464 research outputs found

    Medically important trombiculids: a systematic review of the global distribution and clinical consequences of their bites

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    Background: Mites are among the smallest arthropods that can be seen without magnification, were the use of dermatoscopy is an invaluable tool. They are a cosmopolitan pest, and at the moment more than 250 species have been shown to produce problems for humans and animals alike. These mites are capable of producing a wide array of clinical signs and symptoms, from local to systemic, from mild to severe, as well as transmitting pathogens. This study aimed to provide an update to the clinical impact on human health, the distribution and species involved in the clinical conditions produced by trombiculids through a systematic review. Background: Mites are among the smallest arthropods that can be seen without magnification, were the use of dermatoscopy is an invaluable tool. They are a cosmopolitan pest, and at the moment more than 250 species have been shown to produce problems for humans and animals alike. These mites are capable of producing a wide array of clinical signs and symptoms, from local to systemic, from mild to severe, as well as transmitting pathogens. This study aimed to provide an update to the clinical impact on human health, the distribution and species involved in the clinical conditions produced by trombiculids through a systematic review. Methods: A systematic literature review was conducted in Medline, Lilacs, Redalyc, Scopus, SciELO and Google Scholar, were we use as a threshold of publication date the year 2008. We limited the search strategy to articles published in Portuguese, French, English and Spanish. Eligible studies were case reports and case series that reported outcomes in humans caused by trombiculid bites. Patient-level and study-level information was extracted. Results: The literature search yielded 832 studies; 13 were case reports, 4 case series and 2 descriptive studies reporting a total of 49 cases. Most patients were male, and the median age was 33.7±6.4 years old. The most frequently reported symptoms were local erythema, pruritus and papules. No deaths were documented. Trombiculids from the genera Trombicula, Eutrombicula and Leptotrombidium appear to be the most commonly reported. Discussion: Trombiculiasis is an infestation caused by the larval stage of various types of mites, known as chiggers, they belong to the class Arachnida and the family Trombiculidae. This systematic review provides an overview of the trombiculids of clinical importance, their distribution and effects of the bite on human health. Our results show that there are different species of mites that can have important consequences for human health. No fatal cases owere registered.Even so, the transmission of scrub typhus is important and remains one of the most life-threatening rickettsial infections in some regions of Asia. Conclusions: The bite of different species of trombiculids around the world can cause a wide array of clinical consequences to human health. Even as mortality appear to be nonexistent, trombiculid bites must be adequately diagnosed and treated properly: A systematic literature review was conducted in Medline, Lilacs, Redalyc, Scopus, SciELO and Google Scholar, were we use as a threshold of publication date the year 2008. We limited the search strategy to articles published in Portuguese, French, English and Spanish. Eligible studies were case reports and case series that reported outcomes in humans caused by trombiculid bites. Patient-level and study-level information was extracted. Results: The literature search yielded 832 studies; 13 were case reports, 4 case series and 2 descriptive studies reporting a total of 49 cases. Most patients were male, and the median