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| 1 | Monitoring the impact of climate change and human activities on grassland vegetation dynamics in the northeastern Qinghai-Tibet Plateau of China during 2000–2015显示文摘Climate change and human activities can influence vegetation net primary productivity(NPP), a key component of natural ecosystems. The Qinghai-Tibet Plateau of China, in spite of its significant natural and cultural values, is one of the most susceptible regions to climate change and human disturbances in the world. To assess the impact of climate change and human activities on vegetation dynamics in the grassland ecosystems of the northeastern Qinghai-Tibet Plateau, we applied a time-series trend analysis to normalized difference vegetation index(NDVI) datasets from 2000 to 2015 and compared these spatiotemporal variations with trends in climatic variables over the same time period. The constrained ordination approach(redundancy analysis) was used to determine which climatic variables or human-related factors mostly influenced the variation of NDVI. Furthermore, in order to determine whether current conservation measures and programs are effective in ecological protection and reconstruction, we divided the northeastern Qinghai-Tibet Plateau into two parts: the Three-River Headwater conservation area(TRH zone) in the south and the non-conservation area(NTRH zone) in the north. The results indicated an overall(73.32%) increasing trend of vegetation NPP in grasslands throughout the study area. During the period 2000–2015, NDVI in the TRH and NTRH zones increased at the rates of 0.0015/a and 0.0020/a, respectively. Specifically, precipitation accounted for 9.2% of the total variation in NDVI, while temperature accounted for 13.4%. In addition, variation in vegetation NPP of grasslands responded not only to long-and short-term changes in climate, as conceptualized in non-equilibrium theory, but also to the impact of human activities and their associated perturbations. The redundancy analysis successfully separated the relative contributions of climate change and human activities, of which village population and agricultural gross domestic product were the two most important contributors to the NDVI changes, explaining 17.8% and 17.1% of the total variation of NDVI(with the total contribution >30.0%), respectively. The total contribution percentages of climate change and human activities to the NDVI variation were 27.5% and 34.9%, respectively, in the northeastern Qinghai-Tibet Plateau. Finally, our study shows that the grassland restoration in the study area was enhanced by protection measures and programs in the TRH zone, which explained 7.6% of the total variation in NDVI. | XIONG Qinli XIAO Yang Marwa Waseem A HALMY Mohammed A DAKHIL LIANG Pinghan LIU Chenggang ZHANG Lin Bikram PANDEY PAN Kaiwen Sameh B EL KAFRAWAY CHEN Jun | 2019 | Journal of Arid Land2019，11，5： | 10 |
| 2 | Liver stiffness as a predictor of hepatocellular carcinoma behavior in patients with hepatitis C related liver cirrhosis显示文摘Background: Risk strati cation and prognostication of hepatocellular carcinoma (HCC) help to improve patient outcome. Herein we investigated the role of liver stiffness measurement (LSM) in the prediction of HCC behavior. Methods: Totally 121 na ve patients with HCC were included. HCC radiological evaluation and staging were done. LSM was measured using virtual touch quanti cation. Patients were divided into early to intermediate HCC (BCLC-0, A and B) and late HCC (BCLCC and D). HCC was treated according to the BCLC stage. HCC recurrence-free interval was estimated. Results: The mean LSM inside the tumor was signi cantly lower than the peri-tumoral area and the cirrhotic non-cancerous liver parts (P<0.001). In late HCCs stage, the mean LSM inside the tumor and in the peri-tumoral tissue was lower than the corresponding values in the early to intermediate HCCs stage (P<0.001). LSM