In this paper, we propose an efficient numerical technique based on the Bernstein polynomials for the numerical solution of the equivalent integral form of the derivative dependent Emden–Fowler boundary value problems which arises in various fields of applied mathematics, physical and chemical sciences. The Bernstein collocation method is used to convert the integral equation into a system of nonlinear equations. This system is then solved efficiently by suitable iterative method. The error analysis of the present method is discussed. The accuracy of the proposed method is examined by calculating the maximum absolute error and the \(L_{2}\) error of four examples. The obtained numerical results are compared with the results obtained by the other known techniques.
Conventional human pluripotent stem cell (hPSC) cultures require high concentrations of expensive human fibroblast growth factor 2 (hFGF-2) for hPSC self-renewal and pluripotency in defined media for long-term culture. The thermal instability of the hFGF-2 mandates media change every day, which makes hPSC culture costly and cumbersome. Human DJ-1 (hDJ-1) can bind to and stimulate FGF receptor-1. In this study, for the first time, we have replaced hFGF-2 with hDJ-1 in the essential eight media and maintained the human embryonic stem cells (hESCs), H9, in the defined media at feeder-free condition. After more than ten passages, H9 in both groups still successfully maintained the typical hESC morphology and high protein levels of pluripotency markers, SSEA4, Tra1-60, Oct4, Nanog, and ALP. DNA microarray revealed that more than 97% of the 21,448 tested genes, including the pluripotency markers, Sox2, Nanog, Klf4, Lin28A, Lin28B, and Myc, have similar mRNA levels between the two groups. Karyotyping revealed no chromosome abnormalities in both groups. They also differentiated sufficiently into three germ layers by forming in vitro EBs and in vivo teratomas. There were some variations in the RT-qPCR assay of several pluripotency markers. The proliferation rates and the mitochondria of both groups were also different. Taken together, we conclude that hDJ-1 can replace hFGF-2 in maintaining the self-renewal and the pluripotency of hESCs in feeder-free conditions. 相似文献
Engineering with Computers - An efficient numerical algorithm based on the Laguerre wavelets collocation technique for numerical solutions of a class of Thomas–Fermi boundary value problems,... 相似文献
In the discussion of environmental architecture, we are conjoining two disciplines, the subject of architecture and that of ecology. At their best, green buildings are examples of applied ecology, where designers understand the constitution, organization, and structure of ecosystems, and the impacts of architecture are considered from an environmental perspective. By utilizing the concepts, methods, and language of ecology, designers can create architecture that intentionally engages the natural systems of a site.The establishment of assessment criteria implies the definition of building design criteria. If we establish criteria that are based on our best scientific understanding of environmental capacity, we will begin to develop a building stock that is sustainable. To do this we must quantify the link between the resulting environmental impacts and their cause in building production and use. This is not done in traditional building environmental impact assessment methods, which are based on quantifying assumed negative impacts of man-made interventions on the natural environment, typically using a code compliant reference building as a standard to improve upon. These indexes lack an ecologically derived baseline, or standard of measure, under which sustainable developments can be analyzed and compared on a universal basis.An ecologically derived baseline can be used to measure negative impacts as well as positive impacts of buildings. It also allows vastly different project types, sizes and locations to be compared on an equal basis. This study extends the concept of ecological capacity into an architectural context, and develops carrying capacity as a time and area dependent tool to evaluate the effectiveness of environmental building design. The ecosystem services criteria study uses an objective metric of carrying capacity as an ecologically derived baseline (hectare/years) to assess building sustainability. The farmhouse, a low energy, biological material based building located in Boulder, Colorado is evaluated to show the application of this method. The relative ecological impact of energy and materials for this project is described, as well as identification of effective strategies for reducing environmental impacts of typical buildings. 相似文献
Four posttraumatic stress disorder (PTSD) scales were compared in a community sample of 330 American former prisoners of war and combat veterans of World War II. The Mississippi Scale for Combat-Related PTSD (M-PTSD), the MMPI-2 Pk PTSD scale, and the Impact of Event Scale (IES) all demonstrated moderate relationships with PTSD as defined by the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders-III-Revised (DSM-III-R). Comparative validities were similar to those observed in Vietnam veteran samples. Confirmatory factor analysis indicated that the 3 scales loaded significantly on 1 factor. The impact of Diagnostic and Statistical Manual of Mental Disorders (4th ed.) PTSD criteria changes was examined and found to be minimal. Implications for the use of the M-PTSD, Pk, and IES in combat-related PTSD assessment are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献