854 research outputs found

    Natte natuur is niet kansloos

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    Ook als de meest extreme klimaatscenario’s uitkomen, daalt de grondwaterspiegel in Nederland waarschijnlijk niet dramatisch. Naar verwachting hebben neerslagtekorten in droge zomers een veel grotere invloed op boeren en natuur. Dat is goed nieuws voor natte natuurgebiede

    Ovarian Stimulation and the Endometrium: New Approaches and Insights

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    When one considers the recognized 'causes' of infertility, problems with gamete quality and availability rank highly, as does the means of their transport, whether it be through the fallopian tubes in the female or vas deferens in the male. Conception is seen as the primary goal, and fertility therapies are currently focused on helping couples achieve this. In around 25% of couples with fertility problems, medical investigation reveals no such clear cause. It is now understood however, that while a couple may succeed in conception, implantation failure may be the underlying reason for their difficulties in achieving a pregnancy (Macklon et al., 2002). Implantations depend on the succesful interaction between the embryo and the endometrium of the uterus. Since the earliest days of in vitro fertilization (IVF) the focus of attention has been the embryo. In order to obtain multiple embryos to allow selection for transfer to the uterus, complex ovarian stimulation regimens have been devised which result in many oocytes being harvested for fertilization. In most women, these stimulation regimens succefully achieve this aim. Yet despite the ability to produce large numbers of embryos for selection for transfer, pregnancy rates from IVF remain around 25% per started cycle (ESHRE 2008). Once the embryo is transferred into the uterus, it must interact with the endometrium, and in the majority of treatment cycles, this is the moment in which failure occurs. The role played by the endometrium as a determinant factor of fertility treatment, and in particular IVF outcomes remains unclear. Moreover, the impact of ovarian stimulation on endometrial quality is only now beginning to be elucidated. In this introductory chapter, the hormonal control of endometrial development is reviewed, and current approaches for assessing the receptivity of the endometrium to the embryo are critically assessed (Chapter 1.1.1). The concept of the 'implantation window' is introduced (Chapter 1.1.2) and the molecular regulation of endometrial maturation and implantation is reviewed (Chapter 1.2), with emphasis on the most important of the described markers of receptivity (Chapter 1.3). The challenges of studying the impact of ovarian stimulation on endometrium are described (Chapter 1.4) as a prelude to introducing a novel means of addressing these by studying endometrial secretion fluid (Chapter 1.5). These considerations lead to the defining of the objectives of the research described in this thesis (Chapter 1.6)

    Spectroscopic Analysis and Xray Diffraction of Zinnwaldite

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    This paper describes an X-ray diffraction and spectroscopic study, including infrared, near-infrared and Raman spectroscopy of some selected zinnwaldites. In general, zinnwaldite forms a member of the trioctahedral true micas with characteristically Li in the octahedral positions and low iron contents. Although the infrared spectrum of zinnwaldite has been described before, near infrared and Raman spectroscopy have not been used so far to study this mineral. X-ray diffraction showed that all the samples reported in this study have the 1M structure. The Raman spectra are characterised by a strong band at 700-705 cm-1 plus a broad band associated with the SiO modes around 1100 cm-1. Less intense bands are observed around 560, 475, 403 and 305 cm-1. The corresponding IR spectra show strong overlapping SiO modes around 1020 cm-1 plus less intense bands around 790, 745, 530, 470-475 and 440 cm-1. Two overlapping OH-stretching modes can be observed around 3550-3650 cm-1, in agreement with a broad band in the IR around 3450 cm-1 and a complex band around 3630 cm-1. The near-IR spectra basically reflect combination and overtone bands associated with protons in the zinnwaldite structure. A very broad band observed around 5230 cm-1 is characteristic for adsorbed water while bands around 4530, 4435 and 4260 cm-1 can be ascribed to metal-hydroxyl groups

    Chemotherapy in metastatic cancer of unknown primary

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    In general a patient is considered ta have a carcinoma of unknown primary site if na primary tumor ean be identified af ter a thorough history and physical examination, and a reasonabIe laboratory and radiologie work-up. This definition a180 requires a histological diagnosis of carcinoma. The importance of histologie (re)examination in the management of patients with carcinoma of unknown primary site has been emphasized by several authors. Light microscopie examinat ion may al ready provide a clue ta suggest the site of origin. lnununohistochemistry and/or electron microscopy are of additional value, particularly in patients with undifferentiated tumors. A substantial number of patients with a light microscopie diagnosis of anaplastic tumor or undifferentiated carcinoma ultimately prove to have a lymphomas

    Neoadjuvant treatment in esophageal cancer-established treatments and new developments reviewed

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    As the majority of patients experiences locoregional relapse and/or distant metastasis even after radical resection of esophageal cancer, many efforts have been made and are ongoing to identify the optimal multimodality treatment strategy. The true benefit and harm of neoadjuvant therapy including chemotherapy, radiotherapy or the combination, is still difficult to interpret given the heterogeneity in patient and tumor characteristics. Nonetheless, neoadjuvant chemoradiation with weekly carboplatin and paclitaxel (the CROSS regimen) is considered standard of care for squamous cell carcinoma in Europe. Definitive chemoradiation is considered an equal alternative in the United States. For adenocarcinoma, preoperative chemoradiation with a platinum and 5FU or the CROSS regimen and peri-operative chemotherapy with a platinum and 5FU or the FLOT (fluorouracil, leukovorin, oxaliplatin and docetaxel) regimen are all options. New developments in systemic anti-tumor therapy will most likely involve dual anti-HER2 inhibition or novel anti-HER2 antibody-drug conjugates for adenocarcinoma. Immunotherapy monotherapy in an unselected patient population does not seem to be as effective in esophageal cancer as it is in other cancer types. However, when we can correctly identify the subset of patients which does benefit from this treatment by employing new predictive markers, or find an effective synergistic combination of immunotherapy with chemotherapy and/or radiotherapy, immunotherapy could still improve patient outcome in the future.</p

    A Local Search Algorithm for Clustering in Software as a Service Networks

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    In this paper we present and analyze a model for clustering in networks that offer Software as a Service (SaaS). In this problem, organizations requesting a set of applications have to be assigned to clusters such that the costs of opening clusters and installing the necessary applications in clusters are minimized. We prove that this problem is NP-hard, and model it as an Integer Program with symmetry breaking constraints. We then propose a Tabu search heuristic for situations where good solutions are desired in a short computation time. Extensive computational experiments are conducted for evaluating the quality of the solutions obtained by the IP model and the Tabu Search heuristic. Experimental results indicate that the proposed Tabu Search is promising.integer programming;complexity theory;Tabu Search;software as a service

    Breakout Session E-2: Information

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    Virtuele hydrologie

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    De auteurs van dit artikel vinden dat een platform als de Commissie voor Hydrologisch Onderzoek (CHO) nuttig kan zijn om kennis uit te wisselen. Daarbij moet worden nagedacht hoe deze kennis voor langere tijd kan worden vastgehouden. Een belangrijk deel van de kennis die indertijd via de technische bijeenkomsten van de CHO is uitgewisseld en is vastgelegd in haar verslagen, is momenteel wellicht niet meer paraat. Er wordt een oproep gedaan om de in het H2O-artikel "Omgekeerde hydrologie" (2008) gepresenteerde casus te modelleren. De auteurs stellen voor om over enige tijd de bevindingen onderling te delen in een worksho
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