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

The Piping Plover Problem: A Review of Management Issues for a Threatened Shorebird

Andrew Lydeard and Gerry Harris The Piping Plover (Charadrius melodus) was federally listed in 1986. Since listing, Piping Plovers have been a focus of conservation and management efforts, particularly on their breeding grounds in the Northern Great Plains, Great Lakes, and northern Atlantic Coast. Despite management efforts that have resulted in range-wide population growth of the Piping Plover, growth in individual populations is often slow and reasons for this are poorly understood. A bias towards understanding drivers of declines on breeding sites compared to wintering and migratory stopover sites may be an underlying cause of this lack of understanding. Conducting studies on primarily an organism’s breeding grounds has implications that may lead to costly, ineffective management practices with little to no benefits to species conservation. We analyzed the scientific literature on Piping Plover management by systematically reviewing nine ecological journals and searching for all articles published from 1986 – 2019 including the terms “Piping Plover” and “Charadrius melodus”. The proportion of studies on Piping Plovers within their breeding range drastically outnumber those studies completed on wintering and migratory stopover sites. These seasonal sampling biases could have negative implications for Piping Plover conservation, and we suggest that research on migratory stopovers and wintering grounds should be prioritized to help reverse local population declines. Keywords: Piping Plover; Charadrius melodus; Shorebird Management; Threatened Specie

Do patients who die from an alcohol-related condition ‘drift’ into areas of greater deprivation? Alcohol-related mortality and health selection theory in Scotland

Background: Health selection has been proposed to explain the patterning of alcohol-related mortality by area deprivation. This study investigated whether persons who die from alcohol-related conditions are more likely to experience social drift than those who die from other causes. Methods: Deaths recorded in Scotland (2013, >21 years) were coded as ‘alcohol-related’ or ‘other’ and by deprivation decile of residence at death. Acute hospital admissions data from 1996 to 2012 were used to provide premortality deprivation data. χ² tests estimated the difference between observed and expected alcohol-related deaths by first Scottish Index of Multiple Deprivation (SIMD) decile and type of death. Logistic regression models were fitted using type of death as the outcome of interest and change in SIMD decile as the exposure of interest. Results: Of 47 012 deaths, 1458 were alcohol-related. Upward and downward mobility was observed for both types of death. An estimated 31 more deaths than expected were classified ‘alcohol-related’ among cases whose deprivation score decreased, while 204 more deaths than expected were classified ‘alcohol-related’ among cases whose initial deprivation ranking was in the four most deprived deciles. Becoming more deprived and first deprivation category were both associated with increased odds of type of death being alcohol-related after adjusting for confounders. Conclusion: This study suggests that health selection appears to contribute less to the deprivation gradient in alcohol-related mortality in Scotland than an individual’s initial area deprivation category

Global Journalist: Robert Mugabe’s reelection faces opposition within his party

This Mar. 13, 2008 episode with Stuart Loory highlights Zimbabwe’s upcoming presidential elections, in which, according to the guests, President Robert Mugabe is likely to remain in power because his opposition is split: If only united, they could have a chance, the journalists say

Highly-functionalised difluorinated cyclohexane polyols via the Diels–Alder reaction : regiochemical control via the phenylsulfonyl group

A difluorinated dienophile underwent cycloaddition reactions with a range of furans to afford cycloadducts whichcould be processed regio- and stereoselectively via episulfonium ions, generated by the reaction between their alkenyl groups and phenylsulfenyl chloride. The oxabicyclic products were oxidised to the phenylsulfonyl level and ring opened via E1CB or reductive desulfonative pathways to afford, ultimately, difluorinated cyclohexene or cyclohexane polyols

Fast Radio Burst 121102 Pulse Detection and Periodicity: A Machine Learning Approach

We report the detection of 72 new pulses from the repeating fast radio burst FRB 121102 in Breakthrough Listen C-band (4-8 GHz) observations at the Green Bank Telescope. The new pulses were found with a convolutional neural network in data taken on August 26, 2017, where 21 bursts have been previously detected. Our technique combines neural network detection with dedispersion verification. For the current application we demonstrate its advantage over a traditional brute-force dedis- persion algorithm in terms of higher sensitivity, lower false positive rates, and faster computational speed. Together with the 21 previously reported pulses, this observa- tion marks the highest number of FRB 121102 pulses from a single observation, total- ing 93 pulses in five hours, including 45 pulses within the first 30 minutes. The number of data points reveal trends in pulse fluence, pulse detection rate, and pulse frequency structure. We introduce a new periodicity search technique, based on the Rayleigh test, to analyze the time of arrivals, with which we exclude with 99% confidence pe- riodicity in time of arrivals with periods larger than 5.1 times the model-dependent time-stamp uncertainty. In particular, we rule out constant periods >10 ms in the barycentric arrival times, though intrinsic periodicity in the time of emission remains plausible.Comment: 32 pages, 10 figure

AN EXAMINATION OF MANAGERIAL STRATEGIES FOR INCREASING INFORMATION TECHNOLOGY PENETRATION IN ORGANIZATIONS

This paper describes an empirical study comparing two competing perspectives for explaining information technology (IT) penetration in organizations. IT penetration is defined as the extent to which IT is embedded within an organization\u27s strategic, managerial, and operational work systems. With the first perspective, IT penetration is hypothesized to be related to the implementation of a comprehensive set of management processes for the information systems (IS) function. With the second perspective, IT penetration is hypothesized to be related to the effectiveness of IT-related interactions among an organization\u27s managers, To strengthen the study\u27s research design, the hypotheses are examined separately across two samples of organizations. Senior ]S executives completed the study\u27s research instrument. Respondents in the first sample represented 132 large organizations across a variety of industries, while the respondents in the second sample represented 44 business units within a large, high teChnology firm. IT penetration and IT-related managerial interactions were measured at a subunit level, while IS management processes were measured at an organizational level. The study\u27s findings supported the research hypotheses. *The authors wish to thank Omar El Sawy and anonymous reviewers for their helpful comments on earlier drafts of this paper

Australian perspective regarding recommendations for physical activity and exercise rehabilitation in pulmonary arterial hypertension

Aim: To determine the opinion of health care professionals within Australia, regarding acceptable levels of exertion and symptoms, and referral for exercise rehabilitation in patients with pulmonary arterial hypertension (PAH). Method: In 2010, 76 health care professionals at a specialist pulmonary hypertension meeting in Australia were surveyed using a self-administered questionnaire. The questionnaire included case studies of patients with PAH in World Health Organization (WHO) functional classes II–IV. For each case study, respondents were asked to report their opinion regarding the acceptable level of exertion and symptoms during daily activities, and whether they would refer the patient for exercise rehabilitation. Three additional questions asked about advice in relation to four specific physical activities. Results: The response rate was 70% (n = 53). Overall, 58% of respondents recommended patients undertake daily activities 'as tolerated'. There was no consensus regarding acceptable levels of breathlessness or fatigue, but the majority of respondents considered patients should have no chest pain (73%) and no more than mild light-headedness (92%) during daily activities. Overall, 63% of respondents would have referred patients for exercise rehabilitation. There was little difference in opinion regarding the acceptable level of exertion or symptoms, or referral for exercise rehabilitation, according to functional class. However, the patients' functional class did influence the advice given regarding the specific physical activities. Conclusion: In 2010, there were inconsistencies between individual health care professionals within Australia regarding appropriate levels of physical exertion and acceptable symptoms during daily activities. Almost two-thirds of the respondents reported they would refer patients for exercise rehabilitation