52 research outputs found

    The benefits of strength training on musculoskeletal system health: practical applications for interdisciplinary care

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    Global health organizations have provided recommendations regarding exercise for the general population. Strength training has been included in several position statements due to its multi-systemic benefits. In this narrative review, we examine the available literature, first explaining how specific mechanical loading is converted into positive cellular responses. Secondly, benefits related to specific musculoskeletal tissues are discussed, with practical applications and training programmes clearly outlined for both common musculoskeletal disorders and primary prevention strategies

    All-sky search for long-duration gravitational wave transients in the first Advanced LIGO observing run

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    We present the results of a search for long-duration gravitational wave transients in the data of the LIGO Hanford and LIGO Livingston second generation detectors between September 2015 and January 2016 , with a total observational time of 49 d. The search targets gravitational wave transients of 10 – 500 s duration in a frequency band of 24 – 2048 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. No significant events were observed. As a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. We also show that the search is sensitive to sources in the Galaxy emitting at least ∼ 10 − 8 M c 2 in gravitational waves

    Directly comparing GW150914 with numerical solutions of Einstein's equations for binary black hole coalescence

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    We compare GW150914 directly to simulations of coalescing binary black holes in full general relativity, including several performed specifically to reproduce this event. Our calculations go beyond existing semianalytic models, because for all simulations – including sources with two independent, precessing spins – we perform comparisons which account for all the spin-weighted quadrupolar modes, and separately which account for all the quadrupolar and octopolar modes. Consistent with the posterior distributions reported in LVC-PE[1] (at the 90% credible level), we find the data are compatible with a wide range of nonprecessing and precessing simulations. Followup simulations performed using previously-estimated binary parameters most resemble the data, even when all quadrupolar and octopolar modes are included. Comparisons including only the quadrupolar modes constrain the total redshifted mass Mz ∈ [64M� − 82M�], mass ratio 1/q = m2/m1 ∈ [0.6, 1], and effective aligned spin χeff ∈ [−0.3, 0.2], where χeff = (S1/m1 + S2/m2) · Lˆ /M. Including both quadrupolar and octopolar modes, we find the mass ratio is even more tightly constrained. Even accounting for precession, simulations with extreme mass ratios and effective spins are highly inconsistent with the data, at any mass. Several nonprecessing and precessing simulations with similar mass ratio and χeff are consistent with the data. Though correlated, the components’ spins (both in magnitude and directions) are not significantly constrained by the data: the data is consistent with simulations with component spin magnitudes a1,2 up to at least 0.8, with random orientations. Further