Preservation of Relics from the RNA World through Natural Selection, Symbiosis and Horizontal Gene Transfer

A difficulty arises if we conjecture that the RNA world may have left molecular relics that may still be extant. We discuss the possible roles that natural selection, symbiosis and horizontal gene transfer may have played in the evolutionary pathway of the earliest RNA replicators. The period that concerns us ranges from the time that separates the appearance of contemporary metazoans at the onset of the Phanerozoic, in the Paleozoic era (the Cambrian period, some 540 million years before the present Mybp), from the RNA world, namely in the Early Archean, or even earlier. In order to address this question we extend a previous treatment of this problem to non-pathogenic RNA replicators. The possibility of preservation of relics from the RNA world had been discussed earlier in the context of pathogenic RNA replicators (viroids) We discuss the evolutionary forces that may have been at play in the preservation of life from the RNA world to the present. We conjecture that the genes of the replicases (RNA-directed RNA polyrnerases) associated with putative non-pathogenic DNA-independent replicators of the RNA world may have been transferred vertically, eventually being preserved in some multicellular organisms as RNA replicators independent of DNA. We comment on the outstanding experimental questions that remain to be done, so as to test with new experiments the concept of the preservation of the RNA world relics

Is the Salam phase transition relevant to the causal origin of homochirality?

From the point of view of (a) chemical evolution and (b) exobiology (the origin of life in the universe), we discuss the possibility that phase transitions of the type postulated by Salam in 1991 to occur in a racemic mixture of amino acids, may play instead the role of an amplification mechanism in the novel context of chirally-pure samples of amino acids. Salam's seminal contribution referred to the role of phase transitions in the induction of the observed homochirality of protein amino acids. This was assumed to occur in a racemic mixture that, as a consequence of the conjectured phase transition, turned homochiral beneath a certain critical temperature, T_c. In the present review we discuss selected theoretical aspects of the question of homochirality. The relevance of starting a new generation of experiments is pointed out, as suggested by the present author in 1991. These experiments should test a form of condensed matter that has so far not been at the forefront of research from the point of view of the phase transitions. We discuss those aspects of the origin of homochirality which are still valid and require verification

A Search for Extraterrestrial Eukaryotes: Biological and Planetary Science Aspects

One pressing question in Bioastronomy is to attempt to devise assays in the search for extraterrestrial eukaryotes (SETE). In the positive case of encountering a fossil of a certain microorganism, it is not yet clear how to identify it in an unequivocal manner, even if found arrested and preserved in the midst of biological activity, as in some known Archean sediments on Earth. On the other hand, for living microorganisms the present approach may have some advantages over the straightforward probe of the morphological features of the putative eukaryote, as we argue that we are not constrained to base identification on morphological properties, such as the presence of organelles, which are known to be missing in some higher taxa. The present work suggests one possible assay to detect eukaryotes, namely, the search for cellular division with a delay in replication of heterochromatic chromosome segments; we also discuss the biological and astronomical implications of a SETE program. Further, extremophiles may inhabit deep in the silicate crust of terrestrial planets which may have been deposited with the original sediment and survived over geologic time. Comparative planetology suggests that there are common ingredients in the nature of the landscapes of the terrestrial planets, particularly gradation. Hence, a SETE program should look for indicators of the first steps towards eukaryogenesis, for instance deep in the Martian crust. Additional ingredients in the common landscape of the rocky planets, or satellites, may be volcanism and tectonics. This has led to the belief that hot springs may be present at the bottom of Europa's great ocean. Hence, eukaryotes should also be searched for in this aquatic environment. Our current work emphasising gene silencing, may suggest how to decide whether extraterrestrial microbiota may have taken the first steps towards eukaryogenesis, the process which introduced the basic cellular plan of those Earth-bound organisms that have been raised to the level of intelligent beings

