2,177 research outputs found
Recommendations to Implement a Potential Case Study Module to all CM Labs
California Polytechnic State University, San Luis Obispo [Cal Poly for short] is notable for having one of the best undergraduate Construction Management programs in the nation. From winning consecutive regional competitions, such as the ASC Competition in Reno, to incorporating a “learn-by-doing” philosophy in all its classrooms, Cal Poly’s CM curriculum truly distinguishes itself from other CM programs nationwide. From the Cal Poly Construction Management website, it’s noted that upon graduation, “the department has virtually 100% placement in the construction industry” (“Cal Poly Construction Management”). However, while the CM program at Cal Poly truly excels in preparing its undergraduate students in technical skills, the curriculum lacks preparation for its students in another imperative industry skill: problem-solving. This report will evaluate the benefits of case-based learning, as adopted in the nation’s top universities, such as Yale University, Harvard Business School, and Boston University. Moreover, the report will determine whether there is sufficient interest with implementing a potential case study module in all of Cal Poly’s CM labs
Rates of Sediment Accumulation, Bioturbation and Resuspension in Back Bay, Virginia, a Coastal Lagoon
Back Bay is the northernmost section of the Albemarle-Pamlico lagoon-estuary system. Back Bay lagoon and its associated barrier (Currituck Spit) are moving landward in response to post-glacial sea level rise (2.6 mm yr-1). The long term (100 year time scale) landward migration rate of Currituck Spit may be on the order of a meter per year.
Sediment accumulation, resuspension and bioturbation are processes in Back Bay that control the residence time of organic matter in the bay floor. and therefore, effect the rate of nutrient release. As burial proceeds, nutrients in the zone of mixing may be remineralized and recycled back to to water column, or may pass downwards into the zone of permanent burial.
X-radiographs indicate that Back Bay sediments are bioturbated by the community of insect larvae, polychaetes and oligochaetes that constitute the benthic infauna of this oligohaline water body. However, analysis of wind records suggests that in some respects, wave resuspension is a more important mixing process. Under mild to moderate conditions, waves in the bay are fetch limited. However, under hurricane conditions the bay surface saturates with breaking waves before peak winds are attained. For a 6 km fetch (a typical long fetch for the Bay), the resuspension threshold is 6 ms-1 (13.5 knots). This value is exceeded 35.7 percent of the time, and sediment is resuspended in about 40 events in a year. Radiogeochemical analyses suggest that long term (100 yr) accumulation rates are of the order of 2-3 mm yr-1.
The Bay is floored by mud (silt and clay), with an admixture of sand. Sediment introduction probably occurs largely as a result of \u27wind pumping\u27. During winter storms, strong southerly winds set down southern Back Bay, and drive turbid water from Currituck Sound through the Knotts Island Passage. As the storm progresses, the wind shifts to the north and northwest, sets up lower Back Bay against the Knotts Island Passage, and flushes sediment and water back into Currituck Sound.
In this model, Back Bay is a sediment-accumulating sink. The shallow (1-2 m) floor of Back Bay is controlled by an equilibrium between the rate of sediment supply and mean annual wave power. Concentration profiles of 210Pb and 137Cs measured in 1984 indicate that the short term (30 year) accumulation rate was then twice that of sea level rise. The period of record corresponds with Eurasian Milfoil invasion. The historically dense growth of this plant would have modified the equilibrium by damping wave currents, accelerating the sedimentation rate and shifting the Bay floor to a shallower equilibrium depth. The Bay floor appears to presently be undergoing a reduced rate of sedimentation with some local erosion, perhaps in conjunction with a return to an earlier regime
Cost Scale-Up Factors for Airport Construction
Engineers must often make a quick ballpark cost estimate of a new plant, facility, or piece of equipment before the detailed design phase. One easy way to obtain such an estimate is to base the cost on a known cost for a similar plant, facility, or piece of equipment by using the ratio of the capacities or sizes of the known and proposed item raised to an exponent R. This predesign cost-estimating approach is especially useful for doing sensitivity analyses and feasibility studies for which a high degree of accuracy is not required. This cost-capacity or power-factor model was first developed by Williams in 1947 for equipment costs [7] and by Chilton in 1950 for plant costs [1]. In this article, we present scale-up factors for estimating the costs of terminal expansions to existing airports in the United States and the costs of constructing new international airports
Targeting CXCR4 with CTCE-9908 inhibits prostate tumor metastasis
Abstract
Background
CXCL12/CXCR4 transactivation of epidermal growth factor family receptors in lipid raft membrane microdomains on cell surface is thought to mediate tumor growth and subsequent development of metastatic disease. CTCE-9908 is a known inhibitor of CXCR4. Herein, we tested the efficacy of CTCE-9908 in inhibiting prostate cancer cell growth, invasion, and metastasis.
Methods
We used a panel of in vitro assays utilizing human prostate cancer cell lines and an in vivo orthotopic prostate cancer model to assess the anti-tumoral activity of CTCE-9908.
Results
We demonstrated that (a) CTCE-9908 treatment resulted in no significant change in the growth of PC-3 and C4-2B cells; (b) 50 ÎĽg/ml of CTCE-9908 inhibited the invasive properties of PC-3 cells; (c) 25 mg/kg of CTCE-9908 did not alter primary tumor growth but it did significantly reduce total tumor burden in the animal including the growth of prostate and soft tissue metastases to lymph node and distant organ tissues. Histological analysis showed that CTCE-9908 treatment resulted in tumor necrosis in primary prostate tumors and no significant change in proliferation of tumor cells as measured by Ki-67 staining; (d) CTCE-9908 inhibited the tumor angiogenesis as measured by CD34 positive vessels in tumors.
Conclusions
These data suggest that CXCR4 inhibition by CTCE-9908 decreases the invasion potential in vitro, which then translated to a reduction of tumor spread with associated reduction in angiogenesis. Hence, CTCE-9908 may prove to be an efficacious novel agent to prevent and treat the spread of metastatic prostate cancer
A Prototype Lisp-Based Soft Real-Time Object-Oriented Graphical User Interface for Control System Development
A prototype Lisp-based soft real-time object-oriented Graphical User Interface for control system development is presented. The Graphical User Interface executes alongside a test system in laboratory conditions to permit observation of the closed loop operation through animation, graphics, and text. Since it must perform interactive graphics while updating the screen in real time, techniques are discussed which allow quick, efficient data processing and animation. Examples from an implementation are included to demonstrate some typical functionalities which allow the user to follow the control system's operation
Parallel Machines and Algorithms for Discrete-Event Simulations
A number of recent articles have focused on the design of high speed discrete-event simulation (DES) machines for digital logic simulation. These investigations are in response to the enormous costs associated with the simulation of complex (VLSI) digital circuits for logic verification and fault analysis. One approach to reducing simulation costs is to design special purpose digital computers that are tailored to the logic simulation test. This paper is concerned with the architecture of such logic machines. The paper has three principal parts. First, a taxonomy of logic machine architectures is presented. The taxonomy focuses on the central components of the logic simulation algorithms and on architectural alternatives for increasing the speed of the simulation process. It thus represents a basis for discussing and differentiating between proposed architectures and also results in the identification of several new architectures. Although developed for digital logic simulators., the taxonomy can be used for general DES machines. Second, a performance measure is presented which permits evaluation of DES machines. Finally several DES machine designs are described and categorized using the taxonomy
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