Concordant ages for the giant Kipushi base metal deposit (DR Congo) from direct Rb-Sr and Re-Os dating of sulfides

We report concordant ages of 451.1 ± 6.0 and 450.5 ± 3.4Ma from direct Rb-Sr and Re-Os isochron dating, respectively, of ore-stage Zn-Cu-Ge sulfides, including sphalerite for the giant carbonate-hosted Kipushi base metal (+Ge) deposit in the Neoproterozoic Lufilian Arc, DR Congo. This is the first example of a world-class sulfide deposit being directly dated by two independent isotopic methods. The 451Ma age for Kipushi suggests that the ore-forming solutions did not evolve from metamorphogenic fluids mobilized syntectonically during the Pan-African-Lufilian orogeny but rather were generated in a Late Ordovician postorogenic, extensional setting. The homogeneous Pb isotopic composition of the sulfides indicates that both Cu-Ge- and Zn-rich orebodies of the Kipushi deposit formed contemporaneously from the same fluid system. The sulfide Pb isotope signatures in combination with initial 87Sr/86Sr and 187Os/188Os ratios defined by the isochrons point to metal sources located in the (upper) crust. The concordant Re-Os and Rb-Sr ages obtained in this study provide independent proof of the geological significance of direct Rb-Sr dating of sphalerit

Assessment of genomic instability in Chinese Hamster ovary (CHO) cells

CHO cells are the number one production system for therapeutic proteins due to their ease of handling, their fast growth in suspension culture and their capability to perform complex protein folding and human-like post-translational modifications. This flexibility is in part due to, but at the same time set off by the frequent occurrence of chromosomal rearrangements and other genomic variants, which influences individual cell line performance and the stability of industrial producer cell lines, resulting in prolonged screening phases in order to isolate cells with sufficiently stable properties. Furthermore producer cell properties are also frequently lost again over time and properties within clones derived of the same cell population may vary significantly. The present work focuses on methods for quantification of the rate of chromosomal rearrangements in a given cell line over time in culture. The methods tested include Amplified Fragment Length Polymorphism (AFLP), Chromosome Painting and Chromosome Counting. The principle of AFLP is a restriction enzyme digest of genomic DNA, followed by ligation of the fragments to adapters with a predefined sequence. DNA amplification of restriction fragments is performed using selective AFLP primers complementary to the annealed adapter sequence, but containing extra nucleotides. An initial pattern of bands of digested genomic DNA is defined which allows quantification of chromosomal changes over time using sophisticated statistical techniques. The second technique used is Chromosome Counting of metaphase spreads from a statistically significant number of cells (50-100) in a CHO cell population, with a focus on the spread of counts and ploidy and on how that changes over time. Finally, using chromosome painting, translocations within and across chromosomes and the variation in individual cells within a population can be observed in fine detail. A variety of CHO host cell lines, both pools and subclones were analyzed over a period of six-months in culture. With AFLP we could identify genomic rearrangements for each cell line over time revealing different rates of genomic changes in the analyzed cell lines as well as degrees of relationship between the cell lines and clones at the starting point. Chromosome Counting indicated that the chromosome number and its variation in a CHO cell population differs not only within a population over time, but also between different CHO cell lines. Furthermore the chromosome number of a CHO cell culture changes over time. The older a culture, the more variation and diversity within the population is observed, frequently with a clear tetraploid sub-population appearing after several months in culture. Chromosome painting reveals appearance of new chromosome variants over time, but typically not within the entire population. Overall we can conclude that CHO cells are highly rearranged and that the genomic stability over a production process cannot be guaranteed

Sequence comparisons of plasmids pBJS-O of Spiroplasma citri and pSKU146 of S. kunkelii: implications for plasmid evolution

