57 research outputs found

    Afbraak van organisch materiaal en bacteriële biomassa in aquacultuur productiesystemen

    Get PDF
    Ophoping van mest, voerresten en ander organisch materiaal kan in de vijverteelt tot waterkwaliteitsproblemen leiden. In het laboratorium van de Leerstoelgroep Visteelt en Visserij, Wageningen Universiteit, is de afgelopen jaren onderzoek gedaan naar de omstandigheden die de afbraak van mest, voerresten en ander organisch materiaal bepalen. Dit artikel vat enkele resultaten same

    First record of the Sparkling-tailed Hummingbird (Tilmatura dupontii, Trochilidae) for Sierra de Huautla Biosphere Reserve, Morelos, Mexico

    Get PDF
    In August, 2005 we observed and photographed one male of Sparkling-Tailed hummingbird (Tilmatura dupontii) foraging on Firerbush shrub flowers (Hamelia patens, Rubiaceae). The present observation is the first record of this species for the Sierra de Huautla Biosphere Reserve, in the south of Morelos, Mexico, ca. 50 km southeast of previous reported observations of the species in Morelo

    Optical spectroscopy of EX Lupi during quiescence and outburst: Infall, wind, and dynamics in the accretion flow

    Full text link
    We explore the accretion mechanisms in EX Lupi, prototype of EXor variables, during its quiescence and outburst phases. We analyse high-resolution optical spectra taken before, during, and after its 2008 outburst. In quiescence and outburst, the star presents many permitted emission lines, including typical CTTS lines and numerous neutral and ionized metallic lines. During the outburst, the number of emission lines increases to over a thousand, with narrow plus broad component structure (NC+BC). The BC profile is highly variable on short timescales (24-72h). An active chromosphere can explain the metallic lines in quiescence and the outburst NC. The dynamics of the BC line profiles suggest an origin in a hot, dense, non-axisymmetric, and non-uniform accretion column that suffers velocity variations along the line-of-sight on timescales of days. Assuming Keplerian rotation, the emitting region would be located at ~0.1-0.2 AU, consistent with the inner disk rim, but the velocity profiles of the lines reveal a combination of rotation and infall. Line ratios of ions and neutrals can be reproduced with a temperature of T~6500 K for electron densities of a few times 1012^{12}cm3^{-3} in the line-emitting region. The data confirm that the 2008 outburst was an episode of increased accretion, albeit much stronger than previous EX Lupi and typical EXors outbursts. The line profiles are consistent with the infall/rotation of a non-axisymmetric structure that could be produced by clumpy accretion during the outburst phase. A strong inner disk wind appears in the epochs of higher accretion. The rapid recovery of the system after the outburst and the similarity between the pre-outburst and post-outburst states suggest that the accretion channels are similar during the whole period, and only the accretion rate varies, providing a superb environment for studying the accretion processes.Comment: 15 pages plus 26 pages online material, accepted by A&

    European journalism observatory: An international consolidated platform for training and professional networks in the Faculty of Information Sciences

    Get PDF
    El objetivo principal de este proyecto Innova-Docenia era ampliar y consolidar una plataforma de formación internacional y consolidada, para alumnos y alumnas de la Facultad de Ciencias de la Información, como parte del European Journalism Observatory (EJO), fundado por el Instituto Reuters de la Universidad de Oxford. Se trataba de afianzar EJO Spain como plataforma de formación y escaparate de las acciones implementadas en España, donde la Universidad Complutense de Madrid se convertía en el socio español principal. El Observatorio Europeo de Periodismo (EJO), una red de instituciones independientes y sin ánimo de lucro del campo de la comunicación de 14 países, tiene como objetivo tender puentes entre la investigación y la práctica del periodismo en Europa y fomentar el profesionalismo y la libertad de prensa. Promueve el diálogo entre investigadores y profesionales de los medios. Acerca los resultados de la investigación a las personas que trabajan en los medios. Su objetivo es mejorar la calidad del periodismo, contribuir a una mejor comprensión de los medios y fomentar la libertad de prensa y la responsabilidad de los medios. Nació en 2004, como una red de varios socios europeos, coordinados por la Universidad de Lugano y la Universidad de Oxford. Fue diseñado para observar las tendencias en el periodismo y en los medios de comunicación, desde una perspectiva ética y deontológica muy amplia. Desde entonces, sus artículos, investigaciones y editoriales son publicados en las distintas páginas web de cada socio: https://es.ejo-online.eu/red-ej

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

    Get PDF
    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Organic matter decomposition in simulated aquaculture ponds

