Evaluating the Performance of Government IT Projects in the Caribbean: Beyond the Traditional Approach

The study seeks to empirically apply multiple performance evaluation techniques, including traditional approach to assess the performance of government projects. Studies have shown that while there is an increase in improved project management methods, tools and techniques, including performance evaluation techniques, organizations including governments are still relying on outdated or insufficient tools. We posit that the increased application of alternative approaches to highlight the important dimensions of the project process can help to address this issue. With the increased application of newer techniques over time, stakeholders can be equipped to better identify sources of failures and successes and improve the management of projects. This is crucial for IT projects and government projects that are consistently perceived as underperforming. The research employs a single project from the aviation industry in the Caribbean to apply the perspectives of the Barclay’s Project Performance Scorecard and Delone & McLean’s IS Success Model measurements, and triple constraints method to evaluate project performance and report on the findings

On the Stability of Electrostatic Orbits

We analyze the stability of two charged conducting spheres orbiting each other. Due to charge polarization, the electrostatic force between the two spheres deviates significantly from $1/r^2$ as they come close to each other. As a consequence, there exists a critical angular momentum, $L_c$, with a corresponding critical radius $r_c$. For $L > L_c$ two circular orbits are possible: one at $r > r_c$ that is stable and the other at $r < r_c$ that is unstable. This critical behavior is analyzed as a function of the charge and the size ratios of the two spheres.Comment: Added references, corrected typos, clarified languag

Structure, Pseudorotation, and Vibrational Mode Coupling in IF7: An Electron Diffraction Study

Free vapor‐phase molecules of iodine heptafluoride are pentagonal bipyramids with axial bonds (1.786 ± 0.007 Å esd) shorter than equatorial bonds (1.858 ± 0.004 Å). They are deformed from D5hD5h symmetry on the average by 7.5° ring puckering displacements (e2″e2″ symmetry) and 4.5° axial bend displacements (e1″e1″ symmetry). The distortion from D5hD5h, interpreted in terms of the points‐on‐a‐sphere variant of the valence‐shell electron‐pair theory, is compatible with an effective force law between electron pairs of Vij  ∼  rij−nVij∼rij−n with nn in the broad vicinity of 3.5. Expressing forces harder than simple Coulomb repulsions and much softer than conventional atom–atom nonbonded repulsions, the potential‐energy law is in a range consistent with Gillespie's bond–bond repulsion theory. The simplest interpretation of the diffraction intensities is that the molecules undergo essentially free pseudorotation along a pathway (predominantly e2″e2″ displacement coordinates) connecting 10 equivalent C2C2 structures via CsCs intermediates. The observed pseudoradial displacement suggests a value of about 5 cm−1 for the pseudoangular rotation constant h / 8π2cIeffh∕8π2cIeff. The appreciable axial bend induced by the ring pucker is correlated in phase with the pucker displacement. This correlation is responsible for introducing a pronounced skewing of the Fax⋅⋅⋅FeqFax⋅⋅⋅Feq radial distribution peak (i.e., an “anharmonic shrinkage”) and also presumably imparts significant infrared activity to the e2″e2″ modes in overtones and combination bands. Furthermore, the axial bend gives the molecule a dipole moment which may explain recent molecular‐beam experiments by Klemperer et al.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71219/2/JCPSA6-53-10-4040-1.pd

A cosmic-ray dominated ISM in Ultra Luminous Infrared Galaxies: new initial conditions for star formation

