Utjecaj nanočestica kitozana koje sadržavaju antioksidanse izolirane iz biljke Salvia hispanica L. na svojstva filmova pripremljenih od šćirovog brašna

Research background. Amaranth (Amaranthus hypochondriacus) flour produces films with excellent barrier properties against water vapor, allowing food preservation, but the mechanical properties are poor compared to synthetic films. One strategy to improve these properties is the incorporation of nanoparticles. The particles can also serve as a vehicle for the addition of antioxidant agents into the films. The objective of this work is to optimize the formulation for the preparation of amaranth flour films treated with antioxidant chia (Salvia hispanica L.) extract-loaded chitosan particles using response surface methodology (RSM). Experimental approach. Chitosan nanoparticles with the extract were synthesized by ionic gelation, and the films were made by the casting method. Three independent variables were assigned: amaranth flour (4-6%), glycerol (25-35%) and chitosan nanoparticles loaded with the chia extract (0-0.75%). We then evaluated the physical (thickness), mechanical (tensile strength, Young´s modulus and elongation), barrier (water vapor permeability, moisture and water solubility) and antioxidant properties of the films. The experimental results of the properties were analyzed using a Box-Behnken experimental design generating 15 runs with three replicates at the central point. Results and conclusions. Second and third order polynomial models were obtained from the ANOVA analysis of the evaluated responses, and high coefficients of determination were found (0.91–1.0). The water vapor permeability of the films was 0.82−2.39·10-7 (g·mm)/(Pa·s·m2), tensile strength was 0.33−1.63 MPa and antioxidant activity 2.24−5.65%. The variables had different effects on the films: glycerol negatively affected their properties, and the permeability values increased with increased amaranth flour content. The nanoparticles improved the mechanical, barrier and antioxidant properties of the films compared to the films without nanosystems. The optimal formulation was 4% amaranth flour, 25% glycerol and 0.36% chitosan nanoparticles. The optimized films had better mechanical (1.62 MPa) properties, a low water vapor permeability value (0.91·10-7 (g·mm)/(Pa·s·m2)) and moderate antioxidant activity (6.43%). Novelty and scientific contribution. The results show the effect of chitosan nanoparticles on the properties of amaranth flour films for the first time. The resulting equations are useful in the design of food packaging.Pozadina istraživanja. Brašno od amaranta odnosno šćira (Amaranthus hypochondriacus) može se upotrijebiti za izradu filmova s odličnim svojstvom propusnosti vodene pare, što omogućuje čuvanje hrane, no ti filmovi imaju lošija mehanička svojstva od sintetičkih filmova. Jedan od mogućih načina poboljšanja mehaničkih svojstava filmova je dodatak nanočestica, koje ujedno mogu poslužiti kao nosač antioksidansa. Svrha je ovoga rada bila metodom odzivnih površina optimirati pripremu filmova od šćirovog brašna dodatkom čestica kitozana koje sadržavaju antioksidanse iz ekstrakta chia (Salvia hispanica L.) sjemenki. Eksperimentalni pristup. Nanočestice kitozana s ekstraktom chia sjemenki dobivene su ionskim geliranjem, a filmovi su pripremljeni metodom izlijevanja. Određene su tri nezavisne varijable: šćirovo brašno (4-6 %), glicerol (25–35 %) i nanočestice kitozana s ekstraktom chia sjemenki (0–0,75 %). Zatim su procijenjena fizikalna (gustoća), mehanička (vlačna čvrstoća, Youngov modul elastičnosti i istezljivost), barijerna (propusnost vodene pare, vlaga i topljivost u vodi) i antioksidacijska svojstva filmova. Dobiveni su rezultati ispitani pomoću Box-Behnkenovog plana izvođenjem 15 eksperimenata s tri ponavljanja u centralnoj točki. Rezultati i zaključci. Analizom odziva pomoću ANOVA testa dobiveni su modeli oblika polinoma drugog i trećeg stupnja te visoki koeficijenti određivanja (0,91–1,0). Propusnost vodene pare bila je 0,82−2,39·10–7 (g·mm)/(Pa·s·m2), vlačna čvrstoća 0,33−1,63 MPa, a antioksidacijska aktivnost filmova 2,24−5,65 %. Svaka je varijabla imala drugačiji učinak: povećanje udjela glicerola negativno je utjecalo na svojstva flimova, a njihova propusnost se povećala s povećanjem udjela šćirovog brašna. Dodatkom nanočestica poboljšana su mehanička i antioksidacijska svojstva te propusnost filmova u usporedbi s filmovima koji nisu sadržavali nanočestice. Optimalni dodatak filmovima bio je 4 % šćirovog brašna, 25 % glicerola i 0,36 % nanočestica kitozana. Optimirani filmovi imali su bolja mehanička svojstva (1,62 MPa), malu propusnost vodene pare (0,91·10–7 (g·mm)/(Pa·s·m2)) i umjerenu antioksidacijsku aktivnost (6,43 %). Novina i znanstveni doprinos. Rezultati ispitivanja po prvi put prikazuju utjecaj nanočestica kitozana na svojstva filmova od šćirovog brašna. Dobivene jednadžbe mogu se korisno upotrijebiti u projektiranju jestive ambalaže

