The Diffuse Extreme Ultraviolet Background

Observations of the diffuse EUV background towards 138 different directions using the spectrometers aboard the Extreme Ultraviolet Explorer satellite (EUVE) have been combined into a spectrum from 150A to 730A and represent an effective exposure of 18 million seconds. There is no significant evidence of any non-local line flux in the resultant spectrum such as that from a hot coronal plasma. These results are inconsistent with the Wisconsin C and B broad-band surveys assuming the source is a logT = 5.8 - 6.1 hot plasma in ionization equilibrium with solar abundances, confirming the previous result of Jelinksy, Vallerga and Edelstein) (hereafter Paper 1) using an observation along the ecliptic with the same instrument. To make these results consistent with the previous broad-band surveys, the plasma responsible for the emission must either be depleted in Fe by a factor of approximately 6, be behind an absorbing slab of neutral H with a column of 2 x 10(exp 19)/sq cm, or not be in collisional ionization equilibrium (CIE). One such non-CIE model (Breitswerdt and Schmutzier) that explains the soft x-ray results is also inconsistent with this EUV data

A case of imported Leishmania infantum cutaneous leishmaniasis; an unusual presentation occurring 19 years after travel

BACKGROUND: Leishmania infantum is a flagellated protozoan parasite that is able to parasitize blood and tissue. Leishmania species cause a spectrum of clinical disease with cutaneous, visceral or mucosal involvement. L. infantum is recognised as a cause of visceral leishmaniasis (VL) and is less commonly reported as a cause of cutaneous leishmaniasis (CL) from countries around the Mediterranean basin. This is the first report of imported L. infantum CL to Australia and is remarkable for a 19 year period between the patient's exposure to an endemic region, and the manifestation of symptoms. CASE PRESENTATION: A 76 year old Italian-born man presented to our institution with a non-healing lesion over his upper lip, abutting his nasal mucosa. The patient had travelled to Italy, an endemic area for L. infantum 19 years earlier but had resided in Australia, a non-endemic area since. Histopathology performed on a biopsy of the lesion demonstrated findings consistent with CL. A species specific polymerase chain reaction (PCR) performed on the tissue detected L. infantum. The patient had complete clinical recovery following treatment with Liposomal amphotericin B at a dose of 3 mg/kg for five days followed by a subsequent 3 mg/kg dose at day ten. CONCLUSIONS: L. infantum should be recognised as a cause of imported CL in returned travellers from the Mediterranean. In this case, the incubation period for L. infantum CL was at least 19 years. This case adds to the described spectrum of clinical presentations of leishmaniasis and supports the theory of parasite persistence underlying natural immunity and recurrence of disease. Clinicians should consider L. infantum CL in the differential diagnosis of a non-healing skin lesion in any patient who reports travel to the Mediterranean, even when travel occurred several years before clinical presentation

Ion‐scale structure in Mercury’s magnetopause reconnection diffusion region

The strength and time dependence of the electric field in a magnetopause diffusion region relate to the rate of magnetic reconnection between the solar wind and a planetary magnetic field. Here we use ~150 ms measurements of energetic electrons from the Mercury Surface, Space Environment, GEochemistry, and Ranging (MESSENGER) spacecraft observed over Mercury’s dayside polar cap boundary (PCB) to infer such small‐scale changes in magnetic topology and reconnection rates. We provide the first direct measurement of open magnetic topology in flux transfer events at Mercury, structures thought to account for a significant portion of the open magnetic flux transport throughout the magnetosphere. In addition, variations in PCB latitude likely correspond to intermittent bursts of ~0.3–3 mV/m reconnection electric fields separated by ~5–10 s, resulting in average and peak normalized dayside reconnection rates of ~0.02 and ~0.2, respectively. These data demonstrate that structure in the magnetopause diffusion region at Mercury occurs at the smallest ion scales relevant to reconnection physics.Key PointsEnergetic electrons at Mercury map magnetic topology at ~150 msFirst direct observation of flux transfer event open‐field topology at MercuryModulations of the reconnection rate at Mercury occur at ion kinetic scalesPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/133575/1/grl54476_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/133575/2/grl54476.pd

Parametric resonance of magnetization excited by electric field

Manipulation of magnetization by electric field is a central goal of spintronics because it enables energy-efficient operation of spin-based devices. Spin wave devices are promising candidates for low-power information processing but a method for energy-efficient excitation of short-wavelength spin waves has been lacking. Here we show that spin waves in nanoscale magnetic tunnel junctions can be generated via parametric resonance induced by electric field. Parametric excitation of magnetization is a versatile method of short-wavelength spin wave generation, and thus our results pave the way towards energy-efficient nanomagnonic devices

An interesting diagnosis for a presacral mass: case report

A presacral mass can present a diagnostic dilemma for the surgical oncologist. Differential diagnoses include congenital causes such as teratoma or chordoma, neurological causes such as neurilemoma or neurofibroma or other malignancies such as lymphoma or sarcoma. Diagnosis usually requires imaging such as CT and MRI and tissue biopsy. We present an unusual cause of a presacral mass being extramedullary haematopoiesis, found incidentally in a 71 year old female. Extramedullary haematopoiesis is defined as the production of myeloid and erythroid elements outside of the bone-marrow. This diagnosis is extremely rare in the presacral area especially in a patient with no haematological abnormalities. A review of the literature is presented