Seasonal variations of the physical and optical characteristics of Saharan Dust: results from the Dust outflow and Deposition to the Ocean (DODO) experiment

North African dust is important for climate through its direct radiative effect on solar and terrestrial radiation and its role in the biogeochemical system. The Dust Outflow and Deposition to the Ocean project (DODO) aimed to characterize the physical and optical properties of airborne North African dust in two seasons and to use these observations to constrain model simulations, with the ultimate aim of being able to quantify the deposition of iron to the North Atlantic Ocean. The in situ properties of dust from airborne campaigns measured during February and August 2006, based at Dakar, Senegal, are presented here. Average values of the single scattering albedo (0.99, 0.98), mass specific extinction (0.85 m^2 g^-1 , 1.14 m^2 g^-1 ), asymmetry parameter (0.68, 0.68), and refractive index (1.53--0.0005i,1.53--0.0014i) for the accumulation mode were found to differ by varying degrees between the dry and wet season, respectively. It is hypothesized that these differences are due to different source regions and transport processes which also differ between the DODO campaigns. Elemental ratios of Ca/Al were found to differ between the dry and wet season (1.1 and 0.5, respectively). Differences in vertical profiles are found between seasons and between land and ocean locations and reflect the different dynamics of the seasons. Using measurements of the coarse mode size distribution and illustrative Mie calculations, the optical properties are found to be very sensitive to the presence and amount of coarse mode of mineral dust, and the importance of accurate measurements of the coarse mode of dust is highlighted.

A study of the sensitivity of ocean overturning circulation and climate to freshwater input in different regions of the North Atlantic

The Atlantic meridional overturning circulation (AMOC) is an important component of the climate system. Models indicate that the AMOC can be perturbed by freshwater forcing in the North Atlantic. Using an ocean-atmosphere general circulation model, we investigate the dependence of such a perturbation of the AMOC, and the consequent climate change, on the region of freshwater forcing. A wide range of changes in AMOC strength is found after 100 years of freshwater forcing. The largest changes in AMOC strength occur when the regions of deepwater formation in the model are forced directly, although reductions in deepwater formation in one area may be compensated by enhanced formation elsewhere. North Atlantic average surface air temperatures correlate linearly with the AMOC decline, but warming may occur in localised regions, notably over Greenland and where deepwater formation is enhanced. This brings into question the representativeness of temperature changes inferred from Greenland ice-core records.

Serving GODAE Data and Products to the Ocean Community

The Global Ocean Data Assimilation Experiment (GODAE [http:// www.godae.org]) has spanned a decade of rapid technological development. The ever-increasing volume and diversity of oceanographic data produced by in situ instruments, remote-sensing platforms, and computer simulations have driven the development of a number of innovative technologies that are essential for connecting scientists with the data that they need. This paper gives an overview of the technologies that have been developed and applied in the course of GODAE, which now provide users of oceanographic data with the capability to discover, evaluate, visualize, download, and analyze data from all over the world. The key to this capability is the ability to reduce the inherent complexity of oceanographic data by providing a consistent, harmonized view of the various data products. The challenges of data serving have been addressed over the last 10 years through the cooperative skills and energies of many individuals.

Does speciation impact on Cu uptake by, and toxicity to, the earthworm Eisenia fetida?

Eisenia fetida were exposed to different concentrations (0.009, 0.049 and 0. 125 mg L-1) of Cu in an aqueous medium. Cu speciation was manipulated through the addition of different concentrations (0. 15, 0.35 and 50 mg L-1) of EDTA. Cu speciation (as labile and non-labile pools) was determined using Differential Pulse Anodic Stripping Voltammetry. Labile Cu includes free Cu ions together with weak inorganic Cu complexes and a small fraction of easily dissociable organic complexes. Metal uptake and earthworm mortality increased with total Cu concentration in the EDTA free solutions. In the presence of EDTA both metal uptake and mortality decreased. These experiments demonstrate that Cu speciation governs uptake and consequent toxicity of Cu to E. fetida. (c) 2007 Elsevier Masson SAS. All rights reserved.

