366 research outputs found

    Microsatellite genotyping of apple (Malus × domestica Borkh.) genetic resources in the Netherlands: application in collection management and variety identification

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    A highly informative set of 16 microsatellite markers was used to fingerprint 695 apple accessions from eight Dutch collections. Among the total sample, 475 different genotypes were distinguished based on multi-locus microsatellite variation, revealing a potential redundancy within the total sample of 32%. The majority of redundancies were found between collections, rather than within collections. No single collection covered the total observed diversity well, as each collection consisted of about 50% of unique accessions. These findings reflected the fact that most collection holders focus on common Dutch varieties, as well as on region-specific diversity. Based on the diversity patterns observed, maintenance of genetic resources by a network of co-operating collection holders, rather than by collecting the total diversity in a single collection appears to be an efficient approach. Comparison of microsatellite and passport data showed that for many accessions the marker data did not provide support for the registered variety names. Verification of accessions showed that discrepancies between passport and molecular data were largely due to documentation and phenotypic determination errors. With the help of the marker data the varietal names of 45 accessions could be corrected. Microsatellite genotyping of apple appears to be an efficient tool in the management of collections and in variety identification. The development of a marker database was considered relevant as a reference instrument in variety identification and as a source of information about thus far unexplored diversity that could be of interest in the development of new apple varietie

    Robust, frequency-stable and accurate mid-IR laser spectrometer based on frequency comb metrology of quantum cascade lasers up-converted in orientation-patterned GaAs

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    We demonstrate a robust and simple method for measurement, stabilization and tuning of the frequency of cw mid-infrared (MIR) lasers, in particular of quantum cascade lasers. The proof of principle is performed with a quantum cascade laser at 5.4 \mu m, which is upconverted to 1.2 \mu m by sum-frequency generation in orientation-patterned GaAs with the output of a standard high-power cw 1.5 \mu m fiber laser. Both the 1.2 \mu m and the 1.5 \mu m waves are measured by a standard Er:fiber frequency comb. Frequency measurement at the 100 kHz-level, stabilization to sub-10 kHz level, controlled frequency tuning and long-term stability are demonstrated

    Exercise Stress Testing in Children with Metabolic or Neuromuscular Disorders

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    The role of exercise as a diagnostic or therapeutic tool in patients with a metabolic disease (MD) or neuromuscular disorder (NMD) is relatively underresearched. In this paper we describe the metabolic profiles during exercise in 13 children (9 boys, 4 girls, age 5–15 yrs) with a diagnosed MD or NMD. Graded cardiopulmonary exercise tests and/or a 90-min prolonged submaximal exercise test were performed. During exercise, respiratory gas-exchange and heart rate were monitored; blood and urine samples were collected for biochemical analysis at set time points. Several characteristics in our patient group were observed, which reflected the differences in pathophysiology of the various disorders. Metabolic profiles during exercises CPET and PXT seem helpful in the evaluation of patients with a MD or NMD

    Exercise Stress Testing in Children with Metabolic or Neuromuscular Disorders

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    The role of exercise as a diagnostic or therapeutic tool in patients with a metabolic disease (MD) or neuromuscular disorder (NMD) is relatively underresearched. In this paper we describe the metabolic profiles during exercise in 13 children (9 boys, 4 girls, age 5–15 yrs) with a diagnosed MD or NMD. Graded cardiopulmonary exercise tests and/or a 90-min prolonged submaximal exercise test were performed. During exercise, respiratory gas-exchange and heart rate were monitored; blood and urine samples were collected for biochemical analysis at set time points. Several characteristics in our patient group were observed, which reflected the differences in pathophysiology of the various disorders. Metabolic profiles during exercises CPET and PXT seem helpful in the evaluation of patients with a MD or NMD

