All-dielectric chiral metasurfaces based on crossed-bowtie nanoantennas

Circular dichroism spectroscopy is a technique used to discriminate molecular chirality, which is essential in fields like biology, chemistry, or pharmacology where different chiral agents often show different biological activities. Nevertheless, due to the inherently weak molecular-chiroptical activity, this technique is limited to high concentrations or large analyte volumes. Finding novel ways to enhance the circular dichroism would boost the performance of these techniques. So far, the enhancement of light?matter interaction mediated by plasmons is the most common way to develop chiral plasmonic structures with extraordinarily strong chiroptical responses. However, absorptive losses of metals at optical frequencies has hindered its practical use in many scenarios. In this work, we propose an all-dielectric low-loss chiral metasurface with unit cells built by high-refractive-index crossed-bowtie nanoantennas. These unit cells, built of silicon, strongly increase the chiroptical effect through the simultaneous interaction of their electric and magnetic modes, which in contrast to other recent proposals shows at the same time a high concentration of the electric field in its gap that leads to the presence of hotspots. The proposed structure exhibits a circular dichroism spectra up to 3-fold higher than that of previous proposals that use complex plasmonic or hybrid nanostructures, making it a clear alternative to develop low-loss metasurfaces with potential applications in chiral target sensing/biosensing. For completeness, single triangular shaped and symmetric (achiral) bowtie nanostructures were also studied as possible candidates for a detection up to the single-molecule level due the lack of a circular dichroism background of the nanostructures themselves.J.R.M.-S. acknowledges the financial support from the National Council for Scientific and Technological Development-CNPq (305958/2018-6, 429496/2018-4). F.R.G. thanks the financial support from the Colombian agency COLCIENCIAS. P.A. acknowledges funding from the Ramon y Cajal Fellowship RYC-2016-20831 and from Programa Viera y Clavijo de la Agencia Canaria de Investigacion, Innovacion y Sociedad de la Informacion (ACIISI). This work was also partially supported by RNP, with resources from MCTIC, Grant No. 01250.075413/2018-04, under the Radiocommunication Reference Center (Centro de Referência em Radiocomunicações -CRR) project of the National Institute of Telecommunications (Instituto Nacional de Telecomunicações Inatel), Brazil

Assessment of the wintering area of Red Knots in Maranhão, northern Brazil, in February 2005

To assess population size and the conservation status of the Red Knot Calidris canutus rufa population in Maranhão, N Brazil, an aerial census and field studies were conducted in February 2005. The aerial count showed a population of 7,575 Knots, which is down about 600 from a previous census in the 1980s. However, the count for all shorebird species combined was only 24,000 compared to 198,600 in the 1980s, paralleling a world-wide trend of population decline in shorebirds. Resightings of colour-banded knots confirmed that this is a separate population from the larger wintering population in Tierra del Fuego. All species of shorebirds captured in Maranhão were found to be infested with feather lice and mites. Body masses of knots in Maranhão were significantly lower than in Tierra del Fuego, and about half the birds were below the hypothesized fat-free mass of the species. Blood and feather samples were taken from 38 Knots for subsequent assessment of virus loads, and for detecting sites where primary feather moult had occurred. This will enable us to establish whether significant mortality is associated with pathogen loads and the energetic demands of delayed moulting. The small size of the Maranhão population and the loss of another 13,000 knots this winter from the Tierra del Fuego population means that both are now endangered. Brochures on the need for Red Knot conservation were designed and printed, and have been circulated among fishing communities and school classes in Maranhão.Fil: Baker,Allan J.. Royal Ontario Museum; CanadáFil: González, Patricia M.. Fundación Inalafquen; ArgentinaFil: Serrano, Ines L.. CEMAVE, Centro Nacional de Pesquisa para Conservação das Aves Silvestres; BrasilFil: Júnior, Wallace R. T.. CEMAVE, Centro Nacional de Pesquisa para Conservação das Aves Silvestres; BrasilFil: Efe, Marcio A.. Universidade Federal de Alagoas; BrasilFil: Rice, Susan. Eastern Shore of Virginia National Wildlife Refuge; Estados UnidosFil: D'amico, Veronica Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Rocha, Marcia C.. Belém, Pará; BrasilFil: Echave, María Eugenia. Fundación Inalafquen; Argentin

