Synthesis of Novel Agrochemicals as Potential Plant Immunization Agents.

The world\u27s population is expected to grow from 6 billion to about 10 billion by 2050. The greatest population increase is expected to occur in Africa, Latin America, and Asia. To feed a world with huge increases in population and to sustain the well-being of humans, a large increase in food production must be achieved. The projected increase in food production must be accomplished on the existing cultivated areas because the expansion of new land is limited by environmental concerns, urbanization and increasing water scarcity. Different compounds have been developed for the immunization of plants against several pathogens. These compounds induce systemic acquired resistance (SAR) in plants, leading to broad-based, long-lasting resistance to a wide range of pathogens. The salicylic acid binding protein 2 (SABP 2) has been identified as a key enzyme in the salicylic acid mediated pathogen resistance pathway, converting methyl salicylate (MeSA) to salicylic acid (SA), a key compound responsible for SAR . S-methyl benzo [1, 2, 3,] thiadiazole-7-carbothiate (BTH) was the first commercial compound used for plant immunization. We have synthesized and characterized some new salicylic acid derivatives [methyl-2-(2-hydroxy benzoyl thio) acetate and derivatives], and we have studied the in-vitro activity with SABP2 of BTH by HPLC analysis

Boarding secondary education in the eastern states of Nigeria : influences, characteristics and problems

The issue of boarding education at secondary level has been one of controversy in Nigeria at least throughout the period since Independence. From 1960 onwards the various authorities charged with the provision of secondary schooling have had to relate the educational legacies of colonialism, including the English boarding school model, to the needs and demands of a newly emerging and economically diversifying country.This thesis is therefore concerned inter alia to identify the influences, characteristics and problems of secondary boarding schools in Nigeria, and especially in the Eastern States of that country. It attempts first to identify significant formative influences through an historical / documentary study, and then to ascertain empirically contemporary attitudes and perceptions of the various parties to the provision and operation of such schools today. In so doing, aspects such as organisation, administration, management, discipline, values, routine, facilities and infrastructure are described and discussed.The thesis has twelve chapters, organised in three parts: Part A comprises six chapters dealing with the identification of the problem and contributing factors. Chapters One and Two outline the environmental and educational context. Chapter Three illustrates the history and nature of the problem, whilst Chapter Four provides an explanation of the research context. Chapter Five reviews some previous research on boarding and Chapter Six is a consideration of the nature and development of the most influential model, the English Public School.Part B, the development and nature of boarding in the study area deals mainly with aspects of the history and character of boarding schools in Nigeria and especially in the Eastern States. So Chapter Seven is concerned with the long period up to and including the Nigerian civil war, which ended in 1970. Chapter Eight reviews the post-war situation which is given a more detailed focus by Chapter Nine, an account of a preliminary field survey carried out by the writer in 1981.Part C of the thesis is concerned with the current attitudes of the various parties as ascertained by the writer's main empirical exercise, that is to say staff, students and parents. Chapter Ten describes the empirical methods selected and used, and is followed by Chapter Eleven which is a detailed account of the findings. Chapter Twelve is a discussion of the results obtained.The thesis concludes with a summary, and recommendations for improving provision in this sector, especially in respect of the quality of facilities and staffing. The Study confirmed what was generally assumed and suspected: that boarding school arrangements in the Eastern States of Nigeria continue to be in very high demand more than 25 years after Independence. The main conclusion was that parents, school authorities, members of the public and students, in general prefer boarding to day schools at this level despite the severe problems of plant and staff quality that are very evident.The thesis concludes with a number of alternative strategies, recommendations and comments aimed at improving the condition and provision in this sector of schooling. It is clearly not just a matter of improving physical facilities, there is urgent need for a clarification of the objectives of such provision in modern Nigeria as well as for suitable staff development programmes that will assist their realisation

KINEMATICAL RESEARCH ON 407C OF ELITE CHINESE MALE 3-M SPRINGBOARD DIVERS

INTRODUCTION: Diving is a dominant event of China in the 21th century. This research is to find some common features in kinematical parameters of elite diving athletes and thus to serve athlete training

