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Oerlemans J  Dahl-Jensen D  Masson-Delmotte V 《Science (New York, N.Y.)》2006,313(5790):1043-5; author reply 1043-5
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2.
The development of nondestructive screening methods for single seed protein, vitreousness, density, and hardness index has been studied for single kernels of European wheat. A single kernel procedure was applied involving, image analysis, near‐infrared transmittance (NIT) spectroscopy, laboratory density determination, single kernel characterization system (SKCS), and finally Kjeldahl protein determination on the crushed single kernels. Single kernel NIT spectroscopy showed excellent ability to determine protein content, and some ability for determination of single kernel vitreousness. Nondestructive determination of single kernel density, either based on NIT spectroscopy or based on image analysis and kernel weight, needs to be further improved for practical use. The use of SKCS hardness index as a true single kernel hardness reference in a NIT prediction model resulted in a poor predictability. However, by applying an averaging approach, in which single seed replicate measurements are mathematically simulated, a very good NIT prediction model was achieved. This suggests that the single seed NIT spectra contain hardness information, but that a single seed hardness method with higher accuracy is needed to achieve a good NIT prediction model for single kernel hardness.  相似文献   
3.
Using a group parameter, totalorganic halogens (TOX), high TOX concentrationswere found in leachates and leachate contaminatedgroundwaters at two Danish mixed sanitary andhazardous waste sites. With commonly used screeningprocedures for organic contaminants, the individualhalogenated organic compounds behind the high TOXcould not be found. Conversely, part of the TOX couldbe attributed to halogenated humic substances that cannot be analysed with conventional organic contaminantanalyses. Even though TOX can still be considered anindicator of leachate contamination in the aquifers,attempts to identify the halogenated contaminantsbehind the TOX using screening methods such as GC-MSwill be unsuccessful in most cases.  相似文献   
4.
Abstract

Full-scale experiments with cooling of raw milk of good initial quality from a herd of 70 dairy cows have been performed under practical farm conditions, with different cooling and storage conditions, including instant cooling in a continuous process versus normal cooling in a batch process. During each milking, the milk was divided equally and successively for different cooling procedures. Quality evaluations (number of bacteria, acidity and oxidation of fat, sensoric quality) indicated that instant cooling/continuous process compared with normal cooling/batch process over 2.5 hours, both to 4°C, resulted in a slightly slower bacterial growth and a slightly slower hydrolysis and oxidation of milk fat. Instant raw milk cooled and stored at 2.5°C maintained a good quality for about one to two days more than when normal cooling over 1.5 hours and storing at 4°C was used.  相似文献   
5.
In 2002 the Danish Minister of Environment initiated a process to investigate the possibilities of establishing national parks in Denmark. For this purpose experts were mobilised to investigate the status and potentials of the areas in question.The national park process was extensive in scope and complex, and in theory such complexity is assumed to make it difficult for non-experts to understand all the relevant aspects of policy. This exclusion of non-experts may lead to scientification of politics. Furthermore politicisation of science might occur as experts might advocate political interests disguised as objective science, and policy-makers might select results that further their own interests. As a result policy-makers risk losing a source of legitimacy, scientists risk losing credibility and the citizens risk losing the possibility to hold policy-makers accountable for their decisions, which puts democracy at risk.This paper examines the accountability relationships that experts were a part of in the national park process. These include accountability towards the employer, towards the buyer and towards the general public. The purpose is to determine if these relationships were adequate to circumvent the problems associated with scientification of politics and to discuss how accountability relationships and thereby democracy could be strengthened.The empirical analysis shows that in the national park process experts were mainly accountable towards the National Forest and Nature Agency. There were formal accountability relationships between the experts and the local steering committees and the national advisory group, but these relationships were less significant. Moreover, despite the fact that the process was deemed unusually open to the public by the participants, the relationship between experts and the public cannot be characterised as an accountability relationship and could have been improved by including experts in the deliberative fora of the process.  相似文献   
6.
It is difficult to obtain fossil data from the 10% of Earth's terrestrial surface that is covered by thick glaciers and ice sheets, and hence, knowledge of the paleoenvironments of these regions has remained limited. We show that DNA and amino acids from buried organisms can be recovered from the basal sections of deep ice cores, enabling reconstructions of past flora and fauna. We show that high-altitude southern Greenland, currently lying below more than 2 kilometers of ice, was inhabited by a diverse array of conifer trees and insects within the past million years. The results provide direct evidence in support of a forested southern Greenland and suggest that many deep ice cores may contain genetic records of paleoenvironments in their basal sections.  相似文献   
7.
The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition, reflecting the wetting of Asian deserts. A northern shift of the Intertropical Convergence Zone could be the trigger of these abrupt shifts of Northern Hemisphere atmospheric circulation, resulting in changes of 2 to 4 kelvin in Greenland moisture source temperature from one year to the next.  相似文献   
8.
Soil dwelling (euedaphic) Collembola have evolved to live in soil pores where the atmosphere is saturated with water vapour. Here we show that reproduction in the euedaphic Folsomia candida ceases during drought where soil water potentials are lower than −7 bar (∼99.4% RH). Recovery of the moulting cycle after cessation of drought showed increasing delay with increasing previous drought pressure. However, reproduction was rapidly resumed. Only in F. candida recovering from the most severe drought (−55 bar, 96% RH) was the time lapse between drought and resumed reproduction significantly different from the control (99.4% RH). Furthermore, the final numbers of eggs were unaffected by the degree of drought exposure. Hence, these results suggest that while even very mild drought will stop the reproductive cycle, subsequent recovery is rapid and complete.  相似文献   
9.
Virgin heifers (44) were intravaginally inoculated at estrus with low (10(6)) or high (10(8)) doses of live Tetratrichomonas sp., Pentatrichomonas hominis (P. hominis), or Tritrichomonas foetus (T. foetus). Controls were inoculated with Diamond's trypticase yeast extract maltose media. Genital infection was determined by culture of cervico-vaginal mucus (CVM) in Schneider's media and InPouch TF as well as by polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP). The presence of trichomonads in fecal samples was determined by culture in Schneider's medium and PCR/RFLP. In CVM samples, tetratrichomonads were found by PCR/RFLP and Schneider's culture only sporadically at intermittent weeks. The presence of tetratrichomonads was not associated with the dose in the experimental vaginal inoculation since Tetratrichomonas sp. appeared more frequently in heifers inoculated with a low dose of tetratrichomonads than in heifers inoculated with a high dose of tetratrichomonads. Moreover, Tetratrichomonas spp. were isolated not only in heifers inoculated with tetratrichomonads but also in control heifers and in heifers inoculated with P. hominis. In feces, Tetratrichomonas spp. were frequently identified by culture in Schneider's and by PCR/RFLP in heifers of all groups. P. hominis was never found in CVM or feces by any method. Based on the common appearance of tetratrichomonads in feces and vaginal secretions, it appears that tetratrichomonads were detected periodically in the vagina of heifers as a consequence of repeated contamination from feces and not as a result of experimental infection. In summary, in this study, the strains of Tetratrichomonas sp. and P. hominis did not establish persistent infection in heifers.  相似文献   
10.
Fruit set and quality of highland coffee (Coffea arabica) have been experimentally shown to be higher with bee-mediated or manual pollen supplementation than with autonomous self-pollination. Based on extrapolation from these small-scale experiments, very substantial monetary values for the pollination service have recently been suggested. However, previous research has not included direct measurement of coffee yield at a farm level in relation to pollinator activity, testing if pollinators are not only limiting fruit set and quality, but also coffee yield and farm profit. The extrapolations from small-scale experiments may be subject to error, because resource reallocation during fruit development, associated with enhanced pollination, was neglected, and many studies were restricted to a single coffee farm, limiting the validity of extrapolation. Here, we investigate the relationship between coffee yield and the community of coffee flower-visiting bees on 21 farms in Ecuador, where coffee is grown under tree shade. Our data show, for the first time on a farm-scale, that coffee yield was positively related to the density of non-managed, social flower-visiting bees per coffee shrub, but not to the number of inflorescences per shrub. Our data revealed that a fourfold increase in bee density was associated with an 80% increase in yield and an 800% increase in net revenues. Consequently, in our study higher yield associated with increased pollination generated higher revenues per hectare, so that farm profit was higher when bees were abundant.  相似文献   
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