Latest results on Jovian disk X-rays from XMM-Newton

We present the results of a spectral study of the soft X-ray emission (0.2-2.5 keV) from low-latitude (`disk') regions of Jupiter. The data were obtained during two observing campaigns with XMM-Newton in April and November 2003. While the level of the emission remained approximately the same between April and the first half of the November observation, the second part of the latter shows an enhancement by about 40% in the 0.2-2.5 keV flux. A very similar, and apparently correlated increase, in time and scale, was observed in the solar X-ray and EUV flux. The months of October and November 2003 saw a period of particularly intense solar activity, which appears reflected in the behaviour of the soft X-rays from Jupiter's disk. The X-ray spectra, from the XMM-Newton EPIC CCD cameras, are all well fitted by a coronal model with temperatures in the range 0.4-0.5 keV, with additional line emission from Mg XI (1.35 keV) and Si XIII (1.86 keV): these are characteristic lines of solar X-ray spectra at maximum activity and during flares. The XMM-Newton observations lend further support to the theory that Jupiter's disk X-ray emission is controlled by the Sun, and may be produced in large part by scattering, elastic and fluorescent, of solar X-rays in the upper atmosphere of the planet.Comment: 17 pages, 7 figures, accepted for publication in a special issue of Planetary and Space Scienc

Isotec final report

General Atomic (GA) developed processes to prepare NdSe/sub 1.5-x/. The partial pressure of Se/sub 2/ above the NdSe/sub 1.5-x/ was found to be a function of x. The thermoelectric properties and the friability of the hot pressed element were also a function of x. Process modification changed the value of x, providing a method to control the properties of N-type NdSe/sub 1.5-x/ elements. A method of joining NdSe/sub 1.5-x/ to a nickel hot cap was developed using a gold foil intermediate. NdSe/sub 1.5-x/ was diffusion-bonded to PbTe by the same process developed for Gd/sub 2/Se/sub 3/. Couples were fabricated from (Cu,Ag)/sub 2/Se/Fe/(Bi,Sb)/sub 2/Te/sub 3/ and NdSe/sub 1.5-x/ PbTe elements. Limited couple test data were obtained. General Atomic examined methods to develop high-efficiency couples made from segmented elements containing (Cu,Ag)/sub 2/Se P-type material and NdSe/sub 1.5-x/ N-type material. Techniques were developed to reproducibly prepare and hot press (Cu,Ag)/sub 2/Se segments and elements with a metallurgically joined MoRe hot cap. This hot cap and a W-26/Re wire mesh used to make the hot cap junction were found to be stable in contact with (Cu,Ag)/sub 2/Se at 750/sup 0/C. Stability of (Cu,Ag)/sub 2/Se to current flow in a thermal gradient was examined. This report describes specifications for vapor suppression to improve the stability of P-type (Cu,Ag)/sub 2/Se in thermal gradient life tests and presents life test information on match-loaded (Cu,Ag)/sub 2/Se and (Cu,Ag)/sub 2/Se/Fe/(Bi,Sb)/sub 2/Te/sub 3/ elements

Evolutionarily conserved coding properties of auditory neurons across grasshopper species

We investigated encoding properties of identified auditory interneurons in two not closely related grasshopper species (Acrididae). The neurons can be homologized on the basis of their similar morphologies and physiologies. As test stimuli, we used the species-specific stridulation signals of Chorthippus biguttulus, which evidently are not relevant for the other species, Locusta migratoria. We recorded spike trains produced in response to these signals from several neuron types at the first levels of the auditory pathway in both species. Using a spike train metric to quantify differences between neuronal responses, we found a high similarity in the responses of homologous neurons: interspecific differences between the responses of homologous neurons in the two species were not significantly larger than intraspecific differences (between several specimens of a neuron in one species). These results suggest that the elements of the thoracic auditory pathway have been strongly conserved during the evolutionary divergence of these species. According to the ‘efficient coding’ hypothesis, an adaptation of the thoracic auditory pathway to the specific needs of acoustic communication could be expected. We conclude that there must have been stabilizing selective forces at work that conserved coding characteristics and prevented such an adaptation

Detergents, clothing and the consumer with sensitive skin

A typical detergent formulation for domestic garment washing is a complex formulation comprising: surfactants, builders, bleaches and auxiliary agents. Repeated exposure to surfactants can cause damage to the lipid film layer of the skin. Textile constructions used in clothing are also complex. Most apparel fabrics will be subject to a laundering process containing detergent at some time in the life cycle and thus it can be surmised that the combination of clothing and detergent is likely to be the cause of some skin problems. Certain fibre types show higher absorption rates than others. If surfactants present in domestic detergents are preferentially absorbed into the fabric during laundering and inadequately removed by rinsing a build-up of the surfactant may exacerbate skin irritation. This paper offers a review of the debate on the effects of detergents on skin disorders plus recent research on clothing and detergents