Sulfide-binding hemoglobins: Effects of mutations on active-site flexibility

The dynamics of Hemoglobin I (HbI) from the clam Lucina pectinata, from wild-type sperm whale (SW) myoglobin, and from the L29F/H64Q/V68F triple mutant of SW, both unligated and bound to hydrogen sulfide (H2S), have been studied in molecular dynamics simulations. Features that account for differences in H2S affinity among the three have been examined. Our results verify the existence of an unusual heme rocking motion in unligated HbI that can promote the entrance of large ligands such as H2S. The FQF-mutant partially reproduces the amplitude and relative orientation of the motion of HbI's heme group. Therefore, besides introducing favorable electrostatic interactions with H2S, the three mutations in the distal pocket change the dynamic properties of the heme group. The active-site residues Gln-64(E7), Phe-43(CD1), and His-93(F8) are also shown to be more flexible in unligated HbI than in FQF-mutant and SW. Further contributions to H2S affinity come from differences in hydrogen bonding between the heme propionate groups and nearby amino acid residues.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Sulfide-binding hemoglobins: Effects of mutations on active-site flexibility

The dynamics of Hemoglobin I (HbI) from the clam Lucina pectinata, from wild-type sperm whale (SW) myoglobin, and from the L29F/H64Q/V68F triple mutant of SW, both unligated and bound to hydrogen sulfide (H2S), have been studied in molecular dynamics simulations. Features that account for differences in H2S affinity among the three have been examined. Our results verify the existence of an unusual heme rocking motion in unligated HbI that can promote the entrance of large ligands such as H2S. The FQF-mutant partially reproduces the amplitude and relative orientation of the motion of HbI's heme group. Therefore, besides introducing favorable electrostatic interactions with H2S, the three mutations in the distal pocket change the dynamic properties of the heme group. The active-site residues Gln-64(E7), Phe-43(CD1), and His-93(F8) are also shown to be more flexible in unligated HbI than in FQF-mutant and SW. Further contributions to H2S affinity come from differences in hydrogen bonding between the heme propionate groups and nearby amino acid residues.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Percentage, bacterial etiology and antibiotic susceptibility of acute respiratory infection and pneumonia among children in rural Senegal

Acute respiratory infections (ARI) are still a major health problem in most developing countries. So far no study has evaluated the importance of childhood ARI in rural Senegal. We prospectively studied ARI, the percentage of pneumonia and related mortality, as well as the bacterial composition of nasopharyngeal flora using nasopharyngeal aspirates in 114 children, aged 2-59 months, presenting at Ndioum's pediatric ward. Excluded from the trial were those children that had had antimicrobial therapy in the previous 2 weeks. The Kirby-Bauer method was used to determine antibiotic resistance throughout the study. The percentage of ARI and pneumonia among the population tested was 24 per cent and 11 per cent respectively. Streptococcus pneumonia was often resistant to cotrimoxazole (31 per cent) but only 9 per cent were resistant to chloramphenicol and 14 per cent to penicillin. Haemophilus influenzae (HI) was uniformly sensitive to ampicillin, and only 4 per cent were resistant to chloramphenicol and 11 per cent to cotrimoxazole. We conclude that SP and HI resistance to cotrimoxazole is important and warrants larger clinical trials using chloramphenicol. Information campaigns and intense management of comorbidities are desirable in this type of population. Comorbidities (tuberculosis, malaria, HIV-AIDS, severe malnutrition) are determinant variables in many ARI cases and carry a high negative prognosis value

Isotopic evidence of strong reliance on animal foods and dietary heterogeneity among Early-Middle Neolithic communities of Iberia

