772 research outputs found
THE MATROSHKA-III EXPERIMENT ONBOARD THE ISS - DEVELOPMENT STATUS
Radiation is currently seen as one of the main hazards for humans regarding long duration
space missions especially mission planning beyond Low Earth Orbit (LEO). For the assessment
of the radiation risk relevant radiation field models and tools can be applied. These all need and
have to be benchmarked against real measured space data. The Matroshka-III (MTR-III) experiment
as part of the Russian space experiment Matroshka-R Stage 5 (MTR-R) and realized
within the framework of the Russian space research program will answer the questions about
the distribution of dose within a human body and provide valuable input data for radiation
transport calculations. The objective of the MTR-III experiment is to extend the measurements
performed during the Matroshka (MTR) -1 and 2 experiments in a period of minimal
solar activity to a complete solar cycle thereby covering also depth dose distributions during
solar particle events. For this research the new MTR-III experiment uses an updated interface,
improved software and new developed detector systems to allow the first time a continuous
record of the doses in inner organ locations. Measurements will be performed in different ISS
Modules (SM, MIM-1, MIM-2, MLM, NEM and others). The dose distribution inside the organ
sites will be separately measured for the different sources of the radiation field (Trapped Radiation,
Galactic Cosmic Rays and Solar Energetic Particles and neutrons) for selected locations
inside the modules. The collected data serve to assess the risk of astronauts in dependence on
geo- and heliophysical conditions and of various shielding configurations. They will also help
to reduce the uncertainties in estimates of radiation risk and for the refinement of transport
calculations through realistic shielding distributions that are needed for risk predictions in future
missions. The presentation will give the current design status and detector development
for the upcoming MTR-III mission
Private Landownersâ Willingness to Enroll Their Properties in a Public Hunting Access Program in Northeast Missouri
State wildlife agencies have successfully used public hunting access fees to increase hunting opportunity and to provide a financial incentive to private landowners for maintaining habitat. Typical payments per hectare (ac) include 1.25) on average in Kansas, 3.71(1.50) for pheasant hunting in Colorado, 12.36 (5) in North Dakota for pheasant hunting, and 1.80) on average in South Dakota. We studied the USDA Conservation Reserve Program (CRP) in 2004 in Adair, Knox, Macon, Monroe, Ralls, Randolph, Schuyler, and Scotland counties in northeast Missouri as part of a quail and songbird habitat restoration initiative. CRP is prominent in these counties with 83,040 ha (205,197 ac) enrolled. We conducted a mail-back survey of all CRP contract holders, totaling 3,283 landowners to study their willingness to enroll their properties in a hypothetical public- access hunting program. The survey was designed to provide information about landowner demographics, attitudes toward wildlife and hunting, and knowledge of wildlife habitat management aspects of the CRP. We used the Kansas Department of Wildlife and Parks Walk-In Hunting Access Program as an example for questions related to the concept of public-access hunting, and presented landowners with hypothetical annual lease payments for enrolling, using a discrete-choice modeling framework. Survey response rate was relatively high at 59.5%. The average respondent had 34.6 ha (85.5 ac) enrolled in CRP, and field size averaged 6.47 ha (16.0 ac), ranging from 0.04 to 84.9 ha (0.1â209.7 ac). Wildlife as a product of the CRP was âveryâ or âsomewhat importantâ to 89% of respondents and, among a list of wildlife species and native plants, northern bobwhite (Colinus virginianus) was most popular with 80% of respondents checking âveryâ or âsomewhat importantâ on the survey. The corresponding values were 53â66% for wild turkey (Meleagris gallopavo), deer, rabbit, pheasant, and songbirds. We asked if landowners would enroll any of their CRP land in a public-access hunting program (PAHP). We used 8 different versions of the survey, each with a different âofferâ level in the question to evaluate the potential costs of a PAHP program. The structure of the survey specified whether landowners would accept payment of 1, 3, 5, 10, or 0, 91.9% chose ânoâ, and 8.1% chose âdonât knowâ; respective values (1-1.7%, 91.3%, and 6.9%; 3-4.0%, 84.9%, and 11.2%; 5- 4.7%, 83.4%, and 11.9%; 10-8.4%, 77.0%, and 14.7%; and 2/ac (10,500. About 1,012 ha (2,500 ac) would be designated for quail hunting of this hypothetical PAHP area, based on respondentsâ answers to what type of hunting they would allow. We estimate that 5,261 ha (13,000 ac) would be enrolled with 2,489 ha (6,150 ac) open for quail hunting at an annual cost of about 7/ac ($17.30/ha). There is potential to improve the feasibility of CRP lands for bobwhite hunting in northeast Missouri by adding a public-access hunting incentive, but managers will be challenged to use this approach successfully. Landownersâ inclination to allow access for deer hunting, but not for quail hunting, reduces an agencyâs justification for using quail hunting access as an approach to improve conservation of bobwhites, in addition to the relatively high cost
Grassland management effects on earthworm communities under ambient and future climatic conditions
