The influence of thermal evolution in the magnetic protection of terrestrial planets

Magnetic protection of potentially habitable planets plays a central role in determining their actual habitability and/or the chances of detecting atmospheric biosignatures. Here we develop a thermal evolution model of potentially habitable Earth-like planets and super-Earths (SEs). Using up-to-date dynamo-scaling laws, we predict the properties of core dynamo magnetic fields and study the influence of thermal evolution on their properties. The level of magnetic protection of tidally locked and unlocked planets is estimated by combining simplified models of the planetary magnetosphere and a phenomenological description of the stellar wind. Thermal evolution introduces a strong dependence of magnetic protection on planetary mass and rotation rate. Tidally locked terrestrial planets with an Earth-like composition would have early dayside magnetopause distances between 1.5 and 4.0 Rp , larger than previously estimated. Unlocked planets with periods of rotation ~1 day are protected by magnetospheres extending between 3 and 8 Rp . Our results are robust in comparison with variations in planetary bulk composition and uncertainties in other critical model parameters. For illustration purposes, the thermal evolution and magnetic protection of the potentially habitable SEs GL 581d, GJ 667Cc, and HD 40307g were also studied. Assuming an Earth-like composition, we found that the dynamos of these planets are already extinct or close to being shut down. While GL 581d is the best protected, the protection of HD 40307g cannot be reliably estimated. GJ 667Cc, even under optimistic conditions, seems to be severely exposed to the stellar wind, and, under the conditions of our model, has probably suffered massive atmospheric losses

Economic Aspects of the Missing Data Problem - the Case of the Patient Registry

Registries are indispensable in medical studies and provide the basis for reliable study results for research questions. Depending on the purpose of use, a high quality of data is a prerequisite. However, with increasing registry quality, costs also increase accordingly. Considering these time and cost factors, this work is an attempt to estimate the cost advantages of applying statistical tools to existing registry data, including quality evaluation. Results for quality analysis showed that there are unquestionable savings of millions in study costs by reducing the time horizon and saving on average EUR 523,126 for every reduced year. Replacing additionally the over 25 % missing data in some variables, data quality was immensely improved. To conclude, our findings showed dearly the importance of data quality and statistical input in avoiding biased conclusions due to incomplete data.O

National estimates of the recreational value of streamflow

This paper presents one practical method of valuing the recreational fishing benefits generated by a unit of water as it moves downstream. A cross-sectional analysis is employed to estimate the change in individuals\u27 fishing behavior due to a change in availability of fishery resources. A proxy for the availability of stream fishery resources is derived from the link between changes in streamflow consumption to changes in the quality of fishing downstream. The results show that marginal increases in streamflow can generate recreational benefits that exceed the marginal value of water in agriculture in some regions of the country

Factors affecting adoption of recommended management practices in stocker cattle production

Binary logit regression models were used to estimate factors affecting adoption of recommended management practices. Variables analyzed include aspects of farm structure, human capital, farm objectives, and production system employed by the producer. Results reveal that operation size and dependency upon income from the stocker operation, in particular, influence the adoption of recommended practices. Older producers and those pursuing a year-round production strategy were found to lag in adoption.Peer reviewedAgricultural EconomicsAnimal Scienc

Does board independence influence financial performance in IPO firms? The moderating role of the national business system

Prior evidence suggests that board independence may enhance financial performance, but this relationship has been tested almost exclusively for Anglo-American countries. To explore the boundary conditions of this prominent governance mechanism, we examine the impact of the formal and information institutions of 18 national business systems on the board independence-financial performance relationship. Our results show that while the direct effect of independence is weak, national-level institutions significantly moderate the independence-performance relationship. Our findings suggest that the efficacy of board structures is likely to be contingent on the specific national context, but the type of legal system is insignificant