Experimental Nonlinear Control for Flutter Suppression in a Nonlinear Aeroelastic System

Experimental implementation of input–output feedback linearization in controlling the dynamics of a nonlinear pitch–plunge aeroelastic system is presented. The control objective is to linearize the system dynamics and assign the poles of the pitch mode of the resulting linear system. The implementation 1) addresses experimentally the general case where feedback linearization-based control is applied using as the output a degree of freedom other than that where the physical nonlinearity is located, using a single trailing-edge control surface, to stabilize the entire system; 2) includes the unsteady effects of the airfoil’s aerodynamic behavior; 3) includes the embedding of a tuned numerical model of the aeroelastic system into the control scheme in real time; and 4) uses pole placement as the linear control objective, providing the user with flexibility in determining the nature of the controlled response. When implemented experimentally, the controller is capable of not only delaying the onset of limit-cycle oscillation but also successfully eliminating a previously established limit-cycle oscillation. The assignment of higher levels of damping results in notable reductions in limit-cycle oscillation decay times in the closed-loop response, indicating good controllability of the aeroelastic system and effectiveness of the pole-placement objective. The closed-loop response is further improved by incorporating adaptation so that assumed system parameters are updated with time. The use of an optimum adaptation parameter results in reduced response decay times

Hybrid Models for Learning to Branch

A recent Graph Neural Network (GNN) approach for learning to branch has been shown to successfully reduce the running time of branch-and-bound algorithms for Mixed Integer Linear Programming (MILP). While the GNN relies on a GPU for inference, MILP solvers are purely CPU-based. This severely limits its application as many practitioners may not have access to high-end GPUs. In this work, we ask two key questions. First, in a more realistic setting where only a CPU is available, is the GNN model still competitive? Second, can we devise an alternate computationally inexpensive model that retains the predictive power of the GNN architecture? We answer the first question in the negative, and address the second question by proposing a new hybrid architecture for efficient branching on CPU machines. The proposed architecture combines the expressive power of GNNs with computationally inexpensive multi-linear perceptrons (MLP) for branching. We evaluate our methods on four classes of MILP problems, and show that they lead to up to 26% reduction in solver running time compared to state-of-the-art methods without a GPU, while extrapolating to harder problems than it was trained on.Comment: Preprint. Under revie

Demonstration of Isoleucine 199 as a Structural Determinant for the Selective Inhibition of Human Monoamine Oxidase B by Specific Reversible Inhibitors

Abstract Several reversible inhibitors selective for human monoamine oxidase B (MAO B) that do not inhibit MAO A have been described in the literature. The following compounds: 8-(3-chlorostyryl)caffeine, 1,4-diphenyl-2-butene, and trans,trans-farnesol are shown to inhibit competitively human, horse, rat, and mouse MAO B with Ki values in the low micromolar range but are without effect on either bovine or sheep MAO B or human MAO A. In contrast, the reversible competitive inhibitor isatin binds to all known MAO B and MAO A with similar affinities. Sequence alignments and the crystal structures of human MAO B in complex with 1,4-diphenyl-2-butene or with trans,trans-farnesol provide molecular insights into these specificities. These inhibitors span the substrate and entrance cavities with the side chain of Ile-199 rotated out of its normal conformation suggesting that Ile-199 is gating the substrate cavity. Ile-199 is conserved in all known MAO B sequences except bovine MAO B, which has Phe in this position (the sequence of sheep MAO B is unknown). Phe is conserved in the analogous position in MAO A sequences. The human MAO B I199F mutant protein of MAO B binds to isatin (Ki = 3 μm) but not to the three inhibitors listed above. The crystal structure of this mutant demonstrates that the side chain of Phe-199 interferes with the binding of those compounds. This suggests that the Ile-199 "gate" is a determinant for the specificity of these MAO B inhibitors and provides a molecular basis for the development of MAO B-specific reversible inhibitors without interference with MAO A function in neurotransmitter metabolism

Drugs acting at TRPM7 channels inhibit seizure-like activity

Transient receptor potential cation subfamily M7 (TRPM7) channels are ion channels permeable to divalent cations. They are abundantly expressed with particularly high expression in the brain. Previous studies have highlighted the importance of TRPM7 channels in brain diseases such as stroke and traumatic brain injury, yet evidence for a role in seizures and epilepsy is lacking. Here, we show that carvacrol, a food additive that inhibits TRPM7 channels, and waixenicin A, a novel selective and potent TRPM7 inhibitor, completely suppressed seizure-like activity in rodent hippocampal-entorhinal brain slices exposed to pentylenetetrazole or low magnesium. These findings support inhibition of TRPM7 channels as a novel target for antiseizure medications

Increasing the Use of Permethrin to Prevent Zika Infections among University Students

Background. In summer 2016, Miami-Dade County, Florida, declared a public health emergency when reports of locally acquired Zika infections were confirmed. Officials at a large public university in the county warned students of the risks and advocated the use of repellents and permethrin to prevent mosquito bites. A subsequent study showed few students (2.9%) sprayed their clothes with permethrin. Purpose. In the absence of a safe and effective vaccine, a team of Master of Public Health students sought to determine if a brief educational intervention might increase permethrin use. Methods. Students living in six dormitories were chosen as the population of interest. Three dormitories were randomly assigned to an experimental condition (information about Zika) and three to a control condition (information about psychological counseling services). A questionnaire was distributed to participants immediately before and again immediately after a 20-30-minute educational presentation. The educational intervention was developed following the six steps of Intervention Mapping for Health Promotion Planning. Responses to questionnaire items were coded and analyzed. Results. After exposure to an educational program on Zika infections and prevention, significant increases (pdefinitely use permethrin to prevent mosquito bites increased from 17.3% at baseline to 40.7% at follow-up (p=.01). No significant differences in pre- and post-intervention scores were noted for the 51 students in the control condition. Discussion. A brief educational intervention can be effective in promoting permethrin use to prevent Zika and other mosquito-borne infections among college students. Permethrin and instructions for proper use should be included in Zika prevention kits