BACKGROUND: Spiroplasma citri BR3-3X and S. kunkelii CR2-3X cause serious diseases worldwide on citrus and maize species, respectively. S. citri BR3-3X harbors a plasmid, pBJS-Original (pBJS-O), that encodes the spiroplasma adhesion related protein 1 (SARP1), a protein implicated in binding of the pathogen to cells of its leafhopper vector, Circulifer tenellus. The S. kunkelii CR2-3X plasmid, pSKU146, encodes a homolog of SARP1, Sk-ARP1. Due to the close phylogenetic relationship of the two pathogens, we hypothesized that the two plasmids are closely related as well. RESULTS: The nucleotide sequence of pBJS-O was determined and compared to the sequences of a plasmid from BR3-T (pBJS-T), which is a multiply passaged leafhopper transmissible derivative of BR3-3X, and to known plasmid sequences including that of pSKU146. In addition to arp1, the 13,374 bp pBJS-O sequence putatively contains nine genes, recognized as open reading frames (ORFs). Several pBJS-O ORFs have homologs on pSKU146. However, the sequences flanking soj-like genes on both plasmids were found to be more distant from one another than sequences in any other region. Further, unlike pSKU146, pBJS-O lacks the conserved oriT region characteristic of the IncP group of bacterial plasmids. We were unable to identify a region in pBJS-O resembling a known plasmid origin of transfer. In regions where sequence was available for the plasmid from both BR3-3X and BR3-T, the pBJS-T sequence had a 0.4 kb deletion relative to its progenitor, pBJS-O. Southern blot hybridization of extrachromosomal DNA from various S. citri strains and spiroplasma species to an arp-specific probe and a probe made from the entire plasmid DNA of BR3-3X revealed limited conservation of both sequences in the genus Spiroplasma. Finally, we also report the presence on the BR3-3X chromosome of arp2, an S. citri homolog of arp1 that encodes the predicted protein SARP2. The C-terminal domain of SARP2 is homologous to that of SARP1, but its N-terminal domain is distinct. CONCLUSION: Our data suggest that pBJS is a novel S. citri plasmid that does not belong to any known plasmid incompatibility group. The differences between pBJS-O and pSKU146 suggest that one or more events of recombination have contributed to the divergence of the plasmids of the two sister Spiroplasma species; the plasmid from S. citri itself has diverged slightly during the derivation of S. citri BR3-T from BR3-3X. Our data also show that pBJS-O encodes the putative adhesin SARP1. The presence of traE and mob on pBJS-O suggests a role for the plasmid in spiroplasmal conjugation

Kirigami-inspired, highly stretchable micro-supercapacitor patches fabricated by laser conversion and cutting.

The recent developments in material sciences and rational structural designs have advanced the field of compliant and deformable electronics systems. However, many of these systems are limited in either overall stretchability or areal coverage of functional components. Here, we design a construct inspired by Kirigami for highly deformable micro-supercapacitor patches with high areal coverages of electrode and electrolyte materials. These patches can be fabricated in simple and efficient steps by laser-assisted graphitic conversion and cutting. Because the Kirigami cuts significantly increase structural compliance, segments in the patches can buckle, rotate, bend and twist to accommodate large overall deformations with only a small strain (<3%) in active electrode areas. Electrochemical testing results have proved that electrical and electrochemical performances are preserved under large deformation, with less than 2% change in capacitance when the patch is elongated to 382.5% of its initial length. The high design flexibility can enable various types of electrical connections among an array of supercapacitors residing in one patch, by using different Kirigami designs

Therapeutic effect of Cerebrolysin on reducing impaired cerebral endothelial cell permeability

