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1.
Sequence and analysis of chromosome 2 of the plant Arabidopsis thaliana 总被引:21,自引:0,他引:21
Lin X Kaul S Rounsley S Shea TP Benito MI Town CD Fujii CY Mason T Bowman CL Barnstead M Feldblyum TV Buell CR Ketchum KA Lee J Ronning CM Koo HL Moffat KS Cronin LA Shen M Pai G Van Aken S Umayam L Tallon LJ Gill JE Adams MD Carrera AJ Creasy TH Goodman HM Somerville CR Copenhaver GP Preuss D Nierman WC White O Eisen JA Salzberg SL Fraser CM Venter JC 《Nature》1999,402(6763):761-768
Arabidopsis thaliana (Arabidopsis) is unique among plant model organisms in having a small genome (130-140 Mb), excellent physical and genetic maps, and little repetitive DNA. Here we report the sequence of chromosome 2 from the Columbia ecotype in two gap-free assemblies (contigs) of 3.6 and 16 megabases (Mb). The latter represents the longest published stretch of uninterrupted DNA sequence assembled from any organism to date. Chromosome 2 represents 15% of the genome and encodes 4,037 genes, 49% of which have no predicted function. Roughly 250 tandem gene duplications were found in addition to large-scale duplications of about 0.5 and 4.5 Mb between chromosomes 2 and 1 and between chromosomes 2 and 4, respectively. Sequencing of nearly 2 Mb within the genetically defined centromere revealed a low density of recognizable genes, and a high density and diverse range of vestigial and presumably inactive mobile elements. More unexpected is what appears to be a recent insertion of a continuous stretch of 75% of the mitochondrial genome into chromosome 2. 相似文献
2.
Identification of genes that modify ataxin-1-induced neurodegeneration 总被引:55,自引:0,他引:55
3.
Ana‐María Ríos María‐Dolores Guillamón Bernardino Benito Francisco Bastida 《Journal of forecasting》2018,37(4):457-474
This paper analyzes the impact of transparency on fiscal performance. Our sample considers the 100 largest Spanish municipalities for the years 2008, 2009, 2010, 2012, and 2014. The results show that the level of municipal transparency influences budget forecast deviations in tax revenues and current expenditures. On the one hand, less transparent municipalities overestimate their revenues, allowing them to provide more public services without an immediate increase in taxes. On the other, these local governments, which are aware of the overestimation of their revenues, may spend less than they budgeted. More transparent municipalities, meanwhile, seem to be more prudent in their revenue estimations, since they underestimate their revenues, meaning they can spend more than projected. Our results also show that the behavior of politicians is influenced by the phase of the electoral cycle in which they find themselves, with politicians overestimating expenditures in the year before election. 相似文献
4.
The paper reports results of an experiment conducted to evaluate subjective versus objective combination of forecasts. The subjects were undergraduate students at Texas A&M. The students forecasted two different types of time series. The results found show that the subjective combination of forecasts improves their accuracy as compared with individual efforts. Four ex-ante weighting methods were also used to combine the forecasts. They all improve the accuracy of the forecasts. The best results, though, were from the subjective combination of forecasts. 相似文献
5.
Mutations in the colony stimulating factor 1 receptor (CSF1R) gene cause hereditary diffuse leukoencephalopathy with spheroids 总被引:1,自引:0,他引:1
Rademakers R Baker M Nicholson AM Rutherford NJ Finch N Soto-Ortolaza A Lash J Wider C Wojtas A DeJesus-Hernandez M Adamson J Kouri N Sundal C Shuster EA Aasly J MacKenzie J Roeber S Kretzschmar HA Boeve BF Knopman DS Petersen RC Cairns NJ Ghetti B Spina S Garbern J Tselis AC Uitti R Das P Van Gerpen JA Meschia JF Levy S Broderick DF Graff-Radford N Ross OA Miller BB Swerdlow RH Dickson DW Wszolek ZK 《Nature genetics》2012,44(2):200-205
Hereditary diffuse leukoencephalopathy with spheroids (HDLS) is an autosomal-dominant central nervous system white-matter disease with variable clinical presentations, including personality and behavioral changes, dementia, depression, parkinsonism, seizures and other phenotypes. We combined genome-wide linkage analysis with exome sequencing and identified 14 different mutations affecting the tyrosine kinase domain of the colony stimulating factor 1 receptor (encoded by CSF1R) in 14 families with HDLS. In one kindred, we confirmed the de novo occurrence of the mutation. Follow-up sequencing identified an additional CSF1R mutation in an individual diagnosed with corticobasal syndrome. In vitro, CSF-1 stimulation resulted in rapid autophosphorylation of selected tyrosine residues in the kinase domain of wild-type but not mutant CSF1R, suggesting that HDLS may result from partial loss of CSF1R function. As CSF1R is a crucial mediator of microglial proliferation and differentiation in the brain, our findings suggest an important role for microglial dysfunction in HDLS pathogenesis. 相似文献
6.
