widespread use of herbal drugs because of their protective effects on different organs toxicity has been shown in many studies. these protective effects have been illustrated in the fields of nephrotoxicity, hepatotoxicity, viral hepatitis, cancer, in vitro fertilization, neurotoxicity, depression, lung diseases, prostate diseases etc. silymarin has cytoprotection activities due to its antioxid...

The 781,000 km (193 million acre) United States National Forests and Grasslands system (NF) provides important ecosystem services such as clean water supply, timber production, wildlife habitat, and recreation opportunities to the American public. Quantifying the historical impacts of climate change and drought on ecosystem functions at the national scale is essential to develop sound forest ma...

The Dustbowl Era drought in the 1930s was the principal Midwest drought of the twentieth century, occurring primarily in late spring–summer [April–August (AMJJA)] when 70% of annual rainfall normally occurred. Another major Midwest drought occurred in the 1950s but primarily in fall–early winter [September–December (SOND)] when normal rainfall was 1/2 as much. Optimized canonical correlation an...

Abstract Droughts are widespread disasters worldwide and concurrently influenced by multiple large-scale climate signals. This is particularly true over Japan, where drought has strong heterogeneity due to factors such as monsoon, topography, ocean circulations. Regional poses challenges for prediction management. To overcome this difficulty, study provides a comprehensive analysis of teleconne...

The recent IPCC Fourth Assessment report concluded that Australia has significant vulnerability to the changes in temperature and rainfall projected under climate change (Hennessy et al. 2007). Agriculture and natural resources were two of the key sectors identified as likely to be affected strongly. Extensive grazing is by far the most widespread agricultural land use in Australia. Most of the...

The fir engraver, Scolyfus venrralis LeC., attacks white fir, Abies condor (Gord. and Glend.) Lindl., and other true firs, Abies spp., in western North America. The biology, attack behavior, and ecology of this bark beetle were recently summarized by Berryman and Ferrell(1988). During the summer flight season, the attacking beetles bore into the cambial zone of fir boles, introducing a pathogen...

The development of modernity in early human populations has been linked to pulsed phases of technological and behavioural innovation within the Middle Stone Age of South Africa. However, the trigger for these intermittent pulses of technological innovation is an enigma. Here we show that, contrary to some previous studies, the occurrence of innovation was tightly linked to abrupt climate change...

Droughts negatively impact forests by reducing growth and increasing defoliation leading to forest dieback as the climate becomes warmer and drier. However, the timing and severity of droughts determine how differently or intensively water shortage affects primary (shoot and leaf formation) and secondary growth (stem radial growth based on tree-ring widths). We compare the impact of two severe ...

Tree-ring data from Virginia indicate that the Lost Colony of Roanoke Island disappeared during the most extreme drought in 800 years (1587-1589) and that the alarming mortality and the near abandonment of Jamestown Colony occurred during the driest 7-year episode in 770 years (1606-1612). These extraordinary droughts can now be implicated in the fate of the Lost Colony and in the appalling dea...

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