age was 33.7±6.4 years old. The most frequently reported symptoms were local erythema, pruritus and papules. No deaths were documented. Trombiculids from the genera Trombicula, Eutrombicula and Leptotrombidium appear to be the most commonly reported. Discussion: Trombiculiasis is an infestation caused by the larval stage of various types of mites, known as chiggers, they belong to the class Arachnida and the family Trombiculidae. This systematic review provides an overview of the trombiculids of clinical importance, their distribution and effects of the bite on human health. Our results show that there are different species of mites that can have important consequences for human health. No fatal cases owere registered.Even so, the transmission of scrub typhus is important and remains one of the most life-threatening rickettsial infections in some regions of Asia. Conclusions: The bite of different species of trombiculids around the world can cause a wide array of clinical consequences to human health. Even as mortality appear to be nonexistent, trombiculid bites must be adequately diagnosed and treated properly.Antecedentes: Los ácaros están entre los artrópodos más pequeños que pueden ser vistos a simple vista , donde el uso de la dermatoscopia es una herramienta invaluable. Son una plaga cosmopolita, y hasta el momento se ha demostrado que más de 250 especies producen problemas tanto para los humanos como para los animales. Estos ácaros son capaces de producir una amplia gama de signos y síntomas clínicos, desde los locales hasta los sistémicos, de leves a graves, así como la transmisión de patógenos. El objetivo de este estudio fue proporcionar una actualización del impacto clínico en la salud humana, la distribución y las especies implicadas en estas condiciones clínicas producida por los trombiculidos a través de una revisión sistemática. Métodos: Se realizó una revisión sistemática de la literatura en Medline, Lilacs, Redalyc, Scopus, SciELO y Google Scholar, utilizamos como umbral de fecha de publicación el año 2008. Limitamos la estrategia de búsqueda a los artículos publicados en portugués, francés, inglés y español. Los estudios elegibles fueron informes de casos y series de casos que informaron de resultados en humanos causados por mordeduras de trombicúlidos. Se extrajo información a nivel de paciente y a nivel de estudio. Resultados: La búsqueda bibliográfica arrojó 832 estudios, de los cuales 13 fueron reportes de caso, 4 series de caso and 2 estudios descriptivos de casos que informaban de un total de 49 casos. La mayoría de los pacientes eran varones y la edad media era de 33,7±6,4 años. Los síntomas más frecuentes fueron el eritema local, el prurito y las pápulas. No se documentaron muertes. Los trombicúlidos de los géneros Trombicula, Eutrombicula y Leptotrombidium parecen ser los más comúnmente reportados. Discusión: La trombiculiasis es una infestación causada por varios tipos de ácarosen la etapa larval, también conocidas como niguas o coloraditos, pertenecen a la clase Arachnida y a la familia Trombiculidae. Esta revisión sistemática ofrece una visión general de los trombicúlidos de importancia clínica, su distribución y los efectos de la picadura en la salud humana. Nuestros resultados muestran que hay diferentes especies de ácaros que pueden tener importantes consecuencias para la salud humana. No se registraron casos de mortalidad. Aún así, el tifus de los matorrales sigue siendo una de las enfermedades producidas por rickettsiosis más peligrosas para la vida en algunas regiones de Asia. Conclusiones: La mordedura de diferentes especies de trombicúlidos en todo el mundo puede causar una amplia gama de consecuencias clínicas para la salud humana. Aunque la mortalidad parece no existir, las mordeduras de trombicúlidos deben ser adicionalmente diagnosticadas y tratadas adecuadamente