detailed followup calculations are needed to determine if the data contain a weak imprint from transverse (precessing) spins. For nonprecessing binaries, interpolating between simulations, we reconstruct a posterior distribution consistent with previous results. The final black hole’s redshifted mass is consistent with Mf,z in the range 64.0M� − 73.5M� and the final black hole’s dimensionless spin parameter is consistent with af = 0.62 − 0.73. As our approach invokes no intermediate approximations to general relativity and can strongly reject binaries whose radiation is inconsistent with the data, our analysis provides a valuable complement to LVC-PE[1]

    Effects of waveform model systematics on the interpretation of GW150914

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    PAPER Effects of waveform model systematics on the interpretation of GW150914 B P Abbott1, R Abbott1, T D Abbott2, M R Abernathy3, F Acernese4,5, K Ackley6, C Adams7, T Adams8, P Addesso9,144, R X Adhikari1, V B Adya10, C Affeldt10, M Agathos11, K Agatsuma11, N Aggarwal12, O D Aguiar13, L Aiello14,15, A Ain16, P Ajith17, B Allen10,18,19, A Allocca20,21, P A Altin22, A Ananyeva1, S B Anderson1, W G Anderson18, S Appert1, K Arai1, M C Araya1, J S Areeda23, N Arnaud24, K G Arun25, S Ascenzi15,26, G Ashton10, M Ast27, S M Aston7, P Astone28, P Aufmuth19, C Aulbert10, A Avila-Alvarez23, S Babak29, P Bacon30, M K M Bader11, P T Baker31, F Baldaccini32,33, G Ballardin34, S W Ballmer35, J C Barayoga1, S E Barclay36, B C Barish1, D Barker37, F Barone4,5, B Barr36, L Barsotti12, M Barsuglia30, D Barta38, J Bartlett37, I Bartos39, R Bassiri40, A Basti20,21, J C Batch37, C Baune10, V Bavigadda34, M Bazzan41,42, C Beer10, M Bejger43, I Belahcene24, M Belgin44, A S Bell36, B K Berger1, G Bergmann10, C P L Berry45, D Bersanetti46,47, A Bertolini11, J Betzwieser7, S Bhagwat35, R Bhandare48, I A Bilenko49, G Billingsley1, C R Billman6, J Birch7, R Birney50, O Birnholtz10, S Biscans1,12, A Bisht19, M Bitossi34, C Biwer35, M A Bizouard24, J K Blackburn1, J Blackman51, C D Blair52, D G Blair52, R M Blair37, S Bloemen53, O Bock10, M Boer54, G Bogaert54, A Bohe29, F Bondu55, R Bonnand8, B A Boom11, R Bork1, V Boschi20,21, S Bose16,56, Y Bouffanais30, A Bozzi34, C Bradaschia21, P R Brady18, V B Braginsky49,145, M Branchesi57,58, J E Brau59, T Briant60, A Brillet54, M Brinkmann10, V Brisson24, P Brockill18, J E Broida61, A F Brooks1, D A Brown35, D D Brown45, N M Brown12, S Brunett1, C C Buchanan2, A Buikema12, T Bulik62, H J Bulten11,63, A Buonanno29,64, D Buskulic8, C Buy30, R L Byer40, M Cabero10, L Cadonati44, G Cagnoli65,66, C Cahillane1, J Calderón Bustillo44, T A Callister1, E Calloni5,67, J B Camp68, K C Cannon69, H Cao70, J Cao71, C D Capano10, E Capocasa30, F Carbognani34, S Caride72, J Casanueva Diaz24, C Casentini15,26, S Caudill18, M Cavaglià73, F Cavalier24, R Cavalieri34, G Cella21, C B Cepeda1, L Cerboni Baiardi57,58, G Cerretani20,21, E Cesarini15,26, S J Chamberlin74, M Chan36, S Chao75, P Charlton76, E Chassande-Mottin30, B D Cheeseboro31, H Y Chen77, Y Chen51, H-P Cheng6, A Chincarini47, A Chiummo34, T Chmiel78, H S Cho79, M Cho64, J H Chow22, N Christensen61, Q Chu52, A J K Chua80, S Chua60, S Chung52, G Ciani6, F Clara37, J A Clark44, F Cleva54, C Cocchieri73, E Coccia14,15, P-F Cohadon60, A Colla28,81, C G Collette82, L Cominsky83, M Constancio Jr13, L Conti42, S J Cooper45, T R Corbitt2, N Cornish84, A Corsi72, S Cortese34, C A Costa13, M W Coughlin61, S B Coughlin85, J-P Coulon54, S T Countryman39, P Couvares1, P B Covas86, E E Cowan44, D M Coward52, M J Cowart7, D C Coyne1, R Coyne72, J D E Creighton18, T D Creighton87, J Cripe2, S G Crowder88, T J Cullen23, A Cumming36, L Cunningham36, E Cuoco34, T Dal Canton68, S L Danilishin36, S D'Antonio15, K Danzmann10,19, A Dasgupta89, C F Da Silva Costa6, V Dattilo34, I Dave48, M Davier24, G S Davies36, D Davis35, E J Daw90, B Day44, R Day34, S De35, D DeBra40, G Debreczeni38, J Degallaix65, M De Laurentis5,67, S Deléglise60, W Del Pozzo45, T Denker10, T Dent10, V Dergachev29, R De Rosa5,67, R T DeRosa7, R DeSalvo91, J Devenson50, R C Devine31, S Dhurandhar16, M C Díaz87, L Di Fiore5, M Di Giovanni92,93, T Di Girolamo5,67, A Di Lieto20,21, S Di Pace28,81, I Di Palma28,29,81, A Di Virgilio21, Z Doctor77, V Dolique65, F Donovan12, K L Dooley73, S Doravari10, I Dorrington94, R Douglas36, M Dovale Álvarez45, T P Downes18, M Drago10, R W P Drever1,146, J C Driggers37, Z Du71, M Ducrot8, S E Dwyer37, T B Edo90, M C Edwards61, A Effler7, H-B Eggenstein10, P Ehrens1, J Eichholz1, S S Eikenberry6, R A Eisenstein12, R C Essick12, Z Etienne31, T Etzel1, M Evans12, T M Evans7, R Everett74, M Factourovich39, V Fafone14,15,26, H Fair35, S Fairhurst94, X Fan71, S Farinon47, B Farr77, W M Farr45, E J Fauchon-Jones94, M Favata95, M Fays94, H Fehrmann10, M M Fejer40, A Fernández Galiana12, I Ferrante20,21, E C Ferreira13, F Ferrini34, F Fidecaro20,21, I Fiori34, D Fiorucci30, R P Fisher35, R Flaminio65,96, M Fletcher36, H Fong97, S S Forsyth44, J-D Fournier54, S Frasca28,81, F Frasconi21, Z Frei98, A Freise45, R Frey59, V Frey24, E M Fries1, P Fritschel12, V V Frolov7, P Fulda6,68, M Fyffe7, H Gabbard10, B U Gadre16, S M Gaebel45, J R Gair99, L Gammaitoni32, S G Gaonkar16, F Garufi5,67, G Gaur100, V Gayathri101, N Gehrels68, G Gemme47, E Genin34, A Gennai21, J George48, L Gergely102, V Germain8, S Ghonge17, Abhirup Ghosh17, Archisman Ghosh11,17, S Ghosh11,53, J A Giaime2,7, K D Giardina7, A Giazotto21, K Gill103, A Glaefke36, E Goetz10, R Goetz6, L Gondan98, G González2, J M Gonzalez Castro20,21, A Gopakumar104, M L Gorodetsky49, S E Gossan1, M Gosselin34, R Gouaty8, A Grado5,105, C Graef36, M Granata65, A Grant36, S Gras12, C Gray37, G Greco57,58, A C Green45, P Groot53, H Grote10, S Grunewald29, G M Guidi57,58, X Guo71, A Gupta16, M K Gupta89, K E Gushwa1, E K Gustafson1, R Gustafson106, J J Hacker23, B R Hall56, E D Hall1, G Hammond36, M Haney104, M M Hanke10, J Hanks37, C Hanna74, M D Hannam94, J Hanson7, T Hardwick2, J Harms57,58, G M Harry3, I W Harry29, M J Hart36, M T Hartman6, C-J Haster45,97, K Haughian36, J Healy107, A Heidmann60, M C Heintze7, H Heitmann54, P Hello24, G Hemming34, M Hendry36, I S Heng36, J Hennig36, J Henry107, A W Heptonstall1, M Heurs10,19, S Hild36, D Hoak34, D Hofman65, K Holt7, D E Holz77, P Hopkins94, J Hough36, E A Houston36, E J Howell52, Y M Hu10, E A Huerta108, D Huet24, B Hughey103, S Husa86, S H Huttner36, T Huynh-Dinh7, N Indik10, D R Ingram37, R Inta72, H N Isa36, J-M Isac60, M Isi1, T Isogai12, B R Iyer17, K Izumi37, T Jacqmin60, K Jani44, P Jaranowski109, S Jawahar110, F Jiménez-Forteza86, W W Johnson2, D I Jones111, R Jones36, R J G Jonker11, L Ju52, J Junker10, C V Kalaghatgi94, V Kalogera85, S Kandhasamy73, G Kang79, J B Kanner1, S Karki59, K S