174 research outputs found
Estudo para o melhoramento do sistema cultural da soja no cerrado.
bitstream/item/178527/1/ID09931-CRI1513.pd
Seasonal Migration of Sika Deer in the Oku-Chichibu Mountains, Central Japan
Movements and seasonal home ranges of 6 GPS collared sika deer were investigated at the Oku-Chichibu Mountains, central Honshu, from April 2009 to March 2010. All deer migrated between discrete summer and winter home ranges. The linear migration distance ranged from 2.5 to 31.9 km. Mean elevation during the summer and the winter ranged from 980 to 1,782 m, and from 1,204 to 1,723 m, respectively. Two deer were upward migrants and 4 deer were downward migrants. Taking into consideration of the relatively small snow accumulation in the summer home range, the possibility of autumn migration to avoid deep snow is low. The percentage of steep slope in the winter home range was higher than that in the summer. Bamboo grass was not found in the summer home range, but was predominant in the winter home range. Road density decreased in the winter home range compared to the summer. Only 2 out of 6 deer stayed mainly in the wildlife protection area during the winter. Our results indicate that the autumn migration was affected by winter forage and human disturbance, thereby assured the survival of the deer during winter.ArticleMAMMAL STUDY. 37(2):127-137 (2012)journal articl
A rapid and robust tri-color flow cytometry assay for monitoring malaria parasite development
Microscopic examination of Giemsa-stained thin blood smears remains the gold standard method used to quantify and stage malaria parasites. However, this technique is tedious, and requires trained microscopists. We have developed a fast and simple flow cytometry method to quantify and stage, various malaria parasites in red blood cells in whole blood or in vitro cultured Plasmodium falciparum. The parasites were stained with dihydroethidium and Hoechst 33342 or SYBR Green I and leukocytes were identified with an antibody against CD45. Depending on the DNA stains used, samples were analyzed using different models of flow cytometers. This protocol, which does not require any washing steps, allows infected red blood cells to be distinguished from leukocytes, as well as allowing non-infected reticulocytes and normocytes to be identified. It also allows assessing the proportion of parasites at different developmental stages. Lastly, we demonstrate how this technique can be applied to antimalarial drug testing
Search for Cosmic-ray Boosted Sub-GeV Dark Matter using Recoil Protons at Super-Kamiokande
We report a search for cosmic-ray boosted dark matter with protons using the
0.37 megatonyears data collected at Super-Kamiokande experiment during
the 1996-2018 period (SKI-IV phase). We searched for an excess of proton
recoils above the atmospheric neutrino background from the vicinity of the
Galactic Center. No such excess is observed, and limits are calculated for two
reference models of dark matter with either a constant interaction
cross-section or through a scalar mediator. This is the first experimental
search for boosted dark matter with hadrons using directional information. The
results present the most stringent limits on cosmic-ray boosted dark matter and
exclude the dark matter-nucleon elastic scattering cross-section between
and for dark matter mass
from 10 MeV/ to 1 GeV/.Comment: With 1-page appendi
Search for astrophysical electron antineutrinos in Super-Kamiokande with 0.01wt% gadolinium-loaded water
We report the first search result for the flux of astrophysical electron
antineutrinos for energies O(10) MeV in the gadolinium-loaded Super-Kamiokande
(SK) detector. In June 2020, gadolinium was introduced to the ultra-pure water
of the SK detector in order to detect neutrons more efficiently. In this new
experimental phase, SK-Gd, we can search for electron antineutrinos via inverse
beta decay with efficient background rejection and higher signal efficiency
thanks to the high efficiency of the neutron tagging technique. In this paper,
we report the result for the initial stage of SK-Gd with a exposure at 0.01% Gd mass concentration. No significant excess
over the expected background in the observed events is found for the neutrino
energies below 31.3 MeV. Thus, the flux upper limits are placed at the 90%
confidence level. The limits and sensitivities are already comparable with the
previous SK result with pure-water () owing
to the enhanced neutron tagging
Performance of SK-Gd's Upgraded Real-time Supernova Monitoring System
Among multi-messenger observations of the next galactic core-collapse
supernova, Super-Kamiokande (SK) plays a critical role in detecting the emitted
supernova neutrinos, determining the direction to the supernova (SN), and
notifying the astronomical community of these observations in advance of the
optical signal. On 2022, SK has increased the gadolinium dissolved in its water
target (SK-Gd) and has achieved a Gd concentration of 0.033%, resulting in
enhanced neutron detection capability, which in turn enables more accurate
determination of the supernova direction. Accordingly, SK-Gd's real-time
supernova monitoring system (Abe te al. 2016b) has been upgraded. SK_SN Notice,
a warning system that works together with this monitoring system, was released
on December 13, 2021, and is available through GCN Notices (Barthelmy et al.
2000). When the monitoring system detects an SN-like burst of events, SK_SN
Notice will automatically distribute an alarm with the reconstructed direction
to the supernova candidate within a few minutes. In this paper, we present a
systematic study of SK-Gd's response to a simulated galactic SN. Assuming a
supernova situated at 10 kpc, neutrino fluxes from six supernova models are
used to characterize SK-Gd's pointing accuracy using the same tools as the
online monitoring system. The pointing accuracy is found to vary from
3-7 depending on the models. However, if the supernova is closer than
10 kpc, SK_SN Notice can issue an alarm with three-degree accuracy, which will
benefit follow-up observations by optical telescopes with large fields of view.Comment: 38 pages, 29 figures, 6 table
Search for Periodic Time Variations of the Solar B Neutrino Flux Between 1996 and 2018 in Super-Kamiokande
We report a search for time variations of the solar B neutrino flux using
5,804 live days of Super-Kamiokande data collected between May 31, 1996, and
May 30, 2018. Super-Kamiokande measured the precise time of each solar neutrino
interaction over 22 calendar years to search for solar neutrino flux
modulations with unprecedented precision. Periodic modulations are searched for
in a data set comprised of five-day interval solar neutrino flux measurements
with a maximum likelihood method. We also applied the Lomb-Scargle method to
this data set to compare it with previous reports. The only significant
modulation found is due to the elliptic orbit of the Earth around the Sun. The
observed modulation is consistent with astronomical data: we measured an
eccentricity of (1.530.35)\,\%, and a perihelion shift is
(1.513.5)\,days.Comment: 8 pages, 5 figures, 2 tables, and data file:
"sksolartimevariation5804d.txt
Measurements of the charge ratio and polarization of cosmic-ray muons with the Super-Kamiokande detector
We present the results of the charge ratio () and polarization
() measurements using the decay electron events collected from
2008 September to 2022 June by the Super-Kamiokande detector. Because of its
underground location and long operation, we performed high precision
measurements by accumulating cosmic-ray muons. We measured the muon charge
ratio to be at
, where
is the muon energy and is the zenith angle
of incoming cosmic-ray muons. This result is consistent with the Honda flux
model while this suggests a tension with the model of . We
also measured the muon polarization at the production location to be
at the muon
momentum of at the surface of the
mountain; this also suggests a tension with the Honda flux model of
. This is the most precise measurement ever to experimentally
determine the cosmic-ray muon polarization near . These
measurement results are useful to improve the atmospheric neutrino simulations.Comment: 29 pages, 45 figure
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