A brief study of some aspects of early father-child relationship

Thesis (M.S.)--Boston Universit

On some generalizations of certain retarded nonlinear integral inequalities with iterated integrals and an application in retarded differential equation

AbstractIn this paper, we investigate some new nonlinear retarded integral inequalities of Gronwall–Bellman–Pachpatte type. These inequalities generalize some former famous inequalities and can be used as handy tools to study the qualitative as well as the quantitative properties of solutions of some nonlinear retarded differential and integral equations. An application is also presented to illustrate the usefulness of some of our results in estimation of solution of certain retarded nonlinear differential equations with the initial conditions

A study of the reactions between halamines and varieties of phosphorus species

In this work the oxidation of various low-valent phosphorus species with halomines and halogens has been studied. (^31)P nuclear magnetic resonance spectroscopy has been used to follow the reactions, and the pairwise additivity rule has been tested to determine if it is possible to predict the chemical shifts of the new species prepared. The reaction of Me(_2)NX (X = C1 or Br) with a number of phosphorus(III)species produced the phosphonium salt of the corresponding halide by simple amination at the phosphorus atom. This reaction occurred for(Me(_2)N)(_n)PX((_3-n)), (X = F, C1, Br and n = 1, 2) except for Me(_2)NPF(_2); for Ph(_n)PR((_3-n)) (R = Me, C(_6)H(_11), Me(_2)N, and n = 0-3) except for (Me(_2)N)(_3)P; and for the species Me(_2)PC1, MePC1(_2), (C(_6)H(_11))(_2)PC1 and Bu(^n)(_3)P. The fluorine containing phosphorus species studied, where there was more than one fluorine on the phosphorus (PF(_3) and Me(_2)NPF(_2)), gave more complex reactions which probably occurred due to rearrangement of the intially formed phosphorus(V) species. The overall stoichiometery of one such reaction was found to be: 2Me(_2)NPF(_2) + 3Me(_2)NBr = [(Me(_2)N)(_3)PF]Br + (Me(_2)N)(_2)PF(_3) + Br(_2) In the case of (Me(_2)N)(_3)P halogenation was found to occur with formation of tetramethylhydrazene. Reaction of dimethylchloramine and dimethyl bromamine with phosphorus(III) species containing the MeO group ((MeO)(_n)PX((_3-n), X -= C1 or Ph and n = 1-3) may well have formed a phosphonium salt but the observed products were the halomethane and a phosphorus(V) species contain a P=0 bond, e.g. (MeO)(_3)P + Me(_2)NBr = Me(_2)NPO(OMe)(_2) + MeBr. In the case of the aryl and thioesters studied ((MeS)(_3)P and (PhO)(_3)P) the intermediate species are observed

Flight simulator for hypersonic vehicle and a study of NASP handling qualities

The research goal of the Human-Machine Systems Engineering Group was to study the existing handling quality studies in aircraft with sonic to supersonic speeds and power in order to understand information requirements needed for a hypersonic vehicle flight simulator. This goal falls within the NASA task statements: (1) develop flight simulator for hypersonic vehicle; (2) study NASP handling qualities; and (3) study effects of flexibility on handling qualities and on control system performance. Following the above statement of work, the group has developed three research strategies. These are: (1) to study existing handling quality studies and the associated aircraft and develop flight simulation data characterization; (2) to develop a profile for flight simulation data acquisition based on objective statement no. 1 above; and (3) to develop a simulator and an embedded expert system platform which can be used in handling quality experiments for hypersonic aircraft/flight simulation training

Novel multiplexer topologies based on coupled resonator structures

Novel multiplexer structures based on all-resonator topologies are presented here. The proposed multiplexers consist of only resonators without extra manifolds or circulators or power dividers. They can achieve various requirements of different filtering responses and arbitrary number of channels with miniaturized size. The proposed multiplexers are synthesized using optimization technique where coupling coefficients between coupled resonators are found. Different structures with various properties and responses are presented including symmetrical and asymmetrical channels. Reduction of the complexity of optimization processes is also presented

Therapeutic Effect of Curcumin, Ginger and Tamarind on Oral and Paraoral Tissues: (Histological Overview)

