171 research outputs found
Improving the transfer of machine learning-based video QoE estimation across diverse networks
With video streaming traffic generally being encrypted end-to-end, there is a lot of interest from network operators to find novel ways to evaluate streaming performance at the application layer. Machine learning (ML) has been extensively used to develop solutions that infer application-level Key Performance Indicators (KPI) and/or Quality of Experience (QoE) from the patterns in encrypted traffic. Having such insights provides the means for more user-centric traffic management and enables the mitigation of QoE degradations, thus potentially preventing customer churn. The ML–based QoE/KPI estimation solutions proposed in literature are typically trained on a limited set of network scenarios and it is often unclear how the obtained models perform if applied in a previously unseen setting (e.g., if the model is applied at the premises of a different network operator). In this paper, we address this gap by cross-evaluating the performance of QoE/KPI estimation models trained on 4 separate datasets generated from streaming 48000 video streaming sessions. The paper evaluates a set of methods for improving the performance of models when applied in a different network. Analyzed methods require no or considerably less application-level ground-truth data collected in the new setting, thus significantly reducing the extensiveness of required data collection
Mesoscale cortical dynamics reflect the interaction of sensory evidence and temporal expectation during perceptual decision-making
How sensory evidence is transformed across multiple brain regions to influence behavior remains poorly understood. We trained mice in a visual change detection task designed to separate the covert antecedents of choices from activity associated with their execution. Wide-field calcium imaging across the dorsal cortex revealed fundamentally different dynamics of activity underlying these processes. Although signals related to execution of choice were widespread, fluctuations in sensory evidence in the absence of overt motor responses triggered a confined activity cascade, beginning with transient modulation of visual cortex and followed by sustained recruitment of the secondary and primary motor cortex. Activation of the motor cortex by sensory evidence was modulated by animals’ expectation of when the stimulus was likely to change. These results reveal distinct activation timescales of specific cortical areas by sensory evidence during decision-making and show that recruitment of the motor cortex depends on the interaction of sensory evidence and temporal expectation
Chemoprevention with green propolis green propolis extracted in L-lysine versus carcinogenesis promotion with L-lysine in N-Butyl-N-[4-hydroxybutyl] nitrosamine (BBN) induced rat bladder cancer
In vitro antiproliferative activity of partially purified Trigona laeviceps propolis from Thailand on human cancer cell lines
<p>Abstract</p> <p>Background</p> <p>Cancers are some of the leading causes of human deaths worldwide and their relative importance continues to increase. Since an increasing proportion of cancer patients are acquiring resistance to traditional chemotherapeutic agents, it is necessary to search for new compounds that provide suitable specific antiproliferative affects that can be developed as anticancer agents. Propolis from the stingless bee, <it>Trigona laeviceps</it>, is one potential interesting source that is widely available and cultivatable (as bee hives) in Thailand.</p> <p>Methods</p> <p>Propolis (90 g) was initially extracted by 95% (v/v) ethanol and then solvent partitioned by sequential extractions of the crude ethanolic extract with 40% (v/v) MeOH, CH<sub>2</sub>Cl<sub>2 </sub>and hexane. After solvent removal by evaporation, each extract was solvated in DMSO and assayed for antiproliferative activity against five cancer (Chago, KATO-III, SW620, BT474 and Hep-G2) and two normal (HS27 fibroblast and CH-liver) cell lines using the MTT assay. The cell viability (%) and IC<sub>50 </sub>values were calculated.</p> <p>Results</p> <p>The hexane extract provided the highest <it>in vitro </it>antiproliferative activity against the five tested cancer cell lines and the lowest cytotoxicity against the two normal cell lines. Further fractionation of the hexane fraction by quick column chromatography using eight solvents of increasing polarity for elution revealed the two fractions eluted with 30% and 100% (v/v) CH<sub>2</sub>Cl<sub>2 </sub>in hexane (30DCM and 100DCM, respectively) had a higher anti-proliferative activity. Further fractionation by size exclusion chromatography lead to four fractions for each of 30DCM and 100DCM, with the highest antiproliferative activity on cancer but not normal cell lines being observed in fraction# 3 of 30DCM (IC<sub>50 </sub>value of 4.09 - 14.7 μg/ml).</p> <p>Conclusions</p> <p><it>T. laeviceps </it>propolis was found to contain compound(s) with antiproliferative activity <it>in vitro </it>on cancer but not normal cell lines in tissue culture. The more enriched propolis fractions typically revealed a higher antiproliferative activity (lower IC<sub>50 </sub>value). Overall, propolis from Thailand may have the potential to serve as a template for future anticancer-drug development.</p
Bee products prevent VEGF-induced angiogenesis in human umbilical vein endothelial cells
