4,649 research outputs found
Clumpy streams in a smooth dark halo: the case of Palomar 5
By means of direct N-body simulations and simplified numerical models, we
study the formation and characteristics of the tidal tails around Palomar 5,
along its orbit in the Milky Way potential. Unlike previous findings, we are
able to reproduce the substructures observed in the stellar streams of this
cluster, without including any lumpiness in the dark matter halo. We show that
overdensities similar to those observed in Palomar 5 can be reproduced by the
epicyclic motion of stars along its tails, i.e. a simple local accumulation of
orbits of stars that escaped from the cluster with very similar positions and
velocities. This process is able to form stellar clumps at distances of several
kiloparsecs from the cluster, so it is not a phenomenon confined to the inner
part of Palomar 5's tails, as previously suggested. Our models can reproduce
the density contrast between the clumps and the surrounding tails found in the
observed streams, without including any lumpiness in the dark halo, suggesting
new upper limits on its granularity.Comment: 6 pages, 7 figures. A&A Letters, accepted. Top panel of Fig. A1
replaced, minor typos corrected. High resolution version available at
http://mygepi.obspm.fr/~paola/Pal5
Management of Intra-abdominal Infections due to Carbapenemase-Producing Organisms.
The prevalence of bacterial resistance to carbapenem antibiotics continues to increase because of bacteria producing metallo-β-lactamases (MBL), called carbapenemase-producing organisms (CPO). Enterobacteriaceae, which can be a common cause of intra-abdominal infections (IAIs), have become carbapenem-resistant Enterobacteriaceae (CRE). Updated international guidelines for the treatment of both IAIs and IAIs due to CRE have been published. Given the multifaceted nature of these infections, these recommendations have been jointly reviewed and endorsed by the Surgical Society and the Association of Medical Microbiology and Infectious Disease. The aims of this review are to summarize the general and new generation of multimodal procedure to manage IAIs due to CRE and review the data available on the combination of interventions to reduce CRE. Future research should focus on the development of novel and safe antimicrobial therapies and the quantification of the incremental effect of infection control programmes and new methods to rapidly detect pathogens before patients enter the surgical settin
Suggestive evidence of a multi-cytokine resistin pathway in humans and its role on cardiovascular events in high-risk individuals
In cells and tissues resistin affects IL-1β, IL-6, IL-8, IL-12 and TNF-α expression, thus suggesting the existence of a multi-cytokine "resistin pathway". We investigated whether such pathway does exist in humans and, if so, if it is associated with cardiovascular risk factors and with major adverse cardiovascular events (MACE). Serum cytokines were measured in 280 healthy subjects from the Gargano Study 2 (GS2) whose BMI, waist circumference, HOMA IR, triglycerides, HDL-cholesterol, systolic and diastolic blood pressure data were available and in 353 patients with type 2 diabetes and coronary artery disease from the Gargano Heart Study (GHS)-prospective design (follow-up 5.4 ± 2.5 years; 71 MACE). In GS2, cytokines mRNA levels in white blood cells were also measured. In GS2, resistin mRNA was correlated with all cytokines expression (all p < 0.001), but IL-12B. Consistently, serum resistin was correlated with all serum cytokines (all p < 0.001), but IL-12. Expression (eRPS) and serum (sRPS) resistin pathway scores (excluding IL-12) were each other correlated (p < 0.001) and both associated with cardiovascular risk factors (all p < 0.01). In GHS, sRPS was independently associated with MACE (HR = 1.44, 95% CI = 1.10-1.90). Our data indicate the existence of a resistin pathway, which is associated with cardiovascular risk factors and which strongly and independently predicts MACE
TLR4 and TLR9 Expression in Different Phenotypes of Rhinitis
