A neural model of visually guided steering, obstacle avoidance, and route selection.

A neural model is developed to explain how humans can approach a goal object on foot while steering around obstacles to avoid collisions in a cluttered environment. The model uses optic flow from a 3-dimensional virtual reality environment to determine the position of objects on the basis of motion discontinuities and computes heading direction, or the direction of self-motion, from global optic flow. The cortical representation of heading interacts with the representations of a goal and obstacles so that the goal acts as an attractor of heading and obstacles act as repellers. In addition, the model maintains fixation on the goal object by generating smooth pursuit eye movements. Eye rotations can distort the optic flow field, complicating heading perception, and the model uses extraretinal signals to correct for this distortion and accurately represent heading. The model explains how motion processing mechanisms in cortical areas middle temporal, medial superior temporal, and posterior parietal cortex can be used to guide steering. The model quantitatively simulates human psychophysical data about visually guided steering, obstacle avoidance, and route selection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Revisitation of formaldehyde-aniline condensation. III. The Cyclic Tetramer of N-Methyleneaniline: An X-ray diffraction structure determination

The cyclic tetramer of N -methyleneaniline, one of the products from the condensation between formaldehyde and aniline under neutral condition, has been characterized as 1.3.5.7-tetraphenyltetrazocine ( 3 ) and its crystal structure elucidated by X-ray diffraction.     

Consolidation of soft clay foundation improved by geosynthetic-reinforced granular columns: Numerical evaluation

Soft clays are problematic soils as they present high compressibility and low shear strength. There are several methods for improving in situ conditions of soft clays. Based on the geotechnical problem's geometry and characteristics, the in situ conditions may require reinforcement to restrain instability and construction settlements. Granular columns reinforced by geosynthetic material are widely used to reduce settlements of embankments on soft clays. They also accelerate the consolidation rate by reducing the drainage path's length and increasing the foundation soil's bearing capacity. In this study, the performance of encased and layered granular columns in soft clay is investigated and discussed. The numerical results show the significance of geosynthetic stiffness and the column length on the embankment settlements. Furthermore, the results show that granular columns may play an important role in dissipating the excess pore water pressures and accelerating the consolidation settlements of embankments on soft clays.     

Robust hybrid estimation and rejection of multi‐frequency signals

We consider the problem of output regulation for LTI systems in the presence of unknown exosystems. The knowledge about the multi‐frequency signals exosystem consists in the maximum number of frequencies and their maximal value. The control scheme relies on two main components: an estimation algorithm, to reconstruct the signal generated by the exosystem, and a controller, to enforce the output regulation property to the closed‐loop system. To tackle the first task, we propose a hybrid observer for the estimation of the (possibly piece‐wise continuous) number and values of the frequencies contained in the exogenous signal. The hybrid observer is particularly appealing for numerical implementations, and it is combined with a self‐tuning algorithm of the free parameters (gains), thus improving its performance even in case of noisy measurements. Semi‐global exponential convergence of the estimation error is provided. As far as the second task is concerned, a robust hybrid regulator is designed for practical rejection of the multi‐frequency disturbance signal acting on the plant. The result is achieved by exploiting the frequencies estimated by the hybrid observer. The effectiveness of the proposed control scheme is shown by means of numerical simulations. Copyright © 2016 John Wiley & Sons, Ltd.     

MARTe at FTU: The new feedback control

Keeping in mind the necessities of a modern control system for fusion devices, such as modularity and a distributed architecture, an upgrade of the present FTU feedback control system was planned, envisaging also a possible reutilization in the proposed FAST experiment [1]. For standardization and efficiency purposes we decided to adopt a pre-existent ITER-relevant framework called MARTe [2], already used with success in other European Tokamak devices [3]. Following the developments shown in [4], in this paper we report on the structure of the new feedback system, and how it was integrated in the current control structure and pulse programming interface, and in the other MARTe systems already in FTU: RT-ODIN [5] and the ECRH and LH [6] satellite stations. The new feedback system has been installed in the FTU backup station (known as “Feedback B”), which shares the input signals with the actual feedback system, in order to simplify the validation and debug of the new controller by testing it in parallel with the current one. Experimental results are then presented.     

Expression of cyclins D1 and E in human colon adenocarcinomas

Cyclins D1 and E play critical roles in the progression of cells through the G1 phase of the cell cycle. Amplification and/or overexpression of the cyclin D1 gene and aberrant expression of cyclin E have been described in several forms of human cancer. In the present study, we examined the expression of these two genes by Western, Northern and Southern blot analyses in a series of primary human colon carcinomas of various stages and degrees of differentiation and in paired adjacent normal mucosa samples, and also in a series of human colon carcinoma cell lines. About 50% of the colon carcinomas displayed a two to five fold increase in the expression of cyclin D1 mRNA and protein, when compared with the paired normal mucosa samples. Six out of eight carcinomas examined showed a four to nine fold increase in cyclin E mRNA and about 50% of the carcinomas displayed a two to three fold increase in cyclin E protein. Low molecular weight cyclin E-related proteins were observed in four out of ten carcinomas. These changes in cyclins D1 and E occurred in both early and late stage tumors. Three of the six cell lines examined displayed a high expression of cyclin D1 mRNA and protein. A very high level of cyclin E mRNA expression was seen in HCT116 cells and this was associated with the presence of low molecular weight cyclin E-related proteins. None of the primary colon carcinomas nor the six cell lines examined displayed amplification of either the cyclin D1 or cyclin E genes. Thus, an aberrant expression of both cyclins D1 and E occurs in a significant fraction of human colon carcinomas.     

