2,874 research outputs found

    Data sorting

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    Ovaj rad prikazuje jedno od rješenja problema sortiranja podataka u jednodimenzionalnom polju (nizu) elemenata. U praksi se često pojavljuje potreba za sortiranjem podataka te se zbog toga traži što efikasniji i brži algoritam. U ovom radu detaljno je prikazan jedan od najboljih - merge-sort algoritam. Napravljene su i praktične izvedbe algoritama za sortiranje koje su testirane na različitim skupovima podataka.In this paper one solution of the problem of sorting an one-dimensional vector (array) of data is shown in this paper. A need for data sorting very often arises in the practice and therefore we are constantly searching for more efficient and faster sorting algorithms. One of the best sorting algorithms -merge-sort is shown in this paper in detail. We made two of sorting algorithms and tested them on different types of data

    Using the VALGENT-3 framework to assess the clinical and analytical performance of the RIATOL qPCR HPV genotyping assay

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    Background and objective: The VALGENT framework is developed to assess the clinical performance of HPV tests that offer genotyping capability. Samples from the VALGENT-3 panel are used to identify an optimal viral concentration threshold for the RIATOL qPCR HPV genotyping assay (RIATOL qPCR) to assure non-inferior accuracy to detect high-grade cervical intraepithelial neoplasia (CIN), compared to Qiagen Hybrid Capture 2 (HC2), a standard comparator test validated for cervical cancer screening. Study design: The VALGENT-3 panel comprised 1300 samples from women participating in the Slovenian cervical cancer screening programme, enriched with 300 samples from women with abnormal cytology. In follow-up, 126 women were diagnosed with CIN2+ (defined as diseased) and 1167 women had two consecutive negative Pap smears (defined as non-diseased). All 1600 samples were analyzed with the RIATOL qPCR. Viral concentration was expressed as viral log10 of the number of copies/ml. A zone of viral concentration cut-offs was defined by relative ROC analysis where the sensitivity and specificity were not inferior to HC2. Results: The RIATOL qPCR had a sensitivity and specificity for CIN2+ of 97.6% (CI: 93.2-99.5%) and 85.1% (CI: 82.9-87.1%), respectively, when the analytical cut off was used. At a cut off of 6.5, RIATOL qPCR had a sensitivity of 96.0% (CI: 91.0-98.7%) and a specificity of 89.5% (87.6-91.2%). At optimized cut off, accuracy of the qPCR was non-inferior to the HC2 with a relative sensitivity of 1.00 [CI: 0.95-1.05 (p= 0.006)] and relative specificity of 1.00 [CI: 0.98-1.01 (p= 0.0069)]. Conclusions: The RIATOL qPCR has a high sensitivity and specificity for the detection of CIN2+. By using a fixed cut-off based on viral concentration, the test is non-inferior to HC2. HPV tests that provide viral concentration measurements or other quantifiable signals allow flexibility to optimize accuracy required for cervical cancer screening

    Colorings of complements of line graphs

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    Our purpose is to show that complements of line graphs enjoy nice coloring properties. We show that for all graphs in this class the local and usual chromatic numbers are equal. We also prove a sufficient condition for the chromatic number to be equal to a natural upper bound. A consequence of this latter condition is a complete characterization of all induced subgraphs of the Kneser graph KG(n,2)\operatorname{KG}(n,2) that have a chromatic number equal to its chromatic number, namely n2n-2. In addition to the upper bound, a lower bound is provided by Dol'nikov's theorem, a classical result of the topological method in graph theory. We prove the NP\operatorname{NP}-hardness of deciding the equality between the chromatic number and any of these bounds. The topological method is especially suitable for the study of coloring properties of complements of line graphs of hypergraphs. Nevertheless, all proofs in this paper are elementary and we also provide a short discussion on the ability for the topological methods to cover some of our results

