A Factor Model of the Relationship between Stream Sediment Geochemistry and Adjacent Drainage Basin Lithology, Medvednica Mt., Croatia

A mathematical model is constructed to relate the geochemical composition of recent stream material in a number of catchments on Medvednica Mt. to a broadely defined bedrock lithology which represents the parent material for the former. It is a system based factor model, which synthesizes eight lithological and 25 geochemical variables (major, minor and trace elements), reducing their relationships to six geologically meaningful factors. Five of these divulged a definite relationship between geochemistry and lithology. These are labelled as follows: factor of metamorphic rocks; factor of igneous rocks; factor of Tertiary carbonate rocks; factor of parametamorphic rocks and factor of Mesozoic carbonate rocks. Two lithologies; the Mesozoic clastic rocks and Quaternary sediments showed no clear association to any of the factors. Alternatively, one of the factors (F2) can be identified as “non-lithologic” indicating other, perhaps anthropogenic, contributions to the stream sediment geochemical composition

Modeling the light-induced degradation (LID) in silicon due to ASi-Sii-defects

Light-induced degradation (LID) in silicon is one of the major problems that hamper the progress in silicon solar cell technology. We present a method to model the LID kinetics by a differential equation system based on the assumption of charge-state-change-induced configuration changes of the so-called ASi-Sii-defect. Assuming realistic transition rates, we solve this differential equation system under variation of some of the transition rates. It is found that the LID kinetics can in principle be modeled by this approach but care has to be taken if transition rates put into the model are directly extracted from time-dependent carrier lifetime measurements

Passaging capability of human corneal endothelial cells derived from old donors with and without accelerating cell attachment

In a recent report, we showed that it is possible to establish the culture of Human Corneal Endothelial Cells (HCEnCs) from older donor corneas (usually over 65 year olds) when left to attach in the presence of a viscoelastic solution, potentially increasing the donor pool for culturing HCEnCs. Therefore, we set out to evaluate the outcome of using a viscoelastic solution (Viscoat) to accelerate the attachment of passaged cultured human corneal endothelial cells (HCEnCs). The cells from 28 donor tissues were isolated using peel-and-digest method and evenly seeded into two wells of an 8-well chamber slide. The cells were left to attach after topical application of Viscoat. At confluence, one well was subjected to end-stage characterization, whereas the other well was passaged into another two wells. The cells at P1 were attached with and without the use of Viscoat. The growth rate was monitored; and at confluence, morphometric analysis, corneal endothelial specific (CD166-Tag1A3 & PRDX6-Tag2A12), mitochondrial and respiration assessment (Tom-20 and Seahorse); function-associated (Na+/K+ATPase & ZO-1); proliferative (Ki-67) marker analysis, and viability (Hoechst, Ethidium Homodimer and Calcein AM-HEC) studies were performed. Cells at P0 (with Viscoat) showed 100% confluence at day 9. Cells at P1 with and without Viscoat showed significant difference of confluence 67.0% v 18.8% respectively (p < 0.05). Confluence rate, cell density, hexagonality, Ki-67 positivity and mitochondrial intensity was significantly higher (p < 0.05), whereas cell-area and polymorphism was significantly lower (p < 0.05) in the cells attached with Viscoat compared with the cells attached without Viscoat. There was no significant difference in oxygen consumption rate between the groups. In conclusion, we observed that acceleration in the attachment of passaged HCEnCs with the assistance of Viscoat, could be beneficial for the propagation of HCEnCs isolated from older donors, to increase their propensity to proliferate, without loss of the expression of vital proteins and heterogeneity in cellular morphology