Science and technology for water purification in the coming decades 总被引:26,自引:0,他引:26
One of the most pervasive problems afflicting people throughout the world is inadequate access to clean water and sanitation. Problems with water are expected to grow worse in the coming decades, with water scarcity occurring globally, even in regions currently considered water-rich. Addressing these problems calls out for a tremendous amount of research to be conducted to identify robust new methods of purifying water at lower cost and with less energy, while at the same time minimizing the use of chemicals and impact on the environment. Here we highlight some of the science and technology being developed to improve the disinfection and decontamination of water, as well as efforts to increase water supplies through the safe re-use of wastewater and efficient desalination of sea and brackish water. 相似文献
7.
In this paper an investigation is made of the properties and use of two aggregate measures of forecast bias and accuracy. These are metrics used in business to calculate aggregate forecasting performance for a family (group) of products. We find that the aggregate measures are not particularly informative if some of the one‐step‐ahead forecasts are biased. This is likely to be the case in practice if frequently employed forecasting methods are used to generate a large number of individual forecasts. In the paper, examples are constructed to illustrate some potential problems in the use of the metrics. We propose a simple graphical display of forecast bias and accuracy to supplement the information yielded by the accuracy measures. This support includes relevant boxplots of measures of individual forecasting success. This tool is simple but helpful as the graphic display has the potential to indicate forecast deterioration that can be masked by one or both of the aggregate metrics. The procedures are illustrated with data representing sales of food items. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
8.
The first hominin of Europe 总被引:3,自引:0,他引:3
Carbonell E Bermúdez de Castro JM Parés JM Pérez-González A Cuenca-Bescós G Ollé A Mosquera M Huguet R van der Made J Rosas A Sala R Vallverdú J García N Granger DE Martinón-Torres M Rodríguez XP Stock GM Vergès JM Allué E Burjachs F Cáceres I Canals A Benito A Díez C Lozano M Mateos A Navazo M Rodríguez J Rosell J Arsuaga JL 《Nature》2008,452(7186):465-469
The earliest hominin occupation of Europe is one of the most debated topics in palaeoanthropology. However, the purportedly oldest of the Early Pleistocene sites in Eurasia lack precise age control and contain stone tools rather than human fossil remains. Here we report the discovery of a human mandible associated with an assemblage of Mode 1 lithic tools and faunal remains bearing traces of hominin processing, in stratigraphic level TE9 at the site of the Sima del Elefante, Atapuerca, Spain. Level TE9 has been dated to the Early Pleistocene (approximately 1.2-1.1 Myr), based on a combination of palaeomagnetism, cosmogenic nuclides and biostratigraphy. The Sima del Elefante site thus emerges as the oldest, most accurately dated record of human occupation in Europe, to our knowledge. The study of the human mandible suggests that the first settlement of Western Europe could be related to an early demographic expansion out of Africa. The new evidence, with previous findings in other Atapuerca sites (level TD6 from Gran Dolina), also suggests that a speciation event occurred in this extreme area of the Eurasian continent during the Early Pleistocene, initiating the hominin lineage represented by the TE9 and TD6 hominins. 相似文献
9.
Diola Marina Núñez-Ramírez Aquiles Solís-Soto Javier López-Miranda Benito Pereyra-Alférez Miriam Rutiaga-Quiñónes Luis Medina-Torres Hiram Medrano-Roldán 《矿物冶金与材料学报》2011,18(5):523-526
The iron concentrate from Hercules Mine of Coahuila, Mexico, which mainly contained pyrite and pyrrhotite, was treated by
the bioleaching process using native strain Acidithiobacillus ferrooxidans (A. ferrooxidans) to determine the ability of these bacteria on the leaching of zinc. The native bacteria were isolated from the iron concentrate
of the mine. The bioleaching experiments were carried out in shake flasks to analyze the effects of pH values, pulp density,
and the ferrous sulfate concentration on the bioleaching process. The results obtained by microbial kinetic analyses for the
evaluation of some aspects of zinc leaching show that the native bacteria A. ferrooxidans, which is enriched with a 9K Silverman medium under the optimum conditions of pH 2.0, 20 g/L pulp density, and 40 g/L FeSO4, increases the zinc extraction considerably observed by monitoring during15 d, i.e., the zinc concentration has a decrease of about 95% in the iron concentrate. 相似文献
10.
Summary Rye (Secale cereale L.) -amylase isozymes are controlled by at least four loci located on the 5R (three) and 7R (one) chromosomes. In the case of Imperial and King II cultivars, two of the three 5R chromosome loci could be specifically located on the 5Rl chromosome arm; the other one was located on the 5RS. The locus of 7R chromosome was located on the 7RL chromosome arm of Imperial rye. 相似文献