Role of phenolic compounds on blue light induced retinal pigment cell damage: an in vitro study

Age-related macular degeneration (AMD) is a progressive eye disease that affects the macula, causing blurred central vision making it difficult for diagnosed patients to see fine details and have trouble with everyday tasks. Recent studies have suggested that blue light is able to cause damage to eyes that progresses to AMD. Exposure of blue light to our eyes is a growing concern in our everyday lives due to the prevalence of computers, phones, and tablets. Blue light is responsible for cell damage, cell death, and oxidative stress, all of which can lead to vision loss. Resveratrol and pterostilbene are polyphenols found in the skin of various fruits including grapes and blueberries and have been well studied for their antioxidant properties. The aim of this study was to investigate the biological activity of resveratrol and pterostilbene on cell viability (MTS assay), cell death markers (Caspase-3/7 activity, Caspase-3 protein expression and Propidium Iodide assay), antioxidant potential (catalase and MnSOD), and the levels of oxidative stress (4HNE), in retinal pigment ARPE-19 cells exposed to blue light. ARPE19 cells were incubated with a pre-treatment of 50µM and 100µM of resveratrol or 10µM and 250µM of pterostilbene for 4 hours followed by the exposure of blue light (475nm) for 12 hours. Blue light exposure on ARPE-19 cells resulted in a 56% reduction (p<0.0001) in cell viability along with an increase in caspase 3/7 activation, and a 50% increase (p<0.0001) in cell necrosis. This was accompanied by an increase in protein adduct formation of 4HNE and protein expression of antioxidants such as, catalase, and MnSOD. Resveratrol treatment of 50µM was able to maintain cell viability by 37% (p<0.05), and significantly (p<0.05) reduced the caspase 3/7 fluorescence activity when compared to control cells exposed to blue light. Cellular necrosis was also significantly reduced (p<0.05) by both 50µM and 100µM treatments of resveratrol. In conclusion, the damaging effects of blue light was mitigated by treatments of resveratrol in ARPE-19 cells. Pterostilbene treatments of 10 and 25µM were unable to maintain cellular viability across both MTS assay and caspase 3/7 fluorescence assay. Both concentrations showed opposite results when compared to the 50 and 100µM treatments of resveratrol

The Influence of Magnetic Field on Oscillations in the Solar Chromosphere

Two sequences of solar images obtained by the Transition Region and Coronal Explorer in three UV passbands are studied using wavelet and Fourier analysis and compared to the photospheric magnetic flux measured by the Michelson Doppler Interferometer on the Solar Heliospheric Observatory to study wave behaviour in differing magnetic environments. Wavelet periods show deviations from the theoretical cutoff value and are interpreted in terms of inclined fields. The variation of wave speeds indicates that a transition from dominant fast-magnetoacoustic waves to slow modes is observed when moving from network into plage and umbrae. This implies preferential transmission of slow modes into the upper atmosphere, where they may lead to heating or be detected in coronal loops and plumes.Comment: 8 pages, 6 figures (4 colour online only), accepted for publication in The Astrophysical Journa

Spatial-temporal variability: characterisation of a beach system using high resolution radar data

Intertidal areas experience a series of complex dynamic processes that affect beach morphology. Many of these processes are difficult to monitor, particularly due to the limited availability of high-resolution data. This study utilises high resolution radar-derived DEMs obtained through the temporal waterline method high resolution to perform a spatio-temporal analysis of beach morphology over the macrotidal nearshore of Rossall Beach, UK. Beach elevation changes are characterized, providing new insights into the morphological processes from fortnightly to seasonal time scales. The results of this analysis draw focus to the short-term variations in beach morphology and their contributions to long-term change. Observation of spatio-temporal variation displayed an intertidal system in a seasonal steady state equilibrium, somewhat dominated by elevation changes within the spring and summer months. Furthermore, the upper-intertidal zone displays evidence of continuing accretion. Though the analysis within this study is mostly explorative, it shows the potential of radar data for autonomous monitoring and spatio-temporal characterization of the coast. This enables coastal managers and stakeholders to build a long-term picture of the coastline, reducing vulnerability to coastal hazards and building resilience