USING ART EDUCATION TO CULTIVATE SELF-EFFICACY AND DIVERGENT THINKING

The purpose of this study is to understand the experiences of an art teacher implementing art education with creative learning principles to cultivate students’ creative self-efficacy and divergent thinking at one middle school in the Inland Empire located in Southern California. The research continues to focus on how self-efficacy and divergent thinking cultivate through the process of art creation through project-based learning (Puente-Díaz & Cavazos-Arroyo, 2017). An art education is not a requirement for students to receive throughout their PK-12 general education in low socioeconomic schools due to an emphasis on the general education curriculum to focus on high-stakes standardized testing (Wexler, 2014). For students in California, one art course is a requirement to graduate from high school (California Department of Education, 2020). The framework of this study uses critical race theory and critical pedagogy to examine students in low socioeconomic communities and inequitable opportunities to cultivate self-efficacy and divergent thinking when compared to more affluent communities (Puente-Díaz & Cavazos-Arroyo, 2017; Reichelt et al., 2019)

Targeting a therapeutic LIF transgene to muscle via the immune system ameliorates muscular dystrophy.

Many potentially therapeutic molecules have been identified for treating Duchenne muscular dystrophy. However, targeting those molecules only to sites of active pathology is an obstacle to their clinical use. Because dystrophic muscles become extensively inflamed, we tested whether expressing a therapeutic transgene in leukocyte progenitors that invade muscle would provide selective, timely delivery to diseased muscle. We designed a transgene in which leukemia inhibitory factor (LIF) is under control of a leukocyte-specific promoter and transplanted transgenic cells into dystrophic mice. Transplantation diminishes pathology, reduces Th2 cytokines in muscle and biases macrophages away from a CD163+/CD206+ phenotype that promotes fibrosis. Transgenic cells also abrogate TGFβ signaling, reduce fibro/adipogenic progenitor cells and reduce fibrogenesis of muscle cells. These findings indicate that leukocytes expressing a LIF transgene reduce fibrosis by suppressing type 2 immunity and highlight a novel application by which immune cells can be genetically modified as potential therapeutics to treat muscle disease

Competitividad de la fresa mexicana en el mercado estadounidense de 1992 a 2017

Strawberry exports worldwide have averaged 457,703 t in the last 30 years, with 2012 being the most important year for export, with a total of 852,369 t. For 2013, a value of $2,330,136 and an average of$971,262 was obtained from 1983 to 2013. The Mexican strawberry has increased in production due to programs focused on promoting agriculture and applying production methods. The leading strawberry exporting countries worldwide in 2011 were Spain, the United States, the Netherlands, Belgium, and Mexico. The main destination of the export was the United States that concentrated 96% to complement its demand. The production and export data positions the Mexican strawberry in second place in production, and fifth place in world export. This study aimed to determine the competitiveness of Mexican strawberry in the US market and its behavior compared to exporting countries, such as Spain and the US. The Balassa index and the export opening degree index were used to measure competitiveness, stressing a positive competitiveness. However, higher specialization is required to increase the current competitive levels.Las exportaciones de fresa a nivel internacional han alcanzado un promedio de 457.703 t en los últimos 30 años; el 2012 fue el año más importante con 852.369 t exportadas en total. Para el 2013, el valor de estas exportaciones fue de USD 2.330.136, y entre 1983 y 2013, el promedio fue de USD 971.262. La producción de fresa en México ha incrementado debido a programas enfocados en el fomento de la agricultura y la aplicación de métodos de producción. En 2011, los mayores exportadores de fresa fueron España, EE. UU., Países Bajos, Bélgica y México. El principal destino de exportación fue EE. UU., que concentró el 96 % para complementar su demanda. Los datos de producción y exportación ubican a México en el segundo lugar de producción y el quinto lugar de exportación a nivel mundial. Este estudio tuvo por objetivo determinar la competitividad de la fresa mexicana en el mercado estadounidense y su comportamiento en comparación con otros países exportadores como España y EE. UU. Para medir la competitividad, se utilizó el índice de Balassa y el índice de grado de apertura en exportaciones, que señalaron una competitividad positiva. Sin embargo, se requiere mayor especialización para aumentar los niveles competitivos existentes

