Characterization of L-Serine Deaminase and its Potential Role in the Pathogenicity of Pseudomonas aeruginosa

All pathogens require high energetic influxes to counterattack the host immune system and without this energy bacterial infections are easily cleared. This study is an investigation into one highly bioenergetic pathway in Pseudomonas aeruginosa involving the amino acid L-serine and the enzyme L-serine deaminase (L-SD). P. aeruginosa is an opportunistic pathogen causing infections in patients with compromised immune systems as well as patients with cystic fibrosis. Recent evidence has linked L-SD directly to the pathogenicity of several organisms including but not limited to Campylobacter jejuni, Mycobacterium bovis, Streptococcus pyogenes, and Yersinia pestis. We hypothesized that P. aeruginosa L-SD is likely to be critical for its virulence. Genome sequence analysis revealed the presence of two L-SD homo logs encoded by sdaA and sdaB. We analyzed the ability of P. aeruginosa to utilize serine and the role of SdaA and SdaB in serine deamination by comparing mutant strains of sdaA (PAOsdaA) and sdaB (PAOsdaB) with their isogenic parent P. aeruginosa P AO 1. We demonstrated that P. aeruginosa is unable to use serine as a sole carbon source. However, serine utilization is enhanced in the presence of glycine and this glycine-dependent induction of L-SD activity requires the inducer serine. The amino acid leucine was shown to inhibit L-SD activity from both SdaA and SdaB and the net contribution to L-serine deamination by SdaA and SdaB was ascertained at 34% and 66 %, respectively. These results suggest that P. aeruginosa LSD is quite different from the characterized E. coli L-SD that is glycine-independent but leucine-dependent for activation. Growth mutants able to use serine as a sole carbon source were also isolated and in addition, suicide vectors were constructed which allow for selective mutation of the sdaA and sdaB genes on any P. aeruginosa strain of interest. Future studies with a double mutant will reveal the importance of these genes for pathogenicity.

Data compilation on the biological response to ocean acidification: environmental and experimental context of data sets and related literature

The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

Use of farmer-prioritized vertisol management options for enhanced green gram and tomato production in central Kenya

Green grams (Phaseolus aures L.) and tomato (Solanum lycopersicum L) are widely grown in the vertisols of the Mwea Irrigation Scheme alongside the rice fields. Green grams can fix nitrogen (biological nitrogen fixation) and are grown for its highly nutritious and curative seeds while tomatoes are grown for its fruit rich in fibres, minerals and vitamins. The two can be prepared separately or together in a variety of ways including raw salads and/or cooked/fried. They together form significant delicacies consumed with rice which is the major cash crop grown in the black cotton soils. The crops can grow well in warm conditions but tomato is fairly adaptable except under excessive humidity and temperatures that reduce yields. Socio-economic prioritization by the farming community and on-farm demonstrations of soil management options were instituted to demonstrate enhanced green gram and tomato production in vertisol soils of lower parts of Kirinyaga County (Mwea East and Mwea West districts). Drainage management was recognized by the farming community as the best option although a reduced number of farmers used drainage and furrows/ridges, manure, fertilizer and shifting options with reducing order of importance. Unavailability of labour and/or financial cost for instituting these management options were indicated as major hindrances to adopt the yield enhancing options. Labour force was contributed to mainly by the family alongside hiring (64.2%) although 28% and 5.2% respectively used hired or family labour alone. The female role in farming activities dominated while the male role was minimal especially at weeding. The youth role remained excessively insignificant and altogether absent at marketing. Despite the need for labour at earlier activities (especially when management options needed to be instituted) it was at the marketing stage that this force was directed. Soils were considered infertile by 60% but 40% indicated that their farms had adequate fertility. Analysis showed that ridging and application of farm yard manure and fertilizer improved fertility, crop growth and income considerably. Phosphate and zinc enhancement reduced alkalinity and sodicity. Green gram and tomato yields increased under ridges and farm yard manure application by 17-25% which significantly enhanced household income.

Developing and Delivering L&D Solutions for International Markets

In Chapter 8, ‘Developing and delivering L&D solutions for international markets’, Sa’ad Ali and I examine how different dynamics within and amongst countries can impact the development and delivery of L&D. We build upon the previous chapters, in particular Chapters 5 to 7 that discussed how L&D solutions may be developed in consideration of enhancing engagement, the digital world, and collective and social learning. In doing so, we examine how the effectiveness, and even appropriateness of the concepts discussed in these chapters, may be contingent on country-specific factors such as culture.

