In this paper, we study parallel algorithms for private-cache chip multiprocessors (CMPs), focusing on methods for foundational problems that can scale to hundreds or even thousands of cores. By focusing on private-cache CMPs, we show that we can design efficient algorithms that need no additional assumptions about the way that cores are interconnected, for we assume that all inter-processor communication occurs through the memory hierarchy. We study several fundamental problems, including prefix sums, selection, and sorting, which often form the building blocks of other parallel algorithms. Indeed, we present two sorting algorithms, a distribution sort and a mergesort. All algorithms in the paper are asymptotically optimal in terms of the parallel cache accesses and space complexity under reasonable assumptions about the relationships between the number of processors, the size of memory, and the size of cache blocks. In addition, we study sorting lower bounds in a computational model, which we call the parallel external-memory (PEM) model, that formalizes the essential properties of our algorithms for private-cache chip multiprocessors.

The resting behavior of Aedes aegypti (L.) adults was investigated in 14 districts of Panama City, Panama, in relation to ground ultra-low volume (ULV) applications of malathion. Adults primarily rested inside the premises (75.1%) at a distance Ͼ6 m from the street (86.4%). Both sexes rested mainly in bedrooms, living rooms, and bathrooms. The small ULV aerosol droplets (2Ð 4 m) penetrated all indoor resting sites of Ae. aegypti, but in low amounts. Because of the low amount of insecticide reaching the primary resting sites within the premises, limited control of the Ae. aegypti was obtained. This limited the potential effectiveness of ground vehicle ULV applied insecticide as a dengue epidemic control method.KEY WORDS Aedes aegypti, culicidae, resting behavior, ultra-low volume insecticides DURING THE 1950S and 1960s, Ͼ20 countries in the Americas were able to eradicate Aedes aegypti (L.), but in the last 20 yr, almost every one of these countries including Panama has become reinfested and has had sizable epidemics of dengue fever (Gubler and Kuno 1997). Although future outbreaks of dengue fever may be avoided by eliminating larval habitats through community participation, there are still areas with Ae. aegypti infestation that may allow outbreaks of the disease. For this reason, emergency measures must be available for use in future dengue outbreaks.The intervention used during epidemics is the ground application of small quantities of aerosol insecticide (ultra-low volume or ULV). Elsewhere, ULV applications have been shown repeatedly to give Ͻ100% control of adult Ae. aegypti populations (Hudson 1986, Focks et al. 1987, Perich et al. 1990. One reason for this reduced effectiveness is Ae. aegypti resting behavior. A portion of the population is found in wardrobes, under beds, behind furniture and in closed rooms where it is difÞcult for aerosol droplets to reach. Focks et al. (1987) hypothesized that gravid females remain sequestered during treatment periods in places that are well-protected from aerosols.Schoof (1967) indicated that the resting habits of this mosquito are relatively unknown, but suggested that adults gather at breeding places, resting there and on adjoining surfaces. In Thailand, Pant and Yasuno (1970) demonstrated that 95% of the mosquitoes rest indoors, and of these, Ͼ90% did so on surfaces that could not be sprayed with residual compounds, such as clothing, pictures, decorative objects, coverlets, and mosquito nets. This Þnding indicated that it was of little value to use residual insecticides on indoor walls. Nelson (1986) reported that mosquitoes rested indoors most frequently in bedrooms, bathrooms, and kitchens where they preferred vertical surfaces such as walls, furniture, and hanging articles such as clothing, towels, curtains, and mosquito nets, although they also were found on the ceiling and under furniture such as beds.Detailed investigation of the resting behavior of Ae. aegypti is needed if chemical control is to be adopted for the control of adult mosquitoes. In th...

Bartels and Johnston have recently presented evidence suggesting that the legitimacy of the U.S. Supreme Court is grounded in the ideological preferences and perceptions of the American people. In addition, they offer experimental data purporting to show that dissatisfaction with a single Court decision substantially diminishes the institution's legitimacy. These findings strongly break with earlier research on the Court's institutional support, as the authors recognize. The theoretical implications of their findings are profound. If the authors are correct that legitimacy is strongly dependent upon satisfying the policy preferences and ideological predilections of the American people, the essence of legitimacy is fundamentally transformed. Consequently, we reinvestigate the relationships among ideology, performance satisfaction, and Court legitimacy, unearthing empirical findings that diverge markedly from theirs. We conclude with some thoughts about how the Court's "countermajoritarian dilemma" can be reconceptualized and recalculated, once more drawing conclusions sharply at odds with those of Bartels and Johnston.

Fast protein liquid chromatography of cell extract from methanol- or acetate-grown Methanosarcina thermophila resolved two peaks of CO dehydrogenase activity. The activity of one of the CO dehydrogenases was sixfold greater in acetate-grown compared with methanol-grown cells. This CO dehydrogenase was purified to apparent homogeneity (70 mumol of methyl viologen reduced per min per mg of protein) and made up greater than 10% of the cellular protein of acetate-grown cells. The native enzyme (Mr 250,000) formed aggregates with an Mr of approximately 1,000,000. The enzyme contained five subunits (Mrs 89,000, 71,000, 60,000, 58,000, and 19,000), suggesting a multifunctional enzyme complex. Nickel, iron, cobalt, zinc, inorganic sulfide, and a corrinoid were present in the complex. The UV-visible spectrum suggested the presence of iron-sulfur centers. The electron paramagnetic resonance spectrum contained g values of 2.073, 2.049, and 2.028; these features were broadened in enzyme that was purified from cells grown in the presence of medium enriched with 61Ni, indicating the involvement of this metal in the spectrum. The pattern of potassium cyanide inhibition indicated that cyanide binds at or near the CO binding site. The properties of the enzyme imply an involvement in the dissimilation of acetate to methane, possibly by cleavage of acetate or activated acetate.

Biodegradation of trichloroethylene (TCE) by bacterial strain G4 resulted in complete dechlorination of the compound, as indicated by the production of inorganic chloride. A component of the water from which strain G4 was isolated that was required for TCE degradation was identified as phenol. Strain G4 degraded TCE in the presence of chloramphenicol only when preinduced with phenol. Toluene, o-cresol, and m-cresol could replace the phenol requirement. Two of the inducers of TCE metabolism, phenol and toluene, apparently induced the same aromatic degradative pathway that cleaved the aromatic ring by meta fission. Cells induced with either phenol or toluene had similar oxidation rates for several aromatic compounds and had similar levels of catechol-2,3-dioxygenase. The results indicate that one or more enzymes of an inducible pathway for aromatic degradation in strain G4 are responsible for the degradation of TCE.