62 research outputs found
Optical supernova remnants and their influence on star formation rates derived from H[alpha]
U ovoj disertaciji je analiziran uticaj zracenja ostataka supernovih (OSN) u liniji
H na stopu formiranja zvezda (SFZ) odredenu na osnovu emisije u ovoj liniji. Pri-
kazana je detekcija 16 optickih OSN, od strane autora ove disertacije, u delu galaksije
IC342, kao i dva potencijalna OSN u galaksiji NGC 185. Posmatranja su realizovana
pomocu dvometarskog teleskopa na Nacionalnoj astronomskoj opservatoriji Rozen
u Bugarskoj, koriscenjem uskopojasnih ltera: H, [S ii] i kontinuum ltera na tala-
snoj duzini bliskoj talasnim duzinama ove dve linije. Takode, u sklopu rada na ovoj
disertaciji, pretrazena je literatura kako bi se sastavila lista svih opticki detektovanih
OSN van nase Galaksije. Prilikom odredivanja stope formiranja zvezda iz linije H,
polazna pretpostavka je da zracenje potice iz jonizovanog gasa koji okruzuje mlade
zvezde, tj iz tzv. Hii regiona. Zbog toga opticko zracenje ostataka supernovih u
liniji H ,,kontaminira"
uks na osnovu koga treba da se odredi SFZ. Nalazimo da
je srednja vrednost udela H
uksa OSN u ukupnom
uksu galaksije, za uzorak
od 18 galaksija sa optickim OSN, 5 5%. Zbog postojanja posmatrackih selekcio-
nih efekata, ovaj procenat predstavlja tek donju granicu kontaminacije ukupnog H
uksa galaksije zracenjem OSN. Za M83, galaksiju sa najvecim brojem detektova-
nih optickih OSN, ovaj procenat je 9%, i ocekujemo da je ovaj broj blizu stvarnog
procenta zagadenja u spiralnim galaksijama.
Na primeru dva specicna slucaja, patuljastih galaksija Holmberg IX i NGC
185, pokazujemo da H
uks proizveden od strane ostataka supernovih, ali i drugih
objekata koji ne ukazuju na radanje zvezda, moze biti daleko veci, cak do deset puta,
od onog
uksa koji proizvode Hii regioni.In this dissertation we discuss in
uence of H emission from supernova remnants
(SNRs) on H derived star formation rates (SFRs). We present the detection of 16
optical SNR candidates in a part of nearby spiral galaxy IC342, and two more poten-
tial SNRs in NGC 185 galaxy. The candidates were detected by applying [S ii]/H
ratio criterion on observations made with the 2 m telescope at Rozhen National
Astronomical Observatory in Bulgaria. Also, in this dissertation we present the
most up-to-date list of nearby galaxies with optically detected SNRs. When deri-
ving H star formation rates, assumption is that the radiation is coming from the
ionized gas surrounding hot and young stars { Hii regions. In this case, emission
from SNRs contaminates H
ux used to derive SFR. We found that the contribu-
tion of SNRs'
ux to the total H
ux, for 18 galaxies in our sample of galaxies
with optical SNRs, is 5 5%. Due to the observational selection effects, the SNR
contamination of SFRs derived herein represents only a lower limit. M83 is the
galaxy with the most detected optical SNRs and in this galaxy SNRs account for
9 per cent of the total H emission. We expect that fraction similar to this would
be close to the real contribution of SNR emission to the total H emission in spiral
galaxies.
