2,802 research outputs found

    Effects of historical land-use change in the Mediterranean environment

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    During the Holocene (last ~11,700 years), societies have continuously modified the landscape of the Mediterranean Basin through changes in land-use, exerting extraordinary pressures onto the environment and adding variability to the climate. Despite its importance to current land management, knowledge of how past land-use practices have impacted the regional climate of the Basin remains largely in the scientific sphere. Thereby, this work aims to inform non-scientific actors and practitioners about the environmental effects of past land-use changes on the hydrologic cycle of the Mediterranean Basin. For this purpose we: i) summarize fundamental observed interactions between land-use change and the environment, identified through a semi-systematic review of 23 scientific case-studies from around the Basin; ii) reflect on the consequences to the Mediterranean environment (atmosphere, biosphere, lithosphere, and hydrosphere) in a synthesized and integrated way; iii) argue the need for taking into account the impact of local land-use practices from a regional-scale perspective; iv) highlight the importance of recognizing historical factors, such as past land-use changes, for developing protective strategies in the rural areas of the Basin. With this work, we provide a synthesized and more integrated understanding of the effects of past and local land-use changes in the regional Mediterranean environment, assisting to bridge the gap between scientific findings, Mediterranean watersheds stakeholders, and regional policy-makers. © 2020The authors would like to thank David Moreno (BC3) for his valuable reflections when developing the manuscript, Erik-Logan Hughes (MIT) for his help constructing the feedback network map, Ambika Markanday (BC3) for her language revisions, and three anonymous reviewers that improved this work with their constructive comments. This research is supported by the Basque Government through the BERC 2018-2021 program and by the Spanish Ministry of Economy and Competitiveness MINECO through BC3 María de Maeztu excellence accreditation MDM 2017-0714

    Assessment of sustainable land management practices in Mediterranean rural regions

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    Sustainable land management practices can be suitable vehicles to simultaneously address the causes and consequences of land degradation, desertification, and climate change in land managed systems. Here, we assess the potential of a variety of sustainable land management practices that, beyond addressing specific and local issues, assist in tackling Mediterranean Basin-wide land-use challenges. With this work, we aim to highlight those options that simultaneously promote local and regional Basin-wide adaptation. To do that, we developed a novel multi-objective assessment that evaluates the effectiveness of 104 practices adopted within the Mediterranean Basin and documented in the World Overview of Conservation Approaches and Technologies global database. Results indicate that agroforestry and green covers in perennial woody crops can promote multiple ecosystem services while addressing climate change adaptation. We further argue that these two practices together with reforestation, assist in regulating the hydrological cycle of the Basin and in maintaining its multifunctional landscape. Lastly, we reflect on potential biophysical and socio-economic barriers and opportunities associated with the implementation of the three practices. Our approach provides a Basin-wide integrated view that facilitates the coordination of sustainable management strategies across the Mediterranean region. © 2020 Elsevier LtdThe authors would like to thank two anonymous reviewers whose comments helped improve this work. This research is supported by the Basque Government through the BERC 2018–2021 program and by the Spanish Ministry of Economy and Competitiveness MINECO through BC3 María de Maeztu excellence accreditation MDM 2017–0714. M. Almagro acknowledges financial support from the Juan de la Cierva Program (IJCI-2015-23500)

    On-Farm Information: A Valuable Tool for the Sustainable Management of Mountain Pastures in Protected Natural Areas

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    Mountain pastures have traditionally been maintained by livestock. The analysis of data concerning farms\u27 characteristics, productive-reproductive management and land use of commercial farms can constitute a real approach to study these systems and the changes that are occurring. This information is necessary to develop new utilisation guidelines, making compatible livestock production and conservation of natural resources. This paper describes a methodological framework to study the issues described above through some examples taken out from a wider research project (Mandaluniz et al., 2003)

    Design and psychometric analysis of the COVID-19 prevention, recognition and home-management self-efficacy scale

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    In order to control the spread of COVID-19, people must adopt preventive behaviours that can affect their day-to-day life. People’s self-efficacy to adopt preventive behaviours to avoid COVID-19 contagion and spread should be studied. The aim of this study was to develop and psychometrically test the COVID-19 prevention, detection, and home-management self-efficacy scale (COVID-19-SES). We conducted an observational cross-sectional study. Six-hundred and seventy-eight people participated in the study. Data were collected between March and May 2020. The COVID-19-SES’ validity (content, criterion, and construct), reliability (internal consistency and test-retest reliability), and legibility were studied. The COVID-19-SES’ reliability was high (Cronbach’s alpha = 0.906; intraclass correlation coefficient = 0.754). The COVID-19-SES showed good content validity (scale’s content validity index = 0.92) and good criterion validity when the participants’ results on the COVID-19-SES were compared to their general self-efficacy (r = 0.38; p 0.001). Construct validity analysis revealed that the COVID-19-SES’ three-factor structure explained 52.12% of the variance found and it was congruent with the World Health Organisation’s recommendations to prevent COVID-19 contagion and spread. Legibility analysis showed that the COVID-19-SES is easy to read and understand by laypeople. The COVID-19-SES is a psychometrically robust instrument that allows for a valid and reliable assessment of people’s self-efficacy in preventing, detecting symptoms, and home-managing COVID-19

