Het bepalen van overschrijdingskansen voor rivierdijken uit afvoeren en gekorreleerde golfoplopen

Indien de rivierwaterstand zo hoog is, dat de uiterwaarden onderlopen, kunnen de golven een golfoploop tegen de dijk veroorzaken. Uit het gekombineerd optreden van hoge afvoeren en golfoplopen zijn overschrijdingskansen berekend voor een punt van de zuidelijke Waalbandijk stroomafwaarts van Nijmegen

Desarrollos recientes en el diseño de embarcaciones rápidas

During the last twenty years, Damen Shipyards, a multinational shipbuilding group with 6000 employees worldwide, has done extensive research on the development of hull designs for fast monohull vessels. In the 1990s the Enlarged Ship Concept was developed, leading to highly improved sea keeping capabilities and vessel behaviour in waves at high speed. This hull design concept was applied in the Damen SPa 4207 patrol vessel and has proven extremely successful, reducing vertical accelerations by 50% and, thus, allowing vessels to keep operating at high speed in waves. Over 25 units of the Damen SPa 4207 have been delivered so far. After the successful introduction of the Enlarged Ship Concept, Damen and Delft University continued developing the next generation hull form: the axebow design. Compared to the already good sea keeping capacities of the Enlarged Ship Concept, model tests indicated a further reduction of vertical accelerations. This was proven by real-time measurements on the first built axebow vessels in 2006 and 2007. In the last 3 years, over 30 axe bow supply vessels have been delivered to very satisfied operators. As a next step, Damen has applied the axe bow design to the latest patrol vessel design, the Damen SPa 5009. The first vessel of this design is currently under construction and its trials are scheduled by the end of 2011. The paper describes the background of the research done by Damen and Delft University, focusing on the mathematical and scientific aspects of the axebow design and its application on various ship types. The development and design of the latest Damen patrol vessel, SPa 5009, will be introduced, describing its seakeeping performance, operatability and crew ergonomics. Finally, the paper will mention the current and future research topics that Damen and Delft University are working on together, identifying the developments of the future generation patrol vessels.Durante los últimos 20 años, los astilleros Damen, un grupo multinacional constructor de buques con 6000 empleados alrededor del mundo, han investigado ampliamente sobre el desarrollo de los diseños de cascos para embarcaciones rápidas monocasco. Durante los 90, el Concepto del Buque Ampliado fue desarrollado, conllevando a capacidades mejoradas de navegabilidad y comportamiento de la embarcación en oleaje a alta velocidad. Este concepto de diseño de casco se aplicó en la embarcación de patrullaje Damen SPa 4207, y se ha comprobado extremadamente exitoso, reduciendo aceleraciones verticales por 50% y, así, permitiendo que las embarcaciones sigan operando a alta velocidad en oleaje. Más de 25 unidades del Damen SPa 4207 se han entregado hasta la fecha. Luego de la presentación exitosa del Concepto del Buque Ampliado, Damen y la Universidad Delft continuaron desarrollando la forma de casco de la siguiente generación: el diseño de proa en arco (axebow design). Comparado con las ya buenas capacidades de navegabilidad del Concepto del Buque Ampliado, pruebas del modelo indican adicional reducción de la aceleración vertical. Esto se comprobó mediante mediciones en tiempo real en las primeras embarcaciones construidas con proa en arco (axebow) en 2006 y 2007. En los últimos tres años, más de 30 buques de suministro de proa en arco se han entregado a operadores muy satisfechos. Como paso siguiente, Damen ha aplicado el diseño de proa en arco a su más reciente diseño de embarcación de patrullaje, el Damen SPa 5009. La primera embarcación de este diseño está actualmente bajo construcción y sus pruebas están programadas para fines de 2011. El documento describe los antecedentes de la investigación realizada por Damen y la Universidad Delft, enfocándose en los aspectos matemáticos y científicos del diseño de proa en arco y su aplicación en varios tipos de embarcaciones. El desarrollo y diseño de la más reciente embarcación de patrullaje, SPa 5009, se presentará, describiendo su desempeño de navegabilidad, operabilidad y ergonomía de tripulación. Finalmente, el documento mencionará los temas de investigación actuales y a future sobre los cuales Damen y la Universidad Delft están trabajando conjuntamente, identificando los desarrollos de las embarcaciones de patrullaje de futura generación

Experiences of informal caregivers of people with dementia with nursing care in acute hospitals:A descriptive mixed-methods study

