Forestry processors productivity models in northeastern Argentina

O presente estudo analisou a performance de três processadores florestais operando em plantações de Pinus taeda no nordeste da Argentina e foi desenvolvido um modelo geral para determinar as características dos equipamentos e combinações de produtos processados que afetam a produtividade e os custos operacionais. Foram avaliados por meio de um estudo de tempos e movimentos, um processador florestal John Deere 2154 D equipado com cabeça Waratah HTH 622B, um processador florestal Caterpillar 320D FM equipado com cabeça Log Max 7000b e uma escavadora John Deere 200D LC equipada com cabeça Log Max 7000c. Os equipamentos operaram realizando corte raso em florestas de 13 anos, com volumes médios variando entre 0,42 e 0,57 m3. Foi analisada a potencia dos equipamentos e o desenvolvimento de combinações de productos: toras trituráveis e toras trituráveis e serráveis. Foi ajustado um modelo de misto de efeitos fixos alcançando um coeficiente de R2 de 0,7. O delineamento florestal afetou positivamente a produtividade efetiva implicando também um aumento no custo de produção. A potência apresentou uma interação com o volume das árvores, afetando a produtividade para volumes a 0,5 m3. O desenvolvimento de varios productos afetou negativamente a produtividade.This study analyzed the performance of three forest processors working in Pinus taeda clear-cutting of plantations in the Northeast of Argentina and development a general model for determining how the characteristics of machines and the products sorting affected the productivity and cost of the operation. We evaluated, by a time and motion study, a John Deere 2154 D forestry processor equipped with a head Waratah HTH 622B, a Caterpillar 320D FM forestry processor equipped with a head Log Max 7000B and a John Deere 200D LC excavator hybrid processor equipped with a head Log Max 7000C. The machines clearcut a forest plantation of 13 years, with average volumes between 0.42 and 0.57 m3. Analyzed were the influence of the power of the equipment and the development of two product combinations: pulpwood, and pulpwood and saw timber. The general predictive model resulted in a coefficient of determination (R2) of 0.7. The forest design positively affected the productivity, also involving an increase in the cost of production. The power provided an interaction with the volume of trees, affecting productivity for larger volumes to 0.5 m3. The development of various products negatively affected productivity.Fil: Hildt, Eduardo. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mac Donagh, Patricio Miguel. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Moral Attitudes Toward Pharmacological Cognitive Enhancement (PCE): Differences and Similarities Among Germans With and Without PCE Experience

Pharmacological cognitive enhancement (PCE), the use of illicit and/or prescription drugs to increase cognitive performance, has spurred controversial discussion in bioethics. In a semi-structured interview study with 60 German university students and employees, differences and similarities in moral attitudes toward PCE among 30 experienced participants (EPs) vs. 30 inexperienced participants (IPs) were investigated. Substances EPs used most often are methylphenidate, amphetamines, tetrahydrocannabinol and modafinil. Both EPs and IPs addressed topics such as autonomous decision making or issues related to fairness such as equality in test evaluation and distortion of competition. While most EPs and IPs were convinced that the decision of whether or not to use PCE is part of their individual freedom, their views varied considerably with regard to fairness. IPs considered issues related to fairness as much more critical than EPs. Thus, a person’s moral attitudes toward PCE may not only depend on moral common sense, but also on whether they have used illegal and/or prescription drugs for PCE before. This points to the importance of including the various relevant stakeholder perspectives in debates on the ethical and social implications of PCE

What Users Think about the Differences between Caffeine and Illicit/Prescription Stimulants for Cognitive Enhancement

