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- ItemThe 04 – 10 September 2017 Sun–Earth Connection Events: Solar Flares, Coronal Mass Ejections/Magnetic Clouds, and Geomagnetic Storms(Springer Netherlands, 2019-08-23) Wu, Chin-Chun; Liou, Kan; Lepping, Ronald P.; Hutting, LynnIn early September 2017, a series of solar flares and coronal mass ejections (CMEs) erupted from the Sun. The Cor2a coronagraph, a unit of the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI), onboard the Solar Terrestrial Relations Observatory (STEREO)-A spacecraft recorded two Sun–Earth-directed CMEs on 4 September (referred to as CME04) and 6 September (referred to as CME06). A few days later, the Wind spacecraft ( ≈212.4 solar radii: R⊙ ) recorded two interplanetary shocks, presumably driven by CME04 and CME06, at ≈22:41 UT on 06 September 2017 (referred to as Shock06) and at ≈22:48 UT on 07 September 2017 (referred to as Shock07), respectively. The travel time of the CME04/Shock06 [ Δtshock-CME@18R⊙ ] and CME06/Shock07 from 18 R⊙ to the Wind spacecraft was 41.52 hours and 32.47 hours, respectively. The propagating speed [ VCME ] of the CME04 and CME06 at ≈18 R⊙ was determined with SECCHI/Cor2a as ≈886 kms−1 and ≈1368 kms−1 , respectively. Assuming a constant velocity after 18 R⊙ , the estimated Δtshock-CME@18R⊙ is 42.45 and 27.5 hours for CME04 and CME06, respectively. This simple estimate of the CME propagation speed provides a satisfactory result for the CME04 event (error ≈2.3% ) but not for the CME06 event (error ≈15.3% ). The second event, CME06, was delayed further due to an interaction with the preceding event (CME04). It is suggested that the CME speed estimated near the Sun with coronagraph images can be a good estimator for the interplanetary CME (ICME) transit time when there is no pre-event. A three-dimensional magnetohydrodynamic simulation is performed to address this issue by providing a panoramic view of the entire process not available from the observations. A southward interplanetary magnetic field [ Bs ] increased sharply to −31.6 nT on 7 September at Wind, followed by a severe geomagnetic storm ( Dst=−124 nT ). The sharp increase of the IMF [ Bs ] was a result of the interaction between Shock07 and the driver of Shock06 (CME04). This study suggests that a severe geomagnetic storm can be caused by the interaction between a MC, with an impinging IP shock from behind, and the Earth’s magnetosphere. The intensity of a geomagnetic storm will likely be stronger for an event associated with ICME–ICME interaction than for a geomagnetic event caused by only a single ICME.
- ItemA 0535+26 in the August/September 2005 outburst observed by RXTE and INTEGRAL(EDP Sciences, 2007-02-20) Caballero, I.; Kretschmar, P.; Santangelo, A.; Staubert, R.; Klochkov, D.; Camero, A.; Ferrigno, C.; Finger, M. H.; Kreykenbohm, I.; McBride, V. A.; Pottschmidt, Katja; Rothschild, R. E.; Schönherr, G.; Segreto, A.; Suchy, S.; Wilms, J.; Wilson, C. A.Aims. In this Letter we present results from INTEGRAL and RXTE observations of the spectral and timing behavior of the High Mass X-ray Binary A 0535+26 during its August/September 2005 normal (type I) outburst with an average flux F₍₅₋₁₀₀₎ ₖₑᵥ ~ 400 mCrab. The search for cyclotron resonance scattering features (fundamental and harmonic) is one major focus of the paper. Methods. Our analysis is based on data from INTEGRAL and RXTE Target of Opportunity Observations performed during the outburst. The pulse period is determined. X-ray pulse profiles in different energy ranges are analyzed. The broad band INTEGRAL and RXTE pulse phase averaged X-ray spectra are studied. The evolution of the fundamental cyclotron line at different luminosities is analyzed. Results.The pulse period P is measured to be 103.39315(5) s at MJD 53614.5137. Two absorption features are detected in the phase averaged spectra at E₁ ~ 45 keV and E₂ ~ 100 keV. These can be interpreted as the fundamental cyclotron resonance scattering feature and its first harmonic and therefore the magnetic field can be estimated to be B ~4 × 10¹² G.
