A long life among ruminants: giraffids and other special cases

In order to investigate differences in the relative maximum longevity and other life history parameter between ruminant species, we collated data on mean body mass, maximum longevity, gestation period and newborn mass in wild ruminant and camelid species. Among ruminants, giraffids (giraffe Giraffa camelopardalis and okapi Okapia johnstoni) have particularly high longevities, long gestation periods, and low intrauterine growth rates. A particularly high absolute and relative longevity is also achieved by the anoa (Bubalus depressicornis), a member of the bovinae (cattle-type ruminants) and an insular dwarf (inhabiting the Indonesian island of Sulawesi). The fact that some (but not all) other small ruminants also achieve surprisingly high longevities leads to the hypothesis that extreme relative longevities in this group are an indication for secondary body size reduction.     

Superconducting interfaces between insulating oxides

At interfaces between complex oxides, electronic systems with unusual electronic properties can be generated. We report on superconductivity in the electron gas formed at the interface between two insulating dielectric perovskite oxides, LaAlO3 and SrTiO3. The behavior of the electron gas is that of a two-dimensional superconductor, confined to a thin sheet at the interface. The superconducting transition temperature of congruent with 200 millikelvin provides a strict upper limit to the thickness of the superconducting layer of congruent with 10 nanometers.     

Atlantic meridional overturning circulation during the Last Glacial Maximum

The circulation of the deep Atlantic Ocean during the height of the last ice age appears to have been quite different from today. We review observations implying that Atlantic meridional overturning circulation during the Last Glacial Maximum was neither extremely sluggish nor an enhanced version of present-day circulation. The distribution of the decay products of uranium in sediments is consistent with a residence time for deep waters in the Atlantic only slightly greater than today. However, evidence from multiple water-mass tracers supports a different distribution of deep-water properties, including density, which is dynamically linked to circulation.     

Use of goats as biological agents for the renovation of pastures in the Appalachian region of the United States

Much of hill-land pasture in the Appalachian region of the United States is dominated by herbaceous weeds and brush. Low cost, low input and environmentally acceptable reclamation procedures are needed to maintain the productivity of these pastures. This experiment evaluated the effectiveness of using goats (Capra hircus hircus) alone (30 mature, brush does/ha) or cattle (Bos taurus) with goats (17 mature, brush does/ha + two to three steers/ha -- 225 kg average live weight) to reclaim a pasture from an abandoned, overgrown 5.9 ha orchard left untouched for 15 years. Over four grazing seasons, managed defoliation resulted in a substantial increase in herbaceous vegetative cover in plots grazed by goats alone (65 to 86%) and by goats with cattle (65 to 80%) while vegetative cover decreased from 70 to 22% in the control plot. Similarly, the cover by grass species increased in the grazed plots (goats: 16 to 63%; goats + cattle: 13 to 54%) while averaging 10% in the control plot. Multiflora rose (Rosa multiflora Thumb.) bushes were practically eliminated after four grazing seasons as quantified by an average reduction in height from 2.1 m to 0.6 m, and by the number of dead canes (stems) in both the goat (100%) or goat + cattle (92%) treatments. Results indicated that the foraging habits of goats resulted in the elimination of multiflora rose bushes and in a significant increase in desirable forage species. This revised version was published online in June 2006 with corrections to the Cover Date.     

The Flame Research Project: Introduction and Methods

The FLAME (FLy-Ash and Metals in Europe: Implications for human and environmental health) research project funded by the EU COPERNICUS programme ran from 1994 to 1996. The main aims of the programme were to further develop an automated chemical characterisation to discriminate between fly-ash particles from the major fossil-fuels used throughout Europe (coal, oil, peat, brown coal and oil shale) and apply this to particles extracted from lake sediments taken from the four participating countries (Estonia, Czech Republic, Ireland and U.K.) in order to determine spatial distributions of deposited particulates from large combustion sources. In combination with trace metal analyses from lake surface sediments and catchment mosses, the fly-ash particle data were able to identify areas of elevated pollutant deposition and suggest potential sources for them. Given the transboundary nature of the pollutants, the techniques and results of FLAME are of relevance throughout Europe. Other papers in this volume describe results and interpretation. This paper describes the background and aims of the FLAME project, outlines the methods employed for sampling sediments and mosses and the analytical techniques for particle enumeration and trace metal analysis for sediments and mosses. Finally brief details of the particle characterisation are given showing how a hierarchical discriminant function was developed, based on energy dispersive spectroscopy (EDS) derived particle chemistry which correctly allocated particles from the five fuel-types with 80% accuracy.     

