University of Antwerp

About: University of Antwerp is a education organization based out in Antwerp, Belgium. It is known for research contribution in the topics: Population & Context (language use). The organization has 16682 authors who have published 48837 publications receiving 1689748 citations. The organization is also known as: Universiteit Antwerpen & UAntwerp.

TREECON: A software package for the construction and drawing of evolutionary trees

Abstract: A package of programs (run by a management program called TREECON) was developed for the construction and drawing of evolutionary trees. The program MATRIX calculates dissimilarity values and can perform boostrap analysis on nucleic acid sequences. TREE implements different evolutionary tree constructing methods based on distance matrices. Because some of these methods produce unrooted evolutionary trees, a program ROOT places a root on the tree. Finally, the program DRAW draws the evolutionary tree, changes its size or topology, and produces drawings suitable for publication. Whereas, MATRIX is suited only for nucleic acids, the modules TREE, ROOT and DRAW are applicable to any kind of dissimilarity matrix. The programs run on IBM-compatible microcomputers using the DOS operating system.

Diagnostic Value of Cerebrospinal Fluid Neurofilament Light Protein in Neurology: A Systematic Review and Meta-analysis

Abstract: Importance: Neurofilament light protein (NfL) is elevated in cerebrospinal fluid (CSF) of a number of neurological conditions compared with healthy controls (HC) and is a candidate biomarker for neuroaxonal damage. The influence of age and sex is largely unknown, and levels across neurological disorders have not been compared systematically to date. Objectives: To assess the associations of age, sex, and diagnosis with NfL in CSF (cNfL) and to evaluate its potential in discriminating clinically similar conditions. Data Sources: PubMed was searched for studies published between January 1, 2006, and January 1, 2016, reporting cNfL levels (using the search terms neurofilament light and cerebrospinal fluid) in neurological or psychiatric conditions and/or in HC. Study Selection: Studies reporting NfL levels measured in lumbar CSF using a commercially available immunoassay, as well as age and sex. Data Extraction and Synthesis: Individual-level data were requested from study authors. Generalized linear mixed-effects models were used to estimate the fixed effects of age, sex, and diagnosis on log-transformed NfL levels, with cohort of origin modeled as a random intercept. Main Outcome and Measure: The cNfL levels adjusted for age and sex across diagnoses. Results: Data were collected for 10059 individuals (mean [SD] age, 59.7 [18.8] years; 54.1% female). Thirty-five diagnoses were identified, including inflammatory diseases of the central nervous system (n = 2795), dementias and predementia stages (n = 4284), parkinsonian disorders (n = 984), and HC (n = 1332). The cNfL was elevated compared with HC in a majority of neurological conditions studied. Highest levels were observed in cognitively impaired HIV-positive individuals (iHIV), amyotrophic lateral sclerosis, frontotemporal dementia (FTD), and Huntington disease. In 33.3% of diagnoses, including HC, multiple sclerosis, Alzheimer disease (AD), and Parkinson disease (PD), cNfL was higher in men than women. The cNfL increased with age in HC and a majority of neurological conditions, although the association was strongest in HC. The cNfL overlapped in most clinically similar diagnoses except for FTD and iHIV, which segregated from other dementias, and PD, which segregated from atypical parkinsonian syndromes. Conclusions and Relevance: These data support the use of cNfL as a biomarker of neuroaxonal damage and indicate that age-specific and sex-specific (and in some cases disease-specific) reference values may be needed. The cNfL has potential to assist the differentiation of FTD from AD and PD from atypical parkinsonian syndromes.

Cross-border acquisition abandonment and completion: The effect of institutional differences and organizational learning in the international business service industry, 1981–2001

Abstract: Based on the concepts of North's (1990) political economy of national institutions and economic behavior, we investigate how formal and informal institutional features influence the likelihood that a cross-border acquisition deal will be completed, as well as the time taken for its completion after announcement. Additionally, we study how past experience with completed acquisition deals moderates the effects of institutional differences. We focus on a relatively new context – the pre-completion stage of acquisition processes. We test our hypotheses using data from 2389 announced cross-border acquisition deals in the international business service industry (1981–2001). We find that differences in national formal and informal institutions explain part of the variation in the likelihood that an announced cross-border acquisition deal will be completed, as well as the duration of the deal-making. In addition, organizational learning moderates the effects of institutional distance: past experience with completed cross-border acquisition deals increases the likelihood of a subsequent deal completion in institutionally closer environments, but shortens the deal duration in institutionally distant environments.

The isolation of nucleic acids from fixed, paraffin-embedded tissues-which methods are useful when?

Abstract: Museums and pathology collections around the world represent an archive of genetic material to study populations and diseases. For preservation purposes, a large portion of these collections has been fixed in formalin-containing solutions, a treatment that results in cross-linking of biomolecules. Cross-linking not only complicates isolation of nucleic acid but also introduces polymerase "blocks" during PCR. A wide variety of methods exists for the recovery of DNA and RNA from archival tissues, and although a number of previous studies have qualitatively compared the relative merits of the different techniques, very few have undertaken wide scale quantitative comparisons. To help address this issue, we have undertaken a study that investigates the quality of nucleic acids recovered from a test panel of fixed specimens that have been manipulated following a number of the published protocols. These include methods of pre-treating the samples prior to extraction, extraction and nucleic acid purification methods themselves, and a post-extraction enzymatic repair technique. We find that although many of the published methods have distinct positive effects on some characteristics of the nucleic acids, the benefits often come at a cost. In addition, a number of the previously published techniques appear to have no effect at all. Our findings recommend that the extraction methodology adopted should be chosen carefully. Here we provide a quick reference table that can be used to determine appropriate protocols for particular aims.