Search

The concept of periodontal treatment has radically changed over the past decades from a very aggressive surgical approach of pocket elimination to less invasive treatment. Today the treatment objective is directed towards the removal of the periodontal disease-causing agents, microbial plaque and calculus. The use of lasers in periodontal treatment may be the next step towards even more minimally invasive treatment, Ideally, the treatment objective is selective cleaning of the periodontal pocket, removing the etiological factors of the disease. The selective ablation of calculus with lasers requires preferential absorption by the material to be removed compared to the healthy tissues. The Nd:YAG laser cannot ablate calculus. Conventional CO2 lasers may thermally damage the pulp. Excimer and Er:YAG lasers can remove calculus, but they uncontrolledly ablate healthy tooth structure. The frequency-doubled Alexandrite laser allows selective ablation of calculus based on natural differences in absorption. Calculus and microbial plaque are removed quickly and easily while healthy cementum and other healthy tooth structures remain unchanged. The frequency-doubled Alexandrite laser seems to be a very promising tool for the future of periodontal therapy. Its use will fulfill the requirements for sound periodontal maintenance therapy. [ABSTRACT FROM AUTHOR]

Small hydropower (SHP) has a global reputation as a ‘green’, low-carbon energy source that improves rural livelihoods and contributes to local economic development. In China, SHP has grown rapidly since the early 2000s, particularly in the water-rich provinces in the country’s southwest. However, because SHP plants in China are privately-operated and approved by local governments, there is an incentive to construct large, multiple-cascade systems to generate as much power as possible. In many areas, this has led to over-development of SHP and associated negative environmental and social impacts. In this paper, we identify the factors that shape geographies of SHP over-development, what we refer to as ‘shades’ of green energy. We then analyze the direct and indirect impacts of over-development. We draw on interviews and electricity generation data from six prefectures in Yunnan province, one of the world’s largest hydropower producing regions. We find that prefectures that operate in a semi-autonomous way in electricity management and industrial planning are most prone to over-develop SHP, since they depend on hydropower revenues from electricity generation and local energy-intensive industries. We also find that over-development of SHP causes streamflow reductions and unstable electricity generation, and in some areas, drives an increase in environmentally-destructive mineral processing and reduces irrigation water access. These findings suggest a need for coordinated river basin planning on small watersheds and a reassessment of the role of SHP in local economic development. [ABSTRACT FROM AUTHOR]

• Asia is undergoing a hydropower boom in river basins originating in the Third Pole. • This boom is driven by electricity flows between the mountains and megaregions. • We use a new, comprehensive hydropower database to map flows. • We analyze ten different hydro-powersheds in China, South, and Southeast Asia. • Findings offer new perspective on the boom and framework for energy analysis. Hydropower is booming in Asian river basins originating on the Tibetan Plateau and adjoining mountain ranges – often referred to as the "Third Pole." These plants generate significant power for Asia's megaregions; they also dramatically alter environments, economies, and livelihoods in mountainous regions. Yet, current understanding of these developments is limited to specific rivers or countries, obscuring the important relational drivers and characteristics of the boom. In this article, we deploy a novel powershed framework – defined as the material and socio-political infrastructure linking electricity supply and demand areas – to analyze and compare the regional power geographies that shape Third Pole hydropower development. Using this framework, we identify ten powersheds across China, Southeast Asia, and South Asia basins that incorporate the vast majority of new hydropower generation. Our analysis reveals a clear trend towards developing large-scale hydropower in the mountains for the purpose of exporting electricity to megaregions. These powersheds are complex and in flux, crossing political and basin boundaries in ways that defy traditional hydropower analyses. This article thus reveals power export to be the main driver of the boom and its characteristics; it also provides a framework for analyzing power geographies worldwide. [ABSTRACT FROM AUTHOR]

Abstract: The lower Tarim River had dried up nearly 30years before an ecological water diversion project (EWDP) for ecological restoration was implemented in 2000. Since then, eight intermittent water deliveries have been carried out for restoring this seriously degraded riparian ecosystem. To evaluate the efficacy and effectiveness of these operations, the Normalized Difference Vegetation Index (NDVI) data set derived from bands 1 and 2 of the MODerate-resolution Imaging Spectroradiometer (MODIS) on board NASA''s Terra satellite was applied to identify the spatial and temporal variations of vegetation cover along the river corridor with about 320km in length. The goal of this study is thus to generate seasonally integrated NDVI (SINDVI) in growing seasons between April and October so as to investigate a general vegetation patterns as well as examine the inter-annual SINDVI for discerning the status of ecosystem restoration. The spatiotemporal variations of vegetation cover were further characterized based on those inter-annual SINDVI data with the aid of Coefficient of Variation (CoV). Research findings indicate that ecosystem integrity was strengthened after a series of water diversion efforts and groundwater table control in the past few years. As the degree of ecosystem restoration is in progress, continuous operation of water diversion is still necessary in response to the needs for restoration of dense vegetation in the riparian buffer within this arid or semi-arid region. [Copyright &y& Elsevier]