225 research outputs found
Use of ERTS data for a multidisciplinary analysis of Michigan resources
The author has identified the following significant results. The results of this investigation of ratioing simulated ERTS spectral bands and several non-ERTS bands (all collected by an airborne multispectral scanner) indicate that significant terrain information is available from band-ratio images. Ratio images, which are based on the relative spectral changes which occur from one band to another, are useful for enhancing differences and aiding the image interpreter in identifying and mapping the distribution of such terrain elements as seedling crops, all bare soil, organic soil, mineral soil, forest and woodlots, and marsh areas. In addition, the ratio technique may be useful for computer processing to obtain recognition images of large areas at lower costs than with statistical decision rules. The results of this study of ratio processing of aircraft MSS data will be useful for future processing and evaluation of ERTS-1 data for soil and landform studies. Additionally, the results of ratioing spectral bands other than those currently collected by ERTS-1 suggests that some other bands (particularly a thermal band) would be useful in future satellites
Use of ERTS data for a multidisciplinary analysis of Michigan resources
There are no author-identified significant results in this report
Application of ERTS-1 data to analysis of agricultural crops and forests in Michigan
The results reported are based on analysis of ERTS Frame 1033-15580 collected over southwestern Lower Michigan on August 25, 1972. Major agricultural crops such as corn and soybeans were approaching maturity at this data and forest canopies were dense. Extensive ground truth information was gathered by detailed field study of test strips. This detailed information was supplemented over larger areas by interpretation of RB-57 and C-47 photography and MSS imagery. Recognition processing of ERTS-1 MSS data was carried out on a digital computer. Fields and forest stands were selected as training sets and test areas. Aerial imagery was essential for locating the positions of these selected areas on ERTS digital tapes. The recognition process was successful for each type of vegetation which had a dense green canopy such as forests, corn, and soybeans. Bare soil was also recognizable as a category
CP Violation in B -> pi+ pi- and the Unitarity Triangle
We analyze the extraction of weak phases from CP violation in
decays. We propose to determine the unitarity triangle
by combining the information on mixing induced CP
violation in , , with the precision observable
obtained from the CP asymmetry in . It is then possible to write
down exact analytical expressions for and as simple
functions of the observables and , and of the penguin
parameters and . As an application clean lower bounds on
and can be derived as functions of and ,
essentially without hadronic uncertainty. Computing and within QCD
factorization yields precise determinations of and since
the dependence on and is rather weak. It is emphasized that the
sensitivity to the phase enters only at second order and is extremely
small for moderate values of this phase, predicted in the heavy-quark limit.
Transparent analytical formulas are further given and discussed for the
parameter of direct CP violation in . We also discuss
alternative ways to analyze and that can be useful if new physics
affects -- mixing. Predictions and uncertainties for and
in QCD factorization are examined in detail. It is pointed out that a
simultaneous expansion in and 1/N leads to interesting simplifications.
At first order infrared divergences are absent, while the most important
effects are retained. Independent experimental tests of the factorization
framework are briefly discussed.Comment: 26 pages, 7 figure
Economic evaluation of crop acreage estimation by multispectral remote sensing
The author has identified the following significant results. Photointerpretation of S190A and S190B imagery showed significantly better resolution with the S190B system. A small tendancy to underestimate acreage was observed. This averaged 6 percent and varied with field size. The S190B system had adequate resolution for acreage measurement but the color film did not provide adequate contrast to allow detailed classification of ground cover from imagery of a single date. In total 78 percent of the fields were correctly classified but with 56 percent correct for the major crop, corn
Predictions for decays
We present a phenomenological study of the rare double radiative decay in the Standard Model (SM) and beyond. Using the operator
product expansion (OPE) technique, we estimate the short-distance (SD)
contribution to the decay amplitude in a region of the phase space which is
around the point where all decay products have energy in the rest
frame of the -meson. At lowest order in 1/Q, where is of order ,
the matrix element is then expressed in terms of the
usual form factors known from semileptonic rare decays. The integrated
SD branching ratio in the SM in the OPE region turns out to be . We work
out the di-photon invariant mass distribution with and without the resonant
background through . In the SM,
the resonance contribution is dominant in the region of phase space where the
OPE is valid. The present experimental upper limit on
decays, which constrains the scalar/pseudoscalar Four-Fermi operators with
, leaves considerable room for new physics in the
one-particle-irreducible contribution to decays. In this
case, we find that the SD branching ratio can be
enhanced by one order of magnitude with respect to its SM value and the SD
contribution can lie outside of the resonance peaks.Comment: 17 pages, 4 figures; Note added on Schouten identity and 2 references
added; v4: typos in Eqs (8), (44) and erroneous statement on mixing before Eq
(44) fixed. All results and conclusions unchange
Exploring the Unitarity Triangle through CP violation observables in
We discuss the determination of the CKM parameters from the forthcoming
violation observables in decays. Combining the information on
mixing induced CP violation in , with the
precision observable and the -- mixing phase
, we propose a determination of the unitarity triangle . Computing the penguin parameters within QCD
factorization yield precise determination of , reflected
by a weak dependence on the which is shown as a second order effect.
