Hot Electrons and Cold Photons: Galaxy Clusters and the Sunyaev-Zel'dovich Effect

The hot gas in clusters of galaxies emits thermal bremsstrahlung emission that can be probed directly through measurements in the X-ray band with satellites like ROSAT and ASCA. Another probe of this gas comes from its effect on the cosmic microwave background radiation (CMBR): the hot cluster electrons inverse Compton scatter the CMBR photons and thereby distort the background radiation from its blackbody spectral form. In the last few years, the development of sensitive new instruments for measuring this distortion, called the Sunyaev-Zel'dovich (SZ) effect, has sparked a revolution in the field. Current radio interferometric arrays can now detect and map the SZ effect in even distant (z ~ 1) clusters. It is well known that one of the purposes of conducting such measurements is to determine the Hubble constant. In this review I report on the progress that has been made in this area, quote the current best estimate of Ho from the SZ effect of 8 galaxy clusters (44 - 64 km/s/Mpc +/- 17%), discuss important systematic uncertainties, and highlight what else has been learned about galaxy clusters from these investigations.Comment: 4 pages, including 2 postscript figs, LaTeX. To appear in the proceedings of IAU Symposium 188 "The Hot Universe" (held August 26-30, 1997, Kyoto, Japan

Ceramides: a new player in the inflammation-insulin resistance paradigm?

No abstract available

Error Analysis of Phonetic Fossilization Uttered by English Department Students University of PGRI Semarang

Penelitian ini bertujuan untuk menentukan tipe dan latar belakang fosilisasi fonetik yang diucapkan oleh mahasiswa semester 5 Pendidikan Bahasa Inggris di Universitas PGRI Semarang tahun 2014/2015. Penelitian ini menggunakan desain penelitian deskriptif dengan data kualitatif. Populasi dari penelitian ini adalah para mahasiswa semester 5 yang mengambil mata kuliah English Phonology dengan jumlahmahasiswa 200. Sampel penelitian adalah kelas 5E, kelas yang paling aktif dan dominan.Hasil penelitian menunjukkan bahwa hanya 15% kata di dalam kuesioner penelitian yang berhasil dilafalkan dengan baik oleh para responden. Itu artinya bahwa fosilisasi fonetik dilakukan lebih dari 75% responden. Tipe kesalahan yang dibuat adalah tipe fosilisasi fonetik baik dalam kategori perseorangan maupun kelompok, sementara itu alasan-alasan mereka melakukan kesalahan adalah; 1)Simbol fonetik yang masih tidak familier bagi mahasiswa semester. 2) Terdapat habituasi dan kebiasaan-kebiasaan yang merujuk pada dua faktor: internal dan eksternal. Faktor internalnya adalah mahasiswa itu sendiri, yang berarti motivasi untuk belajar dan hasrat untuk lebih dalam mempelajari simbol -simbol fonetik. Faktor eksternalnya merujuk pada proses pembelajaran dan sudut pandang dosen. 3) Metode yang digunakan oleh para dosen pengampu mata kuliah English Phonology and Pronounciation. Masalah ini harus diturunkan karena 90% dari mahasiswa menyatakan di dalam wawancara bahwa mereka sangat tertarik dengan subjek ini danjuga menyatakan bahwa para dosen tidak memberikan tekanan, namun faktanya persentase kesalahan dalam pelafalan di atas rata-rata.Berdasarkan pada hasil-haasil ini, peneliti memberika saran sebagai berikut; 1) Permasalahan ini menjadi tugas bagi seluruh dosen bahasa Inggris, tidak hanya dosen yang mengajar mata kuliah English Phonology and Pronunciation. 2) Simbolsimbol fonetik harus diterapkan secara intensif dan integral sehingga para mahasiswa dapat familier dengan simbol-simbol tersebut. 3) Kebutuhan akan penelitian lebih lanjut yang terkait dengan metode-metode yang digunakan oleh para dosen

Activity Identification and Local Linear Convergence of Douglas--Rachford/ADMM under Partial Smoothness

