Novel Distances for Dollo Data

We investigate distances on binary (presence/absence) data in the context of a Dollo process, where a trait can only arise once on a phylogenetic tree but may be lost many times. We introduce a novel distance, the Additive Dollo Distance (ADD), which is consistent for data generated under a Dollo model, and show that it has some useful theoretical properties including an intriguing link to the LogDet distance. Simulations of Dollo data are used to compare a number of binary distances including ADD, LogDet, Nei Li and some simple, but to our knowledge previously unstudied, variations on common binary distances. The simulations suggest that ADD outperforms other distances on Dollo data. Interestingly, we found that the LogDet distance performs poorly in the context of a Dollo process, which may have implications for its use in connection with conditioned genome reconstruction. We apply the ADD to two Diversity Arrays Technology (DArT) datasets, one that broadly covers Eucalyptus species and one that focuses on the Eucalyptus series Adnataria. We also reanalyse gene family presence/absence data on bacteria from the COG database and compare the results to previous phylogenies estimated using the conditioned genome reconstruction approach

Stick-Fixed Maneuver Points in Roll, Pitch, and Yaw and Associated Handling Qualities

The stick-fixed pitch maneuver point is an important measure of aircraft longitudinal dynamic response and handling quality characteristics, and includes effects of both aerodynamic and inertia properties of the aircraft about the pitch axis. In the present work, the existence of stick-fixed roll and yaw maneuver points is demonstrated, which are determined from the lateral forces, moments, and inertial properties of the aircraft. These stick-fixed roll and yaw maneuver points are directly related to the predicted lateral handling qualities. Example results are included for several aircraft that demonstrate the importance of this parameter when predicting the dynamic response of the aircraft. A better understanding of stick-fixed roll, pitch, and yaw maneuver points can inform aircraft design during early stages to ensure adequate handling qualities for both longitudinal and lateral modes

On the History and Semantics of Burble in Aerodynamic Theory

The term burble has been in use in aerodynamic theory for over a century. While burble may be unfamiliar to most contemporary aerodynamicists, the word has a rich history based in aerodynamic theory and experimentation. The present paper outlines the fluidity of burble\u27s meaning over time. From analyzing subsonic flow over an airfoil, to the implementation of stochastic turbulence in aircraft carrier landing simulations, the term burble has had a significant impact on the study of aerodynamics. The term burble has fallen out of use in aerodynamic engineering circles. Why did this happen? And what can be learned from the decline in use of the term burble

Systematic review of mindfulness-based cognitive therapy and mindfulness-based stress reduction via group videoconferencing: feasibility, acceptability, safety, and efficacy

Mindfulness-Based Cognitive Therapy (MBCT) and Mindfulness-Based Stress Reduction (MBSR) are effective in reducing distress among people with physical or mental health problems. However, implementation is limited by variable geographic provision, ability to travel, and the need for remote service delivery during the coronavirus disease 2019 (COVID-19) crisis. Integration with Internet-enabled technologies like videoconferencing potentially enhances access. This article reports a systematic review exploring the feasibility, acceptability, safety, and efficacy of delivering MBCT/MBSR by videoconferencing (MBCT/MBSR-VC). No restrictions were made about population or study design. Eleven online databases were searched and 10 studies met inclusion criteria. Narrative synthesis was used because of study heterogeneity. Articles featured physical health and nonclinical samples, but not mental health. Three studies had moderate-strong methodological quality. Results supported the feasibility and acceptability of MBCT/MBSR-VC. Considerations of safety were largely unreported. MBCT/MBSR-VC demonstrated medium positive effects on mental health outcomes compared with inactive controls (ds = 0.44–0.71), and little difference compared with active controls like in-person delivery (all confidence intervals crossed zero). Evidence regarding mindfulness or selfcompassion as potential mechanisms of action was inconclusive. Future implementation research should target mental health populations using noninferiority designs. Adapting MBCT/MBSR to remote delivery will require development of guidelines and training packages to ensure best practice in this medium and adherence to evidence-based MBCT/MBSR model

Generation of directional, coherent matter beams through dynamical instabilities in Bose-Einstein condensates

We present a theoretical analysis of a coupled, two-state Bose-Einstein condensate with non-equal scattering lengths, and show that dynamical instabilities can be excited. We demonstrate that these instabilities are exponentially amplified resulting in highly-directional, oppositely-propagating, coherent matter beams at specific momenta. To accomplish this we prove that the mean field of our system is periodic, and extend the standard Bogoliubov approach to consider a time-dependent, but cyclic, background. This allows us to use Floquet's theorem to gain analytic insight into such systems, rather than employing the usual Bogoliubov-de Gennes approach, which is usually limited to numerical solutions. We apply our theory to the metastable Helium atom laser experiment of Dall et al. [Phys. Rev. A 79, 011601(R) (2009)] and show it explains the anomalous beam profiles they observed. Finally we demonstrate the paired particle beams will be EPR-entangled on formation.Comment: Corrected reference

Ultra-broadband wavelength-swept Tm-doped fiber laser using wavelength-combined gain stages

A wavelength-swept thulium-doped fiber laser system employing two parallel cavities with two different fiber gain stages is reported. The fiber gain stages were tailored to provide emission in complementary bands with external wavelength-dependent feedback cavities sharing a common rotating polygon mirror for wavelength scanning. The wavelength-swept laser outputs from the fiber gain elements were spectrally combined by means of a dichroic mirror and yielded over 500 mW of output with a scanning range from ~1740 nm to ~2070 nm for a scanning frequency of ~340 Hz

Elastic cavitation, tube hollowing, and differential growth in plants and biological tissues

Elastic cavitation is a well-known physical process by which elastic materials under stress can open cavities. Usually, cavitation is induced by applied loads on the elastic body. However, growing materials may generate stresses in the absence of applied loads and could induce cavity opening. Here, we demonstrate the possibility of spontaneous growth-induced cavitation in elastic materials and consider the implications of this phenomenon to biological tissues and in particular to the problem of schizogenous aerenchyma formation

Distinct high-T transitions in underdoped Ba1−x_{1-x}Kx_{x}Fe2_{2}As2_{2}

In contrast to the simultaneous structural and magnetic first order phase transition $T_{0}$ previously reported, our detailed investigation on an underdoped Ba$_{0.84}$K$_{0.16}$Fe$_{2}$As$_{2}$ single crystal unambiguously revealed that the transitions are not concomitant. The tetragonal ($\tau$: I4/mmm) - orthorhombic ($\vartheta$: Fmmm) structural transition occurs at $T_{S}\simeq$ 110 K, followed by an adjacent antiferromagnetic (AFM) transition at $T_{N}\simeq$ 102 K. Hysteresis and coexistence of the $\tau$ and $\vartheta$ phases over a finite temperature range observed in our NMR experiments confirm the first order character of the structural transition and provide evidence that both $T_{S}$ and $T_{N}$ are strongly correlated. Our data also show that superconductivity (SC) develops in the $\vartheta$ phase below $T_{c}$ = 20 K and coexists with long range AFM. This new observation, $T_{S}\neq T_{N}$, firmly establishes another similarity between the hole-doped BaFe$_{2}$As$_{2}$ via K substitution and the electron-doped iron-arsenide superconductors.Comment: 4 pages, 3 figure