Mapping the Galactic halo with main-sequence and RR Lyrae stars

We present an analysis of Galactic halo structure, substructure, and metallicity traced by mainsequence and RR Lyrae stars selected from the SDSS stripe 82 and CFHT Legacy Survey data sets. The main result of the study based on SDSS stripe 82 data is a 2D map of the Galactic halo that reaches distances of 100 kpc and traces previously known and new halo substructures, such as the Sagittarius and Pisces tidal streams. We present strong direct evidence, based on both RR Lyrae and main-sequence stars, that the halo stellar number density profile significantly steepens beyond 30 kpc from the Galactic center. The steepening of the density profile beyond 30 kpc is also evident in the distribution of main-sequence stars observed by the CFHT Legacy Survey along four Galactic lines of sight. In the two CFHT sightlines where we do not detect significant substructure, the median metallicity is found to be independent of distance within systematic uncertainties ([Fe/H] ∼ −1.5 ± 0.1 dex within 30 kpc of the Galactic Center)

The Shape and Profile of the Milky Way Halo as Seen by the Canada-France-Hawaii Telescope Legacy Survey

We use Canada-France-Hawaii Telescope Legacy Survey data for 170 deg^2, recalibrated and transformed to the Sloan Digital Sky Survey ugri photometric system, to study the distribution of near-turnoff main-sequence stars in the Galactic halo along four lines of sight to heliocentric distances of ~35 kpc. We find that the halo stellar number density profile becomes steeper at Galactocentric distances greater than R_(gal) ~ 28 kpc, with the power-law index changing from n_(inner) = –2.62 ± 0.04 to n_(outer) = –3.8 ± 0.1. In particular, we test a series of single power-law models and find them to be strongly disfavored by the data. The parameters for the best-fit Einasto profile are n = 2.2 ± 0.2 and R_e = 22.2 ± 0.4 kpc. We measure the oblateness of the halo to be q ≡ c/a = 0.70 ± 0.01 and detect no evidence of it changing across the range of probed distances. The Sagittarius stream is detected in the l = 173° and b = –62° direction as an overdensity of [Fe/H] ~ -1.5 dex stars at R_(gal) ~ 32 kpc, providing a new constraint for the Sagittarius stream and dark matter halo models. We also detect the Monoceros stream as an overdensity of [Fe/H] > -1.5 dex stars in the l = 232° and b = 26° direction at R_(gal) ≲ 25 kpc. In the two sight lines where we do not detect significant substructure, the median metallicity is found to be independent of distance within systematic uncertainties ([Fe/H] ~ -1.5 ± 0.1 dex)

Template RR Lyrae H alpha, H beta, and H gamma Velocity Curves

We present template radial velocity curves of $ab$-type RR Lyrae stars constructed from high-precision measurements of ${\rm H\alpha}$, ${\rm H\beta}$, and ${\rm H\gamma}$ lines. Amplitude correlations between the Balmer line velocity curves, Johnson $V$-band, and SDSS $g$- and $r$-band light curves are also derived. Compared to previous methods, these templates and derived correlations reduce the uncertainty in measured systemic (center-of-mass) velocities of RR Lyrae stars by up to 15 {\kms}, and will be of particular interest to wide-area spectroscopic surveys such as the Sloan Digital Sky Survey (SDSS) and LAMOST Experiment for Galactic Understanding and Exploration (LEGUE).Comment: 10 pages, 3 figures, accepted to A

Kvaliteta života povezana sa zdravljem u bolesnika s primarnim glaukomom otvorenog kuta

