165 research outputs found
Auto-Ethnographic Reflections : Lessons from Leading a Stem Initiative for Girls in School While We Ourselves Were in School
In this paper, we use an auto-ethnographic approach to describe first-hand the reflections and learnings from leading an organization to help school children, especially girls, familiarize themselves with STEM and Cyber Security. The primary authors and ethnographers are founders of STEM initiatives for young learners. The primary author is a recent high school graduate who has taken up an engineering field, and two other contributing authors are high-schoolers currently leading these initiatives. With help from the three engineering educators on our authorship team, we use our individual self-narratives to develop a set of recommendations for other young engineering educators across the globe looking to start their own initiatives
Space Launch System Ascent Static Aerodynamic Database Development
This paper describes the wind tunnel testing work and data analysis required to characterize the static aerodynamic environment of NASA's Space Launch System (SLS) ascent portion of flight. Scaled models of the SLS have been tested in transonic and supersonic wind tunnels to gather the high fidelity data that is used to build aerodynamic databases. A detailed description of the wind tunnel test that was conducted to produce the latest version of the database is presented, and a representative set of aerodynamic data is shown. The wind tunnel data quality remains very high, however some concerns with wall interference effects through transonic Mach numbers are also discussed. Post-processing and analysis of the wind tunnel dataset are crucial for the development of a formal ascent aerodynamics database
Extracellular Vesicles from Infected Cells Are Released Prior to Virion Release
Here, we have attempted to address the timing of EV and virion release from virally infected cells. Uninfected (CEM), HIV-1-infected (J1.1), and human T cell leukemia virus-1 (HTLV-1)-infected (HUT102) cells were synchronized in G0. Viral latency was reversed by increasing gene expression with the addition of serum-rich media and inducers. Supernatants and cell pellets were collected post-induction at different timepoints and assayed for extracellular vesicle (EV) and autophagy markers; and for viral proteins and RNAs. Tetraspanins and autophagy-related proteins were found to be differentially secreted in HIV-1- and HTLV-1-infected cells when compared with uninfected controls. HIV-1 proteins were present at 6 h and their production increased up to 24 h. HTLV-1 proteins peaked at 6 h and plateaued. HIV-1 and HTLV-1 RNA production correlated with viral protein expression. Nanoparticle tracking analysis (NTA) showed increase of EV concentration over time in both uninfected and infected samples. Finally, the HIV-1 supernatant from the 6-h samples was found not to be infectious; however, the virus from the 24-h samples was successfully rescued and infectious. Overall, our data indicate that EV release may occur prior to viral release from infected cells, thereby implicating a potentially significant effect of EVs on uninfected recipient cells prior to subsequent viral infection and spread
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Short-term effects of experimental burning and thinning on soil respiration in an old-growth, mixed-conifer forest
To understand the roles of forest management
practices in meeting the goals of forest sustainability and CO2
sequestration, we evaluated the effects of burning and thinning
treatments on soil respiration and soil environments in an
old-growth, mixed-conifer forest in California’s southern Sierra
Nevada. Six experimental treatments with two levels of burning
and three levels of thinning were implemented across
three dominant patch types: closed canopy (CC), Ceanothus
shrub (CECO), and open canopy (OC). We measured soil respiration
rate (SRR), soil temperature (T10), moisture (Ms), and
litter depth (LD), in the summers of 2000 and 2002. Soil total
C and total N were measured in 2002. SRR was significantly
different among the three patch types. In 2000, SRR was
0.75, 0.86, and 0.26 g CO2 m-2 hr-1 in CC, CECO, and OC,
respectively. In 2002, SRR was 0.79, 0.97, and 0.44 g CO2
m-2 hr-1 in CC, CECO, and OC, respectively. The analysis of
variance indicated that burning and thinning significantly affected
soil respiration and soil environments. In particular,
SRR significantly decreased in burned CECO patches but increased
in unburned and thinned CECO. SRR in CC and OC
did not significantly change. T10 and Ms increased, whereas
LD and soil C decreased in treated patches. We also developed
pre- and posttreatment exponential models to predict
SRR using soil environmental variables. The effects of burning
and thinning on soil CO2 efflux and soil environments imply
that forest carbon pools would be reorganized with widespread
application of these forest management practices.Keywords: Thinning, Soil moisture, Soil temperature, Prescribed burning, Mixed conifer, Soil respiratio
CyberKnife® enhanced conventionally fractionated chemoradiation for high grade glioma in close proximity to critical structures
