2,492 research outputs found
Modeling diameter distributions with six probability density functions in Pinus halepensis Mill. Plantations using low-density airborne laser scanning data in Aragón (northeast Spain)
Producción CientíficaThe diameter distributions of trees in 50 temporary sample plots (TSPs) established in Pinus halepensis Mill. stands were recovered from LiDAR metrics by using six probability density functions (PDFs): the Weibull (2P and 3P), Johnson’s SB, beta, generalized beta and gamma-2P functions. The parameters were recovered from the first and the second moments of the distributions (mean and variance, respectively) by using parameter recovery models (PRM). Linear models were used to predict both moments from LiDAR data. In recovering the functions, the location parameters of the distributions were predetermined as the minimum diameter inventoried, and scale parameters were established as the maximum diameters predicted from LiDAR metrics. The Kolmogorov–Smirnov (KS) statistic (Dn), number of acceptances by the KS test, the Cramér von Misses (W2) statistic, bias and mean square error (MSE) were used to evaluate the goodness of fits. The fits for the six recovered functions were compared with the fits to all measured data from 58 TSPs (LiDAR metrics could only be extracted from 50 of the plots). In the fitting phase, the location parameters were fixed at a suitable value determined according to the forestry literature (0.75·dmin). The linear models used to recover the two moments of the distributions and the maximum diameters determined from LiDAR data were accurate, with R2 values of 0.750, 0.724 and 0.873 for dg, dmed and dmax. Reasonable results were obtained with all six recovered functions. The goodness-of-fit statistics indicated that the beta function was the most accurate, followed by the generalized beta function. The Weibull-3P function provided the poorest fits and the Weibull-2P and Johnson’s SB also yielded poor fits to the data.Ministerio de Economía, Industria y Competitividad, Ayudas Torres Quevedo- (grant PTQ-16-08445)Fondo Europeo Agrario de Desarrollo Rural (FEADER) Programa de Desarrollo Rural de Aragón 2014-2020 - (project RF-64079
Extreme flooding increases poaching mortality in the southernmost stronghold of the endangered marsh deer
Extreme stochastic perturbations can affect population dynamics, but quantitative assessments are scarce for threatened species. The 2015-2016 El Niño-Southern Oscillation (ENSO) caused extreme flooding in the Delta of the Paraná River in Argentina where the southernmost population of the regionally endangered marsh deer (Blastocerus dichotomus) occurs. Using field surveys and data from informants, we studied the impact of this flood on the mortality, distribution, and abundance of this marsh deer population in an area of 1 236 km2. The occurrence of this extreme flood significantly increased marsh deer mortality. One hundred forty-two marsh deer deaths were recorded over the seven-month flood duration, with poaching accounting for 86.6% of deaths. Mortality of marsh deer was significantly higher near urban areas, embankments, and dirt roads, while mortality from poaching was higher in plantations and permanently inundated lands. Two areas of high spatial clustering of poaching mortality were detected, encompassing plantations with easy access or in proximity to urban areas, while embankments appeared to act as attractive population sinks. Flood-related mortality significantly decreased the occurrence of the species in the study area after the flood, but changes in relative abundance between periods were heterogeneous across the landscape, probably because of local migrations. Since climate change is expected to increase the global frequency and magnitude of extreme flood events, our study provides valuable information for mitigating the negative synergistic effects of extreme flooding on marsh deer, as well as for global wildlife populations subjected to periodic extreme floods.Las perturbaciones estocásticas extremas pueden afectar la dinámica de las poblaciones, pero las evaluaciones cuantitativas son escasas para las especies amenazadas. El fenómeno de “El Niño” de 2015-2016 causó inundaciones extremas en el Delta del río Paraná en Argentina, donde se encuentra la población más austral del ciervo de los pantanos
