Connecting Galaxy Evolution, Star Formation and the X-ray Background

As a result of deep hard X-ray observations by Chandra and XMM-Newton a significant fraction of the cosmic X-ray background (CXRB) has been resolved into individual sources. These objects are almost all active galactic nuclei (AGN) and optical followup observations find that they are mostly obscured Type 2 AGN, have Seyfert-like X-ray luminosities (i.e., L_X ~ 10^{43-44} ergs s^{-1}), and peak in redshift at z~0.7. Since this redshift is similar to the peak in the cosmic star-formation rate, this paper proposes that the obscuring material required for AGN unification is regulated by star-formation within the host galaxy. We test this idea by computing CXRB synthesis models with a ratio of Type 2/Type 1 AGN that is a function of both z and 2-10 keV X-ray luminosity, L_X. The evolutionary models are constrained by parameterizing the observed Type 1 AGN fractions from the recent work by Barger et al. The parameterization which simultaneously best accounts for Barger's data, the CXRB spectrum and the X-ray number counts has a local, low-L_X Type 2/Type 1 ratio of 4, and predicts a Type 2 AGN fraction which evolves as (1+z)^{0.3}. Models with no redshift evolution yielded much poorer fits to the Barger Type 1 AGN fractions. This particular evolution predicts a Type 2/Type 1 ratio of 1-2 for log L_X > 44, and thus the deep X-ray surveys are missing about half the obscured AGN with these luminosities. These objects are likely to be Compton thick. Overall, these calculations show that the current data strongly supports a change to the AGN unification scenario where the obscuration is connected with star formation in the host galaxy rather than a molecular torus alone. The evolution of the obscuration implies a close relationship between star formation and AGN fueling, most likely due to minor mergers or interactions.Comment: 36 pages, 8 figures, ApJ in press. Minor changes to match published versio

Intubación con paciente despierto con fibroscopio retromolar de Bonfils bajo sedación con dexmedetomidina Reporte de 7 casos

SUMMARYAcording to the “Practice Guidelines for management of a difficult airway”, and several algorithnes, an awake intubation is considered the first method to secure a suspected difficult airway. During last years the awake intubation was performed by flexible fiberoptic laringoscopy or with a rigid stylet. Within the last decade, many new devices have been developed to assist anesthesiologist with both routine and difficult airway management, one of wich is the Bonfils Retromolar Intubacion Fiberscope. It is a semi-rigid optical stylet 40 cm long of 5,0 external diameter and a tip curvature of 40 degrees; the adult stylet can accommodate a 6,5 mm endotracheal tube and sliding it in the superior airway, it is possible to entubate the glottis under direct vision. We present seven case report with difficult airway, managed with dexmedotomidine using the Bonfils retromolar fiberscope without topical anesthetic

Precise Therapy for Thoracic Aortic Aneurysm in Marfan Syndrome: A Puzzle Nearing Its Solution.

Abstract Marfan Syndrome (MFS) is a rare connective tissue disorder, resulting from mutations in the fibrillin-1 gene, characterized by pathologic phenotypes in multiple organs, the most detrimental of which affects the thoracic aorta. Indeed, thoracic aortic aneurysms (TAA), leading to acute dissection and rupture, are today the major cause of morbidity and mortality in adult MFS patients. Therefore, there is a compelling need for novel therapeutic strategies to delay TAA progression and counteract aortic dissection occurrence. Unfortunately, the wide phenotypic variability of MFS patients, together with the lack of a complete genotype-phenotype correlation, have represented until now a barrier hampering the conduction of translational studies aimed to predict disease prognosis and drug discovery. In this review, we will illustrate available therapeutic strategies to improve the health of MFS patients. Starting from gold standard surgical overtures and the description of the main pharmacological approaches, we will comprehensively review the state-of-the-art of in vivo MFS models and discuss recent clinical pharmacogenetic results. Finally, we will focus on induced pluripotent stem cells (iPSC) as a technology that, if integrated with preclinical research and pharmacogenetics, could contribute in determining the best therapeutic approach for each MFS patient on the base of individual differences. Finally, we will suggest the integration of preclinical studies, pharmacogenetics and iPSC technology as the most likely strategy to help solve the composite puzzle of precise medicine in this condition

