Adhesion-independent synergy of monocytes and endothelial cells in cytokine production: regulation of IL-6 and GM–CSF production by PAF

Co-Cultures of monocytes (MO) and endothelial cells (EC) were studied for their capacity to synergize in the production of interleukin-6 (IL-6) and granulocyte-macrophage colony-stimulating factor (GM–CSF), two cytokines potentially important in vascular physiopathology. Resting monocytes produced detectable amounts of IL-6 but no GM–CSF, whereas confluent EC produced significant quantities of GM–CSF, but minimal IL-6. In co-cultures without stimuli, additive synthesis of both cytokines was observed. When EC were pretreated, however, with either PAF, TNF or both stimuli, before addition of MO, synergistic production of IL-6 was observed. In contrast, GM–CSF production was not enhanced by coculture of monocytes with activated EC. When either cell population was fixed with paraformaldehyde or killed by freeze-thawing before addition to the co-culture, cytokine levels reverted to those produced by the unaffected population alone. On the other hand, separating the two cell populations by a cell-impermeable membrane in transwell cultures did not affect the synergistic production of the cytokines. Taken together, our data suggest that EC and MO can synergize in response to stimuli by producing IL-6 and that this synergy is dependent on the integrity of both cell populations, but independent of cell-cell contact

Comparative Investigation of Structure and Operating Parameters on the Performance and Reaction Dynamic of CO Conversion on Silica Aerogel and Fumed-Silica-Supported Pd Catalysts

The catalyst morphology, metal-support interaction, and reaction conditions greatly influence the catalytic performance and reaction dynamics. Similarly, the dispersion of the metal within the support plays a crucial role in the thermal stability and sintering of the catalyst. Furthermore, temperature-dependent conversion hysteresis is well-known to occur during ignition and extinction of exothermic CO oxidation over supported Pd catalysts due to the variation of CO adsorption on the surface or bulk oxidation of Pd and the ability of the catalyst to regenerate the active sites. Herein, the catalytic performance and the hysteresis behavior of mesoporous silica aerogel supported Pd (Pd/a-SiO2), and commercial fumed silica-supported Pd (Pd/f-SiO2) were investigated and compared using CO oxidation as a probe reaction under different reaction conditions and operating parameters (i.e., catalyst weight, ramp rate, and flow rate). Surface and morphologic examination using XPS, FTIR, and TEM of Pd/a-SiO2 and Pd/f-SiO2 reveal a strong correlation between the catalyst surface and structure and its catalytic performance and stability under different reaction parameters. Moreover, this study presents the effect of surface area, particle size, and size distribution on diffusion and mass transport of reactants (CO, O2) and products (CO2) and active sites accessibility. This study showed that Pd/f-SiO2 had better efficiency under high (turbulence) flow. Moreover, intrinsic apparent activation energy (Ea) and the number of active sites were calculated from the Kinetics of CO oxidation fitted using Arrhenius plots indicate that the ramp rate has less effect on Pd/f-SiO2 catalytic behavior. Even though, Pd/f-SiO2 had higher relative active sites than Pd/a-SiO2, (Ea) was lower. Cyclic stability and long-term stabilities showed that both catalysts are stable and can regenerate the active sites. The current study contributes to understanding the catalysts\u27 surface, structural and morphological properties on the catalysts\u27 performance toward CO oxidation and other reactions under dynamic conditions

On the Origin of [OII] Emission in Red Sequence and Post-starburst Galaxies

We investigate the emission-line properties of galaxies with red rest-frame colors using spectra from SDSS DR4. Emission lines are detected in more than half of the red galaxies. We focus on the relationship between two emission lines commonly used as star formation rate indicators: Ha 6563 and [OII] 3727. There is a strong bimodality in [OII]/Ha ratio in the full SDSS sample which closely corresponds to the bimodality in rest-frame color. Nearly all of the line-emitting red galaxies have line ratios typical of various types of AGN -- most commonly LINERs, a small fraction of transition objects and, more rarely, Seyferts. Only ~6% of red galaxies display star-forming line ratios. A straight line in the [OII]-Ha equivalent width plane separates LINER-like galaxies from other categories. Quiescent galaxies with no detectable emission lines and LINER-like galaxies combine to form a single, tight red sequence in color-magnitude-concentration space. [OII] EWs in LINER- and AGN-like galaxies can be as large as in star-forming galaxies. Thus, unless objects with AGN/LINER-like line ratios are excluded, [OII] emission cannot be used directly as a proxy for star formation rate. Lack of [OII] emission is generally used to indicate lack of star formation when post-starburst galaxies are selected at high redshift. Our results imply, however, that these samples have been cut on AGN properties as well as star formation, and therefore may provide seriously incomplete sets of post-starburst galaxies. Furthermore, post-starburst galaxies identifed in SDSS by requiring minimal Ha EW generally exhibit weak but nonzero line emission with ratios typical of AGNs; few of them show residual star formation. This suggests that most post-starbursts may harbor AGNs/LINERs.Comment: 21 pages, 15 figures. v2: Added 4 new figures and updated many; extended text. No conclusions change. v3: minor modifications and figure updates to match version accepted by Ap

