Met het oog op wachttijd

Zonder een goed functionerend hoornvlies, hierna genoemd cornea, kunnen de ogen hun taak niet goed uitvoeren. Iets meer dan 100 jaar geleden, in 1905, werd de eerstes uccesvolle transplantatie van een cornea van een overleden donor uitgevoerd in Tsjechië, door oogarts Zirm. Mede door de ontwikkeling van operatiemicroscopen, extra dun hechtdraad en het gebruik van antibiotica worden vandaag de dag in Nederland ongeveer 900 corneatransplantaties per jaar uitgevoerd. In Nederland is de Nederlandse transplantatie Stichting (NTS) verantwoordelijk voor het toewijzen van cornea’s aan patiënten (Bokhorst et al., 2007).\ud De gemiddelde wachttijd voor een cornea in Nederland is ongeveer een half jaar, ofwel 175 dagen. (Zie figuur 1) De door de NTS en oogartsen meest genoemde oorzaken zijn een tekort aan operatiecapaciteit en cornea’s en de fluctuatie in zowel vraag als aanbod van cornea’s. Ons eerste doel was te onderzoeken in welke mate deze zaken de wachttijd beïnvloeden. Een tweede doel was mogelijke verbeteringen aan te dragen

Weak negative associations between avian influenza virus infection and movement behaviour in a key host species, the mallard Anas platyrhynchos

Animal movements may contribute to the spread of pathogens. In the case of avian influenza virus, [migratory] birds have been suggested to play a role in the spread of some highly pathogenic strains (e.g. H5N1, H5N8), as well as their low pathogenic precursors which circulate naturally in wild birds. For a better understanding of the emergence and spread of both highly pathogenic (HPAIV) and low pathogenic avian influenza virus (LPAIV), the potential effects of LPAIVs on bird movement need to be evaluated. In a key host species, the mallard Anas platyrhynchos, we tested whether LPAIV infection status affected daily local ( 100 m) movements by comparing movement behaviour 1) within individuals (captured and sampled at two time points) and 2) between individuals (captured and sampled at one time point). We fitted free-living adult males with GPS loggers throughout the autumn LPAIV infection peak, and sampled them for LPAIV infection at logger deployment and at logger removal on recapture. Within individuals, we found no association between LPAIV infection and daily local and regional movements. Among individuals, daily regional movements of LPAIV infected mallards in the last days of tracking were lower than those of non-infected birds. Moreover, these regional movements of LPAIV infected birds were additionally reduced by poor weather conditions (i.e. increased wind and/or precipitation and lower temperatures). Local movements of LPAIV infected birds in t

Microstructure and thermal stability of Fe, Ti and Ag implanted Yttria-stabilized zirconia

Yttria-stabilized zirconia (YSZ) was implanted with 15 keV Fe or Ti ions up to a dose of 8×1016 at cm−2. The resulting “dopant” concentrations exceeded the concentrations corresponding to the equilibrium solid solubility of Fe2O3 or TiO2 in YSZ. During oxidation in air at 400° C, the Fe and Ti concentration in the outermost surface layer increased even further until a surface layer was formed of mainly Fe2O3 and TiO2, as shown by XPS and ISS measurements. From the time dependence of the Fe and Ti depth profiles during anneal treatments, diffusion coefficients were calculated. From those values it was estimated that the maximum temperature at which the Fe- and Ti-implanted layers can be operated without changes in the dopant concentration profiles was 700 and 800° C, respectively. The high-dose implanted layer was completely amorphous even after annealing up to 1100° C, as shown by scanning transmission electron microscopy. Preliminary measurements on 50 keV Ag implanted YSZ indicate that in this case the amorphous layer recrystallizes into fine grained cubic YSZ at a temperature of about 1000° C. The average grain diameter was estimated at 20 nm, whereas the original grain size of YSZ before implantation was 400 nm. This result implies that the grain size in the surface of a ceramic material can be decreased by ion beam amorphisation and subsequent recrystallisation at elevated temperatures

Towards a population of HMXB/NS microquasars as counterparts of low-latitude unidentified EGRET sources

The discovery of the microquasar LS 5039 well within the 95% conficence contour of the Unidentified EGRET Source (UES) 3EG J1824-1514 was a major step towards the possible association between microquasars (MQs) and UESs. The recent discovery of precessing relativistic radio jets in LS I +61 303, a source associated for long time with 2CG 135+01 and with the UES 3EG J0241+6103, has given further support to this idea. Finally, the very recently proposed association between the microquasar candidate AX J1639.0-4642 and the UES 3EG J1639-4702 points towards a population of High Mass X-ray Binary (HMXB)/Neutron Star (NS) microquasars as counterparts of low-latitude unidentified EGRET sources.Comment: 12 pages, 7 figures. Proceedings of the Conference "The Multiwavelength Approach to Unidentified Gamma-ray Sources", to appear in the journal Astrophysics and Space Scienc

