Development of e-SIWES Portal: A Web based Platform for Student Industrial Work Experience Scheme (SIWES) Management

We developed the e-SIWES portal in order to enhance the manual task of carrying out SIWES activities such as registration, dissemination of information, filling of log book for students’ day-to-day activities and supervision/assessment by lecturers and industry based supervisors. The portal is web-based and allows all tasks to be carried out using the personal computer and the Internet. We digitized the SIWES logbook and assessment forms for filling by students and grading by the supervisors electronically. This will allow supervisors to be assigned immediately the students commence their industrial training and facilitate their monitoring in real-time. With the e-SIWES portal, important messages can be broadcast to all students at once and on a prompt and regular basis

Cosmic ray acceleration to ultrahigh energy in radio galaxies

The origin of ultrahigh energy cosmic rays (UHECRs) is an open question. In this proceeding, we first review the general physical requirements that a source must meet for acceleration to 10-100 EeV, including the consideration that the shock is not highly relativistic. We show that shocks in the backflows of radio galaxies can meet these requirements. We discuss a model in which giant-lobed radio galaxies such as Centaurus A and Fornax A act as slowly-leaking UHECR reservoirs, with the UHECRs being accelerated during a more powerful past episode. We also show that Centaurus A, Fornax A and other radio galaxies may explain the observed anisotropies in data from the Pierre Auger Observatory, before examining some of the difficulties in associating UHECR anisotropies with astrophysical sources.Comment: 6 pages, 4 figures. Proceedings of UHECR 2018, 8-12 October 2018, Paris, Franc

Amplification of perpendicular and parallel magnetic fields by cosmic ray currents

Cosmic ray (CR) currents through magnetised plasma drive strong instabilities producing amplification of the magnetic field. This amplification helps explain the CR energy spectrum as well as observations of supernova remnants and radio galaxy hot spots. Using magnetohydrodynamic (MHD) simulations, we study the behaviour of the non-resonant hybrid (NRH) instability (also known as the Bell instability) in the case of CR currents perpendicular and parallel to the initial magnetic field. We demonstrate that extending simulations of the perpendicular case to 3D reveals a different character to the turbulence from that observed in 2D. Despite these differences, in 3D the perpendicular NRH instability still grows exponentially far into the non-linear regime with a similar growth rate to both the 2D perpendicular and 3D parallel situations. We introduce some simple analytical models to elucidate the physical behaviour, using them to demonstrate that the transition to the non-linear regime is governed by the growth of thermal pressure inside dense filaments at the edges of the expanding loops. We discuss our results in the context of supernova remnants and jets in radio galaxies. Our work shows that the NRH instability can amplify magnetic fields to many times their initial value in parallel and perpendicular shocks.Comment: Published in MNRAS. 14 pages, 12 figures, 2 tables. Replacement corrects some typesetting error

Phosphodiesterase Type 5 Inhibitors and Risk of Malignant Melanoma: Matched Cohort Study Using Primary Care Data from the UK Clinical Practice Research Datalink.

BACKGROUND: Laboratory evidence suggests that reduced phosphodiesterase type 5 (PDE5) expression increases the invasiveness of melanoma cells; hence, pharmacological inhibition of PDE5 could affect melanoma risk. Two major epidemiological studies have investigated this and come to differing conclusions. We therefore aimed to investigate whether PDE5 inhibitor use is associated with an increased risk of malignant melanoma, and whether any increase in risk is likely to represent a causal relationship. METHODS AND FINDINGS: We conducted a matched cohort study using primary care data from the UK Clinical Practice Research Datalink. All men initiating a PDE5 inhibitor and with no prior cancer diagnosis were identified and matched on age, diabetes status, and general practice to up to four unexposed controls. Ever use of a PDE5 inhibitor and time-updated cumulative number of PDE5 inhibitor prescriptions were investigated as exposures, and the primary outcome was malignant melanoma. Basal cell carcinoma, solar keratosis, and colorectal cancer were investigated as negative control outcomes to exclude bias. Hazard ratios (HRs) were estimated from Cox models stratified by matched set and adjusted for potential confounders. 145,104 men with ≥1 PDE5 inhibitor prescription, and 560,933 unexposed matched controls were included. In total, 1,315 incident malignant melanoma diagnoses were observed during 3.44 million person-years of follow-up (mean 4.9 y per person). After adjusting for potential confounders, there was weak evidence of a small positive association between PDE5 inhibitor use and melanoma risk (HR = 1.14, 95% CI 1.01-1.29, p = 0.04). A similar increase in risk was seen for the two negative control outcomes related to sun exposure (HR = 1.15, 95% CI 1.11-1.19, p < 0.001, for basal cell carcinoma; HR = 1.21, 95% CI 1.17-1.25, p < 0.001, for solar keratosis), but there was no increased risk for colorectal cancer (HR = 0.91, 95% CI 0.85-0.98, p = 0.01). There was no evidence that risk increased with number of prescriptions received (p-trend = 0.83). In a post hoc analysis, there was strong evidence that solar keratosis was associated with future PDE5 inhibitor use (odds ratio = 1.28, 95% CI 1.23-1.34, p < 0.001), suggesting that men with higher sun exposure were more likely to become PDE5 inhibitor users. However, a limitation of our study was that we did not have individual-level data on sun exposure, so we could not directly control for this in the primary analysis. CONCLUSIONS: Our results were not consistent with PDE5 inhibitors being causally associated with melanoma risk, and strongly suggest that observed risk increases are driven by greater sun exposure among patients exposed to a PDE5 inhibitor

Measuring Productivity Change and Efficiency on Irish Farms.

