Covariance Adjustments in Discrimination of Mixed Discrete and Continuous Variables

Sufficient conditions are given to ensure a better performance of the plug-in version of the covariates adjusted location linear discriminant function in an asymptotic comparison of the overall expected error rate. Our findings generalize several earlier results on discriminant function with covariance

The case of Clockenflap Music and Arts Festival : do cultural entrepreneurs or the government call a better tune?

published_or_final_versionMedia, Culture and Creative CitiesMasterMaster of Social Sciences in Media, Culture and Creative Citie

DK Conjecture for Derived Categories of Grassmannian Flips

The DK Flip Conjecture of Bondal-Orlov and Kawamata states that there should be an embedding of derived categories for any flip, which is known to be true for toroidal flips. In this paper, we construct new examples of Grassmannian flips that satisfy the DK Flip Conjecture.Comment: All comments are wellcome

On Derived Categories of Generalized Grassmannian Flips

In this paper, we construct and classify a new family of flips, called generalized Grassmannian flips, by generalizing the construction of standard flips for $\mathbb{P}^m\times \mathbb{P}^n$ to any generalized Grassmannian $G/P$, where $P$ is a maximal parabolic subgroup of a complex semi-simple algebraic group. In addition, we show that a 9-fold generalized Grassmannian flip for $Sp(6, \mathbb{C})$ satisfies the DK flip conjecture by Bondal-Orlov and Kawamata via mutation techniques by Kuznetsov and Thomas' chess game method.Comment: To appear in Mathematical Research Letter

Those Wonderful People across the Sea: Positive Out-Group Bias by Caucasians toward Asians

While individuals often favor their in-group, they sometimes favor an out-group, such as when Caucasians positively stereotype Asians\u27 quantitative abilities. It is unclear, however, whether positive stereotypes of Asians extend into other domains and create a generalized halo effect that influences judgments on other attributes. To examine this, three studies were performed. In Study 1, Asians and Caucasians were equally biased toward an Asian\u27s response to a calculus problem. In Study 2, Asians, but not Caucasians, gave lower grades to essay writers they guessed were Asian. In Study 3, Caucasians rated their ethnic group with fewer positive terms and more negative terms than they rated Asians on general personality characteristics. Results suggest that Caucasians\u27 views of Asians are more positive than self-judgments of each group, and that Caucasians’ judgments about Asians may be influenced by a generalized halo effect

Convergence of validity for the results of a summative assessment with confidence measurement and traditional assessment

This research examines the use in IT education of an innovative online assessment tool that incorporates confidence measurement. The tool is based on the traditional Multiple Choice Question (MCQ) format with an additional component that permits the user to register their confidence for each answer. The tool is referred to as the Multiple Choice Question with Confidence Measurement (MCQCM). A cohort of 52 Data Communication students utilized the MCQCM as their primary revision tool throughout a semester and then for a test in class. As part of the review they were then asked to give feedback on using the MCQCM as a formal summative assessment tool. The test was graded using the traditional method as well as by calculating a further grade from the student’s registered confidence. The results demonstrated a good correlation and convergence of validity between the dual marks supporting the use of the system as a summative assessment option. It was also observed that the majority of high achievers scored less for the MCQCM grade than for the traditional MCQ. In addition, the students’ perception of the MCQCM as a graded assessment task was quite positive. These results are very encouraging and will be further investigated as part of this ongoing research

Validation and interval scale transformation of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) in patients undergoing knee arthroplasty, using the Rasch model

OBJECTIVES: Interval scale reduce measurement bias compared to ordinal scale. We aimed to evaluate the fit of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) to the Rasch model and derive the transformation table for interval scale measurement. METHODS: Data from osteoarthritis patients listed for knee arthroplasty (KA) pre-operatively, and at 6- and 12- months post-operative was used. WOMAC was calibrated for fit to the Rasch model for monotonicity, homogeneity, local item independence and absence of differential item functioning (DIF) in a randomly selected 900 patients, 300 from each time point; parameter estimates were then imported into the full data set. Responsiveness was reported through Standard Error of Measurement (SEM); Smallest Detectable Difference (SDD), %SDD and effect sizes (ES) between baseline and 6-months. WOMAC was transformed from ordinal to interval values. RESULTS: 1136 patients (mean age 65.9 years, 69.9% female) were included. WOMAC pain (0−20), function (0−68) and total scores (0−96) had adequate fit to Rasch model with good reliability (Person Separation Index: 0.76, 0.80 and 0.79). No item deletion was required. The SEM, SDD, %SDD and ES of WOMAC total were 4.4, 6.9, 10.1, and 1.97. No significant DIF was seen for age, sex, body mass index, type of KA, languages, and education level. WOMAC pain, function and total scores were transformed to interval scales. CONCLUSION: WOMAC total, pain and function scales had adequate fit to the Rasch model, providing unidimensional measure with good reliability and responsiveness. Transformation of WOMAC to interval scale measurement is applicable to other studies

KIR2DL2/2DL3-E(35) alleles are functionally stronger than -Q(35) alleles.

KIR2DL2 and KIR2DL3 segregate as alleles of a single locus in the centromeric motif of the killer cell immunoglobulin-like receptor (KIR) gene family. Although KIR2DL2/L3 polymorphism is known to be associated with many human diseases and is an important factor for donor selection in allogeneic hematopoietic stem cell transplantation, the molecular determinant of functional diversity among various alleles is unclear. In this study we found that KIR2DL2/L3 with glutamic acid at position 35 (E(35)) are functionally stronger than those with glutamine at the same position (Q(35)). Cytotoxicity assay showed that NK cells from HLA-C1 positive donors with KIR2DL2/L3-E(35) could kill more target cells lacking their ligands than NK cells with the weaker -Q(35) alleles, indicating better licensing of KIR2DL2/L3(+) NK cells with the stronger alleles. Molecular modeling analysis reveals that the glutamic acid, which is negatively charged, interacts with positively charged histidine located at position 55, thereby stabilizing KIR2DL2/L3 dimer and reducing entropy loss when KIR2DL2/3 binds to HLA-C ligand. The results of this study will be important for future studies of KIR2DL2/L3-associated diseases as well as for donor selection in allogeneic stem cell transplantation