•History of the development of capillary separation techniques is described.•Remarkable changes in microcolumn technology aspects during three decades.•Capillary LC plays a crucial role in LC/tandem ...MS.•The method is a cornerstone of most omics technologies.
This is a historical account on the development of capillary LC from its beginning to the present day. The first investigations into the viability of capillary LC date back to the late 1970s, a decade after the pioneering efforts in HPLC. The drastically reduced column dimensions were required to counter the slow solute diffusion in liquids. There were numerous instrumental difficulties with sample introduction and detection in the picoliter or even femtoliter volumes. High-efficiency separations were needed in the analysis of complex biological mixtures. Miniaturization brought distinct advantages in spectroscopic and electrochemical detection. Since the 1980s, column technologies underwent significant changes: (a) from glass-drawn microcapillaries to slurry-packed, small-diameter fused silica columns; and (b) in microcapillaries packed alternatively with sub-2-μm particles or monoliths. The viability of LC–MS combination has dramatically promoted the use of small-diameter capillaries. Through “omics technologies”, capillary LC/tandem MS accounts for most applications in proteomics, glycomics and metabolomics.
Stream flow records (up to the year 2002) from 36 USGS gauging stations in five major river basins of Minnesota were studied. Seven annual stream flow statistics were extracted and analyzed: mean ...annual flow, 7-day low flow in winter, 7-day low flow in summer, peak flow due to snow melt runoff, peak flow due to rainfall as well as high and extreme flow days (number of days with flow rates greater than the mean plus one or two standard deviations, respectively). The Mann–Kendal non-parametric test was used to detect significant trends over time windows from 90 to 10 years in combination with the Trend Free Pre-Whitening (TFPW) method for correcting time series data for serial correlation. Streamflows in the state of Minnesota have varied over the period of record. Trends differed significantly from one river basin to another, and became more accentuated for shorter time windows. Periodicity was detected in the trends for the
Red River of the North, the
Mississippi River, and the
Minnesota River basins for six of the statistics studied. Periods were on the order of 13–15 and 25 years, and the amplitudes were particularly strong after 1980.
Peak flow due to snowmelt, typically the highest flow in each year, appears to be the only streamflow statistic that has not changed at a significant rate. Peak flows due to rainfall events in the summer are increasing, as well as the number of days with higher flows (high flow days). Increases in low flow (base flow) in summer and in winter have been significant. Wetter summers and more frequent snow melt events due to warmer winters are the likely cause.
Stream flows in Minnesota reflect observed changes in precipitation with increases in mean annual precipitation, a larger number of intense rainfall events, more days with precipitation and earlier and more frequent snowmelt events. For water resources management the results suggest that the threat of snowmelt flooding has not increased, but floods due to rainfall events are more likely. Higher summer and winter base flows may benefit water quality.
Beta-caryophyllene is an odoriferous bicyclic sesquiterpene found in various herbs and spices. Recently, it was found that beta-caryophyllene is a ligand of the cannabinoid receptor 2 (CB2). ...Activation of CB2 will decrease pain, a major signal for inflammatory responses. We hypothesized that beta-caryophyllene can affect wound healing by decreasing inflammation. Here we show that cutaneous wounds of mice treated with beta-caryophyllene had enhanced re-epithelialization. The treated tissue showed increased cell proliferation and cells treated with beta-caryophyllene showed enhanced cell migration, suggesting that the higher re-epithelialization is due to enhanced cell proliferation and cell migration. The treated tissues also had up-regulated gene expression for hair follicle bulge stem cells. Olfactory receptors were not involved in the enhanced wound healing. Transient Receptor Potential channel genes were up-regulated in the injured skin exposed to beta-caryophyllene. Interestingly, there were sex differences in the impact of beta- caryophyllene as only the injured skin of female mice had enhanced re-epithelialization after exposure to beta-caryophyllene. Our study suggests that chemical compounds included in essential oils have the capability to improve wound healing, an effect generated by synergetic impacts of multiple pathways.
Signals given off by plants to alert predators to herbivore attack may provide exciting examples of coevolution among organisms from multiple trophic levels. We examined whether signals from ...mechanically damaged trees (simulating damage by herbivores) attract predators of insects along a complete elevational rainforest gradient in tropical region, where various predators are expected to occur at particular elevational belts. We studied predation of artificial caterpillars on trees with and without ‘herbivorous’ damage; as well as diversity and abundances of potential predators at eight study sites along the elevational gradient (200–3700 m a.s.l.). We focused on attacks by ants and birds, as the main predators of herbivorous insect. The predation rate decreased with elevation from 10% d−1 at 200 m a.s.l. to 1.8% d−1 at 3700 m a.s.l. Ants were relatively more important predators in the lowlands, while birds became dominant predators above 1700 m a.s.l. Caterpillars exposed on trees with herbivorous damage were attacked significantly more than caterpillars exposed on trees without damage. Results suggest that relative importance of predators varies along elevational gradient, and that observed predation rates correspond with abundances of predators. Results further show that herbivorous damage attracts both ants and birds, but its effect is stronger for ants.
This article discusses the link between water conservation, reclamation, reuse and energy use as related to the goal of achieving the net zero carbon emission footprint in future sustainable cities. ...It defines sustainable ecocities and outlines quantitatively steps towards the reduction of energy use due to water and used water flows, management and limits in linear and closed loop water/stormwater/wastewater management systems. The three phase water energy nexus diagram may have a minimum inflection point beyond which reduction of water demand may not result in a reduction of energy and carbon emissions. Hence, water conservation is the best alternative solution to water shortages and minimizing the carbon footprint. A marginal water/energy chart is developed and proposed to assist planners in developing future ecocities and retrofitting older communities to achieve sustainability.
Land-use regression models (LUR) estimate outdoor air pollution at high spatial resolution. Previous LURs have generally focused on individual cities. Here, we present an LUR for year-2006 ...ground-level NO(2) concentrations throughout the contiguous United States. Our approach employs ground- and satellite-based NO(2) measurements, and geographic characteristics such as population density, land-use (based on satellite data), and distance to major and minor roads. The results provide reliable estimates of ambient NO(2) air pollution as measured by the U.S. EPA (R(2) = 0.78; bias = 22%) at a spatial resolution (∼ 30 m) that is capable of capturing within-urban and near-roadway gradients in NO(2). We explore several aspects of temporal (time-of-day; day-of-week; season) and spatial (urban versus rural; U.S. region) variability in the model. Results are robust to spatial autocorrelation, to selection of an alternative input data set, and to minor perturbations in input data (using 90% of the data to predict the remaining 10%). The modeled population-weighted (unweighted) mean outdoor concentration in the United States is 10.7 (4.8) ppb. Our approach could be implemented in other areas of the world given sufficient road network and pollutant monitoring data. To facilitate future use and evaluation of the results, concentration estimates for the ∼ 8 million U.S. Census blocks in the contiguous United States are publicly available via the Supporting Information.
When exposed to the odor of a sympatric predator, prey animals typically display escape or defensive responses. These phenomena have been well-documented, especially in rodents, when exposed to the ...odor of a cat, ferret, or fox. As a result of these experiments new discussions center on the following questions: (1) is a single volatile compound such as a major or a minor mixture constituent in urine or feces, emitted by the predator sufficient to cause defensive reactions in a potential prey species or (2) is a whole array of odors required to elicit a response and (3) will the relative size or escapability of the prey as compared to the predator influence responsiveness. Most predator-prey studies on this topic have been performed in the laboratory or under semi-natural conditions. Field studies could help to find answers to these questions. Australian mammals are completely naïve toward the introduced placental carnivores. That offers ideal opportunities to analyze in the field the responses of potential prey species to unknown predator odors. During the last decades researchers have accumulated an enormous amount of data exploring the effects of eutherian predator odors on native marsupial mammals. In this review, we will give a survey about the development of olfactory research, chemical signals and their influence on the behavior and-in some cases-physiology of prey species. In addition, we report on the effects of predator odor experiments performed under natural conditions in Australia. When studying all these literature we learned that data gained under controlled laboratory conditions elucidate the role of individual odors on brain structures and ultimately on a comparatively narrow range behaviors. In contrast to single odors odor arrays mimic much more the situation prey animals are confronted to in nature. Therefore, a broad range of methodology-from chemistry to ecology including anatomy, physiology, and behavior-is needed to understand all the different (relevant) stimuli that govern and guide the interactions between a predator and its potential prey.
PDF