Using two dwarf galaxies as an example, Holmberg IX and NGC 185, we show
that the contamination of H
ux by SNRs, or other sources, can be much larger,
up to ten times higher than total H
ux coming from Hii regions of the observed
galaxy
Molecular mechanisms of metabolic regulation in hibernation and during cold-acclimation in European ground squirrel (Spermophilus citellus)
Fenomen hibernacije predstavlja fascinantan primer plastičnosti kod sisara. Hibernirajući sisari podliježu složenom nizu biohemijskih, fizioloških i bihevioralnih promjena u odgovoru na senzonske energetski-zahtijevne periode kuplovane sa redukovanom dopstupnošću hrane. Cilj disertacije je da se ispitaju promjene ćelijskog metabolizma u tkivima i organima tekunica, ključnim za održanje ukupne energetske homeostaze - mrko i bijelo masno tkivo (engl. brown adipose tissue, BAT i white adipose tissue, WAT), mišići i jetra, tokom perioda aklimacije na nisku temperaturu, kao i u fazi hibernacije.
Efekat aklimacije/hibernacije na metaboličko remodeliranje u tkivima i organima tekunica praćen je određivanjem: mitohondrijalnog kapaciteta (genska i/ili proteinska ekspresije komponenti respiratornog lanca i ATP sintaze); termogenog kapaciteta (ekspresija dekuplujućeg proteina 1); ekspresionih profila enzima ključnih metaboličkih puteva: glikolize, β-oksidacije, Krebsovog ciklusa, metabolizama triacilglicerola i glikogena. Ispitivani su i transkripcioni faktori uključeni u metaboličku regulaciju, kao i enzimi antioksidativne odbrane. Takođe, ispitivane su promjene u BAT i depoima WAT na strukturnom i ultrastrukturnom nivou.
Mužjaci evropske tekunice Spermophilus citellus su početkom septembra podijeljeni u dvije grupe: kontrolnu, koja je boravila na sobnoj temeraturi (22 ± 1 ºC) i grupu aklimiranu na nisku temperaturu (4 ± 1 ºC). Aktivne, eutermične tekunice, koje nisu ušle u duboku hibernaciju tokom aklimacije, žrtvovane su nakon 1, 3, 7, 12, odnosno 21 dan. Tekunice koje su ušle u hibernaciju žrtvovane su nakon 2-5 dana trajanja hibernacije (kontinuirana rektalna temperatura 4 ºC). BAT, subkutano, retroperitonealno i epididimalno WAT (sWAT, rWAT i eWAT), skeletni mišić (musculus quadriceps) i jetra su uzorkovani odmah po žrtvovanju. Kako bi se ispitali mehanizmi metaboličke regulacije u BAT, specifični za hibernatore, paralelno je rađena komparativna studija aklimacije pacova na nisku temperaturu...The phenomenon of hibernation is a fascinating example of plasticity in mammals. Hibernating mammals are subjected to a complex series of biochemical, physiological and behavioral changes in response to seasonal energy-demanding periods coupled with reduced food availability. The aim of the thesis was to investigate metabolic changes in the key tissues and organs of the ground squirrel, responsible for maintaining overall energy homeostasis - brown and white adipose tissue (BAT and WAT), skeletal muscle and liver, during the acclimation to low temperature, as well as in the hibernation.
Effects of acclimation/hibernation on metabolic remodeling in the tissues and organs of the ground squirrel were determined by: mitochondrial capacity (gene and/or protein expression of the components of the respiratory chain and ATP synthase); thermogenic capacity (uncoupling protein 1 content), the expression profile of the key metabolic enzymes involved in: glycolysis, β-oxidation, Krebs cycle, glycogen and triglycerides metabolism. Furthermore, transcription factors involved in the metabolic regulation, as well as antioxidant enzymes, were examined. In parallel, we examined the changes in BAT and WAT depots on the structural and ultrastructural level.
Males of the European ground squirrel Spermophilus citellus were divided into two groups in early September: the control group, kept at room temperature (22 ± 1 º C) and a group acclimated to low temperature (4 ± 1 ºC). Active, euthermic ground squirrels, which did not enter into deep hibernation during acclimation, were sacrificed after 1, 3, 7, 12, or 21 days. Ground squirrels that entered hibernation were sacrificed after 2-5 days of hibernation (continuous rectal temperature of 4 ºC). BAT, subcutaneous, retroperitoneal and epididimal WAT (sWAT, rWAT and eWAT), skeletal muscle (musculus quadriceps) and liver were sampled. Parallel, in order to examine the mechanisms of metabolic regulation in the BAT specific for hibernation, comparative study with rats acclimated to low temperatures, was made.
