113 research outputs found

    Approximation Algorithms for Fair Range Clustering

    Full text link
    This paper studies the fair range clustering problem in which the data points are from different demographic groups and the goal is to pick kk centers with the minimum clustering cost such that each group is at least minimally represented in the centers set and no group dominates the centers set. More precisely, given a set of nn points in a metric space (P,d)(P,d) where each point belongs to one of the \ell different demographics (i.e., P=P1P2PP = P_1 \uplus P_2 \uplus \cdots \uplus P_\ell) and a set of \ell intervals [α1,β1],,[α,β][\alpha_1, \beta_1], \cdots, [\alpha_\ell, \beta_\ell] on desired number of centers from each group, the goal is to pick a set of kk centers CC with minimum p\ell_p-clustering cost (i.e., (vPd(v,C)p)1/p(\sum_{v\in P} d(v,C)^p)^{1/p}) such that for each group ii\in \ell, CPi[αi,βi]|C\cap P_i| \in [\alpha_i, \beta_i]. In particular, the fair range p\ell_p-clustering captures fair range kk-center, kk-median and kk-means as its special cases. In this work, we provide efficient constant factor approximation algorithms for fair range p\ell_p-clustering for all values of p[1,)p\in [1,\infty).Comment: ICML 202

    Evaluation of coronary arteries in non-ischemic cardiomyopathies: A case report

    Get PDF
    Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is a congenital cardiac disease with myocardial involvement, most probably right ventricular (RV) dysfunction, accounting for 20 of sudden cardiac deaths. Characterized by the fibro-fatty infiltration of the RV free wall, ARVD/C presents in adolescents with ventricular arrhythmias and heart failure symptoms and as biventricular failure in adults. The coronary risk in these patients is not clear. We present an incidental finding: the left anterior descending artery cut-off in a middle-aged man with ARVD/C. He had been under treatment for heart failure symptoms, which had decompensated frequently commencing 6 months earlier, and therefore he was scheduled for stem cell injection. He had no chest pain or coronary artery disease risk factors. Two-dimensional transthoracic echocardiography demonstrated RV enlargement with moderate to severe dysfunction and left ventricular ejection fraction (LVEF) of 35-40, which was 45-50 two years before. Selective coronary angiography performed 8 years previously was normal but a new one revealed the cut-off of the left anterior descending artery at the proximal portion, for which percutaneous coronary intervention was performed and showed no significant lesion in the other vessels. One should consider coronary artery disease in uncontrolled heart failure with LVEF reduction, even in the absence of typical chest pain. It may not be the natural course of the underlying disease. © 2016, Tehran Heart Center. All rights reserved

    Risk factors of regression and undercorrection in photorefractive keratectomy: A case-control study

    Get PDF
    �AIM: To determine risk factors of regression and undercorrection following photorefractive keratectomy (PRK) in myopia or myopic astigmatism. �METHODS: A case-control study was designed in which eyes with an indication for re-treatment (RT) were defined as cases; primary criteria for RT indication, as assessed at least 9mo postoperatively, included an uncorrected distance visual acuity (UDVA) of 20/30 or worse and a stable refraction for more than 3mo. Additional considerations included optical quality symptoms and significant higher order aberrations (HOAs). Controls were chosen from the same cohort of operated eyes which had complete post-operative follow up data beyond 9mo and did not need RT. The cohort included patients who had undergone PRK by the Tissue-Saving (TS) ablation profile of Technolas 217z100 excimer laser (Bausch & Lomb, Rochester, NY, USA). Mitomycin C had been used in all of the primary procedures. �RESULTS: We had 70 case eyes and 158 control eyes, and they were comparable in terms of age, sex and follow-up time (P values:0.58, 1.00 and 0.89, respectively). Pre-operative spherical equivalent of more than -5.00 diopter (D), intended optical zone (OZ) diameter of less than 6.00 mm and ocular fixation instability during laser ablation were associated with RT indications (all P values -5.00 D), smaller OZ (<6.00 mm) and unstable fixation during laser ablation of PRK for myopia and myopic astigmatism were found to be strong predictors of undercorrection and regression. © 2015 International Journal of Ophthalmology (c/o Editorial Office). All Rights Reserved

    Dark or Bright Half of the Moon: A Qualitative Study Exploring the Experience of Iranian Heart Failure Patients Regarding their Quality of Life

