53 research outputs found

    Application of the Genetic Algorithm at Initial Stages of Ships Design

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    The main tasks for which the genetic algorithm is currently applied in shipbuilding are shown. The possibility of applying the genetic algorithm for determining the optimal characteristics of ships at the initial stages of design is considered.The formulation of the problem of parametric optimization for the initial stages of design is given. The features of such a problem and possible approaches to its solution are considered. Using the example of the problem of parametric optimization of small waterplane area twin hull ships, it is shown that the traditional methods of non-linear programming are not very effective. It is shown that one of the possible options for increasing the efficiency of searching for the optimal solution is the application of genetic algorithms. The mathematical bases of GA are considered and the scheme for finding the optimal solution using this method is described. The examples of test functions show the effectiveness of the genetic algorithm in comparison with traditional optimization methods. The results of solving the problem of parametric optimization of high-speed SWATH passenger ships are presented

    EVALUATION OF EFFICIENCY OF HEAT EXCHANGING DEVICES BUILT INTO THE THERMAL CYCLIC MACHINES

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    The focus of this work is a method of exergy-economizing calculation for the recuperative and regenerative heat-exchangers that are built-in the thermal cyclic machines. The method is intended for the analysis of efficiency of a prospective design and material for the heat-exchanger that is incorporated into the closed thermodynamic cycle of thermal machines at the initial stage of designing

    The versatile role of homologous recombination in plant cell : repair of DNA damage, stress-directed genome evolution and foreign DNA integration

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    xxi, 246 leaves : ill. ; 29 cm. --Homologous recombination represents a DNA repair pathway. Its role in a plant cell is not limited to double strand break repair. It also extends to genome evolution via rearranging of DNA sequences, and has an important application in foreign DNA integration in the plant genome. Our study demonstrated that effects exerted by stress on homologous recombination and genome stability are not restricted to the exposed generation. The progeny of plants exposed to stress exhibited elevated spontaneous homologous recombination, changes in DNA methylation and higher tolerance to stress. These heritable changes are mediated by an unknown stress-inducible epigenetic signal. Furthermore, we demonstrated that using factors that enhance homologous recombination can improve the efficiency of genetic transformation by Agrobacterium. We have developed and patented a plant growth medium enhancing homologous recombination and significantly increasing the transformation frequency. The role of several other chemicals for the improvement of transformation was also evaluated

    Influence of various factors on plant homologuous recombination

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    xiv, 121 leaves ; 29 cm.The genome of living organisms is constantly subjected to the environmental influences that result in different negative, negligible or positive impacts. The ability to maintain the genome integrity and simultaneously provide its flexibility is the main determinant for the evolutionary success of any species. One of the important aspects of genome maintenance is the precise regulation of the DNA repair machinery. Results reported here indicate the existence of a tight, age-dependent regulation of homologous recombination, one of the two main DNA double-strand break repair pathways. We show that recombination is influenced by conditions such as the change of temperature (cold or warm), day length, water availability (drought or overwatering stress) and salinity. These stresses not only influence the genome stability of stress-subjected generations but also change the recombination in subsequent generations. This indicates the possible involvement of homologous recombination in plant evolution and development of plant stress tolerance

    Wpływ Z56822977 na biosyntezę serotoniny w mózgu szczurów z otyłością wywołaną przez podawanie glutaminianu sodu