Results show that, when hibernating animals are exposed to low temperature, the cellular metabolism in all examined tissues/organs is initially subordinated to maintaining euthermia, i.e. thermogenic process. In the early period of the cold-exposure, shivering and nonshivering thermogenesis is induced in the muscle and BAT, respectively..
Spanish themes in the 1930s Yugoslav literary periodicals in the Serbo-Croatian speaking region ; Испанские темы в югославской литературной периодике традцатых годов двадцатого века на сербскохорватской языковой территории
У жижи светске, али и југословенске јавности тридесетих година
двадесетог века, нашли су се снажни утисци о друштвеним, политичким и
културним приликама у Другој шпанској републици, а потом и о сукобима и
страхотама Шпанског грађанског рата. Ова појава одразила се у великој мери на
периодику.
Све до тада код нас је перцепција Шпаније била претежно романтична и
површна. Писало се о њеном романтичном декору. Она је за многе била непозната
земља, те су информације о тадашњим тешким догађајима неретко постајале
предмет противречних и погрешних тумачења. Почетна претпоставка овог
истраживања јесте да је по обиму и интензитету присуства шпанских тема,
првенствено у књижевној периодици, то био јединствен период, односно
феномен, имајући у виду наше иначе недовољно развијене везе са Шпанијом и
слабу хиспанистичку традицију до тада...In the 1930s, the Yugoslav public shared a global fascination with the social,
political and cultural conditions in the Second Spanish Republic, and a keen interest in
the conflicts and atrocities of the Spanish Civil War. This fascination was largely
reflected in Yugoslav literary periodicals.
Until the 1930s, the perception of Spain in Yugoslavia was predominantly
romantic and superficial. It was an unfamiliar country for many, and the available
information about the ongoing conflict was often misunderstood and/or misinterpreted.
This research claims that this period was unique for the scope and intensity of the
presence of Spanish themes, primarily in the literary periodicals. It was a veritable
phenomenon, bearing in mind the otherwise underdeveloped ties with Spain and the
weak Hispanic tradition in Yugoslavia..
Revealing the nature of central emission nebulae in the dwarf galaxy NGC 185
In this paper we present new optical observations of the galaxy NGC 185
intended to reveal the status of supernova remnants (SNRs) in this dwarf
companion of the Andromeda galaxy. Previously, it was reported that this galaxy
hosts one SNR. Our deep photometric study with the 2m telescope at Rozhen
National Astronomical Observatory using narrow-band H and [SII] filters
revealed complex structure of the interstellar medium in the center of the
galaxy. To confirm the classification and to study the kinematics of the
detected nebulae, we carried out spectroscopic observations using the SCORPIO
multi-mode spectrograph at the 6m telescope at the Special Astrophysical
Observatory of the Russian Academy of Science, both in low- and high-resolution
modes. We also searched the archival X-ray and radio data for counterparts of
the candidate SNRs identified by our optical observations. Our observations
imply the presence of one more SNR, one possible HII region previously
cataloged as part of an SNR, and the presence of an additional source of shock
ionization in one low-brightness PN. We detected enhanced [SII]/H_alpha and
[NII]/H_alpha line ratios, as well as relatively high (up to 90 km s)
expansion velocities of the two observed nebulae, motivating their
classification as SNRs (with diameters of 45 pc and 50 pc), confirmed by both
photometric and spectral observations. The estimated electron density of
emission nebulae is 30 - 200 cm. Archival XMM-Newton observations
indicate the presence of an extended, low-brightness, soft source in projection
of one of the optical SNRs, whereas the archival VLA radio image shows weak,
unresolved emission in the center of NGC 185.Comment: 15 pages, 14 figures, accepted for publication in A&
