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El trabajo buscó generar información relativa a las características de los caficultores del Estado de Puebla, las afecciones climáticas experimentadas y las actividades que llevan a cabo para enfrentarlas. Para ello se aplicaron entrevistas en las macroregiones cafetaleras de la entidad, se generó estadística descriptiva y se propusieron recomendaciones generales susceptibles de ser aplicadas a partir de un análisis de campo de fuerzas. El 84% de los entrevistados son cafetaleros por herencia. Las variedades más empleadas son Arábiga y Costa Rica. La sequía es la afectación climática más referida. El 46% de los productores reporta impactos por fenómenos meteorológicos extremos. Para contrarrestar los efectos del cambio climático se emplean acciones con alcances diversos como barreras vivas, chapeo y limpieza. La macrorregión con mayores afectaciones es la Sierra Nororiental. La Sierra Norte presenta el número más elevado de estrategias de adaptación, así como actividades de innovación diferentes a las utilizadas en las otras zonas de estudio. Todas las macrorregiones han sustituido variedades con cepas que impactan el modelo productivo tradicional. Se recomiendan 20 acciones sinérgicas a nivel de productor, finca y paisaje para fortalecer la caficultura en Puebla.

This study was conducted to investigate the potential of using sodium silicate with nanosilica as a treatment to inhibit the progress of corrosion in steel specimens that are already corroded. Steel specimens measuring 16 mm in diameter and 4 mm in thickness were prepared and subjected to pre-corrosion by immersion to 3.5% NaCl solution. Two sets of specimens were then dip-coated with sodium silicate containing nanosilica. One set was coated with 1% nanosilica, and the other was coated with 2.5% nanosilica. The coated specimens were then subjected to Complex Impedance Spectroscopy (CIS) at 20 Hz to 20 MHz frequency range. Compared with the sodium silicate coating with 1% nanosilica, the sodium silicate coating with 2.5% nanosilica had a larger semi-circle curve in the Nyquist plot. Similarly, the sodium silicate coating with 2.5% nanosilica also showed larger magnitudes of impedance at the low-frequency region and larger phase angles at the high-frequency regions in the Bode plot. These results imply that the sodium silicate coating with 2.5% nanosilica coating demonstrated better capacitive behavior. In addition, equivalent circuit modelling results also showed that the sodium silicate coating with 2.5% nanosilica had higher coating resistance and lower coating capacitance as compared to the sodium silicate coating with 1% nanosilica. Doi: 10.28991/cej-2021-03091761 Full Text: PDF

Cultivated tomato Solanum lycopersicum (Slyc) is sensitive to water shortages, while its wild relative Solanum peruvianum L. (Sper), an herbaceous perennial small shrub, can grow under water scarcity and soil salinity environments. Plastic Sper modifies the plant architecture when suffering from drought, which is mediated by the replacement of leaf organs, among other changes. The early events that trigger acclimation and improve these morphological traits are unknown. In this study, a physiological and transcriptomic approach was used to understand the processes that differentiate the response in Slyc and Sper in the context of acclimation to stress and future consequences for plant architecture. In this regard, moderate (MD) and severe drought (SD) were imposed, mediating PEG treatments. The results showed a reduction in water and osmotic potential during stress, which correlated with the upregulation of sugar and proline metabolism-related genes. Additionally, the senescence-related genes FTSH6 protease and asparagine synthase were highly induced in both species. However, GO categories such as “protein ubiquitination” or “endopeptidase inhibitor activity” were differentially enriched in Sper and Slyc, respectively. Genes related to polyamine biosynthesis were induced, while several cyclins and kinetin were downregulated in Sper under drought treatments. Repression of photosynthesis-related genes was correlated with a higher reduction in the electron transport rate in Slyc than in Sper. Additionally, transcription factors from the ERF, WRKY and NAC families were commonly induced in Sper. Although some similar responses were induced in both species under drought stress, many important changes were detected to be differentially induced. This suggests that different pathways dictate the strategies to address the early response to drought and the consequent episodes in the acclimation process in both tomato species.

