Reconfigurable Circularly Polarized Hemispherical DRA Using Plasmonic Graphene Strips for MIMO Communications

Plasmonics - This paper investigates the radiation characteristics of a Hemispherical- Dielectric Resonator Antenna (DRA) loaded with graphene strips and fed by ridge-gap waveguide (RGW)...     

Nutrient recovery from domestic wastewater using a UASB-duckweed ponds system

The pilot-scale wastewater treatment system used in this study comprised a 40-l UASB reactor (6-h HRT) followed by three duckweed ponds in series (total HRT 15 days). During the warm season, the treatment system achieved removal values of 93%, 96% and 91% for COD, BOD and TSS, respectively. Residual values of ammonia, TKN and total phosphorus were 0.41 mg N/l, 4.4 mg N/l and 1.11 mg P/l, with removal efficiencies of 98%, 85% and 78%, respectively. The system achieved 99.998% faecal coliform removal during the warm season with final effluent containing 4 x 10(3) cfu/100 ml. During the winter, the system was efficient in removing COD, BOD and TSS but not nutrients. The system was deficient in the removal of faecal coliforms during the winter, producing effluent with 4.7 x 10(5) cfu/100 ml. During the warm season, the N removal consisted of 80% by plant uptake, 5% by sedimentation and 15% unaccounted for. A duckweed production rate of 33 t dry matter per hectare per 8 months was achieved.     

Vegetation history of the western Rif mountains (NW Morocco): origin,late-Holocene dynamics and human impact

Unlike southern Spain, northern Morocco has been little investigated for palaeoecological purposes. Consequently, the origin and history of the Rifan vegetation is largely unknown, as well as the past role of human activities. A review of the Plio-Pleistocene fossil data available from North Africa clearly reveals the ancient origin of much of the present-day flora and vegetation structures of the region. A well-dated pollen record covering the last 5,000 years, obtained from a fen, is compared to previous regional pollen data in order to understand the late-Holocene vegetation dynamics and the influence of anthropogenic disturbances. Modern pollen spectra have allowed the calibration of pollen diversity and evenness as indicators of tree-cover density. The results obtained show the long-term persistence of regional forests until the onset of Arab Sharifian dynasties in the 16th century, with a surprising lack of human impact during the late Neolithic, and little impact during Roman colonisation. The increasing density of deciduous forests recorded from 3,800 to 1,900 cal bp, concomitant with the expansion of cedar in the Middle Atlas, could reveal the onset of widespread cooler and moister climatic conditions. The weak and late human impact in the Rifan mountains explains, at least in part, their high diversity and the conservation of their forest ecosystems. Anthropogenic activities however have led to severe modification of the understorey structure of these forests during the four last centuries, and to the worrying on-going deforestation that presently threatens the survival of this invaluable biological heritage.     

Dielectric Resonator Antenna Loaded with Reconfigurable Plasma Metamaterial Polarization Converter

In this paper, a plasma based metamaterial (MM) polarizer is optimized for linear to circular polarization conversion in Ku-band wireless applications. The plasma MM polarizer is design based on the transmission mode. The proposed plasma MM polarizer unit-cell element consists of back-to-back plasma arcs placed on the top and the bottom faces of a dielectric substrate. Polarization Conversion from linear polarized (LP) wave to circular polarized (CP) wave requires that the incident wave is splitted into two orthogonal components with equal magnitudes and π/2 phase difference. The polarization characteristics of the plasma MM polarizer have bandwidth of 17.5% centered around 13.7 GHz. A linearly polarized dielectric resonator antenna (DRA) is designed with impedance bandwidth of 27.05%. The LP-DRA loaded with plasma MM polarizer radiates CP-waves with improved gain of 8.89 dBi. Reconfigurable CP radiation right-hand, left-hand, or linear polarization is achieved when the argon gas in the lower, upper, or both arc-shaped containers is ionized to plasma state. The proposed plasma MM polarizer and the DRA structures are examined utilizing a full-wave simulator.

     

Phytochemical profile,enzyme inhibition activity and molecular docking analysis of Feijoa sellowiana O. Berg

Feijoa sellowiana leaves and fruits have been investigated as a source of diverse bioactive metabolites. Extract and eight metabolites isolated from F. sellowiana leaves were evaluated for their enzymatic inhibitory activity against α-glucosidase, amylase, tyrosinase, acetylcholinestrerase and butyrylcholinesterase both in vitro and in silico. Feijoa leaves’ extract showed strong antioxidant activity and variable levels of inhibitions against target enzymes with a strong anti-tyrosinase activity (115.85 mg Kojic acid equivalent/g). Additionally, α-tocopherol emerged as a potent inhibitor of AChE and BChE (5.40 & 10.38 mmol galantamine equivalent/g, respectively). Which was further investigated through molecular docking and found to develop key enzymatic interactions in AChE and BChE active sites. Also, primetin showed good anti BChE (11.70 mmol galantamine equivalent/g) and anti-tyrosinase inhibition (90.06 mmol Kojic acid equivalent/g) which was also investigated by molecular docking studies.

Highlights

• Isolation of eight bioactive constituents from Feijoa sellowiana leaves.
• In vitro assays using different enzymatic drug targets were investigated.
• In silico study was performed to define compound interactions with target proteins.
• Feijoa leaf is an excellent source of anti-AChE and antityrosinase bioactives.

