On the Entropy of Oscillator-Based True Random Number Generators under Ionizing Radiation

The effects of ionizing radiation on field-programmable gate arrays (FPGAs) have been investigated in depth during the last decades. The impact of these effects is typically evaluated on implementations which have a deterministic behavior. In this article, two well-known true-random number generators (TRNGs) based on sampling jittery signals have been exposed to a Co-60 radiation source as in the standard tests for space conditions. The effects of the accumulated dose on these TRNGs, an in particular, its repercussion over their randomness quality (e.g., entropy or linear complexity), have been evaluated by using two National Institute of Standards and Technology (NIST) statistical test suites. The obtained results clearly show how the degradation of the statistical properties of these TRNGs increases with the accumulated dose. It is also notable that the deterioration of the TRNG (non-deterministic component) appears before that the degradation of the deterministic elements in the FPGA, which compromises the integrated circuit lifetime.Ministerio de Economía y Competitividad (ESP-2015-68245-C4-1-P)Ministerio de Economía y Competitividad (ESP-2015-68245-C4-4-P)Ministerio de Economía y Empresa (TIN2016-79095-C2-2-R)CAM (S2013/ICE-3095

Aedes ægypti control in urban areas: A systemic approach to a complex dynamic.

The available strategy for controlling the diseases transmitted by Aedes ægypti (dengue fever, Zika, and chikungunya) relies on continued community participation. Despite slogans emphasizing how easy it should be, no country has achieved it since the seventies. To better investigate potentially sustainable interventions, we developed a systemic model based on a multidisciplinary approach, integrating as deeply as possible specialized knowledge and field experience. The resulting model is composed of 4 external and 8 internal subsystems and 31 relationships, consistent with the literature and checked over multiple iterations with specialists of the many areas. We analyzed the model and the main feedback loops responsible for the system's stability, searching for possible interventions that could shift the existing balance. We suggest the introduction of 1 more player, the local primary health care structure, with the potential to change the undesired equilibrium. The health agents in the areas are the first to detect disease cases, and they could stimulate individuals to inform about potential mosquitoes' breeding sites and bring timely information to the vector-control program. Triggering such an action could introduce changes in people's attitude through a positive feedback loop in the desired direction

Implementación de mecanismos para lograr el cumplimiento del principio de probidad en las instituciones públicas

El presente trabajo de investigación tiene como finalidad analizar qué mecanismos se implementarán para lograr el cumplimiento del principio de probidad en las instituciones públicas. Se justifica debido a la existencia de intereses particulares por parte de funcionarios y servidores públicos, que no respetan los principios éticos, precisamente el principio de probidad que se viene vulnerando, por ello se van a proponer mecanismos que coadyuvaran a las instituciones públicas a reforzar un eficiente control y fiscalización permanente. El enfoque es cualitativo, tipo de investigación básica, diseño aplicado fenomenológico, técnica entrevista a profundidad, instrumento guía de entrevista conformada por 7 preguntas, se tuvo 6 participantes, herramienta de interpretación de datos se utilizó el Atlas Ti. Como resultado se obtuvo que el control realizado por el Estado deba apegarse a postulados de transparencia, honradez, integridad y espíritu de servicio. Se concluyó que los mecanismos por implementar para dar cumplimiento al principio de probidad son: La creación de herramientas tecnológicas del Estado que conllevaría al comienzo de una nueva gestión y disminución de riesgos; mejorar los filtros de contratación; incorporación de un área específica en las instituciones públicas, cuya finalidad sea dar cumplimiento a la ética e integridad en la función pública

Identifying and quantifying the abundance of economically important palms in tropical moist forest using UAV imagery

Sustainable management of non-timber forest products such as palm fruits is crucial for the long-term conservation of intact forest. A major limitation to expanding sustainable management of palms has been the need for precise information about the resources at scales of tens to hundreds of hectares, while typical ground-based surveys only sample small areas. In recent years, small unmanned aerial vehicles (UAVs) have become an important tool for mapping forest areas as they are cheap and easy to transport, and they provide high spatial resolution imagery of remote areas. We developed an object-based classification workflow for RGB UAV imagery which aims to identify and delineate palm tree crowns in the tropical rainforest by combining image processing and GIS functionalities using color and textural information in an integrative way to show one of the potential uses of UAVs in tropical forests. Ten permanent forest plots with 1170 reference palm trees were assessed from October to December 2017. The results indicate that palm tree crowns could be clearly identified and, in some cases, quantified following the workflow. The best results were obtained using the random forest classifier with an 85% overall accuracy and 0.82 kappa index.Publisher PDFPeer reviewe

Classificação das fraturas toracolombares: comparação entre as classificações de AO e Vaccaro

