Generatieconflict en waardige zorg voor kwetsbare ouderen

Vergrijzing is ‘oud nieuws’, zeker voor gerontologen. Gevolgen van de vergrijzing en kansen of problemen die de samenleving zou kunnen zien vanwege de vergrijzing, zouden het kennisdomein van gerontologen moeten zijn, zeker voor Nederlandse. Nederland is een van de eerste landen in de wereld geweest, waar de vergrijzing als maatschappelijk vraagstuk werd onderkend én aanleiding was tot specifieke beleidsvoornemens. Ouderen heetten toen nog bejaarden. In 1970 en 1975 heeft Nederland met de eerste beleidsnota’s een bejaardenbeleid geformuleerd, waarin versterking van zelfstandigheid, stimulering van participatie en bevordering van kwaliteit van zorg centraal stonden met aandacht voor kostenbeheersing en rechtvaardige verdeling. Nederland leek op weg naar een volwassen samenleving

Kolb in de klas: vijf docenten in het hoger onderwijs onderzoeken de waarde van Kolbs leerstijlen voor hun eigen onderwijspraktijk

Deze bundel bevat de resultaten van vijf kortlopende onderzoeken door deelnemers aan de masteropleiding Teaching in Higher Education, allen docenten in het hoger onderwijs, naar de waarde van de leerstijlen van Kolb voor hun eigen lespraktijk. Uit de onderzoeken komt naar voren dat het onderwijsaanbod niet geheel bepaald wordt door de leerstijl van de docent, maar dat het zou kunnen zijn dat het wel deels hierdoor beïnvloed wordt. Ook zijn vier manieren geïdentificeerd waarop docenten rekening houden met individuele verschillen tussen studenten. Ten aanzien van het verrichten van dit type onderzoek blijkt een noodzaak om het vóórkomen van en voorkeuren voor bepaalde leerstijlen op verschillende manieren te meten en om zowel met kwalitatieve als kwantitatieve methoden te werken; daarbij kan de Chi-square goodness-of-fit test voor één groep, goede diensten bewijzen. Ook lijkt het dat aangetroffen verschillen in leerstijlen wel eens veroorzaakt zouden kunnen zijn tussen verschillen in wat en hoe men meet, en geen reflectie zijn van feitelijke verschillen in leerstijlen

Different Aspects of Classical Pathway Overactivation in Patients With C3 Glomerulopathy and Immune Complex-Mediated Membranoproliferative Glomerulonephritis

The rare and heterogeneous kidney disorder C3 glomerulopathy (C3G) is characterized by dysregulation of the alternative pathway (AP) of the complement system. C3G is often associated with autoantibodies stabilizing the AP C3 convertase named C3 nephritic factors (C3NeF). The role of classical pathway (CP) convertase stabilization in C3G and related diseases such as immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN) remains largely unknown. Here, we investigated the CP convertase activity in patients with C3G and IC-MPGN. Using a refined two-step hemolytic assay, we measured the stability of CP convertases directly in the serum of 52 patients and 17 healthy controls. In four patients, CP convertase activity was prolonged compared to healthy controls, i.e. the enzymatic complex was stabilized. In three patients (2 C3G, 1 IC-MPGN) the convertase stabilization was caused by immunoglobulins, indicating the presence of autoantibodies named C4 nephritic factors (C4NeFs). Importantly, the assay also enabled detection of non-immunoglobulin-mediated stabilization of the CP convertase in one patient with C3G. Prolonged CP convertase activity coincided with C3NeF activity in all patients and for up to 70 months of observation. Crucially, experiments with C3-depleted serum showed that C4NeFs stabilized the CP C3 convertase (C4bC2a), that does not contain C3NeF epitopes. All patients with prolonged CP convertase activity showed clear signs of complement activation, i.e. lowered C3 and C5 levels and elevated levels of C3d, C3bc, C3bBbP, and C5b-9. In conclusion, this work provides new insights into the diverse aspects and (non-)immunoglobulin nature of factors causing CP convertase overactivity in C3G/IC-MPGN.</p

The Effect of Statins and Other Cardiovascular Medication on Ischemia-Reperfusion Damage in a Human DIEP Flap Model: Theoretical and Epidemiological Considerations

Background. Statins and other cardiovascular medication possess antioxidant capacity. It was examined whether chronic use of these medications protects from the development of ischemia-reperfusion (I/R) related complications after DIEP (Deep Inferior Epigastric Perforator Free Flap) surgery. This paper contains a literature study on the antioxidant working mechanisms of these drugs. Methods. Medical information of 134 DIEP patients (173 flaps) was studied from their medical files. Patient and operative characteristics were registered, as well as I/R related complications. Results. Of the group that didnot use statins, 16.3% developed complications versus 30.8% amongst patients that did use these drugs (P = 0.29). Amongst patients that chronically use other cardiovascular medication, 26.8% developed I/R related complications versus 14.4% of the patients without medication (P = 0.10). Conclusions. Chronic use of statins or other cardiovascular medication didnot decrease the occurrence of I/R related complications after DIEP surgery. Therefore, research should be aimed at evaluating short-term pre-treatment with statins