EPIC Fields: Marrying 3D Geometry and Video Understanding

Neural rendering is fuelling a unification of learning, 3D geometry and video understanding that has been waiting for more than two decades. Progress, however, is still hampered by a lack of suitable datasets and benchmarks. To address this gap, we introduce EPIC Fields, an augmentation of EPIC-KITCHENS with 3D camera information. Like other datasets for neural rendering, EPIC Fields removes the complex and expensive step of reconstructing cameras using photogrammetry, and allows researchers to focus on modelling problems. We illustrate the challenge of photogrammetry in egocentric videos of dynamic actions and propose innovations to address them. Compared to other neural rendering datasets, EPIC Fields is better tailored to video understanding because it is paired with labelled action segments and the recent VISOR segment annotations. To further motivate the community, we also evaluate two benchmark tasks in neural rendering and segmenting dynamic objects, with strong baselines that showcase what is not possible today. We also highlight the advantage of geometry in semi-supervised video object segmentations on the VISOR annotations. EPIC Fields reconstructs 96% of videos in EPIC-KITCHENS, registering 19M frames in 99 hours recorded in 45 kitchens, and is available from: http://epic-kitchens.github.io/epic-field

El Impacto del descenso en los Tipos de Interés sobre el margen financiero de las Cajas de Ahorros españolas

El sistema de financiación de las Comunidades Autónomas de régimen común que entró en vigor en el año 2002, ha significado un incremento importante de las competencias en materia tributaria (coparticipación de impuestos) de que disponen las mismas, estableciendo asimismo un nuevo sistema de transferencias intergubernamentales que tiene como objetivo asegurar la suficiencia financiera de las regiones. Este nuevo modelo se implanta en el momento en que todas las Comunidades Autónomas han alcanzado su techo competencial, asumiendo las competencias previstas en la Constitución Española de 1978, circunstancia que hace posible que se diseñe un sistema estable e integrado de financiación. Conocidos ya los primeros resultados del funcionamiento del sistema, al disponer de las liquidaciones correspondientes a los ejercicios 2002 y 2003, en este trabajo se analizan los avances conseguidos en términos de suficiencia financiera y de nivelación interterritorial, y se ofrecen algunas conclusiones relevantes respecto a las principales cuestiones que aún quedan por resolver.

Undertaking a scoping review: a practical guide for nursing and midwifery students, clinicians, researchers, and academics.

Aim: The aim of this study is to discuss the available methodological resources and best-practice guidelines for the development and completion of scoping reviews relevant to nursing and midwifery policy, practice, and research. Design: Discussion Paper. Data Sources: Scoping reviews that exemplify best practice are explored with reference to the recently updated JBI scoping review guide (2020) and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Scoping Review extension (PRISMA-ScR). Implications for nursing and midwifery: Scoping reviews are an increasingly common form of evidence synthesis. They are used to address broad research questions and to map evidence from a variety of sources. Scoping reviews are a useful form of evidence synthesis for those in nursing and midwifery and present opportunities for researchers to review a broad array of evidence and resources. However, scoping reviews still need to be conducted with rigour and transparency. Conclusion: This study provides guidance and advice for researchers and clinicians who are preparing to undertake an evidence synthesis and are considering a scoping review methodology in the field of nursing and midwifery. Impact: With the increasing popularity of scoping reviews, criticism of the rigour, transparency, and appropriateness of the methodology have been raised across multiple academic and clinical disciplines, including nursing and midwifery. This discussion paper provides a unique contribution by discussing each component of a scoping review, including: developing research questions and objectives; protocol development; developing eligibility criteria and the planned search approach; searching and selecting the evidence; extracting and analysing evidence; presenting results; and summarizing the evidence specifically for the fields of nursing and midwifery. Considerations for when to select this methodology and how to prepare a review for publication are also discussed. This approach is applied to the disciplines of nursing and midwifery to assist nursing and/or midwifery students, clinicians, researchers, and academics

Gravitational spin-orbit and aligned spin1_1-spin2_2 couplings through third-subleading post-Newtonian orders

The study of scattering encounters continues to provide new insights into the general relativistic two-body problem. The local-in-time conservative dynamics of an aligned-spin binary, for both unbound and bound orbits, is fully encoded in the gauge-invariant scattering-angle function, which is most naturally expressed in a post-Minkowskian (PM) expansion, and which exhibits a remarkably simple dependence on the masses of the two bodies (in terms of appropriate geometric variables). This dependence links the PM and small-mass-ratio approximations, allowing gravitational self-force results to determine new post-Newtonian (PN) information to all orders in the mass ratio. In this paper, we exploit this interplay between relativistic scattering and self-force theory to obtain the third-subleading (4.5PN) spin-orbit dynamics for generic spins, and the third-subleading (5PN) spin$_1$-spin$_2$ dynamics for aligned spins. We further implement these novel PN results in an effective-one-body framework, and demonstrate the improvement in accuracy by comparing against numerical-relativity simulations.Comment: 29 pages, 2 figures, supplemental material; v2: added reference