    On the intersystem crossing rate in a Platinum(ii) donor–bridge–acceptor triad

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    The rates of ultrafast intersystem crossing in acceptor–bridge–donor molecules centered on Pt(II) acetylides are investigated. Specifically, a Pt(II) trans-acetylide triad NAP–[triple bond, length as m-dash]–Pt–[triple bond, length as m-dash]–Ph-CH2-PTZ [1], with acceptor 4-ethynyl-N-octyl-1,8-naphthalimide (NAP) and donor phenothiazine (PTZ), is examined in detail. We have previously shown that optical excitation in [1] leads to a manifold of singlet charge-transfer states, S*, which evolve via a triplet charge-transfer manifold into a triplet state 3NAP centered on the acceptor ligand and partly to a charge-separated state 3CSS (NAP−–Pt–PTZ+). A complex cascade of electron transfer processes was observed, but intersystem crossing (ISC) rates were not explicitly resolved due to lack of spin selectivity of most ultrafast spectroscopies. Here we revisit the question of ISC with a combination and complementary analysis of (i) transient absorption, (ii) ultrafast broadband fluorescence upconversion, FLUP, which is only sensitive to emissive states, and (iii) femtosecond stimulated Raman spectroscopy, FSR. Raman resonance conditions allow us to observe S* and 3NAP exclusively by FSR, through vibrations which are pertinent only to these two states. This combination of methods enabled us to extract the intersystem crossing rates that were not previously accessible. Multiple timescales (1.6 ps to ∼20 ps) are associated with the rise of triplet species, which can now be assigned conclusively to multiple ISC pathways from a manifold of hot charge-transfer singlet states. The analysis is consistent with previous transient infrared spectroscopy data. A similar rate of ISC, up to 20 ps, is observed in the trans-acetylide NAP–[triple bond, length as m-dash]–Pt–[triple bond, length as m-dash]–Ph [2] which maintains two acetylide groups across the platinum center but lacks a donor unit, whilst removal of one acetylide group in mono-acetylide NAP–[triple bond, length as m-dash]–Pt–Cl [3] leads to >10-fold deceleration of the intersystem crossing process. Our work provides insight on the intersystem crossing dynamics of the organo-metallic complexes, and identifies a general method based on complementary ultrafast spectroscopies to disentangle complex spin, electronic and vibrational processes following photoexcitation

    Nac-mediated repression of the serA promoter of Escherichia coli

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    Escherichia coli and related bacteria contain two paralogous PII-like proteins involved in nitrogen regulation, the glnB product, PII, and the glnK product, GlnK. Previous studies have shown that cells lacking both PII and GlnK have a severe growth defect on minimal media, resulting from elevated expression of the Ntr regulon. Here, we show that this growth defect is caused by activity of the nac product, Nac, a LysR-type transcription factor that is part of the Ntr regulon. Cells with elevated Ntr expression that also contain a null mutation in nac displayed growth rates on minimal medium similar to the wild type. When expressed from high-copy plasmids, Nac imparts a growth defect to wild-type cells in an expression level-dependent manner. Neither expression of Nac nor lack thereof significantly affected Ntr gene expression, suggesting that the activity of Nac at one or more promoters outside the Ntr regulon was responsible for its effects. The growth defect of cells lacking both PII and GlnK was also eliminated upon supplementation of minimal medium with serine or glycine for solid medium or with serine or glycine and glutamine for liquid medium. These observations suggest that high Nac expression results in a reduction in serine biosynthesis. β -Galactosidase activity expressed from a Mu d1 insertion in serA was reduced approximately 10-fold in cells with high Nac expression. We hypothesize that one role of Nac is to limit serine biosynthesis as part of a cellular mechanism to reduce metabolism in a co-ordinated manner when cells become starved for nitrogen.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72401/1/j.1365-2958.2002.02994.x.pd

    Технологические решения для строительства эксплуатационной наклонно-направленной скважины глубиной 2850 метров на Игольско-Таловом нефтяном месторождении (Томская область)

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    Объектом работы эффективный являются эксплуатационная работы скважина для добычи нефти. Цель работы - продуктивный разработка техники и конструкция технологии бурения буровой эксплуатационной скважины технологии глубиной 2850 метров на Игольско-Тaловом месторождении. Работа разработка выполнена по сроки геологическим материалам Игольско-Тaлового месторождения.Ob"yekt raboty effektivnyy - ekspluatatsionnaya rabota skvazhina dlya dobychi nefti. Tselevaya rabota - produktivnaya razrabotka i razrabotka tekhnologiy bureniya burovoy ekspluatatsionnoy skvazhiny tekhnologii glubinoy 2850 metrov na Igol'sko-Talovom mestorozhdenii. Rabota razrabotka po pogodnym geologicheskim materialam Igol'sko-Talovogo mestorozhdeniya

    Разработка нейросетевого подхода сегментации и распознавания номерных знаков автомобилей на изображениях реальных сцен

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    Объектом исследования являются методы искусственного интеллекта, используемые в алгоритмах сегментации и распознавания автомобильных номерных знаков. Целью работы является разработка и реализация алгоритма детектирования и распознавания автомобильных номерных знаков на изображениях реальных сцен с применением аппарата искусственных нейронных сетейThe object of research is the artificial intelligence methods used in the segmentation and recognition of automobile license plates. The aim of the work is to develop and implement an algorithm for detecting and recognizing car license plates on images of real scenes using the apparatus of artificial neural network
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