Quantification and Classification of Microplastics (Mps) in Urban, Suburban, Rural and Natural Beaches of Colima and Jalisco, México

Los microplásticos son una forma de contaminación marina, por ello, se debe identificar su presencia en ecosistemas como las playas, activos ambientales de valor económico que ofrecen diferentes servicios a la población. El presente trabajo identifica y clasifica los microplásticos en 12 playas de tipo urbano, sub-urbanos, rural y natural, ubicadas en los estados de Colima y Jalisco, México. Se colectaron, analizaron y clasificaron un total de 94 muestras de sedimento en la línea de pleamar, identificando mediante flotación e inspección visual un total de 12,001 microplásticos que fueron clasificados por forma, color y tamaño. Los resultados revelan que la presencia de microplásticos en playas naturales o rurales con escaso desarrollo o poco accesibles presentan niveles comparables a las urbanas y suburbanas. Esto muestra que el desplazamiento de estos contaminantes no tiene factores ambientales o antropogénicos limitantes, lo que requiere especial atención ante sus potenciales efectos en los ambientes marinos y costerosMicroplastics (Mps) are a form of marine pollution; therefore, their presence must be identified in ecosystems such as beaches, environmental assets of economic value that offer different services to the population. The present work identifies and classifies microplastics in 12 urban, suburban, rural and natural beaches located in the states of Colima and Jalisco, Mexico. A total of 94 sediment samples were collected, analyzed and classified at the high tide line, identifying by flotation and visual inspection a total of 12,001 plastic particles that were classified by shape, color and size. The results reveal that the presences of microplastics on natural or rural beaches that are poorly developed or inaccessible have levels comparable to urban and suburban beaches. This shows that the movement of these contaminants has no limiting environmental or anthropogenic factors, which requires special consideration because of their potential effects on marine and coastal environments

Clasificación de Microplásticos en Playas Urbanas, Suburbanas, Rurales y Naturales de Colima y Jalisco, México

Los microplásticos son una forma de contaminación marina, por ello, se debe identificar su presencia en ecosistemas como las playas, activos ambientales  de valor económico que ofrecen diferentes  servicios a la población. El presente trabajo identifica y clasifica los microplásticos  en 12 playas de tipo urbano, sub-urbanos, rural y natural, ubicadas en los estados de Colima y Jalisco, México. Se colectaron, analizaron y clasificaron un total de 94 muestras de sedimento en la línea de pleamar, identificando mediante flotación e inspección visual un total de 12,001 microplásticos que fueron clasificados  por forma, color y tamaño. Los resultados revelan que la presencia de microplásticos en playas naturales o rurales con escaso desarrollo o poco accesibles presentan  niveles comparables a las urbanas y suburbanas. Esto muestra que el desplazamiento de estos contaminantes no tiene factores ambientales o antropogénicos limitantes, lo que requiere especial atención ante sus potenciales efectos en los ambientes marinos y costeros

Transcriptome analyses throughout chili pepper fruit development reveal novel insights into the domestication process

Chili pepper (Capsicum spp.) is an important crop, as well as a model for fruit development studies and domestication. Here, we performed a time-course experiment to estimate standardized gene expression profiles with respect to fruit development for six domesticated and four wild chili pepper ancestors. We sampled the transcriptomes every 10 days from flowering to fruit maturity, and found that the mean standardized expression profiles for domesticated and wild accessions significantly differed. The mean standardized expression was higher and peaked earlier for domesticated vs. wild genotypes, particularly for genes involved in the cell cycle that ultimately control fruit size. We postulate that these gene expression changes are driven by selection pressures during domestication and show a robust network of cell cycle genes with a time shift in expression, which explains some of the differences between domesticated and wild phenotypes

Growth kinetics of Fe2B layers formed on the AISI 4150 steel by different approaches

In the present work, the AISI 4150 steel has been pack-borided in the temperature range of 1123-1273 K for a treatmenttime of 2 to 8 h. The mixture of powders containing 20% B4C, 10% KBF4 and 70% SiC has been used for producing a singleboride layer (Fe2B) at the surface of AISI 4150 steel. The presence of Fe2B phase has been confirmed by XRD analysis.The SEM observations have been done to investigate the morphology of boride layers and measure their thicknesses.The cohesion of boride layers has been evaluated by using the Daimler-Benz Rockwell-C indentation technique.The borided sample at 1173 K for 8 h has shown a best cohesion of boride layer to the substrate in comparison to the sampletreated at 1173 K during 2 h. Kinetically, different approaches have been used to estimate the boron diffusion coefficients inthe Fe2B layers and to predict the value of Fe2B layer thickness obtained at 1253 K for a treatment time of 2.5 h. Theestimated values of activation energies for boron diffusion in AISI 4150 steel have been in the range of 193.45 to 199.74 kJmol-1. These values of activation energies have been depended on the diffusion models used. In addition, a good agreementhas been observed between the experimental value of Fe2B layer thickness obtained at 1253 K for 2.5 h with the predictedvalues from these different diffusion models

Growth kinetics of Fe2B layers formed on the AISI 4150 steel by different approaches

277-287In the present work, the AISI 4150 steel has been pack-borided in the temperature range of 1123-1273 K for a treatment time of 2 to 8 h. The mixture of powders containing 20% B4C, 10% KBF4 and 70% SiC has been used for producing a single boride layer (Fe2B) at the surface of AISI 4150 steel. The presence of Fe2B phase has been confirmed by XRD analysis. The SEM observations have been done to investigate the morphology of boride layers and measure their thicknesses. The cohesion of boride layers has been evaluated by using the Daimler-Benz Rockwell-C indentation technique. The borided sample at 1173 K for 8 h has shown a best cohesion of boride layer to the substrate in comparison to the sample treated at 1173 K during 2 h. Kinetically, different approaches have been used to estimate the boron diffusion coefficients in the Fe2B layers and to predict the value of Fe2B layer thickness obtained at 1253 K for a treatment time of 2.5 h. The estimated values of activation energies for boron diffusion in AISI 4150 steel have been in the range of 193.45 to 199.74 kJ mol-1. These values of activation energies have been depended on the diffusion models used. In addition, a good agreement has been observed between the experimental value of Fe2B layer thickness obtained at 1253 K for 2.5 h with the predicted values from these different diffusion models

Gene Functional Networks from Time Expression Profiles: A Constructive Approach Demonstrated in Chili Pepper (Capsicum annuum L.)