Pharmacological cognitive enhancement (CE) is a topic of increasing public awareness. In the scientific literature on student use of CE as a study aid for academic performance enhancement, there are high prevalence rates regarding the use of caffeinated substances (coffee, caffeinated drinks, caffeine tablets) but remarkably lower prevalence rates regarding the use of illicit/prescription stimulants such as amphetamines or methylphenidate. While the literature considers the reasons and mechanisms for these different prevalence rates from a theoretical standpoint, it lacks empirical data to account for healthy students who use both, caffeine and illicit/prescription stimulants, exclusively for the purpose of CE. Therefore, we extensively interviewed a sample of 18 healthy university students reporting non-medical use of caffeine as well as illicit/prescription stimulants for the purpose of CE in a face-to-face setting about their opinions regarding differences in general and morally-relevant differences between caffeine and stimulant use for CE. 44% of all participants answered that there is a general difference between the use of caffeine and illicit/prescription stimulants for CE, 28% did not differentiate, 28% could not decide. Furthermore, 39% stated that there is a moral difference, 56% answered that there is no moral difference and one participant was not able to comment on moral aspects. Participants came to their judgements by applying three dimensions: medical, ethical and legal. Weighing the medical, ethical and legal aspects corresponded to the students' individual preferences of substances used for CE. However, their views only partly depicted evidence-based medical aspects and the ethical issues involved. This result shows the need for well-directed and differentiated information to prevent the potentially harmful use of illicit or prescription stimulants for CE

Desarrollo de modelos de productividad para harvesters y forwarders en plantaciones de Pinus spp. del noreste argentino : efectos de la densidad del rodal, la intensidad de raleo y los productos elaborados

Las operaciones de raleo en bosques de Pinus spp. han sido mecanizadas mediante los harvesters y forwarders. Su resultado final depende del valor de la madera elaborada y del costo de su elaboración. En este sentido la hipótesis planteada es que los rodales con alta densidad y los raleos con una baja intensidad de extracción favorecen la cosecha de árboles con un bajo volumen individual, generando una mayor proporción de trozas triturables con bajo valor industrial. Esto afecta al resultado general de la operación de raleo, reduciendo la productividad del harvester y del forwarder, incrementando el costo del corte y la extracción, y limitando el margen obtenido en la operación. En primer lugar, se desarrollaron estudios de tiempos a campo, ajustando modelos mixtos para describir la duración de las actividades realizadas por nueve harvesters. Se determinó que su productividad se vio favorecida al aumentar la intensidad de raleo, disminuyendo al incrementarse la complejidad del trozado. Luego, se estudió la operación de 5 forwarders. Mediante el ajuste de modelos mixtos se determinó que la productividad de la extracción decayó rápidamente al disminuir el volumen medio de las trozas extraídas y al disminuir la concentración de trozas sobre la vía de saca. Por último, se evaluó el efecto de tres intensidades de raleo y once instrucciones de trozado, empleando los modelos desarrollados en combinación con un simulador de trozado. Se determinó que la intensidad de raleo es el principal condicionante del valor neto recuperado. Por otra parte, el aprovechamiento de tres productos limitó la productividad del corte y la extracción, generando un menor valor neto respecto a instrucciones más simples

Desarrollo de modelos de productividad para harvesters y forwarders en plantaciones de Pinus spp. del noreste argentino : efectos de la densidad del rodal, la intensidad de raleo y los productos elaborados

Las operaciones de raleo en bosques de Pinus spp. han sido mecanizadas mediante los harvesters y forwarders. Su resultado final depende del valor de la madera elaborada y del costo de su elaboración. En este sentido la hipótesis planteada es que los rodales con alta densidad y los raleos con una baja intensidad de extracción favorecen la cosecha de árboles con un bajo volumen individual, generando una mayor proporción de trozas triturables con bajo valor industrial. Esto afecta al resultado general de la operación de raleo, reduciendo la productividad del harvester y del forwarder, incrementando el costo del corte y la extracción, y limitando el margen obtenido en la operación. En primer lugar, se desarrollaron estudios de tiempos a campo, ajustando modelos mixtos para describir la duración de las actividades realizadas por nueve harvesters. Se determinó que su productividad se vio favorecida al aumentar la intensidad de raleo, disminuyendo al incrementarse la complejidad del trozado. Luego, se estudió la operación de 5 forwarders. Mediante el ajuste de modelos mixtos se determinó que la productividad de la extracción decayó rápidamente al disminuir el volumen medio de las trozas extraídas y al disminuir la concentración de trozas sobre la vía de saca. Por último, se evaluó el efecto de tres intensidades de raleo y once instrucciones de trozado, empleando los modelos desarrollados en combinación con un simulador de trozado. Se determinó que la intensidad de raleo es el principal condicionante del valor neto recuperado. Por otra parte, el aprovechamiento de tres productos limitó la productividad del corte y la extracción, generando un menor valor neto respecto a instrucciones más simples

