De ruimtebeleving in Vestdijks Verzamelde verhalen III

in Vestdijkkroniek (1995), 88-89

Rules for Member Stability in EN 1993-1-1: Background documentation and design guidelines

Book published by ECCS European Convention for Constructional Steelwork (2006)

This volume intends at helping in the understanding of the new design rules for member stability in Eurocode 3 Part 1.1 (EN 1993-1-1:2005). In particular, the new recommendations for lateral torsional ... [more ▼]

This volume intends at helping in the understanding of the new design rules for member stability in Eurocode 3 Part 1.1 (EN 1993-1-1:2005). In particular, the new recommendations for lateral torsional buckling and beam-column stability in chapter 6.3.3 (4) of Eurocode 3 are concerned. It is divided into two independent parts A and B. Part A, devoted to the background of the proposed formulae, gives further information on the way the formulae have been built and validated. Moreover, the different basic concepts used in the formulae are detailed, for the two sets of formulae proposed in the code. It is to be noted that a great number of papers prepared within the development of the formulae are made available by means of a CD-Rom that is part of this publication. Part B is dedicated to practitioners; it contains fully detailed worked examples on isolated members, from basic situations to the most complex one. In addition, an example of design of a member extracted from a frame is also given. Furthermore an annex shows especially the determination of the elastic lateral torsional buckling moment for different loading and support conditions. [less ▲]

Rumen Escape Of Methionine And Lysine Administered Intraruminally To Growing Double-Muscled Belgian Blue Bulls

in Reproduction Nutrition Development (2002), 42(6), 537-544

In many dietary conditions, methionine (Met) and lysine (Lys) are the most limiting amino acids (AA) for ruminants. The AA protected from ruminal fermentation are not commercially available, with the ... [more ▼]

In many dietary conditions, methionine (Met) and lysine (Lys) are the most limiting amino acids (AA) for ruminants. The AA protected from ruminal fermentation are not commercially available, with the exception of Met which is not always economical, especially for meat production. This study measured ruminal escape of free Met and Lys supplemented intraruminally to fast growing bulls. Six double-muscled Belgian Blue bulls, fed a high concentrate diet and fitted with a rumen cannula, received free Met (40 g.d–1) and free Lys (60 g.d–1), individually or simultaneously, in a duplicated Latin square design. The mean ruminal escape of Met and Lys reached 37 and 45% respectively, and did not differ if administered separately or together. Plasma Lys and Met concentrations were increased by 504 and 126%, respectively. Substantial proportions of free AA escaped ruminal fermentation and were available for absorption from the small intestine when they were administered at physiologically high levels. [less ▲]

Le rumex à feuilles obtuses dans les systèmes herbagers : importance de la problématique, lutte chimique et méthodes alternatives

in Fourrages (2008), 192

Parmi les questions relatives à l'entretien des prairies, la lutte contre le rumex est une préoccupation fréquente, du fait de la vigueur et de la capacité d’adaptation considérables de la plante et de la ... [more ▼]

Parmi les questions relatives à l'entretien des prairies, la lutte contre le rumex est une préoccupation fréquente, du fait de la vigueur et de la capacité d’adaptation considérables de la plante et de la difficulté de la lutte contre cette adventice invasive dans des couverts complexes... Une enquête réalisée en région wallonne auprès d'exploitants agricoles et portant sur leurs pratiques de gestion et d'entretien des prairies montre l’importance de la pression exercée par Rumex obtusifolius L. qui représente un problème pour 40% d'entre eux ; la complémentation et l'épandage de lisier et de fumier de bovins sont corrélés avec la difficulté exprimée par les éleveurs. Une revue complète des traitements chimiques est effectuée selon la nature du couvert et l'âge de la prairie. Diverses méthodes de lutte alternatives sont également présentées (faux semis, type de travail du sol, gestion du pâturage…) ainsi que leur efficacité sur les jeunes plantules et sur les repousses de plantes de rumex. [less ▲]

Ruminal, cardiorespiratory and adrenocortical sequelae of Na2EDTA-induced hypocalcemia in calves

in Veterinary Research Communications (1996), 20

A study was undertaken to provide further information on the ruminal, cardiorespiratory and hypothalamo-pituitary-adrenocortical (HPAC) physiological sequelae of hypocalcaemia in dairy calves. The ... [more ▼]

