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.

Concentrations of progesterone in milk of cows administered an intravaginal progesterone insert.

Milk from pregnant cows contains concentrations of progesterone (P4) considered safe for human consumption. The objective of this study was to determine if concentrations of P4 in milk during administration of an intravaginal progesterone insert (CIDR insert) are less than concentrations of P4 in milk associated with pregnancy. Results have implications for human use of milk from cows receiving CIDR inserts. Holstein cows (N = 64; > 40 and < 150 d after calving) were administered 25 mg of PGF2alpha i.m. (study d 0) and 20 cows detected in estrus from 2 to 4 d later were assigned randomly to either control (N = 10; no further treatment) or CIDR insert (N = 10; 1.38 g of P4) inserted on study d 17 (14 +/- 1 d after estrus) and removed 7 d later. Composite milk samples were collected contemporaneously from each of the 20 estrous cycling cows and from 10 pregnant cows (> or = 60 and < or = 220 d of gestation) twice daily from study d 17 to 27. Concentrations of P4 in defatted milk samples were quantified using a validated radioimmunoassay. Mean logs of areas under the curve of concentrations of P4 from the afternoon on study d 17 through the afternoon on study d 27 were 3.05 ng day/ml for control, 3.33 ng day/ml for CIDR insert, and 3.81 ng day/ml for pregnant cows. Therefore, increased P4 due to pregnancy was 0.76 ng day/ml (3.81-3.05), whereas the increase in P4 due to CIDR insert was only 0.28 ng day/ml (3.33-3.05). Applying a 95% confidence interval to 0.28 ng day/ml provided an upper value of 0.70 ng day/ml, lower than the increase due to pregnancy. Because milk from pregnant cows is considered safe for human consumption, it follows that milk from cows administered CIDR inserts should also be considered safe, based on concentrations of P4.

Higher-education administrators: when the future does not make a difference.

The relationships between administrative actions and their long-term consequences were investigated in 14 people beginning training to become high-level college and university administrators, 19 people who had just finished that training, and 44 provosts (chief academic officers) at colleges and universities in the northeastern United States. The experienced administrators (those who had completed the training plus the provosts) were significantly more likely than the trainees to mention long-term consequences when describing their past and possible future administrative actions. However, in hypothetical choice situations, the experienced administrators were also significantly more likely than the trainees to choose smaller amounts offunds available immediately for their units versus larger amounts of promised future funds. With experience, administrators may both become more aware of their actions' long-term consequences and learn that they are unlikely to receive promised future funds. The contingencies in effect for higher-education administrators may lead them to make choices that do not result in their institutions meeting the highest standards.

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.

High serum D-lactate in patients on continuous ambulatory peritoneal dialysis.

BACKGROUND: As abnormally high serum D-lactate levels may cause neurological impairment, we determined whether patients undergoing continuous ambulatory peritoneal dialysis (CAPD) with lactate-containing fluids have increased serum D-lactate concentrations. METHODS: D- and L-lactate concentrations were determined in peritoneal dialysis fluids and in serum from control subjects (n = 10), haemodialysis patients (n = 10), and CAPD patients (n = 30) before and after 1 h of dialysis. RESULTS: We found the median D-lactate concentration in Dianeal CAPD fluid to be 26 mM (range 19-27), whereas it was less than 0.5 mM in DPCA2 fluid. Control, haemodialysis, and CAPD (DPCA2) patient median serum D-lactate concentrations were below 0.07 mM. However, CAPD (Dianeal) patient serum D-lactate concentrations were 4-fold higher than controls (P < 0.0001), at 0.28 mM, an hour after instillation of D-lactate-containing fluid. Three patients, whose serum D-lactate averaged 0.59 mM, were found to have D-lactate concentrations at 0.22 mM after overnight cessation of dialysis. CONCLUSION: We conclude that CAPD with D-lactate-containing fluids raises serum D-lactate to abnormal levels.

Cystic fibrosis newborn screening: impact of early screening results on parenting stress.

Newborn screening for cystic fibrosis (CF) is currently available through dried blood analysis for immunoreactive trypsinogen (IRT). The possible parenting stress associated with false-positive results or the early diagnosis of an asymptomatic infant has yet to be systematically addressed. This exploratory study examined levels of parenting stress among mothers of these infants. Results indicated significantly less total parenting stress but greater defensiveness in responding among families of false-positive screened children relative to their healthy comparison families. Parents of children diagnosed with CF through newborn screening did not show significantly higher stress scores than their healthy or "traditionally-diagnosed" CF comparison families. They did however have high frequencies of "at-risk scores" warranting referral based on clinical cut-off levels for Total Parenting Stress scores (45%) and Child Demandingness subscale score (50%). As the possibility for expanding CF neonatal screening to other states is considered, the need for further exploration of psychosocial sequelae affecting parenting will be increasingly important.

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.

Maturational changes in dermal absorption of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in Fischer 344 rats.

An earlier study indicated that percutaneous absorption of a 40-nmol dose of TCDD decreased with aging in rats, suggesting that the potential for systemic exposure following dermal contact would be decreased in older age groups. In this study, maturational changes in potential for systemic exposure to TCDD following dermal application of a low dose (200 pmol) of this chemical were examined in male Fischer 344 rats. Absorption, tissue distribution, and elimination of TCDD, measured as TCDD-derived radioactivity, were examined 72 hr after dermal application of 200 pmol [3H]TCDD (111 pmol/cm2 applied over 1.8 cm2) to the interscapular region of 3-, 5-, 8-, 10-, and 36-week-old rats. The dose was applied in 60 microliters acetone and the application site was covered with a perforated metal cap; animals were held in individual metabolism cages. Dermal absorption was greatest in 3-week-old rats (approximately 129 pmol; approximately 64% of the administered dose), decreasing to approximately 80 pmol (approximately 40%) in 5-, 8-, and 10-week-old rats and to 45 pmol (approximately 22%) in 36-week-old rats. In each age group, 70 to 80% of the radioactivity remaining at the application site 72 hr after dosing could be removed with acetone swabs. Major tissue depots of radioactivity were liver and fat; skin and muscle were minor depots. Changes in distribution of absorbed TCDD-derived radioactivity reflected changes in body mass of these depots; however, tissue concentration also varied. Whole body dissection was performed on rats to determine body mass of tissue depots. Adipose tissue content (Y) increased linearly with body weight (X), Y = 0.03X + 2.1 (r2 = 0.95). Elimination of absorbed TCDD-derived radioactivity was incomplete in all age groups with larger residues being recovered in the carcass. Results indicate that TCDD is absorbed to a greater degree through skin of very young animals and that a significant decrease in potential for systemic exposure may occur during maturation and again during aging.

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.