Exploring the Problems Experienced by Learners in a MOOC Implementing Active Learning Pedagogies

Although Massive Open Online Courses (MOOCs) have been reported as an effective educational tool offering numerous opportunities in online learning, the high dropout rates and the lack of learners' motivation are factors concerning researchers and instructors. The one-size-fits-all instructional approach that most courses follow, failing to address the individual needs of learners, has been seen as their weakest point. Recent efforts focus on the inclusion of active learning pedagogies in MOOCs to stimulate the interaction among the participants and to keep them engaged. However, taking into account that in these massive contexts the learners face several issues while trying to keep up with the course, the incorporation of active learning strategies may introduce additional problems to the learning process. This study explores the problems that learners experienced in a MOOC implementing collaboration and gamification strategies. As the results reveal, the introduction of collaborative learning activities can generate additional problems to learners and for that reason, a careful design and a proper scaffolding is needed in an early stage to overcome the problems that will occur. No significant problems were reported regarding the implementation of gamification elements

Single-Atom Gating of Quantum State Superpositions

The ultimate miniaturization of electronic devices will likely require local and coherent control of single electronic wavefunctions. Wavefunctions exist within both physical real space and an abstract state space with a simple geometric interpretation: this state space--or Hilbert space--is spanned by mutually orthogonal state vectors corresponding to the quantized degrees of freedom of the real-space system. Measurement of superpositions is akin to accessing the direction of a vector in Hilbert space, determining an angle of rotation equivalent to quantum phase. Here we show that an individual atom inside a designed quantum corral can control this angle, producing arbitrary coherent superpositions of spatial quantum states. Using scanning tunnelling microscopy and nanostructures assembled atom-by-atom we demonstrate how single spins and quantum mirages can be harnessed to image the superposition of two electronic states. We also present a straightforward method to determine the atom path enacting phase rotations between any desired state vectors. A single atom thus becomes a real space handle for an abstract Hilbert space, providing a simple technique for coherent quantum state manipulation at the spatial limit of condensed matter.Comment: Published online 6 April 2008 in Nature Physics; 17 page manuscript (including 4 figures) + 3 page supplement (including 2 figures); supplementary movies available at http://mota.stanford.ed

Prevalence of genetic polymorphisms in the promoter region of the alpha-1 antitrypsin (SERPINA1) gene in chronic liver disease: a case control study

Contains fulltext : 89639.pdf (publisher's version ) (Open Access)BACKGROUND: Alpha-1 antitrypsin (A1AT) deficiency, caused by the Z allele (p.E342K) and S allele (p.E264V) in the SERPINA1 gene, can induce liver and pulmonary disease. Different mechanisms appear to be responsible for the pathogenesis of these divergent disease expressions. The c.-1973T >C polymorphism located in the SERPINA1 promoter region is found more frequent in A1AT deficiency patients with liver disease compared to patients with pulmonary disease, but data are lacking regarding contribution to the development of liver diseases caused by other aetiologies. AIM: To study the prevalence of c.-1973T >C, Z allele and S allele in a cohort of patients with liver disease of various aetiologies compared with healthy controls and to evaluate its effect on disease progression. METHODS: A total of 297 patients with liver disease from various aetiologies and 297 age and gender matched healthy controls were included. The c.-1973T >C polymorphism and Z and S alleles of the SERPINA1 gene were analyzed by real-time PCR. RESULTS: c.-1973T >C was similarly distributed between patients with liver disease of various origins and healthy controls. Furthermore, the distribution of c.-1973T >C was independent from aetiology subgroup. In patients with liver disease mean ages at of onset of liver disease were 44.4, 42.3 and 40.7 years for the c.-1973 T/T, T/C and C/C genotype respectively (NS). S allele heterozygosity was increased in patients with drug induced liver injury (DILI), (OR 4.3; 95%CI 1.1-17.2). CONCLUSION: In our study, c.-1973T >C polymorphism was not a risk factor for liver disease of various aetiologies. In addition, S allele heterozygosity might contribute to the development of DILI

