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This thesis explores the application of stochastic control techniques in a parameter study to examine the implications of climate taxes on a pension fund. The problem at hand involves modeling a pension fund comprising various assets, with a specific focus on the portfolio’s emissions and the associated tax implications. This research aims to find the optimal allocation strategies for managing the pension fund, considering both the portfolio’s performance and the impact of taxes. By utilizing stochastic control, we explore how various factors, such as risk preferences, tax regulations, and emission considerations, influence the optimal investment and consumption policies. To solve this complex problem, the BCOS method is employed to numerically tackle the fully coupled Forward-Backward Stochastic Differential Equations (FBSDEs) arising from the control problem. The BCOS method, known for its effectiveness in solving coupled FBSDEs, is applied to tackle the complexity of the problem. This numerical approach enables the exploration of different control parameters, allowing for a comprehensive parameter study. Numerical experiments are presented to illustrate the different outcomes by varying the parameters, thus revealing the dynamic nature of the solutions.

The geographical features in the Southern part of Limburg forces precipitation from upstream located areas to flow through a bottleneck, which is exactly located at the city centre of Valkenburg. This makes increasing the safety level more complicated than in other areas. The safety level of Valkenburg has a lower standard in comparison to the rest of the country, namely 1 in 25 years. The combination of those two characteristics is not desirable. Official documents state that this lower standard is based on detailed (societal) Cost-Benefit Analyses. In reality however, the safety standard is based on simple back of the envelope calculations. The Limburg Waterboard has indeed developed a Cost-Benefit tool which they could use to find out whether the implementation of safety measures are cost effective, however they have not been able to implement it until now. Additional safety measures to increase the safety level are assumed too costly based on the same brief calculations. It is doubtful whether individual risk laws are met, since the Limburg Waterboard assumes no casualties in the Geul area. The 2021 flood however showed that this might be false for future floods which get more severe over time due to climate change. The citizens and entrepreneurs in Valkenburg were not completely aware of the risks they were exposed to and their sense of safety related to flooding decreased after the flood. Most of the people questioned in a survey demanded a higher safety level than the current standard. They would even be open for an increase in tax to realise this improvement. Raising the quay walls would be a cost-effective solution according to some of the citizens. However, the entrepreneurs who rely on tourist based income, do not prefer this option due to loss in aesthetic value. Hydraulic, structural, and non-technical solutions which are investigated in this report, have the aim to increase the safety level or make the safety level more accept, Multidiciplinairy project

The objective of this paper is to tackle the problems by analysing the choice of safety level in the city of Valkenburg, and redesigning the flood risk management system using different solutions coupled with certain safety levels. This raises the question whether redesigning the river Geul/Valkenburg system is economically feasible to prevent future floods, and if so, what are some feasible designs. Therefore the research question of this project is: How can the flood risk management system of Valkenburg be redesigned in order to improve the overall safety level? Within this main frame, the current safety standards are compared to those preferred by different stakeholders like the municipality and the citizens. The safety level will also be compared to other flood defense systems in The Netherlands. The current standards are further analyzed by assessing the damage of the previous floods and applying other, e.g. more innovative measures which may increase the flood safety at relatively low costs. The range of applicability of those measures (costs and possible safety levels) will be indicated.

Any industry is focusing on creating an environment that is as safe as possible for everyone that is involved. This is no different for the construction industry. However, the construction industry is placed second in the ranking of most dangerous industries. The Dutch Safety Board, being an independent administrative body, has recommended to integrate a third party into the contractual general terms and conditions such as the UAC for integrated contracts. The objective of this research is to examine whether there is any potential to integrate a third party into the UAC-IC 2005 contract. This potential is being examined using a comparison between the UAC-IC 2005 and FIDIC Yellow Book 1999, a contract in which a third party is already present. In this comparison, the main focus points are the "vital tasks & responsibilities" that are necessary in order to safeguard safety on site, safety of the surrounding area & structural safety. This thesis has found that the three types of safety can be improved if the vital tasks & responsibilities are properly performed. These tasks & responsibilities mainly relate to the management of project specific and safety related risks, and to the safety approach that is a result of this risk management system. From a theoretical point of view, the UAC-IC 2005 and the Dutch Building Decree are able to facilitate these vital tasks & responsibilities. The ON is responsible for most of the vital tasks & responsibilities, and the OG has the possibility to use an external control mechanism to verify this. The practical situation is however different. It is not uncommon that other aspects like time, or money can get more important for the contracting party than proper risk management processes and the corresponding safety approach. Work is not executed as intended, but rather as work-as-actually-done. The OG’s incentives in the UAC-IC can be insufficient for him to effectively perform this external control me, Civil Engineering | Construction Management and Engineering