Convex optimization has become ubiquitous in most quantitative disciplines of science, including variational image processing. Proximal splitting algorithms are becoming popular to solve such structured convex optimization problems. Within this class of algorithms, Douglas--Rachford (DR) and alternating direction method of multipliers (ADMM) are designed to minimize the sum of two proper lower semi-continuous convex functions whose proximity operators are easy to compute. The goal of this work is to understand the local convergence behaviour of DR (resp. ADMM) when the involved functions (resp. their Legendre-Fenchel conjugates) are moreover partly smooth. More precisely, when both of the two functions (resp. their conjugates) are partly smooth relative to their respective manifolds, we show that DR (resp. ADMM) identifies these manifolds in finite time. Moreover, when these manifolds are affine or linear, we prove that DR/ADMM is locally linearly convergent. When $J$ and $G$ are locally polyhedral, we show that the optimal convergence radius is given in terms of the cosine of the Friedrichs angle between the tangent spaces of the identified manifolds. This is illustrated by several concrete examples and supported by numerical experiments.Comment: 17 pages, 1 figure, published in the proceedings of the Fifth International Conference on Scale Space and Variational Methods in Computer Visio

Scheduling MapReduce Jobs under Multi-Round Precedences

We consider non-preemptive scheduling of MapReduce jobs with multiple tasks in the practical scenario where each job requires several map-reduce rounds. We seek to minimize the average weighted completion time and consider scheduling on identical and unrelated parallel processors. For identical processors, we present LP-based O(1)-approximation algorithms. For unrelated processors, the approximation ratio naturally depends on the maximum number of rounds of any job. Since the number of rounds per job in typical MapReduce algorithms is a small constant, our scheduling algorithms achieve a small approximation ratio in practice. For the single-round case, we substantially improve on previously best known approximation guarantees for both identical and unrelated processors. Moreover, we conduct an experimental analysis and compare the performance of our algorithms against a fast heuristic and a lower bound on the optimal solution, thus demonstrating their promising practical performance

The non-continuous direction vector I test

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Genetic variation in lipid desaturases and its impact on the development of human disease

Perturbations in lipid metabolism characterize many of the chronic diseases currently plaguing our society, such as obesity, diabetes, and cardiovascular disease. Thus interventions that target plasma lipid levels remain a primary goal to manage these diseases. The determinants of plasma lipid levels are multi-factorial, consisting of both genetic and lifestyle components. Recent evidence indicates that fatty acid desaturases have an important role in defining plasma and tissue lipid profiles. This review will highlight the current state-of-knowledge regarding three desaturases (Scd-1, Fads1 and Fads2) and their potential roles in disease onset and development. Although research in rodent models has provided invaluable insight into the regulation and functions of these desaturases, the extent to which murine research can be translated to humans remains unclear. Evidence emerging from human-based research demonstrates that genetic variation in human desaturase genes affects enzyme activity and, consequently, disease risk factors. Moreover, this genetic variation may have a trans-generational effect via breastfeeding. Therefore inter-individual variation in desaturase function is attributed to both genetic and lifestyle components. As such, population-based research regarding the role of desaturases on disease risk is challenged by this complex gene-lifestyle paradigm. Unravelling the contribution of each component is paramount for understanding the inter-individual variation that exists in plasma lipid profiles, and will provide crucial information to develop personalized strategies to improve health management

Southern Africa Consortium for Research Excellence (SACORE): successes and challenges

Copyright © Mandala et al. Open access article distributed under the terms of CC BY.Published Online November 13, 2014 http://dx.doi.org/10.1016/S2214-109X(14)70321-

Quantitative comparison of linear magnetic gear with different types of PMs

This paper presents a quantitative comparison between the non-rare-earth permanent magnet (PM) and rare-earth PM based linear magnetic gear. By using the finite element analysis, three linear magnetic gears adopting either the non-rare-earth PM or rare-earth PM are analyzed and discussed. Hence, the cost-effectiveness comparison among different types of PMs is conducted. The results indicate that the non-rare-earth PM is preferred to the rare-earth PM for application to linear magnetic gears when cost-effectiveness is emphasized.postprin