Funciones de rendimiento volumétrico en pie y en aserradero para la lenga (Nothofagus pumilio)

Una tarea compleja y azarosa al realizar inventarios forestales en bosques de Nothofagus pumilio es estimar volúmenes aprovechables en pie, así como el rendimiento de un aserradero en función de las trozas a procesar. Los objetivos del presente trabajo fueron desarrollar un sistema de ecuaciones para estimar el rendimiento volumétrico de un bosque de N. pumilio a lo largo de un rango de calidades de sitio, a partir de variables de fácil obtención en árboles en pie, y estimar funciones de rendimiento de madera procesada para un aserradero mediano en Tierra del Fuego. Utilizando variables de uso corriente en inventarios (DAP, clase social, sanidad, forma y obtención de fustes) y durante la fiscalización del aprovechamiento (diámetro y largo de las trozas), se pudieron desarrollar modelos sencillos de fácil construcción. El modelo propuesto para el cálculo de volumen de trozas en árboles en pie contiene dos componentes: un discriminante (I) que pondera a una ecuación (M) que se aplica a árboles individuales; mientras que el modelo de rendimiento de un aserradero quedó conformado por variables simples (largo y diámetro). Estos modelos brindan parte de la información necesaria para una mejor planificación en el aprovechamiento de nuestro recurso forestal, siendo una eficaz herramienta para la realización de planes de manejo.The volume of logs to be harvested in a Nothofagus pumilio forest and the sawn-timber yield after processing in sawmill are often difficult to estimate. The aims of this work were to develop a mathematical model to estimate the timber volume of a N. pumilio forest (along a site quality classes) from simple variables of standing-trees, and to develop a function to predict the yield of a medium-scale sawmill in Tierra del Fuego. Variables from current forest inventories (DBH, crown classes, health, stem form and stem extraction possibility) and yield measurements (diameter and length of logs) were used to fit the models. The proposed yield-log model of standing-trees had two components: one discriminate (I), which weigh up an equation (M) to be applied to the individual trees. The sawmill yield model were finally conformed for simply variables, as length and diameter of logs. These equations provide the necessary information required to improve the management of our forest resource, and could be an efficient tool for the implementation of a forest management.Facultad de Ciencias Agrarias y Forestale

Heritability of longevity in Large White and Landrace sows using continuous time and grouped data models

<p>Abstract</p> <p>Background</p> <p>Using conventional measurements of lifetime, it is not possible to differentiate between productive and non-productive days during a sow's lifetime and this can lead to estimated breeding values favoring less productive animals. By rescaling the time axis from continuous to several discrete classes, grouped survival data (discrete survival time) models can be used instead.</p> <p>Methods</p> <p>The productive life length of 12319 Large White and 9833 Landrace sows was analyzed with continuous scale and grouped data models. Random effect of herd*year, fixed effects of interaction between parity and relative number of piglets, age at first farrowing and annual herd size change were included in the analysis. The genetic component was estimated from sire, sire-maternal grandsire, sire-dam, sire-maternal grandsire and animal models, and the heritabilities computed for each model type in both breeds.</p> <p>Results</p> <p>If age at first farrowing was under 43 weeks or above 60 weeks, the risk of culling sows increased. An interaction between parity and relative litter size was observed, expressed by limited culling during first parity and severe risk increase of culling sows having small litters later in life. In the Landrace breed, heritabilities ranged between 0.05 and 0.08 (s.e. 0.014-0.020) for the continuous and between 0.07 and 0.11 (s.e. 0.016-0.023) for the grouped data models, and in the Large White breed, they ranged between 0.08 and 0.14 (s.e. 0.012-0.026) for the continuous and between 0.08 and 0.13 (s.e. 0.012-0.025) for the grouped data models.</p> <p>Conclusions</p> <p>Heritabilities for length of productive life were similar with continuous time and grouped data models in both breeds. Based on these results and because grouped data models better reflect the economical needs in meat animals, we conclude that grouped data models are more appropriate in pig.</p

Association analysis in over 329,000 individuals identifies 116 independent variants influencing neuroticism

