Testing a Prototype Ion Probe for Europa's Plasma Interaction: Colorado Europa Langmuir Probe

The Colorado Europa Langmuir Probe (CELP) is a plasma instrument de- signed to characterize Europa’s plasma interaction to derive external magnetic fields. In order to accomplish the proposed science goal, CELP must be able to measure ion density, temperature, and flow direction. To do this, a design simi- lar to a cylindrical Faraday Cup is utilized, using three selection grids and four collecting surfaces. Necessary capabilities of the instrument include angular reconstruction in the yaw axis (theta) with respect to an ion beam, and in the roll axis (phi), both with picoamp current resolution. This study involved test- ing a prototype Ion Langmuir Probe using an ion beam in the lab. Data analysis shows angular resolutions of ±10° in theta and ±5° in phi [1] at ion tempera- tures of 400 eV and 900 eV, with currents on the order of 0.01 nA and 100 nA. The instrument must also show current resolution as low as the minimum ex- pected ionospheric currents at Europa of 10 pA/cm2 [2]. Using our experimental setup, current resolution at values as low as 0.1 pA/cm2 was observed. Along with achieving angular and current resolution goals, plots were produced that successfully match experimental data with analytical and simulation models, and the specified goals were achieved

Modeling Early Stage Bone Regeneration With Biomimetic Electrospun Fibrinogen Nanofibers and Adipose-Derived Mesenchymal Stem Cells

The key events of the earliest stages of bone regeneration have been described in vivo although not yet modeled in an in vitro environment, where mechanistic cell-matrix-growth factor interactions can be more effectively studied. Here, we explore an early-stage bone regeneration model where the ability of electrospun fibrinogen (Fg) nanofibers to regulate osteoblastogenesis between distinct mesenchymal stem cells populations is assessed. Electrospun scaffolds of Fg, polydioxanone (PDO), and a Fg:PDO blend were seeded with adipose-derived mesenchymal stem cells (ASCs) and grown for 7-21 days in osteogenic differentiation media or control growth media. Scaffolds were analyzed weekly for histologic and molecular evidence of osteoblastogenesis. In response to osteogenic differentiation media, ASCs seeded on the Fg scaffolds exhibit elevated expression of multiple genes associated with osteoblastogenesis. Histologic stains and scanning electron microscopy demonstrate widespread mineralization within the scaffolds, as well as de novo type I collagen synthesis. Our data demonstrates that electrospun Fg nanofibers support ASC osteogenic differentiation, yet the scaffold itself does not appear to be osteoinductive. Together, ASCs and Fg recapitulate early stages of bone regeneration ex vivo and presents a prospective autologous therapeutic approach for bone repair

Development of the Low Frequency Telescope Focal Plane Detector Modules for LiteBIRD

LiteBIRD is a JAXA-led strategic large-class satellite mission designed to measure the polarization of the cosmic microwave background and Galactic foregrounds from 34 to 448 GHz across the entire sky from L2 in the late 2020s. The scientific payload includes three telescopes which are called the low-, mid-, and high-frequency telescopes each with their own receiver that covers a portion of the mission's frequency range. The low frequency telescope will map synchrotron radiation from the Galactic foreground and the cosmic microwave background. We discuss the design, fabrication, and characterization of the low-frequency focal plane modules for low-frequency telescope, which has a total bandwidth ranging from 34 to 161 GHz. There will be a total of 4 different pixel types with 8 overlapping bands to cover the full frequency range. These modules are housed in a single low-frequency focal plane unit which provides thermal isolation, mechanical support, and radiative baffling for the detectors. The module design implements multi-chroic lenslet-coupled sinuous antenna arrays coupled to transition edge sensor bolometers read out with frequency-domain mulitplexing. While this technology has strong heritage in ground-based cosmic microwave background experiments, the broad frequency coverage, low optical loading conditions, and the high cosmic ray background of the space environment require further development of this technology to be suitable for LiteBIRD. In these proceedings, we discuss the optical and bolometeric characterization of a triplexing prototype pixel with bands centered on 78, 100, and 140 GHz.Comment: SPIE Astronomical Telescope + Instrumentation (AS22

Agriculture in the Trans-Pacific Partnership

The Trans-Pacific Partnership is a trade and investment agreement under negotiation by 12 countries in the Pacific Rim. This report assesses this partnership's potential impacts on the region's agriculture in 2025

Vaccination deep into a pandemic wave: Potential mechanisms for a "third wave" and the impact of vaccination

Background In December 2009, when the H1N1 influenza pandemic appeared to be subsiding, public health officials and unvaccinated individuals faced the question of whether continued H1N1 immunization was still worthwhile. Purpose To delineate what combinations of possible mechanisms could generate a third pandemic wave and then explore whether vaccinating the population at different rates and times would mitigate the wave. Methods As part of ongoing work with the Office of the Assistant Secretary for Preparedness and Response at the USDHHS during the H1N1 influenza pandemic, the University of Pittsburgh Models of Infectious Disease Agent Study team employed an agent-based computer simulation model of the Washington DC metropolitan region to delineate what mechanisms could generate a "third pandemic wave" and explored whether vaccinating the population at different rates and times would mitigate the wave. This model included explicit representations of the region's individuals, school systems, workplaces/commutes, households, and communities. Results Three mechanisms were identified that could cause a third pandemic wave; substantially increased viral transmissibility from seasonal forcing (changing influenza transmission with changing environmental conditions, i.e., seasons) and progressive viral adaptation; an immune escape variant; and changes in social mixing from holiday school closures. Implementing vaccination for these mechanisms, even during the down-slope of the fall epidemic wave, significantly mitigated the third wave. Scenarios showed the gains from initiating vaccination earlier, increasing the speed of vaccination, and prioritizing population subgroups based on Advisory Committee on Immunization Practices recommendations. Conclusions Additional waves in an epidemic can be mitigated by vaccination even when an epidemic appears to be waning. © 2010 American Journal of Preventive Medicine