Getting ready for the manned mission to Mars: the astronauts’ risk from space radiation

Space programmes are shifting towards planetary exploration and, in particular, towards missions by human beings to the Moon and to Mars. Radiation is considered to be one of the major hazards for personnel in space and has emerged as the most critical issue to be resolved for long-term missions both orbital and interplanetary. The two cosmic sources of radiation that could impact a mission outside the Earth’s magnetic field are solar particle events (SPE) and galactic cosmic rays (GCR). Exposure to the types of ionizing radiation encountered during space travel may cause a number of health-related problems, but the primary concern is related to the increased risk of cancer induction in astronauts. Predictions of cancer risk and acceptable radiation exposure in space are extrapolated from minimal data and are subject to many uncertainties. The paper describes present-day estimates of equivalent doses from GCR and solar cosmic radiation behind various shields and radiation risks for astronauts on a mission to Mars.     

Observed LATCH use and misuse characteristics of child restraint systems in seven states

INTRODUCTION: Although the LATCH System (Lower Anchors and Tethers for Children) holds the promise of simplifying the installation of a child restraint system (CRS) to the vehicle's seat, many drivers transporting young children have difficulties using this technology. This paper reports on an observation study of LATCH use and misuse. METHOD: Observations of approximately 1,000 children less than 5 years of age in CRSs, in the back seats of vehicles that were equipped with tether and lower anchors, in seven states. RESULTS: Tethers were used for 51% of the children when the forward-facing CRS had tether straps and the vehicle had tether anchors. Lower anchors were used for 58% of the children when the CRS had lower attachments and the vehicle had lower anchors. The most common tether and lower attachment misuses were loose tether straps (18% of cases) and loose lower attachment installation (30% of the cases), respectively. Vehicle safety belts were used in combination with lower attachments in 20% of all lower anchor installations. CONCLUSION: As more caregivers of young children drive vehicles equipped with LATCH, it will be important to promote the proper installation of CRSs using this technology. LATCH education messages must also emphasize that the lower anchors may not always be the safest choice for CRS attachment -- the safest attachment is the one that results in a tight fit and will be used correctly consistently.     

A juvenile lizard specimen with well-preserved skin impressions from the Upper Jurassic/Lower Cretaceous of Daohugou, Inner Mongolia, China

Lizards are now relatively well known from the Yixian Formation of northeastern China. In this study, we describe a juvenile lizard from a fossil horizon at Daohugou, Inner Mongolia. These beds predate the Yixian Formation, and are probably Late Jurassic or earliest Cretaceous in age. The new specimen thus documents the first lizard material from the Daohugou locality and is the earliest lizard skeleton from China. Comparisons with developmental stages of modern lizards suggest the Daohugou lizard is a hatchling. Although tiny, the specimen is notable in preserving exquisite skin impressions showing the variation in scalation across the body, the shape and position of the cloacal outlet, and details of the manus and pes. These are the earliest recorded lepidosaurian skin traces. In its general proportions and the possession of paired frontals, the small Daohugou lizard resembles both the Yixian taxon Yabeinosaurus tenuis and the questionable Jeholacerta formosa, but it differs from the latter in scalation and, based on other characters, may be distinct from both.     

Further evidence of nuclear reactions in the Pd/D lattice: emission of charged particles

Almost two decades ago, Fleischmann and Pons reported excess enthalpy generation in the negatively polarized Pd/D-D₂O system, which they attributed to nuclear reactions. In the months and years that followed, other manifestations of nuclear activities in this system were observed, viz. tritium and helium production and transmutation of elements. In this report, we present additional evidence, namely, the emission of highly energetic charged particles emitted from the Pd/D electrode when this system is placed in either an external electrostatic or magnetostatic field. The density of tracks registered by a CR-39 detector was found to be of a magnitude that provides undisputable evidence of their nuclear origin. The experiments were reproducible. A model based upon electron capture is proposed to explain the reaction products observed in the Pd/D-D₂O system.

