Effect of visual feedback on the occipital-parietal-motor network in Parkinson's disease with freezing of gait.

Freezing of gait (FOG) is an elusive phenomenon that debilitates a large number of Parkinson's disease (PD) patients regardless of stage of disease, medication status, or deep brain stimulation implantation. Sensory feedback cues, especially visual feedback cues, have been shown to alleviate FOG episodes or even prevent episodes from occurring. Here, we examine cortical information flow between occipital, parietal, and motor areas during the pre-movement stage of gait in a PD-with-FOG patient that had a strong positive behavioral response to visual cues, one PD-with-FOG patient without any behavioral response to visual cues, and age-matched healthy controls, before and after training with visual feedback. Results for this case study show differences in cortical information flow between the responding PD-with-FOG patient and the other two subject types, notably, an increased information flow in the beta range. Tentatively suggesting the formation of an alternative cortical sensory-motor pathway during training with visual feedback, these results are proposed as subject for further verification employing larger cohorts of patients

Ar dreno pašalinimo laikas turi įtakos pirminio spontaninio pneumotorakso pirmojo epizodo gydymo išeitims?

Background / objectives. The main treatment option for the first episode of primary spontaneous pneumothorax is chest tube drainage, however, whether delayed chest tube removal might influence the recurrence is unclear.Methods. A prospective study, which included 50 patients, with an initial episode of primary spontaneous pneumothorax was performed. Patients were randomized into two groups according to the chest tube removal time: 1-day and 5-days after the air-leak has stopped. All patients were followed-up for at least six months. Both groups were compared according to the recurrence rate and possible complications.Results. There were 39 (78%) men and the median age was 27 (23–35) years. Successful management with a chest tube was achieved in 43 (86%) patients, others were operated on because of the continuous air-leak or relapse of the pneumothorax after the chest tube was removed. Significant difference was not found comparing groups by age, gender, side, tobacco smoking, alpha-1-antitrypsin level, rate of prolonged air-leak, necessity of surgery, and the mean follow-up time. There was a significant difference between groups in hospitalization time: 1-day group – 6 (4–12), 5-days group – 8 (7–10) days, p = 0.017. Five (20%) patients from 1-day group and 3 (12%) from 5-days group had a recurrence, however the difference was not significant (p = 0.702). There were no significant differences comparing groups by the recurrence time or complications.Conclusions. The recurrence rate of primary spontaneous pneumothorax was higher if the chest tube was removed earlier, however not significantly. More data and longer follow-up are necessary to confirm these findings.Įvadas / tikslas. Pirminis spontaninis pneumotoraksas yra didelė jaunų sveikų žmonių problema. Pleuros ertmės drenavimas – pagrindinis pirminio spontaninio pneumotorakso pirmojo epizodo gydymo būdas. Vis dėlto nėra žinoma, ar dreno buvimo pleuros ertmėje trukmė gali turėti įtakos recidyvų dažniui.Metodai. Atliktas perspektyvusis tyrimas, į kurį įtraukta 50 pacientų. Tiriamiesiems diagnozuotas pirminio spontaninio pneumotorakso pirmasis epizodas. Visi pacientai gydyti drenuojant pleuros ertmę. Pacientai suskirstyti į dvi grupes, atsižvelgiant į dreno pašalinimo laiką: praėjus vienai dienai ar praėjus penkioms dienoms, kai per dreną nustojo skirtis oras. Visi pacientai atokiu laikotarpiu (mažiausiai šešis mėnesius) stebėti dėl galimo recidyvo. Atlikta abiejų grupių recidyvų dažnio ir galimų komplikacijų lyginamoji analizė.Rezultatai. Vidutinis pacientų amžius – 27 (23–35) metai. 78 proc. tiriamųjų – vyrai. Drenavus pleuros ertmę, sėkmingai išgydyti 43 ligoniai (86 %). Kiti tiriamieji dėl besiskiriančio per dreną oro ar dėl rentgenogramoje matomo pakartotinio pneumotorakso, pašalinus dreną, buvo operuoti. Abiejų tiriamųjų grupių duomenys pagal amžių, lytį, pneumotorakso pasireiškimo krūtinės ląstoje pusę, rūkymą, alfa-1 antitripsino koncentraciją kraujyje, ilgesnį oro skyrimąsi per dreną ar operacijos poreikį statistiškai reikšmingai nesiskyrė. Statistiškai reikšmingai skyrėsi abiejų grupių hospitalizacijos trukmė: tiriamieji, kuriems, nustojus per dreną skirtis orui, drenas pašalintas praėjus vienai dienai, ligoninėje gulėjo vidutiniškai 6 (4–12) dienas, o tiriamieji, kuriems drenas pašalintas praėjus penkioms dienoms, – 8 (7–10) dienas (p = 0,017). Penkiems (20 %) pirmosios grupės ir trims (12 %) antrosios grupės pacientams pneumotoraksas recidyvavo (skirtumas statistiškai nereikšmingas (p = 0,702)). Statistiškai nereikšmingas skirtumas nustatytas ir tarp abiejų grupių recidyvo laiko bei komplikacijų.Išvados. Pirminio spontaninio pneumotorakso recidyvų dažnis kiek didesnis, kai drenas ištraukiamas anksčiau, tačiau lyginamųjų grupių skirtumas statistiškai nereikšmingas. Siekiant patvirtinti gautus rezultatus, reikia atlikti didesnės apimties tyrimą, būtina ilgiau stebėti tiriamuosius

