175 research outputs found
Equatorial symmetry/antisymmetry of stationary axisymmetric electrovac spacetimes
Two theorems are proved concerning how stationary axisymmetric electrovac
spacetimes that are equatorially symmetric or equatorially antisymmetric can be
characterized correctly in terms of the Ernst potentials \E and or in
terms of axis-data.Comment: 8 page
Sequencing of Vellozia Spp. genomes to understand drought tolerance and phosphorus acquisition in angiosperms.
PE1164. PAG 2019
Evaluación de la densidad de siembra y el tamaño del tubérculo semilla en la producción de semilla básica de papa criolla, variedad «yema de huevo» (solanum phureja juz. et buk.)
La producción de semilla básica es fundamental en la cadena de producción de semillas de alta calidad. En Solanum phureja Juz. el Buk., los factores densidad de siembra y tamaño de tubérculo semilla óptimos para su producción no han sido evaluados hasta el momento. El presente trabajo tuvo como objetivo evaluar estos dos factores en condiciones de la Estación Experimental San Jorge JCA. La investigación se realizó bajo un Diseño en Bloques Completos al Azar con arreglo factorial 4 x 3. Se encontró que las distancias entre plantas evaluadas (15; 20; 25 y 30 cm) no afectan la producción de semilla por unidad de área y que la utilización de tubérculos-semilla entre 1,27 y 2,00 cm de diámetro es la más recomendada.The production ofbasic seed is a very important factor, for the seed production chain looking for high quality. The sowing density and the tuber size have not been researched for Solanum phureja Juz. el Buk. The evaluation ofthese factors was conducted at Experimental Center San Jorge - JCA. Randomized Complete Block Design with factorial array (4x3) was used in this assay. It was found that the distance among plants (15; 20; 25 and 30 cm) did not modify the seed production per unit of area. The tuber diameter between 1,27 to 2,00 cm., is the best choose in production of basic seed
Using Evidence in a Highly Fragmented Legislature: The Case of Colombia's Health System Reform
This chapter examines how evidence is used in major policy health policy initiatives in a highly contested political context. Through a case study of legislation proposed in the context of Colombia’s ongoing health systems reformed process, it explores how such use is affected by the specific role played by the legislature within a highly fragmented polity. It draws on an analysis of evidence cited in the drafting of relevant laws in the process of health systems reform. Reflecting the role of the legislature in Colombia’s contested political system, evidence cited in legislative debates was unable to forge consensus amongst relevant policy actors over health system reforms. While scientific research was available and at the disposal of legislators, it was unable to provide the common ground on which to overcome embedded policy positions and form the basis of compromise over the direction of health systems reforms
Effect of disinfectants used in clinical facilities on the induction of the SOS response and mutation frequency in Escherichia coli
Motivation: The development of antibiotic resistance is one of the mechanism used to study adaptive evolution. Antibiotics not only select for preexisting resistant strains in a population, but they can also promote the appearance of resistant strains (1, 2). Antibiotics at high concentrations can be lethal to bacteria, but it has been shown that sub-inhibitory concentrations of some antibiotics can stimulate horizontal transfer of DNA and mutation in different chromosomal loci (1, 3). These antibiotics can increase the mutation rate through several mechanisms, such as oxidative stress and the SOS response, which is triggered by DNA damage (2, 3). In this context, we wanted to determine if commonly-used disinfectants also promote mutation. Methods: The disinfectants used were ethanol, sodium hypochlorite, chlorhexidine, silver nitrate, benzalkonium chloride, triclosan and povidone-iodine complex. The E.coli strain used was IBDS1, which includes a tetracycline gene regulated by the cI (Ind-) repressor gene, that allows us to measure the mutation rate.To study the effect of these disinfectants, the strain IBDS1 was tested with a window of concentrations very close to the minimum inhibitory concentration (MIC) by evaluating the appearance of mutants resistant to rifampicin or tetracycline (3). To determine if this effect could be linked to the induction of the SOS system, we used a plasmid which expresses the "Green Fluorescence Protein" (GFP) under the control of the promoter of the recA gene to detect when the SOS system is activated by measuring fluorescence.Results: Three of the disinfectants tested increased mutation frequency. Concentrations of 0.013 μg/ml and 0.026 μg/ml of NaClO (1/4x CMI y 1/2x MIC) increased the mutation frequency approximatly 4 fold and 0.5 μg/ml of clorhexidine (1/4x MIC) and 0.125 μg/ml of triclosan (1/4x MIC) 3 fold, approximately. In relation to the SOS system, none of the concentrations tested induced the SOS response. Conclusions: These results show that certain concentrations of sodium hypochlorite, chlorhexidine and triclosan increase the mutation frequency and therefore may facilitate the appearance of resistant strains, although it appears that this mutagenic effect is not related to the induction of the SOS system. Therefore, it would be interesting to study whether this mutagenic effects is due to the reactive oxygen species (ROS) produced by disinfectants.
