On a Hybrid Preamble/Soft-Output Demapper Approach for Time Synchronization for IEEE 802.15.6 Narrowband WBAN

In this paper, we present a maximum likelihood (ML) based time synchronization algorithm for Wireless Body Area Networks (WBAN). The proposed technique takes advantage of soft information retrieved from the soft demapper for the time delay estimation. This algorithm has a low complexity and is adapted to the frame structure specified by the IEEE 802.15.6 standard for the narrowband systems. Simulation results have shown good performance which approach the theoretical mean square error limit bound represented by the Cramer Rao Bound (CRB)

Tunis's New Mosques Constructed Between 1975 and 1995: Morphological Knowledge

The mosque has always been a prominent unit that used to structure the old Islamic cites. Its architecture through the Muslim world has always aroused the interest of many researchers. Actually, mosques are still built while undergoing the changes which occurred on the modern societies. However, only few research who have been interested in the new mosques. This paper targets the architecture of mosques built in Tunis governorate between 1975 and 1995. Through a morphological analysis of 24 mosques we were able to determine their identity and their morphological structure. According to their form and position, we discovered classes of specimen and classes of segments. Our corpus presents several constants and variations that we can explain though the introduction of some extrinsic attributes. In fact, these architectural objects possess some morphological specifications related to some urban, functional and historical factors

Performance Study of a Near Maximum Likelihood Code-Aided Timing Recovery Technique

International audienceIn this paper, we propose a new code-aided (CA) timing recovery algorithm for various linear constant modulus constellations based on the Maximum Likelihood (ML) estimator. The first contribution is the derivation of a soft estimator expression of the transmitted symbol instead of its true or hard estimated value which is fed into the timing error detector (TED) equation. The proposed expression includes the Log-Likelihood Ratios (LLRs) obtained from a turbo decoder. Our results show that the proposed CA approach achieves almost as good results as the data-aided (DA) approach over a large interval of SNR values while achieving a higher spectral efficiency. We also derive the corresponding CA Cramer Rao Bounds (CRB) for various modulation orders. Contrarily to former work, we develop here the CRB analytical expression for different M-PSK modulation orders and validate them through comparison to empirical CRB obtained by Monte Carlo iterations. The proposed CA estimator realizes an important gain over the non data-aided approach (NDA) and achieves a smaller gap when compared to its relative CA CRB, especially at moderate SNR values where modern systems are constrained to work

CRB derivation and new Code-Aided timing recovery technique for QAM modulated signals

International audience— * In this paper, we propose a maximum likelihood based Code-Aided (CA) timing recovery algorithm for square-QAM modulated signals. We also theoretically derive the analytical expression of the CA Cramer-Rao Bound for time delay estimation. Our simulations show that the proposed CA approach realizes a performance equivalent to the Data-Aided (DA) approach over a large interval of signal to noise ratio (SNR) values

Ethylene Response Factor Sl-ERF.B.3 Is Responsive to Abiotic Stresses and Mediates Salt and Cold Stress Response Regulation in Tomato

Sl-ERF.B.3 (Solanum lycopersicum ethylene response factor B.3) gene encodes for a tomato transcription factor of the ERF (ethylene responsive factor) family. Our results of real-time RT-PCR showed that Sl-ERF.B.3 is an abiotic stress responsive gene, which is induced by cold, heat, and flooding, but downregulated by salinity and drought. To get more insight into the role of Sl-ERF.B.3 in plant response to separate salinity and cold, a comparative study between wild type and two Sl-ERF.B.3 antisense transgenic tomato lines was achieved. Compared with wild type, Sl-ERF.B.3 antisense transgenic plants exhibited a salt stress dependent growth inhibition. This inhibition was significantly enhanced in shoots but reduced in roots, leading to an increased root to shoot ratio. Furthermore, the cold stress essay clearly revealed that introducing antisense Sl-ERF.B.3 in transgenic tomato plants reduces their cell injury and enhances their tolerance against 14 d of cold stress. All these results suggest that Sl-ERF.B.3 gene is involved in plant response to abiotic stresses and may play a role in the layout of stress symptoms under cold stress and in growth regulation under salinity