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    Wstęp: Badanie przeprowadzono w celu wyjaśnienia wpływu Z56822977 na biosyntezę serotoniny w mózgu szczurów z otyłością wy­wołaną podawaniem glutaminianu sodu (monosodium glutamate, MSG). Materiał i metody: W badaniu wykorzystano 18 samców szczura. Zwierzęta podzielono na trzy grupy: 1 — grupa kontrolna, 2 — grupa MSG, 3 — grupa MSG + Z56822977. Szczurzym oseskom w grupie 2 i 3 podawano podskórnie MSG rozpuszczony w soli fizjologicznej w dawce 4 mg/g masy ciała w objętości 8 μl/g w 2., 4., 6., 8. i 10. dniu życia. Grupie 3 podawano doustnie wodny roztwór Z56822977 w dawce 25 mg/kg w objętości 1 ml/kg. Pierwszą dawkę Z56822977 podawano po ukończeniu 4 tygodni życia, a następnie kontynuowa­no podawanie badanej substancji cyklicznie wedlug schematu tydzień podawania substancji badanej/3 tygodnie przerwy. Zwierzętom z grupy MSG podawano odpowiednio 1 ml/kg wody doustnie. Przez pierwsze 4 miesiące życia szczury otrzymywały standardową karmę. Zmierzono zawartość serotoniny, tryptofanu i 5-hydroksytryptofanu (5-HTr) oraz aktywność hydroksylazy tryptofanowej (tryptophan hydroxylase, TRH), dekarboksylazy aminokwasów (amino acid decarboxylase, AADC) i monoaminooksydazy (MAO) w tkance mózgowej. Wyniki: Wykazano, że podawanie Z56822977 ma pozytywny wpływ na główne wskaźniki otyłości, co odzwierciedlają zmiany podsta­wowych parametrów fizjologicznych i biochemicznych [zmniejszenie masy ciała o 13% vs. MSG (p < 0,05); zmniejszenie wskaźnika masy ciała (body mass index, BMI), wskaźnika Lee oraz masy tkanki tłuszczowej trzewnej odpowiednio o 18%, 7% i 55%, (p < 0,05) w porównaniu z grupą MSG]. Zawartość tryptofanu i serotoniny była istotnie niższa (p < 0,05) u szczurów z otyłością wywołaną przez MSG. W badaniach wykazano, że u otyłych szczurów aktywność MAO zwiększa się o 97% (p < 0,05), a aktywność TRH i AADC odpowiednio o 44% i 53% (p < 0,05). Podawanie Z56822977 powodowało zwiększenie zawartości serotoniny i tryptofanu w mózgach szczurów i przywracało poziom aktywności enzymów (MAO, TRH, AADC) do wartości mierzonych u zwierząt kontrolnych. Wnioski: Wiadomo, że otyłość wiąże się z zaburzeniem syntezy serotoniny w mózgu szczurów. Jednak podawanie Z56822977 prowadzi do normalizacji stężenia serotoniny i tryptofanu oraz przywrócenia prawidłowej aktywności enzymów uczestniczących w biosynte­zie i degradacji serotoniny. Podawanie Z56822977, cząsteczki wpływającej na układ serotoninergiczny, może powodować korzystne efekty w leczeniu otyłości wywołanej przez MSG u szczurów. Można rozważać zastosowanie cząsteczki Z56822977 jako nowego leku stosowanego w otyłości, jednak konieczne są dalsze badania w celu potwierdzenia jej działania

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors

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    Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe

    Physiological parameters for Prognosis in Abdominal Sepsis (PIPAS) Study : a WSES observational study

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    BackgroundTiming and adequacy of peritoneal source control are the most important pillars in the management of patients with acute peritonitis. Therefore, early prognostic evaluation of acute peritonitis is paramount to assess the severity and establish a prompt and appropriate treatment. The objectives of this study were to identify clinical and laboratory predictors for in-hospital mortality in patients with acute peritonitis and to develop a warning score system, based on easily recognizable and assessable variables, globally accepted.MethodsThis worldwide multicentre observational study included 153 surgical departments across 56 countries over a 4-month study period between February 1, 2018, and May 31, 2018.ResultsA total of 3137 patients were included, with 1815 (57.9%) men and 1322 (42.1%) women, with a median age of 47years (interquartile range [IQR] 28-66). The overall in-hospital mortality rate was 8.9%, with a median length of stay of 6days (IQR 4-10). Using multivariable logistic regression, independent variables associated with in-hospital mortality were identified: age > 80years, malignancy, severe cardiovascular disease, severe chronic kidney disease, respiratory rate >= 22 breaths/min, systolic blood pressure 4mmol/l. These variables were used to create the PIPAS Severity Score, a bedside early warning score for patients with acute peritonitis. The overall mortality was 2.9% for patients who had scores of 0-1, 22.7% for those who had scores of 2-3, 46.8% for those who had scores of 4-5, and 86.7% for those who have scores of 7-8.ConclusionsThe simple PIPAS Severity Score can be used on a global level and can help clinicians to identify patients at high risk for treatment failure and mortality.Peer reviewe

    Measurements of top-quark pair differential cross-sections in the eμe\mu channel in pppp collisions at s=13\sqrt{s} = 13 TeV using the ATLAS detector

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