The future of coffee and cocoa agroforestry in a warmer Mesoamerica

Climate change threatens cofee production and the livelihoods of thousands of families in Mesoamerica that depend on it. Replacing cofee with cocoa and integrating trees in combined agroforestry systems to ameliorate abiotic stress are among the proposed alternatives to overcome this challenge. These two alternatives do not consider the vulnerability of cocoa and tree species commonly used in agroforestry plantations to future climate conditions. We assessed the suitability of these alternatives by identifying the potential changes in the distribution of cofee, cocoa and the 100 most common agroforestry trees found in Mesoamerica. Here we show that cocoa could potentially become an alternative in most of cofee vulnerable areas. Agroforestry with currently preferred tree species is highly vulnerable to future climate change. Transforming agroforestry systems by changing tree species composition may be the best approach to adapt most of the cofee and cocoa production areas. Our results stress the urgency for land use planning considering climate change efects and to assess new combinations of agroforestry species in cofee and cocoa plantations in Mesoamerica

Bose-Glass behaviour in Bi_{2}Sr_{2}Ca_{1-x}Y_{x}Cu_{2}O_{8} crystals with columnar defects: experimental evidence for variable-range hopping

We report on vortex transport in Bi_{2}Sr_{2}Ca_{1-x}Y_{x}Cu_{2}O_{8} crystals irradiated at different doses of heavy ions. We show evidence of a flux-creep resistivity typical of a variable-range vortex hopping mechanism as predicted by Nelson and Vinokur.Comment: 5 pages LaTeX2e (uses elsart.cls), 1 Encapsulated PostScript figur

Comparison between two common methods for measuring Giardia lamblia susceptibility to antiparasitic drugs in vitro

In this study a comparison between two different methods for measuring the susceptibility of Giardia lamblia trophozoites to metronidazole and albendazole is performed. Modifications of Meloni’s method, based on the loss of adherence of parasites to surfaces, and the Hill method, based on the loss of parasite division capacity, are compared. A logistic model was used to calculate the inhibitory concentrations IC10, IC50 and IC90 that were further compared using the respective standard errors. The results obtained, after contact of parasites with the antiparasitic drugs for 24 h, show that the adherence method is more sensitive than the multiplication method for low and moderate inhibitory concentrations of albendazole. Conversely for metronidazole the multiplication method seems to be more sensitive for high inhibitory concentrations of the drug. For screening the IC50, both methods seem to be effective, however, the inhibition of adherence method have even better performance for the benzimidazole like drugs.info:eu-repo/semantics/publishedVersio

The Safe-Port project: an approach to port surveillance and protection

SAFE-PORT is a recently started project addressing the complex issue of determining the best configurations of resources for harbour and port surveillance and protection. More specifically, the main goal is to find, for any given scenario, an adequate set of configuration solutions — i.e., number and type of sensors and equipments, their locations and operating modes, the corresponding personnel and other support resources — that maximize protection over a specific area. The project includes research and development of sensors models, novel algorithms for optimization and decision support, and a computer-based decision support system (DSS) to assist decision makers in that task. It includes also the development of a simulation environment for modelling relevant aspects of the scenario (including sensors used for surveillance, platforms, threats and the environment), capable to incorporate data from field-trials, used to test and validate solutions proposed by the DSS. Test cases will consider the use of intelligent agents to model the behaviour of threats and of NATO forces in a realistic way, following experts’ definitions and parameters

EPISYNC study : Predictors of patient-ventilator asynchrony in a prospective cohort of patients under invasive mechanical ventilation - Study protocol

