537 research outputs found

    Differentiate Through Christ-Centered International Business Travel

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    The purpose of this paper is to stimulate educators to consider methods in which global business travel with students can be more meaningful, productive, and culturally enriching — both for business students and also for the international communities visited. From a Christian perspective, ideas are shared on the need to understand diverse cultures and to overcome ethnocentrism — a prerequisite for doing business anywhere. Methods are suggested for achieving profound results in international travel with business students

    Could the Pioneer anomaly have a gravitational origin?

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    If the Pioneer anomaly has a gravitational origin, it would, according to the equivalence principle, distort the motions of the planets in the Solar System. Since no anomalous motion of the planets has been detected, it is generally believed that the Pioneer anomaly can not originate from a gravitational source in the Solar System. However, this conclusion becomes less obvious when considering models that either imply modifications to gravity at long range or gravitational sources localized to the outer Solar System, given the uncertainty in the orbital parameters of the outer planets. Following the general assumption that the Pioneer spacecraft move geodesically in a spherically symmetric spacetime metric, we derive the metric disturbance that is needed in order to account for the Pioneer anomaly. We then analyze the residual effects on the astronomical observables of the three outer planets that would arise from this metric disturbance, given an arbitrary metric theory of gravity. Providing a method for comparing the computed residuals with actual residuals, our results imply that the presence of a perturbation to the gravitational field necessary to induce the Pioneer anomaly is in conflict with available data for the planets Uranus and Pluto, but not for Neptune. We therefore conclude that the motion of the Pioneer spacecraft must be non-geodesic. Since our results are model independent within the class of metric theories of gravity, they can be applied to rule out any model of the Pioneer anomaly that implies that the Pioneer spacecraft move geodesically in a perturbed spacetime metric, regardless of the origin of this metric disturbance.Comment: 16 pages, 6 figures. Rev. 3: Major revision. Accepted for publication in Phys. Rev. D. Rev. 4: Added two reference

    Nonlinear electrodynamics and the Pioneer 10/11 spacecraft anomaly

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    The occurrence of the phenomenon known as photon acceleration is a natural prediction of nonlinear electrodynamics (NLED). This would appear as an anomalous frequency shift in any modeling of the electromagnetic field that only takes into account the classical Maxwell theory. Thus, it is tempting to address the unresolved anomalous, steady; but time-dependent, blueshift of the Pioneer 10/11 spacecrafts within the framework of NLED. Here we show that astrophysical data on the strength of the magnetic field in both the Galaxy and the local (super)cluster of galaxies support the view on the major Pioneer anomaly as a consequence of the phenomenon of photon acceleration. If confirmed, through further observations or lab experiments, the reality of this phenomenon should prompt to take it into account in any forthcoming research on both cosmological evolution and origin and dynamical effects of primordial magnetic fields, whose seeds are estimated to be very weak.Comment: Final version accepted for publication in Europhysics Letters, uses EPL style, 7 page

    Treatment options for muscle-invasive urothelial cancer for patients who were not eligible for cystectomy or neoadjuvant chemotherapy with methotrexate, vinblastine, doxorubicin, and cisplatin

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    BACKGROUND. Many patients with invasive urothelial cell cancer are poor candidates for cisplatin-based chemotherapy, and many are high risk for cystectomy. Southwest Oncology Group Trial 8733 was designed to address treatment for such patients. METHODS. Eligible patients had primary or recurrent muscle-invasive disease with transitional cell or squamous cell histology, a performance status from 0 to 2, no extrapelvic disease, a life expectancy >3 months, and adequate hematologic function. The treating clinician assigned patients to operable or inoperable groups. All patients received 2 cycles of 5-fluorouracil (5-FU) at a dose of 1000mg/m 2 per day × 4 starting concurrently with radiation at a dose of 200 centigrays per day × 10 each cycle. After 2 cycles, operable patients with positive biopsies underwent cystectomy, and patients with negative biopsies received a third cycle of chemoradiotherapy. Patients in the inoperable group received 3 cycles without interim biopsy. RESULTS. Eighteen of 24 eligible patients in the operable group were evaluable for response. Five patients had a complete response (CR), 9 patients had stable disease, 1 patient had progressive disease, and 3 patients were not assessable. The median progression-free survival was 10 months (95% confidence interval [95% CI], 4–14 months), and the median overall survival was 18 months (95% CI, 7–28 months). In the inoperable group, 35 of 37 eligible patients were evaluable for response with 17 CRs (49%; 95% CI, 31%–66%). The median progression-free survival was 13 months (95% CI, 10–17 months), and the median overall survival was 20 months (95% CI, 11–53 months). There were no episodes of grade 4 toxicity. CONCLUSIONS. In the current study, the combination of 5-FU and radiation was found to be tolerated well by patients with numerous comorbidities who could not tolerate cisplatin-based therapy or cystectomy. Cancer 2008. © 2008 American Cancer Society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58591/1/23420_ftp.pd

    Land use effects on pesticides in sediments of prairie pothole wetlands in North and South Dakota

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    Prairie potholes are the dominant wetland type in the intensively cultivated northern Great Plains of North America, and thus have the potential to receive pesticide runoff and drift. We examined the presence of pesticides in sediments of 151 wetlands split among the three dominant land use types, Conservation Reserve Program(CRP), cropland, and native prairie, in North and South Dakota in 2011. Herbicides (glyphosate and atrazine) and fungicides were detected regularly, with no insecticide detections. Glyphosate was the most detected pesticide, occurring in 61% of all wetlands, with atrazine in only 8% of wetlands. Pyraclostrobin was one of five fungicides detected, but the only one of significance, being detected in 31% of wetlands. Glyphosate was the only pesticide that differed by land use, with concentrations in cropland over four-times that in either native prairie or CRP, which were equal in concentration and frequency of detection. Despite examining several landscape variables, such as wetland proximity to specific crop types, watershed size, and others, land use was the best variable explaining pesticide concentrations in potholes. CRP ameliorated glyphosate in wetlands at concentrations comparable to native prairie and thereby provides another ecosystem service from this expansive program
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