(Blastocerus dichotomus), categorizada como En Peligro a nivel regional. En base a relevamientos de campo y datos de informantes, estudiamos el impacto de esta inundación sobre la mortalidad, distribución y abundancia de esta población de ciervo de los pantanos dentro de un área de 1 236 km2. La ocurrencia de esta inundación incrementó signicativamente la mortalidad del ciervo de los pantanos. Hemos registrado 142 individuos muertos durante los siete meses de duración de la inundación, y la caza furtiva representó el 86.6% de las muertes. La mortalidad del ciervo de los pantanos fue signicativamente mayor en proximidad a áreas urbanas, terraplenes y caminos vehiculares, mientras que la mortalidad por cacería fue mayor en plantaciones y terrenos permanentemente inundados. Se detectaron dos áreas de alta concentración espacial de mortalidad por cacería, que abarcaron plantaciones de fácil acceso o próximas a áreas urbanas, mientras que los terraplenes parecen haber funcionado como sumideros atractivos para los ciervos. La mortalidad relacionada con las inundaciones disminuyó signicativamente la presencia de la especie dentro del área de estudio luego de la inundación, pero los cambios en la abundancia relativa entre períodos fueron heterogéneos en todo el paisaje, probablemente como resultado de migraciones locales. Dado que se espera que el cambio climático aumente la frecuencia global y la magnitud de las inundaciones extremas, nuestro estudio proporciona información valiosa para mitigar los efectos sinérgicos negativos de las inundaciones extremas tanto en el ciervo de los pantanos como en poblaciones de otras especies sujetas a inundaciones extremas periódicas.EEA Delta del ParanáFil: Pereira, Javier A. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Pereira, Javier Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Varela, Diego. Universidad Nacional de Misiones. Instituto de Biología Subtropical; ArgentinaFil: Varela, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología Subtropical; ArgentinaFil: Varela, Diego. Asociación Civil Centro de Investigaciones del Bosque AtlánticoFil: Thompson, Jeffrey J. Consejo Nacional de Ciencia y Tecnología. Guyra Paraguay; ParaguayFil: Thompson, Jeffrey J. Instituto Saite; ParaguayFil: Lartigau, Bernardo V. Asociación para la Conservación y el Estudio de la Naturaleza; ArgentinaFil: Fracassi, Natalia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Delta del Paraná; ArgentinaFil: Kittlein, Marcelo J. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología. Instituto de Investigaciones Marinas y Costeras (IIMyC); ArgentinaFil: Kittlein, Marcelo J. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Marinas y Costeras (IIMyC); Argentin
Phytoplankton composition in a neritic area of the Balearic Sea (Western Mediterranean)
From September 2000 to September 2001 the concentration of chlorophyll a, and the abundance and composition of the phytoplanktonic community was studied in a neritic station of the Mallorca Channel (Western Mediterranean). Sampling was performed approximately every 12 days. Chlorophyll a concentration and phytoplankton abundance reached maxima of 1.79 mg L2l and 352 cells mL21, respectively. It was a relatively productive period, as a result of the high convective mixing in winter and the prevalence of northern waters during most of the cycle. Phytoplankton proliferations (chlorophyll-a concentration .1 mg L21) were detected in January, February, March and June. Those blooms mainly happened under the influence of northern waters, with the exception of the February proliferation, when mixing conditions were found. During bloom conditions it highlights the presence of coccolithophores as proliferation precursors. During no-bloom situations the phytoplankton community was mainly constituted by nanoplanktonic flagellated forms. The Winter Mixing period was dominated by different groups of nanoflagellates, including coccolithophores, undetermined flagellates and dinoflagellates. However, in the most oligotrophic conditions (from April until November) dinoflagellates were clearly dominant, except in the DCM in summer where diatoms prevailed.Versión del edito
Energy efficiency and lighting design in courtyards and atriums: A predictive method for daylight factors
The proper design of courtyards and atriums is key in providing sufficient daylight inside buildings as well as major energy
savings in electric lighting. Although a suitable design requires calculations using lighting simulation software or complex
algorithms, architects lack a quick and precise procedure to determine proper design. The aim of this research is therefore to
offer a fast accurate method for determining the daylight factor for different points on a rectangular courtyard or the central
space of an atrium, based on the variable geometry and reflectance of the inner surfaces. Firstly, daylight factors are defined
using measurements in scale models in an artificial sky and values obtained in real courtyards under real overcast skies. The
sky component is subsequently defined based on earlier studies and Tregenza algorithms in order to quantify the reflected
component. Following the curve fitting process, a predictive method of daylight factors is defined and compared with the
previous measures. The comparison demonstrates that the predictive method offers an average accuracy of over 90% based on
a quick and easy calculation. Finally, the energy saving in electric lighting is quantified following the predictive method
established
Sensitivity Analysis of Lumped-Parameter Thermal Networks for the Experimental Calibration of eMotor Models
