187 research outputs found
A Population-level Analysis of Morning Song: Exploring the Implications for Point Counts
Point counts are widely used for conducting ecological surveys of wild birds. Vocal output of birds varies with time of day, and therefore the results of ecological surveys should also vary with time of day. We modeled how malesā singing rates change over the morning. We calculated song rates in 3 min sampling periods (the standard sampling period used by the North American Breeding Bird Survey) and compared how detection rates vary as sampling period increases. We recorded singing activity in 15 neighbourhoods of breeding Black-capped Chickadees (Poecile atricapillus) with 16-element microphone arrays that recorded every song from every male in every neighbourhood. We calculated the proportion of males that produced one or more songs during 3, 5, and 10 min count periods between nautical twilight and late morning. our results show a strong peak in singing activity just before sunrise followed by a steady decline in singing activity over the course of the morning. We found that longer sampling periods yielded significantly higher detection rates at all times after sunrise. After sunrise, detection rates never exceeded 60%, even with 10 min sampling periods. We found that unpaired males had significantly higher detection rates than paired males but we found no difference between paired males with fertile versus incubating mates. our results provide strong evidence that, for black-capped Chickadees, surveys during the dawn chorus provide the most comprehensive assessment of the number of birds present, and that longer sampling periods yield significantly better estimates of population sizes at all times after sunrise
Emissions of major gaseous and particulate species during experimental burns of southern African biomass
Characteristic vegetation and biofuels in major ecosystems of southern Africa were sampled during summer and autumn 2000 and burned under semicontrolled conditions. Elemental compositions of fuels and ash and emissions of CO2, CO, CH3COOH, HCOOH, NOX, NH3, HONO, HNO3, HCl, total volatile inorganic Cl and Br, SO2and particulate C, N, and major ions were measured. Modified combustion efficiencies (MCEs, median = 0.94) were similar to those of ambient fires. Elemental emissions factors (EFel) for CH3COOH were inversely correlated with MCEs; EFels for heading and mixed grass fires were higher than those for backing fires of comparable MCEs. NOX, NH3, HONO, and particulate N accounted for a median of 22% of emitted N; HNO3emissions were insignificant. Grass fires with the highest EFels for NH3corresponded to MCEs in the range of 0.93; grass fires with higher and low MCEs exhibited lower EFels. NH3emissions for most fuels were poorly correlated with fuel N. Most Cl and Br in fuel was emitted during combustion (median for each = 73%). Inorganic gases and particulate ions accounted for medians of 53% and 30% of emitted Cl and Br, respectively. About half of volatile inorganic Cl was HCl indicating significant emissions of other gaseous inorganic Cl species. Most fuel S (median = 76%) was emitted during combustion; SO2and particulate SO42āaccounted for about half the flux. Mobilization of P by fire (median emission = 82%) implies large nutrient losses from burned regions and potentially important exogenous sources of fertilization for downwind ecosystems
The Detection of Magnetic Fields Toward M17 through the HI Zeeman Effect
We have carried out VLA Zeeman observations of HI absorption lines toward the
HII region in the M17 giant molecular cloud complex. The HI absorption lines
toward M17 show between 5 and 8 distinct velocity components which vary
spatially in a complex manner across the source. We explore possible physical
connections between these components and the M17 region based on calculations
of HI column densities, line of sight magnetic field strengths, as well as
comparisons with a wide array of previous optical, infrared, and radio
observations.
