51 research outputs found
The Black Hole Spin Controversy
Astrophysical black holes are the simplest possible objects. They are completely described by only two parameters in general relativity, their mass and the specific angular momentum, spin. The spin is a fundamental characteristic of a black hole, but unlike mass it leaves a mark on space-time only very close to the event horizon, and is therefore more difficult to measure. The observational relevance of the spin comes from the fact that it sets the size scale of the last stable orbit around the accreting black hole, dragging the accretion disc farther in the faster it spins.
Black hole spin is a very controversial topic in both stellar and supermassive black holes. There are two methods to determine spin in binary systems, using either the direct disc continuum or the reflected emission. These can give significantly different values, and understanding the source of this discrepancy is important especially for interpreting AGN spin, where only the reflection method can be used.
We have strived to understand and carefully model the time-averaged energy spectra from several Galactic black hole binaries, in order to ultimately measure the black hole spin. Achieving this has required in-depth understanding of the instruments as well as the data analysis methods. The spin leaves only minor traces in the data, and these can be affected by calibration uncertainties, uncertainties in the models and systematic uncertainties. This knowledge is absolutely essential for a detailed analysis of all relativistically smeared atomic features seen in the time-averaged energy spectra of compact objects
The Low-Spin Black Hole in LMC X-3
Building upon a new dynamical model for the X-ray binary LMC X-3, we measure
the spin of its black hole primary via the continuum-fitting method. We
consider over one thousand thermal-state RXTE X-ray spectra of LMC X-3. Using a
large subset of these spectra, we constrain the spin parameter of the black
hole to be spin = 0.21(+0.18,-0.22), 90% confidence. Our estimate of the
uncertainty in spin takes into account a wide range of systematic errors. We
discuss evidence for a correlation between a black hole's spin and the
complexity of its X-ray spectrum.Comment: Submitted to ApJL, 5 pages emulateapj, 2 figures and 1 tabl
The truncated disk from Suzaku data of GX 339-4 in the extreme very high state
We report on the geometry of accretion disk and high energy coronae in the
strong Comptonization state (the very high/steep power law/hard intermediate
state) based on a Suzaku observation of the famous Galactic black hole GX
339-4. These data were taken just before the peak of the 2006-2007 outburst,
and the average X-ray luminosity in the 0.7-200 keV band is estimated to be
2.9E38 erg/s for a distance of 8 kpc. We fit the spectrum with both simple
(independent disk and corona) and sophisticated (energetically coupled disk and
corona) models, but all fits imply that the underlying optically thick disk is
truncated significantly before the innermost stable circular orbit around the
black hole. We show this directly by a comparison with similarly broadband data
from a disk dominated spectrum at almost the same luminosity observed by
XMM-Newton and RXTE 3 days after the Suzaku observation.
During the Suzaku observation, the QPO frequency changes from 4.3 Hz to 5.5
Hz, while the spectrum softens. The energetically coupled model gives a
corresponding 5+/- 8 % decrease in derived inner radius of the disk. While this
is not significant, it is consistent with the predicted change in QPO frequency
from Lense-Thirring precession of the hot flow interior to the disk and/or a
deformation mode of this flow, as a higher QPO frequency implies a smaller size
scale for the corona. This is consistent with the truncated disk extending
further inwards towards the black hole.Comment: Accepted to ApJ, 41 pages, 9 figures, 3 table
Modelling the high mass accretion rate spectra of GX 339-4: Black hole spin from reflection?
We extract all the XMM-Newton EPIC pn burst mode spectra of GX 339-4,
together with simultaneous/contemporaneous RXTE data. These include three disc
dominated and two soft intermediate spectra, and the combination of broad
bandpass/moderate spectral resolution gives some of the best data on these
bright soft states in black hole binaries. The disc dominated spectra span a
factor three in luminosity, and all show that the disc emission is broader than
the simplest multicolour disc model. This is consistent with the expected
relativistic smearing and changing colour temperature correction produced by
atomic features in the newest disc models. However, these models do not match
the data at the 5 per cent level as the predicted atomic features are not
present in the data, perhaps indicating that irradiation is important even when
the high energy tail is weak. Whatever the reason, this means that the data
have smaller errors than the best physical disc models, forcing use of more
phenomenological models for the disc emission. We use these for the soft
intermediate state data, where previous analysis using a simple disc continuum
found an extremely broad residual, identified as the red wing of the iron line
from reflection around a highly spinning black hole. However, the iron line
energy is close to where the disc and tail have equal fluxes, so using a
broader disc continuum changes the residual 'iron line' profile dramatically.
