Spatial disparity coding in the superior colliculus of the cat

We investigate the spatial and temporal aspects of firing patterns in a network of integrate-and-fire neurons arranged in a one-dimensional ring topology. The coupling is stochastic and shaped like a Mexican hat with local excitation and lateral inhibition. With perfect precision in the couplings, the attractors of activity in the network occur at every position in the ring. Inhomogeneities in the coupling break the translational invariance of localized attractors and lead to synchronization within highly active as well as weakly active clusters. The interspike interval variability is high, consistent with recent observations of spike time distributions in visual cortex. The robustness of our results is demonstrated with more realistic simulations on a network of McGregor neurons which model conductance changes and after-hyperpolarization potassium currents.     

Monitoring production process of cisplatin‐loaded PLGA nanoparticles by FT‐IR microspectroscopy and univariate data analysis

Cisplatin‐loaded PLGA nanoparticles for drug delivery have been prepared using a well‐established water/oil/water double emulsion‐solvent evaporation method. The production process has been monitored by using Fourier Transform Infrared (FT‐IR) microspectroscopy without using KBr tablets and any preliminary sample preparation. Significant spectra have been obtained for all chemical compounds and for samples at different steps of production process. The use of a linear or univariate approach using a R² determination coefficient has been proposed for discriminating among FT‐IR spectra even when small differences are present. The obtained results confirm that new geometries of data acquisition contribute to make infrared microspectroscopy a very useful tool for a rapid and detailed monitoring of production processes of pharmacological interest. Moreover, morphological and physiological characterizations have been performed on cisplatin‐loded samples showing results in good agreement with those reported in literature. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41305.     

A Bayesian control chart for monitoring the ratio of Weibull percentiles

This paper introduces a new Bayesian control chart to compare two processes by monitoring the ratio of percentiles of two quality characteristics that are assumed to be independent Weibull distributed random variables with the same and stable shape parameter larger than one. The chart analyses the sampling data directly, instead of transforming them in order to comply with the usual normality assumption, as many charts do. A real application in the wood industry and a wide simulation illustrate the features of the chart and its performance, depending on the number of training data, the quality of prior information, and the magnitude of the shift.     

Submicrometre gate length scaling of inversion channelheterojunction field effect transistor

The scaling to 0.5 μm of the inversion channel HFET with a single strained InGaAs quantum well is described. A unity current gain frequency of 40 GHz, g_m=205 mS/mm and V_TH=-0.34 V have been obtained for 0.5×100 μm² devices. For shorter gate lengths, threshold shifts are sizeable so that in order to scale further, modifications to the growth and processing are required     

Reliability among neurologists in the severity assessment of blepharospasm and oromandibular dystonia: a multicenter study

The reliability of a scale of 0 to 4 (where 0 is normal) in rating the severity of blepharospasm (BS) and oromandibular dystonia (OMD) was evaluated by the concordance among six neurologists from different neurological institutions. As expressed by k index, interobserver agreement was moderate either for BS or for OMD according to the Landis classification. Neurologists showed different rating attitude toward BS and OMD. In fact, the category analysis showed that raters were inclined to overestimate BS and to underestimate OMD. The familiarity with dystonia influenced reliability more than the length of professional experience in neurology. In fact, when examiners were subdivided into subgroups (each of three raters) according to the former criteria, the level of interobserver agreement increased significantly. Almost perfect agreement was obtained in intrarater comparisons. These results may be of value with regard to the conduct of multicenter epidemiologic and clinical studies on focal dystonias.     

Relay Redox and Lewis Acid Catalysis in the Titanocene‐ Catalyzed Multicomponent Assembly of 1,5‐Enynes

Herein we describe a direct, multicomponent assembly of 1,5‐enynes. The titanocene‐catalyzed coupling of an aryl aldehyde, iodoalkyne, and allylsilane enables the convergent and rapid synthesis of this versatile architectural motif in good to excellent yields.     

Sensory modality distribution in the anterior ectosylvian cortex (AEC) of cats

Modality specificity of neuronal responses to visual, somesthetic and auditory stimuli was investigated in the anterior ectosylvian cortex (AEC) of cats, using single-unit recording techniques. Seven classes of neurons were found, and according to their responsiveness to sensory stimuli regrouped into three categories: unimodal, bimodal and trimodal. Unimodal cells that responded to only one of the three stimulus modalities formed 59% of the units; 30.2% were bimodal, in that they showed a clear increase of neuronal discharges to two of the three stimulus types; 10.8% were defined as trimodal because they responded to all three stimulus modalities. Although the different categories of cells were intermingled within the AEC, indicating a certain degree of overlap between sensory modalities, some clustering of cell types was nonetheless evident. Thus, the somatosensory responsive cells were mainly located in the anterior two-thirds of the dorsal bank of the anterior ectosylvian sulcus. Visually responsive cells were concentrated on the ventral bank of the sulcus, whereas neurons with an auditory response occupied the banks and fundus of the posterior three-quarters of the sulcus. The histological distribution and physiological properties of AEC neurons suggest that this cortical region is a higher-order associative area whose function may be to integrate information from different sensory modalities.     

Abstract thinking following severe traumatic brain injury

Abstract abilities were studied in a sample of 34 individuals with severe TBI and a control group. The results indicate that TBI interferes with performance on tests requiring individuals to process information into new categories. There appears to be a dissociation between verbal abstract abilities and visual-perceptual abstract abilities. There is evidence that Goldstein and Sheerer's [1] postulate of a general 'abstract attitude' was at least partially correct. This attitude does not appear to be related to a general verbal ideational process, as dysphasic subjects were only deficient on a purely verbal abstract task.     

Physico‐optical properties of a crosslinked hyaluronic acid scaffold for biomedical applications

Optical techniques are increasingly employed for monitoring cell–matrix interactions in suitably prepared 3D scaffolds. The ability of designing and realizing synthetic extracellular matrix with well‐controlled optical properties is a crucial need in this field. For this purpose, a crosslinked hyaluronic acid (HA) scaffold is prepared. Fourier transform infrared and ultraviolet–visible spectroscopies enable to monitor the scaffold preparation process and to evidence scaffold high transparency and low fluorescence in the visible range. 3D optical characteristics of the HA scaffold are tested by two‐photon microscopy (TPM) imaging of embedded fluorescent microbeads and alive keratinocytes labeled with vital PKH67 dye at different depths from the scaffold surface. Some useful indications about the potentiality of TPM measurements for the determination of attenuation coefficient of turbid media are also reported. Moreover, the use of the presented HA scaffold for preparing tissue phantoms for fluorescence imaging or diffuse imaging is proposed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45243.