[Abstract] Lumped-parameter thermal networks (LPTNs) are efficient computational models that can be used to replicate the thermal behavior of eMotors in a way that is compatible with real-time execution. The accuracy of the simulation results delivered by LPTNs relies on the selection of an appropriate topology and the accurate tuning of their parameters, namely resistances, capacities and heat sources. It is difficult, however, to obtain an accurate tuning of the parameters starting from theoretical expressions, and these often need to be adjusted based on experimental calibration. Several methods can be used to this end; among these, finite differences are a popular option. This article presents a methodology for the analytical determination of the sensitivity of LPTN dynamics with respect to its lumped parameters. The obtained analytical sensitivities provide information about the effect of the circuit parameters on the thermal dynamics of the overall system, and can be used to enable the use of gradient-based optimization methods to adjust the LPTN parameters. The proposed method overcomes several limitations of finite difference approaches, such as the computational load incurred when the number of parameters to be adjusted is large, and the variability of the results with the increment used to define the finite differences. The analytical sensitivities were tested in the analysis and optimization of a benchmark thermal model and the LPTN representation of a permanent-magnet synchronous motor (PMSM).Xunta de Galicia; ED431B2016/031Xunta de Galicia; ED431F2021/0
Energy-based monitoring and correction to enhance the accuracy and stability of explicit co-simulation
[Abstract] The simulation of complex engineering applications often requires the consideration of component-level dynamics whose nature and time-scale differ across the elements of which the system is composed. Co-simulation offers an effective approach to deal with the modelling and numerical integration of such assemblies by assigning adequate description and solution methods to each component. Explicit co-simulation, in particular, is frequently used when efficient code execution is a requirement, for instance in real-time setups. Using explicit schemes, however, can lead to the introduction of energy artifacts at the discrete-time interface between subsystems. The resulting energy errors deteriorate the accuracy of the co-simulation results and may in some cases develop into the instability of the numerical integration process. This paper discusses the factors that influence the severity of the energy errors generated at the interface in explicit co-simulation applications, and presents a monitoring and correction methodology to detect and remove them. The method uses only the information carried by the variables exchanged between the subsystems and the co-simulation manager. The performance of this energy-correction technique was evaluated in multi-rate co-simulation of mechanical and multiphysics benchmark examples.Xunta de Galicia; ED431B2016/031Xunta de Galicia; ED431F2021/04Ministerio de Economía, Industria y Competitividad; RYC-2016-20222Ministerio de Economía, Industria y Competitividad; TRA2017-86488-
Competition between covalent bonding and charge transfer at complex-oxide interfaces
Here we study the electronic properties of cuprate/manganite interfaces. By
means of atomic resolution electron microscopy and spectroscopy, we produce a
subnanometer scale map of the transition metal oxidation state profile across
the interface between the high superconductor YBaCuO
and the colossal magnetoresistance compound (La,Ca)MnO. A net transfer of
electrons from manganite to cuprate with a peculiar non-monotonic charge
profile is observed. Model calculations rationalize the profile in terms of the
competition between standard charge transfer tendencies (due to band mismatch),
strong chemical bonding effects across the interface, and Cu substitution into
the Mn lattice, with different characteristic length scales.Comment: 11+7 pages, 3+2 figure
Glycosylated Cell Penetrating Peptides, GCPPs
This is the peer reviewed version of the following article: Gallego, I. , Rioboo, A. , Reina, J. ., Díaz, B. , Canales, Á., Cañada, F. ., Guerra-Varela, J. , Sánchez, L. and Montenegro, J. (2019), Glycosylated Cell Penetrating Peptides, GCPPs. ChemBioChem. doi:10.1002/cbic.201800720, which has been published in final form at https://doi.org/10.1002/cbic.201800720. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsThe cell membrane regulates the exchange of molecules and information with the external environment. However, this control barrier hinders the delivery of exogenous bioactive molecules that can be applied to correct cellular malfunctions. Therefore, the traffic of macromolecules across the cell membrane represents a great challenge for the development of the next generation of therapies and diagnostic methods. Cell penetrating peptides are short peptide sequences capable of delivering a broad range of biomacromolecules across the cellular membrane. However, penetrating peptides still suffer from limitations mainly related with their lack of specificity and potential toxicity. Glycosylation has emerged as a potential promising