700 research outputs found
Quality in liver transplantation: perspectives on organ procurement and allocation
In dit proefschrift is gekeken naar de kwaliteit van uitname en naar de uitkomsten na transplantatie om zo goed mogelijk om te gaan met het tekort aan donororganen. Met de ET-DSRI kan de kans op acceptatie voor een donorlever ingeschat worden. Daardoor kunnen er in een vroeg stadium maatregelen genomen worden om de kans op transplantatie te vergroten voor suboptimale levers. Alhoewel het aantal levers geschikt voor transplantatie geoptimaliseerd kan worden zal het tekort de komende jaren blijven bestaan. Daarmee zal ook de toewijzing van levers aan patiënten op de wachtlijsten complex blijven. De uitkomst na transplantatie is daarin een belangrijk punt. De resultaten beschreven in dit proefschrift laten zien dat statistische modellen een goede benadering kunnen geven van deze uitkomsten. Het toepassen van deze modellen zal leiden tot een meer evidence-based manier van het selecteren, toewijzen en daadwerkelijk transplanteren van levers in patiënten op de wachtlijst. Dr. Franz Köhler Chemie GmbH; Universiteit Leiden; Leids Universitair Medisch Centrum, afdeling Transplantatiechirurgie; Nederlandse Transplantatie Vereniging; Chiesi Pharmaceuticals B.V.; Chipsoft B.V.LUMC / Geneeskund
Toepassing van Aquanox in de bollensector : consultancy rapport: aansluiting bij WUR Glastuinbouw project voor alternatieve bestrijding van ziekte en plagen in de bollenteelt
Aquanox wordt gemaakt door een elektrochemische reactie van water en keukenzout (ECA water). Daarbij komen verbindingen zoals chlorige verbindingen vrij welke veelal schadelijk zijn voor micro-organismen zoals schimmels en bacteriën. Het doel van dit project was enkele specifieke ziekte en plagen van de bollensector te testen op hun gevoeligheid voor Aquanox. In de testen zijn meegenomen: Fusarium oxysporum f.sp. tulipae de veroorzaker van zuur in tulp. Het bleek dat de schimmelsporen gevoelig zijn voor Aquanox maar de reductie van het aantal levende sporen is niet groot genoeg om een infectie of besmetting te voorkomen. Een uitgebreidere beheersingsstrategie met meerdere herhalingen van de behandeling zou een uitkomst kunnen bieden. Stromijten, één van de mogelijke veroorzakers van kernrot in tulp, zijn ook blootgesteld aan Aquanox. Echter, dit had geen dodend effect op de mijten. Het bestrijden van mijtenplagen lijkt niet mogelijk met behulp van Aquanox. De gevoeligheid van de veroorzaker van agressief snot (Erwinia chrysanthemi) voor Aquanox is ook onderzocht. Aquanox is zeer effectief in het doden van deze bacterie. In een denksessie georganiseerd aan de hand van deze resultaten is besloten een vervolgproject uit te werken. Hierin wordt de mogelijkheid onderzocht om hyacinten na elke verwerkingsstap te behandelen met Aquanox zodat uitwendige besmettingen met de bacterie, ontstaan tijdens de verschillende stappen in de verwerking, direct aangepakt worden
Mechanisms controlling the intra-annual mesoscale variability of SST and SPM in the southern North Sea
Thermal and optical remote sensing data were used to investigate the spatial and temporal distribution of sea surface temperature (SST) and of suspended particulate matter (SPM) in the southern North Sea. Monthly SST composites showed pronounced seasonal warming of the southern North Sea and delineated the English coastal and continental coastal waters. The East-Anglia Plume is the dominant feature of the English coastal waters in the winter and autumn SPM composites, and the Rhine region of freshwater influence (ROFI), including the Flemish Banks, is the dominant feature of the continental waters. These mesoscale spatial structures are also influenced by the evolution of fronts, such as the seasonal front separating well-mixed water in the southern Bight, from the seasonally stratified central North Sea waters. A harmonic analysis of the SST and SPM images showed pronounced seasonal variability, as well as spring-neap variations in the level of tidal mixing in the East Anglia Plume, the Rhine ROFI and central North Sea. The harmonic analysis indicates the important role played by the local meteorology and tides in governing the SST and near-surface SPM concentrations in the southern North Sea. In the summer, thermal stratification affects the visibility of SPM to satellite sensors in the waters to the north of the Flamborough and Frisian Fronts. Haline stratification plays an important role in the visibility of SPM in the Rhine ROFI throughout the year. When stratified, both regions typically exhibit low surface SPM values. A numerical model study, together with the harmonic analysis, highlights the importance of tides and waves in controlling the stratification in the southern North Sea and hence the visibility of SPM. © 2011 Elsevier Ltd
Overrepresentation of IL-17A and IL-22 Producing CD8 T Cells in Lesional Skin Suggests Their Involvement in the Pathogenesis of Psoriasis
Spacetime Virasoro algebra from strings on zero radius AdS_3
We study bosonic string theory in the light-cone gauge on AdS_3 spacetime
with zero radius of curvature (in string units) R/\sqrt{\alpha^\prime}=0. We
find that the worldsheet theory admits an infinite number of conserved
quantities which are naturally interpreted as spacetime charges and which form
a representation of (two commuting copies of) a Virasoro algebra. Near the
boundary of AdS_3 these charges are found to be isomorphic to the infinite set
of asymptotic Killing vectors of AdS_3 found originally by Brown and Henneaux.
