The high strain-rate behaviour of three molecular weights of polyethylene examined with a magnesium alloy split-Hopkinson pressure bar

A traditional split-Hopkinson pressure bar system has been modified by the addition of ZK60A magnesium alloy pressure bars in order to increase the resolution of data when examining specimens of low-density, high-density and ultra-high molecular weight polyethylene. It was found that the low density of the ZK60A allowed a decent increase in transmitted pulse amplitude, whilst its relatively high yield strength afforded long-term reliability of the system. The accuracy of data obtained from the fitted strain gauges was verified with the use of a high-speed video camera, and was found to be an excellent match.Comment: Will be shortly submitted to 'Polymer Testing

A Meta-Analytic Review of Competitive Aggressiveness Research

Competitive aggressiveness has been at the center of competitive dynamics literature for decades, however there is no consensus as to its primary drivers and performance consequences. Thus, we present the results of a meta-analysis of the antecedents to and consequences of competitive aggressiveness using three aggressiveness components—competitive volume, complexity, and heterogeneity. Leveraging the awareness, motivation, capability framework as a guide of the drivers of competitive aggressiveness, we find that greater organizational size and age, lower slack resources and prior performance, greater market growth, lower market concentration, and more heterogeneous top management teams lead to more aggressive actions. In addition, we found that among the different components of aggressiveness competitive volume improved operating performance

Suicide in post agreement Northern Ireland: A Study of the Role of Paramilitary Intimidation 2007-2009

Since the end of the ‘Troubles’ in Northern Ireland, there has been a rise in the number of acts of intimidation and Paramilitary Punishment Attacks (PPA). Anecdotally, some suicides have been linked to such incidents. To date, there has been a lack of research examining this association. This article details a case series study exploring how individual deaths by suicide in Northern Ireland were connected to intimidation. Data from Coroners, GP records and interviews with family members were examined to identify experiences of intimidation among a two-year cohort who died by suicide. Further case based analysis was conducted using a modified version of the psychological autopsy method. Our results indicate that in 19 male suicides there were incidents of intimidation in the twelve months prior to death. The suicides of these men are discussed in relation to the suicide model of entrapment. Our findings highlight the continuing problem of intimidation in Northern Ireland and suggest further research into the connection between these incidents and suicide is warranted

An efficient scheme for the deterministic maximal entanglement of N trapped ions

We propose a method for generating maximally entangled states of N two-level trapped ions. The method is deterministic and independent of the number of ions in the trap. It involves a controlled-NOT acting simultaneously on all the ions through a dispersive interaction. We explore the potential application of our scheme for high precision frequency standards.Comment: 4 pages, no figures, submitted to PRL, under review, Revised Version: Incorporated referee comment

Impact Evaluation of the European Employment Strategy in Ireland. ESRI General Papers

Recent years have seen dramatic growth in employment following unprecedented economic growth and development during the 1990s. Total employment in Ireland grew by a remarkable 534,000, or by 46%, in the eight years from 1993 to 2001, and over 220,000 of this was achieved between 1998 and 2001. In very recent years, the rate of growth in employment fallen somewhat, from a peak of almost 7% in 1997-1998 to about 4% in 2000- 2001. The rapid growth in the economy and in employment after 1993 led to a steady decline in unemployment from 220,000 in 1993 to 127,000 in the 2nd quarter of 1998 and to 65,000 in the 2nd quarter of 2001. The unemployment rate thus fell from 15.7% of the labour force in 1993 to 7.8% in the 2nd quarter of 1998 and to 3.7% in the 2nd quarter of 2001. With the deterioration in the international economy, and the slowdown in the Irish growth rate in 2001, unemployment increased to just under 80,000, or 4.3% of the labour force, in the 3rd quarter of 2001

Interdisciplinary integration of Inquiry-oriented Learning in Science

A substantial body of research has demonstrated the considerable value, across a range of educational domains, of integrating inquiry-oriented learning (IOL) activities in undergraduate science, particularly laboratory- and field-based modalities. These initiatives have often been introduced into single disciplines, or at particular year levels by lone but skilled and highly motivated innovators. While praiseworthy, such initiatives may lack the synergies and impact that could be gained through more broad scale integration of IOL both horizontally, across a range of science disciplines, and vertically, through the year levels of a science degree. Such an approach provides considerable potential benefits to students, through articulation of a consistent model and template for laboratory activities, and importantly, through the contextual amplification that can be generated through interdisciplinary, inquiry-oriented learning. It also has the potential to strengthen graduate outcomes through greater resolution of curriculum mapping, and resonates strongly with other initiatives including the Learning and Teaching Academic Standards (LTAS) in the sciences project. The current project has engaged 1st year science educators across a range of disciplines (initially biology, chemistry and physics) to collaborate in the development, implementation and evaluation of meaningful IOL initiatives for students as they progress through their degree

Interdisciplinary Collaboration to Integrate Inquiry-Oriented Learning in Undergraduate Science Practicals

