2,206 research outputs found

    Understanding Online Brand Communities: Netnographic Study of Apple iPhone Consumers

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    This study extends the concept of brand communities. The netnography approach has been applied to two online brand communities, both central to Apple iPhone consumers. This study reveals two cultural manifestations with their own passions and communal norms not detected by previous research. This study, thus, enriches the conceptual understanding of brand communities. It also offers contribution toward understanding consumers of high technology brands, an area where few studies have been conducted to date

    Functional Imagery Training to reduce snacking: Testing a novel motivational intervention based on Elaborated Intrusion theory

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    Functional Imagery Training (FIT) is a new theory-based, manualized intervention that trains positive goal imagery. Multisensory episodic imagery of proximal personal goals is elicited and practised, to sustain motivation and compete with less functional cravings. This study tested the impact of a single session of FIT plus a booster phone call on snacking. In a stepped-wedge design, 45 participants who wanted to lose weight or reduce snacking were randomly assigned to receive a session of FIT immediately or after a 2-week delay. High-sugar and high-fat snacks were recorded using timeline follow back for the previous 3 days, at baseline, 2 and 4 weeks. At 2 weeks, snacking was lower in the immediate group than in the delayed group, and the reduction after FIT was replicated in the delayed group between 2 and 4 weeks. Frequencies of motivational thoughts about snack reduction rose following FIT for both groups, and this change correlated with reductions in snacking and weight loss. By showing that FIT can support change in eating behaviours, these findings show its potential as a motivational intervention for weight management

    Cell Population Growth Kinetics in the Presence of Stochastic Heterogeneity of Cell Phenotype

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    Recent studies at individual cell resolution have revealed phenotypic heterogeneity in nominally clonal tumor cell populations. The heterogeneity affects cell growth behaviors, which can result in departure from the idealized uniform exponential growth of the cell population. Here we measured the stochastic time courses of growth of an ensemble of populations of HL60 leukemia cells in cultures, starting with distinct initial cell numbers to capture a departure from the {uniform exponential growth model for the initial growth (``take-off'')}. Despite being derived from the same cell clone, we observed significant variations in the early growth patterns of individual cultures with statistically significant differences in growth dynamics, which could be explained by the presence of inter-converting subpopulations with different growth rates, and which could last for many generations. Based on the hypothesis of existence of multiple subpopulations, we developed a branching process model that was consistent with the experimental observations

    Cardiometabolic Risk Factors and Its Association with Hyperandrogenemia Among Sudanese Reproductive Women with Polycystic Ovary Syndrome

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    Background: Risk factors for cardiovascular disease (CVD) are more common and frequently occur among PCOS women. The objective of this study was to evaluate atherogenic index of plasma (AIP) as a predictor of CVD and its association with hyperandrogenemia among PCOS women. Methods and Results: This hospital-based study, conducted in Khartoum (Sudan) from October 2020 to September 2021, used a case-control design. The patients (n=150) were women with diagnosed PCOS, according to Rotterdam criteria. The controls were 150 infertile women who did not have PCOS. An ELISA reader (ASYS Expert Plus Microplate, Austria) was used to quantify serum insulin, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and anti-Mullerian hormone (AMH) by indirect methods and total testosterone (TT) by competitive method during the follicular phase of the menstrual cycle. Serum samples of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and fasting plasma glucose (FPG) were assayed on the Cobas c311 system (Roche Diagnostics GmbH, Germany). The triglyceride–glucose index (TyGI) and TyGI-BMI, as a marker for insulin resistance (IR), were calculated. The logarithmically converted ratio of the molar concentrations of TG to HDL-C was used to determine the AIP. Low CVD risk was defined as 0.24. PCOS women had a significant increase in BMI, compared to non-PCOS (P0.1. PCOS women with hyperandrogenemia showed significantly increased AIP and decreased HDL-C. Additionally, about 73% of PCOS women with hyperandrogenemia had lower HDL-C, and 29.9% had a high risk of CVD (AIP>0.24). A Spearman correlation revealed that PCOS women’s TT correlates positively with TC, TG, TyGI, and AIP and inversely correlates with HDL-C. AIP positively correlates with TT, TC, TyGI, and TyGI-BMI index. Conclusion: Our data revealed a significant occurrence of hyperandrogenemia, dyslipidemia, AIP, and obesity, all of which are considered risk factors for CVD in PCOS women

    The caspase-3-p120-RasGAP module generates a NF-ÎșB repressor in response to cellular stress.

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    The nuclear factor ÎșB (NF-ÎșB) transcription factor is a master regulator of inflammation. Short-term NF-ÎșB activation is generally beneficial. However, sustained NF-ÎșB might be detrimental, directly causing apoptosis of cells or leading to a persistent damaging inflammatory response. NF-ÎșB activity in stressed cells needs therefore to be controlled for homeostasis maintenance. In mildly stressed cells, caspase-3 cleaves p120 RasGAP, also known as RASA1, into an N-terminal fragment, which we call fragment N. We show here that this fragment is a potent NF-ÎșB inhibitor. Fragment N decreases the transcriptional activity of NF-ÎșB by promoting its export from the nucleus. Cells unable to generate fragment N displayed increased NF-ÎșB activation upon stress. Knock-in mice expressing an uncleavable p120 RasGAP mutant showed exaggerated NF-ÎșB activation when their epidermis was treated with anthralin, a drug used for the treatment of psoriasis. Our study provides biochemical and genetic evidence of the importance of the caspase-3-p120-RasGAP stress-sensing module in the control of stress-induced NF-ÎșB activation

