Taming the Hurricane of Acquisition Cost Growth – Or At Least Predicting It

Cost growth is a persistent adversary to efficient budgeting in the Department of Defense. Despite myriad studies to uncover causes of this cost growth, few of the proposed remedies have made a meaningful impact. A key reason may be that DoD cost estimates are formulated using the highly unrealistic assumption that a program’s current baseline characteristics will not change in the future. Using a weather forecasting analogy, the authors demonstrate how a statistical approach may be used to account for these inevitable baseline changes and identify related cost growth trends. These trends are then used to reduce the error in initial acquisition cost estimates by over one third for major defense acquisition programs, representing a more efficient allocation of $6 billion annually

Measuring the Stellar Masses of z~7 Galaxies with Spitzer Ultrafaint Survey Program (SURFS UP)

We present Spitzer/IRAC observations of nine $z'$-band dropouts highly magnified (2<mu<12) by the Bullet Cluster. We combine archival imaging with our Exploratory program (SURFS UP), which results in a total integration time of ~30 hr per IRAC band. We detect (>3sigma) in both IRAC bands the brightest of these high-redshift galaxies, with [3.6]=23.80+-0.28 mag, [4.5]=23.78+-0.25 mag, and (H-[3.6])=1.17+-0.32 mag. The remaining eight galaxies are undetected to [3.6]~26.4 mag and [4.5]~26.0 mag with stellar masses of ~5x10^7 M_sol. The detected galaxy has an estimated magnification of mu=12+-4, which implies this galaxy has an ultraviolet luminosity of L_1500~0.3 L*_{z=7} --- the lowest luminosity individual source detected in IRAC at z>7. By modeling the broadband photometry, we estimate the galaxy has an intrinsic star-formation rate of SFR~1.3 M_sol/yr and stellar mass of M~2x10^9 M_sol, which gives a specific star-formation rate of sSFR~0.7 Gyr^-1. If this galaxy had sustained this star-formation rate since z~20, it could have formed the observed stellar mass (to within a factor of ~2), we also discuss alternate star-formation histories and argue the exponentially-increasing model is unlikely. Finally, based on the intrinsic star-formation rate, we estimate this galaxy has a likely [C II] flux of = 10^{-17} erg/s/cm2.Comment: Accepted to ApJL. 6 pages, 3 figures, 2 table

Can changing the timing of outdoor air intake reduce indoor concentrations of traffic-related pollutants in schools?

Traffic emissions have been associated with a wide range of adverse health effects. Many schools are situated close to major roads, and as children spend much of their day in school, methods to reduce traffic-related air pollutant concentrations in the school environment are warranted. One promising method to reduce pollutant concentrations in schools is to alter the timing of the ventilation so that high ventilation time periods do not correspond to rush hour traffic. Health Canada, in collaboration with the Ottawa-Carleton District School Board, tested the effect of this action by collecting traffic-related air pollution data from four schools in Ottawa, Canada, during October and November 2013. A baseline and intervention period was assessed in each school. There were statistically significant (P \u3c 0.05) reductions in concentrations of most of the pollutants measured at the two late-start (9 AM start) schools, after adjusting for outdoor concentrations and the absolute indoor–outdoor temperature difference. The intervention at the early-start (8 AM start) schools did not have significant reductions in pollutant concentrations. Based on these findings, changing the timing of the ventilation may be a cost-effective mechanism of reducing traffic-related pollutants in late-start schools located near major roads. © 2015 Her Majesty the Queen in Right of Canada. Indoor Air published by John Wiley & Sons Ltd. Reproduced with the permission of the Minister of Health Canada

Minute-of-Arc Resolution Gamma ray Imaging Experiment—MARGIE

MARGIE (Minute-of-Arc Resolution Gamma-ray Imaging Experiment) is a large area(∼104 cm2), wide field-of-view (∼1 sr), hard X-ray/gamma-ray (∼20–600 keV) coded-mask imaging telescope capable of performing a sensitive survey of both steady and transient cosmic sources. MARGIE has been selected for a NASA mission-concept study for an Ultra Long Duration (100 day) Balloon flight. We describe our program to develop the instrument based on new detector technology of either cadmium zinc telluride (CZT) semiconductors or pixellated cesium iodide (CsI) scintillators viewed by fast-timing bi-directional charge-coupled devices (CCDs). The primary scientific objectives are to image faint Gamma-Ray Bursts (GRBs) in near-real-time at the low intensity (high-redshift) end of the logN-logS distribution, thereby extending the sensitivity of present observations, and to perform a wide field survey of the Galactic plane

