485 research outputs found
Effects of cropping practice dynamics on permanent grassland vegetation during the conversion to organic farming
The aim of this work was to identify the impact of farming practices on permanent grassland vegetation during the conversion from conventional to organic farming. We considered functional and species diversities in order to compare the different grassland categories based on the farming practices used over a period of six years - five years before conversion and one year after. We identified three categories of grasslands: those generally cut twice a year, those intensely grazed, and those that were used under diversified practices. We showed that grasslands characterised by cutting and low fertilization level have the highest species richness compared to the other two categories (23.2, 16.9 and 17 species, respectively), and the lowest pastoral index (45.9, 66.8 and 68.6, respectively). These cut paddocks also presented the highest functional diversity (i.e., richness of functional property attributes) for two of the properties studied: means of dispersal and establishment strategy as defined by Grime. Grasslands with diversified practices (grazing, cutting and nitrogen supply) were not characterised by any single or combined functional property attribute, to the contrary of the two other categories. Finally, farming practices alone do not explain all of the differences in vegetation. We therefore hypothesize that, first, the dynamics of permanent grassland vegetation following conversion to organic farming is only initiated by agricultural practices and, second, other key factors such as landscape characteristics affect these dynamics
Improving the accuracy of RF alternate test using multi-VDD conditions: application to envelope-based test of LNAs
Trabajo presentado al "20 Asina Test Symposium" celebrado en Nueva Delhi (India) del 20 al 23 de Noviembre del 2011.-- Reprinted from (relevant publication info). This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the products or services of CSIC Spanish National Research Council, Digital.CSIC. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.This work demonstrates that multi-VDD conditions may be used to improve the accuracy of machine learning mod- els, significantly decreasing the prediction error. The proposed technique has been successfully applied to a previous alternate test strategy for LNAs based on response envelope detection. A prototype has been developed to show its feasibility. The prototype consists of a low-power 2.4GHz LNA and a simple envelope detector, integrated in a 90nm CMOS technology. Post- layout simulation results are provided to verify the functionality of the approach. Copyright © 2011 IEEE.This work has been partially funded by a CSIC JAE-Doc contract (cofinanced by FSE), a Spanish MAE-AECID grant and projects: SR2 - Short Range Radio (Catrene European project 2A105SR2 and Avanza I+D Spanish project TSI-020400-2010-55, cofinanced with FEDER program), Auto-calibración y auto-test en circuitos analógicos, mixtos y de
radio frecuencia (Andalusian Government project P09-TIC-5386, cofinanced with FEDER program), and Catrene project TOETS (CT 302).Peer reviewe
Exploring Pompeii: discovering hospitality through research synergy
Hospitality research continues to broaden through an ever-increasing dialogue and alignment with a greater number of academic disciplines. This paper demonstrates how an enhanced understanding of hospitality can be achieved through synergy between archaeology, the classics and sociology. It focuses on classical Roman life, in particular Pompeii, to illustrate the potential for research synergy and collaboration, to advance the debate on hospitality research and to encourage divergence in research approaches. It demonstrates evidence of commercial hospitality activities through the excavation hotels, bars and taverns, restaurants and fast food sites. The paper also provides an example of the benefits to be gained from multidisciplinary analysis of hospitality and tourism
Enraizamento de estacas herbáceas de mirtileiro 'clÃmax': influência do ácido indolbutirico e do número de gemas.