Neuroticism is a relatively stable personality trait characterized by negative emotionality (for example, worry and guilt)1; heritability estimated from twin studies ranges from 30 to 50%2, and SNP-based heritability ranges from 6 to 15%3,4,5,6. Increased neuroticism is associated with poorer mental and physical health7,8, translating to high economic burden9. Genome-wide association studies (GWAS) of neuroticism have identified up to 11 associated genetic loci3,4. Here we report 116 significant independent loci from a GWAS of neuroticism in 329,821 UK Biobank participants; 15 of these loci replicated at P &lt; 0.00045 in an unrelated cohort (N = 122,867). Genetic signals were enriched in neuronal genesis and differentiation pathways, and substantial genetic correlations were found between neuroticism and depressive symptoms (rg = 0.82, standard error (s.e.) = 0.03), major depressive disorder (MDD; rg = 0.69, s.e. = 0.07) and subjective well-being (rg = –0.68, s.e. = 0.03) alongside other mental health traits. These discoveries significantly advance understanding of neuroticism and its association with MDD

Baseline characteristics of patients in the reduction of events with darbepoetin alfa in heart failure trial (RED-HF)

&lt;p&gt;Aims: This report describes the baseline characteristics of patients in the Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF) which is testing the hypothesis that anaemia correction with darbepoetin alfa will reduce the composite endpoint of death from any cause or hospital admission for worsening heart failure, and improve other outcomes.&lt;/p&gt; &lt;p&gt;Methods and results: Key demographic, clinical, and laboratory findings, along with baseline treatment, are reported and compared with those of patients in other recent clinical trials in heart failure. Compared with other recent trials, RED-HF enrolled more elderly [mean age 70 (SD 11.4) years], female (41%), and black (9%) patients. RED-HF patients more often had diabetes (46%) and renal impairment (72% had an estimated glomerular filtration rate &#60;60 mL/min/1.73 m2). Patients in RED-HF had heart failure of longer duration [5.3 (5.4) years], worse NYHA class (35% II, 63% III, and 2% IV), and more signs of congestion. Mean EF was 30% (6.8%). RED-HF patients were well treated at randomization, and pharmacological therapy at baseline was broadly similar to that of other recent trials, taking account of study-specific inclusion/exclusion criteria. Median (interquartile range) haemoglobin at baseline was 112 (106–117) g/L.&lt;/p&gt; &lt;p&gt;Conclusion: The anaemic patients enrolled in RED-HF were older, moderately to markedly symptomatic, and had extensive co-morbidity.&lt;/p&gt

Timber production of Nothofagus pumilio forests by a shelterwood system in Tierra del Fuego (Argentina)

Nothofagus pumilio is the most important timber native species from south Patagonia of Argentina and Chile. The total volume and timber production vary according to site quality, stocking, growth phase and previous land management. The aim of this work was to evaluate the existence and the productive potential of wood for the sawmill industry in a shelterwood seed cut of N. pumilio forests along the range of site classes. Sample plots were established in 3 ha of an old-growth virgin forest without regeneration patches (SDI 95-131%) along the five classes of site (I-V). Total stand volumes varied from 400 to 1100 m3/ha and volume density index (ratio of total volume over basal area) varied from 6 to 14 m3/m2. The volume yield present differ significantly among site qualities with log volumes between 40 and 400 m3/ha. The number of timber logs decreases from the better sites towards the worst (800-200 logs/ha), as well as their volume average (0.5-0.2 m3/log). Several published studies in timber production were compared and discussed with the obtained results. Considering new alternatives in the N. pumilio timber management allow managers to obtain higher harvesting indexes, increasing the benefits for the forest company and diminishing the annual wood areas necessary to supply the requirements of the sawmills in Tierra del Fuego.Fil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Cellini, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria; Argentina. Universidad Nacional de la Patagonia Austral; ArgentinaFil: Vukasovic, R. F.. Los Castores sawmill and Servicios Forestales consultancy; ArgentinaFil: Fernández, M.C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin