282 research outputs found

    Rapid plant regeneration of chrysanthemum (Chrysanthemum morifolium l.) through shoot tip culture

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    Shoot multiplication of chrysanthemum was achieved from shoot tip explant, using MS media supplemented with different concentrations and combinations of plant growth regulators. Different parameters including shoot initiation percentage, average number of shoots per explant, length of shoots (cm), number of leaves per shoot and number of nodes per shoot were studied during the course of study. Low concentration of indole-acetic acid (IAA, 0.1 mg/l) excelled all the other concentrations in almost all the parameters studied when used alone, as maximum shoot initiation (86.6%), shoot per explants (3.9), length of shoots (4.3 cm), number of leaves (10.0) and nodes (4.8)were recorded in it. Intermediate concentration of benzyladenine purine (BAP, 1.0 mg/l) is superior to all the other BAP concentrations used when used alone. MS media fortified with 1.0 mg/l BAP hadproduced the maximum shoot initiation (93.3%), shoot per explant (4.1), length of shoots (5.0 cm) number of leaves (11.0) and nodes (5.5). Similarly, when the combination of different concentrations ofIAA and BAP were used, significant results regarding the regeneration of chrysanthemum plantlets were achieved. MS media supplemented with intermediate levels of BAP (1.0 and 2.0 mg/l) along withlower concentrations of IAA (0.1 and 0.2 mg/l) showed better results as compared to other concentrations and combinations. Satisfactory rooting response was obtained in half strength MS media supplemented with 0.2 mg/l indole butyric acid (IBA)

    Efficient in vitro

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    Efficient plant regeneration system has been developed from the nodal segments of chrysanthemum (Chrysanthemum morifolium L). Nodal segments, after being sterilized with 1.0% mercuric chloride for three minutes, were inoculated in Murashige and Skoog (MS) media with varied concentrations of indole acetic acid (IAA), benzylaminopurine (BAP) and their combinations. Different parameters including shoot initiation percentage, average number of shoots per explant, length of shoots (cm), number of leaves per shoot and number of nodes per shoot were studied during the course of study. Intermediate level (0.3 mg/l) of IAA exceeded all the other concentrations of IAA by producing 80.0 % shoot initiation, an average of 4.0 shoots per explants, 5.1 cm long shoots, 11.3 leaves and 5.6 nodes per shoot, when used alone. Similarly, intermediate level of BAP (1.0 mg/l) showed its supremacy over all the other concentrations as it produced 100% shoot initiation, 4.9 shoots per explant, 5.8 cm long shoots, 13.4 leaves and 6.3 nodes per shoot, when used alone. When the combination of different concentrations of IAA and BAP were used, significant results regarding the regeneration of chrysanthemum plantlets were also achieved. MS media supplemented with lower concentrations of IAA (0.1 and 0.2 mg/l) along with intermediate levels of BAP (1.0 and 2.0 mg/l) had a favorable effect on the regeneration of chrysanthemum plantlets using nodal segments of chrysanthemum, as compared to other concentrations and combinations. Satisfactory rooting response was obtained in half strength MS media supplemented with 0.2 mg/l indole butyric acid (IBA), followed by 0.2 mg/l naphthalene acetic acid (NAA) and IAA, respectively.Key words: Chrysanthemum, Dendranthema morifolium, growth regulators, in vitro culture, nodal segments, auxins, rooting

    Inter-Ethnic and Demic-Group Variations in Craniofacial Anthropometry: A Review

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    yesCraniofacial anthropometry plays an important role in facial structure. This review paper evaluates existing research surrounding population norms of studied facial parameters. The purpose is two-fold: (1) to determine variations in facial measurements due to demi-group or ethnic variations based on traditional (direct) caliper based and image based (indirect) anthropometric methods. (2) to compare where possible, measured facial parameters between referenced studies. Inter and intra-population variations in addition to sexual dimorphism of facial parameters such as the nose and eyes, singularly or in combination with one another, have been concluded. Ocular measurements have exhibited ethnic variations between males and females of the Saudi, Turkish, Egyptian and Iranian group. Moreover, demic variations are reported when the native language has been used a key criterion. It has been concluded that with the current state of migration and inter-demic marriages, the study of homogenous populations will prove difficult. Subsequently, this will result in ambiguous physical traits that are not representative for any one demic or ethnic population. In this paper, results for the following adult male and female populations have been discussed: African American, Azerbaijani, Caribbean, Chinese, Croatian, Egyptian, Italian, Iranian, Turkish, Saudi Arabian, Syrian and South African. The qualitative research presented serves as a knowledge base for learners and strikes up thought provoking concepts about the direction anthropometrical research is heading

