99 research outputs found

    Ferrocarril del Melocotón al Volcán

    Get PDF

    3D Claying: 3D Printing and Recycling Clay

    Get PDF
    Clay is of great interest as a 3D printing material thanks to its ease of use, recyclability and reusability. This paper analyses the technical aspects of the whole printing process. The behaviour of 3D printing clay is studied with respect to the environment and its specific application as a temporary or definitive formwork system for cement parts. The study addresses the performance of clay and the loss of its properties and characteristics according to the type of protection, whether it is in direct contact with air or cement, or protected with plastics, metal sheets, or combinations of both. A 3D printing system with various printers and 3D models has been considered, observing a direct relationship between the prototype shape, extrusion process and resulting material. The most important variables in 3D printing have been considered: layer height, line thickness, base definition, total model height, overhang angles, overlap between layers, etc. The main technical aspects have been analysed such as raw material properties, kneading, process control, post-treatments and material hardening. As a natural material, clay can be reused indefinitely under certain conditions to be part of a circular economy with low energy consumption and minimal resources. It is concluded that the option of using ceramics in 3D printing for very diverse uses in the architecture, engineering & construction (AEC) sector is very promising due to their ease of implementation, recycling capability and suitability to different environment

    Renewable generation and demand response integration in micro-grids: development of a new energy management and control system

