Estimating Forage Biomass using Unmanned Ground and Aerial Vehicles

The assessment of the amount of biomass in the field is one of the critical factors that helps to manage and optimize numerous operations associated with forage management in the livestock industry. Pasture management decisions about stocking rate, grazing duration, and fertilizer application rate depend on accurate forage availability measurements. The objective of this study was to develop different nondestructive methods of forage biomass estimation using unmanned vehicles based on the relationship between crop height (CH) and the measured above-ground biomass. The unmanned vehicle-based methods were developed and tested on Alfalfa (Medicago Sativa) and Tall Fescue (Schedonorus phoenix (Scop.) Holub) fields. The real-time compressed crop height was measured using the ultrasound proximal sensor and a compression ski installed on the unmanned ground vehicle (UGV) and orthomosaic from aerial images was used for plot identification for site-specific analysis. The experiment was carried out before and after harvest to calculate the harvested CH to generate its regression relation with wet and dry biomass yield of forage. The results show that these systems produce promising results with R-square values of 0.8 and 0.5 for biomass estimation in Alfalfa and Tall Fescue respectively. These methods will significantly reduce the on-field destructive forage sampling for biomass estimation and aid in predicting the available biomass along with reducing the human efforts and resources for performing biomass sampling tasks, resulting in reduction of time and cost

Country and Time Variation in Exchange Rate Pass Through: What Drives it?

A large sample of developed and emerging economies is utilized to investigate import exchange rate pass-through. Panel models reveal that various economic aspects of the destination country can explain about one third of the total variation in pass-through elasticities and the remaining variation comes largely in the form of unobserved country-specific effects. Inflation, exchange rate volatility, openness and relative wealth play a clear role as drivers of emerging markets’ pass-through whereas the output gap and protectionism appear influential more generally. Nonlinearity regarding large-versus-small changes in the exchange rate is quite pervasive. Our evidence challenges the widely-held view that pass-through has been universally falling in developed markets and that it is higher for emerging markets. The economic drivers are shown to play a role as out-of-sample predictors of pass-through. The findings confirm pricing-to-market theories and have implications for the optimal conduct of monetary policy

Familias aborígenes del área del río Pinturas, noroeste de la provincia de Santa Cruz

El presente trabajo intenta profundizar el conocimiento de la composición étnica de la población aborigen del área del Río Pinturas, durante la primera mitad del siglo XX, que ha sido constatada a través de informantes locales, topónimos y documentos escritos de diversa índole. Se analiza la genealogía de determinadas familias emparentadas, remontándonos hasta comienzos del siglo XIX: Quilchamal, Almendra, Yatel, Chapalala, Kolpolke, Pescán, Sacamanta, Liempichum, Foyel, Kankel, Saynahuel, Sapa, Pascual y Vera. Presentamos también, una visión de los desplazamientos y territorios ocupados por dichas familias o de algunos de sus integrantes, que nos lleva mucho más allá de los límites de la cuenca del río Pinturas y permite postular su vinculación con los tehuelches septentrionales, ubicándolos en el siglo XIX, en parajes de la Provincia del Chubut y aún de Rio Negro. Nos interesa conocer y comprender los eventos que sufrieron estos últimos descendientes de tehuelches que perdiendo sus antiguos territorios, debieron reacomodarse a nuevas estrategias de subsistencia, replegándose a zonas poco pobladas.An attempt is made to deepen the knowledge of the ethnic composition of the aboriginal population of the Río Pinturas area in the first half of the twentieth century, verified through local informants, toponyms, and written documents of different kinds. The genealogy of the following related families is analyzed, reaching back to the beginnings of the nineteenth century: Quilchamal, Almendra, Yatel, Chapalala, Kolpolke, Pescán, Sacamanta, Liempichum, Foyel, Kankel, Saynahuel, Sapa, Pascual y Vera. A view of the moves and the territories occupied by these families or by some of their members is presented, which takes us far beyond the limits of the Rio Pinturas basin and supports the idea of ties with the northern tehuelches: in the nineteenth century these people could be found in localities of the provinces of Chubut and even of Rio Negro. We are interested in getting to know and understand the events suffered by these last descendants of tehuelches, who lost their ancient territories and had to readapt themselves to new subsistence strategies, retreating to scarcely populated areas.Sociedad Argentina de Antropologí

Familias aborígenes del área del río Pinturas, noroeste de la provincia de Santa Cruz

