274 research outputs found
Projection effects in galaxy cluster samples: insights from X-ray redshifts
Up to now, the largest sample of galaxy clusters selected in X-rays comes
from the ROSAT All-Sky Survey (RASS). Although there have been many interesting
clusters discovered with the RASS data, the broad point spread function (PSF)
of the ROSAT satellite limits the amount of spatial information of the detected
objects. This leads to the discovery of new cluster features when a
re-observation is performed with higher resolution X-ray satellites. Here we
present the results from XMM-Newton observations of three clusters:
RXCJ2306.6-1319, ZwCl1665 and RXCJ0034.6-0208, for which the observations
reveal a double or triple system of extended components. These clusters belong
to the extremely expanded HIghest X-ray FLUx Galaxy Cluster Sample
(eeHIFLUGCS), which is a flux-limited cluster sample ( erg s cm in the keV energy band). For
each structure in each cluster, we determine the redshift with the X-ray
spectrum and find that the components are not part of the same cluster. This is
confirmed by an optical spectroscopic analysis of the galaxy members.
Therefore, the total number of clusters is actually 7 and not 3. We derive
global cluster properties of each extended component. We compare the measured
properties to lower-redshift group samples, and find a good agreement. Our flux
measurements reveal that only one component of the ZwCl1665 cluster has a flux
above the eeHIFLUGCS limit, while the other clusters will no longer be part of
the sample. These examples demonstrate that cluster-cluster projections can
bias X-ray cluster catalogues and that with high-resolution X-ray follow-up
this bias can be corrected
Education to gain sustainability : analysis and approach from the experience obtained from two high school systems in mexican rural communities
The decade “Education for Sustainability” is just emerging and one of its goals emphasized the importance of considering the currícula in a transdisciplinary and community based programs. This includes recognizing local and regional interests as relevant topics into the currícula. “Education for sustainability” does not appear to have a strong basis on their actions as its theoretical discourse does. The study we present here about content analysis in the curricula of two high schools systems in rural Mexican communities is an example. In this research we analyzed: 1) how the curricula is oriented towards forest management and the way is connected to the social reality of the communities; 2) how does the learning process develops in the classroom and its dynamics with teachers and students and 3) how does the environmental learning take place. Results revealed that more research is needed with adolescents in order to change the educational structure in rural Mexican high schools.<br /
A novel D-xylose isomerase from the gut of the wood feeding beetle Odontotaenius disjunctus efficiently expressed in Saccharomyces cerevisiae
Carbohydrate rich substrates such as lignocellulosic hydrolysates remain one of the primary sources of potentially renewable fuel and bulk chemicals. The pentose sugar D-xylose is often present in significant amounts along with hexoses. Saccharomyces cerevisiae can acquire the ability to metabolize D-xylose through expression of heterologous D-xylose isomerase (XI). This enzyme is notoriously difficult to express in S. cerevisiae and only fourteen XIs have been reported to be active so far. We cloned a new D-xylose isomerase derived from microorganisms in the gut of the wood-feeding beetle Odontotaenius disjunctus. Although somewhat homologous to the XI from Piromyces sp. E2, the new gene was identified as bacterial in origin and the host as a Parabacteroides sp. Expression of the new XI in S. cerevisiae resulted in faster aerobic growth than the XI from Piromyces on D-xylose media. The D-xylose isomerization rate conferred by the new XI was also 72% higher, while absolute xylitol production was identical in both strains. Interestingly, increasing concentrations of xylitol (up to 8 g L-1) appeared not to inhibit D-xylose consumption. The newly described XI displayed 2.6 times higher specific activity, 37% lower KM for D-xylose, and exhibited higher activity over a broader temperature range, retaining 51% of maximal activity at 30 °C compared with only 29% activity for the Piromyces XI.This work was supported by the project FatVal PTDC/EAM-AMB/32506/2017 (POCI-01-0145-FEDER-032506), co-funded by the European Regional Development Fund (ERDF), through the Operational Programme for Competitiveness and Internationalization (COMPETE 2020), under Portugal 2020, and by the Fundacao para a Ciencia e a Tecnologia-FCT I.P through national funds. CBMA was supported by the "Contrato-Programa" UIDB/04050/2020 funded by national funds through the FCT I.P. PCS is recipient of a FCT PhD fellowship (SFRH/BD/140039/2018), and was supported by a Fulbright Scholarship Portugal grant from January to May 2020 at Lawrence Berkeley National Laboratory, Berkeley, CA, USA. BJ was awarded a Fulbright grant from The Swedish Fulbright Commission for Visiting Lecturers and Research Scholars between September 2014 and January 2015 visiting Lawrence Berkeley National Laboratory, Berkeley, CA, USA. This work was supported in part by the United States Department of Energy's Genomic Science Program (grant SCW1039). Part of this work was performed at Lawrence Berkeley National Laboratory under US Department of Energy contract number DE-AC02-05CH11231. DNA sequencing was performed at the Vincent J. Coates Genomics Sequencing Laboratory at the University of California Berkeley, supported by NIH S10 Instrumentation grants S10RR029668 and S10RR027303
