The use of ecosystem-based adaptation practices by smallholder farmers in Central America

There is growing interest in promoting the use of Ecosystem-based Adaptation (EbA) practices to help smallholder farmers adapt to climate change, however there is limited information on how commonly these practices are used by smallholder farmers and what factors influence their use. Using participatory mapping and field surveys, we examined the prevalence and characteristics of EbA practices on 300 smallholder coffee and maize farmers in six landscapes in Central America and explored the socioeconomic and biophysical factors associated with their use. The prevalence of individual EbA practices varied across smallholder farms. Common EbA practices included live fences, home gardens, shade trees in coffee plantations, and dispersed trees in maize fields. We found a mean of 3.8 EbA practices per farm. Factors that were correlated with the total number of EbA practices on farms included the mean area of coffee plantations, farmer age, farmer experience, the farm type and the landscape in which farms were located. Factors associated with the presence or characteristics of individual EbA practices included the size of coffee plantations, farmer experience, farmer education, land tenure, landscape and farm type. Our analysis suggests that many smallholder farmers in Central America are already using certain EbA practices, but there is still scope for greater implementation. Policy makers, donors and technicians can encourage the broader use of EbA by smallholder farmers by facilitating farmer-to-farmer exchanges to share knowledge on EbA implementation, assessing the effectiveness of EbA practices in delivering adaptation benefits, and tailoring EbA policies and programs for smallholder farmers in different socioeconomic and biophysical contexts. (Résumé d'auteur

Esquizofrenia, genética, epigênesis, ambiente: uma revisão sistemática das hipóteses etiológicas unifi cadas e do perfi l genética; e um novo algoritmo para o tratamento dos achados principais

Context: schizophrenia is a highly complex syndrome, related to genes, and to non-genetic risk factors. Famous epidemiological studies reported its presence among all cultures and geographic regions. In that sense, Unifi ed Etiological hypothesis face the challenge to both present experimental data, and to show that the fi ndings may cope with the syndrome’s universal profi le. Objectives: systematically review the most prominent Unifi ed Etiological hypothesis, as much as the semantic distribution of genetic fi ndings (under up to date data mining techniques), and propose a new model, based on the dynamic effects of epigenics over genetic activation in both neurodevelopment and early adulthood. Results: in general, Unifi ed Etiological Hypothesis contradict the main genetic fi ndings (which suggest that schizophrenias’ genes are mostly associated with neurotransmitter profi - les, like D-1 and the Glutamate-NMDA cascade); also in general, genetic fi ndings are spread all over the genome (as we reveal with a topological map of the 3519 studies on the matter). The key for this conundrum may be represented by the association between the perspective that each polymorphism associated with schizophrenia represents a statistical risk factor (e.g. increasing the risk of developmental instability) while epigenetic molecular cascades and environmental factors considerably infl uence this picture, affecting genetic activation within critical periods.Contexto: la esquizofrenia es un síndrome complejo relacionado con genes y factores de riesgo no genéticos. Estudios epidemiológicos reconocidos reportan su presencia en todas las culturas y regiones geográficas. En este sentido, las Hipótesis Etiológicas Unificadas enfrentan simultáneamente el desafío de presentar los datos experimentales y demostrar que éstos dan cuenta del perfil universal del síndrome. Objetivos: revisar sistemáticamente las más prominentes Hipótesis Etiológicas Unifi - cadas, así como la distribución semántica de los hallazgos genéticos (mediante técnicas de minería de datos) y proponer un nuevo modelo, basado en los efectos dinámicos de carácter epigenético sobre la activación genética en el neurodesarrollo y la pubertad. Resultados: de manera general, las Hipótesis Etiológicas Unificadas contradicen los  principales hallazgos genéticos (que sugieren que la esquizofrenia está asociada al perfil de neurotransmisores como D-1 y la cascada Glutamato-NMDA); también, por regla general, los hallazgos genéticos se encuentran esparcidos por todo el genoma (tal como revelamos en un mapa topológico de los 3519 estudios en el asunto). La clave para este estado complejo de cosas puede estar representada por la asociación entre la perspectiva de que cada polimorfismo asociado a la esquizofrenia representa un factor de riesgo estadístico (es decir, aumentando el riesgo de inestabilidades del desarrollo), mientras que las cascadas moleculares de carácter epigenético y los factores de riesgo ambientales permanecen actuantes mediante la activación de genes en períodos críticos

Photodegradation of ciprofloxacin, clarithromycin and trimethoprim: influence of pH and humic acids

In view of the rising relevance of emerging pollutants in the environment, this work studies the photodegradation of three antibiotics, evaluating the effects of the pH of the medium and the concentration of dissolved organic matter. Simulated light (with a spectrum similar to that of natural sunlight) was applied to the antibiotics Ciprofloxacin (Cip), Clarithromycin (Cla) and Trimethoprim (Tri), at three different pH, and in the presence of different concentrations of humic acids. The sensitivity to light followed the sequence: Cip > Cla > Tri, which was inverse for the half-life (Tri > Cla > Cip). As the pH increased, the half-life generally decreased, except for Cla. Regarding the kinetic constant k, in the case of Cip and Tri it increased with the rise of pH, while decreased for Cla. The results corresponding to total organic carbon (TOC) indicate that the complete mineralization of the antibiotics was not achieved. The effect of humic acids was not marked, slightly increasing the degradation of Cip, and slightly decreasing it for Tri, while no effect was detected for Cla. These results may be relevant in terms of understanding the evolution of these antibiotics, especially when they reach different environmental compartments and receive sunlight radiation.Ministerio de Ciencia, Innovación y Universidades | Ref. RTI2018-099574-B-C21Ministerio de Ciencia, Innovación y Universidades | Ref. RTI2018-099574-B-C2

