512 research outputs found
Dual-Career Relocation Benefits: A Study of Executive Search Firms
C. Richard Scott is an Assistant Professor of Management in the Department of Management at Radford University. Robert W. Holloway is a Technical Writer for Hercules, lnc. (Aerospace Division), Radford, Virginia
Factors Associated with Immunization Opinion Leadership among Men Who Have Sex with Men in Los Angeles, California
We sought to identify the characteristics of men who have sex with men (MSM) who are opinion leaders on immunization issues and to identify potential opportunities to leverage their influence for vaccine promotion within MSM communities. Using venue-based sampling, we recruited and enrolled MSM living in Los Angeles (N = 520) from December 2016 to February 2017 and evaluated characteristic differences in sociodemographic characteristics, health behaviors, and technology use among those classified as opinion leaders versus those who were not. We also asked respondents about their past receipt of meningococcal serogroups A, C, W, and Y (MenACWY) and meningococcal B (MenB) vaccines, as well as their opinions on the importance of 13 additional vaccines. Multivariable results revealed that non-Hispanic black (aOR = 2.64; 95% CI: 1.17â5.95) and other race/ethnicity (aOR = 2.98; 95% CI: 1.41â6.29) respondents, as well as those with a history of an STI other than HIV (aOR = 1.95; 95% CI: 1.10â3.48), were more likely to be opinion leaders. MenACWY (aOR = 1.92; 95% CI: 1.13â3.25) and MenB (aOR = 3.09; 95% CI: 1.77â5.41) vaccine uptake, and perceived importance for these and seven additional vaccines, were also associated with being an opinion leader. The results suggest that the co-promotion of vaccination and other health promotion initiatives via opinion leaders could be a useful strategy for increasing vaccination among MSM
Electron exchange coupling in a naturally occurring tetramangano cluster in the mineral helvite, (Mn4S)(SiBeO4)3
The mineral helvite, (Mn4S)(BeSiO4)3, contains discrete tetrahedral Mn4S+6 clusters in which the S-2 is tetrahedrally coordinated and each Mn(II) is in a distorted tetrahedron of one S-2 and three oxygens; the cluster is situated within an encompassing lattice of SiO4-4 and BeO4-6 tetrahedra. Mn4S+6 centers provide an interesting model for comparison to the polynuclear manganese center that is associated with photosynthetic water oxidation. Magnetic susceptibility data between 77 and 298 K have been measured for a natural helvite sample containing principally Mn4S+6 centers but with significant contamination from Mn3FeS+6 and Mn3CaS+6. The data exhibited Curie-Weiss behavior with [mu]eff = 5.969 B.M. and [theta] = 178.3 K. An analysis of the magnetic susceptibility, based on Van Vleck's formalism, demonstrated the presence of antiferromagnetic coupling, with a coupling constant J = -5.83 cm-1. Mossbauer spectra of Mn3FeS centers in helvite and of Fe4S centers in the related mineral danalite have also been recorded. Isomer shifts show little temperature dependence and lie in the range 1.23-1.43 mm/sec.. This range is typical of tetrahedrally coordinated Fe(II) in several ionic crystals but is significantly above that of Fe(II) in ferredoxins and below that in the [quinone-Fe(II)-quinone] complex of the photosynthetic bacterium,Rhodopseudomonas sphaeroides. Quadrupole splittings are highly temperature dependent, ranging from 2.4 mm/sec at 4.2 K to less than 0.5 mm/sec at 248 K.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25645/1/0000197.pd
Evaluation of Floorpan Tearing and Cable Splices for Cable Barrier Systems
This research effort consisted of two objectives related to components of a prototype cable barrier system. The first objective was to mitigate the potential for vehicle floorpan tearing by modifying the cable guardrail posts. A bogie vehicle was equipped with a simulated floorpan designed to replicate the height, thickness, and strength of the floorpan of a Kia Rio vehicle. Baseline testing demonstrated that the top of the Midwest Weak Post (MWP) would contact, and crease the simulated floorpan, which matched the damage observed in actual full-scale vehicle crash tests. Once the test setup provided the desired results, various post configurations were tested including S3x5.7 (S76x8.4) posts, MWPs with edge rounding, MWPs with steel plate edge protectors, and MWPs with weakening holes/slots. Three different weakening patterns were evaluated: Ÿ-in. (19-mm) diameter hole; three â
-in. (10-mm) diameter holes; and â
-in. x 1â
-in. (10-mm x 29-mm) slots. All three weakening patterns showed the ability to reduce the propensity for floorpan tearing. However, additional bogie testing of the posts resulted in significant reductions in strong-axis strength for the latter two weakening patterns. The Ÿ-in. (19-mm) diameter hole resulted in a 10 percent reduction in strong-axis bending strength, and thus, was recommended for further evaluation through full-scale vehicle crash testing.
