36,042 research outputs found
Double Phase Transitions in Magnetized Spinor Bose-Einstein Condensation
It is investigated theoretically that magnetized Bose-Einstein condensation
(BEC) with the internal (spin) degrees of freedom exhibits a rich variety of
phase transitions, depending on the sign of the interaction in the spin
channel. In the antiferromagnetic interaction case there exist always double
BEC transitions from single component BEC to multiple component BEC. In the
ferromagnetic case BEC becomes always unstable at a lower temperature, leading
to a phase separation. The detailed phase diagram for the temperature vs the
polarization, the spatial spin structure, the distribution of non-condensates
and the excitation spectrum are examined for the harmonically trapped systems.Comment: 6 pages, 7 figures. Submitted to J. Phys. Soc. Jp
Protein transduction: A novel tool for tissue regeneration
Tissue regeneration in humans is limited and excludes vitals organs like heart and brain. Transformation experiments with oncogenes like T antigen have shown that retrodifferentiation of the respective cells is possible but hard to control. To bypass the risk of cancer formation a protein therapy approach has been developed. The transient delivery of proteins rather than genes could still induce terminallydifferentiated cells to reenter the cell cycle. This approach takes advantage of proteintransducing domains that mediate the transfer of cargo proteins into cells. The goal of this brief review is to outline the basics of protein transduction and to discuss potential applications for tissue regeneration
Topological Excitations in Spinor Bose-Einstein Condensates
We investigate the properties of skyrmion in the ferromagnetic state of
spin-1 Bose-Einstein condensates by means of the mean-field theory and show
that the size of skyrmion is fixed to the order of the healing length. It is
shown that the interaction between two skyrmions with oppositely rotating spin
textures is attractive when their separation is large, following a unique
power-law behavior with a power of -7/2.Comment: 4 pages, 5 figure
Two--Electron Atoms in Short Intense Laser Pulses
We discuss a method of solving the time dependent Schrodinger equation for
atoms with two active electrons in a strong laser field, which we used in a
previous paper [A. Scrinzi and B. Piraux, Phys. Rev. A 56, R13 (1997)] to
calculate ionization, double excitation and harmonic generation in Helium by
short laser pulses. The method employs complex scaling and an expansion in an
explicitly correlated basis. Convergence of the calculations is documented and
error estimates are provided. The results for Helium at peak intensities up to
10^15 W/cm^2 and wave length 248 nm are accurate to at least 10 %. Similarly
accurate calculations are presented for electron detachment and double
excitation of the negative hydrogen ion.Comment: 14 pages, including figure
A large accretion disk of extreme eccentricity in the TDE ASASSN-14li
In the canonical model for tidal disruption events (TDEs), the stellar debris
circularizes quickly to form an accretion disk of size about twice the orbital
pericenter of the star. Most TDEs and candidates discovered in the optical/UV
have broad optical emission lines with complex and diverse profiles of puzzling
origin. Liu et al. recently developed a relativistic elliptical disk model of
constant eccentricity in radius for the broad optical emission lines of TDEs
and well reproduced the double-peaked line profiles of the TDE candidate
PTF09djl with a large and extremely eccentric accretion disk. In this paper, we
show that the optical emission lines of the TDE ASASSN-14li with radically
different profiles are well modelled with the relativistic elliptical disk
model, too. The accretion disk of ASASSN-14li has an eccentricity 0.97 and
semimajor axis of 847 times the Schwarzschild radius (r_S) of the black hole
(BH). It forms as the consequence of tidal disruption of a star passing by a
massive BH with orbital pericenter 25r_S. The optical emission lines of
ASASSN-14li are powered by an extended X-ray source of flat radial distribution
overlapping the bulk of the accretion disk and the single-peaked asymmetric
line profiles are mainly due to the orbital motion of the emitting matter
within the disk plane of inclination about 26\degr and of pericenter
orientation closely toward the observer. Our results suggest that modelling the
complex line profiles is powerful in probing the structures of accretion disks
and coronal X-ray sources in TDEs.Comment: 10 pages, 8 figures, accepted for publication in the MNRA
Modeling Information Linkages in the Stock and Options Markets
When markets are assumed to be complete, option trading should not contain new information for market participants, as options derive their prices from the underlying stocks. However, if markets are incomplete, then this unidirectional relationship may not be true, because informed traders may prefer to trade options instead of the underlying stocks for several reasons: one, option trading involves lower transaction costs and higher financial leverage; and two, investors who have private information about stock price volatility can only make their bet on volatility in the option market. Compared with the research on the relationship between options trading activity and stock prices, there is little analysis on the information embodied in option transactions volume for stock market volatility, which undoubtedly is an important variable for risk management and portfolio