Post-license education for novice drivers: evaluation of a training programme implemented in Spain

INTRODUCTION: This study evaluated the implementation of a second phase training program for novice drivers in Spain, which puts the primary focus of the training on the higher hierarchical levels of driver behavior. METHOD: Two hundred and sixty-three participants took part throughout the study, which was implemented as an experimental design with the test and control groups assessed before and after the one day safety training. Measurement of the impact of the training program focused on the participants' self-evaluation and self-reporting of some driving behavior indicators related to accident risk. RESULTS: Data analysis showed a change in the expected direction in the scale related to the skills for careful driving, but not for the other four scales considered. A feedback survey about the training course offered some important input for evaluating the organization, contents, tuition, and results of the three parts of the training program (discussion group, on-road and track training) as reported by the participants in the test group. CONCLUSIONS AND SUGGESTIONS: The results of the experiment show that using a one day driver safety course, it is possible to change some of the drivers' evaluations connected to safe driving style into safe direction. The follow-up period was exceptionally long (9 months) and the design (randomly divided experimental and control groups with before and after measurements) was reliable. More effort should be devoted to improving the on-road part of the training, which was often perceived as a typical driving lesson rather than a feedback drive. IMPACT ON INDUSTRY: The findings suggest consideration of a mandatory 2nd phase driver training programme as a means to raise awareness of the full range of risks encountered by novice drivers, and as already introduced in 5 EU countries: Austria, Estonia, Finland, Luxembourg and Switzerland.     

Application of winery and distillery waste composts to a Jumilla (SE Spain) vineyard: Effects on the characteristics of a calcareous sandy-loam soil

The effects on different physico-chemical, chemical and biological soil properties of the incorporation of different organic materials into a calcareous vineyard soil were studied in an experiment during three growing seasons. The organic materials used were sheep manure and four composts derived from the treatment of winery and distillery wastes. A multivariate technique, factor analysis (FA), was also used for interpreting the data obtained from the samplings carried out throughout the three vine growing seasons. The application of the organic materials induced an increase in the activity of the soil microorganisms and in the soil macro and micronutrient contents, as well as a slow release of inorganic N. Through FA of the soil properties studied, three factors that explained 74.7% of the variability were established and the effects of the treatments after the whole experimental period were assessed.     

Soil fertility dynamics in runoff-capture agriculture, Canary Islands, Spain

In the extremely arid (∼150 mm yr⁻¹) eastern Canary Islands of Lanzarote, Fuerteventura and La Graciosa, agriculture has been sustained for decades by a traditional runoff-capture (RC) farming system known as “gavias”. Although the main goal of these systems is to increase water supply for crops, making unnecessary conventional irrigation, a secondary and equally important factor is that this system allows for sustainable agricultural production without addition of chemical or organic fertilizers. A field study was conducted to assess the impact of long-term agriculture (>50 yr) on soil fertility and to evaluate key factors affecting the nutrient sustainability of RC agricultural production. Soil fertility and nutrient dynamics were studied through chemical characterization of the arable layer (0-25 cm) of RC agricultural plots, adjacent natural soils (control) not affected by runoff and cultivation, and sediments contributed by a series of RC events. Results showed that RC soils have enhanced fertility status, particularly because they are less affected by salinity and sodicity (mean electrical conductivity = 1.8 dS m⁻¹ vs. 51.0 dS m⁻¹ in control soils; mean exchangeable sodium percentage = 11.1% vs. 30.6% in control soils), and have higher water and nutrient holding capacities (mean clay plus silt contents ≈87% vs. 69% in control soils). In general, sediments transported with the runoff and deposited in RC plots (average sediment yield ≈ 46 ton ha⁻¹ yr⁻¹), contain sufficient nutrients to prevent a progressive reduction of essential plant nutrients below natural levels in spite of nutrient uptake and removal by the harvested crop. Average additions of nitrogen, phosphorus and potassium with the runoff sediments were 33.6, 35.3 and 48.8 kg ha⁻¹ yr⁻¹, respectively. Results of this study show how a crop production system can be sustained in the long term by natural hydrological and biogeochemical catchment processes. This system maintains a nutrient balance that is not based on energy-intensive inputs of fertilizers, but is integrated in natural nutrient cycling processes, unlike other tropical farming agroecosystems.     

