179 research outputs found
Problemas en el cultivo de la yuca
Information on some diseases and pests that attack cassava, as well as the symptoms induced by nutritional deficiencies and toxicities and damage resulting from the misuse of herbicides are given in this manual. Specific and general recommendations regarding the control of the described problems are included. Disease control on a commercial scale is discussed. Formulae suggested for stake treatment before planting and storage and a key for identifying some cassava diseases are annexed. Color photos on symtomatology are included. (AS)En este manual se presenta informacion sobre algunas de las enfermedades y plagas que atacan a la yuca, como tambien los sintomas inducidos por deficiencias y toxicidades nutricionales y danos debidos al uso incorrecto de los herbicidas. Se incluyen recomendaciones generales y especificas para el control de los problemas descritos. Se discute el control de las enfermedades en escala comercial. Se anexan formulas sugeridas para el tratamiento de la estaca antes de la siembra y del almacenamiento y una clave para identificar algunas de las enfermedades de la yuca. Se incluyen fotos a color sobre la sintomatologia. (RA
Field problems in cassava
Information on some diseases and pests that attack cassava, as well as the symptoms induced by nutritional deficiencies and toxicities and damage resulting from the misuse of herbicides are given in this manual. Specific and general recommendations regarding the control of the described problems are included. Disease control on a commercial scale is discussed. Formulae suggested for stake treatment before planting and storage and a key for identifying some cassava diseases are annexed. Color photos on symtomatology are included. (AS)En este manual se presenta informacion sobre algunas de las enfermedades y plagas que atacan a la yuca, como tambien los sintomas inducidos por deficiencias y toxicidades nutricionales y danos debidos al uso incorrecto de los herbicidas. Se incluyen recomendaciones generales y especificas para el control de los problemas descritos. Se discute el control de las enfermedades en escala comercial. Se anexan formulas sugeridas para el tratamiento de la estaca antes de la siembra y del almacenamiento y una clave para identificar algunas de las enfermedades de la yuca. Se incluyen fotos a color sobre la sintomatologia. (RA
Change in angina symptom status after acute myocardial infarction and its association with readmission risk: An analysis of the translational research investigating underlying disparities in acute myocardial infarction patients' health status (TRIUMPH) registry
Angina is common both before and after myocardial infarction (MI). Whether the change in angina status within the first 30Â days after MI is associated with subsequent readmission and angina persistence is unknown.We studied 2915 MI patients enrolled at 24 hospitals in the Translational Research Investigating Underlying Disparities in Acute Myocardial Infarction Patients' Health Status (TRIUMPH) registry. Angina before and 30Â days after MI was assessed with the Seattle Angina Questionnaire. Patients were divided into angina-free pre- and post-MI (-/-), resolved angina (+/-), new angina (-/+), and persistent angina (+/+) groups. Multivariable proportional hazards and hierarchical modified Poisson models were performed to assess the association of each group with all-cause readmission, readmission for MI or unplanned revascularization, and angina persistence at 1Â year. Overall, 1293 patients (44%) had angina before their MI and 849 (29%) reported angina within 30Â days of discharge. Patients with post-MI angina were more likely to be younger, nonwhite, and uninsured. Compared with patients who were angina-free pre- and post-MI, 1-year all-cause readmission risks were significantly higher for patients with persistent angina (hazard ratio [HR], 1.35; 95% CI 1.06-1.71) or new angina (HR, 1.40; 95% CI, 1.08-1.82). At 1Â year, angina was present in 22% of patients and was more likely if angina was persistent (HR, 3.55; 95% CI, 3.05-4.13) or new (HR, 3.38; 95% CI, 2.59-4.42) at 30Â days compared with patients who were angina-free pre- and post-MI.Post-MI angina, whether new or persistent, is associated with higher likelihood of readmission. Prioritizing post-MI angina management is a potential means of improving 1-year outcomes.Jacob A. Doll, Fengming Tang, Sharon Cresci, P. Michael Ho, Thomas M. Maddox, John A. Spertus and Tracy Y. Wan
New interpretation of arterial stiffening due to cigarette smoking using a structurally motivated constitutive model
Cigarette smoking is the leading self-inflicted risk factor for cardiovascular diseases; it causes arterial stiffening with serious sequelea including atherosclerosis and abdominal aortic aneurysms. This work presents a new interpretation of arterial stiffening caused by smoking based on data published for rat pulmonary arteries. A structurally motivated âfour fiber familyâ constitutive relation was used to fit the available biaxial data and associated best-fit values of material parameters were estimated using multivariate nonlinear regression. Results suggested that arterial stiffening caused by smoking was reflected by consistent increase in an elastin-associated parameter and moreover by marked increase in the collagen-associated parameters. That is, we suggest that arterial stiffening due to cigarette smoking appears to be isotropic, which may allow simpler phenomenological models to capture these effects using a single stiffening parameter similar to the approach in isotropic continuum damage mechanics. There is a pressing need, however, for more detailed histological information coupled with more complete biaxial mechanical data for a broader range of systemic arteries
Weak ferromagnetism with very large canting in a chiral lattice: (pyrimidine)2FeCl2
The transition metal coordination compound (pyrimidine)2FeCl2 crystallizes in
a chiral lattice, space group I 4_1 2 2 (or I4_3 2 2). Combined magnetization,
Mossbauer spectroscopy and powder neutron diffraction studies reveal that it is
a canted antiferromagnet below T_N = 6.4 K with an unusually large canting of
the magnetic moments of 14 deg. from their general antiferromagnetic alignment,
one of the largest reported to date. This results in weak ferromagnetism with a
ferromagnetic component of 1 mu_B. The large canting is due to the interplay
between the antiferromagnetic exchange interaction and the local single-ion
anisotropy in the chiral lattice. The magnetically ordered structure of
(pyrimidine)2FeCl2, however, is not chiral. The implications of these findings
for the search of molecule based materials exhibiting chiral magnetic ordering
is discussed.Comment: 6 pages, 5 figure
In vivo and in vitro synthesis of CM-proteins (A-hordeins) from barley (Hordeum vulgare L.)
