986 research outputs found

    Computing a rectilinear shortest path amid splinegons in plane

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    We reduce the problem of computing a rectilinear shortest path between two given points s and t in the splinegonal domain \calS to the problem of computing a rectilinear shortest path between two points in the polygonal domain. As part of this, we define a polygonal domain \calP from \calS and transform a rectilinear shortest path computed in \calP to a path between s and t amid splinegon obstacles in \calS. When \calS comprises of h pairwise disjoint splinegons with a total of n vertices, excluding the time to compute a rectilinear shortest path amid polygons in \calP, our reduction algorithm takes O(n + h \lg{n}) time. For the special case of \calS comprising of concave-in splinegons, we have devised another algorithm in which the reduction procedure does not rely on the structures used in the algorithm to compute a rectilinear shortest path in polygonal domain. As part of these, we have characterized few of the properties of rectilinear shortest paths amid splinegons which could be of independent interest

    Apolipoprotein C3 SstI polymorphism and triglyceride levels in Asian Indians

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    BACKGROUND: A close association between Sst I polymorphism in the 3' untranslated region of the apolipoproteinC3 (APOC3) gene and levels of plasma triglycerides (TG) had been reported by different investigators. Hypertriglyceridemia(HTG) is a known risk factor for coronary artery disease (CAD) in the context of Asian Indians. We conducted a study on the relationship between APOC3 SstI polymorphism (S1S1, S1S2 and S2S2 genotypes) and plasma TG levels in a group of 139 male healthy volunteers from Northern India. METHODS: DNA samples were analyzed by polymerase chain reaction (PCR) followed by SstI digestion. Digested PCR products were run on 3% agarose gel and visualized by ethidium bromide staining. RESULTS: Rare S2 allele was highly prevalent in our study population (0.313) as compared to the Caucasians (0.00–0.11). The genotypic distribution was in agreement with Hardy-Weinberg equilibrium. S2 allele was almost two times more prevalent in the HTG group (N = 34) as compared to NTG group (N = 105) (p = 0.001). Multiple logistic regression revealed S1S2 individuals had age-adjusted odds ratio of 2.43 (95%CI = 0.99–6.01, p = 0.054) and S2S2 had 9.9 (95%CI = 2.66–37.29, p = 0.0006) for developing HTG in comparison to S1S1 genotype. CONCLUSIONS: Our study shows a significant association between rare S2 allele and HTG in Asian Indians

    Lower bounds on the dilation of plane spanners

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    (I) We exhibit a set of 23 points in the plane that has dilation at least 1.43081.4308, improving the previously best lower bound of 1.41611.4161 for the worst-case dilation of plane spanners. (II) For every integer n13n\geq13, there exists an nn-element point set SS such that the degree 3 dilation of SS denoted by δ0(S,3) equals 1+3=2.7321\delta_0(S,3) \text{ equals } 1+\sqrt{3}=2.7321\ldots in the domain of plane geometric spanners. In the same domain, we show that for every integer n6n\geq6, there exists a an nn-element point set SS such that the degree 4 dilation of SS denoted by δ0(S,4) equals 1+(55)/2=2.1755\delta_0(S,4) \text{ equals } 1 + \sqrt{(5-\sqrt{5})/2}=2.1755\ldots The previous best lower bound of 1.41611.4161 holds for any degree. (III) For every integer n6n\geq6 , there exists an nn-element point set SS such that the stretch factor of the greedy triangulation of SS is at least 2.02682.0268.Comment: Revised definitions in the introduction; 23 pages, 15 figures; 2 table

    Prediction of Face-Lift Outcomes Using the Preoperative Supine Test

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    Patients considering a facelift (facial rhytidectomy) need some means of predicting their surgical outcomes. This will help them decide whether to proceed with the operation. A total of 50 consecutive patients were asked to examine themselves with a hand-held mirror while lying supine on an examining table to give them a reasonable approximation of their postoperative result. The tissues of the face redrape in a very aesthetic manner when lying completely supine. The appearance that the patient sees of himself or herself during the “supine test” correlated very well with the actual postop result after rhytidectomy consisting of subcutaneous undermining, SMAS plication, and platysmaplasty. This supine test may be useful in helping patients preoperatively predict their facelift outcomes and may serve as a good adjunct to imaging

