Occupational segregation in a Roy model with composition preferences

We propose a model of labor market sector self-selection that combines comparative advantage, as in the Roy model, and sector composition preference. Two groups choose between two sectors based on heterogeneous potential incomes and group compositions in each sector. Potential incomes incorporate group specific human capital accumulation and wage discrimination. Composition preferences are interpreted as reflecting group specific amenity preferences as well as homophily and aversion to minority status. We show that occupational segregation is amplified by the composition preferences and we highlight a resulting tension between redistribution and diversity. The model also exhibits tipping from extreme compositions to more balanced ones. Tipping occurs when a small nudge, associated with affirmative action, pushes the system to a very different equilibrium, and when the set of equilibria changes abruptly when a parameter governing the relative importance of pecuniary and composition preferences crosses a threshold

Ирано-Азербайджанские отношения в первый год президентства М. Хатами

The article is devoted to the study of the Iran-Azerbaijan relations during the first year of Muhammad Khatami’s presidency. The main task of the research is to follow the evolution of Iran-Azerbaijan relations during that period, to describe the most important events of these relations and to find an answer to the question why such a successful beginning of the period led Iran and Azerbaijan to the verge of a diplomatic catastrophe. The coming of the liberal president Khatami to power in Iran created an opportunity to overcome mutual mistrust in the Iran-Azerbaijan relations and to direct them into a constructive course. The fact that in 1997-1998 Iran and Azerbaijan foreign policy agendas partly coincided also contributed to this concept. The first serious attempts to stabilize the Iran-Azerbaijan relations were made during the eighth OIC summit in Tehran, when Iran initiated passing of several documents, condemning the actions of Armenia in the Karabakh conflict. However, this proved insufficient to stabilize the relationship. Soon, because of problems in ethnic and energy spheres the Iran-Azerbaijan relations began rapidly to deteriorate. The priority given to relations with the United States by Azerbaijan served as an additional source of irritation for Iran. That eventually became the main reason for Iran to change its position on the international legal status of the Caspian Sea that created the basis for Iranian claims to Azerbaijan oilfields. In three years dramatic events of the first year of Khatami presidency led Iran and Azerbaijan to a military conflict in the Caspian Sea when Iranian warships drove away Azerbaijan research vessels from a contract zone Araz-Alov-Sharg

Trapping ultracold atoms at 100 nm from a chip surface in a 0.7-micrometer-period magnetic lattice

We report the trapping of ultracold 87Rb atoms in a 0.7 micron-period 2D triangular magnetic lattice on an atom chip. The magnetic lattice is created by a lithographically patterned magnetic Co/Pd multilayer film plus bias fields. Rubidium atoms in the F=1, mF=-1 low-field seeking state are trapped at estimated distances down to about 100 nm from the chip surface and with calculated mean trapping frequencies as high as 800 kHz. The measured lifetimes of the atoms trapped in the magnetic lattice are in the range 0.4 - 1.7 ms, depending on distance from the chip surface. Model calculations suggest the trap lifetimes are currently limited mainly by losses due to surface-induced thermal evaporation following loading of the atoms from the Z-wire trap into the very tight magnetic lattice traps, rather than by fundamental loss processes such as surface interactions, three-body recombination or spin flips due to Johnson magnetic noise. The trapping of atoms in a 0.7 micrometer-period magnetic lattice represents a significant step towards using magnetic lattices for quantum tunneling experiments and to simulate condensed matter and many-body phenomena in nontrivial lattice geometries.Comment: 11 pages, 7 figure

Geomagnetic Survey Interpolation with the Machine Learning Approach

This paper portrays the method of UAV magnetometry survey data interpolation. The method accommodates the fact that this kind of data has a spatial distribution of the samples along a series of straight lines (similar to maritime tacks), which is a prominent characteristic of many kinds of UAV surveys. The interpolation relies on the very basic Nearest Neighbours algorithm, although augmented with a Machine Learning approach. Such an approach enables the error of less than 5 percent by intelligently adjusting the Nearest Neighbour algorithm parameters. The method was pilot tested on geomagnetic data with Borok Geomagnetic Observatory UAV aeromagnetic survey data

Substantiation of Parameters and Operating Modes for the Bunch Planting Device of the Pneumatic Seeder

