Search results for "ToF"
showing 10 items of 841 documents
Molecular events associated with glucose repression of invertase in Saccharomyces cerevisiae.
1986
When S. cerevisiae growing in the presence of glucose (repressive condition) was shifted to higher temperatures, invertase was secreted. This secretion required protein synthesis, but was independent of RNA formation (Mormeneo & Sentandreu 1982). In addition accumulation of invertasespecific messenger RNA occurred in the absence of protein synthesis but was expressed only after synthesis of protein. Invertase mRNA was continuously synthesized under repressive conditions and the levels of this mRNA were regulated by the presence of glucose. The hexose regulated the concentration of this mRNA at the level of transcription and/or by sensitization of this messenger RNA. The expression of the in…
DNase I sensitivity of the chromatin of the yeast SUC2 gene for invertase.
1986
The DNase I sensitivity of chromatin of the yeast SUC2 gene, which encodes two forms of invertase, has been studied both in the genome and in a multicopy plasmid carrying the gene and its flaking sequences. Whereas little if any difference in the DNase I sensitivity of the flanking regions was found between the repressed and the derepressed states, derepression of the gene was accompanied by a large increase in the sensitivity of the transcribed region. A well-defined DNase I hypersensitive site was found centered at approximately 120 bp downstream from the end of the coding region. This site seems to be flanked in the 3' non-coding region by strictly positioned nucleosomes, and the structu…
Biofuel blending reduces particle emissions from aircraft engines at cruise conditions.
2017
Aviation-related aerosol emissions contribute to the formation of contrail cirrus clouds that can alter upper tropospheric radiation and water budgets, and therefore climate1. The magnitude of air-traffic-related aerosol–cloud interactions and the ways in which these interactions might change in the future remain uncertain. Modelling studies of the present and future effects of aviation on climate require detailed information about the number of aerosol particles emitted per kilogram of fuel burned and the microphysical properties of those aerosols that are relevant for cloud formation. However, previous observational data at cruise altitudes are sparse for engines burning conventional fuel…
When does Regression discontinuity design work? Evidence from random election outcomes
2018
We use elections data in which a large number of ties in vote counts between candidates are resolved via a lottery to study the personal incumbency advantage. We benchmark non‐experimental regression discontinuity design (RDD) estimates against the estimate produced by this experiment that takes place exactly at the cutoff. The experimental estimate suggests that there is no personal incumbency advantage. In contrast, conventional local polynomial RDD estimates suggest a moderate and statistically significant effect. Bias‐corrected RDD estimates that apply robust inference are, however, in line with the experimental estimate. Therefore, state‐of‐the‐art implementation of RDD can meet the re…
Divdimensionālās šķidruma hromatogrāfijas augstas izšķirtspējas masspektrometrijas metodes izstrāde mikotoksīnu noteikšanai Puer tējās
2019
Maģistra darba ietvaros tika izstrādāta inovatīva divdimensionālās šķidruma hromatogrāfijas metode tandēmā ar augstas izšķirtspējas nolidojuma laika masspektrometriju (2D-LC-TOF-HRMS) 70 “jauno” un reglamentēto mikotoksīnu noteikšanai Puer tēju matricā. Šis uzdevums tika izvirzīts ar mērķi palielināt nosakāmo mikotoksīnu skaitu, uzlabot metodes selektivitāti un novērst traucējošo matricas komponentu efektu, pielietojot savienojumu atdalīšanu ar 2D-LC sistēmas palīdzību. Metode tika validēta saskaņā ar Eiropas Savienības analīzes metodes vadlīnijām. Izstrādātā online-heart-cutting-2D-HPLC-HRMS metode tika pielietota 20 Latvijā komerciāli pieejamajiem Puer tēju paraugiem, veicot analizēto mik…
Phytochemical-rich extracts of Helianthemum lippii possess antimicrobial, anticancer, and anti-biofilm activities
2022
Helianthemum lippii is a perennial shrubby plant growing in the sandy environments of Italy, Mediterranean countries of North Africa and Middle East. H. lippii is used in traditional medicine but there are very few reports referring to the phytochemical characterization, the ethnopharmacology, and the biological activity of H. lippii. The goal of this study was todetermine the phytochemical composition of different H. lippii extracts, cold (CME) and hot (HME) methanol, cold (CPEE) and hot (HPEE) petroleum ether, as well as to evaluate their anticancer and antimicrobial activities and biofilm formation reduction. Fifty-fours phytocompounds have been determined by HPLC-UV-ESI-QTOF-MS analysis…
Aportaciones de la herpetofauna al conocimiento de la paleobiología y paleoclimatología del tramo temporal Pleistoceno Superior y Holoceno de la Comu…
2022
El periodo Cuaternario se caracteriza climáticamente por la alternancia de fases glaciales e interglaciales, y, asociadas a ellas, importantes fluctuaciones de la línea de costa. Dado que este marco temporal es altamente relevante en el campo de la evolución humana y, por ello, gran parte de su estudio se ha centrado en esta temática; también lo es para entender diversos aspectos de la historia natural de otros grupos de vertebrados, como es el caso de los reptiles y anfibios. Hasta ahora son escasos los estudios del componente herpetológico de las faunas de vertebrados en el este de la península ibérica durante el Pleistoceno Superior y Holoceno, habiéndose centrado fundamentalmente este e…
Book review : Ziarek, Krzysztof. Language after Heidegger
2015
Auszüge aus Einer alten geschriebenen Liefländ
1771
Auszüge aus Einer alten geschriebenen Liefländ : CHRONICA von Jürgen Helms welche der Landrichter des Rigisch. Kreyßes H. v. Aderkas. besitzet u. die den Titel führt Warhafftige auß Copiae derre Lyfflandische Vndt Churlandische Chronnica Vndt Etzliche Geschichte so sich alhie begeben vndt zu getragenn haben Vohrnemblich zu Riga 1.) Von Erfindung, Erbavwung, Fruchtbarkeit, vnd dero ersten Regierung oderRegenten deß Landeß ist biß auff die Schwertbrüder 2) Vonn Ersten Herre Meister Teutsches Ordens, biß auff den Letzten pp 3.) Von dem Ersten Königen vnd Fürsten in Lyfflant vnd Churlant pp J.C.B. [2], 150, [8] S; Ill. [164 Federzeichn., grau laviert, Tusche]; [1] Bl.Karte. 31,4 x 20 cm. Handsc…