<p>Abstract</p> <p>Introduction</p> <p>With conventional radiation technique alone, it is difficult to deliver radical treatment (≥ 60 Gy) to gliomas that are close to critical structures without incurring the risk of late radiation induced complications. Temozolomide-related improvements in high-grade glioma survival have placed a higher premium on optimal radiation therapy delivery. We investigated the safety and efficacy of utilizing highly conformal and precise CyberKnife radiotherapy to enhance conventional radiotherapy in the treatment of high grade glioma.</p> <p>Methods</p> <p>Between January 2002 and January 2009, 24 patients with good performance status and high-grade gliomas in close proximity to critical structures (i.e. eyes, optic nerves, optic chiasm and brainstem) were treated with the CyberKnife. All patients received conventional radiation therapy following tumor resection, with a median dose of 50 Gy (range: 40 - 50.4 Gy). Subsequently, an additional dose of 10 Gy was delivered in 5 successive 2 Gy daily fractions utilizing the CyberKnife<sup>® </sup>image-guided radiosurgical system. The majority of patients (88%) received concurrent and/or adjuvant Temozolmide.</p> <p>Results</p> <p>During CyberKnife treatments, the mean number of radiation beams utilized was 173 and the mean number of verification images was 58. Among the 24 patients, the mean clinical treatment volume was 174 cc, the mean prescription isodose line was 73% and the mean percent target coverage was 94%. At a median follow-up of 23 months for the glioblastoma multiforme cohort, the median survival was 18 months and the two-year survival rate was 37%. At a median follow-up of 63 months for the anaplastic glioma cohort, the median survival has not been reached and the 4-year survival rate was 71%. There have been no severe late complications referable to this radiation regimen in these patients.</p> <p>Conclusion</p> <p>We utilized fractionated CyberKnife radiotherapy as an adjunct to conventional radiation to improve the targeting accuracy of high-grade glioma radiation treatment. This technique was safe, effective and allowed for optimal dose-delivery in our patients. The value of image-guided radiation therapy for the treatment of high-grade gliomas deserves further study.</p
Clinical faculty associates serving as hybrid teacher educators: Personal and professional impacts
BackgroundUniversity supervisors in teacher education assume a complex and demanding role, which is essential to the development of prospective teachers, but is often underappreciated or ignored.AimThis descriptive study was designed to explore former clinical faculty associates’ (CFAs’) perceptions of the challenges and opportunities inherent in their work as CFAs, and the influence of this experience on their future professional work.Materials and methodsUsing survey research methodology, followed by selected individual interviews, this paper focuses on the experiences of CFAs, highly respected PK-6 teachers employed by the university for 2–3 years to serve as university supervisors.Results and conclusionAlthough participants reported facing several professional and personal challenges as CFAs, they also described opportunities to participate in a wide variety of professional experiences that positively impacted their future work. Furthermore, most reported feeling the CFA experience was professionally renewing and brought opportunities to build strong personal and professional relationships that cross institutional boundaries
Radiometric approach for the detection of picophytoplankton assemblages across oceanic fronts
Cell abundances of Prochlorococcus, Synechococcus, and autotrophic picoeukaryotes were estimated in surface waters using principal component analysis (PCA) of hyperspectral and multispectral remote-sensing reflectance data. This involved the development of models that employed multilinear correlations between cell abundances across the Atlantic Ocean and a combination of PCA scores and sea surface temperatures. The models retrieve high Prochlorococcus abundances in the Equatorial Convergence Zone and show their numerical dominance in oceanic gyres, with decreases in Prochlorococcus abundances towards temperate waters where Synechococcus flourishes, and an emergence of picoeukaryotes in temperate waters. Fine-scale in-situ sampling across ocean fronts provided a large dynamic range of measurements for the training dataset, which resulted in the successful detection of fine-scale Synechococcus patches. Satellite implementation of the models showed good performance (R2 > 0.50) when validated against in-situ data from six Atlantic Meridional Transect cruises. The improved relative performance of the hyperspectral models highlights the importance of future high spectral resolution satellite instruments, such as the NASA PACE mission’s Ocean Color Instrument, to extend our spatiotemporal knowledge about ecologically relevant phytoplankton assemblages
Cerebropulmonary dysgenetic syndrome
Author Posting. © The Author(s), 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Experimental and Molecular Pathology 85 (2008): 112-116, doi:10.1016/j.yexmp.2008.04.006.Ventilatory treatment of neonatal respiratory distress often results in bronchopulmonary dysplasia
from congenital surfactant deficiency due to mutants of transporter protein ABCA3. Association
of this condition with other severe disorders in premature newborns has not heretofore been
reported. A neonatal autopsy included an in vivo whole blood sample for genetic tcsting.
Autopsy revealed severe interstitial pulmonary fibrosis at age 8 days with heterozygotic mutation
p.E292V of ABCA3 and severe dystrophic retardation of cerebral cortcx and cerebellum.
Subsequently, 1300 archival neonatal autopsies, 1983-2006, were reviewed for comparable
concurrent findings and bronchopulmonary dysplasia or retarded cerebral dystrophy lacking the
other principal feature of this syndrome. Archival review revealed four similar cases and eight
less so, without gene analysis. Further review for bronchopulmonary dysplasia revealed 59 cases,
1983-2006. Several other examples of similar retarded migration of germinal matrix and
underdevelopment of cortical mantle, without pulmonary lesions of this type, were identified. The
determination of an ABCA3 mutation in one case of severe pulmonary fibrosis with significant
dystrophy of the brain and the identification of four highly similar archival cases and eight others
with partial pathological findings supports the designation of an independent disorder, here
referred to as the cerebroprrlmonary dysgenetic syndrome
Skunk River Review Fall 2001, vol 13
https://openspace.dmacc.edu/skunkriver/1022/thumbnail.jp
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