Changes in the visual system in low birth weight children

PURPOSE: Evaluation of the visual system, especially refraction, in children with low birth weight under observation between 1990-1992. MATERIAL AND METHODS: 248 children with birth weight 600-2500 g and gestational age 26-37 weeks underwent ophthalmological examination including USG, ERG and VER. The children were first examined between 3-4 weeks of life, then at 8 and 12 weeks and 6, 12, 18 and 24 months. RESULTS: Refractive errors were found in 216 of patients, in 85.2% hypermetropia. ROP occurred in 7 children with birth weight below 1500 g and gestational age 27-32 weeks. Other ocular changes were observed in 19 (7.6%) of the examined children.     

Transfer learning with Partially Constrained Models: Application to reinforcement learning of linked multicomponent robot system control

Transfer learning is a hierarchical approach to reinforcement learning of complex tasks modeled as Markov Decision Processes. The learning results on the source task are used as the starting point for the learning on the target task. In this paper we deal with a hierarchy of constrained systems, where the source task is an under-constrained system, hence called the Partially Constrained Model (PCM). Constraints in the framework of reinforcement learning are dealt with by state-action veto policies. We propose a theoretical background for the hierarchy of training refinements, showing that the effective action repertoires learnt on the PCM are maximal, and that the PCM-optimal policy gives maximal state value functions. We apply the approach to learn the control of Linked Multicomponent Robotic Systems using Reinforcement Learning. The paradigmatic example is the transportation of a hose. The system has strong physical constraints and a large state space. Learning experiments in the target task are realized over an accurate but computationally expensive simulation of the hose dynamics. The PCM is obtained simplifying the hose model. Learning results of the PCM Transfer Learning show an spectacular improvement over conventional Q-learning on the target task.     

The effect of preliminary processing and period of storage on the quality of frozen Boletus edulis (Bull: Fr.) mushrooms

This paper investigates the effect on the quality of frozen Boletus edulis (Bull: Fr.) mushrooms of blanching or soaking and blanching in aqueous solutions containing combinations of added substances safe for human consumption, or period of frozen storage. During 12 months of storage, sensory evaluations, instrumental colour measurements and chemical analyses of the frozen products were carried out every four months. Based on the results of the sensory evaluation, a maximum storage period of four months was set for the frozen product obtained from unblanched mushrooms. Frozen products having undergone preliminary processing retained good sensory quality for up to 12 months. Soaking, blanching and freezing resulted in the appearance of colours, such as yellow, honey and pink–violet. As a result of freezing, decreases in the contents of thiamine, riboflavin and vitamin C were noted. Blanching in water, as a method of pre-processing, was sufficient for maintaining acceptable sensory quality.     

Microwave-Assisted Digestion Using Diluted Nitric Acid for Multi-element Determination in Rice by ICP OES and ICP-MS

In this work, microwave-assisted digestion using the diluted nitric acid procedure for trace elements determination in rice samples by inductively coupled plasma optical emission spectrometry (ICP OES) and inductively coupled plasma mass spectrometry (ICP-MS) was investigated in a multivariate way. The response surface methodology (RSM), based on the Box–Behnken design, was employed to obtain the optimum conditions of the significant parameters. The optimal conditions, for 250 mg of sample, could be obtained at a temperature of 200 °C, digestion time of 20 min, and 4.5 mol L^?1 for nitric acid concentration. The accuracy of the optimized method was evaluated by analysis of the rice flour certified reference materials (NIST SRM 1568a) and spike recoveries. The results showed good agreement with the reference values of the CRM samples. The analytical method was applied to the determination of Al, As, Ca, Cd, Cu, Fe, K, Mg, Mn, Mo, Se, and Zn in rice samples. Considering some critical parameters such as cost, green chemistry, and analyst safety, the proposed method has advantages compared to classical microwave-assisted digestion procedures based on concentrated acids.     

Antioxidant effects of Satureja montana L. essential oil on TBARS and color of mortadella-type sausages formulated with different levels of sodium nitrite

This study aimed to evaluate the effect of adding winter savory (Satureja montana L.) essential oil (EO) at concentrations of 7.80, 15.60 and 31.25 μl/g on color and lipid oxidation (TBARS) in mortadella-type sausages formulated with different sodium nitrite (NaNO₂) levels (0, 100 and 200 mg/kg) and stored at 25 °C for 30 days. The EO was extracted by hydrodistillation and analyzed by gas chromatography–mass spectrometry (GC–MS). Twenty-six chemical compounds were identified; the most prominent of which were thymol (28.99 g/100 g), p-cymene (12.00 g/100 g), linalool (11.00 g/100 g) and carvacrol (10.71 g/100 g). Among the nitrite levels tested, a concentration of 100 mg/kg of sodium nitrite appeared to be sufficient for the formation of the characteristic red color. The use of EO at concentrations exceeding 15.60 μl/g adversely affected the color of the product by reducing redness (a¹) (p ≤ 0.05) and increasing yellowness (b¹ h¹). The EO antioxidant activity was confirmed by β-carotene bleaching method and DPPH assay. Reduced values of thiobarbituric acid reactive substances (TBARS) (p ≤ 0.05) were observed in mortadellas formulated with the lowest concentrations of EO without added nitrite. This significant effect on lipid oxidation was also observed in samples containing EO and reduced amounts of sodium nitrite. The results suggest possible benefits from the combined use of EOs and minimal amounts of sodium nitrite in cured meat products.     

Feed-in tariffs for promotion of energy storage technologies

Faster market integration of new energy technologies can be achieved by use of proper support mechanisms that will create favourable market conditions for such technologies. The best examples of support mechanisms presented in the last two decades have been the various schemes for the promotion of renewable energy sources (RES). In the EU, the most successful supporting schemes are feed-in tariffs which have significantly increased utilisation of renewable energy sources in Germany, Spain, Portugal, Denmark and many other EU countries. Despite the successful feed-in tariffs for RES promotion, in many cases RES penetration is limited by power system requirements linked to the intermittency of RES sources and technical capabilities of grids. These problems can be solved by implementation of energy storage technologies like reversible or pumped hydro, hydrogen, batteries or any other technology that can be used for balancing or dump load. In this paper, feed-in tariffs for various energy storage technologies are discussed along with a proposal for their application in more appropriate regions. After successful application on islands and outermost regions, energy storage tariffs should be also applied in mainland power systems. Increased use of energy storage could optimise existing assets on the market.