Trace Metal Contamination Characteristics and Health Risks Assessment of Commelina africana L. and Psammitic Sandflats in the Niger Delta, Nigeria

The purpose of this study was to investigate and quantify trace metal concentrations in Commelina africana L. and psammitic sandflats from an intertidal coastal ecosystem in Niger Delta, Nigeria, and to evaluate their spatial distribution, degree of contamination, and source apportionment.The environmental risks associated with soil contamination were elaborately assessed using potential ecological risk index, sediment quality guidelines, and enrichment relative to background levels. The mean concentrations of Cd, Cr, Ni, Pb, and Zn in sandflat soil samples are 0.76 ± 9.0 × 10−2, 7.39 ± 8.7 × 10−1, 2.28 ± 0.35, 0.024 ± 4.0 × 10−3, and 74.51 ± 2.55mg/kg, respectively. Metal levels indicate strong variability with sampling sites. The order of trace metal concentrations in the Commelina africana L. samples is Zn > Ni > Cr > Pb > Cd.The concentrations varied with the sample locations; and the levels of Pb (0.05 to 0.08mg/kg) at all locations are found to be significantly below permissible level of 0.3mg/kg. Potential sources of metal loadings may be associated with localised or diffused anthropogenic activities.The average carcinogenic risks are below 1.0 × 10−6 threshold values, and the sandflat soils are not considered to pose significant health effects to children and adult males and females. However, the carcinogenicity and noncarcinogenicity risks ranking decrease following the order children > adult males > adult females. Comparatively, the hazard quotient and hazard index indicate that the psammitic sandflats might pose a health risk to children in future

Evidence against Wolbachia symbiosis in Loa loa

BACKGROUND: The majority of filarial nematode species are host to Wolbachia bacterial endosymbionts, although a few including Acanthocheilonema viteae, Onchocerca flexuosa and Setaria equina have been shown to be free of infection. Comparisons of species with and without symbionts can provide important information on the role of Wolbachia symbiosis in the biology of the nematode hosts and the contribution of the bacteria to the development of disease. Previous studies by electron microscopy and PCR have failed to detect intracellular bacterial infection in Loa loa. Here we use molecular and immunohistological techniques to confirm this finding. METHODS: We have used a combination of PCR amplification of bacterial genes (16S ribosomal DNA [rDNA], ftsZ and Wolbachia surface protein [WSP]) on samples of L. loa adults, third-stage larvae (L3) and microfilariae (mf) and immunohistology on L. loa adults and mf derived from human volunteers to determine the presence or absence of Wolbachia endosymbionts. Samples used in the PCR analysis included 5 adult female worms, 4 adult male worms, 5 mf samples and 2 samples of L3. The quality and purity of nematode DNA was tested by PCR amplification of nematode 5S rDNA and with diagnostic primers from the target species and used to confirm the absence of contamination from Onchocerca sp., Mansonella perstans, M. streptocerca and Wuchereria bancrofti. Immunohistology was carried out by light and electron microscopy on L. loa adults and mf and sections were probed with rabbit antibodies raised to recombinant Brugia malayi Wolbachia WSP. Samples from nematodes known to be infected with Wolbachia (O. volvulus, O. ochengi, Litomosoides sigmodontis and B. malayi) were used as positive controls and A. viteae as a negative control. RESULTS: Single PCR analysis using primer sets for the bacterial genes 16S rDNA, ftsZ, and WSP were negative for all DNA samples from L. loa. Positive PCR reactions were obtained from DNA samples derived from species known to be infected with Wolbachia, which confirmed the suitability of the primers and PCR conditions. The quality and purity of nematode DNA samples was verified by PCR amplification of 5S rDNA and with nematode diagnostic primers. Additional analysis by 'long PCR' failed to produce any further evidence for Wolbachia symbiosis. Immunohistology of L. loa adults and mf confirmed the results of the PCR with no evidence for Wolbachia symbiosis. CONCLUSION: DNA analysis and immunohistology provided no evidence for Wolbachia symbiosis in L. loa

Prevalence of soil transmitted helminths and impact of Albendazole on parasitic indices in Kotto Barombi and Marumba II villages (South-West Cameroon)

