Are the deficits in navigational abilities present in the Williams syndrome related to deficits in the backward inhibition?

Williams syndrome (WS) is associated with a distinct profile of relatively proficient skills within the verbal domain compared to the severe impairment of visuo-spatial processing. Abnormalities in executive functions and deficits in planning ability and spatial working memory have been described. However, to date little is known about the influence of executive function deficits on navigational abilities in WS. This study aimed at analyzing in WS individuals a specific executive function, the backward inhibition (BI) that allows individuals to flexibly adapt to continuously changing environments. A group of WS individuals and a mental age- and gender-matched group of typically developing children were subjected to three task-switching experiments requiring visuospatial or verbal material to be processed. Results showed that WS individuals exhibited clear BI deficits during visuospatial task-switching paradigms and normal BI effect during verbal task-switching paradigm. Overall, the present results suggest that the BI involvement in updating environment representations during navigation may influence WS navigational abilitie

Dynamics of stripe patterns in type-I superconductors subject to a rotating field

The evolution of stripe patterns in type-I superconductors subject to a rotating in-plane magnetic field is investigated magneto-optically. The experimental results reveal a very rich and interesting behavior of the patterns. For small rotation angles, a small parallel displacement of the main part of the stripes and a co-rotation of their very ends is observed. For larger angles, small sideward protrusions develop, which then generate a zigzag instability, ultimately leading to a breaking of stripes into smaller segments. The short segments then start to co-rotate with the applied field although they lag behind by approximately $10^\circ$. Very interestingly, if the rotation is continued, also reconnection of segments into longer stripes takes place. These observations demonstrate the importance of pinning in type-I superconductors.Comment: To appear in Phys. Rev.

Learning by observation: insights from Williams syndrome.

Observing another person performing a complex action accelerates the observer's acquisition of the same action and limits the time-consuming process of learning by trial and error. Observational learning makes an interesting and potentially important topic in the developmental domain, especially when disorders are considered. The implications of studies aimed at clarifying whether and how this form of learning is spared by pathology are manifold. We focused on a specific population with learning and intellectual disabilities, the individuals with Williams syndrome. The performance of twenty-eight individuals with Williams syndrome was compared with that of mental age- and gender-matched thirty-two typically developing children on tasks of learning of a visuo-motor sequence by observation or by trial and error. Regardless of the learning modality, acquiring the correct sequence involved three main phases: a detection phase, in which participants discovered the correct sequence and learned how to perform the task; an exercise phase, in which they reproduced the sequence until performance was error-free; an automatization phase, in which by repeating the error-free sequence they became accurate and speedy. Participants with Williams syndrome beneficiated of observational training (in which they observed an actor detecting the visuo-motor sequence) in the detection phase, while they performed worse than typically developing children in the exercise and automatization phases. Thus, by exploiting competencies learned by observation, individuals with Williams syndrome detected the visuo-motor sequence, putting into action the appropriate procedural strategies. Conversely, their impaired performances in the exercise phases appeared linked to impaired spatial working memory, while their deficits in automatization phases to deficits in processes increasing efficiency and speed of the response. Overall, observational experience was advantageous for acquiring competencies, since it primed subjects' interest in the actions to be performed and functioned as a catalyst for executed action

Type-1.5 Superconductors

We demonstrate the existence of a novel superconducting state in high quality two-component MgB2 single crystalline superconductors where a unique combination of both type-1 (kappa_1 0.707) superconductor conditions is realized for the two components of the order parameter. This condition leads to a vortex-vortex interaction attractive at long distances and repulsive at short distances, which stabilizes unconventional stripe- and gossamer-like vortex patterns that we have visualized in this type-1.5 superconductor using Bitter decoration and also reproduced in numerical simulations.Comment: accepted in Phys. Rev. Let

Response to ranibizumab therapy in neovascular AMD - an evaluation of good and bad responders

