A long-period radio transient active for three decades

Several long-period radio transients have recently been discovered, with strongly polarized coherent radio pulses appearing on timescales between tens to thousands of seconds^1,2. In some cases, the radio pulses have been interpreted as coming from rotating neutron stars with extremely strong magnetic fields, known as magnetars; the origin of other, occasionally periodic and less-well-sampled radio transients is still debated³. Coherent periodic radio emission is usually explained by rotating dipolar magnetic fields and pair-production mechanisms, but such models do not easily predict radio emission from such slowly rotating neutron stars and maintain it for extended times. On the other hand, highly magnetic isolated white dwarfs would be expected to have long spin periodicities, but periodic coherent radio emission has not yet been directly detected from these sources. Here we report observations of a long-period (21 min) radio transient, which we have labelled GPM J1839-10. The pulses vary in brightness by two orders of magnitude, last between 30 and 300 s and have quasiperiodic substructure. The observations prompted a search of radio archives and we found that the source has been repeating since at least 1988. The archival data enabled constraint of the period derivative to <3.6 × 10^-13 s s^-1, which is at the very limit of any classical theoretical model that predicts dipolar radio emission from an isolated neutron star.

Gamma-ray emission concurrent with the nova in the symbiotic binary V407 Cygni

Novae are thermonuclear explosions on a white dwarf surface fueled by mass accreted from a companion star. Current physical models posit that shocked expanding gas from the nova shell can produce x-ray emission, but emission at higher energies has not been widely expected. Here, we report the Fermi Large Area Telescope detection of variable gamma-ray emission (0.1 to 10 billion electron volts) from the recently detected optical nova of the symbiotic star V407 Cygni. We propose that the material of the nova shell interacts with the dense ambient medium of the red giant primary and that particles can be accelerated effectively to produce pi(0) decay gamma-rays from proton-proton interactions. Emission involving inverse Compton scattering of the red giant radiation is also considered and is not ruled out.

Detection of high-energy gamma-ray emission from the globular cluster 47 Tucanae with Fermi

We report the detection of gamma-ray emissions above 200 megaelectron volts at a significance level of 17sigma from the globular cluster 47 Tucanae, using data obtained with the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope. Globular clusters are expected to emit gamma rays because of the large populations of millisecond pulsars that they contain. The spectral shape of 47 Tucanae is consistent with gamma-ray emission from a population of millisecond pulsars. The observed gamma-ray luminosity implies an upper limit of 60 millisecond pulsars present in 47 Tucanae.

Detection of 16 gamma-ray pulsars through blind frequency searches using the Fermi LAT

Pulsars are rapidly rotating, highly magnetized neutron stars emitting radiation across the electromagnetic spectrum. Although there are more than 1800 known radio pulsars, until recently only seven were observed to pulse in gamma rays, and these were all discovered at other wavelengths. The Fermi Large Area Telescope (LAT) makes it possible to pinpoint neutron stars through their gamma-ray pulsations. We report the detection of 16 gamma-ray pulsars in blind frequency searches using the LAT. Most of these pulsars are coincident with previously unidentified gamma-ray sources, and many are associated with supernova remnants. Direct detection of gamma-ray pulsars enables studies of emission mechanisms, population statistics, and the energetics of pulsar wind nebulae and supernova remnants.

Prolactin response to thyrotropin-releasing hormone as a guideline for cyclical mastalgia treatment

METHODS

We studied a group of 36 fertile women affected with moderate-to-severe cyclical mastalgia (mean age: 26.0 years) showing a normal menstrual history and normal basal levels of circulating hormones, including prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E2), progesterone (P), testosterone (T), dehydroepiandrosterone sulphate (delta HEAs), androstenedione (A). Using serial measurements of PRL plasma levels after an intravenous injection of thyrotropin-releasing hormone (TRH), (TRH test), patients were divided in two groups: 19 patients with abnormal PRL response to TRH and the remaining 17 with normal response.

RESULTS

Bromocriptine treatment, 2.5 mg b.i.d. for 3-6 months, was effective in 73.6% of patients with abnormal TRH test and in 23.5% of patients with normal TRH test: the difference was statistically significant. On the other hand, 76.9% of patients with either normal TRH test or resistant to bromocriptine therapy had a favourable response to percutaneous progesterone and systemic non-steroidal antiinflammatory drugs (NSAIDs).

CONCLUSIONS

These results seem to confirm the hypothesis that PRL response to TRH could be used to identify patients affected with cyclical mastalgia that are likely to benefit by bromocriptine treatment.

[Warthin's tumor. Description of 2 cases]

Warthin's tumor is a debated pathological condition. There are many controversies concerning this disease such as its origin (hereditary or acquired), its nature (whether neoplastic or no), its topographical relation with the salivary glands, its relationship with possible concomitant pathologies (dysmetabolic, infective, neoplastic, etc.), the problems of diagnosis and of differential diagnosis with all possible causes of cervical swelling, and also the problems of surgical treatment in relation to the possible involvement of the salivary glands. In this paper two clinical cases are described. The first one is characterized by a latero-cervical bilateral Warthin's tumor, apparently independent of the salivary glands, associated with rhinopharyngeal lymphatic hyperplasia and nodular colloid goiter. The second case is characterized by a latero-cervical uni-lateral Warthin's tumor, linked by a slender layer with the ipsilateral parotid gland, associated with breast cancer. Starting point from the discussion of these two cases, the Authors make remarks in order to answer some of the aforementioned questions.