    Impedance-Based Water-Quality Monitoring Using the Parallel-Plate Method

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    The application of electromagnetic (EM) waves to measure the electrical properties (dielectric constant and loss tangent) of materials is a well-known approach. The electrical properties can be used to indirectly measure several physical properties of solutions in water such as the concentration and chemical composition of contaminants in water, as a representative of the liquid phase in soil. A capacitive method of measuring dielectric properties of solutions is proposed to detect and determine low-concentration chemical and biological contaminations in water. The primary objective of this project is to design a low-cost sensor that would require small volumes of samples to detect low concentrations of dissolved contaminants in water. A forward model was developed using a finite-element method (FEM) to simulate the experimental setup (EXP). A calibration function was also developed to minimize deviations between FEM and EXP results for benchmark/reference solutions with known dielectric properties. The validated, calibrated forward model was then inverted to calculate the electrical properties of unknown solutions using the corresponding EXP results

    Ultrashort laser sintering of printed silver nanoparticles on thin, flexible, and porous substrates

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    The fabrication of low-cost and mechanically robust flexible electronic patterns has increasingly gained attention due to their growing applications in flexible displays, touch screen panels, medical devices, and solar cells. Such applications require cost-effective deposition of metals in a well-controlled manner potentially using nanoparticles (NPs). The presence of solvent and precursors in NP based inks impacts the electrical conductivity of the printed pattern and a post-processing heating step is typically performed to restore the electrical properties and structure of the material. We report printing with picolitre droplet volumes of silver (Ag) NPs on flexible substrates using an acoustic microdroplet dispenser. The low-cost, controlled deposition of Ag ink is performed at room temperature on photopaper, polyimide and clear polyimide substrates. A localized, ultrashort pulsed laser with minimal heat affected zone is employed to sinter printed Ag patterns. For comparison, oven sintering is performed, and the results are analysed with scanning electron microscopy, four-point probe and Hall measurements. The femtosecond laser sintering revealed highly organized, connected nanostructure that is not achievable with oven heating. A significant decrease in sheet resistance, up to 93% in Ag NPs on clear polyimide confirms the laser sintering improves the connectivity of the printed film and as a result, the electrical properties are enhanced. The surface morphology attained by the laser sintering process is interpreted to be due to a joining of NPs as a result of a solid-state diffusion process in the near surface region of NPs

    Proposal of RT-PCReBased Mass Population Screening for Severe Acute Respiratory Syndrome Coronavirus 2 (Coronavirus Disease 2019)

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    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing has lagged in many countries because of test kit shortages and analytical process bottlenecks. This study investigated the feasibility and accuracy of a sample pooling approach for wide-scale population screening for coronavirus disease 2019. A total of 940 nasopharyngeal swab samples (934 negative and 6 positive) previously tested for SARS-CoV-2 were deidentified and assigned random numbers for analysis, and 94 pools of 10 samples each were generated. Automated RNA extraction, followed by RT-PCR, was performed in a 96-well plate. Positive pools were identified, and the individual samples were reanalyzed. Of the 94 pools/wells, four were positive [Ct values: N (22.7 to 28.3), ORF1ab (23.3 to 27.2), and internal control (34.4 to 35.4)]. The 40 samples comprising the four pools were identified and reanalyzed individually; six samples were positive, with Ct values of N gene, ORF1ab, and internal control comparable to their respective wells. Additional experiments were performed on samples with high Ct values, and overall results showed 91.6% positive and 100% negative agreement compared with individual testing approach. Thus, 940 samples were tested in 148 reactions compared with 940 reactions in routine screening. The sample pooling strategy may help catch up with testing needs and minimal turnaround times and facilitate enormous savings on laboratory supplies, extraction, and PCR kits currently in short supply
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