Multicolor Photometry of the Vela Pulsar

Multicolor photometry of the Vela pulsar (PSR B0833-45), updated by recent HST/WFPC2 observations obtained in the 555W, 675W and 814W filters, is presented. The available data provide the best characterization so far of the pulsar spectral shape, which is dominated by a flat power law continuum with spectral index \alpha = -0.2 +/- 0.2, consistent with the extrapolation in the optical domain of the power law component of the X-ray spectrum detected by Chandra. In addition, a marginally significant dip (~ 3 sigma) seems to be present at about 6500 AA. Spectroscopic observations with the VLT, now in progress, will undoubtly provide a much better assessment of the reality and characteristics of this feature.Comment: 4 pages, LaTex, 2 Postscript figures. Astronomy & Astrophysics, accepte

A model for the radiations from the compact strong sources

Model for origins and time variations of radiation spectrum over all wave band

Second malignancies in breast cancer patients following radiotherapy: a study in Florence, Italy.

ntroduction: Patients diagnosed with breast cancer are often treated with surgery followed by radiation therapy. In this paper, we evaluate the effect that radiotherapy may have had on the subsequent risk of second malignancies, including the possible influences of age at treatment and menopausal status.Methods: In order to evaluate the long-term consequences of radiotherapy, a cohort study was conducted based on clinical records for 5,248 women treated for breast cancer in Florence (Italy), with continuous follow-up from 1965 to 1994. The Cox proportional hazards model for ungrouped survival data was used to estimate the relative risk for second cancer after radiotherapy.Results: This study indicated an increased relative risk of all second cancers combined following radiotherapy (1.22, 95% CI: 0.88 to 1.69). The increased relative risk appeared five or more years after radiotherapy and appeared to be highest amongst women treated after the menopause (1.61, 95% CI: 1.13 to 2.29). Increased relative risks were observed specifically for leukaemia (8.13, 95% CI: 0.96 to 69.1) and other solid cancers (1.84, 95% CI: 1.06 to 3.16), excluding contralateral breast cancer. For contralateral breast cancer, no raised relative risk was observed during the period more than five years after radiotherapy.Conclusions: The study indicated a raised risk of second malignancies associated with radiotherapy for breast cancer, particularly for women treated after the menopause

Structure and diversity of fish communities in man-made ponds of the Niger Delta (southern Nigeria)

1. A survey of eight local earthen hand-dug ponds located within the freshwater swamps of a Niger Delta area (southern Nigeria) was conducted over a period of 3 months. A total of 4,313 fishes representing 19 species from 12 families were recorded.2. The most abundant species was Xenomystus nigri (905 individuals), whereas the least common was Protopterus annectens (13). Cichlidae and Clariidae counted three species each, whereas Anabantidae, Hepsetidae, Mochokidae, Protopteridae, Phractolaemidae, Malapteruridae and Gymnarchidae were represented by a single species each.3. A lotic species, Synodontis sp., was recorded possibly as a result of the episodic flood of 2012.4. The Engenni swamps harbour a moderately diverse ichthyofauna. Regulations should be put in place to further enhance the fisheries potential of these local ponds

Type II superconductivity and magnetic flux transport in neutrons stars

The transition to a type II proton superconductor which is believed to occur in a cooling neutron star is accompanied by changes in the equation of hydrostatic equilibrium and by the formation of proton vortices with quantized magnetic flux. Analysis of the electron Boltzmann equation for this system and of the proton supercurrent distribution formed at the transition leads to the derivation of a simple expression for the transport velocity of magnetic flux in the liquid interior of a neutron star. This shows that flux moves easily as a consequence of the interaction between neutron and proton superfluid vortices during intervals of spin-down or spin-up in binary systems. The differences between the present analysis and those of previous workers are reviewed and an error in the paper of Jones (1991) is corrected.Comment: 7 pages, no figures. To be published in Monthly Notices of the Royal Astronomical Societ

Role of angiotensin-converting enzyme and vitamin D receptor gene polymorphisms in cancer anorexia-cachexia syndrome

The ubiquitin-proteasome pathway is a crucial connection between aberrant immune system activation, systemic inflammation and Cancer Anorexia-Cachexia Syndrome (CACS), a syndrome that culminates in hyper-activation of the ubiquitin-proteasome pathway. Angiotensin directly up-regulates this pathway, while vitamin D down-regulates it indirectly through the insulin-like growth factor-1 pathway. We investigated the genetic predisposition towards CACS in a cancer population, examining Insertion/Deletion (I/D) polymorphism of angiotensin-converting enzyme gene and FokI and BsmI polymorphisms of vitamin D receptor gene. Sixty-two cancer patients were recruited and divided into three groups: primary cachectic (C1, n = 14; dysmetabolic body weight loss ≥5% in 6 months); secondary cachectic (C2, n = 34; similar weight loss, mechanic or iatrogenic origin); and non-cachectic (NC, n = 16). C2+NC were merged in the control group. The three groups showed significant differences in average prognostic inflammatory nutritional index (C1: 26.4±23.4; C2: 5.4±5.6; NC: 0.37±0.5), C-reactive protein serum levels (C1: 6.6±2.1; C2: 2.4±2.2; NC: 1.0±2.0 mg/dL), albumin serum levels (C1: 3.1±0.6; C2: 3.5±0.4; NC 3.7±0.6 g/dL), weight loss (C1: 22±8; C2: 15±6.7; NC 5±6%) and life expectancy (C1: 6.4±3.3; C2: 25±28; NC: 45±25 months). However, none of the chosen polymorphisms showed any statistically significant correlation with CACS. The complexity of the changes of the immune system in the chronic inflammation state associated with CACS is far greater than expected and further studies are required to identify genetic independent markers of progression toward CACS.

Isolated pulsar spin evolution on the P-Pdot Diagram

We look at two contrasting spin-down models for isolated radio pulsars and, accounting for selection effects, synthesize observable populations. While our goal is to reproduce all of the observable characteristics, in this paper we pay particular attention to the form of the spin period vs. period derivative (P-Pdot) diagram and its dependence on various pulsar properties. We analyse the initial spin period, the braking index, the magnetic field, various beaming models, as well as the pulsar's luminosity. In addition to considering the standard magnetic dipole model for pulsar spin-down, we also consider the recent hybrid model proposed by Contopoulos & Spitkovsky. The magnetic dipole model, however, does a better job of reproducing the observed pulsar population. We conclude that random alignment angles and period dependent luminosity distributions are essential to reproduce the observed P-Pdot diagram. We also consider the time decay of alignment angles, and attempt to reconcile various models currently being studied. We conclude that, in order to account for recent evidence for the alignment found by Weltevrede & Johnston, the braking torque on a neutron star should not depend strongly on the inclination. Our simulation code is publically available and includes a web-based interface to examine the results and make predictions for yields of current and future surveys.Comment: 9 pages, 4 figure

Subacute pericardial abscess after aortic valve replacement: a case report

BACKGROUND: Purulent pericarditis is an infectious disease, frequently caused by gram-positive bacteria, that is rarely observed in healthy individuals, and is often associated with predisposing conditions. CASE PRESENTATION: Here, we present the case of an Escherichia coli post-surgical localized purulent pericarditis complicated by transient constrictive pericarditis and its diagnostic and therapeutic management. CONCLUSIONS: Our case report focuses on the importance of imaging-guided treatment of purulent pericardial diseases, in particular on the emerging role of 18\u2009F-labelled 2-fluoro-2-deoxy-D-glucose Positron Emission Tomography/Computed Tomography in pericardial diseases and on the management of transient constrictive pericarditis, often seen after thoracic surgery