До ювілею В.П. Кухаря

26 січня 2012 року виповнилося сімдесят років видатному вченому в галузі біоорганічної, органічної та елементоорганічної хімії, засновнику нового наукового напряму хімії біорегуляторних процесів, відомому досліднику екологічних та ресурсоощадливих аспектів енергетики, нафтопереробки і нафтохімії, директору Інституту біоорганічної хімії та нафтохімії Національної академії наук України, академіку НАН України Валерію Павловичу Кухарю

Stochastic User Equilibrium Traffic Assignment with Price-sensitive Demand: Do Methods matter (much)?

We compare three stochastic user equilibrium traffic assignment models multinomial probit, nested logit, and generalized nested logit), using a congestible transport network. We test the models in two situations: one in which they have theoretically equivalent coefficients, and one in which they are calibrated to have similar traffic flows. In each case, we examine the differences in traffic flows between the SUE models, and use them to evaluate policy decisions, such as profit-maximizing tolling or second-best socially optimal tolling. We then investigate how the optimal tolls, and their performance, depend on the model choice, and hence, how important the differences between models are. We show that the differences between models are small, as a result of the congestibility of the network, and that a better calibration does not always lead to better traffic flow predictions. As the outcomes are so similar, it may be better to use computationally more efficient logit models instead of probit models, in at least some applications, even if the latter is preferable from a conceptual viewpoint

Minder en anders bemesten : onderzoeksresultaten tuinbouw op klei. Rozendaal, courgette 2009

In het kader van het project Minder en Anders Bemesten is op het bedrijf van Jan en Hans van Lierop een vervolgonderzoek uitgevoerd. In een veldexperiment in herhalingen is getracht de productie van courgette gelijkmatiger in het seizoen te verdelen door op twee peilers te steunen: een bescheiden bemesting om de productie in het begin van het seizoen te verhogen, en grasklaver als voorvrucht om de productie verderop in het seizoen te verhogen. De resultaten tonen dat deze aanpak werkt: met een relatief kleine bemesting is er geen sprake van een verlaagde opbrengst in de eerste helft van de productieperiode. Verder is de bodemstructuur verbeterd door de grasklaver en is de mestgift lager dan anders het geval zou zijn geweest

A simulation model shows how individual differences affect major life decisions

Individuals are faced with a number of major decisions throughout their lives, including the choice of a suitable education, career, and life partner. Making such ‘major life decisions’ is challenging, as is evidenced by substantial rates of divorce and drop-out from higher education. Although poor major life decisions can lead to considerable costs for both individuals and society, little is known about how people make these decisions. This is because major life decisions are not simple short-term weighings of options – they are strongly intertwined with identity development. Here, we present a simulation model of major life decisions that integrates the short-term perspective of decision science with the long-term perspective of identity theory. We model major life decisions as a process comprising many explorations of available options, resulting in changing commitments, and eventually leading to a decision. Using our model, we run a large-scale in silico experiment, systematically simulating how three key individual characteristics affect the choice process and the quality of the decision: (1) exploration tendency (broad vs in-depth), (2) accuracy in assessing how well options fit, and (3) selectiveness. We identify the types of individuals who are at risk of exhibiting ‘maladaptive’ decision dynamics, including ruminative exploration and rash decision making, and conclude that these features often, but not always, lead to bad decisions. Our simulation results generate concrete predictions that can be empirically tested and may eventually result in individually tailored tools to aid individuals in making major life decisions

Health-related quality of life and mental health problems after a disaster: Are chronically ill survivors more vulnerable to health problems?

Studies have shown that the chronically ill are at higher risk for reduced health-related quality of life (HRQL) and for mental health problems. A combination with traumatic events might increase this risk. This longitudinal study among 1216 survivors of a disaster examines whether chronically ill survivors had a different course of HRQL and mental health problems compared to survivors without chronic diseases. HRQL and mental health problems were measured 3 weeks, 18 months and 4 years post-disaster. Data on pre-disaster chronic diseases was obtained from the electronic medical records of general practitioners. Random coefficient analyses showed significant interaction effects for social functioning, bodily pain and emotional role limitations at T2 only. Chronically ill survivors did not consistently have a different course of general health, physical role limitations, and mental health problems. In conclusion, chronic diseases were not an important risk factor for impaired HRQL and mental health problems among survivors

Essential non-clinical skills and training required by dentists in South Africa

Dentists possess clinical experience garnered within supervised clinical settings, primarily aimed at diagnosing, treating and preventing oral cavity related diseases.1 Undergraduate dentistry training mostly focuses on the scientific underpinnings of this discipline and building clinical experience, not allowing adequate time for additional coursework.1 According to Haslach et al.2, dentists choose dental careers because they want to help and work with people, as well as desire job and financial security. The current economic downturn has led to a revenue plunge for many independent dental practices, attributed partially to less per capita patient expenditure.3 In response, patients have increasingly embraced preventative measures over more costly procedures, seeking to minimise expenses.4 The global financial crisis further underscores the value of leadership development, given its potential impact on the efficacy of clinic leaders

Pulmonary hypertension after transjugular intrahepatic portosystemic shunt (TIPS)

We reported the case of a patient in whom severe, and ultimately fatal, pulmonary hypertension developed 1.5 yrs after transjugular intrahepatic portosystemic shunt (TIPS). Pulmonary artery pressures were not affected by 100% oxygen, prostacyclin or nifedipine. Postmortem examinations showed pulmonary and vascular abnormalities typical of pulmonary hypertension. Pulmonary artery pressures should be measured in each patient with otherwise not readily explained dyspnoea following transjugular intrahepatic portosystemic shunt

Increased expression of chemokines DC-CK1, ELC and TARC by dendritic cells and in synovium from patients with rheumatoid arthritis

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