End of Project ReportThis report investigates technical change and levels of technical efficiency on Irish farms using National Farm Survey (N.F.S.) data. It also examines whether levels of technical efficiency are influenced by contact with the extension service. The study utilises a stochastic production frontier approach to measure productivity growth and the technical efficiency of a panel of Irish farms over the period 1984 to 1998. This sample was used to calculate (a) technical change over time as measured by best practice farms and (b) technical efficiency levels of all farms over this period. It, therefore, provides disaggregated estimates of technical change by farming system as well as quantifying the average level of technical efficiency. The project also examines the factors associated with differences in technical efficiency between farms and the impact of extension service contact on farm-level technical efficiency. Mean technical change (i.e. changes in best practice) continued, albeit at a declining rate, throughout the period studied. Significant differences were revealed in the rate of technical change on farms of different types. For example technical change on dairy and crop farms averaged nearly 2 per cent per annum while technical regress occurred on beef and sheep farms. In addition to examining technical change, farm efficiency relative to best practice within each farming system was also measured. Results indicate that farms achieved, on average, approximately 65 per cent of the efficiency level of best practice farms. The average level of farm efficiency has been decreasing by 0.4 per cent per annum indicating that the gap between best practice farms and all farms has been increasing by this amount over time. Thirty one percent of the most efficient farms were dairy farms while 23 per cent were arable farms. Approximately 52 per cent of the least efficient farms were cattle farms while a further 31 per cent were sheep farms. Average efficiency over the period was 34.2 per cent in the least efficient quintile of farms. This compared to almost 90 per cent for the most efficient quintile of farms. A positive relationship between age and efficiency was found up to the age of 49 years after which the relationship between age and efficiency becomes negative. The farm debt to assets ratio was positively related to efficiency while farm size and location in the West of Ireland was negatively related to efficiency. Farms in contact with the extension service were found to be on average 6.5 per cent more efficient than farms without contact. Contact farms with a lower than average dependency on direct payments were a further 6.6 per cent than contact farms with an average dependency on direct payments. Contact farms with a higher than average dependence on direct payments were 1.9 per cent less efficient than the same group of contact farms. However, efficiency on these farms with a high dependence on direct payments was still, on average, higher than on farms with no extension contact.Teagasc Walsh Fellowshi

The Orlando TDWR testbed and airborne wind shear date comparison results

The focus of this talk is on comparing terminal Doppler Weather Radar (TDWR) and airborne wind shear data in computing a microburst hazard index called the F factor. The TDWR is a ground-based system for detecting wind shear hazards to aviation in the terminal area. The Federal Aviation Administration will begin deploying TDWR units near 45 airports in late 1992. As part of this development effort, M.I.T. Lincoln Laboratory operates under F.A.A. support a TDWR testbed radar in Orlando, FL. During the past two years, a series of flight tests has been conducted with instrumented aircraft penetrating microburst events while under testbed radar surveillance. These tests were carried out with a Cessna Citation 2 aircraft operated by the University of North Dakota (UND) Center for Aerospace Sciences in 1990, and a Boeing 737 operated by NASA Langley Research Center in 1991. A large data base of approximately 60 instrumented microburst penetrations has been obtained from these flights

Na(v )1.8-null mice show stimulus-dependent deficits in spinal neuronal activity

BACKGROUND: The voltage gated sodium channel Na(v )1.8 has a highly restricted expression pattern to predominantly nociceptive peripheral sensory neurones. Behaviourally Na(v )1.8-null mice show an increased acute pain threshold to noxious mechanical pressure and also deficits in inflammatory and visceral, but not neuropathic pain. Here we have made in vivo electrophysiology recordings of dorsal horn neurones in intact anaesthetised Na(v )1.8-null mice, in response to a wide range of stimuli to further the understanding of the functional roles of Na(v )1.8 in pain transmission from the periphery to the spinal cord. RESULTS: Na(v )1.8-null mice showed marked deficits in the coding by dorsal horn neurones to mechanical, but not thermal, -evoked responses over the non-noxious and noxious range compared to littermate controls. Additionally, responses evoked to other stimulus modalities were also significantly reduced in Na(v )1.8-null mice where the reduction observed to pinch > brush. The occurrence of ongoing spontaneous neuronal activity was significantly less in mice lacking Na(v )1.8 compared to control. No difference was observed between groups in the evoked activity to electrical activity of the peripheral receptive field. CONCLUSION: This study demonstrates that deletion of the sodium channel Na(v )1.8 results in stimulus-dependent deficits in the dorsal horn neuronal coding to mechanical, but not thermal stimuli applied to the neuronal peripheral receptive field. This implies that Na(v )1.8 is either responsible for, or associated with proteins involved in mechanosensation