. The Amazon basin is likely to be increasingly affected by environmental changes: higher temperatures, changes in precipitation, CO2 fertilization and habitat fragmentation. To examine the important ...ecological and biogeochemical consequences of these changes, we are developing an international network, RAINFOR, which aims to monitor forest biomass and dynamics across Amazonia in a co‐ordinated fashion in order to understand their relationship to soil and climate. The network will focus on sample plots established by independent researchers, some providing data extending back several decades. We will also conduct rapid transect studies of poorly monitored regions. Field expeditions analysed local soil and plant properties in the first phase (2001–2002). Initial results suggest that the network has the potential to reveal much information on the continental‐scale relations between forest and environment. The network will also serve as a forum for discussion between researchers, with the aim of standardising sampling techniques and methodologies that will enable Amazonian forests to be monitored in a coherent manner in the coming decades.
We present a survey of the early evolution of 12 Type IIn supernovae (SNe IIn) at ultraviolet and visible light wavelengths. We use this survey to constrain the geometry of the circumstellar material ...(CSM) surrounding SN IIn explosions, which may shed light on their progenitor diversity. In order to distinguish between aspherical and spherical CSM, we estimate the blackbody radius temporal evolution of the SNe IIn of our sample, following the method introduced by Soumagnac et al. We find that higher-luminosity objects tend to show evidence for aspherical CSM. Depending on whether this correlation is due to physical reasons or to some selection bias, we derive a lower limit between 35% and 66% for the fraction of SNe IIn showing evidence for aspherical CSM. This result suggests that asphericity of the CSM surrounding SNe IIn is common-consistent with data from resolved images of stars undergoing considerable mass loss. It should be taken into account for more realistic modeling of these events.
Bovine viral diarrhea viruses (BVDV) are a common global viral pathogen of ruminants. Considerable genetic variability is found amongst BVDV1 isolates, with at least 21 subgenotypes being described. ...In the United States, BVDV1a and 1b are the only subgenotypes described to date. Here, the genomic sequence of CA2005, a cytopathic BVDV1, was determined. This virus, isolated in California, did not segregate into either BVDV1a or 1b subgenotypes. BLAST analysis showed CA2005 was most closely related to BVDV1i isolates. CA2005 was also the first cytopathic BVDV1i and one of few non-1a, non-1b cytopathic viruses reported. The genomic sequence was 15,752 nucleotides in length. Cytopathogenicity was conferred by duplication of the NS3 protein with a small ubiquitin B insertion at the border of the NS2/NS3 proteins. Virus neutralization assays using antisera against BVDV1a vaccine viruses revealed variable neutralization, suggesting modified live vaccines may not be totally protective against CA2005 and similar viruses.
•Cytopathic BVDV1 (CA2005) isolated from cow in 2005.•5′ UTR sequence analysis showed this virus did not segregate with BVDV1a or 1b•Genomic sequencing showed this virus to be BVDV1i with genomic rearrangement.•Virus neutralization assays showed limited cross-reaction with BVDV1a vaccine strains.•CA2005 is the first BVDV1i reported in the United States.
The Amazon basin is likely to be increasingly affected by environmental changes: higher temperatures, changes in precipitation, CO2 fertilization and habitat fragmentation. To examine the important ...ecological and biogeochemical consequences of these changes, we are developing an international network, RAINFOR, which aims to monitor forest biomass and dynamics across Amazonia in a co-ordinated fashion in order to understand their relationship to soil and climate. The network will focus on sample plots established by independent researchers, some providing data extending back several decades. We will also conduct rapid transect studies of poorly monitored regions. Field expeditions analysed local soil and plant properties in the first phase (2001–2002). Initial results suggest that the network has the potential to reveal much information on the continental-scale relations between forest and environment. The network will also serve as a forum for discussion between researchers, with the aim of standardising sampling techniques and methodologies that will enable Amazonian forests to be monitored in a coherent manner in the coming decades. Abbreviation: PSP = Permanent sample plot.
We present optical light curves of 29 novae in M31 during the 2009 and 2010 observing seasons of the Palomar Transient Factory (PTF). The dynamic and rapid cadences in PTF monitoring of M31, from one ...day to ten minutes, provide excellent temporal coverage of nova light curves, enabling us to record the photometric evolution of M31 novae in unprecedented detail. We also detect eight of these novae in the near-ultraviolet (UV) band with the Galaxy Evolution Explorer (GALEX) satellite. Novae M3 IN 2009-10b and M3 IN 2010-11a show prominent UV emission peaking a few days prior to their optical maxima, possibly implying aspherical outbursts. Additionally, our blueshifted spectrum of the recent outburst of PT And (M3IN2010-12a) indicates that it is a recurrent nova in M31 and not a dwarf nova in the Milky Way as was previously assumed. Finally, we systematically searched for novae in all confirmed globular clusters (GCs) of M31 and found only M31N 2010-10f associated with Bol 126. The specific nova rate in the M31 GC system is thus about one per year, which is not enhanced relative to the rate outside the GC system.
Abstract Like other members from the Pestivirus genus, ‘HoBi’-like pestiviruses cause economic losses for cattle producers due to both acute and persistent infections. The present study analyzed for ...the first time PI animals derived from a controlled infection with two different ‘HoBi’-like strains where the animals were maintained under conditions where superinfection by other pestiviruses could be excluded. The sequence of the region coding for viral glycoproteins E1/E2 of variants within the swarms of viruses present in the PI calves and two viral inoculums used to generate them were compared. Differences in genetic composition of the viral swarms were observed suggesting that host factors can play a role in genetic variations among PIs. Moreover, PIs generated with the same inoculum showed amino acid substitutions in similar sites of the polyprotein, even in serum from PIs with different quasispecies composition, reinforcing that some specific sites in E2 are important for host adaptation.
Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the ...tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.
We combine high-redshift Type Ia supernovae from the first three years of the Supernova Legacy Survey (SNLS) with other supernova (SN) samples, primarily at lower redshifts, to form a high-quality ...joint sample of 472 SNe (123 low-z, 93 SDSS, 242 SNLS, and 14 Hubble Space Telescope). SN data alone require cosmic acceleration at >99.999% confidence, including systematic effects. For the dark energy equation of state parameter (assumed constant out to at least z = 1.4) in a flat universe, we find w = --0.91+0.16 --0.20(stat)+0.07 --0.14(sys) from SNe only, consistent with a cosmological constant. Our fits include a correction for the recently discovered relationship between host-galaxy mass and SN absolute brightness. We pay particular attention to systematic uncertainties, characterizing them using a systematic covariance matrix that incorporates the redshift dependence of these effects, as well as the shape-luminosity and color-luminosity relationships. Unlike previous work, we include the effects of systematic terms on the empirical light-curve models. The total systematic uncertainty is dominated by calibration terms. We describe how the systematic uncertainties can be reduced with soon to be available improved nearby and intermediate-redshift samples, particularly those calibrated onto USNO/SDSS-like systems.
In this paper, we empirically examine the International Financial Reporting Standards (IFRS) adoption decision of 61 countries in an attempt to determine why some countries have adopted IFRS while ...others, at least to this point in time, have chosen not to adopt. In particular, we examine the influence of cultural diversity and country size on the adoption decision. Our results indicate that the IFRS adoption decision is significantly related to the size of the country, while we are unable to document any cultural influences on the decision. Our chief result is that larger countries are less likely to adopt International Financial Reporting Standards than small countries. This result is consistent with the notion that larger countries have a well-established set of financial accounting and reporting standards already in place, and therefore would be reluctant to incur the costs of changing to an international set of standards.
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