On the Dirac equation with PT-symmetric potentials in the presence of position-dependent mass

The relativistic problem of fermions subject to a PT-symmetric potential in the presence of position-dependent mass is reinvestigated. The influence of the PT-symmetric potential in the continuity equation and in the orthonormalization condition are analyzed. In addition, a misconception diffused in the literature on the interaction of neutral fermions is clarified.Comment: 8 page

Avaliação do potencial das imagens dos Satélites Sentinel 2 na monitorização do cumprimento de alguns dos requisitos da PAC

A Política Agrícola Comum (PAC) é um sistema de ajudas e programas de apoio aos agricultores da União Europeia (UE). Para receber apoios no âmbito das medidas da PAC, cada agricultor deve, anualmente, submeter à autoridade nacional competente, em Portugal o Instituto de Financiamento da Agricultura e Pescas, I.P. (IFAP), um formulário com os dados referentes à sua exploração. Posteriormente estes dados são sujeitos a ações de controlo administrativo e em alguns casos a inspeções físicas no terreno. De acordo com as atuais regras da PAC, cada estado membro deve, segundo uma análise de risco, realizar uma série de inspeções físicas no terreno de modo a garantir que os critérios de elegibilidade e os compromissos assumidos são cumpridos. Com o objetivo de simplificar e modernizar a Política Agrícola Comum, a Comissão Europeia, em 22 de maio de 2018, adotou novas regras que permitem o uso dos dados dos satélites Sentinel do programa Copernicus, como evidência principal na verificação do cumprimentos de alguns dos requisitos das ajudas da PAC. Pretende-se que as evidências digitais obtidas remotamente reduzam significativamente o número de inspeções físicas no terreno, diminuindo os custos e a burocracia associada ao processo de controlo. Neste estudo é proposta uma abordagem que pretende avaliar o potencial dos dados das imagens do satélite Sentinel 2 para confirmar, com recurso a um índice de vegetação simples (NDVI, “Normalised Difference Vegetation Index”), a presença da cultura de milho numa amostra de parcelas fornecidas pelo IFAP. A confirmação no terreno da presença de um determinado tipo de cultura, é fundamental para concluir da elegibilidade dessas áreas a determinada ajuda ou regime de apoio. Os resultados obtidos demonstraram que a aplicação de uma metodologia hierárquica, priorizando numa primeira abordagem a utilização de um índice simples e fácil de aplicar (NDVI), pode permitir a confirmação da cultura presente e desta forma excluir com relativa segurança uma percentagem significativa de parcelas da amostra de controlo, reduzindo consideravelmente o número de inspeções físicas no terreno; EVALUATION OF THE SENTINEL 2 SATELLITE IMAGE POTENTIAL IN MONITORING COMPLIANCE WITH SOME OF THE CAP REQUIREMENTS. ABSTRACT: The Common Agricultural Policy (CAP) is a system of subsidies and support programs for farmers in the European Union (EU). In order to receive support under the CAP measures, each farmer must submit annually its declaration to the competent national authority, in Portugal the Instituto de Financiamento da Agricultura e Pescas, I.P. (IFAP). Subsequently these declarations are subject to administrative control actions and in some cases to field inspections. Under current CAP rules, each member state must, according to a risk analysis, conduct a series of physical checks on farms to ensure that the eligibility criteria and commitments are met. In order to simplify and modernize the Common Agricultural Policy, the European Commission on 22 May 2018 adopted new rules allowing the use of the data from the EU’s Copernicus Sentinel satellites, as main evidence when checking farmers’ fulfilment of requirements under the CAP payments. Is intended that evidences obtained by digital means will significantly reduce the number of field inspections, reducing costs and bureaucracy associated with the control process. This study proposes an approach that aims to assess the potential of Sentinel 2 satellite image data to confirm, using a standardized satellite index (NDVI), the presence of maize crop in a sample of parcels provided by IFAP. Confirmation on the field of the presence of a particular crop type is crucial for concluding the eligibility of these areas for a particular subsidy payment scheme. The results show that the application of a hierarchical methodology, prioritizing in the first approach the use of a simple and easy to apply index (NDVI), can allow the field confirmation of the crop type, and thus relatively safely exclude a significant percentage of plots of the sample control, considerably reducing the number of physical field inspections

S100B chaperone multimers suppress the formation of oligomers during Aβ42 aggregation

Extracellular aggregation of the amyloid-β 1–42 (Aβ42) peptide is a major hallmark of Alzheimer’s disease (AD), with recent data suggesting that Aβ intermediate oligomers (AβO) are more cytotoxic than mature amyloid fibrils. Understanding how chaperones harness such amyloid oligomers is critical toward establishing the mechanisms underlying regulation of proteostasis in the diseased brain. This includes S100B, an extracellular signaling Ca2+-binding protein which is increased in AD as a response to neuronal damage and whose holdase-type chaperone activity was recently unveiled. Driven by this evidence, we here investigate how different S100B chaperone multimers influence the formation of oligomers during Aβ42 fibrillation. Resorting to kinetic analysis coupled with simulation of AβO influx distributions, we establish that supra-stoichiometric ratios of dimeric S100B-Ca2+ drastically decrease Aβ42 oligomerization rate by 95% and AβO levels by 70% due to preferential inhibition of surface-catalyzed secondary nucleation, with a concomitant redirection of aggregation toward elongation. We also determined that sub-molar ratios of tetrameric apo-S100B decrease Aβ42 oligomerization influx down to 10%, while precluding both secondary nucleation and, more discreetly, fibril elongation. Coincidently, the mechanistic predictions comply with the independent screening of AβO using a combination of the thioflavin-T and X-34 fluorophores. Altogether, our findings illustrate that different S100B multimers act as complementary suppressors of Aβ42 oligomerization and aggregation, further underpinning their potential neuroprotective role in AD

