18 research outputs found
Reconstructing Native American Population History
The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved1–5. One contentious issue is whether the settlement occurred via a single6–8 or multiple streams of migration from Siberia9–15. The pattern of dispersals within the Americas is also poorly understood. To address these questions at higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. We show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call “First American”. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan-speakers on both sides of the Panama Isthmus, who have ancestry from both North and South America
VIII Encuentro de Docentes e Investigadores en Historia del Diseño, la Arquitectura y la Ciudad
Acta de congresoLa conmemoración de los cien años de la Reforma Universitaria de 1918 se presentó como una ocasión propicia para debatir el rol de la historia, la teoría y la crítica en la formación y en la práctica profesional de diseñadores, arquitectos y urbanistas.
En ese marco el VIII Encuentro de Docentes e Investigadores en Historia del Diseño, la Arquitectura y la Ciudad constituyó un espacio de intercambio y reflexión cuya realización ha sido posible gracias a la colaboración entre Facultades de Arquitectura, Urbanismo y Diseño de la Universidad Nacional y la Facultad de Arquitectura de la Universidad Católica de Córdoba, contando además con la activa participación de mayoría de las Facultades, Centros e Institutos de Historia de la Arquitectura del país y la región.
Orientado en su convocatoria tanto a docentes como a estudiantes de Arquitectura y Diseño Industrial de todos los niveles de la FAUD-UNC promovió el debate de ideas a partir de experiencias concretas en instancias tales como mesas temáticas de carácter interdisciplinario, que adoptaron la modalidad de presentación de ponencias, entre otras actividades.
En el ámbito de VIII Encuentro, desarrollado en la sede Ciudad Universitaria de Córdoba, se desplegaron numerosas posiciones sobre la enseñanza, la investigación y la formación en historia, teoría y crítica del diseño, la arquitectura y la ciudad; sumándose el aporte realizado a través de sus respectivas conferencias de Ana Clarisa Agüero, Bibiana Cicutti, Fernando Aliata y Alberto Petrina. El conjunto de ponencias que se publican en este Repositorio de la UNC son el resultado de dos intensas jornadas de exposiciones, cuyos contenidos han posibilitado actualizar viejos dilemas y promover nuevos debates.
El evento recibió el apoyo de las autoridades de la FAUD-UNC, en especial de la Secretaría de Investigación y de la Biblioteca de nuestra casa, como así también de la Facultad de Arquitectura de la UCC; va para todos ellos un especial agradecimiento
Biodegradación de Bifenilos Policlorados (BPCs) por Microorganismos Biodegradación de Bifenilos Policlorados (BPCs) por Microorganismos
One of the problems that Mexico faces is the treatment of hazardous materials generated by different industrial processes. Polychlorinated biphenyls (PCBs) are pollutants of great concern because of their impact on human health and the environment. This paper is a review of PCB´s effects on the environment and human health, and also shows that diverse fungi have been used to reduce their presence in the environment.Uno de los problemas que enfrenta México en la actualidad es el tratamiento de los residuos peligrosos que generan los diversos procesos industriales. Dentro de estos residuos se encuentran los bifenilos policlorados (BPCs), que se han convertido en un grave problema ambiental. En este artículo se presentan algunos de sus efectos en el ambiente y en el ser humano, así como las alternativas de tratamiento empleando microorganismos que se están estudiando para disminuir su presencia del medio ambiente
Comparative Study of Methane Production in a One-Stage vs. Two-Stage Anaerobic Digestion Process from Raw Tomato Plant Waste
An anaerobic digestion process performed in two stages has the advantages of the production of hydrogen in addition to methane, and of further degradation of the substrate over the conventional process. The effectiveness of the implementation of this system for the treatment of lignocellulosic waste has been demonstrated. In 2020, more than 180 million tons of organic waste were generated worldwide from tomato crop production, posing a serious environmental risk. In the present investigation, methane production was compared in a two-stage system versus one-stage system from non-pretreated tomato plant residues. For this, different temperature (37 and 55 °C) and initial pH (5.5 and 6.5) conditions were evaluated during hydrogenesis and a constant temperature (37 °C, without pH adjustment) during methanogenesis. At the same time, a one-stage treatment (37 °C, without pH adjustment) was run for comparison purposes. The two-stage treatment in which the highest production of hydrogen, 12.4 mL/g VS, and methane, 252.3 mL/g VS, was observed occurred under the conditions of pH 6.5 and at 37 °C. However, this energy production was statistically similar (p 4/g VS). Furthermore, there were also no significant differences in the removal of volatile solids between the different treatments
