Hilbert space structure of covariant loop quantum gravity

We investigate the Hilbert space in the Lorentz covariant approach to loop quantum gravity. We restrict ourselves to the space where all area operators are simultaneously diagonalizable, assuming that it exists. In this sector quantum states are realized by a generalization of spin network states based on Lorentz Wilson lines projected on irreducible representations of an SO(3) subgroup. The problem of infinite dimensionality of the unitary Lorentz representations is absent due to this projection. Nevertheless, the projection preserves the Lorentz covariance of the Wilson lines so that the symmetry is not broken. Under certain conditions the states can be thought as functions on a homogeneous space. We define the inner product as an integral over this space. With respect to this inner product the spin networks form an orthonormal basis in the investigated sector. We argue that it is the only relevant part of a larger state space arising in the approach. The problem of the noncommutativity of the Lorentz connection is solved by restriction to the simple representations. The resulting structure shows similarities with the spin foam approach.Comment: 20 pages, RevTE

Reality conditions for Ashtekar gravity from Lorentz-covariant formulation

We show the equivalence of the Lorentz-covariant canonical formulation considered for the Immirzi parameter $\beta=i$ to the selfdual Ashtekar gravity. We also propose to deal with the reality conditions in terms of Dirac brackets derived from the covariant formulation and defined on an extended phase space which involves, besides the selfdual variables, also their anti-selfdual counterparts.Comment: 14 page

Physiological and Cellular Targets of Neurotrophic Anxiolytic Phytochemicals in Food and Dietary Supplements

Diet impacts anxiety in two main ways. First anxiety can be caused by deficiencies in antioxidants, neurotransmitter precursors, amino acids, cations and vitamins and other cofactors. Second, anxiety can be reduced by anxiolytic nutraceuticals which are food molecules that bind to molecular targets of the amygdala and the hypothalamus-pituitary–adrenal axis (HPA-axis). Anxiety is a feeling of fear that arises from a perceived threat and can be a beneficial coping mechanism to threats and stressors. However excessive anxiety is a disorder that interferes with healthy responses to stressors. The amygdala is responsible for assigning value to a threat or stressor and triggering the HPA-axis to support the body wide system responses to the threat. The amygdala also communicates with the neuroplastic learning and memory centers of the hippocampus to fix or set a learned value to the threat. Interestingly, many anxiolytic nutraceuticals that show benefits in human clinical trials have neurotrophic activity and increase neuronal plasticity. Moreover, anxiolytic nutraceuticals either act like the neurotrophins, nerve growth factor (NGF), brain derived neurotrophic factor (BDNF and neurotrophin-3 (NT3) by either directly binding to or potentiating the tyrosine receptor kinase (TRK) family of receptors (TRKA, TRKB and TRKC) and activating the ERK1/2 signal transduction pathway associated with neurite outgrowth and neural plasticity. This chapter will explore the neuritogenic activity of clinically proven plant-based anxiolytic nutraceuticals and examine the commonality of TRKA-C receptors and the ERK1/2 signaling pathway in the pharmacological and nutraceutical treatment of anxiety disorders

Area spectrum in Lorentz covariant loop gravity

We use the manifestly Lorentz covariant canonical formalism to evaluate eigenvalues of the area operator acting on Wilson lines. To this end we modify the standard definition of the loop states to make it applicable to the present case of non-commutative connections. The area operator is diagonalized by using the usual shift ambiguity in definition of the connection. The eigenvalues are then expressed through quadratic Casimir operators. No dependence on the Immirzi parameter appears.Comment: 12 pages, RevTEX; improved layout, typos corrected, references added; changes in the discussion in sec. IIIB and

Design of a polishing tool for collaborative robotics using minimum viable product approach