Hubble Space Telescope Planetary Camera images of R136

The Planetary Camera of the Hubble Space Telescope has been used to obtain broad and narrowband images ofR136, the core of the massive star cluster 30 Doradus in the Large Magellanic Cloud. R136a, the brightest component ofR136, is shown to have at least 12 separate components, including the eight originally identified by speckle interferometry. Three of the 12 components are previously unidentified close companions of the speckle components. The stars within R136a are found to have luminosities and colors of normal evolved (Wolf-Rayet and blue supergiants) and zero-age main-sequence (ZAMS) massive stars. A narrowband He II filter was used to investigate the Wolf-Rayet stellar population. We find that three stars in R136a are of the Wolf-Rayet type; of the two identified from ground-based data, one is now resolved into two components. We present color-magnitude diagrams and a luminosity function of the stars within the larger region (~2 pc) defined as R136. We find that the stars in R136 are similar in color and luminosity to those of cluster members that lie outside that crowded inner region. The lower end of the color-magnitude diagram corresponds to ZAMS spectral type B3. No red supergiants have been detected within R136. The luminosity per unit area in the inner 1" (0.25 pc) of R136 is ≥ 50 times that of the center of Orion for a comparable area and seven times that of the core of NGC 3603. The luminosity per unit area of all of R136 is comparable to that of Orion but is sustained over 130 times the area. An F336W surface brightness profile is constructed for R136 based on the stellar photometry. The distribution is found to be consistent with a pure power law with l(r}ɑ r^y with y=-1.72±0.06 or with a small core with r_c 5 X 10^4 M_☉ pc^(-3). The implied upper limit on the relaxation time for the cluster is much smaller than the age of 3.5 X 10^6 yrs required by the presence of Wolf-Rayet stars. This suggests that relaxation effects have been very important in determining the observed structure of the cluster unless a large population of lower mass stars is also present

OCS Reduction According to the Presence of Nasal Polyps or Atopic Status in the PONENTE Study

Peer reviewedPostprin

Adrenal Insufficiency is Not a Barrier to OCS Elimination in the PONENTE Study

Peer reviewedPostprin

A method for incorporating organ motion due to breathing into 3D dose calculations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134856/1/mp8577.pd

Ionization fronts and shocked flows - The structure of the Orion Nebula at 0".1

We present HST Wide-Field Camera images of a field in the Orion Nebula obtained in emission from [S II], Hβ, and [O II]. The morphology of the [S II] emission is markedly different from the other lines. While Hβ and [O II] are distributed fairly smoothly, [S II] is dominated by filamentary features with widths between 0".1 and 1" which sharply highlight ionization fronts moving into dense neutral material. These photoionization fronts act as probes of the structure of the cavity walls of this blister H II region. Their morphology indicates that while the surfaces into which they are moving are textured, subarcsecond clumps with high density contrast are uncommon. An exception is a bow shock-shaped ionization front seen along the face of a solar system-sized (0".6 = 270 AU) clump which is itself seen in extinction. The field contains a number of HH objects and related structures, many of which were previously recognized as such, but whose complex structure is revealed here by the resolution of HST. These include M42 HH 1, which is seen to be an intricate structure of knots and filaments with a head-tail morphology. M42 HH 2 shows structure from both the shocked cavity walls and the shocked atomic outflow. M42 HH 5-7 break into numerous condensations with an appearance reminiscent of HH 7-11. All objects with a bow shockshaped structure (i.e., M42 HH 1, 5, 7, and 10) show enhanced Hβ emission at the apex of the structure where the shock should be strongest. M42 HH 8 and 9 may be HH objects viewed face-on, or alternatively condensations photoionized by a nearby A or B star. Emission from [S II] traces shocks at the walls of an ionized jet apparently emanating from a star in a dark cloud. This cloud seen in extinction is coincident with H_2 Peak 1, which we propose is on the near side of the nebula

