233 research outputs found
An Investigation of the Control-surface Flutter Derivatives of an NACA 65(sub 1)-213 Airfoil in the Ames 16-foot High-speed Wind Tunnel
Effects of Modifications to a Control Surface on a 6-percent-thick Unswept Wing on the Transonic Control-surface Flutter Derivatives
Preliminary Investigation of the Pressure Fluctuations in the Wakes of Two-dimensional Wings at Low Angles of Attack
Free Re-boost Electrodynamic Tether on the International Space Station
The International Space Station (ISS) currently experiences significant orbital drag that requires constant make up propulsion or the Station will quickly reenter the Earth's Atmosphere. The reboost propulsion is presently achieved through the firing of hydrazine rockets at the cost of considerable propellant mass. The problem will inevitably grow much worse as station components continue to be assembled, particularly when the full solar panel arrays are deployed. This paper discusses many long established themes on electrodynamic propulsion in the context of Exploration relevance, shows how to couple unique ISS electrical power system characteristics and suggests a way to tremendously impact ISS's sustainability. Besides allowing launch mass and volume presently reserved for reboost propellant to be reallocated for science experiments and other critically needed supplies, there are a series of technology hardware demonstrations steps that can be accomplished on ISS, which are helpful to NASA s Exploration mission. The suggested ElectroDynamic (ED) tether and flywheel approach is distinctive in its use of free energy currently unusable, yet presently available from the existing solar array panels on ISS. The ideas presented are intended to maximize the utility of Station and radically increase orbital safety
Modeling cancer genomic data in yeast reveals selection against ATM function during tumorigenesis
The DNA damage response (DDR) comprises multiple functions that collectively preserve genomic integrity and suppress tumorigenesis. The Mre11 complex and ATM govern a major axis of the DDR and several lines of evidence implicate that axis in tumor suppression. Components of the Mre11 complex are mutated in approximately five percent of human cancers. Inherited mutations of complex members cause severe chromosome instability syndromes, such as Nijmegen Breakage Syndrome, which is associated with strong predisposition to malignancy. And in mice, Mre11 complex mutations are markedly more susceptible to oncogene- induced carcinogenesis. The complex is integral to all modes of DNA double strand break (DSB) repair and is required for the activation of ATM to effect DNA damage signaling. To understand which functions of the Mre11 complex are important for tumor suppression, we undertook mining of cancer genomic data from the clinical sequencing program at Memorial Sloan Kettering Cancer Center, which includes the Mre11 complex among the 468 genes assessed. Twenty five mutations in MRE11 and RAD50 were modeled in S. cerevisiae and in vitro. The mutations were chosen based on recurrence and conservation between human and yeast. We found that a significant fraction of tumor-borne RAD50 and MRE11 mutations exhibited separation of function phenotypes wherein Tel1/ATM activation was severely impaired while DNA repair functions were mildly or not affected. At the molecular level, the gene products of RAD50 mutations exhibited defects in ATP binding and hydrolysis. The data reflect the importance of Rad50 ATPase activity for Tel1/ATM activation and suggest that inactivation of ATM signaling confers an advantage to burgeoning tumor cells
Correction: Radioprotectant Activity of 5-Diethylsulfonamoylsalicylatocopper(II) in Gamma Irradiated Mice
Radioprotectant Activity of 5-Diethylsulfonamoylsalicylatocopper(II) in Gamma Irradiated Mice
Survival and changes in mean body mass of whole-body irradiated mice were determined to examine the
radioprotectant activity of 5-diethylsulfonamoylsalicylatocopper(II) [Cu(II) (5-DESS)]. One of four groups of 25
female C57BL/6 mice were treated subcutaneously (sc)with 0, 10, 20, 40, 60, 80, 100, or 120 μmol
Cu(II)(5-
DESS)/kg of body mass 3 hours before exposure to 8.0 Gy, gamma irradiation. In this paradigm, doses of Cu(II)(5-
DESS) increased survival up to 92% above vehicle-treated control mice (P = 0.008). Mean body mass
determinations revealed that mice treated with 80 to 120 μmol
Cu(II)(5-DESS)/kg of body mass exhibited a smaller
decrease in body mass than other complex-treated groups. These results support the hypothesis that Cu(II)(5-DESS)
is an effective radioprotectant
Speech Communication
Contains reports on three research projects.National Institutes of Health (Grant 2 ROI NS04332)National Institutes of Health (Training Grant 5 T32 NS07040)C. J. LeBel FellowshipsNational Institutes of Health (Grant 5 RO1 NS13028)National Science Foundation (Grant BNS76-80278)National Science Foundation (Grant BNS77-26871
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