3,177 research outputs found

    Chemical Composition, Fiber Morphology, and Pulping of P. Bolleana Lauche

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    The chemical composition and fiber morphology of the P. bolleana Lauche was assessed for its suitability for pulping and papermaking. The P. bolleana Lauche used in this study contained a low amount of lignin, but higher quantities of cellulose and hemicelluloses. It was found that morphological indices of P. bolleana Lauche were adequate for pulping and papermaking. The pulping of this wood was carried out using conventional kraft and soda pulping process under varying conditions. The results indicated that at higher sulfidity (24%-32%) with lower EA (14-16%), higher yields, and viscosity of pulping were obtained with an acceptable kappa number. Kraft pulp of P. bolleana Lauche obtained at given conditions (EA 14-16%; sulfidity 24-32%) provided paper sheets with greater tensile strength, burst index and tear index, at the same beating degree

    Surveillance and Genome Analysis of Human Bocavirus in Patients with Respiratory Infection in Guangzhou, China.

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    Human bocavirus (HBoV) is a novel parvovirus associated with respiratory tract diseases and gastrointestinal illness in adult and pediatric patients throughout the world. To investigate the epidemiological and genetic variation of HBoV in Guangzhou, South China, we screened 3460 throat swab samples from 1686 children and 1774 adults with acute respiratory infection symptoms for HBoV between March 2010 and February 2011, and analyzed the complete genome sequence of 2 HBoV strains. Specimens were screened for HBoV by real-time PCR and other 6 common respiratory viruses by RT-PCR or PCR. HBoV was detected in 58 (1.68%) out of 3460 samples, mostly from pediatric patients (52/58) and inpatient children (47/58). Six adult patients were detected as HBoV positive and 5 were emergency cases. Of these HBoV positive cases, 19 (32.76%) had co-pathogens including influenza virus (n = 5), RSV (n = 5), parainfluenza (n = 4), adenovirus (n = 1), coronavirus (n = 7). The complete genome sequences of 2 HBoVs strains (Genbank no. JN794565 and JN794566) were analyzed. Phylogenetic analysis showed that the 2 HBoV strains were HBoV1, and were most genetically close to ST2 (GenBank accession number DQ0000496). Recombination analysis confirmed that HBoV strain GZ9081 was an intra-genotype recombinant strain among HBoV1 variants.published_or_final_versio

    Sacrificial-template-free synthesis of core-shell C@Bi2S3 heterostructures for efficient supercapacitor and H-2 production applications

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    Core-shell heterostructures have attracted considerable attention owing to their unique properties and broad range of applications in lithium ion batteries, supercapacitors, and catalysis. Conversely, the effective synthesis of Bi2S3 nanorod core@ amorphous carbon shell heterostructure remains an important challenge. In this study, C@Bi2S3 core-shell heterostructures with enhanced supercapacitor performance were synthesized via sacrificial-template-free one-pot-synthesis method. The highest specific capacities of the C@Bi2S3 core shell was 333.43 F g(-1) at a current density of 1 A g(-1). Core-shell-structured C@Bi2S3 exhibits 1.86 times higher photocatalytic H-2 production than the pristine Bi2S3 under simulated solar light irradiation. This core-shell feature of C@Bi2S3 provides efficient charge separation and transfer owing to the formed heterojunction and a short radial transfer path, thus efficiently diminishing the charge recombination; it also facilitates plenty of active sites for the hydrogen evolution reaction owing to its mesoporous nature. These outcomes will open opportunities for developing low-cost and noble-metal-free efficient electrode materials for water splitting and supercapacitor applications

    Development of a LAMP assay for detection of Leishmania infantum infection in dogs using conjunctival swab samples

