Scale Microstructures of Pygopodid Lizards (Gekkota: Pygopodidae): Phylogenetic Stability and Ecological Plasticity

The skin, as the interface of the body with the outside world, is directly exposed to the impacts of the environment. We have examined the microstructure of scale surfaces and the numerical distribution and morphology of skin sensory organs (SSO) in Australian limbless lizards of the family Pygopodidae. We have shown that the hairy sensory organs, as complex morphological structures, are a stable characteristic of the scale integument of pygopodids. This feature reflects their relationship to geckos and is shared homoplastically with some iguanian families (Dactyloidae, Leiosauridae, Opluridae, Chamaeleonidae). At the same time, scale micro-ornamentation as an elementary morphological structure is more plastic and, although the basic spinulate pattern is dominant, other variants occur on the scales of the serpentine body of pygopodids. We accept the spinules of MiO and the hairs of SSO as homologous structures at the cellular level since they are both derivatives of the Oberhäutchen cell surface. We propose to characterize the hair-bearing SSO of gekkotan and iguanian lizards as Oberhäutchen hairy sensory organs (ObHSO). Domination of SP MiO and presence of ObHSO in the integument of Gekkota and several families of Iguania, and sporadic occurrence of SP MiO in autarchoglossan taxa provide justification for regarding these characters as plesiomorphic. We characterize the high abundance (iterative state) of SSO in the scales of the head of pygopodids as representing the phenomenon of «overiteration», in which the phylogenetically established condition is enhanced by functional demands on the organism.

Brief growth mindset and mindfulness inductions to facilitate effort after negative feedback

Negative feedback in academic settings is often unavoidable, although it may directly interfere with the ultimate goal of education, as setbacks can diminish motivation, and may even lead to dropping out of school. Previous research suggests that certain predispositions, inductions, and interventions might mitigate the harmful effects of negative feedback. Among others, growth mindset beliefs and mindfulness meditation were proposed as the most promising candidates that may help students to retain motivation. In a pre-registered, randomized experiment, we gave a disappointing evaluation to 383 university students in a bogus laboratory IQ test situation. Half of the participants previously received a growth mindset induction referring to intelligence as a malleable characteristic, while the other half received a fixed mindset induction referring to intelligence as a stable characteristic that cannot be changed. Then participants had a brief mindfulness meditation session or a control condition. Subsequently, they could choose to complete practice tasks before the final IQ assessment. The number of completed optional tests was used as a behavioral proxy for effort. The results showed no difference in effort for the growth mindset or the mindfulness meditation groups, compared to the other conditions. However, those that reported having higher dispositional mindfulness completed more optional tasks after mindfulness meditation. We concluded that our brief mindset and mindfulness inductions may not be adequate for everyone to alleviate the demotivating effects of negative feedback, but it does not necessarily mean that mindfulness cannot help implementing a growth mindset.

Shock Resistance Design of High-Speed Maglev Motor–Stability Considerations and Quantitative Shock Tests

Large external disturbances (such as shock loads) can cause contact between the rotor and touchdown bearings (TDBs). Hence, maintaining the stability of systems with active magnetic bearings (AMBs) is a major challenge for mobile applications such as on-board steam turbines or vehicle turbochargers. In this paper, two key factors (power bandwidth and bi-stable characteristic) that affect the shock stability of AMB-rotor systems are considered in the design of a high-speed maglev motor. Insufficient power bandwidth can induce current saturation leading to destabilization, while a bi-stable characteristic can cause persistent contact between the rotor and TDBs under external disturbances. Theoretical analyzes and criteria are provided, and the influence of these two factors is investigated by base shock experiments of a high-speed maglev motor. These experiments involved mounting a high-speed maglev motor on a shock table then subjecting it to shock loads of different amplitudes. The designed motor continued to operate stably under shock loads up to 20 G, verifying the correctness of the stability considerations.

Paleolatitude and Tectonic Rotations of the Early Carboniferous Fountain Lake Group, Cobequid Highlands, Nova Scotia, Canada

The ca. 355 Ma Fountain Lake Group, in the Cobequid Highlands of Nova Scotia, is part of the transtensional basin fill which formed during dextral strike-slip motion between Avalonia and the Meguma terranes following the Acadian Orogeny. Paleomagnetic analysis of the Fountain Lake Group offers a paleolatitude estimate for the Laurentian accretionary margin in the Early Carboniferous and locality-specific paleomagnetic directions which indicate clockwise-sense block rotations during dextral strike-slip motion along the Cobequid Fault zone. Stepwise demagnetization of 142 specimens from 20 sites in three Fountain Lake Group localities across the Cobequid Highlands (Squally Point, West Moose River, and Wentworth exposures) reveals remanence consisting of an easily removed component of probable recent origin, and more persistent components carried by magnetite and hematite, which in petrographic and electron beam analysis appear to be of primary igneous and volcanic oxidation origins, respectively. Sites from all three localities carry stable characteristic remanent magnetization (ChRM) directions that assume similar moderate downward inclinations when tilt-corrected. A Block Rotation Fisher analysis inclination-only fold test demonstrated best agreement at 90% unfolding, showing that remanence acquisition pre-dates Alleghenian deformation in the Late Carboniferous and is most likely of primary 355 Ma age. Paleomagnetic results for the Squally Point, West Moose River and Wentworth localities show relative rotations between the blocks that are variously clockwise-rotated compared with a Laurentia cratonic reference frame. Inclinations at all three localities imply a subtropics paleolatitude for the margin (at Squally Point, 27.2° ± 9.4°; N= 7 sites), directly supporting the depicted location of Laurentia and its Appalachian accretionary margin in most Devonian to Early Carboniferous reconstructions.

On the Mechanism of Spike Stall Inception and Near Stall Non-Synchronous Vibration in an Axial Compressor

The aerodynamic and aeroelastic behavior of an engine-like transonic compressor stage is investigated in this paper. Simulations were carried out for the transonic compressor at the Technical University of Darmstadt using the AU3D flow solver. A comparison with previous experimental investigations shows close agreement for both steady and transient data. The simulations enable a detailed flow analysis during spike stall inception and non-synchronous vibrations (NSV) at operating points close to the stall limit. The aerodynamic structure of shear layer fluctuations in the rotor tip region during the initial phase of spike stall inception is investigated. Already before the stall limit is reached such fluctuations can occur. In this case, the compressor continues to operate on the aerodynamically stable characteristic and NSV might be excited due to the unsteady blade force. This paper concludes with a joint analytical interpretation of the shear layer fluctuations observed at the beginning of spike stall and during near stall NSV by basic flow principles.

On the Mechanism of Spike Stall Inception and Near Stall Non-Synchronous Vibration in an Axial Compressor

The aerodynamic and aeroelastic behavior of an engine-like transonic compressor stage is investigated in this paper. Simulations were carried out for the transonic compressor at the Technical University of Darmstadt using the AU3D flow solver. A comparison with previous experimental investigations shows close agreement for both steady and transient data. The simulations enable a detailed flow analysis during spike stall inception and non-synchronous vibrations (NSV) at operating points close to the stall limit. The aerodynamic structure of shear layer fluctuations in the rotor tip region during the initial phase of spike stall inception is investigated. Already before the stall limit is reached such fluctuations can occur. In this case, the compressor continues to operate on the aerodynamically stable characteristic and NSV might be excited due to the unsteady blade force. This paper concludes with a joint analytical interpretation of the shear layer fluctuations observed at the beginning of spike stall and during near stall NSV by basic flow principles.