Aims To explore the experiences of informal caregivers of people with dementia with the hospitalization of their relative concerning patient care, interactions with nurses, caregivers' situation and the acute hospital environment. Design Mixed-methods design. Methods The data were collected using an online questionnaire among a panel of caregivers (n = 129), together with a focus group and individual interviews from February to November 2019. The data were triangulated and analysed using a conceptual framework. Results Almost half of the respondents were satisfied with the extent to which nurses considered the patient's dementia. Activities to prevent challenging behaviours and provide person-centred care were rarely seen by the caregivers. Caregivers experienced strain, intensified by a perceived lack of adequate communication and did not feel like partners in care; they also expressed concern about environmental safety. A key suggestion of caregivers was to create a special department for people with dementia, with specialized nurses. Conclusion Positive experiences of caregivers are reported in relation to how nurses take dementia into account, involvement in care and shared decision making. Adverse experiences are described in relation to disease-oriented care, ineffective communication and an unfamiliar environment. Caregivers expressed increased involvement when included in decisions and care when care was performed as described by the triangle of care model. Caregivers reported better care when a person-centred approach was observed. Outcomes can be used in training to help nurses reflect and look for improvements. Impact This study confirms that caregivers perceive that when they are more involved in care, this can contribute to improving the care of patients with dementia. The study is relevant for nurses to reflect on their own experiences and become aware of patients' caregivers' perspectives. It also provides insights to improve nurses' training and for organizations to make the care and environment more dementia-friendly

Nurses' perceptions in caring for people with dementia in Dutch acute hospitals

AIMS AND OBJECTIVES: Overall, this study aimed to describe nursing care for patients with dementia in acute hospitals, with the objectives of describing the provided nursing care (a), nurses’ attitudes and perceptions in caring for patients with dementia (b), and exploring how nurses deal with challenging behaviour (c). Additionally, we determined background variables associated with caring for people with dementia. BACKGROUND: Due to comorbidities, people with dementia are frequently admitted to acute care hospitals. Here, they are at high risk of complications. Nurses strive for good care but regularly experience insufficient knowledge and skills regarding caring for people with dementia. DESIGN: A cross‐sectional survey study design. METHODS: Data were collected in seven Dutch acute hospitals and through social media. In total, 229 hospital nurses completed the questionnaire. We used the Geriatric In‐Hospital Nursing Care Questionnaire and two subscales of Hynninen on managing challenging behaviour. This report followed the STROBE checklist. RESULTS: Nurses express that they often apply general preventive interventions not explicitly related to dementia care. In general, nurses have mixed feelings about the nursing care provided in their department. For challenging behaviour, a variety of approaches, including restrictive measures and medication, is applied. The nurses’ attitudes and perceptions are influenced by the type of hospital where the nurses work, the level of education, the number of hours nurses work, and if the nurses completed a course on dementia in the last year. CONCLUSIONS: Despite a positive attitude, nurses do not have the specific knowledge and skills needed to provide proper care. Nurses who recently completed a course on dementia had more positive attitudes and perceptions towards caring for patients with dementia. RELEVANCE TO CLINICAL PRACTICE: The results of this research can be used to improve the quality of nursing care for patients with dementia in acute hospitals

De relatie tussen de samenstelling van koeie-urine en het optreden van urinebrandplekken in grasland

Het gehalte aan ureum, stikstof, hippuurzuur, kalium, natrium en de geleidbaarheid van elke urine-lozing van 10 melkkoeien werd gemeten, waarbij de bijbehorende schade aan de grasmat werd geregistreerd, om de relatie tussen urine-samenstelling en de mate van verbranding van de graszode nader te onderzoeken. De lozingen van 6.00-12.00 uur hadden gemiddeld het hoogste gehalte aan ureum en N-totaal en de lozingen van 18.00-24.00 uur het laagste. Hetzelfde geldt voor de geleidbaarheid. Het ureumgehalte in de urine bleek de mate van verbranding het beste te verklare

Structure-based directed evolution improves S. cerevisiae growth on xylose by influencing in vivo enzyme performance

Background: Efficient bioethanol production from hemicellulose feedstocks by Saccharomyces cerevisiae requires xylose utilization. Whereas S. cerevisiae does not metabolize xylose, engineered strains that express xylose isomerase can metabolize xylose by converting it to xylulose. For this, the type II xylose isomerase from Piromyces (PirXI) is used but the in vivo activity is rather low and very high levels of the enzyme are needed for xylose metabolism. In this study, we explore the use of protein engineering and in vivo selection to improve the performance of PirXI. Recently solved crystal structures were used to focus mutagenesis efforts. Results: We constructed focused mutant libraries of Piromyces xylose isomerase by substitution of second shell residues around the substrate- and metal-binding sites. Following library transfer to S. cerevisiae and selection for enhanced xylose-supported growth under aerobic and anaerobic conditions, two novel xylose isomerase mutants were obtained, which were purified and subjected to biochemical and structural analysis. Apart from a small difference in response to metal availability, neither the new mutants nor mutants described earlier showed significant changes in catalytic performance under various in vitro assay conditions. Yet, in vivo performance was clearly improved. The enzymes appeared to function suboptimally in vivo due to enzyme loading with calcium, which gives poor xylose conversion kinetics. The results show that better in vivo enzyme performance is poorly reflected in kinetic parameters for xylose isomerization determined in vitro with a single type of added metal. Conclusion: This study shows that in vivo selection can identify xylose isomerase mutants with only minor changes in catalytic properties measured under standard conditions. Metal loading of xylose isomerase expressed in yeast is suboptimal and strongly influences kinetic properties. Metal uptake, distribution and binding to xylose isomerase are highly relevant for rapid xylose conversion and may be an important target for optimizing yeast xylose metabolism