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    Background: Leishmania infantum infections in dogs play a crucial role in the transmission of pathogens causing visceral leishmaniasis to humans in the Gansu province, northwest China. To be able to control zoonotic transmission of the parasite to humans, a non-invasive loop-mediated isothermal amplification (LAMP) assay to specifically detect L. infantum infections in dogs was developed. Methods: The primers used in the LAMP assay were designed to target kinetoplast DNA minicircle sequences of the L. infantum isolate MCAN/CN/90/SC and tested using DNA isolated from promastigotes of different Leishmania species. The LAMP assay was evaluated with conjunctional swab samples obtained from 111 and 33 dogs living in an endemic and a non-endemic region of zoonotic visceral leishmaniasis in the Gansu province, respectively. The LAMP assay was also compared with conventional PCR, ELISA and microscopy using conjunctional swab, serum and bone marrow samples from the dogs, respectively. Results: The LAMP assay detected 1 fg of L. infantum DNA purified from cultured promastigotes which was 10-fold more sensitive than a conventional PCR test using Leishmania genus-specific primers. No cross reaction was observed with DNA isolated from promastigotes of L. donovani, L. major, L. tropica, and L. braziliensis, and the L. infantum reference strain MHOM/TN/80/IPT1. The L. infantum-positive rates obtained for field-collected samples were 61.3%, 58.6%, 40.5% and 10.8% by LAMP, PCR, ELISA and microscopy, respectively. As only one out of the 33 samples from control dogs from the non-endemic region of zoonotic visceral leishmaniasis was positive by the LAMP assay and the PCR test, the observed true negative rate (specificity) was 97% for both methods. Conclusion: This study has shown that the non-invasive, conjunctional swab-based LAMP assay developed was more sensitive in the detection of leishmaniasis in dogs than PCR, ELISA and microscopy. The findings indicate that the LAMP assay is a sensitive and specific method for the field surveillance of domestic dogs, particularly of asymptomatic canines, in ZVL-endemic areas in western China

    Phenomenological Implications of Deflected Mirage Mediation: Comparison with Mirage Mediation

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    We compare the collider phenomenology of mirage mediation and deflected mirage mediation, which are two recently proposed "mixed" supersymmetry breaking scenarios motivated from string compactifications. The scenarios differ in that deflected mirage mediation includes contributions from gauge mediation in addition to the contributions from gravity mediation and anomaly mediation also present in mirage mediation. The threshold effects from gauge mediation can drastically alter the low energy spectrum from that of pure mirage mediation models, resulting in some cases in a squeezed gaugino spectrum and a gluino that is much lighter than other colored superpartners. We provide several benchmark deflected mirage mediation models and construct model lines as a function of the gauge mediation contributions, and discuss their discovery potential at the LHC.Comment: 29 pages, 9 figure

