Seasonal modulation of mesoscale processes alters nutrient availability and plankton communities in the Red Sea

Hydrographic and atmospheric forcing set fundamental constraints on the biogeochemistry of aquatic ecosystems and manifest in the patterns of nutrient availability and recycling, species composition of communities, trophic dynamics, and ecosystem metabolism. In the Red Sea, latitudinal gradients in environmental conditions and primary production have been ascribed to fluctuations in Gulf of Aden Water inflow, upwelling/mixing, and regenerated nutrient utilization i.e. rapidly recycled nitrogen in upper layers. However, our understanding of upper layer dynamics and related changes in plankton communities, metabolism and carbon and nitrogen export is limited. We surmised that stratification and mesoscale eddies modulate the nutrient availability and taxonomic identity of plankton communities in the Red Sea. Based on remote-sensing data of sea level anomalies and high resolution in situ measurements (ScanFish) we selected stations for hydrographic CTD profiles, water sampling (nutrients, seawater oxygen stable isotopes [δ18OSW]), phytoplankton and zooplankton collections. In fall 2014, strong stratification subjected the plankton community to an overall nitrogen and phosphorus shortage. The nutrient deficiency increased numbers of heterotrophic dinoflagellates, microzooplankton, and diazotrophs (Trichodesmium, diatom-diazotroph associations [DDAs]), albeit largely decreased phytoplankton and mesozooplankton abundances. In spring 2015, mesoscale eddies increased the nutrient availability, and the thermohaline characteristics and low δ18OSW point to the interaction of eddies with Gulf of Aden Surface Water (GASW). Cyclonic eddies and, most likely, the availability of nutrients associated with the GASW, increased the abundances of autotrophs (diatoms, Prasinophytes) and supported larger numbers of zooplankton and their larvae. We demonstrate that the interplay of stratification, advection of Gulf of Aden water and mesoscale eddies are key elements to better understand changes in plankton community composition, ecosystem metabolism, and macronutrient export in the Red Sea in space and time

Meiobenthic assemblage of the grey mangrove (Avicennia marina) along the Saudi Arabian coast of the Red Sea with emphasis on free-living nematodes

Spatial variability in the population density of meiofauna and the assemblage of free-living marine nematodes was studied at 20 mangrove sites located along the Saudi Arabian coast of the Red Sea. The total abundance of meiofauna varied between the locations and ranged from 119 to 1380 ind. 10 cm−2. A total of seven main taxa were recorded. Nematodes dominated (64.3%) in all sediment samples. They were followed by harpacticoid copepods (13.2%) and polychaetes (12.9%) with significant differences in their density between the locations surveyed (p < 0.001). The Pearson correlation analysis showed significant positive correlations between the sand fraction and nematodes, harpacticoid copepods and turbellarians. Twenty-five genera of free-living nematodes belonging to 15 families were recorded in the study area. Microlaimidae were the most abundant family, while Xyalidae, Desomodridae and Chromidoridae were the most diverse families. Microlaimus, Halalaimus and Terschellingia were the most frequent genera. ANOSIM values obtained for the distribution of different nematode genera in various habitats showed no significant differences. Feeding types of different nematode genera were also documented and the epistrate feeders along with the deposit feeders were found to be the common feeding types in the present study.Spatial variability in the population density of meiofauna and the assemblage of free-living marine nematodes was studied at 20 mangrove sites located along the Saudi Arabian coast of the Red Sea. The total abundance of meiofauna varied between the locations and ranged from 119 to 1380 ind. 10 cm−2. A total of seven main taxa were recorded. Nematodes dominated (64.3%) in all sediment samples. They were followed by harpacticoid copepods (13.2%) and polychaetes (12.9%) with significant differences in their density between the locations surveyed (p < 0.001). The Pearson correlation analysis showed significant positive correlations between the sand fraction and nematodes, harpacticoid copepods and turbellarians. Twenty-five genera of free-living nematodes belonging to 15 families were recorded in the study area. Microlaimidae were the most abundant family, while Xyalidae, Desomodridae and Chromidoridae were the most diverse families. Microlaimus, Halalaimus and Terschellingia were the most frequent genera. ANOSIM values obtained for the distribution of different nematode genera in various habitats showed no significant differences. Feeding types of different nematode genera were also documented and the epistrate feeders along with the deposit feeders were found to be the common feeding types in the present study

