Coherent diffraction of thermal currents in Josephson tunnel junctions

We theoretically investigate heat transport in temperature-biased Josephson tunnel junctions in the presence of an in-plane magnetic field. In full analogy with the Josephson critical current, the phase-dependent component of the heat flux through the junction displays coherent diffraction. Thermal transport is analyzed in three prototypical junction geometries highlighting their main differences. Notably, minimization of the Josephson coupling energy requires the quantum phase difference across the junction to undergo \pi-slips in suitable intervals of magnetic flux. An experimental setup suited to detect thermal diffraction is proposed and analyzed.Comment: 6.5 pages, 4 color figures, updated versio

The Study of PPAL and its Role in the Development of Physcomitrella patens

Protein Prenylation is the addition of lipids to select proteins that play a key role during the development of plants. There are three enzymes that play a role in protein prenylation: protein farnesyltransferase (PFT), protein geranylgeranyl-transferase-I (PGGT), and Rab geranylgeranyltransferase (Rab-GGT). However, there is a protein called PPAL that has a similar alpha subunit of PFT, PGGT, and RAB-GGT but its biochemical function is unknown. Physconmitrella patens, a type of moss, was chosen to explore the role of PpPPAL in the development process. There are two copies of PPAL found in moss. PPAL1 and PPAL2. To study the role of these genes, a partial knockdown line was created where one or both alpha and beta subunit genes was reduced. An artificial microRNA was created to target the PpPPAL1 and PpPPAL2 genes and was introduced into the moss via a plasmid. Once the microRNA was inserted into the moss, the moss was grown in DMSO/ beta-estradiol medium to start the suppression of gene expression. The results showed that the knockout of PpPPAL 1 and PpPPAL 2 inhibits the growth and propagation of physconmitrella patens. They also resulted in a few gametophore contents. The result indicates that PPAL plays an important role in the developmental process in P.patents. The role of PPAL in protein prenylation of physconmitrella patens give insights into how prenylation works in humans since defects in prenylation can lead to health problemshttps://ir.library.louisville.edu/uars/1069/thumbnail.jp

The Effects of PPAL-1 in Arabidopsis Gamete Development

Prenylation is a type of post-translational modification in which a 15- or 20-carbon lipid is added to the carboxyl (C) terminus of the protein. Arabidopsis thaliana contains the PROTEIN PRENYLTRANSFERASE ALPHA SUBUNIT-LIKE (PPAL) gene, which encodes a protein with homology to the α-subunits of the three known prenylation enzymes, PFT, PGGT, and Rab-GGT. We previously identified two mutations in PPAL, one of which is ppal-1, which contains a T-DNA insertion in the fourth intron. We have previously observed that self-fertilizing heterozygous ppal-1 plants produce progeny in which homozygous ppal-1 is underrepresented. This project attempts to ascertain possible affects of ppal-1 in gametophyte growth and development that might cause this underrepresented homozygous ppal-1 population. Crosses were performed between homozygous ppal-1 and wild-type (WT) plants. Both F0 and F1 generations were genotyped. The results indicated that there was WT contamination of the ppal-1 F0 population. The data also indicated the ppal-1 primers were nonfunctional. Additionally, a pollen germination test was performed for both ppal-1and WT plants. The results indicated that ppal-1 pollen had developmental delays for germination, but upon germination, they could form pollen tubules of equal length to the WT pollen. However, due to the likely WT contamination in the ppal-1 population used, these experiments must be replicated in further studies

Macropore Formation and Pore Morphology Characterization of Heavily Doped p-Type Porous Silicon

Tuning the pore diameter of porous silicon films is essential for some applications such as biosensing, where the pore size can be used for filtering analytes or to control the biofunctionalization of its walls. However, macropore (>50nm) formation on p-type silicon is not yet fully controlled due to its strong dependence on resistivity. Electrochemical etching of heavily doped p-type silicon usually forms micropores (<5nm), but it has been found that bigger sizes can be achieved by adding an organic solvent to the electrolyte. In this work, we compare the results obtained when adding dimethylformamide (DMF) and dimethylsulfoxide (DMSO) to the electrolyte as well as the effect of a post-treatment of the sample with potasium hydroxide (KOH) and sodium hydroxide (NaOH) for macropore formation in p-type silicon with resistivities between 0.001 and 10Ω·cm, achieving pore sizes from 5 to 100nm

