Pulsar Prospects for the Cherenkov Telescope Array

In the last few years, the Fermi-LAT telescope has discovered over a 100 pulsars at energies above 100 MeV, increasing the number of known gamma-ray pulsars by an order of magnitude. In parallel, imaging Cherenkov telescopes, such as MAGIC and VERITAS, have detected for the first time VHE pulsed gamma-rays from the Crab pulsar. Such detections have revealed that the Crab VHE spectrum follows a power-law up to at least 400 GeV, challenging most theoretical models, and opening wide possibilities of detecting more pulsars from the ground with the future Cherenkov Telescope Array (CTA). In this contribution, we study the capabilities of CTA for detecting Fermi pulsars. For this, we extrapolate their spectra with "Crab-like" power-law tails in the VHE range, as suggested by the latest MAGIC and VERITAS results.Comment: 4 pages, 3 figures. In Proceedings of the 2012 Heidelberg Symposium on High Energy Gamma-Ray Astronomy. All CTA contributions at arXiv:1211.184

A simulation analysis of an influenza vaccine production plant in areas of high humanitarian flow. A preliminary study for the region of norte de santander (colombia)

The production of vaccines of biological origin presents a tremendous challenge for re-searchers. In this context, animal cell cultures are an excellent alternative for the isolation and production of biologicals against several viruses, since they have an affinity with viruses and a great capacity for their replicability. Different variables have been studied to know the system’s ideal parameters, allowing it to obtain profitable and competitive products. Consequently, this work fo-cuses its efforts on evaluating an alternative for producing an anti‐influenza biological from MDCK cells using SuperPro Designer v8.0 software. The process uses the DMEN culture medium supple-mented with nutrients as raw material for cell development; the MDCK cells were obtained from a potential scale‐up with a final working volume of 500 L, four days of residence time, inoculum volume of 10%, and continuous working mode with up to a total of 7400 h/Yr of work. The scheme has the necessary equipment for the vaccine’s production, infection, and manufacture with yields of up to 416,698 units/h. In addition, it was estimated to be economically viable to produce recom-binant vaccines with competitive prices of up to 0.31 USD/unit

Loss of neuronal 3d chromatin organization causes transcriptional and behavioural deficits related to serotonergic dysfunction

The interior of the neuronal cell nucleus is a highly organized three-dimensional (3D) structure where regions of the genome that are linearly millions of bases apart establish sub-structures with specialized functions. To investigate neuronal chromatin organization and dynamics in vivo, we generated bitransgenic mice expressing GFP-tagged histone H2B in principal neurons of the forebrain. Surprisingly, the expression of this chimeric histone in mature neurons caused chromocenter declustering and disrupted the association of heterochromatin with the nuclear lamina. The loss of these structures did not affect neuronal viability but was associated with specific transcriptional and behavioural deficits related to serotonergic dysfunction. Overall, our results demonstrate that the 3D organization of chromatin within neuronal cells provides an additional level of epigenetic regulation of gene expression that critically impacts neuronal function. This in turn suggests that some loci associated with neuropsychiatric disorders may be particularly sensitive to changes in chromatin architecture

A simulation analysis of a microalgal-production plant for the transformation of inland-fisheries wastewater in sustainable feed

The present research evaluates the simulation of a system for transforming inland-fisheries wastewater into sustainable fish feed using Designer® software. The data required were obtained from the experimental cultivation of Chlorella sp. in wastewater supplemented with N and P. According to the results, it is possible to produce up to 11,875 kg/year (31.3 kg/d) with a production cost of up to 18 (USD/kg) for dry biomass and 0.19 (USD/bottle) for concentrated biomass. Similarly, it was possible to establish the kinetics of growth of substrate-dependent biomass with a maximum production of 1.25 g/L after 15 days and 98% removal of available N coupled with 20% of P. It is essential to note the final production efficiency may vary depending on uncontrollable variables such as climate and quality of wastewater, among others

Novel structurally related compounds reactivate latent HIV-1 in a bcl-2-transduced primary CD4+ T cell model without inducing global T cell activation

Background: The latent reservoir of HIV-1 in resting memory CD4+ T cells is a major barrier to curing HIV-1 infection. Eradication strategies involve reactivation of this latent reservoir; however, agents that reactivate latent HIV-1 through non-specific T cell activation are toxic. Methods: Using latently infected Bcl-2-transduced primary CD4+ T cells, we screened the MicroSource Spectrum library for compounds that reactivate latent HIV-1 without global T cell activation. Based on the structures of the initial hits, we assembled 50 derivatives from commercial sources and mostly by synthesis. The doseresponse relationships of these derivatives were established in a primary cell model. Activities were confirmed with another model of latency (J-Lat). Cellular toxicity and cytokine secretion were tested using freshly isolated human CD4+ T cells. Results: We identified two classes of quinolines that reactivate latent HIV-1. Class I compounds are the Mannich adducts of 5-chloroquinolin-8-ol. Class II compounds are quinolin-8-yl carbamates. Most EC 50 values were in the 0.5 -10 mM range. HIV-1 reactivation ranged from 25% to 70% for anti-CD3+ anti-CD28 co-stimulation. All quinolin-8-ol derivatives that reactivate latent HIV-1 follow Lipinski's Rule of Five, and most follow the stricter rule of three for leads. After 48 h of treatment, none of the analogues induced detectable cytokine secretion in primary resting CD4+ T cells. Conclusions: We discovered a group of quinolin-8-ol derivatives that can induce latent HIV-1 in a primary cell model without causing global T cell activation. This work expands the number of latency-reversing agents and provides new possible scaffolds for further drug development research

