Conceptualisation, development and validation of T-QoL© (Teenagers' Quality of Life): a patient-focused measure to assess quality of life of adolescents with skin diseases

Aim To develop and validate a dermatology-specific quality of life (QoL) instrument for adolescents with skin diseases. Methods Qualitative semi-structured interviews were conducted with adolescents with skin disease to gain in-depth understanding of how skin diseases affect their QoL. A prototype instrument based on the themes identified from content analysis of interviews was tested in several stages, using Classical Test Theory (CTT) and Item Response Theory (IRT) models to develop this new tool and conduct its psychometric evaluation. Results Thirty-three QoL issues were identified from semi-structured interviews with 50 adolescents. A questionnaire based on items derived from content analysis of interviews was subjected to Rasch analysis: factor analysis identified three domains, therefore not supporting the validity of T-QoL as a unidimensional measure. Psychometric evaluation of the final 18-item questionnaire was carried out in a cohort of 203 adolescents. Convergent validity was demonstrated by significant correlation with Skindex-Teen and CDLQI or DLQI. The T-QoL showed excellent internal consistency reliability: Cronbach's α=0.89 for total scale score and 0.85, 0.60, and 0.74 respectively for domains 1, 2 and 3. Test-retest reliability was high in stable subjects. T-QoL showed sensitivity to change in two sub-groups of patients who indicated change in their self-assessed disease severity. Conclusion Built on rich qualitative data from patients, the T-QoL is a simple and valid tool to quantify the impact of skin disease on adolescents’ QoL; it could be used as an outcome measure in both clinical practice and clinical research

Sequence selective capture, release and analysis of DNA using a magnetic microbead-assisted toehold-mediated DNA strand displacement reaction

This paper reports on the modification of magnetic beads with oligonucleotide capture probes with a specially designed pendant toehold (overhang) aimed specifically to capture double-stranded PCR products. After capture, the PCR products were selectively released from the magnetic beads by means of a toehold-mediated strand displacement reaction using short artificial oligonucleotide triggers and analysed using capillary electrophoresis. The approach was successfully shown on two genes widely used in human DNA genotyping, namely human c-fms (macrophage colony-stimulating factor) proto-oncogene for the CSF-1 receptor (CSF1PO) and amelogenin

Conceptualising computerized adaptive testing for measurement of latent variables associated with physical objects

The notion of that more or less of a physical feature affects in different degrees the users' impression with regard to an underlying attribute of a product has frequently been applied in affective engineering. However, those attributes exist only as a premise that cannot directly be measured and, therefore, inferences based on their assessment are error-prone. To establish and improve measurement of latent attributes it is presented in this paper the concept of a stochastic framework using the Rasch model for a wide range of independent variables referred to as an item bank. Based on an item bank, computerized adaptive testing (CAT) can be developed. A CAT system can converge into a sequence of items bracketing to convey information at a user's particular endorsement level. It is through item banking and CAT that the financial benefits of using the Rasch model in affective engineering can be realised

Measurements of branching fraction ratios and CP-asymmetries in suppressed B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^- decays

We report the first reconstruction in hadron collisions of the suppressed decays B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^-, sensitive to the CKM phase gamma, using data from 7 fb^-1 of integrated luminosity collected by the CDF II detector at the Tevatron collider. We reconstruct a signal for the B^- -> D(-> K^+ pi^-)K^- suppressed mode with a significance of 3.2 standard deviations, and measure the ratios of the suppressed to favored branching fractions R(K) = [22.0 \pm 8.6(stat)\pm 2.6(syst)]\times 10^-3, R^+(K) = [42.6\pm 13.7(stat)\pm 2.8(syst)]\times 10^-3, R^-(K)= [3.8\pm 10.3(stat)\pm 2.7(syst]\times 10^-3, as well as the direct CP-violating asymmetry A(K) = -0.82\pm 0.44(stat)\pm 0.09(syst) of this mode. Corresponding quantities for B^- -> D(-> K^+ pi^-)pi^- decay are also reported.Comment: 8 pages, 1 figure, accepted by Phys.Rev.D Rapid Communications for Publicatio

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO