1,857 research outputs found

    Rapid deconvolution of low-resolution time-of-flight data using Bayesian inference

    Get PDF
    The deconvolution of low-resolution time-of-flight data has numerous advantages, including the ability to extract additional information from the experimental data. We augment the well-known Lucy-Richardson deconvolution algorithm using various Bayesian prior distributions and show that a prior of second-differences of the signal outperforms the standard Lucy-Richardson algorithm, accelerating the rate of convergence by more than a factor of four, while preserving the peak amplitude ratios of a similar fraction of the total peaks. A novel stopping criterion and boosting mechanism are implemented to ensure that these methods converge to a similar final entropy and local minima are avoided. Improvement by a factor of two in mass resolution allows more accurate quantification of the spectra. The general method is demonstrated in this paper through the deconvolution of fragmentation peaks of the 2,5-dihydroxybenzoic acid matrix and the benzyltriphenylphosphonium thermometer ion, following femtosecond ultraviolet laser desorption

    Adapting to Complexities in Dialogue

    Get PDF
    The world is getting a VUCA place. A world that is more volatile, uncertain, complex and ambiguous. Changing conditions can be seen at a global level, on the level of societies and organizations but also at a micro level of people. Dealing with differences requires awareness about our own world views, and an open mind to understand the viewpoint of others. For interaction to be productive, participants need to recognize the different voices that come into play. This ‘social complexity’ is a underlying aspect relevant for understanding how to cope with VUCA situations. The aim of this chapter is to describe the conversational processes that take place during interactions between different professionals in organizations. Applying the ‘ladder of complexity’ and discourse analysis in three cases reveal that different ‘voices’ can be distinguished in the process of organizational change. We promote incorporating sociolinguistics into the field of organizational change. Section 1 introduces the ‘playground’ we live in followed by different paradigms about communicating and change management. Section 3 introduces the ‘ladder of complexity’ aligning social complexity and dialogue. Section 4 describes 3 cases using discourse analysis to understand the interaction in conversations. Section 5 draws conclusions and give directions for future research

    Religious beliefs and ethnocentrism: A comparison between the Dutch and white South Africans

    Get PDF
    Contains fulltext : 3344.pdf (publisher's version ) (Open Access

    Plural religious beliefs: A comparison between the Dutch and white South Africans

    Get PDF
    Contains fulltext : 3355.pdf (publisher's version ) (Open Access)wetenschappelijk tijdschrift van de Nederduits Hervormde Kerk in Zuid-Afrik

    ’n Kort rit in ’n vinnige voertuig

    Get PDF
    In 1986 het Piet Roodt en Elize Botha my genader om deel van Tydskrif vir Letterkunde se skakelredaksie te word. My hooftaak was om ingestuurde poësie te keur en later te help met die saamstel van die tydskrif. Een hoogtepunt was die saamstel van ’n gerf geleentheidsverse ter nagedagtenis aan Stephen le Roux (Etienne Leroux, 1990). Teen die einde van die tagtigerjare het ek en Piet die meeste van die werk gedoen; prof. Elize kondig einde 1992 aan dat sy uittree as redakteur

    Carbonic anhydrases CA1 and CA4 function in atmospheric CO2-modulated disease resistance

    Get PDF
    Main conclusion Carbonic anhydrases CA1 and CA4 attenuate plant immunity and can contribute to altered disease resistance levels in response to changing atmospheric CO2 conditions. Abstract β-Carbonic anhydrases (CAs) play an important role in CO2 metabolism and plant development, but have also been implicated in plant immunity. Here we show that the bacterial pathogen Pseudomonas syringae and application of the microbe-associated molecular pattern (MAMP) flg22 repress CA1 and CA4 gene expression in Arabidopsis thaliana. Using the CA double-mutant ca1ca4, we provide evidence that CA1 and CA4 play an attenuating role in pathogen- and flg22-triggered immune responses. In line with this, ca1ca4 plants exhibited enhanced resistance against P. syringae, which was accompanied by an increased expression of the defense-related genes FRK1 and ICS1. Under low atmospheric CO2 conditions (150 ppm), when CA activity is typically low, the levels of CA1 transcription and resistance to P. syringae in wild-type Col-0 were similar to those observed in ca1ca4. However, under ambient (400 ppm) and elevated (800 ppm) atmospheric CO2 conditions, CA1 transcription was enhanced and resistance to P. syringae reduced. Together, these results suggest that CA1 and CA4 attenuate plant immunity and that differential CA gene expression in response to changing atmospheric CO2 conditions contribute to altered disease resistance levels

    Pericytes promote skin regeneration by inducing epidermal cell polarity and planar cell divisions.

    Get PDF
    The cellular and molecular microenvironment of epithelial stem/progenitor cells is critical for their long-term self-renewal. We demonstrate that mesenchymal stem cell-like dermal microvascular pericytes are a critical element of the skin's microenvironment influencing human skin regeneration using organotypic models. Specifically, pericytes were capable of promoting homeostatic skin tissue renewal by conferring more planar cell divisions generating two basal cells within the proliferative compartment of the human epidermis, while ensuring complete maturation of the tissue both spatially and temporally. Moreover, we provide evidence supporting the notion that BMP-2, a secreted protein preferentially expressed by pericytes in human skin, confers cell polarity and planar divisions on epidermal cells in organotypic cultures. Our data suggest that human skin regeneration is regulated by highly conserved mechanisms at play in other rapidly renewing tissues such as the bone marrow and in lower organisms such as Drosophila. Our work also provides the means to significantly improve ex vivo skin tissue regeneration for autologous transplantation

    Развитие ионизационного монитора поперечного сечения протонного пучка линейного ускорителя ИЯИ РАН

    Get PDF
    Для обеспечения прозрачных измерений поперечного сечения и профилей токовых импульсов в широком диапазоне энергий и амплитуд разработан и установлен на ускорителе специальный ионизационный монитор поперечного сечения (ИМПС) на остаточном газе. ИМПС оборудован зеркально-линзовым трактом для транспортировки изображения пучка от детектора до ТВ-камеры и защиты ПЗС-матрицы и электроники ТВ-камеры от бомбардировки нейтронами и γ-квантами. В работе приводится схема и описание датчика, а также некоторые детали программного и аппаратного обеспечения системы съема и обработки изображений. Представлены полученные результаты измерений импульсного тока протонов.Для забезпечення прозорих вимірів поперечного переріза й профілів струмових імпульсів у широкому діапазоні енергій і амплітуд розроблений і встановлений на прискорювачі спеціальний іонізаційний монітор поперечного переріза (ІМПС) на залишковому газі. ІМПС обладнаний дзеркально-лінзовим трактом для транспортування зображення пучка від детектора до ТВ-камери і захисту Пзс-матриці й електроніки ТВ-камеры від бомбардування нейтронами і γ-квантами. У роботі приводиться схема й опис датчика, а також деякі деталі програмного й апаратного забезпечення системи знімання й обробки зображень. Представлено отримані результати вимірів імпульсного струму протонів.To provide non-intercepting measurements of beam pulse transverse section and profile the special residual gas ion transverse section monitor (ITSM) for wide energy and amplitude range is developed and installed on the accelerator. ITSM is provided by lens-mirror line for transport beam image from the detector to TV camera and saving CCD and electronics of TV camera from neutron and γ hitting. The ITSM functioning details and image processing system are described. The available results of beam pulse measurements are presented
    corecore