Overview and response to reviewers of The Singing Neanderthals

Why are humans musical? Why do people in all cultures sing or play instruments? Why do we appear to have specialized neurological apparatus for hearing and interpreting music as distinct from other sounds? And how does our musicality relate to language and to our evolutionary history? Anthropologists and archaeologists have paid little attention to the origin of music and musicality — far less than for either language or ‘art’. While art has been seen as an index of cognitive complexity and language as an essential tool of communication, music has suffered from our perception that it is an epiphenomenal ‘leisure activity’, and archaeologically inaccessible to boot. Nothing could be further from the truth, according to Steven Mithen; music is integral to human social life, he argues, and we can investigate its ancestry with the same rich range of analyses — neurological, physiological, ethnographic, linguistic, ethological and even archaeological — which have been deployed to study language. In The Singing Neanderthals Steven Mithen poses these questions and proposes a bold hypothesis to answer them. Mithen argues that musicality is a fundamental part of being human, that this capacity is of great antiquity, and that a holistic protolanguage of musical emotive expression predates language and was an essential precursor to it. This is an argument with implications which extend far beyond the mere origins of music itself into the very motives of human origins. Any argument of such range is bound to attract discussion and critique; we here present commentaries by archaeologists Clive Gamble and Iain Morley and linguists Alison Wray and Maggie Tallerman, along with Mithen's response to them. Whether right or wrong, Mithen has raised fascinating and important issues. And it adds a great deal of charm to the time-honoured, perhaps shopworn image of the Neanderthals shambling ineffectively through the pages of Pleistocene prehistory to imagine them humming, crooning or belting out a cappella harmonies as they went.

Communicating information about medication side effects: effects on satisfaction, perceived risk to health, and intention to comply

Previous research has shown that people's evaluations of explanations about medication and their intention to comply with the prescription are detrimentally affected by the inclusion of information about adverse side effects of the medication. The present study (Experiment 1) examined which particular aspects of information about side effects (their number, likelihood of occurrence, or severity) are likely to have the greatest effect on people's satisfaction, perception of risk, and intention to comply, as well as how the information about side effects interacts with information about the severity of the illness for which the medication was prescribed. Across all measures, it was found that manipulations of side effect severity had the greatest impact on people's judgements, followed by manipulations of side effect likelihood and then number. Experiments 2 and 3 examined how the severity of the diagnosed illness and information about negative side effects interact with two other factors suggested by Social Cognition models of health behaviour to affect people's intention to comply: namely, perceived benefit of taking the prescribed drug, and the perceived level of control over preventing or alleviating the side effects. It was found that providing people with a statement about the positive benefit of taking the medication had relatively little effect on judgements, whereas informing them about how to reduce the chances of experiencing the side effects had an overall beneficial effect on ratings.

Habituation and dishabituation to speech and office noise

The authors examined whether background noise can be habituated to in the laboratory by using memory for prose tasks in 3 experiments. Experiment 1 showed that background speech can be habituated to after 20 min exposure and that meaning and repetition had no effect on the degree of habituation seen. Experiment 2 showed that office noise without speech can also be habituated to. Finally, Experiment 3 showed that a 5-min period of quiet, but not a change in voice, was sufficient to partially restore the disruptive effects of the background noise previously habituated to. These results are interpreted in light of current theories regarding the effects of background noise and habituation; practical implications for office planning are discussed.

Independent evaluation of the ability of spaceborne radar and lidar to retrieve the microphysical and radiative properties of ice clouds

The combination of radar and lidar in space offers the unique potential to retrieve vertical profiles of ice water content and particle size globally, and two algorithms developed recently claim to have overcome the principal difficulty with this approach-that of correcting the lidar signal for extinction. In this paper "blind tests" of these algorithms are carried out, using realistic 94-GHz radar and 355-nm lidar backscatter profiles simulated from aircraft-measured size spectra, and including the effects of molecular scattering, multiple scattering, and instrument noise. Radiation calculations are performed on the true and retrieved microphysical profiles to estimate the accuracy with which radiative flux profiles could be inferred remotely. It is found that the visible extinction profile can be retrieved independent of assumptions on the nature of the size distribution, the habit of the particles, the mean extinction-to-backscatter ratio, or errors in instrument calibration. Local errors in retrieved extinction can occur in proportion to local fluctuations in the extinction-to-backscatter ratio, but down to 400 m above the height of the lowest lidar return, optical depth is typically retrieved to better than 0.2. Retrieval uncertainties are greater at the far end of the profile, and errors in total optical depth can exceed 1, which changes the shortwave radiative effect of the cloud by around 20%. Longwave fluxes are much less sensitive to errors in total optical depth, and may generally be calculated to better than 2 W m(-2) throughout the profile. It is important for retrieval algorithms to account for the effects of lidar multiple scattering, because if this is neglected, then optical depth is underestimated by approximately 35%, resulting in cloud radiative effects being underestimated by around 30% in the shortwave and 15% in the longwave. Unlike the extinction coefficient, the inferred ice water content and particle size can vary by 30%, depending on the assumed mass-size relationship (a problem common to all remote retrieval algorithms). However, radiative fluxes are almost completely determined by the extinction profile, and if this is correct, then errors in these other parameters have only a small effect in the shortwave (around 6%, compared to that of clear sky) and a negligible effect in the longwave.

