Examinando variables de paisaje alternativas para una planificación forestal ecológica: caso de estudio para el urogallo en Cataluña

This study examined the performance of four different landscape metrics in a landscape ecological forest planning situation in Catalonia: (1) proportion of suitable habitat (non-spatial) (%H); (2) spatial autocorrelation; (3) the proportion of habitat-habitat boundary of the total compartment boundary (H-H) and (4) the proportion of habitat-non-habitat boundary (H-nonH). They were analysed in a case study problem that aimed at the maintenance and improvement of capercaillie habitats in two simulated forests of 14,400 hectares consisting mainly of Pinus uncinata, P. sylvestris and P. nigra stands. The habitats were determined by using a stand-level habitat suitability index (HSI). Stands in which the HSI exceed a specified threshold value were considered as habitats. Then, four different planning problems were formulated to test the four landscape metrics as one of the management objectives. The objective functions of the problems were written in the form of an additive utility model, and the problems were solved using heuristic optimization techniques. Before this, five different heuristic optimization techniques: random ascent; Hero, simulated annealing (SA), tabu search and genetic algorithms (GA), were compared in a non-spatial and a spatial planning problem. Based on these comparisons, GA was selected for solving the spatial planning problems while SA was used for non-spatial problems. The spatial pattern of habitat patches was comparable when using the %H, H-H or spatial autocorrelation as a management objective. However, the limitations of using the non-spatial %H objective were clear in the second forest landscape with lacking trends in forest features. H-H and spatial autocorrelation yielded a more clustered landscape with larger habitat patches. The largest proportions of habitat and habitat–habitat boundaries were created when using the H-H as the ecological management objective. The use of spatial autocorrelation as a management objective resulted in a smaller habitat area and shorter habitat-habitat boundary than when %H and H-H were used as objectives, but the proportion of large habitat patches was rather high. H-H was very suitable for connecting habitat patches. When H-nonH was used as the ecological management objective a very fragmented landscape was generated.El presente estudio examinó el funcionamiento de cuatro variables de paisaje diferentes; (1) proporción de hábitat (%H), (2) autocorrelación espacial (3) proporción de límites separando parcelas clasificadas como hábitat (H-H), (4) proporción de límites separando parcelas clasificadas cómo hábitat y no hábitat (H-Non-H) como objetivos para una planificación forestal ecológica a escala de paisaje en Cataluña. Tales variables de paisaje fueron analizadas en un caso de estudio cuyo propósito era mejorar el hábitat del urogallo en dos montes simulados de 14.400 ha compuestos mayoritariamente por rodales de Pinus uncinata, Pinus sylvestris y Pinus nigra. La aptitud de los rodales como hábitat fue estimada mediante un índice de adecuación de hábitat (HSI) a nivel de rodal. A continuación cuatro problemas de planificación fueron formulados para analizar el funcionamiento de las cuatro variables de paisaje como uno de los objetivos en el problema de planificación forestal. Para ello se formularon cuatro funciones objetivo en forma de función de utilidad aditiva, la cual fue resuelta mediante técnicas de optimización heurística. Con anterioridad, cinco técnicas de optimización heurística: ascensión aleatoria (RA), Hero, templado simulado (SA), búsqueda tabú (TS) y algoritmos genéticos (GA), fueron comparadas en dos problemas distintos, (1) que incluía %H y (2) que tenia H-H como uno de los objetivos en la función objetivo. Basándonos en tales comparaciones, GA fue seleccionada como técnica más adecuada para problemas de consideración espacial [tipo (2)] y SA para problemas no espaciales [tipo (1)]. La distribución espacial de los rodales considerados hábitat fue similar cuando %H, autocorrelación espacial y H-H fueron incluidos como objetivo ecológico en el problema de planificación. Sin embargo, H-H y autocorrelación espacial generaron un paisaje con teselas de hábitat más agrupadas y de mayor tamaño. La mayor proporción de H-H se consiguió cuando H-H se incluyó como objetivo ecológico. Además, el uso de H-H como objetivo fomentó la formación de áreas núcleo de hábitat y la conexión de teselas, reduciendo simultáneamente la cantidad de bordes. Por otro lado, el uso de autocorrelación espacial como objetivo generó una menor superficie de hábitat y de H-H que cuando se utilizó %H y H-H como uno de los objetivos. Aún así el uso de autocorrelación espacial elevó la proporción de teselas de hábitat de gran tamaño. En contraposición, cuando H-Non-H se incluyó como objetivo en el problema de planificación, se obtuvo un paisaje fragmentado con respecto al hábitat del urogallo. Por otro lado, las limitaciones de %H como objetivo ecológico se acentuaron cuando se utilizó el segundo paisaje forestal que a diferencia del primero no se caracterizaba por una correlación de factores relacionados con la calidad de sitio, que afectaban la composición de especies así como las tasas de crecimiento de los rodales

Optimización de la gestión de rodales de Pinus nigra Arn. bajo riesgo endógeno de incendio en Cataluña

