14,244 research outputs found
A new root-knot nematode, Meloidogyne moensi n. sp. (Nematoda : Meloidogynidae), parasitizing Robusta coffee from Western Highlands, Vietnam
A new root-knot nematode, parasitizing Robusta coffee in Dak Lak Province, Western Highlands of Vietnam, is described as Meloidogyne moensi n. sp. Morphological and molecular analyses demonstrated that this species differs clearly from other previously described root-knot nematodes. Morphologically, the new species is characterized by a swollen body of females with a small posterior protuberance that elongated from ovoid to saccate; perineal patterns with smooth striae, continuous and low dorsal arch; lateral lines marked as a faint space or linear depression at junction of the dorsal and ventral striate; distinct phasmids; perivulval region free of striae; visible and wide tail terminus surrounding by concentric circles of striae; medial lips of females in dumbbell-shaped and slightly raised above lateral lips; female stylet is normally straight with posteriorly sloping stylet knobs; lip region of second stage juvenile (J2) is not annulated; medial lips and labial disc of J2 formed dumbbell shape; lateral lips are large and triangular; tail of J2 is conoid with rounded unstriated tail tip; distinct phasmids and hyaline; dilated rectum. Meloidogyne moensi n. sp. is most similar to M. africana, M. ottersoni by prominent posterior protuberance. Results of molecular analysis of rDNA sequences including the D2-D3 expansion regions of 28S rDNA, COI, and partial COII/16S rRNA of mitochondrial DNA support for the new species status
LED based lighting and communications: An emerging technology for a greener more sustainable future
The paper discusses on the effect that the growth in our energy consumption as a species is having upon the planet, and how the global lighting and telecommunications industries are major contributors. We demonstrate that through the adoption of LED based lighting combined with visible light communications, substantial economical and power savings by orders of magnitude can be made over existing technologies, contributing towards a greener more sustainable future. The future of LED technology is also discussed with a focus on organic technology, promising increased savings
Human Oral Mucosa and Gingiva: A Unique Reservoir for Mesenchymal Stem Cells
Mesenchymal stem cells (MSCs) represent a heterogeneous population of progenitor cells with self-renewal and multipotent differentiation potential. Aside from their regenerative role, extensive in vitro and in vivo studies have demonstrated that MSCs are capable of potent immunomodulatory effects on a variety of innate and adaptive immune cells. In this article, we will review recent experimental studies on the characterization of a unique population of MSCs derived from human oral mucosa and gingiva, especially their immunomodulatory and anti-inflammatory functions and their application in the treatment of several in vivo models of inflammatory diseases. The ease of isolation, accessible tissue source, and rapid ex vivo expansion, with maintenance of stable stem-cell-like phenotypes, render oral mucosa- and gingiva-derived MSCs a promising alternative cell source for MSC-based therapies. © 2012 International & American Associations for Dental Research
Flocculation of Reactive Blue 19 (RB19) using Alum and the Effects of Catalysts Addition
There are a variety of primary coagulants which can be used in a water treatment plant. One of the earliest, and still the most extensively used, is aluminum sulfate, also known as alum. Aluminum Sulfate (Alum) is one of the most commonly used flocculent in waste water treatment processes. Effectiveness of Alum in flocculation process is determined by many factors such as the effluents pH, flocculent dose as well as the use of catalyst to improve efficiency rate of flocculation. Hence special attention to these factors especially the use of catalyst has been brought about by this study. Experiments were carried out using Reactive Blue 19 Dye as the contaminant of waste water and two catalysts namely Calcium Hydroxide (CaOH2) and Poly Aluminum Chloride (PACl) were evaluated. The results obtained proved that indeed after addition of catalysts, removal efficiency rates of Alum can be increased up to 25% using Calcium Hydroxide and up to 35% using Poly Aluminum Chloride compared to Alum alone. The optimum conditions for this study were at pH 5.5 ~7.5, 300 mg/L of Alum 30seconds of rapid mixing time with 300 rpm , 30rpm of mixing rate for 5 minutes and 30 minutes of settling time. Moreover, Alum showed the highest performance under these conditions and using 50 mg/L PACl as catalyst with 98.52% of COD reduction and 90.60% of color reduction. In conclusion, Alum with the support of PACl as catalyst is an effective coagulant, which can reduce the level of COD and Dye Color in Reactive Blue 19 contaminated wastewater
Well-Being Correlates of Perceived Positivity Resonance: Evidence from Trait and Episode-Level Assessments
