Neuromorphic Tactile Sensing System for Textural Features Classification

Artificial tactile sensing systems have gained significant attention in recent years due to their potential to enhance human-machine interaction. Numerous initiatives have been introduced to shift the computational paradigms of these systems towards a more biologically inspired approach, by incorporating neuromorphic computing methods. Despite the significant advances made by these systems, dependence on complex offline methods for classification (i.e. hand-crafted encoding features), remains a limitation for their real-time deployment. In this work, we present a neuromorphic tactile PVDF-based sensing system for textural features classification, that employs raw signals directly for classification. We first converted raw signals into spikes and then trained recurrent spiking neural networks (RSNNs) using Backpropagation Through Time (BPTT) with surrogate gradients to perform classification. We proposed an optimization method based on tuning the refractory period of the encoding neurons, to explore a potential trade-off between the computational cost and classification accuracy of the RSNN. The proposed method effectively identified two RSNNs with refractory period configurations that achieved a trade-off between the two evaluation metrics. Following this, we reduced the inference time steps of the selected RSNN during inference using a rate-coding based method. This method succeeded in saving around 26.6% out of the total original time steps. In summary, the proposed system paves the way for establishing an end-to-end neuromorphic approach for tactile textural features classification, through deploying the selected RSNNs on a dedicated neuromorphic hardware device for real-time inferences

Alkaline protease production by alkaliphilic marine bacteria isolated from Marsa-Matrouh (Egypt) with special emphasis on Bacillus cereus purified protease

Among the eighteen (18) alkaliphilic marine bacterial isolates studied in ten sampling sites in Marsa-Matrouh beaches, the highest alkaliphilic and proteolytic activities were detected in Bacillus cereus. Alkaline protease from B. cereus was purified by ammonium sulfate precipitation and Sephadex G-200. The molecular mass determined using SDS-PAGE, was nearly 31.0 39 kDa. Some fundamental properties like effects of different temperatures, pH, metal ions (Ca2+, Mg2+, Cu2+, Pb3+, Mn2+ and Cd2+) and ethylene diamine tetraacetic acid (EDTA) on protease activity were also studied. Maximum activities were obtained at pH 10, 50°C and only Cu2+ ions enhanced the relative enzyme activity up to 112%. The application of alkaline protease for the removal of blood stains from cotton cloth indicates its potential use in detergent formulations. B. cereus protease showed excellent stability in the presence of locally available detergents and retained about 60% of its activity with most of them even after 3 h of incubation at temperature of 50°C.Key words: Protease producing bacteria, detergents, Bacillus cereus, purification, enzyme stability and activity

Optimization, economization and characterization of cellulase produced by marine Streptomyces ruber

Cellulase is a very important enzyme due to its great industrial applications. Six marine strains of actinomycetes were screened for their carboxymethyl cellulase (CMCase) productivity. Streptomyces ruber was chosen to be the best producing strain. The highest enzyme production (25.6 U/ml) was detected at pH 6 and 40°C after 7 days of incubation. Plackett-Burman design was applied to optimize the different culture conditions affecting enzyme production. Results showed that a high concentration of KH2PO4, and a low concentration of MgSO4 had a significant effect on enzyme production. Rice straw was used as a low cost source of cellulose. It was found that 30 g/l rice straw was the suitable concentration for maximum enzyme production. Partial purification of cellulase enzyme using an anionexchange chromatography resulted in the detection of two different types of CMCases, type I and II, with specific activity of 4239.697 and 846.752 U/mg, respectively. Moreover, estimation of their molecular weight revealed 27.0 kDa for cellulase type I and 24.0 kDa for cellulase type II. It could be concluded that S. ruber is a powerful cellulase producer strain under our tested experimental conditions.Key words: Cellulase production, Streptomyces ruber, Plackett-Burman design, rice straw, enzyme characterization

Bone marrow manifestations in multicentric Castleman disease

This study aimed to document the morphological and immunophenotypic features, and describe the diagnostic features of bone marrow (BM) involvement in human herpes virus 8 Multicentric Castleman disease (HHV8-MCD). BM trephine biopsy (BMTB) specimens from 28 patients were revisited. Samples were evaluated for expression of CD3, CD20, CD138, CD68R, glycophorin C, CD42b, HHV8-latency-associated nuclear antigen (LANA1), Epstein–Barr virus-encoded small RNA and light chains. Presence of significant numbers of HHV8-LANA1+ lymphoid/plasmacytic cells, noted in 10/28 cases, was indicative of BM involvement and was associated with low CD4 and CD8 counts in peripheral blood. The characteristic morphological appearance of MCD seen in lymph nodes is a rare finding in BMTB. 4/5 cases with lymphoid aggregates were involved by MCD, whereas 6/23 cases without lymphoid aggregates were involved by MCD (P = 0·023). 9/18 cases with hypercellular marrow were involved by MCD, whilst only 1/8 cases with normo/hypocellular marrow showed involvement by MCD (P = 0·070). While 9/21 cases with increased marrow reticulin were involved by MCD, none of the cases with no increase in reticulin were involved by MCD (P = 0·080). Reactive plasmacytosis is a frequent finding. We conclude that bone marrow is involved in a significant proportion of patients with MCD (36%), and involvement can be identified by HHV8-LANA1 immunohistochemistry

Early and total yield enhancement of the globe artichoke using an ecofriendly seaweed extract-based biostimulant and PK fertilizer

This is the final version. Available from MDPI via the DOI in this record.This study evaluated the effect of phosphorus and potassium (PK) fertilizer levels and foliar seaweed extract on early and total yield productivity and the growth of globe artichoke plants. Field experiments were conducted over two seasons on loamy–clay soil at the vegetable research farm, of the Faculty of Agriculture, Alexandria University, Egypt. Fertilizer levels of 0, 25, 50 and 75 mL L−1, and seaweed extract concentrations of 0, 5 and 10 mg L−1, individually and in combination, were used. Globe artichoke plants treated with PK liquid fertilizer, with and without seaweed extract, showed critical increases in growth (plant height and number of leaves per plant as well as foliage dry weight), yield, and some chemical constituents compared to untreated plants. The PK3 fertilizer level and 10 mL L−1 seaweed extract as a foliar spray showed greater effects than other combinations.King Saud University Researchers Supporting Projec