    Towards a determination of the chiral couplings at NLO in 1/N(C): L_8(mu) and C_38(mu)

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    We present a dispersive method which allows to investigate the low-energy couplings of chiral perturbation theory at the next-to-leading order (NLO) in the 1/N(C) expansion, keeping full control of their renormalization scale dependence. Using the resonance chiral theory Lagrangian, we perform a NLO calculation of the scalar and pseudoscalar two-point functions, within the single-resonance approximation. Imposing the correct QCD short-distance constraints, one determines their difference Pi(t)=Pi_S(t)-Pi_P(t) in terms of the pion decay constant and resonance masses. Its low momentum expansion fixes then the low-energy chiral couplings L_8 and C_38. At mu_0=0.77 GeV, we obtain L_8(mu_0)^{SU(3)} = (0.6+-0.4)10^{-3} and C_{38}(mu_0)^{SU(3)}=(2+-6)10^{-6}.Comment: Extended version published at JHEP01(2007)039. A NLO prediction for the O(p6) chiral coupling C_38 has been added. The original L_8 results remain unchange

    Characterization of goat colostrum oligosaccharides by nano-liquid chromatography on chip quadrupole time-of-flight mass spectrometry and hydrophilic interaction liquid chromatography-quadrupole mass spectrometry

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    A detailed qualitative and quantitative characterization of goat colostrum oligosaccharides (GCO) has been carried out for the first time. Defatted and deproteinized colostrum samples, previously treated by size exclusion chromatography (SEC) to remove lactose, were analyzed by nanoflow liquid chromatography–quadrupole-time of flight mass spectrometry (Nano-LC-Chip–Q-TOF MS). Up to 78 oligosaccharides containing hexose, hexosamine, fucose, N-acetylneuraminic acid or Nglycolylneuraminic acid monomeric units were identified in the samples, some of them detected for the first time in goat colostra. As a second step, a hydrophilic interaction liquid chromatography coupled to mass spectrometry (HILIC-MS) methodology was developed for the separation and quantitation of the main GCO, both acidic and neutral carbohydrates. Among other experimental chromatographic conditions, mobile phase additives and column temperature were evaluated in terms of retention time, resolution, peak width and symmetry of target carbohydrates. Narrow peaks (wh: 0.2–0.6 min) and good symmetry (As: 0.8–1.4) were obtained for GCO using an acetonitrile:water gradient with 0.1% ammonium hydroxide at 40 ◦C. These conditions were selected to quantify the main oligosaccharides in goat colostrum samples. Values ranging from 140 to 315 mg L−1 for neutral oligosaccharides and from 83 to 251 mg L−1 for acidic oligosaccharides were found. The combination of both techniques resulted to be useful to achieve a comprehensive characterization of GCO.This work has been funded by Junta de Andalucía (project AGR2011-7626), CSIC (project i-link0827), Comunidad Autónoma de Madrid (Spain) and European funding from FEDER program (AVANSECAL-CM S2013/ABI-3028) and Fundación Ramón Areces. This work was also supported by the UC Davis RISE program and the National Institutes of Health awards R21AT006180, R01AT007079, R01AT008759-02.Peer reviewe

    The knee prosthesis constraint dilemma: Biomechanical comparison between varus-valgus constrained implants and rotating hinge prosthesis. A cadaver study

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    The real degree of constriction of rotating hinge knee (RHK) and condylar constrained prostheses (CCK) is a matter of discussion in revision knee arthroplasty. The objectives of this study are to compare the tibial rotation of both implants and validate the use of inertial sensors with optical tracking system as movement measurement tools. A total of 16 cadaver knees were used. Eight knees were replaced using a RHK (Endomodel LINK), and the remaining eight received a CCK prosthesis (LCCK, Zimmer). Tibial rotation range of motion was measured in full extension and at 30°, 60°, and 90° of flexion, with four continuous waveforms for each measurement. Measurements were made using two inertial sensors with specific software and compared with measurements obtained using the gold standard technique - the motion capture camera. The comparison of the accuracy of both measurement methods showed no statistically significant differences between inertial sensors and motion capture cameras, with p > .1; the mean error for tibial rotation was 0.21°. Tibial rotation in the RHK was significantly greater than in the CCK (5.25° vs. 2.28°, respectively), p < .05. We have shown that RHK permit greater tibial rotation, being closer to physiological values than CCKs. Inertial sensors have been validated as an effective and accurate method of measuring knee movement. The clinical significance: RHK appears to represent a lower constriction degree than CCK systems.This study wassupported by Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III and European Regional Development Fund "Una manera de hacer Europa" (grant number PI18/01625