A novel D-xylose isomerase from the gut of the wood feeding patent-leather beetle Odontotaenius disjunctus
D-Xylose Isomerase (XI) is a key enzyme for the metabolism of D-xylose in renewable carbohydrate rich feedstocks such as lignocellulosic hydrolysates. The widely used industrial organism baker’s yeast Saccharomyces cerevisiae can metabolize xylose upon heterologous expression of this enzyme. This enzyme is notoriously difficult to express in S. cerevisiae and only about ten active genes are known from prokaryotic and eukaryotic sources. We cloned a new XI from microorganisms in the gut of the wood feeding beetle Odontotaenius disjunctus. The new enzyme was functionally screened from a pool of enzymes with potential XI activity based on its sequence similarity to XI from Piromyces sp. strain E2. Interestingly, the newly identified enzyme and XI from Piromyces shared the highest sequence identity among the assayed enzymes. Cells carrying the new XI grew in media with D-xylose as the sole carbon source at a superior rate to that of XI from Piromyces, yet at a considerably inferior rate to that of the alternative xylose reductase–xylitol dehydrogenase pathway. Furthermore, optimal conditions of temperature and pH, kinetic parameters, and inhibition kinetics by xylitol were determined for the new enzyme. The physiological characterization of D-xylose fermenting S. cerevisiae expressing the new XI will be further discusse
Functional screening for novel D-xylose isomerases from the gut of a wood feeding beetle reveals efficient expression in Saccharomyces cerevisiae
Renewable sugar rich feedstocks such as lignocellulosic hydrolysates remain one of the primary sources of potentially renewable fuel and bulk chemicals. The pentose sugar D-xylose is often present in significant amounts along with hexoses such as glucose and galactose. The yeast Saccharomyces cerevisiae can acquire the ability to metabolize D-xylose through expression of heterologous D-xylose isomerase (XI). This enzyme is notoriously difficult to express in S. cerevisiae and only fourteen genes have been reported to be active. We cloned a new XI from microorganisms in the gut of the wood feeding beetle Odontotaenius disjunctus. The new enzyme, 8454_2 XI, was functionally screened from a pool of enzymes with potential XI activity based on its sequence similarity to the XI from Piromyces sp. strain E2. A phylogenetic analysis revealed that the enzyme 8454_2 XI shares high identity with XIs from Bacteroidia class of the Bacteroidetes phylum, and all XIs from Bacteroidia screened in yeast so far have exhibited high activity. Cells carrying the new XI in D-xylose containing media as the sole carbon source showed higher growth and D-xylose consumption rates to those of XI of Piromyces. Remarkably, the 8454_2 XI also exhibited 2.6 times higher Vmax and 37 % higher affinity, and retained substantially higher relative activity at 30 ºC. The new XI is a useful addition to the molecular toolbox for genetic modification of S. cerevisiae for the metabolism of second-generation substrates.FatVal POCI-01-0145-FEDER-032506. Ph.D. scholarship SFRH/BD/140039/201
HTAD: A Home-Tasks Activities Dataset with Wrist-Accelerometer and Audio Features
In this paper, we present HTAD: A Home Tasks Activities Dataset. The dataset contains wrist-accelerometer and audio data from people performing at-home tasks such as sweeping, brushing teeth, washing hands, or watching TV. These activities represent a subset of activities that are needed to be able to live independently. Being able to detect activities with wearable devices in real-time is important for the realization of assistive technologies with applications in different domains such as elderly care and mental health monitoring. Preliminary results show that using machine learning with the presented dataset leads to promising results, but also there is still improvement potential. By making this dataset public, researchers can test different machine learning algorithms for activity recognition, especially, sensor data fusion methodsacceptedVersio
A novel D-xylose isomerase: from the gut of a wood feeding beetle for improved conversion in Saccharomyces cerevisiae
Carbohydrate rich substrates such as lignocellulosic hydrolysates remain one of the primary sources of potentially renewable fuel and bulk chemicals. The pentose sugar D-xylose is often present in significant amounts along with hexoses. For low value/high volume products, yield is of paramount importance for process economy. Saccharomyces cerevisiae can acquire the ability to metabolize D-xylose through expression of heterologous D-xylose isomerase (XI). This enzyme is notoriously difficult to express in S. cerevisiae and only fourteen genes have been reported to be active so far. We cloned a new D-xylose isomerase derived from microorganisms in the gut of the wood-feeding beetle Odontotaenius disjunctus. Although somewhat homologous to the current gold-standard from Piromyces sp. E2, metagenome scaffold gene neighborhoods and metagenome binning identified the gene as of bacterial in origin and the host as a Parabacteroides sp. Expression of the new XI enzyme in S. cerevisiae resulted in faster aerobic growth on D-xylose than the XI from Piromyces. The D-xylose isomerization rate of the yeast expressing this new XI was also 72 % higher. Interestingly, increasing concentrations of xylitol (up to 8 g/L) appeared not to inhibit xylose consumption in both strains. The newly described XI displayed 2.6 times higher specific activity, 37 % higher affinity for D-xylose, and exhibited higher activity over a broader temperature range, retaining 51 % of maximal activity at 30 ºC compared with only 29% activity for the Piromyces XI. This new enzyme represents a highly valuable addition to the S. cerevisiae molecular toolbox and shows promise for improved industrial conversion of carbohydrates.FatVal PTDC/EAM-AMB/32506/2017. “Contrato-Programa” UIDB/04050/2020. PhD fellowship SFRH/BD/140039/201