Social Change and Betty Friedan's The Feminine Mystique: A Study of the Charismatic Author-Leader

In this thesis I explore the significance of the publication of Betty Friedan's The Feminine Mystique (1963) to the emergence of the second wave Women's Liberation Movement in the US in the late 1960s. To this end, I deploy key concepts provided through social movement theory (eg collective identity, collective action frames, social problem construction). I also incorporate Max Weber and Antonio Gramsci's insights on the indispensable role played by leaders who demonstrate a clear and effective political will. Weber's three part model of pure charisma is used as a general template for understanding the impact of Friedan's text. I critique aspects of Weber's theory of charisma, in particular his failure to appreciate that the written word can mark the initial emergence phase of charisma rather than its routinisation. I augment Weber's insights on charismatic leadership by attending to Gramsci's emphasis on the necessity of winning the 'war of ideas' that must be waged at the level of civil society within advanced capitalist societies. I examine Gramsci's understanding of the power available to the organic intellectual who is aligned with the interests of subaltern groups and who succeeds in revealing the hegemonic commitments of accepted 'common sense'. In the latter part of this thesis, I apply these many useful concepts to my case study analysis of Betty Friedan's The Feminine Mystique. I argue that Friedan's accessible, middlebrow text gave birth to a new discursive politics which was critically important not only for older women, but for a younger generation of more radicalised women. I emphasise how Friedan's text mounted a concerted attack on the discursive construction of femininity under patriarchal capitalism. I question Friedan's diagnostic claim that the problems American women faced were adequately captured by the terminology of the trapped housewife syndrome. I conclude by arguing that social movement researchers have to date failed to appreciate the leadership potential of the charismatic author-leader who succeeds in addressing and offering a solution to a pressing social problem through the medium of a best-selling, middlebrow text

Colossal dielectric constants in transition-metal oxides

Many transition-metal oxides show very large ("colossal") magnitudes of the dielectric constant and thus have immense potential for applications in modern microelectronics and for the development of new capacitance-based energy-storage devices. In the present work, we thoroughly discuss the mechanisms that can lead to colossal values of the dielectric constant, especially emphasising effects generated by external and internal interfaces, including electronic phase separation. In addition, we provide a detailed overview and discussion of the dielectric properties of CaCu3Ti4O12 and related systems, which is today's most investigated material with colossal dielectric constant. Also a variety of further transition-metal oxides with large dielectric constants are treated in detail, among them the system La2-xSrxNiO4 where electronic phase separation may play a role in the generation of a colossal dielectric constant.Comment: 31 pages, 18 figures, submitted to Eur. Phys. J. for publication in the Special Topics volume "Cooperative Phenomena in Solids: Metal-Insulator Transitions and Ordering of Microscopic Degrees of Freedom

Inter-method reliability of the modified Rankin Scale in patients with subarachnoid hemorrhage

Background and objectives The modified Rankin Scale (mRS) is one of the most frequently used outcome measures in trials in patients with an aneurysmal subarachnoid hemorrhage (aSAH). The assessment method of the mRS is often not clearly described in trials, while the method used might influence the mRS score. The aim of this study is to evaluate the inter-method reliability of different assessment methods of the mRS.Methods This is a prospective, randomized, multicenter study with follow-up at 6 weeks and 6 months. Patients aged >= 18 years with aSAH were randomized to either a structured interview or a self-assessment of the mRS. Patients were seen by a physician who assigned an mRS score, followed by either the structured interview or the self-assessment. Inter-method reliability was assessed with the quadratic weighted kappa score and percentage of agreement. Assessment of feasibility of the self-assessment was done by a feasibility questionnaire.Results The quadratic weighted kappa was 0.60 between the assessment of the physician and structured interview and 0.56 between assessment of the physician and self-assessment. Percentage agreement was, respectively, 50.8 and 19.6%. The assessment of the mRS through a structured interview and by self-assessment resulted in systematically higher mRS scores than the mRS scored by the physician. Self-assessment of the mRS was proven feasible.Discussion The mRS scores obtained with different assessment methods differ significantly. The agreement between the scores is low, although the reliability between the assessment methods is good. This should be considered when using the mRS in clinical trials.Scientific Assessment and Innovation in Neurosurgical Treatment Strategie