Aplicación de productos derivados del insecto Dactylopius coccus Costa (Homóptera, Dactylopiidae) Aplicación de productos derivados del insecto Dactylopius coccus Costa (Homóptera, Dactylopiidae)
<p class="Default"> </p> <p>Nowadays many industries want to replace synthetic dyes by natural, due to its harmful effects and the high contamination of the environment. <em>Dactylopius coccus </em>Costa (cochineal) is an insect to obtain natural products that are used as dyes. The aim of this study was to promote the application of cochineal and the products derivates of these insect, in the dyeing of cotton fabric and in the coloration of a lipstick bullet at the laboratory. Was applied to the aqueous extract of cochineal on cotton fabric, obtaining homogeneous colors, with average values in the CIELab scale of: 43.81±0.33 L*, 44.64±0.15 a* y -4.03±0.55 b*. It also was applied the carmine pigment in the elaboration of a lipstick bullet, was obtained consistent color with the following average values on the CIELab scale: 13.25±3.62 L*, 4.80±1.41 a* y -0.23±0.84 b*.</p><br><span style="font-family: Times New Roman; font-size: small;"> </span><p class="MsoNormal" style="margin: 0cm 0cm 10pt;"><span style="color: black; line-height: 115%; font-size: 7.5pt; mso-bidi-font-family: "Bookman Old Style";"><span style="font-family: Calibri;">Actualmente muchas industrias buscan sustituir los colorantes sintéticos por naturales, debido a su efecto nocivo y a la alta contaminación del medio ambiente. Del insecto <em>Dactylopius coccus </em>Costa (grana carmín) se obtienen productos naturales que se pueden usar como colorantes, por lo que el objetivo de este trabajo fue difundir la aplicación del insecto grana carmín y los productos derivados del mismo en el teñido de una tela de algodón y en la coloración de una bala labial a nivel laboratorio. Al aplicar el extracto acuoso de la grana carmín sobre la tela de algodón, se consiguieron colores homogéneos, con valores promedio en la escala CIELab de: 43.81±0.33 L*, 44.64±0.15 a* y -4.03±0.55 b*. Asimismo al aplicar el pigmento laca carmín en la elaboración de una bala labial se lograron colores uniformes con los siguientes valores promedio en la escala CIELab: 13.25±3.62 L*, 4.80±1.41 a* y -0.23±0.84 b*.</span></span></p><span style="font-family: Times New Roman; font-size: small;"> </span
Characterization of a Lignocellulolytic Consortium and Methane Production from Untreated Wheat Straw: Dependence on Nitrogen and Phosphorous Content
Impacts of microbial diversity and macronutrients levels (expressed as C:N and C:P ratios) on the methane production from an untreated lignocellulosic feedstock were assessed. Next-generation sequencing technology revealed the bacterial diversity of a lignocellulolytic inoculum. This inoculum comprised 75 bacterial species that were well distributed in 14 phyla, 67% of which belonged to Firmicutes and Bacteroidetes. The families Ruminococcaceae, Clostridiaceae, Bacteroidaceae, Bacillaceae, and Fibrobacteraceae comprised 46% of the identified families and were associated with hydrolytic members. Nutrient adjustment reduced 40% of the length of the lag phase and doubled methane production rate compared with a control. The highest methane production of 0.197 m3 per kg of total volatile solids observed at C:N of 31:1 and C:P of 428:1, peaked 20 days earlier than in previous studies using untreated lignocellulosic feedstock. Interestingly, the highest hydrolytic activities and solids removal rates were observed at high nitrogen contents; however, the conditions (pH > 8.0) inhibited methanogenesis
Cambios en las propiedades fisicoquímicas y microbiológicas del suelo generados por la producción de carbón vegetal en el bosque templado de (quercus spp.) en Santa Rosa, Gto. México
The temperate forest of Quercus spp. Santa Rosa is one of the most extensive forests in central Mexico. In this forest, charcoal is produced traditionally by rural communities. This study evaluated the impact of the activity of charcoal production in three sampling sites of the forest, soil from the impact site, land adjacent to the site of charcoal production and control soil without charcoal production activity on physicochemical and microbiological properties. We determined pH, concentration of macro-and micro-elements was performed by calculating microbial colony forming units (CFU) of bacteria, fungi, actinomycetes and promoting growth of plants rhizobacteria (PGPR). Finally, we determined microbial biomass by fumigation-incubation method. On the floor of coal production, an increase in pH, the concentration of cations forming bases (Ca2 + and K+) and a high regard microbial fungi, bacteria and actinomycetes, but the microbial biomass and organic matter content was higher in the control soil, in terms of RPCP only isolated in the