Trees Wanted—Dead or Alive! Host Selection and Population Dynamics in Tree-Killing Bark Beetles

Bark beetles (Coleoptera: Curculionidae, Scolytinae) feed and breed in dead or severely weakened host trees. When their population densities are high, some species aggregate on healthy host trees so that their defences may be exhausted and the inner bark successfully colonized, killing the tree in the process. Here we investigate under what conditions participating with unrelated conspecifics in risky mass attacks on living trees is an adaptive strategy, and what this can tell us about bark beetle outbreak dynamics. We find that the outcome of individual host selection may deviate from the ideal free distribution in a way that facilitates the emergence of tree-killing (aggressive) behavior, and that any heritability on traits governing aggressiveness seems likely to exist in a state of flux or cycles consistent with variability observed in natural populations. This may have implications for how economically and ecologically important species respond to environmental changes in climate and landscape (forest) structure. The population dynamics emerging from individual behavior are complex, capable of switching between “endemic” and “epidemic” regimes spontaneously or following changes in host availability or resistance. Model predictions are compared to empirical observations, and we identify some factors determining the occurrence and self-limitation of epidemics

Ten-Year Mortality and Cardiovascular Morbidity in the Finnish Diabetes Prevention Study—Secondary Analysis of the Randomized Trial

The Finnish Diabetes Prevention Study (DPS) was a randomized controlled trial, which showed that it is possible to prevent type 2 diabetes by lifestyle changes. The aim of the present study was to examine whether the lifestyle intervention had an effect on the ten-year mortality and cardiovascular morbidity in the DPS participants originally randomized either into an intervention or control group. Furthermore, we compared these results with a population-based cohort comprising individuals of varying glucose tolerance states.Middle-aged, overweight people with IGT (n = 522) were randomized into intensive intervention (including physical activity, weight reduction and dietary counseling), or control "mini-intervention" group. Median length of the intervention period was 4 years and the mean follow-up was 10.6 years. The population-based reference study cohort included 1881 individuals (1570 with normal glucose tolerance, 183 with IGT, 59 with screen-detected type 2 diabetes, 69 with previously known type 2 diabetes) with the mean follow-up of 13.8 years. Mortality and cardiovascular morbidity data were collected from the national Hospital Discharge Register and Causes of Death Register. Among the DPS participants who consented for register linkage (n = 505), total mortality (2.2 vs. 3.8 per 1000 person years, hazard ratio HR = 0.57, 95% CI 0.21-1.58) and cardiovascular morbidity (22.9 vs. 22.0 per 1000 person years, HR = 1.04, 95% CI 0.72-1.51) did not differ significantly between the intervention and control groups. Compared with the population-based cohort with impaired glucose tolerance, adjusted HRs were 0.21 (95% CI 0.09-0.52) and 0.39 (95% CI 0.20-0.79) for total mortality, and 0.89 (95% CI 0.62-1.27) and 0.87 (0.60-1.27) for cardiovascular morbidity in the intervention and control groups of the DPS, respectively. The risk of death in DPS combined cohort was markedly lower than in FINRISK IGT cohort (adjusted HR 0.30, 95% CI 0.17-0.54), but there was no significant difference in the risk of CVD (adjusted HR 0.88, 95% CI 0.64-1.21).Lifestyle intervention among persons with IGT did not decrease cardiovascular morbidity during the first 10 years of follow-up. However, the statistical power may not be sufficient to detect small differences between the intervention and control groups. Low total mortality among participants of the DPS compared with individuals with IGT in the general population could be ascribed to a lower cardiovascular risk profile at baseline and regular follow-up.ClinicalTrials.gov NCT00518167

Isolation and fine mapping of Rps6: An intermediate host resistance gene in barley to wheat stripe rust