Karvinen10, M Kasprzack2, E Katsavounidis12, W Katzman7, S Kaufer19, T Kaur52, K Kawabe37, F Kéfélian54, D Keitel86, D B Kelley35, R Kennedy90, J S Key112, F Y Khalili49, I Khan14, S Khan94, Z Khan89, E A Khazanov113, N Kijbunchoo37, Chunglee Kim114, J C Kim115, Whansun Kim116, W Kim70, Y-M Kim114,117, S J Kimbrell44, E J King70, P J King37, R Kirchhoff10, J S Kissel37, B Klein85, L Kleybolte27, S Klimenko6, P Koch10, S M Koehlenbeck10, S Koley11, V Kondrashov1, A Kontos12, M Korobko27, W Z Korth1, I Kowalska62, D B Kozak1, C Krämer10, V Kringel10, B Krishnan10, A Królak118,119, G Kuehn10, P Kumar97, R Kumar89, L Kuo75, A Kutynia118, B D Lackey29,35, M Landry37, R N Lang18, J Lange107, B Lantz40, R K Lanza12, A Lartaux-Vollard24, P D Lasky120, M Laxen7, A Lazzarini1, C Lazzaro42, P Leaci28,81, S Leavey36, E O Lebigot30, C H Lee117, H K Lee121, H M Lee114, K Lee36, J Lehmann10, A Lenon31, M Leonardi92,93, J R Leong10, N Leroy24, N Letendre8, Y Levin120, T G F Li122, A Libson12, T B Littenberg123, J Liu52, N A Lockerbie110, A L Lombardi44, L T London94, J E Lord35, M Lorenzini14,15, V Loriette124, M Lormand7, G Losurdo21, J D Lough10,19, G Lovelace23, H Lück10,19, A P Lundgren10, R Lynch12, Y Ma51, S Macfoy50, B Machenschalk10, M MacInnis12, D M Macleod2, F Magaña-Sandoval35, E Majorana28, I Maksimovic124, V Malvezzi15,26, N Man54, V Mandic125, V Mangano36, G L Mansell22, M Manske18, M Mantovani34, F Marchesoni33,126, F Marion8, S Márka39, Z Márka39, A S Markosyan40, E Maros1, F Martelli57,58, L Martellini54, I W Martin36, D V Martynov12, K Mason12, A Masserot8, T J Massinger1, M Masso-Reid36, S Mastrogiovanni28,81, F Matichard1,12, L Matone39, N Mavalvala12, N Mazumder56, R McCarthy37, D E McClelland22, S McCormick7, C McGrath18, S C McGuire127, G McIntyre1, J McIver1, D J McManus22, T McRae22, S T McWilliams31, D Meacher54,74, G D Meadors10,29, J Meidam11, A Melatos128, G Mendell37, D Mendoza-Gandara10, R A Mercer18, E L Merilh37, M Merzougui54, S Meshkov1, C Messenger36, C Messick74, R Metzdorff60, P M Meyers125, F Mezzani28,81, H Miao45, C Michel65, H Middleton45, E E Mikhailov129, L Milano5,67, A L Miller6,28,81, A Miller85, B B Miller85, J Miller12, M Millhouse84, Y Minenkov15, J Ming29, S Mirshekari130, C Mishra17, S Mitra16, V P Mitrofanov49, G Mitselmakher6, R Mittleman12, A Moggi21, M Mohan34, S R P Mohapatra12, M Montani57,58, B C Moore95, C J Moore80, D Moraru37, G Moreno37, S R Morriss87, B Mours8, C M Mow-Lowry45, G Mueller6, A W Muir94, Arunava Mukherjee17, D Mukherjee18, S Mukherjee87, N Mukund16, A Mullavey7, J Munch70, E A M Muniz23, P G Murray36, A Mytidis6, K Napier44, I Nardecchia15,26, L Naticchioni28,81, G Nelemans11,53, T J N Nelson7, M Neri46,47, M Nery10, A Neunzert106, J M Newport3, G Newton36, T T Nguyen22, A B Nielsen10, S Nissanke11,53, A Nitz10, A Noack10, F Nocera34, D Nolting7, M E N Normandin87, L K Nuttall35, J Oberling37, E Ochsner18, E Oelker12, G H Ogin131, J J Oh116, S H Oh116, F Ohme10,94, M Oliver86, P Oppermann10, Richard J Oram7, B O'Reilly7, R O'Shaughnessy107, D J Ottaway70, H Overmier7, B J Owen72, A E Pace74, J Page123, A Pai101, S A Pai48, J R Palamos59, O Palashov113, C Palomba28, A Pal-Singh27, H Pan75, C Pankow85, F Pannarale94, B C Pant48, F Paoletti21,34, A Paoli34, M A Papa10,18,29, H R Paris40, W Parker7, D Pascucci36, A Pasqualetti34, R Passaquieti20,21, D Passuello21, B Patricelli20,21, B L Pearlstone36, M