soil adjacent to coal production site and the control soil. The physicochemical changes produced by the warming effect of soil significantly affected the microbial community favoring the reduction or elimination of dominant groups sensitive to high temperatures that are actively involved in the dynamics of soil processesEl bosque templado de Quercus spp. en Santa Rosa constituye uno de los bosques más extensos del centro de México. En este bosque, se produce carbón vegetal de manera tradicional, por las comunidades rurales. En este trabajo se evaluó el impacto de la actividad de producción de carbón vegetal en tres sitios de muestreo del bosque, en suelo del sitio de impacto, suelo adyacente al sitio de producción de carbón vegetal y suelo control sin actividad de producción de carbón, sobre las propiedades fisicoquímicas y microbiológicas. Se determinó pH, concentración de macro- y micro- elementos, se realizó cuenta microbiana en placa calculando las unidades formadoras de colonias (UFC) de bacterias, hongos, actinomicetos y rizobacterias promotoras de crecimiento de plantas (RPCP). Por último se determinó la biomasa microbiana por el método de fumigación-incubación. En el suelo de producción de carbón se obtuvo un aumento en el pH, en la concentración de cationes formadores de bases (Ca2+ y K+) y una elevada cuenta microbiana de hongos, bacterias y actinomicetos, pero la biomasa microbiana y el contenido de materia orgánica fue mayor en el suelo no control, en cuanto a las RPCP sólo se aislaron en los suelos adyacentes a sitio de producción de carbón y en el suelo no control. Los cambios fisicoquímicos generados por el efecto del calentamiento del suelo afectaron de manera importante a la comunidad microbiana favoreciendo la reducción o eliminación de grupos dominantes sensibles a altas temperaturas que participan activamente en la dinámica de los procesos del suelo
Treatment of a Textile Effluent from Dyeing with Cochineal Extracts Using Trametes versicolor Fungus
Trametes versicolor (Tv) fungus can degrade synthetic dyes that contain azo groups, anthraquinone, triphenylmethane polymers, and heterocyclic groups. However, no references have been found related to the degradation of natural dyes, such as the carminic acid that is contained in the cochineal extract. Experiments to determine the decolorization of the effluent used in the cotton dyeing process with cochineal extract by means of Tv fungus were done. Treatments to determine decolorization in the presence or absence of Kirk's medium, glucose, and fungus, with an addition of 50% (v v-1) of nonsterilized effluent were performed. Physicochemical characterization was performed at the start and end of the treatment. Degradation kinetics were determined. A direct relationship was found between the dry weight of fungi, pH, and the decolorization system, with higher decolorization at lower pH levels (pH ~4.3). High decolorization (81% ± 0.09; 88% ± 0.17; and 99% ± 0.04) for three of the eight treatments (Kirk's medium without glucose, Kirk's medium with glucose, and without medium with glucose, respectively) was found. Toxicity tests determined an increase in the initial effluent toxicity (7.33 TU) compared with the final treatment (47.73 TU) in a period of 11 days. For this system, a degradation sequence of the carminic acid structure present in the effluent by the Tv fungus is suggested, in which it is seen that metabolites still containing aromatic structures are generated
Biological Control of Downy Mildew and Yield Enhancement of Cucumber Plants by Trichoderma harzianum and Bacillus subtilis (Ehrenberg) under Greenhouse Conditions
The downy mildew disease of cucurbits is considered the most economically damaging disease of Cucurbitaceae worldwide. The causal agent, Pseudoperonospora cubensis (Berkeley & Curtis), may cause complete crop losses of cucurbits. Few commercial cucurbit cultivars are resistant to this disease. Commercially, P. cubensis is controlled primarily with synthetic fungicides that inhibit or eliminate the pathogen. Several biological agents have also been identified that provide some level of control. In our study, foliar applications of three strains of Trichoderma harzianum and two native strains of Bacillus subtilis were evaluated for the control of the disease on cucumber plants grown under commercial greenhouse conditions. The study was conducted using a completely randomized design with six individual treatments during two production cycles: fall 2015 and spring 2016. The response variables included disease incidence and severity, plant height, total yield, fruit quality, and weight. B. subtilis provided the best control over the incidence and severity of the disease in both production cycles. Interestingly, while T. harzianum was less effective at controlling the disease, it enhanced plant growth and productivity, and produced a higher number of better-quality fruits per plot. This increased yield with higher quality fruits may result in higher profit for the growers