233 research outputs found
Nitrogen placement, row spacing, and furrow irrigation water positioning effects on corn yield
Furrow irrigation often leaches NO3-N. We hypothesized that
banding and sidedressing N fertilizer on a non-irrigated side of a
corn (Zea mays L.) row would maintain yield and decrease NO3-N
leaching. In a 2-yr field study in southern Idaho on a Portneuf silt
loam (coarse silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid),
we evaluated the effects of (i) N placement (broadcast vs.
banded), (ii) row spacing (0.76 m vs. a modified 0.56 m), and (iii)
irrigation water positioning (applying water to the same side or alternating
sides of a row with successive irrigations) on field corn yield
and N uptake. We irrigated every second furrow nine times in 1988 and
seven times in 1989. Compared with broadcasting, banding maintained
grain yield in 1988 and increased it by 11% in 1989. Where N was
banded in 0.56-m rows in 1989, silage yield when only the non-fertilized
furrow was irrigated was 22.9 Mg ha -1, which was 22% greater than
when alternating furrows were irrigated. Compared with 0.56-m rows,
the 0.76-m rows had no effect on 2-yr average grain yield but tended
to increase 2-yr average silage N. Banding N on one side of a row,
rather than broadcasting, and applying water all season to the furrow
on the other side of the row maintained or increased grain yield,
increased silage yield by up to 26%, and increased N uptake in silage
by up to 21%, particularly from N-depleted profiles. Applying water
to the same furrow, rather than alternating furrows, did not reduce
yield or N uptake
Furrow irrigation and N management strategies to protect water quality
N management under furrow irrigation is difficult because nitrate-nitrogen
(NO3-N) is frequently leached to groundwater. Banding
and sidedressing N fertilizer on a non-irrigated side of a row of
corn (Zea mays L.) might increase N uptake and minimize nitrate
leaching potential by reducing the NO 3 -N in soil profiles at harvest,
thereby protecting water quality. For two years in the field,
we evaluated two N placements (broadcast vs. banded), two row
spacings (0.76-m vs. a modified 0.56-m), and two ways of positioning
irrigation water (applying water to the same side or alternating
sides of the row with successive irrigations) for their effects
on N uptake in corn silage and soil profile NO3-N (to the 0.9-m
depth). In southern Idaho, we grew field corn in Portneuf silt loam
(coarse silty, mixed superactive, mesic Durinodic Xeric Haplocalcid)
by irrigating every second furrow nine times in 1988 and
seven times in 1989. We measured N uptake by harvesting whole
plants at physiological maturity and NO3-N in soil samples taken
at two in-row locations in selected plots after each irrigation.
Where irrigating alternating sides of the row, two-year average N
uptake from 0.76-m rows was 131 kg ha- 1 , 15% greater (P<0.001)
than from 0.56-m rows. Where irrigating the same furrow all season,
N uptake from banding equaled that from broadcasting the
first year but was 21% greater (P<0.001) the second. Applying
water to the same furrow decreased profile N by about 170 kg ha- 1
under 0.76-m rows by season's end in 1988. In 1989, irrigating the
same furrow and banding N into an adjacent, never-irrigated furrow
produced season-average profile N of a) 303 kg ha- 1 , the least
under all fertilized 0.76-m rows, and b) 152 kg ha- 1 under 0.56-m
rows, half that under similarly treated 0.76-m rows. Our findings
suggest that corn in 0.76-m rows should be fertilized by banding
N into every second furrow and irrigated season-long using the
remaining, non-fertilized furrows because those practices maintained
or increased N uptake in silage and minimized residual
NO3-N in 0.9-m soil profiles at season's end
Electron-acoustic plasma waves: oblique modulation and envelope solitons
Theoretical and numerical studies are presented of the amplitude modulation
of electron-acoustic waves (EAWs) propagating in space plasmas whose
constituents are inertial cold electrons, Boltzmann distributed hot electrons
and stationary ions. Perturbations oblique to the carrier EAW propagation
direction have been considered. The stability analysis, based on a nonlinear
Schroedinger equation (NLSE), reveals that the EAW may become unstable; the
stability criteria depend on the angle between the modulation and
propagation directions. Different types of localized EA excitations are shown
to exist.Comment: 10 pages, 5 figures; to appear in Phys. Rev.