Spatio-temporal variation of microphytoplankton communities in Obhur Creek, the central Red Sea

The abundance and distribution of microphyto-plankton and related physicochemical factors were assessed monthly in Obhur Creek, the central Red Sea. Sampling was carried out near the entrance, the middle and end parts of the creek. During the course of the present study, the Red Sea was characterized by predominantly oligotrophic conditions. Nutrient concentrations were relatively higher in the end part of the creek compared to the two other study sites. Chlorophyll a was also low throughout the year (average: 0.35 ± 0.32 mg m−3), except in May when it showed clear peaks at open-water and middle sites of the creek (1.85 and 1.04 mg m−3, respectively). Phytoplankton abundance followed a similar pattern to that of chlorophyll a with considerably higher abundance at these sites in May (3063.27 × 103 and 1082.34 × 103 individuals m−3, respectively). This unusually higher abundance was mostly due to the proliferation of the diatom Pseudo-nitzschia cf. delicatissima (Cleve) Heiden. Silicate concentrations were statistically significantly correlated with total phytoplankton. A total of 220 phytoplankton species were recorded during the study period (117 diatoms, 99 dinoflagellates and four cyanophytes). Diatoms dominated in the phytoplankton abundance (75%) and were followed by dinoflagellates (20%), while cyanophytes accounted for a minimal proportion. Of all phytoplankton species observed during the study, 21 diatom and four dinoflagellate species were considered as new records for the Red Sea, and two diatom and 14 dinoflagellate species were listed as harmful algal species worldwide

Distribution and community structure of microphytoplankton in relation to increasing anthropogenic impact along coastal waters of Jeddah, the central Red Sea

Seasonal distribution and diversity of surface phytoplankton have been studied in relation to anthropogenic activities at seven locations along the coastal waters of Jeddah, Saudi Arabia in 2017. The concentration of nitrite, nitrate, ammonia, phosphate and silicate varied over wide ranges: 0.04–20.27, 0.05–29.3, 0.22–78.16, 0.02–25.90 and 43–24.50 µmol l−1, respectively. Inorganic nutrients, phytoplankton biomass and density were at eutrophic levels at two lagoon locations (4 and 5), while other coastal locations showed oligotrophic characteristics of the Red Sea. Phytoplankton biomass was positively correlated with all measured inorganic nutrients. The total phytoplankton density varied between 52.4  ×  103 and 40800  ×  103 cells m−3 (average 6249.9 × 103 ± 10 797 × 103 cells m−3). A total of 174 species of phytoplankton (95 diatoms, 75 dinoflagellates, 3 cyanophytes and 1 silicoflagellates) were recorded in this study, with the dominance of diatoms (95.1%). Higher densities observed at lagoon locations were mainly due to the proliferation of the diatom species Skeletonema costatum and Chaetoceros decipiens. In terms of diversity, dinoflagellates were more numerous than diatoms in July, otherwise mostly diatoms dominated. On the other hand, cyanophytes were more abundant in November. Based on the present study, anthropogenic activities (especially sewage effluent) in Jeddah coastal waters had a significant impact on the phytoplankton densities and diversity.Seasonal distribution and diversity of surface phytoplankton have been studied in relation to anthropogenic activities at seven locations along the coastal waters of Jeddah, Saudi Arabia in 2017. The concentration of nitrite, nitrate, ammonia, phosphate and silicate varied over wide ranges: 0.04–20.27, 0.05–29.3, 0.22–78.16, 0.02–25.90 and 43–24.50 µmol l−1, respectively. Inorganic nutrients, phytoplankton biomass and density were at eutrophic levels at two lagoon locations (4 and 5), while other coastal locations showed oligotrophic characteristics of the Red Sea. Phytoplankton biomass was positively correlated with all measured inorganic nutrients. The total phytoplankton density varied between 52.4  ×  103 and 40800  ×  103 cells m−3 (average 6249.9 × 103 ± 10 797 × 103 cells m−3). A total of 174 species of phytoplankton (95 diatoms, 75 dinoflagellates, 3 cyanophytes and 1 silicoflagellates) were recorded in this study, with the dominance of diatoms (95.1%). Higher densities observed at lagoon locations were mainly due to the proliferation of the diatom species Skeletonema costatum and Chaetoceros decipiens. In terms of diversity, dinoflagellates were more numerous than diatoms in July, otherwise mostly diatoms dominated. On the other hand, cyanophytes were more abundant in November. Based on the present study, anthropogenic activities (especially sewage effluent) in Jeddah coastal waters had a significant impact on the phytoplankton densities and diversity