Treatment strategies for penetrating rectal injuries (PRI) in civilian settings are still not uniformly agreed, in part since high-energy transfer PRI, such as is frequently seen in military settings, are not taken into account. Here, we describe three cases of PRI, treated in a deployed combat environment, and outline the management strategies successfully employed. We also discuss the literature regarding PRI management. Where there is a major soft tissue component, repetitive debridement and vacuum therapy is useful. A loop or end colostomy should be used, depending on the degree of damage to the anal sphincter complex.

BACKGROUND: Routine surgical exploration after penetrating upper extremity trauma (PUET) to exclude arterial injury leads to a large number of negative explorations and iatrogenic injuries. Selective non-operative management (SNOM) is gaining in favor for patients with PUET. The present study was undertaken to assess the validity of SNOM in PUET and to present a practical management algorithm. METHODS: All consecutive patients presenting to a tertiary referral center following PUET were included in this prospective observational cohort study. Patients were managed along Advanced Trauma Life Support (ATLS (c)) guidelines, and based on clinical manifestations, either underwent emergency surgery or were treated conservatively with or without additional diagnostic investigations. Computed tomography angiography (CTA) was indicated by a preset protocol based on the physical examination. RESULTS: During the four-month study period, 161 patients with PUET were admitted. Sixteen (9.9%) patients underwent emergency surgery, revealing 14 vascular injuries. Another 8 (5.0%) patients underwent vascular exploration following CTA. The remaining patients (n=137) were managed non-operatively for vascular matters. Eighteen (11.2%) patients required semi-elective surgical intervention for fractures or nerve injuries. During the follow- up, no missed vascular injuries were detected. CONCLUSION: Neither routine exploration nor routine CTA is indicated after PUET. Stable patients should undergo additional investigation based on clinical findings only. SNOM is a feasible and safe strategy after PUET.

Treatment of perforated diverticulitis depends on disease severity classified according to Hinchey's preoperative classification. This study assessed the accuracy of preoperative staging of perforated diverticulitis by computerized tomography (CT) scanning. All patients who presented with perforated diverticulitis between 1999 and 2009 in two teaching hospitals of Rotterdam, the Netherlands, and in addition had a preoperative CT scan within 24 h before emergency surgery were included. Two radiologists reviewed all CT scans and were asked to classify the severity of the disease according to the Hinchey classification. The CT classification was compared to Hinchey's classification at surgery. Seventy-five patients were included, 48 of whom (64 %) were classified Hinchey 3 or 4 perforated diverticulitis during surgery. The positive predictive value of preoperative CT scanning for different stages of perforated diverticulitis ranged from 45 to 89 %, and accuracy was between 71 and 92 %. The combination of a large amount of free intra-abdominal air and fluid was strongly associated with Hinchey 3 or 4 and therefore represented a reliable indicator for required surgical treatment. The accuracy of predicting Hinchey's classification by preoperative CT scanning is not very high. Nonetheless, free intra-abdominal air in combination with diffuse fluid is a reliable indication for surgery as it is strongly associated with perforated diverticulitis with generalized peritonitis. In 42 % of cases, Hinchey 3 perforated diverticulitis is falsely classified as Hinchey 1 or 2 by CT scanning.

