Wavelet ridges for musical instrument classification

The time-varying frequency structure of musical signals have been analyzed using wavelets by either extracting the instantaneous frequency of signals or building features from the energies of sub-band coefficients. We propose to benefit from a combination of these two approaches and use the time-frequency domain energy localization curves, called as wavelet ridges, in order to build features for classification of musical instrument sounds. We evaluated the representative capability of our feature in different musical instrument classification problems using support vector machine classifiers. The comparison with the features based on parameterizing the wavelet sub-band energies confirmed the effectiveness of the proposed feature.     

An Organoid for Woven Bone

Bone formation (osteogenesis) is a complex process in which cellular differentiation and the generation of a mineralized organic matrix are synchronized to produce a hybrid hierarchical architecture. To study the mechanisms of osteogenesis in health and disease, there is a great need for functional model systems that capture in parallel, both cellular and matrix formation processes. Stem cell-based organoids are promising as functional, self-organizing 3D in vitro models for studying the physiology and pathology of various tissues. However, for human bone, no such functional model system is yet available. This study reports the in vitro differentiation of human bone marrow stromal cells into a functional 3D self-organizing co-culture of osteoblasts and osteocytes, creating an organoid for early stage bone (woven bone) formation. It demonstrates the formation of an organoid where osteocytes are embedded within the collagen matrix that is produced by the osteoblasts and mineralized under biological control. Alike in in vivo osteocytes, the embedded osteocytes show network formation and communication via expression of sclerostin. The current system forms the most complete 3D living in vitro model system to investigate osteogenesis, both in physiological and pathological situations, as well as under the influence of external triggers (mechanical stimulation, drug administration).     

Effects of pomegranate sauce on quality of marinated anchovy during refrigerated storage

Effects of pomegranate sauce on the quality of marinated anchovy during storage at 4 °C were investigated. Anchovy were marinated with 30 g/L acetic acid and 150 g/L salt, put into glass jars, filled with either sunflower oil or pomegranate sauce and stored at 4 °C. Total volatile basic nitrogen (TVB-N) and trimethylamine (TMA-N) values increased during the storage. Higher values for free fatty acid (FFA), conjugated diens (k-dien) and para-anisidine (p-Av) were found in samples with sunflower oil than those with pomegranate sauce. Samples in pomegranate sauce showed better oxidative stability. Higher taste and flavour and lower appearance scores were found for samples in pomegranate sauce than those samples in sunflower oil. It was found that pomegranate sauce was as least effective as the traditional sunflower oil to keep quality. Pomegranate sauce also produced desirable taste and flavour but the coloration should be studied in further studies.     

Separation of squalene from olive oil deodorizer distillate using supercritical fluids

In this study, an integrated strategy using supercritical fluids for extraction of squalene from olive oil deodorizer distillate (OODD), one of the most important by‐products of the olive oil refining process is presented. First, OODD was esterified in supercritical methanol, and then squalene was extracted from the sample consisting of 66% methyl ester using supercritical CO₂. The extraction conditions, i.e., pressure (88.2–121.8 bar), temperature (41.6–58.4°C) and extraction time (129.6–230.4 min), were optimized via RSM to achieve the highest squalene content. The optimal results were obtained at a temperature of 52.05°C, pressure of 104.8 bar and extraction time of 180 min. Consequently, two kinds of value‐added products such as biodiesel (up to 96% FAME, in extract) and olive squalene (up to 75%, in raffinate) were produced in shorter processing times when compared with distillation results of 70 h. Practical applications: Traditionally, squalene is extracted from liver oil of rare deep‐sea sharks. Here we present the recovery of vegetal squalene in high purity from OODD. Our approach also presents a simple, reliable, and mobile solution. Squalene is widely used in cosmetics as a protective agent and natural moisturizer and as an adjuvant in influenza vaccines.     