Incidence of particle size distribution in peanut husks bonded panels
El propósito de esta etapa de la investigación fue conocer la influencia de la variación del tamaño y de la forma de partÃculas cáscaras de manà en las propiedades de paneles aglomerados encolados con resina ureica. Se formularon paneles con cáscaras molidas (densidad de las partÃculas: de 81 Kg/m3), paneles con cáscaras enteras (densidad de las partÃculas: 200 Kg/m3) y dos combinaciones de las mismas. Los resultados alcanzados demostraron que los paneles compuestos por partÃculas de cáscaras de manà molidas (finas) mejoraron las propiedades fÃsicas y mecánicas respecto de las placas que incorporaron partÃculas de mayor tamaño. Los valores de densidad en paneles con partÃculas molidas fueron 628,67 Kg/m3; absorción de agua 65,3% y 79,75% a 2 h y 24 h respectivamente; e hinchamiento de 9,9% y 14,35% medidos a 2 h y 24 h respectivamente. En relación a la caracterización de propiedades mecánicas de flexión, los valores registrados en muestras elaboradas con partÃculas finas de cáscaras de manà resultaron en MOR: 3,58 MPa, LOP 2,26 MPa y MOE 627 MPa. Con respecto a tenacidad, el mayor valor fue observado en los tableros elaborados con partÃculas enteras de cáscaras de manÃ: 1,58 MPa. Las propiedades caracterizadas se encuentran aun por debajo de las propiedades de las placas comerciales de madera de tipo MDF y aglomerados convencionales. Ajustes al proceso de elaboración de las placas de cáscaras de manà serán incorporados en futuros trabajosThe purpose of this stage was to determine the influence of particle size and shape of peanut husks on the properties of panels made with urea resin. Panels were made with milled husks200 Kg/m3 ) and unmilled husks (81 Kg/m3 ) and two combinations thereof. The results showed that the panels made with milled husks improved physical and mechanical properties with respect to the panels that incorporated unmilled particles. The density values in panels with milled particles were 628.67 Kg / m3 ; water absorption 65.3% and 79.75% at 2 and 24 hours respectively, and swelling of 9.9% and 14.35% measured at 2 and 24 hours respectively. Regarding the characterization of mechanical properties of bending, the values recorded in samples prepared with fine particles of peanut husks resulted in MOR: 3.58 MPa, LOP 2.26 MPa and MOE 627 MPa. With respect to toughness, the highest value was observed in particle boards made from unmilled peanut husks: 1.58MPa. The characterized properties are still below the properties of commercial wood panels. Adjustments to the process of preparing the peanut husks plates will be incorporated in future experiencesFil: Granero, Ana Victoria. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico Cordoba. Centro Experimental de la Vivienda Economica(i); ArgentinaFil: Gatani, Mariana Pilar. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico Cordoba. Centro Experimental de la Vivienda Economica(i); ArgentinaFil: Medina, J. C. Universidad Nacional de Santiago del Estero. Facultad de Cs.forestales. Instituto de Tecnologia de la Madera; ArgentinaFil: Ruiz, A.. Universidad Nacional de Santiago del Estero. Facultad de Cs.forestales. Instituto de Tecnologia de la Madera; ArgentinaFil: Fiorelli, J.. Universidade de Sao Paulo; Brasil. Laboratorio de Construções e Ambiência. Faculdade de Zootecnia e Enghenaria de Alimentos; BrasilFil: Kreiker, Jeronimo Rafael. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico Cordoba. Centro Experimental de la Vivienda Economica(i); ArgentinaFil: Lerda, Maria Josefina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico Cordoba. Centro Experimental de la Vivienda Economica(i); Argentin
Respiração basal do solo influenciada por diferentes sistemas de preparo do solo e sucessão de culturas.