    Virtual Blocks: a serious game for spatial ability improvement on mobile devices

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    This paper presents a novel spatial instruction system for improving spatial abilities of engineering students. A 3D mobile game application called Virtual Blocks has been designed to provide a 3D virtual environment to build models with cubes that help students to perform visualization tasks to promote the development of their spatial ability during a short remedial course. A validation study with 26 freshman engineering students at La Laguna University (Spain) has concluded that the training had a measurable and positive impact on students spatial ability. In addition, the results obtained using a satisfaction questionnaire show that Virtual Blocks is considered an easy to use and stimulating application.This work has been partially supported by the (Spanish) National Program for Studies and Analysis project "Evaluation and development of competencies associated to the spatial ability in the new engineering undergraduate courses" (Ref. EA2009-0025) and the (Spanish) National Science Project "Enhancing Spatial REasoning and VIsual Cognition with advanced technological tools (ESREVIC)" (Ref TIN2010-21296-C02-02)Martín Dorta, NN.; Sanchez Berriel, I.; Bravo, M.; Hernández, J.; Saorin, JL.; Contero, M. (2014). Virtual Blocks: a serious game for spatial ability improvement on mobile devices. Multimedia Tools and Applications. 73(3):1575-1595. https://doi.org/10.1007/s11042-013-1652-0S15751595733Baartmans BG, Sorby SA (1996) Introduction to 3-D spatial visualization. Prentice Hall, Englewood CliffsClements D, Battista M (1992) Geometry and spatial reasoning. In: Grouws DA (ed) Handbook of research on mathematics teaching and learning. New York, pp 420–464Cohen J (1988) Statistical power analysis for the behavioral sciences, 2nd edn. Erlbaum, HillsdaleDe Lisi R, Cammarano DM (1996) Computer experience and gender differences in undergraduate mental rotation performance. Comput Hum Behav 12:351–361Deno JA (1995) The relationship of previous experiences to spatial visualization ability. Eng Des Graph J 59(3):5–17Feng J, Spence I, Pratt J (2007) Playing an action video game reduces gender differences in spatial cognition. Psychol Sci 18(10):850–855French JW (1951) The description of aptitude and achievement tests in terms of rotated factors. Psychometric monograph 5Guilford JP, Lacy JI (1947) Printed classification tests, A.A.F. Aviation Psychological Progress Research Report, 5. US. Government Printing Office, Washington DCHalpern DF (2000) Sex differences and cognitive abilities. Erlbaum, MahwahHöfele C (2007) Mobile 3D graphics: learning 3D graphics with the Java Micro Edition. Editorial ThomsonKajiya JT, Kay TL (1989) Rendering fur with three dimensional textures. In Proceedings of the 16th Annual Conference on Computer Graphics and interactive Techniques SIGGRAPH ’89. ACM Press, New York pp 271–280Linn MC, Petersen AC (1985) Emergence and characterization of gender differences in spatial abilities: a meta-analysis. Child Dev 56:1479–1498Martin-Dorta N, Sanchez-Berriel I, Bravo M, Hernandez J, Saorin JL, Contero M (2010) A 3D educational mobile game to enhance student’s spatial skills, ICALT, pp.6–10, 2010 10th IEEE International Conference on Advanced Learning TechnologiesMartin-Dorta N, Saorin J, Contero M (2008) Development of a fast remedial course to improve the spatial abilities of engineering students. J Eng Educ 27(4):505–514Martin-Dorta N, Saorin JL, Contero M (2011) Web-based spatial training using handheld touch screen devices. Educ Technol Soc 14(3):163–177McGee MG (1979) Human spatial abilities: psychometric studies and environmental, genetic, hormonal, and neurological influences. Psychol Bull 86:889–918Noguera JM, Segura RJ, Ogayar CJ, Joan-Arinyo R (2011) Navigating large terrains using commodity mobile devices. Comput Geosci 37:1218–1233Okagaki L, Frensch PA (1994) Effects of video game playing on measures of spatial performance: gender effects in late adolescence. J Appl Dev Psychol 15(1):33–58Pulli K, Aarnio T, Miettinen V, Roimela K, Vaarala J (2007) Mobile 3D graphics with OpenGL ES and M3G. Editorial Morgan KaufmannQuaiser-Pohl C, Geiser C, Lehmann W (2005) The relationship between computer-game preference, gender, and mental-rotation ability. Personal Individ Differ 40(3):609–619Smith IM (1964) Spatial ability- its educational and social significance. The University of London Press, LondonSorby S (2007) Developing 3D spatial skills for engineering students. Australas Assoc Eng Educ 13(1):1–11Terlecki MS, Newcombe NS (2005) How important is the digital divide? The relation of computer and videogame usage to gender differences in mental rotation ability. Sex Roles 53(5/6):433–441Terlecki MS, Newcombe NS, Little M (2008) Durable and generalized effects of spatial experience on mental rotation: gender differences in growth patterns. Appl Cogn Psychol 22:996–1013Thurstone LL (1950) Some primary abilities in visual thinking (Tech. Rep. No. 59). IL University of Chicago Psychometric Laboratory, ChicagoThurstone LL, Thurstone TG (1941) Factorial studies of intelligence. Psychometric monographs. Chicago Press, ChicagoVanderberg S, Kuse A (1978) Mental Rotation, a group test of three dimensional spatial visualization. Percept Mot Skills 47:599–604Zimmerman WS (1954) Hypotheses concerning the nature of the spatial factors. Educ Psychol Meas 14:396–40

    Tool path pattern and feed direction selection in robotic milling for increased chatter-free material removal rate

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    Robotic milling becomes increasingly relevant to large-scale part manufacturing industries thanks to its cost-effective and portable manufacturing concept compared to large-scale CNC machine tools. Integration of milling processes with industrial robots is proposed to be well aligned with the aims and objective of the recent fourth industrial revolution. However, the industrial robots introduce position-dependent and asymmetrical dynamic flexibility, which may reflect to the tool tip dynamics under several conditions. Under such circumstances, the stability limits become dependent on the machining location and the feed direction. In this respect, selection of machining tool path patterns is crucial for increased chatter-free material removal rates (MRR). This paper proposes an approach to evaluate and select tool path patterns, offered by the existing CAM packages, for increased chatter-free MRR. The machining area is divided into number of machining locations. The optimal feed direction is decided based on the absolute stability at each region considering the asymmetrical and position-dependent tool tip dynamics. Then, the alternative tool path patterns are evaluated and the corresponding optimum feed direction is decided for increased chatter-free material removal. The application of the proposed approach is demonstrated through simulations and representative experiments

