5,730 research outputs found
Empowerment: Trait Relatedness
The purpose of this study was to determine whether the extent that variances in the level of empowerment can be influenced by the willingness of supervisor to empower, the willingness of subordinates to be empowered and the subordinators’ age. The results indicate that there is a positive relationship between subordinates’ empowerment level and the subordinates’ willingness to be empowered; but there is no significant relationship between subordinates’ empowerment level and the supervisors’ willingness to empower
Simulating multiple merger pathways to the central kinematics of early-type galaxies
Two-dimensional integral field surveys such as ATLAS^3D are producing rich
observational data sets yielding insights into galaxy formation. These new
kinematic observations have highlighted the need to understand the evolutionary
mechanisms leading to a spectrum of fast-rotators and slow-rotators in
early-type galaxies. We address the formation of slow and fast rotators through
a series of controlled, comprehensive hydrodynamical simulations sampling
idealized galaxy merger scenarios constructed from model spiral galaxies.
Idealized and controlled simulations of this sort complement the more
'realistic' cosmological simulations by isolating and analyzing the effects of
specific parameters, as we do in this paper. We recreate minor and major binary
mergers, binary merger trees with multiple progenitors, and multiple sequential
mergers. Within each of these categories of formation history, we correlate
progenitor gas fraction, mass ratio, orbital pericenter, orbital ellipticity,
and spin with remnant kinematic properties. We create kinematic profiles of
these 95 simulations comparable to ATLAS^3D data. By constructing remnant
profiles of the projected specific angular momentum (lambda_R = /
, triaxiality, and measuring the incidences of kinematic
twists and kinematically decoupled cores, we distinguish between varying
formation scenarios. We find that binary mergers nearly always form fast
rotators. Slow rotators can be formed from zero initial angular momentum
configurations and gas-poor mergers, but are not as round as the ATLAS^3D
galaxies. Remnants of binary merger trees are triaxial slow rotators.
Sequential mergers form round slow rotators that most resemble the ATLAS^3D
rotators.Comment: MNRAS, in press, 12 pages, 15 figure
Realizing Hopf Insulators in Dipolar Spin Systems
The Hopf insulator represents a topological state of matter that exists
outside the conventional ten-fold way classification of topological insulators.
Its topology is protected by a linking number invariant, which arises from the
unique topology of knots in three dimensions. We predict that three-dimensional
arrays of driven, dipolar-interacting spins are a natural platform to
experimentally realize the Hopf insulator. In particular, we demonstrate that
certain terms within the dipolar interaction elegantly generate the requisite
non-trivial topology, and that Floquet engineering can be used to optimize
dipolar Hopf insulators with large gaps. Moreover, we show that the Hopf
insulator's unconventional topology gives rise to a rich spectrum of edge mode
behaviors, which can be directly probed in experiments. Finally, we present a
detailed blueprint for realizing the Hopf insulator in lattice-trapped
ultracold dipolar molecules; focusing on the example of KRb, we
provide quantitative evidence for near-term experimental feasibility.Comment: 6 + 7 pages, 3 figure
PROGRESS IN ESTIMATING THE MARGINAL COSTS OF GREENHOUSE GAS EMISSIONS
The unjust distributional consequences of climate change, and its potentially negative aggregate effect on economic growth and welfare are two reasons to be concerned about climate change. Our knowledge of the impact of climate change is incomplete. Monetary valuation is difficult and controversial. The effect of other developments on the impacts of climate change is largely speculative. Nonetheless, it can be shown that poorer countries and people are more vulnerable than are richer countries and people. A modest global warming is likely to have a net negative effect on poor economics in hot climates, but may have a positive effect on rich economies in temperate climates. If one counts dollars, the world aggregate impact may be positive. If one counts people, the world aggregate effect is probably negative. For more substantial warming, negative effects become more negative, and positive effects turn negative. The marginal costs of carbon dioxide emissions are uncertain and sensitive to assumptions that partially reflect ethical and methodological positions, but are unlikely to exceed 250/tCH4; the marginal costs of nitrous oxide emissions are probably lower than $7000/tN2O. Global warming potentials, the official manner to trade-off the various greenhouse gases, do not reflect, conceptually or numerically, the real tradeoffs in either a cost-benefit or a cost-effectiveness framework.Impacts of climate change, economic valuation, equity, marginal costs