A technique to dissect the alimentary canal of the coffee berry borer (Hypothenemus hampei ), with isolation of internal microorganisms
A technique for dissecting the alimentary canal of the coffee berry borer, Hypothenemus hampei, is presented. The technique was developed to isolate and identify alimentary canal-associated microorganisms that might be involved in caffeine detoxification
Effect of different lignocellulosic diets on bacterial microbiota and hydrolytic enzyme activities in the gut of the cotton boll weevil (Anthonomus grandis)
Cotton boll weevils, Anthonomus grandis, are omnivorous coleopteran that can feed on diets with different compositions, including recalcitrant lignocellulosic materials. We characterized the changes in the prokaryotic community structure and the hydrolytic activities of A. grandis larvae fed on different lignocellulosic diets. A. grandis larvae were fed on three different artificial diets: cottonseed meal (CM), Napier grass (NG) and corn stover (CS). Total DNA was extracted from the gut samples for amplification and sequencing of the V3-V4 hypervariable region of the 16S rRNA gene. Proteobacteria and Firmicutes dominated the gut microbiota followed by Actinobacteria, Spirochaetes and a small number of unclassified phyla in CM and NG microbiomes. In the CS feeding group, members of Spirochaetes were the most prevalent, followed by Proteobacteria and Firmicutes. Bray-Curtis distances showed that the samples from the CS community were clearly separated from those samples of the CM and NG diets. Gut extracts from all three diets exhibited endoglucanase, xylanase, ß-glucosidase and pectinase activities. These activities were significantly affected by pH and temperature across different diets. We observed that the larvae reared on a CM showed significantly higher activities than larvae reared on NG and CS. We demonstrated that the intestinal bacterial community structure varies depending on diet composition. Diets with more variable and complex compositions, such as CS, showed higher bacterial diversity and richness than the two other diets. In spite of the detected changes in composition and diversity, we identified a core microbiome shared between the three different lignocellulosic diets. These results suggest that feeding with diets of different lignocellulosic composition could be a viable strategy to discover variants of hemicellulose and cellulose breakdown systems.Fil: Ben Guerrero, Emiliano. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias Castelar; ArgentinaFil: Soria, Marcelo Abel. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos. Cátedra de Microbiología Agrícola; ArgentinaFil: Salvador, Ricardo. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Ceja Navarro, Javier A.. Lawrence Berkeley National Laboratory; Estados UnidosFil: Campos, Eleonora. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias Castelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Brodie, Eoin L.. Lawrence Berkeley National Laboratory; Estados UnidosFil: Talia, Paola Monica. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias Castelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Simulador de negocios Capstone planeación estratégica de Digby en la industria de los sensores
En el presente documento de obtención de grado se analizan los resultados de la empresa Digby como parte la industria de sensores dentro del simulador de negocios CAPSTONE de CAPSIM, cuyo objetivo es recrear el diseño de una estrategia y la toma de decisiones dentro de una organización.
Dentro del primer capítulo se encuentra el marco teórico donde se definen los conceptos necesarios para entender y desarrollar una estrategia dentro de una empresa, además de lo anterior se podrán encontrar una serie de análisis de casos en los que se aplica la teoría revisada previamente. En el segundo apartado se describe la industria de los sensores dentro de CAPSTONE. Además, se detalla la estructura de Digby como organización, su modelo de negocios, así como la planeación estratégica en la que se definen los objetivos de cada una de las áreas, el organigrama de la empresa y responsabilidad del equipo directivo de la misma.
Del capítulo número tres al seis se revisan, analizan e interpretan los resultados obtenidos por la empresa Digby durante los ocho periodos de simulación, además se comparan con los que obtuvo la competencia.
En el capítulo siete se encuentran las conclusiones a las que llegó el equipo después de la obtención de los resultados finales de la simulación, también se exponen las experiencias y aprendizajes de los distintos miembros del equipo a través de los distintos cursos de la asignatura de Investigación, Desarrollo e Innovación (IDI) y la maestría en el ITESO.
Durante la realización del presente trabajo se acrecentó la experiencia en el manejo de una organización por parte de un equipo directivo mediante la práctica en la toma de decisiones de diferentes áreas de una compañía, así como del análisis del entorno económico e industrial.ITESO, A.C
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