Efectos de los sistemas de labranza de los cereales sobre los organismos perjudiciales y benéficos del suelo en el sudeste bonaerense (Argentina)

El objetivo de esta Tesis fue estudiar las poblaciones de organismos perjudiciales y benéficos durante el desarrollo de los cultivos de trigo y maíz en siembra directa (SD) y laboreo convencional (LC) en el sudeste de la provincia de Buenos Aires. El estudio fue realizado sobre 46 lotes comerciales durante los ciclos agrícolas 2002/03, 2003/04 y 2004/05. En cada lote se tomaron muestras de suelo y se colocaron trampas pitfall para determinar el número de individuos de la macrofauna y mesofauna y la densidad activa de macrofauna y de carábidos. No se observaron diferencias en la composición y en la abundancia relativa de la macrofauna entre LC y SD, pero sí efectos leves sobre la macrofauna y los Enchytraeidae. Hubo una mayor densidad activa en SD para ciclo 1 en trigo y ciclos 1 y 3 de maíz. Diplopoda y crustáceos tenían mayor densidad activa en SD que LC. La densidad activa total fue mayor en SD, pero hubo diferencias dentro de grupos taxonómicos. La densidad activa total de los carábidos no estuvo relacionada a los sistemas de labranza. La riqueza (S) fue mayor en LC respecto a SD en un ciclo de trigo y en un ciclo de maíz. Calosoma sp., Scarites anthracinus y Trirammatus striatulus, representaron entre el 46 y el 69% del total de individuos capturados en LC y entre el 66 y el 78% en SD. S. anthracinus fue la especie de mayor densidad activa en ambos cultivos y no fue afectada por el sistema de labranza. Los cultivos bajo SD no presentaron mayor ataque de plagas, aunque el rastrojo en superficie y el no laboreo permitió el desarrollo de babosas y bichos bolita.L’objectiu d’aquesta Tesi fou estudiar les poblacions d’organismes perjudicials i beneficiosos durant el desenvolupament dels cultius de blat i panís en sembra directa (SD) i conreu convencional (LC) en el sud-est de la província de Buenos Aires. L’estudi es va fer en 46 camps comercials durant les campanyes 2002/03, 2003/04 i 2004/05. En cada camp es van prendre mostres de sòl i es van disposar trampes pitfall per a determinar el nombre d’individus de la macrofauna y de la mesofauna i la densitat activa de macrofauna i de caràbids. No es van observar diferències en la composició i en l’abundància relativa de la macrofauna entre LC i SD, però sí efectes lleus sobre la macrofauna i els Enchytraeidae. Es va observar una major densitat activa a SD per la primera campanya de blat i la primera i la tercera de panís. Diplopoda i crustacis van tenir major densitat activa en SD que a LC. La densitat activa total va ser major a SD, però hi va haver diferències dins de grups taxonòmics. La densitat activa total dels caràbids no va estar relacionada amb els sistemes de conreu. La riquesa (S) va ser majoir a LC que a SD en una campanya de blat i de panís. Calosoma sp., Scarites anthracinus i Trirammatus striatulus, que van representar entre el 46 i el 69% del total d’individus capturats a LC i entre el 66 i el 78% a SD. S. anthracinus fou l’espècie amb major densitat activa en els dos cultius i no va estar afectada pel sistema de conreu. Els cultius sota SD no van presentar major atac de plagues, tot i que el rostoll en superfície i el no conreu va permetre el desenvolupament de llimacs i de porquets de Sant Antoni.The objective of the Thesis was to determine the damaging and beneficial organisms in no-till (SD) and conventional till (LC) wheat and corn crops in the south-east of the Buenos Aires province. The study was carried out in 46 commercial plots during the 2002/03, 2003/04 and 2004/05 growing seasons. In each plots soil samples were taken and pitfall traps displayed in order to determine the number of individuals of the macrofauna and mesofauna and the activity-density of the macrofauna and ground beetles. No differences in the composition and in the relative abundance were observed between LC and SD, but there were light effects on the macrofauna and Enchytraeidae. A higher activity-density was observed in SD than in LC during the first growing season of wheat and the first and the third growing seasons of corn. Diplopoda and crustaceans showed a ahigher activity-density in SD than in LC. The total activity-density was higher in SD, but there were differences within taxonomic groups. The total activity-density of ground beetles was not related with the tillage systems. The richness (S) was higher in LC than in SD in one growing season of wheat and corn. Calosoma sp., Scarites anthracinus and Trirammatus striatulus, represented between 46% and 69% of the total individuals captured in LC and between 66% and 78% in SD. S. anthracinus was the species with the highest activity-density in the two crops and it was not affected by the tilling system. The crops under SD did not suffered a higher pest attack than those developed under LC, although the surface stubble and the no tillage allow the development of slugs and pillbugs