We employed a microwave-assisted two-pot in-situ deposition technique to incorporate zinc oxide particulates in the structure of filter paper to produce antimicrobial paper. The process involved successive immersion of filter paper samples in ZnSO4 (precursor solution) and NaOH (precipitating agent) to form Zn(OH)2, which transformed into ZnO during microwave treatment. Successful deposition of ZnO particles on the filter paper was confirmed via X-ray diffraction and the corresponding morphologies were observed using field emission scanning electron microscopy. The ZnO-deposited papers were tested for antimicrobial activity and were found to be more effective against Staphylococcus aureus (gram-positive) than Escherichia coli (gram-negative). Bacterial populations were reduced by up to 92 ± 2% and 57 ± 4% for S. aureus and E. coli, respectively. Also, it was found that the samples prepared using higher concentrations of ZnSO4 and NaOH exhibited better antimicrobial properties.

Introduction: Immune checkpoint inhibitors (ICI) therapy has led to a paradigm shift in cancer drug development and in the clinical evaluation of approaches to combination cancer treatment. Dysregu...

We give a characterization of a matroid to be paving, through its set of hyperplanes and give an algorithm to construct all of them., Comment: arXiv admin note: text overlap with arXiv:1502.01806

Using terahertz time-domain spectroscopy, the frequency-dependent conductivities of polyaniline emeraldine salt-polyethylene (PAni-PE) pellets were measured at different mass concentrations. THz conductivities were compared to the behavior of DC conductivities measured using impedance spectroscopy. The DC conductivity behavior with mass concentration showed a low percolation threshold. The frequency-dependent behavior in the THz region follows the Mott-Davis behavior which shows stronger correlation at higher PAni concentration. At the same time, the conductivity increases exponentially with increasing PAni concentration over the frequency range studied without an apparent percolation threshold. The mechanisms in the two regions studied suggest that there is more dominant localization in the THz regime in contrast with a more dominant percolative transport in the Hz-MHz region. Temperature-dependent measurements showed a decreasing value of parameter S with increasing temperature consistent with a correlated barrier hopping model. Lastly, the parameter S increases in magnitude with a decreasing amount of PAni in the composites reflective of varying conducting and nonconducting compositions.

The low frequency conductivity of bentonite was investigated using an impedance analyzer (20 Hz–20 MHz). Pellets of pure bentonite clay were hydrated at different hydration levels. Results reveal that the AC conductivity increases with hydration of bentonite. Also, an equivalent circuit model with resistor, capacitor and constant phase elements was obtained from fitting of the Nyquist plots. The resistance of equivalent circuit components decreased with increasing hydration.

Carbon-polymer composites are being developed for industrial applications including sensing, electromagnetic shielding and electronics among others. In this work, ground Polyaniline emeraldine salt (PAni-ES) and coconut shell charcoal (C) powder were mixed with polyvinyl acetate (PVAc). The resulting mixture was fabricated into sheets using simple casting method. The resulting air-dried PAni-ES/PVAc/C sheets were characterized using SEM for morphological studies. The SEM micrographs of the samples showed that the globular aggregates appear within the surface when PAni-ES is introduced in the sample. Also, visible light spectroscopy shows the variation of compositions of the fabricated samples. Using an impedance analyzer (20 Hz to 20 MHz), it was observed that the conductivities of the sample increase with increasing frequency and polyaniline content. The AC conductivity of the fabricated samples also exhibit universal power law behavior at which the mode of charge transfer happens hopping conduction.

