Uncertainties in Arctic sea ice thickness and volume: new estimates and implications for trends

Sea ice volume has decreased in the last decades, evoked by changes in sea ice area and thickness. Estimates of sea ice area and thickness rely on a number of geophysical parameters which introduce large uncertainties. To quantify these uncertainties we use freeboard retrievals from ICESat and investigate different assumptions about snow depth, sea ice density and area. We find that uncertainties in ice area are of minor importance for the estimates of sea ice volume during the cold season in the Arctic basin. The choice of mean ice density used when converting sea ice freeboard into thickness mainly influences the resulting mean sea ice thickness, while snow depth on top of the ice is the main driver for the year-to-year variability, particularly in late winter. The absolute uncertainty in the mean sea ice thickness is 0.28 m in February/March and 0.21 m in October/November. The uncertainty in snow depth contributes up to 70% of the total uncertainty and the ice density 30–35%, with higher values in October/November. We find large uncertainties in the total sea ice volume and trend. The mean total sea ice volume is 10 120 ± 1280 km³ in October/November and 13 250 ± 1860 km³ in February/March for the time period 2005–2007. Based on these uncertainties we obtain trends in sea ice volume of −1450 ± 530 km³ a^−1 in October/November and −880 ± 260 km³ a^−1 in February/March over the ICESat period (2003–2008). Our results indicate that, taking into account the uncertainties, the decline in sea ice volume in the Arctic between the ICESat (2003–2008) and CryoSat-2 (2010–2012) periods may have been less dramatic than reported in previous studies. However, more work and validation is required to quantify these changes and analyse possible unresolved biases in the freeboard retrievals

The shortwave infrared bands response to stomatal conductance in Conference" Pear Trees (Pyrus communis L.)"

Published: 8 October 201

Therapeutic approach to idiopathic hypertrophic cardiomyopathy

Идиопатичната хипертрофична кардиомиопатия е рядко срещана в детска възраст с висок потенциален риск от фатален край. Отличителен белег е миокардната хипертрофия при липса на хемодинамична причина. От първия описан случай на експериментално лечение на кърмаче през 1971 г. бета-блокерите имат водеща роля в медикаментозното лечение с вариации в дозовите режими. По последни литературни данни и клинични проучвания употребата на високи дози бета-блокер неоспоримо показва значим процент на преживяемост в дългосрочен план.Представяме клиничен случай на 11-месечно кърмаче, което постъпва в нашата клиника с данни за сърдечна недостатъчност. От проведените образни изследвания - рентгенография на гръден кош и ехокардиография, се установи изразена симетрична хипертрофична необструктивна кардиомиопатия. Започна се медикаментозно лечение с пропранолол в постепенно покачваща се доза до 5 мг / кг / 24 часа. Няколко седмици по-късно при контролно ехокардиографско изследване се установи значително подобрение в диастолната функция на лява камера с известна регресия в хипертрофията на миокарда. Контролираното прилагане на високи дози бета-блокери би могло съществено да подобри прогнозата и дългосрочната преживяемост при пациентите с идиопатична хипертрофична кардиомиопатия.Idiopathic hypertrophic cardiomyopathy is a rare disease in childhood with a high potential of a lethal outcome. The hallmark of the disorder is myocardial hypertrophy that occurs in the absence of an obvious hemodynamic stimulus. Since the first case of an experimental treatment of an infant described in 1971, beta blockers have become one of the leading medication options with variations of the dose regimens. According to the current literature data and clinical trials the use of beta blockers in high doses is consistent with a high percentage of survival.We`re presenting a clinical case of an 11-month old infant, who was admitted to our clinic with symptoms of congestive cardiac failure. The chest radiography and echocardiography results showed a severe symmetric hypertrophic cardiomyopathy without an obstruction in the left ventricular outflow tract. The treatment was started with Propranolol in a titrating dose until reaching the dose of 5mg/kg/24hours. Several weeks later, echocardiography examination showed a significant improvement in the left ventricle diastolic function with some degree of regression of myocardial hypertrophy.The use of high doses of beta blockers together with the monitoring of the clinical state could improve the prognosis and survival in patients with idiopathic hypertrophic cardiomyopathy

Supernova Ia: a Converging Delayed Detonation Wave

A model of a carbon-oxygen (C--O) presupernova core with an initial mass 1.33 M_\odot, an initial carbon mass fraction 0.27, and with an average mass growth-rate 5 x 10^{-7} M_\odot/yr due to accretion in a binary system was evolved from initial central density 10^9 g/cm^3, and temperature 2.05 x 10^8 K through convective core formation and its subsequent expansion to the carbon runaway at the center. The only thermonuclear reaction contained in the equations of evolution and runaway was the carbon burning reaction 12C + 12C with an energy release corresponding to the full transition of carbon and oxygen (with the same rate as carbon) into 56Ni. As a parameter we take \alpha_c - a ratio of a mixing length to the size of the convective zone. In spite of the crude assumptions, we obtained a pattern of the runaway acceptable for the supernova theory with the strong dependence of its duration on \alpha_c. In the variants with large enough values of \alpha_c=4.0 x 10^{-3} and 3.0 x 10^{-3} the fuel combustion occurred from the very beginning as a prompt detonation. In the range of 2.0 x 10^{-3} >= \alpha_c >= 3.0 x 10^{-4} the burning started as a deflagration with excitation of stellar pulsations with growing amplitude. Eventually, the detonation set in, which was activated near the surface layers of the presupernova (with m about 1.33 M_\odot) and penetrated into the star down to the deflagration front. Excitation of model pulsations and formation of a detonation front are described in detail for the variant with \alpha_c=1.0 x 10^{-3}.Comment: 13 pages, 11 figures, to appear in Astronomy Letter

STUDIES ON CYTOMEGALOVIRAL (CMV) INFECTIONS IN NEWBORN CHILDREN

No abstrac

Detrended fluctuation analysis as a statistical tool to monitor the climate

Detrended fluctuation analysis is used to investigate power law relationship between the monthly averages of the maximum daily temperatures for different locations in the western US. On the map created by the power law exponents, we can distinguish different geographical regions with different power law exponents. When the power law exponents obtained from the detrended fluctuation analysis are plotted versus the standard deviation of the temperature fluctuations, we observe different data points belonging to the different climates, hence indicating that by observing the long-time trends in the fluctuations of temperature we can distinguish between different climates.Comment: 8 pages, 4 figures, submitted to JSTA

Results of investigation of muon fluxes of superhigh energy cosmic rays with X-ray emulsion chambers

The overall data from the investigation of the cosmic ray muon flux in the range of zenith angles (0-90) deg within the energy range (3.5 to 5.0) TeV is presented. The exposure of large X-ray emulsion chambers underground was 1200 tons. year. The data were processe using the method which was applied in the experiment Pamir and differred from the earlier applied one. The obtained value of a slope power index of the differential energy spectrum of the global muon flux is =3.7 that corresponds to the slope of the pion generation differential spectrum, gamma sub PI = 2.75 + or - .04. The analysis of the muon zenith-angular distribution showed that the contribution of rapid generation muons in the total muon flux agree the best with the value .2% and less with .7% at a 90% reliability level

NOTES ON THE ROLE PLAYED BY MICROBIOLOGICAL FACTORS IN THE OCCURRENCE AND COURSE OF SCHIZOPHRENIA

No abstrac