Vrije Universiteit Brussel

About: Vrije Universiteit Brussel is a education organization based out in Brussels, Belgium. It is known for research contribution in the topics: Population & Context (language use). The organization has 14295 authors who have published 38258 publications receiving 1203970 citations. The organization is also known as: VUB.

Acute dopamine/noradrenaline reuptake inhibition enhances human exercise performance in warm, but not temperate conditions

Abstract: Nine healthy endurance-trained males were recruited to examine the effect of a dual dopamine/noradrenaline reuptake inhibitor on performance, thermoregulation and the hormonal responses to exercise. Subjects performed four trials, ingesting either a placebo (pla) or 2 x 300 mg bupropion (bup), prior to exercise in temperate (18 degrees C) or warm (30 degrees C) conditions. Trials consisted of 60 min cycle exercise at 55% W(max) immediately followed by a time trial (TT). TT performance in the heat was significantly improved by bupropion (pla: 39.8 +/- 3.9 min, bup: 36.4 +/- 5.7 min; P = 0.046), but no difference between treatments was apparent in temperate conditions (pla: 30.6 +/- 2.2 min, bup: 30.6 +/- 1.9 min; P = 0.954). While TT power output was consistently lower in the heat when compared to temperate conditions, this decrement was attenuated by bupropion. At the end of the TT in the heat, both core temperature (pla 39.7 +/- 0.3 degrees C, bup 40.0 +/- 0.3 degrees C; P = 0.017) and HR (pla 178 +/- 7 beats min(-1), bup 183 +/- 12 beats min(-1); P = 0.039), were higher in the bupropion trial than in the placebo. Circulating pituitary and adrenal hormone concentrations increased throughout exercise in all trials. Circulating serum prolactin was elevated above temperate levels during exercise in a warm environment (P < 0.001). These data indicate that performance in warm conditions is enhanced by acute administration of a dual dopamine/noradrenaline reuptake inhibitor. No such effect was apparent under temperate conditions. It appears that bupropion enabled subjects to maintain a greater TT power output in the heat with the same perception of effort and thermal stress reported during the placebo trial, despite the attainment of a higher core temperature.

The alphabet of intrinsic disorder: I. Act like a Pro: On the abundance and roles of proline residues in intrinsically disordered proteins.

Abstract: A significant fraction of every proteome is occupied by biologically active proteins that do not form unique three-dimensional structures. These intrinsically disordered proteins (IDPs) and IDP regions (IDPRs) have essential biological functions and are characterized by extensive structural plasticity. Such structural and functional behavior is encoded in the amino acid sequences of IDPs/IDPRs, which are enriched in disorder-promoting residues and depleted in order-promoting residues. In fact, amino acid residues can be arranged according to their disorder-promoting tendency to form an alphabet of intrinsic disorder that defines the structural complexity and diversity of IDPs/IDPRs. This review is the first in a series of publications dedicated to the roles that different amino acid residues play in defining the phenomenon of protein intrinsic disorder. We start with proline because data suggests that of the 20 common amino acid residues, this one is the most disorder-promoting.

Utilization of mangrove wood products around Mida Creek (Kenya) amongst subsistence and commercial users

Abstract: Mida Creek (Kenya) comprises mangrove forests and other marine resources that are of economic, ecological, and environmental importance to the local village communities. In total 116 households (100 of which could be used for numerical analysis), which are estimated to correspond to a coverage of ca. 30% of the total Mida Creek population, were interviewed to assess the human reliance on mangrove resources in Mida Creek. The survey indicates that mangroves are a major resource of wood for house construction, fuel wood, charcoal, and boat building. Minor uses of mangrove products include pharmaceutical and medicinal applications, tanning material, and furniture making. Rhizophora mucronata, Ceriops tagal, and Bruguiera gymnorrhiza are the major resources for house construction and fuel wood, while Sonneratia alba and Xylocarpus granatum were reported to be useful for boat building and medicinal uses respectively. The survey further describes harvesting activities and house construction, and reveals species preferences within this one particular use. As a result of depletion of the supply and the banning of mangrove harvesting, the local people are turning to other wood materials and to poaching. In our view, local utilization patterns rather than global usefulness data are required to establish a conservation policy of both mangroves and users’ subsistence requirements.

