131 research outputs found
The Phase Space and Stellar Populations of Cluster Galaxies at z ~ 1: Simultaneous Constraints on the Location and Timescale of Satellite Quenching
We investigate the velocity vs. position phase space of z ~ 1 cluster
galaxies using a set of 424 spectroscopic redshifts in 9 clusters drawn from
the GCLASS survey. Dividing the galaxy population into three categories:
quiescent, star-forming, and poststarburst, we find that these populations have
distinct distributions in phase space. Most striking are the poststarburst
galaxies, which are commonly found at small clustercentric radii with high
clustercentric velocities, and appear to trace a coherent ``ring" in phase
space. Using several zoom simulations of clusters we show that the coherent
distribution of the poststarbursts can be reasonably well-reproduced using a
simple quenching scenario. Specifically, the phase space is best reproduced if
satellite quenching occurs on a rapid timescale (0.1 < tau_{Q} < 0.5 Gyr) after
galaxies make their first passage of R ~ 0.5R_{200}, a process that takes a
total time of ~ 1 Gyr after first infall. We compare this quenching timescale
to the timescale implied by the stellar populations of the poststarburst
galaxies and find that the poststarburst spectra are well-fit by a rapid
quenching (tau_{Q} = 0.4^{+0.3}_{-0.4} Gyr) of a typical star-forming galaxy.
The similarity between the quenching timescales derived from these independent
indicators is a strong consistency check of the quenching model. Given that the
model implies satellite quenching is rapid, and occurs well within R_{200},
this would suggest that ram-pressure stripping of either the hot or cold gas
component of galaxies are the most plausible candidates for the physical
mechanism. The high cold gas consumption rates at z ~ 1 make it difficult to
determine if hot or cold gas stripping is dominant; however, measurements of
the redshift evolution of the satellite quenching timescale and location may be
capable of distinguishing between the two.Comment: 10 pages, 4 figures, submitted to the Ap
The SAMI Galaxy Survey: the intrinsic shape of kinematically selected galaxies
Using the stellar kinematic maps and ancillary imaging data from the Sydney
AAO Multi Integral field (SAMI) Galaxy Survey, the intrinsic shape of
kinematically-selected samples of galaxies is inferred. We implement an
efficient and optimised algorithm to fit the intrinsic shape of galaxies using
an established method to simultaneously invert the distributions of apparent
ellipticities and kinematic misalignments. The algorithm output compares
favourably with previous studies of the intrinsic shape of galaxies based on
imaging alone and our re-analysis of the ATLAS3D data. Our results indicate
that most galaxies are oblate axisymmetric. We show empirically that the
intrinsic shape of galaxies varies as a function of their rotational support as
measured by the "spin" parameter proxy Lambda_Re. In particular, low spin
systems have a higher occurrence of triaxiality, while high spin systems are
more intrinsically flattened and axisymmetric. The intrinsic shape of galaxies
is linked to their formation and merger histories. Galaxies with high spin
values have intrinsic shapes consistent with dissipational minor mergers, while
the intrinsic shape of low-spin systems is consistent with dissipationless
multi-merger assembly histories. This range in assembly histories inferred from
intrinsic shapes is broadly consistent with expectations from cosmological
simulations.Comment: 15 pages, 11 figures, MNRAS in prin
Case report of an adolescent girl with Kabuki syndrome and kyphoscoliosis, resistant at the conservative orthopedic treatment
Children’s perception of visual and auditory ambiguity and its link to executive functions and creativity
