58 research outputs found
Categorical view of the Partite Lemma in structural Ramsey Theory
We construct of the main object of the Partite Lemma as the colimit over a
certain diagram. This gives a purely category theoretic take on the Partite
Lemma and establishes the canonicity of the object. Additionally, the
categorical point of view allows us to unify the direct Partite Lemma in the
Ne\v{s}et\v{r}il--R\"odl Theorem with the dual Paritite Lemma by Solecki
Narcissism at the CEO–TMT interface: measuring executive narcissism and testing its effects on TMT composition
Extant strategic leadership literature has established the substantial and nuanced implications of narcissism in chief executive officers (CEOs) for firm outcomes, and psychological research on narcissism in groups highlights the importance of narcissism for interpersonal dynamics. However, there is little research on strategic leaders’ narcissism and the CEO–top management team (TMT) interface, especially related to its configuration by way of TMT composition. In this article, we therefore study two issues. First, we examine how CEO narcissism directly affects two aspects of TMT composition—the narcissism of newly appointed TMT members and TMT turnover. Second, we consider the moderating effect of TMT narcissism on the relationship between CEO narcissism and TMT turnover. To be able to test our theory, we develop and extensively validate a novel measure based on LinkedIn profiles that allows us to capture the narcissism of non-CEO executives. We find substantial support for our predictions in a large sample of executives of S&P 1500 corporations across a 5-year time frame. We discuss the contributions and implications of our findings for the literatures on executive narcissism, TMT composition, and the CEO–TMT interface
Habitat adaptation rather than genetic distance correlates with female preference in fire salamanders (Salamandra salamandra)
Caspers B, Junge C, Weitere M, Steinfartz S. Habitat adaptation rather than genetic distance correlates with female preference in fire salamanders (Salamandra salamandra). Frontiers in Zoology. 2009;6(1):13.Background: Although some mechanisms of habitat adaptation of conspecific populations have been recently elucidated, the evolution of female preference has rarely been addressed as a force driving habitat adaptation in natural settings. Habitat adaptation of fire salamanders (Salamandra salamandra), as found in Middle Europe (Germany), can be framed in an explicit phylogeographic framework that allows for the evolution of habitat adaptation between distinct populations to be traced. Typically, females of S. salamandra only deposit their larvae in small permanent streams. However, some populations of the western post-glacial recolonization lineage use small temporary ponds as larval habitats. Pond larvae display several habitat-specific adaptations that are absent in stream-adapted larvae. We conducted mate preference tests with females from three distinct German populations in order to determine the influence of habitat adaptation versus neutral genetic distance on female mate choice. Two populations that we tested belong to the western post-glacial recolonization group, but are adapted to either stream or pond habitats. The third population is adapted to streams but represents the eastern recolonization lineage. Results: Despite large genetic distances with F-ST values around 0.5, the stream-adapted females preferred males from the same habitat type regardless of genetic distance. Conversely, pond-adapted females did not prefer males from their own population when compared to stream-adapted individuals of either lineage. Conclusion: A comparative analysis of our data showed that habitat adaptation rather than neutral genetic distance correlates with female preference in these salamanders, and that habitat-dependent female preference of a specific pond-reproducing population may have been lost during adaptation to the novel environmental conditions of ponds
Микропроцессорный блок управления полупроводниковым коммутатором для накачки CUBR-лазера
Разработка приборов, позволяющих проводить обработку материалов с помощью высококонцентрированных потоков энергии, является весьма актуальной задачей. Одним из классов таких приборов являются лазерные системы, которые могут применяться как в технике, так и в медицине. Разработка устройств, позволяющих формировать «силовой» пучок с заданной конфигурацией позволит значительно увеличить скорость обработки материалов и минимизировать побочные действия при использовании в медицинских целях. В работе представлено подобное устройство, позволяющее изменять распределение интенсивности по пучку с использованием активных оптических систем с усилителями яркости на парах металлов. В качестве усилителя яркости использовался CuBr-лазер с тиратронным источником питания с импульсным зарядом рабочей емкости. Мощность источника питания варьировалась от 900 до 1500 Вт. Проведены исследования зависимости контраста получаемых изображений и влияние параметров используемого дисплея