    Stochastic Bundle Adjustment for Efficient and Scalable 3D Reconstruction

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    Current bundle adjustment solvers such as the Levenberg-Marquardt (LM) algorithm are limited by the bottleneck in solving the Reduced Camera System (RCS) whose dimension is proportional to the camera number. When the problem is scaled up, this step is neither efficient in computation nor manageable for a single compute node. In this work, we propose a stochastic bundle adjustment algorithm which seeks to decompose the RCS approximately inside the LM iterations to improve the efficiency and scalability. It first reformulates the quadratic programming problem of an LM iteration based on the clustering of the visibility graph by introducing the equality constraints across clusters. Then, we propose to relax it into a chance constrained problem and solve it through sampled convex program. The relaxation is intended to eliminate the interdependence between clusters embodied by the constraints, so that a large RCS can be decomposed into independent linear sub-problems. Numerical experiments on unordered Internet image sets and sequential SLAM image sets, as well as distributed experiments on large-scale datasets, have demonstrated the high efficiency and scalability of the proposed approach. Codes are released at https://github.com/zlthinker/STBA.Comment: Accepted by ECCV 202

    Allele-specific miRNA-binding analysis identifies candidate target genes for breast cancer risk

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    Most breast cancer (BC) risk-associated single-nucleotide polymorphisms (raSNPs) identified in genome-wide association studies (GWAS) are believed to cis-regulate the expression of genes. We hypothesise that cis-regulatory variants contributing to disease risk may be affecting microRNA (miRNA) genes and/or miRNA binding. To test this, we adapted two miRNA-binding prediction algorithms-TargetScan and miRanda-to perform allele-specific queries, and integrated differential allelic expression (DAE) and expression quantitative trait loci (eQTL) data, to query 150 genome-wide significant ( P≤5×10-8 ) raSNPs, plus proxies. We found that no raSNP mapped to a miRNA gene, suggesting that altered miRNA targeting is an unlikely mechanism involved in BC risk. Also, 11.5% (6 out of 52) raSNPs located in 3'-untranslated regions of putative miRNA target genes were predicted to alter miRNA::mRNA (messenger RNA) pair binding stability in five candidate target genes. Of these, we propose RNF115, at locus 1q21.1, as a strong novel target gene associated with BC risk, and reinforce the role of miRNA-mediated cis-regulation at locus 19p13.11. We believe that integrating allele-specific querying in miRNA-binding prediction, and data supporting cis-regulation of expression, improves the identification of candidate target genes in BC risk, as well as in other common cancers and complex diseases.Funding Agency Portuguese Foundation for Science and Technology CRESC ALGARVE 2020 European Union (EU) 303745 Maratona da Saude Award DL 57/2016/CP1361/CT0042 SFRH/BPD/99502/2014 CBMR-UID/BIM/04773/2013 POCI-01-0145-FEDER-022184info:eu-repo/semantics/publishedVersio

    Truncated Inference for Latent Variable Optimization Problems: Application to Robust Estimation and Learning

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    Optimization problems with an auxiliary latent variable structure in addition to the main model parameters occur frequently in computer vision and machine learning. The additional latent variables make the underlying optimization task expensive, either in terms of memory (by maintaining the latent variables), or in terms of runtime (repeated exact inference of latent variables). We aim to remove the need to maintain the latent variables and propose two formally justified methods, that dynamically adapt the required accuracy of latent variable inference. These methods have applications in large scale robust estimation and in learning energy-based models from labeled data.Comment: 16 page

