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Determining indoor air quality and identifying the origin of odour episodes in indoor environments

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Journal of Environmental Sciences 2009年第3期21卷 333-339页

作者： Eva Gallego Xavier Roca Jose francisco Perales Xavier Guardino Environmental Centre Laboratory Polytechnic University of Catalonia (LCMA-UPC) Avda Diagonal 647 E 08028 Barcelona Spain National Centre of Work Conditions (INSHT) Dulcet 2-10 E 08034 Barcelona Spain

A methodology for identifying volatile organic compounds （VOCs） and determining air quality of indoor air has been developed. The air samples are collected using pump samplers by the inhabitants when they perceive odorous and/or discomfort episodes. Glass multi-sorbent tubes are connected to the pump samplers for the retention of VOC. The analysis is performed by automatic thermal desorption （ATD） coupled with gas chromatography-mass spectrometry （GC/MS）. This methodology can be applied in cases of sick building syndrome （SBS） evaluation, in which building occupants experience a series of varied symptoms that appear to be linked to time spent in the building. Chemical pollutants concentrations （e.g., VOC） have been described to contribute to SBS. To exemplify the methodology, a qualitative determination and an evaluation of existing VOC were performed in a dwelling where the occupants experienced the SBS symptoms. Higher total VOC （TVOC） levels were detected during episodes in indoor air （1.33 ±1.53 mg/m^3） compared to outdoor air （0.71± 0.46 mg/m^3）. The concentrations of individual VOCs, such as ethanol, acetone, isopropanol, 1-butanol, acetic acid, acetonitrile and 1-methoxy-2-propanol, were also higher than the expected for a standard dwelling. The external source of VOC was found to be an undeclared activity of storage and manipulation of solvents located at the bottom of a contiguous building.

关键词： indoor air thermal desorption TVOC VOC sick building syndrome

Bioleaching of zinc from gold ores using Acidithiobacillus ferrooxidans

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International Journal of Minerals,Metallurgy and Materials 2009年第4期16卷 368-374页

作者： Pakawadee Kaewkannetra francisco Jose Garcia-Garcia Tze Yen Chiu Department of Biotechnology Faculty of TechnologyKhon Kaen University Corrosion and Protection Centre School of MaterialsThe University of Manchester Centre of Water Science Cranfield University

The present work investigated microbial leaching of zinc from ore using Acidithiobacillus ferrooxidans （ATCC 14859）. The ore samples, consisted of 13wt% zinc, were obtained from a gold mine in north-eastern Thailand. A shake flask study was performed on the ore samples using a rotary shaker under the following fixed conditions （250 r·min^-1, 30℃ for 16 d）. The influence of various conditions, namely medium type （with and without iron）, particle ore size （〈20, 20-40, 40-60, 60-100, and 〉100 mesh）, ore density （20 kg·m^-3, 50 kg·m^-3, and 100 kg·m^-3）, and pH of the medium （2, 2.5, 2.8, and 3）, were investigated. The microbial leaching was assessed by determining the concentration of zinc in the medium and compared with the initial sample concentration. The results show that Acidithiobacillus ferrooxidans can successfully leach zinc by as much as 6 times compared with the control experiment （without Acidithiobacillus ferrooxidans ferrooxidans）. The maximum efficiency （92.3%） for microbial leaching is obtained in iron-containing medium, 20-40 mesh ore sizes, 20 kg·m^-3 ore density at pH 2.8, and the zinc content is found in the medium at about 120 mg·m^-1.

关键词： bioleaching Acidithiobacillusferrooxidans gold ores gold mine

Geography of Talent in China During 2000-2015:An Eigenvector Spatial Filtering Negative Binomial Approach

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Chinese Geographical Science 2021年第2期31卷 297-312页

作者： GU Hengyu francisco ROWE LIU Ye SHEN Tiyan School of Government Peking UniversityBeijing 100871China Geographic Data Science Lab Department of Geography and PlanningUniversity of LiverpoolLiverpool L69United Kingdom School of Geography and Planning Sun Yat-sen UniversityGuangzhou 510275China Guangdong Key Laboratory for Urbanization and Geo-Simulation Sun Yat-sen UniversityGuangzhou 510275China

