Local‐Regional Similarity in Drylands Increases During Multiyear Wet and Dry Periods and in Response to Extreme Events

Climate change is predicted to impact ecosystems through altered precipitation (PPT) regimes. In the Chihuahuan Desert, multiyear wet and dry periods and extreme PPT pulses are the most influential climatic events for vegetation. Vegetation responses are most frequently studied locally, and regional responses are often unclear. We present an approach to quantify correlation of PPT and vegetation responses (as Normalized Difference Vegetation Index [NDVI]) at the Jornada ARS‐LTER site (JRN; 550 km2 area) and the surrounding dryland region (from 0 to 500 km distance; 400,000 km2 study area) as a way to understand regional similarity to locally observed patterns. We focused on fluctuating wet and dry years, multiyear wet or dry periods of 3–4 yr, and multiyear wet periods that contained one or more extreme high PPT pulses or extreme low rainfall. In all but extreme high PPT years, JRN PPT was highly correlated... (See article for full abstract)

Southeastern U.S. Vegetation Response to ENSO Events (1989–1999)

El Niño/Southern Oscillation (ENSO) is considered one of the most powerful forces driving anomalous global weather patterns. Large-scale seasonal precipitation and temperature changes influenced by ENSO have been examined in many areas of the world. The southeastern United States is one of the regions affected by ENSO events. In this study, remote sensing detection of vegetation response to ENSO phases is demonstrated with one-kilometer biweekly Normalized Difference Vegetation Index (NDVI) data (1989–1999) derived from the Advanced Very High Resolution Radiometer (AVHRR). The impacts of three ENSO phases, cold, warm and neutral, on vegetation were analyzed with a focus on two vegetation cover types, two seasons and two geographic regions within the southeastern U.S. Significant ENSO effects on vegetation were found in cropland and forest vegetation cover types based on image and statistical analysis of the NDVI data. The results indicate that vegetation condition was optimal during the ENSO neutral phase for both agricultural and natural vegetatio

Connecting Disasters and Climate Change to the Humanitarian-Development-Peace Nexus

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Prediction of the intramembranous tissue formation during perisprosthetic healing with uncertainties. Part 2. Global clinical healing due to combination of random sources

This work proposes to examine the variability of the bone tissue healing process in the early period after the implantation surgery. The first part took into account the effect of variability of individual biochemical factors on the solid phase fraction, which is an indicator of the quality of the primary fixation and condition of its long-term behaviour. The next issue, addressed in this second part, is the effect of cumulative sources of uncertainties on the same problem of a canine implant. This paper is concerned with the ability to increase the number of random parameters to assess the coupled influence of those variabilities on the tissue healing. To avoid an excessive increase in the complexity of the numerical modelling and further, to maintain efficiency in computational cost, a collocation-based polynomial chaos expansion approach is implemented. A progressive set of simulations with an increasing number of sources of uncertainty is performed. This information is helpful for future implant design and decision process for the implantation surgical act

Limited efficacy of zonisamide in the treatment of refractory infantile spasms.

A series of relatively small studies collectively suggest that zonisamide may be effective in the treatment of infantile spasms. Using a large single-center cohort of children with infantile spasms, we set out to evaluate the efficacy and safety of zonisamide. We retrospectively identified all patients with infantile spasms who were treated with zonisamide at our center. For each patient, we recorded dates of birth, infantile spasms onset, response (if any), and most recent follow-up. To quantify zonisamide exposure, we recorded daily dosage and patient weight at each sequential encounter so as to allow calculation of peak and weighted-average weight-based dosage. We identified 87 children who were treated with zonisamide, of whom 78 had previously been treated with hormonal therapy or vigabatrin. Peak and weighted-average zonisamide dosage were 7.1 (interquartile range 3.6, 10.2) and 5.4 (interquartile range 3.0, 8.9) mg/kg/day, respectively. Whereas five (6%) patients exhibited resolution of epileptic spasms, only two (2%) patients exhibited video-EEG confirmed resolution of both epileptic spasms and hypsarrhythmia (electroclinical response). Importantly, both electroclinical responders had not previously been treated with hormonal therapy or vigabatrin; in contrast, none of the 78 children with prior failure of hormonal therapy or vigabatrin subsequently responded to zonisamide. Zonisamide was well tolerated, and there were no deaths. This study suggests that zonisamide exhibits favorable tolerability but very limited efficacy among patients who do not respond to first-line therapy