inside the tumor and in the peri-tumoral tissue negatively correlated with serum AFP, tumor vascular invasion, and stage (P<0.05). The recurrence-free interval was directly correlated to LSM inside the tumor and inversely to LSM in cirrhotic non tumorous liver part. Kaplan-Meier analysis showed that the recurrence-free interval was signi cantly longer in patients with LSM inside the tumor of ≥1.25m/s compared to those with LSM inside the tumor of<1.25m/s. Conclusions: LSM can serve as a potential non-invasive predictor for HCC clinical behavior and the recurrence-free interval following loco-regional treatments. | Sameh A Lashen Mohamed M Elshafei Fahmy H Hablass Eman A Alsayed Asmaa A Hassan | 2020 | Hepatobiliary & Pancreatic Diseases International2020，19，1： | 4 |
| 3 | The Trace Minimization Method for the Symmetric Generalized Eigenvalue Problem 显示文摘 | Sameh A Tong Zhanye | 2000 | International Journal of Applied Mathematics and Computer2000，123，12： | 1 |
| 4 | A trace minimization algorithm for The generalized eigenvalue problem compuations显示文摘 | SAMEH A H WISNIEWSKI J A | 1982 | SIAM Journal on Numerical Analysis1982，19，： | 1 |
| 5 | A Fuzzy Hyperspectral Classifier for Automatic Target Recognition(ATR) Systems显示文摘 | M Sameh Yamanu A Aly Farag Shin-Yi Hsu | 1999 | Pattern Recognition Letters1999，20，： | 1 |
| 6 | A modified fuzzy C-means algorithm for bias field estimation and segmentation of MRI data显示文摘 | MOHAMED N A SAMEH M Y NEVIN M | 2002 | IEEE Frans On Medical Imaging2002，21，3： | 1 |
| 7 | Parallel Implementations of the Trace Minimization Scheme TraceMIN for the Sparse Symmetric Eigenvalue Problem 显示文摘 | Klinvex A Saied F Sameh A | 2013 | Computers and Mathematics with Applications2013，65，3： | 1 |
| 8 | A trace minimization algorithm for the generalized eigenvalue problem 显示文摘 | Sameh A Wisniewski J | 1982 | SIAM J Numer Anal1982，19，： | 1 |
| 9 | Evaluation of isolated starter lactic acid bacteria in Ras cheese ripening and flavour development显示文摘 | Sameh A Nour A El S M | | 0，，03： | 1 |
| 10 | Hepatoprotective and antioxidant activities of Tamarix nilotica flowers显示文摘 | Sameh A Z Amany S | 2011 | Pharmaceutical Biology2011，49，4： | 1 |
| 11 | Preconditioning techniques for nonsymmetric linear systems in the computation of incompressible flows 显示文摘 | Manguoglu M Sameh A H Saied F | 2009 | Journal of Applied Mechanics2009，76，2： | 1 |
| 12 | A trace minimization methods for the symmetric generalized eigenvalue problem显示文摘 | SAMEH A TONG Z | 2000 | Journal of Computational and Applied Mathematics2000，123，： | 1 |
| 13 | Performance models for the Spike banded linear system solver显示文摘 | Manguoglu M Saied F Sameh A Grama A | 2011 | Scientific Programming2011，19，1： | 1 |
| 14 | New techniques for modeling pavement deterioration显示文摘 | SHAHIN M Y NUNEZ M M BROTEN M R CARPEN-ITER S A SAMEH A | 1987 | Transportation Research Record1987，1123，6： | 1 |
| 15 | Parallel ant colony optimization显示文摘 | SAMEH A AYMAN A HASAN N | 2010 | International Journal of Research and Reviews in Computer Sci-ence2010，1，2： | 1 |
| 16 | IL-27 enhances LPS- induced proinflammatory cytokine production via upregu- lation of TLR4 expression and signaling in human mono- cytes显示文摘 | Christina G Amit A Sameh B | 2012 | J Immunol2012，188，2： | 1 |
| 17 | Numerical linear algebra algorithms on the cedar system 显示文摘 | Chen Hsin Chu Sameh A H | 1987 | Parallel Computations and Their Impact on Mechanics1987，86，1： | 1 |
| 18 | 显示文摘 | Abdel-Ghaffar A Ali Laila I Ali Sameh M Aboul-Fotouh | 2001 | Apllied Catalysis A:General2001，215，： | 1 |
| 19 | A modified fuzzy C-means algorithm for bias field estimation and segmentation of MRI data显示文摘 | Mohamed N A Sameh M Y Aly A F | 2002 | IEEE Transactions on Medical Imaging2002，21，3： | 1 |
| 20 | Parallel algorithms for dense linear algebra computations显示文摘 | Gallivan K A Plemmons R J Sameh A | 1990 | SIAM review1990，32，1： | 1 |
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