68 research outputs found
One Hundred Voices: Harrisburg’s Historic African American Community, 1850-1920
In 2020, a coalition of citizens, organizers, legislators, and educators came together to commemorate the Fifteenth and Nineteenth Amendments by establishing a new monument in Harrisburg, Pennsylvania. This would be a memorial dedicated to the capital city’s significant African American community and its historic struggle for the vote. The Commonwealth Monument, located on the Irvis Equality Circle on the South Lawn of Pennsylvania’s State Capitol Grounds, features a bronze pedestal inscribed with one hundred names of change agents who pursued the power of suffrage and citizenship between 1850 and 1920.
This book is a companion to this monument and tells the stories of those one hundred freedom seekers, abolitionists, activists, suffragists, moralists, policemen, masons, doctors, lawyers, musicians, poets, publishers, teachers, preachers, housekeepers, janitors, and business leaders, among many others. In their committed advocacy for freedom, equality, and justice, these inspiring men and women made unique and lasting contributions to the standing and life of African Americans—and, indeed, the political power of all Americans—within their local communities and across the country.
Calobe Jackson, Jr., is an historian of Harrisburg African American studies, Katie Wingert McArdle is a writer and researcher currently serving as the head swim coach at Dickinson College, and David Pettegrew is a professor of history at Messiah University.
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This book emerged at the intersection of the Commonwealth Monument Project (for more on that go here) and the Digital Harrisburg project (for more on that go here). This work is continuing. For example, check out the work of the Digital Harrisburg team discussing the region’s difficult history of racial injustice here.https://commons.und.edu/press-books/1016/thumbnail.jp
Mass and Angular Momentum Transfer in the Massive Algol Binary RY Persei
We present an investigation of H-alpha emission line variations observed in
the massive Algol binary, RY Per. We give new radial velocity data for the
secondary based upon our optical spectra and for the primary based upon high
dispersion UV spectra. We present revised orbital elements and an estimate of
the primary's projected rotational velocity (which indicates that the primary
is rotating 7 times faster than synchronous). We use a Doppler tomography
algorithm to reconstruct the individual primary and secondary spectra in the
region of H-alpha, and we subtract the latter from each of our observations to
obtain profiles of the primary and its disk alone. Our H-alpha observations of
RY Per show that the mass gaining primary is surrounded by a persistent but
time variable accretion disk. The profile that is observed outside-of-eclipse
has weak, double-peaked emission flanking a deep central absorption, and we
find that these properties can be reproduced by a disk model that includes the
absorption of photospheric light by the band of the disk seen in projection
against the face of the star. We developed a new method to reconstruct the disk
surface density distribution from the ensemble of H-alpha profiles observed
around the orbit, and this method accounts for the effects of disk occultation
by the stellar components, the obscuration of the primary by the disk, and flux
contributions from optically thick disk elements. The resulting surface density
distribution is elongated along the axis joining the stars, in the same way as
seen in hydrodynamical simulations of gas flows that strike the mass gainer
near trailing edge of the star. This type of gas stream configuration is
optimal for the transfer of angular momentum, and we show that rapid rotation
is found in other Algols that have passed through a similar stage.Comment: 39 pages, 12 figures, ApJ in press, 2004 June 20 issu
Binary and Multiple O-Type Stars in the Cas OB6 Association
We present the results of time-resolved spectroscopy of 13 O-type stars in
the Cas OB6 stellar association. We conducted a survey for radial velocity
variability in search of binary systems, which are expected to be plentiful in
young OB associations. Here we report the discovery of two new single-lined
binaries, and we present new orbital elements for three double-lined binaries
(including one in the multiple star system HD 17505). One of the double-lined
systems is the eclipsing binary system DN Cas, and we present a preliminary
light curve analysis that yields the system inclination, masses, and radii. We
compare the spectra of the single stars and the individual components of the
binary stars with model synthetic spectra to estimate the stellar effective
temperatures, gravities, and projected rotational velocities. We also make fits
of the spectral energy distributions to derive E(B-V), R=A_V/E(B-V), and
angular diameter. A distance of 1.9 kpc yields radii that are consistent with
evolutionary models. We find that 7 of 14 systems with spectroscopic data are
probable binaries, consistent with the high binary frequency found for other
massive stars in clusters and associations.Comment: 40 pages, ApJ, in pres
3D printing of twisting and rotational bistable structures with tuning elements
Three-dimensional (3D) printing is ideal for the fabrication of various customized 3D components with fine details and material-design complexities. However, most components fabricated so far have been static structures with fixed shapes and functions. Here we introduce bistability to 3D printing to realize highly-controlled, reconfigurable structures. Particularly, we demonstrate 3D printing of twisting and rotational bistable structures. To this end, we have introduced special joints to construct twisting and rotational structures without post-assembly. Bistability produces a well-defined energy diagram, which is important for precise motion control and reconfigurable structures. Therefore, these bistable structures can be useful for simplified motion control in actuators or for mechanical switches. Moreover, we demonstrate tunable bistable components exploiting shape memory polymers. We can readjust the bistability-energy diagram (barrier height, slope, displacement, symmetry) after printing and achieve tunable bistability. This tunability can significantly increase the use of bistable structures in various 3D-printed components
BMP Signaling Modulates Hepcidin Expression in Zebrafish Embryos Independent of Hemojuvelin