LOL2 and LOL5 loci control latex production by laticifer cells in Euphorbia lathyris

[EN] Laticifers are specialized plant cells capable of indefinite elongation that ramify extensively and are responsible for latex biosynthesis and accumulation. However, the mechanisms underlying laticifer cell differentiation, growth and production of latex remain largely unknown. In a search for mutants showing enhanced accumulation of latex we identified two LOT OF LATEX (LOL) loci in Euphorbia lathyris. lol2 and lol5 mutants show enhanced production of latex contained within laticifer cells. The recessive lol2 mutant carries increased biosynthesis of the plant hormone jasmonoyl-isoleucine (JA-Ile) and therefore establishes a genetic link between jasmonic acid (JA) signaling and latex production in laticifers. Instead, heightened production of latex in lol5 plants obeys to enhanced proliferation of laticifer cells. Phylogenetic analysis of laticifer-expressed genes in E. lathyris and in two other latex-bearing species, Euphorbia corallioides and Euphorbia palustris, allowed the identification of canonical JA responsive elements present in the gene promoter regions of laticifer marker genes. Moreover, we identified that the hormone JA functions not as a morphogen for laticifer differentiation but as a trigger for the fill out of laticifers with latex and the associated triterpenoids. The identification of LOL loci represents a further step towards the understanding of mechanisms controlling latex production in laticifer cells.This work was supported by Spanish MINECO (BFU2015 -68199 -R to P.V.) and Generalitat Valenciana (Prometeo 2014/024 to P.V.).Castelblanque, L.; Balaguer Zamora, B.; Marti, C.; Orozco, M.; Vera Vera, P. (2018). LOL2 and LOL5 loci control latex production by laticifer cells in Euphorbia lathyris. 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A Latex Metabolite Benefits Plant Fitness under Root Herbivore Attack. PLOS Biology, 14(1), e1002332. doi:10.1371/journal.pbio.1002332James, J., Tugizimana, F., Steenkamp, P., & Dubery, I. (2013). Metabolomic Analysis of Methyl Jasmonate-Induced Triterpenoid Production in the Medicinal Herb Centella asiatica (L.) Urban. Molecules, 18(4), 4267-4281. doi:10.3390/molecules18044267Jefferson, R. A., Kavanagh, T. A., & Bevan, M. W. (1987). GUS fusions: beta-glucuronidase as a sensitive and versatile gene fusion marker in higher plants. The EMBO Journal, 6(13), 3901-3907. doi:10.1002/j.1460-2075.1987.tb02730.xKonno, K. (2011). Plant latex and other exudates as plant defense systems: Roles of various defense chemicals and proteins contained therein. Phytochemistry, 72(13), 1510-1530. doi:10.1016/j.phytochem.2011.02.016Laosombut, T., Arreewichit, P., Nirapathpongporn, K., Traiperm, P., Kongsawadworakul, P., Viboonjun, U., & Narangajavana, J. (2016). 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Stellar photometry with the Hubble Space Telescope Wide-field/Planetary camera - A progress report

We describe the prospects for the use of the Wide-Field/Planetary Camera (WFPC) for stellar photometry. The large halos of the point-spread function (PSF) resulting from spherical aberration and from spatial, temporal, and color variations of the PSF are the main limitations to accurate photometry. Degradations caused by crowding are exacerbated by the halos of the PSF. Here we attempt to quantify these effects and determine the current accuracy of stellar photometry with the WFPC. In realistic cases, the brighter stars in crowded fields have 0.09 mag errors; fainter stars have larger errors depending on the degree of crowding. We find that measuring Cepheids in Virgo Cluster galaxies is not currently possible without inordinate increases in exposure times