Layoff and Employment Guarantee Announcements: How Do Shareholders Respond?

Event study methodology was used to assess the effects of both layoff and employment guarantee announcements on shareholder returns. The Wall Street Journal was used to identify 368 firms that announced layoffs and 13 firms that announced employment guarantees in 1993 or 1994. The results were used to test the validity of four hypotheses: labor-cost, efficiency, industrial-relation-effect, and signalling-effect hypotheses. The results show that both layoff announcements and employment guarantee announcements induced a decrease in the shareholder returns of the firms that made the announcements. Each of the above four models received partial support.layoffs; downsizing; event study; employment guarantee

The Plight of Bolivian Coca Leaves: Bolivia\u27s Quest for Decriminalization in the Face of Inconsistent International Legislation

Part One will discuss the importance of the coca leaf to Bolivia and give a brief background of the forced eradication and anti-drug efforts that Bolivia has faced. Part Two will explore the various relevant United Nations legislation, Bolivia’s relevant domestic laws, and the troublesome conflicts these regulation attempts have presented. Part Three will briefly discuss the monist and dualist systems of international law, and how Bolivia’s monist system approaches the coca leaf issue. Lastly, Part Four will propose a number of suggestions on how Bolivia could alternatively approach this dispute, how the United Nations could help disentangle the conflicting legislation, and ways that further coca leaf concessions could benefit Bolivia and the world while also potentially influencing other drug legislation

A Bayesian analysis of the 27 highest energy cosmic rays detected by the Pierre Auger Observatory

It is possible that ultra-high energy cosmic rays (UHECRs) are generated by active galactic nuclei (AGNs), but there is currently no conclusive evidence for this hypothesis. Several reports of correlations between the arrival directions of UHECRs and the positions of nearby AGNs have been made, the strongest detection coming from a sample of 27 UHECRs detected by the Pierre Auger Observatory (PAO). However, the PAO results were based on a statistical methodology that not only ignored some relevant information (most obviously the UHECR arrival energies but also some of the information in the arrival directions) but also involved some problematic fine-tuning of the correlation parameters. Here we present a fully Bayesian analysis of the PAO data (collected before 2007 September), which makes use of more of the available information, and find that a fraction F_AGN = 0.15^(+0.10)_(-0.07) of the UHECRs originate from known AGNs in the Veron-Cetty & Veron (VCV) catalogue. The hypothesis that all the UHECRs come from VCV AGNs is ruled out, although there remains a small possibility that the PAO-AGN correlation is coincidental (F_AGN = 0.15 is 200 times as probable as F_AGN = 0.00).Comment: MNRAS, accepted; 8 pages, 7 figure

A statistical test of emission from unresolved point sources

We describe a simple test of the spatial uniformity of an ensemble of discrete events. Given an estimate for the point source luminosity function and an instrumental point spread function (PSF), a robust upper bound on the fractional point source contribution to a diffuse signal can be found. We verify with Monte Carlo tests that the statistic has advantages over the two-point correlation function for this purpose, and derive analytic estimates of the statistic's mean and variance as a function of the point source contribution. As a case study, we apply this statistic to recent gamma-ray data from the Fermi Large Area Telescope (LAT), and demonstrate that at energies above 10 GeV, the contribution of unresolved point sources to the diffuse emission is small in the region relevant for study of the WMAP Haze.Comment: 11 pages, 7 figures. Final version, accepted by Mon. Not. R. Astron. Soc. The definitive version is available at www.blackwell-synergy.com

Equivalent Linear Two-Body Equations for Many-Body Systems

A method has been developed for obtaining equivalent linear two-body equations (ELTBE) for the system of many ($N$) bosons using the variational principle. The method has been applied to the one-dimensional N-body problem with pair-wise contact interactions (McGurie-Yang N-body problem) and to the dilute Bose-Einstein condensation (BEC) of atoms in anisotropic harmonic traps at zero temperature. For both cases, it is shown that the method gives excellent results for large N.Comment: 12 pages, Late

