scholarly journals Photosynthesis in Global Cycle of Biospheric Carbon

10.5772/62222 ◽  
2016 ◽  
Author(s):  
A. A. Ivlev
Keyword(s):  
Global Cycle

Solar Corona Investigation by the Coronal Line Photometer at Lomnický Peak

1994 ◽  
Vol 144 ◽  
pp. 431-434
Author(s):  
M. Minarovjech ◽  
M. Rybanský
Keyword(s):  
Solar Corona ◽  
Time Resolution ◽  
Active Regions ◽  
High Time ◽  
High Time Resolution ◽  
List Type ◽  
Type Number ◽  
Coronal Line ◽  
Global Cycle

AbstractThis paper deals with a possibility to use the ground-based method of observation in order to solve basic problems connected with the solar corona research. Namely:1.heating of the solar corona2.course of the global cycle in the corona3.rotation of the solar corona and development of active regions.There is stressed a possibility of high-time resolution of the coronal line photometer at Lomnický Peak coronal station, and use of the latter to obtain crucial observations.

Risk and Regulation: Methylmercury Exposure and Fish Consumption

2010 ◽  
Vol 6 ◽  
Author(s):  
Jonathan M Gendzier
Keyword(s):  
Environmental Protection Agency ◽  
Fish Consumption ◽  
Government Regulation ◽  
Mercury Emissions ◽  
Methylmercury Exposure ◽  
Exposure Levels ◽  
Aquatic Food ◽  
Reference Doses ◽  
Fish And Shellfish ◽  
Global Cycle

Exposure to organic mercury (methylmercury) occurs almost universally due to ingestion via contaminated fish and shellfish tissue. Ultimate sources of mercury consist of air release by domestic industrial combustion, mining, and international mercury emissions transported via a global cycle. Deposition of mercury from air to surface waters results in methylation to organic methylmercury and bioaccumulation in the aquatic food web. Health effects from methylmercury exposure consist mainly of neurological and neurodevelopmental effects, with fetuses particularly sensitive. Thus regulation of methylmercury exposure has concentrated on acceptable exposure levels and reference doses aimed toward protecting developing fetuses. The risk of methylmercury exposure in humans is regulated largely by the federal government, especially by the Environmental Protection Agency (EPA) and the Food and Drug Administration (FDA). The EPA imposes limits on mercury emissions and seeks to research methylmercury levels in fish and humans. The EPA sets a reference dose for methylmercury exposure. The FDA conducts uses date on methylmercury levels in fish to advise consumers on how to make informed decisions regarding fish consumption. There are numerous shortcoming to government regulation of this issue. Further scientific research, improved implementation of available data and scientific conclusions, and improved public communication of risk would all lead to more effective treatment of the risk of methylmercury exposure via ingestion of fish and shellfish. This could include more effective monitoring systems of human and fish methylmercury levels, research into the process of bioaccumulation, and implementation of stricter fish labeling standards, as well as research into higher-risk subpopulations allowing for targeted standards and recommendations.

scholarly journals Multi-Cycle-Consistent Adversarial Networks for Edge Denoising of Computed Tomography Images

2021 ◽  
Vol 17 (4) ◽  
pp. 1-16
Author(s):  
Xiaowe Xu ◽  
Jiawei Zhang ◽  
Jinglan Liu ◽  
Yukun Ding ◽  
Tianchen Wang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Denoising ◽  
Ct Images ◽  
High Dose ◽  
Ct Image ◽  
Paired Data ◽  
High Quality ◽  
Computed Tomography Images ◽  
Significant Difference ◽  
Global Cycle

