4,690 research outputs found

    Microbunching And Coherent Acceleration Of Electrons By Subcycle Laser Pulses

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    The pick up and acceleration of all plasma electrons irradiated by an intense, subcyclic laser pulse is demonstrated via analytical and numerical calculations. It is shown that the initial low emittance of the plasma electrons is conserved during the process of acceleration, leading to an extremely cold, bunched electron beam. Compression of the electron bunch along the longitudinal coordinate is naturally achieved due to the interaction of electrons and laser pulse. In this paper, we find the localized solutions to Maxwell's equations of a subcyclic laser pulse and use these to determine the acceleration of charged particles and we suggest future application for this acceleration mechanism as low energy particle injector and as electron source for coherent x-ray generation.Physic

    Kajian Hukum Efektifitas Penerapan (Asas Contante Justitie) Asas Peradilan Cepat, Sederhana Dan Biaya Ringan

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    Tujuan dilakukannya penelitian ini adalah untuk mengetahui bagaimana pengaturan tentang asas contante justitie (asas peradilan cepat, sederhana dan biaya ringan) dalam peraturan Perundang-undangan dan bagaimana efektifitas penerapan asas Contante Justitie (asas peradilan cepat, sederhana dan biaya ringan). Dengan menggunakan metode penelitian yuridis normatif, disimpulkan: 1. Keberadaan asas contante justitie (asas peradilan cepat, sederhana dan biaya ringan) terdapat dalam hukum acara pidana, yaitu terdapat dalam beberapa pasal dari Kitab Undang-Undang Hukum Acara Pidana. Perumusan tentang proses pengembalian berkas perkara dari penuntut umum kepada penyidik, yaitu tidak diberikan batasan berapa kali berkas perkara dari penyidik kepada penuntut umum dapat dikembalikan, yang menimbulkan akibat berkas perkara hasil penyidikan yang telah diserahkan oleh penyidik kepada penuntut umum bolak batik terus menerus sehingga berakibat berlarut-larutnya suatu proses dalam acara pidana. 2. Efektifitas penerapan asas contante justitie (asas peradilan cepat, sederhana dan biaya ringan) tersebut tidak mempunyai sanksi yang mengikat bagi para pelanggar. Kemudian Pasal 67 KUHAP tidak dapat menjerat pelaku tindak pidana yang telah diputus bebas oleh pengadilan tingkat pertama karena dalam ketentuan Pasal 67 KUHAP tersebut tidak dapat dimintakan banding terhadap pengadilan tingkat banding terhadap putusan bebas, lepas dari segala tuntutan hukum yang menyangkut masalah kurang tepatnya penerapan hukum dan putusan pengadilan dalam acara cepat

    Dissection of GTPase activating proteins reveals functional asymmetry in the COPI coat of budding yeast.

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    The Arf GTPase controls formation of the COPI vesicle coat. Recent structural models of COPI revealed the positioning of two Arf1 molecules in contrasting molecular environments. Each of these pockets for Arf1 is expected to also accommodate an Arf GTPase-activating protein (ArfGAP). Structural evidence and protein interactions observed between isolated domains indirectly suggests that each niche may preferentially recruit one of the two ArfGAPs known to affect COPI, Gcs1/ArfGAP1 and Glo3/ArfGAP2/3, although only partial structures are available. The functional role of the unique non-catalytic domain of either ArfGAP has not been integrated into the current COPI structural model. Here, we delineate key differences in the consequences of triggering GTP hydrolysis via the activity of one versus the other ArfGAP. We demonstrate that Glo3/ArfGAP2/3 specifically triggers Arf1 GTP hydrolysis impinging on the stability of the COPI coat. We show that the yeast homologue of AMP kinase, Snf1, phosphorylates the region of Glo3 that is critical for this effect and thereby regulates its function in the COPI-vesicle cycle. Our results revise the model of ArfGAP function in the molecular context of COPI

    Part-Time Work in Chile

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    This article discusses the evolution and determinants of part-time work in Chile. It tests some hypotheses found in the international literature, to determine whether part-time work is precarious, whether hourly payment is smaller, and whether it constitutes a step toward full-time employment. Evidence is found that part-time work is mostly feminine, and can be precarious in that it can be less stable and more informal. However, hourly wage is slightly higher than in full-time jobs. This gap is examined through a decomposition of Oaxaca, which reveals that wage differences cannot be explained by observable factors. It concludes with a Markov chain analysis using the Casen surveys to determine whether part-time jobs are a transition to full-time jobs, and also steady-state part-time participation is projected, as are long-term participation and employment rates. The results show that, given the current dynamics, the relative share of part-time work over total employment will remain stable, and labor participation will attain the level of developed economies in no less than 25 years.

    Modelling the atmosphere of the carbon-rich Mira RU Vir

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    Context. We study the atmosphere of the carbon-rich Mira RU Vir using the mid-infrared high spatial resolution interferometric observations from VLTI/MIDI. Aims. The aim of this work is to analyse the atmosphere of the carbon-rich Mira RU Vir, with state of the art models, in this way deepening the knowledge of the dynamic processes at work in carbon-rich Miras. Methods. We compare spectro-photometric and interferometric measurements of this carbon-rich Mira AGB star, with the predictions of different kinds of modelling approaches (hydrostatic model atmospheres plus MOD-More Of Dusty, self-consistent dynamic model atmospheres). A geometric model fitting tool is used for a first interpretation of the interferometric data. Results. The results show that a joint use of different kind of observations (photometry, spectroscopy, interferometry) is essential to shed light on the structure of the atmosphere of a carbon-rich Mira. The dynamic model atmospheres fit well the ISO spectrum in the wavelength range {\lambda} = [2.9, 25.0] {\mu}m. Nevertheless, a discrepancy is noticeable both in the SED (visible), and in the visibilities (shape and level). A possible explanation are intra-/inter-cycle variations in the dynamic model atmospheres as well as in the observations. The presence of a companion star and/or a disk or a decrease of mass loss within the last few hundred years cannot be excluded but are considered unlikely.Comment: 15 pages. Accepted in A&
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