Pedraza1, R Pedurand65,132, L Pekowsky35, A Pele7, S Penn133, C J Perez37, A Perreca1, L M Perri85, H P Pfeiffer97, M Phelps36, O J Piccinni28,81, M Pichot54, F Piergiovanni57,58, V Pierro9, G Pillant34, L Pinard65, I M Pinto9, M Pitkin36, M Poe18, R Poggiani20,21, P Popolizio34, A Post10, J Powell36, J Prasad16, J W W Pratt103, V Predoi94, T Prestegard18,125, M Prijatelj10,34, M Principe9, S Privitera29, G A Prodi92,93, L G Prokhorov49, O Puncken10, M Punturo33, P Puppo28, M Pürrer29, H Qi18, J Qin52, S Qiu120, V Quetschke87, E A Quintero1, R Quitzow-James59, F J Raab37, D S Rabeling22, H Radkins37, P Raffai98, S Raja48, C Rajan48, M Rakhmanov87, P Rapagnani28,81, V Raymond29, M Razzano20,21, V Re26, J Read23, T Regimbau54, L Rei47, S Reid50, D H Reitze1,6, H Rew129, S D Reyes35, E Rhoades103, F Ricci28,81, K Riles106, M Rizzo107, N A Robertson1,36, R Robie36, F Robinet24, A Rocchi15, L Rolland8, J G Rollins1, V J Roma59, J D Romano87, R Romano4,5, J H Romie7, D Rosińska43,134, S Rowan36, A Rüdiger10, P Ruggi34, K Ryan37, S Sachdev1, T Sadecki37, L Sadeghian18, M Sakellariadou135, L Salconi34, M Saleem101, F Salemi10, A Samajdar136, L Sammut120, L M Sampson85, E J Sanchez1, V Sandberg37, J R Sanders35, B Sassolas65, B S Sathyaprakash74,94, P R Saulson35, O Sauter106, R L Savage37, A Sawadsky19, P Schale59, J Scheuer85, E Schmidt103, J Schmidt10, P Schmidt1,51, R Schnabel27, R M S Schofield59, A Schönbeck27, E Schreiber10, D Schuette10,19, B F Schutz29,94, S G Schwalbe103, J Scott36, S M Scott22, D Sellers7, A S Sengupta137, D Sentenac34, V Sequino15,26, A Sergeev113, Y Setyawati11,53, D A Shaddock22, T J Shaffer37, M S Shahriar85, B Shapiro40, P Shawhan64, A Sheperd18, D H Shoemaker12, D M Shoemaker44, K Siellez44, X Siemens18, M Sieniawska43, D Sigg37, A D Silva13, A Singer1, L P Singer68, A Singh10,19,29, R Singh2, A Singhal14, A M Sintes86, B J J Slagmolen22, B Smith7, J R Smith23, R J E Smith1, E J Son116, B Sorazu36, F Sorrentino47, T Souradeep16, A P Spencer36, A K Srivastava89, A Staley39, M Steinke10, J Steinlechner36, S Steinlechner27,36, D Steinmeyer10,19, B C Stephens18, S P Stevenson45, R Stone87, K A Strain36, N Straniero65, G Stratta57,58, S E Strigin49, R Sturani130, A L Stuver7, T Z Summerscales138, L Sun128, S Sunil89, P J Sutton94, B L Swinkels34, M J Szczepańczyk103, M Tacca30, D Talukder59, D B Tanner6, M Tápai102, A Taracchini29, R Taylor1, T Theeg10, E G Thomas45, M Thomas7, P Thomas37, K A Thorne7, E Thrane120, T Tippens44, S Tiwari14,93, V Tiwari94, K V Tokmakov110, K Toland36, C Tomlinson90, M Tonelli20,21, Z Tornasi36, C I Torrie1, D Töyrä45, F Travasso32,33, G Traylor7, D Trifirò73, J Trinastic6, M C Tringali92,93, L Trozzo21,139, M Tse12, R Tso1, M Turconi54, D Tuyenbayev87, D Ugolini140, C S Unnikrishnan104, A L Urban1, S A Usman94, H Vahlbruch19, G Vajente1, G Valdes87, N van Bakel11, M van Beuzekom11, J F J van den Brand11,63, C Van Den Broeck11, D C Vander-Hyde35, L van der Schaaf11, J V van Heijningen11, A A van Veggel36, M Vardaro41,42, V Varma51, S Vass1, M Vasúth38, A Vecchio45, G Vedovato42, J Veitch45, P J Veitch70, K Venkateswara141, G Venugopalan1, D Verkindt8, F Vetrano57,58, A Viceré57,58, A D Viets18, S Vinciguerra45, D J Vine50, J-Y Vinet54, S Vitale12, T Vo35, H Vocca32,33, C Vorvick37, D V Voss6, W D Vousden45, S P Vyatchanin49, A R Wade1, L E Wade78, M Wade78, M Walker2, L Wallace1, S Walsh10,29, G Wang14,58, H Wang45, M Wang45, Y Wang52, R L Ward22, J Warner37, M Was8, J Watchi82, B Weaver37, L-W Wei54, M Weinert10, A J Weinstein1, R Weiss12, L Wen52, P Weßels10, T Westphal10, K Wette10, J T Whelan107, B F Whiting6, C Whittle120, D Williams36, R D Williams1, A R Williamson94, J L Willis142, B Willke10,19, M H Wimmer10,19, W Winkler10, C C Wipf1, H Wittel10,19, G Woan36, J Woehler10, J Worden37, J L Wright36, D S Wu10, G Wu7, W Yam12, H Yamamoto1, C C Yancey64, M J Yap22, Hang Yu12, Haocun Yu12, M Yvert8, A Zadrożny118, L Zangrando42, M Zanolin103, J-P Zendri42, M Zevin85, L Zhang1, M Zhang129, T Zhang36, Y Zhang107, C Zhao52, M Zhou85, Z Zhou85, S J Zhu10,29, X J Zhu52, M E Zucker1,12, J Zweizig1 (LIGO Scientific Collaboration, Virgo Collaboration), M Boyle143, T Chu97, D Hemberger51, I Hinder29, L E Kidder143, S Ossokine29, M Scheel51, B Szilagyi51, S Teukolsky143 and A Vano Vinuales94 Hide full author list Published 12 April 2017 • © 2017 IOP Publishing Ltd Classical and Quantum Gravity, Volume 34, Number 10 Focus Issue: Gravitational Waves Article PDF Figures References Citations PDF 258 Total downloads Cited by 1 articles Article has an altmetric score of 3 Turn on MathJax Get permission to re-use this article Share this article Article information Abstract Parameter estimates of GW150914 were obtained using Bayesian inference, based on three semi-analytic waveform models for binary black hole coalescences. These waveform models differ from each other in their treatment of black hole spins, and all three models make some simplifying assumptions, notably to neglect sub-dominant waveform harmonic modes and orbital eccentricity. Furthermore, while the models are calibrated to agree with waveforms obtained by full numerical solutions of Einstein's equations, any such calibration is accurate only to some non-zero tolerance and is limited by the accuracy of the underlying phenomenology, availability, quality, and parameter-space coverage of numerical simulations. This paper complements the original analyses of GW150914 with an investigation of the effects of possible systematic errors in the waveform models on estimates of its source parameters. To test for systematic errors we repeat the original Bayesian analysis on mock signals from numerical simulations of a series of binary configurations with parameters similar to those found for GW150914. Overall, we find no evidence for a systematic bias relative to the statistical error of the original parameter recovery of GW150914 due to modeling approximations or modeling inaccuracies. However, parameter biases are found to occur for some configurations disfavored by the data of GW150914: for binaries inclined edge-on to the detector over a small range of choices of polarization angles, and also for eccentricities greater than ~0.05. For signals with higher signal-to-noise ratio than GW150914, or in other regions of the binary parameter space (lower masses, larger mass ratios, or higher spins), we expect that systematic errors in current waveform models may impact gravitational-wave measurements, making more accurate models desirable for future observations

    Search for Post-merger Gravitational Waves from the Remnant of the Binary Neutron Star Merger GW170817