A plant may be considered a nonhost of a pathogen if all known genotypes of a plant species are resistant to all known isolates of a pathogen species. However, if a small number of genotypes are susceptible to some known isolates of a pathogen species this plant maybe considered an intermediate host. Barley (Hordeum vulgare) is an intermediate host for Puccinia striiformis f. sp. tritici (Pst), the causal agent of wheat stripe rust. We wanted to understand the genetic architecture underlying resistance to Pst and to determine whether any overlap exists with resistance to the host pathogen, Puccinia striiformis f. sp. hordei (Psh). We mapped Pst resistance to chromosome 7H and show that host and intermediate host resistance is genetically uncoupled. Therefore, we designate this resistance locus Rps6. We used phenotypic and genotypic selection on F2:3 families to isolate Rps6 and fine mapped the locus to a 0.1 cM region. Anchoring of the Rps6 locus to the barley physical map placed the region on two adjacent fingerprinted contigs. Efforts are now underway to sequence the minimal tiling path and to delimit the physical region harbouring Rps6. This will facilitate additional marker development and permit identification of candidate genes in the region

Alpha-1-antitrypsin phenotypes in adult liver disease patients

Alpha-1-antitrypsin (AAT) is an important serine protease inhibitor in humans. Hereditary alpha-1-antitrypsin deficiency (AATD) affects lungs and liver. Liver disease caused by AATD in paediatric patients has been previously well documented. However, the association of liver disease with alpha-1-antitrypsin gene polymorphisms in adults is less clear. Therefore, we aimed to study AAT polymorphisms in adults with liver disease. We performed a case-control study. AAT polymorphisms were investigated by isoelectric focusing in 61 patients with liver cirrhosis and 9 patients with hepatocellular carcinoma. The control group consisted of 218 healthy blood donors. A significant deviation of observed and expected frequency of AAT phenotypes from Hardy-Weinberg equilibrium (chi-square = 34.77, df 11, P = 0.000) in the patient group was caused by a higher than expected frequency of Pi ZZ homozygotes (f = 0.0143 and f = 0.0005, respectively, P = 0.000). In addition, Pi M homozygotes were more frequent in patients than in controls (63% and 46%, respectively, P = 0.025). Our study results show that Pi ZZ homozygosity in adults could be associated with severe liver disease. Presence of Pi M homozygosity could be associated with liver disease via some mechanism different from Z allele-induced liver damage through accumulation of AAT polymers

Effect of lifestyle intervention for people with diabetes or prediabetes in real-world primary care: propensity score analysis

<p>Abstract</p> <p>Background</p> <p>Many lifestyle interventions for patients with prediabetes or type 2 diabetes mellitus (T2DM) have been investigated in randomised clinical trial settings. However, the translation of these programmes into primary care seems challenging and the prevalence of T2DM is increasing. Therefore, there is an urgent need for lifestyle programmes, developed and shown to be effective in real-world primary care. We evaluated a lifestyle programme, commissioned by the Dutch government, for patients with prediabetes or type 2 diabetes in primary care.</p> <p>Methods</p> <p>We performed a retrospective comparative medical records analysis using propensity score matching. Patients with prediabetes or T2DM were selected from ten primary healthcare centres. Patients who received the lifestyle intervention (n = 186) were compared with a matched group of patients who received usual care (n = 2632). Data were extracted from the electronic primary care records. Propensity score matching was used to control for confounding by indication. Outcome measures were exercise level, BMI, HbA1c, fasting glucose, systolic and diastolic blood pressure, total cholesterol, HDL and LDL cholesterol and triglycerides and the follow-up period was one year.</p> <p>Results</p> <p>There was no significant difference at follow-up in any outcome measure between either group. The reduction at one year follow-up of HbA1c and fasting glucose was positive in the intervention group compared with controls, although not statistically significant (-0.12%, <it>P </it>= 0.07 and -0.17 mmol/l, <it>P </it>= 0.08 respectively).</p> <p>Conclusions</p> <p>The effects of the lifestyle programme in real-world primary care for patients with prediabetes or T2DM were small and not statistically significant. The attention of governments for lifestyle interventions is important, but from the available literature and the results of this study, it must be concluded that improving lifestyle in real-world primary care is still challenging.</p