Exploring bioactive properties of marine cyanobacteria Isolated from the Portuguese coast: high potential as a source of anticancer compounds

The oceans remain a major source of natural compounds with potential in pharmacology. In particular, during the last few decades, marine cyanobacteria have been in focus as producers of interesting bioactive compounds, especially for the treatment of cancer. In this study, the anticancer potential of extracts from twenty eight marine cyanobacteria strains, belonging to the underexplored picoplanktonic genera, Cyanobium, Synechocystis and Synechococcus, and the filamentous genera, Nodosilinea, Leptolyngbya, Pseudanabaena and Romeria, were assessed in eight human tumor cell lines. First, a crude extract was obtained by dichloromethane:methanol extraction, and from it, three fractions were separated in a Si column chromatography. The crude extract and fractions were tested in eight human cancer cell lines for cell viability/toxicity, accessed with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and lactic dehydrogenase release (LDH) assays. Eight point nine percent of the strains revealed strong cytotoxicity; 17.8% showed moderate cytotoxicity, and 14.3% assays showed low toxicity. The results obtained revealed that the studied genera of marine cyanobacteria are a promising source of novel compounds with potential anticancer activity and highlight the interest in also exploring the smaller filamentous and picoplanktonic genera of cyanobacteria.

Screening of Brazilian soybean genotypes with high potential for somatic embryogenesis and plant regeneration

The aim of this work was to identify Brazilian soybean (Glycine max) genotypes with potential to respond to in vitro culture stimuli for primary somatic embryo induction, secondary embryo proliferation and plant regeneration. Differences among eight tested cultivars were observed at each stage. Two cultivars, IAS-5 and BRSMG 68 Vencedora, were selected for the evaluation of the capacity for embryo differentiation and plant regeneration. These cultivars had high embryo induction frequencies, repetitive embryogenic proliferation, and low precocious embryo germination in the initial experiment. The effect of abscisic acid (ABA) and charcoal addition on plant regeneration was investigated. The addition of ABA to proliferation medium and of ABA and activated charcoal to maturation medium increased embryo differentiation rates, which resulted in a higher number of regenerated plants. The BRSMG 68 Vencedora cultivar was found to have a high potential for embryo induction, embryo proliferation and plant regeneration. The potential of this cultivar for somatic embryogenesis was similar to that observed for cultivar IAS-5, which is currently used for soybean transformation in Brazil. BRSMG 68 Vencedora may be a good alternative genotype for soybean genetic engineering via somatic embryogenesis protocols.

Emerging, non-PCV13 serotypes 11A and 35B of Streptococcus pneumoniae show high potential for biofilm formation in vitro

Background: Since the use of pneumococcal conjugate vaccines PCV7 and PCV13 in children became widespread, invasive pneumococcal disease (IPD) has dramatically decreased. Nevertheless, there has been a rise in incidence of Streptococcus pneumoniae non-vaccine serotypes (NVT) colonising the human nasopharynx. Nasopharyngeal colonisation, an essential step in the development of S. pneumoniae-induced IPD, is associated with biofilm formation. Although the capsule is the main pneumococcal virulence factor, the formation of pneumococcal biofilms might, in fact, be limited by the presence of capsular polysaccharide (CPS). Methodology/Principal Findings: We used clinical isolates of 16 emerging, non-PCV13 serotypes as well as isogenic transformants of the same serotypes. The biofilm formation capacity of isogenic transformants expressing CPSs from NVT was evaluated in vitro to ascertain whether this trait can be used to predict the emergence of NVT. Fourteen out of 16 NVT analysed were not good biofilm formers, presumably because of the presence of CPS. In contrast, serotypes 11A and 35B formed >45% of the biofilm produced by the non-encapsulated M11 strain. Conclusions/Significance This study suggest that emerging, NVT serotypes 11A and 35B deserve a close surveillance.

Understanding E-Bike Users' Behaviour, Motives, and Barriers to the Use - An Empirical Study with high Potential for Mobility Management

A representative study among e-bike owners and tenants in Switzerland (n = 1652) provides a deeper understanding of e-bike users characteristics, motives, values, usage behavior, and barriers to the use. In a micro simulation the implications of the findings for the energy demand and CO2 emissions are estimated.