The present study considers the risk of fire as an endogenous component in a stand management optimisation problem for even-aged Pinus nigra Arn. stands in Catalonia (North-east Spain). A simulation-optimisation system, RODAL, was used to determine the optimal stand management when maximal soil expectation value (SEV) was the objective. This system was modified to include fire occurrence and post-fire tree survival models. The fire occurrence and post-fire survival models used in the study have been developed for forest planning purposes using explanatory variables that relate the probability of fire occurrence and the expected loss to such stand variables which can be affected by management actions. Non-linear stochastic optimisation was used to find the optimal stand management schedule. The rotation length as well as the timing and intensity of thinnings were optimised. The inclusion of the risk of fire had a clear effect on the optimal stand management schedule, especially on the regime of thinnings which tended to include early thinnings as means of reducing the risk and expected loss. The regeneration cuts tended to be earlierwith increasing fire risk.El presente estudio, presenta como optimizar la gestión selvícola de masas regulares de Pinus nigra Arn. en Cataluña cuando se incluye el riesgo endógeno de incendios. Para ello, se utilizó el sistema de simulación-optimización RODAL con el fin de determinar la gestión óptima del rodal, considerando como objetivo de gestión el valor esperado del suelo. El sistema RODAL actualmente incluye modelos para predecir la probabilidad de ocurrencia de un incendio en una masa determinada y la probabilidad de supervivencia de los árboles afectados en caso de producirse el incendio en dicha masa. Estos modelos fueron desarrollados para ser utilizados en la planificación forestal, por lo tanto utilizan variables independientes regularmente utilizadas y obtenidas en el proceso decisorio de la planificación de la gestión forestal. Con el fin de encontrar el plan de gestión óptimo a nivel de masa se utilizó un proceso de optimización estocástica no linear. El plan de gestión óptimo queda definido por la combinación óptima del turno de corta y el momento e intensidad de las claras. La inclusión del riesgo de incendios tiene un claro efecto sobre la gestión óptima del rodal; las claras tienden a ser más tempranas para reducir el riesgo de incendios y el turno de corta también tiende a acortarse para reducir las perdidas esperadas

Size-Controlled Water-Soluble Ag Nanoparticles

Ag nanoparticles of two different sizes (1 and 4 nm) were prepared within an apoferritin cavity by using an Ag+-loaded apoferritin as a nanoconfined environment for their construction. The initial amount of Ag' ions injected in the apoferritin cavity dictates the size of the final Ag particles. The protein shell prevents bulk aggregation of the metal particles, which renders them water soluble and extremely stable

Computer-based tools for supporting forest management. The experience and the expertise world-wide

Report of Cost Action FP 0804 Forest Management Decision Support Systems (FORSYS)Computer-based tools for supporting forest management. The experience and the expertise world-wide answers a call from both the research and the professional communities for a synthesis of current knowledge about the use of computerized tools in forest management planning. According to the aims of the Forest Management Decision Support Systems (FORSYS) (http://fp0804.emu.ee/) this synthesis is a critical success factor to develop a comprehensive quality reference for forest management decision support systems. The emphasis of the book is on identifying and assessing the support provided by computerized tools to enhance forest management planning in real-world contexts. The book thus identifies the management planning problems that prevail world-wide to discuss the architecture and the components of the tools used to address them. Of importance is the report of architecture approaches, models and methods, knowledge management and participatory planning techniques used to address specific management planning problems. We think that this synthesis may provide effective support to research and outreach activities that focus on the development of forest management decision support systems. It may contribute further to support forest managers when defining the requirements for a tool that best meets their needs. The first chapter of the book provides an introduction to the use of decision support systems in the forest sector and lays out the FORSYS framework for reporting the experience and expertise acquired in each country. Emphasis is on the FORSYS ontology to facilitate the sharing of experiences needed to characterize and evaluate the use of computerized tools when addressing forest management planning problems. The twenty six country reports share a structure designed to underline a problem-centric focus. Specifically, they all start with the identification of the management planning problems that are prevalent in the country and they move on to the characterization and assessment of the computerized tools used to address them. The reports were led by researchers with background and expertise in areas that range from ecological modeling to forest modeling, management planning and information and communication technology development. They benefited from the input provided by forest practitioners and by organizations that are responsible for developing and implementing forest management plans. A conclusions chapter highlights the success of bringing together such a wide range of disciplines and perspectives. This book benefited from voluntary contributions by 94 authors and from the involvement of several forest stakeholders from twenty six countries in Europe, North and South America, Africa and Asia over a three-year period. We, the chair of FORSYS and the editorial committee of the publication, acknowledge and thank for the valuable contributions from all authors, editors, stakeholders and FORSYS actors involved in this project

On the Dirac Structure of the Nucleon Selfenergy in Nuclear Matter

The relativistic structure of the self-energy of a nucleon in nuclear matter is investigated including the imaginary and real components which arise from the terms of first and second order in the NN interaction. A parameterized form of Brueckner $G$ matrix is used for the NN interaction. The effects of the terms beyond the DBHF approximation on quasiparticle energies and the optical potential for nucleon-nucleus scattering are discussed.Comment: 18 pages, Latex including 10 figures using psfi

