Xanthan gum production and rheological behavior using different strains of Xanthomonas sp.

The proposal of the present study was to select and carry out the molecular characterization of strains of Xanthomonas sp. in order to correlate with gum production and determine possible genetic alterations during the study. The gums produced were also evaluated rheologically. Ten strains of Xanthomonas were used in the screening and the best ones in terms of productivity were Xanthomonas campestris pv. mangiferaeindicae 1230 (8.93 g/L), X. campestris pv. campestris 254 (9.49 g/L) and X. campestris pv. campestris 1078 (9.67 g/L). The gum produced by X. campestris pv. mangiferaeindicae presented the best apparent viscosity. The results for the profiles of the bands produced by RAPD showed considerable genetic variability amongst the evaluated strains, making not possible to neither group the strains according to pathovar or species, nor correlate the band profile with the productivity obtained. According to the RAPD analysis, no detectable mutations occurred in these bacteria during the study.     

Foraminiferal ecological zonation along a Brazilian mangrove transect: Diversity, morphotypes and the influence of subaerial exposure time

Two foraminiferal associations comprising only arenaceous species define two distinct environments in a 340 m-long mangrove transect at Cardoso Island, Trapandé Bay (Cananéia-Iguape estuarine system, SP, Brazil). The “lower muddy flat” (LMF), from the outer mangrove fringe inwards towards land (100 m), is positioned in the lower plain between 0.04 and 0.23 m above the mean sea level (msl), and remains subaerially exposed between 48.5 and 65.6% of the time. This environment is characterized by higher foraminiferal diversity and evenness (McIntosh's D = 0.54 ± 0.21 and Pielou's E = 0.68 ± 0.25, respectively) and is dominated by Arenoparrella mexicana and Trochammina inflata, and to a lesser extent by Ammotium directum and Textularia earlandi. The mangrove plant of this segment is a Rhizophoretum with average height of 8.4 ± 1.2 m. The sediment is characterized by higher concentration of organic matter (93.5 ± 32.3 g dm⁻³) and metals (e.g. V = 53.4 ± 21.8 ppm and Zn = 46.4 ± 21.3 ppm). The “upper sandy flat” (USF), 240 m wide along the transect, is positioned in the upper plain between 0.28 and 0.89 m above the msl, and remains subaerially exposed between 69.7 and 98.5% of the time. This environment is characterized by a lower diversity and evenness (D = 0.33 ± 0.17 and E = 0.49 ± 0.20, respectively). The association is dominated by species T. inflata and Miliammina fusca. The Rhizophoretum exhibits a lower average height of 3.6 ± 0.6 m. The sediment is poorer in organic matter (39.3 ± 15.0 g dm⁻³) and metals (e.g. V = 13.0 ± 6.8 ppm and Zn = 6.9 ± 3.7 ppm). Whereas “elongate” tests (uniserial, biserial and planospiral followed by a uniserial portion) are restricted to the LMF, “spiraled” species dominate the USF. Subaerial exposure time seems to exert a primary influence on species distribution, in addition to salinity and sediment type. Species may be adapted to different exposure times, a factor dependent on their position on the intertidal zone and the tidal regime, which should be taken into account in relative sea level reconstructions based on intertidal foraminifera. These patterns have important implications for studies investigating the ecology and paleoecology of foraminifera and subtle fluctuations in relative sea level during the Quaternary.     

Characterization of novel long-chain 1,2-diols in Thermus species and demonstration that Thermus strains contain both glycerol-linked and diol-linked glycolipids.

In this study, we purified and characterized tetra- and triglycosyl glycolipids (GL-1 and GL-2, respectively) from two different colonial forms of Thermus scotoductus X-1, from T. filiformis Tok4 A2, and from T. oshimai SPS-11. Acid hydrolysis of the purified glycolipids liberated, in addition to the expected long-chain fatty acids, two components which were identified by gas chromatography-mass spectrometry as 16-methylheptadecane-1,2-diol and 15-methylheptadecane-1,2-diol. Fast atom bombardment mass spectrometry of the intact glycolipids indicated that a major proportion consisted of components with glycan head groups linked to long-chain 1,2-diols rather than to glycerol, although in all cases glycerol-linked compounds containing similar glycan head groups were also present. As in other Thermus strains, the polar head group of GL-1 from T. filiformis Tok4 A2 and from T. scotoductus X-1 colony type t2 was a glucosylgalactosyl-(N-acyl)glucosaminylglucosyl moiety. However, GL-2 from T. scotoductus X-1 colony type t1 and from T. oshimai SPS-11 was a truncated analog which lacked the nonreducing terminal glucose. Long-chain 1,2-diols have been previously reported in the polar lipids of Thermomicrobium roseum and (possibly) Chloroflexus aurantiacus, but to our knowledge, this is the first report of their detection in other bacteria and the first account of the structural determination of long-chain diol-linked glycolipids.     

