The volumetric rate of calcium-rich transients in the local universe

We present a measurement of the volumetric rate of `calcium-rich' optical transients in the local universe, using a sample of three events from the Palomar Transient Factory (PTF). This measurement builds on a detailed study of the PTF transient detection efficiencies, and uses a Monte Carlo simulation of the PTF survey. We measure the volumetric rate of calcium-rich transients to be higher than previous estimates: $1.21^{+1.13}_{-0.39}\times10^{-5}$ events yr$^{-1}$ Mpc$^{-3}$. This is equivalent to 33-94% of the local volumetric type Ia supernova rate. This calcium-rich transient rate is sufficient to reproduce the observed calcium abundances in galaxy clusters, assuming an asymptotic calcium yield per calcium-rich event of ~0.05$\mathrm{M}_{\odot}$. We also study the PTF detection efficiency of these transients as a function of position within their candidate host galaxies. We confirm as a real physical effect previous results that suggest calcium-rich transients prefer large physical offsets from their host galaxies.Comment: Accepted for publication in ApJ. 9 pages, 5 figure

Exploring the notion of quality in quality higher education assessment in a collaborative future

The purpose of this paper is to contribute to the debate on the notion of quality in higher education with particular focus on ‘objectifying through articulation’ the assessment of quality by professional experts. The paper gives an overview of the differentiations of quality as used in higher education. It explores a substantial piece of evaluation research which was carried out between 2009 and 2011 by the authors at the Institute for Work Based Learning at Middlesex University

Employing dynamic fuzzy membership functions to assess environmental performance in the supplier selection process

The proposed system illustrates that logic fuzzy can be used to aid management in assessing a supplier's environmental performance in the supplier selection process. A user-centred hierarchical system employing scalable fuzzy membership functions implement human priorities in the supplier selection process, with particular focus on a supplier's environmental performance. Traditionally, when evaluating supplier performance, companies have considered criteria such as price, quality, flexibility, etc. These criteria are of varying importance to individual companies pertaining to their own specific objectives. However, with environmental pressures increasing, many companies have begun to give more attention to environmental issues and, in particular, to their suppliers’ environmental performance. The framework presented here was developed to introduce efficiently environmental criteria into the existing supplier selection process and to reflect on its relevant importance to individual companies. The system presented attempts to simulate the human preference given to particular supplier selection criteria with particular focus on environmental issues when considering supplier selection. The system considers environmental data from multiple aspects of a suppliers business, and based on the relevant impact this will have on a Buying Organization, a decision is reached on the suitability of the supplier. This enables a particular supplier's strengths and weaknesses to be considered as well as considering their significance and relevance to the Buying OrganizationPeer reviewe

The question of ‘alternatives’ within food and drink markets and marketing: introduction to the special issue

The question of 'alternatives' within food and drink markets and marketing: introduction to the special issu

CONSIDERATIONS FOR A DOMESTIC TERRORISM STATUTE

While the crime of international terrorism is clearly defined in U.S. law, the lack of a domestic terrorism charge has broad implications for the government’s actual and perceived ability to respond to acts of domestic violent extremism. The creation of a federal domestic terrorism statute would codify the severity of the threat into enforceable law and allow the government to respond more effectively. Such a statute could directly impact the First Amendment rights of U.S. citizens, however, via the monitoring of free speech and association. What then are the potential costs, benefits, and consequences of a domestic terrorism statute in the United States, especially pertaining to First Amendment constitutional rights? A qualitative case study was conducted to focus on three cases of political violence that may be interpreted as domestic terrorism in the United States: the Capitol riot, the Charlottesville attack, and the Pittsburgh synagogue incident. The findings of this study indicate that a statute can also be instrumental in the investigation and prosecution of domestic terrorism incidents by protecting targeted racial groups, preventing abuse of power and authority, increasing penalties, and giving victims and their families the justice they deserve. The main challenge is the argument that a statute would infringe on civil liberties, which could be prevented by having specific provisions about the limits of these civil liberties and a benchmark for inciting terrorism.Civilian, New York City Police DepartmentApproved for public release. Distribution is unlimited

Generation of wavelength tunable optical pulses with SMSR exceeding 50 dB by self-seeding a gain-switched source containing two FP lasers

In this letter, we show the generation of shorter pulses (∼20 ps) that exhibit side mode suppression ratios (SMSR's) greater than 50 dB and wider tuning range (48.91 nm). Our technique is based on the self-seeding of a gain-switched source containing two FP lasers

The crustal structure of the east Africa through earthquake seismology

First arrivals of local and regional earthquakes, recorded at the Kaptagat array station on the western flank of the Gregory Rift Valley in Kenya, have been analysed to determine the crustal structure westward from the Rift axis. Apparent velocities have been interpreted in terms of crustal velocities. Azimuth and epicentral distance of event has provided lateral and vertical control on crustal boundaries. Normal shield crust, underlain by normal Moho is concluded to exist on the western flank of the Rift Valley. From the satisfactory propagation of S(_n) from events originating around the western Rift, normal Moho is considered to exist across the East African Plateau. A massive mantle derived intrusion is concluded to have penetrated the crust to within approximately 8 km of the Rift floor. This intrusion reaches to within about 7 km of the Elgeyo escarpment, the major Rift Valley boundary fault immediately to the east of Kaptagat. In order to aid second arrival analysis, a synthetic seismogram programme based on short wavelength asymptotic theory for reflected and refracted waves has been written. A qualitative analysis of real and synthetic seismograms of events originating to the west of Kaptagat, suggests that the crustal structure is more complex than the simple two- layered model initially produced. It is considered that the structure beneath the Gregory Rift is more equivalent to that beneath ocean Rift Systems than that beneath continental Rifts. However, rather than being a direct extension of the "World Rift System, the Eastern Rift and associated Kenya dome should be considered as a single physical unft