The increase in China’s skilled labor force has drawn much attention from policymakers,national and international firms and *** how educated talent locates and re-locates across the country can guide future policy discussions of equality,firm localization and service *** studies have tended to adopt a static cross-national approach providing valuable insights into the relative importance of economic and amenity differentials driving the distribution of talent in ***,few adopt longitudinal analysis to examine the temporal dynamics in the stregnth of existing *** released official statistical data now enables space-time analysis of the geographic distribution of talent and its determinants in *** four-year city-level data from national population censuses and 1%population sample surveys conducted every five years between 2000 and 2015,we examine the spatial patterns of talent across Chinese cities and their underpinning drivers evolve over *** reveal that the spatial distribution of talent in China is persistently unequal and spatially concentrated between 2000 and *** also shows gradually strengthened and significantly positive spatial autocorrelation in the distribution of *** eigenvector spatial filtering negative binomial panel is employed to model the spatial determinants of talent *** indicate the influences of both economic opportunities and urban amenities,particularly urban public services and greening rate,on the distribution of *** results highlight that urban economic-and amenity-related factors have simultaneously driven China’s talent’s settlement patterns over the first fifteen years of the 21st century.

关键词： talent distribution determinants eigenvector spatial filtering panel data analysis China

Candidate genes underlying QTL for flowering time and their interactions in a wide spring barley(Hordeum vulgare L.) cross

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The Crop Journal 2021年第4期9卷 862-872页

作者： Ana M.Casas Carlota R.Gazulla Arantxa Monteagudo Carlos P.Cantalapiedra Marian Moralejo MPilar Gracia francisco J.Ciudad William T.B.Thomas Jose L.molina-Cano Scott Boden Bruno Contreras-Moreira Ernesto Igartua Department of Genetics and Plant Production Aula Dei Experimental Station(EEAD-CSIC)Avda Montanana 1005E-50059 ZaragozaSpain University of Lleida-AGROTECNIO Center Avda.Rovira Roure 19125198 LleidaSpain Instituto de Tecnologia Agraria Junta de Castilla y LeonITACyLP.O.Box 17247071 ValladolidSpain The James Hutton Institute InvergowrieDundee DD25DAUK Institut de Recerca i Tecnologia Agroalimentaries(UdL-IRTA) Avda Rovira Roure 19125198 LleidaSpain John Innes Centre Norwich Research ParkNorwich NR47UHUK Fundacion ARAID calle Maria de Luna 1150018 ZaragozaSpain Present address:Centro de Biotecnologia y Genomica de Plantas Universidad Politecnica de Madrid(UPM)and Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria(INIA)Madrid 28223Spain Present address:School of Agriculture Food and WineWaite Research InstituteUniversity of AdelaideGlen OsmondSA 5064Australia Present address:The European Bioinformatics Institute(EMBL-EBI) Wellcome Trust Genome CampusHinxtonUK

Response to vernalization and photoperiod are the main determinants controlling the time to flowering in temperate cereals. While the individual genes that determine a plant's response to these environmental signals are well characterized, the combinatorial effect on flowering time of allelic variants for multiple genes remains unresolved. This study investigated the genetic control of flowering-time in a biparental population of spring barley, derived from a wide cross between a late-flowering European and an early-flowering North-American cultivar. While the major flowering time genes are not segregating in the Beka ×Logan cross, large variation in flowering was observed. We identified five QTL, with both parents found to contribute early alleles. The catalog of QTL discovered aligns with several candidate genes affecting flowering time in barley. The combination of particular alleles at HvCEN, HvELF3 and HvFT1 in Logan are responsible for the earliness of this cultivar. Interestingly, earliness for flowering could be further enhanced, with Beka found to contribute three early alleles, including a QTL colocating with a HvFD-like gene, suggesting that there are diverse aspects of the flowering-time pathway that have been manipulated in these two cultivars. Epistatic interactions between flowering-time QTL or candidate genes were observed in field data and confirmed under controlled conditions. The results of this study link photoperiod-dependent flowering-time genes with earliness per se genes into a single model, thus providing a unique framework that can be used by geneticists and breeders to optimize flowering time in barley.

