Search results for " evolution."
showing 10 items of 9653 documents
Analysis of MAC-level throughput in LTE systems with link rate adaptation and HARQ protocols
2015
LTE is rapidly gaining momentum for building future 4G cellular systems, and real operational networks are under deployment worldwide. To achieve high throughput performance, in addition to an advanced physical layer design LTE exploits a combination of sophisticated mechanisms at the radio resource management layer. Clearly, this makes difficult to develop analytical tools to accurately assess and optimise the user perceived throughput under realistic channel assumptions. Thus, most existing studies focus only on link-layer throughput or consider individual mechanisms in isolation. The main contribution of this paper is a unified modelling framework of the MAC-level downlink throughput of …
Device-to-device communication for LTE-advanced network system
2014
Device-to-device (D2D) communication has been proposed as a mean for local connections in future ellular networks in order to provide improved throughput, spectrum savings, and longer battery lives. Here we widen the investigations of D2D communication to a 3GPP Long Term Evolution (LTE) system simulated in the interference limited macro-cellular environment, in which D2D communication is applied with D2D specific power control and resource allocation schemes and with a wide range of deployment ratios. Furthermore, we introduce channel model parameters applicable for a fair performance comparison between conventional cellular and D2D enhanced systems. The simulation results demonstrate that…
From Mobile Crimes to Crimes of Mobility
2020
Piipponen, Mäntymäki and Rodi-Risberg suggest that many contemporary crime narratives across the globe host a heightened interest in diverse and ambiguous mobilities, border crossings and borderlands. They propose that such mobilities and crossings reflect on recent sociocultural developments on local and global levels and communicate specific geopolitical anxieties. They position their own mobilities research perspective within existing crime fiction scholarship, especially within the so-called transnational and spatial turns. Introducing some key observations of mobilities research, they suggest that mobility can be considered both as an object of study in its own right and a critical len…
Biological and Mechanical Characterization of the Random Positioning Machine (RPM) for Microgravity Simulations
2021
The rapid improvement of space technologies is leading to the continuous increase of space missions that will soon bring humans back to the Moon and, in the coming future, toward longer interplanetary missions such as the one to Mars. The idea of living in space is charming and fascinating; however, the space environment is a harsh place to host human life and exposes the crew to many physical challenges. The absence of gravity experienced in space affects many aspects of human biology and can be reproduced in vitro with the help of microgravity simulators. Simulated microgravity (s-μg) is applied in many fields of research, ranging from cell biology to physics, including cancer biology. In…
Fatty acid composition as biomarkers of freshwater microalgae: analysis of 37 strains of microalgae in 22 genera and in seven classes
2013
The fatty acid (FA) composition of algae is an important determinant of their food quality for consumers, and FAs can also be used as biomarkers for biochemical and energetic pathways in food webs. FA analyses of 7 freshwater algal classes and 37 strains showed clear similarity within classes and strong differences amongst classes. Class was a dominant factor (66.4%) explaining variation in FA signatures of microalgae. The 7 algal classes comprised 4 separate groups according to their FA profiles: (1) Chlorophyceae and Trebouxiophyceae, (2) Bacillariophyceae, (3) Cryptophyceae, Chrysophyceae, and Raphidophyceae, and (4) Euglenophyceae. Each group had a characteristic FA composition, althoug…
Adaptation to fluctuations in temperature by nine species of bacteria.
2017
Abstract Rapid environmental fluctuations are ubiquitous in the wild, yet majority of experimental studies mostly consider effects of slow fluctuations on organism. To test the evolutionary consequences of fast fluctuations, we conducted nine independent experimental evolution experiments with bacteria. Experimental conditions were same for all species, and we allowed them to evolve either in fluctuating temperature alternating rapidly between 20°C and 40°C or at constant 30°C temperature. After experimental evolution, we tested the performance of the clones in both rapid fluctuation and in constant environments (20°C, 30°C and 40°C). Results from experiments on these nine species were comb…
La desheredación del menor de edad
2021
This work aims to answer the eternal question of the disinheritance of the child under legal age. To this end, we will approach the institute of disinheritance, its foundation and its jurisprudential evolution. We will also address the capacity and responsibility of the child under legal age and the emancipated minor. Subsequently, we will carry out the study of the disinheritance of the child under legal age, subject to the whim of the specific disinherited causes, since each of the causes provided for in art. 853 Spanish Civil Code are endowed with their own idiosyncrasy, being very complicated, if not impossible, to deal with the subject of this work apart from the vicissitudes that can …
Catalogue of the Diptera (Insecta) of Morocco— an annotated checklist, with distributions and a bibliography
2022
The faunistic knowledge of the Diptera of Morocco recorded from 1787 to 2021 is summarized and updated in this first catalogue of Moroccan Diptera species. A total of 3057 species, classified into 948 genera and 93 families (21 Nematocera and 72 Brachycera), are listed. Taxa (superfamily, family, genus and species) have been updated according to current interpretations, based on reviews in the literature, the expertise of authors and contributors, and recently conducted fieldwork. Data to compile this catalogue were primarily gathered from the literature. In total, 1225 references were consulted and some information was also obtained from online databases. Each family was reviewed and the c…
ALHAMBRA Ks band selected catalogue
2017
Galaxy formation and evolution are an essential part of astronomy and cosmology today. To better understand the processes that are involved in the mechanism behind them it is necessary to study the physical processes in the observable universe at different epochs, which requires large astronomical surveys. In the case of the ALHAMBRA Survey, near infrared images (NIR) provide extra information that significantly increases the scientific value of the data, particularly for strongly-reddened elliptical galaxies, AGN or moderate-redshift starburst galaxies. The selection in the optical band F814W (used for ALHAMBRA’s original catalogue in Molino et al. (2014)) creates a bias against intrinsica…
Measuring, comparing and interpreting phenotypic selection on floral scent
2022
Natural selection on floral scent composition is a key element of the hypothesis that pollinators and other floral visitors drive scent evolution. The measure of such selection is complicated by the high-dimensional nature of floral scent data and uncertainty about the cognitive processes involved in scent-mediated communication. We use dimension reduction through reduced-rank regression to jointly estimate a scent composite trait under selection and the strength of selection acting on this trait. To assess and compare variation in selection on scent across species, time and space, we reanalyse 22 datasets on six species from four previous studies. The results agreed qualitatively with prev…