    Full text link
    The aim of this research resides in the development of an energy management and control system (EMCS) to control a micro-grid based on the use of renewable generation and demand resources to introduce the application of demand response concepts to the management of micro-grids in order to effectively integrate the demand side as an operation resource for the grid and improve energy efficiency of the elements. As an additional result, the evaluation of reductions in the total amount of CO2 emitted into the atmosphere due to the improvement of the energy efficiency of the system is assessed.Álvarez, C.; Escrivá-Escrivá, G.; Alcázar-Ortega, M. (2013). Renewable generation and demand response integration in micro-grids: development of a new energy management and control system. Energy Efficiency. 6(2):695-706. doi:10.1007/s12053-013-9207-9S69570662Alcázar-Ortega, M. (2011). “Evaluation and assessment of new demand response programs based on the use of flexibility in industrial processes: Application to the food industry”. Ph.D. Dissertation. University of South Florida and Universidad Politécnica de Valencia. FebruaryAlcázar-Ortega, M., Álvarez-Bel, C., Escrivá-Escrivá, G., & Domijan, A. (2012). Evaluation and assessment of demand response potential applied to the meat industry. Applied Energy, 92, 84–91.Álvarez Bel, C., Alcázar Ortega, M., Escrivá Escrivá, G., & Gabaldón Marín, A. (2009). Technical and economical tools to assess customer demand response in the commercial sector. Energy Conversion and Management, 50(10), 2605–2612.Álvarez, C., Gabaldón, A., & Molina, A. (2004). Assessment and simulation of the responsive demand potential in end-user facilities: application to a university customer. Institute of Electrical and Electronics Engineers Transactions on Power Systems, 19, 1223–1231.Amorim, A., Cardoso, A.L., Oyarzabal, J. and Melo, N. (2005). “Analysis of the Connection of a Microturbine to a Low Voltage Grid”. Future Power Systems, International Conference on 16–18 Nov. 2005 Page(s):1–5Chiu A., Ipakchi A., Chuang A., Qiu B., Brooks D., Koch E., et al. (2009), Framework for integrated demand response (DR) and distributed energy resources (DER) models. NAESB & UCAIug. September; 2009. .Cowart, R. (2001). “Efficient reliability, the critical role of demand-side resources in power systems and markets”. The national association of regulatory utility commissioners, junioDimeas, A. L., & Hatziargyriou, N. D. (2005). Operation of a multiagent system for microgrid control. Institute of Electrical and Electronics Engineers Transactions on Power Systems, 20(3), 1447–1455.Elgerd, O. (1982). Electric energy systems: theory and introduction. New York: McGraw-Hill.Escrivá, G., Alcázar,M., Alvarez,C. (2009). “Integral management system for the energy efficiency improvement in commercial facilities: Application to the Polytechnic University of Valencia”. International conference on renewable energy and power quality (ICREPQ’09), AprilEscrivá-Escrivá, G., Segura-Heras, I., & Alcázar-Ortega, M. (2010). Application of an energy management and control system to assess the potential of different control strategies in HVAC systems. Energy and Buildings, 42(11), 2258–2267.European Commission (2003), “New ERA for electricity in Europe”. Directorate General for Research.Ghiani, E. Mocci, S. and Pilo, F. (2005). “Optimal reconfiguration of distribution networks according to the microgrid paradigm”. Future Power Systems, International Conference on16-18 Nov. 2005 Page(s):6 ppGlover, J., Sarma, M., & Overbye, T. (2008). Power systems: analysis and design. Toronto: Thompson.Hatziargyriou, N.D., Dimeas, A., Tsikalakis, A.G., Pecas Lopes, J.A., Kariniotakis, G.G, and Oyarzabal, J. (2005). “Management of Microgrids in Market Environment”. Future Power Systems, International Conference on 16–18 Nov. Page(s):1 – 7.ICF Consulting. (2002). “Economic assessment of RTO policy Report”. FERC, mayo 2002.Jayawarna, N., Wu, S., Zhang, Y., Jenkins N. and Barnes, M. (2006). “Stability of a Microgrids”. Power Electronics, Machines and Drives. The 3rd IET International Conference on Mar. 2006 Page(s):316 – 320Kennedy, J., Fox, B., & Morrow, D. J. (2007). Distributed generation as a balancing resource for wind generation. IET Renewable Power Generation, 1(3), 167–174.Kirschen, D. S. (2003). Demand-side view of electricity markets. Institute of Electrical and Electronics Engineers Transactions, 18, 520–527.Kojima, Y., Koshio, M., Nakamura, S., Maejima, H., Fujioka, Y. and Goda, T. (2007). “A Demonstration Project in Hachinohe: Microgrids with Private Distribution Line”. System of Systems Engineering. SoSE ‘07. IEEE International Conference on 16–18 April 2007 Page(s):1 – 6Lasseter, R.H. and Piagi, P. (2007). “Extended Microgrids Using (DER) Distributed Energy Resources”. Power Engineering Society General Meeting. IEEE24- 28 June 2007 Page(s):1–5Lopes, J. A. P., Moreira, C. L., & Madureira, A. G. (2006). Defining control strategies for microgrids islanded operation. Institute of Electrical and Electronics Engineers Transactions on Power Systems, 21(2), 916–924.Marnay, C., Venkataramanan, G., Stadler, M., Siddiqui, M. A., Firestone, R. and Chandran, B. (2007). “Optimal Technology Selection and Operation of Microgrids in Commercial Buildings”. 67 Power Engineering Society General Meeting. IEEE 24–28 June 2007 Page(s):1 – 7Nikkhajoei, H. and Lasseter R.H. (2007). “Microgrids Protection”. Power Engineering Society General Meeting, 2007. IEEE 24–28 June Page(s):1 – 6Rassanti, S., Smith, V. and Wilson, B. (2001). “Controlling market power and price spikes in electricity networks: Demand-side bidding”. Interdisciplinary centre for economic science, George Mason University, JulyThe Federal Energy Regulatory Commission Staff: Draft for Comment of the National Action Plan on Demand Response. March; 2010. .Yunwei, L., Vilathgamuwa, D. M., & Poh Chiang, L. (2004). Design, analysis, and realtime testing of a controller for multibus microgrid system”. Institute of Electrical and Electronics Engineers Transactions on Power Electronics, 19(5), 1195–1204

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

    Get PDF
    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Quantification of carbon and phosphorus co-limitation in bacterioplankton: new insights on an old topic