Temperature-mediated biosynthesis of the phytotoxin phaseolotoxin by Pseudomonas syringae pv. phaseolicola depends on the autoregulated expression of the phtABC genes

Abstract Pseudomonas syringae pv. phaseolicola produces phaseolotoxin in a temperature dependent manner, being optimally synthesized between 18˚C and 20˚C, while no detectable amounts are present above 28˚C. The Pht cluster, involved in the biosynthesis of phaseolotoxin, contains 23 genes that are organized in five transcriptional units. The function of most of the genes from the Pht cluster is still unknown and little information about the regulatory circuitry leading to expression of these genes has been reported. The purpose of the present study was to investigate the participation of pht genes in the regulation of the operons coded into the Pht cluster. We conducted Northern blot, uidA fusions and reverse transcription-PCR assays of pht genes in several mutants unable to produce phaseolotoxin. This allowed us to determine that, in P. syringae pv. phaseolicola NPS3121, genes phtABC are essential to prevent their own expression at 28˚C, a temperature at which no detectable amounts of the toxin are present. We obtained evidence that the phtABC genes also participate in the regulation of the phtD, phtM and phtL operons. According to our results, we propose that PhtABC and other Pht product activities could be involved in the synthesis of the sulfodiaminophosphinyl moiety of phaseolotoxin, which indirectly could be involved in the transcriptional regulation of the phtA operon

Improving Cognitive Visual-Motor Abilities in Individuals with Down Syndrome

Down syndrome causes a reduction in cognitive abilities, with visual-motor skills being particularly affected. In this work, we have focused on this skill in order to stimulate better learning. The proposal relies on stimulating the cognitive visual-motor skills of individuals with Down Syndrome (DS) using exercises with a gestural interaction platform based on the KINECT sensor named TANGO:H, the goal being to improve them. To validate the proposal, an experimental single-case study method was designed using two groups: a control group and an experimental one, with similar cognitive ages. Didactic exercises were provided to the experimental group using visual cognitive stimulation. These exercises were created on the TANGO:H Designer, a platform that was designed for gestural interaction using the KINECT sensor. As a result, TANGO:H allows for visual-motor cognitive stimulation through the movement of hands, arms, feet and head. The “Illinois Test of Psycholinguistic Abilities (ITPA)” was applied to both groups as a pre-test and post-test in its four reference sections: visual comprehension, visual-motor sequential memory, visual association, and visual integration. Two checks were made, one using the longitudinal comparison of the pre-test/post-test of the experimental group, and another that relied on comparing the difference of the means of the pre-test/post-test. We also used an observational methodology for the working sessions from the experimental group. Although the statistical results do not show significant differences between the two groups, the results of the observations exhibited an improvement in visual-motor cognitive skills

Expression of the gene for resistance to phaseolotoxin (argK) depends on the activity of genes phtABC in Pseudomonas syringae pv. Phaseolicola

