Search results for " data"
showing 10 items of 7516 documents
Triterpene saponins from the roots ofAmpelozizyphus amazonicus
1992
A new triterpene saponin was isolated from the roots of Ampelozizyphus amazonicus together with the known 3-O-beta-D-glucopyranosyl-20-O-alpha-L-rhamnopyranosyljujubogenin and the known triterpenes melaleucic acid, 3 beta,27 alpha-dihydroxylup-20(29)-en-28 beta-oic acid, betulinic acid, betulin, lupeol. The structure of this saponin was elucidated as 3-O-[beta-D-glucopyranosyl(1----2)alpha-L-arabinopyranosyl]- 20-O-alpha-L-rhamnopyranosyljujubogenin by spectral analysis and chemical transformations.
Evolutionary History and Functional Characterization of the Amphibian Xenosensor CAR
2011
AbstractThe xenosensing constitutive androstane receptor (CAR) is widely considered to have arisen in early mammals via duplication of the pregnane X receptor (PXR). We report that CAR emerged together with PXR and the vitamin D receptor from an ancestral NR1I gene already in early vertebrates, as a result of whole-genome duplications. CAR genes were subsequently lost from the fish lineage, but they are conserved in all taxa of land vertebrates. This contrasts with PXR, which is found in most fish species, whereas it is lost from Sauropsida (reptiles and birds) and plays a role unrelated to xenosensing in Xenopus. This role is fulfilled in Xenopus by CAR, which exhibits low basal activity a…
Is the painted frog Discoglossus pictus a declining species in Italy? On the reliability of a distributional atlas approach
2013
The conservation status of amphibians is often assessed using public databases because of a lack of up-to-date field data. However, it is crucial that this kind of data is used carefully, evaluating the reliability and the consistency of the information. In Italy, the conservation status of the painted frog, Discoglossus pictus, was recently assessed using public databases, and the outcome highlighted a worrying situation for the species. We analyzed the reliability of these conclusions and reassessed the status of the painted frog, taking into account its insular distribution and new data of species occurrence. Our results contrast with the previous analysis and show how an incautious use …
N-Terminal amino acid sequence analysis indicates that isolated atrial amyloid is derived from atrial natriuretic peptide
1988
Isolated atrial amyloid, the most frequent senile cardiac amyloid type, was chemically analysed. Amyloid fibrils obtained from a patient (NIP) were extracted and the predominant low-molecular-weight polypeptide (approximately 3.5 kDa, designated ASc2 NIP) was isolated by size exclusion high performance liquid chromatography in 60% formic acid. N-Terminal amino acid sequence analysis of this polypeptide was identical to that of the atrial natriuretic peptide alpha-hANP for the first 12 residues determined.
Alla ricerca dei fattori rilevanti nell’adozione dei sistemi di gestione della performance nelle amministrazioni pubbliche territoriali. L’analisi di…
2013
La ricerca scientifica ha dimostrato che la gestione della performance nelle amministrazioni pubbliche sta oggi spostando il proprio focus dalla mera attività di raccolta e rendicontazione di dati alla generazione di informazioni atte a supportare la formulazione di decisioni. L’analisi comparativa dei casi di studio analizzati in questo articolo mira ad identificare i fattori critici sottostanti alla progettazione e all’utilizzo dei sistemi di gestione della performance nelle amministrazioni regionali. Da questa analisi emerge che alcune variabili risultano essenziali ai fini di un’efficace adozione dei sistemi di performance management. Tra queste variabili sono annoverabili: il ruolo del…
K-means Clustering to Study How Student Reasoning Lines Can Be Modified by a Learning Activity Based on Feynman’s Unifying Approach
2017
Background:Research in Science Education has shown that often students need to learn how to identify differences and similarities between descriptive and explicative models. The development and use of explicative skills in the field of thermal science has always been a difficult objective to reach. A way to develop analogical reasoning is to use in Science Education unifying conceptual frameworks.Material and methods:A questionnaire containing six open-ended questions on thermally activated phenomena was administered to the students before instruction. A second one, similar but focused on different physical content was administered after instruction. Responses were analysed using k-means Cl…
Statistical methods for the comparison of measurements derived from orthodontic imaging
2000
Biometric comparison procedures for dental imaging methods with continuous outcome were reviewed, mainly concentrating on assessment and comparison of accuracy and precision according to the study design. Univariate graphical and numerical representations of corresponding deviations were summarized to derive a 'check list' of minimum information necessary to compare the measurement methods. The methods reviewed in this investigation are illustrated by the comparison of conventional (radiographic) cephalometry versus assessment using the DigiGraph in 50 female children. A paired t-test and the corresponding confidence interval approach were used to assess deviations in location of two imagin…
Investigating the level of significance of the coherence function in cardiovascular variability analysis
2002
Although the presence of significant coupling between cardiovascular variability series is usually verified according to the threshold value of 0.5 in the coherence function (CF), spectral estimator parameters should also be considered. In this study, the surrogate data technique was introduced to define the level of significance of the CF. The proposed method determined a frequency-dependent threshold over which the hypothesis of zero coherence was rejected. The weighted covariance method and the autoregressive method were used to estimate the CF on simulated series with different degrees of linear coupling and on real cardiovascular data. The threshold was dependent on the type and parame…
Speichel als Matrix für das Humanbiomonitoring in der Arbeits- und Umweltmedizin [Biomonitoring Methods in German Language, 2015]
2016
Saliva as a matrix for human biomonitoring in occupational and environmental medicine Purpose: Human biomonitoring (HBM) implies the assessment of internal exposure to hazardous substances by measuring the substances, their metabolites or reaction products, as well as effect parameters in human body fluids. Along with blood, plasma and urine, saliva is of increasing interest as an alternative matrix for HBM. Methods: This paper reviews studies that measure salivary background levels of hazardous substances, elevated levels after environmental or occupational exposure, as well as references which deal with physiological and toxicokinetic behaviour of saliva and salivary parameters, respectiv…
Studiju programmās studentu saņemto atzīmju analīzes metodika un programmatūra
2021
Bakalaura darbs „Studiju programmās studentu saņemto atzīmju analīzes metodika un programmatūra” tika izstrādāts ar mērķi izveidot programmatūru un analizēt Latvijas Universitātes studiju programmas, apskatot studentu iegūtās atzīmes mācību priekšmetos. Bakalaura darba tēmas aizsācēji ir Kārlis Podnieks un Pēteris Ručevskis ar pētījumu „Kā Datorikas fakultātes pasniedzēji liek atzīmes: divi klasteri”, kas tika prezentēts Latvijas Universitātes 75.zinātniskajā konferencē. Bakalaura darba mērķis bija izstrādāt programmatūru, kas ļautu efektīvi apstrādāt studiju datus. Iegūtos datus izmantot eksperimentiem, lai apskatītu studiju programmas un to kursos studentu nopelnīto atzīmju sakarības. Izs…