Contribution of plant phytochemicals to organic homeostasis: focus on the aging process and opportunistic infections

Aging process is conceived as a normal stage during human life cycle, but it is also considered a hot topic among scientists and medical community. Alarming rates of premature aging and oxidative stress-related diseases have increasingly affect human individuals. Stress, pollution and exposition to chemical substances are considered the main triggering factors for those conditions; in addition, they also suppress the immune system and, therefore, improve organic vulnerability and occurrence of opportunistic infections [I]. Apart from the associated morbidity and mortality, the increasing rates of antimicrobial resistance improve the severity of the clinical conditions [2]. Botanical preparations possess a multitude of bioactive properties, namely acting as antimicrobials, antioxidants, and homeostasis modulators. Thus, upcoming alternatives, mainly based in plant phytochemicals, are necessary to improve the wellbeing as also life expectancy of individuals. The present study aims to evaluate and to compare both antioxidant and antimicrobial properties of plant extracts rich in phenolic compounds. Among the tested plants, Glycyrrhiza glabra L. (licorice) evidenced the most pronounced free radicals scavenging and antimicrobial effects, followed by Salvia officina/is L. (sage), Thymus vulgaris L. (thyme) and Origanum vulgare L. (oregano). Eucalyptus globulus Labill. (blue gum) and Juglans regia L. (walnut) also showed a high effect, while Pterospartum tridentatum (L.) Willk. (carqueja) and Rubus ulmifolius Schott (elm leaf blackberry) displayed moderate effects, and lastly, Tabebuia impetigirwsa (Mart. ex DC) Standley (pau d'arco), Foeniculum vulgare Miller (fennel), Rosa canina L. (rose hips) and Matricaria recutita L. (chamomile) gave only slight effects. In general, the most pronounced bioactivities were observed in the plant preparations (infusion>decoction>hydromethanolic extract) with higher levels of phenolic compounds (both flavonoids and phenolic acids). The observed synergisms between the phenolic compounds present in the extracts highlight the use of phytochemicals as future health promoters. However, further studies are necessary to understand the effective mode of action of individual phenolic constituents as also the existence of polyvalence relationships between them.

Relations between zero-inflated variables in trials with horticultural crops

Certain characteristics of some vegetable crops allow multiple harvests during the production cycle; however, to our knowledge, no study has described the behavior of fruit production with progression of the production cycle in vegetable crops with multiple harvests that present data overdispersion. We aimed to characterize the data overdispersion of zero-inflated variables and identify the behavior of these variables during the production cycle of several vegetable crops with multiple harvests. Data from 11 uniformity trials were used without applying treatments; these comprise the database from the Experimental Plants Group at the Federal University of Santa Maria, Brazil. The trials were conducted using four horticultural species grown during different cultivation seasons, cultivation environments, and experimental structures. Although at each harvest, a larger number of basic units with harvest fruit was observed than units without harvest fruit, the basic unit percentage without fruit was high, generating an overdispersion within each individual harvest. The variability within each harvest was high and increased with the evolution of the production cycle of Capsicum annuum, Solanum lycopersicum var. cerasiforme, Phaseolus vulgaris, and Cucurbita pepo species. However, the correlation coefficient between the mean weight and number of harvest fruits tended to remain constant during the crop production cycle. These behaviors show that harvest management should be done individually, at each harvest, such that data overdispersion is reduced.

Effect of myrrh and thyme on Trichinella spiralis enteral and parenteral phases with inducible nitric oxide expression in mice

Trichinellosis is a serious disease with no satisfactory treatment. We aimed to assess the effect of myrrh ( Commiphora molmol ) and, for the first time, thyme ( Thymus vulgaris L.) against enteral and encysted (parenteral) phases of Trichinella spiralis in mice compared with albendazole, and detect their effect on inducible nitric oxide synthase (iNOS) expression. Oral administration of 500 mg/kg of myrrh and thyme led to adult reduction (90.9%, 79.4%), while 1,000 mg/kg led to larvae reduction (79.6%, 71.3%), respectively. Administration of 50 mg/kg of albendazole resulted in adult and larvae reduction (94.2%, 90.9%). Positive immunostaining of inflammatory cells infiltrating intestinal mucosa and submucosa of all treated groups was detected. Myrrh-treated mice showed the highest iNOS expression followed by albendazole, then thyme. On the other hand, both myrrh and thyme-treated groups showed stronger iNOS expression of inflammatory cells infiltrating and surrounding encapsulated T. spiralis larvae than albendazole treated group. In conclusion, myrrh and thyme extracts are highly effective against both phases of T. spiralis and showed strong iNOS expressions, especially myrrh which could be a promising alternative drug. This experiment provides a basis for further exploration of this plant by isolation and retesting the active principles of both extracts against different stages of T. spiralis.

