Water-soluble quantum dots for multiphoton fluorescence imaging in vivo   总被引：1，自引：0，他引：1  

Larson DR  Zipfel WR  Williams RM  Clark SW  Bruchez MP  Wise FW  Webb WW 《Science (New York, N.Y.)》2003,300(5624):1434-1436

The use of semiconductor nanocrystals (quantum dots) as fluorescent labels for multiphoton microscopy enables multicolor imaging in demanding biological environments such as living tissue. We characterized water-soluble cadmium selenide-zinc sulfide quantum dots for multiphoton imaging in live animals. These fluorescent probes have two-photon action cross sections as high as 47,000 Goeppert-Mayer units, by far the largest of any label used in multiphoton microscopy. We visualized quantum dots dynamically through the skin of living mice, in capillaries hundreds of micrometers deep. We found no evidence of blinking (fluorescence intermittency) in solution on nanosecond to millisecond time scales.  相似文献   

Global analysis of protein activities using proteome chips   总被引：1，自引：0，他引：1  

Zhu H  Bilgin M  Bangham R  Hall D  Casamayor A  Bertone P  Lan N  Jansen R  Bidlingmaier S  Houfek T  Mitchell T  Miller P  Dean RA  Gerstein M  Snyder M 《Science (New York, N.Y.)》2001,293(5537):2101-2105

To facilitate studies of the yeast proteome, we cloned 5800 open reading frames and overexpressed and purified their corresponding proteins. The proteins were printed onto slides at high spatial density to form a yeast proteome microarray and screened for their ability to interact with proteins and phospholipids. We identified many new calmodulin- and phospholipid-interacting proteins; a common potential binding motif was identified for many of the calmodulin-binding proteins. Thus, microarrays of an entire eukaryotic proteome can be prepared and screened for diverse biochemical activities. The microarrays can also be used to screen protein-drug interactions and to detect posttranslational modifications.  相似文献   

Assessing environmental changes in grasslands     

Mitchell CE  Reich PB 《Science (New York, N.Y.)》2003,299(5614):1844-5; author reply 1844-5

  相似文献   

The rice genome and the minor grains     

Goodman RM  Naylor R  Tefera H  Nelson R  Falcon W 《Science (New York, N.Y.)》2002,296(5574):1801

  相似文献   

Translocation of a Radioactive Plant-Growth Regulator in Bean and Barley Plants     

Wood JW  Mitchell JW  Irving GW 《Science (New York, N.Y.)》1947,105(2726):337-339

  相似文献   

Microwave‐oven drying of rice leaves for rapid determination of dry weight and nitrogen concentration     

Shaobing Peng  Ma. Rebecca C. Laza  Felipe V. Garcia  Kenneth G. Cassman 《Journal of plant nutrition》2013,36(1):209-217

Predicting the need for fertilizer‐nitrogen (N) topdressing based on plant N status is an important N management strategy for increasing both grain yield and N‐use efficiency of irrigated rice. Plant N analysis by conventional‐oven drying and micro‐Kjeldahl procedure generally requires several days. Accurate estimation of leaf N content per unit dry weight (Ndw) at different growth stages by the chlorophyll meter requires that meter‐reading values (SPAD values) be adjusted for specific leaf weight (SLW). This study demonstrated that a microwave oven can be used for drying rice leaves for quick estimation of leaf dry weight without significantly influencing the estimation of Ndw by micro‐Kjeldahl procedure. Microwave oven drying of 0.5 g (dry weight) leaf samples required only two minutes. Extended exposure duration up to six minutes did not alter the measured Kjeldahl N concentration. Specific leaf weight determined with microwave‐oven drying improved the prediction of Ndw by SPAD. The chlorophyll meter with SLW adjustment can provide another tool to make rapid, in‐season diagnosis of crop N status.  相似文献   

Soil Ecology and Ecosystem Services ‐ edited by Wall,D.H., Bardgett,R.D., Behan‐Pelletier,V., Herrick,J.E., Jones,T.H., Ritz,K., Six,J., Strong,D.R. & van der Putten,W.H.     

R. Mitchell 《European Journal of Soil Science》2013,64(4):546-546

  相似文献   

From a research study to a conservation partnership: Developing approaches to restoring common scoter populations     

Mark H. Hancock  Hannah J. Robson  Trevor D. Smith  Alastair Stephen  Paul Byrne  Alison MacLennan  Daniela Klein  Carl Mitchell  Larry R. Griffin  Geoff Hilton  Henry Dobson  Andy Douse 《水产资源保护:海洋与淡水生态系统》2020,30(9):1770-1774

• 1. Like many sea‐duck populations, the British breeding population of common scoters Melanitta nigra has declined markedly. In 2009, a study was established to measure factors affecting lake use by breeding scoters, to inform conservation measures. That study, published in Aquatic Conservation: Marine and Freshwater Ecosystems (AQC) in 2016, showed that lakes used by scoters had relatively more shallow water and large invertebrates. Furthermore, lakes with abundant large invertebrates had relatively few brown trout Salmo trutta. These results probably reflect the importance of foraging habitat (shallow water), prey abundance (large invertebrates), and competition for prey (trout abundance) in influencing scoter lake use.
• 2. To develop this study, additional research, and scoter conservation measures, we formed a long‐term partnership, comprising nature conservation non‐governmental organizations, statutory agencies, fisheries managers and the regional hydropower company. The partnership meets regularly to coordinate and review research and develop conservation measures, building on the earlier lake‐use study.
• 3. At key scoter lakes managed for hydropower, the partnership negotiated a revised water level management regime, favouring shallow water availability in the breeding season. This regime was informed by additional research, showing the value of certain islands for nesting scoters, and water level requirements to maintain these as islands.
• 4. In a different key scoter area — an extensive near‐natural peatland where recreational angling takes place — the partnership established a trial of increased brown trout angling, with increased fish removal, to determine whether this would increase invertebrate prey abundance and benefit breeding scoters. Both conservation interventions are currently being evaluated by detailed monitoring.
• 5. Overall, the earlier study published in AQC, was important in strengthening and informing our researcher–practitioner partnership, as we collaborated within an adaptive management framework to reverse scoter declines. Long‐term interdisciplinary partnerships are likely to have an important role to play in general, for the successful conservation of aquatic biodiversity.

  相似文献   

Essential fatty acid requirement of juvenile red drum (Sciaenops ocellatus)     

Rebecca T. Lochmann  Delbert M. Gatlin III 《Fish physiology and biochemistry》1993,12(3):221-235

Feeding experiments and laboratory analyses were conducted to establish the essential fatty acid (EFA) requirement of red drum (Sciaenops ocellatus). Juvenile red drum were maintained in aquaria containing brackish water (5 ± 2‰ total dissolved solids) for two 6-week experiments. Semipurified diets contained a total of 70% lipid consisting of different combinations of tristearin [predominantly 18:0] and the following fatty acid ethyl esters: oleate, linoleate, linolenate, and a mixture of highly unsaturated fatty acids (HUFA) containing approximately 60% eicosapentaenoate plus docosahexaenoate. EFA-deficient diets (containing only tristearin or oleate) rapidly reduced fish growth and feed efficiency, and increased mortality. Fin erosion and a “shock syndrome” also occurred in association with EFA deficiency. Of the diets containing fatty acid ethyl esters, those with 0.5–1% (n-3) HUFA (0.3–0.6% eicosapentaenoate plus docosahexaenoate) promoted the best growth, survival, and feed efficiency; however, the control diet containing 7% menhaden fish oil provided the best performance. Excess (n-3) HUFA suppressed fish weight gain; suppression became evident at 1.5% (n-3) HUFA, and was pronounced at 2.5%. Fatty acid compositions of whole-body, muscle and liver tissues from red drum fed the various diets generally reflected dietary fatty acids, but modifications of these patterns also were evident. Levels of saturated fatty acids appeared to be regulated independent of diet. In fish fed EFA-deficient diets (containing only tristearin or oleate), monoenes increased and (n-3) HUFA were preferentially conserved in polar lipid fractions. Eicosatrienoic acid [20:3(n-9)] was not elevated in EFA-deficient red drum, apparently due to their limited ability to transform fatty acids. Red drum exhibited some limited ability to elongate and desaturate linoleic acid [18:2(n-6)] and linolenic acid [18:3(n-3)]; however, metabolism of 18:3(n-3) did not generally result in increased tissue levels of (n-3) HUFA. Based on these responses, the red drum required approximately 0.5% (n-3) HUFA in the diet (approximately 7% of dietary lipid) for proper growth and health.  相似文献   

Assessing the spatial–temporal response of groundwater-fed anchialine ecosystems to sea-level rise for coastal zone management     

Lisa Marrack  Chad Wiggins  John J. Marra  Ayesha Genz  Rebecca Most  Kim Falinski  Eric Conklin 《水产资源保护:海洋与淡水生态系统》2021,31(4):853-869

1. As a result of sea-level rise (SLR), coastal anchialine pool habitats will be lost in some locations and will expand inland into low-lying areas in others. New and existing habitats may risk additional SLR-related degradation from non-native species transmission, groundwater pollution, and increased contact with human infrastructure. Despite a worldwide distribution, anchialine ecosystems and biota have been largely omitted from SLR risk assessments for coastal ecosystems.
2. Anchialine pools and caves are composed of brackish groundwater that connects to the marine environment through porous rocky substrate but have no overland connection to the ocean. They support unique endemic biota.
3. The goal of this study was to develop methods to assess potential impacts to anchialine pools from future coastal flooding, using the island of Hawai'i as a case study. Flood predictions incorporated pool surveys, groundwater-level measurements, and statistical analysis of flood frequencies observed in tide gauges combined with regional scenario-based projections of future sea levels. High-resolution geospatial models were then generated to predict anchialine pool location, density, and risk factors for the next 60 years.
4. Along 40 km of coastline, up to 80% of current anchialine pools will be lost by 2080 as pools merge with ocean habitats; however, as groundwater flooding occurs more frequently and new habitats are created inland, the total pool counts will rise from 509 in 2018 to 1,000 by 2080. As a result of extreme water-level events, non-native fishes are predicted to disperse into 42% of pools by 2030. Based on current conditions, development and cesspool risks are quite low for anchialine pools in the study area.
5. Outcomes from this study are guiding conservation actions, including habitat restoration, non-native fish removal, and development planning decisions in coastal areas. This study illustrates methods that can be used to assess the effects of SLR on anchialine pool habitats worldwide.

  相似文献