Loss in Hepatocytes Promotes Hepatocellular Cancer after Diethylnitrosamine and Phenobarbital Administration to Mice

Hepatocellular Carcinoma (HCC) is the fifth most common cancer worldwide. β-Catenin, the central orchestrator of the canonical Wnt pathway and a known oncogene is paramount in HCC pathogenesis. Administration of phenobarbital (PB) containing water (0.05% w/v) as tumor promoter following initial injected intraperitoneal (IP) diethylnitrosamine (DEN) injection (5 µg/gm body weight) as a tumor inducer is commonly used model to study HCC in mice. Herein, nine fifteen-day male β-catenin knockout mice (KO) and fifteen wild-type littermate controls (WT) underwent DEN/PB treatment and were examined for hepatic tumorigenesis at eight months. Paradoxically, a significantly higher tumor burden was observed in KO (p<0.05). Tumors in KO were β-catenin and glutamine synthetase negative and HGF/Met, EGFR & IGFR signaling was unremarkable. A significant increase in PDGFRα and its ligand PDGF-CC leading to increased phosphotyrosine-720-PDGFRα was observed in tumor-bearing KO mice (p<0.05). Simultaneously, these livers displayed increased cell death, stellate cell activation, hepatic fibrosis and cell proliferation. Further, PDGF-CC significantly induced hepatoma cell proliferation especially following β-catenin suppression. Our studies also demonstrate that the utilized DEN/PB protocol in the WT C57BL/6 mice did not select for β-catenin gene mutations during hepatocarcinogenesis. Thus, DEN/PB enhanced HCC in mice lacking β-catenin in the liver may be due to their ineptness at regulating cell survival, leading to enhanced fibrosis and regeneration through PDGFRα activation. β-Catenin downregulation also made hepatoma cells more sensitive to receptor tyrosine kinases and thus may be exploited for therapeutics

How robust are value judgements of health inequality aversion? Testing for framing and cognitive effects

Background: Empirical studies have found that members of the public are inequality averse and value health gains for disadvantaged groups with poor health many times more highly than gains for better off groups. However, these studies typically use abstract scenarios that involve unrealistically large reductions in health inequality, and face-to-face survey administration. It is not known how robust these findings are to more realistic scenarios or anonymous online survey administration. Methods: This study aimed to test the robustness of questionnaire estimates of inequality aversion by comparing the following: (1) small versus unrealistically large health inequality reductions; (2) population-level versus individual-level descriptions of health inequality reductions; (3) concrete versus abstract intervention scenarios; and (4) online versus face to face mode of administration. Fifty-two members of the public participated in face-to-face discussion groups, while 83 members of the public completed an online survey. Participants were given a questionnaire instrument with different scenario descriptions for eliciting aversion to social inequality in health. Results: The median respondent was inequality averse under all scenarios. Scenarios involving small rather than unrealistically large health gains made little difference in terms of inequality aversion, as did population-level rather than individual-level scenarios. However, the proportion expressing extreme inequality aversion fell 19 percentage points when considering a specific health intervention scenario rather than an abstract scenario, and was 11-21 percentage points lower among online public respondents compared to the discussion group. Conclusions: Our study suggests that both concrete scenarios and online administration reduce the proportion expressing extreme inequality aversion but still yield median responses implying substantial health inequality aversion

Consumer perceptions of co-branding alliances: Organizational dissimilarity signals and brand fit

This study explores how consumers evaluate co-branding alliances between dissimilar partner firms. Customers are well aware that different firms are behind a co-branded product and observe the partner firms’ characteristics. Drawing on signaling theory, we assert that consumers use organizational characteristics as signals in their assessment of brand fit and for their purchasing decisions. Some organizational signals are beyond the control of the co-branding partners or at least they cannot alter them on short notice. We use a quasi-experimental design and test how co-branding partner dissimilarity affects brand fit perception. The results show that co-branding partner dissimilarity in terms of firm size, industry scope, and country-of-origin image negatively affects brand fit perception. Firm age dissimilarity does not exert significant influence. Because brand fit generally fosters a benevolent consumer attitude towards a co-branding alliance, the findings suggest that high partner dissimilarity may reduce overall co-branding alliance performance

Health care professionals' views on discussing sexual wellbeing with patients who have had a stroke: A qualitative study

OBJECTIVES: To examine the experiences of health care professionals discussing sexual wellbeing with patients who have had a stroke. DESIGN: In-depth qualitative interview study with purposive sampling and thematic analysis. PARTICIPANTS: 30 health care professionals purposively recruited to include different roles and settings along the stroke patient pathway in secondary and primary care. SETTING: Two hospitals and three general practices in the West Midlands, UK. RESULTS: Sexual wellbeing was a topic that participants did not raise with patients and was infrequently raised by patients. Barriers to raising discussion were on four levels: structural, health care professional, patient, and professional-patient interface. Barriers within these levels included: sexual wellbeing not present within hospital stroke policy; the perception that sexual wellbeing was not within participants' role; participants' concern that raising the issue could cause harm to the patient; and the views that discussion would be inappropriate with older people or unimportant to women. Resources exist to aid discussion but many participants were unaware of them, and most of those that were, did not use them routinely. CONCLUSIONS: Participants lacked motivation, ownership, and the confidence and skills to raise sexual wellbeing routinely after stroke. Similar findings have been reported in cancer care and other taboo subjects such as incontinence potentially resulting in a sub-optimal experience for patients. Normalisation of the inclusion of sensitive topics in discussions post-stroke does not seem to need significant structural intervention and simple changes such as information provision and legitimisation through consideration of the issue in standard care policies may be all that is required. The experiences recounted by professionals in this study suggest that such changes are needed now

Psychological distress as predictor of quality of life in men experiencing infertility: a cross-sectional survey

<p>Abstract</p> <p>Background</p> <p>Infertility is associated with impairment in human life. The quality of life (QOL) construct allows measuring the impact of health conditions in a broader way. The study aimed to explore the impact of the psychological distress on QOL's dimensions in men experiencing infertility.</p> <p>Methods</p> <p>162 men were completed a socio-demographic form, SF-36, WHOQOL-BREF, Beck Anxiety Inventory and Beck Depression Inventory. Hierarchical regressions included demographic and clinic variables, and subsequently depression and anxiety were added.</p> <p>Results and Discussion</p> <p>Model 1 was not accurate in predicting QOL. R²values ranged from 0.029 (Social Functioning) to 0.149 (Mental Health). Eight domains were not associated with any of the predictors. In the second model, a R²increase was observed in all domains. R²of QOL scores ranged from .209 (Role Physical) to .406 (Social Functioning). The intensity of the depression was a significant predictor for all outcomes. The load of depression was higher than the ones of the socio-demographic and clinical variables. Anxiety levels have also presented the same effect, but with less intensity.</p> <p>Conclusion</p> <p>Subthreshold depression and anxiety were major predictors of QOL in men experiencing infertility. Health professionals need to include assessment of psychological symptomatology to plan more efficient interventions to infertile patients.</p