Magma dynamics during the 2007 Stromboli eruption (Aeolian Islands. Italy): mineralogical, geochemical and isotopic data

After the 6 month-long effusive event of 2002-2003, a new lava effusion occurred at Stromboli between 27 February and 2 April 2007. Despite the different durations, approximately the same volume of magma was emitted in both eruptions, in the order of 107 m3 . A paroxysmal eruption occurred at the summit craters in both the 2002–2003 and 2007 episodes, during which a significant amount of low porphyritic (LP), volatile- rich magma was erupted. In both cases, the paroxysm did not interrupt the lava emission. Here, we present compositional data, including texture, mineralogy, chemistry and Sr and Nd isotope ratios of bulk-rock, groundmass and separated minerals of lavas erupted in 2007, together with chemistry and Sr and Nd isotope composition of the pumices emitted during the 15 March paroxysm. As a whole, the lavas have the same texture and chemistry that characterize the highly porphyritic (HP) products usually erupted at Stromboli during normal Strombolian activity and effusive events. Compared to the previous HP products, the 2007 lavas show minor but systematic mineralogical and isotopic variations which are consistent with a modest increase of the magma supply rate of the volcano. Compositional variations during the entire duration of the event are very modest. Glass chemistry changes in lavas erupted in the second half of March can be explained by theminormixing between the volatile-rich LPmagma rising through the shallowmagmatic systemduring the 15 March paroxysm and the degassed residing HP magma. A first conclusion of this study is that there is no compositional evidence supporting major changes in the magma dynamics of the volcano accompanying the effusive activity, as also suggested for the 2002–2003 event. The activity of Stromboli is controlled by a steady state feeding system in which refilling, mixing, degassing and crystallization at shallow level continuously operate,withmodest oscillations in themagma supply rate. Switching between normal Strombolian and effusive activity is related to periods of relatively more vigorous refilling of the shallow system, leading to progressive pressure increase in the upper conduits associated with only minor compositional variations in the erupted products

Identifying recycled ash in basaltic eruptions

Deposits of mid-intensity basaltic explosive eruptions are characterized by the coexistence of different types of juvenile clasts, which show a large variability of external properties and texture, reflecting alternatively the effects of primary processes related to magma storage or ascent, or of syn-eruptive modifications occurred during or immediately after their ejection. If fragments fall back within the crater area before being re-ejected during the ensuing activity, they are subject to thermally- and chemically-induced alterations. These ‘recycled’ clasts can be considered as cognate lithic for the eruption/explosion they derive. Their exact identification has consequences for a correct interpretation of eruption dynamics, with important implications for hazard assessment. On ash erupted during selected basaltic eruptions (at Stromboli, Etna, Vesuvius, Gaua-Vanuatu), we have identified a set of characteristics that can be associated with the occurrence of intra-crater recycling processes, based also on the comparison with results of reheating experiments performed on primary juvenile material, at variable temperature and under different redox conditions

Arrival of extremely volatile-rich high-Mg magmas changes explosivity of Mount Etna

The volcanic hazard potential of Mount Etna volcano is currently nourished by long-lasting, powerful eruptions of basaltic magmas coupled with increased seismicity and ground deformation, and the world's largest discharge of volcanic gases. The current evolutionary cycle of Mount Etna activity is consistent with subduction-related chemical modifications of the mantle source. Arrival of a new mantle-derived magma batch beneath the volcano has been hypothesized, but is still elusive among the erupted products. Here we demonstrate petrological and geochemical affinities between the magmas supplying modern eruptions and high-Mg, fall-stratified (FS) basalts ejected violently 4 k.y. ago. The FS primitive magmas (13 wt% MgO) are characteristically volatile enriched (at least 3.8 wt% H2O and 3300 ppm CO2), and bear a trace element signature of a garnet-bearing, metasomatized source (high Gd/Yb, K/La, U/Nb, Pb/Ce, Ca/Al). They started crystallizing olivine (Fo91), clinopyroxene (Mg# 92.5), and Cr spinel deep in the plumbing system (>5 kbar), contributing to the cumulate piles at depth and to differentiated alkaline basalt and trachybasalt magmas in the shallow conduit. Continuous influx of mantle-derived, volatile-rich magmas, such as those that supplied the FS fallout, provides a good explanation for major compositional and eruptive features of Mount Etna

