991 research outputs found

    Localised anti-branes in non-compact throats at zero and finite T

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    We investigate the 3-form singularities that are typical to anti-brane solutions in supergravity and check whether they can be cloaked by a finite temperature horizon. For anti-D3-branes in the Klebanov-Strassler background, this was already shown numerically to be impossible when the branes are partially smeared. In this paper, we present analytic arguments that also localised branes remain with singular 3-form fluxes at both zero and finite temperature. These results may have important, possibly fatal, consequences for constructions of meta-stable de Sitter vacua through uplifting.Comment: 18 + 9 page

    The Driving Factors of Passenger Transport

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    Over the past few decades passenger transport has grown rapidly resulting in a multitude of problems including severe traffic congestion and pollution. It is expected that passenger transport will continue to grow rapidly in the future, which will worsen the situation even further. The traditional approach to deal with the problems is to expand the infrastructure. However, transport policy is a broad and versatile field. Many different types of policy measures can be observed in literature and practice. Sound transport policy-making requires knowledge on the drivers of transport demand This article is aimed at (re)structuring the many different insights in a single conceptual model, which reviews the key drivers, and how each affects the various choices that travellers make (activity type, destination, mode, time-of-day and route) and the resulting impact on overall passenger transport demand. The model was derived on the basis of a review of literature, which was supplemented by a review of thirteen exemplary urban area cases. In addition, a quantitative data analysis was carried out to assess the transport demand elasticities for various drivers. Current study has been carried out in response to the search for effective transport policy, which is discussed in the concluding section. The outcomes are of particular relevance of policy analysts and policy makers developing passenger transport policy, but are also useful for scholars and students in the field of transport

    Investigating the Effects of a Persuasive Digital Game on Immersion, Identification, and Willingness to Help

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    Recent years have seen a tremendous rise in the development and distribution of persuasive games: digital games that are used to influence players’ attitudes and/or behavior. Three studies (NStudy 1 = 134; NStudy 2 = 94; NStudy 3 = 161) tested the effects of a persuasive game on immersion, identification, and willingness to help. The results showed that playing the persuasive game did not result in substantially stronger willingness to help, relative to the control conditions. Video and printed text resulted in more immersion than the digital game, but playing the game resulted in substantially higher perceptions of embodied presence

    The additive value of CA19.9 monitoring in a pancreatic cyst surveillance program

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    Pancreatic cysts; Surgical intervention; SurveillanceQuists pancreàtics; Intervenció quirúrgica; VigilànciaQuistes pancreáticos; Intervención quirúrgica; VigilanciaBackground Surveillance of pancreatic cysts focuses on the detection of (mostly morphologic) features warranting surgery. European guidelines consider elevated CA19.9 as a relative indication for surgery. We aimed to evaluate the role of CA19.9 monitoring for early detection and management in a cyst surveillance population. Methods The PACYFIC-registry is a prospective collaboration that investigates the yield of pancreatic cyst surveillance performed at the discretion of the treating physician. We included participants for whom at least one serum CA19.9 value was determined by a minimum follow-up of 12 months. Results Of 1865 PACYFIC participants, 685 met the inclusion criteria for this study (mean age 67 years, SD 10; 61% female). During a median follow-up of 25 months (IQR 24, 1966 visits), 29 participants developed high-grade dysplasia (HGD) or pancreatic cancer. At baseline, CA19.9 ranged from 1 to 591 kU/L (median 10 kU/L [IQR 14]), and was elevated (≥37 kU/L) in 64 participants (9%). During 191 of 1966 visits (10%), an elevated CA19.9 was detected, and these visits more often led to an intensified follow-up (42%) than those without an elevated CA19.9 (27%; p < 0.001). An elevated CA19.9 was the sole reason for surgery in five participants with benign disease (10%). The baseline CA19.9 value was (as continuous or dichotomous variable at the 37 kU/L threshold) not independently associated with HGD or pancreatic cancer development, whilst a CA19.9 of ≥ 133 kU/L was (HR 3.8, 95% CI 1.1–13, p = 0.03). Conclusions In this pancreatic cyst surveillance cohort, CA19.9 monitoring caused substantial harm by shortening surveillance intervals (and performance of unnecessary surgery). The current CA19.9 cutoff was not predictive of HGD and pancreatic cancer, whereas a higher cutoff may decrease false-positive values. The role of CA19.9 monitoring should be critically appraised prior to implementation in surveillance programs and guidelines

    Dynamics of Generalized Assisted Inflation

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    We study the dynamics of multiple scalar fields and a barotropic fluid in an FLRW-universe. The scalar potential is a sum of exponentials. All critical points are constructed and these include scaling and de Sitter solutions. A stability analysis of the critical points is performed for generalized assisted inflation, which is an extension of assisted inflation where the fields mutually interact. Effects in generalized assisted inflation which differ from assisted inflation are emphasized. One such a difference is that an (inflationary) attractor can exist if some of the exponential terms in the potential are negative.Comment: 27 page

    Synchronous and metachronous urothelial carcinoma of the upper urinary tract and the bladder: Are they clonally related? A systematic review