Incluye material complementarioThe bacterium Pseudomonas syringae pv. phaseolicola produces phaseolotoxin in a temperature dependent manner, being optimally produced between 18 degrees C and 20 degrees C, while no detectable amounts are present above 28 degrees C. Phaseolotoxin is an effective inhibitor of ornithine carbamoyltransferase (OCTase) activity from plant, mammalian and bacterial sources and causes a phenotypic requirement for arginine. To protect the cell from its own toxin, P. syringae pv. phaseolicola synthesizes a phaseolotoxin-resistant OCTase (ROCT). The ROCT is the product of the argK gene and is synthesized only under conditions leading to phaseolotoxin synthesis. The argK gene is included in a chromosomal fragment named Pht cluster, which contains genes involved in the synthesis of phaseolotoxin. The aim of the present work was to investigate the possible involvement of other genes included in the Pht cluster in the regulation of gene argK. We conducted transcriptional analyses of argK in several mutants unable to produce phaseolotoxin, transcriptional fusions and electrophoretic mobility shift assays, which allowed us to determine that genes phtABC, located within the Pht cluster, participate in the transcriptional repression of gene argK at temperatures not permissive for phaseolotoxin biosynthesis. This repression is mediated by a protein present in both toxigenic and nontoxigenic strains of P. syringae and in E. coli, and requires the coordinated participation of phtA, phtB and phtC products in order to carry out an efficient argK repression.This work was funded by grants from CONACYT (Consejo Nacional de Ciencia y Tecnología; http://www.conacyt.mx), research grant SEP-2006-C01-49958/24089 to AAM and SA (Postdoctoral scholarship), and from the Spanish Plan Nacional I+D+I grant AGL2008-55311-CO2-01 (Ministerio de Ciencia e Innovación; http://micinn.es/), co financed by FEDER, to JM

Factors that trigger childhood obesity, a public health problem

Obesity is a global pandemic and children are a vulnerable group. Obesity in childhood and adolescence has a negative impact on the health and burden of diseases at that stage of life and later on in adulthood. Therefore, it is crucial to seek strategies and interventions that prevent overweight and obesity in children and adolescents to improve the health conditions of a country. Aim. To determine the triggers of childhood obesity in Hidalgo as a public health problem in children aged 6 to 12 years. Material and methods. For the study the population relative to the parents will be taken as reference point, being a secondary source, of students of the six grades of primary education that comprise ages of 6 to 12 years. Results. The results show that 100% of people are aware of the concept of childhood obesity, but they continue with bad habits such as sedentary lifestyle and the consumption of junk food. Conclusion. People are aware of what childhood obesity is and the problems or consequences that it brings ith it, however, obesity and sedentary lifestyle predominate in several homes, and despite this knowledge, they do not modify their routine or their diet, Which is very important to prevent chronic degenerative diseases such as diabetes, hypertension, dyslipidemia and atherosclerosis

Phytoremediation Potential of <em>Chrysopogon zizanioides</em> for Toxic Elements in Contaminated Matrices

Many researchers have demonstrated the advantages of plants in the phytoremediation of soils and waters contaminated with heavy metals, herbicides, pesticides, leachates, etc. The unique morphological characteristics of Chrysopogon zizanioides, commonly known as vetiver, make it a hyperaccumulator of metals; its roots can store high concentrations of heavy metals such as As, Cd, Cr, Cu, Hg, Ni, Pb, Se, and Zn, and it has thus been successfully used in the field of environmental protection. This chapter presents the importance of vetiver, its characterization, and its potential use as phytoremediation potential for toxic elements in contaminated matrices

Vía aérea pequeña: de la definición al tratamiento

La vía aérea pequeña, presente desde los orígenes de la humanidad y descrita hace apenas un siglo, se ha descubierto recientemente como el sitio anatómico donde inicia la inflamación provocada por algunas enfermedades pulmonares obstructivas: asma y enfermedad pulmonar obstructiva crónica (EPOC), per se. Se ha identificado disfunción de la vía aérea pequeña en el 91% de los pacientes asmáticos y en una gran proporción de quienes padecen EPOC. En los pacientes sin enfermedad, la vía aérea pequeña representa el 98.8% (4500 mL) del volumen pulmonar total, y solo aporta del 10 al 25% de la resistencia pulmonar total; sin embargo, en sujetos con obstrucción puede suponer el 90% de la resistencia total. A pesar de esto, sus características morfológicas y funcionales permiten que la disfunción pase inadvertida por métodos diagnósticos convencionales, por ejemplo la espirometría. Con base en lo anterior, el objetivo de este estudio fue revisar el panorama general de los métodos disponibles para evaluar la vía aérea pequeña y los posibles tratamientos asociados con esta zona silente. Palabras clave: Vía aérea pequeña; resistencia al flujo aéreo; asma; EPOC

Las barreras a la participación política de las mujeres con doble jornada laboral en Nuevo León, México