Policy narratives of circular economy in the EU: assessing the embeddedness of water and land in national action plans

Following the challenges of the European Union (EU), member states have adopted circular economy (CE) plans and strategies, with objectives and measures to foster circularity. Although the concept of CE refers to various natural resources such as water and land, little is known on how current CE policies are integrating these environmental resources. This article assesses how water and land concerns are embedded in the EU CE action plans issued in 2015 and 2020 and a set of nine member states’ subse- quent national plans. The assessment used a content analysis based on two variables, the frequency of water and land’ related terms and the consistency of their inclusion within the plans. The findings reveal that neither water nor land emerge as major concerns in the CE plans, in comparison to materials or waste. Also, they are not consistently associated with the typical components of the plans namely problem-showcase, objectives, strategies and measures, stakeholders, and CE performance indicators. Nevertheless, the embeddedness of water is more evident in the plans of southern countries, whereas land concerns are much more erratic. If water and land concerns, are to be at the forefront of the transition to circularity, as the literature recommends, and if these plans are expected to offer an inte-grated approach of the CE concept, further efforts should be made to ensure their embeddednes.publishe

CHROMATOGRAPHIC, RHEOLOGICAL AND CYTOCHEMISTRY EVALUATION OF “BACURI” PULP (Platonia insignis MART.)

“Bacuri” pulp was evaluated for volatile compounds, rheological behavior, and cytochemical analysis. The pulp was also submitted to physicochemical characterization. The effect of temperature on rheological behavior of whole “bacuri” pulp was investigated in this work. The rheological measurements were carried out using a Brookfield Rheometer (Model DV-II +) at shear rate range from 0.25 to 1.50 s-1 at temperatures of 30, 40, 50, 60 and 70 °C. A total of 36 compounds were detected in the headspace of the “bacuri” pulp - 34 of which were identified. The major compounds were the following: linalool, cis-linalool, trans-linalool oxide, and hotrienol, respectively. The experimental data was adjusted using a power law rheological model, with good agreement. “Bacuri” pulp shows a non-Newtonian behavior, with an apparent viscosity decreasing with increasing temperature. The “bacuri” pulp obtained activation energy at shear rate 1.50 s-1 was -14.03 kJ/mol

Quasinormal Modes of Extremal BTZ Black Hole

Motivated by several pieces of evidence, in order to show that extreme black holes cannot be obtained as limits of non-extremal black holes, in this article we calculate explicitly quasinormal modes for Ba\~{n}ados, Teitelboim and Zanelli (BTZ) extremal black hole and we showed that the imaginary part of the frequency is zero. We obtain exact result for the scalar an fermionic perturbations. We also showed that the frequency is bounded from below for the existence of the normal modes (non-dissipative modes).Comment: 6 pp. Accepted Classical and Quantum Gravity. Typos corrected and some references was added. Final Versio

Mapping the Lisbon potential foodshed in Ribatejo e Oeste: a suitability and yeld model for assessing the potential for localized food production

ArticleResearch on food planning has been recently proposed in North American and European planning to account for how cities might change their food provision to respond to the rising demands for a more sustainable and ethical food system. The purpose of this paper was to evaluate the agro-ecological potential of the Lisbon city region, Ribatejo e Oeste, to increase its Regional Food Self-Reliance (RFSR), through adopting demand restraint and food system relocalization approaches to food system sustainability. Three new diet scenarios were considered: meat-based, plant-based and strict vegetarian, defined in accordance with healthy dietary patterns. We used agro-climatic and agro-edaphic agricultural suitability models to evaluate the agro-ecological potential for RFSR, and proposed the use of Foodshed Landscape Plans within a landscape planning methodology. Results showed the extent of local food production that could improve food self-reliance, with 72%, 76%, 84% of total food needs in the meat-based, plant-based, and strict vegetarian scenarios, respectively. Thus, food system transformation by means of relocalization, is therefore ecologically feasible and would ensure the sustainable use of the ecological basis of food security. Additionally, a dietary transition would imply significant land sparing, which strengthens the demand restraint perspective for a transition to food system sustainabilityinfo:eu-repo/semantics/publishedVersio

Quasinormal modes from potentials surrounding the charged dilaton black hole

We clarify the purely imaginary quasinormal frequencies of a massless scalar perturbation on the 3D charged-dilaton black holes. This case is quite interesting because the potential-step appears outside the event horizon similar to the case of the electromagnetic perturbations on the large Schwarzschild-AdS black holes. It turns out that the potential-step type provides the purely imaginary quasinormal frequencies, while the potential-barrier type gives the complex quasinormal modes.Comment: 19 pages, 8 figure