The calculation of accurate normal coordinates I: general theory, and application to methane

The calculation of accurate and reliable vibrational potential functions and normal co-ordinates is discussed, for such simple polyatomic molecules as it may be possible. Such calculations should be corrected for the effects of anharmonicity and of resonance interactions between the vibrational states, and should be fitted to all the available information on all isotopic species: particularly the vibrational frequencies, Coriolis zeta constants and centrifugal distortion constants. The difficulties of making these corrections, and of making use of the observed data are reviewed. A programme for the Ferranti Mercury Computer is described by means of which harmonic vibration frequencies and normal co-ordinate vectors, zeta factors and centrifugal distortion constants can be calculated, from a given force field and from given G-matrix elements, etc. The programme has been used on up to 5 × 5 secular equations for which a single calculation and output of results takes approximately l min; it can readily be extended to larger determinants. The best methods of using such a programme and the possibility of reversing the direction of calculation are discussed. The methods are applied to calculating the best possible vibrational potential function for the methane molecule, making use of all the observed data.

Apparent digestibility and nitrogen utilization of diets based on maize silage harvested at three stages of maturity and fed to steers

Advancing maize crop maturity is associated with changes in ear-to-stover ratio which may have consequences for the digestibility of the ensiled crop. The apparent digestibility and nitrogen retention of three diets (Early, Mid and Late) containing maize silages made from maize of advancing harvest date [dry matter (DM) contents of the maize silages were 273, 314 and 367 g kg(-1) for the silages in the Early, Mid and Late diets respectively], together with a protein supplement offered in sufficient quantities to make the diets isonitrogenous, were measured in six Holstein-Friesian steers in an incomplete Latin square design with four periods. Dry-matter intake of maize silage tended to be least for the Early diet and greatest for the Medium diet (P=0(.)182). Apparent digestibility of DM and organic matter did not differ between diets. Apparent digestibility of energy was lowest in the Late diet (P = 0(.)057) and the metabolizable energy concentrations of the three silages were calculated as 11(.)0, 11(.)1 and 10(.)6 MJ kg(-1) DM for the Early, Medium and Late diets respectively (P = 0(.)068). No differences were detected between diets in starch digestibility but the number of undamaged grains present in the faeces of animals fed the Late diet was significantly higher than with the Early and Mid diets (P = 0(.)006). The apparent digestibility of neutral-detergent fibre of the diets reduced significantly as silage DM content increased (P = 0(.)012) with a similar trend for the apparent digestibility of acid-detergent fibre (P = 0(.)078). Apparent digestibility of nitrogen (N) was similar for the Early and Mid diets, both being greater than the Late diet (P = 0(.)035). Nitrogen retention did not differ between diets. It was concluded that delaying harvest until the DM content is above 300 g kg(-1) can negatively affect the nutritive value of maize silage in the UK.

The relationships of time and temperature to body weight and numbers of endospores in Pasteuria penetrans-infected Meloidogyne javanica females

Tomato plants inoculated with Meloidogyne javanica juveniles infected with Pasteuria penetrans were grown in a glasshouse (20-32degreesC) for 36, 53, 71 and 88 days and in a growth room (26-29degreesC) for 36, 53, 71 and 80 days. Over these periods the numbers of P penetrans endospores in infected M. javanica females and the weights of individual infected females increased. In the growth room, most spores (2.03 x 10(6)) were found after 71 days. However, in the glasshouse the rate of increase was slower and spore numbers were still increasing at the final sampling at 88 days (2.04 x 10(6)), as was the weight of the nematodes (72 mug). Weights of uninfected females reached a maximum of 36.2 and 43.1 mug after 71 days in the growth room and glasshouse, respectively.

Foods derived from animals: the impact of animal nutrition on their nutritive value and ability to sustain long-term health

Foods derived from domestic animals are a significant source of nutrients in the UK diet. However, certain aspects of some animal-derived foods, notably levels of saturated fatty acids, have given rise to concerns that these foods may contribute to the risk of cardiovascular disease, the metabolic syndrome and other conditions. However, the composition of the many animal-derived foods is not constant and can often be enhanced by manipulating the nutrition of the animal. This paper reviews these possibilities with particular attention to lipids, and draws attention to the fact that milk in particular, contains a number of compounds which may, for example, exert anti-carcinogenic effects. It is clear that the role of animal nutrition in creating foods closer to the optimum composition for long-term human health will not only be more relevant in the future, but will be vital in attempts to improve the health of the human population.