Inhibition effects of green tea and grape seed extracts on lipid oxidation in bonito fillets during frozen storage

The aim of this study was to investigate inhibition effects of green tea and grape seed extracts on lipid oxidation in bonito (Sarda sarda) fillets during frozen storage. Dried and powdered green tea and grape seed were extracted using ethanol. Extract solutions of 1 g 100 g^?1 were prepared using concentrated extracts and distilled water. Bonito fillets were divided into two groups. The first group was dipped into extract solutions and then frozen. The second group of fillets was glazed by extract solutions. Oxidation increased progressively through the storage period. 2‐Thiobarbituric acid and para‐anisidine values of samples treated with green tea and grape seed extracts remained at low levels. Both plant extracts displayed successful effects in delaying lipid oxidation compared to the control groups. The best results were obtained by extract treatment of fillets before freezing.     

Separation and purification of hyaluronic acid by glucuronic acid imprinted microbeads

The purification of hyaluronic acid (HA) is relatively significant to use in biomedical applications. The structure of HA is formed by the repetitive units of glucuronic acid and N-acetyl glucosamine. In this study, glucuronic acid-imprinted microbeads have been supplied for the purification of HA from cell culture (Streptococcus equi). Histidine-functional monomer, methacryloylamidohistidine (MAH) was chosen as the metal-complexing monomer. The glucuronic acid-imprinted poly(ethyleneglycoldimethacrylate-MAH-Copper(II)) [p(EDMA-MAH-Cu²⁺)] microbeads have been synthesized by typical suspension polymerization procedure. The template glucuronic acid has been removed by employing 5 M methanolic KOH solution. p(EDMA-MAH-Cu²⁺) microbeads have been characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) images and swelling studies. Moreover, HA adsorption experiments have been performed in a batch experimental set-up. Purification of HA from cell culture supernatant has been also investigated by determining the hyaluronidase activity using purified HA as substrate. The glucuronic acid imprinted p(EDMA-MAH-Cu²⁺) particles can be used many times with no significant loss in adsorption capacities. Also, the selectivity of prepared molecular imprinted polymers (MIP) has been examined. Results have showed that MIP particles are 19 times more selective for glucuronic acid than N-acetylglucose amine.     

Robust optimal decisions with imprecise forecasts

A robust minimax approach for optimal investment decisions with imprecise return forecasts and risk estimations in financial portfolio management is considered. Single-period and multi-period mean-variance optimization models are extended to worst-case design with multiple rival risk estimations and return forecasts. In multi-period stochastic formulation of classical mean-variance portfolio optimization problem, an investor makes an investment decision based on expectations and/or scenarios up to some intermediate times prior to the horizon and, consequently, rebalances or restructures the portfolio. Multi-period portfolio optimization entails the construction of a scenario tree representing a discretized estimate of uncertainties and associated probabilities in future stages. It is well known that return forecasts and risk estimations are inherently inaccurate and there are different rival estimates, or scenario trees. Robust optimization models are presented and imprecise nature of moment forecasts to reduce the risk of making a decision based on the wrong scenario is addressed. The worst-case performance is guaranteed in view of all rival risk and return scenarios and will only improve when any scenario other than the worst-case is realized. The ex-ante performance of minimax models is tested using historical data and backtesting results are presented.     

Characterization of protein functionality and texture of tumbled squid,octopus and cuttlefish muscles

The aim of this study was to investigate the effects of tumbling on the physicochemical and textural characteristics of squid (Loligo vulgaris), octopus (Octopus vulgaris) and cuttlefish (Sepia officinalis) muscles. Before tumbling the cephalopod samples were placed in plastic bags and 0.5 M NaCl was added. Tumbling process was performed continuously in three different tumbling times (2, 4, and 6 h). The results of the analyses showed that tumbling affected the physicochemical properties of cephalopod muscles. The increase in the time of tumbling resulted in the tenderness of the cephalopod muscles. The total soluble protein, the total free amino acid, and pH values increased with the increase of the tumbling time. The water holding capacity decreased and the cooking loss increased. The squid and octopus hardness and shear force values decreased after tumbling, according to instrumental and sensorial texture measurements. As a result, tumbling was found to be an effective method for tenderizing of squid and octopus muscle, but not for cuttlefish.