The phenomenon of perceptual bistability provides insights into aspects of perceptual processing not normally accessible to everyday experience. However, most experiments have been conducted in adults, and it is not clear to what extent key aspects of perceptual switching change through development. The current research examined the ability of 6-, 8-, and 10-year-old children (N?=?66) to switch between competing percepts of ambiguous visual and auditory stimuli and links between switching rate, executive functions, and creativity. The numbers of switches participants reported in two visual tasks (ambiguous figure and ambiguous structure from motion) and two auditory tasks (verbal transformation and auditory streaming) were measured in three 60-s blocks. In addition, inhibitory control was measured with a Stroop task, set shifting was measured with a verbal fluency task, and creativity was measured with a divergent thinking task. The numbers of perceptual switches increased in all four tasks from 6 to 10?years of age but differed across tasks in that they were higher in the verbal transformation and ambigous structure-from-motion tasks than in the ambigous figure and auditory streaming tasks for all age groups. Although perceptual switching rates differed across tasks, there were predictive relationships between switching rates in some tasks. However, little evidence for the influence of central processes on perceptual switching was found. Overall, the results support the notion that perceptual switching is largely modality and task specific and that this property is already evident when perceptual switching emerges
Jarlmanns saga og Hermanns: A Translation
Agnete Lothʼs edition of the longer version of Jarlmanns saga og Hermanns included an accompanying English paraphrase (by Gillian Fellows Jensen), but there has never been a full translation into English, much less of the shorter version as edited by Hugo Rydberg. We rectify that omission here, providing a normalized text of Rydbergʼs edition with an English translation alongside in the hopes of making this entertaining saga more accessible to a wider audience
Round robin testing initiative for fiber reinforced polymer (FRP) reinforcement
An international Round Robin Testing (RRT) programme on FRP reinforcement was
conducted within the framework of the Marie Curie Research Training Network, ENCORE,
and with the support of Task Group 9.3 of the International Federation for
Structural Concrete (fib). Eleven laboratories and six manufacturers and suppliers
participated in this exercise. As part of this extensive experimental endeavour, one or more
of the following tests were performed by the participating laboratories: 1) tensile tests on
FRP bars and strips; 2) tensile tests on FRP laminates; 3) double bond shear tests on FRP
laminates (Externally Bonded Reinforcement, EBR) and FRP bars/strip (Near Surface
Mounted reinforcement, NSM). This paper will discusses the results of the RRT initiative,
among which the experimental results of bond tests on concrete specimens strengthened
with EBR and NSM FRP
Classic and modern in the therapy of hepatic hidatid cysts – experience of a general surgery center
Clinica II Chirurgie, Spitalul Județean de Urgențe ”Sf. Spiridon”, Iași UMF ”Gr.T. Popa” Iași, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011INTRODUCERE. În ultimii 20 de ani, asistăm la o tendință de afirmare a terapiilor mai puțin invazive pentru pacienții cu chist hidatic hepatic (radiologie intervențională, endoscopie intervențională, puncții eco sau CT-ghidate, tehnici chirurgicale laparoscopice precum şi asocieri ale acestora).
SCOP. Ne-am propus o comparație între rezultatele după abordul clasic şi cel minim-invaziv pentru tratamentul echinococozei hepatice. MATERIAL ŞI METODĂ. Au fost analizate retrospectiv 180 cazuri de chist hidatic hepatic operate în Clinica I Chirurgie Iaşi, România în perioada 2004-2010.
Au fost selectate pentru analiză următoarele variabile: localizarea chistului, tipul acestuia (conform clasificării propuse de Informal Working Group
on Echinococcosis), calea de abord, tehnica chirurgicală, durata evoluției postoperatorii, complicațiile survenite, recidivele şi asocierea chimioterapiei
antiparazitare. Pentru analiza statistică s-au folosit testele neparametrice Mann-Whitney U şi Spearman cu pragul de semnificație p<0.05. REZULTATE.
