934 resultados para economic statistical design
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The flow of sediment from cropped land is the main pollutant of water sources in rural areas. Due to this fact, it is necessary to develop and implement technologies that will reduce water and sediment discharges. Accordingly, an experiment was conducted in the Department of Biosystems Engineering - ESALQ / USP, Piracicaba - SP with the objective to evaluate the effect of different soil cover (bean, grass and bare ground) and erosion control practices (wide base terraces and infiltration furrows in slopes (no practices to control erosion)) while measuring water losses in runoff. The statistical design adopted was randomized blocks in a 3x3 factorial scheme resulting in 9 treatments with 3 replicates (blocks). The period of rainfall data collection was December 6, 2007 to April 11, 2008. A 21.1 cm diameter rain gauge was installed in the experimental area. Terraces were the most efficient practices for reducing erosion losses in the treatments with infiltration furrows being better than the control treatment. Bean was more effective than grass in reducing erosion. Bare ground was the least efficient.
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Plant growth and development are proportional to biological time, or the thermal time of the species, which can be defined as the integral of the temperature over time between the lower and upper temperature developmental thresholds. The objective of this study was to investigate the efficiency of the growing degree-day (GDD) approach for vines of the 'Niagara Rosada' cultivar pruned in winter and summer seasons, and physiological phases (mobilisation and reserve accumulation) in a humid subtropical region. The experiment was carried out on 13-year-old plants in Piracicaba, So Paulo State-Brazil, evaluating 24 production cycles, 12 from the winter pruning, and 12 from the summer pruning. The statistical design was comprised of randomised blocks, using the pruning dates as treatment: 20 July, 4 August, 19 August, and 3 September (winter); 1 February, 15 February, 2 March, and 16 March (summer). Comparison of the mean values of GDD among pruning dates was evaluated by the Tukey test, and comparison between pruning seasons was made by the F test for orthogonal contrasts, both at the 5% probability level. The results showed good agreement between the values of GDD required to complete the cycle from the winter pruning until harvest when compared with other studies performed with the same cultivar grown in the Southern and Southeastern regions of Brazil. However, there was a consistent statistical difference between GDD computed for winter and summer pruning, which allowed us to conclude that this bio-meteorological index is not sufficient to distinguish vines pruned in different seasons and physiological phases applied in humid subtropical climates.
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Lasiodiplodan, an exopolysaccharide of the (1 -> 6)-beta-d-glucan type, is produced by Lasiodiplodia theobromae MMPI when grown under submerged culture on glucose. The objective of this study was to evaluate lasiodiplodan production by examining the effects of carbon (glucose, fructose, maltose, sucrose) and nitrogen sources (KNO3, (NH4)(2)SO4, urea, yeast extract, peptone), its production in shake flasks compared to a stirred-tank bioreactor, and to study the rheology of lasiodiplodan, and lasiodiplodan's anti-proliferative effect on breast cancer MCF-7 cells. Although glucose (2.05 +/- A 0.05 g L-1), maltose (2.08 +/- A 0.04 g L-1) and yeast extract (2.46 +/- A 0.06 g L-1) produced the highest amounts of lasiodiplodan, urea as N source resulted in more lasiodiplodan per unit biomass than yeast extract (0.74 +/- A 0.006 vs. 0.22 +/- A 0.008 g g(-1)). A comparison of the fermentative parameters of L. theobromae MMPI in shake flasks and a stirred-tank bioreactor at 120 h on glucose as carbon source showed maximum lasiodiplodan production in agitated flasks (7.01 +/- A 0.07 g L-1) with a specific yield of 0.25 +/- A 0.57 g g(-1) and a volumetric productivity of 0.06 +/- A 0.001 g L-1 h(-1). A factorial 2(2) statistical design developed to evaluate the effect of glucose concentration (20-60 g L-1) and impeller speed (100-200 rpm) on lasiodiplodan production in the bioreactor showed the highest production (6.32 g L-1) at 72 h. Lasiodiplodan presented pseudoplastic behaviour, and the apparent viscosity increased at 60A degrees C in the presence of CaCl2. Anti-proliferative activity of lasiodiplodan was demonstrated in MCF-7 cells, which was time- and dose-dependent with an IC50 of 100 mu g lasiodiplodan mL(-1).
