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.     

Dynamic workplans and field analytics: Metals assessment by inductively coupled plasma/optical emission spectroscopy

Hazardous waste site investigations were carried out at the Marine Corps Air Station (MCAS) in Yuma, Arizona and at Hanscom Air Force Base (HAFB) in Bedford, Massachusetts. The purpose of the first was to determine the location and extent of metals contamination throughout the base. The objective of the second was to evaluate the risk of metals contamination to groundwater from soil at three locations within the airfield. Dynamic workplans were developed and an adaptive sampling and analysis plan carried out with the data produced in the field used to support the goals of each project. An inductively coupled plasma/optical emission spectrometer (ICP/OES) was modified for field operation. A more efficient microwave digestion method and pressurized Teflon filtration system were developed for the HAFB project. Results were comparable to standard Environmental Protection Agency (EPA) methods, which must rely on two digestion procedures to recover EPA-targeted metals within the prescribed recovery range. The MCAS investigation, conducted over a five-month period, advanced the Navy's efforts from 30 months behind schedule to 18 months ahead of schedule, while the data generated at HAFB showed no risk to groundwater from metals.     

The resource curse revisited and revised: A tale of paradoxes and red herrings

We critically evaluate the empirical basis for the so-called resource curse and find that, despite the topic's popularity in economics and political science research, this apparent paradox may be a red herring. The most commonly used measure of “resource abundance” can be more usefully interpreted as a proxy for “resource dependence”—endogenous to underlying structural factors. In multiple estimations that combine resource abundance and dependence, institutional, and constitutional variables, we find that (i) resource abundance, constitutions, and institutions determine resource dependence, (ii) resource dependence does not affect growth, and (iii) resource abundance positively affects growth and institutional quality.     

PUMP-CTD-System for trace metal sampling with a high vertical resolution. A test in the Gotland Basin, Baltic Sea

It is a great challenge to sample seawater across interfaces, for example the halocline or the redoxcline, to investigate trace metal distribution. With the use of 10l sampling bottles mounted to a wire or a CTD-Rosette it is possible to obtain a maximum vertical resolution of 5m. For the detection of small vertical structures in the vertical distribution of trace metals across the redoxcline, the CTD-Bottle-Rosette is not sufficient. Therefore, a PUMP-CTD-System was developed, which enables water sampling with high resolution (1m maximum) along a vertical profile. To investigate the suitability and possible contamination sources of this device two experiments were carried out in the Gotland Basin. The first experiment consisted of two separate profiles. The first profile was obtained with the CTD-Bottle-Rosette and the second with the PUMP-CTD-System. Both were taken from the bottom to the surface water layer. The second experiment was a combined profile obtained from the surface to the bottom with the PUMP-CTD-System attached to the CTD-Bottle-Rosette. Concentrations of dissolved Pb, Cd, Cu, Zn, Fe, Mn, Co and Ni from the "Niskin Bottles" and from the PUMP were measured and compared for each investigation. We demonstrate that it is useful to perform vertical sampling from lower to higher concentrations, e.g. surface to bottom in this environment, and that a longer flushing is required for sampling seawater in the anoxic bottom water. A comparison of the two systems for oxygen and hydrogen sulphide measurements showed an improvement of the precision and the quality of the sampling when using the PUMP. Thus, metal speciation at the oxic-anoxic gradient zone and on a high vertical resolution will be accessible. As concentrations of dissolved Pb, Cd, Cu, Zn, Co, Ni, Fe and Mn in seawater sampled with both devices were in the same range, we conclude that the PUMP-CTD-System is well suited to sample seawater for trace metal analyses.     

Monogamy in a new species of wild guinea pigs (Galea sp.)

A new species of wild guinea pigs from Bolivia was recently discovered: Galea sp. So far no data are available concerning its social and mating systems. We therefore investigated behavioural compatibility, sexual dimorphism, paternity in a male-competing situation, testicular and epididymal size, and sperm morphology and motility. The results showed a complete intrasexual and moderate intersexual behavioural incompatibility between unfamiliar animals, a reversed sexual dimorphism with females larger than males, and litters always fathered by single males. Furthermore, both the reproductive organ weights and the percentage of motile sperm and sperm with intact acrosomes were significantly lower compared with the promiscuous congeneric Galea musteloides. In summary, these data strongly suggest a monogamous social and mating system for the recently discovered Galea sp.     

Hazard assessment of chemicals in soil

Based on a stepwise (tiered) approach, degradation, adsorption and leaching tests as well as various effect tests (using plants, microorganisms and animals) are recommended for the testing of environmental chemicals. If, after the tests of tiers 1 and 2, the results of a monospecies-effect-test (including a safety factor) are within the range of the predicted exposure, the ecotoxicological hazard should be determined using a terrestrial model ecosystem. Some of the tests for the proposed strategy were selected from practical experience in testing environmental chemicals in the laboratory, and some on the basis of a comprehensive literature review.     

RAINGAGE NETWORK DESIGN USING NEXRAD PRECIPITATION ESTIMATES1

ABSTRACT: A general framework is proposed for using precipitation estimates from NEXRAD weather radars in raingage network design. NEXRAD precipitation products are used to represent space time rainfall fields, which can be sampled by hypothetical raingage networks. A stochastic model is used to simulate gage observations based on the areal average precipitation for radar grid cells. The stochastic model accounts for subgrid variability of precipitation within the cell and gage measurement errors. The approach is ideally suited to raingage network design in regions with strong climatic variations in rainfall where conventional methods are sometimes lacking. A case study example involving the estimation of areal average precipitation for catchments in the Catskill Mountains illustrates the approach. The case study shows how the simulation approach can be used to quantify the effects of gage density, basin size, spatial variation of precipitation, and gage measurement error, on network estimates of areal average precipitation. Although the quality of NEXRAD precipitation products imposes limitations on their use in network design, weather radars can provide valuable information for empirical assessment of rain‐gage network estimation errors. Still, the biggest challenge in quantifying estimation errors is understanding subgrid spatial variability. The results from the case study show that the spatial correlation of precipitation at subgrid scales (4 km and less) is difficult to quantify, especially for short sampling durations. Network estimation errors for hourly precipitation are extremely sensitive to the uncertainty in subgrid spatial variability, although for storm total accumulation, they are much less sensitive.