In addition to the spacetime Virasoro algebra, there is a worldsheet Virasoro
algebra that generates diffeomorphisms of the spatial coordinate of the string
worldsheet. We find that if the worldsheet Virasoro algebra has a central
extension then the spacetime Virasoro algebra acquires a central extension via
a mechanism similar to that encountered in the context of the SL(2,R) WZW
model.Our observations are consistent with a recently proposed duality between
bosonic strings on zero radius AdS_d+1 and free field theory in d dimensions.Comment: 23 pages, uses JHEP.cls. References adde
Development and validation of a patient- tailored dose regime in myocardial perfusion imaging using conventional SPECT
Background\ud
The decreasing image quality in heavier patients can be compensated by administration of a patient-specific dose in myocardial perfusion imaging (MPI) using a cadmium zinc telluride-based SPECT camera. Our aim was to determine if the same can be achieved when using a conventional SPECT camera.\ud
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Methods\ud
148 patients underwent SPECT stress MPI using a fixed Tc-99m tetrofosmin tracer dose. Measured photon counts were normalized to administered tracer dose and scan time and were correlated with body weight, body mass index, and mass per length to find the best predicting parameter. From these data, a protocol to provide constant image quality was derived, and subsequently validated in 125 new patients.\ud
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Results\ud
Body weight was found to be the best predicting parameter for image quality and was used to derive a new dose formula; Aadmin (MBq) = 223·body weight (kg)0.65/Tscan (min). The measured photon counts decreased in heavier patients when using a fixed dose (P < .01) but this was no longer observed after applying a body-weight-dependent protocol (P = .20).\ud
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Conclusions\ud
Application of a patient-specific protocol resulted in an image quality less depending on patient’s weight. The results are most likely independent of the type of SPECT camera used, and, hence, adoption of patient-specific dose and scan time protocols is recommended
Thermodynamics of Black Holes in Two (and Higher) Dimensions
A comprehensive treatment of black hole thermodynamics in two-dimensional
dilaton gravity is presented. We derive an improved action for these theories
and construct the Euclidean path integral. An essentially unique boundary
counterterm renders the improved action finite on-shell, and its variational
properties guarantee that the path integral has a well-defined semi-classical
limit. We give a detailed discussion of the canonical ensemble described by the
Euclidean partition function, and examine various issues related to stability.
Numerous examples are provided, including black hole backgrounds that appear in
two dimensional solutions of string theory. We show that the Exact String Black
Hole is one of the rare cases that admits a consistent thermodynamics without
the need for an external thermal reservoir. Our approach can also be applied to
certain higher-dimensional black holes, such as Schwarzschild-AdS,
Reissner-Nordstrom, and BTZ.Comment: 63 pages, 3 pdf figures, v2: added reference
Universal Features of Holographic Anomalies
We study the mechanism by which gravitational actions reproduce the trace
anomalies of the holographically related conformal field theories. Two
universal features emerge: a) the ratios of type B trace anomalies in any even
dimension are independent of the gravitational action, being uniquely
determined by the underlying algebraic structure b) the normalization of the
type A and the overall normalization of the type B anomalies are given by
action dependent expressions with the dimension dependence completely fixed.Comment: 17 pages, harvma
Occurrence and phenomenology of hallucinations in the general population: A large online survey
Although epidemiological studies report that hallucinations occur in 6–15% of the general population, little is known about their phenomenology. To overcome this paucity, this study investigates the phenomenological characteristics of hallucinations in the general population, by using a nationally promoted online survey to assess hallucination phenomenology in four sensory modalities, through a self-report version of the Questionnaire for Psychotic Experiences (QPE), in 10,448 participants (aged 14–88 years). The phenomenology of hallucinations was assessed if hallucinations reportedly occurred in the past month. In the past month, auditory hallucinations were reported most frequently (29.5%), followed by visual (21.5%), tactile (19.9%), and olfactory hallucinations (17.3%); hallucinations in two or more modalities were reported by 47.6%. Substantial numbers of participants rated their hallucinations as severe, due to negative content (16.0–31.6%), previous bothersome experiences (14.8–20.2%), ensuing distress (10.5–16.8%), and/or ensuing disfunctioning (12.7–17.3%). Decreased insight was found in 10.2–11.4%. Hypnagogia was reported by 9.0–10.6%, and bereavement hallucinations by 2.8%. Despite a low prevalence of delusions (7.0%), these phenomena were significantly associated with recent hallucinations, observed in up to 13.4% of the participants with hallucinations during the past week (p < 0.001). Our results indicate a wide variety of the phenomenology of hallucinations in the general population and support the existence of a phenomenological continuum.publishedVersio
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