Where does the gas fueling star formation in BCGs originate?

We investigate the relationship between X-ray cooling and star formation in brightest cluster galaxies (BCGs). We present an X-ray spectral analysis of the inner regions, 10-40 kpc, of six nearby cool core clusters (z<0.35) observed with Chandra ACIS. This sample is selected on the basis of the high star formation rate (SFR) observed in the BCGs. We restrict our search for cooling gas to regions that are roughly cospatial with the starburst. We fit single- and multi-temperature mkcflow models to constrain the amount of isobarically cooling intracluster medium (ICM). We find that in all clusters, below a threshold temperature ranging between 0.9 and 3 keV, only upper limits can be obtained. In four out of six objects, the upper limits are significantly below the SFR and in two, namely A1835 and A1068, they are less than a tenth of the SFR. Our results suggests that a number of mechanisms conspire to hide the cooling signature in our spectra. In a few systems the lack of a cooling signature may be attributed to a relatively long delay time between the X-ray cooling and the star burst. However, for A1835 and A1068, where the X-ray cooling time is shorter than the timescale of the starburst, a possible explanation is that the region where gas cools out of the X-ray phase extends to very large radii, likely beyond the core of these systems.Comment: to appear in A&

Expressão gênica diferencial em fruto de Coffea arabica L. em diferentes estádios de desenvolvimento e maturação.

O cafeeiro arábica apresenta além da florada principal outras sucessivas floradas, o que resulta em uma maturação desuniforme dos frutos. A diferença de maturação entre e dentro de floradas, traz inconvenientes à colheita, tornando-a onerosa e prejudicando a qualidade final da bebida. Durante o processo de desenvolvimento e maturação dos frutos de café vários genes são ativados. O objetivo desse trabalho é então avaliar como os genes ?galactosidase e ?mannanase relacionados ao desenvolvimento e aturação dos frutos se comportam nas diferentes fases de maturação dos frutos. O datamining foi realizado utilizando-se seqüências dos genes ?galactosidase e ?mannanase de Coffea presentes no GenBank. Oligos gene específicos foram desenhados a partir das seqüências identificadas no Banco do Genoma Café. Análises do padrão de expressão demonstraram que transcritos correspondentes à galactosidase são observados a partir da fase de frutos em expansão e se mantém presentes até o estágio de fruto cereja. Já a expressão da ?mannanase é observada ao longo de todo o desenvolvimento do fruto, com um maior acúmulo na fase de frutos verdes. Estes resultados, apesar de representarem uma caracterização inicial do padrão de expressão em frutos, são essenciais para estabelecimento de parâmetros agronômicos e da metodologia para análise molecular em frutos de cultivares comerciais do IA

A textbook example of ram-pressure stripping in the Hydra A/A780 cluster

In the current epoch, one of the main mechanisms driving the growth of galaxy clusters is the continuous accretion of group-scale halos. In this process, the ram pressure applied by the hot intracluster medium on the gas content of the infalling group is responsible for stripping the gas from its dark-matter halo, which gradually leads to the virialization of the infalling gas in the potential well of the main cluster. Using deep wide-field observations of the poor cluster Hydra A/A780 with XMM-Newton and Suzaku, we report the discovery of an infalling galaxy group 1.1 Mpc south of the cluster core. The presence of a substructure is confirmed by a dynamical study of the galaxies in this region. A wake of stripped gas is trailing behind the group over a projected scale of 760 kpc. The temperature of the gas along the wake is constant at kT ~ 1.3 keV, which is about a factor of two less than the temperature of the surrounding plasma. We observe a cold front pointing westwards compared to the peak of the group, which indicates that the group is currently not moving in the direction of the main cluster, but is moving along an almost circular orbit. The overall morphology of the group bears remarkable similarities with high-resolution numerical simulations of such structures, which greatly strengthens our understanding of the ram-pressure stripping process

The evolving cluster cores: Putting together the pieces of the puzzle

In this work we address the issue of whether the division of clusters in cool cores (CCs) and non-cool cores (NCCs) is due to a primordial difference or to how clusters evolve across cosmic time. Our first goal is to establish if spectra from the central regions of a subclass of NCCs known as cool core remnants (CCRs) are consistent with having a small but significant amount of short cooling time gas, thereby allowing a transformation to CC systems on a timescale of a giga year. Our second goal is to determine if low ionization Fe lines emitted from this residual cool gas will be detectable by the calorimeters that will fly on board XRISM and ATHENA. We performed a spectral analysis of CCR systems with a multi temperature model and, assuming the different components to be in pressure equilibrium with one another, derived entropy and cooling time distributions for the X-ray emitting gas. We find that in most of our systems, the spectral model allows for a fraction of low entropy, short cooling time gas with a mass that is comparable to the one in CC systems. Moreover, simulations show that future spectrometers on board XRISM and ATHENA will have the power to directly resolve emission lines from the low temperature gas, thereby providing incontrovertible evidence for its presence. Within the scenario that we have explored, the constant fraction of CCs measured across cosmic time emerges from a dynamical equilibrium where CCs transformed in NCCs through mergers are balanced by NCCs that revert to CCs. Furthermore, CCs and NCCs should not be viewed as distinct sub classes, but as ``states" between which clusters can move.Comment: To appear in Astronomy & Astrophysic

Role of 0.4% glyceryl trinitrate ointment after haemorrhoidectomy: results of a prospective randomised study