Problemas en la Implementación del Programa de Reparación en la Salud Mental de los Afectados por el Conflicto Armado Interno: Ayacucho 2006-2014

La presente investigación documenta el “proceso dificultoso de la implementación del programa de reparación en salud mental en la región de Ayacucho – Perú”. Dicho programa se implementa como respuesta a las secuelas del conflicto armado interno ocurrida entre los años 1980 y el año 2000, entre las que destaca las psicosociales que afectaron y siguen afectando a la salud mental de la población, conocida y expresada por las víctimas: “estamos traumados”. Analizando las fuentes secundarias respecto al tema y la fuente primaria consistente en las entrevistas semi estructuradas a los actores que tuvieron el rol directo e indirecto en la implementación del programa de reparaciones, se demuestra que la “situación problemática” de la salud mental como “creación del problema” fue implementada como programa de reparación a favor de los afectados por el conflicto armado interno en Ayacucho entre los años 2006 al 2014 obteniéndose resultados limitados, porque dicho proceso de “creación del problema” o estructuración del problema ha sido definido en el interior de la estructura gubernamental, prescindiendo de las propuestas “exógenas” de los afectados por la violencia y experiencias locales de intervención, por la “brecha existente entre la gestión pública y las políticas públicas (o sea se dio menos importancia a la deliberación de los problemas públicos)”; por ello, los “técnicos” del ejecutivo hicieron posible que una “situación problemática” o “creación de problema” sea “problema tratable” y/o “solución factible”, prescindiendo de las propuestas de los afectados por la violencia política(ANFASEP, CORAVIP) y experiencias de segmentación e intervención en salud mental no gubernamentales (ONGs: IPAZ, Paz y Esperanza)

Problemas en la Implementación del Programa de Reparación en la Salud Mental de los Afectados por el Conflicto Armado Interno: Ayacucho 2006-2014

La presente investigación documenta el “proceso dificultoso de la implementación del programa de reparación en salud mental en la región de Ayacucho – Perú”. Dicho programa se implementa como respuesta a las secuelas del conflicto armado interno ocurrida entre los años 1980 y el año 2000, entre las que destaca las psicosociales que afectaron y siguen afectando a la salud mental de la población, conocida y expresada por las víctimas: “estamos traumados”. Analizando las fuentes secundarias respecto al tema y la fuente primaria consistente en las entrevistas semi estructuradas a los actores que tuvieron el rol directo e indirecto en la implementación del programa de reparaciones, se demuestra que la “situación problemática” de la salud mental como “creación del problema” fue implementada como programa de reparación a favor de los afectados por el conflicto armado interno en Ayacucho entre los años 2006 al 2014 obteniéndose resultados limitados, porque dicho proceso de “creación del problema” o estructuración del problema ha sido definido en el interior de la estructura gubernamental, prescindiendo de las propuestas “exógenas” de los afectados por la violencia y experiencias locales de intervención, por la “brecha existente entre la gestión pública y las políticas públicas (o sea se dio menos importancia a la deliberación de los problemas públicos)”; por ello, los “técnicos” del ejecutivo hicieron posible que una “situación problemática” o “creación de problema” sea “problema tratable” y/o “solución factible”, prescindiendo de las propuestas de los afectados por la violencia política(ANFASEP, CORAVIP) y experiencias de segmentación e intervención en salud mental no gubernamentales (ONGs: IPAZ, Paz y Esperanza).Tesi

Vertical Electrical Sounding Method to Detect Groundwater and Design of A Tubular Well for the Pampas District – Peru