Pathogenic Acinetobacter species have a functional type I secretion system and contact-dependent inhibition systems
Pathogenic Acinetobacter species, including Acinetobacter
baumannii and Acinetobacter nosocomialis, are opportunistic
human pathogens of increasing relevance worldwide. Although
their mechanisms of drug resistance are well studied, the virulence factors that governAcinetobacter pathogenesis are incompletely characterized. Here we define the complete secretome of
A. nosocomialis strain M2 in minimal medium and demonstrate
that pathogenicAcinetobacter species produce both a functional
type I secretion system (T1SS) and a contact-dependent inhibition (CDI) system. Using bioinformatics, quantitative proteomics, and mutational analyses, we show that Acinetobacter uses
its T1SS for exporting two putative T1SS effectors, an Repeatsin-Toxin (RTX)-serralysin-like toxin, and the biofilm-associated protein (Bap). Moreover, we found that mutation of any
component of the T1SS system abrogated type VI secretion
activity under nutrient-limited conditions, indicating a previously unrecognized cross-talk between these two systems. We
also demonstrate that the Acinetobacter T1SS is required for
biofilm formation. Last, we show that both A. nosocomialis and
A. baumannii produce functioning CDI systems that mediate
growth inhibition of sister cells lacking the cognate immunity
protein. The Acinetobacter CDI systems are widely distributed
across pathogenicAcinetobacter species, with manyA. baumannii isolates harboring two distinct CDI systems. Collectively,
these data demonstrate the power of differential, quantitative
proteomics approaches to study secreted proteins, define the
role of previously uncharacterized protein export systems, and
observe cross-talk between secretion systems in the pathobiology of medically relevant Acinetobacter speciesSubprograma Sara Borrell from the Instituto de Salud Carlos IIISubdirección General de Evaluación y Fomento de la InvestigaciónMinisterio de Economía y Competitividad de España CD14/0001
Cardioneuroablation: Catheter Vagal Denervation as a New Therapy for Cardioinhibitory Syncope
The vasovagal syncope is the most frequent cause of transient loss of consciousness, especially in young people without significant heart disease. The malignant cardioinhibitory form is caused by abrupt and intense vagal reflex with or without defined triggers. Refractory cases to preventive measures and pharmacological handling has been treated with definitive pacemaker implantation. Besides showing questionable results, pacemaker implantation is highly rejected by young patients. In the late 1990s, we proposed specific vagal denervation by catheter ablation and spectral mapping, for paroxysmal AF, functional bradyarrhythmias and severe cases of malignant cardioinhibitory syncope giving rise to cardioneuroablation. Recently, many authors worldwide have been reproducing the cardioneuroablation results where elimination or significant reduction of the vagal response were observed, which abolished symptoms in more than 75% of patients followed up to 14 years, without complications. Therefore, cardioneuroablation has shown to be a real therapeutic option in malignant syncope cardioinhibitory and in any exclusive vagal mediated bradyarrhythmia without the need for pacemaker implantation
The Physical Basis for Long-lived Electronic Coherence in Photosynthetic Light Harvesting Systems
The physical basis for observed long-lived electronic coherence in
photosynthetic light-harvesting systems is identified using an analytically
soluble model. Three physical features are found to be responsible for their
long coherence lifetimes: i) the small energy gap between excitonic states, ii)
the small ratio of the energy gap to the coupling between excitonic states, and
iii) the fact that the molecular characteristics place the system in an
effective low temperature regime, even at ambient conditions. Using this
approach, we obtain decoherence times for a dimer model with FMO parameters of
160 fs at 77 K and 80 fs at 277 K. As such, significant
oscillations are found to persist for 600 fs and 300 fs, respectively, in
accord with the experiment and with previous computations. Similar good
agreement is found for PC645 at room temperature, with oscillations persisting
for 400 fs. The analytic expressions obtained provide direct insight into the
parameter dependence of the decoherence time scales.Comment: 5 figures; J. Phys. Chem. Lett. (2011
Análisis sensorial de tres líneas de frijoles rojos mejorados nutricionalmente por jefes de familia Nicaraguenses
HALLAZGOS DEL BRONCE FINAL EN LA PROVINCIA DE JAÉN. LA NECRÓPOLIS DE CERRO ALCALÁ, TORRES (JAÉN)
Los materiales arqueológicos que damos a conocer en este trabajo son fruto de hallazgos fortuitos, debidos a las tareas agrícolas, que se efecúdan de manera periódica en el lugar denominado "Cerro Alcalá".En este sitio, se encuentra un yacimiento bastante conocido para la arqueología local e incluso peninsular. El 'Cerro Alcalá' durante la Edad Media, recibía el nombre de 'Heredamiento de Recena', donde se ubicaba una aldea que, al parecer, concedió Alfonso X en 1253 a la localidad de Baeza. De los abundantes restos arqueológicos que aparecen en su superficie, tenemos noticias por M. Gómez Moreno, quien nos dice que en este sitio apareció el célebre vaso de plata hallado en 1618, y al que, erróneamente, se ha venido llamando 'de Cástulo'
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