Der klinische Befund der Mundhöhle bei Patienten mit chronischen Erkrankungen des Verdaungs- und Harnleitungsapparats
Klinički je analizirana usna šupljina 30 bolesnika s gastroduodenalnim ulkusom, odnosno hiperacidnim gastritisom, 20 bolesnika s cirozom jetre ili kroničnim hepatitisom, 21 bolesnika s bolesti žučnog mjehura i 65 bolesnika s kroničnim pijelonefritisom. Klinički nalazi u usnoj šupljini su komparirani s onima u kontrolnoj grupi, kojta se sastojala od 93 osobe. Ovim ispitivanjima bolesnika s gastroduodenalnom bolesti, statistički značajno je utvrđeno češće blijedilo sluznice tvrdog nepca, vjerojatno zbog anemije i krvarenja, koja su mnogi bolesnici imali. U ovih bolesnika je češće nađen i zubni kamenac. U bolesnika s bolesti holeciste nađene su statistički značajno češće nego u kontrolnoj grupi impresije na jeziku, kronični gingivitis, parodontopatija, a češći je bio i nalaz zubnog kamenca, što sve zahtijeva daljnja istraživanja eventualne veze ovih bolesti. U bolesnika koji boluju od kroničnog pijelonefritisa nađena je češće blijeda obrazna sluznica, vjerojatno zbog anemije, koja je postojala u mnogih ovih bolesnika.The clinical analysis of oral cavity in 30 patients with gastroduodenal ulcer and (or hyperacid gastritis), in 20 patients with liver cirrhosis or chronic hepatitis, in 21 patients with cholelithiasis and or cholecystitis, and in 65 patients with chronic pyelonephritis was analysed and compared with the findings in the control group consisting of 93 persons.On the basis of these examinations it was established that in patients with gastroduodenal diseases the paleness of mucosa on hard palate was significantly more frequent, probably because of bleeding ulcer which many of these patients suffered. In these patients dental calculus is also found more often than in the control group. In patients with cholecystic diseases, impressions on the tongue, chronic gingivitis, periodontopathia and dental calculus were found statistically more frequent than in the control group. These findings require a more detalied study of association of oral and cholecystic diseases. In patients who suffer from chronic pyelonephritis a pale bucal mucosa was found more frequent, probably due to anemia which existed in many of these patients.Es wurde die Mundhöhle klinisch analysiert bei 30 Patienten mit Magen-Darm-Geschwüren, bzw. hyperacider Gastritis, 20 Patienten mit Leberzyrrose oder chronischer Hepatitis, 21 Patienten mit Erkrankungen der Gallenblase und 65 Patienten mit chronischen Pyelonephritis. Der klinische Befund in der Mundhöhle wurde mit 93 Personen in der Kontrollgruppe verglichen. Auf Grund dieser Untersuchungen wurde bei Patienten mit Magen-Darmgeschwüren eine statistisch bedeutungsvolle Blässe der Schleimhaut des harten Gaumens, wahrscheinlich wegen Anaemie und Blutungen, nachgewiesen. Auch war der Zahnsteinbefund häufig. Bei Patienten mit Gallenblasener\u27krankungen waren Impressionen an der Zunge, chronische Zahnfleischentzündungen, Parodontopathien, und Zahnsteinbefund, viel häufiger als in der Kontrollgruppe, was weitere Untersuchungen über diese Beziehungen erfordert. Bei Patienten die an chronischer Pyelonephritis litten wurde häufig Blässe der Schleimhaut, in Zusammenhang mit der bestehenden Anämie, voraefunden
Risk Management of a Hydro Power Plant - Fracture Mechanics Approach
Risk management of a hydro power plant has been analysed from fracture mechanics point of view. The research is focused on the risk and integrity assessment of pressure equipment in a reversible hydro power plant in order to determine to what extent it poses a risk to Bajina Basta settlement and its inhabitants. The risk matrix has been used to assess risk level according to probability and consequence in a more descriptive way, whereas the failure assessment diagram has been used as an alternative engineering approach, including level II analysis
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