The second objective was to investigate the structural capacity of other cable splice hardware that would reduce the propensity for vehicle snag and sheet metal tearing. A review of existing hardware was conducted to identify possible couplers. Next, three component tests were conducted to evaluate two models of Bennett Bolt Works mechanical couplers. Test results for the new coupler, model no. CGBBWTH, showed promise, however the targeted failure strength of 39 kips (174 kN) was not satisfied for either the new coupler, model no. CGBBWTH, or current coupler, model no. CGBBHT. There is potential that the couplers used in test no. BBNC-3 sustained damage in previous testing which would make them susceptible to premature failure, therefore further testing and evaluation of both coupler models will be necessary to gain a better understanding of their strengths and durability
MASH Test No. 3-10 of a Non-Proprietary, High-Tension, Cable Median Barrier for Use in 6H:1V V-Ditch (Test No. MWP-9)
The Midwest Pooled Fund Program has been developing a prototype design for a non-proprietary, high-tension, cable median barrier for use in a 6H:1V median V-ditch. This system incorporates four evenly spaced cables, Midwest Weak Posts (MWPs) spaced at 8 to 16 ft (2.4 to 4.9 m) intervals, and a bolted, tabbed bracket to attach the cables to each post. Full-scale crash testing was needed to evaluate the barrierâs safety performance. According to the Manual for Assessing Safety Hardware 2016 (MASH) testing matrix for cable barriers installed within a 6H:1V median V-ditch, a series of eight full-scale crash tests are required to evaluate the safety performance of a system.
Several previous tests have failed due to the posts penetrating into the occupant compartment. In order to mitigate the floor pan tearing, a modified MWP was designed. Test no. MWP-9 was conducted on the modified barrier system, consisting of MWPs with 3â4-in. (19-mm) diameter weakening holes at the ground line. Additionally, a two-part cap with a single retainer bolt was added to the top of the posts. The cap shielded the free edges of the MWPs during the post-to-vehicle contact. This test was conducted according to MASH 2016 test designation no. 3-10 and utilized an 1100C small car impacting the barrier on level terrain. The vehicle was contained by the system. The two-piece cap mitigated the floor pan tearing. However, one cable (cable no. 3) snagged on the cap retainer bolt and caused two cables (cable nos. 3 and 4) to become interlocked with the left-side A-pillar on the impact side of the vehicle, which resulted in excessive A-pillar crush. Therefore, test no. MWP-9 was deemed unacceptable. However, the two-part cap demonstrated that a closed-section post should be capable of mitigating floor pan tearing
Phase II Evaluation of Floor Pan Tearing for Cable Barrier Systems
The objective of this research effort was to mitigate the potential for floor pan tearing and penetration into the occupant compartment by modifying the posts utilized in a prototype cable barrier system. A series of dynamic component tests were conducted on the modified Midwest Weak Post (MWP). A bogie vehicle was equipped with a simulated floor pan designed to replicate the height, thickness, and strength of the floor pan of a Kia Rio. Two methods of post modification were investigated, including edge protection on the top of the MWP as well as weakening of the MWP at the ground line.