     

Whole-Genome Sequencing Reveals Lactase Persistence Adaptation in European Dogs

Coexistence and cooperation between dogs and humans over thousands of years have supported convergent evolutionary processes in the two species. Previous studies found that Eurasian dogs evolved into a distinct geographic cluster. In this study, we used the genomes of 242 European dogs, 38 Southeast Asian indigenous (SEAI) dogs, and 41 gray wolves to identify adaptation of European dogs . We report 86 unique positively selected genes in European dogs, among which is LCT (lactase). LCT encodes lactase, which is fundamental for the digestion of lactose. We found that an A-to-G mutation (chr19:38,609,592) is almost fixed in Middle Eastern and European dogs. The results of two-dimensional site frequency spectrum (2D SFS) support that the mutation is under soft sweep . We inferred that the onset of positive selection of the mutation is shorter than 6,535 years and behind the well-developed dairy economy in central Europe. It increases the expression of LCT by reducing its binding with ZEB1, which would enhance dog’s ability to digest milk-based diets. Our study uncovers the genetic basis of convergent evolution between humans and dogs with respect to diet, emphasizing the import of the dog as a biomedical model for studying mechanisms of the digestive system.     

Clean Biotechnology for Sustainable Farming

Sustainability would never be achieved farewell as agricultural practices continue beyond the carrying capacity of the ecosystem through the exaggerated abuse of agricultural chemicals. The rapid growth of agricultural productivity in chemical farming systems is shrinking off. Moreover, environmental torrent from agricultural activities jeopardizes agricultural growth in several countries. Problems associated with the wealthy agricultural production in the developed world and underproduction in developing countries necessitate a widely accepted assessment of the present status of agriculture. It is time to install new farming systems committed to following environmental and sustainable approaches, and producing healthy food free from agrochemical residues. Ecologically oriented farming routines are being developed within the frame of the recent achievements in environmental biotechnology, the most important of which is the clean farming system which is increasingly acknowledged as a potential solution to copious problems overlaying present world agriculture. It is a farming system, which aims at evading the routine use of agricultural chemicals and reducing their rates of application. Clean farming systems directly give rise to four environmental biotechnologies, i.e., recycling of composted organic waste, fortifying the rhizosphere soil with biofertilizers, encouraging the use of biopesticides in agricultural practices and bioremediation of polluted agro‐ecosystems.     

Saudi honey alleviates indomethacin-induced gastric ulcer via improving antioxidant and anti-inflammatory responses in male albino rats

Recent years have reported a rise in the occurrence of gastric ulceration especially among young children and adults. This study investigated the mechanism by which two types of Saudi honey: Alnahal Aljawal honey (Wadi) or Bin Ghaithan honey (Talh) exerted their antiulcer potential in indomethacin-induced gastric ulceration. Four cohorts of rats were used: Group 1; Healthy controls, Group 2; Ulcerative animals, Group 3; Ulcerative + Wadi honey treatment, Group 4; Ulcerative + Talh honey treatment. We profiled the levels of different indicators of oxidative stress including the activities of gastric mucosal glutathione superoxide dismutase (SOD), catalase (CAT), peroxidase (GPx), reduced glutathione (GSH), and lipid peroxidation (measured as malondialdehyde; MDA). CRP content, IL-10, and plasma tumor necrosis factor-α were also evaluated. The stomach was visually examined for macroscopic lesions and using light microscope for histopathological changes in the glandular mucosa.Wadi or Talh honey significantly reduced the ulcer indices, and essentially protected the glandular mucosa from lesions. Wadi or Talh honey also significantly reduced the gastric mucosal concentrations of GPx, SOD and GSH. In addition, the administration of Wadi or Talh honey decreased gastric mucosal plasma TNF-α and MDA, CRP content, and IL-10 levels. In conclusion, Wadi or Talh honey possibly exerted their antiulcer potential via restoring the homeostasis and stabilizing the enzymatic (SOD and GPx) and non-enzymatic (GSH) antioxidants as well as reducing the levels of inflammatory cytokines (TNF-α, CRP content, IL-10 and, NF-κB activity), and inhibiting the lipid peroxidation in the gastric mucosa. Consequently, Wadi or Talh honey may be of beneficial therapy for patients diagnosed with gastric ulceration. Clinical studies need to be conducted to further support these findings.     

Effect of phosphorus deficiency on acid phosphatase and phytase activities in common bean (Phaseolus vulgaris L.) under symbiotic nitrogen fixation

Changes in growth, symbiotic nitrogen fixation (SNF), acid phosphatase (ACP), and phytase activities to phosphorus availability (15 and 60 μmol KH₂PO₄ plant⁻¹ week⁻¹) were compared in two recombinant lines (115 and 147) of common bean. Plant growth, nodulation and SNF were genotype and P level-dependent. 147 was more affected by P shortage (15 μmol P) than 115. Four ACP types were revealed in the nodules of both lines, ACP1 exhibiting a higher specific activity under P shortage as compared to the 60 μmol P treatment, especially in 115. A single phytase was revealed for the nodules of both lines and was significantly enhanced by P deficiency. Three ACP types were found in roots and leaves, showing increasing activity under P deficiency, especially in 115. Regardless of P supply, leaf ACP specific activity was higher than that of nodules and roots in the both lines. Interestingly, phosphorus use efficiency for N₂ fixation significantly correlated to nodule ACP activity under P shortage in the both lines. The relatively better performance of 115 as compared to 147 under P deficiency could be partly ascribed to the ability of 115 to maintain higher ACP activity. This enzyme might be involved in the remobilization of the plant Pi and its utilization for SNF.