Process-based models in Eucalyptus plantation management : reality and perspectives

Yield prediction in commercial forestry has been dominated by empirical modelling. Increasingly, however, process-based models are finding application either in support or instead of these traditional models. In this paper we draw the new forestry demands and how these models can answer different kinds of questions such as forest productivity in planted areas and new plantation, water-use, carbon sequestration and effects of climate change on forest production. In this paper we review current performance against management needs, concentrating in particular on the application of the 3-PG (Landsberg and Waring, 1997) and CABALA (Battaglia et al., 2004) process-based models. In general we find that process-based models have met many of the expectations of a decade ago. The paper briefly indicates new opportunities of process-based models in the area of wood properties and wood products prediction and in the area of forest health assessment.___________________________________La predicción de rendimientos en la silvicultura comercial ha estado dominada hasta ahora por el empleo de técnicas de modelización empíricas. Sin embargo, los modelos basados en procesos se están utilizando cada vez más como suplementos o incluso sustitutos de los tradicionales. En este artículo apuntamos nuevas demandas forestales y la forma en que los nuevos modelos pueden dar respuesta a diferentes cuestiones como la productividad forestal tanto en zonas plantadas como en nuevas plantaciones, el uso del agua, el secuestro de carbono y los efectos del cambio climático en la producción forestal. Asimismo, valoramos la eficacia de los modelos frente a las necesidades actuales de gestión, sobre todo en lo relativo a la aplicación de dos modelos basados en procesos: 3-PG (Landsberg y Waring, 1997) y CABALA (Battaglia et al., 2004). En general, los modelos de este tipo han colmado muchas de las expectativas que suscitaron hace una década. En este artículo se esbozan nuevas aplicaciones para estos modelos en cuanto a la predicción de propiedades y productos de la madera, así como a la valoración de la salud de los bosques

Credibility in Monetary Policy

This essay examines credibility in monetary policy. In particular it follows Blinder’s (2000) survey in focusing on why such credibility is important and the role that central bank transparency plays in determining it. It also considers what happens when credibility changes. It finds that credibility is particularly important for maintaining low and stable inflation through its effect on inflation expectations and that transparency’s role involves influencing those expectations. Improving credibility may actually increase volatility unless central banks take the change into account and adjust their reaction functions accordingly

Notes on Finite Element Discretization for a Model Convection-Diffusion Problem

We present recent finite element numerical results on a model convection-diffusion problem in the singular perturbed case when the convection term dominates the problem. We compare the standard Galerkin discretization using the linear element with a saddle point least square discretization that uses quadratic test functions, trying to control and explain the non-physical oscillations of the discrete solutions. We also relate the up-winding Petrov-Galerkin method and the stream-line diffusion discretization method, by emphasizing the resulting linear systems and by comparing appropriate error norms. Some results can be extended to the multidimensional case in order to come up with efficient approximations for more general singular perturbed problems, including convection dominated models.Comment: 24 pages, 12 figure

Credibility in Monetary Policy

This essay examines credibility in monetary policy. In particular it follows Blinder’s (2000) survey in focusing on why such credibility is important and the role that central bank transparency plays in determining it. It also considers what happens when credibility changes. It finds that credibility is particularly important for maintaining low and stable inflation through its effect on inflation expectations and that transparency’s role involves influencing those expectations. Improving credibility may actually increase volatility unless central banks take the change into account and adjust their reaction functions accordingly

Investigation of pellet-clad interaction during load-follow operation in a pressurized water reactor using VERA-CS

This thesis is a comprehensive study on the effect load-follow operation has on fuel failure risk in a PWR. PWR1, a commercial reactor that performed load-follow power maneuvers in cycle 21, was modeled using VERA-CS. The effects of a jump-in approach, starting depletion in cycle 17 as compared to cycle 1, were shown to be negligible after two cycles of depletion. Both low power physics tests and critical boron comparisons show excellent agreement between the VERA-CS predictions and the plant-measured data after cycle 19. In addition to cycle depletion, five load-follow power maneuvers in the first 24 days of cycle 21 were simulated using hourly depletion steps. Predictions showed an overestimation of the axial offset behavior during the load-follow operation but the overall reactivity of the core was in good agreement. The linear heat rate and coolant temperature calculated by VERA-CS were used as boundary conditions for BISON fuel performance calculations. Using the maximum hoop stress as the indicator of fuel failure risk, the different load-follow power maneuvers were compared to the initial start-up ramp. The maximum clad hoop stress occurred during the start-up ramp and was estimated to be 94 MPa, the subsequent maneuvers showed similar magnitudes regardless of the change in power. No correlation was observed between the characteristics of the load-follow power maneuver and the resulting maximum clad hoop stress. Neither the magnitude of the decrease in power, hold period, nor intermediate power steps showed a variation in the maximum clad hoop stress observed after a return to full power this early in the cycle. To reduce the number of fuel performance calculations required to determine the safety of a power maneuver, a screening process was developed based on a weighted change in conditioned power. By selecting the top 1000 fuel rods showing a positive weighted change in linear heat rate, the limiting fuel pin for the maneuver is included, with most of the selected pins showing elevated hoop stresses

