34 research outputs found
Dry and Humid Periods Reconstructed from Tree Rings in the Former Territory of Sogdiana (Central Asia) and Their Socio-economic Consequences over the Last Millennium
One of the richest societies along the Silk Road developed in Sogdiana,
located in present-day Tajikistan, Uzbekistan, and Kyrgyzstan. This urban civilisation
reached its greatest prosperity during the golden age of the Silk Road (sixth to
ninth century ce). Rapid political and economic changes, accelerated by climatic
variations, were observed during last millennium in this region. The newly developed
tree-ring-based reconstruction of precipitation for the pastmillennium revealed
a series of dry and wet stages. During the Medieval Climate Anomaly (MCA), two
dry periods occurred (900–1000 and 1200–1250), interrupted by a phase of wetter
conditions. Distinct dry periods occurred around 1510–1650, 1750–1850, and
1920–1970, respectively. The juniper tree-ring record of moisture changes revealed
that major dry and pluvial episodes were consistent with those indicated by hydroclimatic
proxy data from adjacent areas. These climate fluctuations have had longand
short term consequences for human history in the territory of former Sogdiana
Recommended from our members
Northern Eurasia Future Initiative (NEFI): facing the challenges and pathways of global change in the 21st century
During the past several decades, the Earth system has changed significantly, especially across Northern Eurasia. Changes in the socio-economic conditions of the larger countries in the region have also resulted in a variety of regional environmental changes that can
have global consequences. The Northern Eurasia Future Initiative (NEFI) has been designed as an essential continuation of the Northern Eurasia Earth Science
Partnership Initiative (NEESPI), which was launched in 2004. NEESPI sought to elucidate all aspects of ongoing environmental change, to inform societies and, thus, to
better prepare societies for future developments. A key principle of NEFI is that these developments must now be secured through science-based strategies co-designed
with regional decision makers to lead their societies to prosperity in the face of environmental and institutional challenges. NEESPI scientific research, data, and
models have created a solid knowledge base to support the NEFI program. This paper presents the NEFI research vision consensus based on that knowledge. It provides the reader with samples of recent accomplishments in regional studies and formulates new NEFI science questions. To address these questions, nine research foci are identified and their selections are briefly justified. These foci include: warming of the Arctic; changing frequency, pattern, and intensity of extreme and inclement environmental conditions; retreat of the cryosphere; changes in terrestrial water cycles; changes in the biosphere; pressures on land-use; changes in infrastructure; societal actions in response to environmental change; and quantification of Northern Eurasia's role in the global Earth system. Powerful feedbacks between the Earth and human systems in Northern Eurasia (e.g., mega-fires, droughts, depletion of the cryosphere essential for water supply, retreat of sea ice) result from past and current human activities (e.g., large scale water withdrawals, land use and governance change) and
potentially restrict or provide new opportunities for future human activities. Therefore, we propose that Integrated Assessment Models are needed as the final stage of global
change assessment. The overarching goal of this NEFI modeling effort will enable evaluation of economic decisions in response to changing environmental conditions and justification of mitigation and adaptation efforts
Detection of novel papillomavirus in pigmented plaques of four pugs
Pugs are predisposed to the development of deeply pigmented, slightly elevated hyperkeratotic noncancerous plaques. Polymerase chain reaction amplification of a papillomavirus (PV)-like DNA fragment from such lesions suggested that PV may be responsible for them, although the predicted virus has not yet been identified. The goal of the present study was to make use of pigmented plaques from four pugs to identify and sequence the predicted virus. Taking advantage of the circular nature of PV DNA, the entire viral genome was amplified by rolling circle amplification and restriction enzyme analysis disclosed the same pattern in all four cases. Sequencing of one of the amplificates revealed a novel canine PV, termed CPV4, related to the recently described CPV3 but clearly distinct from canine oral PV and CPV2. Thus, a novel canine PV and a method for its future diagnosis are described