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Journal of Environmental Sciences 2019年第2期31卷 403-414页

作者： Cesar Nieto-delgado Joel Gutiérrez-Martínez J.Rene Rangel-Méndez Environmental Sciences Division Potosino Institute of Scientific and Technological ResearchIPICyT

The arsenic removal efficiency of iron-modified activated carbons depends greatly on the number of available iron oxide surface sites, which are given by the surface area of the anchored particles. In this sense, aiming the generation of an adsorbent with superior arsenic adsorption capacity, we developed a protocol to anchor interconnected fibrils of iron oxyhydroxides, using Mn^(2+) as a morphology regulator. The protocol was based on a microwave-assisted hydrothermal method, using bituminous based activated carbon and both Fe^(2+) and Mn^(2+) ions in the hydrolysis solution. The elemental analysis of modified carbons revealed that Mn does not anchor to the carbon. However, when Mn is included in the hydrolysis solution, the iron content in the activated carbon increased up to 3.5 wt%,without considerable decreasing the adsorbent surface area. Under specific hydrothermal conditions, the Mn^(2+) promoted the formation of iron oxide nanoparticles shaped as interconnected fibrils. This material showed a superior arsenic adsorption capacity in comparison to similar iron modified activated carbons(5 mg As/g carbon, at 2 mg As/L),attributed to the increase in quantity and availability of active sites located on the novel interconnected fibrils of iron oxyhydroxides nanostructures.

关键词： Iron oxide nanostructures Hydrothermal synthesis Microwave Adsorption capacity Kinetics

Effect of indaziflam on microbial activity and nitrogen cycling processes in an orchard soil

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Pedosphere 2022年第6期32卷 803-811页

作者： Amir M.GONZÁLEZ-delgado Pierre-AndréJACINTHE Manoj K.SHUKLA Department of Plant and Environmental Sciences New Mexico State UniversityLas Cruces NM 88003(USA) Department of Earth Sciences Indiana University Purdue UniversityIndianapolis IN 46202(USA)

Indaziflam is a preemergent herbicide widely used for the control of weeds in pecan(Carya illinoinensis)orchards in the southwestern region of the United *** the paucity of data regarding the effect of indaziflam on the biochemical properties of soils supporting pecan production,this study was conducted to evaluate the effects of different application rates of indaziflam on soil microbial activity,diversity,and biochemical processes related to nitrogen(N)*** two consecutive growing seasons(2015 and 2016),soil samples were obtained from experimental mesocosms consisting of soil-filled pots where pecan saplings were grown and treated with indaziflam applied at two different rates(25 and 50 g active ingredient(ai)ha^(-1),with the higher rate being slightly lower than the recommended field application rate of 73.1 g ai ha^(-1)).Soil samples were collected approximately one week before and one week after herbicide application for determination of soil microbial biomass and diversity,N mineralization,andβ-glucosaminidase *** samples collected from the control mesocosms without herbicide application were treated in the laboratory with two rates of indaziflam(75 and 150 g ai ha^(-1))to determine the immediate effect on microbial *** significant effect of herbicide treatment on soil respiration and microbial biomass was *** results showed a slight to moderate decrease in microbial diversity(7%in 2015 and 44%in 2016).However,decreasedβ-glucosaminidase activity with herbicide treatment was observed in soils from the mesocosms(33%)and soils treated with indaziflam in the laboratory(45%).The mineral N pool was generally dominated by ammonium after indaziflam application,which was consistent with the drastic decrease(75%)in nitrification activity measured in the laboratory *** results of this study indicate that indaziflam,even when applied at higher than recommended rates,has limited effects on soil microbial activity,but

关键词： Carya illinoinensis β-glucosaminidase activity mesocosm experiment microbial biomass microbial diversity mineral nitrogen speciation nitrification

Bar Presence in Local Galaxies:Dependence on Morphology in Field Galaxies

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Research in Astronomy and Astrophysics 2024年第11期24卷 143-152页

作者： M.A.Chacón R.delgado-Serrano B.Cervantes Sodi Dirección Nacional de Ciencias Espaciales Universidad Tecnológica de PanamáPanamá Instituto de Radioastronomía y Astrofísica Universidad Nacional Autónoma de MéxicoMéxico

