5,527 research outputs found
Border is better than distance? Contagious corruption in one belt one road economies
Employing data of one belt one road (OBOR) countries from 2002 to 2013, this study compares the contagious corruption difference between geographic border and distance through the dynamic spatial econometric model. The empirical results not only confirm that corruption in OBOR countries exists under various contagious channels, but also indicate that border effects, serving as contagious channels for corruption, are better than distance effects. The empirical implication is that OBOR countries with a common border tend to possess contagious corruption due to the hostsâ demonstration effect and the convenience of transferring illegal assets. We advise that those OBOR countries should enhance the supervision of cash flow, look for any opportunity of kicking back a portion of the stolen money, and establish a specific task force on corruption
Development of genomic SSR and potential EST-SSR markers in Bupleurum chinense DC.
Nineteen genomic SSR markers were developed using inter-simple sequence repeat (ISSR)- suppression PCR technique in Bupleurum chinense DC., a widely used Chinese medicinal plant. A total of 126 alleles were detected across 22 individual plants of B. chinense DC. f. octoradiatum (Bunge) Shan et Sheh, with an average of 3 - 13 alleles per locus. The observed heterozygosity (HO) and the expected heterozygosity (HE) values ranged from 0.23 to 1.00 and from 0.29 to 0.92, respectively. Nine loci deviated from Hardy-Weinberg equilibrium (HWE) (P < 0.05) and eight pairs of loci showed significant linkage disequilibrium (LD) (Fisherâs exact test, P < 0.01). The species transferability of these genomic SSR markers was also detected in seven other Bupleurum species. Eight SSR markers were successfully amplified in all tested species. In addition, forty four EST-SSRs which can be amplified with expected sizes were identified from a B. chinense root cDNA library. The genomic SSR markers and potential EST-SSR markers developed in the present study should be useful for genetic diversity and molecular marker assistant selection breeding research in Bupleurum species
Determination and Improvement of Building Speed in Rapid Freeze Prototyping 514
Rapid freeze prototyping (RFP) is a solid freeform fabrication process that builds an ice part by rapidly freezing water in a layer by layer manner. One advantage of this process is the ability to build ice parts faster than other SFF processes. The factors that affect the speed of contour building and interior filling in RFP are identified. The influence of these factors is
analyzed through heat transfer and material flow analyses. A model based on heat transfer analysis is proposed to determine the maximum achievable speed of contour building under stable conditions. Experiments are conducted to validate the performance of the proposed model for determination of building speed.Mechanical Engineerin
Addressing the implementation challenge of the global biodiversity framework
A Global Biodiversity Framework (GBF) is under discussion for the period 2021â2030, which will replace the âAichi Targetsâ adopted by the Convention on Biological Diversity (CBD) in 2010. Given the limited success in meeting most of the Aichi Targets, this new framework must adopt a different approach. A key challenge the GBF must address is its implementation at national scales. Four ways this implementation challenge can be addressed include:The framework must move away from numerical targets to pursue positive trends in biodiversity, through adopting a âvectors of changeâ approach;The framework should be structured to focus on ecosystems and processes;The framework should synergise more extensively with existing biodiversity-relevant global agreements to maximise leverage and reduce overlap of resource use;The framework must adopt a much stronger theory of change than is in the current GBF Draft, to serve as the roadmap governments can use in upscaling their implementation of biodiversity conservation, sustainable use and benefit sharing. Finally, the GBF must become a âlearning frameworkâ, committed to facilitating and enabling governments to each meet their specific biodiversity challenges, while sharing back experiences with the global community, leading ultimately to realising the 2050 CBD vision of people living in harmony with nature. © 2020, The Author(s)
Post-Oligarchic Evolution of Protoplanetary Embryos and the Stability of Planetary Systems
We investigate the orbit-crossing time (T_c) of protoplanet systems both with
and without a gas-disk background. The protoplanets are initially with equal
masses and separation (EMS systems) scaled by their mutual Hill's radii. In a
gas-free environment, we find log (T_c/yr) = A+B \log (k_0/2.3). Through a
simple analytical approach, we demonstrate that the evolution of the velocity
dispersion in an EMS system follows a random walk. The stochastic nature of
random-walk diffusion leads to (i) an increasing average eccentricity ~
t^1/2, where t is the time; (ii) Rayleigh-distributed eccentricities
(P(e,t)=e/\sigma^2 \exp(-e^2/(2\sigma^2)) of the protoplanets; (iii) a
power-law dependence of T_c on planetary separation. As evidence for the
chaotic diffusion, the observed eccentricities of known extra solar planets can
be approximated by a Rayleigh distribution. We evaluate the isolation masses of
the embryos, which determine the probability of gas giant formation, as a
function of the dust and gas surface densities.Comment: 15 pages, 13 figures (2 color ones), accepted for publication in Ap
Design Modifications for a Small, Affordable Low Intensity Focused Ultrasound Device
Depression is a prevalent and serious medical illness, and while there are antidepressant drugs to mitigate depressive symptoms, 10 - 30% of patients either do not respond or develop a tolerance to these medications. Literature supports that there is an interrelation between the inflammatory response and treatment-resistant depression. A promising method to tackle depressive symptoms is to block the inflammatory signaling pathway with vagus nerve stimulation (VNS), reducing pro-inflammatory cytokine levels. Although electrical VNS devices exist, they are invasive, expensive, and have side effects including voice alteration, dyspnea, and cough. Low intensity focused ultrasound (LIFU) is a promising method that can stimulate a desired region noninvasively and without long term negative side effects. Nonetheless, the existing LIFU devices can be expensive, cumbersome, and large. The Center of Implantable Devices designed a prototype called the SonicNode that incorporates a transducer, matching network, and an amplifier into a 50 mm x 57 mm x 76 mm package. We modified the transducer head and created an intensity map of the focal region to demonstrate the improved performance of the device. The SonicNode and LIFU technology can be employed for long term, noninvasive treatment of a variety of neurological disorders
A Study on Effects of Process Parameters in Rapid Freeze Prototyping
Rapid Freeze Prototyping (RFP) is a relatively new solid freeform fabrication
process, which builds a three-dimensional part according to a CAD model by depositing
and freezing water droplets layer by layer. A study on the effects of RFP process
parameters including the nozzle scanning speed, droplet size, and droplet frequency in
building ice parts with a single-nozzle work head is made. Presented in this paper are the
results of this study which indicate that these process parameters determine the ice layer
thickness and ice line width, which in turn determine the surface roughness and the
waiting time required after depositing each layer of water (i.e. between successive layers)
during the ice part building process.This project is supported by a National Science Foundation Grant (DMI-0128313)
and a Department of Education GAANN Fellowship Grant (P200A010446).Mechanical Engineerin
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