706 research outputs found
Catch crop strategy and nitrate leaching following grazed grass-clover
Cultivation of grassland presents a high risk of nitrate leaching. This study aimed to determine if leaching could be reduced by growing spring barley (Hordeum vulgare L.) as a green crop for silage with undersown Italian ryegrass (Lolium multiïŹorum Lam.) compared with barley grown to maturity with or without an undersown conventional catch crop of perennial ryegrass (Lolium perenne L.). All treatments received 0,60 or 120 kg of ammonium-N ha-1 in cattle slurry. In spring 2003, two grass-clover ïŹelds (3 and 5 years old, respectively, with different management histories) were ploughed. The effects of the treatments on yield and nitrate leaching were determined in the ïŹrst year, while the residual effects of the treatments were determined in the second year in a crop of spring barleyâperennial ryegrass. Nitrate leaching was estimated in selected treatments using soil water samples from ceramic cups. The experiment showed that compared with treatments without catch crop, green barleyâItalian ryegrass reduced leaching by 163â320 kg Nha-1, corresponding to 95â99%, and the perennial ryegrass reduced leaching to between 34 and 86 kg Nha-1, corresponding to a reduction of 80 and 66%. Also, in the second growing season, leaching following catchcrops was reduced compared with the bare soil treatment. It was concluded that the green barleyâItalian ryegrass offers advantages not only for the environment but also for farmers, for whom it provides a fodder high in roughage and avoids the difïŹculties with clover fatigue increasingly experienced by Danish farmers
Algebraic varieties with automorphism groups of maximal rank
We confirm, to some extent, the belief that a projective variety X has the
largest number (relative to the dimension of X) of independent commuting
automorphisms of positive entropy only when X is birational to a complex torus
or a quotient of a torus. We also include an addendum to an early paper though
it is not used in the present paper.Comment: Mathematische Annalen (to appear
Angular dependence of novel magnetic quantum oscillations in a quasi-two-dimensional multiband Fermi liquid with impurities
The semiclassical Lifshitz-Kosevich-type description is given for the angular
dependence of quantum oscillations with combination frequencies in a multiband
quasi-two-dimensional Fermi liquid with a constant number of electrons. The
analytical expressions are found for the Dingle, thermal, spin, and amplitude
(Yamaji) reduction factors of the novel combination harmonics, where the latter
two strongly oscillate with the direction of the field. At the "magic" angles
those factors reduce to the purely two-dimensional expressions given earlier.
The combination harmonics are suppressed in the presence of the non-quantized
("background") states, and they decay exponentially faster with temperature
and/or disorder compared to the standard harmonics, providing an additional
tool for electronic structure determination. The theory is applied to
SrRuO.Comment: 5 pages, 2 figures, minor typos correcte
The Kodaira dimension of the moduli of K3 surfaces
The moduli space of polarised K3 surfaces of degree 2d is a quasi-projective
variety of dimension 19. For general d very little has been known about the
Kodaira dimension of these varieties. In this paper we present an almost
complete solution to this problem. Our main result says that this moduli space
is of general type for d>61 and for d=46,50,54,58,60.Comment: 47 page
Clinical and genomic assessment of PD-L1 SP142 expression in triple-negative breast cancer
Purpose: The SP142 PD-L1 assay is a companion diagnostic for atezolizumab in metastatic triple-negative breast cancer (TNBC). We strove to understand the biological, genomic, and clinical characteristics associated with SP142 PD-L1 positivity in TNBC patients. Methods: Using 149 TNBC formalin-fixed paraffin-embedded tumor samples, tissue microarray (TMA) and gene expression microarrays were performed in parallel. The VENTANA SP142 assay was used to identify PD-L1 expression from TMA slides. We next generated a gene signature reflective of SP142 status and evaluated signature distribution according to TNBCtype and PAM50 subtypes. A SP142 gene expression signature was identified and was biologically and clinically evaluated on the TNBCs of TCGA, other cohorts, and on other malignancies treated with immune checkpoint inhibitors (ICI). Results: Using SP142, 28.9% of samples were PD-L1 protein positive. The SP142 PD-L1-positive TNBC had higher CD8+ T cell percentage, stromal tumor-infiltrating lymphocyte levels, and higher rate of the immunomodulatory TNBCtype compared to PD-L1-negative samples. The recurrence-free survival was prolonged in PD-L1-positive TNBC. The SP142-guided gene expression signature consisted of 94 immune-related genes. The SP142 signature was associated with a higher pathologic complete response rate and better survival in multiple TNBC cohorts. In the TNBC of TCGA, this signature was correlated with lymphocyte-infiltrating signature scores, but not with tumor mutational burden or total neoantigen count. In other malignancies treated with ICIs, the SP142 genomic signature was associated with improved response and survival. Conclusions: We provide multi-faceted evidence that SP142 PDL1-positive TNBC have immuno-genomic features characterized as highly lymphocyte-infiltrated and a relatively favorable survival
Rationality of the moduli spaces of plane curves of sufficiently large degree
We prove that the moduli space of plane curves of degree d is rational for
all sufficiently large d.Comment: 18 pages; 1 figure; Macaulay2 scripts used can be found at
http://www.uni-math.gwdg.de/bothmer/rationality/ or at the end of the latex
source fil
Occupational Communication as Boundary Mechanism
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69000/2/10.1177_073088847400100404.pd
Further Experimental Studies of Two-Body Radiative \Upsilon Decays
Continuing our studies of radiative Upsilon(1S) decays, we report on a search
for Upsilon to gamma eta and Upsilon to gamma f_{J}(2220) in 61.3 pb^{-1} of
e^{+}e^{-} data taken with the CLEO II detector at the Cornell Electron Storage
Ring. For the gamma eta search the three decays of the eta meson to
pi^{+}pi^{-}pi^{0}, pi^{0}pi^{0}pi^{0}, and gamma gamma were investigated. We
found no candidate events in the two (3\pi)^{0} modes and no significant excess
over expected backgrounds in the gamma gamma mode to set a limit on the
branching fraction of B(Upsilon to gamma eta) < 2.1 x 10^{-5} at 90% C.L. The
three charged two-body final states h h-bar (h = pi^{+}, K^{+}, p) were
investigated for f_{J}(2220) production, with one, one, and two events found,
respectively. Limits at 90% C.L. of B(\Upsilon to gamma f_{J}) x B(f_{J} to h
h-bar) ~ 1.5 x 10^{-5} have been set for each of these modes. We compare our
results to measurements of other radiative Upsilon decays, to measurements of
radiative J/psi decays, and to theoretical predictions.Comment: 19 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to Physical Review
Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up
Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated
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