Institution
University of Johannesburg
Education•Johannesburg, South Africa•
About: University of Johannesburg is a education organization based out in Johannesburg, South Africa. It is known for research contribution in the topics: Population & Tourism. The organization has 8070 authors who have published 22749 publications receiving 329408 citations. The organization is also known as: UJ.
Topics: Population, Tourism, Large Hadron Collider, Adsorption, Higher education
Papers published on a yearly basis
Papers
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TL;DR: In this paper, the authors discuss the possibility that the IceCube neutrino telescope might be observing the Fermi bubbles, which should be strong emitters of high energy neutrinos.
Abstract: We discuss the possibility that the IceCube neutrino telescope might be observing the Fermi bubbles. If the bubbles discovered in gamma rays originate from accelerated protons, they should be strong emitters of high energy ($\ensuremath{\gtrsim}\mathrm{GeV}$) neutrinos. These neutrinos are detectable as showerlike or tracklike events at a ${\mathrm{Km}}^{3}$ neutrino observatory. For a primary cosmic ray flux with spectrum $\ensuremath{\propto}{E}^{\ensuremath{-}2.1}$ and cutoff energy at or above 10 PeV, the Fermi bubble flux substantially exceeds the atmospheric background, and could account for up to $\ensuremath{\sim}4--5$ of the 28 events detected above $\ensuremath{\sim}30\text{ }\text{ }\mathrm{TeV}$ at IceCube. Running the detector for $\ensuremath{\sim}5--7$ more years should be sufficient to discover this flux at high significance. For a primary cosmic ray flux with steeper spectrum, and/or lower cutoff energy, longer running times will be required to overcome the background.
80 citations
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National Radio Astronomy Observatory1, University of Maryland, College Park2, Rutgers University3, UK Astronomy Technology Centre4, University of Edinburgh5, Durham University6, Open University7, National Institute of Astrophysics, Optics and Electronics8, Ghent University9, University of Bristol10, University of Hertfordshire11, Centre national de la recherche scientifique12, INAF13, Spanish National Research Council14, Imperial College London15, University of California, Irvine16, University of Paris17, Cardiff University18, International School for Advanced Studies19, University of Nottingham20, Search for extraterrestrial intelligence21, University of Johannesburg22, Institut d'Astrophysique de Paris23, University of Padua24, University of British Columbia25, Ames Research Center26, Leiden University27, University of Oxford28
TL;DR: In this article, the GBT was used to measure the redshifts and constrain the masses of the cold molecular gas reservoirs for two candidate high-redshift lensed sources.
Abstract: The Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) has uncovered a population of strongly lensed submillimeter galaxies (SMGs). The Zpectrometer instrument on the Green Bank Telescope (GBT) was used to measure the redshifts and constrain the masses of the cold molecular gas reservoirs for two candidate high-redshift lensed sources. We derive CO(1-0) redshifts of z = 3.042 ± 0.001 and z = 2.625 ± 0.001, and measure molecular gas masses of (1-3) ×10(10) M ☉, corrected for lens amplification and assuming a conversion factor of α = 0.8 M ☉( K km s–1 pc2)–1. We find typical L(IR)/L'(CO) ratios of 120 ± 40 and 140 ± 50 L ☉( K km s–1 pc2)–1, which are consistent with those found for local ultraluminous infrared galaxies (ULIRGs) and other high-redshift SMGs. From analysis of published data, we find no evidence for enhanced L(IR)/L'(CO(1-0)) ratios for the SMG population in comparison to local ULIRGs. The GBT results highlight the power of using the CO lines to derive blind redshifts, which is challenging for the SMGs at optical wavelengths given their high obscuration.
80 citations
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TL;DR: This analysis delineates the Drimolen P. robustus dental sample as characterized by smaller teeth overall than the Swartkrans sample (and in some cases also smaller than the Kromdraai sample), as well as a greater size range.
80 citations
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TL;DR: This study aimed to establish if the dose and/or wavelength influenced the biological responses of irradiated in vitro fibroblasts – 1 h after laser irradiation.
Abstract: Background and objective: Despite contradictory reports on the effect of laser light on cell proliferation, studies have shown that appropriate doses and wavelengths of laser light are therapeutically beneficial in tissue repair and pain control. This study aimed to establish if the dose and/or wavelength influenced the biological responses of irradiated in vitro fibroblasts – 1 h after laser irradiation.
Materials and methods: This study aimed to establish cellular responses of normal and wounded human skin fibroblasts to helium-neon (632.8 nm), diode (830 nm) and Nd:YAG (1064 nm) laser irradiation using one exposure of 5 or 16 J/cm2 on day 1 and again on day 4.
Results: Wounded cells exposed to 5 J/cm2 using 632.8 nm showed an increase in cell migration and haptotaxis, a stable increase in the release of interleukin-6 (IL-6), a decrease in caspase 3/7 activity, an increase in ATP viability and an increase in cell proliferation – 1 h after the final exposure. The results confirm that changes in parameters such as ATP viability, cytokine expression (IL-6), cell proliferation (alkaline phosphatase enzyme activity) and DNA damage can be observed directly after the laser irradiation. The amount of DNA damage and cytotoxicity may be related to duration of the laser irradiation, which is dependent on the power density (mW/cm2) of each laser.
Conclusion: The results indicate that 5 J/cm2 using 632.8 nm results in a stimulatory effect that is more effective than 830 and 1064 nm. The results suggest possible mechanisms by which the wavelength may potentially influence the cellular responses of wounded cells.
80 citations
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TL;DR: A key lemma is presented, known as the Total Continuation Principle, to compare the Dominator-start total domination game and the Staller-starttotal domination game.
Abstract: In this paper, we continue the study of the domination game in graphs introduced by Bresar et al. (SIAM J Discret Math 24:979---991, 2010). We study the total version of the domination game and show that these two versions differ significantly. We present a key lemma, known as the Total Continuation Principle, to compare the Dominator-start total domination game and the Staller-start total domination game. Relationships between the game total domination number and the total domination number, as well as between the game total domination number and the domination number, are established.
80 citations
Authors
Showing all 8414 results
Name | H-index | Papers | Citations |
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Vinod Kumar Gupta | 165 | 713 | 83484 |
Arnold B. Bakker | 135 | 506 | 103778 |
Trevor Vickey | 128 | 873 | 76664 |
Ketevi Assamagan | 128 | 934 | 77061 |
Diego Casadei | 123 | 733 | 69665 |
Michael R. Hamblin | 117 | 899 | 59533 |
E. Castaneda-Miranda | 117 | 545 | 56349 |
Xiaoming Li | 113 | 1932 | 72445 |
Katharine Leney | 108 | 459 | 52547 |
M. Aurousseau | 103 | 403 | 44230 |
Mika Sillanpää | 96 | 1019 | 44260 |
Sahal Yacoob | 89 | 408 | 25338 |
Evangelia Demerouti | 85 | 236 | 49228 |
Lehana Thabane | 85 | 994 | 36620 |
Sahal Yacoob | 84 | 399 | 35059 |