Improvement of Omega-3-rich Microalgae Biomass Production to Support Qatar Food Security

Recently, algae have received considerable interest as one of the most promising feedstocks suitable for animal feed production due to their fast growth, less nutrients requirements and their ability to produce primary and secondary metabolites with high-added value. Different strategies were applied to improve both biomass and metabolites productivities aiming to produce high-quality biomass with low cost and high nutritional value. Tetraselmis subcoliformis QUCCCM50, a local marine green alga presenting fast growth, high metabolites content and easy to harvest, was selected as a candidate for feed production. Three different stress conditions were applied to enhance its potential to produce high-value products such as Nitrogen or Phosphorus depletion and high salinity of 100ppt. An assessment of the growth properties and biomass productivity was performed during the growth. After 15 days of cultivation using tubular photobioreactors, the biomass was subjected to metabolites characterization and Fatty Acids Methyl Ester profiling. Results showed that the three stress conditions present different impacts on biomass productivity and, lipid quantity and quality. Cultivation under 100 ppt led to the highest increase in lipid content. This culture condition led to 25% increase of the omega-3 fatty acids with the appearance of the docosahexaenoic acid (DHA) and a remarkable increase of the alpha-linolenic acid, comparatively to the control. The enrichment of the Tetraselmis subcoliformis' biomass in terms of omega-3 fatty acids enhanced its nutritional value and make it very suitable for animal feed production. The optimized culture conditions obtained from the current study will be applied at large scale to enhance the quality of the biomass towards omega-3 enriched animal feed supplement production, hence support achieving food security in the State of Qatar

1-(4-Chloro­phen­yl)piperazine-1,4-diium tetra­chlorido­zincate(II) monohydrate

In the crystal structure of the title compound, (C10H15ClN2)[ZnCl4]·H2O, the Zn atom is coordinated by four Cl atoms in a tetrahedral geometry. The water mol­ecules and the 1-(4-chloro­phen­yl)piperazine-1,4-diium cations inter­act with the [ZnCl4]2− anions through O—H⋯Cl, N—H⋯Cl, N—H⋯O and C—H⋯Cl hydrogen bonds (five simple and one bifurcated). Inter­molecular π–π stacking inter­actions are present between adjacent aromatic rings of 1-(4-chloro­phenyl)­piperazine-1,4-diium cations (the centroid–centroid distance is 3.453 Å)

Piperazinediium tetra­chloridocadmate monohydrate

In the title compound, (C4H12N2)[CdCl4]·H2O, the [CdCl4]2− anions adopt a slightly distorted tetra­hedral configuration. In the crystal, O—H⋯Cl hydrogen bonds link the anions and water mol­ecules into corrugated inorganic chains along the b axis which are inter­connected via piperazinediiumN—H⋯O and N—H⋯Cl inter­actions into a three-dimensional framework structure

Evaluation of Roholtiella sp. Extract on Bell Pepper (Capsicum annuum L.) Yield and Quality in a Hydroponic Greenhouse System

This study was carried out to investigate the impacts of cyanobacteria (Roholtiella sp.) high-value product extract (HVPE) and water resuspended biomass WRB treatments on bell pepper production using the hydroponic system under greenhouse conditions. Six cyanobacteria treatments (6 ml L−1, 4 ml L−1, and 2 ml L−1 – HVPE, 6 ml L−1, 4 ml L−1, and 2 ml L−1 – WRB, and TR0 as control) were evaluated using the foliar application method. The results showed that foliar application of HVPE with treatments of 2 ml L−1, 4 ml L−1, and 6 ml L−1 produced significantly higher values of physical growth parameters of bell pepper (BP) plants (shoot length, the number of leaves, plant leaf length, plant leaf width, and the diameter of the shoot), SPAD index, yield components (the fruit length, fruit width, the number of fruit per plant, and fresh weight per fruit), biochemical composition [ascorbic acid, phenolic acid, and total soluble solids (TSS)], and the total yield compared to the control group TR0. Also, significant higher values of growth parameters (shoot length, the number of leaves, plant leaf length, plant leaf width, the diameter of the shoot), SPAD index, yield components (the fruit length, fruit width, the number of fruits per plant, and fresh weight per fruit), biochemical composition [ascorbic acid, phenolic acid, and total soluble solids (TSS)], and the total yield were obtained with foliar spraying WRB at 2 ml L−1, 4 ml L−1, and 6 ml L−1 compared to the control group TR0. Consequently, the treated bell pepper with Roholtiella sp. HVPE and WRB were more efficient in enhancing production and chemical constituents compared with the control group.This study was funded by the Graduate Student Grant (QUST-1-CAS-2020-10) provided by Qatar University, the NPRP8 project, and Qatar University IDC funds of RB-H