Abstract The purpose of this work is to develop a dosing system that provides high-quality bunch planting of watermelon seeds with a given seeding rate and their uniform distribution over the plant nutrition area. It is important to know how many seeds it is needed in the bunch in order to provide the required number of plants in a certain plant nutrition area. The method to achieve this goal is to determine the optimal operating modes for the seeding device, in which the dosing system would supply the seed to the bunch without gaps, searching for dependencies that can determine the required number of the sown seeds in the bunch, taking into account their germination and the number of plants specified by agrotechnical conditions in every bunch. Based on the obtained dependencies, determining the probability of bunches with various numbers of plants, while sowing four seeds in the seedbed with maximum field germination, the design of experimental seed discs is proposed, allowing bunch planting and germination due to easy destruction of the soil crust. At the same time, optimal use of the nutritional area for plants, and, consequently, an increase in the yield of the sown crops is ensured. Experimental seed discs with a group arrangement of suction holes (four cells each) will provide bunch planting of watermelon seeds in accordance with agrotechnical requirements

Phototherapy of Alzheimer’s Disease: Photostimulation of Brain Lymphatics during Sleep: A Systematic Review

The global number of people with Alzheimer’s disease (AD) doubles every 5 years. It has been established that unless an effective treatment for AD is found, the incidence of AD will triple by 2060. However, pharmacological therapies for AD have failed to show effectiveness and safety. Therefore, the search for alternative methods for treating AD is an urgent problem in medicine. The lymphatic drainage and removal system of the brain (LDRSB) plays an important role in resistance to the progression of AD. The development of methods for augmentation of the LDRSB functions may contribute to progress in AD therapy. Photobiomodulation (PBM) is considered to be a non-pharmacological and safe approach for AD therapy. Here, we highlight the most recent and relevant studies of PBM for AD. We focus on emerging evidence that indicates the potential benefits of PBM during sleep for modulation of natural activation of the LDRSB at nighttime, providing effective removal of metabolites, including amyloid-β, from the brain, leading to reduced progression of AD. Our review creates a new niche in the therapy of brain diseases during sleep and sheds light on the development of smart sleep technologies for neurodegenerative diseases.RSFRF GovernmentalAcademic leadership program Priority 2030 proposed by the First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University)Peer Reviewe

Radiofrequency spectroscopy of a linear array of Bose-Einstein condensates in a magnetic lattice

We report site-resolved radiofrequency spectroscopy measurements of Bose-Einstein condensates of 87Rb atoms in about 100 sites of a one-dimensional 10 micron-period magnetic lattice produced by a grooved magnetic film plus bias fields. Site-to-site variations of the trap bottom, atom temperature, condensate fraction and chemical potential indicate that the magnetic lattice is remarkably uniform, with variations in trap bottoms of only +/- 0.4 mG. At the lowest trap frequencies (radial and axial frequencies 1.5 kHz and 260 Hz, respectively), temperatures down to 0.16 microkelvin are achieved in the magnetic lattice and at the smallest trap depths (50 kHz) condensate fractions up to 80% are observed. With increasing radial trap frequency (up to 20 kHz, or aspect ratio up to about 80) large condensate fractions persist and the highly elongated clouds approach the quasi-1D Bose gas regime. The temperature estimated from analysis of the spectra is found to increase by a factor of about five which may be due to suppression of rethermalising collisions in the quasi-1D Bose gas. Measurements for different holding times in the lattice indicate a decay of the atom number with a half-life of about 0.9 s due to three-body losses and the appearance of a high temperature (about 1.5 microkelvin) component which is attributed to atoms that have acquired energy through collisions with energetic three-body decay products

The “NMDNI” Project

The article is devoted to the study of the social reception of the Soviet past in the contemporary Russian media practice. The authors proceeded from the hypothesis that the specifics of the reproduction and perception of media images representing the Soviet period of history can be revealed through the social phenomenon of nostalgia. The authors distinguish two types of nostalgia: reflexive and restorative. The research interest is focused on the reflexive type of nostalgia as a process of formation of mythologized and idealized images of the past. In addition, the study uses the concept of post-memory proposed by M. Hirsch. Leonid Parfyonov’s Internet project “NMDNI” was used as an example of such a mediator, which also represents a reflexive type of nostalgia. The purpose of the study was the viewers’ reaction to the content of the project. Thus, the aim of the article is to study the impact of the media strategies of constructing the image of the USSR on the YouTube audience. Active viewers’ reaction in the YouTube-project “NMDNI” allows us to consider Leonid Parfyonov as a significant subject of the construction of the post-memory of the Soviet Union. As a result of the analysis of the most popular comments, it was concluded that there is a public demand for reflective nostalgia as a way of perceiving the Soviet past