Levels of PCDD/PCDFs and PCBs in edible marine species and human intake: a literature review

Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) are lipophilic organic compounds whose origin comes from many different sources. PCDD/Fs and PCBs are ubiquitous and persistent environmental pollutants with a well known potential toxicity, which were included at the 1998 UN-EC POP protocol. Although human exposure to PCDD/Fs and PCBs can occur by various routes, food is the primary source. A number of studies have shown that the major food sources of these organic pollutants are fat-containing animal products, including fish and other seafood. Because of the frequent health recommendations concerning fish consumption, to determine the contribution to the dietary intake of chemical contaminants such as PCDD/Fs and PCBs through fish and other seafood consumption is an issue of special interest. This paper reviews the state of the science regarding recent literature on PCDD/F and PCB levels in marine species and human intake through fish and seafood consumption. The concentrations of these pollutants depend basically on the environment in which the respective species are caught. It is concluded that some groups of population frequently consuming high quantities of certain species could be significantly increasing health risks due to PCDD/F and PCB exposure.     

On the radiocesium carbonate barrier in organics-rich sediments of Lake Juodis, Lithuania

Radiocesium vertical profiles in organics-rich sediments of running shallow eutrophic Lake Juodis (Lithuania) were studied in relation to seasonal variations of vertical profiles (in water column and sediments) of standard variables (pH, redox potential, temperature, oxygen concentrations, conductivity). It is shown that the sedimentation rate, radiocesium mobility and its vertical profiles in sediments are controlled by the vital cycle (processes of the growth, accumulation and decomposition) of green algae covering the main bottom areas of the lake. It is also shown that calcite deposits are formed in the shallow bottom areas that are oxygenated throughout the year because of the photosynthetic activity of the green algae covering the sediment. Formation of the calcite coatings on freshly accumulated organics is remarkable for causing elevated densities of sediment solids in the upper part of the respective vertical profiles. These calcite deposits behave as a barrier for radiocesium backward flux to the bottom water making the respective bottom areas a radionuclide sink. Together with the jelly-structured sediments lying below these deposits, the calcite preserves the shape of the primary radiocesium vertical profiles formed due to free-ion diffusion after the deposition event. It was determined that bottom areas anaerobic in winter are the main radiocesium source in the water column and cause characteristic radiocesium redistribution in surface sediments.     

Perfluorinated chemicals in blood of residents in Catalonia (Spain) in relation to age and gender: a pilot study

Fluorinated organic compounds (FOCs) are a group of chemicals widely used as surfactants, lubricants, polymers, and fire-fighting foams. Recent studies have shown the ubiquitous distribution of FOCs in the environment, wildlife, and humans. We here report the results of a pilot study conducted to provide preliminary data on the levels of 13 FOCs in the blood of 48 residents in Catalonia, Spain, in relation to gender and age (25+/-5 and 55+/-5 years). The highest mean concentration was obtained for perfluorooctane sulfonate (PFOS, 7.64 ng/ml), followed by perfluorohexane sulfonate (PFHxS, 3.56 ng/ml) and perfluorooctanoic acid (PFOA, 1.80 ng/ml). Four other FOCs showed mean levels between 0.30 and 0.44 ng/ml, whereas those of the remaining 6 compounds were below the detection limit. Regarding gender, the blood levels of PFHxS and PFOA were significantly higher (p<0.05) in men than in women, while differences according to age were only noted for PFHxS (p<0.05) and perfluorooctane sulfonamide (PFOSA) (p<0.001), for which the levels were higher in the younger (25+/-5 years) group of subjects. A significant correlation between PFOS levels and those of the remaining detected FOCs (except PFDA) was found. In general terms, the current FOC concentrations were lower than those found in recent studies concerning levels of these chemicals in human blood and serum of subjects from different countries.