Restoring an eroded legitimacy: the adaptation of nonfinancial disclosure after a scandal and the risk of hypocrisy

Purpose \u2013 This study contributes to the literature on hypocrisy in corporate social responsibility by investigating how organizations adapt their nonfinancial disclosure after a social, environmental or governance scandal. Design/methodology/approach \u2013 The present research employs content analysis of nonfinancial disclosures by 11 organizations during a 3-year timespan to investigate how they responded to major scandals in terms of social, environmental and sustainability reporting and a content analysis of independent counter accounts to detect the presence of views that contrast with the corporate disclosure and suggest hypocritical behaviors. Findings \u2013 Four patterns in the adaptation of reporting \u2013 genuine, allusive, evasive, indifferent \u2013 emerge from information collected on scandals and socially responsible actions. The type of scandal and cultural factors can influence the response to a scandal, as environmental and social scandal can attract more scrutiny than financial scandals. Companies exposed to environmental and social scandals are more likely to disclose information about the scandal and receive more coverage by external parties in the form of counter accounts. Originality/value \u2013 Using a theoretical framework based on legitimacy theory and organizational hypocrisy, the present research contributes to the investigation of the adaptation of reporting when a scandal occurs and during its aftermath

DESIGN, CONSTRUCTION AND EVALUATION OF A THERMAL CONDUCTIVITY METER BASED ON ASTM E1225 STANDARD

The focus of this work is the design, construction and evaluation of a thermal conductivity meter apparatus based on ASTM E- 1225 standard. The thermal conductivity is a heat-transport propriety and with the development of new materials the determination of thermophysical properties for its correct use becomes necessary. The apparatus was projected in CAD software and the material selection was done following the standard recommendations. For the meter bars were used 304 stainless steel, since its thermal conductivity is known. The heater was made with an aluminum cylinder block and a cartridge electric resistance. The cooling system was assembled using a Peltier thermoelectric plate and a fin heat sink equipped with a fan. Lastly, a steel pipe was used for building the guard cylinder. In order to evaluate the apparatus, the first specimen tested was the 304 stainless steel, the same material as the meter bars. The result of thermal conductivity showed an error of 6% relative to the value found in literature. However, in this test the temperature of isothermal guard cylinder was lower than the temperature required by the standard. Thus, the future goals will be the development of a temperature control for the guard cylinder and realization of more tests with different materials

The importance of being little: MA-XRF on manuscripts on a Venetian island

The XRF scanning spectrometer developed in the framework of CHNet-INFN (Cultural Heritage Network - National Institute of Nuclear Physics), is specifically customised for cultural heritage applications, designed with a focus on having a lightweight scanner (weighing approximately 10 kg), easy to handle and thus easily transportable in two medium-sized boxes. The research presented here deals with the study of a set of choir books preserved in the Abbey of San Giorgio Maggiore on the homonymous island in Venice. Produced for the Abbey itself from the mid-15th century onwards, the manuscripts have never left the island, making the study of the materials of particular interest as they have undergone little or no modification over time. During their history in the Abbey, however, the volumes have been disassembled and reassembled in various ways, bringing complexity to the current cataloguing work. Thus, analytical investigations of the pigments and painting techniques might help identify the original arrangement of displaced leaves and provide evidence for the attribution of individual illuminations to certain artists. Thanks to its easy transportability, it was possible to take the scanner to the small island by means of the water-based Venetian public transport. Selected results are presented, derived from the high-quality MA-XRF maps obtained