We analyzed the fractions of barred galaxies in the local Universe using a volume-limited sample of galaxies from the Sloan Digital Sky Survey Data Release *** examined 116 field galaxies with redshifts between 0.0207 and 0.030,using r and z-band ***,the bar fraction was 26%in the r-band and 19%in the *** distinct morphological groups,barred spiral galaxies had fractions of 33%in the r-band and 22%in the z-band while barred lenticular galaxies had 25%in the r-band and 12%in the *** observed that the bar fraction in spiral galaxies increases for stellar masses log(M*/M_(⊙))>10.5 and for galaxies with red colors(u-r)>2.0Additionally,most barred galaxies have a bulge-to-total ratio B/T≤*** results indicate that the bar fraction i more dependent on internal morphology than on the galaxy environment.

关键词： Galaxy evolution galaxies general galaxies luminosity function mass function Galaxy disk

Internal migrations as phenomenon of social mobility and territorial experience among architecture students, University of Tolima,Ibagué, Colombia

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Frontiers of Architectural Research 2024年第5期13卷 1158-1169页

作者： Luisa Fernanda Ramírez-Lozano Andrés Ernesto Francel-delgado Department of Architecture and Design University of Tolima

Internal migration motivated by access to higher education is a relatively unexplored topic in Colombia, leading to a lack of data on its dimensions, characteristics, and impacts on urban space and the emotional conditions of migrants. For this reason, an academic program of architecture in a public university was selected to comprehend the internal migrations of students, exploring their territorial experiences, living conditions, and social mobility capacity. An exploratory methodology was designed to recognize the phenomenon through a descriptive analysis, utilizing institutional data, surveys, and interviews. The research identifies the primary reasons, barriers, and impacts experienced by the migrant population in Ibagué, Colombia. The study concludes with recommendations pertaining to both institutional and urban planning to address these identified challenges.

关键词： Inequality Internal migration Meaningfulness Social mobility Urban development

The influence of mitochondrial-directed regulation of Wnt signaling on tumorigenesis

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Gastroenterology Report 2020年第3期8卷 215-223,I0002页

作者： Yaritza delgado-Deida Kibrom M.Alula Arianne L.Theiss Division of Gastroenterology and Hepatology Department of MedicineUniversity of Colorado School of MedicineAuroraCO 80045USA

Mitochondria are dynamic organelles that play a key role in integrating cellular *** alterations are evident in all stages of tumorigenesis and targeting mitochondrial pathways has emerged as an anticancer therapeutic *** Wnt-signaling pathway regulates many fundamental cellular functions such as proliferation,survival,migration,stem-cell maintenance,and mitochondrial metabolismand *** evidence demonstrates that mitochondrial-induced regulation of Wnt signaling provides an additional mechanism to influence cell-fate *** between mitochondria and Wnt signaling presents a feedforward loop in which Wnt activation regulates mitochondrial function that,in turn,drives Wnt *** this mini-review,we will discuss the recent evidence revealing the mitochondrial control of Wnt signaling and its implications for tumorigenesis and anticancer therapeutic targeting.

关键词： bb-catenin cancer stem cells metabolic reprogramming metabolism PGAM5

Abiotic and biotic drivers of struvite solubilization in contrasting soils

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Pedosphere 2023年第6期33卷 828-837页

作者： Antonio RUIZ-NAVARRO Manuel delgado-BAQUERIZO Concha CANO-DíAZ Carlos GARCíA Felipe BASTIDA Centro de Edafologia y Biologia Aplicada del Segura Consejo Superior de Investigaciones Cientificas(CEBAS-CSIC)Department of Soil and Water ConservationEspinardoMurcia E-30100Spain ICL Specialty Fertilizers Iberia TotanaMurcia E-30850Spain Laboratorio de Biodiversidad y Funcionamiento Ecosistemico Instituto de Recursos Naturales y Agrobiologia de Sevilla(IRNAS)CSICAv.Reina Mercedes 10Sevilla E-41012Spain IRNAS-CSIC Unidad Asociada Universidad Pablo de OlavideUniversidad Pablo de Olavide(UPO)Sevilla 41013Spain Centre for Research and Development in Agrifood Systems and Sustainability(CISAS) Instituto Politecnico de Viana do Castelo(IPVC)Rua Escola Industrial e Comercial Nun'Alvares 34Viana do Castelo 4900-347Portugal

