412 research outputs found
Spectroscopic identification of a redshift 1.55 supernova host galaxy from the Subaru Deep Field Supernova Survey
Context: The Subaru Deep Field (SDF) Supernova Survey discovered 10 Type Ia
supernovae (SNe Ia) in the redshift range 1.5<z<2.0, as determined solely from
photometric redshifts of the host galaxies. However, photometric redshifts
might be biased, and the SN sample could be contaminated by active galactic
nuclei (AGNs).
Aims: We aim to obtain the first robust redshift measurement and
classification of a z > 1.5 SDF SN Ia host galaxy candidate
Methods: We use the X-shooter (U-to-K-band) spectrograph on the Very Large
Telescope to allow the detection of different emission lines in a wide spectral
range.
Results: We measure a spectroscopic redshift of 1.54563 +/- 0.00027 of
hSDF0705.25, consistent with its photometric redshift of 1.552 +/- 0.018. From
the strong emission-line spectrum we rule out AGN activity, thereby confirming
the optical transient as a SN. The host galaxy follows the fundamental
metallicity relation defined in Mannucci et al. (2010, 2011) showing that the
properties of this high-redshift SN Ia host galaxy is similar to other field
galaxies.
Conclusions: Spectroscopic confirmation of additional SDF SN hosts would be
required to confirm the cosmic SN rate evolution measured in the SDF.Comment: 14 pages, 2 figures, Accepted A&A Upload of the Journal versio
Universality of Long-Range Correlations in Expansion-Randomization Systems
We study the stochastic dynamics of sequences evolving by single site
mutations, segmental duplications, deletions, and random insertions. These
processes are relevant for the evolution of genomic DNA. They define a
universality class of non-equilibrium 1D expansion-randomization systems with
generic stationary long-range correlations in a regime of growing sequence
length. We obtain explicitly the two-point correlation function of the sequence
composition and the distribution function of the composition bias in sequences
of finite length. The characteristic exponent of these quantities is
determined by the ratio of two effective rates, which are explicitly calculated
for several specific sequence evolution dynamics of the universality class.
Depending on the value of , we find two different scaling regimes, which
are distinguished by the detectability of the initial composition bias. All
analytic results are accurately verified by numerical simulations. We also
discuss the non-stationary build-up and decay of correlations, as well as more
complex evolutionary scenarios, where the rates of the processes vary in time.
Our findings provide a possible example for the emergence of universality in
molecular biology.Comment: 23 pages, 15 figure
Sublimation and deposition in gaseous mixtures
The sublimation and deposition behaviors of the Helium-Argon mixture is analyzed numerically in the temperature range where Helium is only in gaseous state while Argon can sublimate and deposit on its own solid phase. The McCormack model is implemented to model the Boltzmann collision term. Three kinds of potential are used for simulation of the intermolecular collisions: Hard Sphere, Lennard-Jones potential, and ab initio. The matrices of the kinetic coefficients have been obtained for different values of the rarefaction parameters and molar fraction of non-sublimating gas. The influence of the intermolecular potential on the kinetic coefficients as well as on the gas macroscopic profiles has been analyzed. © 2020 Elsevier LtdThe work of A. Polikarpov was financially supported by the Ministry of Science and Higher Education of the Russian Federation, the research project no. FEUZ-2020-0057. I. Graur would like to acknowledge the financial support provided by the European Union network program H2020, MIGRATE project under Grant Agreement No. 643095. F. Sharipov acknowledges the Brazilian Agency CNPq for the support of his research, grant 304831/2018-2
Perioperative management of patients undergoing pancreaticoduodenectomies (PD). Surgical clinic no. III Cluj expertise
Clinica Chirurgie III, Institutul Regional de Gastroenterologie si Hepatologie, UMF “Iuliu Hatieganu” Cluj-Napoca, România, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și
al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: În 2009, în Clinica Chirurgie III Cluj-Napoca a fost introdus un protocol care cuprinde aspecte legate de pregătirea
preoperatorie a pacienților pentru DPC, de tactica și tehnica intraoperatorie, și tratament postoperator.
