Omgaan met schaarste

Schaarste, het thema van mijn oratie, is één van de centrale begrippen in de economie. Volgens Van Dale is schaarste de omstandigheid dat iets in onvoldoende hoeveelheid beschikbaar is. Dagelijks ervaren we de schaarste aan een bepaald goed. Er zijn te weinig betaalbare huizen voor jonge mensen en te weinig leraren in het onderwijs. Soms is er een tekort aan bedden op de afdeling of onvoldoende MRI capaciteit. Maar ook het ontbreken van tijd en geld om die wereldreis te maken met je geliefde is een vorm van schaarste. Kortom schaarste hoort bij het leven…….. en bij de dood. Want die is vaak heel nabij als door een tekort aan organen de transplantatie van een nier, lever of hart niet mogelijk is. Schaarste dwingt tot het maken van keuzes. Schaarste stimuleert ook het zoeken naar creatieve oplossingen. Soms is schaarste de reden voor revolutie en misdaad, aldus de Griekse fi losoof Aristoteles. In het tweede gedeelte van mijn oratie zal ik aantonen dat de zorg voor ernstig zieke leverpatiënten soms tekortschiet door schaarste aan donororganen, nog ontbrekende wetenschappelijke kennis, schaarste aan hepatologen en schaarste aan transplantatiechirurgen. Dat zijn geen natuurverschijnselen die ons overkomen, maar problemen die of met politieke wil of met voldoende onderzoeksgeld zijn op te lossen. Ik zal daarvoor een aantal suggesties doen. Maar eerst zal ik in het kort de geschiedenis van de levertransplantatie (LTx) schetsen. Uiteraard kijk ik daarbij ook speciaal naar Rotterdam

Modeling of transpiration reduction in van Genuchten-Mualem type soils

We derive an analytic expression for the matric flux potential (M) for van Genuchten-Mualem (VGM) type soils which can also be written in terms of a converging infinite series. Considering the first four terms of this series, the accuracy of the approximation was verified by comparing it to values of M estimated by numerical finite difference integration. Using values of the parameters for three soils from different texture classes, the proposed four-term approximation showed an almost perfect match with the numerical solution, except for effective saturations higher than 0.9. Including more terms reduced the discrepancy but also increased the complexity of the equation. The four-term equation can be used for most applications. Cases with special interest in nearly saturated soils should include more terms from the infinite series. A transpiration reduction function for use with the VGM equations is derived by combining the derived expression for M with a root water extraction model. The shape of the resulting reduction function and its dependency on the derivative of the soil hydraulic diffusivity D with respect to the soil water content theta is discussed. Positive and negative values of dD/d theta yield concave and convex or S-shaped reduction functions, respectively. On the basis of three data sets, the hydraulic properties of virtually all soils yield concave reduction curves. Such curves based solely on soil hydraulic properties do not account for the complex interactions between shoot growth, root growth, and water availabilit

God as First Known: The Common Ground of Philosophy and Theology in Bonaventure s Thought

Goris, W. [Promotor

Diagnosis and prevention of cytomegalovirus infection after organtransplantation

Although the introduction of cyclosporin A (GsA) as the main immunosuppressive agent seems to have influenced the incidence and severity of CMV disease in a positive way, the reported incidence of clinical overt CMV infection is still 2 - 23 % and 1 - 3 % of the transplant recipients die from CMV infection. It is therefore obvious that this virus remains a major pathogen after organ transplantation. DIAGNOSIS OF CMV INFECTION When CMV disease is diagnosed, reduction of immunosuppressive therapy will markedly decrease morbidity and mortality without affecting graft survival. Moreover, antiviral therapy with either ganciclovir or foscarnet can be considered in patients with severe symptomatic disease. This management of symptomatic CMV infections (tapering of immunosuppressive drugs and j or antiviral therapy) makes rapid and early diagnosis necessary. Although the measurement of virus specific antibodies is sensitive, the long physiological response-time of antibody synthesis (one to two weeks ) during active CMV infection makes this method inappropriate for rapid and early diagnosis. Moreover, in patients with immunosuppression antibody synthesis can be impaired. Detection of a morphological cytopathological effect (CPE) of CMV in tissue cultures has the same disadvantage. The method takes long time and is sometimes impossible due to bacterial contaminated specimens or coinfection with the herpes simplex virus. In this thesis two methods for rapid and early diagnosis of CMV infection are described. First, we compared in our patients the results obtained by a low-speed centrifugation assay in combination with immunofluorescence by a monoclonal antibody against early antigen of CMV with the results from the conventional tissue culture method. Second, an indirect method for detection of active CMV infection is described. In the peripheral blood of renal transplant recipients mononuclear subpopulations were monitored with monoclonal antibodies before, during and after CMV infection