    Assessment of sperm quality traits in relation to fertility in boar semen

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    <p>Abstract</p> <p>Background</p> <p>Several studies have been published where sperm plasma membrane integrity correlated to fertility. In this study we describe a simple fluorometer-based assay where we monitored the fluorescence intensity of artificially membrane-ruptured spermatozoa with a fixed time staining with fluorescent DNA dyes.</p> <p>Methods</p> <p>Membrane-impermeant fluorescent dyes Hoechst 33258 (H258) and propidium iodide (PI) were used to measure the fluorescence of the nucleus in artificially membrane ruptured spermatozoa and membrane-permeant dye Hoechst 33342 (H342) was used to measure fluorescence of intact spermatozoa. The concentration of spermatozoa in insemination doses varied from 31.2 × 10<sup>6</sup>/ml to 50 × 10<sup>6</sup>/ml and the average value was 35 × 10<sup>6</sup>/ml. Each boar was represented by three consecutive ejaculates, collected at weekly intervals. Nonreturn rate within 60 days of first insemination (NR %) and litter size (total number of piglets born) of multiparous farrowings were used as fertility measures.</p> <p>Results</p> <p>Sperm fluorescence intensity of H258 and H342, but not the fluorescence intensity of PI-stained spermatozoa correlated significantly with the litter size of multiparous farrowings, values being r = - 0.68 (P < 0.01) for H258, r = - 0.69 (P < 0.01) for H342 and r = - 0.38, (P = 0.11) for PI.</p> <p>Conclusions</p> <p>The increase in fluorescence values of membrane-ruptured H258 and unruptured H342-stained spermatozoa in boar AI doses can be associated with smaller litter size after AI. This finding indicates that the fluorescence properties of the sperm nucleus could be used to select for AI doses with greater fertilizing potential.</p

    Alcohol dehydrogenase 1B (ADH1B) genotype, alcohol consumption and breast cancer risk by age 50 years in a German case–control study

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    In a population-based study of 613 cases and 1082 controls, alcohol dehydrogenase 1B (ADH1B) genotype was not an independent risk factor for breast cancer, athough the possibility was raised that it modifies risk associated with high levels of alcohol consumption (OR 1.1, 95% confidence interval (CI) 0.8–1.6 for ADH1B*1/*1 genotype vs 0.2, 95% CI 0.1–1.0 for ADH1B*2 carriers)

    Impact of concomitant thyroid pathology on preoperative workup for primary hyperparathyroidism

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    BACKGROUND: The former standard surgical treatment in patients with primary hyperparathyroidism (pHPT) has been bilateral cervical exploration. New localization techniques and the possibility of intraoperative measurement of intact parathormone (iPTH) permit a focused, minimally invasive parathyroidectomy (MIP). The introduction of MIP without complete neck exploration leads to the potential risk of missing thyroid pathology. The aim of the present study is to evaluate the value of MIP in respect to coexisting thyroid findings and their impact on preoperative workup for primary hyperparathyroidism. METHODS: This is a prospective study including 30 consecutive patients with pHPT (median age 65 years; 17 females, 13 males). In all patients preoperative localization was performed by ultrasonography and 99m Tc-MIBI scintigraphy- Intraoperative iPTH monitoring was routinely done. RESULTS: Ten patients (33%) had a concurrent thyroid finding requiring additional thyroid surgery, and two patients (7%) with negative localization results underwent bilateral neck exploration. Therefore, MIP was attempted in 18 (60%) patients. The conversion rate to a four gland exploration was 6% (1/18). The sensitivities of 99m Tc-MIBI scanning and ultrasonography were 83.3% and 76.6%, respectively. The respective accuracy rates were 83.3% and 76.6%. Of note, the combination of the two modalities did not improve the sensitivity and accuracy in our patient population. During a median follow-up of 40 months, none of the patients developed persistent or recurrent hypocalcaemia, resulting in a 100% cure rate. CONCLUSION: Coexisting thyroid pathology is relatively frequent in patients with pHPT in our region. Among patients having pHPT without any thyroid pathology, the adenoma localization is correct with either ultrasonography or 99m Tc-MIBI scintigraphy in the majority of cases. MIP with iPTH monitoring are highly successful in this group of patients and this operative technique should be the method of choice
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