2,630 research outputs found

    Infection of Norway lobster (Nephrops norvegicus) by the parasite Hematodinium sp.: insights from 30 years of field observations

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    The Norway lobster, Nephrops norvegicus, is an important representative of the benthos and also supports valuable fisheries across Europe. Nephrops are susceptible to infection by Hematodinium sp., an endoparasitic dinoflagellate that causes morbidity and mortality. From an epizootiological perspective, the Clyde Sea Area (CSA; west of Scotland) is the best-studied Hematodinium–Nephrops pathosystem, with historical data available between 1988 and 2008. We have revisited this pathosystem by curating and updating prevalence values, differentiating host traits associated with disease exposure and progression, and comparing Hematodinium sp. disease dynamics in the CSA to other locations and to other decapod hosts (Cancer pagurus, Carcinus maenas). Prevalence from a 2018/2019 survey (involving 1739 lobsters) revealed Hematodinium sp. still mounts a synchronized patent infection in the CSA; hence this pathogen can be considered as enzootic in this location. We highlight for the first time that Nephrops size is associated with high severity infection, while females are more exposed to Hematodinium sp. More generally, regardless of the host (Norway lobster, brown and shore crabs) or the geographical area (Ireland, Wales, Scotland), Hematodinium sp. patent infections peak in spring/summer and reach their nadir during autumn. We contend that Hematodinium must be considered one of the most important pathogens of decapod crustaceans in temperate waters

    Life cycle assessment of a wastewater hybrid system for rural communities, Marcelino Maridueña case of study.

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    International audienceWastewater management (WWM) is an issue in low and middle-income countries' rural areas; the lack of technology and funding have been identified as the most critical. Marcelino Maridueña (MM) is a rural village in Ecuador that uses an oxidation pond to treat its household wastewater. As a result, the organic load in the effluent varies depending on the season and the volume treated. Also, it may generate emissions that could harm the environment. Therefore, a hybrid system, i.e., activated sludge (conventional) coupled with an algal photobioreactor system (APS), was developed at a laboratory scale. This study's target was to assess the environmental impact of the developed hybrid system, i.e., the impact of the hybrid system versus a solely a conventional system. Notably, the ecological footprint of the APS alternative may vary depending on the climate. In this study, the APS was fixed for a tropical region with warm temperatures ranging from 25 to 45°C and plenty of solar light. The environmental impact categories were identified in literature and then analyzed through a Life Cycle Assessment (LCA) methodology. The model demonstrates a percent reduction in most impact categories from switching to the proposed hybrid wastewater system. The percent reductions modeled were as follows: Freshwater Eutrophication would be reduced by 98.09%, Marine Eutrophication would be reduced by 98.61%, and Human Non-carcinogenic Toxicity would be reduced by 98.45% between the proposed and the current system of wastewater treatmen

    Models of classroom assessment for course-based research experiences

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    Course-based research pedagogy involves positioning students as contributors to authentic research projects as part of an engaging educational experience that promotes their learning and persistence in science. To develop a model for assessing and grading students engaged in this type of learning experience, the assessment aims and practices of a community of experienced course-based research instructors were collected and analyzed. This approach defines four aims of course-based research assessment—(1) Assessing Laboratory Work and Scientific Thinking; (2) Evaluating Mastery of Concepts, Quantitative Thinking and Skills; (3) Appraising Forms of Scientific Communication; and (4) Metacognition of Learning—along with a set of practices for each aim. These aims and practices of assessment were then integrated with previously developed models of course-based research instruction to reveal an assessment program in which instructors provide extensive feedback to support productive student engagement in research while grading those aspects of research that are necessary for the student to succeed. Assessment conducted in this way delicately balances the need to facilitate students’ ongoing research with the requirement of a final grade without undercutting the important aims of a CRE education

    Identification and distribution of new candidate T6SS effectors encoded in Salmonella Pathogenicity Island 6

