1,787 research outputs found
Human resource management as a substitute for trade unions in British workplaces
The authors use British workplace data for 1980–98 to examine whether increased human resource management (HRM) practices coincided with union decline, consistent with the hypothesis that such practices act as a substitute for unionization. Two initial analyses show no important differences between union and non-union sectors or between newer workplaces (which are likelier to be non-union) and older ones in the pattern of HRM practices over time; and the study’s longitudinal analysis picks up no evidence of faster union decline in workplaces or industries that adopted HRM practices than in those that did not. Not only is the hypothesized substitution effect thus not supported, but the authors even uncover some evidence of a complementarity between unions and HRM practices. The authors conclude that increased use of HRM practices is probably not an important factor underpinning union decline in Britain
Hazardous near Earth asteroid mitigation campaign planning based on uncertain information on fundamental asteroid characteristics
Given a limited warning time, an asteroid impact mitigation campaign would hinge on uncertainty-based information consisting of remote observational data of the identified Earth-threatening object, general knowledge of near-Earth asteroids (NEAs), and engineering judgment. Due to these ambiguities, the campaign credibility could be profoundly compromised. It is therefore imperative to comprehensively evaluate the inherent uncertainty in deflection and plan the campaign accordingly to ensure successful mitigation. This research demonstrates dual-deflection mitigation campaigns consisting of primary (instantaneous/quasi-instantaneous) and secondary (slow-push) deflection missions, where both deflection efficiency and campaign credibility are taken into account. The results of the dual-deflection campaign analysis show that there are trade-offs between the competing aspects: the launch cost, mission duration, deflection distance, and the confidence in successful deflection. The design approach is found to be useful for multi-deflection campaign planning, allowing us to select the best possible combination of missions from a catalogue of campaign options, without compromising the campaign credibility
Accuracy and Limitations of Fitting and Stereoscopic Methods to Determine the Direction of Coronal Mass Ejections from Heliospheric Imagers Observations
Using data from the Heliospheric Imagers (HIs) onboard STEREO, it is possible
to derive the direction of propagation of coronal mass ejections (CMEs) in
addition to their speed with a variety of methods. For CMEs observed by both
STEREO spacecraft, it is possible to derive their direction using simultaneous
observations from the twin spacecraft and also, using observations from only
one spacecraft with fitting methods. This makes it possible to test and compare
different analyses techniques. In this article, we propose a new fitting method
based on observations from one spacecraft, which we compare to the commonly
used fitting method of Sheeley et al. (1999). We also compare the results from
these two fitting methods with those from two stereoscopic methods, focusing on
12 CMEs observed simultaneously by the two STEREO spacecraft in 2008 and 2009.
We find evidence that the fitting method of Sheeley et al. (1999) can result in
significant errors in the determination of the CME direction when the CME
propagates outside of 60deg \pm 20 deg from the Sun-spacecraft line. We expect
our new fitting method to be better adapted to the analysis of halo or limb
CMEs with respect to the observing spacecraft. We also find some evidence that
direct triangulation in the HI fields-of-view should only be applied to CMEs
propagating approximatively towards Earth (\pm 20deg from the Sun-Earth line).
Last, we address one of the possible sources of errors of fitting methods: the
assumption of radial propagation. Using stereoscopic methods, we find that at
least seven of the 12 studied CMEs had an heliospheric deflection of less than
20deg as they propagated in the HI fields-of-view, which, we believe, validates
this approximation.Comment: 17 pages, 6 figures, 2 tables, accepted to Solar Physic
The occurrence of anti-retroviral compounds used for HIV treatment in South African surface water
The study and quantification of personal care products, such as pharmaceuticals, in surface water has
become popular in recent years; yet very little description of these compounds’ presence in South African
surface water exists in the literature. Antiretrovirals (ARVs), used to treat human immunodeficiency virus
(HIV) are rarely considered within this field. A new method for the simultaneous quantification of 12
antiretroviral compounds in surface water using the standard addition method is described. Water
samples were concentrated by a generic automated solid phase extraction method and analysed by ultrahigh
pressure liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Substantial matrix
effect was encountered in the samples with an average method detection limit of 90.4 ng/L. This is the
first reported countrywide survey of South African surface water for the quantification of these compounds
with average concentrations ranging between 26.5 and 430 ng/L.South African Military Health Services.http://www.elsevier.com/locate/envpolhb2016Chemistr
Anthocyanin-rich extract decreases indices of lipid peroxidation and DNA damage in vitamin E-depleted rats
Anthocyanins are secondary plant metabolites responsible for the blue, purple, and red color of many plant
tissues. The phenolic structure of anthocyanins conveys marked antioxidant activity in model systems via donation of
electrons or hydrogen atoms from hydroxyl moieties to free radicals. Dietary intakes of anthocyanins may exceed 200 mg/day, however, little is known about their antioxidant potency in vivo. Consequently, the aim of this study was to
establish whether anthocyanins could act as putative antioxidant micronutrients. Rats were maintained on vitamin
E-deficient diets for 12 weeks in order to enhance susceptibility to oxidative damage and then repleted with rations
containing a highly purified anthocyanin-rich extract at a concentration of 1 g/kg diet. The extract consisted of the
3-glucopyranoside forms of delphinidin, cyanidin, petunidin, peonidin, and malvidin. Consumption of the anthocyanin repleted
diet significantly improved (p < 0.01) plasma antioxidant capacity and decreased (p < 0.001) the vitamin E
deficiency-enhanced hydroperoxides and 8-Oxo-deoxyguanosine concentrations in liver. These compounds are indices
of lipid peroxidation and DNA damage, respectively. Dietary consumption of anthocyanin-rich foods may contribute to
overall antioxidant status, particularly in areas of habitually low vitamin E intake.Fundação para Ciência e Tecnologi
The role of composition and phase upon the lattice nitrogen reactivity of ternary molybdenum nitrides
The reactivity of the lattice nitrogen in the filled β-Mn structured Co2Mo3N and the η-carbide structured Co3Mo3N and Fe3Mo3N has been investigated under 3:1 H2/Ar at temperatures up to 900 °C. The lattice nitrogen in Co3Mo3N was found to be reactive, as reported previously, whereas Co2Mo3N was shown to be stable up to 800 °C. Upon H2/Ar treatment at 900 °C, the Co2Mo3N, Co3Mo3N and Fe3Mo3N phases decomposed. These results suggest that both metal composition and phase have an influence on the bulk lattice nitrogen reactivity of the ternary nitrides
Evidence for Shape Co-existence at medium spin in 76Rb
Four previously known rotational bands in 76Rb have been extended to moderate
spins using the Gammasphere and Microball gamma ray and charged particle
detector arrays and the 40Ca(40Ca,3pn) reaction at a beam energy of 165 MeV.
The properties of two of the negative-parity bands can only readily be
interpreted in terms of the highly successful Cranked Nilsson-Strutinsky model
calculations if they have the same configuration in terms of the number of g9/2
particles, but they result from different nuclear shapes (one near-oblate and
the other near-prolate). These data appear to constitute a unique example of
shape co-existing structures at medium spins.Comment: Accepted for publication in Physics Letters
- …