Knowledge-base for interpretation of cerebrospinal fluid data patterns. Essentials in neurology and psychiatry

ABSTRACT The physiological and biophysical knowledge base for interpretations of cerebrospinal fluid (CSF) data and reference ranges are essential for the clinical pathologist and neurochemist. With the popular description of the CSF flow dependent barrier function, the dynamics and concentration gradients of blood-derived, brain-derived and leptomeningeal proteins in CSF or the specificity-independent functions of B-lymphocytes in brain also the neurologist, psychiatrist, neurosurgeon as well as the neuropharmacologist may find essentials for diagnosis, research or development of therapies. This review may help to replace the outdated ideas like “leakage” models of the barriers, linear immunoglobulin Index Interpretations or CSF electrophoresis. Calculations, Interpretations and analytical pitfalls are described for albumin quotients, quantitation of immunoglobulin synthesis in Reibergrams, oligoclonal IgG, IgM analysis, the polyspecific ( MRZ- ) antibody reaction, the statistical treatment of CSF data and general quality assessment in the CSF laboratory. The diagnostic relevance is documented in an accompaning review

Theoretical justification of sampling choices in international marketing research: Key issues and guidelines for researchers.

NoSampling in the international environment needs to satisfy the same requirements as sampling in the domestic environment, but there are additional issues to consider, such as the need to balance within-country representativeness with cross-national comparability. However, most international marketing research studies fail to provide theoretical justification for their choice of sampling approach. This is because research design theory and sampling theory have not been well integrated in the context of international research. This paper seeks to fill the gap by developing a framework for determining a sampling approach in international studies. The framework is based on an assessment of the way in which sampling affects the validity of research results, and shows how different research objectives impact upon (a) the desired sampling method and (b) the desired sample characteristics. The aim is to provide researchers with operational guidance in choosing a sampling approach that is theoretically appropriate to their particular research aims

Why do people participate in Web surveys? Applying survey participation theory to Internet survey data collection

In recent years Web surveys have emerged as the most popular mode of primary data collection in market and social research. To improve our understanding about the influence of different societal-level factors, characteristics of the sample person, and attributes of the survey design on participation in Web surveys, this paper establishes a systematic link between theoretical frameworks used to explain survey participation behavior and state-of-the-art empirical research on online data collection methods. The concepts of self-perception, cognitive dissonance, commitment and involvement, social exchange, compliance, leverage-salience, and planned behavior are discussed and their relationship with factors that have empirically proven to influence Web survey participation are analyzed using data from an expert survey. This paper will help researchers and practitioners to make informed decisions about the use of techniques increasing participation in Web surveys