Another Look at Persistent Inequality in Israeli Education

This is a study of change in inequality of educational opportunity in Israel. Recent studies in Israel and elsewhere have found declining inequality of opportunity at the primary and secondary levels of education coupled with more persistent inequality at higher levels. However, these studies ignore the fact that the relative value of qualifications change as education expands over time. Many scholars agree that that the value of qualifications lies in their relative position in the distribution of education. And yet, in empirical research education is typically represented in absolute rather than relative terms. I analyze all available Israeli mobility data for the cohorts born between1951-1981 and estimate models of both absolute and relative education, as well as of education recoded into its earning value. When education is defined in absolute terms, I find the familiar decline in the effects of parents’ education. When it is measured in terms of its earning value or in relative terms, the results show significant increases in the effect of parents’ education on education. I also study change in the effects of ethnicity and of gender.

Freely flowing currents and electric field expulsion in viscous electronics

Electronic fluids bring into hydrodynamics a new setting: equipotential flow sources embedded inside the fluid. Here we show that nonlocal relation between current and electric field due to momentum-conserving inter-particle collisions leads to a total or partial field expulsion from such flows. That results in freely flowing currents in the bulk and boundary jump in electric potential at current-injecting electrodes. We derive the appropriate boundary conditions, analyze current distribution in free flows, discuss how the field expulsion depends upon geometry of the electrode, and link the phenomenon to breakdown of conformal invariance.Comment: 5 pages, 2 figure

Generative Compression

Traditional image and video compression algorithms rely on hand-crafted encoder/decoder pairs (codecs) that lack adaptability and are agnostic to the data being compressed. Here we describe the concept of generative compression, the compression of data using generative models, and suggest that it is a direction worth pursuing to produce more accurate and visually pleasing reconstructions at much deeper compression levels for both image and video data. We also demonstrate that generative compression is orders-of-magnitude more resilient to bit error rates (e.g. from noisy wireless channels) than traditional variable-length coding schemes

Nuclear DNA and protein content evaluation in Taxus plant cell cultures using multiparameter flow cytometry

Plant cell cultures of Taxus provide the most reliable production methods for the anti-cancer drug paclitaxel. In order to comprehend the inherent culture heterogeneity and production variability in cell cultures, it is essential that the cellular metabolism is studied at the genomic level. Genomic stability in plant cell cultures is crucial as it affects cell growth and division, metabolite accumulation and protein synthesis. A rapid and efficient method to prepare nuclei suspensions from aggregated cell cultures of Taxus was employed. Methods were subsequently developed to simultaneously stain them for DNA and protein content using Propidium Iodide and Fluorescein Isothiocyanate respectively. Flow cytometry was used to analyze and quantify the DNA content and genome size of Taxus using known reference species as standards. Furthermore, their genomic stability was evaluated by correlating DNA content and genome size with cell size and complexity, protein content, and elicitation effects using multiparameter flow cytometry. These techniques to evaluate and correlate various culture characteristics can be very useful in designing superior bio processes for enhanced production.


&#xa

Azimuthally unidirectional transport of energy in magnetoelectric fields. Topological Lenz effect

Magnetic dipolar modes (MDMs) in a quasi 2D ferrite disk are microwave energy eigenstate oscillations with topologically distinct structures of rotating fields and unidirectional power flow circulations. At the first glance, this might seem to violate the law of conservation of an angular momentum, since the microwave structure with an embedded ferrite sample is mechanically fixed. However, an angular momentum is seen to be conserved if topological properties of electromagnetic fields in the entire microwave structure are taken into account. In this paper we show that due to the topological action of the azimuthally unidirectional transport of energy in a MDM resonance ferrite sample there exists the opposite topological reaction on a metal screen placed near this sample. We call this effect topological Lenz effect. The topological Lenz law is applied to opposite topological charges, one in a ferrite sample and another on a metal screen. The MDM originated near fields, the magnetoelectric (ME) fields, induce helical surface electric currents and effective charges on a metal. The fields formed by these currents and charges will oppose their cause

Are Lock-Free Concurrent Algorithms Practically Wait-Free?

Lock-free concurrent algorithms guarantee that some concurrent operation will always make progress in a finite number of steps. Yet programmers prefer to treat concurrent code as if it were wait-free, guaranteeing that all operations always make progress. Unfortunately, designing wait-free algorithms is generally a very complex task, and the resulting algorithms are not always efficient. While obtaining efficient wait-free algorithms has been a long-time goal for the theory community, most non-blocking commercial code is only lock-free. This paper suggests a simple solution to this problem. We show that, for a large class of lock- free algorithms, under scheduling conditions which approximate those found in commercial hardware architectures, lock-free algorithms behave as if they are wait-free. In other words, programmers can keep on designing simple lock-free algorithms instead of complex wait-free ones, and in practice, they will get wait-free progress. Our main contribution is a new way of analyzing a general class of lock-free algorithms under a stochastic scheduler. Our analysis relates the individual performance of processes with the global performance of the system using Markov chain lifting between a complex per-process chain and a simpler system progress chain. We show that lock-free algorithms are not only wait-free with probability 1, but that in fact a general subset of lock-free algorithms can be closely bounded in terms of the average number of steps required until an operation completes. To the best of our knowledge, this is the first attempt to analyze progress conditions, typically stated in relation to a worst case adversary, in a stochastic model capturing their expected asymptotic behavior.Comment: 25 page