    Spatio-temporal Models of Lymphangiogenesis in Wound Healing

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    Several studies suggest that one possible cause of impaired wound healing is failed or insufficient lymphangiogenesis, that is the formation of new lymphatic capillaries. Although many mathematical models have been developed to describe the formation of blood capillaries (angiogenesis), very few have been proposed for the regeneration of the lymphatic network. Lymphangiogenesis is a markedly different process from angiogenesis, occurring at different times and in response to different chemical stimuli. Two main hypotheses have been proposed: 1) lymphatic capillaries sprout from existing interrupted ones at the edge of the wound in analogy to the blood angiogenesis case; 2) lymphatic endothelial cells first pool in the wound region following the lymph flow and then, once sufficiently populated, start to form a network. Here we present two PDE models describing lymphangiogenesis according to these two different hypotheses. Further, we include the effect of advection due to interstitial flow and lymph flow coming from open capillaries. The variables represent different cell densities and growth factor concentrations, and where possible the parameters are estimated from biological data. The models are then solved numerically and the results are compared with the available biological literature.Comment: 29 pages, 9 Figures, 6 Tables (39 figure files in total

    ZaĆĄtitno djelovanje selenija protiv prekomjerne ekspresije apoptotskih gena povezanih s karcinomom u ĆĄtakora izloĆŸenih o-krezolu

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    Cresols are monomethyl derivatives of phenol frequently used as solvents and intermediates in the production of disinfectants, fragrances, pesticides, dyes, and explosives, which is probably why they are widely distributed in the environment. General population may be exposed to cresols mainly through inhalation of contaminated air. In this study we evaluated the toxicological effects of o-cresol on differential gene expression profile of rat liver and prostate. Experiments were conducted on 80 male rats, 60 of which were exposed to o-cresol (1.5 g kg-1, 5 g kg-1, or 15 g kg-1) through feed for 8 weeks. Three groups of rats were supplemented with 0.1 mg kg-1 selenium (Se, in the form of, sodium selenite) in addition to o-cresol to evaluate its effectiveness against o-cresol toxicity. Control group received neither o-cresol nor Se, while one group received Se alone. Survival was similar between the exposed and control animals. Rats exposed to 15 g kg-1 of o-cresol showed a 16 % loss in body weight by the end of the study, which may have been related to o-cresol making feed unpalatable at this concentration. Liver and prostate tissue samples were collected at the end of the treatment. mRNA analysis revealed that apoptotic genes (CYP3A, COX-2, PPARÎł, BAX, BCL2, AKT-1, and PKCα) related to cancer were up-regulated in liver and prostate tissues isolated from groups exposed to 5 g kg-1 and 15 g kg-1 o-cresol in comparison to control. Changes in gene expression profile were prevented when rats were supplemented with Se. The exact mechanisms underlying its protective effect remain to be clarified by future studies.Krezoli su monometilni derivati fenola koji se često rabe kao otapala te kao posrednici u proizvodnji dezinfekcijskih sredstava, mirisa, pesticida, boja i eksploziva. Otuda i njihova rasprostranjenost u okoliĆĄu. Opća je populacija izloĆŸena krezolima uglavnom putem zraka. U ovome se toksikoloĆĄkom istraĆŸivanju ocijenilo djelovanje o-krezola, jednoga od tri krezolova izomera, na ekspresiju gena u tkivima jetre i prostate muĆŸjaka ĆĄtakora. IstraĆŸivanje je provedeno na 80 muĆŸjaka, od kojih je 60 tijekom osam tjedana bilo izloĆŸeno o-krezolu (1,5 g kg-1, 5 g kg-1, odnosno 15 g kg-1) preko krmiva. Tri skupine ĆĄtakora primale su uz o-krezol nadomjestak selenija u dozi od 0.1 mg kg-1 (Se, u obliku natrijeva selenita) radi ocjene njegove djelotvornosti protiv toksičnosti o-krezola. Kontrolna skupina nije primala ni o-krezol ni Se, dok je jedna skupina primala samo Se. PreĆŸivljenje je bilo podjednako u svih skupina ĆŸivotinja. Ć takori izloĆŸeni najviĆĄoj dozi o-krezola (15 g kg-1) imali su 16 % manju tjelesnu masu od kontrolne skupine na kraju ispitivanja, ĆĄto moĆŸe biti povezano s loĆĄim okusom krmiva zbog primjese visoke doze o-krezola. S istekom osmotjednoga izlaganja o-krezolu ĆŸivotinje su eutanazirane te su prikupljeni uzorci tkiva jetre i prostate. Analiza m-RNA pokazala je značajno poviĆĄenu ekspresiju apoptotskih gena CYP3A, COX-2, PPARÎł, BAX, BCL2, AKT-1 i PKCα, koji su povezani s nastankom karcinoma u skupinama ĆĄtakora izloĆŸenim o-krezolu (5 g kg-1 i 15 g kg-1 u odnosu na kontrolu. Ova je prekomjerna ekspresija poniĆĄtena u ĆĄtakora koji su primali selenij. JoĆĄ nisu jasni mehanizmi iza ovoga zaĆĄtitnog djelovanja, na ĆĄto će odgovoriti buduća istraĆŸivanja

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≄20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≀pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≀{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal
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