Copper-based precipitates were synthesized using a straightforward wet chemical reduction method with copper sulfate salts as precursor and L-ascorbic acid as reducing agent. Scanning electron micrographs of the precipitates reveal particle-like structures with edges. The percent age yield was observed to increase with the reaction temperature and the reductant-to-precursor concentration ratio. Comparison of samples prepared at different times showed that the bulk of the precipitates was formed during the first 24 hours. New yield added to the bulk decreased over time. Here, the ascorbic acid served as a capping agent, which impeded the oxidation. This capping was not visible in the electron micrographs but may be inferred from the infrared spectra. Faster capping reduced the amount of oxides in the precipitates. This was seen in samples prepared at a higher temperature and with a lower reductant-to-precursor concentration ratio. Antimicrobial testing under dynamic contact conditions showed that the copper-based precipitates were more effective against Staphylococcus aureus (a gram-positive bacteria) than Escherichia coli (a gram-negative bacteria). Copper-based precipitates collected after the first 24 hours were more potent than those collected after eight days. Furthermore, samples prepared at room temperature and lower reductant-to-precursor concentration ratios were found to be more effective in reducing the number of S. aureus after one hour of contact. The synthesized copper-based precipitates was observed to reduce the population of S. aureus (CFU/mL) by up to 98% after one hour of contact. Keywords: Wet-chemical method, Capping, Antimicrobial, Staphylococcus aureus, Escherichia coli

Summary: In the second cycle of laying hens, egg production and quality decrease. This is mainly due to decreased absorption of calcium from the gastrointestinal tract. Hence, serum concentrations of calcium tend to decrease and are compensated through bone reabsorption. There are several sources of calcium with different solubilities and absorption rates. The choice of one of them may be of importance for the referred second laying cycle in hens. Hence, relative bioavailability (Fr) of 4 sources of Ca were evaluated in 300 Bovans-White 85-wk-old hens. Animals were randomly assigned to 5 groups as follows: the control group receiving baseline doses of calcium carbonate as required by this hen's linage (control group [GC]); GCca group (receiving additional calium carbonate); the GFtc group (receiving tricalcium phosphate); the GLgc group (which received calcium lactate-gluconate), and the GCcaCp group, which received calcium carbonate plus 10 μg of capsicum oleoresin (COr). Each hen was orally dosed with 1 g of Ca equivalent by probe, and serum Ca was quantified at predetermined times. The Ca-kinetic behavior was characterized by calculating the following: maximum serum concentration (CMAX); time to achieve CMAX; area under the concentration curve vs. time (AUC0-24). Fr as compared with GCca were calculated. GLgc and GCcaCp had the greatest CMAX and Fr values, that is, 34.7 and 37.2 μg/dL for CMAX and 109.6 and 112.9% for FR, respectively, and they were statistically indistinguishable between them (P

Neurocysticercosis (NCC) rarely presents as acute meningitis; however, when it does, it is not distinguishable clinically from other more common infectious etiologies. Here, we report a case of NCC presenting as acute meningitis, which also highlights the importance of brain MRI imaging rather than CT where possible, the need to include MRI of the spine in patients with the subarachnoid disease, and the limitations of NCC antigen detection assay in cerebrospinal fluid when used in ventriculoperitoneal shunt specimens. A prolonged course of albendazole, praziquantel, and corticosteroids led to the resolution of our patient's NCC.

Understanding how water molecules interact with one another and with clay under a confined geometry at different temperatures are key information in energy storage applications and nuclear waste disposal. Here we present an investigation of the dielectric response from 100 MHz to 1.8 THz of sodium bentonite at different hydration levels from 233 K to 293 K. Figure 1 shows the complex dielectric spectra of hydrated bentonite. Our previous studies have shown that for hydrated soft matters such as protein [1] and lipid bilayers [2] the dielectric response in the frequency region from sub-GHz to THz are due to the relaxation processes and vibrational processes, which are modeled using a Cole-Cole function and Lorentzian function, respectively, as shown below. The first term is the ion conductivity term, which may be important for conducting materials. Published version

The electrical conductivity of simulated cement paste matrixes with water-to-cement ratios of 0·50 and 2·0% amorphous nanosilica, synthesized from rice hull ash, has been related to the effect of hydration stages on the ions dissociated in the capillary pore solution of the cement paste mesostructure. The increase in ions, as the hydration proceeded, has also been implied by the increasing trend of the conductivity spectra obtained from the complex impedance spectroscopy in the frequency region from 100 kHz to 20 MHz. In the 105–107 Hz spectra, the conductivity was also found to exhibit a power-law behavior. To consider the effect of capillary pores, a comparable set of cement pastes with a similar macrostructure has been established using a modified method of simple grinding and pelletizing with a similar techniques. From the results of the Kramers–Kronig validation test, the impedance data have been found to exhibit a causal, linear and stable behavior in the high-frequency region from 6 to 20 MHz.