The benefits of inquiry-oriented learning (IOL) in undergraduate science courses have been validated through a considerable range of studies incorporating observation and examination data, as well as qualitative and quantitative feedback from students and employers. However, IOL initiatives often occur in single subject or discipline areas, meaning that students may experience IOL in isolated or disjunct forms, without the synergies made possible through interdisciplinary collaboration by educators. This paper reports on the progress of an interdisciplinary approach to develop, implement and evaluate IOL practicals in first year biology, chemistry and physics laboratory teaching programs. This initiative, founded on principles of collegiality and mentorship among the team members, has involved professional development of teaching associates (aka demonstrators), collaboration in the design and branding of inquiry-oriented practicals, and a degree of interdisciplinary alignment of practical assessments. The initiative has generated a more student-centred and coherent approach to enhancement of scientific literacy and a range of associated skills, provided greater clarity and transparency for students, and scaffolded inquiry-oriented approaches throughout the degree

Three steps forward for predictability : Consideration of methodological robustness, indexical and prosodic factors, and replication in the laboratory

There is now abundant evidence that phonetic forms are shaped by probabilistic effects reflecting predictability or informativity. We outline a number of challenges for such work, where theoretical claims are often based on small differences in acoustic measurements, or interpretations of small statistical effect sizes. We outline caveats about the methods and assumptions encountered in many studies of predictability effects, particularly regarding corpus-based approaches. We consider the wide range of factors that influence patterns of variability in phonetic forms, taking a broad perspective on what is meant by “the message” in order to show that predictability effects need to be considered alongside many others, including indexical and prosodic factors. We suggest a number of ways forward to extend our understanding of the form-predictability relationship.Full Tex

When health services are powerless to prevent suicide: results from a linkage study of suicide among men with no service contact in the year prior to death

Aims: To investigate cases of suicide in which there was no healthcare contact, by looking at history of help-seeking and evidence of previous mental health vulnerability. To identify any life events associated with suicide for which individuals did not seek help. Background: Previous research has suggested that non-consultation is the main barrier to suicide prevention among men. Estimates suggest approximately 22% of men who die by suicide have not consulted their GP in the year before their death. Little is known about the lifetime pattern of engagement with services among these individuals and whether or not this may influence their help-seeking behaviour before death. Methods: Coroner records of suicide deaths in Northern Ireland over 2 years were linked to general practice (GP) records. This identified 63 individuals who had not attended health services in the 12 months before death. Coroner’s data were used to categorise life events associated with the male deaths. Lifetime mental health help-seeking at the GP was assessed. Findings: The vast majority of individuals who did not seek help were males (n=60, 15% of all suicide deaths). Lack of consultation in the year before suicide was consistent with behaviour over the lifespan; over two-thirds had no previous consultations for mental health. In Coroner’s records, suicides with no prior consultation were primarily linked to relationship breakdown and job loss. These findings highlight the limitations of primary care in suicide prevention as most had never attended GP for mental health issues and there was a high rate of supported consultation among those who had previously sought help. Public health campaigns that promote service use among vulnerable groups at times of crisis might usefully be targeted at those likely to be experiencing financial and relationship issues

A Very Hot, High Redshift Cluster of Galaxies: More Trouble for Omega_0 = 1

We have observed the most distant (z=0.829) cluster of galaxies in the Einstein Extended Medium Sensitivity Survey, with the ASCA and ROSAT satellites. We find an X-ray temperature of 12.3 +3.1/-2.2 keV for this cluster, and the ROSAT map reveals significant substructure. The high temperature of MS1054-0321 is consistent with both its approximate velocity dispersion, based on the redshifts of 12 cluster members we have obtained at the Keck and the Canada-France-Hawaii telescopes, and with its weak lensing signature. The X-ray temperature of this cluster implies a virial mass ~ 7.4 x 10^14 h^-1 solar masses, if the mean matter density in the universe equals the critical value, or larger if Omega_0 < 1. Finding such a hot, massive cluster in the EMSS is extremely improbable if clusters grew from Gaussian perturbations in an Omega_0 = 1 universe. Combining the assumptions that Omega_0 = 1 and that the intial perturbations were Gaussian with the observed X-ray temperature function at low redshift, we show that the probability of this cluster occurring in the volume sampled by the EMSS is less than a few times 10^{-5}. Nor is MS1054-0321 the only hot cluster at high redshift; the only two other $z > 0.5$ EMSS clusters already observed with ASCA also have temperatures exceeding 8 keV. Assuming again that the initial perturbations were Gaussian and Omega_0 = 1, we find that each one is improbable at the < 10^{-2} level. These observations, along with the fact that these luminosities and temperatures of the high-$z$ clusters all agree with the low-z L_X-T_X relation, argue strongly that Omega_0 < 1. Otherwise, the initial perturbations must be non-Gaussian, if these clusters' temperatures do indeed reflect their gravitational potentials.Comment: 20 pages, 4 figures, To appear in 1 Aug 1998 ApJ (heavily revised version of original preprint