Constructing monotone homotopies and sweepouts

This article investigates when homotopies can be converted to monotone homotopies without increasing the lengths of curves. A monotone homotopy is one which consists of curves which are simple or constant, and in which curves are pairwise disjoint. We show that, if the boundary of a Riemannian disc can be contracted through curves of length less than $L$, then it can also be contracted monotonously through curves of length less than $L$. This proves a conjecture of Chambers and Rotman. Additionally, any sweepout of a Riemannian $2$-sphere through curves of length less than $L$ can be replaced with a monotone sweepout through curves of length less than $L$. Applications of these results are also discussed.Comment: 16 pages, 6 figure

Wide bandwidth LFM transmission through a wavelength-controlled photonic true time delay device

We demonstrate for the first time high quality wide bandwidth (600 MHz) LFM transmission through a wavelength-controlled photonic true time delay device with bandwidth-limited resolution and peak sidelobe level below -37 dB at 5 GHz

Bridging languages through images with deep partial canonical correlation analysis

We present a deep neural network that leverages images to improve bilingual text embeddings. Relying on bilingual image tags and descriptions, our approach conditions text embedding induction on the shared visual information for both languages, producing highly correlated bilingual embeddings. In particular, we propose a novel model based on Partial Canonical Correlation Analysis (PCCA). While the original PCCA finds linear projections of two views in order to maximize their canonical correlation conditioned on a shared third variable, we introduce a non-linear Deep PCCA (DPCCA) model, and develop a new stochastic iterative algorithm for its optimization. We evaluate PCCA and DPCCA on multilingual word similarity and cross-lingual image description retrieval. Our models outperform a large variety of previous methods, despite not having access to any visual signal during test time inference. Our code and data are available at: https://github.com/rotmanguy/DPCCA

Performance issues with photonic beamformers

A photonic beamformer is presented, having smooth behavior. Third-order nonlinearities, resulting from its optoelectronic components, are investigated, with emphasis on their impact on the contrast of imaging radars. This contrast is shown to be severely limited by the induced RF nonlinearities. Limitations on the allowable modulation index are studied for linearly-chirped pulses returned from clutter

Muscle glycogen recovery after exercise measured by13C-magnetic resonance spectroscopy in humans: effect of nutritional solutions

The rate of glycogen resynthesis in human skeletal muscle after glycogen-depleting exercise is known to depend on carbohydrate intake and is reported to reach a platean after an adequate amount of carbohydrate (CHO) consumption. Efforts to maximize the rate of glycogen storage by changing the type and form of CHO, as well as by adding proteins or lipids have yielded inconsistent results. The objective of this study was to assess whether isocaloric addition of proteins and arginine to a CHO diet in the first 4 h after an endurance exercise would increase the rate of glycogen synthesis. The CHO solution, given twice at a 2 h interval according to earlier optimized protocols, contained 1.7 g CHO kgbody weight. The effects of this solution were compared to those of an isocaloric solution containing 1.2 g CHO/kgbody weight plus 0.5 g protein/kgbody weight (including 5 g arginine). Glycogen was measured in quadriceps muscle in vivo with natural abundance13C-magnetic resonance spectroscopy before exercise and twice after exercise, before and at the end of a 4-h period following the intake of one of the solutions. Eight subjects took part in a randomized cross-over trial separated by at least 1 week. Glycogen synthesis was found to be significantly increased with both regimes compared to a zero-caloric placebo diet, but no significant difference in glycogen resynthesis was found between the CHO-only diet and the one supplemented by proteins and arginine. It is estimated that significance would have been reached for an increase of 34%, while the effectively measured synthesis rates only differed by 5

The Effect of Charge Display on Cost of Care and Physician Practice Behaviors: A Systematic Review

BACKGROUND: While studies have been published in the last 30 years that examine the effect of charge display during physician decision-making, no analysis or synthesis of these studies has been conducted. OBJECTIVE: We aimed to determine the type and quality of charge display studies that have been published; to synthesize this information in the form of a literature review. METHODS: English-language articles published between 1982 and 2013 were identified using MEDLINE, Web of Knowledge, ABI-Inform, and Academic Search Premier. Article titles, abstracts, and text were reviewed for relevancy by two authors. Data were then extracted and subsequently synthesized and analyzed. RESULTS: Seventeen articles were identified that fell into two topic categories: the effect of charge display on radiology and laboratory test ordering versus on medication choice. Seven articles were randomized controlled trials, eight were pre-intervention vs. post-intervention studies, and two interventions had a concurrent control and intervention groups, but were not randomized. Twelve studies were conducted in a clinical environment, whereas five were survey studies. Of the nine clinically based interventions that examined test ordering, seven had statistically significant reductions in cost and/or the number of tests ordered. Two of the three clinical studies looking at medication expenditures found significant reductions in cost. In the survey studies, physicians consistently chose fewer tests or lower cost options in the theoretical scenarios presented. CONCLUSIONS: In the majority of studies, charge information changed ordering and prescribing behavior

Symmetric Groups and Quotient Complexity of Boolean Operations

The quotient complexity of a regular language L is the number of left quotients of L, which is the same as the state complexity of L. Suppose that L and L' are binary regular languages with quotient complexities m and n, and that the transition semigroups of the minimal deterministic automata accepting L and L' are the symmetric groups S_m and S_n of degrees m and n, respectively. Denote by o any binary boolean operation that is not a constant and not a function of one argument only. For m,n >= 2 with (m,n) not in {(2,2),(3,4),(4,3),(4,4)} we prove that the quotient complexity of LoL' is mn if and only either (a) m is not equal to n or (b) m=n and the bases (ordered pairs of generators) of S_m and S_n are not conjugate. For (m,n)\in {(2,2),(3,4),(4,3),(4,4)} we give examples to show that this need not hold. In proving these results we generalize the notion of uniform minimality to direct products of automata. We also establish a non-trivial connection between complexity of boolean operations and group theory

Monotone contractions of the boundary of the disc

In this paper, we study contractions of the boundary of a Riemannian 2-disc where the maximal length of the intermediate curves is minimized. We prove that with an arbitrarily small overhead in the lengths of the intermediate curves, there exists such an optimal contraction that is monotone, i.e., where the intermediate curves are simple closed curves which are pairwise disjoint. This proves a conjecture of Chambers and Rotman