1,289 research outputs found
Multiple tidal disruption flares in the active galaxy IC 3599
Tidal disruption events occur when a star passes too close to a massive black
hole and it is totally ripped apart by tidal forces. It may also happen that
the star is not close enough to the black hole to be totally disrupted and a
less dramatic event might happen. If the stellar orbit is bound and highly
eccentric, just like some stars in the centre of our own Galaxy, repeated
flares should occur. When the star approaches the black hole tidal radius at
periastron, matter might be stripped resulting in lower intensity outbursts
recurring once every orbital period. We report on Swift observations of a
recent bright flare from the galaxy IC 3599 hosting a middle-weight black hole,
where a possible tidal disruption event was observed in the early 1990s. By
light curve modelling and spectral fitting we can consistently account for the
events as the non-disruptive tidal stripping of a star into a highly eccentric
orbit. The recurrence time is 9.5 yr. IC 3599 is also known to host a
low-luminosity active galactic nucleus. Tidal stripping from this star over
several orbital passages might be able to spoon-feed also this activity.Comment: Accepted for publication to Astronomy & Astrophysic
Older adults report moderately more detailed autobiographical memories
Autobiographical memory (AM) is an essential component of the human mind. Although the([A-z]+) amount and types of subjective detail (content) that compose AMs constitute important dimensions of recall, age-related changes in memory content are not well characterized. Previously, we introduced the Cue-Recalled Autobiographical Memory test (CRAM; see http://cramtest.info), an instrument that collects subjective reports of AM content, and applied it to college-aged subjects. CRAM elicits AMs using naturalistic word-cues. Subsequently, subjects date each cued AM to a life period and count the number of remembered details from specified categories (features), e.g., temporal detail, spatial detail, persons, objects, and emotions. The current work applies CRAM to a broad range of individuals (18–78 years old) to quantify the effects of age on AM content. Subject age showed a moderately positive effect on AM content: older compared with younger adults reported ∼16% more details (∼25 vs. ∼21 in typical AMs). This age-related increase in memory content was similarly observed for remote and recent AMs, although content declined with the age of the event among all subjects. In general, the distribution of details across features was largely consistent among younger and older adults. However, certain types of details, i.e., those related to objects and sequences of events, contributed more to the age effect on content. Altogether, this work identifies a moderate age-related feature-specific alteration in the way life events are subjectively recalled, among an otherwise stable retrieval profile
Metastatic breast cancer patients treated with low-dose metronomic chemotherapy with cyclophosphamide and celecoxib: clinical outcomes and biomarkers of response
Background
Preclinical results showing therapeutic effect and low toxicity of metronomic chemotherapy with cyclophosphamide (Cy) + celecoxib (Cel) for mammary tumors encouraged its translation to the clinic for treating advanced breast cancer patients (ABCP).
Patients and methods
A single-arm, mono-institutional, non-randomized, phase II, two-step clinical trial (approved by Bioethics Committee and Argentine Regulatory Authority) was designed. Patients received Cy (50 mg po.d) + Cel (200 mg p.o.bid). Patient eligibility criteria included: ABCP who progressed to anthracyclines, taxanes and capecitabine, ≤4 chemotherapy schemes, with good performance status. Several pro- and anti-angiogenic molecules and cells were determined as biomarkers. Informed consent was signed by all patients. Primary endpoint was clinical benefit (CB).
Results
Twenty patients were enrolled. Main clinical outcomes were prolonged disease stabilization and partial remission in 10/20 and 1/20 patients, respectively. CB was 55 %, and time to progression (TTP) was 21.1 weeks. Median TTP in patients who achieved CB was 35.6 weeks, and mean overall survival was 44.20 weeks. There were no grade 3/4 toxicities associated with treatment. Circulating endothelial cells (CECs) increased at the time of progression in patients who showed CB (P = 0.014). Baseline CECs and circulating endothelial progenitor cells showed marginal associations with TTP. Serum VEGF decreased (P = 0.050), sVEGFR-2 increased (P = 0.005) and VEGF/sVEGFR-2 ratio decreased during treatment (P = 0.041); baseline VEGF and VEGF/sVEGFR-2 were associated with TTP (P = 0.035 and P = 0.030, respectively), while sVEGFR-2 did not.
Conclusions
Treatment was effective, showing low toxicity profile and excellent tolerability. The combination had anti-angiogenic effect. Increased levels of CEC could be useful for detecting progression. Baseline VEGF and VEGF/sVEGFR-2 values could be useful as early predictors of response.