As one of the most commonly ordered imaging tests, the computed tomography (CT) scan comes with inevitable radiation exposure that increases cancer risk to patients. However, CT image quality is directly related to radiation dose, and thus it is desirable to obtain high-quality CT images with as little dose as possible. CT image denoising tries to obtain high-dose-like high-quality CT images (domain Y ) from low dose low-quality CT images (domain X ), which can be treated as an image-to-image translation task where the goal is to learn the transform between a source domain X (noisy images) and a target domain Y (clean images). Recently, the cycle-consistent adversarial denoising network (CCADN) has achieved state-of-the-art results by enforcing cycle-consistent loss without the need of paired training data, since the paired data is hard to collect due to patients’ interests and cardiac motion. However, out of concerns on patients’ privacy and data security, protocols typically require clinics to perform medical image processing tasks including CT image denoising locally (i.e., edge denoising). Therefore, the network models need to achieve high performance under various computation resource constraints including memory and performance. Our detailed analysis of CCADN raises a number of interesting questions that point to potential ways to further improve its performance using the same or even fewer computation resources. For example, if the noise is large leading to a significant difference between domain X and domain Y , can we bridge X and Y with a intermediate domain Z such that both the denoising process between X and Z and that between Z and Y are easier to learn? As such intermediate domains lead to multiple cycles, how do we best enforce cycle- consistency? Driven by these questions, we propose a multi-cycle-consistent adversarial network (MCCAN) that builds intermediate domains and enforces both local and global cycle-consistency for edge denoising of CT images. The global cycle-consistency couples all generators together to model the whole denoising process, whereas the local cycle-consistency imposes effective supervision on the process between adjacent domains. Experiments show that both local and global cycle-consistency are important for the success of MCCAN, which outperforms CCADN in terms of denoising quality with slightly less computation resource consumption.

Behavior of Mercury in Natural Systems and Its Global Cycle

1975 ◽  
pp. 145-166 ◽  
Author(s):  
R. Wollast ◽  
G. Billen ◽  
F. T. Mackenzie
Keyword(s):  
Natural Systems ◽  
Global Cycle

E-learning systems reengineering

2008 ◽  
pp. 175-196 ◽  
Author(s):  
Lahcen Oubahssi ◽  
Monique Grandbastien
Keyword(s):  
Software Component ◽  
Learning Systems ◽  
Reference Models ◽  
Learning Platform ◽  
E Learning ◽  
Learning Platforms ◽  
Global Cycle

In this chapter we propose functional specifications and a component-based architecture for designing e-learning platforms. An important feature is that the proposed specifications and architecture are based on the experience gained in an e-learning company and result from a reengineering process. To guide the reengineering process, we used two reference models, which are the e-learning global process and the e-learning global cycle. The functional specifications are described according to the e-learning global cycle phases and they are used to propose a software component based architecture. The proposed kernel of components was completed with services to allow interoperability and standard compliance between several e-learning platforms. We hope that this case-study exemplifies e-learning platform suppliers’ needs and available pragmatic solutions. We conclude on foreseeable evolutions of e-learning actors needs and practices and on new platform features for fulfilling such needs.

scholarly journals Navigating the chaos of an unfolding global cycle

2020 ◽  
Vol 25 (4) ◽  
Author(s):  
Brian Walker ◽  
Stephen R. Carpenter ◽  
Carl Folke ◽  
Lance Gunderson ◽  
Garry D. Peterson ◽  
...  
Keyword(s):  
Global Cycle

The nitrogen cycle: perturbations due to man and their impact on atmospheric N 2 O and O 3

1977 ◽  
Vol 277 (954) ◽  
pp. 159-181 ◽  
Keyword(s):  
Nitrogen Cycle ◽  
Additional Data ◽  
Agricultural Practices ◽  
World Population ◽  
Recent Past ◽  
Fixed Nitrogen ◽  
Global Cycle

Features of the global cycle of fixed nitrogen are reviewed with an emphasis on perturbations due to man. It is argued that agricultural practices and combustion may lead to an increase in the concentration of atmospheric N 2 O with consequent effects on 0 3 . The level of 0 3 may drop by about 20 % over the next 100 years if world population and the demand for food should continue to grow at anything like rates which prevailed in the recent past. Uncertainties in the model are highlighted and note is taken of areas where there is need for additional data.

Structure properties of min-max systems and existence of global cycle time

2001 ◽  
Vol 46 (1) ◽  
pp. 148-151 ◽  
Author(s):  
Qianchuan Zhao ◽  
Da-Zhong Zheng ◽  
Xinping Zhu
Keyword(s):  
Cycle Time ◽  
Global Cycle ◽  
Structure Properties
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