The high-density star formation typical of the merger/starburst events that power the large IR luminosities of Ultra Luminous Infrared Galaxies (ULIRGs) (L_{IR}>10^{12}Lsol) throughout the Universe results to extraordinarily high cosmic ray (CR) energy densities of U_CR~(few)x(10^3--10^4)U_{CR,Gal} permeating their interstellar medium (ISM), a direct consequence of the large supernovae remnants (SNRs) number densities in such systems. Unlike far-UV photons emanating from their numerous star forming sites, these large CR energy densities in ULIRGs will volumetrically heat and raise the ionization fraction of dense (n>10^4 cm^{-3}) UV-shielded gas cores throughout their compact star-forming volumes. Such conditions can turn most of the large molecular gas masses found in such systems and their high redshift counterparts (M(H2)~10^9-10^10 M_{sol}) into giant CR-dominated Regions (CRDRs) rather than ensembles of Photon-dominated Regions (PDRs) which dominate in less IR-luminous systems where star formation and molecular gas distributions are much more extended. The molecular gas in CRDRs will have a {\it minimum} temperature of T_{kin}~(80--160)K, and very high ionization fractions of x(e)>10^{-6} throughout its UV-shielded dense cores, which in turn will {\it fundamentally alter the initial conditions for star formation in such systems.}. Observational tests of CRDRs can be provided by ......Comment: Accepted by The Astrophysical Journal on June 23, published August 9 (ApJ, 720, 226), 2010. This version for the ADD-A

Influence of Nonbonded Interactions on Molecular Geometry and Energy: Calculations for Hydrocarbons Based on Urey—Bradley Field

A modified Urey—Bradley potential energy function comprised of quadratic terms for bond stretches, bond‐angle bends, and torsional displacements together with analytical expressions for pairwise nonbonded interactions was chosen to represent the force field for hydrocarbon molecules. Quadratic constants were taken from the spectroscopic U☒B analyses of Schachtschneider and Snyder [Spectrochim. Acta 19, 117 (1963)], while the nonbonded functions adopted were those proposed by Bartell [J. Chem. Phys. 32, 827 (1960)]. Reference bond angles for the quadratic terms were taken to be 109.5° or 120° for tetrahedral or trigonal coordination, respectively. Reference single‐bond lengths and the torsional constant were adjusted to fit the experimental data for CH4 and C2H6. Double bonds and ring bonds in cyclopropyl compounds were considered to be rigid. The above selections served to establish a universal model force field for hydrocarbons with no remaining adjustable parameters. The potential energy functions for a variety of saturated hydrocarbons and several olefins and cyclopropyl derivatives were minimized with respect to independent structure parameters (i.e., bond stretches, bends, and internal rotations). Even though all C☒H (and C☒C) bonds were input to be identical to those in CH4 (and C2H6) except for nonbonded environment, the bond lengths and angles corresponding to the minimum potential energy exhibited an appreciable variation from molecule to molecule, as did also the strain energies of geometric and rotational isomers. Calculated trends in structures, isomerization energies, and barriers to rotation agreed quite well with experimentally observed trends, provided that experimental isomerization energies were corrected to 0°K and zero‐point energies were taken into account. Some novel features of the results and applications of the model for predicting deformations in strained systems are discussed. The present study differs from previous work in the area of ``molecular mechanics'' in the use of a more general force field, in allowing the strained molecules to relax in all degrees of freedom (except for unsaturated groups and cyclopropyl rings), in the selection of molecular systems, and in a detailed comparison with experiment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70433/2/JCPSA6-47-10-3736-1.pd