With a broader disc continuum model, the inferred line is formed outside of 30
, so cannot constrain black hole spin. We caution that a robust
determination of black hole spin from the iron line profile is very difficult
where the disc makes a significant contribution at the iron line energy i.e. in
most bright black hole states.Comment: 12 pages, 16 figures, published in MNRA
Metabolic profiles reflect weight loss maintenance and the composition of diet after very-low-energy diet
Background & aims: Diet and weight loss affect circulating metabolome. However, metabolite profiles induced by different weight loss maintenance diets and underlying longer term weight loss maintenance remain unknown. Herein, we investigated after-weight-loss metabolic signatures of two isocaloric 24-wk weight maintenance diets differing in satiety value due to dietary fibre, protein and fat contents and identified metabolite features that associated with successful weight loss maintenance. Methods: Non-targeted LC-MS metabolomics approach was used to analyse plasma metabolites of 79 women and men (mean age \ub1 SD 49.7 \ub1 9.0 years; BMI 34.2 \ub1 2.5 kg/m2) participating in a weight management study. Participants underwent a 7-week very-low-energy diet (VLED) and were thereafter randomised into two groups for a 24-week weight maintenance phase. Higher satiety food (HSF) group consumed high-fibre, high-protein, and low-fat products, while lower satiety food (LSF) group consumed isocaloric low-fibre products with average protein and fat content as a part of their weight maintenance diets. Plasma metabolites were analysed before the VLED and before and after the weight maintenance phase. Metabolite features discriminating HSF and LSF groups were annotated. We also analysed metabolite features that discriminated participants who maintained ≥10% weight loss (HWM) and participants who maintained <10% weight loss (LWM) at the end of the study, irrespective of the diet. Finally, we assessed robust linear regression between metabolite features and anthropometric and food group variables. Results: We annotated 126 metabolites that discriminated the HSF and LSF groups and HWM and LWM groups (p < 0.05). Compared to LSF, the HSF group had lower levels of several amino acids, e.g. glutamine, arginine, and glycine, short-, medium- and long-chain acylcarnitines (CARs), odd- and even-chain lysoglycerophospholipids, and higher levels of fatty amides. Compared to LWM, the HWM group in general showed higher levels of glycerophospholipids with a saturated long-chain and a C20:4 fatty acid tail, and unsaturated free fatty acids (FFAs). Changes in several saturated odd- and even-chain LPCs and LPEs and fatty amides were associated with the intake of many food groups, particularly grain and dairy products. Increase in several (lyso)glycerophospholipids was associated with decrease in body weight and adiposity. Increased short- and medium-chain CARs were related to decreased body fat-free mass. Conclusions: Our results show that isocaloric weight maintenance diets differing in dietary fibre, protein, and fat content affected amino acid and lipid metabolism. Increased abundances of several phospholipid species and FFAs were related with greater weight loss maintenance. Our findings indicate common and distinct metabolites for weight and dietary related variables in the context of weight reduction and weight management. The study was registered in isrctn.org with identifier 67529475
Aluekehittämisen verkostoyhteistyön toiminta- ja rahoitusmallit: Kohti vaikuttavaa verkostotyötä
Aluekehittämisessä kyse on useimmiten joko ”ilkeistä ongelmista” tai ”monitahoisista mahdollisuuksista”, joiden ratkaiseminen tai hyödyntäminen ei ole mahdollista vain yhden toimijan kyvyillä, osaamisella ja resursseilla. Tämä korostaa verkostomaista otetta kehittämistyöhön. Hallitusohjelman mukaisen alue- ja kaupunkikehittämisen sekä kansallisten alueiden kehittämisen painopisteiden ja instrumenttien valmistelun tueksi on tarvittu analyysiä erilaisista verkostoyhteistyön toiminta- ja rahoitusmalleista.