Diseño de un driver de disco duro para sistemas de ficheros indetectables

Se desarrollará un controlador de disco duro, especialmente diseñado para funcionar bajo Linux con una serie de discos duros presentes en el mercado actual, capaz escribir en y leer de las áreas reservadas del disco duro y de presentar el espacio disponible al sistema operativo como un dispositivo de bloques formateable y usable como cualquier otra unidad de disco. El desarrollo se enmarca dentro del ámbito de la informática forense, facilitando y ampliando las capacidades de investigación del analista forense, y se hará en el lenguaje de programación C con las cabeceras adecuadas de Linux, teniendo como objetivo ser funcional para versiones del kernel de Linux compatibles con la 2.6, en cuanto a la capa de dispositivos de bloque se refiere.The aim of this project is to develop a hard disk driver, especially crafted to work under Linux with a series of hard disk drives very present in the market, which is able to write to and read from the reserved areas of the disk, and present the space available as block device to the operating system, which in turn will be able to format it and use it as any other block device registered on the system. This development is framed inside the scope of the Computer Forensics investigations, making it possible for the forensic examiner to access previously unreachable areas of the disk, and will be written in the C programming language, with the appropriate Linux headers, with the aim of being fully functional under Linux kernel versions compatible with —regarding the block device layer— version 2.6.Ingeniería Técnica en Sonido e Imáge

The Towuti Drilling Project:paleoenvironments, biological evolution, and geomicrobiology of a tropical Pacific lake

The Towuti Drilling Project (TDP) is an international research program, whose goal is to understand long-term environmental and climatic change in the tropical western Pacific, the impacts of geological and environmental changes on the biological evolution of aquatic taxa, and the geomicrobiology and biogeochemistry of metal-rich, ultramafic-hosted lake sediments through the scientific drilling of Lake Towuti, southern Sulawesi, Indonesia. Lake Towuti is a large tectonic lake at the downstream end of the Malili lake system, a chain of five highly biodiverse lakes that are among the oldest lakes in Southeast Asia. In 2015 we carried out a scientific drilling program on Lake Towuti using the International Continental Scientific Drilling Program (ICDP) Deep Lakes Drilling System (DLDS). We recovered a total of  ∼ 1018 m of core from 11 drilling sites with water depths ranging from 156 to 200 m. Recovery averaged 91.7 %, and the maximum drilling depth was 175 m below the lake floor, penetrating the entire sedimentary infill of the basin. Initial data from core and borehole logging indicate that these cores record the evolution of a highly dynamic tectonic and limnological system, with clear indications of orbital-scale climate variability during the mid- to late Pleistocene

Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing

Australian marine radiocarbon reservoir effects: ΔR atlas and ΔR calculator for Australian mainland coasts and near-shore islands

Studies of pre-bomb mollusks live-collected around the Australian coastline have concluded that near-shore marine radiocarbon reservoir effects are small and relatively uniform. These studies are based on limited samples of sometimes dubious quality representing only selective parts of Australia’s lengthy coastline. We systematically examine spatial variability in the marine radiocarbon reservoir effect (ΔR) through analysis of 292 live-collected mollusk samples across the Australian mainland coasts and near-shore islands subject to strict selection criteria. This study presents 233 new ΔR values combined with an evaluation of 59 previously published values. Results demonstrate significant spatial variability in marine radiocarbon reservoir effects across the study region. ΔR values range from 68 ± 24 14C years off the Pilbara region of Western Australia to –337 ± 46 14C years in the southern Gulf of Carpentaria in Queensland. Most sets of local values exhibit internal consistency, reflecting the dominant influence of regional oceanography, including depletion in ΔR values southwards along the eastern Australian coastline coincident with the East Australian Current. Anomalous values are attributed to inaccurate documentation, species-specific relationships with the carbon cycle and/or short-term fluctuations in marine radiocarbon activities. To account for the heterogeneous distribution of marine 14C, we recommend using a location specific ΔR value calculated using the Australian ΔR Calculator, available at: https://delta-r-calc.jcu.io/

Nanopore metagenomics enables rapid clinical diagnosis of bacterial lower respiratory infection

The gold standard for clinical diagnosis of bacterial lower respiratory infections (LRIs) is culture, which has poor sensitivity and is too slow to guide early, targeted antimicrobial therapy. Metagenomic sequencing could identify LRI pathogens much faster than culture, but methods are needed to remove the large amount of human DNA present in these samples for this approach to be feasible. We developed a metagenomics method for bacterial LRI diagnosis that features efficient saponin-based host DNA depletion and nanopore sequencing. Our pilot method was tested on 40 samples, then optimized and tested on a further 41 samples. Our optimized method (6 h from sample to result) was 96.6% sensitive and 41.7% specific for pathogen detection compared with culture and we could accurately detect antibiotic resistance genes. After confirmatory quantitative PCR and pathobiont-specific gene analyses, specificity and sensitivity increased to 100%. Nanopore metagenomics can rapidly and accurately characterize bacterial LRIs and might contribute to a reduction in broad-spectrum antibiotic use