    Vertex Pavilion. Deployable arches structure with triangular section

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    The research study presented in this paper focused on the potential of scissor-like deployable structures with straight bars to create compact, light and cost-effective solutions for temporary shelters and emergency architecture. The design and construction process included parametric design; various scale model prototypes and a final 1:1 scale prototype. The ‘Vertex’ structure is comprised of three triangles made up of 27 scissor-like straight bars. When unfolded the triangles scissor-like bars deploy to create three arches. The arches are joined to each other at ground level and secured in place using three bases. Finally, the arches’ stability is secured at the upper level by the tension force of the textile membrane. The fabrication process included both conventional fabrication and assembly of materials as well as the use of 3D printing and laser cutting technology. The assembly of the 1:1 prototype was carried out in one hour. Each triangle weights 9 kg, and the entire structure including the bases and the textile is 70kg. The prototype was fabricated and tested by the MArch Architecture students and Lab at Nottingham Trent University, as part of a workshop on deployable structures conducted by the SMiA (Structural Morphology in Architecture) Research Group

    La formación de un equipo de orientación sistémica en la institución.

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    Se describen las circunstancias que atraviesa un grupo de profesionales de la salud mental trabajando en un centro institucional y cómo su libertad de acción, condicionada a no perder en cada una de las jugadas que se plantean en cada momento y frente a otros jugadores con los que se encuentra en relación, le lleva a una organización del trabajo singular. Este ordenamiento está basado en un modelo sistémico, centrado en lo relacional, lo que se deduce de la historia del grupo humano que lo crea, pero también de la naturaleza de la tarea a la que se dedica. Finalmente se da cuenta de esta organización y de su funcionalidad, dado que es un producto de participantes diversos, libres y nunca pasivos o maleables

    La formación de un equipo de orientación sistémica en la institución.

    Get PDF
    Se describen las circunstancias que atraviesa un grupo de profesionales de la salud mental trabajando en un centro institucional y cómo su libertad de acción, condicionada a no perder en cada una de las jugadas que se plantean en cada momento y frente a otros jugadores con los que se encuentra en relación, le lleva a una organización del trabajo singular. Este ordenamiento está basado en un modelo sistémico, centrado en lo relacional, lo que se deduce de la historia del grupo humano que lo crea, pero también de la naturaleza de la tarea a la que se dedica. Finalmente se da cuenta de esta organización y de su funcionalidad, dado que es un producto de participantes diversos, libres y nunca pasivos o maleables

    Valorisation of the liquid fraction from hydrothermal carbonisation of sewage sludge by anaerobic digestion

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    This is the peer reviewed version of the following article: Journal of Chemical Technology and Biotechnology 93.2 (2018): 450-456, which has been published in final form at https://doi.org/10.1002/jctb.5375. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsBACKGROUND: The mesophilic anaerobic digestion of the liquid fraction from hydrothermal carbonisation (208°C, 1 h) of dehydrated sewage sludge has been studied. Two initial inoculum concentrations (IC) (10 and 25 g COD L-1) and four inoculum to substrate ratios (ISR) (2, 1, 0.5 and 0.4 on a COD basis) have been selected to analyse their influence on the evolution of the anaerobic digestion process. RESULTS: The substrate is characterised by a high COD (95.5 g L-1) and TKN (8.7 g N L-1) values. High inoculum concentration (25 g COD L-1) and/or low ISR (≤ 0.5) inhibited methanogenesis due to the high ammonia nitrogen (1.4 g TAN L-1) and VFA (>4 g COD L-1) released. For the inhibited samples final COD removals lower than 15% and IA/TA ratios higher than 0.3 were found. The greatest methane yield (177±5 mL CH4 STP g-1 CODadded) was achieved at 25 g COD L-1 of IC and at an ISR of 2. CONCLUSION: During anaerobic digestion of the liquid fraction from the hydrothermal carbonisation of sewage sludge, the IC and ISR must be adequately selected for proper operation of the process and successful valorisation. According to the results, working at an ISR ≥ 1 is recommendedThe authors wish to express their gratitude to the UAM-Santander (Project CEAL-AL/2015-29) and Spanish MINECO (CTM2016-76564-R) for providing financial support. MA de la Rubia acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (RYC-2013-12549

    Fouling control in membrane bioreactors with sewage-sludge based adsorbents

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    The potential application of powdered activated carbon (PAC) to mitigate membrane fouling has been tested in membrane bioreactors (MBRs) fed with cosmetic wastewater. Inexpensive powder activated carbon was prepared from sewage sludge biosolids (B-PAC) by pyrolysis (750 °C; 0.5 h) and air-activation (400 °C; 2 h). Adsorption capacities of 143 and 570 mg g −1 were reached for carbohydrates and proteins, respectively, quite similar to those of a commercial activated carbon (C-PAC). To check the effect of PAC addition on membrane fouling, three MBRs were simultaneously operated without (control-MBR) and with PAC (B-MBR and C-MBR) for 150 days in continuous mode at 8 L m −2  h −1 flux. Similar COD removal efficiencies were achieved in these three MBR systems. After 100 days of operation, the effect of the PACs on the sludge filterability was studied in the MBRs for 10 days. B-MBR showed stable transmembrane pressure (TMP) after 9 days of operation, unlike of control-MBR and C-MBR, where the TMP increased after the 2nd and 5th days, respectively. Therefore, operational cost saving can be achieved in the membrane cleaning due to decrease of fouling rate. Operating at stable state condition the addition of PAC gave rise to an increase of the critical flux of 25%. In an extra shear test, carried out at the end of the continuous experiment, a clear reduction in mean size of the flocs from 45 to 28 μm was observed in control-MBR. However, the extra shear led to a slight reduction of the mean size of flocs (less than 5%) in MBRs with PAC, with average sizes of 62 and 71 μm in C-MBR and B-MBR, respectively. The molecular weight fractionation of the MBR demonstrated a higher selectivity of B-PAC toward the adsorption of proteins smaller than 1 μm which prevents the irreversible fouling of the membranes. The membranes lifetime was increased because the B-PAC extended the filtration for a longer period than C-PAC, probably due to its easier in-situ regenerationThe authors greatly appreciatefinancial support by the SpanishMinisterio de Economia y Competitividad and Comunidad deMadrid through the projects CTM2013-43803-P and P2013/MAE-2716, respectivel

