Crater Morphology in the Phoenix Landing Ellipse: Insights Into Net Erosion and Ice Table Depth

Icebreaker [1] is a Discovery class mission being developed for future flight opportunities. Under this mission concept, the Icebreaker payload is carried on a stationary lander, and lands in the same landing ellipse as Phoenix. Samples are acquired from the subsurface using a drilling system that penetrates into materials which may include loose or cemented soil, icy soil, pure ice, rocks, or mixtures of these. To avoid the complexity of mating additional strings, the drill is single-string, limiting it to a total length of 1 m

Tissue microarrays: one size does not fit all

<p>Abstract</p> <p>Background</p> <p>Although tissue microarrays (TMAs) are commonly employed in clinical and basic-science research, there are no guidelines for evaluating the appropriateness of a TMA for a given biomarker and tumor type. Furthermore, TMA performance across multiple biomarkers has not been systematically explored.</p> <p>Methods</p> <p>A simulated TMA with between 1 and 10 cores was designed to study tumor expression of 6 biomarkers with varied expression patterns (B7-H1, B7-H3, survivin, Ki-67, CAIX, and IMP3) using 100 patients with clear cell renal cell carcinoma (RCC). We evaluated agreement between whole tissue section and TMA immunohistochemical biomarker quantification to assess how many TMA cores are necessary to adequately represent RCC whole tissue section expression. Additionally, we evaluated associations of whole tissue section and TMA expression with RCC-specific death.</p> <p>Results</p> <p>The number of simulated TMA cores necessary to adequately represent whole tissue section quantification is biomarker specific. Although 2-3 cores appeared adequate for B7-H3, Ki-67, CAIX, and IMP3, even as many as 10 cores resulted in poor agreement for B7-H1 and survivin compared to RCC whole tissue sections. While whole tissue section B7-H1 was significantly associated with RCC-specific death, no significant associations were detected using as many as 10 TMA cores, suggesting that TMAs can result in false-negative findings if the TMA is not optimally designed.</p> <p>Conclusions</p> <p>Prior to TMA analysis, the number of TMA cores necessary to accurately represent biomarker expression on whole tissue sections should be established as there is not a one-size-fits-all TMA. We illustrate the use of a simulated TMA as a cost-effective tool for this purpose.</p

The Transition from Atomic to Molecular Hydrogen in Interstellar Clouds: 21cm Signature of the Evolution of Cold Atomic Hydrogen in Dense Clouds

We have investigated the time scale for formation of molecular clouds by examining the conversion of HI to H2 using a time-dependent model. H2 formation on dust grains and cosmic ray and photo destruction are included in one-dimensional model slab clouds which incorporate time-independent density and temperature distributions. We calculate 21cm spectral line profiles seen in absorption against a background provided by general Galactic HI emission, and compare the model spectra with HI Narrow Self-Absorption, or HINSA, profiles absorbed in a number of nearby molecular clouds. The time evolution of the HI and H2 densities is dramatic, with the atomic hydrogen disappearing in a wave propagating from the central, denser regions which have a shorter H2 formation time scale, to the edges, where the density is lower and the time scale for H2 formation longer. The model 21cm spectra are characterized by very strong absorption at early times, when the HI column density through the model clouds is extremely large. The minimum time required for a cloud to have evolved to its observed configuration, based on the model spectra, is set by the requirement that most of the HI in the outer portions of the cloud, which otherwise overwhelms the narrow absorption, be removed. The characteristic time that has elapsed since cloud compression and initiation of the HI to H2 conversion is a few x 10^{14} s or ~ 10^7 yr. This sets a minimum time for the age of these molecular clouds and thus for the star formation that may take place within them

The GALFA-HI Survey: Data Release 1

We present the Galactic Arecibo L-Band Feed Array HI (GALFA-HI) survey, and its first full data release (DR1). GALFA-HI is a high resolution (~ 4'), large area (13000 deg^2), high spectral resolution (0.18 km/s), wide band (-700 < v_LSR < +700 km/s) survey of the Galactic interstellar medium in the 21-cm line hyperfine transition of neutral hydrogen conducted at Arecibo Observatory. Typical noise levels are 80 mK RMS in an integrated 1 km/s channel. GALFA-HI is a dramatic step forward in high-resolution, large-area Galactic HI surveys, and we compare GALFA-HI to past, present, and future Galactic HI surveys. We describe in detail new techniques we have developed to reduce these data in the presence of fixed pattern noise, gain variation, and inconsistent beam shapes, and we show how we have largely mitigated these effects. We present our first full data release, covering 7520 square degrees of sky and representing 3046 hours of integration time, and discuss the details of these data.Comment: Accepted to the ApJ

a cognitive future internet architecture

This Chapter proposes a novel Cognitive Framework as reference architecture for the Future Internet (FI), which is based on so-called Cognitive Managers. The objective of the proposed architecture is twofold. On one hand, it aims at achieving a full interoperation among the different entities constituting the ICT environment, by means of the introduction of Semantic Virtualization Enablers, in charge of virtualizing the heterogeneous entities interfacing the FI framework. On the other hand, it aims at achieving an inter-network and inter-layer cross-optimization by means of a set of so-called Cognitive Enablers, which are in charge of taking consistent and coordinated decisions according to a fully cognitive approach, availing of information coming from both the transport and the service/content layers of all networks. Preliminary test studies, realized in a home environment, confirm the potentialities of the proposed solution

A Survey on Facilities for Experimental Internet of Things Research

The initial vision of the Internet of Things was of a world in which all physical objects are tagged and uniquely identified by RFID transponders. However, the concept has grown into multiple dimensions, encompassing sensor networks able to provide real-world intelligence and goal-oriented collaboration of distributed smart objects via local networks or global interconnections such as the Internet. Despite significant technological advances, difficulties associated with the evaluation of IoT solutions under realistic conditions in real-world experimental deployments still hamper their maturation and significant rollout. In this article we identify requirements for the next generation of IoT experimental facilities. While providing a taxonomy, we also survey currently available research testbeds, identify existing gaps, and suggest new directions based on experience from recent efforts in this field