allocation. This study focuses on the dynamic linkages between option trading volume and stock market volatility. We compare the significance of option trading activity in explaining the volatilities of the underlying stocks with that of stock market volume by selecting 15 New York Stock Exchange (NYSE) stocks that are most actively traded in the option markets during the period from December 11 2002 to August 31 2006. Our approach implies the following two distinctive features: - instead of the put/call volume ratio conventionally used in the literature, we measure the influence of option volume on stock market volatility by constructing the relative put (RPUT) and relative call (RCALL) ratios. - our approach also allows us to quantify the impact of option volume on the existence of persistence and asymmetry in stock market volatility. Instead of the usual generalized autoregressive conditional heteroskedasticity (GARCH) model that is commonly used to analyze the stock volume-volatility relation, we adopt Nelsonâs (1991) exponential GARCH (EGARCH) approach in this study. For each stock, it is noted that the trading activities in the put and call options markets have significant explanatory power for stock market volatility. In addition, the results indicate that the call options trading activity has a stronger impact on stock volatility compared with that of the put options. Our results demonstrate that information and sentiment in the option market is useful for the estimation of stock market volatility. Also, the significance of the effects of option trading activity on stock price volatility is observed to be comparable to that of stock market trading activity. Furthermore, the persistence and asymmetric effects in the volatility of some stocks tend to disappear once option trading activity is taken into account
A survey of the treatment and management of patients with severe chronic spontaneous urticaria.
Chronic spontaneous urticaria (CSU) is characterized by the recurrent appearance of weals, angioâoedema or both, occurring at least twice weekly for longer than 6 weeks.1 It is often managed with antihistamines, but occasionally requires other systemic agents in recalcitrant cases.
A crossâsectional survey was conducted by means of an internetâbased survey tool (Typeform; https://www.typeform.com). Participating consultants with a specialist interest in urticaria were identified through the specialist registers of the British Society of Allergy and Clinical Immunology (BSACI), the Improving Quality in Allergy Services (IQAS) Group and the British Association of Dermatologists (BAD), and invited to take part.
The survey content was based on current CSU treatment guidelines from EAACI/GA2LEN/EDF/WAO1 and the British Society for Allergy and Clinical Immunology (BSACI).2 The EAACI/GA2LEN/EDF/WAO guidelines are a joint initiative of the Dermatology Section of the European Academy of Allergy and Clinical Immunology (EAACI), the Global Allergy and Asthma European Network (GA2LEN) (a European Unionâfunded network of excellence), the European Dermatology Forum (EDF), and the World Allergy Organization (WAO). To standardize responses, all participants were presented with a case of recalcitrant CSU (failed on maximum dose of nonsedating antihistamines and montelukast), requiring alternative systemic treatment. Questions covered usage of systemic treatments, routine disease severity assessments, adherence to treatment guidelines and perceived barriers to prescribing.
Responses (Table 1) were received from 19 UK consultants (26 surveys sent; completion rate 73%), 15 of whom had > 10 yearsâ experience in the treatment of CSU. The majority were allergy (58%) and dermatology consultants (37%). Of the 19 consultants, 56% provide a dedicated urticaria service, 37% treat both adult and paediatric patients, and the majority (79%) use systemic medications other than antihistamines and montelukast. Omalizumab and ciclosporin were the most commonly used firstâline agents (47% and 27% respectively) (Fig. 1). The majority (84%) of consultants use validated measures to assess disease severity, including the weekly Urticaria Activity Score (UASâ7, 63%), the Physician Global Assessment (63%), the Patient Global Assessment (44%) and the Dermatology Quality of Life Index (DLQI) (38%). Guidelines are used by 89% to direct their management of CSU, with 50% using the EAACI/GA2LEN/EDF/WAO guideline,1 compared with 31% primarily using the BSACI guideline.2 The main perceived barriers to prescribing systemic medications were potential adverse effects (AEs) (32% strongly agreed), potential longâterm toxicity (26% strongly agreed), cost of treatment (42% strongly agreed), and views expressed by the patient and their family (37% agreed)
Destructive Hostility: The Jeffrey Dahmer Case: A Psychiatric and Forensic Study of a Serial Killer
We were involved as forensic experts in the case of the serial killer Jeffrey Dahmer. We discuss the scene and victim autopsy findings, with a brief consideration of the basic emotion of hostility. These findings support the thesis that at the basis of this serial killer\u27s behavior were primary unconscious feelings of hate that he had channeled into a sadistic programmed destruction of 17 young men. The interview of the serial killer, the photographic scene documentation, and the autopsy findings stress the ambivalent homosexuality of the killer, his sexual sadism, his obsessive fetishism, and his possible cannibalism and necrophilia
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