703 research outputs found
The Impact of Large-scale Employee Share Ownership Plans on Labour Productivity: The Case of Eircom
Large-scale Employee Share Ownership Plans (ESOPs) have been a distinctive characteristic of Irish public enterprise reform, with shareholdings of 14.9 per cent being allocated to employees as part of firm restructuring and privatisation programmes. This paper presents a case study analysis of a large-scale ESOP in Eircom, Ireland’s former national telecommunications operator. We identify changes in labour productivity during the eight years before and after the establishment of the company’s ESOP and use a framework based on Pierce et al. (2001, 1991) to explore the role played by the ESOP. The ESOP was found to play a key role in enabling firm-level reform through concession bargaining and changes in employee relations, and thereby indirectly affecting labour productivity. However, despite the substantial shareholding and influence of the ESOP, we find it has failed to create a sense of psychological ownership among employees, and thereby further impact on productivit
Comprehensive Solution to the Cosmological Constant, Zero-Point Energy, and Quantum Gravity Problems
We present a solution to the cosmological constant, the zero-point energy,
and the quantum gravity problems within a single comprehensive framework. We
show that in quantum theories of gravity in which the zero-point energy density
of the gravitational field is well-defined, the cosmological constant and
zero-point energy problems solve each other by mutual cancellation between the
cosmological constant and the matter and gravitational field zero-point energy
densities. Because of this cancellation, regulation of the matter field
zero-point energy density is not needed, and thus does not cause any trace
anomaly to arise. We exhibit our results in two theories of gravity that are
well-defined quantum-mechanically. Both of these theories are locally conformal
invariant, quantum Einstein gravity in two dimensions and Weyl-tensor-based
quantum conformal gravity in four dimensions (a fourth-order derivative quantum
theory of the type that Bender and Mannheim have recently shown to be
ghost-free and unitary). Central to our approach is the requirement that any
and all departures of the geometry from Minkowski are to be brought about by
quantum mechanics alone. Consequently, there have to be no fundamental
classical fields, and all mass scales have to be generated by dynamical
condensates. In such a situation the trace of the matter field energy-momentum
tensor is zero, a constraint that obliges its cosmological constant and
zero-point contributions to cancel each other identically, no matter how large
they might be. Quantization of the gravitational field is caused by its
coupling to quantized matter fields, with the gravitational field not needing
any independent quantization of its own. With there being no a priori classical
curvature, one does not have to make it compatible with quantization.Comment: Final version, to appear in General Relativity and Gravitation (the
final publication is available at http://www.springerlink.com). 58 pages,
revtex4, some additions to text and some added reference
Radiative Mechanism to Light Fermion Masses in the MSSM
In a previous work we have showed that the Symmetry,
imply that the light fermions, the electron and the quarks, and , get
their masses only at one loop level. Here, we considere the more general
hypothesis for flavour mixing in the sfermion sector in the MSSM. Then, we
present our results to the masses of these light fermions and as a final result
we can explain why the quark is heavier than the quarks. This
mechanism is in agrement with the experimental constraint on the sfermion's
masses values.Comment: 22 pages, 8 figures, TeX mistakes corrected, accepted for publication
in JHE
Weak-Localization in Chaotic Versus Non-Chaotic Cavities: A Striking Difference in the Line Shape
We report experimental evidence that chaotic and non-chaotic scattering
through ballistic cavities display distinct signatures in quantum transport. In
the case of non-chaotic cavities, we observe a linear decrease in the average
resistance with magnetic field which contrasts markedly with a Lorentzian
behavior for a chaotic cavity. This difference in line-shape of the
weak-localization peak is related to the differing distribution of areas
enclosed by electron trajectories. In addition, periodic oscillations are
observed which are probably associated with the Aharonov-Bohm effect through a
periodic orbit within the cavities.Comment: 4 pages revtex + 4 figures on request; amc.hub.94.
