The evolution of early diagenetic processes at the Mozambique margin during the last glacial-interglacial transition

The Mozambique continental margin experienced large variations in sedimentation rates, primarily due to re-routing of sediment deposition from the Zambezi River during the last glacial-Holocene transition. As changes in sediment accumulation and organic matter deposition impose a strong control on the formation of authigenic minerals in the sediment, the distribution of these minerals may reflect the regional paleoenvironmental and paleoclimatic evolution. Combining geochemical analyses of porewaters and sediments with a reactive transport modeling approach, we reconstruct the depositional history and its effect on pyrite formation and other biogeochemical transformations at a site on the Mozambique margin over the past 27 kyr. Fitting the model to match the observed geochemical patterns, most importantly authigenic pyrite, allowed for the reconstruction of past sulfate-methane transition zone depth, which migrated in response to changes in the sediment accumulation and organic matter deposition. Changes in sediment deposition quickly affected organoclastic sulfate reduction and associated pyrite formation, but the effect on anaerobic methane oxidation and subsequent pyrite formation occurred with a lag on the order of thousands of years. Model results reveal a transition from high diagenetic reaction rates representative of near-shore depositional environments during the late glacial maximum, to a setting typical of offshore sediments with low reaction rates at the present day. Notably, the remnants of methane and dissolved iron pools produced in the past still shape the diagenetic processes at and below the sulfate-methane transition zone today. Since deglacial shelf-flooding and corresponding changes in sediment deposition occurred along continental margins worldwide, our analysis highlights the important role of non-steady state diagenesis in continental margin sediments and its relevance for paleoceanographic interpretation of sediment cores experiencing strong variations in sediment input

Versterken van de positie van de school in de regio

Samen met studenten werken aan een betere toekomst voor de regio. Dat is regioleren. Ondernemers, overheden en maatschappelijke organisaties bepalen de agenda en werken samen met onderwijs en onderzoek aan oplossingen. Waar liggen de uitdagingen? Voor de instellingen is het een belangrijke uitdaging om aansluiting te vinden bij de regio. Hoe verander je van een onderwijsinstelling in een regionaal kenniscentrum? Hoe wordt je een volwaardige partner in een kenniswerkplaats? Een tweede belangrijke uitdaging ligt in de koppeling van het leren in de regio aan de lerende regio. In het programma Regionale Transitie is deze taak bij de kenniswerkplaatsen gelegd. De kenniswerkplaats is gebaseerd op een gezamenlijke regionale kennisagenda van overheid, ondernemers, maatschappelijke organisaties, onderwijs en onderzoek

ESPNIC clinical practice guidelines: intravenous maintenance fluid therapy in acute and critically ill children- a systematic review and meta-analysis

PURPOSE Intravenous maintenance fluid therapy (IV-MFT) prescribing in acute and critically ill children is very variable among pediatric health care professionals. In order to provide up to date IV-MFT guidelines, the European Society of Pediatric and Neonatal Intensive Care (ESPNIC) undertook a systematic review to answer the following five main questions about IV-MFT: (i) the indications for use (ii) the role of isotonic fluid (iii) the role of balanced solutions (iv) IV fluid composition (calcium, magnesium, potassium, glucose and micronutrients) and v) and the optimal amount of fluid. METHODS A multidisciplinary expert group within ESPNIC conducted this systematic review using the Scottish Intercollegiate Guidelines Network (SIGN) grading method. Five databases were searched for studies that answered these questions, in acute and critically children (from 37 weeks gestational age to 18 years), published until November 2020. The quality of evidence and risk of bias were assessed, and meta-analyses were undertaken when appropriate. A series of recommendations was derived and voted on by the expert group to achieve consensus through two voting rounds. RESULTS 56 papers met the inclusion criteria, and 16 recommendations were produced. Outcome reporting was inconsistent among studies. Recommendations generated were based on a heterogeneous level of evidence, but consensus within the expert group was high. "Strong consensus" was reached for 11/16 (69%) and "consensus" for 5/16 (31%) of the recommendations. CONCLUSIONS Key recommendations are to use isotonic balanced solutions providing glucose to restrict IV-MFT infusion volumes in most hospitalized children and to regularly monitor plasma electrolyte levels, serum glucose and fluid balance

Lumbar spine motion pattern analysis: A study in asymptomatic volunteers and in chronic low back patients.

info:eu-repo/semantics/publishedEurospine 2000 – Antwerp (B) – Octobre 2000

Mechanism of Ultrasound Scission of a Silver-Carbene Coordination Polymer

Scission of a supramolecular polymer??metal complex can be carried out using collapsing cavitation bubbles created by ultrasound. Although the most plausible scission mechanism of the coordinative bonds is through mechanical force, the influence of radicals and high hot-spot temperatures on scission has to be considered. A silver(I)??N-heterocyclic carbene complex was exposed to 20 kHz ultrasound in argon, nitrogen, methane, and isobutane saturated toluene. Scission percentages were almost equal under argon, nitrogen, and methane. Radical production differs by a factor of 10 under these gases, indicating that radical production is not a significant contributor to the scission process. A model to describe the displacement of the bubble wall, strain rates, and temperature in the gas shows that critical strain rates for coil-to-stretch transition, needed for scission, are achieved at reactor temperatures of 298 K, an acoustic pressure of 1.2??105 Pa, and an acoustic frequency of 20 kHz. Lower scission percentages were measured under isobutane, which also shows lower strain rates in model simulations. The activation of the polymer??metal complexes in toluene under the influence of ultrasound occurs through mechanical force

Non-covalent bond scission by ultrasound under radical-suppressing conditions

Abstract only

Kinetic-spectrophotometric determination of trace levels of iron

SCOPUS: no.jinfo:eu-repo/semantics/publishe

Response to an unsolicited intervention offer to persons aged >/= 75 years after screening positive for depressive symptoms: a qualitative study

Item does not contain fulltextBACKGROUND: Screening can increase detection of clinically relevant depressive symptoms, but screen-positive persons are not necessarily willing to accept a subsequent unsolicited treatment offer. Our objective was to explore limiting and motivating factors in accepting an offer to join a "coping with depression" course, and perceived needs among persons aged >/=75 years who screened positive for depressive symptoms in general practice. METHODS: In a randomized controlled trial, in which 101 persons who had screened positive for depressive symptoms were offered a "coping with depression" course, a sample of 23 persons were interviewed, of whom five (22%) accepted the treatment offer. Interview transcripts were coded independently by two researchers. RESULTS: All five individuals who accepted a place on the course felt depressed and/or lonely and had positive expectations about the course. The main reasons for declining to join the course were: not feeling depressed, or having negative thoughts about the course effect, concerns about group participation, or about being too old to change and learn new things. Although perceived needs to relieve depressive symptoms largely matched the elements of the course, most of those who had been screened were not (yet) prepared to accept an intervention offer. Many expressed the need to discuss this treatment decision with their general practitioner. CONCLUSIONS: Although the unsolicited treatment offer closely matched the perceived needs of people screening positive for depressive symptoms, only those who combined feelings of being depressed or lonely with positive expectations about the offered course accepted it. Treatment should perhaps be more individually tailored to the patient's motivational stage towards change, a process in which general practitioners can play an important role