Cerebrolysin has been shown to promote neurovascular protection and repair in preclinical models of stroke and neural injury and is demonstrating promise for stroke and neural injury therapeutic application in the clinic. The effect of Cerebrolysin on the human cerebral endothelial cell function has not been investigated. Using an in-vitro cerebral endothelial cell permeability assay and western blot analyses of tight junction and proinflammatory and procoagulant proteins, the present study showed that tissue plasminogen activator (tPA) and fibrin substantially impaired human cerebral endothelial cell barrier function and increased permeability, which persisted for at least 24 h. western blot analysis revealed that tPA and fibrin significantly increased proinflammatory and procoagulation proteins of intercellular adhesion molecule 1, high mobility group box 1, tumor necrosis factor α and phosphorylated nuclear factor kappa B-p65, and significantly reduced tight junction proteins zonular 1, occludin and claudin. However, Cerebrolysin significantly diminished and reversed tPA- and fibrin-impaired endothelial cell permeability, which was associated with significant reductions of tPA- and fibrin-augmented proinflammatory and procoagulation proteins and significant elevations of tPA- and fibrin-decreased tight junction proteins. The beneficial effect of Cerebrolysin appears specific because cerebroprotein hydrolysate, with a distinct peptide composition, failed to show the reduction of tPA- and fibrin-impaired permeability. These data indicate that cererbrolysin has a therapeutic effect on tPA- and fibrin-impaired cerebral endothelial cell permeability by reducing proinflammatory and procoagulation proteins and by elevating tight junction proteins

Community terminal restriction fragment length polymorphisms reveal insights into the diversity and dynamics of leaf endophytic bacteria

Background: Plant endophytic bacteria play an important role benefiting plant growth or being pathogenic to plants or organisms that consume those plants. Multiple species of bacteria have been found co-inhabiting plants, both cultivated and wild, with viruses and fungi. For these reasons, a general understanding of plant endophytic microbial communities and their diversity is necessary. A key issue is how the distributions of these bacteria vary with location, with plant species, with individual plants and with plant growing season.Results: Five common plant species were collected monthly for four months in the summer of 2010, with replicates from four different sampling sites in the Tallgrass Prairie Preserve in Osage County, Oklahoma, USA. Metagenomic DNA was extracted from ground, washed plant leaf samples, and fragments of the bacterial 16S rDNA genes were amplified for analysis of terminal restriction fragment length polymorphism (T-RFLP). We performed mono-digestion T-RFLP with restriction endonuclease DdeI, to reveal the structures of leaf endophytic bacterial communities, to identify the differences between plant-associated bacterial communities in different plant species or environments, and to explore factors affecting the bacterial distribution. We tested the impacts of three major factors on the leaf endophytic bacterial communities, including host plant species, sampling dates and sampling locations.Conclusions: Results indicated that all of the three factors were significantly related (α = 0.05) to the distribution of leaf endophytic bacteria, with host species being the most important, followed by sampling dates and sampling locations.Peer reviewedBiochemistry and Molecular BiologyBotan

The effect of floorball training on health status, psychological health and social capital in older men

This article presents the results of a multidisciplinary study which investigated the effects of a period with floorball training on health status, psychological health and social capital of older men. Thirty-nine untrained men aged 69.9 ± 0.6 (range: 65–76) were randomized into a group playing floorball (n = 22) or a group playing petanque (n = 17) one hour twice a week for 12 weeks. Both groups filled out the Health Survey Short Form (SF-12) and the Hospital Anxiety and Depression Scale (HADS) before and after the 12-week intervention. Linear regression analyses with bootstrapping showed that the men in the floorball group improved in the SF-12 composite score for mental health, as well as the HADS subscales anxiety and depression, compared to the men in the petanque group. In addition, 21 interviews were conducted with a sample of the men engaged in floorball. According to the statements in the interviews, the men in the floorball group experienced a high degree of solidarity and group cohesion which seemed to have increased their social capital during the intervention. In particular, the fun and joyful experiences of playing led to a high degree of social connectedness, which were mentioned by many of the men as the main reason for their participation throughout the 12-week period. The statistical results and the interview findings suggest that participation in a ball game such as floorball has several benefits regarding health status, psychological health and social capital and in addition that playing floorball is experienced as enjoyable amongst older men. Thus, it can be concluded that floorball is an activity that benefits older men and should be provided in relevant contexts, such as e.g. sport clubs or centres for seniors

Plant Virus Biodiversity and Ecology

The Plant Virus Biodiversity and Ecology (PVBE) project has been initiated to survey the biodiversity of viruses affecting vascular plants