Large Deviations in Some Queueing Systems

Logarithmic asymptotics of probabilities of large delays are derived for the “last come—first served” system and system with priorities. Trajectories that determine the mean dynamics of arrival flow under the condition of large delay are described

Large deviations provide good approximation to queueing system with dynamic routing

We consider a system with two infinite-buffer FCFS servers (of speed one). The arrivals processes are three independent Poisson flows Ξ_i , of rates λ_i, i = 0, 1, 2, each with IID task service times. The tasks from Ξ_i are directed to server i, i = 1, 2 (dedicated traffic). The tasks from Ξ_0 are directed to the server that has the shorter workload in the buffer at the time of arrival (opportunistic traffic). We compare the analytical data for the large deviation (LD) probabilities for the virtual waiting time in flow Ξ_0 and empercial delay freqencies from simulations

Percolation properties of non-ideal gas

We estimate locations of the regions of the percolation and of the non-percolation in the plane $(\lambda,\beta)$: the Poisson rate -- the inverse temperature, for interacted particle systems in finite dimension Euclidean spaces. Our results about the percolation and about the non-percolation are obtained under different assumptions. The intersection of two groups of the assumptions reduces the results to two dimension Euclidean space, $\R^2$, and to a potential function of the interactions having a hard core. The technics for the percolation proof is based on a contour method which is applied to a discretization of the Euclidean space. The technics for the non-percolation proof is based on the coupling of the Gibbs field with a branching process.Comment: 28 pages, 3 figure

Thermomagnetic analysis of native iron from the upper sedimentary horizons of Lake Baikal, section GC-99 (Posolskaya Bank)

© 2017 We present results of a thermomagnetic analysis of Late Pleistocene-Holocene bottom sediments from the gravity core GC-99 of the borehole BDP-99 drilled at Posolskaya Bank of Lake Baikal in the framework of the Baikal Drilling Project. The results are compared with the earlier analytical data on the samples from the lower (Miocene) section of the BDP-98 drilled on the Akademichesky Ridge. Native-iron particles were found in only 14 of 61 samples. Their content varies from ~ 10 -5 to 10 -4 %, and their distribution is near-bimodal, with a distinct “zero” mode. The results of the thermomagnetic analysis are confirmed by a probe microanalysis: Only occasional native-iron particles were found. Nickel was detected in only one sample. The samples have a large number of magnetite and titanomagnetite grains. It is shown that the distribution of native-iron particles in the Baikal sediments depends on the rate of sedimentation: The rate increase is accompanied by the increase in the number of the “zero” group samples (free of iron particles). The conclusion is drawn that the native-iron particles in the studied sediments are predominantly of cosmic origin

Thermomagnetic analysis of native iron from the upper sedimentary horizons of Lake Baikal, section GC-99 (Posolskaya Bank)

© 2017 We present results of a thermomagnetic analysis of Late Pleistocene-Holocene bottom sediments from the gravity core GC-99 of the borehole BDP-99 drilled at Posolskaya Bank of Lake Baikal in the framework of the Baikal Drilling Project. The results are compared with the earlier analytical data on the samples from the lower (Miocene) section of the BDP-98 drilled on the Akademichesky Ridge. Native-iron particles were found in only 14 of 61 samples. Their content varies from ~ 10 -5 to 10 -4 %, and their distribution is near-bimodal, with a distinct “zero” mode. The results of the thermomagnetic analysis are confirmed by a probe microanalysis: Only occasional native-iron particles were found. Nickel was detected in only one sample. The samples have a large number of magnetite and titanomagnetite grains. It is shown that the distribution of native-iron particles in the Baikal sediments depends on the rate of sedimentation: The rate increase is accompanied by the increase in the number of the “zero” group samples (free of iron particles). The conclusion is drawn that the native-iron particles in the studied sediments are predominantly of cosmic origin

Material composition of copper slag of the Almalyk copper-smelting plant (Uzbekistan)

Relevance. Copper production is accompanied by release of a large volume of slag. Today, huge quantities of copper slags have accumulated all over the world, in which the copper content is even greater than that in original ores. The slags that result from the smelting of ores and concentrates of both ferrous and non-ferrous metals, together with other metallurgical wastes such as tailings, are increasingly the subject of significant environmental controversy. The only way to reduce the negative impact of slag waste on the environment can be their disposal, by complex extraction of valuable components from them and further use of slag waste for construction purposes. In addition to the main component of copper, copper slags contain elevated contents of gold, silver, zinc, iron, etc. The form of finding valuable metals such as iron, copper, lead and zinc in copper slags is complex. A detailed study of the mineral composition of slags is used in development of an effective technology for processing slags. Aim. To study mineral composition of copper slags, the form of finding valuable components. Object. Copper slag waste from the copper-smelting plant of the Almalyk MMC. Methods. Chemical composition of copper slags was established by phase analysis, atomic absorption, X-ray fluorescence research methods. Mineral composition of the ores was established as a result of complex studies, including: optical microscopy in transmitted and reflected light, X-ray diffraction, microprobe studies and electron microscopy. Results. Copper content in composition of copper slag samples is higher than in copper ores and it is 0.77–0.97%. In addition to copper, copper slags contain elevated contents of a complex of metals (g/t): Au – 0.17–0.26; Ag 8.42–10.64, Zn 4.288–10216, Pb – 2014-3360. Ferrous silicates (fayalite, ferrosillite), vitreous mass of ferruginous-silicate composition predominate in the composition of copper slags. Ore minerals are mainly represented by magnetite. The mineral content is approximately 10–15%. Among сopper sulfides minerals bornite, chalcocite, less often cubanite, chalcopyrite, covellite sharply predominate. Cuprite is observed in small amounts, and native copper is metallic. The mineral form of finding molybdenum is molybdenite. Among the native silver minerals, native silver was found in association with lead minerals. Gold is included in the composition of native copper and chalcocite as an impurity and passes into copper concentrate during processing slags

Discovery and Clinical Proof-of-Concept of RLY-2608, a First-in-Class Mutant-Selective Allosteric PI3Kα Inhibitor That Decouples Antitumor Activity from Hyperinsulinemia

PIK3CA (PI3Kα) is a lipid kinase commonly mutated in cancer, including ∼40% of hormone receptor–positive breast cancer. The most frequently observed mutants occur in the kinase and helical domains. Orthosteric PI3Kα inhibitors suffer from poor selectivity leading to undesirable side effects, most prominently hyperglycemia due to inhibition of wild-type (WT) PI3Kα. Here, we used molecular dynamics simulations and cryo-electron microscopy to identify an allosteric network that provides an explanation for how mutations favor PI3Kα activation. A DNA-encoded library screen leveraging electron microscopy-optimized constructs, differential enrichment, and an orthosteric-blocking compound led to the identification of RLY-2608, a first-in-class allosteric mutant-selective inhibitor of PI3Kα. RLY-2608 inhibited tumor growth in PIK3CA-mutant xenograft models with minimal impact on insulin, a marker of dysregulated glucose homeostasis. RLY-2608 elicited objective tumor responses in two patients diagnosed with advanced hormone receptor–positive breast cancer with kinase or helical domain PIK3CA mutations, with no observed WT PI3Kα-related toxicities. Significance: Treatments for PIK3CA-mutant cancers are limited by toxicities associated with the inhibition of WT PI3Kα. Molecular dynamics, cryo-electron microscopy, and DNA-encoded libraries were used to develop RLY-2608, a first-in-class inhibitor that demonstrates mutant selectivity in patients. This marks the advance of clinical mutant-selective inhibition that overcomes limitations of orthosteric PI3Kα inhibitors