A alteração provocada pelo uso contÃnuo do solo de maneira convencional modifica os estoques de carbono contribuindo para degradação do solo, através da emissão de CO2 para a atmosfera. O experimento para avaliar a Respiração do Solo está sendo realizado no Campus Experimental da Fundação Universidade Federal de Rondônia - UNIR, localizado no municÃpio de Rolim de Moura/RO. Para avaliar a emissão de dióxido de carbono CO2 em diferentes formas de preparo do solo e sucessão de culturas. Para os teores de gás carbônico (C-CO2) liberados para a atmosfera, a análise de variância mostrou que houve valores significativos para o tratamento preparos do solo e também para sucessão de culturas, variando de 2,54 a 2,85 mg C m-2 dia -1. O sistema de preparo que apresentou maior efluxo foi o plantio direto alternativo (PDA) com 2,853 mg C m-2 dia -1, e o que apresentou menor efluxo foi o preparo alternativo (PRA) com 2,545 mg C m-2 dia -1 o qual não diferiu estatisticamente do plantio direto convencional (PDC) e do plantio tradicional (PRT). Para o fator sucessão de culturas o maior valor de emissão de gás carbônico foi encontrado no ambiente onde havia leguminosa + leguminosa (3,185 mg.kg-1 m2 dia-1), ou seja, onde havia menor relação C/N da palhada para ser atacada pelos microrganismos. Por outro lado o menor valor de gás carbônico foi encontrado no tratamento leguminosa+gramÃnea (2,416 mg.kg-1 m2 dia-1), apesar de não ter valores estatisticamente diferentes das sucessões gramÃnea+leguminosa e gramÃnea+gramÃnea
Towards VocBench 3: Pushing collaborative development of thesauri and ontologies further beyond
More than three years have passed since the release of the second edition of VocBench, an open source collaborative web platform for the development of thesauri complying with Semantic Web standards. In these years, a vibrant user community has gathered around the system, consisting of public organizations, companies and independent users looking for open source solutions for maintaining their thesauri, code lists and authority resources. The focus on collaboration, the differentiation of user roles and the workflow management for content validation and publication have been the strengths of the platform, especially for those organizations requiring a centralized and controlled publication environment. Now the time has come to widen the scope of the platform: funded by the ISA2programme of the European Commission, VocBench 3 will offer a general-purpose collaborative environment for development of any kind of RDF dataset, improving the editing capabilities of its predecessor, while still maintaining the peculiar aspects that determined its success. In this paper, we review the requirements and the new objectives set for version 3, and then introduce the new characteristics that were implemented for this next iteration of the platform
Atualizações em calagem de solos em Rondônia.
Este artigo trata da degradação quÃmica dos solos e apresenta métodos de recomendação de calagem.Editado por: Paulo Guilherme Salvador Wadt; Alaerto Luiz Marcolan; Stella Cristiani Gonçalves Matoso e Marcos Gervasio Pereira
Evaluation of semiautomated internal carotid artery stenosis quantification from 3-dimensional contrast-enhanced magnetic resonance angiograms
Rationale and Objectives: The performance of a semiautomatic technique for internal carotid artery (ICA) stenosis quantification of the internal carotid artery in contrast-enhanced magnetic resonance angiography was evaluated. Materials and Methods: The degree of stenosis of 52 ICAs was quantified by measuring the cross-sectional area along the center lumen line. This was performed both by 3 independent observers and the semiautomated method. The degree of stenosis was defined as the amount of cross-sectional lumen reduction. Results: Agreement between the method and observers was good (weighted-kappa, kappa(w) = 0.89). Reproducibility of measurements of the semiautomated technique was better (kappa(w) = 0.97) than that of the observers (kappa(w) = 0.76), and the evaluated technique was considerably less time-consuming. Conclusions: Because the user interaction is limited, this technique can be used to replace an expert observer in 3-dimensional stenosis quantification of the ICA at CE-MRA in clinical practice
Produção de matéria seca da palhada em diferentes sistemas de preparo de solo e sucessão de culturas.
O objetivo deste trabalho foi avaliar a produção de matéria seca das culturas cultivadas em diferentes sistemas de preparo do solo e plantio e sequências de culturas. O experimento foi instalado em um Latossolo Vermelho-Amarelo em julho de 2007, no campus experimental do Curso de Agronomia da Universidade Federal de Rondônia - UNIR. O experimento foi instalado em esquema fatorial 4x4, onde, os tratamentos do fator de preparo de solo com diferentes nÃveis de mobilização, foram: 1- PRT - preparo tradicional (uma operação com grade aradora e uma com grade niveladora), 2 - PRA - preparo alternativo (uma operação de subsolagem), 3 - PDA - plantio direto com um preparo alternativo a cada quatro anos e 4 - PDC - plantio direto contÃnuo. Os tratamentos do fator seqüência de culturasem safra/safrinha, foram: 1) S/F: soja - feijão; 2) M/F: milho - feijão; 3) S/M: soja - milho; 4) M/M: milho - milho. Na análise conjunta para os resultados da produção e conservação de palhada produzida pelas culturas, não houve diferença estatÃstica para a interação entre os tratamentos, porém as médias da sucessão M/F e M/M e do PDC e PDA apresentaram maiores valores
- …