Aspects of Hearing Aid Fitting Procedures

Sensorineural hearing loss is a common and chronic disorder that affects almost ten percent of the world population. In the Netherlands, it is also the major disorder in the working population [NCvB, 2008]. Hearing loss leads to restriction in the interaction with others and withdrawal from participation in (social) activities. Due to the size of the problem and the vast impact on the function, hearing rehabilitation is an important issue. Although hearing rehabilitation focuses on many more aspects such as learning of communication strategies and adaptation to the acoustical environment, hearing aid fitting is one of its first essential steps. Hearing aids have to amplify sound to a level above the hearing threshold to utilize the residual hearing capacity of the ear as much as possible. In the 20th century, a number of technological advances have taken place in amplification devices. These started from nonelectronic ear horns that were replaced by electronic hearing aids. Amplification was initially achieved by analogue circuits, while from the 1990s digital signal processors have entered the market. An enormously wide variety of hearing aid models has become available since [Bentler & Duve, 2000]. Aside from differences that have to do with the sound that is being produced, hearing aids can be classified with respect to type. While the technological development started with body-worn hearing aids, we nowadays distinguish behind-the-ear (BTE), in-the-ear (ITE) and hearing aids that fit partly or completely in the ear canal (CIC). These types are available in a wide variety of models, colours and sizes and are of various brands. A classical feature is the telecoil for use with induction loops. Options that are available for modern hearing aids are remote controls, infrared and fm-receivers, the use of multiple programs and water resistant housings. Last but not least, every hearing aid has its own price. It is obvious that the search for the hearing aid that is most suitable for the individual patient can be regarded as a real challenge. It is not only based on measures like speech perception but may also be determined by listening comfort, wearing comfort and functionality. This is all devised during the selection phase of a hearing aid fitting. Aside from differences in the exterior and the above-mentioned features, hearing aids can be distinguished with respect to the sound that they produce. For a long time the amount of amplification and the frequency characteristic were the main issues. Later on, electronic compression circuits were added to limit the maximum output and/or gain of the hearing aid. More recently developed features are feedback reduction, noise cancellation and the use of directional microphones. To adjust the various controls of the hearing aid in order to optimally compensate for the affected cochlea is a challenge on its own. This is done during the adjustment phase of a hearing aid fitting. Procedures for hearing aid fitting have been invented in parallel with the development of hearing aid technology

General procedure to initialize the cyclic soil water balance by the Thornthwaite and Mather method

The original Thornthwaite and Mather method, proposed in 1955 to calculate a climatic monthly cyclic soil water balance, is frequently used as an iterative procedure due to its low input requirements and coherent estimates of water balance components. Using long term data sets to establish a characteristic water balance of a location, the initial soil water storage is generally assumed to be at field capacity at the end of the last month of the wet season, unless the climate is (semi-) arid when the soil water storage is lower than the soil water holding capacity. To close the water balance, several iterations might be necessary, which can be troublesome in many situations. For (semi-) arid climates with one dry season, Mendon a derived in 1958 an equation to quantify the soil water storage monthly at the end of the last month of the wet season, which avoids iteration procedures and closes the balance in one calculation. The cyclic daily water balance application is needed to obtain more accurate water balance output estimates. In this note, an equation to express the water storage for the case of the occurrence of more than one dry season per year is presented as a generalization of Mendon a's equation, also avoiding iteration procedures

Живописець козацької звитяги

Sustainable supply chain governance approaches aim for improvement of environmental and community living conditions at the developing country's side of the global supply chains. Impact evaluation in remote and multiple sourcing countries is hardly done in practice because of its complexity and costs. Evaluating the impact potential with this methodology enables an easier route for assessing and comparing the fast growing number of standard systems. This article describes a methodology for assessing the system performance and impact potential of 'sustainable supply chain governance (SSCG) systems' and uses two cases of certifying sustainable products in the coffee sector (Fairtrade and Utz Certified) for verification of the method. The approach rests on the assumption that a certification system can have substantial impact reduction if it is well organised in its content and organisation: the governance system impact potential (GSIP). Two exemplary pilot cases show that changes made over the years in both systems are directly visible with the methodology and it can be used for monitoring the progress in markets for sustainable products

The mechanical properties of thin alumina film deposited by metal-organic chemical vapour deposition

Amorphous alumina films were deposited by metal-organic chemical vapour deposition (MOCVD) on stainless steel, type AISI 304. The MOCVD experiments were performed in nitrogen at low and atmospheric pressures. The effects of deposition temperature, growth rate and film thickness on the mechanical properties have been studied.\ud \ud The experiments were performed with the dynamic ultra-micro-hardness tester, DUH-200, and the scanning scratch tester, SST-101, both developed by Shimadzu. The DUH-200 is associated with crack formation during indentation. This technique involves a qualitative method to study the crack behaviour of the thin alumina films as well as a method to estimate the fracture toughness of the film and the film/substrate interface. The experiments performed with the SST-101 are based on the estimation of the film adhesion to the substrate by determining a critical load; the load where the film starts to spall or to delaminate.\ud \ud The best mechanical properties were obtained using low deposition rates and high deposition temperatures. Therefore, low-pressure MOCVD is recommended in addition to the deposition of alumina films at high temperatures

Епоха "пост": людина в перспективі "нової духовності"

Розглянуто основні проблеми сучасного суспільства, пов’язані із антропологічною кризою, кардинальними змінами у темпоральності, способі буття людини. Проаналізовано ситуацію заміни попередніх гуманістичних ціннісних систем на більш “технізовані”, що призводить до виникнення нового типу людини – “постлюдини”. Посилюється вплив на людей “світу віртуальної реальності”. Нове штучне середовище “сканує”, приймає лише інформаційний аспект людини, вводячи її як цілісну істоту в стан кризи. Доведено актуальність відповідей на смислові запитання епохи, пов’язані із світоглядом, духовністю та цінностями.The main problems of modern society, related to the anthropological crisis, fundamental changes in temporality, ways of human being are considered. There is an analysis of situation of replacing the previous humanistic value systems on a more “technicized”, which causes a new type of man – “posthuman”. The impact on “the world of virtual reality” people is growing. New artifi cial environment “scans”, takes only informational aspect of human, introducing it as complete being in a state of crisis. The urgency of responses to semantic question of the epoch, related to the outlook, spirituality and values is justifi ed