Dusty Caches to Save Memory Traffic

Reference counting is a garbage-collection technique that maintains a per-object count of the number of pointers to that object. When the count reaches zero, the object must be dead and can be collected. Although it is not an exact method, it is well suited for real-time systems and is widely implemented, sometimes in conjunction with other methods to increase the overall precision. A disadvantage of reference counting is the extra storage trac that is introduced. In this paper, we describe a new cache write-back policy that can substantially decrease the reference-counting traffic to RAM. We propose a new cache design that remembers the first-fetched value of a cache subblock, so that the subblock need not be written back to RAM unless a different value is present. We present results from experiments that show the effectiveness of this approach, particularly in mitigating the storage traffic due to reference counting

First Amendment and Foreign-Controlled U.S. Corporations: Why Congress Ought to Affirm Domestic Subsidiaries\u27 Corporate Political-Speech Rights

Political spending in the modern-day, prolonged election cycle continues to exceed historic proportions. With money equated to speech, whether the First Amendment entitles certain contributors to engage in this political activity remains an open question. Unlike France and Israel, which prohibit corporate contributions, and Canada and the United Kingdom, which turn to public funding for campaign finance, the United States has pushed candidates to rely on political party contributions, personal wealth, and the generosity of individuals, political action committees, and corporations. Concerns about corporate and foreign influence on politics have been especially salient during this lengthy economic downturn, as shown by the prominence of the nationwide Occupy Wall Street protests. Those who trumpet restrictions on so-called foreign corporate political influence are concerned with infringements on U.S. sovereign independence and citizens\u27 political self-determination. This Note responds to the uproar against corporate and foreign influence in the wake of Citizens United v. Federal Election Commission, arguing the debate in Congress and, thus, the law, ought to distinguish between domestic subsidiaries of foreign corporations and foreign corporations themselves. Under the current legal regime, no distinction between U.S. corporations and domestic subsidiaries exists; despite proposed legislation to the contrary, it should remain this way

A study of a multi-pinned phase CCD detector for use as a star tracker

This grant has supported studies of the use of charge coupled devices (CCD's) in star trackers in a number of different areas. Among the tasks we have pursued are the following: (1) radiation modeling and the increase in noise equivalent angle as a result of exposure to protons and bremsstrahlung gamma rays; (2) the development of pattern matching software to identify field locations from a CCD image and a pre-existing map of the local area; (3) observations of various stellar fields from the 24 inch telescope at the Offit Observatory at JHU, primarily to test the pattern matching software (these included crowded fields as well as moving objects, like comets); and (4) tracking of very faint objects to determine the faint limit of the CCD system

The Role of Chemokines in Acute Liver Injury

Chemokines are small molecular weight proteins primarily known to drive migration of immune cell populations. In both acute and chronic liver injury, hepatic chemokine expression is induced resulting in inflammatory cell infiltration, angiogenesis, and cell activation and survival. During acute injury, massive parenchymal cell death due to apoptosis and/or necrosis leads to chemokine production by hepatocytes, cholangiocytes, Kupffer cells, hepatic stellate cells, and sinusoidal endothelial cells. The specific chemokine profile expressed during injury is dependent on both the type and course of injury. Hepatotoxicity by acetaminophen for example leads to cellular necrosis and activation of Toll-like receptors while the inciting insult in ischemia reperfusion injury produces reactive oxygen species and subsequent production of pro-inflammatory chemokines. Chemokine expression by these cells generates a chemoattractant gradient promoting infiltration by monocytes/macrophages, NK cells, NKT cells, neutrophils, B cells, and T cells whose activity are highly regulated by the specific chemokine profiles within the liver. Additionally, resident hepatic cells express chemokine receptors both in the normal and injured liver. While the role of these receptors in normal liver has not been well described, during injury, receptor up-regulation, and chemokine engagement leads to cellular survival, proliferation, apoptosis, fibrogenesis, and expression of additional chemokines and growth factors. Hepatic-derived chemokines can therefore function in both paracrine and autocrine fashions further expanding their role in liver disease. More recently it has been appreciated that chemokines can have diverging effects depending on their temporal expression pattern and the type of injury. A better understanding of chemokine/chemokine receptor axes will therefore pave the way for development of novel targeted therapies for the treatment of liver disease