The Impact of User Effects on the Performance of Dual Receive Antenna Diversity Systems in Flat Rayleigh Fading Channels

In this paper we study the impact of user effects on the performance of receive antenna diversity systems in flat Rayleigh fading channels. Three diversity combining techniques are compared: maximal ratio combining (MRC), equal gain combining (EGC), and selection combining (SC). User effects are considered in two scenarios: 1) body loss (the reduction of effective antenna gain due to user effects) on a single antenna, and 2) equal body loss on both antennas. The system performance is assessed in terms of mean SNR, link reliability, bit error rate of BPSK, diversity order and ergodic capacity. Our results show that body loss on a single antenna has limited (bounded) impact on system performance. In comparison, body loss on both antennas has unlimited (unbounded) impact and can severely degrade system performance. Our results also show that with increasing body loss on a single antenna the performance of EGC drops faster than that of MRC and SC. When body loss on a single antenna is larger than a certain level, EGC is not a “sub-optimal” method anymore and has worse performance than SC

Comparative study of the phenolic composition of seeds from grapes cv cardinal and alphonse lavallee during last month of ripening

During the last month of ripening, the phenolic composition of seeds from two widely distributed table grapes, cv Cardinal and Alphonse Lavallee, was determined by HPLC/DAD/ESI/MS. Besides, the concentrations of nutrients in leaf blades of grapevine were measured. Generally, the most abundant phenolic in grape seed was gallic acid, followed by methyl gallate and monomeric flavan-3-ols. In comparison to Alphonse Lavallee, the amounts of phenolics were higher in grape seed of Cardinal, in which gallic acid glucoside was not detected. Among analyzed phenolics, the increase of gallic acid was evidenced in grape seed of Cardinal. The most of phenolics decreased during the last month of grape ripening, and some of them had no significantly different content. Results of bivariate correlations showed that the amounts of some phenolics in grape seed of Cardinal increased with increasing of the content of potassium and phosphorus in leaves

Validación y reproducibilidad de un cuestionario de frecuencia de consumo alimentario para valorar la ingesta de lípidos y fitoquímicos.

Background: epidemiological studies have been related food intake with the incidence of nontransmissible chronic diseases. Objective: the purpose of the present study was to analyze the validity and reproducibility of a food frequency questionnaire (FFQ) aimed at assessing lipid and phytochemical intake. Material and Methods: FFQ was administered to 45 people of both sexes, aged between 20 and 72 years old and resident in Cordoba, Argentina. The FFQ included 257 questions referring to foods, their consumption frequency and portion size. Regarding consumption of fruit and vegetables, the season was also taken into account. The questionnaire was applied at two different periods (FFQ1 and FFQ2) with a break of six months in between. As a reference, the 24-hour dietary recall was used (24HDR) three times. The mid intake of FFQ1-FFQ2, the 24HDR-FFQ2 median intake, median difference, Mean Absolute Deviation from the median differences (MAD), Wilcoxon signed rank sum test and Spearman rank order correlation coefficients were calculated to analyze the accuracy of the FFQ data. Results: the correlation coefficients for FFQ1-FFQ2 varied from 0.52 for 20:5 n3 eicosapentanoic (EPA) fatty acid to 0.89 for 4:0 butyric fatty acid (p<0.05). For 24HDR-FFQ2, the values ranged from 0.19 for lycopene to 0.93 for EPA fatty acid (p<0.05). Conclusion: the analysis carried out showed an acceptable validity and reproducibility of the FFQ, thus enabling it to be used in research relating the intake of lipids and phytochemicals and the risk of non-transmissible diseases.publishedVersio

Synthesis of polymer Janus particles with tunable wettability profiles as potent solid surfactants to promote gas delivery in aqueous reaction media