This study assessed the actual prevalence of geohelminths and the impact of albendazole on parasitic indices in Kotto Barombi and Marumba II. Stools samples were collected from 420 school children and examined using the Kato-katz faecal technique. Participants were treated with 600 mg of albendazole. Baseline prevalence of infections and mean parasite loads were 26.4% and 6226.9e/g (Ascaris lumbricoides), 31.0% and 252.4 e/g (Trichuris trichiura), and 1.4% and 468.0e/g (Necator americanus). Four children (0.9%) were infected with Strongyloides stercoralis. A significant difference of prevalence was observed between the two villages for A. lumbricoides (P = 0.0001) and T. trichiura (P = 0.0005), and parasite loads for T. trichiura (P = 0.0001). Single infection (T. trichiura or A. lumbricoides) and double infection (A. lumbricoides - T. trichiura) were more prevalent. Post treatment control showed a decrease of prevalence and mean parasite load to 24.4% and 2969.5e/g (A. lumbricoides), and 24.0% and 112.8e/g (T. trichiura), and 0.0% for N. americanus and S. stercoralis. Efficacy and egg reduction rates were 84.6% and 55.3% (T. trichiura), 82.0% and 52.2% (A. lumbricoides), and 100.0% for N. americanus and S. stercoralis. These results suggest that geohelminths infections remain a serious health problem in school children in Kotto Barombi focus

Distribution and risk assessment of trace metals in Leptodius exarata, surface water and sediments from Douglas Creek, Qua Iboe estuary

Five trace metals in Leptodius exarata, epipellic sediments and surface water from an intertidal ecosystem in Niger Delta (Nigeria) were investigated to evaluate their spatial distribution, degree of contamination, ecological and health risks. Results show Cd (cadmium), Cr (chromium), Ni (nickel), Pb (lead) and Zn (zinc) concentrations in sediment ranged between 0.550 – 1.142, 9.57 – 15.95, 9.15 – 13.96, 2.00 – 8.90 and 91.5 – 121.6 mg/kg dw, respectively; while L. exarata tissue metal content vary from 0.162 – 0.931, 3.81 – 8.62, 4.45 – 17.15, 1.90 – 7.35, and 125.55 – 269.75 mg/kg, dw, respectively. The bioconcentration factor ranking for trace metals followed the sequence Zn>Ni>Pb >Cr>Cd. High biota to sediment accumulation factor (BSAF) in L. exarata reveals a sentinel metal bioindicator. Sediments from most sites were uncontaminated to moderately contaminated (geoaccumulation, Igeo > 0) with Cd and Zn associated with anthropogenic intrusions. Low mean-ERM (effect range-median) and mean-PEL (probable effect level) quotients of sediments are observed, indicating low–medium degree of contamination with 30% and 21% probability of being toxic. The multi-metal potential ecological risk index (RI) for the intertidal ecosystem indicates low–moderate risk. Health risks associated with crabs (L. exarata) consumption are significant in children than adults

Understanding of research, genetics and genetic research in a rapid ethical assessment in north west Cameroon

BACKGROUND There is limited assessment of whether research participants in low-income settings are afforded a full understanding of the meaning of medical research. There may also be particular issues with the understanding of genetic research. We used a rapid ethical assessment methodology to explore perceptions surrounding the meaning of research, genetics and genetic research in north west Cameroon. METHODS Eleven focus group discussions (including 107 adults) and 72 in-depth interviews were conducted with various stakeholders in two health districts in north west Cameroon between February and April 2012. RESULTS Most participants appreciated the role of research in generating knowledge and identified a difference between research and healthcare but gave varied explanations as to this difference. Most participants' understanding of genetics was limited to concepts of hereditary, with potential benefits limited to the level of the individual or family. Explanations based on supernatural beliefs were identified as a special issue but participants tended not to identify any other special risks with genetic research. CONCLUSION We demonstrated a variable level of understanding of research, genetics and genetic research, with implications for those carrying out genetic research in this and other low resource settings. Our study highlights the utility of rapid ethical assessment prior to complex or sensitive research