This is an Author's Accepted Manuscript of an article published in Carlos Perez-Vidal, Luis Gracia, Samuel Sanchez-Caballero, J. Ernesto Solanes, Alessandro Saccon & Josep Tornero (2019) Design of a polishing tool for collaborative robotics using minimum viable product approach, International Journal of Computer Integrated Manufacturing, 32:9, 848-857, DOI: 10.1080/0951192X.2019.1637026 [copyright Taylor & Francis], available online at: http://www.tandfonline.com/10.1080/0951192X.2019.1637026[EN] A collaborative tool for robotic polishing is developed in this work in order to allow the simultaneous operation of the robot system and human operator to cooperatively carry out the polishing task. For this purpose, the collaborative environment is detailed and the polishing application is designed. Moreover, the polishing tool is developed and its implementation using the minimum viable product approach is obtained. Furthermore, a robust hybrid position-force control is proposed to use the developed tool attached to a robot system and some experiments are given to show its performance.This work was supported in part by the Ministerio de Ciencia e Innovacion (Spanish Government) under project [DPI2017-87656-C2-1-R] and the Generalitat Valenciana under Grant [VALi+ d APOSTD/2016/044].Perez-Vidal, C.; Gracia Calandin, LI.; Sanchez-Caballero, S.; Solanes Galbis, JE.; Saccon, A.; Tornero Montserrat, J. (2019). Design of a polishing tool for collaborative robotics using minimum viable product approach. International Journal of Computer Integrated Manufacturing. 32(9):848-857. https://doi.org/10.1080/0951192X.2019.1637026S848857329Alders, K., M. Lehe, and G. Wan. 2001. “Method for the Automatic Recognition of Surface Defects in Body Shells and Device for Carrying Out Said Method” US Patent 6,320,654, Accessed 2001 November. https://www.google.ch/patents/US6320654Alexopoulos, K., Mavrikios, D., & Chryssolouris, G. (2013). ErgoToolkit: an ergonomic analysis tool in a virtual manufacturing environment. International Journal of Computer Integrated Manufacturing, 26(5), 440-452. doi:10.1080/0951192x.2012.731610Andres, J., Gracia, L., & Tornero, J. (2011). Calibration and control of a redundant robotic workcell for milling tasks. International Journal of Computer Integrated Manufacturing, 24(6), 561-573. doi:10.1080/0951192x.2011.566284Arnal, L., Solanes, J. E., Molina, J., & Tornero, J. (2017). Detecting dings and dents on specular car body surfaces based on optical flow. Journal of Manufacturing Systems, 45, 306-321. doi:10.1016/j.jmsy.2017.07.006Blank, S. 2010. “Perfection By Subtraction - The Minimum Feature Set”. Accessed 2018 August. http://steveblank.com/2010/03/04/perfection-by-subtraction-the-minimum-feature-set/Dimeas, F., & Aspragathos, N. (2016). Online Stability in Human-Robot Cooperation with Admittance Control. IEEE Transactions on Haptics, 9(2), 267-278. doi:10.1109/toh.2016.2518670Fitzgerald, C. “Developing Baxter, A new industrial robot with common sense for U.S. manufacturing.” 2013.Gracia, L., Sala, A., & Garelli, F. (2012). A supervisory loop approach to fulfill workspace constraints in redundant robots. Robotics and Autonomous Systems, 60(1), 1-15. doi:10.1016/j.robot.2011.07.008Gracia, L., Sala, A., & Garelli, F. (2014). Robot coordination using task-priority and sliding-mode techniques. Robotics and Computer-Integrated Manufacturing, 30(1), 74-89. doi:10.1016/j.rcim.2013.08.003Gracia, L., Solanes, J. E., Muñoz-Benavent, P., Valls Miro, J., Perez-Vidal, C., & Tornero, J. (2018). Adaptive Sliding Mode Control for Robotic Surface Treatment Using Force Feedback. Mechatronics, 52, 102-118. doi:10.1016/j.mechatronics.2018.04.008Julius, R., Schürenberg, M., Schumacher, F., & Fay, A. (2017). Transformation of GRAFCET to PLC code including hierarchical structures. Control Engineering Practice, 64, 173-194. doi:10.1016/j.conengprac.2017.03.012. E. K. (2016). TOWARDS AN AUTOMATED POLISHING SYSTEM - CAPTURING MANUAL POLISHING OPERATIONS. International Journal of Research in Engineering and Technology, 05(07), 182-192. doi:10.15623/ijret.2016.0507030Khan, A. M., Yun, D., Zuhaib, K. M., Iqbal, J., Yan, R.-J., Khan, F., & Han, C. (2017). Estimation of Desired Motion Intention and compliance control for upper limb assist exoskeleton. International Journal of Control, Automation and Systems, 15(2), 802-814. doi:10.1007/s12555-015-0151-7Kirschner, D., Velik, R., Yahyanejad, S., Brandstötter, M., & Hofbaur, M. (2016). YuMi, Come and Play with Me! A Collaborative Robot for Piecing Together a Tangram Puzzle. Interactive Collaborative Robotics, 243-251. doi:10.1007/978-3-319-43955-6_29Mohammad, A. E. K., Hong, J., & Wang, D. (2018). Design of a force-controlled end-effector with low-inertia effect for robotic polishing using macro-mini robot approach. Robotics and Computer-Integrated Manufacturing, 49, 54-65. doi:10.1016/j.rcim.2017.05.011Nagata, F., Hase, T., Haga, Z., Omoto, M., & Watanabe, K. (2007). CAD/CAM-based position/force controller for a mold polishing robot. Mechatronics, 17(4-5), 207-216. doi:10.1016/j.mechatronics.2007.01.003Nakamura, Y., Hanafusa, H., & Yoshikawa, T. (1987). Task-Priority Based Redundancy Control of Robot Manipulators. The International Journal of Robotics Research, 6(2), 3-15. doi:10.1177/027836498700600201Ries, E. 2009. “What is the Minimum Viable Product”. March. Accessed 2018 August. http://venturehacks.com/articles/minimum-viable-productRobinson, F. 2001 “A Proven Methodology to Maximize Return on Risk”. Accessed 2018 August. http://www.syncdev.com/minimum-viable-productShepherd, S., & Buchstab, A. (2014). KUKA Robots On-Site. Robotic Fabrication in Architecture, Art and Design 2014, 373-380. doi:10.1007/978-3-319-04663-1_26SYMPLEXITY. “Symbiotic Human-Robot Solutions for Complex Surface Finishing Operations.” European project funded by E.U. through the H2020. Project no. 637080. Call: H2020-FoF-2014. Topic: FoF-06-2014. Starting date: 01/ 01/2015.Duration: 48 months. Accessed 2019 March. https://www.symplexity.eu/Vihlborg, P., I. Bryngelsson, B. Lindgren, L. G. Gunnarsson, and P. Graff. 2017. “Associatio between vibration exposure and hand-arm vibration symptoms in a Swedish mechanical industry.” February 2017.Vogel, J., Haddadin, S., Jarosiewicz, B., Simeral, J. D., Bacher, D., Hochberg, L. R., … van der Smagt, P. (2015). An assistive decision-and-control architecture for force-sensitive hand–arm systems driven by human–machine interfaces. The International Journal of Robotics Research, 34(6), 763-780. doi:10.1177/027836491456153