Gene co-expression networks are powerful tools to understand functional interactions between genes. However, large co-expression networks are difficult to interpret and do not guarantee that the relations found will be true for different genotypes. Statistically verified time expression profiles give information about significant changes in expressions through time, and genes with highly correlated time expression profiles, which are annotated in the same biological process, are likely to be functionally connected. A method to obtain robust networks of functionally related genes will be useful to understand the complexity of the transcriptome, leading to biologically relevant insights. We present an algorithm to construct gene functional networks for genes annotated in a given biological process or other aspects of interest. We assume that there are genome-wide time expression profiles for a set of representative genotypes of the species of interest. The method is based on the correlation of time expression profiles, bound by a set of thresholds that assure both, a given false discovery rate, and the discard of correlation outliers. The novelty of the method consists in that a gene expression relation must be repeatedly found in a given set of independent genotypes to be considered valid. This automatically discards relations particular to specific genotypes, assuring a network robustness, which can be set a priori. Additionally, we present an algorithm to find transcription factors candidates for regulating hub genes within a network. The algorithms are demonstrated with data from a large experiment studying gene expression during the development of the fruit in a diverse set of chili pepper genotypes. The algorithm is implemented and demonstrated in a new version of the publicly available R package “Salsa” (version 1.0).Publishe

Synergistic Antimicrobial Effects of Silver/Transition-metal Combinatorial Treatments

Due to the emergence of multi-drug resistant strains, development of novel antibiotics has become a critical issue. One promising approach is the use of transition metals, since they exhibit rapid and significant toxicity, at low concentrations, in prokaryotic cells. Nevertheless, one main drawback of transition metals is their toxicity in eukaryotic cells. Here, we show that the barriers to use them as therapeutic agents could be mitigated by combining them with silver. We demonstrate that synergism of combinatorial treatments (Silver/transition metals, including Zn, Co, Cd, Ni, and Cu) increases up to 8-fold their antimicrobial effect, when compared to their individual effects, against E. coli and B. subtilis. We find that most combinatorial treatments exhibit synergistic antimicrobial effects at low/ non-toxic concentrations to human keratinocyte cells, blast and melanoma rat cell lines. Moreover, we show that silver/(Cu, Ni, and Zn) increase prokaryotic cell permeability at sub-inhibitory concentrations, demonstrating this to be a possible mechanism of the synergistic behavior. Together, these results suggest that these combinatorial treatments will play an important role in the future development of antimicrobial agents and treatments against infections. In specific, the cytotoxicity experiments show that the combinations have great potential in the treatment of topical infections

Recuperación monumental ambiental de la Alameda Central de la Ciudad de México

752 páginas. Especialización en Diseño.El presente trabajo se centra en el estudio, análisis y rescate de la Alameda Central de la Ciudad de México, la cual se sitúa hoy en el corazón de la gran ciudad, siendo ésta el paseo más antiguo de América y lugar que ha visto acontecer los cambios políticos, sociales y culturales de una nación, que es hoy México. El estudio es una recopilación cronológica de los sucesos que dieron origen al primer parque público de México, así como su desarrollo y los cambios morfológicos que ha presentado a lo largo de los años, lo que le otorga un carácter relevante y lo define como el paseo más importante del país

Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}} = 2.76 TeV

The inclusive transverse momentum ($p_{\rm T}$) distributions of primary charged particles are measured in the pseudo-rapidity range $|\eta|<0.8$ as a function of event centrality in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}=2.76$ TeV with ALICE at the LHC. The data are presented in the $p_{\rm T}$ range $0.15<p_{\rm T}<50$ GeV/$c$ for nine centrality intervals from 70-80% to 0-5%. The Pb-Pb spectra are presented in terms of the nuclear modification factor $R_{\rm{AA}}$ using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-$p_{\rm T}$ particles strongly depends on event centrality. In central collisions (0-5%) the yield is most suppressed with $R_{\rm{AA}}\approx0.13$ at $p_{\rm T}=6$-7 GeV/$c$. Above $p_{\rm T}=7$ GeV/$c$, there is a significant rise in the nuclear modification factor, which reaches $R_{\rm{AA}} \approx0.4$ for $p_{\rm T}>30$ GeV/$c$. In peripheral collisions (70-80%), the suppression is weaker with $R_{\rm{AA}} \approx 0.7$ almost independently of $p_{\rm T}$. The measured nuclear modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/284

Charge separation relative to the reaction plane in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}= 2.76 TeV

Measurements of charge dependent azimuthal correlations with the ALICE detector at the LHC are reported for Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV. Two- and three-particle charge-dependent azimuthal correlations in the pseudo-rapidity range $|\eta| < 0.8$ are presented as a function of the collision centrality, particle separation in pseudo-rapidity, and transverse momentum. A clear signal compatible with a charge-dependent separation relative to the reaction plane is observed, which shows little or no collision energy dependence when compared to measurements at RHIC energies. This provides a new insight for understanding the nature of the charge dependent azimuthal correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286