The COVID-19 Challenges to the Unfold of Entrepreneurship Education

This article reviews and discusses along the development and deployment of universities' entrepreneurship teaching and learning. It emphasizes on the detection, interpretation and analysis of entrepreneurial skill sets that can be directly established by structured educational programs. This analytical review and opinions also aims to illustrate and also describe how entrepreneurial discipline needs to evolve on the basis of the technological advancements that the current COVID-19 disaster has rendered reasonable to expect. The numerous relevant theories in entrepreneurial learning are indeed discussed, indicating the need to consider regarding future potential educational strategies in various possibilities. Some issues were established in a study of the previous research including the teaching substance, the teaching methodologies, the institutional characteristics and the proper teaching instructor that should deliver entrepreneurship education. The article concludes that educators should continuously evolve the instructional framework, practices, as well and instruction in response to an evolving entrepreneurship climate

Star Formation in Emission-Line Galaxies Between Redshifts of 0.8 and 1.6

Optical spectra of 14 emission-line galaxies representative of the 1999 NICMOS parallel grism Ha survey of McCarthy et al. are presented. Of the 14, 9 have emission lines confirming the redshifts found in the grism survey. The higher resolution of our optical spectra improves the redshift accuracy by a factor of 5. The [O II]/Ha values of our sample are found to be more than two times lower than expected from Jansen et al. This [O II]/Ha ratio discrepancy is most likely explained by additional reddening in our Ha-selected sample [on average, as much as an extra E(B-V) = 0.6], as well as to a possible stronger dependence of the [O II]/Ha ratio on galaxy luminosity than is found in local galaxies. The result is that star formation rates (SFRs) calculated from [O II]3727 emission, uncorrected for extinction, are found to be on average 4 +/- 2 times lower than the SFRs calculated from Ha emission. Classification of emission-line galaxies as starburst or Seyfert galaxies based on comparison of the ratios [O II]/Hb and [Ne III]3869/Hb is discussed. New Seyfert 1 diagnostics using the Ha line luminosity, H-band absolute magnitude, and Ha equivalent widths are also presented. One galaxy is classified as a Seyfert 1 based on its broad emission lines, implying a comoving number density for Seyfert 1s of 2.5{+5.9, -2.1} times 10^{-5} Mpc^{-3}. This commoving number density is a factor of 2.4{+5.5,-2.0} times higher than estimated by other surveys.Comment: 51 pages, 18 figures; Accepted for publication in the Astrophysical Journal; Revised version with minor changes and an additional reference which gives further support to our conclusion

Retinal Architecture in ​\u3cem\u3eRGS9-\u3c/em\u3e and ​\u3cem\u3eR9AP\u3c/em\u3e-Associated Retinal Dysfunction (Bradyopsia)

Purpose To characterize photoreceptor structure and mosaic integrity in subjects with RGS9- and R9AP-associated retinal dysfunction (bradyopsia) and compare to previous observations in other cone dysfunction disorders such as oligocone trichromacy. Design Observational case series. Methods setting: Moorfields Eye Hospital (United Kingdom) and Medical College Wisconsin (USA). study population: Six eyes of 3 subjects with disease-causing variants in RGS9 or R9AP. main outcome measures: Detailed retinal imaging using spectral-domain optical coherence tomography and confocal adaptive-optics scanning light ophthalmoscopy. Results Cone density at 100 μm from foveal center ranged from 123 132 cones/mm2to 140 013 cones/mm2. Cone density ranged from 30 573 to 34 876 cones/mm2 by 600 μm from center and from 15 987 to 16,253 cones/mm2 by 1400 μm from center, in keeping with data from normal subjects. Adaptive-optics imaging identified a small, focal hyporeflective lesion at the foveal center in both eyes of the subject with RGS9-associated disease, corresponding to a discrete outer retinal defect also observed on spectral-domain optical coherence tomography; however, the photoreceptor mosaic remained intact at all other observed eccentricities. Conclusions Bradyopsia and oligocone trichromacy share common clinical symptoms and cannot be discerned on standard clinical findings alone. Adaptive-optics imaging previously demonstrated a sparse mosaic of normal wave-guiding cones remaining at the fovea, with no visible structure outside the central fovea in oligocone trichromacy. In contrast, the subjects presented in this study with molecularly confirmed bradyopsia had a relatively intact and structurally normal photoreceptor mosaic, allowing the distinction between these disorders based on the cellular phenotype and suggesting different pathomechanisms

Caffeine Consumption among Zayed University Students in Dubai, United Arab Emirates: A Cross-Sectional Study