Toxic arsenic compounds in environmental samples : Speciation and validation

Abstract: Speciation of arsenic (As) compounds in environmental samples requires rigorous analytical procedures at each stage of sample collection, treatment and measurement. In view of the very high number of As species occurring in environmental samples, this article deals with only those that are considered toxic, including As-containing warfare agents and arsenobetaine (AB), because this is the most abundant As species in marine fish. With the exception of the tetramethylarsonium ion, acute toxicity generally decreases with increasing degree of methylation. The warfare agents considered are mostly phenylarsenic compounds. During storage, events, such as changes in oxidation state or induced by microbial activity or losses by volatilization or adsorption, have to be avoided. Extraction of arsenicals from soils and sediments is still a critical step that is not very well controlled. As long as marine animals are considered, extraction efficiencies >90% are commonly obtained [K.A. Francesconi, D. Kuehnelt, Analyst (Cambridge, UK) 129 (2004) 373]. This is logical, since marine animals are rich in AB, and this small molecule is soluble in water and methanol and in mixtures of them. In terrestrial organisms and plants, extraction efficiencies can be much lower and vary according to the extraction conditions. Since most environmental As species are generally present in soluble forms, liquid-separation techniques, first high-performance liquid chromatography (HPLC) but also capillary electrophoresis (CE), are most frequently used for separating As species. Fast separations can be performed with narrow-bore reversed-phase HPLC columns. Pre-column derivatizations with hydride generation [e.g., As(III), As(V), MA, DMA] and mercaptans/dimercaptans (e.g., Clarks I and II and Pfiffikus) allow separation of the arsenicals by gas chromatography (GC). The most popular detectors are inductively coupled mass spectrometry (ICP–MS) and atomic fluorescence spectrometry (AFS), especially after HPLC separation and hydride formation, increasingly replacing atomic absorption spectrometry (AAS), while HPLC–MS or HPLC–MS–MS (HPLC–MS2) is the detector of choice for (less toxic) arsenosugars and arsenolipids. For phenylarsenic warfare species, ultraviolet (UV) detection is also still used frequently. Finally, as other measurement fields, speciation analysis requires the availability of suitable reference materials (RMs) for verification of accuracy and quality assurance. We address these important aspects although the number of certified RMs is rather limited.

Expression of all Wnt genes and their secreted antagonists during mouse blastocyst and postimplantation development.

Abstract: In this extensive study, real-time reverse transcriptase-polymerase chain reaction was used to analyze the expression levels of all 19 Wnt genes and their 11 potential antagonists in mouse blastocysts, pregastrula, gastrula, and neurula stages. By complementing these results with in situ hybridization, we revealed new expression domains for Wnt2b and Sfrp1, respectively, in the future primitive streak at the posterior side and in the anterior visceral endoderm before the initiation of gastrulation. Moreover, the anterior visceral endoderm expresses three secreted Wnt antagonists (Sfrp1, Sfrp5, and Dkk1) in partially overlapping domains. We also identified expression patterns for the Wnt1, Wnt3a, Wnt6, Wnt7b, Wnt9a, Wnt10b, and Sfrp1 genes at the blastocyst stage. In particular, the expression of Wnt1 and Sfrp1 predominantly in the inner cell mass and of Wnt9a in the mural trophoblast and inner cell mass cells surrounding the blastocoele suggests new roles for the Wnt pathway in preimplantation development. This article is the first report on the regional expression of Wnt genes in the mouse blastocyst. Developmental Dynamics 233:1064 –1075, 2005. © 2005 Wiley-Liss, Inc.