Pozadinski geokemijski šum u tlima Istre

The geochemical background is postulated for two major groups of soils of the Istrian Peninsula, depending on the type of bedrock, or parent material as one of the main soil-forming factors. An effort is made to combine conceptual fundamentals of non-linear dynamic theory with the principles, methods and practical application of basic statistics in order to elucidate the nature and origin of elemental subpopulations hidden in the original geochemical data of Istrian topsoils. In this sense, the 4σ-outlier test and iterative 2σ-statistical technique are utilized, by which the outliers and anomalous values are removed from the total data set and assigned to the consequences of non-linear system dynamics, which prevents the development of a simple cause-and-effect relationship between geochemical variables. The geochemical background is then defined as the normal range of data of the remaining data set. As confirmed by the study, the carbonate-derived soils have a higher natural or geogenic baseline and are also more strongly loaded with heavy metals and other trace elements, in some places critically. On the other hand, flysch-derived soils, except for higher Ca contents, are actually depleted in many elements and also devoid of outliers. Such behaviour implies »dilution« due to the characteristic nature of the weathering of the underlying parent material and other soil-forming processes controlling their fate. In a general sense, the character of the probability distribution curves among chemical elements in the topsoil (or soils in general) can be used as reliable indicator of their evolutionary trends, that is, their enrichment or depletion, or, as regards the geochemical background, the equilibrium between the two, which in the case studied depends principally upon the contrasting Istrian bedrock lithology.U radu je razmatran geokemijski šum zasebno za dvije skupine tala na Istarskom poluotoku, ovisno o tipu geološke podloge, odnosno ishodišnog materijala kao jednog od glavnih čimbenika u razvitku tla. Povezana je teorija nelinearnih dinamičkih sustava s načelima, metodama i praktičnom primjenom elementarne statistike s ciljem da se razjasni priroda i porijeklo elementnih subpopulacija skrivenih u izvornim geokemijskim podacima površinskog horizonta istarskih tala. U tu svrhu korištene su statističke metode – 4σ-test za određivanje ekstremnih vrijednosti i 2σ-metoda iteracije – kojima su ekstremi i anomalne vrijednosti odvojeni od glavnog skupa podataka i pripisani posljedicama nelinearne sistemske dinamike koje su brana uspostavi jednostavnih, uzročno-posljedičnih odnosa među geokemijskim varijablama. U skladu s navedenim, geokemijski šum je određen kao raspon normalnih vrijednosti reduciranog skupa podataka nastalog nakon oba statistička postupka. Pokazalo se da tla razvijena na karbonatnim stijenama imaju višu prirodnu razinu kemijskih elemenata, a također sadrže i veću koncentraciju teških metala i elemenata u tragovima koja je na pojedinim lokacijama i ekstremno visoka. S druge strane, tla razvijena na flišu, s izuzetkom povišenog sadržaja kalcija, u stvarnosti su siromašnija sadržajem većine elemenata i ne sadrže ekstremnih vrijednosti. Takvo ponašanje ukazuje na »razrjeđenje« zbog karakteristične prirode trošenja ishodišnog materijala i drugih čimbenika koji utječu na raspodjelu elemenata u površinskom horizontu tla. U općem slučaju, karakter krivulje statističke distribucije elemenata kemijskih elemenata u površinskom horizontu (i u tlu općenito) može se uzeti kao pouzdan pokazatelj evolucijskih trendova, odnosno obogaćenja ili osiromašenja pojedinim elementima ili, kad je riječ o geokemijskom šumu, ravnoteže među ovim procesima. Kod tala na području Istre na ove odnose primarno utječe izrazita razlika u karakteru geološke podloge

Phenotypic and functional characterization of corneal endothelial cells during in vitro expansion.

The advent of cell culture-based methods for the establishment and expansion of human corneal endothelial cells (CEnC) has provided a source of transplantable corneal endothelium, with a significant potential to challenge the one donor-one recipient paradigm. However, concerns over cell identity remain, and a comprehensive characterization of the cultured CEnC across serial passages has not been performed. To this end, we compared two established CEnC culture methods by assessing the transcriptomic changes that occur during in vitro expansion. In confluent monolayers, low mitogenic culture conditions preserved corneal endothelial cell state identity better than culture in high mitogenic conditions. Expansion by continuous passaging induced replicative cell senescence. Transcriptomic analysis of the senescent phenotype identified a cell senescence signature distinct for CEnC. We identified activation of both classic and new cell signaling pathways that may be targeted to prevent senescence, a significant barrier to realizing the potential clinical utility of in vitro expansion

Granulocyte-targeted therapies for airway diseases

The average respiration rate for an adult is 12–20 breaths per minute, which constantly exposes the lungs to allergens and harmful particles. As a result, respiratory diseases, which includes asthma, chronic obstructive pulmonary disease (COPD) and acute lower respiratory tract infections (LTRI), are a major cause of death worldwide. Although asthma, COPD and LTRI are distinctly different diseases with separate mechanisms of disease progression, they do share a common feature – airway inflammation with intense recruitment and activation of granulocytes and mast cells. Neutrophils, eosinophils, basophils, and mast cells are crucial players in host defense against pathogens and maintenance of lung homeostasis. Upon contact with harmful particles, part of the pulmonary defense mechanism is to recruit these cells into the airways. Despite their protective nature, overactivation or accumulation of granulocytes and mast cells in the lungs results in unwanted chronic airway inflammation and damage. As such, understanding the bright and the dark side of these leukocytes in lung physiology paves the way for the development of therapies targeting this important mechanism of disease. Here we discuss the role of granulocytes in respiratory diseases and summarize therapeutic strategies focused on granulocyte recruitment and activation in the lungs