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The aim of this study was to evaluate the immunoexpression of MMP-2, MMP-9 and CD31/microvascular density in squamous cell carcinomas of the floor of the mouth and to correlate the results with demographic, survival, clinical (TNM staging) and histopathological variables (tumor grade, perineural invasion, embolization and bone invasion). Data from medical records and diagnoses of 41 patients were reviewed. Histological sections were subjected to immunostaining using primary antibodies for human MMP-2, MMP-9 and CD31 and streptavidin-biotin-immunoperoxidase system. Histomorphometric analyses quantified positivity for MMPs (20 fields per slide, 100?points grade, ×200) and for CD31 (microvessels <50?µm in the area of the highest vascularization, 5 fields per slide, 100?points grade, ×400). Statistical design was composed by non-parametric Mann-Whitney U test (investigating the association between numerical variables and immunostainings), chi-square frequency test (in contingency tables), Fisher's exact test (when at least one expected frequency was less than 5 in 2×2 tables), Kaplan-Meier method (estimated probabilities of overall survival) and Iogrank test (comparison of survival curves), all with a significance level of 5%. There was a statistically significant correlation between immunostaining for MMP-2 and lymph node metastasis. Factors associated negatively with survival were N stage, histopathological grade, perineural invasion and immunostaining for MMP-9. There was no significant association between immunoexpression of CD31 and the other variables. The intensity of immunostaining for MMP-2 can be indicative of metastasis in lymph nodes and for MMP-9 of a lower probability of survival
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This article gives an overview over the methods used in the low--level analysis of gene expression data generated using DNA microarrays. This type of experiment allows to determine relative levels of nucleic acid abundance in a set of tissues or cell populations for thousands of transcripts or loci simultaneously. Careful statistical design and analysis are essential to improve the efficiency and reliability of microarray experiments throughout the data acquisition and analysis process. This includes the design of probes, the experimental design, the image analysis of microarray scanned images, the normalization of fluorescence intensities, the assessment of the quality of microarray data and incorporation of quality information in subsequent analyses, the combination of information across arrays and across sets of experiments, the discovery and recognition of patterns in expression at the single gene and multiple gene levels, and the assessment of significance of these findings, considering the fact that there is a lot of noise and thus random features in the data. For all of these components, access to a flexible and efficient statistical computing environment is an essential aspect.
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En la evaluación regional de riego con equipos presurizados, se observa que la mayoría de los establecimientos no hacen uso de programas de riego basados en necesidades hídricas, dando lugar a un uso inadecuado de los recursos hídricos. Por ello, en el presente trabajo se evalúa la producción de trigo (Triticum aestivum L.) bajo riego programado considerando las variables clima-suelo-cultivo. La experiencia se desarrolló en el campo experimental de la Universidad Nacional de Río Cuarto durante los ciclos 1999, 2000 y 2001. Se contó con la información climática de la estación meteorológica instalada en el lugar. En los ensayos se consideró un diseño estadístico en parcelas totalmente al azar con seis repeticiones. Los tratamientos fueron los siguientes: 1. sin riego; 2. reponiendo desde un umbral de marchitez incipiente hasta capacidad de campo; 3. reponiendo desde umbral de marchitez incipiente hasta un nivel que permita el aprovechamiento del agua de lluvia con un 75 % de probabilidad de ocurrencia; 4. riego sólo en el período comprendido entre las etapas fenológicas de macollaje y grano lechoso y 5. considerando el modelo de programación YACU. Los resultados de esta experiencia en los tres años considerados establecen una respuesta significativa al riego complementario, con una producción promedio de los tratamientos bajo riego de 4980 kg.ha-1 en 1999, 5895 kg.ha-1 en el 2000 y 6271 kg.ha-1 en el 2001, contra 3296 kg.ha-1, 4054 kg.ha-1 y 3197 kg.ha-1, respectivamente, para los tratamientos sin riego. Dentro de los tratamientos bajo riego, en los dos primeros años se obtuvieron valores significativamente menores en las parcelas regadas sólo entre macollaje y grano lechoso: 4704 kg.ha-1 en 1999 y 4973 kg.ha-1 en el 2000.
