1,624 research outputs found
On the mixing property for a class of states of relativistic quantum fields
Let be a factor state on the quasi-local algebra of
observables generated by a relativistic quantum field, which in addition
satisfies certain regularity conditions (satisfied by ground states and the
recently constructed thermal states of the theory). We prove that
there exist space and time translation invariant states, some of which are
arbitrarily close to in the weak* topology, for which the time
evolution is weakly asymptotically abelian
Tackling 3D ToF Artifacts Through Learning and the FLAT Dataset
Scene motion, multiple reflections, and sensor noise introduce artifacts in
the depth reconstruction performed by time-of-flight cameras. We propose a
two-stage, deep-learning approach to address all of these sources of artifacts
simultaneously. We also introduce FLAT, a synthetic dataset of 2000 ToF
measurements that capture all of these nonidealities, and allows to simulate
different camera hardware. Using the Kinect 2 camera as a baseline, we show
improved reconstruction errors over state-of-the-art methods, on both simulated
and real data.Comment: ECCV 201
Role of the Nuclear and Electromagnetic Interactions in the Coherent Dissociation of the Relativistic Li Nucleus into the H + He Channel
The differential cross section in the transverse momentum and a total
cross section of mb for the coherent dissociation of a 3-A-GeV/
Li nucleus through the HHe channel have been measured on emulsion
nuclei. The observed dependence of the cross section is explained by the
predominant supposition of the nuclear diffraction patterns on light (C, N, O)
and heavy (Br, Ag) emulsion nuclei. The contributions to the cross section from
nuclear diffraction ( MeV/) and Coulomb MeV/)
dissociations are calculated to be 40.7 and 4 mb, respectively.Comment: ISSN 0021-3640, Pleiades Publishing, Ltd., 200
A systematic review comparing the evidence for kidney function outcomes between oral antidiabetic drugs for type 2 diabetes.
Background: The development of kidney disease is a serious complication among people with type 2 diabetes mellitus, associated with substantially increased morbidity and mortality. Â We aimed to summarise the current evidence for the relationship between treatments for type 2 diabetes and long-term kidney outcomes, by conducting a systematic search and review of relevant studies. Methods: We searched Medline, Embase and Web of Science, between 1st January 1980 and 15th May 2018 for published clinical trials and observational studies comparing two or more classes of oral therapy for type 2 diabetes. We included people receiving oral antidiabetic drugs. Studies were eligible that; (i) compared two or more classes of oral therapy for type 2 diabetes; (ii) reported kidney outcomes as primary or secondary outcomes; (iii) included more than 100 participants; and (iv) followed up participants for 48 weeks or more. Kidney-related outcome measures included were Incidence of chronic kidney disease, reduced eGFR, increased creatinine, 'micro' and 'macro' albuminuria. Results: We identified 15 eligible studies, seven of which were randomised controlled trials and eight were observational studies. Reporting of specific renal outcomes varied widely. Due to variability of comparisons and outcomes meta-analysis was not possible. The majority of comparisons between treatment with metformin or sulfonylurea indicated that metformin was associated with better renal outcomes. Little evidence was available for recently introduced treatments or commonly prescribed combination therapies. Conclusions: Comparative evidence for the effect of treatments for type 2 diabetes on renal outcomes, either as monotherapy or in combination is sparse
Electromagnetic vertex function of the pion at T > 0
The matrix element of the electromagnetic current between pion states is
calculated in quenched lattice QCD at a temperature of . The
nonperturbatively improved Sheikholeslami-Wohlert action is used together with
the corresponding improved vector current. The electromagnetic
vertex function is extracted for pion masses down to and
momentum transfers .Comment: 17 pages, 8 figure
Photoproduction of Long-Lived Holes and Electronic Processes in Intrinsic Electric Fields Seen through Photoinduced Absorption and Dichroism in Ca_3Ga_{2-x}Mn_xGe_3O_{12} Garnets
Long-lived photoinduced absorption and dichroism in the
Ca_3Ga_{2-x}Mn_xGe_3O_{12} garnets with x < 0.06 were examined versus
temperature and pumping intensity. Unusual features of the kinetics of
photoinduced phenomena are indicative of the underlying electronic processes.
The comparison with the case of Ca_3Mn_2Ge_3O_{12}, explored earlier by the
authors, permits one to finally establish the main common mechanisms of
photoinduced absorption and dichroism caused by random electric fields of
photoproduced charges (hole polarons). The rate of their diffusion and
relaxation through recombination is strongly influenced by the same fields,
whose large statistical straggling is responsible for a broad continuous set of
relaxation components (observed in the relaxation time range from 1 to about
1000 min). For Ca_3Ga_{2-x}Mn_xGe_3O_{12}, the time and temperature dependences
of photoinduced absorption and dichroism bear a strong imprint of structure
imperfection increasing with x.Comment: 20 pages, 10 figure
ASSESSMENT OF REFRACTORY GOLD-BEARING ORES BASED OF INTERPRETATION OF THERMAL ANALYSIS DATA
The article presents the results of a study on the possibility to assess refractory gold-bearing ores using thermal analysis data. It studies the flotation concentrates obtained during the enrichment of double refractory sulfide gold-bearing ores. This type of ore is complicated by the fine impregnation of gold in sulphide minerals and the presence of sorption-active scattered carbonaceous matter, which is in close association with sulphides. The results of thermogravimetric and mass spectrometric studies of refractory gold-bearing ores are presented.
The obtained fragments for kerogen CH (m/z = 15), C2H (m/z = 29) and C3H (m/z = 43) indicate the presence of various types of carbonaceous matter in the studied samples. It is justified that the degree of sorption activity of carbonaceous matter depends on the presence of kerogen and bitumen in the ore. High sorption activity of scattered carbonaceous material significantly affects the processing technology of ores and concentrates, both flotation and pyro- and hydrometallurgical methods.
Thermogravimetric and mass spectroscopic analyzes can be used to determine the degree of preg-robbing of refractory gold-bearing ores. The obtained results predetermine the direction of creating new methods and technologies in the field of decarburization of refractory gold-bearing ores in the integrated development of solid minerals in the mining regions of Russia
Field dependence of magnetization reversal by spin transfer
We analyse the effect of the applied field (Happl) on the current-driven
magnetization reversal in pillar-shaped Co/Cu/Co trilayers, where we observe
two different types of transition between the parallel (P) and antiparallel
(AP) magnetic configurations of the Co layers. If Happl is weaker than a rather
small threshold value, the transitions between P and AP are irreversible and
relatively sharp. For Happl exceding the threshold value, the same transitions
are progressive and reversible. We show that the criteria for the stability of
the P and AP states and the experimentally observed behavior can be precisely
accounted for by introducing the current-induced torque of the spin transfer
models in a Landau-Lifschitz-Gilbert equation. This approach also provides a
good description for the field dependence of the critical currents
Mitogenomics and the genetic differentiation of contemporary <i>Balaena mysticetus</i> (Cetacea) from Svalbard
Full mitochondrial genomes were assembled for 12 recently sampled animals from the Svalbard bowhead whale (Balaena mysticetus) stock via high-throughput sequencing data, facilitating analysis of the demographic history of the population for the first time. The Svalbard population has retained noticeable amounts of mitochondrial genome diversity despite extreme historical harvest levels. Haplotype and nucleotide diversities were similar to those estimated earlier for other bowhead whale populations. The reconstructed demographic history was in accordance with a boom–bust scenario, combining a slight Pleistocene population growth 25 000–35 000 years ago and a Holocene decline. Employing a mutation rate of 3.418 × 10–8 substitutions per site per year, the time to the most recent common ancestor for the mitochondrial genomes of the contemporary Svalbard bowhead whales was estimated to be 68 782 (54 353–83 216) years before the present. Based on 370 bp fragments of the D-loop region, significant genetic differentiation was detected between all extant bowhead whale populations across the circumpolar Arctic. Thus, the Svalbard bowhead whales can be regarded as a population with its own genetic legacy
Use of the Alaskan Beaufort Sea by Bowhead Whales (Balaena mysticetus) Tagged with Satellite Transmitters, 2006 – 18
We used satellite telemetry to examine bowhead whale movement behavior, residence times, and dive behavior in the Alaskan Beaufort Sea, 2006 – 18. We explored the timing and duration of use of three subregions (western, central, eastern) within the Alaskan Beaufort Sea and applied a two-state switching state-space model to infer bowhead whale behavior state as either transiting or lingering. Transiting whales made direct movements whereas lingering whales changed direction frequently and were presumably feeding. In spring, whales migrated across the Alaskan Beaufort Sea in 7.17 ± 0.41 days, primarily off the continental shelf over deep water. During the autumn migration, whales spent over twice as much time crossing the Alaskan Beaufort Sea than in spring, averaging 18.66 ± 2.30 days, spending 10.05 ± 1.22 days in the western subregion near Point Barrow. Most whales remained on the shelf during the autumn migration and frequently dove to the seafloor, where they spent 45% of their time regardless of behavioral state. Consistent dive behavior in autumn suggests that the whales were looking for food while migrating, and the identification of lingering locations likely reflects feeding. The lack of lingering locations in the eastern and central subregions suggests that prey densities are rarely sufficient to warrant whales pausing their migration for multiple days, unlike in the western subregion near Point Barrow, where bowhead whales regularly lingered for long periods of time.À l’aide de la télémétrie satellitaire, nous avons examiné les comportements de déplacement des baleines boréales, leurs temps de séjour et leurs comportements de plongée dans les eaux alaskiennes de la mer de Beaufort entre 2006 et 2018. Nous avons exploré le moment et la durée d’utilisation de trois sous-régions (ouest, centre et est) des eaux alaskiennes de la mer de Beaufort et appliqué un modèle à changement binaire espace-état afin de déduire l’état du comportement des baleines boréales comme étant soit en mode transit, soit en mode flânerie. Les baleines en mode transit se déplaçaient de manière directe, tandis que celles en mode flânerie changeaient souvent de direction et étaient probablement en train de se nourrir. Au printemps, les baleines migraient dans les eaux alaskiennes de la mer de Beaufort en 7,17 ± 0,41 jours, principalement au large du plateau continental, dans les profondeurs. Durant la migration automnale, les baleines passaient plus de deux fois plus de temps à traverser les eaux alaskiennes de la mer de Beaufort qu’au printemps, en moyenne 18,66 ± 2,30 jours, passant 10,05 ± 1,22 jours dans la sous-région de l’ouest, près de Point Barrow. Pendant la migration automnale, la plupart des baleines restaient dans le plateau continental et plongeaient souvent jusqu’au plancher océanique, où elles passaient 45 % de leur temps, peu importe leur état de comportement. À l’automne, le comportement de plongée régulier suggère que les baleines étaient à la recherche de nourriture pendant leur migration, et les lieux où elles flânaient étaient vraisemblablement indicateurs d’un mode d’alimentation. L’absence de lieux de flânerie dans les sous-régions de l’est et du centre suggère que la densité des proies est rarement suffisante pour que les baleines justifient d’interrompre leur migration pendant plusieurs jours, contrairement à la sous-région de l’ouest, près de Point Barrow, où les baleines boréales flânaient régulièrement pendant de longues périodes
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