A study was undertaken to provide further information on the ruminal, cardiorespiratory and hypothalamo-pituitary-adrenocortical (HPAC) physiological sequelae of hypocalcaemia in dairy calves. The functional picture observed in standing calves experiencing Na2EDTA-induced progressive hypocalcaemia showed a biphasic pattern. During the first phase (Ca2+ varying between 1.20 +/- 0.09 and 0.64 +/- 0.15 mmol/L, mean +/- SD), the animals became dull and lethargic, shifting their weight from one hind limb to the other, with cool extremities and hypersalivation. Their ventilation was slightly increased but their heart rate, thoracoabdominal pressure, pulmonary mechanics, haemoglobin and temperature remained constant. Conversely, their systemic arterial pressure (SAP) and the amplitude of their ruminal contractions (RCA) were severely decreased. During the second phase (Ca2+ < 0.64 +/- 0.15 mmol/L), there was restlessness, tachycardia, hypertension, polycythaemia and, finally, inability to stay upright. It is suggested that the diminished Ca2+ availability caused smooth-muscle and myocardial dysfunctions which could explain the RCA and SAP changes recorded during the first phase, whereas neural and/or humoral sympathetic discharge probably accounted for the reversal in SAP and heart rate when Ca2+ was decreased further. Serum cortisol increased regularly and remained significantly correlated with Ca2+ in each animal. Moreover, regression of delta cortisol/delta Ca2+ on delta Ca2+/delta Na2EDTA was significant (p < or = 0.001). It was concluded that mild asymptomatic hypocalcaemia severely impairs ruminal function, which will progressively worsen the Ca2+ deficit; that the inability to maintain posture in hypocalcaemia is not due to hypotension; and that the higher the HPAC response to hypocalcaemia, the higher the resistance to its effects. An asymptomatic periparturient cow with barely detectable ruminal activity may merit preventive calcium borogluconate therapy. Also, the physiological role of hypotension in explaining the clinical picture may be less important than other processes, such as neuromuscular failure. Finally, the present results imply a possible HPAC exhaustion in cows with periparturient paretic hypocalcaemia [less ▲]

Ruminant alphaherpesviruses related to bovine herpesvirus 1.

in Veterinary Research (2006), 37(2), 169-90

Herpesviruses have mainly co-evolved with their hosts for millions of years. Consequently, different related host species may have been infected by various genetically related herpesviruses. Illustrating ... [more ▼]

Herpesviruses have mainly co-evolved with their hosts for millions of years. Consequently, different related host species may have been infected by various genetically related herpesviruses. Illustrating this concept, several ruminant alphaherpesviruses have been shown to form a cluster of viruses closely related to bovine herpesvirus 1 (BoHV-1): namely bovine herpesvirus 5, bubaline herpesvirus 1, caprine herpesvirus 1, cervid herpesviruses 1 and 2 and elk herpesvirus 1. These viruses share common antigenic properties and the serological relationships between them can be considered as a threat to BoHV-1 eradication programmes. BoHV-1 is a herpesvirus responsible for infectious bovine rhinotracheitis, which is a disease of major economic concern. In this article, the genetic properties of these ruminant alphaherpesviruses are reviewed on a comparative basis and the issue of interspecific recombination is assessed. The pathogenesis of these infections is described with emphasis on the host range and crossing of the host species barrier. Indeed, the non bovine ruminant species susceptible to these ruminant alphaherpesviruses may be potential BoHV-1 reservoirs. The differential diagnosis of these related infections is also discussed. In addition, available epidemiological data are used to assess the potential of cross-infection in ruminant populations. A better knowledge of these ruminant alphaherpesvirus infections is essential to successfully control infectious bovine rhinotracheitis. [less ▲]

Ruminant herpesviruses

in Lefèvre, P. C.; Blancou, Jean; Chermette, R. (Eds.) Infectious and parasitic diseases of Livestock (2008)