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    The type VI secretion system (T6SS) is a contact-dependent contractile multiprotein apparatus widely distributed in Gram-negative bacteria. These systems can deliver different effector proteins into target bacterial and/or eukaryotic cells, contributing to the environmental fitness and virulence of many bacterial pathogens. Salmonella harbors five different T6SSs encoded in different genomic islands. The T6SS encoded in Salmonella Pathogenicity Island 6 (SPI-6) contributes to Salmonella competition with the host microbiota and its interaction with infected host cells. Despite its relevance, information regarding the total number of effector proteins encoded within SPI-6 and its distribution among different Salmonella enterica serotypes is limited. In this work, we performed bioinformatic and comparative genomics analyses of the SPI-6 T6SS gene cluster to expand our knowledge regarding the T6SS effector repertoire and the global distribution of these effectors in Salmonella. The analysis of a curated dataset of 60 Salmonella enterica genomes from the Secret6 database revealed the presence of 23 new putative T6SS effector/immunity protein (E/I) modules. These effectors were concentrated in the variable regions 1 to 3 (VR1-3) of the SPI-6 T6SS gene cluster. VR1-2 were enriched in candidate effectors with predicted peptidoglycan hydrolase activity, while VR3 was enriched in candidate effectors of the Rhs family with C-terminal extensions with predicted DNase, RNase, deaminase, or ADP-ribosyltransferase activity. A global analysis of known and candidate effector proteins in Salmonella enterica genomes from the NCBI database revealed that T6SS effector proteins are differentially distributed among Salmonella serotypes. While some effectors are present in over 200 serotypes, others are found in less than a dozen. A hierarchical clustering analysis identified Salmonella serotypes with distinct profiles of T6SS effectors and candidate effectors, highlighting the diversity of T6SS effector repertoires in Salmonella enterica. The existence of different repertoires of effector proteins suggests that different effector protein combinations may have a differential impact on the environmental fitness and pathogenic potential of these strains

    Black list and Alert list of the Aquatic Invasive Alien Species in the Iberian Peninsula: an action of the LIFE INVASAQUA

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    Resumen del trabajo presentado en VI Congreso Nacional sobre Especies Exóticas Invasoras y I Congreso Ibérico sobre EEI (EEI 2022) celebrado en Navarra del 20 al 23 de abril de 2022.One of the objectives of LIFE INVASQUA project is to develop tools that will be more efficient the Early Warning and Rapid Response (EWRR) framework for Invasive Alien Species in the Iberian Peninsula. Horizon scanning for high-risk IAS is basic in implementing measures to reduce new invasions, developing Alert lists, and to focus effort in the species already established, for instance making a Black list. We developed a trans national horizon scanning exercise focused on inland waters of Spain and Portugal in order to provide a prioritized lists (Black list and Alert list) of aquatic IAS that may pose a threat to aquatic ecosystems and socio economic sectors in the future. We followed a step approach of existing information about IAS (Plants, Freshwater Invertebrates, Estuarine Invertebrates and Vertebrates; 127 established taxa in Black list; 90 non established taxa in Alert list) combining with an expert scoring of prioritized taxa. IAS established in the Iberian aquatic system consistently highlighted as the worst included vertebrates (e.g. Cyprinus carpio, Gambusia holbrooki, Silurus glanis), freshwater and estuarine invertebrates (e.g. Procambarus clarkii, Dreissena polymorpha, Pacifastacus leniusculus, Ficopomatus enigmaticus, Callinectes sapidus, Corbicula fluminea) and plants (e.g. Eichhornia crassipes, Azolla filiculoides, Ludwigia grandiflora). Amongst taxa not yet established (Alert list), expert pointed to Perna viridis, Hydroides dirampha, Dreissena bugensis, Procambarus fallax f. virginallis, Perccottus glenii with higher risk of invasion, ecological and socioeconomic impacts. Over 20.6% of the taxa in the preliminary black list received no votes (no prioritization) by experts, 17.8% in the innitial alert list. Our horizon scanning approach is inclusive of all-taxa, prioritizes both established and emerging biological threats across trans-national scales, and considers not only the ecological impact, but also potential direct economic consequences as well as the manageability of invasive species.This work received funds from the LIFE Programme (LIFE17 GIE/ES/000515)

    “Alperujo” Compost Improves Nodulation and Symbiotic Nitrogen Fixation of Soybean Inoculated with <i>Bradyrhizobium diazoefficiens</i>