Neutron Star Masses and Radii as Inferred from kilo-Hertz QPOs

Kilo-Hertz (kHz) Quasi-periodic oscillations (QPOs) have been discovered in the X-ray fluxes of 8 low-mass X-ray binaries (LMXBs) with the Rossi X-ray Timing Explorer (RXTE). The characteristics of these QPOs are remarkably similar from one source to another. In particular, the highest observed QPO frequencies for 6 of the 8 sources fall in a very narrow range: 1,066 to 1,171 Hz. This is the more remarkable when one considers that these sources are thought to have very different luminosities and magnetic fields, and produce very different count rates in the RXTE detectors. Therefore it is highly unlikely that this near constancy of the highest observed frequencies is due to some unknown selection effect or instrumental bias. In this letter we propose that the highest observed QPO frequency can be taken as the orbital frequency of the marginally stable orbit. This leads to the conclusions that the neutron stars in these LMXBs are inside their marginally stable orbits and have masses in the vicinity of 2.0 solar masses. This mass is consistent with the hypothesis that these neutron stars were born with about 1.4 solar masses and have been accreting matter at a fraction of the Eddington limit for 100 million years.Comment: 7 pages, uses aas2pp4.sty, Accepted by ApJ

Transmembrane Domain Single-Nucleotide Polymorphisms Impair Expression and Transport Activity of ABC Transporter ABCG2

To study the function and expression of nine naturally occurring single-nucleotide polymorphisms (G406R, F431L, S441N, P480L, F489L, M515R, L525R, A528T and T542A) that are predicted to reside in the transmembrane regions of the ABC transporter ABCG2. The transport activity of the variants was tested in inside-out membrane vesicles from Sf9 insect and human derived HEK293 cells overexpressing ABCG2. Lucifer Yellow and estrone sulfate were used as probe substrates of activity. The expression levels and cellular localization of the variants was compared to the wild-type ABCG2 by western blotting and immunofluorescence microscopy. All studied variants of ABCG2 displayed markedly decreased transport in both Sf9-ABCG2 and HEK293-ABCG2 vesicles. Impaired transport could be explained for some variants by altered expression levels and cellular localization. Moreover, the destructive effect on transport activity of variants G406R, P480L, M515R and T542A is, to our knowledge, reported for the first time. These results indicate that the transmembrane region of ABCG2 is sensitive to amino acid substitution and that patients harboring these ABCG2 variant forms could suffer from unexpected pharmacokinetic events of ABCG2 substrate drugs or have an increased risk for diseases such as gout where ABCG2 is implicated.Peer reviewe

Properties of Deflagration Fronts and Models for Type Ia Supernovae

Detailed models of the explosion of a white dwarf, which include self-consistent calculations of the light curve and spectra, provide a link between observational quantities and the underlying explosion.These calculations assume spherical geometry and are based on parameterized descriptions of the burning front during the deflagration phase. Recently, first multi-dimensional calculations for nuclear burning fronts have been performed. Although a fully consistent treatment of the burning fronts is beyond the current state of the art, these calculations provided a new and better understanding of the physics, and new descriptions for the flame propagation have been proposed. Here, we have studied the influence on the results of previous analyses of Type Ia Supernovae, namely, the nucleosynthesis and structure of the expanding envelope. Our calculations are based on a set of delayed detonation models with parameters that give a good account of the optical and infrared light curves, and of the spectral evolution. In this scenario, the burning front propagates first in a deflagration mode and, subsequently, turns into a detonation. The explosions and light curves are calculated using a one-dimensional Lagrangian radiation-hydro code, including a detailed nuclear network.Comment: 9 pages, 4 figures, macros 'crckapb.sty'. The Astrophysical Journal (accepted

The role of habit in compulsivity.

Compulsivity has been recently characterized as a manifestation of an imbalance between the brain׳s goal-directed and habit-learning systems. Habits are perhaps the most fundamental building block of animal learning, and it is therefore unsurprising that there are multiple ways in which the development and execution of habits can be promoted/discouraged. Delineating these neurocognitive routes may be critical to understanding if and how habits contribute to the many faces of compulsivity observed across a range of psychiatric disorders. In this review, we distinguish the contribution of excessive stimulus-response habit learning from that of deficient goal-directed control over action and response inhibition, and discuss the role of stress and anxiety as likely contributors to the transition from goal-directed action to habit. To this end, behavioural, pharmacological, neurobiological and clinical evidence are synthesised and a hypothesis is formulated to capture how habits fit into a model of compulsivity as a trans-diagnostic psychiatric trait.CM Gillan is supported by a Sir Henry Wellcome Postdoctoral Fellowship (101521/Z/12/Z).This is the final version of the article. It was first available from Elsevier via https://doi.org/10.1016/j.euroneuro.2015.12.03

A Massive White Dwarf Companion to the Eccentric Binary Pulsar System PSR B2303+46

Pulsars in close, eccentric binary systems are usually assumed to have another neutron star as a companion. These double neutron star binaries have proven to be the best laboratories for experimental General Relativity and are the most secure candidates for gravitational wave interferometers. We present deep B, V, and R images of the field containing the eccentric binary pulsar system PSR B2303+46. We find a faint, blue object (B=26.60+/-0.09; (B-R)_0=-0.4+/-0.2) coincident with the timing position. We suggest this object is the optical counterpart to the PSR B2303+46 system. The counterpart is too bright to reflect emission from the pulsar or a neutron star companion. Most likely, the companion of PSR B2303+46 is not a neutron star but a massive white dwarf. We show that the observations are consistent with a hot white dwarf companion (T_eff>~5*10^4 K) with cooling age equal the characteristic age of the pulsar (t_cool~30 Myr) and mass within the range set by timing observations and the Chandrasekhar mass (1.2<M_C<1.4 M_sun). Given the eccentric orbit, the white dwarf must have formed before the neutron star, from what was originally the more massive star in the binary. Due to mass transfer, the originally less massive star could become sufficiently massive to end its life in a supernova explosion and form the radio pulsar. We constrain the mass of the pulsar to be in the range 1.24<M_psr<1.44 M_sun.Comment: Revised version, with only very small changes. 6 pages, 1 figure, uses aas4pp2.sty, psfig.sty. Accepted for publication in Astrophysical Journal Letter