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    The first observation of a binary neutron star coalescence by the Advanced LIGO and Advanced Virgo gravitational-wave detectors offers an unprecedented opportunity to study matter under the most extreme conditions. After such a merger, a compact remnant is left over whose nature depends primarily on the masses of the inspiralling objects and on the equation of state of nuclear matter. This could be either a black hole or a neutron star (NS), with the latter being either long-lived or too massive for stability implying delayed collapse to a black hole. Here, we present a search for gravitational waves from the remnant of the binary neutron star merger GW170817 using data from Advanced LIGO and Advanced Virgo. We search for short (1\lesssim1 s) and intermediate-duration (500\lesssim 500 s) signals, which includes gravitational-wave emission from a hypermassive NS or supramassive NS, respectively. We find no signal from the post-merger remnant. Our derived strain upper limits are more than an order of magnitude larger than those predicted by most models. For short signals, our best upper limit on the root-sum-square of the gravitational-wave strain emitted from 1--4 kHz is hrss50%=2.1×1022h_{\rm rss}^{50\%}=2.1\times 10^{-22} Hz1/2^{-1/2} at 50% detection efficiency. For intermediate-duration signals, our best upper limit at 50% detection efficiency is hrss50%=8.4×1022h_{\rm rss}^{50\%}=8.4\times 10^{-22} Hz1/2^{-1/2} for a millisecond magnetar model, and hrss50%=5.9×1022h_{\rm rss}^{50\%}=5.9\times 10^{-22} Hz1/2^{-1/2} for a bar-mode model. These results indicate that post-merger emission from a similar event may be detectable when advanced detectors reach design sensitivity or with next-generation detectors

    On the progenitor of binary neutron star merger GW170817

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    On 2017 August 17 the merger of two compact objects with masses consistent with two neutron stars was discovered through gravitational-wave (GW170817), gamma-ray (GRB 170817A), and optical (SSS17a/AT 2017gfo) observations. The optical source was associated with the early-type galaxy NGC 4993 at a distance of just ~40 Mpc, consistent with the gravitational-wave measurement, and the merger was localized to be at a projected distance of ~2 kpc away from the galaxy's center. We use this minimal set of facts and the mass posteriors of the two neutron stars to derive the first constraints on the progenitor of GW170817 at the time of the second supernova (SN). We generate simulated progenitor populations and follow the three-dimensional kinematic evolution from binary neutron star (BNS) birth to the merger time, accounting for pre-SN galactic motion, for considerably different input distributions of the progenitor mass, pre-SN semimajor axis, and SN-kick velocity. Though not considerably tight, we find these constraints to be comparable to those for Galactic BNS progenitors. The derived constraints are very strongly influenced by the requirement of keeping the binary bound after the second SN and having the merger occur relatively close to the center of the galaxy. These constraints are insensitive to the galaxy's star formation history, provided the stellar populations are older than 1 Gyr.B. P. Abbott … Miftar Ganija … Won Kim … Jesper Munch … David J Ottaway … Peter J Veitch … et al. (LIGO Scientific Collaboration and Virgo Collaboration

    Is vitamin D supplementation effective for low back pain? A systematic review and meta-analysis