Runcaria, a middle Devonian seed plant precursor

in Science (2004), 306(5697), 856-858

The emergence of the seed habit in the Middle Pateozoic was a decisive evolutionary breakthrough. Today, seed plants are the most successful plant lineage, with more than 250,000 living species. We have ... [more ▼]

The emergence of the seed habit in the Middle Pateozoic was a decisive evolutionary breakthrough. Today, seed plants are the most successful plant lineage, with more than 250,000 living species. We have identified a middle Givetian (385 million years ago) seed precursor from Belgium predating the earliest seeds by about 20 million years. Runcaria is a small, radially symmetrical, integumented megasporangium surrounded by a cupule. The megasporangium bears an unopened distal extension protruding above the multilobed integument. This extension is assumed to be involved in anemophilous pollination. Runcaria sheds new light on the sequence of character acquisition leading to the seed. [less ▲]

Runoff control of soil degassing at an active volcano. The case of Piton de la Fournaise, Reunion Island

in Earth And Planetary Science Letters (2002), 197(1-2), 83-94

Airborne atmospheric and in-situ soil gas analyses demonstrate that distal gas leaks are non-existent at Piton de la Fournaise (PF) despite frequent eruptions. Airborne traverses made at a constant ... [more ▼]

Airborne atmospheric and in-situ soil gas analyses demonstrate that distal gas leaks are non-existent at Piton de la Fournaise (PF) despite frequent eruptions. Airborne traverses made at a constant altitude indicated that no detectable large-scale CO2 degassing occurs from the volcano. In-situ soil gas traverses (CO2, He-4, Rn-222) across the active riftzones, the summit crater and the caldera rims, show both a lack of positive anomalies and evidence of strong depleted concentrations for He and CO2 with respect to air. Depletions in soil He is explained by intense rain water infiltration. A more unexpected result lies in the very low CO2 concentrations (down to 92 ppm) in bare soils in the summit region. Such a depletion was not previously reported and is attributed to considerable basalt weathering operating as the result of huge runoff. A model has enabled both the runoff and the CO2 consumption occurring within the basaltic layers to be calculated. Data obtained are consistent with values expected from large-scale erosion models and with the local calculated diffusive flux of CO2 in soils. The huge runoff, together with the basaltic lithology of the volcano, are found to be the main factor controlling the soil gas signatures at PF. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

Runx2-and histone deacetylase 3-mediated repression is relieved in differentiating human osteoblast cells to allow high bone sialoprotein expression

in Journal of Biological Chemistry (2007), 282(50), 36240-36249

Bone sialoprotein (BSP) is a bone matrix glycoprotein whose expression coincides with terminal osteoblastic differentiation and the onset of mineralization. In this study we show that BSP expression is ... [more ▼]

Bone sialoprotein (BSP) is a bone matrix glycoprotein whose expression coincides with terminal osteoblastic differentiation and the onset of mineralization. In this study we show that BSP expression is considerably increased in confluent Saos-2 human osteosarcoma cells and in differentiating normal human osteoblasts, concomitantly with the decrease of Runx2, a key transcription factor controlling bone formation. Therefore, we investigated the role of Runx2 in the regulation of BSP expression in Saos-2 cells. Using a mobility shift assay, we demonstrated that Runx2 binds to the BSP promoter only in preconfluent cells. Histone deacetylase 3 (HDAC3) has been recently shown to act as a Runx2 co-repressor. Chromatin immunoprecipitation assays demonstrated that both Runx2 and HDAC3 are detectable at the BSP promoter in preconfluent Saos-2 cells but not when they are confluent and overexpress BSP. Consistently, nuclear Runx2 protein level is down-regulated, whereas Saos-2 cells became increasingly confluent. Finally, the suppression of HDAC3, Runx2, or both by RNA interference induced the expression of BSP at both mRNA and protein levels in Saos-2 cells. Our data demonstrate that Runx2 and HDAC3 repress BSP gene expression and that this repression is suspended upon osteoblastic cell differentiation. Both the nuclear disappearance of Runx2 and the non-recruitment of HDAC3 represent new means to relieve Runx2-mediated suppression of BSP expression, thus allowing the acquisition of a fully differentiated and mineralization-competent phenotype by osteoblast cells. [less ▲]