Background: Biocompatible substances from plant origin have been more in focus in contemporary dentistry. Aim: This review, aimed to highpoint the influence of curcumin, ginger and tamarind on different oral and paraoral tissues from histological point of view. Material and methods: A narrative review was carried out based on publications in PubMed, google and Scopus database. The documents published up to 2021 were included. The research was based on inclusion criteria of 89 studies.Results: Curcumin inhibits alveolar bone resorption, reduces inflammatory cell infiltration, aids in epithelial regeneration and improves salivary glands architecture. Ginger was found to be beneficial in re-organization of periodontal ligaments, reducing inflammatory cells and osteoclasts differentiation, as well as restoring mucosal and salivary glands configuration. On the other hand, tamarind is a potent anti-inflammatory agent in periodontitis, enhances collagen synthesis and fibroblasts proliferation, acts as a matrix for hydroxyapatite crystals growth and aids in regaining of tongue papillae. However, it may be an underlying cause for oral submucous fibrosis.Conclusions: Dental applications of curcumin, ginger and tamarind are based on their anti-inflammatory and anti-oxidant effects. Curcumin is valuable in treatment of periodontitis and wound healing. Though, ginger has regenerative ability on various tissues. Limited studies are available concerning the effect of tamarind on oral tissues

Evaluation of Biological Control Potential for Different Trichoderma Strains Against Root-Knot Nematode Meloidogyne Javanica

Twenty strains of four Trichoderma species (Trichoderma harzianum, Trichoderma viride, Trichoderma koningii and Trichoderma asperellum) were evaluated for its potential to control the root-knot nematode Meloidogyne javanica. Culture filtrates from Trichoderma strains were tested in 24-well tissue culture plates for effects on Meloidogyne javanica. Chitwood egg hatch and mobility of hatched second-stage juveniles (J2) were evaluated, all the twenty Trichoderma strains showed the ability to colonize M. javanica separated eggs and second-stage juveniles (J2) in sterile in vitro assays. T. asperellum possess the strongest egg-parasitic ability and very effective against 2nd stage larvae of M. javanica. In this investigation, randomly amplified polymorphic DNA (RAPD) markers was used to estimate the genetic variations between four strains of Trichoderma asperellum (KC898190, KC898191, KC898192 and KC898193) which were previously isolated from the rhizospheres of different plants growing in Fayoum Governorate, Egypt as a new strain of T. asperellum in Egypt. RAPD assay using 6 random primers identified T. asperellum strains with 5 specific unique markers

Influence of lysozyme utilization with lactic acid bacteria in yoghurt on some foodborne pathogens

Despite the existence of many different food preservation methods, foodborne pathogens are still the most common related problems to dairy products. Developing naturally alternative techniques to control such problems is necessary. This research was planned to assess the bacteriological quality of yoghurt samples commercially available in Kafr El-Sheikh city, Egypt. Also to study the impact of natural antibacterial agents on the inhibition of selected foodborne pathogens artificially inoculated in yoghurt samples. The obtained results revealed poor bacteriological quality of the examined yoghurt samples, as total staphylococci and coliforms were detected in 80% and 90% yoghurt samples, with mean values of 2.4 ×103±0.13× 103cfu/gm and 3.6×105± 2.4×105 MPN/gm, respectively. S. aureus was noticed in 4% of examined samples, polymerase chain reaction (PCR) confirmed the pres­ence of virulence adhesion gene (clfA) in one isolate. E. coli was detected in 14% of yoghurt samples, then serologically identified as O146:H5 (2), O111:H2 (2), O125:H11 (1), O26:H10 (1) and O158:H7 (1). Artificially inoculated yoghurt with S. aureus (7.39 log cfu/gm) and E. coli (8.3 log cfu/gm), were used to investigate the ability of hen egg-white lysozyme either with LAB classic or with ABT-5 (L. acidophilus LA5+ S. thermophiles + Bifidobacterium Bb12) starter cultures to inhibit the growth of these pathogens. During refrigerated storage, all yoghurt batches showed a reduction in pH value. It was observed that both pathogens couldn't be detected in the yoghurt batch containing LAB classic starter + heated lysozyme. Furthermore, S. aureus was completely inhibited in that containing ABT-5 cultures alone, while E. coli decreased by 6.23 log. Conversely, there was not complete inhibition in other batches containing (LAB classic starter, LAB classic starter+ native lysozyme, ABT-5 culture+ native lysozyme and ABT-5 culture+ heated lysozyme) as the reduction rate during all storage periods for S. aureus count was 1.66, 2.63, 4.47  and 4.19 log, While for E. coli count was  3.3, 3.81, 5.53 and 4.89 log,  respectively. This study highlighted the importance of adding natural antibacterial agents like lysozyme with LAB culture to yoghurt as a bio-control strategy to overcome foodborne pathogens that cause a public health hazard