The expression of RUNX3 in colorectal cancer is associated with disease stage and patient outcome

RUNX3 is believed to have tumour suppressor properties in several cancer types. Inactivation of RUNX3 has been shown to occur by methylation-induced transcriptional silencing and by mislocalization of the protein to the cytoplasm. The aim of this study was to examine the clinical significance of RUNX3 expression in a large series of colorectal cancers using immunohistochemistry and tissue arrays. With advancing tumour stage, expression of RUNX3 in the nucleus decreased, whereas expression restricted to the cytoplasmic compartment increased. Nuclear RUNX3 expression was associated with significantly better patient survival compared to tumours in which the expression of RUNX3 was restricted to the cytoplasm (P=0.025). These results support a role for RUNX3 as a tumour suppressor in colorectal cancer

Management Effects on Greenhouse Gas Dynamics in Fen Ditches

Globally, large areas of peatland have been drained through the digging of ditches, generally to increase agricultural production. By lowering the water table it is often assumed that drainage reduces landscape-scale emissions of methane (CH4) into the atmosphere to negligible levels. However, drainage ditches themselves are known to be sources of CH4 and other greenhouse gases (GHGs), but emissions data are scarce, particularly for carbon dioxide (CO2) and nitrous oxide (N2O), and show high spatial and temporal variability. Here, we report dissolved GHGs and diffusive fluxes of CH4 and CO2 from ditches at three UK lowland fens under different management; semi-natural fen, cropland, and cropland restored to low-intensity grassland. Ditches at all three fens emitted GHGs to the atmosphere, but both fluxes and dissolved GHGs showed extensive variation both seasonally and within-site. CH4 fluxes were particularly large, with medians peaking at all three sites in August at 120-230 mg m-2 d-1. Significant between site differences were detected between the cropland and the other two sites for CO2 flux and all three dissolved GHGs, suggested that intensive agriculture has major effects on ditch biogeochemistry. Multiple regression models using environmental and water chemistry data were able to explain 29-59% of observed variation in dissolved GHGs. Annual CH4 fluxes from the ditches were 37.8, 18.3 and 27.2 g CH4 m-2 yr-1 for the semi-natural, grassland and cropland, and annual CO2 fluxes were similar (1100 to 1440 g CO2 m-2 yr-1) among sites. We suggest that fen ditches are important contributors to landscape-scale GHG emissions, particularly for CH4. Ditch emissions should be included in GHG budgets of human modified fens, particularly where drainage has removed the original terrestrial CH4 source, e.g. agricultural peatlands

Plasma exchange and glucocorticoid dosing in the treatment of anti-neutrophil cytoplasm antibody associated vasculitis (PEXIVAS): protocol for a randomized controlled trial.

BACKGROUND: Granulomatosis with polyangiitis (GPA, Wegener's) and microscopic polyangiitis (MPA) are small vessel vasculitides collectively referred to as anti-neutrophil cytoplasm antibody-associated vasculitis (AAV). AAV is associated with high rates of morbidity and mortality due to uncontrolled disease and treatment toxicity. Small randomized trials suggest adjunctive plasma exchange may improve disease control, while observational evidence suggests that current oral glucocorticoid doses are associated with severe infections in patients with AAV. A randomized study of both plasma exchange and glucocorticoids is required to evaluate plasma exchange and oral glucocorticoid dosing in patients with AAV. METHODS/DESIGN: PEXIVAS is a two-by-two factorial randomized trial evaluating adjunctive plasma exchange and two oral glucocorticoid regimens in severe AAV. Five hundred patients are being randomized at centers across Europe, North America, Asia, and Australasia to receive plasma exchange or no plasma exchange, and to receive standard or reduced oral glucocorticoid dosing. All patients receive immunosuppression with either cyclophosphamide or rituximab. The primary outcome is the time to the composite of all-cause mortality and end-stage renal disease.PEXIVAS is funded by the National Institute of Health Research (UK), the Food and Drug Administration (USA), the National Institutes of Health (USA), the Canadian Institute of Health Research (Canada), the National Health and Medical Research Council (Australia), and Assistance Publique (France). Additional in-kind supplies for plasma exchange are provided by industry partners (TerumoBCT, Gambro Australia, and Fresenius Australia). DISCUSSION: This is the largest trial in AAV undertaken to date. PEXIVAS will inform the future standard of care for patients with severe AAV. The cooperation between investigators, funding agencies, and industry provides a model for conducting studies in rare diseases. TRIAL REGISTRATION: Current Controlled Trials: (ISRCTN07757494) and clinicaltrials.gov: (NCT00987389).RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are