Electron spectroscopy of carbon materials: Experiment and theory

We present a comparative spectroscopic study of carbon as graphite, diamond and C60 using C1s K-edge electron energy-loss spectroscopy (EELS), X-ray emission spectroscopy, and theoretical modelling. The first principles calculations of these spectra are obtained in the local density approximation using a self-consistent Gaussian basis pseudo-potential method. Calculated spectra show excellent agreement with experiment and are able to discriminate not only between various carbon hybridisations but also local variation in environment. Core-hole effects on the calculated spectra are also investigated. For the first time, the EEL spectrum of carbyne is calculated

Necrosis grasa subcutánea múltiple: correlación ecográficohistopatológica. Multiple encapsulated fat necrosis: histopathological relation to ultrasound findings

Encapsulated fat necrosis is a benign entity that has multiple possible conditions in the differential diagnosis. Because of this, the ultrasound and histological studies become highly relevant. We present a 14-year-old boy with this condition who exhibited numerous nodules that were detected after an intentional weight loss of 20kg. The ultrasound and histopathological examinations were necessary to confirm the diagnosis. Even though there is not a clear traumatic record in all cases, trauma constitutes the main hypothesis for its development, by decreasing the blood supply to the adipose tissue lobules and causing subsequent ischemic necrosis. Similar lesions have been described in the omentum and in the breast after surgical procedures or invasive diagnostic tests. In the ultrasound study, at least three presentation patterns have been described, which might match the three histological states, from early fat tissue degeneration to ultimate necrosis and even calcification. It is important to know the clinical characteristics, the ultrasound patterns, and the histological findings of this condition for an accurate diagnosis

Chemically active substitutional nitrogen impurity in carbon nanotubes

We investigate the nitrogen substitutional impurity in semiconducting zigzag and metallic armchair single-wall carbon nanotubes using ab initio density functional theory. At low concentrations (less than 1 atomic %), the defect state in a semiconducting tube becomes spatially localized and develops a flat energy level in the band gap. Such a localized state makes the impurity site chemically and electronically active. We find that if two neighboring tubes have their impurities facing one another, an intertube covalent bond forms. This finding opens an intriguing possibility for tunnel junctions, as well as the functionalization of suitably doped carbon nanotubes by selectively forming chemical bonds with ligands at the impurity site. If the intertube bond density is high enough, a highly packed bundle of interlinked single-wall nanotubes can form.Comment: 4 pages, 4 figures; major changes to the tex

¿Es mayor la mortalidad en los pacientes que han sufrido una fractura de cadera?

Introducción y objetivos El objetivo de este estudio es valorar si los pacientes que han sufrido una fractura de cadera tienen una mortalidad más alta de la esperada. Material y métodos Se realizó un estudio prospectivo, observacional donde se toma como muestra los pacientes con fractura de cadera a lo largo de un año, cuya cifra fue de 284 y el seguimiento mínimo fue de 2 años. La edad media de estos pacientes fue de 84, 26 años, siendo el 21, 48% (61/284) varones y el 78, 5% (223/284) mujeres. La supervivencia y las enfermedades previas que afectan a la mortalidad como factores de riesgo se recogieron y se analizaron mediante el método de Kaplan-Meier y mediante la regresión de Cox. Se comparó la mortalidad real con la esperada según el Índice de Comorbilidad de Charlson, ajustado por la edad. Resultados La patología previa fue el principal factor de mortalidad, siendo la cardiopatía la más significativa (HR: 1, 817; IC95%: 1, 048; 3, 149). La mortalidad real al año de la muestra fue del 22, 5%, mientras que la mortalidad anual estimada según el Índice de Comorbilidad de Charlson era de un 29, 68% (IC95%: 44, 36-15). Conclusiones La fractura de cadera no provoca un aumento de mortalidad según la estimación del Índice de Comorbilidad de Charlson. Background and objective The aim of this study is to value whether patients who have suffered a hip fracture have a higher mortality than expected. Material and methods A prospective, observational study was carried out where patients with hip fracture were collected as a sample over a year. The study included 284 patients and a minimum follow-up was 2 years. The mean age of these patients was 84.26 years, with 21.48% (61/284) males and 78.5% (223/284) females. Survival and previous diseases that affect mortality, as risk factors, were collected and analyzed using the Kaplan-Meier method and the Cox regression model. Actual mortality was compared with that expected according to the Charlson Comorbidity Index, adjusted for age. Results Previous pathology was the main mortality factor, with heart disease being the most significant (OR 1.817, CI95%: 1.048; 3.149). The real mortality at one year of the sample was 22.5%, while the estimated annual mortality according to the Charlson Comorbidity Index was 29.68% (CI95%:44, 36-15). Conclusions Hip fracture does not cause an increase in mortality according to the Charlson Comorbidity Index estimate