El presente trabajo intenta profundizar el conocimiento de la composición étnica de la población aborigen del área del Río Pinturas, durante la primera mitad del siglo XX, que ha sido constatada a través de informantes locales, topónimos y documentos escritos de diversa índole. Se analiza la genealogía de determinadas familias emparentadas, remontándonos hasta comienzos del siglo XIX: Quilchamal, Almendra, Yatel, Chapalala, Kolpolke, Pescán, Sacamanta, Liempichum, Foyel, Kankel, Saynahuel, Sapa, Pascual y Vera. Presentamos también, una visión de los desplazamientos y territorios ocupados por dichas familias o de algunos de sus integrantes, que nos lleva mucho más allá de los límites de la cuenca del río Pinturas y permite postular su vinculación con los tehuelches septentrionales, ubicándolos en el siglo XIX, en parajes de la Provincia del Chubut y aún de Rio Negro. Nos interesa conocer y comprender los eventos que sufrieron estos últimos descendientes de tehuelches que perdiendo sus antiguos territorios, debieron reacomodarse a nuevas estrategias de subsistencia, replegándose a zonas poco pobladas.An attempt is made to deepen the knowledge of the ethnic composition of the aboriginal population of the Río Pinturas area in the first half of the twentieth century, verified through local informants, toponyms, and written documents of different kinds. The genealogy of the following related families is analyzed, reaching back to the beginnings of the nineteenth century: Quilchamal, Almendra, Yatel, Chapalala, Kolpolke, Pescán, Sacamanta, Liempichum, Foyel, Kankel, Saynahuel, Sapa, Pascual y Vera. A view of the moves and the territories occupied by these families or by some of their members is presented, which takes us far beyond the limits of the Rio Pinturas basin and supports the idea of ties with the northern tehuelches: in the nineteenth century these people could be found in localities of the provinces of Chubut and even of Rio Negro. We are interested in getting to know and understand the events suffered by these last descendants of tehuelches, who lost their ancient territories and had to readapt themselves to new subsistence strategies, retreating to scarcely populated areas.Sociedad Argentina de Antropologí

The relative role of executive control and personality traits in grit

Although grit is predictive of wellbeing, educational achievement, and success in life, it has been conceptualized as largely distinct from cognitive ability. The present study investigated the link between grit and executive functions since regulation abilities might underlie the expression of grit. A hundred thirty-four people were administered personality questionnaires (grit, impulsiveness, and mindfulness) and four experimental tasks tapping into Miyake’s and Braver’s models of executive functioning (including measures of flexibility, inhibition, working memory, and control mode dimensions). Multivariate analyses showed that two composite scores (trait and executive functioning) were reliably predictive of grit, although it was the trait composite (characterized by low impulsivity and high mindfulness) that explained more variance. Importantly, gritty participants did not demonstrate enhanced executive functioning. Instead, they exhibited a different pattern of performance that might be reflecting a cautious profile of control, characterized by paying attention to all available information, less reliance on previous contextual cues but sensitive to conflicting information of the current context. These findings converge with Duckworth’s idea that high grit people do not necessarily have a greater cognitive capacity. Rather, they use it in a different way.This work was supported by the Spanish Ministry of Economy and Competitiveness and the Andalusian Government (Fondos FEDER) grants: doctoral research Grant ES-2016-078667 to NA; PSI2015-65502-C2-1-P, A.CTS.111.UGR18 and PGC2018-093786-B-I00 to TB; and PSI2015- 65502-C2-2-P to CG-A. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Spéciation des organoétains dans les eaux et sédiments du bassin Adour-Garonne