strategy for the biological improvement of synthetic materials. In this work we have developed a new convergent strategy for the synthesis of penetrating peptides functionalized with glycan residues by an oxime bond connection. We have systematically characterized the uptake efficiency and the intracellular distribution of these glycopeptides by flow cytometry, confocal microscopy and in zebrafish animal models. The incorporation of these glycan residues into the peptide structure influenced the internalization efficiency and the cellular toxicity of the resulting glycopeptide hybrids in the different cell lines tested. The results reported here highlight the potential of the glycosylation of penetrating peptides to modulate their activityWe acknowledge funding from the Spanish Agencia Estatal de Investigación (AEI) [CTQ2014-59646-R, SAF2017-89890-R, CTQ2016-76263-P, CTQ2015-64597-C2-2P], the Xuntade Galicia (ED431G/09, ED431C 2017/25 and 2016-AD031) and the ERDF. I. G. received a predoctoral fellowship from the Xunta de Galicia (ED481A-2018/116). A. R. received a predoctoral fellowship from the Fundación Segundo Gil Dávila. J.G.-V. and L.S. acknowledge the financial support received from the Xunta de Galicia (Galicia, Spain) under the Grupos de Referencia Competitiva Programme: Project GRC2014/010. J. M. received a Ramón y Cajal (RYC-2013-13784), an ERC Starting Investigator Grant (DYNAP-677786) and a Young Investigator Grant from the HFSP (RGY0066/2017)S
Propensity score matched comparison of transcatheter aortic valve implantation versus conventional surgery in intermediate and low risk aortic stenosis patients: A hint of real-world
Background: Recently, the use of transcatheter aortic valve implantation (TAVI) in intermediate-low risk patients has been evaluated in the PARTNER II randomized trial. However, in the last years, this therapy has been employed in this scenario with underreported results, as compared to surgical aortic valve replacement (SAVR).
Methods: We enrolled 362 consecutive patients with severe symptomatic aortic stenosis and intermediate-low surgical risk (logEuroSCORE < 20%), treated in our center with TAVI (103 patients) or single SAVR (259 patients) between 2009 and 2014. Patients were matched according to age, gender, logEuroSCORE, and use of bioprosthesis.
Results: Mean age of the patients was 73 ± 10.4 years, and 40.3% were women. LogEuroSCORE and Society Thoracic Surgeons score were 7.0 ± 4.4% and 4.2 ± 2.5%, respectively, with mean left ventricular ejection fraction of 52 ± 9%. There were no differences regarding other comorbidities. The length-of-hospitalization was 11 ± 5 days after TAVI vs. 17 ± 9 days after SAVR (p = 0.003). After matched comparison, no differences in terms of in-hospital mortality (5.7% after TAVI vs. 2.9% after SAVR, p = 0.687) and 1-year mortality (11.4% vs. 7.1%, p = 0.381) were found. The combined endpoint of stroke and mortality at 1-year was also similar between both groups (15.7% in TAVI patients vs. 14.4% after SAVR, p = 0.136). Multivariate analysis determined that aortic regurgitation (AR) was an independent predictor of mortality (OR = 3.623, 95% CI: 1.267–10.358, p = 0.016). Although the rate of AR was higher after TAVI, none of the patients treated with the newest generation devices (10.7%) presented more than a mild degree of AR.
Conclusions: TAVI is feasible and shows comparable results to surgery in terms of early, 1-year mortality, as well as cerebrovascular events in patients with severe aortic stenosis and intermediate-low operative risk. Better transvalvular gradients, yet higher rates of AR were found, however, newer devices presented comparable rate of AR.
Allelopathic studies with furanocoumarins isolated from Ducrosia anethifolia. In vitro and in silico investigations to protect legumes, rice and grain crops
Six different furanocoumarins were isolated from the aerial parts of Ducrosia anethifolia and tested in vitro for plant cell elongation in etiolated wheat coleoptile. They were also tested for their ability to control three different weeds: ribwort plantain, annual ryegrass, and common purslane. These compounds exhibited strong inhibition of plant cell elongation. In the case of (+)-heraclenin, the IC50 was lower than 20 μM, indicating a better inhibition than the positive control Logran®. Computational experiments for docking and molecular dynamics revealed for the investigated furanocoumarins bearing an epoxide moiety an improved fitting and stronger interaction with the auxin-like TIR1 ubiquitin ligase. Furthermore, the formed inhibition complex remained also stable during dynamic evaluation. Bidental interaction at the active site, along with an extended hydrogen-bond lifetime, explained the enhanced activity of the epoxides. The in vitro weed bioassay results showed that Plantago lanceolata was the most affected weed for germination, root, and shoot development. In addition, (+)-heraclenin displayed better inhibition values than positive control even at 300 μM concentration
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