Extreme Networks (United States)

Low-velocity large-scale shocks impacting on the ISM may efficiently shape molecular clouds and trigger star formation within them. These shocks, both driven by galactic bubbles and/or cloud-cloud collisions, leave specific signatures in the gas morphology and kinematics. Observational studies of such signatures are crucial to investigate if and how shocks affect the clouds formation process and trigger their future star formation. We have analysed the shocked and dense gas tracers SiO(2-1) and H13CO+(1-0) emission toward the IRDC G035.39-00.33, using new, larger-scale maps obtained with the 30m telescope at the Instituto de Radioastronom\`ia Millim\'etrica. We find that the dense gas is organised into a northern and a southern filament having different velocities and tilted orientation with respect to each other. The two filaments are spatially separated yet connected by a faint bridge feature also seen in a position-velocity diagram extracted across the cloud. This bridge-feature, typical of cloud-cloud collisions, also coincides with a very spectrally narrow SiO-traced emission. The northern filament is suggested to be interacting with the nearby supernova remnant G035.6-0.4. Toward the southern filament, we also report the presence of a parsec-scale, spectrally narrow SiO emission likely driven by the interaction between this filament and a nearby expanding shell. The shell is visible in the 1.3 GHz and 610 MHz continuum images and our preliminary analysis suggests it may be the relic of a supernova remnant. We conclude that the two filaments represent the densest part of two colliding clouds, pushed toward each other by nearby Supernova Remnants. We speculate that this cloud-cloud collision driven by stellar feedback may have assembled the infrared dark cloud. We also evaluate the possibility that star formation may have been triggered within G035.39-00.33 by the collision.

Alcohol is considered a leading risk factor for osteopenia. Our previous research indicated that the Akt/GSK-3β/β-catenin pathway plays a critical role in the ethanol-induced antiosteogenic effect in bone mesenchymal stem cells (BMSCs). PI3K/Akt is negatively regulated by the phosphatase and tensin homolog (PTEN) phosphatase. In this study, we found that ethanol increased PTEN expression in the BMSCs and bone tissue of ethanol-treated Sprague-Dawley rats. PTEN upregulation impaired Akt recruitment to the plasma membrane and suppressed Akt phosphorylation at Ser473, thereby inhibiting Akt/GSK3β/β-catenin signaling and the expression of COL1 and OCN in BMSCs in vitro and in vivo. The results of in vivo assays indicated that PTEN inhibition protected bone tissue against ethanol. Interestingly, our data revealed that following ethanol stimulation, PTEN and PTEN pseudogene 1 (PTENP1) mRNA expression was increased in a time-dependent manner, resulting in an increased PTEN protein level. In addition, ethanol upregulated PTEN expression and decreased PTEN phosphorylation (p-PTEN), indicating an increase in functional PTEN levels. In summary, the ethanol-mediated transcriptional and post-transcriptional regulation of PTEN impaired downstream Akt/GSK3β/β-catenin signaling and BMSC osteogenic differentiation. Therefore, we propose that Akt/GSK3β/β-catenin activation via PTEN inhibition may be a potential therapeutic approach for preventing the development of alcohol-induced osteopenia.

There is an age-old debate regarding whether human factors/usability professionals should play the role of police or collaborative team member. While the prevalent practice is that we avoid the authoritarian role of “police”, two questions remain: 1) is the softer approach really working in most organizations? and 2) which role will ensure usability when development is outsourced? This panel will explore usability cultures and challenges in several different government and industry organizations. Panel members from NASA will present some advances in developing usability requirements for verifying contractor products, and will describe recent work to objectify usability-related characteristics, such as consistency and legibility. Panel members representing large (Hewlett-Packard) and small (Extreme Networks) information technology companies will describe their unique challenges and attempts made toward ensuring usability of their products.