关键词： Barley Flowering HvELF3 HvCEN HvFT1

A Sylvester-Based IMEXMethod via Differentiation Matrices for Solving Nonlinear Parabolic Equations

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Communications in Computational Physics 2013年第9期14卷 1001-1026页

作者： francisco de la Hoz Fernando Vadillo Department of Applied Mathematics Statistics and Operations ResearchFaculty of Science and TechnologyUniversity of the Basque Country UPV/EHUBarrio Sarriena S/N48940 LeioaSpain

In this paper we describe a new pseudo-spectral method to solve numerically two and three-dimensional nonlinear diffusion equations over unbounded domains,taking Hermite functions,sinc functions,and rational Chebyshev polynomials as basis *** idea is to discretize the equations by means of differentiation matrices and to relate them to Sylvester-type equations by means of a fourth-order implicit-explicit scheme,being of particular interest the treatment of three-dimensional Sylvester equations that we *** resulting method is easy to understand and express,and can be implemented in a transparent way by means of a few lines of *** test numerically the three choices of basis functions,showing the convenience of this new approach,especially when rational Chebyshev polynomials are considered.

关键词： Semi-linear diffusion equations pseudo-spectral methods differentiation matrices Hermite functions sinc functions rational Chebyshev polynomials IMEX methods Sylvester equations blow-up

EQUIVALENT UNIFORM DOSE SENSITIVITY TO CHANGES IN ABSORBED DOSE DISTRIBUTION

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International Journal of Biomathematics 2013年第1期6卷 129-142页

作者： francisco CUTANDA-HENRIQUEZ SILVIA VARGAS-CASTRILLON Hospital General Universitario Gregorio Mara~Sn Calle Doctor Esquerdo 46 28007 Madrid Spain Universidad Politdcnica de Madrid Ciudad Universitaria s/n 28040 Madrid Spain

Treatment planning in external beam radiation therapy （EBRT） utilizes dose volume histograms （DVHs） as optimization and evaluation tools. They present the fraction of planning target volume （PTV） receiving more than a given absorbed dose, against the absorbed dose values, and a number of radiobiological indices can be computed with their help. Equivalent uniform dose （EUD） is the absorbed dose that, uniformly imparted, would yield the same biological effect on a tumor as the dose distribution described by the DVH. Uncertainty and missing information can affect the dose distribution, therefore DVHs can be modeled as samples from a set of possible outcomes. This work studies the sensitivity of the EUD index when a small change in absorbed dose distribution takes place. EUD is treated as a functional on the set of DVHs. Defining a Levy distance on this set and using a suitable expansion of the functional, a very simple expression for a bound on the variation of EUD when the dose distribution changes is found. This bound is easily interpreted in terms of standard treatment planning practice.

关键词： Equivalent uniform dose DVH von Mises differential.

Clinical Profiles at the Time of Diagnosis of SARS-CoV-2 Infection in Costa Rica During the Pre-vaccination Period Using a Machine Learning Approach

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Phenomics 2022年第5期2卷 312-322页

作者： Jose Arturo molina-Mora Alejandra González Sergio Jiménez-Morgan Estela Cordero-Laurent Hebleen Brenes Claudio Soto-Garita Jorge Sequeira-Soto francisco Duarte-Martínez Centro de Investigación en Enfermedades Tropicales(CIET)and Facultad de Microbiología Universidad de Costa RicaSan José2060Costa Rica Instituto Costarricense de Investigación y Enseñanza en Nutrición y Salud(INCIENSA) Tres Ríos 30301Costa Rica Escuela de Medicina Universidad de Costa RicaSan José2060Costa Rica

