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Remote sensing vegetation index methods to evaluate changes in greenness and evapotranspiration in riparian vegetation in response to the Minute 319 environmental pulse flow to Mexico
During the spring of 2014, 130 million m(3) of water were released from the United States' Morelos Dam on the lower Colorado River to Mexico, allowing water to reach the Gulf of California for the first time in 13 years. Our study assessed the effects of water transfer or ecological environmental flows from one nation to another, using remote sensing. Spatial applications for water resource evaluation are important for binational, integrated water resources management and planning for the Colorado River, which includes seven basin states in the US plus two states in Mexico. Our study examined the effects of the historic binational experiment (the Minute 319 agreement) on vegetative response along the riparian corridor. We used 250 m Moderate Resolution Imaging Spectroradiometer (MODIS), Enhanced Vegetation Index (EVI) and 30 m Landsat 8 satellite imagery to track evapotranspiration (ET) and the normalized difference vegetation index (NDVI). Our analysis showed an overall increase in NDVI and evapotranspiration (ET) in the year following the 2014 pulse, which reversed a decline in those metrics since the last major flood in 2000. NDVI and ET levels decreased in 2015, but were still significantly higher (P < 0.001) than pre-pulse (2013) levels. Preliminary findings show that the decline in 2015 persisted into 2016 and 2017. We continue to analyse results for 2018 in comparison to short-term (2013-2018) and long-term (2000-2018) trends. Our results support the conclusion that these environmental flows from the US to Mexico via the Minute 319 "pulse" had a positive, but short-lived (1 year), impact on vegetation growth in the delta.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Antiferromagnetic Order in MnO Spherical Nanoparticles
We have performed unpolarized and polarized neutron diffraction experiments
on monodisperse 8 nm and 13 nm antiferromagnetic MnO nanoparticles. For the 8
nm sample, the antiferromagnetic transition temperature (114 K) is
suppressed compared to the bulk material (119 K) while for the 13 nm sample
(120 K) is comparable to the bulk. The neutron diffraction data of the
nanoparticles is well described using the bulk MnO magnetic structure but with
a substantially reduced average magnetic moment of 4.20.3 /Mn for
the 8 nm sample and 3.90.2 /Mn for the 13 nm sample. An analysis of
the polarized neutron data on both samples shows that in an individual MnO
nanoparticle about 80 of Mn ions order. These results can be explained by a
structure in which the monodisperse nanoparticles studied here have a core that
behaves similar to the bulk with a surface layer which does not contribute
significantly to the magnetic order.Comment: 7 pages, 5 figure
Remote sensing vegetation index methods to evaluate changes in greenness and evapotranspiration in riparian vegetation in response to the Minute 319 environmental pulse flow to Mexico
During the spring of 2014, 130 million m3 of water were
released from the United States' Morelos Dam on the lower Colorado River to
Mexico, allowing water to reach the Gulf of California for the first time in
13 years. Our study assessed the effects of water transfer or ecological
environmental flows from one nation to another, using remote sensing.
Spatial applications for water resource evaluation are important for
binational, integrated water resources management and planning for the
Colorado River, which includes seven basin states in the US plus two
states in Mexico. Our study examined the effects of the historic binational
experiment (the Minute 319 agreement) on vegetative response along the
riparian corridor. We used 250 m Moderate Resolution Imaging
Spectroradiometer (MODIS), Enhanced Vegetation Index (EVI) and 30 m Landsat 8 satellite imagery to track
evapotranspiration (ET) and the normalized difference vegetation index
(NDVI). Our analysis showed an overall increase in NDVI and
evapotranspiration (ET) in the year following the 2014 pulse, which reversed
a decline in those metrics since the last major flood in 2000. NDVI and ET
levels decreased in 2015, but were still significantly higher (P < 0.001) than pre-pulse (2013) levels. Preliminary findings show that the
decline in 2015 persisted into 2016 and 2017. We continue to analyse results
for 2018 in comparison to short-term (2013–2018) and long-term (2000–2018)
trends. Our results support the conclusion that these environmental flows
from the US to Mexico via the Minute 319 “pulse” had a positive, but
short-lived (1 year), impact on vegetation growth in the delta.</p
Weak ferromagnetism and field-induced spin reorientation in K2V3O8
Magnetization and neutron diffraction measurements indicate long-range
antiferromagnetic ordering below TN=4 K in the 2D, S=1/2 Heisenberg
antiferromagnet K2V3O8. The ordered state exhibits ``weak ferromagnetism'' and
novel, field-induced spin reorientations. These experimental observations are
well described by a classical, two-spin Heisenberg model incorporating
Dzyaloshinskii-Moriya interactions and an additional c-axis anisotropy. This
additional anisotropy can be accounted for by inclusion of the symmetric
anisotropy term recently described by Kaplan, Shekhtman, Entin-Wohlman, and
Aharony. This suggests that K2V3O8 may be a very unique system where the
qualitative behavior relies on the presence of this symmetric anisotropy.Comment: 5 pages, 4 ps figures, REVTEX, submitted to PR
A universal anti-Xa assay for rivaroxaban, apixaban, and edoxaban measurements: method validation, diagnostic accuracy and external validation.
A universal anti-Xa assay for the determination of rivaroxaban, apixaban and edoxaban drug concentrations would simplify laboratory procedures and facilitate widespread implementation. Following two pilot studies analysing spiked samples and material from 698 patients, we conducted a prospective multicentre cross-sectional study, including 867 patients treated with rivaroxaban, apixaban or edoxaban in clinical practice to comprehensively evaluate a simple, readily available anti-Xa assay that would accurately measure drug concentrations and correctly predict relevant levels in clinical practice. Anti-Xa activity was measured by an assay calibrated with low-molecular-weight heparin (LMWH) in addition to ultra-high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). As an external validation, LMWH-calibrated anti-Xa activity was also determined in nine external laboratories. The LMWH-calibrated anti-Xa activity correlated strongly with rivaroxaban, apixaban or edoxaban drug levels [r <sub>s</sub> = 0·98, 95% confidence interval (CI) 0·98-0·98]. The sensitivity for the clinically relevant cut-off levels of 30, 50 and 100 µg/l was 96·2% (95% CI 94·4-97·4), 96·4% (95% CI 94·4-97·7) and 96·7% (95% CI 94·3-98·1) respectively. Concordant results were obtained in the external validation study. In conclusion, a universal, LMWH-calibrated anti-Xa assay accurately measured rivaroxaban, apixaban and edoxaban concentrations and correctly predicted relevant drug concentrations in clinical practice
Long-range antiferromagnetic order in the S=1 chain compound LiVGe2O6
The phase transition in the compound LiVGe2O6 has been proposed as a unique
example of a spin-Peierls transition in an S=1 antiferromagnetic chain. We
report neutron and x-ray diffraction measurements of LiVGe2O6 above and below
the phase transition at T=24 K. No evidence is seen for any structural
distortion associated with the transition. The neutron results indicate that
the low temperature state is antiferromagnetic, driven by ferromagnetic
interchain couplings.Comment: 4 pages, 4 ps figures, REVTEX, submitted to PR
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