Rare earth elements, iron and manganese in ochre-precipitates and wetland soils of a passive treatment system for acid mine drainage

The rare earth elements (REE) along with iron and manganese distribution in ochre-precipitates and wetland soils in a passive system for acid mine drainage treatment (Jales, Portugal) was studied. The results obtained by instrumental neutron activation analysis showed a higher incorporation of the light REE (particularly La and Ce) by the ochre-precipitates resulting from the mine water-limestone interaction. These fluffy materials influence the entrance of the first wetland where a correlation between Fe and La and Ce was found. Then Mn phases appear to play a more important role controlling REE distribution in the remaining area of the wetland soils.Thanks to EDM (Empresa de Desenvolvimento Mineiro, S.A.) for providing access to the water treatment plant, and to the staff of the Portuguese Research Reactor (RPI) of CTN/IST. C2TN authors gratefully acknowledge the FCT (the Portuguese Science and Technology Foundation) support through the UID/Multi/04349/2013. This work is co-funded by European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Internacionalização), project ICT (UID/GEO/04683/2013) with reference POCI-01-0145-FEDER-007690 and national funds provided by FCT.info:eu-repo/semantics/publishedVersio

Metalaxyl-M, phosphorous acid and potassium silicate applied as soil drenches show different chestnut seedling performance and protection against Phytophthora root rot

The application as soil drenches of three commercial products containing metalaxyl, phosphorous acid or potassium silicate, were studied as a means of controlling Phytophthora in chestnut (Castanea sativa Mill.) seedlings. In the metalaxyl treatment no plant deaths were recorded, whereas with the phosphorous acid and potassium silicate applications, and in the untreated control, the mortality rate was respectively 33.3, 44.4 and 77.8%. The presence of Phytophthora was detected in plants and soils at the end of the experiment which means that the three products did not eliminate the pathogen, and that they only gave temporary protection to the plant. In the treatments receiving metalaxyl or phosphorous acid, the plants showed a sharp drop in growth compared to the surviving plants of the control. Soil analyses revealed a high increase in exchangeable acidity, a high reduction in pH and a high increase in Mn levels in the soils treated with the products containing metalaxyl or phosphorous acid. In these treatments, elemental tissue analysis and nutrient recovery by plants revealed Mn levels far above the upper limit of the sufficiency range, with the toxicity of Mn being the suspected cause for the strong reduction in plant growth. These results indicate that when applying such products to the soil, their concentration and/or their ability to influence the soil pH should be evaluated and adequate measures of pH adjustment undertaken. In the case of phosphorous acid, its use can be replaced by phosphite salts. K-silicate did not show adverse effects on plant growth but provided less protection against Phytophthora than metalaxyl or phosphorous acid.This research was funded by the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UIDB/00690/2020). The research was integrated in the activities of the Operational Group EGIS – Estratégias de Gestão Integrada do Solo e da Água em Espécies Produtoras de Frutos Secos, and Operational Group Biochetnut IPM, funded by PT2020 and EAFRD (European Agricultural Fund for Rural Development).info:eu-repo/semantics/publishedVersio

Nitrogen fertilization can significantly reduce the incidence of the olive fruit fly

The olive fruit fly (Bactrocera oleae Rossi) is one of the most important pests of the olive groves. Its negative impact is manifested by yield reduction, due to the consumption of pulp by larvae and increased fruit drop, and loss of quality of the oil, due to oxidation phenomena. All cropping techniques that reduce the incidence of this pest are able to contribute to increase crop yield and improve olive oil quality and help reducing pesticide use. Nitrogen fertilization can greatly influence the development of the canopy and the productivity of the olive tree, although little is known about the effect of nitrogen fertilization on the incidence of this pest. Two field trials were conducted in rainfed olive groves during the years 2017 and 2018, one of the cultivar Madural and the other of the cv. Cobrançosa. Three (0, 40 and 120 kg N ha-1) and four (0, 20, 40 and 120 kg N ha-1) nitrogen rates were tested respectively in 'Madural' and 'Cobrançosa'. The results showed a very significant reduction in the level of pest incidence as the nitrogen rate increased, with the exception of 'Madural' in 2017, a year in which productivity was low as well as the overall level of pest incidence. In 2018, incidence levels varied between 60.7 and 12.7%, respectively in the N0 and N120 treatments in 'Cobrançosa' and between 70.7 and 46.7% in the treatments N0 and N120 in 'Madural'. The most fertilized treatments showed significantly higher yields in both cultivars in 2018, with the higher fruit load inducing increased water stress, with more wrinkled fruits at the beginning of autumn, and delays in maturation. Probably these were the causes which may justify the lower incidence of the pest in the treatments fertilized with the higher nitrogen rates.projet “BioSave: Promoção do potencial económico e da sustentabilidade dos setores do azeite e da castanha “Concurso nº 02/SAICT/2016”, projeto nº 023721.info:eu-repo/semantics/publishedVersio

