Search results for "WAITING TIME"
showing 10 items of 18 documents
Nonlinear Diffusion in Transparent Media
2021
Abstract We consider a prototypical nonlinear parabolic equation whose flux has three distinguished features: it is nonlinear with respect to both the unknown and its gradient, it is homogeneous, and it depends only on the direction of the gradient. For such equation, we obtain existence and uniqueness of entropy solutions to the Dirichlet problem, the homogeneous Neumann problem, and the Cauchy problem. Qualitative properties of solutions, such as finite speed of propagation and the occurrence of waiting-time phenomena, with sharp bounds, are shown. We also discuss the formation of jump discontinuities both at the boundary of the solutions’ support and in the bulk.
High-urgency kidney transplantation in the Eurotransplant Kidney Allocation System : success or waste of organs? The Eurotransplant 15-year all-centr…
2016
Item does not contain fulltext BACKGROUND: In the Eurotransplant Kidney Allocation System (ETKAS), transplant candidates can be considered for high-urgency (HU) status in case of life-threatening inability to undergo renal replacement therapy. Data on the outcomes of HU transplantation are sparse and the benefit is controversial. METHODS: We systematically analysed data from 898 ET HU kidney transplant recipients from 61 transplant centres between 1996 and 2010 and investigated the 5-year patient and graft outcomes and differences between relevant subgroups. RESULTS: Kidney recipients with an HU status were younger (median 43 versus 55 years) and spent less time on the waiting list compared…
L’attesa come condizione esistenziale: SAID Landschaften einer fernen Mutter, 2001 e Marjane Satrapi Persepolis, 2007
2018
In this paper the author intends to analyze the concept of ‘waiting time’ that, in a different way, also seen the substantial artistic diversity, is present in the film Persepolis by Marjane Satrapi, 2007, based on the namesake graphic novel written by the French-Iranian director in 2000, and in the novel Landschaften einer fernen Mutter written by the German-Iranian author SAID, 2001. The analysis that is conducted here wants to investigate how both, in the film and in the literary work, the ‘waiting time’ for the exile takes on totally personal connotations, becoming also not only part of the life of Satrapi and SAID, but above all a state of mind.
Stochastic ordering of classical discrete distributions
2010
For several pairs $(P,Q)$ of classical distributions on $\N_0$, we show that their stochastic ordering $P\leq_{st} Q$ can be characterized by their extreme tail ordering equivalent to $ P(\{k_\ast \})/Q(\{k_\ast\}) \le 1 \le \lim_{k\to k^\ast} P(\{k\})/Q(\{k\})$, with $k_\ast$ and $k^\ast$ denoting the minimum and the supremum of the support of $P+Q$, and with the limit to be read as $P(\{k^\ast\})/Q(\{k^\ast\})$ for $k^\ast$ finite. This includes in particular all pairs where $P$ and $Q$ are both binomial ($b_{n_1,p_1} \leq_{st} b_{n_2,p_2}$ if and only if $n_1\le n_2$ and $(1-p_1)^{n_1}\ge(1-p_2)^{n_2}$, or $p_1=0$), both negative binomial ($b^-_{r_1,p_1}\leq_{st} b^-_{r_2,p_2}$ if and on…
Efficient GRASP+VND and GRASP+VNS metaheuristics for the traveling repairman problem
2011
Abstract: The traveling repairman problem is a customer-centric routing problem, in which the total waiting time of the customers is minimized, rather than the total travel time of a vehicle. To date, research on this problem has focused on exact algorithms and approximation methods. This paper presents the first metaheuristic approach for the traveling repairman problem.
Bleach interference in forensic luminol tests on porous surfaces: more about the drying time effect.
2009
As criminals try to avoid leaving clues at the scene of a crime, bloodstains are often washed away, but fortunately for investigators, they are difficult to eliminate completely. Porous surfaces easily retain blood traces, which are sometimes invisible to the naked eye. The reagent of choice for detecting latent blood traces on all types of surfaces is luminol, but its main disadvantage is a high degree of sensitivity to oxidising contaminants in the blood sample. If household bleach is used to clean bloodstains, presumptive tests are invalidated. Hypochlorites, however, are known to be unstable and deteriorate over time, and this feature could be of help in preventing household bleach-indu…
Effects of the Blair/Brown NHS Reforms on Socioeconomic Equity in Health Care
2012
The central objectives of the ‘Blair/Brown’ reforms of the English NHS in the 2000s were to reduce hospital waiting times and improve the quality of care. However, critics raised concerns that the choice and competition elements of reform might undermine socioeconomic equity in health care. By contrast, the architects of reform predicted that accelerated growth in NHS spending combined with increased patient choice of hospital would enhance equity for poorer patients. This paper draws together and discusses the findings of three large-scale national studies designed to shed empirical light on this issue. Study one developed methods for monitoring change in neighbourhood level socioeconomic…
The waiting time for prostate cancer treatment in Italy: analysis from the PROS-IT CNR Study.
2022
Background Prostate cancer (PCa) is the second most common neoplasm in male patients. To date, there's no certain indication about the maximum waiting time (WT) acceptable for treatment beginning and the impact on oncological and functional outcomes has not been well established. Methods Data from the National Research Council PCa monitoring multicenter project in Italy (Pros-IT CNR) were prospectively collected and analyzed. WT was defined as the time from the bioptical diagnosis of PCa to the first treatment received. Patients were divided in two groups, using a time frame of 90 days. Quality of life was measured through the Italian version of the University of California Los Angeles-Pros…
Influence of delay between dental bleaching with 35% hydrogen peroxide and orthodontic brackets on the bond strength at the enamel/adhesive interface
2019
Background The aim of this study was to evaluate the influence of waiting time between the bleaching with 35% hydrogen peroxide and orthodontic brackets bonding on shear bond strength (SBS) in enamel. Material and Methods Eighty bovine teeth were randomly divided into four groups (G): G1(negative control) and G2, G3 and G4 (experimental groups). The experimental groups were submitted to bleaching. Prior to orthodontic brackets bonding to enamel the procedure was adopted different waiting times, as follows: G2 (1 day); G3 (7 days) and G4 (14 days). It was performed enamel etching (30s), washing water (30s), application of adhesive system followed by photoactivation (20s). A thin layer of com…
On solving single elevator-like problems using a learning automata-based paradigm
2020
This paper concentrates on a host of problems with characteristics similar to those that are related to moving elevators within a building. These are referred to as Elevator-like problems (ELPs), and their common phenomena will be expanded on in the body of the paper. We shall resolve ELPs using a subfield of AI, namely the field of learning automata (LA). Rather than working with the well-established mathematical formulations of the field, our intention is to use these tools to tackle ELPs, and in particular, those that deal with single “elevators” moving between “floors”. ELPs have not been tackled before using AI. In a simplified domain, the ELP involves the problem of optimizing the sch…