MARGIE: A gamma-ray burst ultra-long duration balloon mission

We are designing MARGIE as a 100 day ULDB mission to: a) detect and localize gamma-ray bursts; and b) survey the hard X-ray sky. MARGIE will consist of one small field-of-view (FOV) and four large FOV coded mask modules mounted on a balloon gondola. The burst position will be calculated onboard and disseminated in near-real time, while information about every count will be telemetered to the ground for further analysis. In a 100-day mission we will localize ∼40 bursts with peak photon fluxes from 0.14 to ∼5 ph cm−2 s−1 using 1 s integrations; the typical localization resolution will be better than ∼2 arcminutes

Spectrum and Morphology of the Two Brightest Milagro Sources in the Cygnus Region: MGRO J2019+37 and MGRO J2031+41

The Cygnus region is a very bright and complex portion of the TeV sky, host to unidentified sources and a diffuse excess with respect to conventional cosmic-ray propagation models. Two of the brightest TeV sources, MGRO J2019+37 and MGRO J2031+41, are analyzed using Milagro data with a new technique, and their emission is tested under two different spectral assumptions: a power law and a power law with an exponential cutoff. The new analysis technique is based on an energy estimator that uses the fraction of photomultiplier tubes in the observatory that detect the extensive air shower. The photon spectrum is measured in the range 1 to 200 TeV using the last 3 years of Milagro data (2005-2008), with the detector in its final configuration. MGRO J2019+37 is detected with a significance of 12.3 standard deviations ($\sigma$), and is better fit by a power law with an exponential cutoff than by a simple power law, with a probability $>98$% (F-test). The best-fitting parameters for the power law with exponential cutoff model are a normalization at 10 TeV of $7^{+5}_{-2}\times10^{-10}$ $\mathrm{s^{-1}\: m^{-2}\: TeV^{-1}}$, a spectral index of $2.0^{+0.5}_{-1.0}$ and a cutoff energy of $29^{+50}_{-16}$ TeV. MGRO J2031+41 is detected with a significance of 7.3$\sigma$, with no evidence of a cutoff. The best-fitting parameters for a power law are a normalization of $2.4^{+0.6}_{-0.5}\times10^{-10}$ $\mathrm{s^{-1}\: m^{-2}\: TeV^{-1}}$ and a spectral index of $3.08^{+0.19}_{-0.17}$. The overall flux is subject to an $\sim$30% systematic uncertainty. The systematic uncertainty on the power law indices is $\sim$0.1. A comparison with previous results from TeV J2032+4130, MGRO J2031+41 and MGRO J2019+37 is also presented.Comment: 11 pages, 10 figure

p90 Ribosomal S6 Kinase 2, a Novel GPCR Kinase, Is Required for Growth Factor-Mediated Attenuation of GPCR Signaling

The 5-hydroxytryptamine 2A (5-HT2A) receptor is a member of the G protein-coupled receptor superfamily (GPCR) and plays a key role in transducing a variety of cellular signals elicited by serotonin (5-HT; 5-hydroxytryptamine) in both peripheral and central tissues. Recently, we discovered that the ERK/MAPK effector p90 ribosomal S6 kinase 2 (RSK2) phosphorylates the 5-HT2A receptor and attenuates 5-HT2A receptor signaling. This raised the intriguing possibility of a regulatory paradigm whereby receptor tyrosine kinases (RTKs) attenuate GPCR signaling (i.e., ‘inhibitory cross-talk’) by activating RSK2 [Strachan et al. (2009) J. Biol. Chem. 284, 5557-5573]. We report here that activation of multiple endogenous RTKs such as the epidermal growth factor receptor (EGFR), the platelet-derived growth factor receptor (PDGFR), and ErbB4 significantly attenuates 5-HT2A receptor signaling in a variety of cell types including mouse embryonic fibroblasts (MEFs), mouse vascular smooth muscle cells (mVSMCs), and primary cortical neurons. Importantly, genetic deletion of RSK2 completely prevented signal attenuation, thereby suggesting that RSK2 is a critical mediator of inhibitory cross-talk between RTKs and 5-HT2A receptors. We also discovered that P2Y purinergic receptor signaling was similarly attenuated following EGFR activation. By directly testing multiple endogenous growth factors/RTK pathways and multiple Gq-coupled GPCRs, we have now established a cellular mechanism whereby RTK signaling cascades act via RSK2 to attenuate GPCR signaling. Given the pervasiveness of growth factor signaling, this novel regulatory mechanism has the potential to explain how 5-HT2A receptors are regulated in vivo, with potential implications for human diseases in which 5-HT2A or RTK activity is altered (e.g. neuropsychiatric and neurodevelopmental disorders)