Single-Trial EEG Analysis Predicts Memory Retrieval and Reveals Source-Dependent Differences

We used pattern classifiers to extract features related to recognition memory retrieval from the temporal information in single-trial electroencephalography (EEG) data during attempted memory retrieval. Two-class classification was conducted on correctly remembered trials with accurate context (or source) judgments vs. correctly rejected trials. The average accuracy for datasets recorded in a single session was 61% while the average accuracy for datasets recorded in two separate sessions was 56%. To further understand the basis of the classifier’s performance, two other pattern classifiers were trained on different pairs of behavioral conditions. The first of these was designed to use information related to remembering the item and the second to use information related to remembering the contextual information (or source) about the item. Mollison and Curran (2012) had earlier shown that subjects’ familiarity judgments contributed to improved memory of spatial contextual information but not of extrinsic associated color information. These behavioral results were similarly reflected in the event-related potential (ERP) known as the FN400 (an early frontal effect relating to familiarity) which revealed differences between correct and incorrect context memories in the spatial but not color conditions. In our analyses we show that a classifier designed to distinguish between correct and incorrect context memories, more strongly involves early activity (400–500 ms) over the frontal channels for the location distinctions, than for the extrinsic color associations. In contrast, the classifier designed to classify memory for the item (without memory for the context), had more frontal channel involvement for the color associated experiments than for the spatial experiments. Taken together these results argue that location may be bound more tightly with the item than an extrinsic color association. The multivariate classification approach also showed that trial-by-trial variation in EEG corresponding to these ERP components were predictive of subjects’ behavioral responses. Additionally, the multivariate classification approach enabled analysis of error conditions that did not have sufficient trials for standard ERP analyses. These results suggested that false alarms were primarily attributable to item memory (as opposed to memory of associated context), as commonly predicted, but with little previous corroborating EEG evidence

Polypyrrole-Fe2O3 nanohybrid materials for electrochemical storage

We report on the synthesis and electrochemical characterization of nanohybrid polypyrrole (PPy) (PPy/Fe2O3) materials for electrochemical storage applications. We have shown that the incorporation of nanoparticles inside the PPy notably increases the charge storage capability in comparison to the “pure” conducting polymer. Incorporation of large anions, i.e., paratoluenesulfonate, allows a further improvement in the capacity. These charge storage modifications have been attributed to the morphology of the composite in which the particle sizes and the specific surface area are modified with the incorporation of nanoparticles. High capacity and stability have been obtained in PC/NEt4BF4 (at 20 mV/s), i.e., 47 mAh/g, with only a 3% charge loss after one thousand cyles. The kinetics of charge–discharge is also improved by the hybrid nanocomposite morphology modifications, which increase the rate of insertion–expulsion of counter anions in the bulk of the film. A room temperature ionic liquid such as imidazolium trifluoromethanesulfonimide seems to be a promising electrolyte because it further increases the capacity up to 53 mAh/g with a high stability during charge–discharge processes