Prospects for Observations of Pulsars and Pulsar Wind Nebulae with CTA

The last few years have seen a revolution in very-high gamma-ray astronomy (VHE; E>100 GeV) driven largely by a new generation of Cherenkov telescopes (namely the H.E.S.S. telescope array, the MAGIC and MAGIC-II large telescopes and the VERITAS telescope array). The Cherenkov Telescope Array (CTA) project foresees a factor of 5 to 10 improvement in sensitivity above 0.1 TeV, extending the accessible energy range to higher energies up to 100 TeV, in the Galactic cut-off regime, and down to a few tens GeV, covering the VHE photon spectrum with good energy and angular resolution. As a result of the fast development of the VHE field, the number of pulsar wind nebulae (PWNe) detected has increased from one PWN in the early '90s to more than two dozen firm candidates today. Also, the low energy threshold achieved and good sensitivity at TeV energies has resulted in the detection of pulsed emission from the Crab Pulsar (or its close environment) opening new and exiting expectations about the pulsed spectra of the high energy pulsars powering PWNe. Here we discuss the physics goals we aim to achieve with CTA on pulsar and PWNe physics evaluating the response of the instrument for different configurations.Comment: accepted for publication in Astroparticle Physic

The effect of LEDs on biomass and phycobiliproteins production in thermotolerant oscillatoria sp

Featured Application: The selection of LEDs wavelength, intensity, and light: Dark cycle positively enhances the biomass production and phycocyanin synthesis in Oscillatoria sp. This study evaluates the role of different LED lights (white, blue/red), intensity (µmol m−2 s−1), and photoperiod in the production of biomass and phycocyanin-C, allophycocyanin and phycoerythrin (C-PC, APC, and PE respectively) from a novel thermotolerant strain of Oscillatoria sp. Results show that a mixture of white with blue/red LEDs can effectively double the biomass concentration up to 1.3 g/L, while the concentration of the selected phycobiliproteins increased proportionally to biomass. Results also indicate that high light intensities (>120 µmol m−2 s−1) can diminish the final concentration of C-PC, APC, and PE, significantly reducing the overall biomass produced. Finally, the photoperiod analysis showed that longer light exposure times (18:6 h) improved both biomass and phycobiliproteins concentration. These results demonstrate that the application of LEDs to produce a novel strain of Oscillatoria sp can double the biomass concentration, and the photoperiod regulation can eventually enhance the final concentration of specific phycobiliproteins such as APC and PE

Acoustically Levitated Whispering-Gallery Mode Microlasers

Acoustic levitation has become a crucial technique for contactless manipulation in several fields, particularly in biological applications. However, its application in the photonics field remains largely unexplored. In this study, we implement an affordable and innovative phased-array levitator that enables stable trapping in the air of micrometer dye-doped droplets, thereby enabling the creation of microlasers. For the first time, this paper presents a detailed performance of the levitated microlaser cavity, supported by theoretical analysis concerning the hybrid technology based on the combination of whispering-gallery modes and acoustic fields. The pressure field distribution inside the acoustic cavity is numerically solved and qualitatively matched with the schlieren deflectometry technique. The optical lasing features of the levitated microlasers are highly comparable with those devices based On-a-Chip registering maximum Q-factors of ~ 105, and minimum lasing thresholds ~ 150 nJ cm−2. The emission comb is explained as a sum of multiple individual-supported whispering-gallery modes. The use of novel touchless micrometric lasers, produced with an acoustic levitator brings new technological opportunities based on photonic-acoustic technological platforms

Multi-Wavelength Observations of the Blazar 1ES 1011+496 in Spring 2008

The BL Lac object 1ES 1011+496 was discovered at Very High Energy gamma-rays by MAGIC in spring 2007. Before that the source was little studied in different wavelengths. Therefore a multi-wavelength (MWL) campaign was organized in spring 2008. Along MAGIC, the MWL campaign included the Metsahovi radio observatory, Bell and KVA optical telescopes and the Swift and AGILE satellites. MAGIC observations span from March to May, 2008 for a total of 27.9 hours, of which 19.4 hours remained after quality cuts. The light curve showed no significant variability. The differential VHE spectrum could be described with a power-law function. Both results were similar to those obtained during the discovery. Swift XRT observations revealed an X-ray flare, characterized by a harder when brighter trend, as is typical for high synchrotron peak BL Lac objects (HBL). Strong optical variability was found during the campaign, but no conclusion on the connection between the optical and VHE gamma-ray bands could be drawn. The contemporaneous SED shows a synchrotron dominated source, unlike concluded in previous work based on nonsimultaneous data, and is well described by a standard one zone synchrotron self Compton model. We also performed a study on the source classification. While the optical and X-ray data taken during our campaign show typical characteristics of an HBL, we suggest, based on archival data, that 1ES 1011+496 is actually a borderline case between intermediate and high synchrotron peak frequency BL Lac objects.Comment: 13 pages, accepted for publication in MNRA