46 research outputs found
The influence of human activity in the Arctic on climate and climate impacts
Human activities in the Arctic are often mentioned as recipients of climate-change impacts. In this paper we consider the more complicated but more likely possibility that human activities themselves can interact with climate or environmental change in ways that either mitigate or exacerbate the human impacts. Although human activities in the Arctic are generally assumed to be modest, our analysis suggests that those activities may have larger influences on the arctic system than previously thought. Moreover, human influences could increase substantially in the near future. First, we illustrate how past human activities in the Arctic have combined with climatic variations to alter biophysical systems upon which fisheries and livestock depend. Second, we describe how current and future human activities could precipitate or affect the timing of major transitions in the arctic system. Past and future analyses both point to ways in which human activities in the Arctic can substantially influence the trajectory of arctic system change
Analysis of Long-Chain Unsaturated Fatty Acids by Ionic Liquid Gas Chromatography
Four
ionic liquid (IL) columns, SLB-IL59, SLB-IL60, SLB-IL65, and
SLB-IL111, were evaluated for more rapid analysis or improved resolution
of long-chain methyl and ethyl esters of omega-3, omega-6, and additional
positional isomeric and stereoisomeric blends of fatty acids found
in fish oil, flaxseed oil, and potentially more complicated compositions.
The three structurally distinct IL columns provided shorter retention
times and more symmetric peak shapes for the fatty acid methyl or
ethyl esters than a conventional polyethylene glycol column (PEG),
resolving <i>cis</i>- and <i>trans</i>-fatty acid
isomers that coeluted on the PEG column. The potential for improved
resolution of fatty acid esters is important for complex food and
supplement applications, where different forms of fatty acid can be
incorporated. Vacuum ultraviolet detection contributed to further
resolution for intricate mixtures containing <i>cis</i>-
and <i>trans</i>-isomers, as exemplified in a fatty acid
blend of shorter chain C18:1 esters with longer chain polyunsaturated
fatty acid (PUFA) esters
Thigh-length compression stockings and DVT after stroke
Controversy exists as to whether neoadjuvant chemotherapy improves survival in patients with invasive bladder cancer, despite randomised controlled trials of more than 3000 patients. We undertook a systematic review and meta-analysis to assess the effect of such treatment on survival in patients with this disease