Funding: The Episync study is supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), grant number 2015/19122-4.Introduction: Patient-ventilator asynchrony is common during the entire period of invasive mechanical ventilation (MV) and is associated with worse clinical outcomes. However, risk factors associated with asynchrony are not completely understood. The main objectives of this study are to estimate the incidence of asynchrony during invasive MV and its association with respiratory mechanics and other baseline patient characteristics. Methods and analysis: We designed a prospective cohort study of patients admitted to the intensive care unit (ICU) of a university hospital. Inclusion criteria are adult patients under invasive MV initiated for less than 72 hours, and with expectation of remaining under MV for more than 24 hours. Exclusion criteria are high flow bronchopleural fistula, inability to measure respiratory mechanics and previous tracheostomy. Baseline assessment includes clinical characteristics of patients at ICU admission, including severity of illness, reason for initiation of MV, and measurement of static mechanics of the respiratory system. We will capture ventilator waveforms during the entire MV period that will be analysed with dedicated software (Better Care, Barcelona, Spain), which automatically identifies several types of asynchrony and calculates the asynchrony index (AI). We will use a linear regression model to identify risk factors associated with AI. To assess the relationship between survival and AI we will use Kaplan-Meier curves, log rank tests and Cox regression. The calculated sample size is 103 patients. The statistical analysis will be performed by the software R Programming (www.R-project.org) and will be considered statistically significant if the p value is less than 0.05. Ethics and dissemination: The study was approved by the Ethics Committee of Instituto do Coração, School of Medicine, University of São Paulo, Brazil, and informed consent was waived due to the observational nature of the study. We aim to disseminate the study findings through peer-reviewed publications and national and international conference presentations. Trial registration number: NCT02687802; Pre-results

A proposed bidirectional three-level DC-DC power converter for applications in smart grids: an experimental validation

The integration of renewable energy sources (RES), energy storage systems (ESS), and electric mobility into smart grids requires the use of DC-DC back-end power converters for adjusting voltage levels. Although a DC-DC converter applied for RES only operates in unidirectional mode, when applied to ESS or EM, the bidirectional mode is a fundamental requisite for exchanging power with the electrical power grid. In this context, this paper presents an experimental validation of a proposed bidirectional three-level DC-DC converter considering its application for smart grids. Traditionally, the DC-DC power converters of such applications are two-level converters. However, by employing a three-level topology, it is possible to improve the quality of the variables controlled by the power converter. Moreover, since the proposed DC-DC converter is controlled to produce a controlled current, the proposed current control and modulation strategies are introduced and described. A complete analysis of the operation principle of the proposed bidirectional three-level DC-DC power converter is presented, supported by experimental validation, employing a laboratory prototype.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work has been supported by FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017, and by the FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by FCT

New petrographic, geochemical and isotopic data on the Boa Fé gold prospect (Montemor-o-Novo, Ossa-Morena Zone)

A área de estudo situa-se na Zona de Cisalhamento de Montemor-o-Novo (Maciço de Évora, Zona de Ossa-Morena - ZOM). O trabalho incidiu sobre amostras de metassedimentos e metabasitos da Série Negra (Ediacarano), bem como de granitos tardi-variscos. Os metassedimentos vão de micaxistos a paragnaisses evidenciando a associação mineral de pico metamórfico constituída por Qz+Pl+Bt+Ms+Opq±Tur±Sil±Crd+Zrn. Os metabasitos são anfibolitos incorporando Pl+Hbl+Qz+Mag+Ilm±Bt. Quer nos metassedimentos quer nos metabasitos, existem testemunhos de duas fases de deformação importantes, sendo uma xistosidade de crenulação a estrutura mais penetrativa. Estas duas fases de deformação deverão corresponder a D1 e D2 Variscas previamente reconhecidas no autóctone da ZOM. Ocorreu ainda deformação posterior, testemunhada por kinks e processos de subgranulação e recristalização dinâmica afetando alguns grãos minerais em domínios confinados às proximidades imediatas de zonas de falha tardias, a qual deverá relacionar-se com a fase D3. Os granitos tardi-variscos são fortemente peraluminosos, tendo como minerais mais abundantes quartzo, microclina, plagioclase sódica e moscovite. Como acessórios ocorrem biotite, zircão, apatite, opacos, turmalina e silimanite. Em termos isotópicos, os valores de εSr320Ma variam entre +93 e +182, enquanto a gama de valores para εND320Ma se distribui no intervalo -6.7 a -9.0, sugerindo importante contributo via anatexia dos metassedimentos da Série Negra na génese dos magmas que deram origem aos granitos tardi-variscos.The study area is located within the Montemor-o-Novo Shear Zone (Évora Massif, Ossa-Morena Zone - OMZ). The analysed samples represent metasediments and metabasites of the Série Negra lithostratigraphic unit (Ediacaran), besides late-Variscan granites. The metasediments are micaschists to paragneisses displaying the peak metamorphic mineral assemblage Qz+Pl+Bt+Ms+Opq±Tur±Sil±Crd+Zrn. The metabasites are amphibolites comprising Pl+Hbl+Qz+Mag+Ilm±Bt. Microstructures observed in both types of metamorphic rocks document two major ductile deformation phases. The most penetrative tectonic anisotropy is a crenulation schistosity. These major deformation phases should correspond to the Variscan D1 and D2, previously recognized in the autochthon of the OMZ. There is also evidence for a later deformation phase, likely related to the D3 Variscan: some grains, in narrow domains adjoining late fault zones, show kinks or are affected by dynamic subgranulation and recrystallization. The studied late-Variscan granites are strongly peraluminous, and have quartz, microcline, Na-plagioclase and muscovite as prime minerals. Biotite, zircon, apatite, opaques,tourmaline and sillimanite occur as accessory phases. Considering the available isotope geochemistry data, εSr320Ma varies between +93 and +182, while εND320Ma values are scattered in the -6.7 to -9.0 range. These data suggest a strong involvement of anatexis products derived from the Série Negra metasediments in the genesis of the granitic magmas