<p>Abstract</p> <p>Background</p> <p>Vascular endothelial growth factor (VEGF) is a key regulator of pathogenic angiogenesis in diseases such as cancer and diabetic retinopathy. Bee products [royal jelly (RJ), bee pollen, and Chinese red propolis] from the honeybee, <it>Apis mellifera</it>, have been used as traditional health foods for centuries. The aim of this study was to investigate the anti-angiogenic effects of bee products using human umbilical vein endothelial cells (HUVECs).</p> <p>Methods</p> <p>In an <it>in vitro </it>tube formation assay, HUVECs and fibroblast cells were incubated for 14 days with VEGF and various concentrations of bee products [RJ, ethanol extract of bee pollen, ethanol extract of Chinese red propolis and its constituent, caffeic acid phenethyl ester (CAPE)]. To clarify the mechanism of <it>in vitro </it>angiogenesis, HUVEC proliferation and migration were induced by VEGF with or without various concentrations of RJ, bee pollen, Chinese red propolis, and CAPE.</p> <p>Results</p> <p>RJ, bee pollen, Chinese red propolis, and CAPE significantly suppressed VEGF-induced <it>in vitro </it>tube formation in the descending order: CAPE > Chinese red propolis >> bee pollen > RJ. RJ and Chinese red propolis suppressed both VEGF-induced HUVEC proliferation and migration. In contrast, bee pollen and CAPE suppressed only the proliferation.</p> <p>Conclusion</p> <p>Among the bee products, Chinese red propolis and CAPE in particular showed strong suppressive effects against VEGF-induced angiogenesis. These findings indicate that Chinese red propolis and CAPE may have potential as preventive and therapeutic agents against angiogenesis-related human diseases.</p
Challenges of future multimedia QoE monitoring for internet service providers
The ever-increasing network traffic and user expectations at reduced cost make the delivery of high Quality of Experience (QoE) for multimedia services more vital than ever in the eyes of Internet Service Providers (ISPs). Real-time quality monitoring, with a focus on the user, has become essential as the first step in cost-effective provisioning of high quality services. With the recent changes in the perception of user privacy, the rising level of application-layer encryption and the introduction and deployment of virtualized networks, QoE monitoring solutions need to be adapted to the fast changing Internet landscape. In this contribution, we provide an overview of state-of-the-art quality monitoring models and probing technologies, and highlight the major challenges ISPs have to face when they want to ensure high service quality for their customers
Antitumoral and antiangiogenic activity of Portuguese propolis in in vitro and in vivo models
Propolis, a natural product, has important biological properties, however, studies with Portuguese propolis are scarce. Thus, we aimed to characterize the chemical composition and the antitumoural and antiangiogenic activities of a sample from Pereiro (Portugal). The chemical profile of our propolis sample (P10.EE) is similar to the poplar propolis type. P10.EE decreased cell viability of different tumour cells, being less cytotoxic against non-tumoural cells. P10.EE decreased MDA-MB-231 and DU145 cell proliferation and migration, with cell cycle changes and increased cell death. The increased glucose consumption and lactate production in MDA-MB-231 cells is explained by an increased expression of different metabolism-related proteins. P10.EE induced a decrease in HBMEC cells total biomass and proliferation and decreased vessel sprouting in the chicken chorioallantoic membrane. Additionally, P10.EE potentiates paclitaxel effect in MDA-MB-231 and DU145 cells. Concluding, P10.EE can be a good candidate for cancer drug development since it affects different characteristics that dictate tumorigenesis.This work was supported by the Life and Health Sciences Research Institute, University of Minho, Portugal, and Fundacao para a Ciencia e Tecnologia (FCT) (SFRH/BD/5199712012 to V.M.G.), through Fundo Europeu de Desenvolvimento Regional-QREN-COMPETE, projects PTDC/AAC-CLI1098308/2008 and PTDC/AAC-CLI/11809212010 and also CERNAS (project PEst-OE/AGR/UI0681/2011)
Antioxidant and anti-inflammatory activities of freeze-dried grapefruit phenolics as affected by gum arabic and bamboo fibre addition and microwave pretreatment
This is the peer reviewed version of the following article: GarcÃa MartÃnez, Eva MarÃa, Andújar Pérez, Isabel, Yuste Del Carmen, Alberto, Prohens Tomás, Jaime, MartÃnez Navarrete, Nuria. (2018). Antioxidant and anti-inflammatory activities of freeze-dried grapefruit phenolics as affected by gum arabic and bamboo fibre addition and microwave pretreatment..Journal of the Science of Food and Agriculture, 98, 8, 3076-3083. , which has been published in final form at http://doi.org/10.1002/jsfa.8807. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] BACKGROUND: Recent epidemiological studies have suggested that phenolic compounds present in grapefruit play an important role in the bioactive properties of this fruit. However, the consumption of fresh grapefruit is low. Freeze dried powdered grapefruit can be an alternative to promote this fruit consumption. To improve the quality and stability of the powdered fruit, the addition of encapsulating and anticaking agents can be used. In this work, different grapefruit powders obtained by freeze drying with addition of gum arabic (1.27 g/100 g), and bamboo fibre (0.76 g/100 g) with and without a pre-drying microwave treatment were compared with the fresh and freeze-dried fruit with no carriers added in order to evaluate the effect of these preservation processes on phenolics content and on its antioxidant (DPPH, ABTS and FRAP) and anti-inflamatory (evaluated in RAW 264.7 macrophages) capacities.
