2,584 research outputs found
Should diastolic and systolic blood pressure be considered for cardiovascular risk evaluation: a study in middle-aged men and women
AbstractOBJECTIVESThe goal of this study was to evaluate the role of diastolic blood pressure (DBP) in cardiovascular mortality for different systolic blood pressure (SBP) levels in middle-aged men and women.BACKGROUNDIn middle-aged subjects it is unclear whether DBP, in addition to SBP, should be considered for risk evaluation.METHODSSubjects (77,023 men; 48,480 women) aged 40 to 70 years old, had no major cardiovascular disease, no antihypertensive treatment and were examined at the Centre d’Investigations Préventives et Cliniques between 1972 and 1988. Mortality was assessed for an 8- to 12-year period.RESULTSIn both genders, cardiovascular mortality increased with the SBP level. In men and women with normal SBP levels, DBP did not influence cardiovascular mortality after adjustment for age and SBP. In men with systolic hypertension, a U-shaped curve relationship between cardiovascular mortality and DBP was observed, with the lowest mortality rates in the group with DBP 90 to 99 mm Hg. Compared with this group, age- and SBP-adjusted cardiovascular mortality was higher by 73% (p < 0.02) in the group with DBP <90 mm Hg and by 65% (p < 0.001) in the group with DBP ≥110 mm Hg. In women with systolic hypertension, however, DBP was positively correlated with cardiovascular mortality.CONCLUSIONSIn middle-aged subjects, classification of cardiovascular risk according to DBP levels should take into account gender, especially when SBP levels are elevated. Men with systolic hypertension are at higher risk when their DBP is “normal” than when they present a mild to moderate increase in DBP. In women of the same age, however, systolic-diastolic hypertension represents a higher risk than isolated systolic hypertension
Source geometry from exceptionally high resolution long period event observations at Mt Etna during the 2008 eruption
During the second half of June, 2008, 50 broadband seismic stations were
deployed on Mt Etna volcano in close proximity to the summit, allowing us to
observe seismic activity with exceptionally high resolution. 129 long period
events (LP) with dominant frequencies ranging between 0.3 and 1.2 Hz, were
extracted from this dataset. These events form two families of similar
waveforms with different temporal distributions. Event locations are performed
by cross-correlating signals for all pairs of stations in a two-step scheme. In
the first step, the absolute location of the centre of the clusters was found.
In the second step, all events are located using this position. The hypocentres
are found at shallow depths (20 to 700 m deep) below the summit craters. The
very high location resolution allows us to detect the temporal migration of the
events along a dike-like structure and 2 pipe shaped bodies, yielding an
unprecedented view of some elements of the shallow plumbing system at Mount
Etna. These events do not seem to be a direct indicator of the ongoing lava
flow or magma upwelling
Sorghum Tillage in the Texas High Plains
6 pp., 1 figure, 1 tableWater management is the most important factor in sorghum production. Tillage practices can affect the water content of the soil and play a large role in successful sorghum production. This publication discusses the types of tillage and ways to reduce evaporation and erosion and conserve water
The metabolic syndrome: similar deleterious impact on all-cause mortality in hypertensive and normotensive subjects
Objectives Few data are available on the impact of the metabolic syndrome on all-cause mortality risk according to the presence of hypertension. Our aim was to evaluate the 5-year impact of the metabolic syndrome, according to blood pressure status, on all-cause mortality risk in a large French population. Methods The study population included 39 998 men and 20 756 women with no personal history of cardiovascular disease, who had a health check-up at the IPC Center (Paris, France) between 1999 and 2002, and who were followed up for 4.7 W 1.2 years. The metabolic syndrome was defined according to the National Cholesterol Educational Program classification (2001). Cox regression models were used to evaluate risk of all-cause mortality after adjustment for age, sex, classical risk factors and socioeconomic categories. Subjects were classified according to blood pressure status: hypertensive subject (systolic blood pressure > -140 mmHg and/or diastolic blood pressure > -90 mmHg or treatment) and normotensive subject. Results The risk of all-cause mortality associated with the metabolic syndrome was 1.50 (1.24-1.82) [hazard ratio (HR) (95% confidence interval)]. The risk of all-cause mortality associated with the presence of hypertension was 1.60 (1.38-1.85). During the 4.7 years of follow-up, the impact of the metabolic syndrome was similar among normotensive and hypertensive subjects [HR: 1.09 (0.68-1.75) and 1.40 (1.13-1.74), respectively, P for interaction U 0.35]. Conclusion The findings from this study show that, in a large middle-aged French population, the metabolic syndrome has the same deleterious impact on all-cause mortality in hypertensive subjects and normotensive subjects
An Inflationary Scenario in Intersecting Brane Models
We propose a new scenario for D-term inflation which appears quite
straightforwardly in the open string sector of intersecting brane models. We
take the inflaton to be a chiral field in a bifundamental representation of the
hidden sector and we argue that a sufficiently flat potential can be brane
engineered. This type of model generically predicts a near gaussian red
spectrum with negligible tensor modes. We note that this model can very
naturally generate a baryon asymmetry at the end of inflation via the recently
proposed hidden sector baryogenesis mechanism. We also discuss the possibility
that Majorana masses for the neutrinos can be simultaneously generated by the
tachyon condensation which ends inflation. Our proposed scenario is viable for
both high and low scale supersymmetry breaking.Comment: 30 pages, 2 figures; v2 references and comments adde
Cosmology of the Tachyon in Brane Inflation