The purpose of this research was to evaluate the relationship between general health-related quality of life (GHRQL) and sociodemographic factors in primary open-angle glaucoma (POAG) patients. A prospective cross-sectional study included 207 glaucoma patients. GHRQL was determined via two self-administered questionnaires: the 36-Item Short Form Survey (SF-36) and the EuroQol-5D (EQ-5D) questionnaire. Male and 50- to 69-year-old glaucoma patients, followed by patients who regularly used antiglaucoma therapy and those without progression of glaucoma reported a significantly higher quality of life as measured by the EQ-5D index and the EQ-5D visual analog scale (VAS) (p<0.05 all). Similarly, the Physical Component Summary (PCS) and Mental Component Summary (MCS) of SF-36 had significantly higher values for these patients (p<0.05 all). Furthermore, glaucoma patients with higher education and economic status, glaucoma patients who lived in rural areas, and those who were married achieved higher scores on EQ-5D and SF-36. In conclusion, progression of the disease, female sex, older age, lower education and economic status, urban area and unmarried status negatively affect quality of life in glaucoma patients.Svrha ovoga istraživanja bila je utvrditi odnos između kvalitete života povezane s općim zdravljem (GHRQL) i sociodemografskih čimbenika u bolesnika s primarnim glaukomom otvorenog kuta (POAG). Riječ je o presječnoj studiji u kojoj je sudjelovalo 207 bolesnika s POAG. GHRQL mjerena je pomoću dva upitnika: kratkog upitnika zdravstvenog statusa s 36 pitanja (SF-36) i upitnika EuroQol-5D (EQ-5D). Muškarci i bolesnici s glaukomom u dobi od 50-69 godina, zatim bolesnici koji su redovito koristili antiglaukomsku terapiju i oni bez progresije glaukoma izvijestili su o znatno višoj kvaliteti života mjerenoj indeksom EQ-5D i vizualnom analognom ljestvicom EQ-5D (VAS) (p<0,05 za sve usporedbe). Slično tome, Sažetak fizičkih komponenata (PCS) i Sažetak mentalnih komponenata (MCS) upitnika SF-36 imali su značajno veće vrijednosti za ove bolesnike (p<0,05 za sve usporedbe). Nadalje, ispitanici s visokim stupnjem obrazovanja i ekonomskim statusom, ispitanici koji žive u ruralnim područjima i oni koji su u braku postigli su veće rezultate na EQ-5D i SF-36. Zaključno, napredovanje bolesti, ženski spol, starija životna dob, niži stupanj obrazovanja i ekonomski status, urbano područje življenja i samoća negativno utječu na kvalitetu života bolesnika s glaukomom

Influence and character of surface water in Maksimir park

Park Maksimir je sagrađen u 19. st., i od tada plijeni pozornost zbog svoje estetike, načina građenja ali i kulturne i ekološke raznolikosti. Svakodnevno, bez obzira na godišnja doba možemo vidjeti različite ljude kako dolaze u park sa različitim interesima, neki dolaze proučavati floru i faunu parka, neki ljudi dolaze zbog rekreacije a neki samo zbog odmora. U sklopu parka Maksimir nalazi se i Zoološki vrt koji rado posjećuju mladi ali i stariji ljudi, kako bi naučili neke nove stvari o životinjskom svijetu. Osim Zoološkog vrta veliku pozornost privlače i maksimirska jezera koja svakom čovjeku izvlači divljenje ili barem uzdah. Iako dosta blizu centra grada, park Maksimir predstavlja zaista jedno kulturno, povijesno i ekološko bogatstvo. No proučavajući malo bolje sam park nije sve tako bajno kako se čini. Premda je park zaštićen, ljudi odlažu smeće na puteljke, bacaju na livade, grmove, pa čak i ju jezera. Proučavajući park i tu ljepotu prirode čovjek veoma lako može uočiti kako postoji određeni stupanj eutrofikacije u jezerima. Pretpostavlja se da dolazi do eutrofikacije zbog prirodnog ali i antropogenog utjecaja. Pitanje je samo koliko to 'onečišćenje' utječe na samu floru i faunu jezera ali i samog parka. Danas postoji nekoliko veoma uspješnih metoda pročišćavanja jezera, tako da sumnjam da će se situacija u jezerima i okolišu pogoršati, dapače očekujem suprotno.Maksimir Park was built in the 19th century, and from that period he's gathering attention because of his esthetic, the way it was built but also because of the cultural and ecological variety. Every day, no matter the season, we can see different people walking in the park with different interests, some of them are coming to explore the flora and fauna, some because of the recreation and some people just want to relax. In the complex of Makismir Park is the ZOO which gathers all kindds of people who want to learn more about the animal world. Except from the ZOO, the lakes of Maksimir also attracts big attention and leaves some people fully surprised and admired. Although Maksimir is near the centre of the city it presents a big cultural, historical and ecological wealth. After carefully studying the park not everything is all that good. Althought the park is protected, every day people throw their garbage on the sidewalks, meadows, bushes and even in the lakes. Examining the park and the beauty of nature, we can very easy see that there is a significant grade of euphrofication in the lakes. The presumption is that the euphrofication is caused by natural and anthropogenic influence. The question is how that 'pollution' affects the flora and fauna of the lakes and the whole park. Today we know a few successful methods of purification the lakes so I don't doubt that the conditions of lakes and the nature will get any worse, infact I expect the opposite