Stable carbon and nitrogen isotope research on past populations in the Iberian Neolithic has emphasized the Atlantic and Mediterranean coasts. This study provides the first isotopic insights into the diet and subsistence economy of Early and Middle Neolithic populations from open-air sites in interior north-central Iberia. We present bone collagen carbon (?13C) and nitrogen (?15N) isotope ratios for 44 humans and 33 animals recovered from six cemeteries of the Ebro valley and the northern Iberian Plateau. The results obtained are consistent with the C3 terrestrial diets typical of other contemporary south-western European populations, but the spacing between human and herbivore values from Los Cascajos and Paternanbidea sites is higher than expected, and a significant positive correlation is identified between the ?13C and ?15N human values at both. Moreover, the results clearly differ from those of the Late Neolithic/Early Chalcolithic in the same region, which show significantly lower ?13C and ?15N values. These findings contribute to an understanding of the implementation of an agro-pastoral economy in interior Iberia, suggesting a stronger reliance on animal foods among the first Neolithic groups of inner Iberia than in subsequent periods as well as differential access to some resources (possibly suckling herbivores) in the diet, which may point to the existence of early social or economic inequalities that do not seem to be linked to age and sex parameters or to mortuary treatment.This research was funded by the Basque Government (POS_2013_1_147; POS_2014_2_24; POS_2015_2_ 0001) and the Spanish Ministry of Economy and Competitiveness (project ‘Coastal societies in a changing world: A diachronic and comparative approach to the Prehistory of SWEurope from the late Palaeolithic to the Neolithic (CoChange)’ (HAR2014-51830-P)). The study has also been supported by a Newton International Fellowship funded by the British Academy (NF170854); the Basque Government (IT542/10); the University of the Basque Country (UPV/EHU) (UFI11/09); and the Spanish Ministry of Science and Innovation (projects ‘Los Caminos del Neolítico’ (HAR2009-09027) and ‘Los Caminos del Neolítico II’ (HAR2013-46800-P))

Struvite precipitation in wastewater treatment plants anaerobic digestion supernatants using a magnesium oxide by-product

Struvite precipitation is a well-known technology to recover and upcycle phosphorus from municipal wastewater as a slow-release fertiliser. However, the economic and environmental costs of struvite precipitation are constrained by using technical-grade reagents as a magnesium source. This research evaluates the feasibility of using a low-grade magnesium oxide (LG-MgO) by-product from the calcination of magnesite as a magnesium source to precipitate struvite from anaerobic digestion supernatants in wastewater treatment plants. Three distinct LG-MgOs were used in this research to capture the inherent variability of this by-product. The MgO content of the LG-MgOs varied from 42 % to 56 %, which governed the reactivity of the by-product. Experimental results showed that dosing LG-MgO at P:Mg molar ratio close to stoichiometry (i.e. 1:1 and 1:2) favoured struvite precipitation, whereas higher molar ratios (i.e. 1:4, 1:6 and 1:8) favoured calcium phosphate precipitation due to the higher calcium concentration and pH. At a P:Mg molar ratio of 1:1 and 1:2, the percentage of phosphate precipitated was 53-72 % and 89-97 %, respectively, depending on the LG-MgO reactivity. A final experiment was performed to examine the composition and morphology of the precipitate obtained under the most favourable conditions, which showed that (i) struvite was the mineral phase with the highest peaks intensity and (ii) struvite was present in two different shapes: hopper and polyhedral. Overall, this research has demonstrated that LG-MgO is an efficient source of magnesium for struvite precipitation, which fits the circular economy principles by valorising an industrial by-product, reducing the pressure on natural resources, and developing a more sustainable technology for phosphorus recovery

Valorization of kiwi agricultural waste and industry by-products by recovering bioactive compounds and applications as food additives: a circular economy model

