Psychometric properties of the adapted school culture survey-teacher form in the selected virtual school

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Title from PDF of title page (University of Missouri--Columbia, viewed on February 15, 2012).Thesis advisor: Dr. Phillip E. MessnerVita.Ph. D. University of Missouri-Columbia 2010.The study of the Selected Virtual School teachers' perceptions on culture was conducted to determine the psychometric properties of Virtual School Culture Survey-Teacher Form (VSCS-TF). The VSCS-TF was sent out to approximately 225 teachers in the Selected Virtual School and 78 agreed to complete the survey. Cronbach's alpha, item total analysis, an Expert Online Education Panel, and factor analysis were applied to investigate properties of validity and reliability. The instrument was determined to be reliable with face and content validity but no construct validity with the School Culture Survey-Teacher Form (Gruenert, 1998). Principal component analysis yielded seven factors. Additional data reduction criteria produced four factors: (a) Collegial Collaboration, (b) School Improvement, (c) Collegial Communication, and (d) Leader Partnership. A revised version of the VSCS-TF was created with 21 items and four factors.Includes bibliographical reference

‘When is a hotspot a good nanospot’:review of analytical and hotspot-dominated surface enhanced Raman spectroscopy nanoplatforms

Substrate development in surface-enhanced Raman spectroscopy (SERS) continues to attract research interest. In order to determine performance metrics, researchers in foundational SERS studies use a variety of experimental means to characterize the nature of substrates. However, often this process would appear to be performed indiscriminately without consideration for the physical scale of the enhancement phenomena. Herein, we differentiate between SERS substrates whose primary enhancing structures are on the hundreds of nanometer scale (analytical SERS nanosubstrates) and those whose main mechanism derives from nanometric-sized gaps (hot-spot dominated SERS substrates), assessing the utility of various characterization methods for each substrate class. In this context, characterization approaches in white-light spectroscopy, electron beam methods, and scanning probe spectroscopies are reviewed. Tip-enhanced Raman spectroscopy, wavelength-scanned SERS studies, and the impact of surface hydrophobicity are also discussed. Conclusions are thus drawn on the applicability of each characterization technique regarding amenability for SERS experiments that have features at different length scales. For instance, while white light spectroscopy can provide an indication of the plasmon resonances associated with 10 s–100 s nm-scale structures, it may not reveal information about finer surface texturing on the true nm-scale, critical for SERS’ sensitivity, and in need of investigation via scanning probe techniques

Responding to Turbulent Times: Where Does Leadership Come In?

Leadership is a major twenty-first-century concern because of the need to make sense of an increasingly complex context and to make choices between options for the positive changes that are deemed required. Reviewing the success of leadership responses to challenges of violent conflict and health pandemics as well as the extent to which we see futures through fragmented or solidarity lenses has created real interest in global perspectives in leadership and a new research agenda that is associated with this imperative. The article concludes by identifying work in progress, that is, by assessing the universality of characteristics that have been associated with good leadership and how globalization is changing leaders’ perspectives and required competencies

Defection on the bounty? Kinship and cooperative exploitation of a rich, essential but dangerous resource

We develop a game-theoretic model to explore the question of whether two animals should cooperate in the dangerous activity of obtaining a rich and essential resource. We consider variation in the risks incurred to individuals and in how the activities of the two animals interact to influence the probability of success. We also consider that the animals may be relatives and thus share evolutionary interests. The model is general and can, for instance, be applied to mammalian predators attempting to capture and subdue large and dangerous prey or to female parasitoid wasps that attack and, if successful, paralyse aggressive hosts that then provide the only feeding resource for their offspring. This minimal model of cooperation contains three dimensionless parameters: vulnerability (the ratio between the average time for a lone attacker to subdue the defending resource and the average time for the defender to fatally strike the attacker), the dilution ratio (the extent to which attack by animals acting in tandem reduces a defender's ability to kill its attackers) and the relatedness between the potential attackers. The model predicts that higher values of all three parameters favour cooperation and that for small values cooperation is not evolutionarily stable. Cooperation can arise from an ancestral state of non-cooperation if values of all parameters are sufficiently high but cannot arise among non-relatives, irrespective of other parameter values. Once cooperation has emerged in a population, it can be maintained among nonrelatives at modest values of dilution ratio and vulnerability. We discuss these general predictions in particular relation to the parasitoid genus Sclerodermus, in which multiple females may attack unusually large and aggressive hosts and in which host attack behaviour is mediated by kinship. (c) 2021 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.Peer reviewe

The evolutionarily stable strategy, animal contests, parasitoids, pest control and sociality

The evolutionarily stable strategy, ESS, concept was first used in biology to understand sex ratio bias and, shortly afterwards, to explore the logic of contests over essential and indivisible resources. ESS models formed the basis of much subsequent research on animal behaviour and placed game-theoretic thinking firmly within the behavioural ecology approach. Among behavioural ecologists studying parasitoids, it was those asking questions about the evolution of sex ratios who first made extensive use of the game-theoretic approach. A later growth of interest in parasitoid host defence and fighting behaviour made use of these tractable study species to explore contests and their connections to further aspects of life-history evolution plus some pest control applications. Our aims are to (i) introduce the topic of contests, which are engaged in by a very wide array of animal taxa, and the importance, both historical and conceptual, of the game-theoretic approach to their study, and (ii) review recent studies of parasitoid contests, including those that have considered the context of social evolution and the performance of parasitoids as agents of biological control. We consider that game-theoretic models are eminently testable and applicable and will likely endure as valuable tools in studies of parasitoid biology.This article is part of the theme issue 'Half a century of evolutionary games: a synthesis of theory, application and future directions'.Peer reviewe

Onset of a boson mode at superconducting critical point of underdoped YBa2Cu3Oy

The thermal conductivity $\kappa$ of underdoped \Y was measured in the $T \to 0$ limit as a function of hole concentration $p$ across the superconducting critical point at $p_{SC}$ = 5.0%. ``Time doping'' was used to resolve the evolution of bosonic and fermionic contributions with high accuracy. For $p \leqslant p_{SC}$, we observe an additional $T^3$ contribution to $\kappa$ which we attribute to the boson excitations of a phase with long-range spin or charge order. Fermionic transport, manifest as a linear term in $\kappa$, is seen to persist unaltered through $p_{SC}$, showing that the state just below $p_{SC}$ is a thermal metal. In this state, the electrical resistivity varies as log$(1/T)$ and the Wiedemann-Franz law is violated