Estudos bioecológicos da mosca mineira Liriomyza (diptera: agromyzidae) e dos seus parasitóides, em culturas protegidas, no Algarve

Tese de dout. em Ciências Agrárias, especialidade Protecção de Plantas, Faculdade de Engenharia e Recursos Naturais, Univ. do Algarve, 2001

Drought impact on rainfed common bean production areas in Brazil.

Common bean production in Goiás, Brazil is concentrated in the same geographic area, but spread acrossthree distinct growing seasons, namely, wet, dry and winter. In the wet and dry seasons, common beansare grown under rainfed conditions, whereas the winter sowing is fully irrigated. The conventional breed-ing program performs all varietal selection stages solely in the winter season, with rainfed environmentsbeing incorporated in the breeding scheme only through the multi environment trials (METs) wherebasically only yield is recorded. As yield is the result of many interacting processes, it is challengingto determine the events (abiotic or biotic) associated with yield reduction in the rainfed environments(wet and dry seasons). To improve our understanding of rainfed dry bean production so as to produceinformation that can assist breeders in their efforts to develop stress-tolerant, high-yielding germplasm,we characterized environments by integrating weather, soil, crop and management factors using cropsimulation models. Crop simulations based on two commonly grown cultivars (Pérola and BRS Radi-ante) and statistical analyses of simulated yield suggest that both rainfed seasons, wet and dry, can bedivided in two groups of environments: highly favorable environment and favorable environment. Forthe wet and dry seasons, the highly favorable environment represents 44% and 58% of production area,respectively. Across all rainfed environment groups, terminal and/or reproductive drought stress occursin roughly one fourth of the seasons (23.9% for Pérola and 24.7% for Radiante), with drought being mostlimiting in the favorable environment group in the dry TPE. Based on our results, we argue that eventhough drought-tailoring might not be warranted, the common bean breeding program should adapttheir selection practices to the range of stresses occurring in the rainfed TPEs to select genotypes moresuitable for these environments.

Liver injury from ampicillin-induced intestinal microbiota distresses in rats fed carbohydrate- and protein-rich diets

Purpose: To investigate the effect of ampicillin on rat intestinal microflora and liver in the presence of high carbohydrate and protein diets. Methods: Male Wistar albino rats were divided into four groups. The first group served as the control, the second group was treated with ampicillin (50 mg/kg for 3 weeks) and fed with a standard diet, while the third and fourth groups were treated with the same dose of ampicillin and fed with acarbohydrateand protein-rich diets, respectively, to observe the effect of diet on gut flora and liver. Fecal specimens were collected and used for qualitative determination of gut microbiota composition. Serum hepatospecific markers (AST, ALT and ALP) were estimated. The antioxidant status of liver tissues was estimated for GSH, MDA, GST, LDH and vitamin C l, in addition to sodium and potassium. Results: Administration of orogastric dose of ampicillin for 3 weeks induced inhibition of E.coli, yeasts, total anaerobes, and anaerobic lactobacilli with new growth of P. vulgaris and K. pneumonia. The levels of serum AST, ALT and ALP showed significant (p Ë‚ 0.05) increase to 163, 112.38 and 115.35 %, respectively in ampicillin-treated animals, compared to control. Also significant (p Ë‚ 0.05) increase in lipid peroxidation (120 %) and LDH (111 %) coupled with significant (p Ë‚ 0.05) decrease in glutathione (74.57 %), vitamin C (63.49 %) and glutathione S-transferase (41.51 %) were observed in ampicillintreated groups. No significant variation (p Ë‚ 0.05) in sodium and potassium levels were found between control and the treated group after 3 weeks of treatment. Conclusion: These results confirm that extended ampicillin therapy disrupts gut flora, which results in liver injury; hence, overuse of antibiotics should be avoid.

Major loci controlling resistance to the angular leaf spot of common bean.

Based on the evidences presented in this paper, results from classical genetic studies, fine-mapping information and physical position analysis using the reference genome sequence of P. vulgaris, the BIC Genetic Committee has formally accepted the proposed new gene symbols.

Marker-assisted selection integrated to the embrapa common bean breeding program.

The establishment of a specific Marker-Assisted Selection Facility at the Embrapa Rice and Beans Biotechnology Laboratory, in 2014, has better supported the routine analysis with molecular markers demanded by the Embrapa Common Bean Breeding Program. In addition, it has also supported other Embrapa plant breeding programs, such as rice and cotton.

L'Afrique du Sud post-apartheid : le temps de la reconstruction, des réformes et des mutations à travers le Globe and Mail de Toronto et le Times de Londres (1994-2004)

La décennie 1994-2004 est d’une importance majeure pour l’Afrique du Sud nouvellement démocratique. Au cours de cette période, le pays jette les bases de sa reconstruction à travers la mise en place de réformes politiques, économiques et sociales afin de combattre les méfaits de quarante années d’apartheid et de poser les jalons de son développement. Dans ce contexte, les médias internationaux ont porté une attention particulière à ces nombreux changements, plus spécifiquement la presse écrite canadienne et britannique, en particulier le Globe and Mail et le Times. Notre mémoire s’intéresse donc au traitement fait par ces deux quotidiens, l’un torontois l’autre londonien, de la reconstruction sud-africaine et ce, à travers l’analyse de thèmes précis et de ses réformes marquantes. Il sera plus spécifiquement question des réformes politiques et constitutionnelles avec la figure de Nelson Mandela, héros de la lutte contre l’apartheid, père de la « nation arc-en-ciel » ainsi que celle de son successeur à la présidence sud-africaine en 1999, Thabo Mbéki. Aussi, la Commission Vérité et Réconciliation et la nouvelle Constitution, toutes deux mises en place durant l’année 1996 sont majeures puisqu’elles dictent la nouvelle identité donnée au pays. Les réformes socioéconomiques de la reconstruction ont également attirés l’attention de nos deux journaux. Particulièrement, nous analyserons les points de vue de ceux-ci concernant le Reconstruction and Development Programme (RDP) ainsi que de la « discrimination positive » et du Black Economic Empowerment (BEE), deux mesures censées contribuer à l’amélioration de la qualité de vie de la population et à effacer les profondes inégalités socioéconomiques léguées par l’apartheid. Or, cet espoir d’une vie meilleure laisse rapidement place à un désenchantement. La forte criminalité et la dramatique explosion du VIH-sida dans une nouvelle Afrique du Sud qui cherche à se reconstruire a beaucoup retenu l’attention du Globe and Mail et du Times. Ces deux défis de taille s’avèrent être l’envers de la médaille du miracle sud-africain et ne manquent pas d’attirer l’attention des deux journaux, mettant clairement en évidence les « ratés » socioéconomiques » de la reconstruction.

Nutritional technological characterization and secondary metabolites in stored carioca bean cultivars.

The recommendation of bean cultivars and the use of appropriate storage techniques allow the quality characteristics of these grains to be preserved for human consumption. The aim of this study was to characterize the effects of storage on three cultivars of the common carioca bean in raw form and to determine the relationships between storage time and technological quality parameters involved in the darkening and hardening of grains, the chemical composition of the beans and the presence of secondary metabolites. The experiment followed a completely randomized design (CRD) with a full factorial scheme consisting of two factors: bean cultivars, with three levels and storage time, with five levels. The color parameters and the storage times significantly differed between the cultivars. The cooking time, when compared to the water absorption index, indicated that the cultivars had, on average, a high percentage of moisture (>95%) and an average cooking time of 17 min., this applies to the control, while values increase during the storage time. Storage under ambient conditions led to a reduction in grain brightness parameters, characterized by darkening and hardening; no reduction in protein and mineral content; and an increase in iron, phosphorous, tannin, and phytic acid contents at 180 days.

Growth, nutrient accumulation in leaves and grain yield of super early genotypes of common bean.

There is a lack of researches that evaluate the development and nutrient accumulation in super early genotypes of common bean for the elaboration of fertilization programs. This study aimed at characterizing the development; N, P, K, Ca and Mg accumulation by leaves; grain yield; and yield components of super early genotypes of common bean. Field experiments were conducted in a randomized blocks design, with four replications. The treatments consisted of the IPR Colibri (control), CNFC 15873, CNFC 15874 and CNFC 15875 genotypes. Plants were sampled throughout the common bean development, being divided into leaves, stems and pods. After determining the dry matter, the contents of N, P, K, Ca and Mg accumulated in leaves were estimated. At harvesting, the grain yield and yield components were evaluated. The biomass accumulation in stems and leaves occurred until the flowering stage, and then it started in the pods until harvesting. The genotypes that absorbed more nitrogen and phosphorus had a higher grain yield. The average growing season of super early genotypes was 70 days (winter) and 63 days (summer). CNFC 15874 was the most productive genotype in the winter, with grain yield similar to the IPR Colibri cultivar (control). In the summer, CNFC 15873 and CNFC 15875 achieved grain yield similar to the IPR Colibri cultivar.