Dasatinib Reduces Lung Inflammation and Fibrosis in Acute Experimental Silicosis

Silicosis is an occupational lung disease with no effective treatment. We hypothesized that dasatinib, a tyrosine kinase inhibitor, might exhibit therapeutic efficacy in silica-induced pulmonary fibrosis. Silicosis was induced in C57BL/6 mice by a single intratracheal administration of silica particles, whereas the control group received saline. After 14 days, when the disease was already established, animals were randomly assigned to receive DMSO or dasatinib (1 mg/kg) by oral gavage, twice daily, for 14 days. On day 28, lung morphofunction, inflammation, and remodeling were investigated. RAW 264.7 cells (a macrophage cell line) were incubated with silica particles, followed by treatment or not with dasatinib, and evaluated for macrophage polarization. On day 28, dasatinib improved lung mechanics, increased M2 macrophage counts in lung parenchyma and granuloma, and was associated with reduction of fraction area of granuloma, fraction area of collapsed alveoli, protein levels of tumor necrosis factor-α, interleukin-1β, transforming growth factor-β, and reduced neutrophils, M1 macrophages, and collagen fiber content in lung tissue and granuloma in silicotic animals. Additionally, dasatinib reduced expression of iNOS and increased expression of arginase and metalloproteinase-9 in silicotic macrophages. Dasatinib was effective at inducing macrophage polarization toward the M2 phenotype and reducing lung inflammation and fibrosis, thus improving lung mechanics in a murine model of acute silicosis.     

Kinetic and growth parameters of Arthrospira (Spirulina) platensis cultivated in tubular photobioreactor under different cell circulation systems

Arthrospira platensis was cultivated in tubular photobioreactor in order to evaluate growth and biomass production at variable photosynthetic photon flux density (PPFD = 60, 120, and 240 μmol photons m(-2)s(-1)) and employing three different systems for cell circulation, specifically an airlift, a motor-driven pumping and a pressurized system. The influence of these two independents variables on the maximum cell concentration (X(m)), cell productivity (P(x)), nitrogen-to-cell conversion factor (Y(X/N) ), photosynthetic efficiency (PE), and biomass composition (total lipids and proteins), taken as responses, was evaluated by analysis of variance. The statistical analysis revealed that the best combination of responses' mean values (X(m) = 4,055 mg L(-1), P(x) = 406 mg L(-1)day(-1), Y(X/N) = 5.07 mg mg(-1), total lipids = 8.94%, total proteins = 30.3%, PE = 2.04%) was obtained at PPFD = 120 μmol photons m(-2)s(-1); therefore, this light intensity should be considered as the most well-suited for A. platensis cultivation in this photobioreactor configuration. The airlift system did not exert any significant positive statistical influence on the responses, which suggests that this traditional cell circulation system could successfully be substituted by the others tested in this work.     

Epidemiological Trends of Dengue Disease in Brazil (2000–2010): A Systematic Literature Search and Analysis

A literature survey and analysis was conducted to describe the epidemiology of dengue disease in Brazil reported between 2000 and 2010. The protocol was registered on PROSPERO (CRD42011001826: http://www.crd.york.ac.uk/prospero/display_record.asp?ID=CRD42011001826). Between 31 July and 4 August 2011, the published literature was searched for epidemiological studies of dengue disease, using specific search strategies for each electronic database. A total of 714 relevant citations were identified, 51 of which fulfilled the inclusion criteria. The epidemiology of dengue disease in Brazil, in this period, was characterized by increases in the geographical spread and incidence of reported cases. The overall increase in dengue disease was accompanied by a rise in the proportion of severe cases. The epidemiological pattern of dengue disease in Brazil is complex and the changes observed during this review period are likely to have been influenced by multiple factors. Several gaps in epidemiological knowledge regarding dengue disease in Brazil were identified that provide avenues for future research, in particular, studies of regional differences, genotype evolution, and age-stratified seroprevalence.