Background: Over the past decade, the global caffeine consumption rate has increased dramatically. Coffee and tea are among the common sources, but energy drinks are becoming an important contributor to total caffeine consumption. Recommendations for daily caffeine intake is not being followed due to the perceived benefits of caffeine which include mood improvement, concentration, social factors, and energy boosting. This study was important to add to the limited data about caffeine consumption in the Gulf region and mainly in the UAE.Objectives: The objectives were to determine the prevalence of caffeinated beverage consumption among university students and perceived benefits in addition to the estimation of daily caffeine consumption (mg/day).Design: Data was collected through a self-reported questionnaire from a total of 175 participants (129 females and 46 males) who were conveniently selected from different settings at Zayed University - Dubai. Usual Caffeine intake was calculated from all caffeine containing beverages.  Results: Eighty-six percent of the 175 participants, both males and females, at Zayed University-Dubai consumed caffeinated beverages with an average intake of 249.7±235.9 mg. The intake among the 150 caffeine consumers varied from 4.2 mg/day to 932.2 mg/day. Average intake of caffeine was not significantly different between genders (P=0.125). Thirty-five percent of the population consumed more than 400 mg/day of caffeine, with no statistical difference between males and females (P=0.202). Coffee was the most commonly consumed drink among both genders, followed by tea. Most perceived benefits of caffeine consumption were not significantly different except for the relationship between caffeine and improved exercise performance (P=0.018) and caffeine in relation to weight loss (P=0.001) among males.Conclusion: The prevalence of caffeine consumption at Zayed University was high among both males and females. Further research is necessary to estimate the total caffeine intake from all dietary sources, mainly the cultural foods and beverages, and to determine the relationship between accessibility to caffeine containing beverages and caffeine consumption among University student

Wide-Field Chandra X-Ray Observations of AGN in Abell 85 & Abell 754

To better understand the mechanism or mechanisms that lead to AGN activity today, we measure the X-ray AGN fraction in a new sample of nearby clusters and examine how it varies with galaxy properties, projected cluster-centric radius, and cluster velocity dispersion. We present new wide-field Chandra X-ray Observatory observations of Abell 85, Abell 754 and the background cluster Abell 89B out to their virial radii. Out of seventeen X-ray sources associated with galaxies in these clusters, we classify seven as X-ray AGN with L_{X,B} > 10^{41} erg/s. Only two of these would be classified as AGN based on their optical spectra. We combine these observations with archival data to create a sample of X-ray AGN from six z < 0.08 clusters and find that 3.4+1.1/-0.8% of M_R 10^{41} erg/s. We find that more X-ray AGN are detected in more luminous galaxies and attribute this to larger spheriods in more luminous galaxies and increased sensitivity to lower Eddington-rate accretion from black holes in those spheroids. At a given X-ray luminosity limit, more massive black holes can be accreting less efficiently, yet still be detected. If interactions between galaxies are the principal drivers of AGN activity, then the AGN fraction should be higher in lower velocity dispersion clusters and the outskirts of clusters. However, the tendency of the most massive and early-type galaxies to lie in the centers of the richest clusters could dilute such trends. While we find no variation in the AGN fraction with projected cluster-centric radius, we do find that the AGN fraction increases significantly from 2.6+1.0/-0.8% in rich clusters to 10.0+6.2/-4.3% in those with lower velocity dispersions.Comment: Accepted by Astrophysical Journal, 17 pages using emulateapj.cls, 10 B & W Figures (degraded): Full resolution paper available at http://www.astronomy.ohio-state.edu/~sivakoff/AGN/XAGN_A85_A754.pd

Caffeine consumption among Zayed University students in Dubai, United Arab Emirates: A cross-sectional study

Background: Over the past decade, the global caffeine consumption rate has increased dramatically. Coffee and tea are among the common sources, but energy drinks are becoming an important contributor to total caffeine consumption. Recommendations for daily caffeine intake is not being followed due to the perceived benefits of caffeine which include mood improvement, concentration, social factors, and energy boosting. This study was important to add to the limited data about caffeine consumption in the Gulf region and mainly in the UAE. Objectives : The objectives were to determine the prevalence of caffeinated beverage consumption among university students and perceived benefits in addition to the estimation of daily caffeine consumption (mg/day). Design: Data was collected through a self-reported questionnaire from a total of 175 participants (129 females and 46 males) who were conveniently selected from different settings at Zayed University - Dubai. Usual Caffeine intake was calculated from all caffeine containing beverages.  Results: Eighty-six percent of the 175 participants, both males and females, at Zayed University-Dubai consumed caffeinated beverages with an average intake of 249.7±235.9 mg. The intake among the 150 caffeine consumers varied from 4.2 mg/day to 932.2 mg/day. Average intake of caffeine was not significantly different between genders (P=0.125). Thirty-five percent of the population consumed more than 400 mg/day of caffeine, with no statistical difference between males and females (P=0.202). Coffee was the most commonly consumed drink among both genders, followed by tea. Most perceived benefits of caffeine consumption were not significantly different except for the relationship between caffeine and improved exercise performance (P=0.018) and caffeine in relation to weight loss (P=0.001) among males. Conclusion: The prevalence of caffeine consumption at Zayed University was high among both males and females. Further research is necessary to estimate the total caffeine intake from all dietary sources, mainly the cultural foods and beverages, and to determine the relationship between accessibility to caffeine containing beverages and caffeine consumption among University student