Currently, agricultural production generates large amounts of organic waste, both from the maintenance of farms and crops (agricultural wastes) and from the industrialization of the product (food industry waste). In the case of Actinidia cultivation, agricultural waste groups together leaves, flowers, stems and roots while food industry by-products are represented by discarded fruits, skin and seeds. All these matrices are now underexploited and so, they can be revalued as a natural source of ingredients to be applied in food, cosmetic or pharmaceutical industries. Kiwifruit composition (phenolic compounds, volatile compounds, vitamins, minerals, dietary fiber, etc.) is an outstanding basis, especially for its high content in vitamin C and phenolic compounds. These compounds possess antioxidant, anti-inflammatory or antimicrobial activities, among other beneficial properties for health, but stand out for their digestive enhancement and prebiotic role. Although the biological properties of kiwi fruit have been analyzed, few studies show the high content of compounds with biological functions present in these by-products. Therefore, agricultural and food industry wastes derived from processing kiwi are regarded as useful matrices for the development of innovative applications in the food (pectins, softeners, milk coagulants, and colorants), cosmetic (ecological pigments) and pharmaceutical industry (fortified, functional, nutraceutical, or prebiotic foods). This strategy will provide economic and environmental benefits, turning this industry into a sustainable and environmentally friendly production system, promoting a circular and sustainable economy.The research leading to these results was supported by MICINN supporting the Ramón y Cajal grant for M.A. Prieto (RYC-2017-22891); by Xunta de Galicia for supporting the program EXCELENCIA-ED431F 2020/12, the post-doctoral grant of M. Fraga-Corral (ED481B-2019/096), the pre-doctoral grant of M. Carpena (ED481A 2021/313), the program BENEFICIOS DO CONSUMO DAS ESPECIES TINTORERA-(CO-0019-2021) that supports the work of F. Chamorro and by the program Grupos de Referencia Competitiva (GRUPO AA1-GRC 2018) that supports the work of J. Echave. Authors are grateful to Ibero-American Program on Science and Technology (CYTED—AQUA-CIBUS, P317RT0003), to the Bio Based Industries Joint Undertaking (JU) under grant agreement No 888003 UP4HEALTH Project (H2020-BBI-JTI-2019). The JU receives support from the European Union’s Horizon 2020 research and innovation program and the Bio Based Industries Consortium. The project SYSTEMIC Knowledge hub on Nutrition and Food Security, has received funding from national research funding parties in Belgium (FWO), France (INRA), Germany (BLE), Italy (MIPAAF), Latvia (IZM), Norway (RCN), Portugal (FCT), and Spain (AEI) in a joint action of JPI HDHL, JPI-OCEANS and FACCE-JPI launched in 2019 under the ERA-NET ERA-HDHL (n° 696295). Funding for open access charge: Universidade de Vigo/CISUG.info:eu-repo/semantics/publishedVersio

Transparència, publicitat, rendició de comptes i govern obert aplicades a una administració tributària del segle XXI

Aquest document és fruit d'una recerca promoguda a partir de la subvenció a treballs de recerca sobre l'Administració pública de l'Escola d'Administració Pública de Catalunya (resolució GRI/2711/2014, de 21 de novembre), i ha estat sotmès a una avaluació externa que n'ha validat el contingut i n'ha recomanat la publicació

Sulfide-binding hemoglobins: Effects of mutations on active-site flexibility

The dynamics of Hemoglobin I (HbI) from the clam Lucina pectinata, from wild-type sperm whale (SW) myoglobin, and from the L29F/H64Q/V68F triple mutant of SW, both unligated and bound to hydrogen sulfide (H2S), have been studied in molecular dynamics simulations. Features that account for differences in H2S affinity among the three have been examined. Our results verify the existence of an unusual heme rocking motion in unligated HbI that can promote the entrance of large ligands such as H2S. The FQF-mutant partially reproduces the amplitude and relative orientation of the motion of HbI's heme group. Therefore, besides introducing favorable electrostatic interactions with H2S, the three mutations in the distal pocket change the dynamic properties of the heme group. The active-site residues Gln-64(E7), Phe-43(CD1), and His-93(F8) are also shown to be more flexible in unligated HbI than in FQF-mutant and SW. Further contributions to H2S affinity come from differences in hydrogen bonding between the heme propionate groups and nearby amino acid residues.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada