First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment.

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9 GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36 GeV/c^{2}, rejecting cross sections above 9.2×10^{-48} cm at the 90% confidence level.

Unusual Near-Horizon Cosmic-Ray-like Events Observed by ANITA-IV.

ANITA's fourth long-duration balloon flight in 2016 detected 29 cosmic-ray (CR)-like events on a background of 0.37_{-0.17}^{+0.27} anthropogenic events. CRs are mainly seen in reflection off the Antarctic ice sheets, creating a phase-inverted waveform polarity. However, four of the below-horizon CR-like events show anomalous noninverted polarity, a p=5.3×10^{-4} chance if due to background. All anomalous events are from locations near the horizon; ANITA-IV observed no steeply upcoming anomalous events similar to the two such events seen in prior flights.

Observation of an Unusual Upward-Going Cosmic-Ray-like Event in the Third Flight of ANITA.

We report on an upward traveling, radio-detected cosmic-ray-like impulsive event with characteristics closely matching an extensive air shower. This event, observed in the third flight of the Antarctic Impulsive Transient Antenna (ANITA), a NASA-sponsored long-duration balloon payload, is consistent with a similar event reported in a previous flight. These events could be produced by the atmospheric decay of an upward-propagating τ lepton produced by a ν_{τ} interaction, although their relatively steep arrival angles create tension with the standard model neutrino cross section. Each of the two events have a posteriori background estimates of ≲10^{-2} events. If these are generated by τ-lepton decay, then either the charged-current ν_{τ} cross section is suppressed at EeV energies, or the events arise at moments when the peak flux of a transient neutrino source was much larger than the typical expected cosmogenic background neutrinos.

Characteristics of Four Upward-Pointing Cosmic-Ray-like Events Observed with ANITA.

We report on four radio-detected cosmic-ray (CR) or CR-like events observed with the Antarctic Impulsive Transient Antenna (ANITA), a NASA-sponsored long-duration balloon payload. Two of the four were previously identified as stratospheric CR air showers during the ANITA-I flight. A third stratospheric CR was detected during the ANITA-II flight. Here, we report on characteristics of these three unusual CR events, which develop nearly horizontally, 20-30 km above the surface of Earth. In addition, we report on a fourth steeply upward-pointing ANITA-I CR-like radio event which has characteristics consistent with a primary that emerged from the surface of the ice. This suggests a possible τ-lepton decay as the origin of this event, but such an interpretation would require significant suppression of the standard model τ-neutrino cross section.

Detection of pulsed gamma rays above 100 GeV from the Crab pulsar.

We report the detection of pulsed gamma rays from the Crab pulsar at energies above 100 giga-electron volts (GeV) with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) array of atmospheric Cherenkov telescopes. The detection cannot be explained on the basis of current pulsar models. The photon spectrum of pulsed emission between 100 mega-electron volts and 400 GeV is described by a broken power law that is statistically preferred over a power law with an exponential cutoff. It is unlikely that the observation can be explained by invoking curvature radiation as the origin of the observed gamma rays above 100 GeV. Our findings require that these gamma rays be produced more than 10 stellar radii from the neutron star.

Radio imaging of the very-high-energy gamma-ray emission region in the central engine of a radio galaxy.

The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10(12) electron volts and are bright sources of very-high-energy (VHE) gamma-ray emission, it is not yet known where the VHE emission originates. Here we report on radio and VHE observations of the radio galaxy Messier 87, revealing a period of extremely strong VHE gamma-ray flares accompanied by a strong increase of the radio flux from its nucleus. These results imply that charged particles are accelerated to very high energies in the immediate vicinity of the black hole.

Incommensurate strain-induced ordering of interstitial oxygen in Nb.

We present a semi-phenomenological theory of the strain-induced interaction between interstitial oxygen dissolved in Nb and predict an incommensurate oxygen ordering wave which is mediated by the intrinsic bcc instability at k = 2/3(111). We discuss the stability range of this ordering phenomenon, which may play a role in the performance of Nb radio frequency (RF) cavities for high energy particle accelerators.

Competition between order and phase separation in Au-Ni.

We have measured and theoretically analyzed the diffuse scattering in the binary alloy system Au-Ni, which has been proposed as a testing ground for theories of alloy phase stability. We found strong evidence that in the alloys Au3Ni and Au3Ni2, fluctuations of both ordering- and clustering-type are competing with each other. Our results resolve a long-standing controversy on the balance of relaxation and mixing energies in this alloy system and explain recent findings of ordering in thin Au-Ni films.

Absence of 2kF splitting in the diffuse scattering from Cu3Au at the (001) surface.

We report a new type of short-range order correlations at the (001) surface of Cu3Au which no longer produces the 2k(F)-splitting characteristic for the bulk short-range order scattering. We present the temperature dependence of this phenomenon and a theoretical interpretation of its origin. We argue that this new surface effect is caused by a drastic change of the strain-induced interactions at the surface.

Strain-induced nonanalytic short-range order in the spin glass Cu(83)Mn(17).

We present a theoretical and experimental study of the effect of lattice distortions on the short-range order and the energetics of ordering binary alloys. Applying a reciprocal space approach which accounts for the elastic response of the lattice, the diffuse scattering of the model system Cu(83)Mn(17) can be explained with only a few physical parameters. The model calculations point to a nonanalytic diffuse intensity at q = 0. X-ray scattering experiments are presented providing clear evidence for this phenomenon which carries detailed information on the strain-induced interaction.

[The concept of constructing a uniform state information system on transplantation in Ukraine]. / Kontseptsiia postroeniia edinoi gosudarstvennoi informatsionnoi sistemy transplantatsii v Ukraine.

A conception is submitted of setting-up a state information system of transplantation in Ukraine (Ukrtransplant) integrated into systems of transplantation of other countries (the European Bank of Transplants-Eurotransplant-included). The information system Ukrtransplant is designed for automatization of processes of taking, genetic and tissue typing, reliable and safe preservation of organs and tissues, delivery of data from the State Register (the bank of data on graft donors and recipients), processing of information about availability of and demand for organs and transplantations performed, and for speedy providing all forms and activities of the state system Ukrtransplant with valid information incident to managerial/administrative matters.

[Balanced vegetarian diet in combined rehabilitation of patients suffering from ischemic heart disease]. / Opyt ispol'zovaniia sbalansirovannoi vegetarianskoi diety v kompleksnoi reabilitatsii bol'nykh izhemicheskoi bolezn'iu serdtsa.

The clinical status of 30 patients suffering from ischemic heart disease, their serum lipids and other biochemical parameters, exercise tolerance were studied. 20 patients from the group were on a specially developed antiatherosclerosis vegetarian diet VA-1; the control group comprised 10 patients who had a mixed diet A-1. It is shown that the vegetarian diet used made it possible to normalize the serum lipid spectrum, the levels of the blood pressure, to increase the tolerance to exercise, to eliminate functional disturbances of the digestive system. The investigation demonstrated the effectiveness of the vegetarian diet as a means of rehabilitation of patients suffering from ischemic heart disease.

[Feasibility of correcting lipid metabolism in patients with cardiovascular diseases using a balanced vegetarian diet]. / Vozmozhnosti korrektsii obmena lipidov u bol'nykh s serdechno-sosudistoi patologiei s pomoshch'iu sbalansirovannoi vegetarianskoi diety.

The spectrum of lipids in 20 patients with dyslipoproteinemia type IIa and IIb (group I and group II) was studied. The patients were treated for 24 days with a lactoovovegetarian diet used for the first time in the country. No drugs were employed. A decrease in the levels of cholesterol, atherogenic lipoproteins and atherogenic coefficient was observed after the treatment. The patients, who were offered a questionnaire highly appreciated the diet.

[Level and pattern of morbidity of children residing in the Ukrainian S.S.R. exposed to radioactive pollution as the result of the Chernobyl AES accident]. / Uroven' i struktura zabolevaemosti detei, prozhivaiushchikh na territoriiakh USSR, podvergshikhsia radioaktivnomu zagriazneniiu v rezul'tate avarii na Chernobyl'skoi AES.

It has been shown that there is a significant increase in total morbidity in children residing in the areas exposed to radioactive pollution due to the accident at the Chernobyl Atomic Power Station. This is due largely to higher morbidity of respiratory disease. There is also an increased in the incidence of digestive diseases, iron-deficiency anemias, mental disorders. The recorded growth of childhood morbidity in the areas examined is much higher than that in the children living in other areas unexposed to radioactive pollution.

[Specifics of surgical approach in purulent cholangitis]. / Osobennosti khirurgicheskoi taktiki pri gnoinom kholangite.

When analysing the results of examination of 773 patients with obstructive jaundice (OJ) of benign genesis, purulent cholangitis (PC) was revealed in 323. In PC diagnosis, the ultrasound study is a valuable adjunctive method. In presence of the clinical signs of PC in patients and absence of the effect from conservative therapy, and as well in preservation of the high indices of bilirubinemia, the early operative treatment performed, as a rule, no later than 48 h after hospitalization is indicated. PC in patients with OJ is most frequently caused by choledocholithiasis. The causative agents of PC are represented by aerobic and anaerobic microorganisms, requiring the use of broad spectrum antibiotics before the operation and 6-12 h after it. Adequate restoration of bile passage and pathogenetically substantiated local influencing upon the inflammatory process in the bile ducts are tasks of operative intervention. Direct administration into the bile ducts of antibiotics and antiinflammatory preparations, in particular of quercitrol, via the external drain of the common bile duct is expedient.

[Peculiarities of the functional parameters of performance in late ontogenesis]. / Besonderheiten funktioneller Parameter der Leistungsfähigkeit in der späten Ontogenese.

The age parameters of physiological characteristic values of the capability of 647 persons doing non-mechanised work in agriculture and of 799 practically healthy machine operators and female machine sewers were determined. Data on the adaptabilities of physiological functions were obtained that are responsible for the activity at physical work. The functional importance of changes of the organism in ontogenesis for maintaining the occupational capability is reviewed. It was found that the nervous system and the muscular system as well as the cardiovascular system restrict the job opportunities of age workers. With self-determined pace and rhythm of work the nervous and muscular system of aged people shows long-term capability.