82 research outputs found
Effects of Filter Strips on Habitat Use and Home Range of Northern Bobwhites on Alligator River National Wildlife Refuge
Lack of breeding habitat for northern bobwhites (Colinus virginianus) on agricultural landscapes is a factor that limits populations. Therefore, we examined how the addition of filter strips around crop fields and along crop field drainage ditches impacted northern bobwhites. Our study focused on habitat use, home range and brood-rearing range of bobwhites, from April through September I 993-94. Two farms on Alligator River National Wildlife Refuge were sub-divided into filter strip (FS) and non-filter strip (NFS) sections. More bobwhites were found on FS sections than on NFS sections based on flush counts (4.3x more on FS areas: P = 0.02). We used log-linear analysis to examine the distribution of telemetry locations (n = 1796) of radio-marked bobwhites (n = 218) across 5, 4.6m bands parallel to drainage ditches. Bobwhite locations were skewed towards ditches, particularly on FS sections before soybeans matured to a size that was sufficient to provide canopy cover for bobwhites. Bobwhites captured on FS sections had significantly smaller breeding season ranges than those captured on NFS sections (P = 0.001). Adult and sub-adult breeding season (May-Aug) ranges (n = 23) averaged 32 ha (SE = 26) and 182 ha (SE = 41) on FS and NFS sections, respectively. Brood ranges to 14 days (n = 9) ranged from 0.8 ha to 2.2 ha depending on habitat and calculation method. Presence of filter strips shifted habitat use patterns, especially during spring and early summer, and improved crop fields as habitat for breeding bobwhites
Contrasting patterns of population structure and gene flow facilitate exploration of connectivity in two widely distributed temperate octocorals
This is the final version of the article. Available from Springer Nature via the DOI in this record.Connectivity is an important component of metapopulation dynamics in marine systems and can influence population persistence, migration rates and conservation decisions associated with Marine Protected Areas (MPAs). In this study, we compared the genetic diversity, gene flow and population structure of two octocoral species, Eunicella verrucosa and Alcyonium digitatum, in the northeast Atlantic (ranging from the northwest of Ireland and the southern North Sea, to southern Portugal), using two panels of thirteen and eight microsatellite loci, respectively. Our results identified regional genetic structure in E. verrucosa partitioned between populations from southern Portugal, northwest Ireland, and Britain/France; subsequent hierarchical analysis of population structure also indicated reduced gene flow between southwest Britain and northwest France. However, over a similar geographical area, A. digitatum showed little evidence of population structure, suggesting high gene flow and/or a large effective population size; indeed, the only significant genetic differentiation detected in A. digitatum occurred between North Sea samples and those from the English Channel/northeast Atlantic. In both species the vast majority of gene flow originated from sample sites within regions, with populations in southwest Britain being the predominant source of contemporary exogenous genetic variants for the populations studied. Unsurprisingly, historical patterns of gene flow appeared more complex, though again southwest Britain appeared an important source of genetic variation for both species. Our findings have major conservation implications, particularly for E. verrucosa, a protected species in UK waters and listed by the IUCN as ‘Vulnerable’, and for the designation and management of European MPAs.We thank Natural England (project No. RP0286, contract No. SAE 03-02-146), the NERC (grant No. NE/L002434/1) and the University of Exeter for funding this research. Additional funding for sample collection, travel and microsatellite development was provided by the EU Framework 7 ASSEMBLE programme, agreement no. 227799, and NERC grant No. NBAF-362
A ruthenium polypyridyl intercalator stalls DNA replication forks, radiosensitizes human cancer cells and is enhanced by Chk1 inhibition
Ruthenium(II) polypyridyl complexes can intercalate DNA with high affinity and prevent cell
proliferation; however, the direct impact of ruthenium-based intercalation on cellular DNA replication
remains unknown. Here we show the multi-intercalator [Ru(dppz)2(PIP)]2+ (dppz =
dipyridophenazine, PIP = 2-(phenyl)imidazo[4,5-f][1,10]phenanthroline) immediately stalls
replication fork progression in HeLa human cervical cancer cells. In response to this replication
blockade, the DNA damage response (DDR) cell signalling network is activated, with checkpoint
kinase 1 (Chk1) activation indicating prolonged replication-associated DNA damage, and cell
proliferation is inhibited by G1-S cell-cycle arrest. Co-incubation with a Chk1 inhibitor achieves
synergistic apoptosis in cancer cells, with a significant increase in phospho(Ser139) histone H2AX (γ-
H2AX) levels and foci indicating increased conversion of stalled replication forks to double-strand
breaks (DSBs). Normal human epithelial cells remain unaffected by this concurrent treatment.