An exhaustive epistatic SNP association analysis on expanded Wellcome Trust data
We present an approach for genome-wide association analysis with improved power on the Wellcome Trust data consisting of seven common phenotypes and shared controls. We achieved improved power by expanding the control set to include other disease cohorts, multiple races, and closely related individuals. Within this setting, we conducted exhaustive univariate and epistatic interaction association analyses. Use of the expanded control set identified more known associations with Crohn's disease and potential new biology, including several plausible epistatic interactions in several diseases. Our work suggests that carefully combining data from large repositories could reveal many new biological insights through increased power. As a community resource, all results have been made available through an interactive web server
Experimental assessment of mixed-mode partition theories for generally laminated composite beams
NOTICE: this is the author’s version of a work that was accepted for publication in Composite Structures. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version will be subsequently published in Composite Structures.Three different approaches to partitioning mixed-mode delaminations are assessed for their ability to predict the interfacial fracture toughness of generally laminated composite beams. This is by using published data from some thorough and comprehensive experimental tests carried out by independent researchers (Davidson et al., 2000 and 2006). Wang and Harvey’s (2012) Euler beam partition theory is found to give very accurate prediction of interfacial fracture toughness for arbitrary layups, thickness ratios and loading conditions. Davidson et al.’s (2000) non-singular-field partition theory has excellent agreement with Wang and Harvey’s Euler beam partition theory for unidirectional layups. Although Davidson et al.’s partition theory predicts the interfacial fracture toughness of multidirectional layups reasonably well, overall Wang and Harvey’s Euler beam partition theory is found to give better predictions. In general, the singular-field approach based on 2D elasticity and the finite element method gives poor predictions of fracture toughness
Wave Mechanics and General Relativity: A Rapprochement
Using exact solutions, we show that it is in principle possible to regard
waves and particles as representations of the same underlying geometry, thereby
resolving the problem of wave-particle duality
Pentaquark baryon production from photon-neuteron reactions
Extending the hadronic Lagrangians that we recently introduced for studying
pentaquark baryon production from meson-proton, proton-proton, and
photon-proton reactions near threshold to include the anomalous interaction
between and , we evaluate the cross section for
production from photon-neutron reactions, in which the was first
detected in the SPring-8 experiment in Japan and the CLAS experiment at Thomas
Jefferson National Laboratory. With empirical coupling constants and form
factors, and assuming that the decay width of is 20 MeV, the
predicted cross section is found to have a peak value of about 280 nb, which is
substantially larger than that for production from photon-proton
reactions.Comment: 13 pages, 6 figure
A synonymous codon variant in two patients with autosomal recessive bestrophinopathy alters in vitro splicing of BEST1
Purpose: Autosomal recessive bestrophinopathy (ARB) is a newly defined retinal dystrophy caused by biallelic mutations in bestrophin-1 (BEST1) and is hypothesized to represent the null bestrophin-1 phenotype in humans. The aim was to determine whether a synonymous BEST1 variant, c.102C>T, identified in two unrelated ARB patients, alters pre-mRNA splicing of the gene. Additionally a detailed phenotypic characterization of this distinctive condition is presented for both patients.Methods: BEST1 was analyzed by direct sequencing. Patients underwent standard ophthalmic assessment. In silico and in vitro analysis using a minigene system was performed to assess whether a synonymous variant identified, c.102C>T p.Gly34Gly, alters pre-mRNA splicing of BEST1.Results: Both ARB patients harbored either proven (patient 1; c.102C>T p.Gly34Gly and c.572T>C p.Leu191Pro) or presumed (patient 2; c.102C>T p.Gly34Gly and c.1470_1471delCA, p.His490GlnfsX24) biallelic mutations in BEST1 and were found to have phenotypes consistent with ARB. In vitro analysis of the synonymous variant, c.102C>T p.Gly34Gly, demonstrated it to introduce a cryptic splice donor site 52 nucleotides upstream of the actual splice donor site.Conclusions: The novel BEST1 variant identified, c.102C>T p.Gly34Gly, alters pre-mRNA splicing in vitro and is potentially pathogenic. In vivo this splicing variant is predicted to lead to the production of an mRNA transcript with a premature termination codon (p.Glu35TrpfsX11) that is predicted to be degraded by NMD
