3,253 research outputs found
Primordial magnetic fields from preheating at the electroweak scale
We analyze the generation of helical magnetic fields during preheating in a
model of low-scale electroweak (EW) hybrid inflation. We show how the
inhomogeneities in the Higgs field, resulting from tachyonic preheating after
inflation, seed the magnetic fields in a way analogous to that predicted by
Vachaspati and Cornwall in the context of the EW symmetry breaking. At this
stage, the helical nature of the generated magnetic fields is linked to the
non-trivial winding of the Higgs-field. We analyze non-perturbatively the
evolution of these helical seeds through the highly non-linear stages of
symmetry breaking (SB) and beyond. Electroweak SB occurs via the nucleation and
growth of Higgs bubbles which squeeze the magnetic fields into string-like
structures. The W-boson charge density clusters in lumps around the magnetic
strings. After symmetry breaking, a detailed analysis of the magnetic field
Fourier spectrum shows two well differentiated components: a UV radiation tail
at a temperature T ~ 0.23 m_higgs slowly growing with time, and an IR peak
associated to the helical magnetic fields, which seems to follow inverse
cascade. The system enters a regime in which we observe that both the amplitude
(\rho_B/\rho_{EW} ~ 0.01) and the correlation length of the magnetic field grow
linearly with time. During this stage of evolution we also observe a power-law
growth in the helical susceptibility. These properties support the possibility
that our scenario could provide the seeds eventually evolving into the
microgauss fields observed today in galaxies and clusters of galaxies.Comment: 55 pages, late
Comparison of Physiological Responses and Perceived Respiratory Resistance Among Mask Usage During Exercise
Since the beginning of the COVID-19 pandemic, the use of a face mask in public is recommended when social distancing cannot be maintained to decrease the spread of the virus with many fitness facilities requiring their patrons to wear a face mask during exercise. The physiological response of wearing a face mask during exercise is relatively unknown and is speculated among the media resulting in contradicting messages conveyed to the public PURPOSE: The purpose of this study was to determine if a face mask influenced performance (time to exhaustion), physiological responses (heart rate, oxyhemoglobin saturation and temperature) and subjective measurements such as dyspnea, perceived respiratory resistance, and rating of perceived exertion (RPE) during exercise. METHODS: Fifteen healthy males (n =8) and females (n=7) completed three graded exercise treadmill tests with (1) a surgical face mask, (2) a cloth face mask, and (3) no mask randomly with at least 48hrs apart. Heart rate (HR), oxyhemoglobin saturation (SpO2), temperature, RPE, dyspnea, was measured throughout exercise. Participants rated their perceived respiratory resistance for each condition at rest, beginning of exercise, and at fatigue using a 100 mm visual analog scale. RESULTS: Significant differences (p \u3c 0.05) were observed in perceived respiratory resistance between no mask and both surgical and cloth conditions at rest (1.55 ± 2.34mm; 6.33 ± 6.11mm; 9.67 ± 10.77mm respectively) and at the beginning of exercise (5.93 ± 6.64mm; 15.47 ± 12.56mm; 21.07± 15.04mm respectively). During stage 3 of the exercise test, the no mask condition had a significantly lower RPE compared to the cloth mask condition (13.22 ± 2.14;14.60 ± 2.13 respectively). Time to exhaustion was similar for all conditions (mask: 11:51 ± 2:31min; cloth: 11:16 ± 2:24min; surgical: 11:32 ± 2:23min). At all times points, there was no significant (p \u3e 0.05) difference between the conditions for HR, SpO2, temperature, and dyspnea. CONCLUSION: Wearing either a surgical or cloth face mask is safe during exercise in healthy adults and has no effect on HR, SpO2, or body temperature. It appears that wearing a face mask may have a minor influence on subjective measurements such as perceived respiratory resistance or RPE during exercise
Proposal and evaluation of BLE discovery process based on new features of bluetooth 5.0
