The time-of-flight system on the Goddard medium energy gamma-ray telescope

A scintillation counter time of flight system, incorporated into the Goddard 50 cm by 50 cm spark chamber gamma ray telescope is described. The system, which utilizes constant fractions timing and particle position compensation and digitizes up to 10 ns time differences to six bit accuracy in less than 500 ns is analyzed. The performance of this system during balloon flight is discussed

How User Personality and Social Value Orientation Influence Avatar Mediated Friendship

Purpose – The purpose of this paper is to study the influence of user personality and vlaues on the number of connections users make, the number of requests for connections that users give out, and the number of connections invitations users receive. Design/methodology/approach – This is a field study of 179 participants interacting in a novel virtual world. The world’s server logs are used to capture sociometrics about the users and their interaction. Findings – Findings suggest that personality and values influence the number of friends users make and the number of friendship requests users give out, but not the number of friendship invitations users receive. Only one personality trait – conscientiousness – exhibits homophily. Originality/value – Personality and social value orientation have rarely been studied together in information systems (IS) research, despite research showing the two have an impact on IS relevant constructs. The use of server logs for data capture is novel. Avatar friendship is an under-researched concept in IS

Determinants of Friendship in Social Networking Virtual Worlds

This paper examines the determinants of friendship between two users in a virtual world who are unaware of each other's real identities. Drawing on theories of homophily, heterophily and propinquity, three virtual world behaviours are analysed: avatar appearance, avatar location, and avatar communication. Data are collected on 179 participants interacting in a novel virtual world. The main results show that: (1) avatars did not tend to form friendships with avatars that are similar in appearance to themselves but did tend to form friendships with avatars that are dressed differently from themselves; (2) in terms of location, the closer an avatar stands to other avatars, the more likely the avatar is to receive a friend invitation; and (3) the fewer words an avatar uses in communication, the more likely the avatar is to receive a friend invitation. This paper contributes to theories of virtual world interaction and to using virtual worlds as a data collection platform

Polyspecies aquaculture systems: The detrital trophic level

The production of species belonging to the detrital trophic level was investigated in a model-sized aquaculture system, with flowing, filtered seawater and controlled phytoplankton addition to experimental tanks containing the oyster, Crassostrea virginica. The biodeposits of feces and pseudofeces of the oysters supported on the bottom of one tank a population of the nereid polychaete, Nereis virens and in the other tank a mixed community of the capitellid polychaete, Capitella capitata and the amphipod, Corophium sp...

High energy gamma ray balloon instrument

The High Energy Gamma Ray Balloon Instrument was built in part to verify certain subsystems' performance for the Energetic Gamma Ray Experiment Telescope (EGRET) instrument, the high energy telescope to be carried on the Gamma Ray Observatory. This paper describes the instrument, the performance of some subsystems, and some relevant results

Fibrocytes in health and disease

Fibrocytes, a group of bone marrow-derived mesenchymal progenitor cells, were first described in 1994 as fibroblast-like, peripheral blood cells that migrate to regions of tissue injury. These cells are unique in their expression of extracellular matrix proteins concomitantly with markers of hematopoietic and monocyte lineage. The involvement of fibrocytes and the specific role they play in the process of wound repair has been a focus of study since their initial description. Fibrocytes contribute to the healing repertoire via several mechanisms; they produce a combination of cytokines, chemokines, and growth factors to create a milieu favorable for repair to occur; they serve as antigen presenting cells (APCs); they contribute to wound closure; and, they promote angiogenesis. Furthermore, regulatory pathways involving serum amyloid P, leukocyte-specific protein 1, and adenosine A2A receptors have emphasized the significant role that fibrocytes have in wound healing and fibrosis. The therapeutic targeting of fibrocytes holds promise for the augmentation of wound repair and the treatment of different fibrosing disorders

Ethical issues in the use of in-depth interviews: literature review and discussion

This paper reports a literature review on the topic of ethical issues in in-depth interviews. The review returned three types of article: general discussion, issues in particular studies, and studies of interview-based research ethics. Whilst many of the issues discussed in these articles are generic to research ethics, such as confidentiality, they often had particular manifestations in this type of research. For example, privacy was a significant problem as interviews sometimes probe unexpected areas. For similar reasons, it is difficult to give full information of the nature of a particular interview at the outset, hence informed consent is problematic. Where a pair is interviewed (such as carer and cared-for) there are major difficulties in maintaining confidentiality and protecting privacy. The potential for interviews to harm participants emotionally is noted in some papers, although this is often set against potential therapeutic benefit. As well as these generic issues, there are some ethical issues fairly specific to in-depth interviews. The problem of dual role is noted in many papers. It can take many forms: an interviewer might be nurse and researcher, scientist and counsellor, or reporter and evangelist. There are other specific issues such as taking sides in an interview, and protecting vulnerable groups. Little specific study of the ethics of in-depth interviews has taken place. However, that which has shows some important findings. For example, one study shows participants are not averse to discussing painful issues provided they feel the study is worthwhile. Some papers make recommendations for researchers. One such is that they should consider using a model of continuous (or process) consent rather than viewing consent as occurring once, at signature, prior to the interview. However, there is a need for further study of this area, both philosophical and empirical