RESULTS: Freeze drying and gum arabic and bamboo fibre addition significantly increased the total phenolics, and antioxidant and anti-inflammatory activities (by inhibiting NO production of LPS activated RAW 264.7 macrophages) of grapefruit. An additional increase in these parameters was obtained with a microwave pretreatment before freeze-drying.
CONCLUSIONS: The combined addition of gum arabic and bamboo fibre to the grapefruit puree and the application of a microwave pretreatment improve the functional properties of the fruit without showing cytotoxicity in vitro.We thank the Ministerio de Economia y Competitividad and FEDER for financial support given through the Project AGL 2012-39103.GarcÃa MartÃnez, EM.; Andújar Pérez, I.; Yuste Del Carmen, A.; Prohens Tomás, J.; MartÃnez Navarrete, N. (2018). Antioxidant and anti-inflammatory activities of freeze-dried grapefruit phenolics as affected by gum arabic and bamboo fibre addition and microwave pretreatment. Journal of the Science of Food and Agriculture. 98(8):3076-3083. https://doi.org/10.1002/jsfa.8807S3076308398
Antiproliferative effect of Tualang honey on oral squamous cell carcinoma and osteosarcoma cell lines
<p>Abstract</p> <p>Background</p> <p>The treatment of oral squamous cell carcinomas (OSCC) and human osteosarcoma (HOS) includes surgery and/or radiotherapy which often lead to reduced quality of life. This study was aimed to study the antiproliferative activity of local honey (Tualang) on OSCC and HOS cell lines.</p> <p>Methods</p> <p>Several concentrations of Tualang honey (1% - 20%) were applied on OSCC and HOS cell lines for 3, 6, 12, 24, 48 and 72 hours. Morphological characteristics were observed under light and fluorescent microscope. Cell viability was assessed using MTT assay and the optical density for absorbance values in each experiment was measured at 570 nm by an ELISA reader. Detection of cellular apoptosis was done using the Annexin V-FITC Apoptosis Detection Kit.</p> <p>Results</p> <p>Morphological appearance showed apoptotic cellular changes like becoming rounded, reduction in cell number, blebbed membrane and apoptotic nuclear changes like nuclear shrinkage, chromatin condensation and fragmented nucleus on OSCC and HOS cell lines. Cell viability assay showed a time and dose-dependent inhibitory effect of honey on both cell lines. The 50% inhibitory concentration (IC<sub><b>50</b></sub>) for OSCC and HOS cell lines was found to be 4% and 3.5% respectively. The maximum inhibition of cell growth of ≥80% was obtained at 15% for both cell lines. Early apoptosis was evident by flow cytometry where percentage of early apoptotic cells increased in dose and time dependent manner.</p> <p>Conclusion</p> <p>Tualang honey showed antiproliferative effect on OSCC and HOS cell lines by inducing early apoptosis.</p
The Role of Honey and Propolis in the Treatment of Infected Wounds
Honey is defined as the natural substance produced by Apis mellifera bees from plant
nectar, from secretions of the living parts of plants, or from the excretions of plant
sucking insects feeding on the living parts of plants.1,2 Honeybees collect, transform,
and combine this with specific substances of their own, and then store it and leave it
in the honeycomb to ripen and mature. This natural product is generally composed of
a complex mixture of carbohydrates and other less common substances, such as
organic acids, amino acids, proteins, minerals, vitamins, lipids, aroma compounds, flavonoids,
pigments, waxes, pollen grains, several enzymes and other phytochemicals.3 5
However, the specific composition depends on many factors, such as the nectar composition
of the source plant, the species of bee, the climate, environmental and seasonal
conditions, agricultural practices and treatment of honey during extraction and
storage.6-9
As a natural, unprocessed and easily digested food, honey plays an important role in
the human diet, and is also used in pharmaceutical and cosmetic industries.10
Modern science has studied the medical significance of honeys in healing wounds and
burns,11 oncology care,12 as well as its antioxidant and antimicrobial properties.info:eu-repo/semantics/publishedVersio
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