Instruction-Level Abstraction (ILA): A Uniform Specification for System-on-Chip (SoC) Verification

Modern Systems-on-Chip (SoC) designs are increasingly heterogeneous and contain specialized semi-programmable accelerators in addition to programmable processors. In contrast to the pre-accelerator era, when the ISA played an important role in verification by enabling a clean separation of concerns between software and hardware, verification of these "accelerator-rich" SoCs presents new challenges. From the perspective of hardware designers, there is a lack of a common framework for the formal functional specification of accelerator behavior. From the perspective of software developers, there exists no unified framework for reasoning about software/hardware interactions of programs that interact with accelerators. This paper addresses these challenges by providing a formal specification and high-level abstraction for accelerator functional behavior. It formalizes the concept of an Instruction Level Abstraction (ILA), developed informally in our previous work, and shows its application in modeling and verification of accelerators. This formal ILA extends the familiar notion of instructions to accelerators and provides a uniform, modular, and hierarchical abstraction for modeling software-visible behavior of both accelerators and programmable processors. We demonstrate the applicability of the ILA through several case studies of accelerators (for image processing, machine learning, and cryptography), and a general-purpose processor (RISC-V). We show how the ILA model facilitates equivalence checking between two ILAs, and between an ILA and its hardware finite-state machine (FSM) implementation. Further, this equivalence checking supports accelerator upgrades using the notion of ILA compatibility, similar to processor upgrades using ISA compatibility.Comment: 24 pages, 3 figures, 3 table

Intracapillary leucocyte accumulation as a novel antihaemorrhagic mechanism in acute pancreatitis in mice

Background: Pancreatic infiltration by leucocytes represents a hallmark in acute pancreatitis. Although leucocytes play an active role in the pathophysiology of this disease, the relation between leucocyte activation, microvascular injury and haemorrhage has not been adequately addressed.Methods: We investigated intrapancreatic leucocyte migration, leucocyte extravasation and pancreatic microperfusion in different models of oedematous and necrotising acute pancreatitis in lys-EGFP-ki mice using fluorescent imaging and time-lapse intravital microscopy.Results: In contrast to the current paradigm of leucocyte recruitment, the initial event of leucocyte activation in acute pancreatitis was represented through a dose- and time-dependent occlusion of pancreatic capillaries by intraluminally migrating leucocytes. Intracapillary leucocyte accumulation (ILA) resulted in dense filling of almost all capillaries close to the area of inflammation and preceded transvenular leucocyte extravasation. ILA was also initiated by isolated exposure of the pancreas to interleukin 8 or fMLP, demonstrating the causal role of chemotactic stimuli in the induction of ILA. The onset of intracapillary leucocyte accumulation was strongly inhibited in LFA-1-/- and ICAM-1-/- mice, but not in Mac-1-/- mice. Moreover, prevention of intracapillary leucocyte accumulation led to the development of massive capillary haemorrhages and transformed mild pancreatitis into lethal haemorrhagic disease.Conclusions: ILA represents a novel protective and potentially lifesaving mechanism of haemostasis in acute pancreatitis. This process depends on expression of LFA-1 and ICAM-1 and precedes the classical steps of the leucocyte recruitment cascade

Means to Her Dreams

ILA scholar Bre’Anna Metts-Nixon ’13 encourages students to pursue higher education in spite of life’s challenges

Bronchial Epithelial Gene Expression and Interstitial Lung Abnormalities

INTRODUCTION: Interstitial lung abnormalities (ILA) often represent early fibrotic changes that can portend a progressive fibrotic phenotype. In particular, the fibrotic subtype of ILA is associated with increased mortality and rapid decline in lung function. Understanding the differential gene expression that occurs in the lungs of participants with fibrotic ILA may provide insight into development of a useful biomarker for early detection and therapeutic targets for progressive pulmonary fibrosis. METHODS: Measures of ILA and gene expression data were available in 213 participants in the Detection of Early Lung Cancer Among Military Personnel (DECAMP1 and DECAMP2) cohorts. ILA was defined using Fleischner Society guidelines and determined by sequential reading of computed tomography (CT) scans. Primary analysis focused on comparing gene expression in ILA with usual interstitial pneumonia (UIP) pattern with those with no ILA. RESULTS: ILA was present in 51 (24%) participants, of which 16 (7%) were subtyped as ILA with a UIP pattern. One gene, pro platelet basic protein (PPBP) and seventeen pathways (e.g. TNF-α signalling) were significantly differentially expressed between those with a probable or definite UIP pattern of ILA compared to those without ILA. 16 of these 17 pathways, but no individual gene, met significance when comparing those with ILA to those without ILA. CONCLUSION: Our study demonstrates that abnormal inflammatory processes are apparent in the bronchial airway gene expression profiles of smokers with and without lung cancer with ILA. Future studies with larger and more diverse populations will be needed to confirm these findings

India's policy stance on reserves and the currency

Over the last decade, India engaged in substantial liberalisation on the current account and the capital account. At the same time, a fully articulated policy framework defining the currency regime is not known in the public domain. In this paper, we seek to characterise then ature of the currency regime, in the period after the Asian crisis. This is closely linked to better understanding the phenomenon of reserves accumulation of the recent years. Our results suggest that the main focus of the currency regime has been to deliver a low volatility of the nominal exchange rate. The rupee appears to be a de facto peg to the USD. In the last one year, reserves accumulation cannot be explained by insurance motivations; it seems to be a passive side effect of maintaining the currency regime

The Consequences of currency intervention in India

Currency management in India has focused on delivering low levels of currency volatility. In earlier years, the implementation of the currency regime was enabled by the presence of capital controls. In recent years, India has made much progress towards capital account convertibility. This paper closely examines India's experience with the implementation of the currency regime in two episodes: 1993-95 and after 2002. We argue that the implementation of the existing currency regime now induces distorted monetary policy and fiscal costs. These costs of implementing the currency regime need to be factored into the choice of currency regime

The Indian currency regime and its consequences.

While the Indian rupee is claimed to be a `market determined ex-change rate', there is a gulf between the de facto and de jure exchange rate regime. An examination of the data reveals that India has a de facto rupee-dollar pegged exchange rate. From the early 1990s on- wards, as India as reintegrated with the world economy, the implementation of this pegged exchange rate has induced increasing monetary policy distortions. The volatility of the rupee-dollar rate has sub-stantial variation which have considerable implications for economic agents in understanding currency risk and monetary policy. However these changes in course have not been preceded by announcements from RBI.Money

No scale SUGRA SO(10) derived Starobinsky Model of Inflation

We show that a supersymmetric renormalizable theory based on gauge group SO(10) and Higgs system {\bf {10 $\oplus$ 210 $\oplus$ 126 $\oplus$ $\overline{\bf 126}$}} with no scale supergravity can lead to a Starobinsky kind of potential for inflation. Successful inflation is possible in the cases where the potential during inflation corresponds to $SU(3)_C \times SU(2)_L \times SU(2)_R \times U(1)_{B-L}$, $SU(5)\times U(1)$ and flipped $SU(5)\times U(1)$ intermediate symmetry with a suitable choice of superpotential parameters. The reheating in such a scenario can occur via non perturbative decay of inflaton i.e. through "preheating". After the end of reheating, when universe cools down, the finite temperature potential can have a minimum which corresponds to MSSM.Comment: 6 pages, 2 figures, Replaced with version to appear in Phys Lett