In particular, an HI component at the same velocity as the southwestern
molecular cloud (M17 SW) ~20 km/s seems to originate from the edge-on interface
between the HII region and M17 SW, in un-shocked PDR gas. We have detected a
steep enhancement in the 20 km/s HI column density and line of sight magnetic
field strengths (Blos) toward this boundary. A lower limit for the peak 20 km/s
HI column density is N_{HI}/T_s > 5.6 x 10^{19} cm^{-2}/K while the peak Blos
is ~ -450 muG. In addition, blended components at velocities of 11-17 km/s
appear to originate from shocked gas in the PDR between the HII region and an
extension of M17 SW, which partially obscures the southern bar of the HII
region. The peak N_{HI}/T_s and Blos for this component are > 4.4 x 10^{19}
cm^{-2}/K and +550 muG, respectively. Comparison of the peak magnetic fields
detected toward M17 with virial equilibrium calculations suggest that ~1/3 of
M17 SW's total support comes from its static magnetic field and the other 2/3
from its turbulent kinetic energy which includes support from Alfven waves.Comment: Contains 29 pages, 14 figures (Latex). Text and figures can be
downloaded separately at http://www.pa.uky.edu/~brogan, submitted to Ap
In situ tropical peatland fire emission factors and their variability, as determined by field measurements in Peninsula Malaysia.
Fires in tropical peatlands account for >25% of estimated total greenhouse gas emissions from deforestation and degradation. Despite significant global and regional impacts, our understanding of specific gaseous fire emission factors (EFs) from tropical peat burning is limited to a handful of studies. Furthermore, there is substantial variability in EFs between sampled fires and/or studies. For example, methane EFs vary by 91% between studies.
Here we present new fire EFs for the tropical peatland ecosystem; the first EFs measured for Malaysian peatlands, and only the second comprehensive study of EFs in this crucial environment. During August 2015 (under El NiƱo conditions) and July 2016, we embarked on field campaigns to measure gaseous emissions at multiple peatland fires burning on deforested land in Southeast Pahang (2015) and oil palm plantations in North Selangor (2016), Peninsula Malaysia. Gaseous emissions were measured using open-path Fourier transform infrared spectroscopy. The IR spectra were used to retrieve mole fractions of twelve different gases present within the smoke (including carbon dioxide and methane), and these measurements used to calculate EFs. Peat samples were taken at each burn site for physicochemical analysis and to explore possible relationships between specific physicochemical properties and fire EFs. Here we present the first evidence to indicate that substrate bulk density affects methane fire EFs reported here. This novel explanation of inter-plume, within-biome variability should be considered by those undertaking greenhouse gas accounting and haze forecasting in this region, and is of importance to peatland management, particularly with respect to artificial compaction
Identifying Compound-Target Associations by Combining Bioactivity Profile Similarity Search and Public Databases Mining
Molecular target identification is of central importance to drug discovery. Here, we developed a computational approach, named bioactivity profile similarity search (BASS), for associating targets to small molecules by using the known target annotations of related compounds from public databases. To evaluate BASS, a bioactivity profile database was constructed using 4296 compounds that were commonly tested in the US National Cancer Institute 60 human tumor cell line anticancer drug screen (NCI-60). Each compound was used as a query to search against the entire bioactivity profile database, and reference compounds with similar bioactivity profiles above a threshold of 0.75 were considered as neighbor compounds of the query. Potential targets were subsequently linked to the identified neighbor compounds by using the known targets o
Vinflunine: a new active drug for second-line treatment of advanced breast cancer. Results of a phase II and pharmacokinetic study in patients progressing after first-line anthracycline/taxane-based chemotherapy