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    Low back pain (LBP) is the leading cause of years lived with disability worldwide. Current intervention strategies are failing to reduce the enormous global burden of LBP and are prompting researchers to investigate alternative management strategies, such as vitamin D supplementation. Vitamin D supplementation appears to down regulate pro-inflammatory cytokines which lead to pain and up regulate anti-inflammatory cytokines that reduce inflammation. These mechanisms might explain the increasing interest in the use of vitamin D supplementation for LBP.To determine whether vitamin D supplementation improves pain more than a control intervention for individuals with LBP.This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.We performed searches in numerous electronic databases combining key words relating to "vitamin D" and "LBP" until March 2017. Studies were included if they investigated vitamin D supplementation in participants with LBP, provided there was a comparison intervention. There was no restriction on the type of LBP, the intervention parameters investigated, or the type of clinical trial (e.g., randomized, non-randomized). Two reviewers independently performed the selection of studies, extracted data, rated the methodological quality of the included studies, and evaluated the overall quality of the evidence using the Grading of Recommendations Assessment, Delevopment, and Evaulation (GRADE) approach.After screening 3,534 articles, 8 clinical trials were included in this systematic review. There is very low quality evidence (based on the GRADE approach) that vitamin D supplementation is not more effective than any intervention (including placebo, no intervention, and other conservative/pharmacological interventions) (continuous pain measures [0-100]: mean difference [MD] = -2.65, 95% confidence interval [CI]: -10.42 to 5.12, P = 0.504, n = 5; self-reported reduction in pain: pooled odds ratio [OR] = 1.07, 95% CI: 0.35 to 3.26, P = 0.906, n = 5) or placebo/no intervention for individuals with LBP (continuous pain measures: MD = 1.29, 95% CI: -3.81 to 6.39, P = 0.620, n = 4; self-reported reduction in pain: pooled OR = 1.53, 95% CI: 0.38 to 6.20, P = 0.550, n = 4), where 'n' is the number of studies included in the meta-analysis. These results did not change when we stratified the meta-analyses by the type of vitamin supplementation (vitamin D3 vs. alfacalcidol) or the type of LBP (non-specific vs. LBP resulting from osteoporosis or vertebral fractures).The overall quality of evidence was "very low" due to the poor methodological quality and small sample sizes of the included studies.Vitamin D supplementation is not more effective than placebo, no intervention, or other conservative/pharmacological interventions for LBP (based on very low quality evidence). These results are consistent, regardless of the type of LBP or vitamin D supplementation. Until well-designed and adequately powered clinical trials suggest otherwise, the prescription of vitamin D for LBP cannot be recommended. PROSPERO Registration No: CRD42016046874. www.crd.york.ac.uk/PROSPERO/display_record.asp?ID = CRD42016046874.Vitamin D, low back pain, chronic low back pain, alfacalcidol, osteoporosis, vertebral fractures, serum 25-hydroxyvitamin D, systematic review
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