Market and Style Timing: German Equity and Bond Funds

We apply parametric and non-parametric estimates to test market and style timing ability of individual German equity and bond mutual funds using a sample of over 500 equity and 350 bond funds, over the period 1990-2009. For equity funds, both approaches indicate no successful market timers in the 1990-1999 or 2000-2009 periods, but in 2000-2009 the non-parametric approach gives fewer unsuccessful market timers than the parametric approach. There is evidence of successful style timing using the parametric approach, and unsuccessful style timing, particularly in the 2000-2009 period. There is evidence of positive and negative bond timing in the 2000-09 period

What Does Rebalancing Really Achieve?

There is now a substantial literature on the effects of rebalancing on portfolio performance. However, this literature contains frequent misattribution between ‘rebalancing returns’ which are specific to the act of rebalancing, and ‘diversification returns’ which can be earned by both rebalanced and unrebalanced strategies. Confusion on this issue can encourage investors to follow strategies which involve insufficient diversification and excessive transactions costs. This paper identifies the misleading claims that are made for rebalanced strategies and demonstrates theoretically and by simulation that the apparent advantages of rebalanced strategies over infinite horizons give an inaccurate impression of their performance over finite horizons

Temperature dependent optical conductivity of undoped cuprates with weak exchange

The optical conductivity sigma(omega) is calculated at finite temperature T for CuO_2 chain clusters within a pd-Hubbard model. Data at T = 300 K for Li_2CuO_2 are reanalyzed within this approach. The relative weights of Zhang-Rice singlet and triplet charge excitations near 2.5 and 4 eV, respectively, depend strongly on T, and a rather dramatic dependence of sigma(omega) on the ratio of the first to second neighbor exchange integrals is predicted. On the basis of these results, information about exchange interactionsfor frustrated edge-shared cuprates can be obtained from T-dependent optical spectra. Our results are also relevant for magnetically weakly coupled wide-gap insulators in general.Comment: 5 pages, 3 figure

Highly Dispersive Spin Excitations in the Chain Cuprate Li2CuO2

We present an inelastic neutron scattering investigation of Li2CuO2 detecting the long sought quasi-1D magnetic excitations with a large dispersion along the CuO2-chains studied up to 25 meV. The total dispersion is governed by a surprisingly large ferromagnetic (FM) nearest-neighbor exchange integral J1=-228 K. An anomalous quartic dispersion near the zone center and a pronounced minimum near (0,0.11,0.5) r.l.u. (corresponding to a spiral excitation with a pitch angle about 41 degree point to the vicinity of a 3D FM-spiral critical point. The leading exchange couplings are obtained applying standard linear spin-wave theory. The 2nd neighbor inter-chain interaction suppresses a spiral state and drives the FM in-chain ordering below the Ne'el temperature. The obtained exchange parameters are in agreement with the results for a realistic five-band extended Hubbard Cu 3d O 2p model and L(S)DA+U predictions.Comment: 6 pages, 4 figures, submitted to Europhys. Let

Brain glucose utilization in systemic lupus erythematosus with neuropsychiatric symptoms: A controlled positron emission tomography study

In contrast to morphological imaging [such as magnetic resonance imaging (MRI) or computed tomography], functional imaging may be of advantage in the detection of brain abnormalities in cases of neuropsychiatric systemic lupus erythematosus (SLE). Therefore, we studied 13 patients (aged 40±14 years, 11 female, 2 male) with neuropsychiatric SLE who met four of the American Rheumatism Association criteria for the classification of SLE. Ten clinically and neurologically healthy volunteers served as controls (aged 40±12 years, 5 female, 5 male). Both groups were investigated using fluorine-18-labelled fluorodeoxyglucose brain positron emission tomography (PET) and cranial MRI. The normal controls and 11 of the 13 patients showed normal MRI scans. However, PET scan was abnormal in all 13 SLE patients. Significant group-to-group differences in the glucose metabolic index (GMI=region of interest uptake/global uptake at the level of the basal ganglia and thalamus) were found in the parieto-occipital region on both sides: the GMI of the parieto-occipital region on the right side was 0.922±0.045 in patients and 1.066±0.081 in controls (P<0.0001, Mann WhitneyU test), while on the left side it was 0.892±0.060 in patients and 1.034±0.051 in controls (P=0.0002). Parietooccipital hypometabolism is a conspicuous finding in mainly MRI-negative neuropsychiatric SLE. As the parieto-occipital region is located at the boundary of blood supply of all three major arteries, it could be the most vulnerable zone of the cerebrum and may be affected at an early stage of the cerebrovascular diseas

Promoção da Qualidade das Relações Interpessoais, da Saúde e do Bem-Estar dos Enfermeiros do HFF: o Projeto, Resultados T1, e a Fase de Intervenção