Aspectos florísticos de Lacanhá Chansayab, Selva Lacandona, Chiapas

A systematic sampling of the flora was carried out between 1993 and 1999 in several evergreen tropical rainforest stands, “acahuales” (local name for old agricultural fields) of various ages and agricultural fields belonging to the Lacanhá Chansayab community, located at the Lacandonian tropical rainforest. Collected individuals were identified and processed as herbarium specimens, including information on life form, phenology and status of conservation. Four hundred and eighty five vascular plant species were recorded, corresponding to 355 genera from 104 families, which represent 11.23% of all species estimated for the area. Fabaceae, Asteraceae and Rubiaceae were the best represented families, as well as the genera Piper, Eupatorium, Encyclia, Chamaedorea and Solanum.Entre 1993 y 1999 se realizaron herborizaciones sistemáticas en rodales de selva alta perennifolia, acahuales de diferentes edades y milpas pertenecientes a la comunidad de Lacanhá Chansayab, en la Selva Lacandona. Los especímenes recolectados se identificaron y procesaron como ejemplares de herbario, acompañados de información sobre su forma de vida, fenología y estado de conservación. Se registraron 485 especies de plantas vasculares, pertenecientes a 355 géneros de 104 familias, las cuales representan 11.23% del total de especies estimado para la zona. Fabaceae, Asteraceae y Rubiaceae fueron las familias mejor representadas, así como los géneros Piper, Eupatorium, Encyclia, Chamaedorea y Solanum

Background Independent Quantum Gravity: A Status Report

The goal of this article is to present an introduction to loop quantum gravity -a background independent, non-perturbative approach to the problem of unification of general relativity and quantum physics, based on a quantum theory of geometry. Our presentation is pedagogical. Thus, in addition to providing a bird's eye view of the present status of the subject, the article should also serve as a vehicle to enter the field and explore it in detail. To aid non-experts, very little is assumed beyond elements of general relativity, gauge theories and quantum field theory. While the article is essentially self-contained, the emphasis is on communicating the underlying ideas and the significance of results rather than on presenting systematic derivations and detailed proofs. (These can be found in the listed references.) The subject can be approached in different ways. We have chosen one which is deeply rooted in well established physics and also has sufficient mathematical precision to ensure that there are no hidden infinities. In order to keep the article to a reasonable size, and to avoid overwhelming non-experts, we have had to leave out several interesting topics, results and viewpoints; this is meant to be an introduction to the subject rather than an exhaustive review of it.Comment: 125 pages, 5 figures (eps format), the final version published in CQ

2020-04-10 DAILY UNM GLOBAL HEALTH COVID-19 BRIEFING

Executive Summary: Extra NM HSD SNAP benefits. NM cases \u3e1000. Meds supply chain threatened. Mass graves in NY. Surgeon General screening app. Presidential briefing. Italian healthcare worker deaths. Taiwan tiered care model. Communicating risks to public. French public demand hydroxychloroquine. Vaccination pause dangers. Retesting needed after discharge. CDC report geography and incidence. UW clinical informatics response. UW preparedness guidelines. Wuhan outbreak control. CDC asymptomatic exposed worker guidelines. Mask innovation. Unemployment spikes. Workforce gaps. Workspace modifications reduce transmission. Guidelines and recommendations: ER physician, surgery, cardiopulmonary resuscitation, chest imaging, geriatrics, critically ill children, postpyloric tube placement, genitourinary malignancies, obstetrics, and home work health. Remdesivir clinically promising. Hydroxychloroquine safe but higher mortality with azithromycin. Lockdown health risks. Post-ICU syndrome. Tetracyline therapy potential. ACE2 review. Repurposing candidates. Patient self-triage tool. Video of aerosol spread and lingering. Modeling challenges. 34 new clinical trials registered today