Hemojuvelin (Hjv), a member of the repulsive-guidance molecule (RGM) family, upregulates transcription of the iron regulatory hormone hepcidin by activating the bone morphogenetic protein (BMP) signaling pathway in mammalian cells. Mammalian models have identified furin, neogenin, and matriptase-2 as modifiers of Hjv's function. Using the zebrafish model, we evaluated the effects of hjv and its interacting proteins on hepcidin expression during embryonic development. We found that hjv is strongly expressed in the notochord and somites of the zebrafish embryo and that morpholino knockdown of hjv impaired the development of these structures. Knockdown of hjv or other hjv-related genes, including zebrafish orthologs of furin or neogenin, however, failed to decrease hepcidin expression relative to liver size. In contrast, overexpression of bmp2b or knockdown of matriptase-2 enhanced the intensity and extent of hepcidin expression in zebrafish embryos, but this occurred in an hjv-independent manner. Furthermore, we demonstrated that zebrafish hjv can activate the human hepcidin promoter and enhance BMP responsive gene expression in vitro, but is expressed at low levels in the zebrafish embryonic liver. Taken together, these data support an alternative mechanism for hepcidin regulation during zebrafish embryonic development, which is independent of hjv
CHARA Array K'-band Measurements of the Angular Dimensions of Be Star Disks
We present the first K'-band, long-baseline interferometric observations of
the northern Be stars gamma Cas, phi Per, zeta Tau, and kappa Dra. The
measurements were made with multiple telescope pairs of the CHARA Array
interferometer, and in every case the observations indicate that the
circumstellar disks of the targets are resolved. We fit the interferometric
visibilities with predictions from a simple disk model that assumes an
isothermal gas in Keplerian rotation. We derive fits of the four model
parameters (disk base density, radial density exponent, disk normal
inclination, and position angle) for each of the targets. The resulting
densities are in broad agreement with prior studies of the IR excess flux and
the resulting orientations generally agree with those from interferometric
H-alpha and continuum polarimetric observations. We find that the angular size
of the K' disk emission is smaller than that determined for the H-alpha
emission, and we argue that the difference is the result of a larger H-alpha
opacity and the relatively larger neutral hydrogen fraction with increasing
disk radius. All the targets are known binaries with faint companions, and we
find that companions appear to influence the interferometric visibilities in
the cases of phi Per and kappa Dra. We also present contemporaneous
observations of the H-alpha, H-gamma, and Br-gamma emission lines. Synthetic
model profiles of these lines that are based on the same disk inclination and
radial density exponent as derived from the CHARA Array observations match the
observed emission line strength if the disk base density is reduced by
approximately 1.7 dex.Comment: ApJ in press (2007 Jan 1), 55 pages, 14 figure
Genetic Association for Renal Traits among Participants of African Ancestry Reveals New Loci for Renal Function
Chronic kidney disease (CKD) is an increasing global public health concern, particularly among populations of African ancestry. We performed an interrogation of known renal loci, genome-wide association (GWA), and IBC candidate-gene SNP association analyses in African Americans from the CARe Renal Consortium. In up to 8,110 participants, we performed meta-analyses of GWA and IBC array data for estimated glomerular filtration rate (eGFR), CKD (eGFR <60 mL/min/1.73 m2), urinary albumin-to-creatinine ratio (UACR), and microalbuminuria (UACR >30 mg/g) and interrogated the 250 kb flanking region around 24 SNPs previously identified in European Ancestry renal GWAS analyses. Findings were replicated in up to 4,358 African Americans. To assess function, individually identified genes were knocked down in zebrafish embryos by morpholino antisense oligonucleotides. Expression of kidney-specific genes was assessed by in situ hybridization, and glomerular filtration was evaluated by dextran clearance. Overall, 23 of 24 previously identified SNPs had direction-consistent associations with eGFR in African Americans, 2 of which achieved nominal significance (UMOD, PIP5K1B). Interrogation of the flanking regions uncovered 24 new index SNPs in African Americans, 12 of which were replicated (UMOD, ANXA9, GCKR, TFDP2, DAB2, VEGFA, ATXN2, GATM, SLC22A2, TMEM60, SLC6A13, and BCAS3). In addition, we identified 3 suggestive loci at DOK6 (p-value = 5.3×10−7) and FNDC1 (p-value = 3.0×10−7) for UACR, and KCNQ1 with eGFR (p = 3.6×10−6). Morpholino knockdown of kcnq1 in the zebrafish resulted in abnormal kidney development and filtration capacity. We identified several SNPs in association with eGFR in African Ancestry individuals, as well as 3 suggestive loci for UACR and eGFR. Functional genetic studies support a role for kcnq1 in glomerular development in zebrafish
Somatosensory processing in neurodevelopmental disorders
The purpose of this article is to review the role of somatosensory perception in typical development, its aberration in a range of neurodevelopmental disorders, and the potential relations between tactile processing abnormalities and central features of each disorder such as motor, communication, and social development. Neurodevelopmental disorders that represent a range of symptoms and etiologies, and for which multiple peer-reviewed articles on somatosensory differences have been published, were chosen to include in the review. Relevant studies in animal models, as well as conditions of early sensory deprivation, are also included. Somatosensory processing plays an important, yet often overlooked, role in typical development and is aberrant in various neurodevelopmental disorders. This is demonstrated in studies of behavior, sensory thresholds, neuroanatomy, and neurophysiology in samples of children with Fragile X syndrome, autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), and cerebral palsy (CP). Impaired somatosensory processing is found in a range of neurodevelopmental disorders and is associated with deficits in communication, motor ability, and social skills in these disorders. Given the central role of touch in early development, both experimental and clinical approaches should take into consideration the role of somatosensory processing in the etiology and treatment of neurodevelopmental disorders
Spastic diparetic does not directly affect the capacity to ascend and descend access ramps: three-dimensional analysis
The role of visual stimuli on standing posture in children with bilateral cerebral palsy
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