The device discovery process is one of the most crucial aspects in real deployments of sensor networks. Recently, several works have analyzed the topic of Bluetooth Low Energy (BLE) device discovery through analytical or simulation models limited to version 4.x. Non-connectable and non-scannable undirected advertising has been shown to be a reliable alternative for discovering a high number of devices in a relatively short time period. However, new features of Bluetooth 5.0 allow us to define a variant on the device discovery process, based on BLE scannable undirected advertising events, which results in higher discovering capacities and also lower power consumption. In order to characterize this new device discovery process, we experimentally model the real device behavior of BLE scannable undirected advertising events. Non-detection packet probability, discovery probability, and discovery latency for a varying number of devices and parameters are compared by simulations and experimental measurements. We demonstrate that our proposal outperforms previous works, diminishing the discovery time and increasing the potential user device density. A mathematical model is also developed in order to easily obtain a measure of the potential capacity in high density scenarios
Outcome and Prognostic Factors for Pediatric Patients Receiving an Haploidentical Transplantation Using CD3/CD19 Depleted Grafts
Detección del virus del mosaico suave del ñame mediante IC-RT-PCR en Cicadélidos, Rhynchosia minima y Dioscorea rotundata
In Colombia, yam (Dioscorea spp) is grown and is very important to be staple food for the inhabitants of the Caribbean Region. Viral diseases cause losses in production and are essential to identify the vectors involved in their dispersion. The aim of this study was to detect Yam mild mosaic virus (YMMV) in symptomatic samples of Dioscorea rotundata Poir, in weed Rhynchosia minima L. and adult leafhooppers associated with yam crops. Leaf samples of R. minima and D. rotundata cv. “Botón” and leafhoppers were collected. The YMMV was detected by IC-RT-PCR. The results showed that R. minima is a weed host of YMMV, in addition adults of Oncometopia sp, Mareja sp and Parathona cayennensis are able to acquire this virus and the presence of viruses in crops yam in the Colombian Caribbean region was confirmed.En Colombia, el ñame (Dioscorea spp) es cultivado y tiene gran importancia al ser alimento básico para los habitantes de la región Caribe. Las enfermedades de origen viral causan pérdidas en la producción y es fundamental identificar los vectores involucrados en su dispersión. El objetivo de este estudio fue detectar el Virus del mosaico suave del ñame (YMMV) en muestras sintomáticas de Dioscorea rotundata Poir, en el arvense Rhynchosia minima L. y en adultos de cicadélidos asociados al cultivo del ñame. Se tomaron muestras foliares en R. minima y D. rotundata cv. “Botón” y se colectaron cicadélidos. Se detectó el YMMV mediante IC-RT-PCR. Los resultados mostraron que R. minima es un arvense hospedero del YMMV, además que Oncometopia sp, Mareja sp y Parathona cayennensis son capaces de adquirir este virus y se confirma la presencia de virosis en los cultivos de ñame de la Región Caribe Colombiana
Supercritical extraction of lyophilized strawberry anthocyanins with pulsed electric fields pretreatment
Anthocyanins from LSB and with a PEF pretreatment were extracted with ethanol + SCCO2. The extraction at 200 bar, 333.15, 3.3% wt. of ethanol as cosolvent and using LSB with a PEF pretreatment of 1 kV/cm, produced an extraction yield of 0.284 % and a TAC of 0.231 (g/100 g of ethanol + SCCO2). The individual effect of 1.0 kV/cm of PEF pretreatment increases the %EY by 25 % and the TAC by 29 %. The individual effect of the cosolvent increases the %EY by 32% and that of TAC by 36.4%. However, the combined effect of 1.0 kV cm-1 and 3.3 % ethanol, produced an increase of 78.2 % and 85.3% in the %EY and TAC, respectively. Therefore, these results suggest that there is a synergistic effect, which means that both the electroporation caused by PEF in the LSB and the increase in polarity due to the addition of ethanol produce a substantial improvement over %ET and TAC. Furthermore, the process of extracting anthocyanins from LSB using a mixture of ethanol + supercritical carbon dioxide can be satisfactorily described by a solubility-based model such as the Kumar and Johnston model.The