Trial registration
ANMAT#4596/09.Fil: Perroud, Herman A. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; ArgentinaFil: Alasino, Carlos María. Institute of Oncology of Rosario; ArgentinaFil: Rico, María José. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; ArgentinaFil: Mainetti, Leandro Ernesto. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; ArgentinaFil: Queralt, Francisco. Institute of Oncology of Rosario; ArgentinaFil: Pezzotto, Stella Maris. Research Council of the National University of Rosario (CIUNR); ArgentinaFil: Rozados, Viviana R. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; ArgentinaFil: Scharovsky, O. Graciela. Universidad Nacional de Rosario. Consejo de Investigaciones UNR, Facultad de Ciencias Médicas; Argentin
Clostridium difficile infection in children: epidemiology and risk of recurrence in a low-prevalence country
Clostridium difficile infection (CDI) is increasingly found in children worldwide, but limited data are available from children living in southern Europe. A 6-year retrospective study was performed to investigate the epidemiology, clinical features, treatment, and risk of recurrence in Italy. Data of children with community- and hospital-acquired CDI (CA-CDI and HA-CDI, respectively) seen at seven pediatric referral centers in Italy were recorded retrospectively. Annual infection rates/10,000 hospital admissions were calculated. Logistic regression was used to investigate risk factors for recurrence. A total of 177 CDI episodes was reported in 148 children (83 males, median age 55.3 months), with a cumulative infection rate of 2.25/10,000 admissions, with no significant variability over time. The majority of children (60.8 %) had CA-CDI. Children with HA-CDI (39.2 %) had a longer duration of symptoms and hospitalization (p = 0.003) and a more common previous use of antibiotics (p = 0.0001). Metronidazole was used in 70.7 % of cases (87/123) and vancomycin in 29.3 % (36/123), with similar success rates. Recurrence occurred in 16 children (10.8 %), and 3 (2 %) of them presented a further treatment failure. The use of metronidazole was associated with a 5-fold increase in the risk of recurrence [odds ratio (OR) 5.18, 95 % confidence interval (CI) 1.1-23.8, p = 0.03]. Short bowel syndrome was the only underlying condition associated with treatment failure (OR 5.29, 95 % CI 1.17-23.8, p = 0.03). The incidence of pediatric CDI in Italy is low and substantially stable. In this setting, there is a limited risk of recurrence, which mainly concerns children treated with oral metronidazole and those with short bowel syndrome
The data processing pipeline for the Herschel SPIRE Fourier Transform Spectrometer
We present the data processing pipeline to generate calibrated data products from the Spectral
and Photometric Imaging Receiver (SPIRE) imaging Fourier Transform Spectrometer on the
Herschel Space Observatory. The pipeline processes telemetry from SPIRE observations and
produces calibrated spectra for all resolution modes. The spectrometer pipeline shares some
elements with the SPIRE photometer pipeline, including the conversion of telemetry packets
into data timelines and calculation of bolometer voltages.We present the following fundamental
processing steps unique to the spectrometer: temporal and spatial interpolation of the scan
mechanism and detector data to create interferograms; Fourier transformation; apodization;
and creation of a data cube. We also describe the corrections for various instrumental effects
including first- and second-level glitch identification and removal, correction of the effects
due to emission from the Herschel telescope and from within the spectrometer instrument,
interferogram baseline correction, temporal and spatial phase correction, non-linear response
of the bolometers, and variation of instrument performance across the focal plane arrays.
Astronomical calibration is based on combinations of observations of standard astronomical
sources and regions of space known to contain minimal emission
Vegetation trajectories in proglacial primary successions within Gran Paradiso National Park: A comparison between siliceous and basic substrates
PATTERNS OF α AND β-DIVERSITY HIGHLIGHT UNIQUENESS-BASED CONSERVATION PRIORITIES FOR PLANT COMMUNITIES IN ITALIAN AGRICULTURAL LANDSCAPES
Impact of RFID and EPCglobal on Critical Processes of the Pharmaceutical Supply Chain
The need to implement and guarantee effective item-level tracing systems is becoming more and more important for a wide range of business applications, such as manufacturing, logistics, healthcare, and anti-counterfeiting. Among these, the pharmaceutical supply chain, with millions of medicines moving around the world and needing to be traced at item level, represents a very interesting reference scenario. Furthermore, the growing counterfeiting problem raises a significant threat within the supply chain system. Recently, several international institutions (e.g. Food and Drug Administration, European Medicines Agency, European Federation of Pharmaceutical Industries and Associations, GS1) are encouraging the use of innovative solutions in healthcare and in the pharmaceutical supply chain, to improve patient safety and enhance the efficiency of the pharmaceutical supply chain, with better worldwide drug traceability
Relative importance of topography, climate, species composition, and phenology in affecting forage yield and quality in alpine summer pastures
- …