    Peritrophic matrix of Phlebotomus duboscqi and its kinetics during Leishmania major development

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    Light microscopy of native preparations, histology, and electron microscopy have revealed that Phlebotomus duboscqi belongs to a class of sand fly species with prompt development of the peritrophic matrix (PM). Secretion of electron-lucent fibrils, presumably chitin, starts immediately after the ingestion of a blood meal and, about 6 h later, is followed by secretion of amorphous electron-dense components, presumably proteins and glycoproteins. The PM matures in less than 12 h and consists of a thin laminar outer layer and a thick amorphous inner layer. No differences have been found in the timing of the disintegration of the PM in females infected with Leishmania major. In both groups of females (infected and uninfected), the disintegration of the PM is initiated at the posterior end. Although parasites are present at high densities in the anterior part of the blood meal bolus, they escape from the PM at the posterior end only. These results suggest that L. major chitinase does not have an important role in parasite escape from the PM. Promastigotes remain in the intraperitrophic space until the PM is broken down by sand-fly-derived chitinases and only then migrate anteriorly. Disintegration of the PM occurs simultaneously with the morphological transformation of parasites from procyclic forms to long nectomonads. A novel role is ascribed to the anterior plug, a component of the PM secreted by the thoracic midgut; this plug functions as a temporary barrier to stop the forward migration of nectomonads to the thoracic midgut

    Índice de Massa Corporal, Idade, Maturação Sexual e a Incidência de Hiperlordose Lombar em crianças e adolescentes

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    Introduction: Hyperlordosis can cause several degenerative spinal pathologies in children and adolescents. Objective: Determine whether body mass index, age and sexual maturation predict the occurrence of hyperlordosis in children and adolescents. Method: The study analyzed 380 students aged between 10 and 18 years. Body mass index was evaluated using the reference values suggested by the Fitnessgram test battery, and sexual maturation through Tanner’s scale of self-assessed pubic hair growth. Postural assessment was conducted using the DIPA photogrammetry method, version 3.1. (Digital Image Based Postural Assessment) The SPSS 24.0 program was used to analyze the data, and the following statistical tests were applied: chi squared, Mann-Whitney, Fisher’s exact and binary logistic regression. Results: There was statistical significance between hyperlordosis, girls’ age and puberty in boys (p 0.05). Conclusion: The girls’ age and boys’ stage of puberty were associated with the occurrence of hyperlordosis.Introdução: A Hiperlordose lombar pode ocasionar diversas patologias degenerativas na coluna vertebral de crianças e adolescentes. Objetivo: Identificar se o Índice de Massa Corporal, a Idade e a Maturação Sexual são previsores da ocorrência da hiperlordose lombar em crianças e adolescentes. Método: O estudo analisou 380 estudantes entre 10 e 18 anos. O Índice de Massa Corporal foi avaliado por meio dos valores de referência sugeridos pela bateria de testes Fitnessgram e a maturação sexual por meio da auto-avaliação da pilosidade pubiana de Tanner. A avaliação postural foi realizada pelo método de fotogrametria DIPA versão 3.1. (Avaliação Postural Baseada em Imagem Digital). Para análise dos dados foi utilizado o programa SPSS 24.0, tendo sido aplicados os testes estatísticos: Qui-Quadrado, Mann Whitney, Exato de Fisher e Regressão Logística Binária. Resultados: Observou-se que houve significância estatística entre a Hiperlordose lombar e a idade das meninas e a puberdade dos meninos (p0,05). Conclusão: A idade das meninas e a puberdade dos meninos foi associada à ocorrência da hiperlordose lombar.This study was funded by CIEC (Center for Investigations in Childhood Studies), Strategic Project UID/CED/00317/2013, via National FCT (Science and Technology Foundation) funds and co-funded by the European Regional Development Fund (FEDER), via COMPETE 2020 – Competitivity and Internalization Operational Program (POCI) under reference number POCI-01-0145-FEDER-007562
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