Material si metode: Studiul înrolează 444 pacienti cu DPC operați în clinica între 2009-2018, împărțiți în două loturi: 2009-2015 și
2016-2018. Au fost urmăriți factorii incriminați în apariția principalelor complicații postoperatorii, rezultatele fiind comparate cu cele
obținute înainte de 2009. Informaţiile s-au colectat utilizând Excel 2009, analiza statistică efectuandu-se cu software-ul R v3.2.4.
Rezultate: Nu am obtinut reducerea semnificativă a morbidității (53% înainte de 2009, 45,6% între 2009-2015 și 42% între 2016-
2018), însă a scăzut rata de apariție a fistulei pancreatice (de la 10% la 9,06%, respectiv 7,5%) și a stazei gastrice (de la 43% la
20,47%, respectiv 12,8%). Hemoragia bontului pancreatic a apărut mai frecvent (de la 2%, la 6,71%, respectiv 7,2%). Mortalitatea s-a
redus semnificativ (de la 11,9%, la 6,04%, respectiv 3,99%), datorită scăderii fistulelor pancreatice grad C.
Concluzie: Implementarea protocolului de pregătire a DPC și-a dovedit utilitatea, iar preocuparea de îmbunătațire a acestuia, prin
adaptarea la literatură și la propria experiență rămâne o prioritate.Introduction: In 2009, a protocol was introduced at the Surgical Clinic III Cluj-Napoca, which included aspects related to preoperative
preparation of patients for PD, intraoperative tactics and technique, and postoperative treatment.
Material and Method: The study includes 444 patients with PD operated in the clinic between 2009-2018, divided into two batches:
2009-2015 and 2016-2018. We followed the factors involved in the occurrence of the main postoperative complications and the results
were compared with those we obtained before 2009. The information was collected using Excel 2009, the statistical analysis being
performed with the software R v3.2.4.
Results: We have not achieved a significant decrease in morbidity (53% before 2009, 45.6% between 2009-2015 and 42% between
2016-2018), but decreased the rate of pancreatic fistula (from 10% to 9, 06% and 7.5% respectively) and gastric stasis (from 43% to
20.47% and 12.8% respectively). Pancreas bleeding occurred more frequently (from 2% to 6.71% and 7.2%, respectively). Mortality
was significantly reduced (from 11.9% to 6.04% and 3.99%, respectively) due to the reduce rate of grade C pancreatic fistulae.
Conclusion: Implementation of the protocol has proven useful and the concern for improvement by adapting it to literature and our
experience remains a priority
Classic vs laparoscopic approach in colorectal cancer. Experience of a tertiary center, Surgery No 3 Clinic, Cluj-Napoca
Clinica Chirurgie 3, Cluj-Napoca, România, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: Cancerul colorectal este unul dintre cele mai frecvente cancere și cu tendință în creștere la nivel global. Majoritatea
studiilor recente au demonstrat non inferioritatea și chiar o ușoară superioritate în abordul laparoscopic prin prisma rezultatelor
obținute și a supraviețuirii la distanță.
Material și metode: Au fost selectate retrospectiv 2186 de cazuri din baza de date completată prospectiv a Clinicii Chirurgie 3 pentru
perioada ian 2013-dec 2018 (6 ani). Din acestea s-au exclus 76 cazuri laparoscopie/laparotomie exploratorie, 154 cazuri colostomii, 51 derivații interne; în final au fost analizate 1905 cazuri de cancer colorectal.
Rezultate: Din 1905 cazuri s-au efectuat rezecții laparoscopice la un număr de 310 (16.27%) și clasice la un număr de 1595 cazuri
(83.73%). Au fost analizați între cele două loturi următorii parametri: pregătire preoperatorie, durata operației, pierderi sangvine,
complicații postoperatorii (fistulă, abces, hemoragie, ocluzie, complicații generale), supurații de plagă, zile spitalizare, necesar
antibiotic, mobilizare postoperatorie, mortalitate.
Concuzii: Abordul laparoscopic prezintă avantaje privind recuperarea postoperatorie, pierderi sangvine, zile spitalizare, necesar
antialgice/antibiotic, lipsa supurațiilor de plagă. Dezavantajele sunt curba de învățare, aparatura specifică și dificultatea păstrării
principiilor oncologice.Introduction: Colorectal cancer remains one of the most frequently diagnosed malignant pathologies with a continuously increasing
rate worldwide. Most of the recent studies have shown the non-inferiority and slight superiority in the laparoscopic approach through
obtained results.
