40 research outputs found

    Effect of different phytases on the performance, nutrient retention and tibia composition in broiler chickens

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    The effect of different phytases on the performance response, nutrient utilization and tibia characteristics of chickens was investigated. The five pelleted diets were the following: positive control (PC) with added monocalcium phosphate; negative control (NC) formulated with equivalency values of phytase for Ca and digestible P; and three further diets where different phytases were individually added to the NC diet at 500 FTU/kg. The phytases were derived either from Aspergillus (phytase I), or E. coli (phytases II and III). Compared to PC, the performance parameters, as well as apparent metabolizable energy (AMEn), mineral retention, bone breaking force and tibia mineral content were suppressed by the reduction of dietary Ca and digestible P. All phytases enhanced the overall body weight gains and feed conversion ratio in comparison with NC, but none outperformed PC. Only phytase II improved AMEn compared to NC and PC group. However only phytase I outperformed NC group in terms of mineral retention and P retention was higher than phytase II and III. No significant differences were observed in fat digestibility and N retention. Bone strength among phytases did not differ and all improved this parameter compared to the NC diet. However, even though all phytases enhanced tibia minerals content, the improvement was less pronounced with phytase III. Moreover, the differences in all analysed tibia minerals between phytase III and II were significant suggesting that even among 6-phytases derived from and expressed in the same organism, different efficacy or mode of action can occur

    Affine and toric hyperplane arrangements

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    We extend the Billera-Ehrenborg-Readdy map between the intersection lattice and face lattice of a central hyperplane arrangement to affine and toric hyperplane arrangements. For arrangements on the torus, we also generalize Zaslavsky's fundamental results on the number of regions.Comment: 32 pages, 4 figure

    HPV genotypes in the oral cavity/oropharynx of children and adolescents: cross-sectional survey in Poland

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    Human papillomaviruses (HPVs) are a very complex group of pathogenic viruses, with more than 80 types, causing human infection. Given the prevalence of HPV infection and its relationship with the development of cervical and many other cancers, HPV vaccine development has been a major public health initiative worldwide in the last decade. The aim of the presented study was to identify HPV DNA by MY-PCR in 4,150 school children and adolescents, aged 10–18 years in the Wielkopolska region, Poland. All individuals were asked to fill in extensive questionnaires; further normal, oral squamous cells were collected from each pupil. Cellular DNA was isolated and used as a MY-PCR template to estimate the incidence of HPV-active infection. Forty five subjects (1.08% of the sample) were carriers of oropharyngeal HPVs. HPV status and variables of interest, such as age, gender, socioeconomical status, and risk factors (smoking and sexual intercourse history, alcohol consumption) were not correlated. The presence of HPVs in the oral cavity was cumulated in several schools of the region. DNA sequencing of MY-PCR products revealed only four HPV genotypes. The most frequent genotype was HPV11 (38/45 HPV-positive cases), while other more rare genotypes were HPV6 (3/45), HPV12 (3/45), and HPV57 (1/45). Conclusion: Our findings presented herein, reveal a relatively low prevalance of oropharyngeal HPVs in Polish adolescents and fill an important gap in the knowledge of oral HPV infections of children above 10 years and adolescents

    Artificial neural network (ANN) approach for modelling of pile settlement of open-ended steel piles subjected to compression load

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    This study was devoted to examine pile bearing capacity and to provide a reliable model to simulate pile load-settlement behaviour using a new artificial neural network (ANN) method. To achieve the planned aim, experimental pile load test were carried out on model open-ended steel piles, with pile aspect ratios of 12, 17, and 25. An optimised second-order Levenberg-Marquardt (LM) training algorithm has been used in this process. The piles were driven in three sand densities; dense, medium, and loose. A statistical analysis test was conducted to explore the relative importance and the statistical contribution (Beta and Sig) values of the independent variables on the model output. Pile effective length, pile flexural rigidity, applied load, sand-pile friction angle and pile aspect ratio have been identified to be the most effective parameters on model output. To demonstrate the effectiveness of the proposed algorithm, a graphical comparison was performed between the implemented algorithm and the most conventional pile capacity design approaches. The proficiency metric indicators demonstrated an outstanding agreement between the measured and predicted pile-load settlement, thus yielding a correlation coefficient (R) and root mean square error (RMSE) of 0.99, 0.043 respectively, with a relatively insignificant mean square error level (MSE) of 0.0019. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group

