124 research outputs found
Cloud-Aided Interference Management with Cache-Enabled Edge Nodes and Users
This paper considers a cloud-RAN architecture with cache-enabled
multi-antenna Edge Nodes (ENs) that deliver content to cache-enabled end-users.
The ENs are connected to a central server via limited-capacity fronthaul links,
and, based on the information received from the central server and the cached
contents, they transmit on the shared wireless medium to satisfy users'
requests. By leveraging cooperative transmission as enabled by ENs' caches and
fronthaul links, as well as multicasting opportunities provided by users'
caches, a close-to-optimal caching and delivery scheme is proposed. As a
result, the minimum Normalized Delivery Time (NDT), a high-SNR measure of
delivery latency, is characterized to within a multiplicative constant gap of
under the assumption of uncoded caching and fronthaul transmission, and
of one-shot linear precoding. This result demonstrates the interplay among
fronthaul links capacity, ENs' caches, and end-users' caches in minimizing the
content delivery time.Comment: 9 pages, 3 figures, submitte
Efficiency of Ammonium and Nitrate Ratios on Macronutrient Content and Morphological Properties of Gerbera jamesonii Cut Flower
This experiment was carried out to study on the effect of different NO3 ¯:NH4 + ratios on macronutrient content and growth of two cut gerbera (Gerbera jamesonii Bolus ex Hooker f.) cultivars in an open hydroponic system. The plants were nourished with different NO3¯:NH4+ ratios as 100:0, 80:20, 60:40, and 40:60. The application of NO3- and NH4 + at ratio 40:60 caused a reduction in flower height, stem and disk diameter, number of flowers, inflorescence fresh and dry weight, and vase life. Results indicated that N, P and NH4 + concentrations were enhanced in leaves of gerbera cultivars by increase of NH4 + ratio, whereas K, Ca, Mg, and nitrate were decreased. As compared to ‘Double Dutch’, the ‘Stanza’ cultivar could uptake more of N, P, and Mg. Inversely, ‘Double Dutch’ was able to uptake more of K and Ca than ‘Stanza’. Defined optimal ratio of NO3¯:NH4 + 80:20 could be used for gerbera production in vegetative and reproductive stages
Identifying the possible ex-situ origin of the globular clusters of the Milky Way: A kinematic study
This is the second paper in a series, which studies the likelihood that some
globular clusters (GCs) of the Milky Way (MW) could have originated from a
dwarf satellite galaxy (DSG). Using a large suite of three-body simulations we
determine the present-day orbital properties of 154 GCs that could have escaped
from 41 MW DSGs over the past . For the MW we considered two
sets of static and dynamic models which account for the sustained growth of the
MW since its birth. We focus on the Magellanic Clouds and Sagittarius. We
compare the apogalactic distance, eccentricity, and orbital inclination of the
MW GCs with those of runaway GCs from DSGs, to constrain their possible ex-situ
origin. We observe a positive correlation between a DSG mass and the dispersion
of its runaway GCs in the orbital parameter space of (, ). We
provide tables of the identified MW GCs and their likely associated
progenitors. In total, we find 29 (19%) MW GCs which could be kinematically
associated with MW DSGs. We report, for the first time, 6 and 10 new
associations with the Large Magellanic Cloud and the Sagittarius, respectively.
For the Sagittarius we predict a concentration of runaway GCs at large
apogalactic distances of ,
, and a relative inclination of .
So far, there has not been any observed GCs with such orbital elements.
Complemented with photometric and spectroscopic observations, and cosmological
simulations, the findings from the present study could conclusively settle the
debate over the in-situ vs. ex-situ origin of the MW GCs.Comment: 20 pages, 16 figures, 5 tables, references amended. Accepted for
publication in MNRA
Dichlorido{2-[(3,4-dimethylphenyl)iminomethyl]pyridine-κ2 N,N′}copper(II)
In the title complex, [CuCl2(C14H14N2)], the CuII atom exhibits a very distorted tetrahedral coordination geometry involving two chloride ions and two N-atom donors from the Schiff base ligand. The range for the six bond angles about the Cu2+ cation is 81.49 (11)–145.95 (9)°. The chelate ring including the CuII atom is approximately planar, with a maximum deviation of 0.039 (4) Å for one of the C atoms; this plane forms a dihedral angle of 46.69 (9)° with the CuCl2 plane
Cytotoxicity and Radiosensitising Activity of Synthesized Dinitrophenyl Derivatives of 5-Fluorouracil
Background and the purpose of the study: Dual functional agents in which nitroaromatic or nitroheterocyclic compounds are attached through a linker unit to mustards and aziridines have shown higher cytotoxicities than the corresponding counterparts to both aerobic and hypoxic cells and enhanced radiosensitizing activity. In thepresent investigation cytotoxicity and radiosensitizing activity of 2,4-dinitrobenzyl, 2,4-dinitrobenzoyl, and 2,4-dinitrophenacetyl derivatives of 5-fluorouracil which was assumed to release cytotoxic active quinone methidide,and 5-fluorouracil under hypoxic conditions on HT-29 cell line under both aerobic and hypoxic conditions wasinvestigated.Methods: 5-fluorouracil derivative X-XIII were prepared by the reaction of the corresponding di-nitro substitutedbenzyl, benzoyl and phenacetyl halides with 5-fluorouracil protected at N-1 with di-t-butoxydicarbonate (BOC) in dimethyl formamide (DMF) in the presence of the potassium carbonate followed by hydrolysis of the blocking,group by potassium carbonate in methanol. Cytotoxicity of fluorouracil VIII and tested compounds X-XIII against HT-29cell line under both aerobic and hypoxic conditions after 48 hrs incubation were measured by determination of the percent of the survival cells using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and percent of the dead cells using propidium iodide(PI)-digitonine assay and results were used to calculate the corresponding IC50 values. Radiosensitization experiments were carried out by irradiation of the incubations with a 60Co source and clonogenic assay was performed to determine the cell viabilities following treatment with the tested compounds and/or radiation. Sensitization Enhancement Ratio (SER) of each tested compound was obtained from the radiation survival curves in the absence and presence of each sensitizer for 37% survival respectively.Results and major conclusion: Findings of the present study showed that alkylation or acylation of 5-fluorouracilresult in compounds which have little or no cytotoxicity and radiosensitizing activity under aerobic conditions, buthave high cytotoxicity and radiosensitizing effects under hypoxic conditions. Furthermore radiosensitizing activities ofcompounds under hypoxic conditions increased by increase in their concentrations and SER of the tested 5-FU derivatives at concentrations higher than 50 μmol were equal or higher than 1.6 which is the minimum effective SER of a radiosensitizer in an in vitro assay
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