The effect of nitrogen fertilization on the incidence of olive fruit fly, olive leaf spot and olive anthracnose in two olive cultivars grown in rainfed conditions

Pests and diseases can cause significant loss of olive yield and/or justify control measures with pesticides which are harmful to the environment. Several agroecological variables, such as fertilization, can favour or limit the incidence of pests and diseases. However, in olive, few studies exist on the subject than can assist in the implementation of more sustainable phytosanitary measures. In this study the effect of nitrogen fertilization (0, 20, 40 and 120 kg N ha−1) on the incidence of olive fruit fly (Bactrocera oleae), olive leaf spot (Spilocaea oleaginea) and olive anthracnose (Colletotrichum gloeosporioides) was evaluated in two olive orchards of the cultivars ‘Cobrançosa’ and ‘Madural’. The study took place in 2017 and 2018 in Lombo, NE Portugal. Nitrogen fertilization significantly increased olive yield and nitrogen concentrations in plant tissues and induced a delay in fruit maturity. The incidence of the olive fruit fly was significantly lower in the more fertilized treatments of both cultivars. However, ‘Madural’ showed itself to be more susceptible than ‘Cobrançosa’ to olive fruit fly. The effect of nitrogen on the reduction of the incidence of the olive fruit fly was attributed to the delay caused in fruit maturation, which might have desynchronized the attractiveness of the fruits for insects to lay their eggs on their flight curve. In contrast, olive leaf spot and olive anthracnose were not influenced by nitrogen fertilization. As a result, nutrient management in olive groves must balance carefully the requirements of economic rationality with environmental preservation, particularly with regard to the harmful relationship between the use of excessive nitrogen rates and several adverse environmental effects.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and European Agricultural Fund for Rural Development (EAFRD) under the Programme PT2020 for financial support to Centro de Investigação de Montanha, CIMO (UID/AGR/00690/2015) and Project 023721 (02/SAICT/2016) “BioSave: Promoção do potencial económico e da sustentabilidade dos setores do azeite e da castanha”.info:eu-repo/semantics/publishedVersio

Antiresonant hollow core fiber with an octave spanning bandwidth for short haul data communications

We report an effectively single mode tubular antiresonant hollow core fiber with minimum loss of ~25 dB/km at ~1200 nm, and an extremely wide low loss transmission window (lower than 30 dB/km loss from 1000 nm to 1400 nm and 6 dB bandwidth exceeding 1000 nm). Despite the relatively large mode field diameter of 32 µm, the fiber can be interfaced to SMF28 to produce fully connectorized samples. Exploiting an excellent modal purity arising from large modal differential loss and low intermodal coupling, we demonstrate penalty-free 10G on-off keying data transmission through 100m of fiber, at wavelengths of 1065, 1565 and 1963nm

Theory and Applications of Non-Relativistic and Relativistic Turbulent Reconnection

Realistic astrophysical environments are turbulent due to the extremely high Reynolds numbers. Therefore, the theories of reconnection intended for describing astrophysical reconnection should not ignore the effects of turbulence on magnetic reconnection. Turbulence is known to change the nature of many physical processes dramatically and in this review we claim that magnetic reconnection is not an exception. We stress that not only astrophysical turbulence is ubiquitous, but also magnetic reconnection itself induces turbulence. Thus turbulence must be accounted for in any realistic astrophysical reconnection setup. We argue that due to the similarities of MHD turbulence in relativistic and non-relativistic cases the theory of magnetic reconnection developed for the non-relativistic case can be extended to the relativistic case and we provide numerical simulations that support this conjecture. We also provide quantitative comparisons of the theoretical predictions and results of numerical experiments, including the situations when turbulent reconnection is self-driven, i.e. the turbulence in the system is generated by the reconnection process itself. We show how turbulent reconnection entails the violation of magnetic flux freezing, the conclusion that has really far reaching consequences for many realistically turbulent astrophysical environments. In addition, we consider observational testing of turbulent reconnection as well as numerous implications of the theory. The former includes the Sun and solar wind reconnection, while the latter include the process of reconnection diffusion induced by turbulent reconnection, the acceleration of energetic particles, bursts of turbulent reconnection related to black hole sources as well as gamma ray bursts. Finally, we explain why turbulent reconnection cannot be explained by turbulent resistivity or derived through the mean field approach.Comment: 66 pages, 24 figures, a chapter of the book "Magnetic Reconnection - Concepts and Applications", editors W. Gonzalez, E. N. Parke

