Response of Inland Lakes to Climate Change across the Tibetan Plateau Investigated Using Landsat and ICESat Data

The Tibetan Plateau experienced tremendous climate change during the past four decades. Due to the large size, widely distribution of cryosphere, and diverse landforms, different parts of the plateau may experience different climate and cryosphere changing patterns. The changes of inland lakes within the plateau are important indicators of climate change as these lakes are fed by precipitation, permafrost degradation, and glacier melting that are all sensitive to climate change. To examine the spatial and temporal differences of lake variations across the Tibetan Plateau, Landsat images and ICESat/GLAS altimetry data were used to extract the changes in surface areas of 26 lakes selected from six different sub-regions during the 1970s-2010 and the changes in lake elevations of these lakes during 2003-2009. An automated model to extract lake surface area and elevation from Landsat and ICESat data is developed to improve the efficiency of processing the large amount of satellite data. By applying this model, the spatial and temporal changing patterns of selected 26 inland lakes across the Tibetan Plateau during the past four decades are revealed. The lakes from different parts of the Tibetan Plateau show different changing patterns. The lake expansion firstly started from the Central Tibetan Plateau in the 1980s, then moving northward and northwestward; the Northeastern and Northwestern Tibetan Plateau experienced obvious expansion after the late 1990s, and this expansion is still continuing in the northern part, whereas the rapid lake expansion either slowed down or stopped in the central and southern parts of the plateau. The differences in lake changing pattern are caused by diverse climatic regimes and the pattern of the cryospheric distribution in the Tibetan Plateau. For the southern part of the plateau, the change in precipitation and evaporation seems to be the dominating factor to control the lake changes; however, the cryospheric change caused by temperature increase is the most important factor influencing the lake fluctuations in the northern part. These patterns can provide insight into the mechanism of lakes dynamics in response to climate and cryospheric changes; and be applied to assess the potential impacts of climate change on water resources in the Tibetan Plateau

Analysis of Unbalanced Growth Caused by Foreign Direct Investment in China’s Regional Economy

Since reform and opening up in 1979, China’s national economy has grown rapidly, and thenational economic strength has been continuously enhanced. However, the regional economy hasnot grown in a balanced way. Economic imbalances in China’s three regions (eastern, central,and western) has become increasingly large. The eastern region has become the largest beneficiary area for absorption of foreign direct investment (FDI), while the central and westernregions have absorbed less, a trend of “high in the east and low in the west.” Undoubtedly, FDI plays an important role in promoting China’s economic growth and has become an important part of China’s national economy. However, facts that have proved the expansion of regional economic differences has become a serious problem, which has had an impact on the national economy and social development. This paper analyzes the regional economic differences in China after reform and opening up, analyzes the main problems affecting the regional economic differences in China, and then puts forward suggestions for narrowing the regional economic differences and building a harmonious society

On the Evaluation of the Eigendecomposition of the Airy Integral Operator

The distributions of the $k$-th largest level at the soft edge scaling limit of Gaussian ensembles are some of the most important distributions in random matrix theory, and their numerical evaluation is a subject of great practical importance. One numerical method for evaluating the distributions uses the fact that they can be represented as Fredholm determinants involving the so-called Airy integral operator. When the spectrum of the integral operator is computed by discretizing it directly, the eigenvalues are known to at most absolute precision. Remarkably, the Airy integral operator is an example of a so-called bispectral operator, which admits a commuting differential operator that shares the same eigenfunctions. In this manuscript, we develop an efficient numerical algorithm for evaluating the eigendecomposition of the Airy integral operator to full relative precision, using the eigendecomposition of the commuting differential operator. This allows us to rapidly evaluate the distributions of the $k$-th largest level to full relative precision rapidly everywhere except in the left tail, where they are computed to absolute precision. In addition, we characterize the eigenfunctions of the Airy integral operator, and describe their extremal properties in relation to an uncertainty principle involving the Airy transform. We observe that the Airy integral operator is fairly universal, and we describe a separate application to Airy beams in optics. Using the eigenfunctions, we compute a finite-energy Airy beam that is optimal, in the sense that the beam is both maximally concentrated, and maximally non-diffracting and self-accelerating.Comment: 48 pages, 3 tables, 8 figure

Is polynomial interpolation in the monomial basis unstable?

In this paper, we show that the monomial basis is generally as good as a well-conditioned polynomial basis for interpolation, provided that the condition number of the Vandermonde matrix is smaller than the reciprocal of machine epsilon. We also show that the monomial basis is more advantageous than other polynomial bases in a number of applications.Comment: 30 pages, 12 figure

Epigenetic Down-Regulation of Sirt 1 via DNA Methylation and Oxidative Stress Signaling Contributes to the Gestational Diabetes Mellitus-Induced Fetal Programming of Heart Ischemia-Sensitive Phenotype in Late Life.

Rationale: The incidence of gestational diabetes mellitus (GDM) is increasing worldwide. However, whether and how GDM exposure induces fetal programming of adult cardiac dysfunctional phenotype, especially the underlying epigenetic molecular mechanisms and theranostics remain unclear. To address this problem, we developed a late GDM rat model. Methods: Pregnant rats were made diabetic on day 12 of gestation by streptozotocin (STZ). Experiments were conducted in 6 weeks old offspring. Results: There were significant increases in ischemia-induced cardiac infarction and gender-dependent left ventricular (LV) dysfunction in male offspring in GDM group as compared to controls. Exposure to GDM enhanced ROS level and caused a global DNA methylation in offspring cardiomyocytes. GDM attenuated cardiac Sirt 1 protein and p-Akt/Akt levels, but enhanced autophagy-related proteins expression (Atg 5 and LC3 II/LC3 I) as compared to controls. Ex-vivo treatment of DNA methylation inhibitor, 5-Aza directly inhibited Dnmt3A and enhanced Sirt 1 protein expression in fetal hearts. Furthermore, treatment with antioxidant, N-acetyl-cysteine (NAC) in offspring reversed GDM-mediated DNA hypermethylation, Sirt1 repression and autophagy-related gene protein overexpression in the hearts, and rescued GDM-induced deterioration in heart ischemic injury and LV dysfunction. Conclusion: Our data indicated that exposure to GDM induced offspring cardiac oxidative stress and DNA hypermethylation, resulting in an epigenetic down-regulation of Sirt1 gene and aberrant development of heart ischemia-sensitive phenotype, which suggests that Sirt 1-mediated signaling is the potential therapeutic target for the heart ischemic disease in offspring