Screening of Fresh water and Sea water Microalgae strains from Qatar for feed supplement production

The worldwide continuous increasing of population provokes an increasing awareness about the food security. Qatar is one of the first countries establishing a Food Security Strategy Program to satisfy the demand of food and feed. Microalgae is considered as one of the most promising solution based on its ability to produce the essential elements needed for food and feed such as lipids, carbohydrates, proteins... In Qatar University, a diverse collection of Microalgae and Cyanobacteria strains isolated from different environments was established (QUCCCM). Microalgae, These photosynthetic microorganisms are capable of converting solar energy into useful compounds. Microalgae accumulate several kinds of metabolites such as proteins (6-52%), lipids (7-23%), carbohydrates (5-23%). In addition, microalgae produce have the ability to produce high-value metabolites. The aim of our work was to screen the QUCCCM and identify potential strains with high nutritional value for use as feed for poultry and livestock. In this study, Microalgal isolates belonging to 12 different species were investigated for their eligibility to be used as a feed. All strains were cultivated over a period of 10 to15 days depending on species. Optical Density and Dry weights were recorded every three days to follow the algal Growth. The results showed the presence of three categories of isolates (fast, medium and slow growing). Among them, the species Chlamydomonas sp. presented the highest growth rate (?) with 0.89day ? 1 � 0.27 and a doubling time of 1.28/ day. Based on this result, the fast-growing strains were subjected to metabolite investigations in terms of lipids, proteins, carbohydrates, amino acids and Fatty acids to select the ideal strain(s) presenting high growth rate along with metabolites valuable for algae-based feed supplement. The highest protein and Lipid content was observed in the case of a freshwater strain belonging to the Mychonastes sp.with ? 50% w/w and 40.7% � 0.015 respectively. Carbohydrates were seen highest in Chlorococcum sp.with a value of 30% � 0.009%. Considering the marine strains, the isolates had a similar range of protein, Lipids and Carbohydrates content of (22%-34%), (32%-39%) and (8%-20%) respectively. Based on this study, one marine strain (Pichochloris sp.) having 33% � 0.021 content of protein and 32.7% � 0.036 as lipid, and one freshwater (Mychonastes sp.) holding the highest amount of metabolites were selected for deeply investigations in terms of FAME and Amino acid profiling which are crucial parameters that determine the feed quality. The results showed the presence of different essential Amino acids in the total protein fraction. Fatty acid profiling comprised saturated and unsaturated fats for all strains; most of them being rich with C18:0; C16:0 and C16:3. For the selected strains, the metabolite content during the growth period was followed by sampling every 3 days in order to identify the stage having high productivity and rich metabolite content. The analysis of the isolates showed an increase in the production of each metabolite during the growth, wherein lipids and protein amounts are relatively high while carbohydrates were comparatively low. These two selected strains will be improved in terms of lipid and protein production using media and salinity stress in order to enhance the production of essential nutrients such as omegas, amino acids and used for animal bioassay. In Conclusion, this study showed the existence of a diverse and rich collection of valuable strains with important metabolites that can support the country's food security program, by providing microalgae to supplement animal feed. Additionally, the potential candidates can be used for commercial applications.qscienc