    Plant antimicrobial peptides

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    Analiza numeryczna ściany szczelinowej wykonanej w iłach formacji poznańskiej z wykorzystaniem wybranych programów MES

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    The paper presents results of numerical calculations of a diaphragm wall model executed in Poznań clay formation. Two selected FEM codes were applied, Plaxis and Abaqus. Geological description of Poznań clay formation in Poland as well as geotechnical conditions on construction site in Warsaw city area were presented. The constitutive models of clay implemented both in Plaxis and Abaqus were discussed. The parameters of the Poznań clay constitutive models were assumed based on authors’ experimental tests. The results of numerical analysis were compared taking into account the measured values of horizontal displacements.Projektowanie konstrukcji podziemnych w obszarach gęstej zabudowy miejskiej, może wiązać się z wieloma trudnościami. Wykop zwykle jest realizowany w bliskim sąsiedztwie istniejących budynków i infrastruktury podziemnej, jak również istnieje ryzyko wystąpienia w podłożu skomplikowanych warunków gruntowych (np. gruntów ekspansywnych lub antropogenicznych). Obecnie inżynierowie mogą korzystać z różnych programów MES w celu rozwiązywania rzeczywistych problemów projektowych. Niektóre są przeznaczone do specyficznych zastosowań, np. w geotechnice Plaxis, Geo 5 czy z Soil. Inne komercyjne programy MES, jak np. Abaqus, Ansys czy LS-Dyna, są bardzo rozbudowane i nadają się do rozwiązywania różnorodnych zagadnień fizyki technicznej (nie tylko z zakresu mechaniki), ale nie zawsze dysponują dodatkowymi narzędziami przydatnymi w konkretnych zastosowaniach geotechnicznych. W artykule przedstawiono wyniki analizy przemieszczeń wybranej ściany szczelinowej przeprowadzonej z zastosowaniem dwóch uznanych programów MES: Plaxis i Abaqus. Oba zawierają zestaw modeli sprężystoplastycznych gruntów, przydatnych do modelowania zachowania się iłów, ale stosowanie tych modeli wymaga dobrej znajomości mechaniki i geotechniki

    Numerical Analysis of Diaphragm Wall Model Executed in Poznań Clay Formation Applying Selected Fem Codes

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    The paper presents results of numerical calculations of a diaphragm wall model executed in Poznań clay formation. Two selected FEM codes were applied, Plaxis and Abaqus. Geological description of Poznań clay formation in Poland as well as geotechnical conditions on construction site in Warsaw city area were presented. The constitutive models of clay implemented both in Plaxis and Abaqus were discussed. The parameters of the Poznań clay constitutive models were assumed based on authors’ experimental tests. The results of numerical analysis were compared taking into account the measured values of horizontal displacements

    Walidacja przydatności penetrometru stożkowego do określenia stanu gruntu na podstawie porównania z wynikami sondy statycznej CPT

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    The article presents an assessment of the suitability of the cone penetrometer to determine the soil state. The work describes the principle of the device operation, which is similar to commonly used dynamic DPL probes. Then, the results of research conducted in Polish conditions using the new conical penetrometer were presented. A series of measurements were performed in real field conditions. On their basis, an attempt was made to correlate the results obtained with a conical penetrometer and a static probe CPT. Then, the obtained correlations were validated. On this basis preliminary evaluation of the conical penetrometer suitability for the soil state determining.Artykuł przedstawia ocenę przydatności penetrometru stożkowego do określenia stanu gruntu. W pracy opisano zasadę działania urządzenia, podobną do powszechnie stosowanych sond dynamicznych typu DPL. Następnie przedstawiono wyniki badań przeprowadzonych w warunkach polskich z wykorzystaniem nowego penetrometru stożkowego. Szereg pomiarów wykonano w realnych warunkach terenowych. Na ich podstawie podjęto próbę korelacji wyników uzyskanych penetrometrem stożkowym oraz sondą statyczną CPT. Następnie uzyskane korelacje poddano walidacji i na tej podstawie wstępnie oceniono przydatność zastosowania penetrometru stożkowego do określenia stanu gruntu
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