Specific interaction of mutant p53 with regions of matrix attachment region DNA elements (MARs) with a high potential for base-unpairing

Mutant, but not wild-type p53 binds with high affinity to a variety of MAR-DNA elements (MARs), suggesting that MAR-binding of mutant p53 relates to the dominant-oncogenic activities proposed for mutant p53. MARs recognized by mutant p53 share AT richness and contain variations of an AATATATTT “DNA-unwinding motif,” which enhances the structural dynamics of chromatin and promotes regional DNA base-unpairing. Mutant p53 specifically interacted with MAR-derived oligonucleotides carrying such unwinding motifs, catalyzing DNA strand separation when this motif was located within a structurally labile sequence environment. Addition of GC-clamps to the respective MAR-oligonucleotides or introducing mutations into the unwinding motif strongly reduced DNA strand separation, but supported the formation of tight complexes between mutant p53 and such oligonucleotides. We conclude that the specific interaction of mutant p53 with regions of MAR-DNA with a high potential for base-unpairing provides the basis for the high-affinity binding of mutant p53 to MAR-DNA.

tRNAVal-heterodimeric maxizymes with high potential as geneinactivating agents: Simultaneous cleavage at two sites in HIV-1 tat mRNA in cultured cells

It has been demonstrated that shortened forms of (stem II-deleted) hammerhead ribozymes with low intrinsic activity form very active dimers with a common stem II (very active short ribozymes capable of forming dimers were designated maxizymes). Intracellular activities of heterodimeric maxizymes and conventional ribozymes, under the control of a human tRNAVal-promoter, were compared against the cleavage of HIV-1 tat mRNA. The pol III-driven maxizymes formed very active heterodimers, and they successfully cleaved HIV-1 tat mRNA in mammalian cells at two sites simultaneously. The cleaved fragments were identified directly by Northern blotting analysis. Despite the initial concerns that a complicated dimerization process and formation of inactive homodimers were involved in addition to the process of association with the target, the overall intracellular activities of tRNAVal-driven maxizymes were significantly higher in mammalian cells than those of two sets of independent, conventional hammerhead ribozymes that were targeted at the same two sites within HIV-1 tat mRNA. Because the tRNAVal-driven maxizymes tested to date have been more effective than tRNAVal-driven “standard” hammerhead ribozymes, the tRNAVal-driven heterodimeric maxizymes appear to have potential utility as gene-inactivating agents.

Kinetics of photo-induced electron transfer from high-potential iron-sulfur protein to the photosynthetic reaction center of the purple phototroph Rhodoferax fermentans.

The kinetics of photo-induced electrontransfer from high-potential iron-sulfur protein (HiPIP) to the photosynthetic reaction center (RC) of the purple phototroph Rhodoferarfermentans were studied. The rapid photooxidation of heme c-556 belonging to RC is followed, in the presence of HiPIP, by a slower reduction having a second-order rate constant of 4.8 x 10(7) M(-1) x s(-1). The limiting value of kobs at high HiPIP concentration is 95 s(-1). The amplitude of this slow process decreases with increasing HiPIP concentration. The amplitude of a faster phase, observed at 556 and 425 nm and involving heme c-556 reduction, increases proportionately. The rate constant of this fast phase, determined at 425 and 556 nm, is approximately 3 x 10(5) s(-1). This value is not dependent on HiPIP concentration, indicating that it is related to a first-order process. These observations are interpreted as evidence for the formation of a HiPIP-RC complex prior to the excitation flash, having a dissociation constant of -2.5 microM. The fast phase is absent at high ionic strength, indicating that the complex involves mainly electrostatic interactions. The ionic strength dependence of kobs for the slow phase yields a second-order rate constant at infinite ionic strength of 5.4 x 10(6) M(-1) x s(-1) and an electrostatic interaction energy of -2.1 kcal/mol (1 cal = 4.184 J). We conclude that Rhodoferar fermentans HiPIP is a very effective electron donor to the photosynthetic RC.

Role of aromatic residues in stabilization of the [Fe4S4] cluster in high-potential iron proteins (HiPIPs): physical characterization and stability studies of Tyr-19 mutants of Chromatium vinosum HiPIP.

The functional role of residue Tyr-19 of Chromatium vinosum HiPIP has been evaluated by site-directed mutagenesis experiments. The stability of the [Fe4S4] cluster prosthetic center is sensitive to side-chain replacements. Polar residues result in significant instability, while nonpolar residues (especially with aromatic side chains) maintain cluster stability. Two-dimensional NMR data of native and mutant HiPIPs are consistent with a model where Tyr-19 serves to preserve the structural rigidity of the polypeptide backbone, thereby maintaining a hydrophobic barrier for exclusion of water from the cluster cavity. Solvent accessibility results in more facile oxidation of the cluster by atmospheric oxygen, with subsequent rapid hydrolysis of the [Fe4S4]3+ core.

The inventions, researches and writing of Nikola Tesla : with special reference to his work in polyphase currents and high potential lighting /

"Originally published in 1894 by the Electrical Engineer, New York."