First-passage times in complex scale-invariant media

How long does it take a random walker to reach a given target point? This quantity, known as a first passage time (FPT), has led to a growing number of theoretical investigations over the last decade1. The importance of FPTs originates from the crucial role played by first encounter properties in various real situations, including transport in disordered media, neuron firing dynamics, spreading of diseases or target search processes. Most methods to determine the FPT properties in confining domains have been limited to effective 1D geometries, or for space dimensions larger than one only to homogeneous media1. Here we propose a general theory which allows one to accurately evaluate the mean FPT (MFPT) in complex media. Remarkably, this analytical approach provides a universal scaling dependence of the MFPT on both the volume of the confining domain and the source-target distance. This analysis is applicable to a broad range of stochastic processes characterized by length scale invariant properties. Our theoretical predictions are confirmed by numerical simulations for several emblematic models of disordered media, fractals, anomalous diffusion and scale free networks.Comment: Submitted version. Supplementary Informations available on Nature websit

Breast density and polymorphisms in genes coding for CYP1A2 and COMT: the Multiethnic Cohort

BACKGROUND: Mammographic density is a strong predictor of breast cancer risk and is increased by hormone replacement therapy (HRT). Some associations with genetic polymorphisms in enzymes involved in estrogen metabolism have been described. This cross-sectional analysis examined the relation between mammographic density and the CYP1A2*1F and COMT Val(58 )Met polymorphisms among 332 breast cancer cases and 254 controls in the Hawaii component of the Multiethnic Cohort. METHODS: Mammographic density, before diagnosis in cases, was quantified by using a validated computer-assisted method. Blood samples were genotyped by standard PCR/RFLP methods. Adjusted mean percent density was calculated by genotype using mixed models with the unstructured covariance option. RESULTS: A positive association between the C allele in the CYP1A2*1F gene and percent density, but not the dense area, was suggested (p = 0.11). The relation was limited to controls (p = 0.045), postmenopausal women not using HRT (p = 0.08), and normal weight subjects (p = 0.046). We did not observe any relation between the COMT Val(58 )Met polymorphism and breast density. CONCLUSION: The lack of an association between the CYP1A2 genotype and the size of the dense areas suggests an effect on the non-dense, i.e., fatty breast tissue. The discrepancies among studies may be due to differential susceptibility; changes in enzyme activity as a result of the CYP1A2*1F polymorphism may influence breast tissue differently depending on hormonal status. Larger studies with the ability to look at interactions would be useful to elucidate the influence of genetic variation in CYP1A2 and COMT on the risk of developing breast cancer

Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

Search for Neutral Higgs Bosons in Events with Multiple Bottom Quarks at the Tevatron

The combination of searches performed by the CDF and D0 collaborations at the Fermilab Tevatron Collider for neutral Higgs bosons produced in association with b quarks is reported. The data, corresponding to 2.6 fb-1 of integrated luminosity at CDF and 5.2 fb-1 at D0, have been collected in final states containing three or more b jets. Upper limits are set on the cross section multiplied by the branching ratio varying between 44 pb and 0.7 pb in the Higgs boson mass range 90 to 300 GeV, assuming production of a narrow scalar boson. Significant enhancements to the production of Higgs bosons can be found in theories beyond the standard model, for example in supersymmetry. The results are interpreted as upper limits in the parameter space of the minimal supersymmetric standard model in a benchmark scenario favoring this decay mode.Comment: 10 pages, 2 figure

Measurement of CP-violation asymmetries in D0 to Ks pi+ pi-

We report a measurement of time-integrated CP-violation asymmetries in the resonant substructure of the three-body decay D0 to Ks pi+ pi- using CDF II data corresponding to 6.0 invfb of integrated luminosity from Tevatron ppbar collisions at sqrt(s) = 1.96 TeV. The charm mesons used in this analysis come from D*+(2010) to D0 pi+ and D*-(2010) to D0bar pi-, where the production flavor of the charm meson is determined by the charge of the accompanying pion. We apply a Dalitz-amplitude analysis for the description of the dynamic decay structure and use two complementary approaches, namely a full Dalitz-plot fit employing the isobar model for the contributing resonances and a model-independent bin-by-bin comparison of the D0 and D0bar Dalitz plots. We find no CP-violation effects and measure an asymmetry of ACP = (-0.05 +- 0.57 (stat) +- 0.54 (syst))% for the overall integrated CP-violation asymmetry, consistent with the standard model prediction.Comment: 15 page