Background: Treatment of neovascular age-related macular degeneration (AMD) with Lucentis® shows a broad spectrum regarding the course of visual acuity (VA). While some patients show a good response (increase in VA), others disclose much less promising results. Patients and Methods: A retrospective data analysis of all eyes treated for neovascular AMD at the University Hospital of Zurich, Switzerland for at least 12 months was carried out. The courses of VA between the 90th (good responders, GR) and the 10th (bad responders, BR) percentiles were compared at 3, 12 and 24 months from baseline. An analysis regarding demographic data, lesion type and size as well as injection frequency and visits was done and predictive factors for GR and BR were evaluated. Results: Marked differences in the course of VA between GR (n = 30) and BR (n = 30) are already observed 3 months from baseline. In GR the gains in VA after 3, 12 and 24 were 15.7 ± 9 letters ETDRS, 25.3 ± 7 and 14.0 ± 14. BR showed a deterioration of 8.3 ± 11 letters ETDRS after 3, 22.1 ± 8 after 12 and 23.6 ± 13 after 24 months. The gender distribution was equal with a higher percentage of female patients (64 % in BR and 66 % in GR). The baseline VA was statistically significantly lower in GR (45.7 ± 10 vs. 55.4 ± 11, p < 0.05) than in BR. No other significant differences in baseline data were found, and no predictor for group membership could be identified. Conclusions: Only the course of VA in the first three months seems to be of value for an estimation of the response to treatment. In the future the response to treatment in the early phase may influence the treatment algorithm and the injection frequency

Domain regime in two-dimensional disordered vortex matter

A detailed numerical study of the real space configuration of vortices in disordered superconductors using 2D London-Langevin model is presented. The magnetic field $B$ is varied between 0 and $B_{c2}$ for various pinning strengths $\Delta$. For weak pinning, an inhomogeneous disordered vortex matter is observed, in which the topologically ordered vortex lattice survives in large domains. The majority of the dislocations in this state are confined to the grain boundaries/domain walls. Such quasi-ordered configurations are observed in the intermediate fields, and we refer it as the domain regime (DR). The DR is distinct from the low-field and the high-fields amorphous regimes which are characterized by a homogeneous distribution of defects over the entire system. Analysis of the real space configuration suggests domain wall roughening as a possible mechanism for the crossover from the DR to the high-field amorphous regime. The DR also shows a sharp crossover to the high temperature vortex liquid phase. The domain size distribution and the roughness exponent of the lattice in the DR are also calculated. The results are compared with some of the recent Bitter decoration experiments.Comment: 9 pages, 9 figure

TIMP3 interplays with apelin to regulate cardiovascular metabolism in hypercholesterolemic mice

Tissue inhibitor of metalloproteinase 3 (TIMP3) is an extracellular matrix (ECM) bound protein, which has been shown to be downregulated in human subjects and experimental models with cardiometabolic disorders, including type 2 diabetes mellitus, hypertension and atherosclerosis. The aim of this study was to investigate the effects of TIMP3 on cardiac energy homeostasis during increased metabolic stress conditions

Effect of pinning and driving force on the metastability effects in weakly pinned superconductors and the determination of spinodal line pertaining to order-disorder transition

We explore the effect of varying drive on metastability features exhibited by the vortex matter in single crystals of 2H-NbSe$_2$ and CeRu$_2$ with varying degree of random pinning. An optimal balance between the pinning and driving force is needed to view the metastability effects in typically weakly pinned specimen of low temperature superconductors. As one uses samples with larger pinning in order to differentiate the response of different metastable vortex states, one encounters a new phenomena, viz., the second magnetization peak (SMP) anomaly prior to the PE. Interplay between the path dependence in the critical current density and the non-linearity in the electromagnetic response determine the metastability effects seen in first and the third harmonic response of the ac susceptibility across the temperature regions of the SMP and the PE. The limiting temperature above which metastability effects cease can be conveniently located in the third harmonic data, and the observed behavior can be rationalized within the Beans Critical State model. A vortex phase diagram showing the different vortex phases for a typically weakly pinned specimen has been constructed via the ac susceptibility data in a crystal of 2H-NbSe$_2$ which shows the SMP and the PE anomalies. The phase space of coexisting weaker and stronger pinned regions has been identified. It can be bifurcated into two parts, where the order and disorder dominate, respectively. The former part continuously connects to the reentrant disordered vortex phase pertaining to the small bundle pinning regime, where the vortices are far apart, interaction effects are weak and the polycrystalline form of flux line lattice prevails.Comment: Submitted to the Special Volume on Vortex State Studies, Pramana J. Phy