In recent years, the occurrence of unexpected meteorological events during the dry season and population growth have generated shortages in the supply of drinking water in the city of Pampas. This situation led us to look for new search strategies for natural water sources, even underground. Faced with this problem, the possibility of detecting and parameterizing these sources was raised, while the design of a tubular well was raised that allows the economic extraction of water from the aquifer studied through the use of geophysical techniques, generating profile images of geological maps. of the strata and the location of the possible water table of the study area. The preferred locations for locating groundwater collections are alluvial fans and fractured valley bottoms. Using the Schlumberger array, eleven (11) VESs have been made, up to a depth of 150 m. For the field tests, a resistivity meter that we have manufactured by hand was used, this will emit current to the subsoil obtaining layers and horizons through their resistivities, these values vary in the range of 6.32-125.23 Ω.m. The PQWTS-150- Water Detector equipment was also used to measure the depth of the semi-confined aquifer and to know its groundwater flow, the value is 33.33 l/s, this value refers to the three celestial layers that can be seen in the image. description of the profile of the geological map, in this profile clayey, silty, sandy, gravel soils and a combination of them were found. This point 11 was taken in the nursery of the Daniel Hernández district, this area is flat, quite humid and its depth is 51m -115m. In addition, this aquifer has good hydrogeological possibilities making surface recharge possible. The water table was also determined, it is found at a depth of 4-8 m. With the data obtained lines above it was useful for the calculation and design of the tubular well. In conclusion, the designed well has a depth of 115 m and a thickness of 64 m, with a drilling diameter of 18 inches and equipped with a submersible pump with a 25 HP motor, achieving a flow rate of 1000 l/min, which complies with the water requirement of the population. In order to verify the quality of the water from this well, a physical-chemical and bacteriological analysis was carried out

Complex pattern of interaction between in utero hypoxia-ischemia and intra-amniotic inflammation disrupts brain development and motor function

Background: Infants born preterm commonly suffer from a combination of hypoxia-ischemia (HI) and infectious perinatal inflammatory insults that lead to cerebral palsy, cognitive delay, behavioral issues and epilepsy. Using a novel rat model of combined late gestation HI and lipopolysaccharide (LPS)-induced inflammation, we tested our hypothesis that inflammation from HI and LPS differentially affects gliosis, white matter development and motor impairment during the first postnatal month. Methods: Pregnant rats underwent laparotomy on embryonic day 18 and transient systemic HI (TSHI) and/or intra-amniotic LPS injection. Shams received laparotomy and anesthesia only. Pups were born at term. Immunohistochemistry with stereological estimates was performed to assess regional glial loads, and western blots were performed for protein expression. Erythropoietin ligand and receptor levels were quantified using quantitative PCR. Digigait analysis detected gait deficits. Statistical analysis was performed with one-way analysis of variance and post-hoc Bonferonni correction. Results: Microglial and astroglial immunolabeling are elevated in TSHI + LPS fimbria at postnatal day 2 compared to sham (both P < 0.03). At postnatal day 15, myelin basic protein expression is reduced by 31% in TSHI + LPS pups compared to shams (P < 0.05). By postnatal day 28, white matter injury shifts from the acute injury pattern to a chronic injury pattern in TSHI pups only. Both myelin basic protein expression (P < 0.01) and the phosphoneurofilament/neurofilament ratio, a marker of axonal dysfunction, are reduced in postnatal day 28 TSHI pups (P < 0.001). Erythropoietin ligand to receptor ratios differ between brains exposed to TSHI and LPS. Gait analyses reveal that all groups (TSHI, LPS and TSHI + LPS) are ataxic with deficits in stride, paw placement, gait consistency and coordination (all P < 0.001). Conclusions: Prenatal TSHI and TSHI + LPS lead to different patterns of injury with respect to myelination, axon integrity and gait deficits. Dual injury leads to acute alterations in glial response and cellular inflammation, while TSHI alone causes more prominent chronic white matter and axonal injury. Both injuries cause significant gait deficits. Further study will contribute to stratification of injury mechanisms in preterm infants, and guide the use of promising therapeutic interventions