Background. Toll-like receptors (TLRs) represent a family of evolutionarily conserved proteins, that represent a fundamental link between innate and adaptive immune responses. Aim. The purpose of this study was to investigate the expression of TLR4 and TLR9 in the normal nasal mucosa and in the mucosa of subjects with different phenotypes of rhinitis. Methodology. A confocal analysis of TLR4 and TLR9 (co)expression was carried out on biopsies from the inferior turbinate obtained from 4 patients affected by persistent allergic rhinitis, 8 patients with chronic rhino-sinusitis, and 6 patients with vasomotor rhinitis The results were compared with those of specimens obtained from 4 subjects undergoing nasal surgery, but with signs of nasal inflammation. Results. TLR4 and TLR9 were expressed in the healthy nasal mucosa; TLR4 and TLR9 expression was significantly decreased in allergic rhinitis. TLR4 was over expressed in the epithelium of chronic rhino-sinusitis. Both TLRs were co-expressed in the sub-epithelial infiltrate of chronic and vasomotor rhinitis, even though this expression was higher in the former compared with the latter. Conclusions. This study indicates that TLR4 and TLR9 show a different pattern of expression in different phenotypes of rhinitis, possibly related to the type and severity of the disease
SDMT testing and its use in the numerical modelling of a deep excavation
The role of in situ tests in numerical analyses of deep excavations is investigated. The construction of a metro station in Barcelona required a deep excavation in a densely built urban area. Geological conditions were complex and challenging, involving soft alluvial materials below groundwater level. A comprehensive instrumentation system allowed monitoring the deep excavation-induced movements in the area and finite-element numerical analyses were car-ried out to reproduce the complex construction process. Results from two different numerical models are compared to field observations. The first model was based on data resulting from conventional analyses of site and laboratory investi-gations and initial monitoring results. The second model was instead created using only seismic dilatometer data, but using instead a systematic approach to calibrate soil stiffness nonlinearity. Comparison of numerical results and subse-quent monitoring show that, although reasonable agreement is obtained for both modelling approaches, the SDMT-based one appears more accurate. Site characterization based on seismic dilatometer data may prove very useful in deep exca-vation analyses, particularly if the soils are difficult to sample.Postprint (published version
New perspectives in human milk banks
Mother’s own milk (MOM) is the first choice in preterm infant feeding, and when it is not available or is insufficient, donor human milk (DHM) is recommended. It has been shown that feeding preterm infants with human milk is less related to major morbidities, enhances feeding tolerance and prevents metabolic syndrome in childhood. As The Committee on Nutrition of the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) states, specific guidelines for Human Milk Banks (HMB) are needed to guarantee the best possible compromise between microbiological safety and nutritional/biological quality of human milk (HM).
Currently, Holder pasteurization (HoP: pasteurization process at 62.5-63°C for 30 minutes) is recommended by all international guidelines: this method inactivates bacterial and viral pathogens but it also affects some nutritional and biological properties of human milk. New methods to ameliorate the biological quality and safety of DHM are under investigation in the last years. High Pressure Processing (HPP) is a non- thermal process used in food industries: this technology inactivates pathogenic microorganisms by applying hydrostatic high pressure, however further researches are required before applying this technology in milk banking.
Ultraviolet-C irradiation (UV-C) is another non-thermal method capable of reducing vegetative bacteria in human milk and it also seems to preserve higher levels of immunological proteins than HoP.
High-temperature short-time pasteurization (HTST: flash pasteurization, 72°C for 5-15 seconds) currently is available only at industrial level, but it could represent an alternative to HoP seeming to maintain the protein profile and some of the key active components of DHM.
Further researches are needed to define the optimal treatment of DHM.
Proceedings of the 11th International Workshop on Neonatology and Satellite Meetings · Cagliari (Italy) · October 26th-31st, 2015 · From the womb to the adult
Guest Editors: Vassilios Fanos (Cagliari, Italy), Michele Mussap (Genoa, Italy), Antonio Del Vecchio (Bari, Italy), Bo Sun (Shanghai, China), Dorret I. Boomsma (Amsterdam, the Netherlands), Gavino Faa (Cagliari, Italy), Antonio Giordano (Philadelphia, USA
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