11 research outputs found

    The Kuiper Belt and Other Debris Disks

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    We discuss the current knowledge of the Solar system, focusing on bodies in the outer regions, on the information they provide concerning Solar system formation, and on the possible relationships that may exist between our system and the debris disks of other stars. Beyond the domains of the Terrestrial and giant planets, the comets in the Kuiper belt and the Oort cloud preserve some of our most pristine materials. The Kuiper belt, in particular, is a collisional dust source and a scientific bridge to the dusty "debris disks" observed around many nearby main-sequence stars. Study of the Solar system provides a level of detail that we cannot discern in the distant disks while observations of the disks may help to set the Solar system in proper context.Comment: 50 pages, 25 Figures. To appear in conference proceedings book "Astrophysics in the Next Decade

    Research of working area development parameters in conditions of deep steep deposit finalizing

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    Отримано формули розрахунку об’єму запасів корисних копалин в приконтурній та глибинній зоні. Встановлено характер впливу параметрів доробки глибоких крутоспадних родовищ відкритим способом на доцільне положення поточних та проектних контурів кар’єру. Встановлено, що найменший середній коефіцієнт розкриву досягається при мінімальному значенні суми обсягів корисної копалини приконтурної зони лежачого і висячого боків покладу в проектному положенні. Найменший поточний коефіцієнт розкриву досягається при мінімальному значенні суми обсягів корисної копалини приконтурної зони лежачого і висячого боків покладу, а також робочого борту кар'єру в поточному положенні

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Isolation and characterization of a DREB homolog gene from a local drought-tolerant maize cultivar

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    Clarifying the genetic background of the drought-tolerance trait is a crucial task that may help to improve plant performance under stress by a genetic engineering approach. dehydration-responsive element-binding protein (dREB) is a transcription factor family which modulates many stress-responsive genes. In this study, we isolated a DrEB homolog gene named ZmDrEBtv from Zea mays var. Tevang-1. Using bioinformatic tools, a number of Indels and SNPs in ZmDrEBtv sequence different from the reference accession were identified. In addition, based on deduced protein sequence similarity, ZmdREBtv was assigned to transcription factor dREB2 class as featured by a conserved dNa binding domain – aP2. The ZmDrEBtv construct under thecontrol of the rd29a promoter was transformed into a drought-sensitive maize plant, K7 line. The transgenic plants were assessed with reference to molecular and phenotypic characteristics related to the drought-tolenrance trait. The results proved that the maize plants carrying ZmDrEBtv gene showed enhanced tolerance and better performance to the water-deficit environment at different stages, compared to the wild-type plants

    Comparison of in situ aerosol extinction and scattering coefficient measurements made during the Aerosol Intensive Operating Period

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    Journal of Geophysical Research, Vol. 111, No. D5, D05S03The article of record as published may be located at http://dx.doi.org/10.1029/2005JD006056.In May 2003, the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program sponsored the Aerosol Intensive Operating Period (AIOP) which was conducted over the ARM Climate Research Facility (ACRF) in central Oklahoma. One new instrument that flew in the AIOP, called Cadenza, employed a cavity ring-down technique to measure extinction coefficient and a reciprocal nephelometer technique to simultaneously measure scattering coefficient. This instrument is described in this paper, and measurements are compared to those of conventional instrumentation. Agreement between Cadenza extinction coefficient and that derived from combining nephelometer scattering and PSAP absorption (Neph + PSAP) was excellent, about 2%. Agreement between Cadenza scattering coefficient and TSI nephelometer scattering was also excellent, about 2%, well within the uncertainty of the nephelometer and Cadenza scattering measurements. Comparisons between these instruments, made for the special case of plumes, showed that Cadenza measured extinction and scattering several percent higher on average than the Neph + PSAP and nephelometer alone. This difference is likely due to differences in the instrument response time: The response time for Cadenza is 1 s while that for the nephelometer is a minimum of 8 s. Plumes, identified as originating from Siberian biomass burning, are characterized. Composite size distributions from wing-mounted probes showed that two of the plumes had significant large particle modes that resulted in high values of the effective radius. The effect of the large particle mode was not seen in the A ° ngstro¨m coefficient calculated from the in-cabin scattering measurements because of the characteristics of the aircraft inlet

    Synthesis and bioactivity of novel (γ-piperidono)dibenzo-33-aza-14-crown-3 ethers

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    [Figure not available: see fulltext.] Three-component reaction of polyether-linked bisnaphthaldehyde, ketone derivative, and ammonium acetate afforded seven new azacrown ethers containing γ-piperidone fragment with moderate yields. Most of the compounds were tested for their bioactivity. (3,5-Diethylpiperidono)azacrown ether showed significant cytotoxicity against Hep-G2, Lu1, RD, and MCF-7 cell lines. In addition, three of the synthesized azacrown ethers showed positive effect in antimicrobial test against Aspergillus niger. © 2019, Springer Science+Business Media, LLC, part of Springer Nature
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