Can Collaborative Knowledge Building Promote Both Scientific Processes and Science Achievement?

This study investigated the role of collective knowledge building in promoting scientific inquiry and achievements among Hong Kong high-school chemistry students. The participants included 34 Grade 10 (15-16 years old) students who engaged in collective inquiry and progressive discourse, using Knowledge Forum@, a computer-supported learning environment. A comparison class of 35 students also participated in the study. The instructional design, premised on knowledge-building principles including epistemic agency, improvable ideas and community knowledge, consisted of several components: developing a collaborative classroom culture, engaging in problem-centered inquiry, deepening the knowledge-building discourse, and aligning assessment with collective learning. Quantitative findings show that the students in the knowledge-building classroom outperformed the comparison students in scientific understanding with sustained effects in public examination. Analyses of knowledge-building dynamics indicate that the students showed deeper engagement and inquiry over time. Students’ collaboration and inquiry on Knowledge Forum significantly predicted their scientific understanding, over and above the effects of their prior science achievement. Qualitative analyses suggest how student’s knowledge-creation discourse, involving explanatory inquiry, constructive use of information and theory revision,can scaffold scientific understanding

Neurological soft signs in persons with amnestic mild cognitive impairment and the relationships to neuropsychological functions

BACKGROUND: Neurological abnormalities have been reported in people with amnestic mild cognitive impairment (aMCI). The current study aimed to examine the prevalence of neurological soft signs (NSS) in this clinical group and to examine the relationship of NSS to other neuropsychological performances. METHODS: Twenty-nine people with aMCI and 28 cognitively healthy elderly people were recruited for the present study. The NSS subscales (motor coordination, sensory integration, and disinhibition) of the Cambridge Neurological Inventory and a set of neuropsychological tests were administered to all the participants. RESULTS: People with aMCI exhibited significantly more motor coordination signs, disinhibition signs, and total NSS than normal controls. Correlation analysis showed that the motor coordination subscale score and total score of NSS were significantly inversely correlated with the combined Z-score of neuropsychological tests in aMCI group. CONCLUSIONS: These preliminary findings suggested that people with aMCI demonstrated a higher prevalence of NSS compared to healthy elderly people. Moreover, NSS was found to be inversely correlated with the neuropsychological performances in persons with aMCI. When taken together, these findings suggested that NSS may play a potential important role and serve as a tool to assist in the early detection of aMCI

Cortical asymmetries in unaffected siblings of patients with obsessive–compulsive disorder

Obsessive–compulsive disorder (OCD) is considered to be associated with atypical brain asymmetry. However, no study has examined the asymmetry in OCD from the perspective of cortical morphometry. This study is aimed to describe the characteristics of cortical asymmetry in OCD patients, and to investigate whether these features exist in their unaffected siblings – a vital step in identifying putative endophenotypes for OCD. A total of 48 subjects (16 OCD patients, 16 unaffected siblings, and 16 matched controls) were recruited who had complete magnetic resonance imaging scans. Left–right hemispheric asymmetries of cortical thickness were measured using a surface-based threshold-free cluster enhancement method. OCD patients and siblings both showed leftward asymmetries of cortical thickness in the anterior cingulate cortex (ACC), which showed a significant positive correlation with compulsive subscale scores. In addition, siblings and healthy controls showed significantly decreased leftward asymmetries in the orbitofrontal cortex (OFC), and the decreased leftward bias in the OFC was accompanied by lower scales on the Yale–Brown Obsessive–Compulsive Scale. To sum up, leftward asymmetries of cortical thickness in the ACC may represent an endophenotype of increased hereditary risk for OCD, while decreased leftward asymmetries of cortical thickness in the OFC may represent a protective factor

Alterations in the processing of non-drug-related affective stimuli in abstinent heroin addicts.

Long-term exposure to drug may alter the neural system associated with affective processing, as evidenced by both clinical observations and behavioral data documenting dysfunctions in emotional experiences and processing in drug addicts. Although many imaging studies examined neural responses to drug or drug-related cues in addicts, there have been few studies explicitly designed to reveal their neural abnormalities in processing non-drug-related natural affective materials. The present study asked abstinent heroin addicts and normal controls to passively view standardized affective pictures of positive, negative, or neutral valence and compared their brain activities with functional MRI. Compared to normal controls, addicts showed reduced activation in right amygdala in response to the affective pictures, consistent with previous reports of blunted subjective experience for affective stimuli in addicts. Furthermore, in two visual cortical areas BA 19 and 37, while the controls showed greater responses to positive pictures than to negative ones replicating literature findings, the addicts showed the opposite pattern. The results reveal a complex pattern of altered processing of non-drug-related affective materials in addicts showing both heightened and blunted neural responses in different brain regions and for different stimulus valence. The present study highlights the importance of brain imaging research on drug addicts' processing of affective stimuli in understanding disruptions in their emotion circuitry

An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types

Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters

Measurement of isolated photon production in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV

Isolated photon production is measured in proton-proton and lead-lead collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the pseudorapidity range |eta|<1.44 and transverse energies ET between 20 and 80 GeV with the CMS detector at the LHC. The measured ET spectra are found to be in good agreement with next-to-leading-order perturbative QCD predictions. The ratio of PbPb to pp isolated photon ET-differential yields, scaled by the number of incoherent nucleon-nucleon collisions, is consistent with unity for all PbPb reaction centralities.Comment: Submitted to Physics Letters