11β-hydroxysteroid dehydrogenase type I inhibition in solid tumours
Glucocorticoids, key hormonal regulators of the stress response, powerfully influence
inflammation and metabolism. Reducing excessive glucocorticoid exposure is
beneficial in treating metabolic and cognitive disorders, but manipulating systemic
endogenous glucocorticoids risks compromising their beneficial effects. The enzyme
11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) activates glucocorticoids in
target tissues and thus inhibition of this enzyme presents a clinical opportunity to
reduce tissue-specific glucocorticoid action. Active glucocorticoids also exert potent
angiostatic effects by binding the glucocorticoid receptor (GR), and 11β-HSD1
inhibitors have proven beneficial in models of myocardial infarction by promoting
angiogenesis. The possibility that 11β-HSD1 inhibitors may increase pathological
angiogenesis, such as that seen in solid tumours, remains unaddressed. This project
tested the hypothesis that 11β-HSD1 inhibition promotes tumour growth as a result of
increased angiogenesis, using murine models of squamous cell carcinoma (SCC) and
pancreatic ductal adenocarcinoma (PDAC).
Murine SCC or PDAC cells were injected (1x106 cells/flank) into WT female mice fed
either standard diet, or diet containing the 11β-HSD1 inhibitor UE2316 (175 mg/kg,
N=6/group), or into 11β-HSD1 knockout (Del1) mice fed standard diet. Developing
tumours were measured by callipers over several weeks, before animals were culled
and tissues collected. SCC tumours grew more rapidly in UE2316-treated mice to
reach a significantly (P<0.01) larger final volume (0.158 ± 0.037 cm3) than in control
mice (0.051 ± 0.007 cm3). PDA tumours were unaffected by 11β-HSD1 inhibition or
deletion. Immunofluorescent co-staining of tumour sections for CD31/α-smooth
muscle actin revealed no differences in vessel density, and RT-qPCR showed no
difference in angiogenic factor expression, after 11β-HSD1 inhibition/deletion in
either tumour type. GR and 11β-HSD1 RNA expression were greater in SCC vs PDAC
tumours (P<0.001), as was 11β-HSD1 activity (P<0.0001).
In studies using the aortic ring assay of ex vivo angiogenesis, 11β-HSD1 deletion, but
not inhibition with UE2316, was shown to prevent glucocorticoid-mediated
angiostasis. The growth/viability of tumour cell lines was not affected by UE2316 or
corticosterone, as assessed by live cell imaging using the Incucyte imaging system.
RNA-sequencing of SCC tumours revealed that multiple factors involved in the innate
immune/inflammatory response were reduced in UE2316-treated tumours, and that
extracellular matrix regulation was also altered by UE2316. Imaging of tumour
sections using Second Harmonic Generation microscopy confirmed that UE2316
altered Type I collagen deposition in SCC (P<0.001) but not PDAC.
11β-HSD1 inhibition can increase tumour growth, possibly via suppression of
inflammatory/immune cell signalling and alteration of the extracellular matrix, and
tumours with higher GR and 11β-HSD1 content, such as SCC, may be more at risk.
Interestingly this investigation found no evidence of increased angiogenesis in vivo or
ex vivo after UE2316 treatment, suggesting that 11β-HSD1 inhibition does not
promote angiogenesis in all ischaemic environments. Future work must focus on the
effects of 11β-HSD1 inhibition on the immune and extracellular matrix component of
the tumour microenvironment. While promotion of pathological angiogenesis does not
appear to pose a major threat, 11β-HSD1 inhibitors may still interact with the immune
and inflammatory environment in tumours to the detriment of health
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