Objetivo: las clasificaciones han cambiado en el último medio siglo, la más usada desde la pasada década es la Clasificación AO. En 2004, Vaccaro et al. propusieron el Thoraco-Lumbar Injury Classification and Severity Score (TLICS). Métodos: análisis de la reproductividad inter y intra observador, utilizando el test Kappa, de las dos clasificaciones entre tres niveles distintos de traumatólogos en formación, en 30 casos. Resultados: la reproductividad intraobservador en la clasificación de Vaccaro fue: OI: 0,73; OII: 0,6 y OIII: 0,63. Para la clasificación AO: 0,7; 0,7 y 0,6, respectivamente. Entre las dos clasificaciones: OI: 0,59; OII: 0,7 y OIII: 0,62. La evaluación interobservador para la clasificación de Vaccaro es 0,66 y para la clasificación AO de 0,67. Los puntos críticos: rotación y lesiones del complejo ligamentario posterior. Conclusiones: las dos clasificaciones muestran un buen grado de acuerdo (índice de Kappa). Con la de Vaccaro, se observó un acuerdo global del 69%. Con respecto a la indicación de tratamiento ortopédico, el acuerdo fue el 37%. En la indicación de tratamiento quirúrgico, fue del 29%. Cabe remarcar que dicha clasificación dispone de un nivel impreciso donde se puede optar por cualquiera de los dos tratamientos (TLICS 4), esto se observó en el 3%. No hubo concordancia en el 31%. Las mismas indicaciones para la clasificación AO presentaron un acuerdo global del 67%. Para la indicación ortopédica fue del 32%. Se realizó una indicación quirúrgica en el 21%. En las lesiones clasificadas como A3 (14%), su indicación de tratamiento no es definida con unanimidad entre los observadores.Objective: the classifications have changed in the last half century; the most used from the last decade is Classification AO. In 2004, Vaccaro et al. proposed the Thoraco-Lumbar Injury Classification and Severity Score (TLICS). Methods: one analysis of the inter and intra observant reproduction by using the Kappa test, of the two classifications between three different levels from orthopedic surgeons in formation in 30 cases. Results: the intraobservant reproduction in the classification of Vaccaro was: OI: 0.73; OII: 0.6, and OIII: 0.63. For the AO classification: 0.7; 0.7 and 0.6, respectively. Between the two classifications: OI: 0.59; OII: 0.7, and OIII: 0.62. The interobservant evaluation for the classification of Vaccaro is 0.66 and for AO classification was 0.67. The tactically important points were rotation and injuries of the later ligamentary complex. Conclusions: the two classifications show a good degree in agreement (Kappa index). With the Vaccaro, it has been observed a global agreement of 69%. Regarding the indication of orthopedic treatment, the agreement was 37%. In the surgical treatment indication, it was 29%. It is possible to remark that this classification has a vague level where it can be decided on any of the two treatments (TLICS 4). This was observed in 3%. There was no agreement in 31%. The same indications for classification AO presented a global agreement of 67%. For the orthopedic indication, it was 32%. A surgical indication was made in 21%. In the injuries classified as A3 (14%) about the treatment is not defined with unanimity between the observers.Objetivo: as classificações têm mudado na último metade do século, sendo a mais usada desde a última década, a classificação AO. Em 2004, Vaccaro et al. propuseram a Thoraco-Lumbar Injury Classification (TLICS). Métodos: análise da reprodução inter e intraobservador, utilizando o teste Kappa das classificações entre três níveis distintos de traumatólogos em formação, em 30 casos. Resultados: a reprodução intraobservador na classificação de Vaccaro foi: OI: 0,73; OII: 0,6 e OIII: 0,63. Para a classificação AO, 0,77; 0,7 e 0,6, respectivamente. Entre as duas classificações: OI: 0,59; OII: 0,7 e OIII: 0,62. A avaliação interobservador para a classificação de Vaccaro foi de 0,66 e para a classificação AO de 0,67. Os pontos críticos foram rotação e lesões do complexo ligamentar posterior. Conclusões: as duas classificações mostram um bom grau de concordância (índice Kappa). Com a de Vaccaro, observou-se concordância global de 69%. Com respeito à indicação do tratamento ortopédico, a concordância foi de 37%. A indicação de tratamento cirúrgico foi de 29%. Cabe salientar que essa classificação dispõe de um nível impreciso em que pode-se optar por qualquer dos dois tratamentos (TLICS 4), o qual foi observado em 3%. Não houve concordância em 31%. As mesmas indicações para a classificação AO apresentaram concordância global de 67%. Indicação ortopédica foi de 32%. Foi realizada uma cirurgia em 21%. Nas lesões classificadas como A3 (14%), a sua indicação de tratamento não foi definida com unanimidade entre os observadores.Facultad de Ciencias Médica

Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests

Funding: Data collection was largely funded by the UK Natural Environment Research Council (NERC) project TREMOR (NE/N004655/1) to D.G., E.G. and O.P., with further funds from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES, finance code 001) to J.V.T. and a University of Leeds Climate Research Bursary Fund to J.V.T. D.G., E.G. and O.P. acknowledge further support from a NERC-funded consortium award (ARBOLES, NE/S011811/1). This paper is an outcome of J.V.T.’s doctoral thesis, which was sponsored by CAPES (GDE 99999.001293/2015-00). J.V.T. was previously supported by the NERC-funded ARBOLES project (NE/S011811/1) and is supported at present by the Swedish Research Council Vetenskapsrådet (grant no. 2019-03758 to R.M.). E.G., O.P. and D.G. acknowledge support from NERC-funded BIORED grant (NE/N012542/1). O.P. acknowledges support from an ERC Advanced Grant and a Royal Society Wolfson Research Merit Award. R.S.O. was supported by a CNPq productivity scholarship, the São Paulo Research Foundation (FAPESP-Microsoft 11/52072-0) and the US Department of Energy, project GoAmazon (FAPESP 2013/50531-2). M.M. acknowledges support from MINECO FUN2FUN (CGL2013-46808-R) and DRESS (CGL2017-89149-C2-1-R). C.S.-M., F.B.V. and P.R.L.B. were financed by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES, finance code 001). C.S.-M. received a scholarship from the Brazilian National Council for Scientific and Technological Development (CNPq 140353/2017-8) and CAPES (science without borders 88881.135316/2016-01). Y.M. acknowledges the Gordon and Betty Moore Foundation and ERC Advanced Investigator Grant (GEM-TRAITS, 321131) for supporting the Global Ecosystems Monitoring (GEM) network (gem.tropicalforests.ox.ac.uk), within which some of the field sites (KEN, TAM and ALP) are nested. The authors thank Brazil–USA Collaborative Research GoAmazon DOE-FAPESP-FAPEAM (FAPESP 2013/50533-5 to L.A.) and National Science Foundation (award DEB-1753973 to L. Alves). They thank Serrapilheira Serra-1709-18983 (to M.H.) and CNPq-PELD/POPA-441443/2016-8 (to L.G.) (P.I. Albertina Lima). They thank all the colleagues and grants mentioned elsewhere [8,36] that established, identified and measured the Amazon forest plots in the RAINFOR network analysed here. The authors particularly thank J. Lyod, S. Almeida, F. Brown, B. Vicenti, N. Silva and L. Alves. This work is an outcome approved Research Project no. 19 from ForestPlots.net, a collaborative initiative developed at the University of Leeds that unites researchers and the monitoring of their permanent plots from the world’s tropical forests [61]. The authros thank A. Levesley, K. Melgaço Ladvocat and G. Pickavance for ForestPlots.net management. They thank Y. Wang and J. Baker, respectively, for their help with the map and with the climatic data. The authors acknowledge the invaluable help of M. Brum for kindly providing the comparison of vulnerability curves based on PAD and on PLC shown in this manuscript. They thank J. Martinez-Vilalta for his comments on an early version of this manuscript. The authors also thank V. Hilares and the Asociación para la Investigación y Desarrollo Integral (AIDER, Puerto Maldonado, Peru); V. Saldaña and Instituto de Investigaciones de la Amazonía Peruana (IIAP) for local field campaign support in Peru; E. Chavez and Noel Kempff Natural History Museum for local field campaign support in Bolivia; ICMBio, INPA/NAPPA/LBA COOMFLONA (Cooperativa mista da Flona Tapajós) and T. I. Bragança-Marituba for the research support.Tropical forests face increasing climate risk1,2, yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for example, Ψ50) and hydraulic safety margins (for example, HSM50) are important predictors of drought-induced mortality risk3-5, little is known about how these vary across Earth's largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters Ψ50 and HSM50 vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both Ψ50 and HSM50 influence the biogeographical distribution of Amazon tree species. However, HSM50 was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM50 are gaining more biomass than are low HSM50 forests. We propose that this may be associated with a growth-mortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM50 in the Amazon6,7, with strong implications for the Amazon carbon sink.Publisher PDFPeer reviewe

Integrated global assessment of the natural forest carbon potential

Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system 1. Remote-sensing estimates to quantify carbon losses from global forests 2–5 are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced 6 and satellite-derived approaches 2,7,8 to evaluate the scale of the global forest carbon potential outside agricultural and urban lands. Despite regional variation, the predictions demonstrated remarkable consistency at a global scale, with only a 12% difference between the ground-sourced and satellite-derived estimates. At present, global forest carbon storage is markedly under the natural potential, with a total deficit of 226 Gt (model range = 151–363 Gt) in areas with low human footprint. Most (61%, 139 Gt C) of this potential is in areas with existing forests, in which ecosystem protection can allow forests to recover to maturity. The remaining 39% (87 Gt C) of potential lies in regions in which forests have been removed or fragmented. Although forests cannot be a substitute for emissions reductions, our results support the idea 2,3,9 that the conservation, restoration and sustainable management of diverse forests offer valuable contributions to meeting global climate and biodiversity targets

The global biogeography of tree leaf form and habit

Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17–34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling