Promoting sustainability: Efficacy and adoption of tobacco-based insecticides in Nigeria

The promotion of technologies seen to be aiding in the attainment of agricultural sustainability has been Popular amongst Northern-based development donors for many years. One of these, botanical insecticides (e.g., those based on neem, Pyrethrum and tobacco) have been a particular favorite as they are equated with being 'natural' and hence less damaging to human health and the environment. This paper describes the outcome of interactions between one non-government organisation (NGO), the Diocesan Development Services (DDS), based in Kogi State, Nigeria, and a major development donor based in Europe that led to the establishment of a programme designed to promote the Virtues of a tobacco-based insecticide to small-scale farmers. The Tobacco Insecticide Programme (TIP) began in the late 1980s and ended in 200 1, absorbing significant quantities of resource in the process. TIP began with exploratory investigations of efficacy on the DDS seed multiplication farm followed by stages of researcher-managed and farmer-managed on-farm trials. A survey in 2002 assessed adoption of the technology by farmers. While yield benefits from using the insecticide were nearly always positive and statistically significant relative to an untreated control, they were not as good as commercial insecticides. However, adoption of the tobacco insecticide by local farmers was poor. The paper discusses the reasons for poor adoption, including relative benefits in gross margin, and uses the TIP example to explore the differing power relationships that exist between donors, their field partners and farmers. (C) 2004 by The Haworth Press, Inc. All rights reserved.

Tissue culture propagation alters plant-microbe interactions in tobacco rhizosphere

We have compared properties of roots from different lines (genotypes) of tobacco raised either in tissue culture or grown from seed. The different lines included unmodified plants and plants modified to express reduced activity of the enzyme cinnamoyl-CoA reductase, which has a pivotal role in lignin biosynthesis. The size and structure of the rhizosphere microbial community, characterized by adenosine triphosphate and phospholipid fatty acid analyses, were related to root chemistry (specifically the soluble carbohydrate concentration) and decomposition rate of the roots. The root material from unmodified plants decomposed faster following tissue culture compared with seed culture, and the faster decomposing material had significantly higher soluble carbohydrate concentrations. These observations are linked to the larger microbial biomass and greater diversity of the rhizosphere communities of tissue culture propagated plants.

Time patterns in UK demand for alcohol and tobacco: an application of the EM algorithm

Capturing the pattern of structural change is a relevant task in applied demand analysis, as consumer preferences may vary significantly over time. Filtering and smoothing techniques have recently played an increasingly relevant role. A dynamic Almost Ideal Demand System with random walk parameters is estimated in order to detect modifications in consumer habits and preferences, as well as changes in the behavioural response to prices and income. Systemwise estimation, consistent with the underlying constraints from economic theory, is achieved through the EM algorithm. The proposed model is applied to UK aggregate consumption of alcohol and tobacco, using quarterly data from 1963 to 2003. Increased alcohol consumption is explained by a preference shift, addictive behaviour and a lower price elasticity. The dynamic and time-varying specification is consistent with the theoretical requirements imposed at each sample point. (c) 2005 Elsevier B.V. All rights reserved.

The cell wall and secretory proteome of a tobacco cell line synthesising secondary wall

The utility of plant secondary cell wall biomass for industrial and biofuel purposes depends upon improving cellulose amount, availability and extractability. The possibility of engineering such biomass requires much more knowledge of the genes and proteins involved in the synthesis, modification and assembly of cellulose, lignin and xylans. Proteomic data are essential to aid gene annotation and understanding of polymer biosynthesis. Comparative proteomes were determined for secondary walls of stem xylem and transgenic xylogenic cells of tobacco and detected peroxidase, cellulase, chitinase, pectinesterase and a number of defence/cell death related proteins, but not marker proteins of primary walls such as xyloglucan endotransglycosidase and expansins. Only the corresponding detergent soluble proteome of secretory microsomes from the xylogenic cultured cells, subjected to ion-exchange chromatography, could be determined accurately since, xylem-specific membrane yields were of poor quality from stem tissue. Among the 109 proteins analysed, many of the protein markers of the ER such as BiP, HSP70, calreticulin and calnexin were identified, together with some of the biosynthetic enzymes and associated polypeptides involved in polymer synthesis. However 53% of these endomembrane proteins failed identification despite the use of two different MS methods, leaving considerable possibilities for future identification of novel proteins involved in secondary wall polymer synthesis once full genomic data are available.

Modification of hemicellulose content by antisense down-regulation of UDP-glucuronate decarboxylase in tobacco and its consequences for cellulose extractability

Extractability and recovery of cellulose from cell walls influences many industrial processes and also the utilisation of biomass for energy purposes. The utility of genetic manipulation of lignin has proven potential for optimising such processes and is also advantageous for the environment. Hemicelluloses, particularly secondary wall xylans, also influence the extractability of cellulose. UDP-glucuronate decarboxylase produces UDP-xylose, the precursor for xylans and the effect of its down-regulation on cell wall structure and cellulose extractability in transgenic tobacco has been investigated. Since there are a number of potential UDP-glucuronate decarboxylase genes, a 490 bp sequence of high similarity between members of the family, was chosen for general alteration of the expression of the gene family. Sense and antisense transgenic lines were analysed for enzyme activity using a modified and optimised electrophoretic assay, for enzyme levels by western blotting and for secondary cell wall composition. Some of the down-regulated antisense plants showed high glucose to xylose ratios in xylem walls due to less xylose-containing polymers, while arabinose and uronic acid contents, which could also have been affected by any change in UDP-xylose provision, were unchanged. The overall morphology and stem lignin content of the modified lines remained little changed compared with wild-type. However, there were some changes in vascular organisation and reduction of xylans in the secondary walls was confirmed by immunocytochemistry. Pulping analysis showed a decreased pulp yield and a higher Kappa number in some lines compared with controls, indicating that they were less delignified, although the level of residual alkali was reduced. Such traits probably indicate that lignin was less available for removal in a reduced background of xylans. However, the viscosity was higher in most antisense lines, meaning that the cellulose was less broken-down during the pulping process. This is one of the first studies of a directed manipulation of hemicellulose content on cellulose extractability and shows both positive and negative outcomes.

Modification of hemicellulose content by antisense down-regulation of UDP-glucuronate decarboxylase in tobacco and its conscequence for cellulose extractability

Extractability and recovery of cellulose from cell walls influences many industrial processes and also the utilisation of biomass for energy purposes. The utility of genetic manipulation of lignin has proven potential for optimising such processes and is also advantageous for the environment. Hemicelluloses, particularly secondary wall xylans, also influence the extractability of cellulose. UDP-glucuronate decarboxylase produces UDP-xylose, the precursor for xylans and the effect of its down-regulation on cell wall structure and cellulose extractability in transgenic tobacco has been investigated. Since there are a number of potential UDP-glucuronate decarboxylase genes, a 490 bp sequence of high similarity between members of the family, was chosen for general alteration of the expression of the gene family. Sense and antisense transgenic lines were analysed for enzyme activity using a modified and optimised electrophoretic assay, for enzyme levels by western blotting and for secondary cell wall composition. Some of the down-regulated antisense plants showed high glucose to xylose ratios in xylem walls due to less xylose-containing polymers, while arabinose and uronic acid contents, which could also have been affected by any change in UDP-xylose provision, were unchanged. The overall morphology and stem lignin content of the modified lines remained little changed compared with wild-type. However, there were some changes in vascular organisation and reduction of xylans in the secondary walls was confirmed by immunocytochemistry. Pulping analysis showed a decreased pulp yield and a higher Kappa number in some lines compared with controls, indicating that they were less delignified, although the level of residual alkali was reduced. Such traits probably indicate that lignin was less available for removal in a reduced background of xylans. However, the viscosity was higher in most antisense lines, meaning that the cellulose was less broken-down during the pulping process. This is one of the first studies of a directed manipulation of hemicellulose content on cellulose extractability and shows both positive and negative outcomes.

Atopococcus tabaci gen. nov., sp nov., a novel Gram-positive, catalase-negative, coccus-shaped bacterium isolated from tobacco

A novel Gram-positive, aerobic, catalase-negative, coccus-shaped organism originating from tobacco was characterized using phenotypic and molecular taxonomic methods. The organism contained a cell wall murein based on L-lysine (variation A4 alpha, type L-lysine-L-glutamic acid), synthesized long-chain cellular fatty acids of the straight-chain saturated and monounsaturated types (with C(16:1)omega 9, C-16:0 and C(18:1)omega 9 predominating) and possessed a DNA G+C content of 46 mol%. Based on morphological, biochemical and chemical characteristics, the coccus-shaped organism did not conform to any presently recognized taxon. Comparative 16S rRNA gene sequencing studies confirmed the distinctiveness of the unknown coccus, with the bacterium displaying sequence divergence values of greater than 7% with other recognized Gram-positive taxa. Treeing analysis reinforced its distinctiveness, with the unidentified organism forming a relatively long subline branching at the periphery of an rRNA gene sequence cluster which encompasses the genera Alloiococcus, Allolustis, Alkalibacterium, Atopostipes, Dolosigranulum and Marinilactibacillus. Based on phenotypic and molecular phylogenetic evidence, it is proposed that the unknown organism from tobacco be classified as a new genus and species, Atopococcus tabaci gen. nov., sp. nov. The type strain of Atopococcus tabaci is CCUG 48253(T) (= CIP 108502(T)).

Detection of tobacco mosaic tobamovirus in cigarettes through RT-PCR

TMV was tried to recover from a variety of branded cigarettes and cigars. Tobacco from six different brands of cigarettes and cigar were processed and reverse transcriptase polymerase chain reaction was employed for the detection of TMV. RTPCR confirmed the presence of TMV in tobacco from one brand of cigarette and one brand of cigar. Bean plants (Phaseolus vulgaris) were inoculated manually with tobacco sap of cigarettes resulting in the production of localized disease lesions. Together, these results showed that tobacco used to make cigarettes and cigars can function as an effective disease vector, potentially aiding the movement of infectious TMV between countries. This is an important finding prompting a need to test smoking tobacco for other virus particles that infect tobacco plants and survive processing as well as considering biosecurity measures to limit virus transmission

Early Changes in Gene Expression Induced by Tobacco Smoke: Evidence for the Importance of Estrogen within Lung Tissue

Lung cancer is the leading cause of cancer deaths in the United States, surpassing breast cancer as the primary cause of cancer-related mortality in women. The goal of the present study was to identify early molecular changes in the lung induced by exposure to tobacco smoke and thus identify potential targets for chemoprevention. Female A/J mice were exposed to either tobacco smoke or HEPA-filtered air via a whole-body exposure chamber (6 h/d, 5 d/wk for 3, 8, and 20 weeks). Gene expression profiles of lung tissue from control and smoke-exposed animals were established using a 15K cDNA microarray. Cytochrome P450 1b1, a phase I enzyme involved in both the metabolism of xenobiotics and the 4-hydroxylation of 17 beta-estradiol (E(2)), was modulated to the greatest extent following smoke exposure. A panel of 10 genes were found to be differentially expressed in control and smoke-exposed lung tissues at 3, 8, and 20 weeks (P < 0.001). The interaction network of these differentially expressed genes revealed new pathways modulated by short-term smoke exposure, including estrogen metabolism. In addition, E(2) was detected within murine lung tissue by gas chromatography-coupled mass spectrometry and immunohistochemistry. Identification of the early molecular events that contribute to lung tumor formation is anticipated to lead to the development of promising targeted chemopreventive therapies. In conclusion, the presence of E2 within lung tissue when combined with the modulation of cytochrome P450 1b1 and other estrogen metabolism genes by tobacco smoke provides novel insight into a possible role for estrogens in lung cancer. Cancer Prev Res; 3(6); 707-17. (C) 2010 AACR.

Actions of octocoral and tobacco cembranoids on nicotinic receptors

Nicotinic acetylcholine receptors (AChRs) are pentameric proteins that form agonist-gated cation channels through the plasma membrane. AChR agonists and antagonists are potential candidates for the treatment of neurodegenerative diseases. Cembranoids are naturally occurring diterpenoids that contain a 14-carbon ring. These diterpenoids interact with AChRs in complex ways: as irreversible inhibitors at the agonist sites, as noncompetitive inhibitors, or as positive modulators, but no cembranoid was ever shown to have agonistic activity on AChRs. The cembranoid eupalmerin acetate displays positive modulation of agonist-induced currents in the muscle-type AChR and in the related gamma-aminobutyric acid (GABA) type A receptor. Moreover, cembranoids display important biological effects, many of them mediated by nicotinic receptors. Cembranoids from tobacco are neuroprotective through a nicotinic anti-apoptotic mechanism preventing excitotoxic neuronal death which in part could result from anti-inflammatory properties of cembranoids. Moreover, tobacco cembranoids also have anti-inflammatory properties which could enhance their neuroprotective properties. Cembranoids from tobacco affect nicotine-related behavior: they increase the transient initial ataxia caused by first nicotine injection into naive rats and inhibit the expression of locomotor sensitization to repeated injections of nicotine. In addition, cembranoids are known to act as anti-tumor compounds. In conclusion, cembranoids provide a promising source of lead drugs for many clinical areas, including neuroprotection, smoking-cessation, and anti-cancer therapies. (C) 2009 Elsevier Ltd. All rights reserved.

Preventing tobacco use and harm: what is evidence based policy?

The majority of tobacco users commence in early to mid-adolescence. Tobacco smoking can be characterised as a chronic, relapsing disorder. While risk increases with amount smoked, there is no safe level of use (i.e., all use is risky). Duration of use is the most important predictor of premature death with the majority of excess morbidity and mortality avoidable if people quit before middle age. Investment in initiatives that reduce smoking among pregnant women and those at risk of cardiovascular disease provide quickest returns -in reduced health care episodes and expenditure.  Measures that successfully reduce smoking among parents probably reduce smoking uptake by children, and high levels of smoking among both children and parents appear to be associated with higher levels of illicit drug use.
The evidence base for pharmcotherapies in the treatment of tobacco dependence is very strong. Population-level initiatives such as tax increases, mass media-led campaigns and smoke-free policies are all highly cost-effective in reducing population-smoking levels, including among children and young people.
Australian tobacco control initiatives have been based on "social ecology" conceptualisations of the problem, which acknowledge the pivotal role of the media in shaping social values, and public and political opinion.
Broad social change, as well as more focused prevention and cessation initiatives, has drawn heavily on research findings from the behavioural sciences. Considerable effort (mainly, in Australian, in the NGO sector) has gone into documenting policy inputs and monitoring impact and outcome measures.
This chapter discusses why conceptualising tobacco-related harm from legal, economic and social policy perspectives should also help build support for tobacco control policy among academic and practising economists and lawyers, and in the business, welfare and government sectors.

Fighting a tobacco rollback : a political analysis of the 1994 contraband crisis in Canada

We identify factors that led a regional government (Quebec, Canada) to opt for a reduction of its tobacco tax to combat tobacco smuggling. Then we explore the fallout of Quebec's tobacco-tax rollback on its tobacco control policy. We conducted qualitative research using a case-study design and multiple sources of data. We applied the Advocacy Coalition Framework in respect of data collection and analysis. Advocates of the tobacco-tax rollback framed the contraband problem in a way that won the support of an array of actors. However, anti-tobacco activists succeeded in convincing the government to invest more in tobacco control. The new resources were instrumental in enhancing the activists' ability to promote legislative measures. Our approach sheds light on the tobacco industry's strategy to have governments reducing their tobacco tax. Quebec offers an example of how tobacco control activists can transform defeat into the cornerstone of a comprehensive tobacco control policy.

The potential for tobacco control to reduce PBS costs for smoking-related cardiovaccular disease

Objective: To estimate Pharmaceutical Benefits Scheme (PBS) subsidies for drugs to treat smoking-related cardiovascular disease (CVD) in 2001-02, and over the period of the government's Intergenerational Report (IGR), assuming current smoking prevalence rates and a 5% absolute reduction.

Design and setting: An Australian epidemiological study, using prescribing data, aetiological fraction methodology, and IGR trends.

Main outcome measures: Estimated smoking-related PBS subsidy costs in 2001-02 and predicted cumulative subsidies until 2041-42, under current and reduced smoking prevalence assumptions.

Results: The PBS costs of smoking-related CVD in 2001-02 were $126 million, 9.77% of the cost of drugs for CVD and 2.96% of total PBS subsidies. The cumulative difference in these costs over the 40-year period with a 5% drop in smoking prevalence was predicted to be $4.5 billion, a 17% reduction. The saving would be $1.14 billion discounting future costs at 5% per year.

Conclusions: Further investment in tobacco control interventions could curb the increasing cost of the PBS and contribute to government efforts to ensure the viability of Australia's healthcare-financing programs. The net present value of a campaign to reduce smoking prevalence was estimated at $1 billion, with an internal rate of return of 33%.