Focused directed evolution of aryl-alcohol oxidase in Saccharomyces cerevisiae by using chimeric signal peptides

Aryl-alcohol oxidase (AAO) is an extracellular flavoprotein that supplies ligninolytic peroxidases with H2O2 during natural wood decay. With a broad substrate specificity and highly stereoselective reaction mechanism, AAO is an attractive candidate for studies into organic synthesis and synthetic biology, and yet the lack of suitable heterologous expression systems has precluded its engineering by directed evolution. In this study, the native signal sequence of AAO from Pleurotus eryngii was replaced by those of the mating a-factor and the K1 killer toxin, as well as different chimeras of both prepro-leaders in order to drive secretion in Saccharomyces cerevisiae. The secretion of these AAO constructs increased in the following order: preproa-AAO> preaproK-AAO>preKproa-AAO>preproK-AAO. The chimeric preaproK-AAO was subjected to focused-directed evolution with the aid of a dual screening assay based on the Fenton reaction. Random mutagenesis and DNA recombination was concentrated on two protein segments (Meta1]-Val109 and Phe392-Gln566), and an array of improved variants was identified, among which the FX7 mutant (harboring the H91N mutation) showed a dramatic 96-fold improvement in total activity with secretion levels of 2 mg/liter. Analysis of the N-terminal sequence of the FX7 variant confirmed the correct processing of the preaproK hybrid peptide by the KEX2 protease. FX7 showed higher stability in terms of pH and temperature, whereas the pH activity profiles and the kinetic parameters were maintained. The Asn91 lies in the flavin attachment loop motif, and it is a highly conserved residue in all members of the GMC superfamily, except for P. eryngii and P. pulmonarius AAO. The in vitro involution of the enzyme by restoring the consensus ancestor Asn91 promoted AAO expression and stability

The first Frontier Fields cluster: 4.5{\mu}m excess in a z~8 galaxy candidate in Abell 2744

We present in this letter the first analysis of a z~8 galaxy candidate found in the Hubble and Spitzer imaging data of Abell 2744, as part of the Hubble Frontier Fields legacy program. We applied the most commonly-used methods to select exceptionally high-z galaxies by combining non-detection and color-criteria using seven HST bands. We used GALFIT on IRAC images for fitting and subtracting contamination of bright nearby sources. The physical properties have been inferred from SED-fitting using templates with and without nebular emission. This letter is focussed on the brightest candidate we found (m$_{F160W}$=26.2) over the 4.9 arcmin$^2$ field of view covered by the WFC3. It shows a non-detection in the ACS bands and at 3.6{\mu}m whereas it is clearly detected at 4.5{\mu}m with rather similar depths. This break in the IRAC data could be explained by strong [OIII]+H{\beta} lines at z~8 which contribute to the 4.5{\mu}m photometry. The best photo-z is found at z~8.0$^{+0.2}_{-0.5}$, although solutions at low-redshift (z~1.9) cannot be completely excluded, but they are strongly disfavoured by the SED-fitting work. The amplification factor is relatively small at {\mu}=1.49$\pm$0.02. The Star Formation Rate in this object is ranging from 8 to 60 Mo/yr, the stellar mass is in the order of M$_{\star}$=(2.5-10) x 10$^{9}$Mo and the size is r~0.35$\pm$0.15 kpc. This object is one of the first z~8 LBG candidates showing a clear break between 3.6{\mu}m and 4.5{\mu}m which is consistent with the IRAC properties of the first spectroscopically confirmed galaxy at a similar redshift. Due to its brightness, the redshift of this object could potentially be confirmed by near infrared spectroscopy with current 8-10m telescopes. The nature of this candidate will be revealed in the coming months with the arrival of new ACS and Spitzer data, increasing the depth at optical and near-IR wavelengths.Comment: 4 pages, 2 figures, Accepted for publication in Astronomy and Astrophysics Letter

Characterization of LR-115 Type 2 Detectors for Monitoring Indoor Radon 222: Determination of the Calibration Factor

