8,299 research outputs found
Similar biodiversity of ectomycorrhizal fungi in set-aside plantations and ancient old-growth broadleaved forests
Setting aside overmature planted forests is currently seen as an option for preserving species associated with old-growth forests, such as those with dispersal limitation. Few data exist, however, on the utility of set-aside plantations for this purpose, or the value of this habitat type for biodiversity relative to old-growth semi-natural ecosystems. Here, we evaluate the contribution of forest type relative to habitat characteristics in determining species richness and composition in seven forest blocks, each containing an ancient old-growth stand (> 1000 yrs) paired with a set-aside even-aged planted stand (ca. 180 yrs). We investigated the functionally important yet relatively neglected ectomycorrhizal fungi (EMF), a group for which the importance of forest age has not been assessed in broadleaved forests. We found that forest type was not an important determinant of EMF species richness or composition, demonstrating that set-aside can be an effective option for conserving ancient EMF communities. Species richness of above-ground EMF fruiting bodies was principally related to the basal area of the stand (a correlate of canopy cover) and tree species diversity, whilst richness of below-ground ectomycorrhizae was driven only by tree diversity. Our results suggest that overmature planted forest stands, particularly those that are mixed-woods with high basal area, are an effective means to connect and expand ecological networks of ancient old-growth forests in historically deforested and fragmented landscapes for ectomycorrhizal fungi
PMC19 COST-EFFECTIVENESS ANALYSES OF BEHAVIORAL INTERVENTIONS: TOWARDS A MORE REALISTIC COST-EFFECTIVENESS RATIO BY INCLUDING INTERMEDIATE OUTCOME MEASURES
Effect of method of sample preparation on ruminal in situ disappearance of dry matter and nitrogen in annual ryegrass in dairy cows
The objective of this study was to investigate the effect of method of sample preparation on the degradation kinetics of herbage when applying the in situ technique. Ryegrass (Lolium multiflorum cv. Midmar) was harvested at three and four weeks after cutting and fertilizing with 200 kg nitrogen (N)/ha. Freshly cut herbage was used to investigate the following four sample preparation methods. In trial 1, herbage was (1) chopped with a paper-cutting guillotine into 5-10 mm lengths, representing fresh (FR) herbage; (2) chopped and stored frozen at –20 °C in a chest freezer, representing frozen (FN) herbage; (3) chopped, stored frozen at –20 °C for 12 h followed by freeze drying for 48 h and thereafter milled through a 2 mm screen, representing freeze dried (FD) herbage and (4) chopped and oven dried at 65 °C for 48 h and thereafter milled through a 2 mm screen, representing oven dried (OD) herbage. Prepared samples were incubated in three rumen cannulated, lactating Holstein-Friesian cows. The dry matter (DM) and N loss (%) of the FR, FN, FD and OD herbage differed significantly at 0 and 5 hours incubation but not at 24 or 48 hours. Sample characteristics (particle size, wet or dry sample) clearly influenced the degradability of herbage DM and N. Frozen herbage showed similar degradation characteristics to fresh herbage. In trial 2, ryegrass samples were prepared by the same four methods, but at a standardized particle size, namely, chopped into 5–10 mm lengths. The treatments were: chopped fresh, chopped frozen, chopped freeze dried and chopped oven dried. The N losses differed significantly between treatments for the 0, 5 and 10 hour incubations, but not at the 22 and 46 hour incubation periods. Although the a, b and c fractions differed significantly between treatments, the effective degradability did not differ for fresh, frozen and freeze dried chopped samples. Oven dried chopped samples had reduced effective degradability and are not recommended for determining effective degradability. It is proposed that fresh chopped herbage be used in degradability studies.. Keywords: Ruminal disappearance; degradability; nitrogen; annual ryegrass;dairy cows South African Journal of Animal Sciences Vol. 35 (2) 2005: pp.126-13
Combined measurements of prey availability explain habitat selection in foraging seabirds
Understanding links between habitat characteristics and foraging efficiency helps predict how environmental changes influence populations of top predators. This study examines whether measurements of prey (clupeids) availability varied over stratification gradients, and determined if any of those measurements coincided with aggregations of foraging seabirds (common guillemot Uria aalge and Manx shearwater Puffinus puffinus) in the Celtic Sea, UK. The probability of encountering foraging seabirds was highest around fronts between mixed and stratified water. Prey were denser and shallower in mixed water, whilst encounters with prey were most frequent in stratified water. Therefore, no single measurement of increased prey availability coincided with the location of fronts. However, when considered in combination, overall prey availability was highest in these areas. These results show that top predators may select foraging habitats by trading-off several measurements of prey availability. By showing that top predators select areas where prey switch between behaviours, these results also identify a mechanism that could explain the wider importance of edge habitats for these taxa. As offshore developments (e.g. marine renewable energy installations) change patterns of stratification, their construction may have consequences on the foraging efficiency of seabirds
Implementation of MenACWY vaccination because of ongoing increase in serogroup W invasive meningococcal disease, the Netherlands, 2018.
The annual incidence rate of serogroup W invasive meningococcal disease in the Netherlands increased from < 0.05/100,000 (n < 10) before 2015 to 0.5/100,000 (n = 80) in 2017. Most isolates (94%) belong to clonal complex 11. The incidence rate is highest among  < 5 year-olds and 15-24 year-olds. The case fatality rate was 12% (17/138) in 2015-2017. From May 2018, MenACWY vaccination replaces MenC vaccination at age 14 months and from October 2018, 13-14 year-olds are offered MenACWY vaccination
A tree-ring and C-14 chronology of the key Sayan-Altai monuments
We present a radiocarbon chronology of key Sayan-Altai monuments from the Scythian period, based on a statistical analysis of dates produced in the 1980s and now supplemented with new dates. These new C-14 dates were produced for samples from the Tuekta-1 barrows (burial mounds) and were measured both in St. Petersburg and Groningen. These tree-ring samples were fitted to the calibration curve. Chronologies were established for the Arzhan, Tuekta-1 and Pazyryk-5 barrows. The time of the construction of the Arzhan and Pazyryk-5 barrows is the 9th and late 5th-4th centuries BC, respectively, and agrees with archaeology. According to new data obtained, the time of the Tuekta-1 barrow construction is some years older than has been accepted thus far by archaeologists.</p
Fourier Magnetic Imaging with Nanoscale Resolution and Compressed Sensing Speed-up using Electronic Spins in Diamond
Optically-detected magnetic resonance using Nitrogen Vacancy (NV) color
centres in diamond is a leading modality for nanoscale magnetic field imaging,
as it provides single electron spin sensitivity, three-dimensional resolution
better than 1 nm, and applicability to a wide range of physical and biological
samples under ambient conditions. To date, however, NV-diamond magnetic imaging
has been performed using real space techniques, which are either limited by
optical diffraction to 250 nm resolution or require slow, point-by-point
scanning for nanoscale resolution, e.g., using an atomic force microscope,
magnetic tip, or super-resolution optical imaging. Here we introduce an
alternative technique of Fourier magnetic imaging using NV-diamond. In analogy
with conventional magnetic resonance imaging (MRI), we employ pulsed magnetic
field gradients to phase-encode spatial information on NV electronic spins in
wavenumber or k-space followed by a fast Fourier transform to yield real-space
images with nanoscale resolution, wide field-of-view (FOV), and compressed
sensing speed-up.Comment: 31 pages, 10 figure
FORMATION OF SMALL VACANCY CLUSTERS IN TUNGSTEN AROUND SILVER AND INDIUM IMPURITIES STUDIED BY PAC AND THDS
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