Mutual Coupling Reduction of DRA for MIMO Applications

In this paper, A multiple input Multiple Output (MIMO) antenna using two Square Dielectric Resonators (SDRs) is introduced. The mutual coupling between the two SDRAs is reduced using two different methods; the first method is based on splitting a spiral slot in the ground plane, then filling the slot with dielectric material, "E.=2.2". The second method is based on inserting a copper parasitic element, having the same shape of the splitted Spiral, between the two SDRAs.  The effect of replacing the copper parasitic element with Carbon nanotubes (CNTs) parasitic element "SOC12 doped long-MWCNT BP" is also studied. The antenna system is designed to operate at 6 GHz. The analysis and simulations are carried out using finite element method (FEM). The defected ground plane method gives a maximum isolation of l8dB at element spacing of 30mm (0.6λo), whereas the parasitic element method gives a maximum isolation of 42.5dB at the same element spacing

Benefit from integrating zinc oxide nanoparticles with probiotic bacteria to produce strong Biofertilizer for increasing the production of agricultural crops, vegetables and fruits

In this research, new methods were found to produce a strong, In this study, zinc oxide useful and usable biofertilizer in any agricultural soil and with any agricultural crop, whether fruit or vegetables, which is Nanoparticles is combined and it is incubated and prepared with some important nutrients for the growth and reproduction of the probiotic bacteria microorganisms present together to produce a biofertilizer and organic fertilizer rich in important nutrients for plant growth and increased production of agricultural crops, A mixed and combined nutritional medium of many materials and vegetables and fruits. nutrients suitable for the purpose of growing many living microorganisms such as bacteria and fungi and controlling the growth rates of microorganisms with the percentage of food present in the biofertilizer (F/M Ratio ).It was reached to increase the efficiency of agricultural fertilizer production, the work of biological fertilizers, and the production of a new strong and effective biological product in increasing the production of agricultural crops and supplying the plant with what it needs from important nutrients to increase growth, early production and improve the quality of agricultural soil. The main goal of adding many food media is the multiplicity and diversity of the carbon source, the multiplication of the growth of microbial isolates, the increase in their numbers, the reduction of growth, reproduction and regeneration quickly, and to reach an increase in the efficiency and effectiveness of biological fertilizer for soil and plants together, as it is considered an integrated nutrient medium. Biofertilizers, a sustainable ecofriendly agricultural approach to crop improvement is used to supplement chemical fertilizers mainly to maintain soil fertility. Continuous application of expensive chemical fertilizers causes reduction of organic matter content in soil and also microbial activity drastically. Biofertilizers are organic, biodegradable. They contain micro-organisms, provide nutrients viz., N, P, K and other nutrients, antibiotics, hormones like auxins, cytokinin, vitamins which enrich root rhizosphere. The present article highlights biofertilizer mediated crop functional such as plant growth and productivity, nutrient profile, plant protection and there by crop improvement. The knowledge gained from the literature appraised here in will help us to understand the physiological bases of biofertilizers towards sustainable agriculture in reducing problems associated with the use of chemicals fertilizers. Therefore, there is an urgent need to adapt biological sciences applications in agriculture field. Biotechnology is an amalgamation of variety of disciplines- molecular biology, bioinformatics, biochemistry, genetics and microbiology. The usage of combinations of these disciplines in agricultural field leads to generation of biotech crops with increased yield and enhanced quality. Agriculture biotechnology not only upgrades the quality but also utilizes the resources and livestock for the well-being of animals and wild plants. Phosphorus, Probiotic bacteria with yoghurt and sugar Charcoal sodium chloride and some other nutrients such as flour and starch are mixed with zinc oxide nano particles to produce a bio-fertilizer fully of nutrients necessary for plant growth, increase the production of agricultural crops, which improve the quality characteristics of agricultural soil, treat stress and poor production and some agricultural pests that may negatively affect plant growth and work to reduce the rate of increase of agricultural crops, vegetables and fruits , and so it is necessary to find alternative strategy to increase availability of nutrients for plants. One possible way could be application of so called bioeffectors (BE) which should improve the mobilization of nutrients (especially phosphorus) from less available forms in soil, improve plant growth and contribute to mycorrhiza development. BEs are commercially supplied products which contain active substances (live microorganisms and active natural compounds). BEs can be used in organic agriculture, because their application represents no risk for the environment

