Urban Squatting: An Adaptive Response to the Housing Crisis

From introduction: Urban squatting is the unauthorized occupation of empty buildings. Squatting is usually thought to be a Third World phenomenon associated with urbanization, poverty, and rural-urban migration. However, there is a history of squatting in the US and Europe as well. Squatting has been reported in New York, San Francisco, Newark, Boston, Philadelphia, Detroit, and Los Angeles. Since World War II and particularly in the last thirty years, urban squatting has received much attention in Europe. The major European centers for squatting have been London, Amsterdam, and Berlin.\u27 In Britain, the squatting of buildings scheduled for renovation or demolition became an organized and public movement. In the United States, squatting is a criminal offense and has not been widely publicized. Squatting has a dual purpose. It can provide immediate shelter while being a political tactic to draw attention to neighborhood neglect, the lack of available and affordable. low-cost housing, the dwindling stock of housing, and homelessness. This direct-action technique serves to empower its participants who are usually people disempowered through their participation in the housing system. Squatting has a long history in the United States. It was a common form of tenure during the pioneer and settler days of this country. The homesteading acts of the nineteenth century institutionalized it. Since then we have had different terms for the same actions. Whereas homesteading is a legal and institutionalized means of taking over and rehabilitating an abandoned building, squatting is not. Squatting is most common during periods of economic recession or depression. During the Great Depression, many squats or shantytowns appeared in towns all over the country. These Hoovervilles protested the lack of government response to the financial crisis. Additionally, they were organized and focused on mutual aid

Urban Squatting: An Adaptive Response to the Housing Crisis

From introduction: Urban squatting is the unauthorized occupation of empty buildings. Squatting is usually thought to be a Third World phenomenon associated with urbanization, poverty, and rural-urban migration. However, there is a history of squatting in the US and Europe as well. Squatting has been reported in New York, San Francisco, Newark, Boston, Philadelphia, Detroit, and Los Angeles. Since World War II and particularly in the last thirty years, urban squatting has received much attention in Europe. The major European centers for squatting have been London, Amsterdam, and Berlin.\u27 In Britain, the squatting of buildings scheduled for renovation or demolition became an organized and public movement. In the United States, squatting is a criminal offense and has not been widely publicized. Squatting has a dual purpose. It can provide immediate shelter while being a political tactic to draw attention to neighborhood neglect, the lack of available and affordable. low-cost housing, the dwindling stock of housing, and homelessness. This direct-action technique serves to empower its participants who are usually people disempowered through their participation in the housing system. Squatting has a long history in the United States. It was a common form of tenure during the pioneer and settler days of this country. The homesteading acts of the nineteenth century institutionalized it. Since then we have had different terms for the same actions. Whereas homesteading is a legal and institutionalized means of taking over and rehabilitating an abandoned building, squatting is not. Squatting is most common during periods of economic recession or depression. During the Great Depression, many squats or shantytowns appeared in towns all over the country. These Hoovervilles protested the lack of government response to the financial crisis. Additionally, they were organized and focused on mutual aid

Machine Learning Technologies and Psychological Testing of Pre-School and Primary School-Aged Children in Diagnostics of Perinatal Affection of the Central Nervous System

The present study deals with computer-assisted learning technologies used for the analysis of psychological test results of children to diagnosis perinatal affection of the central nervous system. The mathematical models of logistic regression and gradient boosting give the best results within the accuracy of 81%. Keywords: Machine learning, children, central nervous system, perinatal affection

Effect of in-plane magnetic field on the photoluminescence spectrum of modulation-doped quantum wells and heterojunctions

The photoluminescence (PL) spectrum of modulation-doped GaAs/AlGaAs quantum wells (MDQW) and heterojunctions (HJ) is studied under a magnetic field ($B_{\|}$) applied parallel to the two-dimensional electron gas (2DEG) layer. The effect of $B_{\|}$ strongly depends on the electron-hole separation ($d_{eh}$), and we revealed remarkable $B_{\|}$-induced modifications of the PL spectra in both types of heterostructures. A model considering the direct optical transitions between the conduction and valence subband that are shifted in k-space under $B_{\|}$, accounts qualitatively for the observed spectral modifications. In the HJs, the PL intensity of the bulk excitons is strongly reduced relatively to that of the 2DEG with increasing $B_{\|}$. This means that the distance between the photoholes and the 2DEG decreases with increased $B_{\|}$, and that free holes are responsible for the hole-2DEG PL.Comment: 6pages, 5figure

Spin polarized electric currents in semiconductor heterostructures induced by microwave radiation