Sliding mode control of an innovative single-switch three-level active rectifier

This paper presents the sliding mode control (SMC) applied to an innovative active rectifier. This proposed active rectifier is constituted by a single-switch, and operates with three voltage levels, evidencing a set of advantages when compared with conventional approaches of power factor correction topologies. Taking into account the diversity of applications for this type of power converter, the SMC is used in order to obtain a robust current tracking. Since the active rectifier is controlled according to the ac grid-side current, the error between such current and its reference is determined, and by employing the SMC, this error is minimized during each sampling period with the objective of selecting the state of the single-switch. A comprehensive description about the SMC implementation, supported by the overall operation of the active rectifier, is presented throughout the paper. The obtained computational results for a set of different operating conditions, comprising significant power ranges and sudden variations, confirm the accurate application of the SMC when applied to the proposed single-switch three-level active rectifier. A comparison is also established with other current control, allowing to confirm the precise application of the SMC strategy.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work has been supported by FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017, and by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by FCT

A novel multilevel converter for on-grid interface of renewable energy sources in smart grids

The on-grid interface of renewable energy sources involves a dc-ac converter for controlling the injected current. In this perspective, a novel topology of grid-tied converter is proposed, assuming as main feature the produced multilevel voltages (five-levels). The proposed grid-tied converter is intended for on-grid interfaces, which is controlled for guaranteeing sinusoidal currents for all grid voltage conditions. The dc-side can be linked directly to a dc-to-dc intermediary converter, responsible for interfacing renewable energy sources, as solar photovoltaic or wind power systems. Throughout the paper, a complete examination of the operation principle and the adopted control theory, including current control, as well as hardware project, are comprehensively presented. An accurate computational simulation validation is presented, comprising realistic operating conditions in terms of grid voltage disturbances and operating power. The obtained results prove the advantages of the proposed grid-tied multilevel converter, and establish a comparison with the classical solutions.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work has been supported by FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017, and by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by FCT

Fermions in three-dimensional spinfoam quantum gravity

We study the coupling of massive fermions to the quantum mechanical dynamics of spacetime emerging from the spinfoam approach in three dimensions. We first recall the classical theory before constructing a spinfoam model of quantum gravity coupled to spinors. The technique used is based on a finite expansion in inverse fermion masses leading to the computation of the vacuum to vacuum transition amplitude of the theory. The path integral is derived as a sum over closed fermionic loops wrapping around the spinfoam. The effects of quantum torsion are realised as a modification of the intertwining operators assigned to the edges of the two-complex, in accordance with loop quantum gravity. The creation of non-trivial curvature is modelled by a modification of the pure gravity vertex amplitudes. The appendix contains a review of the geometrical and algebraic structures underlying the classical coupling of fermions to three dimensional gravity.Comment: 40 pages, 3 figures, version accepted for publication in GER