VALUMA-hankkeessa on rakennettu kokonaiskuvaa verkostomaisesta alueiden kehittämisestä sekä koottu oppeja aluekehittämisen verkostoista Suomessa ja muissa maissa. Lisäksi selvityksessä on analysoitu erilaisten verkostoyhteistyön toimintamallien mahdollisia vaikutuksia aluekehittämisen kokonaisuudessa sekä valtion roolia ja mahdollisen kannustin- tai ohjelmarahoituksen merkitystä.
Selvityksen perusteella kansallisesti vaikuttava aluekehittämisen verkostotyön kokonaisuus vaatii aluekehittämistoimijoiden yhteistyönä rakennetun tietopohjan, selkeän tavoitteen ja poliittisen tuen aluekehittämiselle, aluekehittämisen kyvykkyyksien ja vertaisoppimisen vahvistamista sekä ilmiö- ja teemapohjaisen rahoituksen järjestämistä verkostotyölle.Tämä julkaisu on toteutettu osana valtioneuvoston selvitys- ja tutkimussuunnitelman toimeenpanoa(tietokayttoon.fi).
Julkaisun sisällöstä vastaavat tiedon tuottajat, eikä tekstisisältö välttämättä edusta valtioneuvoston näkemystä
LongITools: Dynamic longitudinal exposome trajectories in cardiovascular and metabolic noncommunicable diseases
The current epidemics of cardiovascular and metabolic noncommunicable diseases have emerged alongside dramatic modifications in lifestyle and living environments. These correspond to changes in our “modern” postwar societies globally characterized by rural-to-urban migration, modernization of agricultural practices, and transportation, climate change, and aging. Evidence suggests that these changes are related to each other, although the social and biological mechanisms as well as their interactions have yet to be uncovered. LongITools, as one of the 9 projects included in the European Human Exposome Network, will tackle this environmental health equation linking multidimensional environmental exposures to the occurrence of cardiovascular and metabolic noncommunicable diseases.</p
Kuka ottaa kopin? : Seinäjoen koulutus- ja palvelutarjonnan vastaaminen nivelvaiheissa olevien nuorten tarpeisiin
SEINÄJOEN AMMATTIKORKEAKOULU
Tiivistelmä
Koulutusyksikkö: Sosiaali- ja terveysalan yksikkö
Koulutusohjelma: Sosiaalialan koulutusohjelma
Suuntautumisvaihtoehto: Sosionomi (AMK)
Tekijä/t: Mari Filander & Maria Kolehmainen
Työn nimi: Kuka ottaa kopin? Seinäjoen koulutus- ja palvelutarjonnan vastaaminen nivelvaiheissa olevien nuorten tarpeisiin
Ohjaaja(t): Mirva Siltakorpi
Vuosi: 2009 Sivumäärä: 83 Liitteiden lukumäärä: 9
Opinnäytetyön tarkoituksena oli selvittää miten Seinäjoen koulutus- ja palvelutar-jonta vastaa nivelvaiheissa olevien nuorten tarpeisiin. Tutkimuksessa pyrittiin tuomaan esiin nuorten tarpeita, jotta niihin voitaisiin vastata paremmin koulutus- ja palvelutarjonnassa. Teoriaosuudessa käsitellään nuoruutta elämänvaiheena sekä osallisuutta yhteiskunnassa. Tämän lisäksi tarkastellaan suomalaista koululaitosta sekä millaista nuoren elämä nivelvaiheissa voi olla ja miten sen asettamiin haasteisiin voidaan vastata yhteiskunnassa. Työssä esitellään myös Seinäjoen koulutus- ja palvelutarjontaa.