In this study, different mass concentrations of Polyaniline-emeraldine salt (PAni-ES) was mixed with bentonite clay. XRD analysis showed the incorporation of PAni-ES in bentonite. The AC conductivity was calculated from Impedance measurements. The conductivities increased with increasing concentration of PAni-ES. The AC conductivities follow a transition from frequency-independent to frequency-dependent at a critical frequency, ωc. Above ωc, the conductivity follows a universal power law behavior as described for disordered materials. Using jump relaxation model, the conductivity is governed by translational ion hopping in the low-frequency region, and well-localized ion hopping in the high-frequency region.

In this study, polyaniline on silane-functionalized zinc oxide was fabricated. The zinc oxide particles were functionalized by soaking in silane aniline-ethanol solution. Afterwhich, the polyaniline was polymerized on the grafted silane aniline molecules using oxidative polymerization. The FTIR spectra showed vibrational peaks associated with the silane aniline molecules and grafted polyaniline. The sampled soaked in silane aniline coupling agent showed FTIR peaks associated with grafted silane aniline. The sample soaked for one minute showed FTIR peaks associated with ortho-coupled aniline units that is formed during the start of aniline polymerization. The sample soaked for three minutes showed FTIR peaks that is broader compared to others due to ring vibration in long polymeric chain.

Polyaniline emeraldine salt (PAni-ES) was successfully deposited on paper through layer-by-layer technique. In this method, a paper was alternately dipped in aniline monomer and an oxidizing agent for different dipping cycles. This process produced green PAni-ES on paper. The morphology of the samples showed polymeric networks with pores, fiber-like structures and aggregates. There is a transition from frequency-independent to frequency-dependent conductivities of the samples. The conductivity increased with increasing number of dipping cycles. The frequency-dependent conductivities follow the power-law behavior reflecting conducting network and hopping mechanisms. Lastly, the conductivities with frequency followed a scaling behavior reflecting a common physical mechanism in PAni-ES on paper.

The conduction characteristics of Polyaniline emeraldine salt-Graphite (PAni-ES/Gr) pellets were characterized using an impedance analyzer. The pellets were prepared with varying mass fractions of PAni-ES and Gr. FTIR spectra have the stretching vibrations for PAni-ES and absence of peaks for Gr. PAni-ES showed aggregated particles while Gr appeared as sheets and flaky structures. The composition of the pellets was differentiated in the AC conductivity values. The critical frequency representing the transition from frequency-independent to frequency-dependent conductivity decreases with increasing Gr content. Lastly, the frequency-dependent conductivity behavior follows power-law behavior reflecting possible hopping mechanisms and random resistor-capacitor network.

The conduction properties of polyaniline (PAni) with various processing conditions were demonstrated using terahertz time-domain spectroscopy. The effects of protonation were observed by varying the doping time and annealing time. The measurements agreed with the Mott-Davis hopping model with the exponent varying inversely with the protonation conditions. Also, the density of the samples increased with compression pressure thereby increasing the inter-chain and inter-particle charge transport. Lastly, the THz response on PAni-polyethylene pellets showed dominant contribution of PAni network.

This study was conducted to characterize an anti-corrosive epoxy coating for steel with Nano-SiO2-Polyaniline (PANI) composites using low impedance spectroscopy. The epoxy coating was modified using a varying concentration of nano-filler combination. Coated steels were dipped in 3.5 wt% NaCl solution to induce corrosion. Impedances were measured from 20 Hz to 20 MHz. The electrical characterization was related to the coating performance of epoxy coating with varying concentration. The Nyquist and Bode plots were displayed and related to the graphs with the coating resistance and capacitance. Based on Nyquist plots, 40-60% combination of Nano-SiO2 and PANI has the largest semi-circle curve, while on Bode plots, still, the 40-60% combination has the largest magnitude of impedance and phase angles. Equivalent circuit model was fitted to measure directly the coating resistance and coating capacitance of the coated steel. Based on the equivalent circuit model, the 40-60% of Nano-SiO2 to PANI combination had the highest coating resistance equal to 9.50E7 ohms, and lowest coating capacitance of 2.0E-12 Farads. The results presented that all combinations have better corrosion protection performance compared to that of pure epoxy coated steel.