De par leurs nombreuses propriétés physico- chimiques, les organoétains sont très utilisés dans l’industrie et en agriculture et entrent dans la composition de nombreux produits domestiques. Ils sont cependant extrêmement toxiques et la Communauté Européenne les a classés parmi les substances prioritaires dans le domaine de l’eau.Un suivi des organoétains a été réalisé sur onze rivières du bassin Adour-Garonne et sur l’estuaire de l’Adour. Ces composés y sont systématiquement présents, les butylétains et les octylétains étant les espèces les plus fréquemment détectées. Les concentrations varient de la limite de détection (0.2-0.5 ng(Sn)/l en moyenne) à 50 ng(Sn)/l dans les eaux, et de 15 à 300 µg(Sn)/kg dans les sédiments dulcicoles. Des pics de contamination ont été observés en fin de printemps et d’été, dans plusieurs rivières. Ils correspondent à la présence des mono- butyl- et -phénylétains principalement, leurs concentrations pouvant atteindre 700 à 900 ng(Sn)/l d’eau. Les rivières les plus contaminées sont la Garonne, le Gave de Pau, l’Adour, la Charente et le Thoré. Dans les matières en suspension de l’estuaire de l’Adour les concentrations atteignent quelques mg(Sn)/kg. L’ensemble des données recueillies a permis de mieux comprendre les origines et le devenir des organoétains dans le cycle hydrologique.Because of their physico-chemical properties, organotin compounds (OTC) are widely used in industry and are present in a significant number of agricultural pesticides and domestic products. They are highly toxic and the European Community has listed them as priority pollutants in the aquatic environment. Organotins have been monitored in the Adour- Garonne basin and the Adour estuary. They are systematically present in the rivers, with butyl- and octyltins being the species most frequently detected. These species, especially octyltins, probably come from the continuous leaching of plastic tubes. The OTC concentrations ranged from just over detection limits (≥ 0.2-0.5 ng (Sn)/L) to 50 ng (Sn)/L in water and from 15 to 300 µg (Sn)/kg in freshwater sediment. Important seasonal variations were also observed. Thus, at the end of spring and summer, very high monophenyltin (MPhT) concentrations of up to 700-900 ng (Sn)/L were found in the dissolved phase. This phenomenon could be partly attributed to specific triphenyltin (TPhT)-based agricultural treatments, MPhT being one of the TPhT degradation products. High monobutyltin (MBT) concentrations of up to 150 ng (Sn)/L were also detected during the same period. This latter compound comes from leaching of plastics and from tri- and di-butyltin (TBT, DBT) degradation. It represents 80 to 100% of the butyl species found in sediments.Considering OTC concentrations, speciation and toxicity, the most contaminated rivers appeared to be the Garonne, Gave de Pau, Adour, Charente and Thoré. Urban activities have significant influence on the levels of OTC contamination for most of the rivers, demonstrating continuous OTC inputs from domestic and industrial treatment plants. This is especially the case for the Charente and Thoré rivers, where some specific industrial activities devoted to leather and wood are present close to the sampling points.A statistical study was performed on the different physico-chemical parameters (temperature, water flow rate, dissolved oxygen concentration) and OTC concentrations. A significant positive correlation between water flow rate and organotin concentrations in the dissolved phase was observed. This correlation was very important when only sampling points far from potential OTC sources were considered, the octyltin concentrations showing the strongest correlation. These observations confirm the presence of a continuous OTC diffusion into aquatic media. A comparison between the present results in Adour-Garonne and OTC monitoring performed in the Rhin- Meuse basin shows that the level of contamination was quite similar in the two basins, especially considering rivers without fluvial traffic. A similar correlation existed between OTC concentrations in the dissolved phase and water flow rate.Special attention was given to the Adour sub-basin because of its particular geographic position and especially the large built-up area in the estuary. Butyltins remain the main OTC compound present, in terms both of frequency and concentration. According to the different sampling points in this sub-basin, mean OTC concentrations in the estuary did not appear to be really influenced by human activities located upstream, the concentrations in this part reaching 50 ng (Sn)/L in the dissolved phase. In contrast, OTC amounts found in the estuary were considerable higher. The built-up area of the estuary had a strong influence on concentrations, which were 6 to 14 times higher in the city centre than those upstream from the city (in an agricultural region). In addition to the influence of local sources, both a strong dilution effect and significant adsorption/ sedimentation phenomena in the downstream region of the estuary could be important. In the suspended matter of the Adour estuary, organotin concentrations were extremely high, reaching concentrations as high as mg (Sn)/kg. Such concentrations have already been reported for nearby regions of the harbour [Bravo et al. (2004)]. However, in the present case, there should be considerable concern considering the possible environmental consequences. The estuarine sediments appeared obviously contaminated by butyltins, but the concentrations were lower than those that could be expected (2000 µg (Sn)/ kg maximum). This observation could be explained by water flow rates as well as the tide, which could export large amounts of suspended matter outside the estuary. MPhT and TPhT were also detected, especially in sediments from the extreme downstream region of the estuary. Their presence could be attributed to the marina. The different solid/ dissolved partition coefficients were also evaluated. These partition coefficients ranged from over 40x104 for sediments up to 200x104 for suspended matter. Finally, the information on the Adour sub-basin showed that the estuary was more strongly contaminated than the upstream region.Generally, all these data have contributed to the first evaluation of OTC contamination in the Adour-Garonne basin, and identified organotin sources. The statistical study, comparisons between the different parts of the aquatic environment, and the observation of solid/ liquid distributions lead to a better understanding of the environmental fate of OTCs. Even if differences exist between the level of contamination in freshwater and estuarine environments, the ubiquitous presence of OTC must remain a subject of concern, especially with regard to the high toxicity of organotins. For example, TBT and TPhT have lethal effects on trout and algal species at aquatic concentrations in the µg (Sn)/L range or even below this concentration [TOOBY et al. (1975), WONG et al. (1982)]. Considering this high toxicity, other studies will have to be performed in order to increase the current database concerning OTC in rivers. It is also important to know the conditions that control OTC uptake by biota, and in order to propose effective environmental management strategies

Numerical simulation of partially premixed combustion using a flame surface density approach

