1,181 research outputs found
The application of gradient algorithms to the optimization of controlled versions of the World 2 model of Forrester
No abstract
Molecular cytogenetic mapping of Cucumis sativus and C. melo using highly repetitive DNA sequences
Chromosomes often serve as one of the most important molecular aspects of studying the evolution of species. Indeed, most of the crucial mutations that led to differentiation of species during the evolution have occurred at the chromosomal level. Furthermore, the analysis of pachytene chromosomes appears to be an invaluable tool for the study of evolution due to its effectiveness in chromosome identification and precise physical gene mapping. By applying fluorescence in situ hybridization of 45S rDNA and CsCent1 probes to cucumber pachytene chromosomes, here, we demonstrate that cucumber chromosomes 1 and 2 may have evolved from fusions of ancestral karyotype with chromosome number n= 12. This conclusion is further supported by the centromeric sequence similarity between cucumber and melon, which suggests that these sequences evolved from a common ancestor. It may be after or during speciation that these sequences were specifically amplified, after which they diverged and specific sequence variants were homogenized. Additionally, a structural change on the centromeric region of cucumber chromosome 4 was revealed by fiber-FISH using the mitochondrial-related repetitive sequences, BAC-E38 and CsCent1. These showed the former sequences being integrated into the latter in multiple regions. The data presented here are useful resources for comparative genomics and cytogenetics of Cucumis and, in particular, the ongoing genome sequencing project of cucumbe
Scanning tunnelling miscroscopy/spectroscopy and X-ray absorption spectroscopy studies of Co adatoms and anoislands on highly oriented pyrolytic graphite
In this paper, the scanning tunneling microscopy, scanning tunneling spectroscopy and X-ray absorption spectroscopy of cobalt adatoms and nanoislands were studied on a highly oriented pyrolytic graphite. Local electronic structure were observed by STS.\ud
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Measurement of vibroacoustical energy flow through straight pipes
The measurement of vibroacoustical energy flow through straight pipes has been investigated. At frequencies below the cut-on of n=3 shell waves the energy propagates in a limited number of waves. The stnicture-borne energy in these waves can be determined from acceleration measurements on the pipe surface, provided that appropriate accelerometer configurations are chosen to separate the different waves. The energy flow in each wave can then be determined using a two-channel cross-spectral density method. It appears to be impossible to determine the fluid-borne energy flow from acceleration measurements, due to the transverse axis sensitivity of the accelerometers. Experiments on a cooling water pipe of a shipboard diesel engine indicate that energy flow measurements are feasible, although further investigations are necessary to achieve a practicable and reliable method
Напрями та види діяльності у період Центральної Ради, Гетьманату та Директорії: конституційно-правовий аспект
Стаття присвячена одній із актуальних проблем у конституційному праві України - проблемі функцій Верховної Ради України, зокрема це стосується однієї із пріоритетних парламентських функцій - законодавчої. Саме тому, значний інтерес викликає досвід здійснення законодавчої функції за часів Центральної Ради, Гетьманату та Директорії, який має важливе значення як в історичному аспекті, так і в контексті удосконалення сучасного процесу законотворення та державного будівництва в Україні. У статті аналізується цей досвід, що дає можливість вивчити, проаналізувати та практично застосувати законодавчі надбання цієї доби. Ключові слова: законотворення, законодавча функція, законодавча діяльність, закон, Конституція УНР, Центральна Рада, Гетьманат, Директорія.Статья посвящена одной из актуальных проблем в конституционном праве Украины - проблеме функций Верховной Рады Украины, в частности это касается одной из приоритетных парламентских функций - законодательной. Именно поэтому, значительный интерес вызывает опыт осуществления законодательной функции во времена Центральнй Рады, Гетьманата и Директории, который имеет важное значение как в историческом аспекте, так и в контексте усовершенствования современного процесса законодательствования и государственного строительства в Украине. В статье анализируется этот опыт, который дает возможность изучить, проанализировать и практически применить его в наше время. Ключевые слова: законодательствование, законодательная функция, законодательная деятельность, закон, Конституция УНР, Центральная Рада, Гетьманат, Директория.The article is devoted one of issues of the day in a constitutional right for Ukraine . problem of functions of Verkhovna Rada of Ukraine, in particular it touches one of priority parliamentary functions . legislative. For this reason, considerable interest is caused by experience of realization of legislative function in the days of Central Advice, to Get'manatu and Directory which has an important value both historical aspect and in the context of improvement of modern process of zakonotvorennya and state building in Ukraine. This experience which enables to learn is analysed in the article, to analyse and practically apply legislative acquisitions these days. Key words: zakonotvorennya, legislative function, legislative activity, law, Constitution of UNR, Central Advice, Get'manat, Directory
Hypoxanthine production by ischemic heart demonstrated by high pressure liquid chromatography of blood purine nucleosides and oxypurines
An isocratic high pressure liquid chromatographic system was developed for the estimation of purine nucleosides and oxypurines in blood. Use was made of a reversed-phase column. Nucleotides derived from erythrocytes affected the separation; these compounds were removed with A12O3. The recovery of the whole clean-up procedure exceeded 75%, and the lower detection limit of the assay for blood metabolites was 0.1 mumol/l. In 6 healthy volunteers, non-resting, the following blood concentrations (mean values +/- S.D. in mumol/l) were observed: adenosine (less than 0.1), inosine (0.2 +/- 0.1), hypoxanthine (2.2 +/- 1.3) and xanthine (0.2 +/- 0.1). In plasma and serum the total amount of these compounds was 1.9 and 5.4 times higher, respectively, presumably due to nucleotide breakdown during blood processing. The myocardial arterial-venous differences of blood purine nucleosides, oxypurines and lactate were subsequently measured in blood samples from 13 patients with angiographically documented ischemic heart disease, undergoing an atrial pacing stress test. No significant release of adenosine, inosine and xanthine by the heart was detectable in this stu
The dependence on temperature and salinity of dissolved
Recurring latitudinal patterns of the dissolved inorganic carbon (DIC) content and the fugacity of CO2 (fCO2) were observed in East Atlantic surface waters with strong gradients at hydrographic fronts. The dissolved inorganic carbon chemistry clearly displayed the effects of oceanic circulation and of persistent surface water processes. In two cases inorganic carbon components could be used as an indicator of the origin of hydrographic features. Surface water fCO2 below the atmospheric value, low DIC and low salinity north of the equator were ascribed to a combination of high rainfall and low wind speed in the Intertropical Convergence Zone and of biological uptake of CO2. Low surface water DIC and salinity delineated the Congo outflow. Along the cruise tracks calculated titration alkalinity (TA) had an almost linear relationship with salinity, while DIC had an apparent dependence on temperature and salinity. The latter dependence was tested by comparing observed DIC to DIC estimated from fCO2 and a reference value of TA normalised to salinity. Different scenarios of temperature, salinity, fCO2 and nutrient contents were applied. Changes of DIC were found to be indeed related to both temperature and salinity. The latitudinal distribution of DIC could be inferred with an accuracy of 17 μmol kg−1 and a standard deviation of 13 μmol kg−1 from in situ salinity, in situ temperature and the reference values of TA and nutrient contents normalised to in situ salinity (scenario D). The applied technique of estimating DIC from temperature and salinity is a powerful diagnostic tool to evaluate the spatial distribution of DIC.
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