Leziunile s-au tratat prin puncție echoghidată (n=6;3.3%); pe cale laparoscopică (n= 48;26.6%) şi abord clasic (n=126;70.1%). Pe cale laparoscopică
s-au efectuat: inactivare-aspirație-drenaj şi inactivare-aspirație-perichistectomie parțială. Pe cale clasică s-au practicat: inactivare-aspirație-drenaj,
inactivare-aspirație-perichistectomie parțială, perichistectomie ideală, hepatectomie reglată, hepatectomie atipică. Abordul minim-invaziv se corelează
semnificativ cu tipul I-II al chisturilor (p=0.016) şi cu localizarea acestora în segmentele II, III şi VI (p=0.001). Durata evoluției postoperatorii a fost
semnificativ mai redusă după abordul laparoscopic (p=0.003) comparativ cu cea după intervențiile clasice „minimale” (inactivare-aspirație-drenaj
şi inactivare-aspirație-perichistectomie parțială) practicate pentru leziunile tip I-III, dar diferența dintre numărul de zile de îngrijiri după abordul
laproscopic vs. chirurgie radicală (perichistectomie ideală, hepatectomie) este nesemnificativă. Nu am întâlnit corelații semnificative între apariția
recidivelor/complicațiilor şi tipul de abord. Chimioterapia antiparazitară, instituită în 118 de cazuri (65.5%), se corelează semnificativ cu o rată redusă
a recidivelor survenite în 9 cazuri (5%). CONCLUZII. Boala hidatică beneficiază astăzi de o terapie multimodală în care chimioterapia, PAIR-ul, videochirurgia
şi chirurgia clasică trebuie să se completeze cât mai fericit şi nu să se excludă. Chiar dacă „pierde din indicații”, chirurgia clasică rămâne
„rezerva strategică” în terapia chistului hidatic.INTRODUCTION. In the last 20 years, we noticed an outstanding of less invasive therapy for the patients with hidatid disease (interventional radiology,
interventional endoscopy, eco- or CT punctions, laparoscopy and association between these). AIM. We intend to compare the results after classic
and laparoscopic approach as treatment for hepatic echinococcosis. METHODS. We analysed 180 cases operated in 1st Surgical Clinic, Iasi, Romania,
between 2004-200. We recorded the fallowing parameters: location, type (classification approved by Informal Working Group on Echinococcosis),
approaching type, surgical technique, postoperative evolution, complications, recurrences and chemotherapy. We used Mann-Whitney U and Spearman
tests (p<0.05).RESULTS. The cases were solved by eco guidance punction (n=6; 3.3%); laparoscopic (n= 48; 26.6%) and classic approach (n=126; 70.1%).
Minim invasive approach we did inactivation-suction-drainage and partial perichistectomy. Using open approach we did inactivation-suction-drainage,
partial perichistectomy, total perichistectomy and hepatectomy. Laparoscopic treatment has significant correlation with type I-II (p=0.016) located
in segments II, III and IV (p=0.001). Postoperative evolution is significant lower for laparoscopic methods (p=0.003) comparing with the „minimal”
open techniques used for lesions type I-III. There is no significant differentiation between laparoscopic procedures and open radical surgery (total
perichistectomy and hepatectomy). We did not register significant correlations about recurrences and complications. Chemotherapy used in 8 cases is
correlated with a low rate of recurrence 9 cases (5%).CONCLUSIONS. Hidatid disease has the benefits of a multimodal therapy. Chemotherapy, PAIR,
video surgery and open approach are completing themselves and not excluding each other. Even if classic methods are less frequent used, it remains
as a „back up solution” in the therapy of hidatid cyst disease
Can we detect ecosystem critical transitions and signals of changing resilience from paleo-ecological records?
Nonlinear responses to changing external pressures are increasingly studied in real-world ecosystems. However, as many of the changes observed by ecologists extend beyond the monitoring record, the occurrence of critical transitions, where the system is pushed from one equilibrium state to another, remains difficult to detect. Paleo-ecological records thus represent a unique opportunity to expand our temporal perspective to consider regime shifts and critical transitions, and whether such events are the exception rather than the rule. Yet, sediment core records can be affected by their own biases, such as sediment mixing or compression, with unknown consequences for the statistics commonly used to assess regime shifts, resilience, or critical transitions. To address this shortcoming, we developed a protocol to simulate paleolimnological records undergoing regime shifts or critical transitions to alternate states and tested, using both simulated and real core records, how mixing and compression affected our ability to detect past abrupt shifts. The smoothing that is built into paleolimnological data sets apparently interfered with the signal of rolling window indicators, especially autocorrelation. We thus turned to time-varying autoregressions (online dynamic linear models, DLMs; and time-varying autoregressive state-space models, TVARSS) to evaluate the possibility of detecting regime shifts and critical transitions in simulated and real core records. For the real cores, we examined both varved (annually laminated sediments) and non-varved cores, as the former have limited mixing issues. Our results show that state-space models can be used to detect regime shifts and critical transitions in some paleolimnological data, especially when the signal-to-noise ratio is strong. However, if the records are noisy, the online DLM and TVARSS have limitations for detecting critical transitions in sediment records
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