Phosphorus(P) limitation in the coming decades calls for the utilization of alternative fertilizers in agriculture. Struvite is a promising P source, but its potential role as a fertilizer is dependent on different physical, chemical, and biological properties, which are very heterogeneous in soil, complicating the prediction of the best soil conditions for its application. Here, we evaluated the solubility of struvite in soil, its redistribution into P fractions, and its potential abiotic and biotic drivers in 62 globally distributed soils with contrasting properties through an incubation assay. We found that after 40 d, about 35% of struvite P was redistributed into soil fractions more accessible to plants and microbes. Phosphorus redistribution from struvite was driven by a complex suite of soil physical, chemical, and microbial properties as well as environmental factors that varied across soils. Soil texture played a critical role in determining the redistribution of P in struvite-amended soils in soluble(H2O extraction), labile(NaHCO3 extraction), and moderately labile(NaOH extraction) *** addition, the soil solution cation concentration was one of the most important drivers of available struvite-derived P fractions. The great importance of texture and cations in determining struvite-derived P fractions in soil was contrasted with the relatively minor role of pH. At the microbial level, the number of bacterial operational taxonomic units(OTUs) from the unfertilized soils that correlated with struvite-derived P fractions was higher than that of fungi. The number of OTUs that correlated with the struvite-derived soluble P fraction was dominated by fungi, whereas the number of OTUs that correlated with the struvite-derived labile P fraction was dominated by bacteria. Overall, this study provided a predictive framework for the potential use of struvite as a P fertilizer in contrasting soils.

关键词： bacteria fungi environmental factor operational taxonomic unit phosphorus fertilizer phosphorus fraction phosphorus solubilization soil fertility soil property

Freeze-thaw cycles and associated geomorphology in a post-glacial environment:current glacial,paraglacial,periglacial and proglacial scenarios at Pico de Orizaba volcano,Mexico

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Journal of Mountain Science 2024年第6期21卷 1954-1977页

作者： Víctor SOTO Carlos M.WELSH R. Kenji YOSHIKAWA Hugo delgado GRANADOS Centro de Ciencias de la Tierra Universidad VeracruzanaCircuito Gonzalo Aguirre BeltránS/NZona Universitaria91090XalapaMéxico Water and Environmental Research Center University of Alaska FairbanksFairbanksAlaska 99775USA Instituto de Geofísica Universidad Nacional Autónoma de MéxicoCiudad de México 04150México Department of Earth and Environmental Sciences Ludwig Maximilians UniversitätMunich 80333Germany

The glacial history of Pico de Orizaba indicates that during the Last Glacial Maximum,its icecap covered up to~3000 m asl;due to the air temperature increasing,its main glacier has retreated to 5050 m *** retraction of the glacier has left behind an intense climatic instability that causes a high frequency of freeze-thaw cycles of great intensity;the resulting geomorphological processes are represented by the fragmentation of the bedrock that occupies the upper parts of the *** is a notable lack of studies regarding the fragmentation and erosion occurring in tropical high mountains,and the associated geomorphological risks;for this reason,as a first stage of future continuous research,this study analyzes the freezing and thawing cycles that occur above 4000 m asl,through continuous monitoring of surface ground *** results allow us to identify and characterize four zones:glacial,paraglacial,periglacial and *** was found that the paraglacial zone presents an intense drop of temperature,of up to~9℃ in only sixty *** rock fatigue and intense freeze-thaw cycles that occur in this area are responsible for the high rate of rock disintegration and represent the main factor of the constant slope dynamics that occur at the *** activity decreases,both in frequency and intensity,according to the distance to the glacier,which is where the temperature presents a certain degree of stability,until reaching the proglacial zone,where cycles are almost non-existent,and therefore there is no gelifraction *** geomorphological processes have resulted in significant alterations to the mountain slopes,which can have severe consequences in terms of risk and water.