Computational topology for approximations of knots

[EN] The preservation of ambient isotopic equivalence under piecewise linear (PL) approximation for smooth knots are prominent in molecular modeling and simulation. Sufficient conditions are given regarding:Hausdorff distance, anda sum of total curvature and derivative.High degree Bézier curves are often used as smooth representations, where computational efficiency is a practical concern. Subdivision can produce PL approximations for a given B\'ezier curve, fulfilling the above two conditions. The primary contributions are:       (i) a priori bounds on the number of subdivision iterations sufficient to achieve a PL approximation that is ambient isotopic to the original B\'ezier curve, and       (ii) improved iteration bounds over those previously established. The first, two authors acknowledge, with appreciation, partial support from NSF Grants 1053077 and 0923158 and also from IBM. The findings presented are the responsibility of these authors, not of the funding programs.Li, J.; Peters, TJ.; Jordan, KE. (2014). Computational topology for approximations of knots. Applied General Topology. 15(2):203-220. doi:http://dx.doi.org/10.4995/agt.2014.2281.SWORD203220152Amenta, N., Peters, T. J., & Russell, A. C. (2003). Computational topology: ambient isotopic approximation of 2-manifolds. Theoretical Computer Science, 305(1-3), 3-15. doi:10.1016/s0304-3975(02)00691-6L. E. Andersson, S. M. Dorney, T. J. Peters and N. F. Stewart, Polyhedral perturbations that preserve topological form, CAGD 12, no. 8 (1995), 785-799.Burr, M., Choi, S. W., Galehouse, B., & Yap, C. K. (2012). Complete subdivision algorithms, II: Isotopic meshing of singular algebraic curves. Journal of Symbolic Computation, 47(2), 131-152. doi:10.1016/j.jsc.2011.08.021Chazal, F., & Cohen-Steiner, D. (2005). A condition for isotopic approximation. Graphical Models, 67(5), 390-404. doi:10.1016/j.gmod.2005.01.005W. Cho, T. Maekawa and N. M. Patrikalakis, Topologically reliable approximation in terms of homeomorphism of composite Bézier curves, CAGD 13 (1996), 497-520.Denne, E., & Sullivan, J. M. (2008). Convergence and Isotopy Type for Graphs of Finite Total Curvature. Discrete Differential Geometry, 163-174. doi:10.1007/978-3-7643-8621-4_8G. E. Farin, Curves and surfaces for computer-aided geometric design: A practical code, Academic Press, Inc., 1996.Hirsch, M. W. (1976). Differential Topology. Graduate Texts in Mathematics. doi:10.1007/978-1-4684-9449-5J. Li, T. J. Peters, D. Marsh and K. E. Jordan, Computational topology counterexamples with 3D visualization of Bézier curves, Applied General Topology 13, no. 2 (2012), 115-134.Lin, L., & Yap, C. (2011). Adaptive Isotopic Approximation of Nonsingular Curves: the Parameterizability and Nonlocal Isotopy Approach. Discrete & Computational Geometry, 45(4), 760-795. doi:10.1007/s00454-011-9345-9T. Maekawa, N. M. Patrikalakis, T. Sakkalis and G. Yu, Analysis and applications of pipe surfaces, CAGD 15, no. 5 (1998), 437-458.Milnor, J. W. (1950). On the Total Curvature of Knots. The Annals of Mathematics, 52(2), 248. doi:10.2307/1969467G. Monge, Application de l'analyse à la géométrie, Bachelier, Paris, 1850.Moore, E. L. F., Peters, T. J., & Roulier, J. A. (2007). Preserving computational topology by subdivision of quadratic and cubic Bézier curves. Computing, 79(2-4), 317-323. doi:10.1007/s00607-006-0208-9G. Morin and R. Goldman, On the smooth convergence of subdivision and degree elevation for Bézier curves, CAGD 18 (2001), 657-666.J. Munkres, Topology, Prentice Hall, 2nd edition, 1999.D. Nairn, J. Peters and D. Lutterkort, Sharp, quantitative bounds on the distance between a polynomial piece and its Bézier control polygon, CAGD 16 (1999), 613-63.Reid, M., & Szendroi, B. (2005). Geometry and Topology. doi:10.1017/cbo978051180751

Left Ventricular Hypertrophy is a predictor of cardiovascular events in elderly hypertensives: hypertension in the the very elderly trial (HYVET)

Objective: We assessed the prognostic value of electrocardiographic left ventricular hypertrophy (LVH) using Sokolow-Lyon (SL-LVH), Cornell Voltage (CV-LVH) or Cornell Product (CP-LVH) Criteria in 3043 hypertensive people aged 80 years and over enrolled in the Hypertension in the Very Elderly Trial. Methods: Multivariate Cox proportional hazard models were used to estimate hazard ratios (HR) with 95% confidence intervals (CI) for all-cause mortality, cardiovascular diseases, stroke and heart failure in participants with and without LVH at baseline. The mean follow-up was 2.1 years. Results: LVH identified by CV- or CP-LVH Criteria was associated with a 1.6 to 1.9-fold risk of cardiovascular disease and stroke. The presence of CP-LVH was associated with an increased risk of heart failure (HR 2.38, 95% CL 1.16-4.86). In gender specific analyses, CV-LVH (HR 1.94, 95%Cl 1.06-3.55) and CP-LVH (HR 2.36, 95% CI 1.25-4.45) were associated with an increased risk of stroke in women and of heart failure in men, CV-LVH (HR 6.47, 95 % Cl 1.41-29.79) and CP-LVH (10.63, 95Cl % 3.58-31.57), respectively. There was no significant increase in the risk of any outcomes associated with SL LVH. LVH identified by these three methods was not a significant predictor of all-cause mortality. Conclusions: Use of Cornell Voltage and Cornell Product criteria for LVH predicted the risk of cardiovascular disease and stroke. Only Cornell Product was associated with an increased the risk of heart failure. This was particularly the case in men. The identification of electrocardiographic LVH proved to be important in very elderly hypertensive people