The Validity of Rapid Malaria Test and Microscopy in Detecting Malaria in a Preelimination Region of Egypt

Background. Malaria is a leading cause of morbidity and mortality worldwide. Rapid and accurate diagnosis of malaria would improve control measures and reduce morbidity and mortality. Objective. The aim of this study was to assess the prevalence of malaria in high risk foci in Egypt and the effectiveness of rapid diagnostic tests in diagnosis and subsequently control of malaria. Methodology. A total number of 600 cases of both sexes with different ages were included in the present study. Cases were included in 2 groups; first group (500 cases) were randomly selected from households in Fayoum Governorate and second group (100 cases) were admitted to Fayoum Fever Hospital with signs suggestive of malaria. Cases were subjected to detailed history taking, clinical examination, microscopic examination of thin and thick blood films, and immunological test to detect plasmodial antigens. Results. A total of 3 positive cases were detected by rapid diagnostic tests (RDTs). Out of these 3 cases, one case was positive for malaria parasite by microscopic examination of blood films. All positive cases in the study had history of travel to malaria endemic areas. Conclusion. RDTs are simple and effective for rapid diagnosis of malaria to help in implication of control measures in different localities

Functionalized poly(N-isopropylacrylamide)-based microgels in tumor targeting and drug delivery

Over the past several decades, the development of engineered small particles as targeted and drug delivery systems (TDDS) has received great attention thanks to the possibility to overcome the limitations of classical cancer chemotherapy, including targeting incapability, nonspecific action and, consequently, systemic toxicity. Thus, this research aims at using a novel design of Poly(N-isopropylacrylamide) p(NIPAM)-based microgels to specifically target cancer cells and avoid the healthy ones, which is expected to decrease or eliminate the side effects of chemotherapeutic drugs. Smart NIPAM-based microgels were functionalized with acrylic acid and coupled to folic acid (FA), targeting the folate receptors overexpressed by cancer cells and to the chemotherapeutic drug doxorubicin (Dox). The successful conjugation of FA and Dox was demonstrated by dynamic light scattering (DLS), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), UV-VIS analysis, and differential scanning calorimetry (DSC). Furthermore, viability assay performed on cancer and healthy breast cells, suggested the microgels’ biocompatibility and the cytotoxic effect of the conjugated drug. On the other hand, the specific tumor targeting of synthetized microgels was demonstrated by a co-cultured (healthy and cancer cells) assay monitored using confocal microscopy and flow cytometry. Results suggest successful targeting of cancer cells and drug release. These data support the use of pNIPAM-based microgels as good candidates as TDDS