Estimates on the eigenvalues of complex nonlocal Sturm-Liouville problems

The present paper deals with the eigenvalues of complex nonlocal Sturm-Liouville boundary value problems.The bounds of the real and imaginary parts of eigenvalues for the nonlocal Sturm-Liouville differential equation involving complex nonlocal potential terms associated with nonlocal boundary conditions are obtained in terms of the integrable conditions of coefficients and the real part of the eigenvalues.

Assessment of ecosystem services value in response to prevailing and future land use/cover changes in Lahore,Pakistan

Land use/cover changes(LUCCs)significantly affect ecosystem services(ESs)and their corresponding monetary value.ESs can be evaluated to analyze the ecological and environmental changes caused by LUCCs.This research aims to estimate variations in the ecosystem services value(ESV)due to LUCCs in Lahore of Pakistan,and to offer information and recommendations to policy-makers concerned with the economic improvement of metropolis areas.We first investigated the historical LUCCs from 1990 to 2019,and then simulated the future land use/cover in 2030 and 2050 based on the CA-Markov model under three scenarios,including business-as-usual(BAU),rapid economic growth(REG),and coordinated environmental sustainability(CES).Subsequently,we evaluated the ESV from 1990 to 2050 and evaluated the historical and potential future ESV changes induced by LUCCs during 1990–2019 and 2019–2050,respectively.The results showed that,land use/cover exhibited an increase in built-up land and decreases in vegetation,water body,and unused land both in the past and future.The net ESV decreased from 58.26 million USD in 1990 to 50.31 million USD in 2019.In 2050,the decrease in ESV is most rapid under the REG scenario(decrease ESV of 7.13 million USD and decrease percentage of 14.18%),followed by the BAU(decrease ESV of 5.61 million USD and decrease percentage of 11.15%)and CES(decrease ESV of 5.18 million USD and decrease percentage of 10.30%)scenarios.For each ecosystem service type,the ESV of waste treatment decreased by 18.37%from 1990 to 2019,followed by soil formation and conservation(17.52%),biodiversity and maintenance(13.23%),climate regulation(11.80%),food production(11.69%),hydrological regulation(11.11%),and aesthetic value(3.07%).These outcomes indicate that continuous land use/cover planning should focus on regenerating aquatic areas and vegetation restoration.

A new investigation on drift of base-line value in geomagnetic observation

A new explanation on drift of base line (BL) value in geomagnetic observation was presented by means of detailed analysis on BL value of H variometer at Tianshui Observatory from 1991 to 1995, in association with some numerical simulation. It was confirmed that drift does not always exist. For variometers running normally for many years, drift appears to be zero. The temperature dependence of BL value is reversible below a certain temperature but irreversible above it. This irreversibility is the main reason that causes the BL value to show a monotonous declination with time, which has been mistaken for the drift in the past. As to the H variometer at Tianshui Observatory, no drift exists in BL value in these years. A new method was introduced to study the BL value variation with temperature by separating it into three parts.

A DUAL COUPLED METHOD FOR BOUNDARY VALUE PROBLEMS OF PDE WITH COEFFICIENTS OF SMALL PERIOD

In this paper the homogenization method is improved to develop one kind of dual coupled approximate method, which reflects both the macro-scope properties of whole structure and its loadings, and micro-scope configuration properties of composite materials. The boundary value problem of woven membrane is considered, the dual asymptotic expression of the exact solution is given, and its approximation and error estimation are discussed. Finally the numerical example shows the effectiveness of this dual coupled method.

Diagnostic Utility of Diffusion-weighted Magnetic Resonance Imaging in Differentiating Small Solid Renal Tumors （≤4 cm） at 3.0T Magnetic Resonance Imaging

Background： The aim of this study was to assess the performance of apparent diffusion coefficient （ADC） measurement obtained with diffusion-weighted magnetic resonance imaging （DW-MRI） to distinguish renal cell carcinomas （RCCs） from small benign solid renal tumors （〈4 cm）. Methods： In this cross-sectional study, 49 consecutive patients with histopathologically confirmed small solid renal tumors, and seven healthy volunteers were imaged using nonenhanced MRI and DW-MRI. The ADC map was calculated using the b values of 0, 50, 400, and 600 s/ mm2 and values compared via the Kruskal-Wallis and Mann-Whitney tests. The utility of ADC for differentiating RCCs and benign lesions was assessed using a receiver operating characteristic curve. Multiple nonenhanced MRI features were analyzed by Logistic regression. Results： The tumors consisted of 33 cases of clear-cell RCCs （ccRCCs） and 16 cases of benign tumors, including 14 cases of minimal fat angiomyolipomas and 2 cases ofoncocytomas. The ADCs showed significant differences among benign tumors （[0.90 ±0.52] x 10 x mm2/s）, ccRCCs （[1.53 ± 0.31 ] x 10 ^3 mm2/s） and the normal renal parenchyma （[2.22 ± 0.12]x 10^-3 mmVs） （P 〈 0.001）. Moreover, there was statistically significant difference between high and low-grade ccRCCs （P = 0.004）. Using a cut-offADC of 1.36± 10 3 mm2/s, DW-MRI resulted in an area under the curve （AUC）, sensitivity, and specificity equal to 0.839, 75.8%, and 87.5%, respectively. Nonenhanced MRI alone and the combination of imaging methods led to an AUC, sensitivity and specificity equal to 0.919, 93.9%, and 81.2%, 0.998, 97%, and 100%, respectively. The Logistic regression showed that the location of the center of the tumor （inside the contour of the kidney） and appearance of stiffblood vessel were significantly helpful for diagnosing ccRCCs. Conclusions： DW-MRI has potential in distinguishing ccRCCs from benign lesions in human small solid renal tumors （〈4 cm）, and in increasing the accuracy for diagnosing ccRCCs when combined with nonenhanced MRI.

A New Method to Calculate Investment Multiplier

Based on the analysis of Keynesian investment theory, this paper puts forward the method of calculating investment multiplier with partial\|closed input\|output model, and by using 1995 input\|output table of China, calculates the investment multiplier.

Evaluation of the malignant potential of gliomas using diffusion-weighted and gadolinium-enhanced magnetic resonance imaging

Objective:This study aimed to determine whether the apparent diffusion coefficients(ADCs)determined by diffusion-weighted imaging(DWI)of magnetic resonance imaging(MRI)could facilitate the malignancy grading of various gliomas.Methods:Sixty patients with a primary cerebral glioma underwent diffusion-weighted and gadolinium-enhanced(Gd)T1-weighted MRI using a 1.5-T MRI scanner.Scoring was performed based on signal intensities on DWI and Gd images.The mean and minimum ADC values were calculated,and Ki-67 staining was performed for each histological sample to evaluate their tumor proliferative potential.Then,the DWI,Gd,and combined scores were analyzed and compared with the Ki-67 staining index and malignant grade.The relationships among the mean and minimum ADC values,Ki-67staining index,and malignant grade were also evaluated.Results:The minimum ADC was inversely correlated with the Ki-67staining index,with a low minimum ADC suggestive of tumor malignancy.The qualitative evaluation of the D score of water molecule diffusion on DWI accurately reflected the pathological grades of gliomas,with an effectiveness that was at least as good as the quantitative analysis using the minimum ADC.The diagnostic value of Gd images in determining glioma malignancy grades was inferior to that of DWI.Conclusion:Both DWI and gadolinium-enhanced images of MRI should be considered essential for the diagnosis of tumor malignancy.