    Get PDF
    Because the nature of the main resource that limits bacterioplankton (e.g. organic carbon [C] or phosphorus [P]) has biogeochemical implications concerning organic C accumulation in freshwater ecosystems, empirical knowledge is needed concerning how bacteria respond to these two resources, available alone or together. We performed field experiments of resource manipulation (2×2 factorial design, with the addition of C, P, or both combined) in two Mediterranean freshwater ecosystems with contrasting trophic states (oligotrophy vs. eutrophy) and trophic natures (autotrophy vs. heterotrophy, measured as gross primary production:respiration ratio). Overall, the two resources synergistically co-limited bacterioplankton, i.e. the magnitude of the response of bacterial production and abundance to the two resources combined was higher than the additive response in both ecosystems. However, bacteria also responded positively to single P and C additions in the eutrophic ecosystem, but not to single C in the oligotrophic one, consistent with the value of the ratio between bacterial C demand and algal C supply. Accordingly, the trophic nature rather than the trophic state of the ecosystems proves to be a key feature determining the expected types of resource co-limitation of bacteria, as summarized in a proposed theoretical framework. The actual types of co-limitation shifted over time and partially deviated (a lesser degree of synergism) from the theoretical expectations, particularly in the eutrophic ecosystem. These deviations may be explained by extrinsic ecological forces to physiological limitations of bacteria, such as predation, whose role in our experiments is supported by the relationship between the dynamics of bacteria and bacterivores tested by SEMs (structural equation models). Our study, in line with the increasingly recognized role of freshwater ecosystems in the global C cycle, suggests that further attention should be focussed on the biotic interactions that modulate resource co-limitation of bacteria.This research was supported by Junta de Andalucía (Excelencia P09-RNM-5376 to JMMS) and the Spanish Ministry Ciencia e Innovación (CGL2011-23681 to PC)

    Associations of the FTO rs9939609 and the MC4R rs17782313 polymorphisms with type 2 diabetes are modulated by diet, being higher when adherence to the mediterranean diet pattern is low

    Get PDF
    BACKGROUND: Although the fat mass and obesity (FTO) and melanocortin-4 receptor (MC4R) genes have been consistently associated with obesity risk, the association between the obesity-risk alleles with type 2 diabetes is still controversial. In some recent meta-analyses in which significant results have been reported, the associations disappeared after adjustment for body mass index (BMI). However gene-diet interactions with dietary patterns have not been investigated. Our main aim was to analyze whether these associations are modulated by the level of adherence to the Mediterranean Diet (MedDiet). METHODS: Case-control study in 7,052 high cardiovascular risk subjects (3,430 type 2 diabetes cases and 3,622 non-diabetic subjects) with no differences in BMI. Diet was assessed by validated questionnaires. FTO-rs9939609 and MC4R-rs17782313 were determined. An aggregate genetic score was calculated to test additive effects. Gene-diet interactions were analyzed. RESULTS: Neither of the polymorphisms was associated with type 2 diabetes in the whole population. However, we found consistent gene-diet interactions with adherence to the MedDiet both for the FTO-rs9939609 (P-interaction=0.039), the MC4R-rs17782313 (P-interaction=0.009) and for their aggregate score (P-interaction=0.006). When adherence to the MedDiet was low, carriers of the variant alleles had higher type 2 diabetes risk (OR=1.21, 95%CI: 1.03-1.40; P=0.019 for FTO-rs9939609 and OR=1.17, 95%CI:1.01-1.36; P=0.035 for MC4R-rs17782313) than wild-type subjects. However, when adherence to the MedDiet was high, these associations disappeared (OR=0.97, 95%CI: 0.85-1.16; P=0.673 for FTO-rs9939609 and OR=0.89, 95%CI:0.78-1.02; P=0.097 for MC4R-rs17782313). These gene-diet interactions remained significant even after adjustment for BMI. As MedDiet is rich in folate, we also specifically examined folate intake and detected statistically significant interaction effects on fasting plasma glucose concentrations in non-diabetic subjects. However these findings should be interpreted with caution because folate intake may simply reflect a healthy dietary pattern. CONCLUSIONS: These novel results suggest that the association of the FTO-rs9939609 and the MC4R-rs17782313 polymorphisms with type 2 diabetes depends on diet and that a high adherence to the MedDiet counteracts the genetic predisposition

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

    Get PDF
    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    IMPACT-Global Hip Fracture Audit: Nosocomial infection, risk prediction and prognostication, minimum reporting standards and global collaborative audit. Lessons from an international multicentre study of 7,090 patients conducted in 14 nations during the COVID-19 pandemic

    Get PDF

    Pan-cancer analysis of whole genomes

    Get PDF
    Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

    Get PDF
    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
    corecore