Material and methods: 2186 cases were selected retrospectively from a prospectively completed database of the Surgical no 3
Clinic in Cluj-Napoca over the course of 6 years (ian 2013 – dec 2018). Out of these cases, 76 cases were excluded for exploratory
laparoscopy/laparotomy, 154 which underwent only colostomy, and 51 which underwent internal derivation. At the end of the study,
1905 cases were eligible.
Results: Out of 1905 cases, 310 underwent a laparoscopic approach (16.27%) and 1595 cases underwent a classic approach (83.73%).
Between the two approaches, a series of parameters were analyzed: preoperative care, duration of the surgery, intraoperative blood
loss, postoperative complications (fistula, abscess, hemorrhage, occlusion, general complications), antibiotic necessity, postoperative
mobilization, mortality, prevalence of surgical site infection.
Conclusions: The laparoscopic approach proves many advantages regarding postoperative care, blood loss, hospitalization care,
necessity of antibiotics and painkillers, and surgical site infection, cosmetic advantages. Disadvantages are the learning curve, specific
instruments requirements, difficulty of maintaining the oncology principles
Laparoscopic rectal resections: practical aspects
Abordul laparoscopic in chirurgia cancerului de rect este o considerat standardul de aur ce ofera rezultate oncologice similar cu o
recuperare postoperatorie imbunatatita, si o rata minimala de complicatii. Pe fondul complexitatii crescute, cu toate astea, abordul
laparoscopic ar trebui efectuat in centre tertiare, fiind rezervat chirurgilor cu o curba de invatare adecvata. O selectie atenta a cazurilor
si o planificare adecvata ar trebui luata in considerare in cadrul acestui abord. Prezentarea de fata surprinde aspectele practice de
baza precum si variatii tatice in cadrul rezectiilor de rect laparoscopice, precum si pasii potentiali in atingerea curbei de invatare.Laparoscopic approach is an already established procedure in rectal cancer which offers a similar oncological outcome, with improved
postoperative recovery and fewer complications. Due to its increased complexity, however, the laparoscopic approach should be
reserved for high-volume centers and for experienced surgeons with an adequate learning curve. Appropriate patient selection and
planning must be carefully considered when opting for this approach. In this presentation, the primary practical aspects as well as
certain tactical approaches will be covered regarding the laparoscopic rectal resections as well as the potential steps in achieving the
learning curve
Multi-Epoch Spectroscopy of Dwarf Galaxies with AGN Signatures: Identifying Sources with Persistent Broad H Α Emission
We use time-domain optical spectroscopy to distinguish between broad emission lines powered by accreting black holes (BHs) or stellar processes (i.e., supernovae) for 16 galaxies identified as AGN candidates by Reines \etal (2013). Our study is primarily focused on those objects with narrow emission-line ratios dominated by star formation. Based on follow-up spectra taken with the Magellan Echellette Spectrograph (MagE), the Dual Imaging Spectrograph, and the Ohio State Multi-Object Spectrograph, we find that the broad Hα emission has faded or was ambiguous for all of the star-forming objects (14/16) over baselines ranging from 5 to 14 years. For the two objects in our follow-up sample with narrow-line AGN signatures (RGG 9 and RGG 119), we find persistent broad Hα emission consistent with an AGN origin. Additionally, we use our MagE observations to measure stellar velocity dispersions for 15 objects in the Reines et al. (2013) sample, all with narrow-line ratios indicating the presence of an AGN. Stellar masses range from ∼5×108 to 3×109~\msun, and we measure σ∗ ranging from 28−71 km s−1. These σ∗ correspond to some of the lowest-mass galaxies with optical signatures of AGN activity. We show that RGG 119, the one object which has both a measured σ∗ and persistent broad Hα emission, falls near the extrapolation of the MBH−σ⋆ relation to the low-mass end
Multi-Epoch Spectroscopy of Dwarf Galaxies with AGN Signatures: Identifying Sources with Persistent Broad H Α Emission