The FLAME Project: General Discussion and Conclusions

Detailed discussion of the FLAME data at individual country level is included in other papers in this volume but some aspects of the analyses and data interpretation are best discussed on a broader level and that is the aim of this paper. The spatial distribution of fly-ash particles in the participating countries shows good agreement with expected sources and this implies that the majority of particulates travel less than 100 km from their source although lower concentrations of particles were detected at all sample sites. Areas of elevated concentration mostly coincide with population centres and imply possible impacts on human health by fine particulates (e.g. PM₁₀) from fossil-fuel sources in these areas. Problems with the particle characterisation, developed within the FLAME project, include difficulties in allocation due to the overlap between coal-series fuels and the presence of a 'mineral coal' background at lake sites thought to be due to persistent sediment minerals surviving the chemical pre-treatment and becoming allocated to coal. This leads to implications for the inclusion of further fuels into the classification and the application of the technique to the same fuels beyond Europe. The combination of lake sediment SCP data and sediment and moss metals data can also provide an indication of the impact from anthropogenic contamination at a site and probable source types. Comparison with previous moss analyses from 1990 show that metal concentrations in central Europe may have decreased but levels in the UK have shown little change. Finally, comparisons of FLAME data with the EMEP model for pollutant budgets across Europe generally show good agreement for pathways, although further work is needed in receptor countries for additional confirmation.     

Determination of parotid sulfate secretion in sheep by means of ultrasonic flow probes

The bilateral output of sulfate in parotid saliva, the relationship with its plasma level and with parotid flow, and its variation according to feeding behavior were determined in ad libitum, normal-sulfate (0.28% DM)-fed sheep (n = 6) using a transit time ultrasonic flow meter system to measure salivary flow. Ultrasonic flow meter probes were bilaterally implanted, under general anesthesia, around parotid ducts previously fitted through their oral ends with nonobstructive sampling catheters. Salivary flows were continuously recorded during 24 h, and saliva and blood samples for sulfate determinations were obtained hourly. Jaw movements were monitored with the submandibular balloon technique. The sulfate concentration in parotid saliva (mean of the group = 4.9 +/- 3.7 microg/mL) showed high variability between sheep (individual means from 0.4 +/- 0.3 to 9.3 +/- 5.9 microg/mL) and averaged 12.3% of the more stable plasma level (41.2 +/- 8.1 microg/mL). Pronounced intraindividual variations were also evident (0.1 to 26.3 microg of sulphate/mL of parotid saliva), in strong association with the fluctuations of salivary output. In 4 sheep, a decreasing exponential relationship was observed between parotid sulfate concentration and salivary secretion rate (r2 = 0.36, P < 0.01). This fact and the absence of a relationship between sulfate levels in plasma and in saliva suggest a sulfate secretory process during the passage of primary saliva through the ductal tree of the gland. The greatest rates of bilateral salivary sulfate output were observed during feeding (14.1 +/- 14.0 microg/min) and rumination (12.7 +/- 11.0 microg/min). Nevertheless, 49% of the sulfate output in parotid saliva was present during rest, as a result of the length of the resting times. The contribution of parotid sulfate to the ruminal S pool was highly variable and averaged 13.2 mg/d, representing less than 1% of the S intake. In conclusion, the accurate, reliable, nonobstructive, and bilateral salivary flow monitoring, using a previously characterized ultrasonic flow meter technique, allowed a detailed determination of the secretory dynamics of sulfate in parotid saliva, without disturbing the animal's routine or altering the physiological regulation of salivary output. The results indicated that, in the absence of S deficiency, the recycling of sulfate via saliva seems not to be a major factor in sheep nutrition.