Anticancer activity in Planctomycetes

There is a strong need to develop new drugs against many severe diseases. Therapy resistance is a major problem, for instance, in infectious diseases and cancer. Drug discovery has again turned to nature to search for molecules that can become drug leads. Although many bacterial phyla are extensively studied, some, like the Planctomycetes, remain largely unexplored as potential sources of new leads. Planctomycetes form a diverse group of bacteria with peculiar characteristics such as division by polar budding and absence of the FtsZ gene. Furthermore, they exhibit large genomes up to 12.5 Mb, and possess a high number of secondary metabolites as assessed by in silico genomic analysis. These characteristics have also revealed the presence of potential anticancer activity. Based on these promising characteristics, we wanted to investigate Planctomycetes as a source for natural products with anticancer properties. Organic and aqueous extracts were obtained from cultivated Planctomycetes strains originated from a variety of habitats such as marine systems (free living or attached to marine algae), deep marine iron hydroxide deposits, brackish water and glacier ice system. The extracts were screened for ability to inhibit cell growth, or induce cell death on two cancer cell lines, the human prostatic cancer cell line PC3, and human acute myeloid leukaemia (AML) cell line MOLM-13, as well as normal rat kidney epithelial cell line (NRK). Out of 39 strains, five exhibited cytotoxicity toward NRK cells, whereas 32 of the strains were toxic to the AML cell line, and four were toxic to the PC3 cell line. Two strains showed high toxicity and selectivity toward both the cancer cell lines over the NRK-cells, and are potential producers of anti-cancer compounds. We found no correlation between bioactivity and strains habitat and geographic location but regarding phylogeny some Rhodopirellula spp. showed higher toxicity toward MOLM-13 cells. These results from the first anticancer screening with Planctomycetes showed that these peculiar microorganisms should be further explored for anti-cancer compounds, and that more effort must be put in providing culture collections for drug development purposes.publishedVersio

Scattering statistics of rock outcrops: Model-data comparisons and Bayesian inference using mixture distributions

The probability density function of the acoustic field amplitude scattered by the seafloor was measured in a rocky environment off the coast of Norway using a synthetic aperture sonar system, and is reported here in terms of the probability of false alarm. Interpretation of the measurements focused on finding appropriate class of statistical models (single versus two-component mixture models), and on appropriate models within these two classes. It was found that two-component mixture models performed better than single models. The two mixture models that performed the best (and had a basis in the physics of scattering) were a mixture between two K distributions, and a mixture between a Rayleigh and generalized Pareto distribution. Bayes' theorem was used to estimate the probability density function of the mixture model parameters. It was found that the K-K mixture exhibits significant correlation between its parameters. The mixture between the Rayleigh and generalized Pareto distributions also had significant parameter correlation, but also contained multiple modes. We conclude that the mixture between two K distributions is the most applicable to this dataset.Comment: 15 pages, 7 figures, Accepted to the Journal of the Acoustical Society of Americ

Improving "color rendering" of LED lighting for the growth of lettuce

Light plays a vital role on the growth and development of plant. On the base of white light with high color rendering to the benefit of human survival and life, we proposed to improve “color rendering” of LED lighting for accelerating the growth of lettuce. Seven spectral LED lights were adopted to irradiate the lettuces under 150 μmol·m−2·s−1 for a 16 hd−1 photoperiod. The leaf area and number profiles, plant biomass, and photosynthetic rate under the as-prepared LED light treatments were investigated. We let the absorption spectrum of fresh leaf be the emission spectrum of ideal light and then evaluate the “color rendering” of as-prepared LED lights by the Pearson product-moment correlation coefficient and CIE chromaticity coordinates. Under the irradiation of red-yellow-blue light with high correlation coefficient of 0.587, the dry weights and leaf growth rate are 2-3 times as high as the sharp red-blue light. The optimized LED light for lettuce growth can be presumed to be limited to the angle (about 75°) between the vectors passed through the ideal light in the CIE chromaticity coordinates. These findings open up a new idea to assess and find the optimized LED light for plant growth