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O conhecimento da interferência do porta-enxerto no desenvolvimento da copa é muito importante, pois tais interações para cada combinação porta-enxerto e cultivar copa adotada pode variar. Dessa forma, o objetivo deste trabalho foi avaliar a interferência dos porta-enxertos \'IAC 766\', \'IAC 572\', \'IAC 313\', \'IAC 571-6\' e \'Ripária do Traviú\', no desenvolvimento e fertilidade das gemas da cultivar copa \'Niagara Rosada\'. O estudo foi realizado em videira \'Niagara Rosada\' conduzida sob o sistema de espaldeira, na região de Jundiaí - SP. As avaliações foram realizadas em três ciclos de produção, destes, dois foram realizados no ciclo tradicional, em que a poda de produção é realizada no inverno e a colheita no fim da primavera e início de verão, e um foi realizado na denominada safrinha, em que a poda de produção ocorre no verão e a colheita no fim do outono e início do inverno. Para os ciclos de produção tradicionais avaliou-se a fertilidade da primeira até a quarta ou quinta gema, o número de brotação, o número de cacho e o comprimento final dos ramos em 2014 e 2015. No ciclo de produção safrinha avaliou-se a fertilidade da quinta até a oitava gema e os demais dados biométricos durante o cultivo. Nesse ciclo de produção avaliou-se a produção e qualidade de frutos da videira. O delineamento experimental adotado foi em blocos casualizados em esquema de parcela subdividida para fertilidade de gemas, e em blocos casualizados para as demais variáveis. Os dados coletados foram submetidos à análise de variância, e quando significativo, os dados foram submetidos ao teste de comparação de médias Tukey a 0,05 de probabilidade. Não foi observado efeito dos diferentes porta-enxertos na fertilidade de gemas, no desenvolvimento da planta, na produção e qualidade dos frutos de videira \'Niagara Rosada\'.
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A dinâmica ambiental possui capacidade limitada de reciclagem e a crescente utilização resíduos agroindustriais, especialmente na agricultura, pode levar a situações de poluição do solo e demais componentes ambientais. A manutenção da produtividade de ecossistemas agrícolas e naturais depende do processo de transformação da matéria orgânica e, por conseguinte, da biomassa microbiana do solo, e que é responsável pela decomposição e mineralização de resíduos no mesmo. A dinâmica natural dos microrganismos do solo, em constante mudança e adaptação, os torna um indicador sensível às mudanças resultantes de diferentes práticas de manejo agrícola. Sendo assim, conhecer essas alterações e suas interferências é fundamental para identificar estratégias adequadas de manejo, apontando técnicas de utilização adequadas. O objetivo deste trabalho foi avaliar a qualidade de um solo agrícola, cultivado com três variedades de cana-de-açúcar (Saccharum spp.), comparando a utilização de adubação mineral frente à utilização de fertilizante orgânico composto no período final de formação dos perfilhos (120 dias após o plantio). Foi implantado, em condições de campo, o cultivo de cana-de-açúcar (cana planta), utilizando as variedades RB 867515, RB 962869 e RB 855453, onde cada variedade foi cultivada de três formas distintas, sendo elas: plantio controle (CT) sem aplicação de insumos para adubação; plantio orgânico (OG) com aplicação de fertilizante orgânico; e plantio convencional (CV) com aplicação de adubação mineral, seguindo recomendações de adubação após análise química inicial do solo local. Cada parcela possuía 37 m2, com 5 sulcos de 5,0 m de comprimento e espaçamento de 1,5 m entrelinhas, sendo os três sulcos centrais formando a área útil. De acordo com a variedade e o tipo de adubação, foram formados nove tratamentos: T1 86CT, T2 96CT, T3 85CT, T4 6OG, T5 96OG, T6 85OG, T7 86CV, T8 96CV e T9 85CV, com delineamento estatístico de blocos ao acaso e quatro repetições. Os parâmetros químicos do solo analisados foram macronutrientes e micronutrientes; os parâmetros microbiológicos foram carbono da biomassa microbiana (CBM), respiração basal do solo (RBS), quociente metabólico (qCO2), número mais provável de fungos e bactérias do solo (NMP); e, por fim, a produtividade agrícola (t/ha). Os resultados foram submetidos a análise de variância (ANOVA) e à comparação das médias através do teste de Tukey (10%). Também foi realizada a análise de variância dos dados e correlação cofenética de Pearson para formação de dendogramas. Com base no período estudado, considerado como fase crítica da formação do canavial, concluiu-se que os parâmetros químicos que evidenciaram alterações no solo foram pH e os macronutrientes Mg, Al e SB, sendo os tratamentos orgânicos equivalentes e/ou melhores que os tratamentos convencionais. Para os parâmetros microbiológicos, o NMP de fungos apresentou os maiores valores nos tratamentos convencionais e controle. A produtividade agrícola não foi influenciada pelos diferentes tratamentos e insumos utilizados, independente da variedade de cana-de-açúcar utilizada. Por fim, foram observadas correlações positivas entre as variáveis CTC e quociente metabólico (qCO2) apontando potencial melhoria da qualidade do solo, com o emprego de insumos orgânicos