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    Purpose: Following radical nephroureterectomy for upper urinary tract urothelial carcinoma (UTUC), intravesical recurrence (IVR) is found in 22% to 47% of patients. Patients with a primary urothelial carcinoma of the bladder (UCB) have an increased risk of a future UTUC (1%–5%). Paired UTUC and UCB might represent clonally related tumors due to intraluminal seeding of tumor cells or might be separate entities of urothelial carcinoma caused by field cancerization. We systematically reviewed all the relevant literature to address the possible clonal relation of UTUC and paired UCB. Materials and Methods: MEDLINE, EMBASE, and COCHRANE databases were systematically searched for relevant citations published between January 2000 and July 2019. This study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Of 5038 citations identified, 86 full papers were screened, and 9 studies met the inclusion criteria. Results: The populations studied and the molecular techniques used to assess clonality of UTUC and paired UCB differed largely over time. Eight studies reported on primary UTUC and meta- or synchronous IVR without a history of UCB. A total of 118 tumors

    Combined TLR2 and TLR4 ligation in the context of bacterial or helminth extracts in human monocyte derived dendritic cells: molecular correlates for Th1/Th2 polarization

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    Background: Recognition of pathogens by dendritic cells (DCs) through interaction with pattern recognition receptors, including Toll like receptors (TLR), is crucial for the initiation of appropriate polarized T helper (Th) cell responses. Yet, the characteristics and differences in molecular profiles of DCs with different T cell polarizing capacities are still poorly defined. To address this issue, the molecular profile of human monocyte derived DCs was characterized after exposure to TLR4 ligand LPS in combination with the Th1 promoting bacterial extracts from Listeria monocytogenes and Escherichia coli or the Th2 promoting helminth derived phospholipids from Schistosoma mansoni and Ascaris lumbricoides, all with TLR2 activating capacity. Results: With regard to the signalling pathways activated upon exposure to LPS and the TLR2 activating compounds, we find that the ratio of activated Mitogen Activated Protein Kinases (MAPK) p-ERK/p-p38 is lower in DCs stimulated with the bacterial products compared to DCs stimulated with the helminth products, which correlates with the Th1 and Th2 polarizing capacity of these compounds. Furthermore, analysis of the mRNA expression levels of a set of 25 carefully selected genes potentially involved in modulation of T cell polarization revealed that the mRNA expression of notch ligand delta-4 and transcription factor c-fos are differentially regulated and show a strong correlation with Th1 and Th2 polarization, respectively. Conclusion: This study shows that combined TLR2 and TLR4 activation in the context of different antigen sources can induce very distinct molecular profiles in DCs and suggests that the Th1/Th2 polarizing capacity of compounds can be predicted with the molecular signature they induce in DCs

    Upper gastrointestinal symptoms, psychosocial co-morbidity and health care seeking in general practice: population based case control study

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    <p>Abstract</p> <p>Background</p> <p>The pathophysiology of upper gastrointestinal (GI) symptoms is still poorly understood. Psychological symptoms were found to be more common in patients with functional gastrointestinal complaints, but it is debated whether they are primarily linked to GI symptoms or rather represent motivations for health-care seeking. Purpose of our study was to compare co-morbidity, in particular psychological and social problems, between patients with and without upper GI symptoms. In addition, we investigated whether the prevalence of psychological and social problems is part of a broader pattern of illness related health care use.</p> <p>Methods</p> <p>Population based case control study based on the second Dutch National Survey of general practice (conducted in 2001). Cases (adults visiting their primary care physician (PCP) with upper GI symptoms) and controls (individuals not having any of these complaints), matched for gender, age, PCP-practice and ethnicity were compared. Main outcome measures were contact frequency, prevalence of somatic as well as psychosocial diagnoses, prescription rate of (psycho)pharmacological agents, and referral rates. Data were analyzed using odds ratios, the Chi square test as well as multivariable logistic regression analysis.</p> <p>Results</p> <p>Data from 13,389 patients with upper GI symptoms and 13,389 control patients were analyzed. Patients with upper GI symptoms visited their PCP twice as frequently as controls (8.6 vs 4.4 times/year). Patients with upper GI symptoms presented not only more psychological and social problems, but also more other health problems to their PCP (odds ratios (ORs) ranging from 1.37 to 3.45). Patients with upper GI symptoms more frequently used drugs of any ATC-class (ORs ranging from 1.39 to 2.90), including psychotropic agents. The observed differences were less pronounced when we adjusted for non-attending control patients. In multivariate regression analysis, contact frequency and not psychological or social co-morbidity was strongest associated with patients suffering from upper GI symptoms.</p> <p>Conclusion</p> <p>Patients with upper GI symptoms visit their PCP more frequently for problems of any organ system, including psychosocial problems. The relationship between upper GI symptoms and psychological problems is equivocal and may reflect increased health care demands in general.</p

    Perspectieven geleide bemesting in de open teelten: van deskstudie naar onderzoek

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    Het onderzoekprogramma 398 geeft invulling aan de aanbevelingen van de commissie Spiertz II (“Advisering PrioriteringOnderzoek en Monitoring Fosfaat en Stikstof, november 2000), en aan het thema 1 van de DWK-notitie “Maatschappelijkverantwoord ondernemen en bevordering duurzame productie” (Breimer, d.d. 12-01-2001). Het programma beoogtkennisproducten op te leveren die landbouwbedrijven in staat stellen om te voldoen aan MINAS-normen en tevenshandreikingen te bieden om verdergaande normering op bedrijfsniveau mogelijk te maken
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