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ÐWe investigate the performance implications of providing transaction atomicity for firm-deadline real-time applications operating on distributed data. Using a detailed simulation model, the real-time performance of a representative set of classical transaction commit protocols is evaluated. The experimental results show that data distribution has a(More)
Incorporating distributed data into the real-time framework incurs the well-known additional complexities that are associated with transaction concurrency control and database recovery in distributed database systems. We investigate here the performance implications of supporting transaction atomicity in a distributed real-time database system. Using a(More)
Exposure to excessive manganese (Mn) levels results in neurotoxicity to the extrapyramidal system and the development of Parkinson's disease (PD)-like movement disorder, referred to as manganism. Although the mechanisms by which Mn induces neuronal damage are not well defined, its neurotoxicity appears to be regulated by a number of factors, including(More)
Acute lupus pneumonitis was the presenting manifestation of systemic lupus erythematosus in six of 12 cases in this series. The clinical picture was characterized by severe dyspnea, tachypnea, fever and arterial hypoxemia. Radiographic findings included an acinar filling pattern which was invariably found in the lower lobes and was bilateral in 10 of the(More)
A significant body of literature is available on distributed transaction commit protocols. Surprisingly, however, the relative merits of these protocols have not been studied with respect to their <italic>quantitative</italic> impact on transaction processing performance. In this paper, using a detailed simulation model of a distributed database system, we(More)
OBJECTIVES This study examined the effects of long-term delivery of cardiac contractility modulation (CCM) electric signals on left ventricular (LV) function and global, cellular, and molecular remodeling in dogs with chronic heart failure (HF). BACKGROUND Acute studies in dogs with experimentally induced HF showed that CCM signals applied to the failing(More)
The brain is a well-organized, yet highly complex, organ in the mammalian system. Most investigators use the whole brain, instead of a selected brain region(s), for biochemical analytes as toxicological endpoints. As a result, the obtained data is often of limited value, since their significance is compromised due to a reduced effect, and the investigators(More)
We have previously reported that mono- and dichlorinated biphenyls (PCBs) can be metabolized to dihydroxy compounds and further oxidized to reactive metabolites which form adducts with nitrogen and sulfur nucleophiles including DNA [Amaro et al. (1966) Chem. Res. Toxicol. 9, 623-629; Oakley et al. (1996) Carcinogenesis 17, 109-114]. The former studies also(More)
Ochratoxin A (OTA) is a potent nephrotoxin and renal carcinogen in rats, but the mechanism of OTA tumorigenicity is unknown. Ochratoxin A has been shown to be negative in many genetic toxicology test in vitro. However, the potential of OTA to induce genotoxic effects has not been investigated in male rats, the most sensitive species for OTA-induced tumor(More)
Excessive free radical formation has been implicated as a causative factor in neurotoxic damage associated with exposures to a variety of metals, including manganese (Mn). It is well established that Mn accumulates in astrocytes, affecting their ability to indirectly induce and/or exacerbate neuronal dysfunction. The present study examined the effects of Mn(More)