    Chemical modification of titanium precursor to obtain stable silica-titania sol: acetylacetone

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    [ES] La técnica Sol-Gel se ha utilizado para sintetizar una serie de sistemas multicomponentes, entre ellos SiO2 – TiO2. El mayor problema en la obtención de geles multicomponentes estables es la desigual velocidad de hidrólisis y condensación que presentan los alcóxidos precursores de los cationes de interés. En este trabajo se muestra cómo adicionando acetilacetona, acacH, al sistema TEOS – Ti(OBu)4 – H2O se puede obtener un sol estable. Se tomaron diferentes concentraciones de los precursores de silicio y titanio y una sola concentración de acacH. Se utilizó espectroscopia infrarroja, FTIR, para identificar los grupos funcionales presentes en el sistema y además se midió regularmente la viscosidad para determinar cualitativamente el avance de la policondensación del sistema.[EN] Sol-gel processing has become a well established technique for producing ceramic powders or glasses. This processing has been utilized to synthesize several interesting systems, e.g. the SiO2 – TiO2 system. A major concern in the stable multicomponent geles is that the hydrolysis and condensation velocities are diferent for each precursor, TEOS and Ti(OBu)4 in this work. The chemical control of these reactions is currently performed by adding complexing reagents that react with metal alkoxides at a molecular level, giving rise to new molecular precursors of different structure, reactivity and functionanality. This paper shows that stable TEOS – Ti(OBu)4 – H2O sol can be reproducibly prepared in the presence of acetylacetone. We shall then show that the acac behaves as a ligand, directly bonded to the titanium ion. Thus the formation of precipitate is avoided. Infra-red spectroscopy (FTIR) and viscosity measures were used to demostrated this behaviour of the system.Este trabajo fue financiado a través de los proyectos COLCIENCIAS N° 1103-05-605-93 y VRI-Universidad del Cauca N° 752. Agradecemos a Ecopetrol-ICP la colaboración prestada con los estudios de espectroscopia infrarroja y a la red CyTED VIII.E la ayuda económica y técnica gracias a la cual A. Mafla pudo realizar su pasantía en el ICVCSIC de Madrid-España.Peer reviewe

    Quantum Loops in the Resonance Chiral Theory: The Vector Form Factor

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    We present a calculation of the Vector Form Factor at the next-to-leading order in the 1/N_C expansion, within the framework of Resonance Chiral Theory. The calculation is performed in the chiral limit, and with two dynamical quark flavours. The ultraviolet behaviour of quantum loops involving virtual resonance propagators is analyzed, together with the kind of counterterms needed in the renormalization procedure. Using the lowest-order equations of motion, we show that only a few combinations of local couplings appear in the final result. The low-energy limit of our calculation reproduces the standard Chiral Perturbation Theory formula, allowing us to determine the resonance contribution to the chiral low-energy couplings, at the next-to-leading order in 1/N_C, keeping a full control of their renormalization scale dependence.Comment: 27+1 pages, 9 figure

    Tracing the retina to analyze the integrity and phagocytic capacity of the retinal pigment epithelium

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    We have developed a new technique to study the integrity, morphology and functionality of the retinal neurons and the retinal pigment epithelium (RPE). Young and old control albino (Sprague-Dawley) and pigmented (Piebald Virol Glaxo) rats, and dystrophic albino (P23H-1) and pigmented (Royal College of Surgeons) rats received a single intravitreal injection of 3% Fluorogold (FG) and their retinas were analyzed from 5 minutes to 30 days later. Retinas were imaged in vivo with SD-OCT and ex vivo in flat-mounts and in cross-sections. Fifteen minutes and 24 hours after intravitreal administration of FG retinal neurons and the RPE, but no glial cells, were labeled with FG-filled vesicles. The tracer reached the RPE 15 minutes after FG administration, and this labeling remained up to 30 days. Tracing for 15 minutes or 24 hours did not cause oxidative stress. Intraretinal tracing delineated the pathological retinal remodelling occurring in the dystrophic strains. The RPE of the P23H-1 strain was highly altered in aged animals, while the RPE of the RCS strain, which is unable to phagocytose, did not accumulate the tracer even at young ages when the retinal neural circuit is still preserved. In both dystrophic strains, the RPE cells were pleomorphic and polymegathic
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