Positivity resonance is a type of interpersonal connection characterized by shared positivity, mutual care and concern, and behavioral and biological synchrony. Perceived positivity resonance is hypothesized to be associated with well-being. In three studies (N = 175; N = 120; N = 173), perceived positivity resonance was assessed at the trait level (Study 1) or the episode level, using the Day Reconstruction Method (Studies 2 and 3). Primary analyses reveal that perceived positivity resonance is associated with flourishing mental health, depressive symptoms, loneliness, and illness symptoms. These associations largely remain statistically significant when controlling for daily pleasant emotions or social interaction more generally. Ancillary analyses in Studies 2 and 3 support the construct validity of the episode-level assessment of perceived positivity resonance. The overall pattern of results is consistent with Positivity Resonance Theory. Discussion centers on avenues for future research and the need for behavioral interventions
Retrieval of material properties of monolayer transition-metal dichalcogenides from magnetoexciton energy spectra
Reduced exciton mass, polarizability, and dielectric constant of the
surrounding medium are essential properties for semiconduction materials, and
they can be extracted recently from the magnetoexciton energies. However, the
acceptable accuracy of the previously suggested method requires very high
magnetic intensity. Therefore, in the present paper, we propose an alternative
method of extracting these material properties from recently available
experimental magnetoexciton s-state energies in monolayer transition-metal
dichalcogenides (TMDCs). The method is based on the high sensitivity of exciton
energies to the material parameters in the Rytova-Keldysh model. It allows us
to vary the considered material parameters to get the best fit of the
theoretical calculation to the experimental exciton energies for the ,
, and states. This procedure gives values of the exciton reduced mass
and 2D polarizability. Then, the experimental magnetoexciton spectra compared
to the theoretical calculation gives also the average dielectric constant.
Concrete applications are presented only for monolayers WSe and WS from
the recently available experimental data. However, the presented approach is
universal and can be applied to other monolayer TMDCs. The mentioned fitting
procedure requires a fast and effective method of solving the Schr\"{o}dinger
of an exciton in monolayer TMDCs with a magnetic field. Therefore, we also
develop such a method in this study for highly accurate magnetoexciton
energies.Comment: 8 pages, 4 figures, 4 table
Human Gingiva-Derived Mesenchymal Stromal Cells Attenuate Contact Hypersensitivity via Prostaglandin E2- Dependent Mechanisms
The immunomodulatory and anti-inflammatory functions of mesenchymal stromal cells (MSCs) have been demonstrated in several autoimmune/inflammatory disease models, but their contribution to the mitigation of contact hypersensitivity (CHS) remains unclear. Here, we report a new immunological approach using human gingiva-derived MSCs (GMSCs) to desensitize and suppress CHS and the underlying mechanisms. Our results showed that systemic infusion of GMSCs before the sensitization and challenge phase dramatically suppress CHS, manifested as a decreased infiltration of dendritic cells (DCs), CD8 + T cells, T H-17 and mast cells (MCs), a suppression of a variety of inflammatory cytokines, and a reciprocal increased infiltration of regulatory T cells and expression of IL-10 at the regional lymph nodes and the allergic contact areas. The GMSC-mediated immunosuppressive effects and mitigation of CHS were significantly abrogated on pretreatment with indomethacin, an inhibitor of cyclooxygenases. Under coculture condition of direct cell-cell contact or via transwell system, GMSCs were capable of direct suppression of differentiation of DCs and phorbol 12-myristate 13-acetate-stimulated activation of MCs, whereas the inhibitory effects were attenuated by indomethacin. Mechanistically, GMSC-induced blockage of de novo synthesis of proinflammatory cytokines by MCs is mediated partly by the tumor necrosis factor-alpha/prostaglandin E 2 (PGE 2) feedback axis. These results demonstrate that GMSCs are capable of desensitizing allergic contact dermatitis via PGE 2-dependent mechanisms. © AlphaMed Press
Solving congestions with pumped hydro storage under high penetration of renewable energy in Vietnam: The case of Ninh Thuan HV grid
Renewable energy sources are increasingly penetrating all power networks worldwide, despite the security status of these networks threatened by the fickle nature of these sources. Ninh Thuan Province (Vietnam) experienced a solar power boom in 2019–2021 and, with it, the congestion of both the local transmission and distribution networks. To solve congestions and operational security issues, large-scale storage solutions were considered and, due to land availability, Pumped Hydro Storage (PHS) technology was selected to solve these problems. However, the operational risks of cascade outage when integrating both renewables and a PHS system needs to be carefully considered, especially in a bulk power system. For this reason, this study examined the potential of integrating a large-scale grid-connected PHS system in ensuring operational security against the impacts of solar power plants in Ninh Thuan. The analyses of static and dynamic security were carried out for scenarios with and without the PHS system, including under current operational conditions. The results of the simulations show that the presence of the PHS improves both static and dynamic performance of the system, thus allowing full exploitation of solar power and avoiding curtailment. NEPLAN environment was chosen to simulate all scenarios under the Vietnamese grid code
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