Lymph node metastases in malignant tumors of the paranasal sinuses: prognostic value and treatment

Objective: To assess the frequency of nodal involvement and its prognostic value in malignant tumors of the paranasal sinuses, particularly in maxillary sinus squamous cell carcinoma. Design: Retrospective review. Setting: Tertiary cancer center. Patients: The medical records of 704 consecutive patients surgically treated for malignant tumors of the paranasal sinuses from January 1968 to March 2003 were reviewed. The tumors were staged according to American Joint Committee on Cancer-International Union Against Cancer 2002 classification. Only patients with clinically positive nodes underwent a neck dissection. Main Outcome Measures: Lymph node metastases (at presentation or during follow-up, occurring alone, or with concurrent local recurrence and/or distant metastasis). Also analyzed were local recurrence (occurring alone or with concurrent distant metastasis), distant metastasis (occurring alone), and overall survival. Results: The tumor site was the ethmoid sinus in 305 cases and maxillary sinus in 399 cases. At baseline, 5 patients (1.6%) in the ethmoid sinus group and 33 (8.3%) in the maxillary sinus group presented with positive nodes (P<.001); during follow-up, nodal recurrences (alone or simultaneous with T and/or M recurrence) occurred in 15 and 51 patients, respectively, and the corresponding 5-year incidence estimates were 4.3% and 12.5% (P=.001). The highest incidence of node metastases was found in maxillary sinus squamous cell carcinoma, particularly in T2 tumors. Five-year overall survival estimates were 45.3% for patients with N0 tumors and 0% for those with N+ (N1, N2, or N3) ethmoid sinus tumors, and 50.6% and 16.8%, respectively, for patients with maxillary sinus tumors. Conclusions: Lymph node metastases are a poor prognostic factor for patients with malignant tumors of the paranasal sinuses. The incidence of these metastases is low, particularly in ethmoid sinus tumors. A prophylactic treatment of the neck in patients with N0 tumors (surgery or radiotherapy) might be considered in T2 squamous cell carcinoma of the maxillary sinus and in undifferentiated carcinoma of the ethmoid sinus. ©2008 American Medical Association. All rights reserved

Synthesis of the Initial Scientific Results of the MIS Project (AND-1B Core), Victoria Land Basin, Antarctica

The ANDRILL Program successfully recovered a 1285 m-long succession of cyclic glacimarine sediment with interbedded volcanic deposits in its first season of drilling from the McMurdo Ice Shelf (MIS). The MIS AND-1B drill core represents the longest and most complete (98% recovery) geological record from the Antarctic continental margin to date, and will provide a key reference record of climate and ice-sheet variability through the Late Neogene. Here we present a synopsis of this Initial Science Report with emphasis on the potential of the record for improving our knowledge of Antarctica’s influence on global climate

Inhomogeneous cosmologies, the Copernican principle and the cosmic microwave background: More on the EGS theorem

We discuss inhomogeneous cosmological models which satisfy the Copernican principle. We construct some inhomogeneous cosmological models starting from the ansatz that the all the observers in the models view an isotropic cosmic microwave background. We discuss multi-fluid models, and illustrate how more general inhomogeneous models may be derived, both in General Relativity and in scalar-tensor theories of gravity. Thus we illustrate that the cosmological principle, the assumption that the Universe we live in is spatially homogeneous, does not necessarily follow from the Copernican principle and the high isotropy of the cosmic microwave background.Comment: 17 pages; to appear in GR