    Evaluating Enzymatic Productivity—The Missing Link to Enzyme Utility

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    Kinetic productivity analysis is critical to the characterization of enzyme catalytic performance and capacity. However, productivity analysis has been largely overlooked in the published literature. Less than 0.01% of studies which report on enzyme characterization present productivity analysis, despite the fact that this is the only measurement method that provides a reliable indicator of potential commercial utility. Here, we argue that reporting productivity data involving native, modified, and immobilized enzymes under different reaction conditions will be of immense value in optimizing enzymatic processes, with a view to accelerating biotechnological applications. With the use of examples from wide‐ranging studies, we demonstrate that productivity is a measure of critical importance to the translational and commercial use of enzymes and processes that employ them. We conclude the review by suggesting steps to maximize the productivity of enzyme catalyzed reactions

    Clique-cutsets beyond chordal graphs

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    Truemper configurations (thetas, pyramids, prisms, and wheels) have played an important role in the study of complex hereditary graph classes (eg, the class of perfect graphs and the class of even‐hole‐free graphs), appearing both as excluded configurations, and as configurations around which graphs can be decomposed. In this paper, we study the structure of graphs that contain (as induced subgraphs) no Truemper configurations other than (possibly) universal wheels and twin wheels. We also study several subclasses of this class. We use our structural results to analyze the complexity of the recognition, maximum weight clique, maximum weight stable set, and optimal vertex coloring problems for these classes. Furthermore, we obtain polynomial x-bounding functions for these classes

    Assessment of the human exposure to transient and time-harmonic fields using the enhanced transmission line theory approach

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    The paper deals with the assessment of human exposure to the transient electromagnetic fields and high-frequency (HF) radiation. The formulation of the problem is based on a simplified cylindrical representation of the human body. The analysis is based on the enhanced transmission line (TL) theory. For this purpose, in order to quantify the induced current inside the human body, we solve linear system equations, where the electromagnetic field excitation is represented by two equivalent current and voltage generators. Once the axial current is determined, it is possible to calculate the specific absorption rate (SAR). Some illustrative computational examples are presented in the paper

    The use of isothermal titration calorimetry for the assay of enzyme activity: Application in higher education practical classes

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    Determination of enzyme activity is crucial for discovery, research, and development in life sciences. The activity of enzymes is routinely determined using spectrophotometric assays that measure rates of substrate consumption or product formation. Though colorimetric-based detection systems are simple, rapid, and economical to perform, the majority of enzymes are unsuitable for this technique as their substrates/products do not absorb in the UV or visible range. This limitation can be addressed by the use of coupled-enzyme assays or artificial chromogenic substrates; however these approaches have their own drawbacks. Here, we describe a method based on the use of an isothermal titration calorimeter (ITC) to measure the heat produced or absorbed during any enzyme-catalyzed reaction. The concept of calorimetric enzyme assays was demonstrated for the determination of enzyme hexokinase activity, which cannot be monitored colorimetrically without first coupling it to another enzymatic reaction. The assay is suitable for incorporation into undergraduate laboratory classes, providing students with an appreciation for; the versatility and ease of use of ITC assays; ITC as a flexible generic method for exploring the functional characteristics of uncharacterized enzymes; an activity detection parameter suitable for enzymes that either have no straightforward colorimetric methods available or require the use of nonartificial chromogenic substrates

    Influence of Sex, Age and Presence of Functional Units on Optical Density and Bone Height of the Mandible in the Elderly

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    OBJECTIVES: Mandibular bone height and density were compared with age, sex and the number and type of functional dental units, as represented by Eichner index. MATERIAL AND METHODS: A sample of 150 elderly patients of the Dental Clinic were divided into three age groups, examined and orthopantomograms/OPG/ taken. The OPGs were taken with the copper stepwedge in order to enable computer-assisted calculation of mandibular optical density and calibration of dimensional measurements by specially designed software. RESULTS:Eichner class III was found in 62% of patients. The presence of functional units was positively correlated with age (r=0.67) and bone height values (r=0.88, p<0.05). Optical density and bone height values of measurements performed at the same locations on mandibles showed no significant correlation (r=0.24, p<0.05). Intra-subject measurement showed that the eminentia piriformis region had significantly higher optical density values compared to 1st molar and mental foramen regions (p<0.05). Women had significantly lower bone height values than men (p<0.05), but no significant sex difference was found in optical density values. CONCLUSION: The presence of functional units has significant influence on bone height, although, like age or sex of the patient, it has no influence on mineral content of the mandible. The eminentia piriformis is not susceptible to bone mineral content or height change
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