Promoção da qualidade das relações interpessoais, da saúde e do bem-estar dos enfermeiros do HFF: O projeto, resultados T1 e a fase de intervenção

Challenges and Progress in improving Safety and Managing Radioactive Wastes at Chornobyl NPP and in the Chornobyl Exclusion Zone

The commissioning of the New Safe Confinement at the Chornobyl Nuclear Plant Unit 4 site will mark the achievement of one important milestone within the process “conversion of the Chornobyl Unit 4 into safe ecologic conditions”. New radioactive waste management facilities have been developed at Chornobyl Nuclear Plant and at Vektor Complex to ensure the safe management of radioactive wastes in the Chornobyl Exclusion Zone. The continued investigations and safety assessments of different legacy waste sites which were created as part of the accident response measures confirm the efficiency of the measures of the past are and consolidate the basis for the strategy for the safe management of legacy wastes. All these together demonstrates that the national and international efforts vested to manage the consequences of the Chornobyl accident have achieved substantial and visible progress in safety and long term safety will be achieved by their consistent continuation.Уведення в експлуатацію нового безпечного конфайнмента на майданчику № 4 ЧАЕС ознаменує досягнення однієї важливої віхи у процесі перетворення чорнобильського енергоблока № 4 на екологічну безпечну систему. Нові об'єкти з поводження з радіоактивними відходами були розроблені на ЧАЕС і в комплексі "Вектор" для забезпечення безпечного поводження з радіоактивними відходами в чорнобильській зоні відчуження. Тривалі дослідження та оцінки безпеки різних майданчиків відходів, що були створені в рамках робіт із мінімізації наслідків катастрофи, підтверджують ефективність заходів, проведених у минулому та формують основу стратегії безпечного поводження з відходами, що залишились у спадщину. Усе це разом показує, що національні та міжнародні зусилля, спрямовані на контроль впливу наслідків Чорнобильської аварії, досягли суттєвого й помітного прогресу в галузі безпеки, і довгострокова безпека буде досягнута завдяки їхньому послідовному продовженню.Введение в эксплуатацию нового безопасного конфайнмента на площадке № 4 ЧАЭС ознаменует достижение важной вехи в процессе преобразования чернобыльского энергоблока № 4 в экологически безопасную систему. Новые объекты по обращению с радиоактивными отходами были построены на ЧАЭС и в комплексе "Вектор" для обеспечения безопасного обращения с радиоактивными отходами в чернобыльской зоне отчуждения. Длительные исследования и оценки безопасности различных наследственных площадок отходов, которые были созданы в рамках мероприятий по реагированию на катастрофу, подтверждают эффективность мер прошлого и закрепляют основу стратегии безопасного обращения с наследственными отходами. Все это вместе показывает, что национальные и международные усилия, направленные на контроль над воздействиями последствий Чернобыльской аварии, достигли существенного и заметного прогресса в области безопасности, и долгосрочная безопасность будет достигнута благодаря их последовательному продлению

A stereotaxic, population-averaged T1w ovine brain atlas including cerebral morphology and tissue volumes

Standard stereotaxic reference systems play a key role in human brain studies. Stereotaxic coordinate systems have also been developed for experimental animals including non-human primates, dogs, and rodents. However, they are lacking for other species being relevant in experimental neuroscience including sheep. Here, we present a spatial, unbiased ovine brain template with tissue probability maps (TPM) that offer a detailed stereotaxic reference frame for anatomical features and localization of brain areas, thereby enabling inter-individual and cross-study comparability. Three-dimensional data sets from healthy adult Merino sheep (Ovis orientalis aries, 12 ewes and 26 neutered rams) were acquired on a 1.5 T Philips MRI using a T1w sequence. Data were averaged by linear and non-linear registration algorithms. Moreover, animals were subjected to detailed brain volume analysis including examinations with respect to body weight (BW), age, and sex. The created T1w brain template provides an appropriate population-averaged ovine brain anatomy in a spatial standard coordinate system. Additionally, TPM for gray (GM) and white (WM) matter as well as cerebrospinal fluid (CSF) classification enabled automatic prior-based tissue segmentation using statistical parametric mapping (SPM). Overall, a positive correlation of GM volume and BW explained about 15% of the variance of GM while a positive correlation between WM and age was found. Absolute tissue volume differences were not detected, indeed ewes showed significantly more GM per bodyweight as compared to neutered rams. The created framework including spatial brain template and TPM represent a useful tool for unbiased automatic image preprocessing and morphological characterization in sheep. Therefore, the reported results may serve as a starting point for further experimental and/or translational research aiming at in vivo analysis in this species