Internet users seek solutions for mobility, multi-homing, support for localised address management (i.e. via NATs), and end-to-end security. Existing mobility approaches are not well integrated into the rest of the Internet architecture, instead primarily being separate extensions that at present are not widely deployed. Because the current approaches to these issues were developed separately, such approaches often are not harmonious when used together. Meanwhile, the Internet has a number of namespaces, for example the IP address or the Domain Name. In recent years, some have postulated that the Internet's namespaces are not sufficiently rich and that the current concept of an address is too limiting. One proposal, the concept of separating an address into an Identifier and a separate Locator, has been controversial in the Internet community for years. It has been considered within the IETF and IRTF several times, but always was rejected as unworkable. This paper takes the position that evolving the naming in the Internet by splitting the address into separate Identifier and Locator names can provide an elegant integrated solution to the key issues listed above, without changing the core routing architecture, while offering incremental deployability through backwards compatibility with IPv6.

The large-scale process and environmental variations for today's nanoscale ICs require statistical approaches for timing analysis and optimization. In this paper, we demonstrate why the traditional concept of slack and critical path becomes ineffective under large-scale variations and propose a novel sensitivity framework to assess the ldquocriticalityrdquo of every path, arc, and node in a statistical timing graph. We theoretically prove that the path sensitivity is exactly equal to the probability that a path is critical and that the arc (or node) sensitivity is exactly equal to the probability that an arc (or a node) sits on the critical path. An efficient algorithm with incremental analysis capability is developed for fast sensitivity computation that has linear runtime complexity in circuit size. The efficacy of the proposed sensitivity analysis is demonstrated on both standard benchmark circuits and large industrial examples.

The large-scale process and environmental variations for today's nanoscale ICs are requiring statistical approaches for timing analysis and optimization. Significant research has been recently focused on developing new statistical timing analysis algorithms, but often without consideration for how one should interpret the statistical timing results for optimization. In this paper (Li et al., 2005) we demonstrate why the traditional concepts of slack and critical path become ineffective under large-scale variations, and we propose a novel sensitivity-based metric to assess the criticality of each path and/or arc in the statistical timing graph. We define the statistical sensitivities for both paths and arcs, and theoretically prove that our path sensitivity is equivalent to the probability that a path is critical, and our arc sensitivity is equivalent to the probability that an arc sits on the critical path. An efficient algorithm with incremental analysis capability is described for fast sensitivity computation that has a linear runtime complexity in circuit size. The efficacy of the proposed sensitivity analysis is demonstrated on both standard benchmark circuits and large industry examples.

Does anyone still remember, what happened, when a few years ago Pizza Hut announced their Internet service? Many of the purist Internet community were so outraged by such a bold commercializing invasion that some even suggested to boycott Pizza Hut (or even afflict electronic assault to their Web site for this "belligerent move"). Although, only a short time has passed since, it certainly looks like this incident happened ages ago. Today, no one will probably question the legitimacy of EC (electronic commerce) over the public Internet. New applications and EC Internet services are being deployed probably on a daily basis.

This paper analyzes trends in enterprise LAN and describes solutions for IT managers considering migrating their token ring networks to other technologies. The paper examines forces influencing the decision to migrate, and offers step-by-step solutions for migration to Ethernet/Fast Ethernet and/or ATM network infrastructures. Especial emphasis is given to technology comparison and manageability issues throughout and following the migration process.

High-speed asymmetric and symmetric digital subscriber line loop access systems, designed by numerous computer networking and telecommunications equipment companies, are currently the focus of technical trials, market trials, and commercial services deployment around the world. This is to provide millions of residential and business customers worldwide with high-speed always-on connectivity to the Internet, corporate intranets, and various online services. It is estimated that over 460 million copper loops worldwide could potentially be equipped end-to-end with xDSL access systems. Large-scale deployment of broadband access systems offering always-on connectivity to the global Internet and corporate intranets is seen as a key enabler of the bold vision articulated worldwide to utilize open Internet protocols and emerging technologies such as Java to create a unified software-defined (IP) global networking infrastructure. Such a networking platform would serve as a de facto medium for generation and delivery of integrated multimedia content, and revolutionize the way people around the world learn, do business, and interact with each other.