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UTJECAJ VJEŽBANJA I RAZINE OSPOSOBLJENOSTI NA MIKROCIRKULACIJU RETINE

Aim: To examine differences in retinal microcirculation between people with different degrees of physical fi tness. Methods: The subjects were divided into athletes and non-athletes. Both groups took part in two examinations. The fi rst examination was performed before short-term exercise and the second one immediately after it. First group consisted of 25 athletes (50 eyes), and the second group of 25 non-athletes (50 eyes) who were not previously exposed to acute physical stress. Athletes are defi ned as people who have been engaged in some form of regular physical activity for at least 5 years, and have met certain criteria according to the International Physical Activity Questionnaire (IPAQ). Non-athletes were those who were physically inactive or at least not regularly engaged in physical activity during the same period and did not meet the IPAQ criteria. The subjects were men and women between 18 and 26 years of age who did not have any cardiovascular disease, used drugs affecting the cardiovascular system, nor had an eye disease or a refractive error greater than spherical equivalent of +/-3 diopters. The examination consisted of optical coherence tomography angiography (OCT-A) imaging pre- and post-workout. The parameters taken into account were vascular density (VD) at three different macular areas according to the standard Early Treatment Diabetic Retinopathy Study (ETDRS) grid, i.e., central zone, inner zone and full area; perfusion density (PD), also at the three mentioned zones; and the area of foveal avascular zone (FAZ) in both eyes. The research also included a standardized survey on physical activity of the subjects (IPAQ), which was completed before the examination. The acute physical exercise consisted of the standardized incremental cycling ergometer test (ICET), which was performed on a stationary exercise bike for 5 minutes, at a given load of 12 degrees. On statistical processing of the data obtained, SPSS for Windows (version 13.0, SPSS Inc., Chicago, Illinois, USA) software was used. Results: Baseline measures of VD and PD were similar between the groups. FAZ surface was signifi cantly increased in the athlete group compared with non-athletes both at baseline and after short-term exercise. VD was signifi cantly higher in athletes post-exercise compared with the non-athlete group. Central PD was also signifi -cantly increased after exercise in the athlete group, and not in the non-athlete group. Conclusion: The results obtained in this study demonstrated that athletes exhibited a more intensive vascular reaction to exercise. The parameters in basal conditions did not show signifi cant difference between the two groups, except for FAZ which was larger in athletes. Signifi cant differences present post-workout in other measured values indicated a more dynamic vascular system in physically active individuals.ilj rada: Ispitati razlike u retinalnoj mikrocirkulaciji između osoba s višim i nižim stupnjem tjelesne osposobljenosti. Postupci: Ispitanici su bili podijeljeni na sportaše i nesportaše. Obje skupine pristupile su dvama odvojenim mjerenjima. Prvi pregled obavljen je prije fi zičkog opterećenja, a drugi neposredno nakon njega. Prvu skupinu činilo je 25 sportaša (50 očiju), a drugu 25 nesportaša (50 očiju) koji prethodno nisu bili izloženi akutnom fi zičkom stresu. Sportaše defi niramo kao osobe koje se najmanje 5 godina bave nekim oblikom redovite tjelesne aktivnosti u obliku treniranja nekog sporta, fi tnesa, aerobnog treninga i sl. te ispunjavaju određene uvjete prema međunarodnom upitniku o tjelesnoj aktivnosti (International Physical Activity Questionnaire, IPAQ). Neki sportaši nisu bili fi zički aktivni ili barem ne redovito tijekom istog razdoblja i nisu ispunjavali navedene kriterije IPAQ. Ispitanici su bili muškarci i žene u dobi između 18 i 26 godina koji nisu imali nikakvu srčanožilnu bolest, nisu uzimali lijekove koji utječu na srčanožilni sustav niti su imali ikakvu bolest očiju ili refraktivnu grešku veću od sfernog ekvivalenta +/-3 dioptrije. Prikupljanje podataka provedeno je pomoću optičke koherentne tomografske angiografi je (OCT-A). Analizirani su sljedeći parametri: vaskularna gustoća (VG) u tri različita područja makule prema mreži ETDRS (Early Treatment Diabetic Retinopathy Study): središnja zona, unutarnja zona i puna zona; perfuzijska gustoća (PG), također u tri navedena područja; te površina fovealne avaskularne zone (FAZ). Istraživanje je uključivalo i standardiziranu anketu o tjelesnoj aktivnosti ispitanika (IPAQ) koja se ispunjavala prije samog pregleda. Fizičko opterećenje sastojalo se od standardiziranog testa ICET (incremental cycling ergometer test), koji se izvodio na stacionarnom sobnom biciklu u trajanju od 5 minuta pri zadanom opterećenju od 12 stupnjeva, nakon čega su ispitanicima izmjereni puls i saturacija. Također, prije same vježbe ispitanicima su izmjerene srčana frekvencija i saturacija u mirovanju. Za statističku obradu dobivenih podataka primijenjen je softverski sustav SPSS for Windows (verzija 13.0, SPSS Inc., Chicago, Illinois, SAD). Rezultati: Mjerenja u bazalnim uvjetima pokazala su slične vrijednosti VGi PG između skupina. Površina FAZ bila je statistički značajno veća u skupini sportaša u usporedbi s nesportašima i u bazalnim uvjetima i nakon tjelovježbe. Nakon tjelovježbe VG i središnji PG pokazali su statistički značajno povećanje u sportaša, dok u nesportaša nije bilo razlike prije i nakon tjelovježbe. Zaključak: Rezultati dobiveni u ovoj studiji pokazali su da sportaši imaju intenzivniju vaskularnu reakciju na vježbanje. Parametri u bazalnim uvjetima nisu pokazali značajnu razliku između dviju skupina osim za FAZ, koja je bila veća u sportaša. Značajne razlike bile su prisutne nakon treninga u drugim izmjerenim vrijednostima i ukazuju na dinamičniji vaskularni sustav u fi zički aktivnih pojedinaca