The clinical effectiveness and cost effectiveness of clozapine for inpatients with severe borderline personality disorder (CALMED study): A randomised placebo-controlled trial
Background: Data from case series suggest that clozapine may benefit inpatients with borderline personality disorder (BPD), but randomised trials have not been conducted. Methods: Multicentre, double-blind, placebo-controlled trial. We aimed to recruit 222 inpatients with severe BPD aged 18 or over, who had failed to respond to other antipsychotic medications. We randomly allocated participants on a 1:1 ratio to receive up to 400mg of clozapine per day or an inert placebo using a remote web-based randomisation service. The primary outcome was total score on the Zanarini Rating scale for Borderline Personality Disorder (ZAN-BPD) at six months. Secondary outcomes included self-harm, aggression, resource use and costs, side effects and adverse events. We used a modified intention to treat analysis (mITT) restricted to those who took one or more dose of trial medication, using a general linear model fitted at six months adjusted for baseline score, allocation group and site. Results: The study closed early due to poor recruitment and the impact of the COVID-19 pandemic. Of 29 study participants, 24 (83%) were followed up at six months, of whom 21 (72%) were included in the mITT analysis. At six months, 11 (73%) participants assigned to clozapine and 6 (43%) of those assigned to placebo were still taking trial medication. Adjusted difference in mean total ZAN-BPD score at six months was -3.86 (95% Confidence Intervals = -10.04 to 2.32, p=0.22). There were 14 serious adverse events; six in the clozapine arm and eight in the placebo arm of the trial. There was little difference in the cost of care between groups. Interpretation: We recruited insufficient participants to test the primary hypothesis. The study findings highlight problems in conducting placebo-controlled trials of clozapine and in using clozapine for people with BPD, outside specialist inpatient mental health units. Trial registration ISRCTN18352058. https://doi.org/10.1186/ISRCTN1835205
Changes in the Frontotemporal Cortex and Cognitive Correlates in First-Episode Psychosis
Background: Loss of cortical volume in frontotemporal regions has been reported in patients with schizophrenia and their relatives. Cortical area and thickness are determined by different genetic processes, and measuring these parameters separately may clarify disturbances in corticogenesis relevant to schizophrenia. Our study also explored clinical and cognitive correlates of these parameters.Methods: Thirty-seven patients with first-episode psychosis (34 schizophrenia, 3 schizoaffective disorder) and 38 healthy control subjects matched for age and sex took part in the study. Imaging was performed on an magnetic resonance imaging 1.5-T scanner. Area and thickness of the frontotemporal cortex were measured using a surface-based morphometry method (Freesurfer). All subjects underwent neuropsychologic testing that included measures of premorbid and current IQ, working and verbal memory, and executive function.Results: Reductions in cortical area, more marked in the temporal cortex, were present in patients. Overall frontotemporal cortical thickness did not differ between groups, although regional thinning of the right superior temporal region was observed in patients. There was a significant association of both premorbid IQ and IQ at disease onset with area, but not thickness, of the frontotemporal cortex, and working memory span was associated with area of the frontal cortex. These associations remained significant when only patients with schizophrenia were considered.Conclusions: Our results suggest an early disruption of corticogenesis in schizophrenia, although the effect of subsequent environmental factors cannot be excluded. In addition, cortical abnormalities are subject to regional variations and differ from those present in neurodegenerative diseases
The British Army, information management and the First World War revolution in military affairs
Information Management (IM) â the systematic ordering, processing and channelling of information within organisations â forms a critical component of modern military command and control systems. As a subject of scholarly enquiry, however, the history of military IM has been relatively poorly served. Employing new
and under-utilised archival sources, this article takes the British Expeditionary Force (BEF) of the First World War as its case study and assesses the extent to which its IM system contributed to the emergence of the modern battlefield in 1918. It argues that the
demands of fighting a modern war resulted in a general, but not universal, improvement in the BEFâs IM techniques, which in turn laid the groundwork, albeit in embryonic form, for the IM systems of modern armies.
KEY WORDS: British Army, Information Management, First World War, Revolution in Military Affairs, Adaptatio
Microflares and the Statistics of X-ray Flares
This review surveys the statistics of solar X-ray flares, emphasising the new
views that RHESSI has given us of the weaker events (the microflares). The new
data reveal that these microflares strongly resemble more energetic events in
most respects; they occur solely within active regions and exhibit
high-temperature/nonthermal emissions in approximately the same proportion as
major events. We discuss the distributions of flare parameters (e.g., peak
flux) and how these parameters correlate, for instance via the Neupert effect.
We also highlight the systematic biases involved in intercomparing data
representing many decades of event magnitude. The intermittency of the
flare/microflare occurrence, both in space and in time, argues that these
discrete events do not explain general coronal heating, either in active
regions or in the quiet Sun.Comment: To be published in Space Science Reviews (2011
Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at âNN = 5.02 TeV
The second-order Fourier coefficients (Ï
) characterizing the azimuthal distributions of ΄(1S) and ΄(2S) mesons produced in PbPb collisions at = 5.02 TeV are studied. The ΄mesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb. The scalar product method is used to extract the Ï
coefficients of the azimuthal distributions. Results are reported for the rapidity range |y| < 2.4, in the transverse momentum interval 0 < p < 50 GeV/c, and in three centrality ranges of 10â30%, 30â50% and 50â90%. In contrast to the J/Ï mesons, the measured Ï
values for the ΄ mesons are found to be consistent with zero
Measurement of prompt D and meson azimuthal anisotropy and search for strong electric fields in PbPb collisions at root = 5.02 TeV
The strong Coulomb field created in ultrarelativistic heavy ion collisions is expected to produce a rapiditydependent difference (Av2) in the second Fourier coefficient of the azimuthal distribution (elliptic flow, v2) between D0 (uc) and D0 (uc) mesons. Motivated by the search for evidence of this field, the CMS detector at the LHC is used to perform the first measurement of Av2. The rapidity-averaged value is found to be (Av2) = 0.001 ? 0.001 (stat)? 0.003 (syst) in PbPb collisions at ?sNN = 5.02 TeV. In addition, the influence of the collision geometry is explored by measuring the D0 and D0mesons v2 and triangular flow coefficient (v3) as functions of rapidity, transverse momentum (pT), and event centrality (a measure of the overlap of the two Pb nuclei). A clear centrality dependence of prompt D0 meson v2 values is observed, while the v3 is largely independent of centrality. These trends are consistent with expectations of flow driven by the initial-state geometry. ? 2021 The Author. Published by Elsevier B.V. This is an open access article under the CC BY licens
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