The impact of the direct CP violation observable on the penguin
parameters are investigated and a lower bound on is extracted. We also
discuss the effect of the -- new physics mixing phase on
the penguin parameters and . Using the SU(3)-flavour
symmetry argument and the current -factories data provided by the modes, we complement the CP-violating
observables in a variety of ways, in particular we find that .
Finally we analyze systematically the SU(3)-symmetry breaking factor within QCD
factorization.Comment: 22 pages, 6 figures, typos corrected, reference and some remarks
adde
B -> K1 gamma and tests of factorization for two-body non leptonic Bdecays with axial-vector mesons
The large branching ratio for B-> K1 gamma recently measured at Belle implies
a large B -> K1 transition form factor and large branching ratios for non
leptonic B decays involving an axial-vector meson. In this paper we present an
analysis of two-body B decays with an axial-vector meson in the final state
using naive factorization and the B -> K1 form factors obtained from the
measured radiative decays. We find that the predicted B -> J/psi K1 branching
ratio is in agreement with experiment. We also suggest that the decay rates of
B -> K1 pi, B -> a1 K and B -> b1 K could be used to test the factorization
ansatz.Comment: 8 pages; 7 new references included and a comment on K2(1430) in the
final state adde
Forward-backward and isospin asymmetry for B -> K* l+ l- decay in the standard model and in supersymmetry
We discuss two dedicated observables in exclusive B -> K* l+ l- decay that
can be used to study effects of physics beyond the standard model, namely the
forward-backward asymmetry in the lepton spectrum and the isospin-asymmetry
between decays of charged and neutral B mesons. We consider the region of large
recoil-energy (i.e. small invariant mass of the lepton pair), and employ the
QCD factorization approach to exclusive B meson decays. Sub-leading effects in
the heavy quark mass expansion have been taken into account for the calculation
of the isospin-asymmetry. We give predictions for decay asymmetries in the
standard model, and its supersymmetric extension with minimal flavor violation,
using parameter values allowed by current experimental constraints on B->X_s
gamma decay.Comment: 21 pages, LaTeX with 6 figures, added reference
Triple combination antibiotic therapy for carbapenemase-producing Klebsiella pneumoniae: a systematic review
Abstract Background The spread of carbapenemase-producing K. pneumoniae (CPKP) has become a significant problem worldwide. Combination therapy for CPKP is encouraging, but polymyxin resistance to many antibiotics is hampering effective treatment. Combination therapy with three or more antibiotics is being increasingly reported, therefore we performed a systematic review of triple combination cases in an effort to evaluate their clinical effectiveness for CPKP infections. Methods The PubMed database was searched to identify all published clinical outcomes of CPKP infections treated with triple combination therapy. Articles were stratified into two tiers depending on the level of clinical detail provided. A tier 1 study included: antibiotic regimen, regimen-specific outcome, patient status at onset of infection, and source of infection. Articles not reaching these criteria were considered tier 2. Results Thirty-three studies were eligible, 23 tier 1 and ten tier 2. Among tier 1 studies, 53 cases were included in this analysis. The most common infection was pneumonia (31%) followed by primary or catheter-related bacteremia (21%) and urinary tract infection (17%). Different combinations of antibiotic classes were utilized in triple combinations, the most common being a polymyxin (colistin or polymyxin B, 86.8%), tigecycline (73.6%), aminoglycoside (43.4%), or carbapenem (43.4%). Clinical and microbiological failure occurred in 14/39 patients (35.9%) and 22/42 patients (52.4%), respectively. Overall mortality for patients treated with triple combination therapy was 35.8% (19/53 patients). Conclusions Triple combination therapy is being considered as a treatment option for CPKP. Polymyxin-based therapy is the backbone antibiotic in these regimens, but its effectiveness needs establishing in prospective clinical trials
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