We report on microwave (mw) radiation induced electric currents in (Cd,Mn)Te/(Cd,Mg)Te and InAs/(In,Ga)As quantum wells subjected to an external in-plane magnetic field. The current generation is attributed to the spin-dependent energy relaxation of electrons heated by mw radiation. The relaxation produces equal and oppositely directed electron flows in the spin-up and spin-down subbands yielding a pure spin current. The Zeeman splitting of the subbands in the magnetic field leads to the conversion of the spin flow into a spin-polarized electric current.Comment: 3 pages, 4 figure

Medicinal Chemistry of Oligonucleotide Drugs - Milestones of the Past and Visions for the Future

The oligonucleotide therapeutics field has blossomed in recent years, with thirteen approved drugs today and the promise of accelerated growth in coming years. Much of the progress in this field is due to advances in the medicinal chemistry of oligonucleotides,combined with a judicious choice of molecular targets and disease areas. In this perspective, we describe the growth of this new class of drugs highlighting selected milestones in oligonucleotide medicinal chemistry

Amphibole: A major carrier of helium isotopes in crustal rocks

The first evidence for a specific role of amphiboles in He isotope balance of crustal rocks was presented in early contributions by Gerling et al. (1971, 1976). Since then it was shown that 4He and 3He concentrations in amphiboles generally exceed those in the host rock samples. Recently amphibole was considered as an important carrier of noble gases and other volatiles components in the course of their subduction into the mantle. This paper presents new data on the balance and mobility of noble gas isotopes and major gas constituents in amphibole separates in order to understand sources and evolution of volatile components of 2666 Ma old alkaline granites from Ponoy massif (Kola Peninsula), which underwent metamorphism 1802 Ma ago.In the amphiboles 3He, 4He and 40Ar* were dominantly produced in situ due to radioactive decay of the parent isotopes and associated nuclear reactions. A small fraction of He (≈ 3% of the total) is liberated by crushing and shows 3He/4He ratio indistinguishable from that found by total extraction. The fraction of trapped 40Ar* amounts to ≈ 40%; both these fractions presumably occupy fluid inclusions and show rather low 4He/40Ar* ≈ 0.1, a factor of ≈ 150 below the production ratio (calculated assuming no loss / gain of the species has happened since the time of metamorphism).3He has been better preserved in amphiboles compared with 4He: the retention parameter (measured amount of He / totally produced amount) for 3He (≈ 0.4) exceeds that for 4He (≈ 0.15).He extraction by fast and slow linear heating of amphiboles resulted in different release patterns. The fast heating (within 12 to 40 °C min− 1) revealed a superposition of two peaks. When heating with slower heating rate (below 8 °C min− 1) was applied, the high-temperature peak disappeared (the “disappearing site”). Extractions of He atoms from grain and powder samples at different heating rates have shown that: (1) the “disappearing site” is revealed by the fast heating analyses of different amphibole samples but not only those from the Ponoy massif; (2) amount of He liberated from the “disappearing site” is variable and generally much less than the total amount of He in the sample; (3) analysis of the powder produced in the crushing experiments never reveals the “disappearing site”; the temperature of He release from the powder is lower than that from the mm grain size sample by ≈ 50 °C. Possible explanations of the nature of the “disappearing site” are discussed. However, independently on nature of this effect, repeated gas extractions by heating at different rates would give additional information about structure and its transformation during heating of amphiboles.The simplest explanation of the observed abundances of noble gas isotopes in the amphibole separates from Ponoy granites suggests local production, redistribution and partial loss of noble gases during evolution of the massif

Shake-up Processes in a Low-Density Two-Dimensional Electron Gas: Spin-Dependent Transitions to Higher Hole Landau Levels

A theory of shake-up processes in photoabsorption of an interacting low-density two-dimensional electron gas (2DEG) in strong magnetic fields is presented. In these processes, an incident photon creates an electron-hole pair and, because of Coulomb interactions, simultaneously excites one particle to higher Landau levels (LL's). In this work, the spectra of correlated charged spin-singlet and spin-triplet electron-hole states in the first hole LL and optical transitions to these states (i.e., shake-ups to the first hole LL) are studied. Our results indicate, in particular, the presence of optically-active three-particle quasi-discrete states in the exciton continuum that may give rise to surprisingly sharp Fano resonances in strong magnetic fields. The relation between shake-ups in photoabsorption of the 2DEG and in the 2D hole gas (2DHG), and shake-ups of isolated negative X^- and positive X^+ trions are discussed.Comment: 8 pages, 8 figures. References updated, one figure added (Fig. 6). Accepted in Phys. Rev.