NICMOS Imaging of the HR 4796A Circumstellar Disk

We report the first near infrared (NIR) imaging of a circumstellar annular disk around the young (~8 Myr), Vega-like star, HR 4796A. NICMOS coronagraph observations at 1.1 and 1.6 microns reveal a ring-like symmetrical structure peaking in reflected intensity 1.05 arcsec +/- 0.02 arcsec (~ 70 AU) from the central A0V star. The ring geometry, with an inclination of 73.1 deg +/- 1.2 deg and a major axis PA of 26.8 deg +/- 0.6 deg, is in good agreement with recent 12.5 and 20.8 micron observations of a truncated disk (Koerner, et al. 1998). The ring is resolved with a characteristic width of less than 0.26 arcsec (17 AU) and appears abruptly truncated at both the inner and outer edges. The region of the disk-plane inward of ~60 AU appears to be relatively free of scattering material. The integrated flux density of the part of the disk that is visible (greater than 0.65 arcsec from the star) is found to be 7.5 +/- 0.5 mJy and 7.4 +/- 1.2 mJy at 1.1 and 1.6 microns, respectively. Correcting for the unseen area of the ring yields total flux densities of 12.8 +/- 1.0 mJy and 12.5 +/- 2.0 mJy, respectively (Vega magnitudes = 12.92 /+- 0.08 and 12.35 +/-0.18). The NIR luminosity ratio is evaluated from these results and ground-based photometry of the star. At these wavelengths Ldisk(lambda)/L*(lambda) = 1.4 +/- 0.2E-3 and 2.4 +/- 0.5E-3, giving reasonable agreement between the stellar flux scattered in the NIR and that which is absorbed in the visible and re-radiated in the thermal infrared. The somewhat red reflectance of the disk at these wavelengths implies mean particle sizes in excess of several microns, larger than typical interstellar grains. The confinement of material to a relatively narrow annular zone implies dynamical constraints on the disk particles by one or more as yet unseen bodies.Comment: 14 pages, 1 figure for associated gif file see: http://nicmosis.as.arizona.edu:8000/AAS99/FIGURE1_HR4796A_ApJL.gif . Accepted 13 January 1999, Astrophyical Journal Letter

Myo-Inositol Reduces β-Catenin Activation in Colitis

AIM To assess dietary myo-inositol in reducing stem cell activation in colitis, and validate pβ-cateninS552 as a biomarker of recurrent dysplasia. METHODS We examined the effects of dietary myo-inositol treatment on inflammation, pβ-cateninS552 and pAkt levels by histology and western blot in IL-10-/- and dextran sodium sulfate-treated colitic mice. Additionally, we assessed nuclear pβ-cateninS552 in patients treated with myo-inositol in a clinical trial, and in patients with and without a history of colitis-induced dysplasia. RESULTS In mice, pβ-cateninS552 staining faithfully reported the effects of myo-inositol in reducing inflammation and intestinal stem cell activation. In a pilot clinical trial of myo-inositol administration in patients with a history of low grade dysplasia (LGD), two patients had reduced numbers of intestinal stem cell activation compared to the placebo control patient. In humans, pβ-cateninS552 staining discriminated ulcerative colitis patients with a history of LGD from those with benign disease. CONCLUSION Enumerating crypts with increased numbers of pβ-cateninS552 - positive cells can be utilized as a biomarker in colitis-associated cancer chemoprevention trials

Building up the spectrum of cosmic-rays in star-forming regions

The common approach to compute the cosmic-ray distribution in an starburst galaxy or region is equivalent to assume that at any point within that environment, there is an accelerator inputing cosmic rays at a reduced rate. This rate should be compatible with the overall volume-average injection, given by the total number of accelerators that were active during the starburst age. These assumptions seem reasonable, especially under the supposition of an homogeneous and isotropic distribution of accelerators. However, in this approach the temporal evolution of the superposed spectrum is not explicitly derived; rather, it is essentially assumed ab-initio. Here, we test the validity of this approach by following the temporal evolution and spatial distribution of the superposed cosmic-ray spectrum and compare our results with those from theoretical models that treat the starburst region as a single source. In the calorimetric limit (with no cosmic-ray advection), homogeneity is reached (typically within 20%) across most of the starburst region. However, values of center-to-edge intensity ratios can amount to a factor of several. Differences between the common homogeneous assumption for the cosmic-ray distribution and our models are larger in the case of two-zone geometries, such as a central nucleus with a surrounding disc. We have also found that the decay of the cosmic-ray density following the duration of the starburst process is slow, and even approximately 1 Myr after the burst ends (for a gas density of 35 cm-3) it may still be within an order of magnitude of its peak value. Based on our simulations, it seems that the detection of a relatively hard spectrum up to the highest gamma-ray energies from nearby starburst galaxies favors a relatively small diffusion coefficient (i.e., long diffusion time) in the region where most of the emission originates.Comment: To appear in MNRA