115 research outputs found
Use of Optimization Modeling to Assess the Effect of Timber and Carbon Pricing on Harvest Scheduling, Carbon Sequestration, and Net Present Value of Eucalyptus Plantations
Quantifying the impact of carbon (C) and timber prices on harvest scheduling and economic returns is essential to define strategies for the sustainable management of short-rotation plantations so that they can provide timber products and contribute to C sequestration. In this paper, we present a mixed-integer linear programming model that optimizes harvest scheduling at the forest level, C sequestration, and Net Present Value (NPV) over a planning period of up to 15 years. The model included revenue from the sale of timber (pulplogs) and credits from the net C sequestered during the life of the stands. In addition, plantation establishment, management, harvesting, and transportation costs were included in the analysis. The study area comprised 88 Eucalyptus grandis W. Hill and Eucalyptus dunnii Maiden stands located in Uruguay, totaling a forest area of nearly 1,882 ha. The study investigated the impact of C and timber prices on NPV, harvest schedules, standsâ harvest age, timber flows to customers, and C sequestered per period. The maximum NPV among all the scenarios evaluated (USD 7.53 M) was calculated for a C price of 30 USD tâ1, an interest rate of 6%, and a timber price of 75 USD mâ3. This was USD 2.14 M higher than the scenario with the same parameters but that included only revenue from timber. C prices also impacted standsâ harvest age, C sequestration, and timber flows delivered to end customers. On average, in scenarios that included C prices, timber flows and C sequestration increased by 15.4 and 12.1%, respectively, when C price increased from 5 to 30 USD tâ1. These results demonstrate that harvest scheduling, harvest age, and NPV are very sensitive to C and timber, and that the best economic returns are obtained when the stands are managed to maximize timber production and C sequestration
Stand Characterization of Eucalyptus spp. Plantations in Uruguay Using Airborne Lidar Scanner Technology
Airborne lidar scanner (ALS) technology is used in a variety of applications, including forestry. ALS has enormous potential for the estimation of relevant biometric parameters in forest plantations. This study investigates the use of an object-oriented semi-automated segmentation algorithm for stands delineation, based on modeling ALS data, in plantations of Eucalyptus grandis and E. dunnii in Uruguay. The results show that non-parametric methods delivered more accurate and less biased results for total volume (TV) with R2 0.93, RMSE 20.04 m3 hâ1 for E. grandis and R2 0.93, RMSE 18.43 m3 hâ1 for E.dunnii; and above ground biomass (AGB) with R2 0.95, RMSE 70.2 kg hâ1 for E. grandis and R2 0.96, RMSE: 71.2 Kg hâ1 for E. dunnii. Parametric methods performed better for dominant height (Ho) with R2 0.98, RMSE 0.67 m and R2: 0.96, RMSE: 0.8 m for E. grandis and E. dunnii, respectively. The most informative ALS metrics for the estimation of AGB and TV were metrics related to the elevation in parametric models (Elev.70 and Elev.75), while for the non-parametric models (k-NN) they were Elev.75 and canopy density. For Ho, the ALS metrics selected were also related to elevation both in the parametric (Elev.90 and Elev.99) and random forest models (Elev.max and Elev.75). The segmentation methodology proposed here matched closely the segments delineated by human operators, and provides a low-cost, cost-effective, easy to apply and update model aimed at generating AGB or TV maps for harvest tasks, based on rasters derived from ALS metrics. The present research shows the capacity of ALS metrics to improve extensive strategic inventories; validating and promoting the adoption of ALS technology for inventory forest stands of Eucalyptus spp. in Uruguay
Antibiotic resistance of Staphylococcus aureus associated with subclinical and clinical mastitis in Uruguay during an eight-year period
Records of in vitro susceptibility tests performed between 2008 and 2015 were retrospectively reviewed in order to evaluate the dynamic profiles of possible changes in antimicrobial resistance of Staphylococcus aureus isolated from milk samples of cows with subclinical mastitis from 12 different Uruguayan Provinces. The results of 1,631 isolates tested by disk diffusion techniquefor susceptibility to penicillin and erythromycin were analysed. The possible tendency or changes in the behaviour of this pathogen against penicillin and erythromycin in the 8 year period was evaluated using the chi-square tests for trend and the homogeneity. The highest rate of resistance was observed for penicillin (36.9% in 2010), while erythromycin showed a resistance rate significantly lower (5.7% in 2015). The test for trend showed a significant trend towards decreased resistance to penicillin, whereas for erythromycin an increased resistance trend was observed. The determination of the scope of the problem is essential for the formulation and monitoring of effective response to anti-microbial resistance (AMR). Antibiotic assessment in Uruguay is now being reviewed with the objective of limiting antibiotics prescription to professionals trained to select a successful therapy, choosing the appropriated drug and treatment duration according each situation. To generate knowledge on the magnitude and tendency of the AMR problem using country-specific information must be a priority
