Contribution of transparent exopolymer particles to carbon sinking flux in an oligotrophic reservoir

Transparent exopolymer particles (TEP) compose an important pool of particulate organic matter (POM) in aquatic systems. However, no studies of TEP contribution to C export to sediment exist for freshwaters. We quantify the contribution of TEP to C sinking fluxes in an oligotrophic reservoir (Quéntar, Southern Spain) by monitoring TEP in the water column and TEP, particulate organic carbon (POC) and dry weight in sedimentation traps. TEP sinking fluxes ranged from 0.73 to 183.23 mg C m^?2 day^?1 and from 0.51 to 177.04 mg C m^?2 day^?1 at the surface and at the bottom layer, respectively. These values represent that, over an annual basis, 5.59 Ton TEP-C (over 61.32 Ton POC) are exported, on an average, from the water column to the sediment of Quentar reservoir. TEP concentrations (average = 48.0 μg XG eq l^?1) were lower than the scarce data reported for freshwaters. No significant relationships between TEP and Chl a concentrations or BA were observed. Average value for daily sedimentation flux (6.63 g Dry Weight m^?2 day^?1) in the study reservoir was higher than that documented for low productive natural aquatic ecosystems as a consequence of the high amount of allochthonous material input characterizing reservoirs. TEP contributed to C export to sediment with a value that range from 0.02 to 31%. Our results show that even in man-made systems, which are predominantly controlled by allochthonous inputs, TEP may be relevant for explaining POM settling fluxes.     

Blockade of programmed death-1 in young (New Zealand black x New Zealand white)F1 mice promotes the activity of suppressive CD8+ T cells that protect from lupus-like disease

The programmed death-1 (PD-1)/programmed death-1 ligand 1 (PD-L1) pathway regulates both stimulatory and inhibitory signals. In some conditions, PD-1/PD-L1 inhibits T and B cell activation, induces anergy, and reduces cytotoxicity in CD8(+) T cells. In other conditions, PD-l/PD-L1 has costimulatory effects on T cells. We recently showed that induction of suppressive CD8(+)Foxp3(+) T cells by immune tolerance of lupus-prone (New Zealand black × New Zealand white)F(1) (BWF(1)) mice with the anti-DNA Ig-based peptide pConsensus (pCons) is associated with significantly reduced PD-1 expression on those cells. In this study, we tested directly the role of PD-1 by administering in vivo neutralizing Ab to PD-1 to premorbid BWF(1) and healthy control mice. Anti-PD-1-treated mice were protected from the onset of lupus nephritis for 10 wk, with significantly improved survival. Although the numbers of T cells declined in aging control mice, they were maintained in anti-PD-1-treated mice, including CD8(+)Foxp3(+) T cells that suppressed syngeneic CD4(+)CD25(-) T cell proliferation and IFN-γ production, reduced production of IgG and anti-dsDNA IgG, induced apoptosis in syngeneic B cells, and increased IL-2 and TGF-β production. The administration of anti-PD-1 Ab to BWF(1) mice after induction of tolerance with pCons abrogated tolerance; mice developed autoantibodies and nephritis at the same time as control mice, being unable to induce CD8(+)Foxp3(+) T suppressor cells. These data suggest that tightly regulated PD-1 expression is essential for the maintenance of immune tolerance mediated by those CD8(+)Foxp3(+) T cells that suppress both T(h) cells and pathogenic B cells. PD-1 regulation could represent a target to preserve tolerance and prevent autoimmunity.     

Rapid detection and identification of Mycobacterium tuberculosis by Real Time PCR and Bactec 960 MIGT

We have developed a Real-Time PCR assay to detect M. tuberculosis using the iCycler iQ detection system by TaqMan assay directly on the clinical specimen. A total of 513 clinical samples were taken from patients with suspected tuberculosis and other patients that had an active mycobacterial infection, as well as patients with diagnosed tuberculosis who were receiving antitubercular therapy. The sensitivity and specificity of this assay, 10% and 100%, respectively, were compared to those of conventional microbiological methods.     

