Search results for "199"

A decade of SN 1993J : discovery of radio wavelength effects in the expansion rate

2009

We studied the growth of the shell-like radio structure of supernova SN 1993J in M 81 from September 1993 to October 2003 with very-long-baseline interferometry (VLBI) observations at the wavelengths of 3.6, 6, and 18 cm. We developed a method to accurately determine the outer radius (R) of any circularly symmetric compact radio structure such as SN 1993J. The source structure of SN 1993J remains circularly symmetric (with deviations from circularity under 2%) over almost 4000 days. We characterize the decelerated expansion of SN 1993J until approximately day 1500 after explosion with an expansion parameter m = 0.845 ± 0.005 (R ∝ tm). However, from that day onwards the expansion differs whe…

Elaboration of NMT and GSM standards : from idea to market

2002

The focus of this study is on elaboration of NMT (Nordic Mobile Telephone) and GSM (Global System for Mobile communications) standards. It seeks to understand the standard-making process from a system's philosophy to market entry.The specific objectives of the study are 1) to reconstruct the original ideas of innovation, 2) to reconstruct standardization processes of NMT and GSM systems, 3) to reconstruct interplay and impact of key players during standardization process, and 4) to explain success of NMT and GSM standards. Analyzing processes of two successful mobile communication standard-making aims to reveal what were the specific Nordic standardization practices and principles, and what…

Impact of Plastic Debris on the Gut Microbiota of Caretta caretta From Northwestern Adriatic Sea

2021

Plastic pollution is nowadays a relevant threat for the ecological balance in marine ecosystems. Small plastic debris (PD) can enter food webs through various marine organisms, with possible consequences on their physiology and health. The loggerhead sea turtle (Caretta caretta), widespread across the whole Mediterranean Sea, is a “flagship species,” useful as indicator of the general pollution level of marine ecosystems. Ingested PD accumulate in the final section of turtles’ digestive tract before excretion. During their transit and accumulation, PD also interact with the residing microbial community, with possible feedback consequences on the host’s health. To explore the possible relati…

Virastosta liikeyritys : posti- ja telelaitoksen muutosprosessi 1930-1994

2014

Vēsture: Latvijas Universitātes Žurnāls, 2018, Nr.5

2018

Facebook’s Emotional Contagion Experiment as a Challenge to Research Ethics

2016

This article analyzes the ethical discussion focusing on the Facebook emotional contagion experiment published by the <em>Proceedings of the National Academy of Sciences</em> in 2014. The massive-scale experiment manipulated the News Feeds of a large amount of Facebook users and was successful in proving that emotional contagion happens also in online environments. However, the experiment caused ethical concerns within and outside academia mainly for two intertwined reasons, the first revolving around the idea of research as manipulation, and the second focusing on the problematic definition of informed consent. The article concurs with recent research that the era of social med…

Decisiones automatizadas: problemas y soluciones jurídicas. Más allá de la protección de datos

2021

La creciente capacidad computacional de los sistemas automatizados de procesamiento de datos ha generado un aumento de su utilización en toda clase de actividades humanas. Estos sistemas pueden procesar cantidades masivas de datos y proporcionar resultados muy precisos, ayudando a los responsables de la toma de decisiones, tanto en el sector público como en el privado, a clasificar a los seres humanos y a predecir sus acciones. Sin embargo, en los últimos años se ha venido demostrando que estos sistemas pueden generar importantes riesgos para los derechos fundamentales y otros valores y principios democráticos. Hasta la fecha, las normas en materia de protección de datos han constituido el …

Spatial Convergence Clubs and the European Growth Process, 1980-1995

2003

Bernard Fingleton

History of Sciences and Museology (Scientific Papers University of Latvia, vol. 800)

2014

Zvaigžņotā Debess: 2001, Vasara (172)

2001

Contents: U.Dzērvītis. Sensational Discovery in Experimental Physics ; G.Rozenfelds. Solar Eclipse in Kamishin ; Z.Alksne, A.Alksnis. Search for Exsoplanets: Success and Complications ; Z.Alksne. A Star is Growing in a Bok Globule ; A.Balklavs. Observation of an Interesting Object by Cosmic Radio Interferometer ; A.Balklavs. HALCA – Step in Space Radio Interferometry ; T.Czarnik. Physiological Adaptation to Weightlessness ; Ilgonis Vilks. Spaceflight. Period of Great Success (1961-1973) (concluded) ; Ilgonis Vilks. Spaceflight. Almost Everyday Life (1973-2000) ; V.Straupe. About Astronomy in One of the Biggest Museum of Natural Sciences ; Imants Vilks. Contemporary Science on Eternal Life ;…