Two methods of edge protection were tested, including a 31â2-in. x 21â2-in. x 3/16-in. (89-mm x 64-mm x 5-mm) thick steel tube cap and 21â8-in. x 13â8-in. x 7-gauge (54-mm x 35-mm x 5-mm) bent steel plates. Weakening of the MWPs was accomplished through two 3â4-in. (19-mm) diameter holes drilled through the weak-axis of the posts at the ground line. Both methods of edge protection showed potential for mitigating the propensity for floor pan tearing. In all but one test, the posts caused creasing on the simulated floor pan. In one test, test no. MWPFP-23, the edge protector connection bolt sheared and allowed the postsâ free edges to contact and tear the simulated floor pan, which would not be expected in full-scale crash testing with the 1100C vehicle. The bogie testing of MWPs with 3â4-in. (19-mm) diameter weakening holes with steel plate edge protectors mounted at the top of the posts resulted in only minor creasing on the simulated floor pan. Thus, a combination of weakening holes and edge protectors using steel bent plates at top of the MWP was recommended for further evaluation through full-scale vehicle crash testing
Interleukin-1 receptor 1 knockout has no effect on amyloid deposition in Tg2576 mice and does not alter efficacy following AÎČ immunotherapy
BACKGROUND: Microglial activation has been proposed to facilitate clearance of amyloid ÎČ protein (AÎČ) from the brain following AÎČ immunotherapy in amyloid precursor protein (APP) transgenic mice. Interleukin-1 receptor 1 knockout (IL-1 R1-/-) mice are reported to exhibit blunted inflammatory responses to injury. To further define the role of IL-1-mediated inflammatory responses and microglial activation in this paradigm, we examined the efficacy of passive AÎČ immunotherapy in Tg2576 mice crossed into the IL-1 R1-/- background. In addition, we examined if loss of IL-1 R1-/- modifies AÎČ deposition in the absence of additional manipulations. METHODS: We passively immunized Tg2576 mice crossed into the IL-1 R1-/- background (APP/IL-1 R1-/- mice) with an anti-AÎČ1-16 mAb (mAb9, IgG2a) that we previously showed could attenuate AÎČ deposition in Tg2576 mice. We also examined whether the IL-1 R1 knockout background modifies AÎČ deposition in untreated mice. Biochemical and immunohistochemical AÎČ loads and microglial activation was assessed. RESULTS: Passive immunization with anti-AÎČ mAb was effective in reducing plaque load in APP/IL-1 R1-/- mice when the immunization was started prior to significant plaque deposition. Similar to previous studies, immunization was not effective in older APP/IL-1 R1-/- mice or IL-1 R1 sufficient wild type Tg2576 mice. Our analysis of AÎČ deposition in the untreated APP/IL-1 R1-/- mice did not show differences on biochemical AÎČ loads during normal aging of these mice compared to IL-1 R1 sufficient wild type Tg2576 mice. CONCLUSION: We find no evidence that the lack of the IL-1 R1 receptor influences either AÎČ deposition or the efficacy of passive immunotherapy. Such results are consistent with other studies in Tg2576 mice that suggest microglial activation may not be required for efficacy in passive immunization approaches
Statistical mechanics of Fofonoff flows in an oceanic basin
We study the minimization of potential enstrophy at fixed circulation and
energy in an oceanic basin with arbitrary topography. For illustration, we
consider a rectangular basin and a linear topography h=by which represents
either a real bottom topography or the beta-effect appropriate to oceanic
situations. Our minimum enstrophy principle is motivated by different arguments
of statistical mechanics reviewed in the article. It leads to steady states of
the quasigeostrophic (QG) equations characterized by a linear relationship
between potential vorticity q and stream function psi. For low values of the
energy, we recover Fofonoff flows [J. Mar. Res. 13, 254 (1954)] that display a
strong westward jet. For large values of the energy, we obtain geometry induced
phase transitions between monopoles and dipoles similar to those found by
Chavanis and Sommeria [J. Fluid Mech. 314, 267 (1996)] in the absence of
topography. In the presence of topography, we recover and confirm the results
obtained by Venaille and Bouchet [Phys. Rev. Lett. 102, 104501 (2009)] using a
different formalism. In addition, we introduce relaxation equations towards
minimum potential enstrophy states and perform numerical simulations to
illustrate the phase transitions in a rectangular oceanic basin with linear
topography (or beta-effect).Comment: 26 pages, 28 figure
BARRIER SYSTEM
A barrier system (100) includes first and second barrier segments (102) connected to one another such that crash energy is absorbed. The connection between the segments includes a pair of wedge-shaped connectors (102) disposed between angled faces (118) formed at the opposing ends of the segments. Elastic pads (700) are sandwiched between the respective segment faces and connectors (202)
- âŠ