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    The utilization of compost to enhance plant productivity and symbiotic nitrogen fixation (SNF) has been recognized as an effective alternative to synthetic nitrogen fertilizers. This environmentally sustainable method is readily accessible to farmers. This study investigated the effect of olive pomace (“alperujo”, AL) compost on the nodulation and SNF of soybeans (Glycine max L.) and their natural symbiont (Bradyrhizobium diazoefficiens). For that, soybean plants were subjected to several doses of AL compost under controlled greenhouse conditions. At the end of the experiment, the dry weight of plant biomass (aerial part and roots), the number and fresh weight of nodules, and nitrogen and leghaemoglobin contents were analyzed. The application of AL compost significantly improved soybean growth, as demonstrated by an increase in both plant biomass and height. Furthermore, nodular leghaemoglobin content and nitrogen content were found to be enhanced by the addition of AL compost (7 and 40%, respectively), indicating an increase in nodule effectiveness and symbiotic efficiency. Our results provide clear evidence of the synergetic effect of AL compost on the soybean-B. diazoefficiens association, probably due to AL-compost improved soybean roots development, and rhizospheric organic matter and nutrients assimilation by rhizobia

    Biocompatible nanoporous carbons as a carrier system for controlled release of cephalexin

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    An ordered nanoporous carbon (ONC) was synthesized by the hard-template method and then superficially modified with amino groups from 3-aminopropyltrietoxisilane (ONC-A). Both carbons, ONC and ONC-A, were characterized and tested as carriers of a high-frequency dosing drug such as cephalexin (CFX). Density functional theory calculations were used to study the interactions between ONC and the amino groups of ONC-A and CFX. Finally, the biocompatibility of human colon carcinoma (Caco-2) cells and in vitro release kinetics at gastric and intestinal pH were evaluated. The results show that drug loading capacity was higher in ONC than in ONC-A, which was associated with a localized increase in adsorption energy and a decrease in the textural properties on the surface of the ONC-A sample. Both carbon materials showed cell viability above 80 %, even at high concentrations (1000 µg mL). The CFX release profiles of both carbons reached their maximum at 12 h, whereas the rapid release of pure CFX at gastric and intestinal pH was 30 min. The release mechanisms obeyed the Weibull model governed by Fickian diffusion, influenced by both porosity and functional groups in ONC and ONC-A.The authors thanks the Consejo Nacional de Investigaciones Científicas y Técnicas ( CONICET ), Agencia Nacional de Promocion de Ciencia y Tecnologia ( ANPCYT ) and Universidad Nacional de San Luis (UNSL) from Argentina, and the Project P18-RT-3786 from Spain, for the financial support of different project to realize this work. K.M-C is grateful to the SEGIB-Fundación Carolina for the scholarship awarded to carry out the research stay at the University of Granada, Spain, where many of the results of this work were obtained. She also thanks UNAN-Managua, Nicaragua , for the scholarship awarded

    Non-Standard Errors

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    In statistics, samples are drawn from a population in a datagenerating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants

    Valuation of urban nature-based solutions in Latin American and European cities

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    The potential of urban nature-based solutions (NBS) to provide significant benefits to citizens and to address societal challenges is undervalued, yet the valuation of NBS impacts remains contentious. Further development of monetary and non-monetary valuation of the costs and benefits of urban NBS is required, and effective knowledge exchange on these themes is required at the international level. However, an important gap in research relates to the uptake and application of existing techniques for monetary valuation. This research explored how monetary values of urban NBS are assessed, and how NBS valuation is viewed by city government authorities in particular. Results are presented from a review of peer-reviewed articles reporting urban NBS valuation techniques development and application. Over 200 articles relating specifically to urban NBS interventions were reviewed. The literature indicates that many valuation techniques have been researched, but most studies tend to address just a few indicators of NBS impacts, which are mainly physical-environmental in their focus. To generate deeper insights into perceptions of monetary valuations in NBS impact assessments and their application, focus groups and semi-structured interviews were conducted with local and regional government staff in seven cities in Latin America and Europe. Although a wide range of economic valuation tools exist and can be applied to support NBS development, limited evidence was found for their uptake and application in practice across the contexts examined. We discuss potential reasons for limited uptake, which may include overburdensome data demands, incommensurability with existing decision-making and accounting practices, and limited staffing, financial and technical capacity - even within large cities. Results suggest that successful NBS interventions may portray economic impacts, but NBS propositions should not depend upon monetary valuations alone; social and ecological criteria remain centrally important. Participatory impact assessment methods may support improved business cases and monetary valuations for urban NBS
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