Autonomie. Von den Implikationen eines politisch-moralischen Ideals in Humangenetik und Neurowissenschaften

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The Hepatitis B Virus Large Surface Protein (LHBs) Is a Transcriptional Activator

AbstractIt has been shown that a C-terminally truncated form of the middle-sized hepatitis B virus (HBV) surface protein (MHBst) functions as a transcriptional activator. This function is dependent on the cytosolic orientation of the N-terminal PreS2 domain of MHBst, but in the case of wild-type MHBs, the PreS2 domain is cotranslationally translocated into the ER lumen. Recent reports demonstrated that the PreS2 domain of the large HBV surface protein (LHBs) initially remains on the cytosolic side of the ER membrane after translation. Therefore, the question arose as to whether the LHBs protein exhibits the same transcriptional activator function as MHBst. We show that LHBs, like MHBst, is indeed able to activate a variety of promoter elements. There is evidence for a PKC-dependent activation of AP-1 and NF-κB by LHBs. Downstream of the PKC the functionality of c-Raf-1 kinase is a prerequisite for LHBs-dependent activation of AP-1 and NF-κB since inhibition of c-Raf-1 kinase abolishes LHBs-dependent transcriptional activation of AP-1 and NF-κB

Herramientas computacionales para la simulación de episodios de contaminación atmosférica

The present work briefly details the theoretical aspects of numerical methods for the simulation of turbulent transport and dispersion of gases into the atmospheric boundary layer. Later, we show some laboratory experiments of plume dispersion emitted from contaminant sources and the results of the computational simulation tool in comparison with laboratory simulations. Finally, we present a simulation of a hypothetical delocalisation of an open dump close to the city of Paraná in the province of Entre Ríos, Argentina. The results shown include gas concentrations, as well as their geographical distribution from a downwind source, under the most unfavourable meteorological situation.En este trabajo se presentan brevemente los aspectos teóricos sobre los que se basan los métodos numéricos para la simulación de transporte turbulento de gases y dispersión atmosférica. Posteriormente, se muestran algunos casos de validación de los resultados de distribución de concentración de gases emanados de fuentes de contaminación con experiencias de mediciones de laboratorio y por último se presenta una simulación de polución correspondiente a una hipotética relocalización del basurero a cielo abierto en las cercanías de la ciudad de Paraná, Provincia de Entre Ríos. Se muestran los resultados de la concentración de gases y su distribución geográfica corriente abajo de las fuentes de emisión considerando la situación meteorológica más desfavorable para ambos casos.Fil: Aguirre, Cesar Augusto. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina. Universidad Autónoma de Entre Ríos. Facultad de Ciencia y Tecnología; Argentina. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; ArgentinaFil: Brizuela, Armando Benito. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; ArgentinaFil: Hildt, Leonardo E.. Universidad Autónoma de Entre Ríos. Facultad de Ciencia y Tecnología; Argentin

Time Consumption Analysis of Forwarder Activities in Thinning

Forwarding can be divided into separate work elements. These are affected by several factors: forwarding distance, load volume, and types of assortments harvested. For a detailed planning of thinning, productivity models should include these factors. This study analysed the time consumption of forwarder thinning operations in five pine plantations in the north-east of Argentina, determining how the log size and log concentration affect each work element. Timeand- motion studies were carried out, recording the activities with digital video cameras, and tracking the forwarder movements with global navigation satellite system (GNSS) receivers. Different linear mixed models were fitted to estimate the time consumption of each work element in relation to different predictive factors. When driving on the road, the forwarders had an average speed of 71.6 m min-1 empty and 75.7 m min-1 loaded. When driving in the stand, the average speed was 56.9 m min-1 empty and 52.2 m min-1 loaded. These speeds did not correlate with the forwarder size or load volume. For the loading and unloading elements, the linear mixed model explained 56% and 49% of the variability considering only the fixed effect of the logs size and the load volume. For driving while loading, the total volume loaded, and the log concentration of the assortment loaded explained 50% of the time consumption variability, with 17% being explained by random effects. The general time and productivity model developed can be applied to support accurate decisions in the process of thinning planning