Modelling and analysis of temporal preference drifts using a component-based factorised latent approach

In recommender systems, human preferences are identified by a number of individual components with complicated interactions and properties. Recently, the dynamicity of preferences has been the focus of several studies. The changes in user preferences can originate from substantial reasons, like personality shift, or transient and circumstantial ones, like seasonal changes in item popularities. Disregarding these temporal drifts in modelling user preferences can result in unhelpful recommendations. Moreover, different temporal patterns can be associated with various preference domains, and preference components and their combinations. These components comprise preferences over features, preferences over feature values, conditional dependencies between features, socially-influenced preferences, and bias. For example, in the movies domain, the user can change his rating behaviour (bias shift), her preference for genre over language (feature preference shift), or start favouring drama over comedy (feature value preference shift). In this paper, we first propose a novel latent factor model to capture the domain-dependent component-specific temporal patterns in preferences. The component-based approach followed in modelling the aspects of preferences and their temporal effects enables us to arbitrarily switch components on and off. We evaluate the proposed method on three popular recommendation datasets and show that it significantly outperforms the most accurate state-of-the-art static models. The experiments also demonstrate the greater robustness and stability of the proposed dynamic model in comparison with the most successful models to date. We also analyse the temporal behaviour of different preference components and their combinations and show that the dynamic behaviour of preference components is highly dependent on the preference dataset and domain. Therefore, the results also highlight the importance of modelling temporal effects but also underline the advantages of a component-based architecture that is better suited to capture domain-specific balances in the contributions of the aspects

Assessment of cd93 stem cell growth and survival on three-dimensional biodegradable pcl-gelatin scaffold

Background and purpose: Application of three-dimensional scaffolds with the ability to simulate a three-dimensional in vivo environment has opened new perspective on targeted differentiation and therapeutic use of stem cells. In this study we examined the compatibility of CD93 stem cells with biodegradable pcl- gelatin scaffold. Materials and methods: In this experimental study, three-dimensional scaffolds made of PCL -gelatin using electrospining synthesis and its molecular structure was tested by SEM electron microscopy. The scaffold surface was disinfected by UV ray. The hematopoietic CD93stem cells of those isolated previously were divided into two groups including normal cultured (plate) and culture on scaffolds (scaffold + cell). The survival and growth of the cells were measured through MTT assay and electron microscopy at 7, 14, and 28 days after culturing. Results: Electron microscopic analysis on the seventh day showed appropriate adhesion of CD93 cells on scaffold fibers and secretion of extracellular matrix. Survival rate of the cells at 7, 14, and 28 days after culturing were not significantly different between the two groups. But at the same days significant differences were observed in the Scaffold + Cell group (P< 0.05). Conclusion: This study suggests that PCL nanofiber scaffolds has high compatibility with CD93 stem cells and proximity to this scaffold lead to increased survival and growth of the cells. Further studies on the treatment of tissue damage and scarring by CD93 stem cells using this scaffold can be effective in increasing treatment efficiency. © 2016, Mazandaran University of Medical Sciences. All rights reserved

Remyelination of the corpus callosum by olfactory ensheathing cell in an experimental model of multiple sclerosis

Multiple Sclerosis (MS) causes loss of the myelin sheath, which leads to loss of neurons. Regeneration of myelin sheath stimulates axon regeneration and neurons� survival. In this study, olfactory ensheathing cell (OEC) transplantation is investigated to restore myelin sheath in an experimental model of MS in male mice.OECs were isolated from the olfactory mucosa of seven-day-old infant rats and cultured. Then, cells were evaluated and approved by flow cytometry by p75 and GFAP markers. A total of 32 mice (C57BL /6) were studied in four groups; 1) without any treatment (control), 2) Sham (receiving PBS), 3) MS model and 4) MS and OEC transplantation. MS was induced by adding Cuprizon in the diet of animals for six weeks. After the expiration of 20 days, histologic analysis was performed with approval of the presence of cells in the graft area and the removal of myelin and myelin regeneration with two types of luxal fast blue (LFB) staining and immunohistochemistry. The purity of the cells ensheathing the olfactory was 90. There was a significant difference in Myelin percentage of PBS and OEC recipient groups (P�0.05). MBP and PLP of the myelin sheath in the group receiving OECs were more than MS group.According to the findings, in MS model MBP and PLP of the myelin sheath is reduced. In the group receiving OECs, it was returned to a normal level significantly compared to the sham group received only PBS significant differences were observed. The OECs transplantation can improve myelin restoration. © 2015 Tehran University of Medical Sciences. All rights reserved

Long-term effectiveness of a lifestyle intervention on the prevention of type 2 diabetes in a middle-income country

This study aims to assess the effects of a community-based lifestyle intervention program on the incidence of type 2 diabetes (T2D). For this purpose, three communities in Tehran were chosen; one community received a face-to-face educational session embedded in a long-term community-wide lifestyle intervention aimed at supporting lifestyle changes. We followed up 9,204 participants (control: 5,739, intervention: 3,465) triennially from 1999 to 2015 (Waves 1&ndash;5). After a median follow-up of 3.5 years (wave 2), the risk of T2D was 30% lower in the intervention community as compared with two control communities by (Hazard-ratio: 0.70 [95% CI 0.53; 0.91]); however, the difference was not statistically significant in the following waves. After a median follow-up of 11.9 years (wave 5), there was a non-significant 6% reduction in the incidence of T2D in the intervention group as compared to the control group (Hazard-ratio: 0.94 [0.81, 1.08]). Moreover, after 11.9 years of follow-up, the intervention significantly improved the diet quality measured by the Dietary Approaches to Stop Hypertension concordance (DASH) score. Mean difference in DASH score in the intervention group versus control group was 0.2 [95% CI 0.1; 0.3]. In conclusion, the intervention prevented T2D by 30% in the short-term (3.5 years) but not long-term; however, effects on improvement of the diet maintained in the long-term.Registration: This study is registered at IRCT, a WHO primary registry (https://irct.ir). The registration date 39 is 2008-10-29 and the IRCT registration number is IRCT138705301058N1