- Item0FGL J1830.3+0617: A FERMI BLAZAR NEAR THE GALACTIC PLANE(IOP, 2009-08-10) Mirabal, N.; Halpern, J. P.aas-2018.png iop-2016.png 0FGL J1830.3+0617: A FERMI BLAZAR NEAR THE GALACTIC PLANE N. Mirabal1,3 and J. P. Halpern2 Published 10 August 2009 • © 2009. The American Astronomical Society. All rights reserved. The Astrophysical Journal Letters, Volume 701, Number 2 DownloadArticle PDF Figures References 642 Total downloads 1818 total citations on Dimensions. Turn on MathJax Get permission to re-use this article Share this article Share this content via email Share on Facebook Share on Twitter Share on Google+ Share on Mendeley Article information Abstract We present a multiwavelength study of the unidentified Fermi γ-ray source 0FGL J1830.3+0617, which exhibits variability above 200 MeV on timescales of days to weeks. Within the Fermi 95% confidence error contour lies B1827+0617, a radio source with spectral index α = 0.09 between 1.4 and 4.85 GHz. The flat spectral index and flux density of 443 mJy at 4.85 GHz are consistent with the bulk of Fermi sources associated with blazars. It is also detected in the 0.3-10 keV band by Swift. Optical imaging in 2009 May identifies B1827+0617 at R ≈ 16.9, and shows that it is at least 2 mag brighter than on the Palomar Sky Survey plates. Contemporaneous optical spectroscopy acquired during this high state finds a weak emission line that we attribute to Mg II λ2798 at redshift z = 0.75, supporting a flat spectrum radio quasar classification. The variability characteristics and radio properties together indicate that 0FGL J1830.3+0617 at Galactic latitude b = +7.5 is a blazar. Blazar identifications of three additional low-latitude Fermi sources, 0FGL J0643.2+0858, 0FGL J1326.6 – 5302, and 0FGL J1328.8 – 5604, are also suggested.
- ItemA 100-Gb/s noncoherent silicon receiver for PDM-DBPSK/DQPSK signals(Optica, 2014) Klamkin, Jonathan; Gambini, Fabrizio; Faralli, Stefano; Malacarne, Antonio; Meloni, Gianluca; Berrettini, Gianluca; Contestabile, Giampiero; Potì, LucaAn integrated noncoherent silicon receiver for demodulation of 100-Gb/s polarization-division multiplexed differential quadrature phaseshift keying and polarization-division multiplexed differential binary phaseshift keying signals is demonstrated. The receiver consists of a 2D surface grating coupler, four Mach-Zehnder delay interferometers and four germanium balanced photodetectors.
- Item1000 Paper Cuts: Linguistic Portraits Illustrating the Emotional Toll of Underrepresentation on African American Female Professors at Maryland Community Colleges(2018) Jackson, Carla Ray; Davis, Russell A.; Higher Education Program; Doctor of EducationWhile community colleges are experiencing an increase in the number of minority students enrolling, there has been a lack of substantial growth in the acquisition and retention of full-time minority faculty. For full-time African American female professors, this lack has resulted in the circumstance of underrepresentation. Studies demonstrate that underrepresentation leads to marginalization, resulting in negative outcomes for this population. These conditions compromise the professional identity and well-being of African American female full-time professors, limiting their ability to achieve career satisfaction and advancement. This qualitative study asked full-time African American female professors at predominantly White community colleges in Maryland, to explore the emotional toll of underrepresentation. Through the use of a portraiture research design, in-depth interviews were conducted to develop a written illustration of how African American female professors at predominantly White institutions fulfill their professional duties in an environment that has been shown to lead to emotional burnout. This study will add to the body of research that increases the understanding of the lived experiences of minority faculty, which will assist higher education leaders in creating campus climates that promote the well-being of underrepresented faculty and students.
- Item10th Anniversary Spring Concert, Program, 1995-1996(1996-05-11) Salisbury Symphony OrchestraProgram for the May 11-12, 1996 10th Anniversary spring concert of the Salisbury Symphony Orchestra. Special guests Dr. Richard L. Johnson and Clinton/Narboni piano duo.
- Item150 years of the geography of innovation(Elsevier, 2021-01-25) Andrews, Michael J.; Whalley, AlexanderInnovation has long been seen as central to long-term regional growth. Due to the absence of comprehensive data on the geography of innovation covering long time periods, quantifying long-term innovation-development linkages has been challenging. We use newly available patent data from the United States coded to consistent geographies over 150 years to document changing patterns in the geography of innovation. Our analysis reveals three findings. First, the high levels of spatial concentration of innovation today are similar to those in the decades after the Civil War. Second, changes in share of the top 1% locations’ innovation drive national spatial concentration trends after 1945. Third, regional innovation leadership displays persistence, but the strength of persistence appears to have fallen over time. We relate our analysis recent findings in the literature and suggest promising avenues for future inquiry.