    Experimental workshop in unconventional structures: deployable & tree-like structures SMiA -training and research at Barcelona Tech

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    The purpose of this paper is to share the experience, training and teaching students in non conventional structures area. The research group SMiA Structural Morphology in Architecture performed a practical and theoretical workshop designed to learn unconventional structures in architecture. The main objective was to propose a practical teaching method, the students gain the necessary tools to design lightweight and membrane structures developing an architectural project. Physical and digital tools are utilized, including WinTess3, Sketch Up, Grasshopper, a parametric-geometry-development-and-testing software.Lightweight Construction Course is an elective architecture program at ETSAV School of Architecture of "El Vallès", leading by Professor Dr.-Arch. Ramon Sastre. The main topics that were developed are: Deployable, Tree-Like, Reciprocal Frame, and Tensegrity Structures. In the present article we explain the practical experience in Deployable and Tree-like Structures. The course was offered to students in the last year of career at UPC, international students (Erasmus) and Master students.Peer ReviewedPostprint (published version

    Anaerobic co-digestion of the aqueous phase from hydrothermally treated waste activated sludge with primary sewage sludge. A kinetic study

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    The mesophilic anaerobic co-digestion of the liquid fraction from hydrothermal carbonization (LFHTC) of dewatered waste activated sludge with primary sewage sludge (PSS) has been studied. Mixtures of different composition (25, 50 and 75% of LFHTC on a chemical oxygen demand (COD) basis), as well as the individual substrates, have been tested using two inocula (flocculent (FS) and granular (GS) sludges). Methane production decreased as the LFHTC/PSS ratio increased, which can be related to the presence of recalcitrant compounds in the LFHTC, such as alkenes, phenolics, and other oxygen- and nitrogen-bearing aromatics hard-to-degrade through anaerobic digestion. Methane yield reached 248 ± 11 mL CH4 STP/g CODadded with the GS inoculum and 25% LFHTC. A 74 and a 30% increase of methane production was achieved in the 25% LFHTC runs respect to the obtained in the similar experiments with 100% LFHTC, using the FS and GS inocula, respectively. In those late runs, the COD was reduced more than 86%, with a negligible concentration of total volatile fatty acids. With both inocula, total Kjeldahl nitrogen hydrolysis increased as the LFHTC to PSS mixture ratio decreased, reaching values higher than 79% at the end of the experiments. Methane yield values fitted well the first-order, Cone and Weibull kinetic models for both inocula. Significant differences in the kinetic constant values, ranging from 0.100 to 0.168 d−1 and 0.059–0.068 d−1, were found with the FS and GS inocula, respectively. The results obtained support the potential integration of HTC of dewatered waste activated sludge in wastewater treatment plantsThe authors greatly appreciate financial support from the SpanishMINECO (Project CTM2016-76564-R) and the Community of Madrid(Project P2013/MAE-2716). M.A. de la Rubia acknowledges financialsupport from the Spanish MINECO (RYC-2013-12549). The valuablecontribution of
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