    Get PDF
    BACKGROUND: Heart failure (HF) is a major public health problem in different societies and has numerous impacts on quality of life (QOL). AIM: The present study was carried out with the aim to explore the experience of HF patients regarding the negative effects of the disease on their QOL. METHODS: In this qualitative exploratory study data collection was performed through face-to-face, semi-structured, in-depth interviews with 19 patients with HF, who were selected through purposive sampling method from April to September 2017. Data analysis was carried out based on the framework analysis method. RESULTS: The negative consequences of HF on QOL emerged in the form of 6 main themes including symptoms, disease complications, cognitive impairment, psychological distress, functional limitations and economic problems. Most of the participants (14 out of 19) assessed their QOL as well or very well. CONCLUSION: The majority of the patients in this study, despite the many negative impacts of HF, had a high QOL that could indicate their satisfaction and effective coping with HF by creating a positive outlook and the perceived positive effects of the disease

    Technical Report: Region and Effect Inference for Safe Parallelism

    Get PDF
    In this paper, we present the first full regions-and-effects inference algorithm for explicitly parallel fork-join programs. We infer annotations inspired by Deterministic Parallel Java (DPJ) for a type-safe subset of C++. We chose the DPJ annotations because they give the \emph{strongest} safety guarantees of any existing concurrency-checking approach we know of, static or dynamic, and it is also the most expressive static checking system we know of that gives strong safety guarantees. This expressiveness, however, makes manual annotation difficult and tedious, which motivates the need for automatic inference, but it also makes the inference problem very challenging: the code may use region polymorphism, imperative updates with complex aliasing, arbitrary recursion, hierarchical region specifications, and wildcard elements to describe potentially infinite sets of regions. We express the inference as a constraint satisfaction problem and develop, implement, and evaluate an algorithm for solving it. The region and effect annotations inferred by the algorithm constitute a checkable proof of safe parallelism, and it can be recorded both for documentation and for fast and modular safety checking.Ope

    Automated migration of build scripts using dynamic analysis and search-based refactoring

    Get PDF
    The efficiency of a build system is an important factor for developer productivity. As a result, developer teams have been increasingly adopting new build systems that allow higher build parallelization. However, migrating the existing legacy build scripts to new build systems is a tedious and error-prone process. Unfortunately, there is insufficient support for automated migration of build scripts, making the migration more problematic. We propose the first dynamic approach for automated migration of build scripts to new build systems. Our approach works in two phases. First, from a set of execution traces, we synthesize build scripts that accurately capture the intent of the original build. The synthesized build scripts are typically long and hard to maintain. Second, we apply refactorings that raise the abstraction level of the synthesized scripts (e.g., introduce functions for similar fragments). As different refactoring sequences may lead to different build scripts, we use a search-based approach that explores various sequences to identify the best (e.g., shortest) build script. We optimize search-based refactoring with partial-order reduction to faster explore refactoring sequences. We implemented the proposed two phase migration approach in a tool called METAMORPHOSIS that has been recently used at Microsoft

    Comparison of neutral anolyte solution and malachite green efficiency on fungal contamination control of rainbow trout (Oncorhynchus mykiss) eggs in incubation stage

    Get PDF
    One of the important problems in Rainbow trout production industry is egg fungal infection especially saprolegniasis which is the most important mortality factor in Rainbow trout hatcheries. Controlling saprolegniasis in hatcheries was done using green malachite in the past years, which is a very effective fungicide. Nowadays, due to the prohibition of using green malachite, effort is done to replace it with other materials as an effective fungicide. Some of the most important materials which have been examined are formalin, sodium chloride and hydrogen peroxide etc. The aim of this study was to evaluate the effects of neutral anolyte on the mortality percent of rainbow trout eggs and produced larvae in point of view of growth indices and survival until yolk sac absorption and larvae active feeding in incubation phase comparing with green malachite to be able to introduce a suitable alternative. This study was carried out in a complete randomly plan with 7 treatments and 3 replications (21 troughs in general), in 20*35*70 cm (length*width*depth) Californian troughs containing an incubator. Treatments included anolyte solutions constant bathing with 0.5 and 0.25 ppm concentrations and periodic anolyte treatments with 2 ppm concentrations (every 2 days), positive control infected with fungus without any disinfectant and negative control without any infection or disinfectant. 300 grams of newly propagated green eggs of rainbow trout which were provided from one of the fish hatcheries in Haraz Road and acclimated with the trough’s water temperature, were distributed in one layer at the bottom of the trough basket. All treatments, except negative control, were infected with saprolegnia, taken from infected eggs of rainbow trout which were previously provided from one of the fish hatcheries of 2000 Road in Tonekabon. The treatments took one month to complete. The studied variables included hatching percent, percent of eyed eggs, abnormality percent and percent of unfertilized eggs, from which percent of eyed eggs was calculated and recorded in the middle and the rest of the variables at the end of the test. In this study Paired-sample T-student test, Levene’s test, one-way ANOVA and Bonferroni’s test was used. For examining egg abnormality, hatching, fungus infection and eyed eggs, first the percent of the variables were specified and then for comparing the rate of abnormality in one of the anolyte treatments (which had the least abnormality) and green malachite, Mann-Whitney test was carried out. This comparison was done to analyze the rate of hatching, fungus infections, eyed eggs, resulting from the materials used in different treatments, using one-way ANOVA Bonferroni’s tests. Results showed that in lower anolyte concentrations (0.5 and 0.25 ppm), the number of fungal colonies of hatchery water and the percent of egg fungus infection were significantly higher than higher concentrations of anolyte (100 ppm and 30 ppm) and green malachite. In other words with concentration increase, the fungicidal effect has also increased. In evaluating the percent of eyed eggs, statistical results showed that eyed eggs percent in 0.25 ppm treatment and green malachite treatment were significantly higher than the other three anolyte treatments. This result can explain egg hatching in 0.25 ppm concentrations and not seeing hatching in the (other) remaining three doses. Between the treatments of 0.25 ppm and green malachite, the group of 0.25 ppm anolyte can be a better disinfectant for rainbow trout eggs compared to green malachite, for fish farmers, due to the high percent of eyed eggs and the low total count of fungus. The results of this study showed that the amount of abnormality in 0.25 ppm treatment has been higher compared to the green malachite group. Because this study was the first research on using anolyte as a fungicide in rainbow trout hatcheries, therefore for more specific study of the concentrations, the timing of usage and the factors affecting these two, more vast and general research is needed

