University of Portsmouth

About: University of Portsmouth is a education organization based out in Portsmouth, Portsmouth, United Kingdom. It is known for research contribution in the topics: Population & Galaxy. The organization has 5452 authors who have published 14256 publications receiving 424346 citations. The organization is also known as: Portsmouth and Gosport School of Science and Art & Portsmouth and Gosport School of Science and the Arts.

The XMM Cluster Survey:Optical analysis methodology and the first data release

Abstract: The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters using all publicly available data in the XMM–Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-ray scaling relations. In this paper we present the first data release from the XMM Cluster Survey (XCS-DR1). This consists of 503 optically confirmed, serendipitously detected, X-ray clusters. Of these clusters, 256 are new to the literature and 357 are new X-ray discoveries. We present 463 clusters with a redshift estimate (0.06 1.0, including a new spectroscopically confirmed cluster at ɀ = 1.01); (ii) 66 clusters with high TX (>5 keV); (iii) 130 clusters/groups with low TX (<2 keV); (iv) 27 clusters with measured TX values in the Sloan Digital Sky Survey (SDSS) ‘Stripe 82’ co-add region; (v) 77 clusters with measured TX values in the Dark Energy Survey region; (vi) 40 clusters detected with sufficient counts to permit mass measurements (under the assumption of hydrostatic equilibrium); (vii) 104 clusters that can be used for applications such as the derivation of cosmological parameters and the measurement of cluster scaling relations. The X-ray analysis methodology used to construct and analyse the XCS-DR1 cluster sample has been presented in a companion paper, Lloyd-Davies et al.

Improved cosmological constraints from a joint analysis of the SDSS-II and SNLS supernova samples

Abstract: We present cosmological constraints from a joint analysis of type Ia supernova (SN Ia) observations obtained by the SDSS-II and SNLS collaborations. The data set includes several low-redshift samples (z<0.1), all 3 seasons from the SDSS-II (0.05 < z < 0.4), and 3 years from SNLS (0.2

The Effect of Mobile Phone Screen Size on Video Based Learning

Abstract: This paper investigates the effect of mobile phone screen size (1.65 inches - 2.75 inches) on video based learning. It first examines the educational benefits of video as a teaching medium and surveys the usage and issues related with video based learning. After which, it investigates the value of video for mobile learning. It reports on an empirical investigation that studied the effect that screen-size has on video-based m-learning. Findings indicate that regardless of the screen size of a mobile phone, students tended to have a positive overall opinion of m-learning and watching the video significantly increased their knowledge of the subject area. However, if an m-learning environment that relies heavily on video based material is displayed on a mobile device with a small screen, such as an average mobile phone, then the effectiveness of the learning experience may be inhibited. Paper identifies the underlying reasons why mobile phone screen size may be a problem for video based m-learning. The implications of this finding are discussed.

When time is not space: the social and linguistic construction of time intervals and temporal event relations in an Amazonian culture

Abstract: It is widely assumed that there is a natural, prelinguistic conceptual domain of time whose linguistic organization is universally structured via metaphoric mapping from the lexicon and grammar of space and motion. We challenge this assumption on the basis of our research on the Amondawa (Tupi Kawahib) language and culture of Amazonia. Using both observational data and structured field linguistic tasks, we show that linguistic space-time mapping at the constructional level is not a feature of the Amondawa language, and is not employed by Amondawa speakers (when speaking Amondawa). Amondawa does not recruit its extensive inventory of terms and constructions for spatial motion and location to express temporal relations. Amondawa also lacks a numerically based calendric system. To account for these data, and in opposition to a Universal Space-Time Mapping Hypothesis, we propose a Mediated Mapping Hypothesis, which accords causal importance to the numerical and artefact-based construction of time-based (as opposed to event-based) time interval systems.