关键词： Freeze-Thaw Gelifraction Mountain mechanical erosion Periglacial geomorphology Postglacial scenarios

Stable and efficient metal-biochar supported catalyst:degradation of model pollutants through sulfate radical-based advanced oxidation processes

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Biochar 2020年第3期2卷 319-328页

作者： Fermín delgado Victoria S.Gutierrez Mariana Dennehy Mariana Alvarez INQUISUR Departamento de QuímicaUniversidad Nacional del SurAv.Alem 12538000 Bahía BlancaArgentina Planta Piloto de Ingeniería Química PLAPIQUI(CONICET-UNS)Camino La Carrindanga Km 78000 Bahía BlancaArgentina

This study focuses on the synthesis of metal-based biochar catalysts and their catalytic activation of peroxymonosulfate(PMS,HSO5−)for the degradation of three different wastewater model pollutants employing advanced oxidation processes(AOP).Iron,copper,and two different cobalt-based catalysts were prepared and *** catalysts were supported on a biochar obtained from the pyrolysis of woody pruning *** were characterized by C,H,and N elemental analysis,X-Ray diffraction(XRD),Fourier-transform infrared spectroscopy(FTIR),and scanning electron microscope(SEM).The metal content in each catalyst was determined by means of atomic absorption spectroscopy(AAS).The degradation reac-tions of benzoic acid(BA),catechol(C),and cinnamic acid(CA)were carried out in a lab scale batch glass reactor and were followed by UV-Visible spectroscopy(UV-Vis).A colorimetric technique was employed to verify the presence of oxidant during the reaction *** catalyst/oxidant optimal ratio was determined for the cobalt *** mineralization degree of the pollutants after the degradations was verified by means of total organic carbon(TOC)content in the residual *** 4 h of reaction,the maximum mineralization was reached when C was treated with a cobalt-based catalyst(>80%),and its stability was evaluated through successive cycles of use.

关键词： Biochar Organic pollutants Advanced oxidation processes Sulfate radicals Cobalt catalysts

Antiproton identification below threshold with the AMS-02 RICH detector

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Chinese Physics C 2017年第5期41卷 158-163页

作者：李紫源 Carlos Jose delgado Mendez Francesca Giovacchini Sadakazu Haino Julia Hoffman School of Physics Sun Yat-Sen University Guangdong 510275 China Institute of Physics Academia Sinica Taipei 11529 China Centro de Investigaciones Energeticas Mediambientales y Tecnologicas (CIEMAT) Madrid E-28040 Spain Physics and Astronomy Department University of Hawaii Hawaii 96822 USA

The Alpha Magnetic Spectrometer（AMS-02）,which is installed on the International Space Station（ISS）,has been collecting data successfully since May *** main goals of AMS-02 are the search for cosmic anti-matter,dark matter and the precise measurement of the relative abundance of elements and isotopes in galactic cosmic *** order to identify particle properties,AMS-02 includes several specialized *** these,the AMS-02 Ring Imaging Cherenkov detector（RICH） is designed to provide a very precise measurement of the velocity and electric charge of *** describe a method to reject the dominant electron background in antiproton identification with the use of the AMS-02 RICH detector as a veto for rigidities below 3 GV.A ray tracing integration method is used to maximize the statistics of  with the lowest possible e background,providing 4 times rejection power gain for e background with respect to only 3% of  signal efficiency *** using the collected cosmic-ray data,e contamination can be well suppressed within 3% with β ≈ 1,while keeping 76% efficiency for  below the threshold.

关键词： RICH cosmic goals isotopes rejection specialized contamination maximize installed suppressed

A test on adverse selection of farmers in crop insurance:Results from Inner Mongolia,China

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Journal of Integrative Agriculture 2017年第2期16卷 478-485页

作者： ZHAO Yuan-feng CHAI Zhi-hui Michael S.delgado Paul V.Preckel College of Economics and Management Inner Mongolia Agricultural University Department of Agricultural Economics Purdue University

Adverse selection is an operating risk of crop insurance. Based on survey data on crop insurance collected by questionnaires in Inner Mongolia, China, the paper uses non-parametric analysis and econometric models to estimate the relationship between conditions for crop production and farmers＇ insurance decision in order to test the existence of farmers＇ adverse selection. The results show farmers＇ adverse selection does exist, but settling a claim by negotiation and premium subsidy from governments at all levels can defuse farmers＇ adverse selection under the current system of crop insurance. Risk regionalization, heterogeneous insurance contract and product innovation may decrease adverse selection to some extent.

关键词： crop insurance farmers adverse selection