Sponsorship in focus: a typology of sponsorship contexts and research agenda

PurposeSponsorship has become an important marketing activity. However, research on the topic treats the sponsorship context, characterized according to the type of sponsored property and the social role of these properties, as a stable characteristic or as a dichotomous characteristic within empirical studies. Therefore, the authors outline a multi-level typology of the different types of sponsorship contexts to account for traditional types of sponsorship as well as emerging themes such as online sponsorship. The authors then propose an agenda for future research.Design/methodology/approachThe authors conduct a general review of the sponsorship literature to synthesize established sponsorship types with newly emerging themes to develop a multi-level typology of sponsorship contexts and a research agenda.FindingsThe authors’ conceptual analysis revealed a typology of sponsorship contexts that captures both general and specific types of sports sponsorship, prosocial cause sponsorship, culture and community sponsorship, and media and programming content sponsorship.Research limitations/implicationsThe authors’ typology provides an organizing framework for future research focussing on different sponsorship contexts. However, the emergent categories still require further empirical testing. Therefore, the authors develop a set of questions to guide future research on the topic.Practical implicationsThe authors’ typology outlines the different sponsorship contexts that should be considered by organizations that engage in sponsorship-linked marketing.Originality/valueThis paper provides a multi-level categorization of sponsorship contexts that integrates both traditional categories and newly emerging categories to better inform future research on situational differences in sponsorship.

Evaluation of acoustic emission source localization accuracy in concrete structures

Acoustic emission source localization is a promising monitoring technique for concrete structures. However, the accuracy of acoustic emission source localization is influenced by many factors, such as the presence of cracks, which are commonly observed in existing reinforced concrete structures. In this article, the acoustic emission source localization is evaluated using a numerical model with a total number of 11,827,200 independent simulated tests. In this work, the investigated influential factors include the presence of cracks, arrival time picking error, and senor layout. The accuracy of source localization is quantified by the characteristic error defined in this article. Using the proposed wave propagation properties, a relatively stable characteristic error of 150 mm is estimated in the detection zone with the maximum sensor spacing less than 1 m. The evaluation approach and simulated characteristic error are validated experimentally by comparing the 200 manually generated signals using hammer hits on a cracked concrete beam.

Automatic regime detection for Rotor Track and Balance using vibration only sensor data

ABSTRACTRotor Track and Balance (RTB) is an important part of regular helicopter maintenance. The ability to perform this service assessment during normal operations, rather than with a series of explicit RTB flights, would greatly reduce the time the vehicle is non-operational and the maintenance costs associated with these flights and adjustments. This paper presents a novel methodology for identifying the RTB-related flight regimes, using a minimal number of vibration signals and comparing these to repeatable and stable characteristic vibration profiles. The technique is stable, with an 81% success in correct identification of the flight regime, when applied to a whole flight with a number of unknown regime events. The method can be run in real time, making it an effective way of identifying periods of flight that are suitable for RTB measurements. A new technique for visually representing any real-time flight signal, such as vibration, is also presented.

Preliminary absolute paleointensity estimation from a single volcanic-glass grain extracted from an unwelded pyroclastic flow

<p>Many pyroclastic flows are distributed around Japan. They usually involve volcanic-glass grains. These grains are considered to form at the timing of volcanic eruptions and are expected to have magnetic inclusions consisting of tiny single (titano)magnetites with recording the paleomagnetic field. We have extracted single volcanic-glass grains of pumice-type with a diameter of 0.60-0.84 mm from an unwelded part of the Ito pyroclastic flow deposits (A-Ito, 26-29 ka; Machida and Arai, 2003), Kyusyu, Japan. A series of rock- and paleomagnetic measurements have been made on the grains.</p><p>Sixty-seven out of 88 grains had detectable intensities of natural remanent magnetization. Some of such grains were further investigated. Results of low-temperature magnetometry exhibited inflection points at 105-120 K, suggesting magnetite as a main remenence carrier. Stepwise alternating field demagnetization revealed an existence of stable characteristic remanence (ChRM) which was interpreted to be a primary component. </p><p>Tsunakawa-Shaw method (Tsunakawa and Shaw, 1994; Yamamoto et al., 2003), one of the latest absolute paleointensity (API) techniques to date, was applied to selected grains having stable ChRMs. On the application we newly included measurements related to an isothermal remanent magnetization (IRM). Four successful results were obtained by an adoption of IRM corrections, giving an average API value of about 25 μT. This corresponds to a virtual axial dipole moment (VADM) of about 50 ZAm<sup>2</sup>, which is consistent with the contemporaneous VADM of the sedimentary record (PISO-1500; Channell et al., 2009). </p>