CM-proteins from barley endosperm (CMa, CMb, CMc, CMd), which are the main components of the A-hordein fraction, are synthesized most actively 10 to 30 d after anthesis (maximum at 15â20 d). They are synthesized by membranebound polysomes as precursors of higher apparent molecular weight (13,000â21,000) than the mature proteins (12,000â16,000). The largest in vitro product (21,000) is the putative precursor of protein CMd (16,000), as it is selected with anti-CMd monospecific IgG's, and is coded by an mRNA of greater sedimentation coefficient (9 S) than those encoding the other three proteins (7.5 S). CM-proteins always appear in the soluble fraction, following different homogenization and subcellular fractionation procedures, indicating that these proteins are transferred to the soluble fraction after processing
On noise treatment in radio measurements of cosmic ray air showers
Precise measurements of the radio emission by cosmic ray air showers require
an adequate treatment of noise. Unlike to usual experiments in particle
physics, where noise always adds to the signal, radio noise can in principle
decrease or increase the signal if it interferes by chance destructively or
constructively. Consequently, noise cannot simply be subtracted from the
signal, and its influence on amplitude and time measurement of radio pulses
must be studied with care. First, noise has to be determined consistently with
the definition of the radio signal which typically is the maximum field
strength of the radio pulse. Second, the average impact of noise on radio pulse
measurements at individual antennas is studied for LOPES. It is shown that a
correct treatment of noise is especially important at low signal-to-noise
ratios: noise can be the dominant source of uncertainty for pulse height and
time measurements, and it can systematically flatten the slope of lateral
distributions. The presented method can also be transfered to other experiments
in radio and acoustic detection of cosmic rays and neutrinos.Comment: 4 pages, 6 figures, submitted to NIM A, Proceedings of ARENA 2010,
Nantes, Franc
The LOPES experiment - recent results, status and perspectives
The LOPES experiment at the Karlsruhe Institute of Technology has been taking
radio data in the frequency range from 40 to 80 MHz in coincidence with the
KASCADE-Grande air shower detector since 2003. Various experimental
configurations have been employed to study aspects such as the energy scaling,
geomagnetic dependence, lateral distribution, and polarization of the radio
emission from cosmic rays. The high quality per-event air shower information
provided by KASCADE-Grande has been the key to many of these studies and has
even allowed us to perform detailed per-event comparisons with simulations of
the radio emission. In this article, we give an overview of results obtained by
LOPES, and present the status and perspectives of the ever-evolving experiment.Comment: Proceedings of the ARENA2010 conference, Nantes, Franc
Radio detection of cosmic ray air showers with LOPES
In the last few years, radio detection of cosmic ray air showers has
experienced a true renaissance, becoming manifest in a number of new
experiments and simulation efforts. In particular, the LOPES project has
successfully implemented modern interferometric methods to measure the radio
emission from extensive air showers. LOPES has confirmed that the emission is
coherent and of geomagnetic origin, as expected by the geosynchrotron
mechanism, and has demonstrated that a large scale application of the radio
technique has great potential to complement current measurements of ultra-high
energy cosmic rays. We describe the current status, most recent results and
open questions regarding radio detection of cosmic rays and give an overview of
ongoing research and development for an application of the radio technique in
the framework of the Pierre Auger Observatory.Comment: 8 pages; Proceedings of the CRIS2006 conference, Catania, Italy; to
be published in Nuclear Physics B, Proceedings Supplement
Air Shower Measurements with the LOPES Radio Antenna Array
LOPES is set up at the location of the KASCADE-Grande extensive air shower
experiment in Karlsruhe, Germany and aims to measure and investigate radio
pulses from Extensive Air Showers. Since radio waves suffer very little
attenuation, radio measurements allow the detection of very distant or highly
inclined showers. These waves can be recorded day and night, and provide a
bolometric measure of the leptonic shower component. LOPES is designed as a
digital radio interferometer using high bandwidths and fast data processing and
profits from the reconstructed air shower observables of KASCADE-Grande. The
LOPES antennas are absolutely amplitude calibrated allowing to reconstruct the
electric field strength which can be compared with predictions from detailed
Monte Carlo simulations. We report about the analysis of correlations present
in the radio signals measured by the LOPES 30 antenna array. Additionally,
LOPES operates antennas of a different type (LOPES-STAR) which are optimized
for an application at the Pierre Auger Observatory. Status, recent results of
the data analysis and further perspectives of LOPES and the possible large
scale application of this new detection technique are discussed.Comment: 8 pages, 10 figures, Contribution to the Arena 2008 conference, Rome,
June 200
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