Flow-Induced Voltage Generation Over Monolayer Graphene in the Presence of Herringbone Grooves

While flow-induced voltage over a graphene layer has been reported, its origin remains unclear. In our previous study, we suggested different mechanisms for different experimental configurations: phonon dragging effect for the parallel alignment and an enhanced out-of-plane phonon mode for the perpendicular alignment (Appl. Phys. Lett. 102:063116, 2011). In order to further examine the origin of flow-induced voltage, we introduced a transverse flow component by integrating staggered herringbone grooves in the microchannel. We found that the flow-induced voltage decreased significantly in the presence of herringbone grooves in both parallel and perpendicular alignments. These results support our previous interpretation

Can optimum solar radiation exposure or supplemented vitamin D intake reduce the severity of COVID-19 symptoms?

The foremost mortality-causing symptom associated with COVID-19 is acute respiratory distress syndrome (ARDS). A significant correlation has been identified between the deficiency in vitamin D and the risk of developing ARDS. It has been suggested that if we can reduce or modify ARDS in COVID-19 patients, we may significantly reduce the severity of COVID-19 symptoms and associated mortality rates. The increased mortality of dark-skinned people, who have a reduced UV absorption capacity, may be consistent with diminished vitamin D status. The factors associated with COVID-19 mortality, such as old age, ethnicity, obesity, hypertension, cardiovascular diseases, and diabetes, are all found to be linked with vitamin D deficiency. Based on this review and as a precautionary measure, it is suggested that the adoption of appropriate and safe solar exposure and vitamin D enriched foods and supplements should be considered to reduce the possible severity of COVID-19 symptoms. Safe sun exposure is deemed beneficial globally, specifically in low and middle- income countries, as there is no cost involved. It is also noted that improved solar exposure and vitamin D levels can reduce the impact of other diseases as well, thus assisting in maintaining general human well-being. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Einstein's E = mc^2 derivable from Heisenberg's Uncertainty Relations

Heisenberg's uncertainty relation can be written in terms of the step-up and step-down operators in the harmonic oscillator representation. It is noted that the single-variable Heisenberg commutation relation contains the symmetry of the Sp(2) group which is isomorphic to the Lorentz group applicable to one time-like dimension and two space-like dimensions, known as the O(2,1) group. This group has three independent generators. The one-dimensional step-up and step-down operators can be combined into one two-by-two Hermitian matrix which contains three independent operators. If we use a two-variable Heisenberg commutation relation, the two pairs of independent step-up, step-down operators can be combined into a four-by-four block-diagonal Hermitian matrix with six independent parameters. It is then possible to add one off-diagonal two-by-two matrix and its Hermitian conjugate to complete the four-by-four Hermitian matrix. This off-diagonal matrix has four independent generators. There are thus ten independent generators. It is then shown that these ten generators can be linearly combined to the ten generators for the Dirac's two oscillator system leadingto the group isomorphic to the de Sitter group O(3,2), which can the be contracted to the inhomogeneous Lorentz group with four translation generators corresponding to the four-momentum in the Lorentz-covariant world. This Lorentz-covariant four-momentum is known as Einstein's E = mc^2.Comment: 18 pages with 6 figures, based on an invited paper presented by Young S. Kim at the 16th International Conference on Squeezed States and Uncertainty Relations (Madrid, Spain, 2019

Field Theory Supertubes

Starting with intersecting M2-branes in M-theory, the IIA supertube can be found by compactification with a boost to the speed of light in the compact dimension. A similar procedure applied to Donaldson-Uhlenbeck-Yau instantons on \bC^3, viewed as intersecting membranes of 7D supersymmetric Yang-Mills (SYM) theory, yields (for finite boost) a new set of 1/4 BPS equations for 6D SYM-Higgs theory, and (for infinite boost) a generalization of the dyonic instanton equations of 5D SYM-Higgs theory, solutions of which are interpreted as Yang-Mills supertubes and realized as configurations of IIB string theory.Comment: 11 pages. Contribution to Strings '04. Revised to include minor corrections and additional reference