The Mass Profile of the Galaxy to 80 kpc

The Hypervelocity Star survey presents the currently largest sample of radial velocity measurements of halo stars out to 80 kpc. We apply spherical Jeans modeling to these data in order to derive the mass profile of the Galaxy. We restrict the analysis to distances larger than 25 kpc from the Galactic center, where the density profile of halo stars is well approximated by a single power law with logarithmic slope between -3.5 and -4.5. With this restriction, we also avoid the complication of modeling a flattened Galactic disk. In the range 25 < r < 80 kpc, the radial velocity dispersion declines remarkably little; a robust measure of its logarithmic slope is between -0.05 and -0.1. The circular velocity profile also declines remarkably little with radius. The allowed range of V_c(80 kpc) lies between 175 and 231 km/s, with the most likely value 193 km/s. Compared with the value at the solar location, the Galactic circular velocity declines by less than 20% over an order of magnitude in radius. Such a flat profile requires a massive and extended dark matter halo. The mass enclosed within 80 kpc is 6.9(+3.0-1.2) 10^11 Msun. Our sample of radial velocities is large enough that the biggest uncertainty in the mass is not statistical but systematic, dominated by the density slope and anisotropy of the tracer population. Further progress requires modeling observed datasets within realistic simulations of galaxy formation.Comment: matches version accepted to ApJ Letter