Janus particles exhibit a strong tendency to directionally assemble and segregate to interfaces and thus offer advantages as colloidal analogues of molecular surfactants to improve the stability of multiphasic mixtures. Investigation and application of the unique adsorption properties require synthetic procedures that enable careful design and reliable control over the particles’ asymmetric chemistry and wettability profiles with high morphological uniformity across a sample. Herein, we report on a novel one-step synthetic approach for the generation of amphiphilic polymer Janus particles with highly uniform and tunable wettability contrasts, which is based on using reconfigurable bi-phasic Janus emulsions as versatile particle scaffolds. Two phase-separated acrylate oils were used as the constituent droplet phases and transformed into their solidified Janus particle replicas via UV-induced radical polymerization. Using Janus emulsions as particle precursors offers the advantage that their internal droplet geometry can be fine-tuned by changing the force balance of surface tensions acting at the individual interfaces via surfactants or the volume ratio of the constituent phases. In addition, preassembled functional surfactants at the droplet interfaces can be locked in position upon polymerization, which enables both access toward postfunctionalization reaction schemes and the generation of highly uniform Janus particles with adjustable wettability profiles. Depending on the particle morphology and wettability, their interfacial position can be adjusted, which allows us to stabilize either air bubbles-in-water or water droplets-in-air (liquid marbles). Motivated by the interfacial activity of the particles and particularly the longevity of the resulting particle-stabilized air-in-water bubbles, we explored their ability to promote the delivery of oxygen inside a liquid-phase reaction medium, namely, for the heterogeneous Au-NP-mediated catalytic oxidation of d-glucose. We observed a 2.2-fold increase in the reaction rate attributed to the increase of the local concentration of oxygen around catalysts, thus showcasing a new strategy to overcome the limited solubility of gases in aqueous reaction media

Toward efficient synthesis of porous all-carbon-based nanocomposites for enantiospecific separation

Chiral separation and asymmetric synthesis and catalysis are crucial processes for obtaining enantiopure compounds, which are especially important in the pharmaceutical industry. The efficiency of the separation processes is readily increased by using porous materials as the active material can interact with a larger surface area. Silica, metal–organic frameworks, or chiral polymers are versatile porous materials that are established in chiral applications, but their instability under certain conditions in some cases requires the use of more stable porous materials such as carbons. In addition to their stability, porous carbon materials can be tailored for their ability to adsorb and catalytically activate different chemical compounds from the liquid and the gas phase. The difficulties imposed by the functionalization of carbons with chiral species were tackled in the past by carbonizing chiral ionic liquids (CILs) together with a template to create pores, which results in the entire body of a material that is built up from the precursor. To increase the atomic efficiency of ionic liquids for better economic utilization of CILs, the approach presented here is based on the formation of a composite between CIL-derived chiral carbon and a pristine carbon material obtained from carbohydrate precursors. Two novel enantioselective carbon composite materials are applied for the chiral recognition of molecules in the gas phase, as well as in solution. The enantiomeric ratio of the l-composite for phenylalanine from the solution was (L/D) = 8.4, and for 2-butanol from the gas phase, it was (S/R) = 1.3. The d-composite showed an opposite behavior, where the enantiomeric ratio for phenylalanine was (D/L) = 2.7, and for 2-butanol from the gas phase, it was (R/S) = 1.3

Hemijske karakteristike visoko-krečnjačkih zemljišta koje određuju raspodelu fosfora

Phosphorus fractions from three highly calcareous soils (average, 24.9 +/- 4.8 %CO32-) from sampling sites with a Mediterranean climate were isolated by sequential extraction. In order to provide a more reliable basis for the definition of the obtained P-fractions, principal component analysis was applied and from the chemical characteristics of the 14 investigated soils, those characteristics which define at he content and association features of the P-fractions were assessed. The soils are characterized by a relatively high pH (8.0-8.2) and by significantly differing contents of organic mater, acid-soluble Mg and total P. These differences affected the various association features of the P-fraction with the soil constituents. The NH4F-P fraction (isolated with 0.5 M NH4F, pH 8.2) is defined by the contents of the main metals of the oxide-hydroxide-clay associations (Al, Fe, Mn) or by the the redox potential (Eh) of Mn. The accumulation of NaOH-phosphorus (extractable with 0.1 M NaOH) depended on the constituents of the oxide hydroxide-clay association, the humic substances and Eh-related factors. In those soils in which NaOH-P is defined by the oxide-hydroxide-clay association, the participation of Fe as a bridge-forming metal is proposed. The main part of total P, i.e., Delta P = TP - (NH4F-P + NaOH-P) is defined by the status of Mn- and Fe-humic complexes or by the concentration of hydroxyl-ions.Iz tri visoko-krečnjačka zemljišta (prosečni sadržaj CO 3 2- 24.9 ± 4.8%, pH 8.0 - 8.2), sa lokacija sa sredozemnom klimom, izolovane su frakcije fosfora sekvencijalnom ekstrakcijom. U cilju obezbeđivanja pouzdanije osnove za definisanje dobijenih frakcijafosfora (P-frakcija), primenjena je analiza principalne komponente (PC-analiza). Među 14 hemijskih karakteristika zemljišta, izdvojene su one koje definišu sadržaj pojedinih P-frakcija i prirodu njihove asocijacije sa sastojcima zemljišta. Frakcija NH 4-P (izolovana sa 0,5M NH 4F, pH = 8,2) definisana je sadržajem glavnih metala oksidne-hidroksidne-glinene asocijacije (Al, Fe, Mn) ili Eh-statusom izraženim sadržajem Mn. Akumulacija NaOH-P (ekstrahovanog sa 0,1 M NaOH) zavisila je od sastojaka oksidne-hidroksidne-glinene asocijacije, od huminskih supstanci i od faktora koji stoje u vezi sa Eh. U onim zemljištima u kojima je NaOH-P definisana sastojcima oksidne-hidroksidne-glinene asocijacije, pretpostavljeno je vezivanje fosfora preko Fe-mostova. Glavna količina fosfora ∆P = TP - (NH 4F-P + NaOH-P), u pojedinim zemljištima definisana je ili statusom Mn- i Fe-huminskih kompleksa, ili pH-vrednošću

Time-dependent reduction of structural complexity of the buccal epithelial cell nuclei after treatment with silver nanoparticles

Recent studies have suggested that silver nanoparticles (AgNPs) may affect cell DNA structure in in vitro conditions. In this paper, we present the results indicating that AgNPs change nuclear complexity properties in isolated human epithelial buccal cells in a time-dependent manner. Epithelial buccal cells were plated in special tissue culture chamber / slides and were kept at 37°C in an RPMI 1640 cell culture medium supplemented with L-glutamine. The cells were treated with colloidal silver nanoparticles suspended in RPMI 1640 medium at the concentration 15 mg L−1. Digital micrographs of the cell nuclei in a sample of 30 cells were created at five different time steps: before the treatment (controls), immediately after the treatment, as well as 15 , 30 and 60 min after the treatment with AgNPs. For each nuclear structure, values of fractal dimension, lacunarity, circularity, as well as parameters of grey level co-occurrence matrix (GLCM) texture, were determined. The results indicate time-dependent reduction of structural complexity in the cell nuclei after the contact with AgNPs. These findings further suggest that AgNPs, at concentrations present in today's over-the-counter drug products, might have significant effects on the cell genetic material

Life cycle and host range of Phycitasp. rejected for biological control of prickly acacia in Australia

Prickly acacia (Vachellia nilotica subsp. indica), a native of the Indian subcontinent, is a serious weed of the grazing areas of northern Australia and is a target for classical biological control. Native range surveys in India identified a leaf webber, Phycita sp. (Lepidoptera: Pyralidae) as a prospective biological control agent for prickly acacia. In this study, we report the life cycle and host-specificity test results Phycita sp. and highlight the contradictory results between the no-choice tests in India and Australia and the field host range in India. In no-choice tests in India and Australia, Phycita sp. completed development on two of 11 and 16 of 27 non-target test plant species, respectively. Although Phycita sp. fed and completed development on two non-target test plant species (Vachellia planifrons and V. leucophloea) in no-choice tests in India, there was no evidence of the insect on the two non-target test plant species in the field. Our contention is that oviposition behaviour could be the key mechanism in host selection of Phycita sp., resulting in its incidence only on prickly acacia in India. This is supported by paired oviposition choice tests involving three test plant species (Acacia baileyana, A. mearnsii and A. deanei) in quarantine in Australia, where eggs were laid only on prickly acacia. However, in paired oviposition choice trials, only few eggs were laid, making the results unreliable. Although oviposition choice tests suggest that prickly acacia is the most preferred and natural host, difficulties in conducting choice oviposition tests with fully grown trees under quarantine conditions in Australia and the logistic difficulties of conducting open-field tests with fully grown native Australian plants in India have led to rejection of Phycita sp. as a potential biological control agent for prickly acacia in Australia