Abstract The impacts of climate change on biodiversity can be modulated by other changing environmental conditions, e.g. induced by land-use change. The potential interactive effects of climate change and land use have rarely been studied for soil organisms. To test the effects of changing climatic conditions and land use on soil invertebrates, we examined earthworm communities across different seasons in different grassland-use types (intensively managed grassland, extensively managed meadow, and extensively managed sheep pasture).We predicted that the strength of climate change effects would vary with season and land use. Overall, extracted earthworm populations showed the strongest variations in response to the season, indicating major differences in activity patterns and extraction efficiency, while climate change and different grassland-use types had fewer and weaker effects. Future climate, characterized by slightly higher precipitation in spring and fall but a strong reduction during the summer, had positive effects on the abundance of extracted adult earthworms in spring but then reduced the abundance of active earthworms across the remaining seasons. In contrast, the total biomass of juveniles tended to be consistently lower under future climate conditions. Earthworm species responded differently to the climate change and different grassland management types, and these species-specific responses further varied strongly across seasons. Intensive grassland management had negative effects, due to plant community composition, while sheep grazing favoured earthworm populations, due to dung deposition. There were only limited interactive effects between climate and land use, which thus did not support our main hypothesis. Nevertheless, these results highlight the complex and context-dependent responses of earthworm communities and activity patterns to climate change, with potential consequences for long-term population dynamics and crucial ecosystem functions. This article is protected by copyright. All rights reserved.Peer reviewe
A Smarter Academic Year
The Dutch academic year is exceptionally long. This causes a high work pressure for instructors and students and leaves little time for research and other core scientific duties. The Young Academy compared the Dutch academic year with other countries and is making concrete recommendations for improvement.Het Nederlands academisch jaar is uitzonderlijk lang. Dit veroorzaakt een hoge werkdruk voor docenten en studenten en laat weinig tijd over voor onderzoek en andere wetenschappelijke kerntaken. De Jonge Akademie onderzocht het Nederlands academisch jaar in vergelijking met het buitenland en doet concrete aanbevelingen voor verbetering
Tree Root Zone Microbiome: Exploring the Magnitude of Environmental Conditions and Host Tree Impact
Tree roots attract their associated microbial partners from the local soil community.
Accordingly, tree root-associated microbial communities are shaped by both the
host tree and local environmental variables. To rationally compare the magnitude of
environmental conditions and host tree impact, the âPhytOakmeterâ project planted
clonal oak saplings (Quercus robur L., clone DF159) as phytometers into different
field sites that are within a close geographic space across the Central German
lowland region. The PhytOakmeters were produced via micro-propagation to maintain
their genetic identity. The current study analyzed the microbial communities in the
PhytOakmeter root zone vs. the tree root-free zone of soil two years after out-planting
the trees. Soil DNA was extracted, 16S and ITS2 genes were respectively amplified
for bacteria and fungi, and sequenced using Illumina MiSeq technology. The obtained
microbial communities were analyzed in relation to soil chemistry and weather data
as environmental conditions, and the host tree growth. Although microbial diversity in
soils of the tree root zone was similar among the field sites, the community structure
was site-specific. Likewise, within respective sites, the microbial diversity between
PhytOakmeter root and root-free zones was comparable. The number of microbial
species exclusive to either zone, however, was higher in the host tree root zone
than in the tree root-free zone. PhytOakmeter âcoreâ and âsite-specificâ microbiomes
were identified and attributed to the host tree selection effect and/or to the ambient
conditions of the sites, respectively. The identified PhytOakmeter root zone-associated
microbiome predominantly included ectomycorrhizal fungi, yeasts and saprotrophs.
Soil pH, soil organic matter, and soil temperature were significantly correlated with
the microbial diversity and/or community structure. Although the host tree contributed
to shape the soil microbial communities, its effect was surpassed by the impact of
environmental factors. The current study helps to understand site-specific microbe
recruitment processes by young host trees
Balance between geographic, soil, and host tree parameters to shape soil microbiomes associated to clonal oak varies across soil zones along a European NorthâSouth transect
Tree root-associated microbiomes are shaped by geographic, soil physico-chemical, and host tree parameters. However, their respective impacts on microbiome variations in soils across larger spatial scales remain weakly studied. We out-planted saplings of oak clone DF159 (Quercus robur L.) as phytometer in four grassland field sites along a European NorthâSouth transect. After fourâyears, we first compared the soil microbiomes of the tree root zone (RZ) and the tree root-free zone (RFZ). Then, we separately considered the total microbiomes of both zones, besides the microbiome with significant affinity to the RZ and compared their variability along the transect. Variations within the microbiome of the tree RFZ were shaped by geographic and soil physico-chemical changes, whereby bacteria responded more than fungi. Variations within both microbiomes of the tree RZ depended on the host tree and abiotic parameters. Based on perMANOVA and Mantel correlation tests, impacts of site specificities and geographic distance strongly decreased for the tree RZ affine microbiome. This pattern was more pronounced for fungi than bacteria. Shaping the microbiome of the soil zones in root proximity might be a mechanism mediating the acclimation of oaks to a wide range of environmental conditions across geographic regions
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