Evaluation of Hydroalcoholic Extract of Cinnamon Effect on Testicular Tissue and Fertility of Busulfan-Induced Oligo-Spermic Model Rats

BACKGROUND AND OBJECTIVE: Busulfan is one of the cancer treatment drugs that cause infertility of the patient. In traditional medicine, one of the important properties of cinnamon is enhancement of fertility. The aim of this study was to investigate the effect of cinnamon on the physiological structure of testes and fertility rate of busulfan-treated rats. METHODS: In this experimental study, 24 adult male rats were divided into 3 groups of 8 subjects, Sham: healthy rats without intervention. Control group: Busulfan-sterilized rats (15 mg/kg) intraperitoneal injection, Cinnamon group: Busulfan-treated rats + cinnamon extract (200 mg/kg) for fourteen days. The testicles length, width and weight parameters as well as the formation of germinal cells were analyzed by H &#38; E staining and optical microscopy. FINDINGS: The number of spermatogonia cells, primary spermatocytes and spermatid in the cinnamon group was 72.25&#177;12.63, 61.71&#177;11.47, and 79.1&#177;10.02, and in the control group was 51.83&#177;23.37, 31.67&#177;5.27 and 38.67&#177;15.7 respectively, and the increase in cinnamon group was significant (p&#60;0.005). The testicles length, width and weight parameters in the cinnamon group were increased compared to the control group (busulfan). The thickness of germinal epithelium in the cinnamon and control group was 53.46 &#177; 16.44 and 30.4&#177;10.21 respectively, which was significantly higher in the cinnamon group (p&#60;0.001). CONCLUSION: According to the findings of this study, cinnamon extract has positive therapeutic and protective effects on testicular tissue and increases sperm production in busulfan-treated rats

Context-Aware Neural Video Compression on Solar Dynamics Observatory

NASA's Solar Dynamics Observatory (SDO) mission collects large data volumes of the Sun's daily activity. Data compression is crucial for space missions to reduce data storage and video bandwidth requirements by eliminating redundancies in the data. In this paper, we present a novel neural Transformer-based video compression approach specifically designed for the SDO images. Our primary objective is to efficiently exploit the temporal and spatial redundancies inherent in solar images to obtain a high compression ratio. Our proposed architecture benefits from a novel Transformer block called Fused Local-aware Window (FLaWin), which incorporates window-based self-attention modules and an efficient fused local-aware feed-forward (FLaFF) network. This architectural design allows us to simultaneously capture short-range and long-range information while facilitating the extraction of rich and diverse contextual representations. Moreover, this design choice results in reduced computational complexity. Experimental results demonstrate the significant contribution of the FLaWin Transformer block to the compression performance, outperforming conventional hand-engineered video codecs such as H.264 and H.265 in terms of rate-distortion trade-off.Comment: Accepted to IEEE 22$^{nd}$ International Conference on Machine Learning and Applications 2023 (ICMLA) - Selected for Oral Presentatio

Multi-spectral Entropy Constrained Neural Compression of Solar Imagery

Missions studying the dynamic behaviour of the Sun are defined to capture multi-spectral images of the sun and transmit them to the ground station in a daily basis. To make transmission efficient and feasible, image compression systems need to be exploited. Recently successful end-to-end optimized neural network-based image compression systems have shown great potential to be used in an ad-hoc manner. In this work we have proposed a transformer-based multi-spectral neural image compressor to efficiently capture redundancies both intra/inter-wavelength. To unleash the locality of window-based self attention mechanism, we propose an inter-window aggregated token multi head self attention. Additionally to make the neural compressor autoencoder shift invariant, a randomly shifted window attention mechanism is used which makes the transformer blocks insensitive to translations in their input domain. We demonstrate that the proposed approach not only outperforms the conventional compression algorithms but also it is able to better decorrelates images along the multiple wavelengths compared to single spectral compression.Comment: Accepted to IEEE 22$^{nd}$ International Conference on Machine Learning and Applications 2023 (ICMLA

Let's share: a game-theoretic framework for resource sharing in mobile edge clouds

Mobile edge computing seeks to provide resources to different delay-sensitive applications. This is a challenging problem as an edge cloud-service provider may not have sufficient resources to satisfy all resource requests. Furthermore, allocating available resources optimally to different applications is also challenging. Resource sharing among different edge cloud-service providers can address the aforementioned limitation as certain service providers may have resources available that can be “rented” by other service providers. However, edge cloud service providers can have different objectives or utilities . Therefore, there is a need for an efficient and effective mechanism to share resources among service providers, while considering the different objectives of various providers. We model resource sharing as a multi-objective optimization problem and present a solution framework based on Cooperative Game Theory (CGT). We consider the strategy where each service provider allocates resources to its native applications first and shares the remaining resources with applications from other service providers. We prove that for a monotonic, non-decreasing utility function, the game is canonical and convex. Hence, the core is not empty and the grand coalition is stable. We propose two algorithms, Game-theoretic Pareto optimal allocation (GPOA) and Polyandrous-Polygamous Matching based Pareto Optimal Allocation (PPMPOA) that provide allocations from the core. Hence the obtained allocations are Pareto optimal and the grand coalition of all the service providers is stable. Experimental results confirm that our proposed resource sharing framework improves utilities of edge cloud-service providers and application request satisfaction