Systematic Review Registration

PROSPERO registration number: CRD42011001826.     

Eco-efficiency

Goal, Scope and Background The eco-efficiency analysis and portfolio is a powerful decision support tool for various strategic and marketing issues. Since its original academic development, the approach has been refined during the last decade and applied to a multitude of projects. BASF, as possibly the most prominent company using and developing this tool, has applied the eco-efficiency approach to more than 300 projects in the last 7 years. One of the greatest difficulties is to cover both dimensions of eco-efficiency (costs or value added and environmental impact) in a comparable manner. This is particularly a challenge for the eco-efficiency analyses of products. Methods In this publication, an important approach and field of application dealing with product decisions based on the combination of Life Cycle Cost (LCC) and Life Cycle Assessment (LCA) is described in detail. Special emphasis is put on the quantitative assessment of the relation of costs and environmental impacts. In conventional LCA an assessment of environmental impact categories is often made by normalization with inhabitant equivalents. This is necessary to be able to compare the different environmental impact categories, because of each different unit. For the proposed eco-efficiency analysis, the costs of products or processes are also normalized with adapted gross domestic product figures. Results and Discussion The ratio between normalized environmental impact categories and normalized costs (R_E,C) is used for the graphical presentation of the results in an eco-efficiency portfolio. For the interpretation of the results of an eco-efficiency analysis, it is important to distinguish ratios R_E,C which are higher than one from ratios lower than one. In the first case, the environmental impact is higher than the cost impact, while the inverse is true in the second case. This is very important for defining which kind of improvement is needed and defining strategic management decisions. The paper shows a statistical evaluation of the R_E,C factor based on the results of different eco-efficiency analyses made by BASF. For industries based on large material flows (e.g. chemicals, steel, metals, agriculture), the R_E,C factor is typically higher than one. Conclusions and Recommendations This contribution shows that LCC and LCA may be combined in a way that they mirror the concept of eco-efficiency. LCAs that do not consider LCC may be of very limited use for company management. For that very reason, corporations should install a data management system that ensures equal information on both sides of the eco-efficiency coin.     

Novel model for “calcium paradox” in sympathetic transmission of smooth muscles: Role of cyclic AMP pathway

It is well established that reduction of Ca²⁺ influx through L-type voltage-dependent Ca²⁺ channel (L-type VDCC), or increase of cytosolic cAMP concentration ([cAMP]c), inhibit contractile activity of smooth muscles in response to transmitters released from sympathetic nerves. Surprisingly, in this work we observed that simultaneous administration of L-type VDCC blocker (verapamil) and [cAMP]c enhancers (rolipram, IBMX and forskolin) potentiated purinergic contractions evoked by electrical field stimulation of rat vas deferens, instead of inhibiting them. These results, including its role in sympathetic transmission, can be considered as a “calcium paradox”. On the other hand, this potentiation was prevented by reduction of [cAMP]c by inhibition of adenylyl cyclase (SQ 22536) or depletion of Ca²⁺ storage of sarco-endoplasmic reticulum by blockade of Ca²⁺ reuptake (thapsigargin). In addition, cytosolic Ca²⁺ concentration ([Ca²⁺]_c) evaluated by fluorescence microscopy in rat adrenal medullary slices was significantly reduced by verapamil or rolipram. In contrast, simultaneous incubation of adrenal slices with these compounds significantly increased [Ca²⁺]_c. This effect was prevented by thapsigargin. Thus, a reduction of [Ca²⁺]_c due to blockade of Ca²⁺ influx through L-type VDCC could stimulate adenylyl cyclase activity increasing [cAMP]c thereby stimulating Ca²⁺ release from endoplasmic reticulum, resulting in augmented transmitter release in sympathetic nerves and contraction.     

Alternative Prey and Abundance Covariance Switches an Intraguild Predator’s Functional Response

Positive or negative prey abundance covariances play an important role in determining prey preference of predators. The goal here was to understand how variations in abundance of two blowfly prey species, a native and a non-native species, influence the switching behavior and functional response of Chrysomya albiceps, an intraguild predatory blowfly, under laboratory conditions. The results suggest C. albiceps prefers to consume a native prey species rather than a non-native prey species. However, when prey densities covariate negatively, both species were consumed at the same rate, changing predator’s functional response from type II to type III. The conditions that trigger the switching behavior in blowfly communities are discussed in detail in this study.