    No full text
    Different kinds of organic and inorganic compounds (e.g. formulated food, manures, fertilizers) are added to aquaculture ponds to increase fish production. However, a large part of these inputs are not utilized by the fish and are decomposed inside the pond. The microbiological decomposition of the organic matter is a critical factor for water quality control and nutrient recycle. Usually, management practices are developed to control the survival and health of the cultured animals and to maintain good water quality. The microbiological processes are affected by these practices but usually unintentionally. A better control of culture conditions and sustainability of aquaculture ponds is possible with an improvement of the microbiological processes. The present thesis is divided in two parts, the first is a literature review of the microbial ecology of aquaculture ponds and the second is the description of a series of experiments in lab-sc ale aquaculture ponds.In the first part, the role of the microorganisms in aquaculture ponds is reviewed, focusing on the decomposition of organic matter and its influence on pond dynamics. It was theoretically estimated that the addition of I kg of formulated feed would yield approximately 125 g bacterial biomass. This bacterial biomass is potentially a valuable nutrients source for higher trophic levels. Sedimentation and resuspension processes are important factors affecting the decomposition pathways. Both processes are directly related with the feeding rate and the stocking density applied. The rate of organic matter loading, environmental factors and pond management practices influence the functioning of algae-bacteria interactions, which are extremely important in pond processes. Included is a literature that describes commercial probiotic products that claim to solve: nutritious, water quality and pathogens problems in pond aquaculture, were analyzed. Alternative management practices to steer the decomposition process were also presented (Chapter 2).The second part describes all the experiments that were conducted in lab scale microcosm systems, simulating the conditions of an intensive fish-less aquaculture pond with daily feeding rates. In Chapter 3 the influence of aerobic and anaerobic conditions and the organic C/N ratios on the decomposition process is described. Under aerobic decomposition less organic carbon remained in the systems. The results from this experiment suggest that a C/N ratio ranging between the tested values (6.3 and 12.8) does not have a significant influence on the carbon mineralization in the short term " 50 days). However, a C/N ratio decrease was observed in all the treatments during the experimental period; this reduction was especially fast and steep under aerobic conditions. This decrease in C/N ratio of the organic matter might explain why in all treatments the rate of decomposition slowed down at the end of the experiment. The C/N ratio also determined the concentration of inorganic nitrogen compounds in the water. Higher concentrations were found for the richest protein diet treatments. No nitrification was measured even though oxygen and ammonia were present.Bacterial biomass production was quantified testing two formulated fish feed with different protein content under aerobic and anaerobic conditions (Chapter 4). The oxic status significantly influences the bacterial abundance, bacterial biomass, bacterial respiration and bacterial efficiency. More bacterial biomass was produced under aerobic conditions. The two diets did not influence significantly the bacterial growth. The bacterial abundance at the end of the experiment was 3.4 x 109 cells ml-1 in aerobic treatments and 1.9 x 109 cells m1-1 in anaerobic treatments. The remaining amount of carbon, fixed in bacterial biomass and expressed on a per area basis, was 19 g m-2 day-t for aerobic system and 8 g m-2 day-1 for anaerobic systems.In Chapter 5 the effect of the oxic-anoxic range on fish feed decomposition was investigated. Different ranges, from completely aerobic to completely anaerobic, were tested. To establish intermediate oxic levels the following treatments were used: 1) alternated flows of 02 or N2 at different periods and 2) maintaining the coexistence of aerobic and anaerobic layers while applying short resuspension events. Similar amounts of carbon were converted to CO2 under completely aerobic conditions and under the different ranges of aerobic-anaerobic conditions. Under anaerobic conditions much less carbon was converted into CO2. This means that actually only limited periods of oxic conditions (or resuspension) are needed to stimulate complete organic matter decomposition. From our results it appears that only 6h per day of aerobic conditions or only once mixing of aerobic and anaerobic layers (i.e. resuspension) per four days are needed to reach the same carbon mineralization as in continuous aerobic conditions. Very limited nitrification was observed in the completely aerobic treatment. Nitrification and denitrification were registered for all the systems when aerobic and anaerobic conditions coexisted in time or space. The highest nitrogen removal (around 70%) was found in the resuspension treatments (and 12 h O2 flow treatment).The use of controlled lab scale microcosm simulating intensive aquaculture ponds allowed us to follow the fate of carbon and nitrogen during particular decomposition processes. The results found in the different chapters are discussed in Chapter 6. Both the quality and the quantity of the organic matter influenced the decomposition process and its products. The use of high protein diets increased the concentration of nitrogen species affecting the water quality. The aerobic and anaerobic conditions determined the nutrients pathway (mineralized, assimilated or partially decomposed). More bacterial biomass was produced under aerobic conditions than under anaerobic. The coexistence of aerobic and anaerobic conditions stimulated organic matter decomposition; it avoided the accumulation of ammonia while maintaining good water quality conditions.A better understanding and control of the organic matter decomposition in aquaculture ponds is crucial. The anaerobic decomposition only becomes a problem when it predominates in the sediment, causing the aerobic-anaerobic interface to move up into the water column, and thus remains disconnected from the aerobic decomposition. Management practices that link aerobic and anaerobic processes can stimulate fish production by recycling carbon and nitrogen compounds. The recycling of surplus organic matter through bacterial processes, however, has a limit. Increasing fish pond productivity should come along with practices to stimulate the autotrophic and heterotrophic food webs, without exceeding the capacity of this aquatic system

    Carcinoma epidermoide como complicação letal de lesões crônicas de cromoblastomicose Chromoblastomycosis associated with a lethal squamous cell carcinoma

    No full text
    A cromoblastomicose é uma micose subcutânea, ocasionada por fungos dermatófitos, dos gêneros: Fonsecaea, Phialophora e Cladophialophora. As complicações habituais são: infecções secundárias, linfedema e elefantíase. Em lesões crônicas, tem-se documentado malignização. Relatamos um caso de um homem de 72 anos de idade, com cromoblastomicose de 30 anos de evolução, em região glútea, com desenvolvimento de carcinoma epidermoide.<br>Chromoblastomycosis is a subcutaneous mycosis caused by the dermatophytic fungi Fonsecaea, Phialophora and Cladophialophora. Usual complications include secondary infection, lymphedema and elephantiasis. Associated malignancies have been found in chronic cases. This case report describes a 72 year-old male with a 30 year history of chromoblastomycosis in the gluteal region, who went on to develop a squamous cell carcinoma
    corecore