Partially premixed combustion is characterized by a variable equivalence ratio of the mixture in space and time, and where there are both lean and rich mixture zones. Thus the reaction evolves along with a turbulent mixture process, which modifies the composition of reactants and products. In this situation a so-called triple flame could be encountered, in which a rich and a lean premixed flame front as well as a diffusion flame are present. The diffusion flame develops behind the premixed flame front due to turbulent mixing in the hot combustion products. This kind of combustion could be found in Direct Injection Spark Ignition (DISI) engines when they are operated in the stratified charge mode. The model considered in this work assumes a simplified one-step irreversible chemical reaction in which fuel and oxidant react together in stoichiometric proportions giving products with the composition corresponding to a complete combustion. A transport equation is solved for the oxidant and fuel, from which the amount of products and the combustion progress are computed, while the turbulence is modeled with RANS (Reynolds-Average Navier-Stokes). The reaction rate is assumed in the model as proportional to the product of the Flame Surface Density (FSD) by the local laminar flame speed. Aside from the state and composition of the mixture, the local laminar flame speed is afected by the turbulent mixing process. This mixing process is taken into account by means of the classical β-PDF (Probability Density Function), which is a function of the mixture fraction and its variance. A transport equation is solved for both, the mixture fraction and its variance, and the FSD is computed through a transport equation where several models are available for the source terms. The model is implemented in the open-source toolkit OpenFOAM®. Computational results are obtained for partially premixed combustions inside constant-volume vessels with several initial configurations, which are compared with numerical results available in the literature.Publicado en: Mecánica Computacional vol. XXXV, no. 16.Facultad de Ingenierí

Numerical simulation of partially premixed combustion using a flame surface density approach

Partially premixed combustion is characterized by a variable equivalence ratio of the mixture in space and time, and where there are both lean and rich mixture zones. Thus the reaction evolves along with a turbulent mixture process, which modifies the composition of reactants and products. In this situation a so-called triple flame could be encountered, in which a rich and a lean premixed flame front as well as a diffusion flame are present. The diffusion flame develops behind the premixed flame front due to turbulent mixing in the hot combustion products. This kind of combustion could be found in Direct Injection Spark Ignition (DISI) engines when they are operated in the stratified charge mode. The model considered in this work assumes a simplified one-step irreversible chemical reaction in which fuel and oxidant react together in stoichiometric proportions giving products with the composition corresponding to a complete combustion. A transport equation is solved for the oxidant and fuel, from which the amount of products and the combustion progress are computed, while the turbulence is modeled with RANS (Reynolds-Average Navier-Stokes). The reaction rate is assumed in the model as proportional to the product of the Flame Surface Density (FSD) by the local laminar flame speed. Aside from the state and composition of the mixture, the local laminar flame speed is afected by the turbulent mixing process. This mixing process is taken into account by means of the classical β-PDF (Probability Density Function), which is a function of the mixture fraction and its variance. A transport equation is solved for both, the mixture fraction and its variance, and the FSD is computed through a transport equation where several models are available for the source terms. The model is implemented in the open-source toolkit OpenFOAM®. Computational results are obtained for partially premixed combustions inside constant-volume vessels with several initial configurations, which are compared with numerical results available in the literature.Publicado en: Mecánica Computacional vol. XXXV, no. 16.Facultad de Ingenierí

Electrophysiological correlates of dispositional mindfulness: A quantitative and complexity EEG study

While growing evidence supports that dispositional mindfulness relates to psychological health and cognitive enhancement, to date there have been only a few attempts to characterize its neural underpinnings. In the present study, we aimed at exploring the electrophysiological (EEG) signature of dispositional mindfulness using quantitative and complexity measures of EEG during resting state and while performing a learning task. Hundred twenty participants were assessed with the Five Facet Mindfulness Questionnaire and underwent 5 min eyes-closed resting state and 5 min at task EEG recording. We hypothesized that high mindfulness individuals would show patterns of brain activity related to (a) lower involvement of the default mode network (DMN) at rest (reduced frontal gamma power) and (b) a state of ‘task readiness’ reflected in a more similar pattern from rest to task (reduced overall q-EEG power at rest but not at task), as compared to their low mindfulness counterparts. Dispositional mindfulness was significantly linked to reduced frontal gamma power at rest and lower overall power during rest but not at task. In addition, we found a trend towards higher entropy during task performance in mindful individuals, which has recently been reported during mindfulness meditation. Altogether, our results add to those from expert meditators to show that high (dispositional) mindfulness seems to have a specific electrophysiological pattern characteristic of less involvement of the DMN and mind-wandering processes.The current research was financially supported by the Spanish Ministry of Science, Innovation and Universities and the Andalusian Government (Fondos FEDER) grants: doctoral research grant ES-2016-078667 to NA, PSI2015-65502-C2-2-P to CG-A and A-CTS-111-UGR18, PGC2018-093786-B-I00, and PID2021-127728NB-100 to TB. Funding for open acces charge: Universdad de Granada / CBUA