Preferential heating of light ions during an ionospheric Ar(+) injection experiment

The Argon Release for Controlled Studies (ARCS) 4 sounding rocket was launched northward into high altitude from Poker Flat Research Range on February 23, 1990. The vehicle crossed geomagnetic field lines containing discrete auroral activity. An instrumented subpayload released 100-eV and 200-eV Ar(+) ion beams sequentially, in a direction largely perpendicular to both the local geomagnetic field and the subpayload spin axis. The instrumented main payload was separated along field lines from the beam emitting subpayload by a distance which increased at a steady rate of approximately 2.4 m/s. Three dimensional mass spectrometric ion observations of ambient H(+) and O(+) ions, obtained on board the main payload, are presented. Main payload electric field observations in the frequency range 0-16 kHz, are also presented. These observations are presented to demonstrate the operation of transverse ion acceleration, which was differential with respect to ion mass, primarily during 100-eV beam operations. The preferential transverse acceleration of ambient H(+) ions, as compared with ambient O(+) ions, during the second, third, fourth, and fifth 100-eV beam operations, is attributed to a resonance among the injected Ar(+) ions, beam-generated lower hybrid waves, and H(+) ions in the tail of the ambient thermal distribution. This work provides experimental support of processes predicted by previously published theory and simulations

Anti-Nirvana: crime, culture and instrumentalism in the age of insecurity

‘Anti-Nirvana’ explores the relationship between consumer culture, media and criminal motivations. It has appeared consistently on the list of the top-ten most-read articles in this award-winning international journal, and it mounts a serious neo-Freudian challenge to the predominant naturalistic notion of ‘resistance’ at the heart of liberal criminology and media studies. It is also cited in the Oxford Handbook of Criminology and other criminology texts as a persuasive argument in support of the theory that criminality amongst young people is strongly linked to the acquisitive values of consumerism and the images of possessive individualism that dominate mass media

Fisheries and Oceanography off Galicia, NW Spain: Mesoscale Spatial and Temporal Changes in Physical Processes and Resultant Patterns of Biological Productivity

The Galician shelf off NW Spain (43N degrees 9W degrees) exhibits mesoscale spatial and temporal changes in biological productivity associated with upwelling. Spatial heterogeneity results from local geomorphic and land-sea interactions superimposed on the large scale atmospheric processes that produce upwelling. Wind-induced upwelling events, commonly of short (i.e., week) duration, are more common in the summer than in the winter. A Series of cruises, including some time series sampling, and satellite imagery analysis showed that surface upwelling was more common and persistent on the northern coast compared with the western coast off the coastal embayments, the Rias Bajas. Nearshore off the rias, coastal runoff, which is greater in the rainy winter/spring versus the dry summer, affected upwelling. In early summer, upwelling less often reaches the surface because of increased water column stratification associated with lower surface salinities and thus upwelling is not detected by satellite imagery. Conversely, in late summer, upwelling more often reaches the surface because coastal runoff is reduced during the dry summer months and the water column tends to be less stratified. Plankton biomass and rate processes along the Galician shelf reflected both ambient hydrographic conditions as well as prior history of upwelling or downwelling. Phytoplankton and bacterioplankton were in greatest abundance during upwelling conditions (June through August); in contrast, both zooplankton and fish larvae exhibited highest abundances in March, when there were upwelling conditions prior to our cruise. Spatial differences in the duration and frequency of upwelling events, in combination with advection of water masses, are critical to the patterns of water column productivity and sardine fisheries production off the Galician coast. More persistent upwelling at this NW corner of the Iberian peninsula Supports large sardine fisheries because zooplankton and larval fish populations have time to respond to the higher primary production. Farther down the western Galician coast, the episodic upwelling and resultant intermittent primary production does not support a stable food supply needed to support fisheries. Times series sampling revealed mean response times of bacteria, phytoplankton, and zooplankton to be on the order of a day, days, and weeks, respectively. Sardines showed no spawning response in the relatively short time series sampling. The observed distributional patterns of fish eggs and larvae showed some offshore transport of fish larvae that were spawned inshore during upwelling periods and aggregation of larvae in a convergence zone northwest of Cabo Villano