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National Highway Traffic Safety Administration, National Center for Statistics and Analysis, Washington, D.C.
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National Highway Traffic Safety Administration, Washington, D.C.
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National Highway Traffic Safety Administration, Washington, D.C.
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Purpose – The purpose of this paper is to explore the criminal workplace activities of both employers and employees in Ukrainian enterprises. It challenges traditional definitions of corruption and suggests that the practices that can be observed fit into the category of organised crime because of the country's economic framework. The paper also explores how the practices are partially a legacy of Soviet economic processes. Design/methodology/approach – A total of 700 household surveys were completed in three cities, Kyiv (where 450 surveys were completed), Uzhgorod (150) and Kharkiv (100). To complement these, approximately 25 in-depth interviews were undertaken with workers in each region. Furthermore, ethnographic observations and “kitchen table” interviews also played an important role in the research. Although the research was oriented towards those working in informal economies, business owners (both formal and informal) were also interviewed. Findings – As well as revealing the endemic nature of corruption in Ukrainian workplaces and the high levels of informal activity undertaken by workers, the research found that many people wish for their workplace to become more regulated. Research limitations/implications – Further interviews could have been carried out with state officials and in more locations. The implications are multiple but mainly they demonstrate the difficulty that those charged with economic reform in Ukraine must face. Originality/value – It is one of the first studies to explore these issues in Ukraine using a variety of research methods.
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The work presented in this thesis describes an investigation into the production and properties of thin amorphous C films, with and without Cr doping, as a low wear / friction coating applicable to MEMS and other micro- and nano-engineering applications. Firstly, an assessment was made of the available testing techniques. Secondly, the optimised test methods were applied to a series of sputtered films of thickness 10 - 2000 nm in order to: (i) investigate the effect of thickness on the properties of coatingslcoating process (ii) investigate fundamental tribology at the nano-scale and (iii) provide a starting point for nanotribological coating optimisation at ultra low thickness. The use of XPS was investigated for the determination of Sp3/Sp2 carbon bonding. Under C 1s peak analysis, significant errors were identified and this was attributed to the absence of sufficient instrument resolution to guide the component peak structure (even with a high resolution instrument). A simple peak width analysis and correlation work with C KLL D value confirmed the errors. The use of XPS for Sp3/Sp2 was therefore limited to initial tentative estimations. Nanoindentation was shown to provide consistent hardness and reduced modulus results with depth (to < 7nm) when replicate data was suitably statistically processed. No significant pile-up or cracking of the films was identified under nanoindentation. Nanowear experimentation by multiple nanoscratching provided some useful information, however the conditions of test were very different to those expect for MEMS and micro- / nano-engineering systems. A novel 'sample oscillated nanoindentation' system was developed for testing nanowear under more relevant conditions. The films were produced in an industrial production coating line. In order to maximise the available information and to take account of uncontrolled process variation a statistical design of experiment procedure was used to investigate the effect of four key process control parameters. Cr doping was the most significant control parameter at all thicknesses tested and produced a softening effect and thus increased nanowear. Substrate bias voltage was also a significant parameter and produced hardening and a wear reducing effect at all thicknesses tested. The use of a Cr adhesion layer produced beneficial results at 150 nm thickness, but was ineffective at 50 nm. Argon flow to the coating chamber produced a complex effect. All effects reduced significantly with reducing film thickness. Classic fretting wear was produced at low amplitude under nanowear testing. Reciprocating sliding was produced at higher amplitude which generated three body abrasive wear and this was generally consistent with the Archard model. Specific wear rates were very low (typically 10-16 - 10-18 m3N-1m-1). Wear rates reduced exponentially with reduced film thickness and below (approx.) 20 nm, thickness was identified as the most important control of wear.