CIT-7, a crystalline, molecular sieve with pores bounded by 8 and 10-membered rings
A new crystalline molecular sieve, denoted CIT-7, is synthesized using an imidazolium-based diquaternary organic structure directing agent (OSDA). The framework structure is determined from a combination of rotation electron diffraction and synchrotron X-ray powder diffraction data. The structure has 10 crystallographically unique tetrahedral atoms (T-atoms) in the unit cell, and can be described as an ordered arrangement of the [4^(2)5^(4)6^(2)] mtw building unit and a previously unreported [4^(4)5^(2)] building unit. The framework contains a 2-dimensional pore system that is bounded by 10 T-atom rings (10-ring, 5.1 Å × 6.2 Å opening) that are connected with oval 8-rings (2.9 Å × 5.5 Å opening) through medium-sized cavities (~7.9 Å) at the channel intersections. CIT-7 can be synthesized over a broad range of compositions including pure-silica and heteroatom, e.g., aluminosilicate and titanosilicate, containing variants
ANTI-TUBERCULAR ACTIVITY OF EDTA AND HOUSEHOLD CHEMICALS AGAINST MYCOBACTERIUM SMEGMATIS, A SURROGATE FOR MULTI-DRUG RESISTANT TUBERCULOSIS
Drug discovery efforts are increasingly being directed at re-purposing old drugs for use in treatment of multidrug resistant tuberculosis (MDRTB) which continues to pose serious health challenges worldwide. Recent studies suggest that Mycobacterium smegmatis, with innate resistance to isoniazid, could be used as a surrogate for MDRTB screening in laboratories without adequate containment facilities. The current study utilized resazurin microtiter assay plate (REMA) to screen common household chemicals and non-steroidal anti-inflammatory drugs (NSAIDs) for anti-tubercular activity against Mycobacterium smegmatis, as a non-pathogenic surrogate of MDRTB. A ligand-based approach was adopted in selecting household chemicals; using molecular docking tools to probe for binding affinity to Enoyl-[acyl-carrier-protein] reductase (InhA), the main target of isoniazid. Among household chemicals and analgesics studied, EDTA and lauric acid showed the highest activity with minimum inhibitory concentration (MIC) of 31 μg/mL and 7.8 μg/mL respectively, while Ibuprofen and aspirin exhibited activity with MIC of 125 μg/mL. Taken together, this study demonstrates the potential use of EDTA, lauric acid or NSAIDs in treatment of drug-resistant tuberculosis, a major contribution of the current stud
Fossa Navicularis Strictures Due to 22F Catheters Used in Robotic Radical Prostatectomy
Background and objectivesFossa navicularis strictures following radical prostatectomy are reported infrequently. We recently experienced a series of fossa strictures following robot-assisted laparoscopic radical prostatectomy. Fossa strictures are usually procedure-induced, arising from urethral trauma or infection; catheter size has not been reported as a factor. We describe herein our experience to determine and prevent fossa navicularis stricture development.MethodsFrom June 2002 until February 2005, 248 patients underwent robot-assisted laparoscopic prostatectomy with the da Vinci surgical system at our institution. Fossa strictures were diagnosed based on acute onset of obstructive voiding symptoms, IPSS and flow pattern changes, and bougie calibration. During our series, we switched from an 18F to a 22F catheter to avoid inadvertent stapling of the urethra when dividing the dorsal venous complex. All patients had an 18F catheter placed after the anastomosis for 1 week. Parameters were evaluated using Fisher's exact test and the Student t test for means.ResultsThe 18F catheter group (n=117) developed 1 fossa stricture, whereas the 22F catheter group (n=131) developed 9 fossa strictures (P=0.02). The fossa stricture rate in the 18F group was 0.9% versus 6.9% in the 22F group. The 2 groups had no differences in age, body mass index, cardiovascular disease, International Prostate Symptom Score, urinary bother score, SHIM score, preoperative PSA, operative time, estimated blood loss, cautery use, prostate size, or catheterization time.ConclusionsUsing a larger urethral catheter size during intraoperative dissection appears to increase the risk 8-fold for fossa stricture as compared with the 18F catheter. The pneumoperitoneum and prolonged extreme Trendelenberg position could potentially contribute to local urethral ischemia
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