INTRODUCTION: Conventional haemorrhoidectomy (CH) is well known to cause significant post-operative pain and delayed return to daily activities. Both surgical wounds and sphincterial apparatus spasms are likely responsible for the pain. In this study, we evaluated the role of glyceryl trinitrate ointment (GTN) in reducing post-operative pain, ameliorating wound healing and recovery after CH. PATIENTS AND METHODS: Between 01/08 and 12/11, 203 patients with symptomatic haemorrhoids were enrolled in the study and received (103 patients) or not (100 patients) 0.4 % GTN ointment for 6 weeks after surgery. Pain was assessed using a 10-cm linear visual analogue scale (VAS). Data on post-operative pain, wound secretion and bleeding, return to normal activities and complications were recorded. Data were analysed using Fisher's exact and Mann-Whitney tests. RESULTS: GTN-treated group experienced significantly less pain during the first week after surgery (p < 0.0001). This difference was more evident starting from post-operative day 4 (p < 0.0001). A significant higher percentage of untreated patients experienced severe pain (mean VAS score > 7) (10 % vs 31 %). There were significant differences in terms of secretion time (p = 0.0052) and bleeding time (p = 0.02) in favor of GTN. In addition, the duration of itching was less in the GTN group (p = 0.0145). Patients treated with GTN were able to an early return to daily activities compared to untreated (p < 0.0001). Fifteen GTN-treated patients (14.6 %) discontinued the application because of local discomfort and headache. CONCLUSIONS: GTN ointment enhances significantly post-operative recovery, reducing pain in terms of duration and intensity. This effect might be secondary to a faster wound healing expressed by reduced secretion, bleeding and itching time

AGN Feedback in Galaxy Groups: the Delicate Touch of Self-Regulated Outflows

AGN heating, through massive subrelativistic outflows, might be the key to solve the long-lasting `cooling flow problem' in cosmological systems. In a previous paper, we showed that cold accretion feedback and, to a lesser degree, Bondi self-regulated models are in fact able to quench cooling rates for several Gyr, at the same time preserving the mainc ool core features, like observed density and temperature profiles. Is it true also for lighter systems, such as galaxy groups? The answer is globally yes, although with remarkable differences. Adopting a modified version of the AMR code FLASH 3.2, we found that successful 3D simulations with cold and Bondi models are almost convergent in the galaxy group environment, with mechanical efficiencies in the range 5.e-4 - 1.e-3 and 5.e-2 - 1.e-1, respectively. The evolutionary storyline of galaxy groups is dominated by a quasi-continuous gentle injection with sub-Eddington outflows (with mechanical power and velocity around 1.e44 erg/s and 1.e4 km/s). The cold and hybrid accretion models present, in addition, very short quiescence periods, followed by moderate outbursts (10 times the previous phase), which generate a series of 10-20 kpc size cavities with high density contrast, temperatures similar to the ambient medium and cold rims. After shock heating, a phase of turbulence promotes gas mixing and diffusion of metals, which peak along jet-axis (up to 40 kpc) during active phases. At this stage the tunnel, produced by the enduring outflow (hard to detect in the mock SBx maps), is easily fragmented, producing tiny buoyant bubbles, typically a few kpc in size. In contrast to galaxy clusters, the AGN self-regulated feedback has to be persistent, with a `delicate touch', rather than rare and explosive strokes. This evolutionary difference dictates in the end that galaxy groups are not scaled-down versions of clusters.Comment: Accepted by MNRAS; 22 pages, 7 figure

Prevalence of Defaecatory Disorders in Morbidly Obese Patients Before and After Bariatric Surgery

BACKGROUND: The prevalence of obesity is increasing worldwide and has lately reached epidemic proportions in western countries. Several epidemiological studies have consistently shown that both overweight and obesity are important risk factors for the development of various functional defaecatory disorders (DDs), including faecal incontinence and constipation. However, data on their prevalence as well as effectiveness of bariatric surgery on their correction are scant. The primary objective of this study was to estimate the effect of morbid obesity on DDs in a cohort of patients listed for bariatric surgery. We also evaluated preliminary results of the effects of sleeve gastrectomy on these disorders. PATIENTS AND METHODS: A questionnaire-based study was proposed to morbidly obese patients having bariatric surgery. Data included demographics, past medical, surgical and obstetrics histories, as well as obesity related co-morbidities. Wexner Constipation Score (WCS) and the Faecal Incontinence Severity Index (FISI) questionnaires were used to evaluate constipation and incontinence. For the purpose of this study, we considered clinically relevant a WCS ≥5 and a FISI score ≥10. The same questionnaires were completed at 3 and 6 months follow-up after surgery. RESULTS: A total of 139 patients accepted the study and 68 underwent sleeve gastrectomy and fully satisfied our inclusion criteria with a minimum follow-up of 6 months. Overall, mean body mass index (BMI) at listing was 47 ± 7 kg/m(2) (range 35-67 kg/m(2)). Mean WCS was 4.1 ± 4 (range 0-17), while mean FISI score (expressed as mean±standard deviation) was 9.5 ± 9 (range 0-38). Overall, 58.9% of the patients reported DDs according to the above-mentioned scores. Twenty-eight patients (20%) had WCS ≥5. Thirty-five patients (25%) had a FISI ≥10 while 19 patients (13.7%) reported combined abnormal scores. Overall, DDs were more evident with the increase of obesity grade: Mean BMI decreased significantly from 47 ± 7 to 36 ± 6 and to 29 ± 4 kg/m(2) respectively at 3 and 6 months after surgery (p < 0.0001). According to the BMI decrease, the mean WCS decreased from 3.7 ± 3 to 3.1 ± 4 and to 1.6 ± 3 respectively at 3 and 6 months (p = 0.02). Similarly, the FISI score decreased from 10 ± 8 to 3 ± 4 and to 1 ± 2 respectively at 3 and 6 months (p = 0.0001). CONCLUSIONS: Defaecatory disorders are common in morbidly obese patients. The risk of DDs increases with BMI. Bariatric surgery reduces DDs, mainly faecal incontinence, and these findings correlated with BMI reduction