Site index estimation using airborne laser scanner data in Eucalyptus dunnii maide stands in Uruguay
Intensive silviculture demands new inventory tools for better forest management and planning. Airborne laser scanning (ALS) was shown to be one of the best alternatives for high-precision inventories applied to productive plantations. The aim of this study was to generate multiple stand-scale maps of the site index (SI) using ALS data in the intensive silviculture of Eucalyptus dunnii Maide plantations in Uruguay. Forty-three plots (314.16 m3) were established in intensive E. dunnii plantations in the departments of RĂo Negro and PaysandĂș (Uruguay). ALS data were obtained for an area of 1995 ha. Linear and Random Forest models were fitted to estimate the height and site index, and OrpheoToolBox (OTB) software was used for stand segmentation. Linear models for dominant height (DH) estimation had a better fit (R2 = 0.84, RMSE = 0.94 m, MAPE = 0.04, Bias = 0.002) than the Random Forest (R2 = 0.85, RMSE = 1.27 m, MAPE = 7.20, Bias=â0.173) model when including only the 99th percentile metric. The coefficient between RMSE values of the cross-validation and RMSE of the model had a higher value for the linear model (0.93) than the Random Forest (0.75). The SI was estimated by applying the RF model, which included the ALS metrics corresponding to the 99th height percentile and the 80th height bicentile (R2 = 0.65; RMSE = 1.62 m). OTB segmentation made it possible to define a minimum segment size of 2.03 ha (spatial radius = 30, range radius = 1 and minimum region size = 64). This study provides a new tool for better forest management and promotes the need for further progress in the application of ALS data in the intensive silviculture of Eucalyptus spp. plantations in Uruguay
Scientific production on workplace bullying/harassment in dissertations and theses in the Brazilian scenario
OBJECTIVE To analyze scientific production about workplace bullying and harassment in dissertations and theses in Brazil, with emphasis on the year of publication; educational institution; area of knowledge; professional and academic background of the authors; keywords used; and concept map organization. METHOD Bibliometric study with a quantitative approach with a sample consisting of 57 papers, 5 theses and 52 dissertations, published between 2002 and 2012. RESULTS It was found that 2012 was the year with the highest number of publications in this topic area. The region that stood out was the Southeast. The institution with the highest number of publications was the Federal University of Santa Catarina. There was a predominance of dissertations and most publications were produced by researchers focused on a multidisciplinary perspective. CONCLUSION Expanding the views regarding bullying in order to disseminate scientific production was proposed, promoting further advancement of debates and raising pertinent questions
Do assĂ©dio moral Ă violĂȘncia interpessoal: relatos sobre uma empresa jĂșnior
O objetivo deste artigo Ă© analisar a violĂȘncia interpessoal vivenciada por sujeitos que atuam ou atuaram profissionalmente em uma empresa jĂșnior (EJ). Para tanto, desenvolvemos um referencial teĂłrico que apresenta e pondera sobre a teoria relativa ao assĂ©dio moral no trabalho. De modo sucinto, o assĂ©dio moral geralmente Ă© caracterizado, nos Estudos Organizacionais, como condutas hostis, imprĂłprias, repetitivas e prolongadas por meio de posturas, palavras, gestos e/ou situaçÔes humilhantes que envolvem o trabalhador, ou um grupo, durante a jornada de trabalho. Neste artigo, questionamos o conceito de assĂ©dio moral, que Ă© intimamente relacionado Ă intencionalidade dos sujeitos, e, em contrapartida, propomos o conceito de violĂȘncia interpessoal, isto Ă©, o ato de agredir o sujeito fĂsica e/ou discursivamente e/ou por atitudes e/ou comportamentos prejudiciais, sejam propositais ou nĂŁo. Em seguida, analisamos alguns relatos de violĂȘncia interpessoal experienciadas por atuais ou ex-empresĂĄrios juniores Ă luz desse conceito; realizamos uma pesquisa empĂrica de cunho qualitativo, na qual utilizamos a metodologia da histĂłria oral e analisamos os dados de acordo com a tĂ©cnica hermenĂȘutica/dialĂ©tica. Constatamos que os tipos de violĂȘncia relatados sĂŁo, na maioria dos casos, naturalizados pelas prĂłprias vĂtimas e pelo corpo social em decorrĂȘncia de uma prĂĄxis tida como necessĂĄria para a incorporação do sujeito. Destacamos, ainda, o nĂtido imbricamento das categorias violĂȘncia interpessoal e violĂȘncia simbĂłlica
- âŠ