Este trabajo presenta el desarrollo de un modelo matemático dinámico útil para predecir la concentración de peróxido de hidrogeno usado para la decianuración en el tratamiento de aguas residuales. El modelo cuantitativo está fundamentado en la teoría físico-química clásica del proceso de decianuración desarrollado y validado sobre Matlab® con datos reales del proceso de decianuración. La herramienta será útil en la toma de decisiones para los ingenieros y operadores del proceso involucrados en el control y la supervisión durante la operación en tiempo real de la decianuración de aguas residuales de la industria de recubrimientos metálicos; mejorando en el proceso las condiciones operativas de: eficiencia, fiabilidad y seguridad.

Mitogen-activated protein kinase (MAPK) cascades are key signaling modules controlling development and virulence in fungal pathogens. Down-regulation of MAPK activity by protein phosphatases provides a critical layer of control during desensitization or adaptation to stimuli. In Saccharomyces cerevisiae, the dual-specificity phosphatase Msg5 dephosphorylates target threonine and tyrosine residues in the two MAPKs Mpk1 and Fus3, which regulate the cell wall integrity (CWI) and pheromone responses, respectively. Here we studied the role of the Msg5 ortholog in Fusarium oxysporum, a soilborne phytopathogen that infects host plants through the roots to cause vascular wilt and plant death. F. oxysporum mutants lacking Msg5 showed constitutively high levels of Mpk1 phosphorylation and increased sensitivity to the cell wall targeting compound Calcofluor White. Moreover, these mutants displayed reduced colony growth and conidiation. Importantly, msg5Δ mutants were impaired in hyphal chemotropism towards host plant roots and in virulence on tomato plants. These results reveal a key role of Msg5 in regulation of the CWI MAPK cascade of F. oxysporum as well as in infection-related signaling of this important fungal pathogen.

Resume La comorbidite entre le trouble de stress post-traumatique (TSPT) et le trouble lie a l’usage de substances psychoactives est elevee et celle-ci complique la prise en charge des patients presentant cette comorbidite, avec une efficacite moindre. L’objectif de cette etude est de determiner le role que jouent les schemas precoces inadaptes (SPI) dans la relation de comorbidite qu’entretiennent la severite du TSPT et de l’addiction. Notre hypothese generale est que les SPI presents fonctionneraient comme une variable intermediaire jouant un role mediateur entre l’intensite du TSPT et la severite de l’addiction. Secondairement, nous tenterons d’isoler, parmi les 15 schemas proposes par Young (1994), des SPI specifiques qui, a eux seuls, seraient mediateurs et donc susceptibles d’etre des cibles therapeutiques dans le domaine de la prise en charge des patients. Notre population est composee de 35 patients pris en charge dans un centre de soins, d’accompagnement et de prevention en addictologie. Nous avons utilise l’Addiction Severity Index (ASI) pour mesurer la severite de l’addiction, la Posttraumatic Checklist Scale (PCL-S) pour determiner l’intensite du TSPT, et enfin le Young Schema Questionnaire – Short Form, Second Edition (YSQ-S2) pour evaluer le nombre de SPI presents. Nos resultats confirment que le nombre de SPI presents joue un role mediateur entre l’intensite du TSPT et la severite de l’addiction substances illicites. Secondairement, il apparait que l’intensite du schema « isolement » constitue le cœur de cette mediation. La discussion interroge a la fois les perspectives de recherche futures sur cette question, notamment la necessite d’approfondir la nature des schemas impliques en fonction du niveau de TSPT des patients dependants aux substances, ainsi que les retombees cliniques de ces resultats sur les modeles actuels de leur prise en charge.