Mesoporous carbon nitride-silica composites by a combined sol-gel/thermal condensation approach and their application as photocatalysts
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Mesoporous carbon nitrides, silicas and their composites have been prepared by a combined sol–gel and thermal condensation approach. Precursors for the carbon nitride (cyanamide) and silica (TEOS) are mixed and condensed simultaneously. After condensation and heat treatment it is observed that the carbon nitride and silica formed highly interpenetrating mesophases which leads either to the formation of mesoporous carbon nitride or silica after selective removal of one of the phases. Importantly, the carbon nitride preserves its graphitic stacking even in the spatial confinement introduced by the surrounding silica phase. As both precursors are liquids this approach allows convenient shaping into thin and thick films or monoliths of mesoporous carbon nitrides. Enhanced photocatalytic activity is observed for the production of hydrogen from water when these mesoporous carbon nitrides are applied as photocatalyst in comparison to the bulk, but also to other mesoporous carbon nitrides, prepared by the reported two-step, hard templating approach.BMBF, 03IS2071D, Light2Hydroge
Dual functionality of formamidine polymers, as ligands and as bases, in ruthenium-catalysed hydrogen evolution from formic acid
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.In the present study, the ruthenium-catalysed decomposition of formic acid to yield hydrogen has been examined. A ruthenium complex modified polyformamidine network was used as a solid catalyst. As a dual support the polyformamidine acts both as a ligand and as a base for the activation of formic acid.DFG, EXC 314, Unifying Concepts in Catalysi
Holographic optogenetic stimulation with calcium imaging as an all optical tool for cardiac electrophysiology
All optical approaches to control and read out the electrical activity in a cardiac syncytium can improve our understanding of cardiac electrophysiology. Here, we demonstrate optogenetic stimulation of cardiomyocytes with high spatial precision using light foci generated with a ferroelectric spatial light modulator. Computer generated holograms binarized by bidirectional error diffusion create multiple foci with more even intensity distribution compared with thresholding approach. We evoke the electrical activity of cardiac HL1 cells expressing the channelrhodopsin-2 variant, ChR2(H134R) using single and multiple light foci and at the same time visualize the action potential using a calcium sensitive indicator called Cal-630. We show that localized regions in the cardiac monolayer can be stimulated enabling us to initiate signal propagation from a precise location. Furthermore, we demonstrate that probing the cardiac cells with multiple light foci enhances the excitability of the cardiac network. This approach opens new applications in manipulating and visualizing the electrical activity in a cardiac syncytium
Quality of life in people with dementia living in nursing homes: validation of an eight-item version of the QUALIDEM for intensive longitudinal assessment
Purpose: Our aim was to examine whether quality of life which was repeatedly assessed over time is related with the comprehensive assessment of quality of life (QoL) and thereby to validate a brief QoL assessment.
Method: This longitudinal study used a comprehensive assessment of quality of life at baseline (QUALIDEM; 37 items) to validate an eight-item version of QUALIDEM to assess momentary quality of life which was repeatedly administered using a tablet device after baseline. In all, 150 people with dementia from 10 long-term facilities participated. Momentary quality of life and comprehensive quality of life, age, gender, activities of daily living (Barthel Index), Functional assessment staging (FAST), and Geriatric Depression (GDS) have been assessed.
Results: Comprehensive and momentary quality of life showed good internal consistency with Cronbach’s alpha of .86 and .88 to .93, respectively. For multiple associations of momentary quality of life with the comprehensive quality of life, momentary quality of life was significantly related to comprehensive quality of life (B = .14, CI .08/.20) and GDS (B = − .13, CI − .19/− .06). More specifically, the comprehensive QUALIDEM subscales ‘positive affect’, ‘negative affect’, ‘restlessness’, and ‘social relationships’ showed significant positive associations with momentary quality of life (p < .001).
Conclusion: We found that momentary quality of life, reliably assessed by tablet, was associated with comprehensive measures of quality of life and depressive symptoms in people with dementia. Broader use of tablet-based assessments within frequent QoL measurements may enhance time management of nursing staff and may improve the care quality and communication between staff and people with dementia
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