Direct toxicity of six antibiotics on soil bacterial communities affected by the addition of bio-adsorbents

Reducing the toxicity caused by antibiotics on bacterial communities in the soil is one of the great challenges of this century. For this, the effectiveness of amending the soil with different bioadsorbents such as crushed mussel shell (CMS), pine bark (PB) and biomass ash (BA), as well as combinations of them (CMS + PB and PB + BA) was studied at different doses (0 g kg−1 to 48 g kg−1). Soil samples were spiked, separately, with increasing doses (0–2000 mg kg−1) of cefuroxime (CMX), amoxicillin (AMX), clarithromycin (CLA), azithromycin (AZI), ciprofloxacin (CIP) and trimethoprim (TMP). Their toxicity on bacterial growth was estimated using the tritium-labeled leucine (3H) incorporation method. Toxicity was observed to behave differently depending on the antibiotic family and bioadsorbent, although in different magnitude and at different doses. The toxicity of β-lactams (AMX and CXM) was reduced by up to 54% when the highest doses of bio-adsorbents were added due to the increase in pH (CMS and BA) and carbon (PB) contribution. Macrolides (CLA and AZI) showed slight toxicity in un-amended soil samples, which increased by up to 65% with the addition of the bio-adsorbents. The toxicity of CIP (a fluoroquinolone) increased with the dose of the bio-adsorbents, reaching up to 20% compared with the control. Finally, the toxicity of TMP (a diaminopyrimidine) slightly increased with the dose of bio-adsorbents. The by-products that increase soil pH are those that showed the highest increases of CLA, AZI, CIP and TMP toxicities. These results could help to prevent/reduce environmental pollution caused by different kinds of antibiotics, selecting the most appropriated bio-adsorbents and doses.Agencia Estatal de Investigación | Ref. RTI2018-099574-B-C21Agencia Estatal de Investigación | Ref. RTI2018-099574-B-C22Ministerio de Economía, Industria y Competitividad | Ref. RYC-2016-20411Xunta de Galicia | Ref. ED481B-2022-081Xunta de Galicia | Ref. ED481A-2021/309Financiado para publicación en acceso aberto: Universidade de Vigo/CISU

Clarithromycin as soil and environmental pollutant: Adsorption-desorption processes and influence of pH

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGAntibiotics pollution is a growing environmental issue, as high amounts of these compounds are found in soil, water and sediments. This work studies the adsorption/desorption of the macrolide antibiotic clarithromycin (CLA) for 17 agricultural soils with different edaphic characteristics. The research was carried out using batch-type experiments, with an additional assessment of the specific influence of pH for 6 of the soils. The results show that CLA adsorption reaches between 26 and 95%. In addition, the fit of the experimental data to adsorption models provided values between 1.9 and 19.7 Ln μmol1−n kg−1 for the KF, Freundlich affinity coefficient, and between 2.5 and 10.5 L kg−1 for Kd, distribution constant of Linear model. Regarding the linearity index, n, it varied between 0.56 and 1.34. Desorption showed lower scores than adsorption, with an average of 20%, and with values of 3.1 and 93.0 Ln μmol1−n kg−1 for KF(des) and 4.4 and 95.0 L kg−1 for Kd(des). The edaphic characteristics with the highest influence on adsorption were the silt fraction content and the exchangeable Ca content, while in the case of desorption, they were the total nitrogen, organic carbon, and exchangeable Ca and Mg contents. Regarding the pH, within the range studied (between 3 and 10), its value did not decisively affect the adsorption/desorption process. Overall, the set of these results could be of help to program appropriate measures leading to the retention/elimination of this antibiotic when it reaches the environment as a pollutant.Ministerio de Ciencia, Innovacción y Universidades | Ref. RTI2018-099574-B-C21Xunta de Galicia | Ref. ED431C2021/46-GCRMinisterio de Universidades | Ref. FPU19/03758Xunta de Galicia | Ref. ED481B-2022-081Ministerio de Ciencia e Innovación. | Ref. IJC2020- 044197-IUniversidade de Vigo/CISUGMinisterio de Ciencia, Innovacción y Universidades | Ref. RTI2018-099574-B-C2

Valorization of forest by-products as bio-adsorbents for emerging contaminants

The use of forest by-products as bio-adsorbents allows the recycling of these materials and could reduce the risks of environmental pollution due to different contaminants. This study focuses on the adsorption and release of three antibiotics (ciprofloxacin, clarithromycin and trimethoprim) on pine and oak bark materials and how pHinfluences in these processes. The results showed that the highest adsorption potential corresponds to pine bark, where the Freundlich affinity coefficient varies between 126.6 and 2979.1 Ln µmol1− n kg− 1, while, for oak bark, between 283.9 and 806.9 Ln µmol1− n kg− 1. Both bio-adsorbents show some influence of the pH affectingadsorption. Of the three antibiotics, clarithromycin was the most mobile. In general, both by-products gave satisfactory results as bio-adsorbents for the antibiotics tested. Therefore, their potential use as decontaminants could help to face environmental issues due to these emerging pollutants, reducing human and ecological risk, while contributing to a zero-waste economy.Agencia Estatal de Investigación | Ref. RTI2018-099574-B-C21Agencia Estatal de Investigación | Ref. RTI2018- 099574-B-C22Xunta de Galicia | Ref. ED431C2021/46-GCRXunta de Galicia | Ref. ED481B-2022-081Ministerio de Universidades | Ref. FPU19/03758Agencia Estatal de Investigación | Ref. IJC2020- 044426-IAgencia Estatal de Investigación | Ref. IJC2020-044197-IUniversidade de Vigo/CISU