The lakes of Titan

The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive evidence for the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70 degrees north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table.

Titan Radar Mapper observations from Cassini's T3 fly-by

Cassini's Titan Radar Mapper imaged the surface of Saturn's moon Titan on its February 2005 fly-by (denoted T3), collecting high-resolution synthetic-aperture radar and larger-scale radiometry and scatterometry data. These data provide the first definitive identification of impact craters on the surface of Titan, networks of fluvial channels and surficial dark streaks that may be longitudinal dunes. Here we describe this great diversity of landforms. We conclude that much of the surface thus far imaged by radar of the haze-shrouded Titan is very young, with persistent geologic activity.

The Sand Seas of Titan: Cassini RADAR Observations of Longitudinal Dunes

The most recent Cassini RADAR images of Titan show widespread regions (up to 1500 kilometers by 200 kilometers) of near-parallel radar-dark linear features that appear to be seas of longitudinal dunes similar to those seen in the Namib desert on Earth. The Ku-band (2.17-centimeter wavelength) images show approximately 100-meter ridges consistent with duneforms and reveal flow interactions with underlying hills. The distribution and orientation of the dunes support a model of fluctuating surface winds of approximately 0.5 meter per second resulting from the combination of an eastward flow with a variable tidal wind. The existence of dunes also requires geological processes that create sand-sized (100- to 300-micrometer) particulates and a lack of persistent equatorial surface liquids to act as sand traps.

Cassini Radar Views the Surface of Titan

The Cassini Titan Radar Mapper imaged about 1% of Titan's surface at a resolution of approximately 0.5 kilometer, and larger areas of the globe in lower resolution modes. The images reveal a complex surface, with areas of low relief and a variety of geologic features suggestive of dome-like volcanic constructs, flows, and sinuous channels. The surface appears to be young, with few impact craters. Scattering and dielectric properties are consistent with porous ice or organics. Dark patches in the radar images show high brightness temperatures and high emissivity and are consistent with frozen hydrocarbons.

A European cancer nursing curriculum for a post-basic course in cancer prevention: outcomes of a collaborative project

The core curriculum distance learning project in cancer prevention was funded by Europe Against Cancer and the University of Southampton and supported by the European Oncology Nursing Society. The commitments of the project were to collaborative working, involvement of as many EU countries as possible, joint writing and design of the materials, and a flexible and useful end-product. The ambitions of the project were realized by the collective production of materials on cancer prevention that are available either as a teaching resource in English, French or Portuguese, or an accredited post-graduate course by distance learning in English. This paper will focus on the tensions and issues arising out of the collaborative process; these were connected to funding, translation, dissemination and evaluation.

Cancer beliefs, attitudes and preventive behaviours of nurses working in the community

A study of nurses, comprising district, school and practice nurses and health visitors, working in the community was carried out in 1992/1993. The aims of the research included exploration of the nurses' beliefs about and attitudes to cancer and their own cancer preventive behaviours. Focus group methodology was used, with 11 discussion groups, totalling 86 nurses. Data were analysed qualitatively and reported in relation to emergent themes. The nurses found cancer a terrifying disease, dreading a personal diagnosis and feeling ambivalent about treatment effectiveness. However, they were good role models for cancer prevention, eating a healthy diet, protecting themselves from the sun, attending regularly for cervical and breast screening, and the majority did not smoke.

Outbreak of Escherichia coli O157 in Sweden

The Swedish Institute for Infectious Disease Control (Smittskyddsinstitutet - SMI) received no more than three reports of enterohaemorrhagic E. coli O157 infections (EHEC) each year from 1988 to 1994. About half of these were due to E. coli O157. In July

Effect of tri-iodothyronine administration on skeletal muscle intracellular pH in the rat

1. Male Wistar rats were injected with tri-iodothyronine intraperitoneally for either 3 or 5 days. 2. Using 31P nuclear magnetic resonance spectroscopy, skeletal muscle intracellular bioenergetics of the leg were studied at rest and during sciatic nerve stimulation. 3. Tri-iodothyronine caused intracellular alkalinization of the cell, implying that administration of tri-iodothyronine induces an alteration in the set point for the sodium/proton antiport, the chief controller of intracellular pH. 4. During stimulation, there was less acidification of the skeletal muscle cell in the tri-iodothyronine-injected rats, implying either increased intrinsic buffering capacity of the muscle or increased proton efflux possibly due to increased activity of the sodium/proton antiport. 5. Effective proton efflux from the skeletal muscle cell may be sensitive to circulating levels of tri-iodothyronine.

Standardized instructions: do they improve communication of discharge information from the emergency department?

To determine whether standardized instructions enhance communication of discharge information, we provided 197 parents of children in whom otitis media was diagnosed with one of three types of instruction at the time of discharge from a pediatric emergency department: (1) instruction by individual housestaff and medical students after consultation with an attending physician (control group); (2) standardized verbal instructions given by housestaff and students trained in their use (verbal group); or (3) the same instructions given to the verbal group, together with a type-written copy of the information to take home (verbal + written group). Prior to leaving the emergency department and, again, by phone, 1 and 3 days later, parents were questioned concerning the prescribed medication's name, dose, frequency, and duration of administration (medication data), three signs of improvement, and eight signs indicating the need for medical advice (worrisome signs). The mean percentage of correct responses per parent in each group was computed for each information category. Both at exit interview and at follow-up, parents receiving either form of standardized instructions showed significantly greater knowledge of information related to their child's illness than did controls. Information regarding medication data was more likely to be communicated to parents in all groups than were signs of improvement or worrisome signs. The addition of written instructions to standardized verbal instructions did not improve parental recall of discharge information.

Systemic infection due to group B beta-hemolytic streptococcus in children. A review of 75 outpatient-evaluated cases during 13 years

We reviewed 75 outpatient cases of systemic infection due to group B beta-hemolytic streptococcus (GBS) evaluated during a 13-year period. Patient ages ranged from five days to eight months; 75% were younger than two months. Early-onset (less than or equal to seven days of age) GBS disease occurred in 10% of the patients, and late-onset GBS disease in 90%. The racial distribution was 60% black, 35% white, and 5% Hispanic. Symptoms included fever, irritability, lethargy, and altered-feeding pattern which lasted less than 24 hours in 88% of patients. On presentation, 33% were afebrile (eight had GBS meningitis); 32% did not appear ill (six had GBS meningitis). Of the total, 40% had GBS meningitis, of these, a greater proportion had either early-onset GBS disease or neutropenia. Infection other than meningitis was identified in 24% of all patients: pneumonia (six cases), cellulitis/adenitis (six cases), osteomyelitis/septic arthritis (five cases), and otitis media (one case). All patients survived. Systemic GBS infection in an outpatient population can involve infants up to eight months old, is more common in blacks than in whites, can be present without fever or compromised appearance, and usually has low mortality.