Background: Routine surgical exploration after penetrating neck injury (PNI) leads to a large number of negative neck explorations and potential iatrogenic injury. Selective non-operative management (SNOM) of PNI is gaining favour. The present study assessed the feasibility of SNOM in PNI. Methods: Seventy-seven consecutive patients with PNI presenting to a tertiary trauma centre were included in this prospective study from September 2009 to December 2009. All patients were managed according to Advanced Trauma Life Support guidelines, and either underwent emergency surgery or were managed without surgery, based on clinical presentation and/or outcome of special investigations. Results: Eight patients (10 per cent) were haemodynamically unstable at presentation. Foley catheter balloon tamponade (FCBT) was successful in stopping active bleeding in six of these patients, and diagnostic angiography revealed an arterial injury in five. The remaining 69 patients were managed using SNOM. Angiography or computed tomography was done in 41 patients (53 per cent), and showed arterial injury in 15. These injuries were treated surgically (7 patients), radiologically (stenting in 3 Conclusion: FCBT was useful in patients with PNI and active bleeding. Stable patients should undergo additional investigation based on clinical findings only.

Mechanical bowel preparation (MBP) has been shown to have no influence on the incidence of anastomotic leakage in overall colorectal surgery. The role of MBP in elective surgery in combination with an inflammatory component such as diverticulitis is yet unclear. This study evaluates the effects of MBP on anastomotic leakage and other septic complications in 190 patients who underwent elective surgery for colonic diverticulitis. A subgroup analysis was performed in a prior multicenter (13 hospitals) randomized trial comparing clinical outcome of MBP versus no MBP in elective colorectal surgery. Primary endpoint was the occurrence of anastomotic leakage in patients operated on for diverticulitis, and secondary endpoints were septic complications and mortality. Out of a total of 1,354 patients, 190 underwent elective colorectal surgery (resection with primary anastomosis) for (recurrent or stenotic) diverticulitis. One hundred and three patients underwent MBP prior to surgery and 87 did not. Anastomotic leakage occurred in 7.8 % of patients treated with MBP and in 5.7 % of patients not treated with MBP (p = 0.79). There were no significant differences between the groups in septic complications and mortality. Mechanical bowel preparation has no influence on the incidence of anastomotic leakage, or other septic complications, and may be safely omitted in case of elective colorectal surgery for diverticulitis.

Introduction The existing literature regarding acute perforated diverticulitis only reports about short-term outcome; long-term following outcomes have not been assessed before. The aim of this study was to assess long-term quality of life (QOL) after emergency surgery for perforated diverticulitis. Patients and Methods Validated QOL questionnaires (EQ-VAS, EQ-5D index, QLQ-C30, and QLQ-CR38) were sent to all eligible patients who had undergone emergency surgery for perforated diverticulitis in five teaching hospitals between 1990 and 2005. Differences were compared between patients that had undergone Hartmann's procedure (HP) or resection with primary anastomosis (PA) and also compared to a sex- and age-matched sample of healthy subjects. Results Of a total of 340 patients, only 150 patients (44%) were found still alive in July 2007 (median follow-up 71 months). The response rate was 87%. In patients with PA, QOL was similar to the general population, whereas QOL after HP was significantly lower. The presence of a stoma was found to be an independent factor related to worse QOL. The deterioration in QOL was mainly due to problems in physical function and body image. Conclusions Survivors after perforated diverticulitis had a worse QOL than the general population, which was mainly due to the presence of an end colostomy. QOL may improve if these stomas are reversed or not be performed in the first place.

The supposed optimal treatment of perforated diverticulitis with generalized peritonitis has changed several times during the last century, but at present is still unclear. The first cases of complicated perforated diverticulitis of the colon were reported in the beginning of the twentieth century. At that time the first therapeutic guidelines were postulated in which an initial nonresectional procedure was provided to be the safest plan of management. After many years in which resection had become standard practice, today, one century later, again (laparoscopic) nonresectional surgery is presented as a safe and promising alternative in treatment of complicated perforated diverticulitis. The question rises what had happened to close the circle? This paper includes a historic summary of changing patterns in surgical strategies in perforated diverticulitis complicated by generalized peritonitis.