The clinical manifestations of COVID-19,caused by the SARS-CoV-2,define a large spectrum of symptoms that are mainly dependent on the human host *** Costa Rica,more than 169,000 cases and 2185 deaths were reported during the year 2020,the pre-vaccination *** describe the clinical presentations at the time of diagnosis of SARS-CoV-2 infection in Costa Rica during the pre-vaccination period,we implemented a symptom-based clustering using machine learning to identify clusters or clinical profiles at the population level among 18,974 records of positive *** were compared based on symptoms,risk factors,viral load,and genomic features of the SARS-CoV-2 sequence.A total of 18 symptoms at time of diagnosis of SARS-CoV-2 infection were reported with a frequency>1%,and those were used to identify seven clinical profiles with a specific composition of clinical *** the comparison between clusters,a lower viral load was found for the asymptomatic group,while the risk factors and the SARS-CoV-2 genomic features were distributed among all the *** other distribution patterns were found for age,sex,vital status,and *** conclusion,during the pre-vaccination time in Costa Rica,the symptoms at the time of diagnosis of SARS-CoV-2 infection were described in clinical *** host co-morbidities and the SARS-CoV-2 genotypes are not specific of a particular profile,rather they are present in all the groups,including asymptomatic *** addition,this information can be used for decision-making by the local healthcare institutions(first point of contact with health professionals,case definition,or infrastructure).In further analyses,these results will be compared against the profiles of cases during the vaccination period.

关键词： COVID-19 Costa Rica Machine learning Diagnosis SARS-CoV-2 Clinical profiles

Extracellular vesicles in liver disease and beyond

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World Journal of Gastroenterology 2018年第40期24卷 4519-4526页

作者： Laura Morán francisco Javier Cubero Department of Immunology Ophthalmology and ORLComplutense University School of MedicineMadrid 28040Spain 12 de Octubre Health Research Institute(imas12) Madrid 28041Spain

Extracellular vesicles(EVs) are membrane-derived vesicles which can be released by different cell types, including hepatocytes, hepatic stellate cells and immune cells in normal and pathological conditions. EVs carry lipids, proteins, coding and non-coding RNAs and mitochondrial DNA causing modifications on the recipient cells. These vesicles are considered potential biomarkers and therapeutic agents for human diagnostic and prognostic due to their function as intercellular mediators of cell-cell communication within the liver and between other organs. However, the development and optimization of methods for EVs isolation is required to characterize their biological functions as well as their potential as a treatment option in the clinic. Nevertheless, many questions remain unanswered related to the function of EVs under physiological and pathological conditions. In the current editorial, the results obtained in different studies that investigated the role of intrahepatic EVs during liver diseases, including drug-induced liver injury, non-alcoholic fatty liver, nonalcoholic steatohepatitis, alcoholic liver disease and hepatocellular carcinoma and extrahepatic EVs in remote organs during pathological events such as pulmonary disease, cardiovascular diseases, neurodegenerative disorders e.g., Alzheimer's disease, Parkinson's disease and multiple sclerosis as well as in immunopathological processes, are discussed. Although much light needs to be shed on the mechanisms of EVs, these membranederived vesicles represent both a novel promising diagnostic, and a therapeutic tool for clinical use that we emphasize in the current editorial.

关键词： Extracellular vesicles microRNA Hepatocytes Drug-induced liver injury Alcoholic liver disease Nonalcoholic fatty liver disease Non-alcoholic steatohepatitis Hepatocellular carcinoma

Stability analysis of slopes with planar failure using variational calculus and numerical methods

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Frontiers of Structural and Civil Engineering 2020年第5期14卷 1262-1273页

作者： Norly BELANDRIA RobertoÚCAR francisco M.LEON Ferri HASSANI Geological Engineering School University of Los AndesMérida 5101Venezuela Mechanical Engineering School University of Los AndesMérida 5101Venezuela Department of Mining and Material Engineering McGill UniversityMontrealQC H3A 0E9Canada

This study investigates the technique of variational calculus applied to estimate the slope stability considering the mechanism of planar *** critical plane failure surface should be determined because it theoretically indicates the most unfavorable plane to be considered when stabilizing a slope to rectify the instability generated by several statistically possible *** generates integrals that can be solved by numerical methods,such as the Newton Cotes and the finite differences ***,a system of nonlinear equations is obtained and *** surface of the critical planar failure is determined by applying the condition of transversality in mobile boundaries,for which various examples are *** number of slices is varied in one of the examples,while the surface of the critical planar failure is determined in the *** are compared using analytical methods through axis *** the results obtained by considering normal stress,safety factors,and critical planar failure are nearly the same;however,in this research,a study is carried out for“n”number of slices using programming ***-routines are important because they can be applied in slopes with different geometry,surcharge,interstitial pressure,and pseudo-static load.

关键词： slopes stability planar failure variational calculus numerical methods