To evaluate the single agent activity, pharmacokinetics and tolerability of the novel tubulin targeted agent vinflunine (VFL) (320āmgāmā2 q 21 days) as second-line chemotherapy in patients with metastatic breast carcinoma (MBC). All patients had disease progression after anthracycline/taxane (A/T) therapy. They could have received a nonanthracycline adjuvant treatment and subsequently received a first-line A/T combination for advanced/metastatic disease; or relapsed >6 months after completion of adjuvant A/T therapy and were subsequently treated with the alternative agent; or relapsed within 6 months from an adjuvant A/T combination. Objective response was documented in 18 of 60 patients enrolled (RR: 30% (95% confidence interval (CI): 18.9ā43.2%)). Among the responders, seven patients had relapsed during a period of <3 months from taxane-based regimen yielding a RR of 33.3%. The median duration of response was 4.8 months (95% CI: 4.2ā7.2), median progression-free survival was 3.7 months (95% CI: 2.8ā4.2) and median overall survival was 14.3 months (95% CI: 9.2ā19.6). The most frequent adverse event was neutropenia (grade 3 in 28.3% and grade 4 in 36.7% of patients). No febrile neutropenia was observed. Fatigue (grade 3 in 16.7% of patients) and constipation (grade 3 in 11.7% of patients) were also common; these were non-cumulative and manageable permitting achievement of a good relative dose intensity of 93.5%. Vinflunine is an active agent with acceptable tolerance in the management of MBC patients previously treated with (A/T)-based regimens. These encouraging phase II results warrant further investigation of this novel agent in combination with other active agents in this setting or in earlier stages of disease
Ozone-CO Correlations Determined by the TES Satellite Instrument in Continental Outflow Regions
Collocated measurements of tropospheric ozone (O3) and carbon monoxide (CO) from the Tropospheric Emission Spectrometer (TES) aboard the EOS Aura satellite provide information on O3-CO correlations to test our understanding of global anthropogenic influence on O3. We examine the global distribution of TES O3-CO correlations in the middle troposphere (618 hPa) for July 2005 and compare to correlations generated with the GEOS-Chem chemical transport model and with ICARTT aircraft observations over the eastern United States (July 2004). The TES data show significant O3-CO correlations downwind of polluted continents, with dO3/dCO enhancement ratios in the range 0.4ā1.0 mol molā1 and consistent with ICARTT data. The GEOS-Chem model reproduces the O3-CO enhancement ratios observed in continental outflow, but model correlations are stronger and more extensive. We show that the discrepancy can be explained by spectral measurement errors in the TES data. These errors will decrease in future data releases, which should enable TES to provide better information on O3-CO correlations.Earth and Planetary SciencesEngineering and Applied Science
Saffold Virus, a Human Theiler's-Like Cardiovirus, Is Ubiquitous and Causes Infection Early in Life
The family Picornaviridae contains well-known human pathogens (e.g., poliovirus, coxsackievirus, rhinovirus, and parechovirus). In addition, this family contains a number of viruses that infect animals, including members of the genus Cardiovirus such as Encephalomyocarditis virus (EMCV) and Theiler's murine encephalomyelits virus (TMEV). The latter are important murine pathogens that cause myocarditis, type 1 diabetes and chronic inflammation in the brains, mimicking multiple sclerosis. Recently, a new picornavirus was isolated from humans, named Saffold virus (SAFV). The virus is genetically related to Theiler's virus and classified as a new species in the genus Cardiovirus, which until the discovery of SAFV did not contain human viruses. By analogy with the rodent cardioviruses, SAFV may be a relevant new human pathogen. Thus far, SAFVs have sporadically been detected by molecular techniques in respiratory and fecal specimens, but the epidemiology and clinical significance remained unclear. Here we describe the first cultivated SAFV type 3 (SAFV-3) isolate, its growth characteristics, full-length sequence, and epidemiology. Unlike the previously isolated SAFV-1 and -2 viruses, SAFV-3 showed efficient growth in several cell lines with a clear cytopathic effect. The latter allowed us to conduct a large-scale serological survey by a virus-neutralization assay. This survey showed that infection by SAFV-3 occurs early in life (>75% positive at 24 months) and that the seroprevalence reaches >90% in older children and adults. Neutralizing antibodies were found in serum samples collected in several countries in Europe, Africa, and Asia. In conclusion, this study describes the first cultivated SAFV-3 isolate, its full-length sequence, and epidemiology. SAFV-3 is a highly common and widespread human virus causing infection in early childhood. This finding has important implications for understanding the impact of these ubiquitous viruses and their possible role in acute and/or chronic disease
- ā¦