Abstract:With economic growth and the improvement of the urbanization level, human activities have constantly interfered with landscape patterns, resulting in serious threats to regional ecological security. Therefore, it is of great significance to study the evolution and optimization of the landscape patterns. Based on three TM images from 1990, 2000, and 2010, and selected landscape pattern indexes, the changes in the landscape pattern of Nanjing in the past twenty years were studied based on landscape ecology theory using Remote Sensing (RS) and a Geographical Information System (GIS). The ecological network was built on the basis of extracted ecological nodes and the minimum cumulative resistance. The results show that changes in the landscape pattern of the city of Nanjing were notable. Class-level indexes indicate that the farmland landscape area decreased and the degree of patch fragmentation increased. The construction land area increased, and it tended to show dispersed distribution. The proportion of forest land increased and the shape of patches became more complex. The proportion of water firstly showed a decrease, followed by an increase, and the shape of the water became more regular. Landscape-level indexes indicate that biological diversity and the degree of fragmentation increased. Spatial heterogeneity of the natural landscape increased, and the patch shape of each landscape type developed similarly. The results also call for stepping-stones to enhance the connectivity and optimization of the ecological network, which will help improve ecological services and improve the landscape pattern of the city.
Mining is an important pillar industry to the economic future of many countries, and the mineral resources will be exploited largely and continuously with the growth of economic development for energy demand [1]. However, the exploitation and utilization of mineral resources will inevitably change the material cycle and energy flows of a regional ecosystem, break the balance of the original ecosystem, and bring a series of eco-environmental problems such as surface subsidence, groundwater penetration, soil pollution and biodiversity reduction [2-4]. The composition, structure and functionality of the mining area ecosystem can be seriously damaged and its stability can be lost, leading to reverse evolution of the original ecosystem. Negative
Backgroud: Pompe disease is a rare metabolic disorder with available enzymatic replacement therapy. Contrasting with the classic infantile form, the others subtypes have a heterogeneous presentation that makes an early and accurate diagnosis difficulty. A multicenter observational study was aimed to assess the prevalence of late-onset Pompe disease (LOPD) in high-risk population, using dried blood spot (DBS) as a main screening tool.Methods: 20 Chinese neuromuscular centers were involved in the early LOPD screening study. Inclusion criteria were: (1) age ≥1 years, (2) either one of a) persistent hyperCKemia; or b) muscle weakness of axial and/or limb-girdle muscles; or c) unexplained restrictive respiratory insufficiency. Enzymatic activity of acid α-glucosidase (GAA) was measured on DBS by tandem mass spectrometry (MS/MS) assay. For the final diagnosis genotype was assessed by next-generation sequencing.Result: In a 9-month period, we studied 492 cases: 26 positive samples (5.3%) were detected by DBS screening. Molecular studies finally confirmed LOPD diagnosis in 8 cases (1.6%). The GAA activities in individuals bearing pseudodeficiency alleles were well separated from those in LOPD patients by MS/MS assay. The median interval from the onset of symptoms to diagnosis was 5 years. Besides axial/proximal muscle weakness, all patients showed respiratory insufficiency with a mean forced vital capacity of predicted of 48%. The level of creatine kinase ranged from normal to no more than 5-fold of upper normal limit. LOPD with isolated hyperCKemia was not identified.Conclusions: This study confirms that DBS test is a reliable method for screening for LOPD. Respiratory insufficiency is earlier and more severe among Chinese LOPD patients. LOPD presented with paucisymptomatic hyperCKemia. Therefore, a prompt diagnosis is critical to prognosis.
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