The city of Lima, capital of Peru, has about 11 million inhabitants. Lima has no records about the indoor Radon 222 concentration levels in dwellings. Hereby, we are planning to register the indoor radon concentrations in Lima and in other cities of Peru in the next three years. First, we will determine the calibration factor for the detectors which will be used in our measurements. For this purpose, Solid State Nuclear Tracks Detectors of nitrocellulose nitrate (LR-115 type 2) were used.The calibration process using a Radium 226 source was described to obtain the calibration factor. Linear response in tracks number was found in relation with irradiation time and its stability after time at the calibration chamber

Effects of eicosapentaenoic acid ethyl ester on visfatin and apelin in lean and overweight (cafeteria diet-fed) rats

Previous studies have demonstrated that the n-3 fatty acid EPA improves insulin resistance induced by high-fat diets. The aim of the present study was to investigate the potential role of visfatin and apelin in the insulin-sensitising effects of EPA ethyl ester. The effects of EPA on muscle and adipose GLUT mRNA, as well as on liver glucokinase (GK) and glucose-6-phosphatase (G6Pase) activity, were investigated. Male Wistar rats fed on a standard diet or a high-fat cafeteria diet were daily treated by oral administration with EPA ethyl ester (1 g/kg) for 5 weeks. A significant decrease (P,0·01) in white adipose tissue (WAT) visfatin mRNA levels was found in the cafeteria-fed rats, which was reversed by EPA administration (P,0·05). Moreover, a negative relationship was observed between homeostatic model assessment (HOMA) and the visfatin:total WAT ratio. In contrast, cafeteria-diet feeding caused a significant increase (P,0·01) in apelin mRNA in visceral WAT. EPA increased (P,0·01) apelin gene expression, and a negative relationship between HOMA index with visceral apelin mRNA and serum apelin:total WAT ratio was also observed. EPA treatment did not induce changes in skeletal muscle GLUT1, GLUT4 or insulin receptor mRNA levels. Neither liver GK and G6Pase activity nor the GK:G6Pase ratio was modified by EPA. These data suggest that somehow the insulin-sensitising effects of EPA could be related to its stimulatory action on both visfatin and apelin gene expression in visceral fat, while changes in skeletal muscle GLUT, as well as in hepatic glucose production, are not likely to be the main contributing factors in the improvement in insulin resistance induced by EPA

Determinación reciente de la colesterolemia en población adulta sana de Pamplona

RESUMEN: Objetivo: Los objetivos del estudio fueron estimar la proporción de la población adulta sana de Pamplona que había determinado recientemente su colesterolemia e identificar los factores asociados a esta determinación. Métodos: Estudio transversal con entrevista personal a 1066 habitantes de Pamplona seleccionados por muestreo de rutas aleatorias. Se estratificó la ciudad en tres áreas urbanas según el nivel socioeconómico (alto, medio, bajo). La participación fue de un 91,8%. Utilizando como variable dependiente la determinación del colesterol total en los últimos 5 años, y como variables independientes la edad, el sexo, el nivel socioeconómico y el hábito tabáquico, se calcularon las odds ratios (OR) univariantes y se ajustó un modelo de regresión logística. Resultados: El 71,2% de la muestra estudiada (IC 95%: 68,3-74,O) se había determinado el colesterol en los últimos cinco años. Los no fumadores conocían más su colesterolemia que los fumadores con una OR ajustada de 1,38 (IC 95%: 1 ,O-1,9); los hombres lo conocían más que las mujeres (OR ajustada de 1,5; IC 95% 1,l-2,O). El conocimiento era menos frecuente en el grupo de edad 30 años. La determinación de la colesterolemia se daba más en los individuos de nivel socioeconómico medio y alto (OR ajustadas 3,2; IC 95% 2,2-4,7 y 1,6; IC 95% 1,l-2,3), respectivamente. Conclusiones: La determinación reciente del colesterol era más frecuente en individuos de mayor edad y en varones. La determinación de la colesterolemia era menos frecuente en algunos grupos con peor perfil de riesgo coronario (menor nivel socioeconómico y fumadores). Estos resultados sugieren la necesidad de intervenciones para mejorar el conocimientoy control de la colesterolemia en adultos sanos