validation is an important enterprise especially when a test is a high stakes one. demographic variables like gender and field of study can affect test results and interpretations. differential item functioning (dif) is a way to make sure that a test does not favor one group of test takers over the others. this study investigated dif in terms of gender in the reading comprehension subtest (35 i...

background & objective: autoimmune bullous diseases are associated with autoimmunity against structural components in the skin and mucous membranes. autoantibodies are against the intercellular junctions in pemphigus disease and hemidesmosomal unchoring complex in pemphigiod diseases and epidermolysis bullosa aquisita. the tissue-bound and circulating serum autoantibodies can be detected wi...

One poorly understood mechanism of developmental patterning involves the intermingled differentiation of different cell types that then sort out to generate pattern. Examples of this are known in nematodes and vertebrates, and in Dictyostelium it is the major mechanism. However, a general problem with this mechanism is the possibility that different inducers are required for each cell type that...

In the development of the cellular slime mold Dictyostelium discoideum, two chlorinated compounds, the differentiation-inducing factors DIF-1 and DIF-2, play important roles in the regulation of both cell differentiation and chemotactic cell movement. However, the receptors of DIFs and the components of DIF signaling systems have not previously been elucidated. To identify the receptors for DIF...

Rationale In order to avoid response bias such as agreement bias or acquiescence, it was a common recommendation that both positively-and negatively-worded items should be included in survey that the practice of using positively-and negatively-worded items may introduce systematic measurement errors that disrupt analyses and interpretations of the results (DiStefano & Motl, 2006; Quilty, Oakman...

BACKGROUND In the early stages of development of the cellular slime mold Dictyostelium discoideum, chemotaxis toward cAMP plays a pivotal role in organizing discrete cells into a multicellular structure. In this process, a series of signaling molecules, such as G-protein-coupled cell surface receptors for cAMP, phosphatidylinositol metabolites, and cyclic nucleotides, function as the signal tra...

BACKGROUND Chlamydia pneumoniae causes a variety of respiratory infections and is involved in cardiovascular diseases. Diagnosis of C. pneumoniae infection currently relies on antibody detection by microimmunofluorescence (MIF), which has limited use, and is the retrospective diagnosis for acute infection. OBJECTIVE Find an effective early diagnosis of acute upper respiratory infection, or us...

In this paper we describe and illustrate the Roussos-Stout (1996) multidimensionality-based DIF analysis framework, with emphasis on its implication for the selection of a matching and studied subtest for DIF analyses. Standard DIF practice encourages an exploratory search for matching subtest items based on purely statistical criteria, such as a failure to display DIF. By contrast, the multidi...

Circular chromosomes can form dimers during replication and failure to resolve those into monomers prevents chromosome segregation, which leads to cell death. Dimer resolution is catalysed by a highly conserved site-specific recombination system, called XerCD-dif in Escherichia coli. Recombination is activated by the DNA translocase FtsK, which is associated with the division septum, and is tho...