lyophilized strawberry anthocyanins were extracted using a supercritical extraction (SE) process. The effect of pulsed electric fields (PEF) as pretreatment and the influence of the addition of ethanol as a cosolvent on the percentage of extraction yield (EY) and the total anthocyanin concentration (TAC) were analyzed. The effect of PEF was evaluated at 0.5 and 1.0 kV/cm, while the effect of the cosolvent was studied in mixtures of supercritical carbon dioxide - ethanol (SCCO2 + ethanol) at 1.6 and 3.3% by weight. The best results (% EY = 0.506, TAC = 0.428 g /100 g of lyophilized strawberry) were obtained with a PEF pretreatment of 1.0 kV cm-1, 3.3%wt. ethanol at 200 bar and 333.15 K. The experimental results of solubility were suitably adjusted with the Kumar and Johnston model. The maximum solubility (0.114 g/100 g of solvent mixture) was obtained at 300 bar and 313.15 K.The authors would like to thank the National Council of Science and Technology of Mexico (CONACyT) for the scholarship granted to the master’s student in chemical sciences Marco A. Ávila-Hernández
The epiphytic transcriptome of Podosphaera fusca and its predicted secretome
Comunicación presentada en formato panel en la sesión "Large-scale (omics) approaches"The cucurbit powdery mildew fungus Podosphaera fusca, is a major limiting factor for cucurbit production worldwide. Despite its agronomic and economic importance, very little is known about fundamental aspects of P. fusca biology such as obligate biotrophy and pathogenesis. In order to design novel and more durable control strategies, genomic information of P. fusca is needed. In this work we aimed to analyse the epiphytic transcriptome of P. fusca as starting point. Total RNA was isolated from mycelia and conidia, and the corresponding cDNA library was sequenced using a 454 GS FLX platform. Annotation data was acquired for 62.6% of the assembled sequences, identifying 9,713 putative genes with different orthologues. In the transcript data set, the most represented protein functions were those involved in gene expression, protein metabolism, regulation of biological process and organelle organization. Our analysis also confirmed the existence of “missing ascomycete core genes” (MACGs) found in other powdery mildew species. After analysis of the pool of fungal secreted proteins, 118 putative secreted proteins were identified, including 35 “candidate secreted effector proteins” (CSEPs) specific for P. fusca. In order to validate the in silico assembly, the expression profile of some CSEPs was analysed, which was consequent with a canonical effector expression pattern, with a maximum of expression at the beginning of the infection process 24-48 h after inoculation. Our data open the genomics era of this very important cucurbit pathogen.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Plan Nacional Plan I+D+I del antiguo Ministerio de Ciencia e Innovación (AGL2010-21848-CO2-01), cofinanciado con fondos FEDER (UE)
Effects of dietary fish oil substitution by Echium oil on enterocyte and hepatocyte lipid metabolism of gilthead seabream (Sparus aurata L.)
The fatty acid profile of vegetable oils (VOs), together with the poor ability of marine fish to convert polyunsaturated fatty acids (PUFA) to highly unsaturated fatty acids (HUFA), lead to important changes in the nutritional value of farmed fish fed VO, which include increased fat and 18:2n-6 and reduced n-3 HUFA. Echium oil (EO) has a good n-3/n-6 balance as well as an interesting profile with its high content of unusual fatty acids (SDA, 18:4n-3 and GLA, 18:3n-6) that are of increasing pharmacological interest. The effects of substituting 50 % of dietary fish oil (FO) by EO on gilthead seabream (Sparus aurata L.) enterocyte and hepatocyte lipid metabolism were studied. After 4 months of feeding, cell viability, total lipid contents and lipid class compositions were not affected by EO. The cells clearly reflected the fatty acid profile of the EO showing increased SDA, GLA and its elongation product 20:3n-6, and only minorly decreased n-3 HUFA compared to other VO. Metabolism of [1-14C]18:2n-6 and [1-14C]18:3n-3 was also unaffected by EO in terms of total uptake, incorporation, β-oxidation and elongation-desaturation activities
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