In certain implementations of the brane inflationary paradigm, the exit from
inflation occurs when the branes annihilate through tachyon condensation. We
investigate various cosmological effects produced by this tachyonic era. We
find that only a very small region of the parameter space (corresponding to
slow-roll with tiny inflaton mass) allows for the tachyon to contribute some
e-folds to inflation. In addition, non-adiabatic density perturbations are
generated at the end of inflation. When the brane is moving relativistically
this contribution can be of the same order as fluctuations produced 55 e-folds
before the end of inflation. The additional contribution is very nearly
scale-invariant and enhances the tensor/scalar ratio. Additional
non-gaussianities will also be generated, sharpening current constraints on
DBI-type models which already predict a significantly non-gaussian signal.Comment: 30 pages, 2 figures; v3, minor revision, JCAP versio
Weather and our food supply
The steep rate of increase in yield of grain crops in the United States since the mid-1950\u27s has resulted in the use of the term explosion in technology. Surplus grains piled up to such proportions after the 1960 · harvest that acreage control appeared. to be in order. But despite substantial reductions in acreages after 1960 the increased output per acre has just about compensated for acreage reductions. During this period of rapid increase in output per acre there has been a growing tendency to believe that technology has reduced the influence of weather on grain production so that we no longer need to fear shortages due to unfavorable weather.
There is also a popular belief that acreage control$ fail to achieve the objective of production control, and that public funds are being wasted in storing surplus grains which we don\u27t need.
There is increasing evidence, however, that a period of favorable weather interacted with technology to produce our recent high yields, and that perhaps half of the increase in yield per acre since 1950 has been due to a change to more favorable weather for grain crops.
These findings have important implications in continued support for research in production technology and in the way in which we look at our surplus stocks of feed and food grains. If a period of favorable weather has been responsible for half of the increase in yields since 19501 then what can we expect if the weather trend reverses itself for a few years? Do we have periodicity in weather, and have we just passed through a run of favorable years that might be followed by a run of unfavorable years? Should we treat our surplus grains as reserves? How does our rate of growth in grain output compare with the needs of a growing world population? And of course I in the background of these questions is one big question -- how much of our recent high yields is really due to weather?
To answer these important questions the Center for Agriculture and Economic Development invited outstanding authorities to present their ideas under three main headings: (1) Techniques for Evaluation of Weather Variables in Agricultural Production I (2) Periodicity in Weather Patterns: Implications in Agriculture I and (3) Weather Considerations in Agricultural Policy. The papers have been assembled in the order of their presentation under the general outline above.https://lib.dr.iastate.edu/card_reports/1021/thumbnail.jp
Congressional Seat Swings: Revisiting Exposure in House Elections
Oppenheimer, Stimson, and Waterman's exposure thesis of partisan change contends that shifts in the partisan composition of Congress are related to the long-term stability of the electoral system. Applying their exposure model to elections from 1962-1994 produces seat change estimates that generally follow the actual data pattern, but these estimates produce large predictive errors. When the exposure model is reestimated using data from 1962-1994, exposure is not significantly related to partisan seat swings. This article advances a seat change model that relies on an alter nate measure of exposure: the net exposure of the president's party in open seats. Open-seat exposure is significantly related to the partisan seat swing, and substantially improves on the economic evaluation/surge and-decline/ exposure model of seat change. In an era of high incumbent security and strategic retirement from Congress, the balance of open seats is a better indicator of partisan vulnerability, and better reflects the nature of partisan exposure.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
Nightside clouds and disequilibrium chemistry on the hot Jupiter WASP-43b
Hot Jupiters are among the best-studied exoplanets, but it is still poorly understood how their chemical composition and cloud properties vary with longitude. Theoretical models predict that clouds may condense on the nightside and that molecular abundances can be driven out of equilibrium by zonal winds. Here we report a phase-resolved emission spectrum of the hot Jupiter WASP-43b measured from 5 μm to 12 μm with the JWST’s Mid-Infrared Instrument. The spectra reveal a large day–night temperature contrast (with average brightness temperatures of 1,524 ± 35 K and 863 ± 23 K, respectively) and evidence for water absorption at all orbital phases. Comparisons with three-dimensional atmospheric models show that both the phase-curve shape and emission spectra strongly suggest the presence of nightside clouds that become optically thick to thermal emission at pressures greater than ~100 mbar. The dayside is consistent with a cloudless atmosphere above the mid-infrared photosphere. Contrary to expectations from equilibrium chemistry but consistent with disequilibrium kinetics models, methane is not detected on the nightside (2σ upper limit of 1–6 ppm, depending on model assumptions). Our results provide strong evidence that the atmosphere of WASP-43b is shaped by disequilibrium processes and provide new insights into the properties of the planet’s nightside clouds. However, the remaining discrepancies between our observations and our predictive atmospheric models emphasize the importance of further exploring the effects of clouds and disequilibrium chemistry in numerical models
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