    The Impact of Generic Data Structures: Decoding the Role of Lists in the Linux Kernel

    Get PDF
    International audienceThe increasing adoption of the Linux kernel has been sustained by a large and constant maintenance effort, performed by a wide and heterogeneous base of contributors. One important problem that maintainers face in any code base is the rapid understanding of complex data structures. The Linux kernel is written in the C language, which enables the definition of arbitrarily uninformative datatypes, via the use of casts and pointer arithmetic, of which doubly linked lists are a prominent example. In this paper, we explore the advantages and disadvantages of such lists, for expressivity, for code understanding, and for code reliability. Based on our observations, we have developed a toolset that includes inference of descriptive list types and a tool for list visualization. Our tools identify more than 10,000 list fields and variables in recent Linux kernel releases and succeeds in typing 90%. We show how these tools could have been used to detect previously fixed bugs and identify 6 new ones

    Steam sauna and mother roasting in Lao PDR: practices and chemical constituents of essential oils of plant species used in postpartum recovery

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Fundamental in traditional postpartum recovery in Lao PDR is the use of hotbeds, mother roasting, steam sauna and steam baths. During these treatments medicinal plants play a crucial role, but little has been published about how the treatments are carried out precisely, which species are used, the medicinal properties of these species, and the medicinal efficacy of their chemical constituents.</p> <p>Methods</p> <p>Sixty-five interviews, in 15 rural villages, with women of 4 different ethnic groups were conducted to survey confinement rituals, and postpartum plant use and salience. Essential oils from the main species used were extracted using steam distillation and the main chemical constituents characterized using gas chromatography-mass spectrometry (GC-MS).</p> <p>Results</p> <p>A total of 10 different species were used by three or more of the ethnic groups included in this study. All species were used in steam sauna and bath, but only 3 species were used in hotbed and mother roasting. Essential oils of <it>Amomum villosum, Amomum microcarpum </it>and <it>Blumea balsamifera </it>were found to contain significant amounts of the following terpenes: β-pinene, camphor, bornyl acetate, borneol, linalool, D-limonene, fenchone, terpinen-4-ol and α-terpinene.</p> <p>Conclusions</p> <p>Many of these terpenes have documented antimicrobial and analgesic properties, and some have also synergistic interactions with other terpenes. The mode of application in hotbed and mother roasting differs from the documented mechanisms of action of these terpenes. Plants in these two practices are likely to serve mainly hygienic purposes, by segregating the mother from infection sources such as beds, mats, stools, cloth and towels. Steam sauna medicinal plant use through inhalation of essential oils vapors can possibly have medicinal efficacy, but is unlikely to alleviate the ailments commonly encountered during postpartum convalescence. Steam sauna medicinal plant use through dermal condensation of essential oils, and steam bath cleansing of the perineal area is possibly a pragmatic use of the reported medicinal plants, as terpene constituents have documented antimicrobial, analgesic and anti-inflammatory properties.</p
    corecore