- ItemA 1652 treaty opens up the story of the first “Baltimoreans”(Baltimore Brew, 2019-12-10) Shen, Fern
- ItemThe 17 April 2021 widespread solar energetic particle event(EDP Sciences, 2023-06-09) Dresing, N.; Rodríguez-García, L.; Jebaraj, I. C.; Warmuth, A.; Krupar, Vratislav; da Silva, Daniel ; et al.Context. A complex and long-lasting solar eruption on 17 April 2021 produced a widespread solar energetic particle (SEP) event that was observed by five longitudinally well-separated observers in the inner heliosphere that covered distances to the Sun from 0.42 to 1 au: BepiColombo, Parker Solar Probe, Solar Orbiter, STEREO A, and near-Earth spacecraft. The event was the second widespread SEP event detected in solar cycle 25, and it produced relativistic electrons and protons. It was associated with a long-lasting solar hard X-ray flare that showed multiple hard X-ray peaks over a duration of one hour. The event was further accompanied by a medium-fast coronal mass ejection (CME) with a speed of 880 km s−1 that drove a shock, an extreme ultraviolet wave, and long-lasting and complex radio burst activity that showed four distinct type III burst groups over a period of 40 min. Aims. We aim to understand the reason for the wide spread of elevated SEP intensities in the inner heliosphere as well as identify the underlying source regions of the observed energetic electrons and protons. Methods. We applied a comprehensive multi-spacecraft analysis of remote-sensing observations and in situ measurements of the energetic particles and interplanetary context to attribute the SEP observations at the different locations to the various potential source regions at the Sun. We used an ENLIL simulation to characterize the complex interplanetary state and its role in the energetic particle transport. The magnetic connection between each spacecraft and the Sun was determined using ballistic backmapping in combination with potential field source surface extrapolations in the lower corona. Using also a reconstruction of the coronal shock front, we then determined the times when the shock establishes magnetic connections with the different observers. Radio observations were used to characterize the directivity of the four main injection episodes, which were then employed in a 2D SEP transport simulation to test the importance of these different injection episodes. Results. A comprehensive timing analysis of the inferred solar injection times of the SEPs observed at each spacecraft suggests different source processes being important for the electron and proton events. Comparison among the characteristics and timing of the potential particle sources, such as the CME-driven shock or the flare, suggests a stronger shock contribution for the proton event and a more likely flare-related source for the electron event. Conclusions. In contrast to earlier studies on widespread SEP events, we find that in this event an important ingredient for the wide SEP spread was the wide longitudinal range of about 110° covered by distinct SEP injections, which is also supported by our SEP transport modeling.
- Item17β-Estradiol (E2) may be involved in the mode of crustacean female sex hormone (CFSH) action in the blue crab, Callinectes sapidus(Frontiers, 2022-07-25) Wang, Tao; He, Ke; Blaney, Lee; Chung, J. Sook17β-estradiol (E2) has been proved to control reproduction, sexual differentiation, and the development of the secondary sexual characteristics of vertebrate females. In decapod crustacean species, crustacean female sex hormone (CFSH), a protein hormone, is required for developing adult-specific ovigerous setae for embryo brooding and gonophores for mating at the blue crab Callinectes sapidus puberty molting. However, it is unclear that whether the mode of CFSH action involves a vertebrate-type sex steroid hormone in crustaceans. To this end, E2 levels were first measured using a competitive ELISA in the hemolymph and the potential CFSH target tissues from both prepuberty and adult females; the presence of E2 was further confirmed with a liquid chromatography tandem mass spectrometry method. Then, the cDNAs of the following genes known to be associated with vertebrate steroidogenic pathways were isolated: StAR-related lipid transfer protein 3 (StAR3); 3β-hydroxysteroid dehydrogenase (3βHSD); two isoforms of 17β-hydroxysteroid dehydrogenase 8 (17βHSD8); and, estradiol-related receptor (ERR). RT-PCR analysis revealed that these genes were widely distributed in the eyestalk ganglia, hepatopancreas, brain, ovary, spermathecae, ovigerous and plumose setae tissues of adult females. The 17βHSD8 transcripts were localized in the follicle cells, the periphery of the nuclear membrane of primary oocytes, and yolk granules of the vitellogenic oocytes using in situ hybridization, and the corresponding protein was detected in the follicle cells and ooplasm of primary oocytes using immunohistochemistry. Furthermore, the adult females injected with CFSH-dsRNA (n = 30 times) had E2 and StAR3 transcripts levels lower in the ovigerous and plumose setae, spermathecae than controls. These results suggested that the mode of CFSH action in C. sapidus might involve E2 in these adult-female-specific tissues.
- ItemThe 1816 Philadelphia Emma: A Forgotten Edition and Its Readers(Jane Austen Society of North America, 2016) Wells, Juliette