Ga NMR as a sensitive probe of perfection in gallium phosphide crystals

The ⁶⁹Ga NMR has been studied in an undoped gallium phosphide ingot grown by the liquid encapsulated Czochralski technique. The linewidths and peak intensities are found to vary from top to bottom of the ingot. It is concluded that the bottom contains less lattice defects and is probably more stoichiometric than the top. Heat treatment of the top is found to have an effect on the NMR linewidths and intensities.     

Treatment of dye solutions by vacuum membrane distillation

In this work, the vacuum membrane distillation (VMD) process has been applied to treat water containing different types of dyes. The influence of operating parameters, as feed temperature, feed flow rate, feed concentration, on the permeate flux and on rejection has been investigated. In all experimental tests, a complete rejection has been achieved and pure water has been recovered at the permeate side.Furthermore, experiments with water as feed have been carried out before and after the tests with dyes, in order to analyze the effect of fouling on the performance of the VMD. The water vapor fluxes immediately after the tests with dyes were higher than the values registered before the tests, probably due to an interaction with the polymeric membrane material which promotes a swelling of the membrane when in contact with the dye solutions. However, initial fluxes are recovered after prolonged cleaning with only water.     

Evolution of phenolic compounds in virgin olive oil during storage

Phenolic compounds are of fundamental importance to the shelf life of virgin olive oils because of their antioxidative properties. In this paper, the evolution of simple and complex olive oil phenols during 18 mon of storage is studied by high-performance liquid chromatography (HPLC) analysis. The olive oils under examination were from various olive cultivars, harvested in two sectors in the same region at different stages of ripeness. The findings indicate that it is not the variety but rather the ripeness of the olives and the soil and climate that influence the phenol composition of virgin olive oil. In addition, a positive correlation was found between the age of the oils and the tyrosol to total phenols ratio. Lastly, gas chromatography-mass spectrometry analysis confirmed that the unidentified peaks detected by HPLC were of a phenolic nature.     

Diet quality and therapeutic targets in patients with type 2 diabetes: evaluation of concordance between dietary indexes

Background

This study aimed to evaluate the concordance between two dietary indexes, the Healthy Eating Index (HEI) and the Diabetes Healthy Eating Index (DHEI), in evaluating diet quality and its possible association with therapeutic targets in patients with type 2 diabetes.

Methods

Cross-sectional study of outpatients with type 2 diabetes mellitus treated at a university hospital. Dietary information was obtained from a quantitative food frequency questionnaire (previously validated for use in patients with type 2 diabetes) and converted into daily intakes. Diet quality was assessed using two dietary indexes: HEI (12 components, nine food groups and three moderation components) and DHEI (10 components, six food groups, three nutrient groups, and one for variety of diet). In both indexes, the sum of the scores for each component yields an overall score converted on a scale from 0 to 100%; diet quality is subsequently ranked as low (<51%), needing improvement (51–80%), or high (>80%). Patients underwent clinical and laboratory assessment. Those with fasting blood glucose values 70–130 mg/dL, A1c?<?7%, total cholesterol <200 mg/dL, LDL-cholesterol <100 mg/dL, and triglycerides <150 mg/dL were considered to meet therapeutic targets. All analyses were conducted in PASW Statistics 18.0, and p?<?0.05 deemed significant.

Results

We analyzed 148 patients with type 2 diabetes (73% white, mean age 63.2?±?9.4 years, median diabetes duration 10 [IQR 5–19] years, mean A1c% 8.4?±?2.0%, and mean BMI 30.5?±?4.2 kg/m²). Mean energy intake was 2114?±?649 kcal/day. DHEI scores were 17.0 (95%CI -6.8 to 41.0) points lower than HEI scores (55.9?±?14.2% vs. 72.9?±?10.7%, respectively; P?<?0.001), suggesting there is no agreement (Bland-Altman method), and the Pearson correlation coefficient was 0.55 (P?<?0.001). More patients were classified as having a low-quality diet by the DHEI than by the HEI (38.5% vs. 1.4%; P?<?0.001). A higher proportion of patients (35.7%) with out-of-target total cholesterol levels had a low-quality diet evaluated by the DHEI (P?=?0.03). We did not find associations between overall score of HEI and therapeutic targets.

Conclusions

In its intended population of patients with type 2 diabetes, the DHEI seems to be a more rigorous tool to evaluate association between diet quality and changes in metabolic parameters.