En la presente investigación se abordan los resultados de un estudio dirigido a identificar las principales barreras de participación política que enfrentan las nuevoleonesas con doble jornada laboral. Las participantes entrevistadas se conjuntaron a partir de tres grupos: A) Servidoras Públicas, B) Integrantes de Organizaciones No Gubernamentales (ONG) y C) Grupos de la Sociedad Civil Organizada (GSCO). El estudio se estableció desde una perspectiva cualitativa, se recabaron las experiencias de las participantes mediante entrevistas en profundidad semiestructuradas y el análisis de la información fue por medio del software NVivo 11. En un primer momento se analizaron los discursos de las entrevistadas y en un segundo análisis se identificaron las barreras a las que se enfrentan en el ejercicio de la política. Los hallazgos encontrados se analizaron en cada uno de los tres grupos y se identificó que las barreras para participar en política son diferenciadas entre ellas, además que responden a condiciones y estructuras sociales como: entornos de clase social, familiar y de género. Las principales barreras identificadas fueron: la dedicación a la maternidad, la inequidad política electoral, la violencia política en razón de género y la represión, la sociedad patriarcal, el problema de movilidad urbana, el límite para acceder al sistema de guarderías, además de la instauración de estereotipos de género que conducen al cuidado exclusivo de la familia. Abstract This research addresses the results of a study aimed at identifying the main barriers to conventional and unconventional political participation, faced by women from Nuevo León with doble working hours. The interviewed participants came together from three groups: A) Public Servants, B) Members of Non-Governmental Organizations (NGOs), and C) Organized Civil Society Groups (GSCO). The study was established from a qualitative perspective, the experiences of the participants were collected through semi-structured in-depth interviews and the information analysis was through the Nvivo 11 software. At first, the speeches of the interviewees were analyzed and in a second analysis identified the barriers they face in the exercise of politics. The findings found were analyzed in each of the three groups and it was identified that the barriers to participating in politics are differentiated among them, in addition to responding to social conditions and structures such as: social class, family and gender environments. The main barriers identified were dedication to motherhood, electoral political inequity, political violence based on gender and repression, patriarchal society, the problem of urban mobility, limits to access the day care system, in addition to the establishment of gender stereotypes that lead to exclusive care of the family

Computational Thinking and Down Syndrome: An Exploratory Study Using the KIBO Robot

Computational thinking and coding are key competencies in the 21st century. People with Down syndrome need to be part of this new literacy. For this reason, in this work, we present an exploratory study carried out with students with Down syndrome with cognitive ages of 3–6 years old using a tangible robot We applied the observational method during the sessions to analyze the participants’ emotional states, engagement, and comprehension of the programming sequences. Results show that people with cognitive disabilities can acquire basic programming and computational skills using tangible robots such as KIBO

Functional Characterization of the Gene Cluster from Pseudomonas syringae pv. phaseolicola NPS3121 Involved in Synthesis of Phaseolotoxin

Pseudomonas syringae pv. phaseolicola is the causal agent of halo blight disease of beans (Phaseolus vulgaris L.), which is characterized by water-soaked lesions surrounded by a chlorotic halo resulting from the action of a non-host-specific toxin known as phaseolotoxin. This phytotoxin inhibits the enzyme ornithine carbamoyltransferase involved in arginine biosynthesis. Different evidence suggested that genes involved in phaseolotoxin production were clustered. Two genes had been previously identified in our laboratory within this cluster: argK, which is involved in the immunity of the bacterium to its own toxin, and amtA, which is involved in the synthesis of homoarginine. We sequenced the region around argK and amtA in P. syringae pv. phaseolicola NPS3121 to determine the limits of the putative phaseolotoxin gene cluster and to determine the transcriptional pattern of the genes comprising it. We report that the phaseolotoxin cluster (Pht cluster) is composed of 23 genes and is flanked by insertion sequences and transposases. The mutation of 14 of the genes within the cluster lead to a Tox(−) phenotype for 11 of them, while three mutants exhibited low levels of toxin production. The analysis of fusions of selected DNA fragments to uidA, Northern probing, and reverse transcription-PCR indicate the presence of five transcriptional units, two monocistronic and three polycistronic; one is internal to a larger operon. The site for transcription initiation has been determined for each promoter, and the putative promoter regions were identified. Preliminary results also indicate that the gene product of phtL is involved in the regulation of the synthesis of phaseolotoxin