We use time-domain optical spectroscopy to distinguish between broad emission lines powered by accreting black holes (BHs) or stellar processes (i.e., supernovae) for 16 galaxies identified as AGN candidates by Reines \etal (2013). Our study is primarily focused on those objects with narrow emission-line ratios dominated by star formation. Based on follow-up spectra taken with the Magellan Echellette Spectrograph (MagE), the Dual Imaging Spectrograph, and the Ohio State Multi-Object Spectrograph, we find that the broad Hα emission has faded or was ambiguous for all of the star-forming objects (14/16) over baselines ranging from 5 to 14 years. For the two objects in our follow-up sample with narrow-line AGN signatures (RGG 9 and RGG 119), we find persistent broad Hα emission consistent with an AGN origin. Additionally, we use our MagE observations to measure stellar velocity dispersions for 15 objects in the Reines et al. (2013) sample, all with narrow-line ratios indicating the presence of an AGN. Stellar masses range from ∼5×108 to 3×109~\msun, and we measure σ∗ ranging from 28−71 km s−1. These σ∗ correspond to some of the lowest-mass galaxies with optical signatures of AGN activity. We show that RGG 119, the one object which has both a measured σ∗ and persistent broad Hα emission, falls near the extrapolation of the MBH−σ⋆ relation to the low-mass end
Multi-Epoch Spectroscopy of Dwarf Galaxies with AGN Signatures: Identifying Sources with Persistent Broad H Α Emission
We use time-domain optical spectroscopy to distinguish between broad emission lines powered by accreting black holes (BHs) or stellar processes (i.e., supernovae) for 16 galaxies identified as AGN candidates by Reines \etal (2013). Our study is primarily focused on those objects with narrow emission-line ratios dominated by star formation. Based on follow-up spectra taken with the Magellan Echellette Spectrograph (MagE), the Dual Imaging Spectrograph, and the Ohio State Multi-Object Spectrograph, we find that the broad Hα emission has faded or was ambiguous for all of the star-forming objects (14/16) over baselines ranging from 5 to 14 years. For the two objects in our follow-up sample with narrow-line AGN signatures (RGG 9 and RGG 119), we find persistent broad Hα emission consistent with an AGN origin. Additionally, we use our MagE observations to measure stellar velocity dispersions for 15 objects in the Reines et al. (2013) sample, all with narrow-line ratios indicating the presence of an AGN. Stellar masses range from ∼5×108 to 3×109~\msun, and we measure σ∗ ranging from 28−71 km s−1. These σ∗ correspond to some of the lowest-mass galaxies with optical signatures of AGN activity. We show that RGG 119, the one object which has both a measured σ∗ and persistent broad Hα emission, falls near the extrapolation of the MBH−σ⋆ relation to the low-mass end
SN Refsdal: Classification as a Luminous and Blue SN 1987A-like Type II Supernova
We have acquired Hubble Space Telescope (HST) and Very Large Telescope
near-infrared spectra and images of supernova (SN) Refsdal after its discovery
as an Einstein cross in Fall 2014. The HST light curve of SN Refsdal matches
the distinctive, slowly rising light curves of SN 1987A-like supernovae (SNe),
and we find strong evidence for a broad H-alpha P-Cygni profile in the HST
grism spectrum at the redshift (z = 1.49) of the spiral host galaxy. SNe IIn,
powered by circumstellar interaction, could provide a good match to the light
curve of SN Refsdal, but the spectrum of a SN IIn would not show broad and
strong H-alpha absorption. From the grism spectrum, we measure an H-alpha
expansion velocity consistent with those of SN 1987A-like SNe at a similar
phase. The luminosity, evolution, and Gaussian profile of the H-alpha emission
of the WFC3 and X-shooter spectra, separated by ~2.5 months in the rest frame,
provide additional evidence that supports the SN 1987A-like classification. In
comparison with other examples of SN 1987A-like SNe, SN Refsdal has a blue B-V
color and a high luminosity for the assumed range of potential magnifications.
If SN Refsdal can be modeled as a scaled version of SN 1987A, we estimate it
would have an ejecta mass of 20+-5 solar masses. The evolution of the light
curve at late times will provide additional evidence about the potential
existence of any substantial circumstellar material (CSM). Using MOSFIRE and
X-shooter spectra, we estimate a subsolar host-galaxy metallicity (8.3+-0.1 dex
and <8.4 dex, respectively) near the explosion site.Comment: Submitted to ApJ; 26 page
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