Why not all young firms invest in R&D

This article aims to analyze the different impact that some factors may exert on the probability that a small young firm invests intensively in R&D. Recently, an increasing amount of the literature makes reference to the vital role played by a small number of young firms in generating jobs and increasing efficiency levels. However, not all new firms invest in R&D. Departing from the definition of YICs (firms younger than 6 years old, fewer than 250 employees and with more than 15% of their revenues invested in R&D activities), and with an extensive sample of the Spanish Community Innovation Survey between 2004- 2010, we try to determine: i) those factors that cause firms to become YICs (innovative young small firms) or YNICs (moderately innovative young small firms); ii) what is the difference in the impact of those factors between YICs and YNICs. Our results show that factors such as initial innovation capacity and cooperation in R&D projects enhance the probability of becoming a YIC. Nevertheless, factors such as export potential and market uncertainty may influence the decision to invest moderately and become a YNIC. Keywords: Innovation, Policy, YICs. JEL Classifications: O31, D21

A Drop of Success – Internationalization Readiness of a Young Finnish Company

This study analyzes a young Finnish micro-sized firm that is attempting to reach internationalization readiness in the pre-internationalization stage. The purpose of this research is to analyze and better understand how a young firm reaches internationalization readiness in the pre-internationalization stage. Small firm internationalization is a vastly researched topic. Little emphasis has been placed on the specific antecedents that help the firm reach internationalization readiness in the pre-internationalization stage. The contribution of this research is thus two-fold. First, the research contributes to known theories of firm internationalization. Second, the research further extends knowledge related to how firms reach internationalization readiness specifically in the pre-internationalization stage. The theoretical background of the research involves the traditional stage theory (Uppsala model), pre-internationalization stage theory, international entrepreneurship theory and dynamic capabilities theory. With the help of these four relevant theories, empirical data was collected. The research method utilized in this study was a qualitative single case study combined with critical realist philosophy. The data analysis of this research was conducted using abduction in order to allow freedom in the analysis of the research findings. The empirical data was collected through semi-structured, face-to-face interviews. The key respondents in this study were the two managers of the case company. The findings of this study revealed four important themes from the case company’s perspective towards reaching internationalization readiness in the pre-internationalization stage. Extensive knowledge of the home market and target market were the two most important themes in this research. The next most relevant theme for reaching internationalization readiness in the pre-internationalization stage was the managers’ previous international business experiences. The final theme affecting the firm’s ability to reach internationalization readiness was the firm’s specific resources. Even though the research findings of this study are case sensitive, the research insights and explanations have the potential to be transferred to similar firms and contexts. Future research should therefore aim towards more longitudinal studies in which the context is emphasized. This should include a variety of firms in similar stages of internationalization and contexts. Future studies of this kind would be of great benefit to academia.

Effect of Community of Residence on Neurobehavioral Development in Infants and Young Children in a Flower-Growing Region of Ecuador

In this study we compared neurobehavioral development in Ecuadoran children living in two communities with high potential for exposure to organophosphate (OP) and carbamate pesticides to that of children living in a community with low potential for exposure. Residence in communities with high potential for exposure to OP and carbamate pesticides was associated with poorer neurobehavioral development of the child even after controlling for major determinants of delayed development. Malnourished populations may be particularly vulnerable to neurobehavioral effects of pesticide exposure.

High incidences of DNA ploidy abnormalities in tongue squamous cell carcinoma of young patients: an international collaborative study

Aims: This multi-centre analysis assessed the DNA content of TSCC in 37 young patients (<40 years) and 28 old patients (>50 years) and determined the correlation of DNA ploidy findings with clinicopathological data.Methods and results: Image cytometry was carried out using an automated cellular imaging system on Feulgen-stained histological sections to obtain high-fidelity DNA histograms. Among young patients, 37.8% were females compared to 18.7% in the older group (P = 0.002). In total, 48.6% patients were non-smokers and 40.5% were non-drinkers compared to 10.7% non-smokers and non-drinkers in the older group (P < 0.0001). TNM, clinical stage of disease and histological grade of differentiation did not differ between groups. Tumour aneuploidy was detected in 86.5% and tetraploidy in 24.3% young patients; this was significantly greater than in the older group where 64.3% were aneuploid (P < 0.0001) and 7.2% tetraploid (P < 0.0001). The mean values of DNA index (DI) and DNA heterogeneity index as well as the percentage of cells with DI exceeding 5N were higher in young patients (P < 0.0001).Conclusions: Young patients with TSCC represent a distinct clinical entity. The high incidence of DNA ploidy abnormalities suggest that they may have increased genomic instability and indicates underlying genetic differences between TSCC in young and older patients.

The Impact of Regulation on a Firm's Incentives to Invest in Emergent Smart Grid Technologies

This paper analyzes the implementation of new technologies in network industries through the development of a suitable regulatory scheme. The analysis focuses on Smart Grid (SG) technologies which, among others benefits, could save operational costs and reduce the need for further conventional investments in the grid. In spite of the benefits that may result from their implementation, the adoption of SGs by network operators can be hampered by the uncertainties surrounding actual performances. A decision model has been developed to assess the firms' incentives to invest in "smart" technologies under different regulatory schemes. The model also enables testing the impact of uncertainties on the reduction of operational costs, and of conventional investments. Under certain circumstances, it may be justified to support the development and early deployment of emerging innovations that have a high potential to ameliorate the efficiency of the electricity system, but whose adoption faces many uncertainties.