A Midsummer Night's Dream

A simple, economic, highly sensitive and highly selective method for the detection of caffeine has been developed at bare and Nafion-modified glassy carbon electrodes (GCE). The electrochemical behaviour of caffeine was examined in electrolyte solutions of phosphate buffer saline, sodium perchlorate, and in choline chloride plus oxalic acid, using analytical determinations by fixed potential amperometry, phosphate buffer saline being the best. Modifications of the GCE surface with poly(3,4-ethylenedioxythiophene) (PEDOT), Nafion, and multi-walled carbon nanotubes were tested in order to evaluate possible sensor performance enhancements, Nafion giving the most satisfactory results. The effect of interfering compounds usually found in samples containing caffeine was examined at GCE without and with Nafion coating, to exclude interferences, and the sensors were successfully applied to determine the caffeine content in commercial beverages and drugs

Aedes species (Diptera: Culicidae) ecological and host feeding patterns in the north-eastern parts of South Africa, 2014–2018

BACKGROUND: There is a paucity of recent data and knowledge on mosquito diversity and potential vectors of arboviruses in South Africa, with most of the available data dating back to the 1950s–1970s. Aedes and Culex species are the major vectors of some of the principal arboviruses which have emerged and re-emerged in the past few decades. METHODS: In this study we used entomological surveillance in selected areas in the north-eastern parts of South Africa from 2014 to 2018 to assess mosquito diversity, with special emphasis on the Aedes species. The impact of trap types and environmental conditions was also investigated. Identifcation of the blood meal sources of engorged females collected during the study period was carried out, and DNA barcodes were generated for selected species. RESULTS: Overall, 18.5% of the total Culicidae mosquitoes collected belonged to the genus Aedes, with 14 species recognised or suspected vectors of arboviruses. Species belonging to the Neomelaniconion subgenus were commonly collected in the Bushveld savanna at conservation areas, especially Aedes mcintoshi and Aedes circumluteolus. Aedes aegypti was present in all sites, albeit in low numbers. Temperature was a limiting factor for the Aedes population, and they were almost exclusively collected at temperatures between 18 °C and 27 °C. The cytochrome oxidase subunit I (COI) barcode fragment was amplifed for 21 Aedes species, and for nine of these species it was the frst sequence information uploaded on GenBank. CONCLUSION: This study provides a better understanding of the diversity and relative abundance of Aedes species in the north-east of South Africa. The information provided here will contribute to future arboviral research and implementation of efcient vector control and prevention strategies.The Centers for Disease Control and Preventionhttp://www.parasitesandvectors.compm2022Medical VirologyUP Centre for Sustainable Malaria Control (UP CSMC

Poly(neutral red) based hydrogen peroxide biosensor for chromium determination by inhibition measurements

Amperometric hydrogen peroxide enzyme inhibition biosensors based on horseradish peroxidase (HRP) immobilised on electropolymerised neutral red (NR) or directly on the surface of carbon film electrodes (CFE) have been successfully applied to the determination of toxic Cr(III) and Cr(VI). Parameters influencing the performance of the biosensor including the enzyme immobilisation method, the amount of hydrogen peroxide, applied potential and electrolyte pH were optimised. The inhibition of horseradish peroxidase by the chromium species was studied under the optimised conditions. Results from the quantitative analysis of chromium ions are discussed in terms of detection limit, linear range and sensitivity. The HRP kinetic interactions reveal mixed binding of Cr(III) with I50 = 3.8 μM and inhibition binding constant Ki = 11.3 μM at HRP/PNR/CFE biosensors and uncompetitive binding of Cr(VI) with I50 = 3.9 μM and Ki = 0.78 μM at HRP/CFE biosensors in the presence of H2O2 substrate. Interferences from other heavy metal ions were studied and the inhibition show very good selectivity towards Cr(III) and Cr(VI)

Tranfer+.Tec. Castanha

O Projeto “Tranfer+.Tec.Castanha” tem como objetivo central o dinamizar o ecossistema regional de inovação e estimular a transferência de tecnologia e de conhecimento da fileira da Castanha, para o setor empresarial da região, nacional e internacional, com vista ao desenvolvimento de novos produtos e ao desenvolvimento de projetos de transferência e utilização de conhecimento. Foram definidas seis ações e 19 atividades específicas. As ações são: 1 - Levantamento de Necessidades de Tecnologia e Conhecimento das empresas da fileira da Castanha; 2 - Disseminação e de difusão de novos conhecimentos e tecnologias geradas no âmbito da I&D, através de ações setoriais de experimentação, no domínio das pragas e doenças do castanheiro; 3 - Interação com o ambiente empresarial, para a sensibilização, partilha e mapeamento de oportunidades de desenvolvimento de tecnologias e conhecimentos na fileira da Castanha e criação de comunidades de inovação; 4 - Valorização económica dos resultados da investigação; 5 - Iniciativas de interação com o ambiente empresarial para a promoção nacional e internacional de tecnologias e de conhecimento; 6 - Promoção e divulgação do projeto. Será apresentado um balanço das atividades já realizadas e a realizar no próximo ano.Projeto “Tranfer+.Tec.Castanha: Reforço da transferência de conhecimento científico e tecnológico da fileira da castanha para o setor empresarial. NORTE 2020info:eu-repo/semantics/publishedVersio