Tutkimuksessa keskityttiin nivelvaiheiden ensimmäiseen ja toiseen osuuteen, eli alle 17 -vuotiaisiin nuoriin, jotka eivät ole hakeutuneet tai päässeet jatko-opintoihin, tai ovat keskeyttäneet toisen asteen opintonsa. Tutkimukseen osallis-tui myös nuoria aikuisia, joilla oli jo kokemus nivelvaiheista, sekä ammattilaisia jotka työskentelevät nuorten parissa. Osallistujia oli yhteensä yksitoista henkilöä. Tutkimus oli kvalitatiivinen eli laadullinen ja tutkimusaineisto kerättiin teemahaastatteluilla, kyselyllä ja kirjeellä. Aineisto analysoitiin teoriaohjaavan analyysin avulla ja tukena käytettiin aineistosta esiin nousseita teemoja.
Tulokset osoittivat, että Seinäjoen koulutus- ja palvelutarjonta vastaa nivelvaiheissa olevien nuorten tarpeisiin silloin, kun nuori on vielä koulun oppilas tai opiskelija sekä silloin, kun nuorella on joku erityinen tarve kuulua palvelun piiriin. Ensimmäisessä nivelvaiheessa olevan nuoren tilanne oli hyvä, sillä kouluilla oli vielä tarjolla tukitoimia häntä varten. Toisessa nivelvaiheessa olevan nuoren tilanne saattoi olla heikompi, sillä koulutus- ja palvelutarjonnalla ei ollut välttämättä selkeää syytä tarjota hänelle tukea ja ohjausta.
Avainsanat: nuoruus, koululaitos, nivelvaihe, syrjäytyminen, tukipalvelutSEINÄJOKI UNIVERSITY OF APPLIED SCIENCES
Abstract
Faculty: School of Health Care and Social Work
Degree programme: Degree Programme in Social Work
Specialisation: Bachelor of Social Services
Author/s: Mari Filander & Maria Kolehmainen
Title of thesis: Youth in transitional phases and public education and services provided in Seinäjoki.
Supervisor(s): Mirva Siltakorpi
Year: 2009 Number of pages: 83 Number of appendices: 9
The aim of this thesis was to examine how educational and public services in Seinäjoki meet the needs of young people in transitional phases. The research was aiming to bring out the needs of youngsters so they could be better noticed by the educational and public service systems. The theory section examines Finnish educational institution. Furthermore, we discuss the challenges in youngster’s life during different transitional phases and how these challenges can be overcome. Educational and public services of Seinäjoki are also in-troduced.
The research was focused on the first and the second transitional phase, seven-teen years old youngsters who had not applied for, nor been admitted into further education or had dropped out of school. Young adults, who have experienced transitional phases and professionals, who work with young people, were also participated in the research. This research has a qualitative approach with material based on theme interviews, questionnaire and letter. Analysis was sup-ported by theory and it handles themes which arose from the material.
The results showed that at the first transitional phase, the situation for adolescents is good because schools still have supportive measures to offer. At the second transitional phase, the situation was less bright because educational and public services do not necessarily have a clear reason to offer support and guidance for a youngster.
Keywords: youth, public education, transitional phase, alienation, support service
Kehity ammattikorkeakoulun harjoittelun ohjaajana : koulutuskansio
Harjoittelu on olennainen osa ammattikorkeakouluopintoja. Opiskelijalle harjoittelu
on teoriaa ja käytäntöä yhdistävä koulutusvaihe, joka antaa mahdollisuuden opinnoissa
hankitun osaamisen soveltamiseen ja testaamiseen käytännössä sekä luo
pohjaa oman osaamisen arviointiin ja itsensä kehittämiseen. Harjoittelun onnistuminen
vaatii panostusta kaikilta harjoittelun osapuolilta opiskelijalta, oppilaitokselta
ja harjoittelupaikalta.
Ammattikorkeakoulujen harjoittelun ohjaajakoulutuksen kehittämishankkeessa
(HOKK) tavoitteena oli laaduntaa ammattikorkeakoulujen opiskelijoiden harjoittelun
ohjausta. Tämä hankkeen tuottama koulutusaineisto palvelee kaikkien koulutusalojen
ammattikorkeakouluopiskelijoiden harjoittelun ohjaajia työpaikoilla sekä
harjoittelusta vastaavia tai ohjaavaa henkilöstöä oppilaitoksissa. HOKK-hanketta
hallinnoi Humanistinen ammattikorkeakoulu (HUMAK) opetusministeriön tuella
1.2.2007–31.1.2008
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