New instrumentation and methods for ultrafast pump-probe spectroscopy

Recent advances have led to the demonstration of trains of attosecond pulses and isolated attosecond pulses in the vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) regions of the electromagnetic spectrum in a number of laboratories. This has raised the possibility of direct time resolved measurements of correlation driven electron dynamics within molecules, with a long term aim of unprecedented control over the dynamics of matter at atomic and molecular length scales. Particular interest has arisen towards the possibility of a charge migration mechanism within molecules, in which purely electron driven processes result in the movement of charge around an excited molecule in the absence of any nuclear dynamics. However, even once these sources have been established, using them in time resolved experiments is challenging. This is due to extremely short time-scales involved, the complexity of the processes under study, and the limitations of currently available attosecond sources. In this thesis I describe the development of novel instrumentation and methods for attosecond pump – probe experiments on electron dynamics in molecules. Strategies for the experimental study of charge migration are reviewed in detail which motivates the design and implementation of a purpose built instrument combining an electron velocity map imaging (VMI) spectrometer and an ion time of flight (iTOF) spectrometer. This instrument is designed in tandem with the development and characterisation of an isolated pulse at the new photon energy of 20eV. This 20eV pulse is intrinsically synchronized with another attosecond pulse at 90eV. Together, the new instrument and light source represent a unique capability for the investigation of electron dynamics in molecules. Finally, the first experimental results are presented and perspectives for future studies using the new developments are discussed.Open Acces

Учет физических особенностей передачи энергии по элементу электрической сети в алгоритмах расчета установившихся режимов

Исследован предельный по существованию режим передачи энергии по элементу обобщенной ветви расчетной схемы электрической сети. Проведен анализ неоднозначности математической модели ее режимного состояния. Предложены способ проверки существования решения задачи расчета установившегося режима и алгоритм управления итерационным процессом с целью получения физически приемлемых результатов

A dual function activity-dependent, muscle-specific enhancer from rat nicotinic acetylcholine receptor δ-subunit gene

Nicotinic acetylcholine receptors (nAChR) mediate communication between nerve and muscle. The expression of these receptors increases dramatically during muscle development when myoblasts are fusing into multinucleated myotubes. The molecular mechanisms mediating this muscle developmental stage specific expression are not well understood. We report here the identification of nAChR δ-subunit promoter DNA sequences that differentially interact with nuclear proteins isolated from myoblasts, myotubes, and nonmuscle cells. The functional role these sequences play in mediating muscle-specific expression was explored using mutagenesis and enhancer assays. These studies resulted in the identification of a 47-bp muscle-specific enhancer that mediates increased expression of the nAChR δ-submit gene during myotube formation. This enhancer contains an E-box and an element with similarity to the SV40 core enhancer (SVCE). Point mutations throughout this 47-bp enhancer showed that the E-box and the SVCE sequence are both necessary for conferring muscle-specific expression onto a heterologous promoter. Interestingly, this same DNA sequence also functions as an activity-dependent enhancer. © 1996 John Wiley & Sons, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50088/1/8_ftp.pd

Адаптивная интерпретация нестационарных гидродинамических исследований в системе "Пласт-скважина" методом интегрированных моделей

Рассматриваются проблемы повышения информативности методов интерпретации нестационарных гидродинамических исследований в системе "пласт-скважина", и предлагается подход к их решению, основанный на использовании метода интегрированных моделей и метода адаптивной интерпретации. Приводятся примеры, показывающие преимущества предлагаемого подхода

Structurally parametric identification of object descrete models with delay for tuning smith controllers

Construction of Smith digital controller on the basis of equivalence principle of dynamic object models with delay has been suggeste

Ensamboende äldres syn på vad som främjar deras psykiska hälsa och känsla av mening i tillvaron

Bakgrund: Studier har visat att psykisk ohälsa är utbrett bland ensamboende äldre. Syfte: Att ta del av forskning som undersöker vad äldre ensamboende personer upplever främjar deras psykiska hälsa och känsla av mening i tillvaron. Metod: Denna litteraturstudie innefattar nio artiklar i resultatanalysen. Dataanalys genomfördes med integrerad analys. Resultat: Tre huvudteman som var och ett hade två subteman framkom. Det första temat var betydelsen av att känna socialt sammanhang med att göra saker för och med andra och att söka gemenskap som subteman. Det andra var aktiviteter för ett hälsosamt åldrande med de två subteman; stillasittande aktivitet och fysisk aktivitet. Det tredje huvudtemat som uppkom var betydelsen av att upprätthålla självständighet med betydelsen av hemmet och betydelsen av att vara ensamboende som subteman. Resultatet visar att upplevelsen av psykisk hälsa var relaterat till såväl social gemenskap som meningsfull aktivitet. Resultatet visar även att en känsla av delaktighet och att upprätthålla självständighet var förknippat med psykiskt välmående. Slutsats: Denna litteraturstudie ger en ökad kunskap kring vad äldre upplever som meningsfullt i tillvaron. Studien betonar även vilka roller en känsla av sammanhang och en meningsfull aktivitet spelar för det psykiska måendet

Effects of a Neonicotinoid Insecticide on the Growth of Honey Bee Gut Microbes

The gut microbiome plays an essential role in the overall health of organisms. However, the presence and abundance of these microbes may be altered by environmental factors, such as exposure to pesticides. The goals of this project were to understand 1) the prevalence of pesticide residues in honey bees in eastern Washington, and 2) the impact of pesticides to the honey bee gut microbiome. Accordingly, we tested bees from 24 hives among six sites across eastern Washington. High-performance liquid chromatography-mass spectrometry (HPLC-MS) was used to detect the presence and concentration of six commonly used agricultural pesticides: Carbaryl, Chlorpyrifos, Coumaphos, Cypermethrin, Imidacloprid, and tau-Fluvalinate. In addition to finding that the neonicotinoid insecticide Imidacloprid was present in 41.7% of bees tested, we found that bees from hives with Imidacloprid had significantly different gut microbiomes than bees without the pesticide, based on next-generation 16S rRNA gene amplicon sequencing. Next, we studied the effects of Imidacloprid on the honey bee gut microbiome by exposing bacteria isolated from honey bee guts against three treatments of the pesticide in 96-well plate laboratory assays. The majority of isolates tested exhibited reduced growth compared to controls, even in low concentrations of Imidacloprid. However, several isolates were robust to the Imidacloprid treatments and their growth did not differ from the control group. The combined field and laboratory data will inform hypotheses about the host-microbe-pesticide interactions that occur in the field, which can have important implications for bee, and thus ecosystem, health