The treatment paradigm of several cancers has dramatically changed in recent years with the introduction of immunotherapy. Most oncology trials involving immune checkpoint inhibitors (ICIPs) have routinely excluded patients with HIV infection and chronic viral hepatitis B (HBV) and C (HCV) due to concerns about viral reactivation, fears of increased toxicity, and the potential lack of efficacy in these patient subgroups. However, with current antiviral therapies, HIV and HBV infections have become chronic diseases and HCV infections can even be cured. Broadening cancer trial eligibility criteria in order to include cancer patients with chronic viral infections can maximize the ecological validity of study results and the ability to understand the ICPIs' benefit-risk profile in patients with these comorbidities. In this review, we examined the evidence on the efficacy and safety of using ICPIs in cancer patients with concurrent chronic viral infections.

The THz conductivities of Polyaniline Emeraldine Salt/Bentonite pellets were studied from 80 K to 290 K. Results show that the conductivities increase with increasing temperature. The negative imaginary conductivities reflect backscattering. The complex conductivities were fit by the combined Drude-Smith-Lorentz model. The conduction mechanism in the pellets appear to follow coupling between charges and localized vibrations.

Daily use of backpacks have raised some concerns and it has been an issue of research on children and teenagers. This paper shows results of the gait kinematics of load carriage in healthy college students. The analysis was done with videography on the sagittal plane. Three loads were tested (4.1 kg, 6.8 kg and 10.5 kg). It was observed that the angles of ankle and knee do not change, whereas the initial hip angle and the maximum flexion angle showed an increase. Thus all of the observed differences were at the hip level.

The temperature-dependent conductivity of polyaniline emeraldine salt (PAni-ES) was studied by terahertz (THz) time-domain spectroscopy from 80 to 290 K to investigate conduction properties in the THz region. The absorption coefficient and index of refraction increase with temperature. This reflects an increasing conductivity, which indicates a thermally assisted hopping transition. The frequency-dependent behavior of the conductivity is described by using the Mott–Davis model. The model fitting parameter, S , decreases with increasing temperature, indicating a possible correlated barrier hopping mechanism. Lastly, the activation energy at THz frequencies decreases with increasing frequency, suggesting intraband transitions.

Polyaniline-coated papers were fabricated using two-pot layer-by-layer technique. The process involved successive dipping in monomer-acid and oxidant solutions. The infrared spectra showed vibrational modes associated with the presence of polyaniline molecules and cellulose fibers. The polyaniline-coated papers were observed to have electrical and antimicrobial properties. SEM images showed an interconnected network where charges can flow. Measured AC conductivities varied with the amount and configuration of deposits. The values were higher for samples prepared using a larger acid-to-aniline molar ratio. The polyaniline-coated papers were more effective in reducing S. aureus (gram positive) than E. coli (gram negative) after 1 h of contact. The samples’ ability to reduce these bacterial populations decreased after deprotonation.

The aim of the study was to contribute to the information on agave soluble fibers since research has been focused on chicory fiber but not in agave products; thus we assess the acute toxicity and genotoxicity of two organic and high purity dietary soluble fibers from agave, Metlin? and Metlos?. We performed an acute toxicity assay in Hsd:ICR mice and Hsd:Wistar rats and an in vivo genotoxic test. Results showed that there are no deaths at any doses or genotoxicity, so it can be concluded that these products are non-toxic, at the administrated doses and none showed a cytotoxic, clastogenic or aneuploidic effect.

En este artículo me propongo demostrar cómo la implicación del cuerpo enfermo proyecta uno de los principios artísticos que rigen la escritura de Guadalupe Nettel: el revelamiento de la anormalidad como una categoría estética. Para efecto de mi análisis, me centraré en el cuento “Ptosis” porque considero que la búsqueda del narrador y las reflexiones que subyacen en el texto sobre la fotografía perfilan la sensibilidad artística de la autora.