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A study has been made of the effects of welding and material variables on the occurrence of porosity in tungsten inert gas arc welding of copper. The experiments were based on a statistical design and variables included, welding current, welding speed, arc atmosphere composition, inert gas flow rate, weld preparation, and base material. The extent of weld metal porosity was assessed by density measurement and its morphology by X-ray radiography and metallography. In conjunction with this the copper-steam reaction has been investigated under conditions of controlled atmosphere arc melting. The welding experiments have shown that the extent of steam porosity is increased by increased water vapour content of the arc atmosphere, increased oxygen content of the base material and decreased welding speed. The arc melting experiments have shown that the steam reaction occurs in the body of the weld pool and proceeds to an apparent equi1ibrium state appropriate to to its temperature, the hydrogen and oxygen being supplied by the dissociation of water vapour in the arc atmosphere. It has been shown conclusively that nitrogen porosity can occur in the tungsten inert gas arc welding of copper and that this porosity can be eliminated by using filler wires containing small amounts of aluminum and titanium. Since it has been shown to be much more difficult to produce sound butt welds than melt runs it has been concluded that the porosity associated with joint fit up is due to nitrogen entrained into tho arc atmosphere. Clearly atmospheric entrainment would also, to a much lesser extent, involve water vapour. From a practical welding point of view it has thus been postulated that use of a filler wire containing small amounts of aluminum and/or titanium would eliminate both forms of porosity since these elements are both strongJy deoxidising and denitriding.
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This study examined university students' writing skills as perceived by university students and their English instructors. The goal of the study was to provide English instructors with objective, quantified information about writing perceptions from both the students' and instructors' viewpoints. ^ A survey instrument was developed based on a survey instrument created by Newkirk, Cameron, and Selfe (1977) to identify instructors' perceived knowledge of student writing skills. The present study used a descriptive statistical design. It examined five writing skill areas: attitude, content, grammar and mechanics, literary considerations, and the writing process through a questionnaire completed by a convenience sample of summer and fall admitted freshmen who were enrolled in Essay Writing and Freshman Composition courses and English Department instructors at a large South Florida public university. ^ The study consisted of five phases. The first phase was modifying of the Newkirk, Cameron, and Selfe (1977) questionnaire. Two versions of the revised survey were developed - one for instructors and one for students. The second phase was pilot testing the questionnaire for evaluation of administration and scoring. The third phase was administering the questionnaire to 1,280 students and 48 instructors. The fourth phase was analyzing the data. The study found a significant difference in the perceptions of students and instructors in all areas of writing skills examined by the survey. Responses to 29 of 30 questions showed that students felt they had better attitudes toward writing and better writing skills than instructors thought. ^ The final phase was developing recommendations for practice. Based on findings and theory and empirical evidence drawn from the fields of adult education and composition research, learner-centered, self-directed curriculum guidelines are offered. ^ By objectively quantifying student and instructor perceptions of students' writing skills, this study contributes to a growing body of literature that: (a) encourages instructors to acknowledge the perception disparities between instructors and students; (b) gives instructors a better understanding of how to communicate with students; and (c) recommends the development of new curriculum, placement tests, and courses that meet the needs of students and enables English instructors to provide meaningful instruction. ^