Anticancer Activity in Planctomycetes

There is a strong need to develop new drugs against many severe diseases. Therapy resistance is a major problem, for instance, in infectious diseases and cancer. Drug discovery has again turned to nature to search for molecules that can become drug leads. Although many bacterial phyla are extensively studied, some, like the Planctomycetes, remain largely unexplored as potential sources of new leads. Planctomycetes form a diverse group of bacteria with peculiar characteristics such as division by polar budding and absence of the FtsZ gene. Furthermore, they exhibit large genomes up to 12.5 Mb, and possess a high number of secondary metabolites as assessed by in silico genomic analysis. These characteristics have also revealed the presence of potential anticancer activity. Based on these promising characteristics, we wanted to investigate Planctomycetes as a source for natural products with anticancer properties. Organic and aqueous extracts were obtained from cultivated Planctomycetes strains originated from a variety of habitats such as marine systems (free living or attached to marine algae), deep marine iron hydroxide deposits, brackish water and glacier ice system. The extracts were screened for ability to inhibit cell growth, or induce cell death on two cancer cell lines, the human prostatic cancer cell line PC3, and human acute myeloid leukaemia (AML) cell line MOLM-13, as well as normal rat kidney epithelial cell line (NRK). Out of 39 strains, five exhibited cytotoxicity toward NRK cells, whereas 32 of the strains were toxic to the AML cell line, and four were toxic to the PC3 cell line. Two strains showed high toxicity and selectivity toward both the cancer cell lines over the NRK-cells, and are potential producers of anti-cancer compounds. We found no correlation between bioactivity and strains habitat and geographic location but regarding phylogeny some Rhodopirellula spp. showed higher toxicity toward MOLM-13 cells. These results from the first anticancer screening with Planctomycetes showed that these peculiar microorganisms should be further explored for anti-cancer compounds, and that more effort must be put in providing culture collections for drug development purposes

BETWEEN BROADCASTING POLITICAL MESSAGES AND INTERACTING WITH VOTERS

Politicians across Western democracies are increasingly adopting and experimenting with Twitter, particularly during election time. The purpose of this article is to investigate how candidates are using it during an election campaign. The aim is to create a typology of the various ways in which candidates behaved on Twitter. Our research, which included a content analysis of tweets (n = 26,282) from all twittering Conservative, Labour and Liberal Democrat candidates (n = 416) during the 2010 UK General Election campaign, focused on four aspects of tweets: type, interaction, function and topic. By examining candidates' twittering behaviour, the authors show that British politicians mainly used Twitter as a unidirectional form of communication. However, there were a group of candidates who used it to interact with voters by, for example, mobilizing, helping and consulting them, thus tapping into the potential Twitter offers for facilitating a closer relationship with citizens

Behavioral and Physiological Responses of Scandinavian Brown Bears (Ursus arctos) to Dog Hunts and Human Encounters

Innovations in biologging have offered new possibilities to better understand animals in their natural environment. Biologgers can be used by researchers to measure the impact of human disturbances on wildlife and guide conservation decisions. In this study, the behavioral and physiological responses of brown bears (Ursus arctos) to hunts using dogs (Canis lupus familiaris) and human encounters were assessed to better understand the impact of human outdoor activities on brown bears. In Scandinavia, brown bear hunting and the use of dogs during hunts is increasing in popularity. Nonetheless, not every hunt leads to a killed bear. This means that for each bear that is shot, multiple bears may be chased but not killed. In addition, bears can also be disturbed when encountering non-hunting humans. Heart rates, body temperatures, GPS coordinates and dual-axis activity data were collected from 52 simulated hunts (a simulated hunt using dogs with the bear allowed to flee at the end) and 70 human encounters (humans intentionally approaching the bear) that were carried out on 28 free-ranging female brown bears in two study areas in Sweden. The results showed that: (1) simulated hunts had a greater impact and induced a greater energy cost than human encounters; (2) the amount of time bears rested the day after the simulated hunts increased linearly with the duration of the simulated hunts, implying a lasting behavioral impact relative to the intensity of the disturbance. Although not tested in this study, brown bears that are repeatedly disturbed by dog hunts and human encounters may be unable to compensate the disturbances' energy cost, and their fitness may, therefore, be altered. If it is the case, this effect should be accounted for by managers

Mining for genotype-phenotype relations in Saccharomyces using partial least squares

<p>Abstract</p> <p>Background</p> <p>Multivariate approaches are important due to their versatility and applications in many fields as it provides decisive advantages over univariate analysis in many ways. Genome wide association studies are rapidly emerging, but approaches in hand pay less attention to multivariate relation between genotype and phenotype. We introduce a methodology based on a BLAST approach for extracting information from genomic sequences and Soft- Thresholding Partial Least Squares (ST-PLS) for mapping genotype-phenotype relations.</p> <p>Results</p> <p>Applying this methodology to an extensive data set for the model yeast <it>Saccharomyces cerevisiae</it>, we found that the relationship between genotype-phenotype involves surprisingly few genes in the sense that an overwhelmingly large fraction of the phenotypic variation can be explained by variation in less than 1% of the full gene reference set containing 5791 genes. These phenotype influencing genes were evolving 20% faster than non-influential genes and were unevenly distributed over cellular functions, with strong enrichments in functions such as cellular respiration and transposition. These genes were also enriched with known paralogs, stop codon variations and copy number variations, suggesting that such molecular adjustments have had a disproportionate influence on <it>Saccharomyces </it>yeasts recent adaptation to environmental changes in its ecological niche.</p> <p>Conclusions</p> <p>BLAST and PLS based multivariate approach derived results that adhere to the known yeast phylogeny and gene ontology and thus verify that the methodology extracts a set of fast evolving genes that capture the phylogeny of the yeast strains. The approach is worth pursuing, and future investigations should be made to improve the computations of genotype signals as well as variable selection procedure within the PLS framework.</p