Furthermore, pre-treatment of HeLa cells with [Ru(dppz)2(PIP)]2+ before external beam ionising
radiation results in a supra-additive decrease in cell survival accompanied by increased γ-H2AX
expression, indicating the compound functions as a radiosensitizer. Together, these results indicate ruthenium-based intercalation can block replication fork progression and demonstrate how these
DNA-binding agents may be combined with DDR inhibitors or ionising radiation to achieve more
efficient cancer cell killing
Beam-Target Double Spin Asymmetry A_LT in Charged Pion Production from Deep Inelastic Scattering on a Transversely Polarized He-3 Target at 1.4<Q^2<2.7 GeV^2
We report the first measurement of the double-spin asymmetry for
charged pion electroproduction in semi\nobreakdash-inclusive
deep\nobreakdash-inelastic electron scattering on a transversely polarized
He target. The kinematics focused on the valence quark region,
with . The corresponding neutron
asymmetries were extracted from the measured He asymmetries and
proton over He cross section ratios using the effective polarization
approximation. These new data probe the transverse momentum dependent parton
distribution function and therefore provide access to quark
spin-orbit correlations. Our results indicate a positive azimuthal asymmetry
for production on He and the neutron, while our
asymmetries are consistent with zero.Comment: 6 pages, 2 figures, 1 tables, published in PR
Single Spin Asymmetries in Charged Pion Production from Semi-Inclusive Deep Inelastic Scattering on a Transversely Polarized He Target
We report the first measurement of target single spin asymmetries in the
semi-inclusive reaction on a transversely polarized
target. The experiment, conducted at Jefferson Lab using a 5.9 GeV electron
beam, covers a range of 0.14 0.34 with 1.3 2.7 GeV. The
Collins and Sivers moments were extracted from the azimuthal angular dependence
of the measured asymmetries. The extracted Collins moments for He
are consistent with zero, except for the moment at , which
deviates from zero by 2.3. While the Sivers moments are
consistent with zero, the Sivers moments favor negative values. The
neutron results were extracted using the nucleon effective polarization and the
measured cross section ratio of proton to He, and are largely consistent
with the predictions of phenomenological fits and quark model calculations.Comment: 6 pages, 2 figures, 2 tables, published in PR
Interactive stated choice surveys: a study of air travel behaviour
Stated preference (SP) experiments are becoming an increasingly popular survey methodology for investigating travel behaviour. Nevertheless, some evidence suggests that SP experiments do not mirror decisions in real markets. With an increasing number of real world decisions made using the internet, an opportunity exists to improve the realism of the SP counterparts of such choices by aligning the choice environment with such online portals. In this paper, we illustrate the benefits of such an approach in the context of air travel surveys. Our survey is modelled on the interface and functionality of an online travel agent (OTA). As with a real OTA, many ticket options are presented. Sort tools allow the options to be reordered, search tools allow options to be removed from consideration, and a further tool allows attributes to be hidden and shown. Extensive use of these tools is made by the 462 respondents. A traditional SP component was also completed by the respondents. Our exploratory analysis as well as random utility model estimation results confirm not only that respondents seem to engage more actively with the interactive survey, but also that the resulting data allows for better performance in model estimation compared to a more conventional SP experiment. These results have implications for the study of other complex travel choices where interactive surveys may similarly be preferable to standard approaches
Grain size analysis of California waterbodies to determine the spatial extent and temporal trends of depositional areas where hydrophobic organic compounds could accumulate
Plasma volume and blood metabolites in middle-aged runners during a warm-weather marathon
Guanosine 3',5'-cyclic monophosphate stimulated release of actively accumulated calcium in purified disks from rod outer segments of bovine retina
- …