Bioanthropological analysis of human occipital condyles using geometric morphometric method

Sex differences are present in all parts of the body, including the skeletal system. Several methods are used to analyze the sex differences of skeleton, while more recently, a new method called geometric morphometry has been used. The aim of this study was to examine the sexual dimorphism of occipital condyles on human skulls originating from the population of Bosnia and Herzegovina using the geometric morphometric method.Material and methodsThe study was conducted on 214 human skulls of known gender from Bosnian population. For analysis of sexual dimorphism of occipital condyles, we used geometric morphometry, where all the skulls were scanned to obtain three-dimensional skull models. On the obtained models, we marked anthropometric points on occipital condyles in a Landmark Editor program from which we exported data in the form NTSYS file and analyzed it in MorphoJ program.ResultsFirst principal component PC1 describes 26.917% of total variability, the second principal component PC2 describes 20.992% of total variability, while the first eight principal components together describe 100% of total variability. The greatest variability between the male skulls and female skulls was present in the anterior-posterior diameter (length of occipital condyles). Discriminant functional analysis of the shape and size of the occipital condyles was possible with 69.50% accuracy for male skulls and with 60.27% accuracy for female skulls. The size of the occipital condyles showed a statistically significant effect on sexual determination. Discriminant functional analysis of the shape of the occipital condyles without affecting size enabled the determination of gender with with 65.96% accuracy for male skulls and with 63.01% accuracy for female skulls.ConclusionAnalysis of sexual dimorphism of occipital condyles using geometric morphometry showed statistically significant differences in the shape and size of occipital condyles between the sexes. The accuracy of sex determination based on occipital condyles was higher for male gender.     

Blue light from light-emitting diodes elicits a dose-dependent suppression of melatonin in humans

Light suppresses melatonin in humans, with the strongest response occurring in the short-wavelength portion of the spectrum between 446 and 477 nm that appears blue. Blue monochromatic light has also been shown to be more effective than longer-wavelength light for enhancing alertness. Disturbed circadian rhythms and sleep loss have been described as risk factors for astronauts and NASA ground control workers, as well as civilians. Such disturbances can result in impaired alertness and diminished performance. Prior to exposing subjects to short-wavelength light from light-emitting diodes (LEDs) (peak λ = 469 nm; 1/2 peak bandwidth = 26 nm), the ocular safety exposure to the blue LED light was confirmed by an independent hazard analysis using the American Conference of Governmental Industrial Hygienists exposure limits. Subsequently, a fluence-response curve was developed for plasma melatonin suppression in healthy subjects (n = 8; mean age of 23.9 ± 0.5 years) exposed to a range of irradiances of blue LED light. Subjects with freely reactive pupils were exposed to light between 2:00 and 3:30 AM. Blood samples were collected before and after light exposures and quantified for melatonin. The results demonstrate that increasing irradiances of narrowband blue-appearing light can elicit increasing plasma melatonin suppression in healthy subjects (P < 0.0001). The data were fit to a sigmoidal fluence-response curve (R(2) = 0.99; ED(50) = 14.19 μW/cm(2)). A comparison of mean melatonin suppression with 40 μW/cm(2) from 4,000 K broadband white fluorescent light, currently used in most general lighting fixtures, suggests that narrow bandwidth blue LED light may be stronger than 4,000 K white fluorescent light for suppressing melatonin.     

Secretome compartment is a valuable source of biomarkers for cancer-relevant pathways

In principle, targeted therapies have optimal activity against a specific subset of tumors that depend upon the targeted molecule or pathway for growth, survival, or metastasis. Consequently, it is important in drug development and clinical practice to have predictive biomarkers that can reliably identify patients who will benefit from a given therapy. We analyzed tumor cell-line secretomes (conditioned cell media) to look for predictive biomarkers; secretomes represent a potential source for potential biomarkers that are expressed in intracellular signaling and therefore may reflect changes induced by targeted therapy. Using Gene Ontology, we classified by function the secretome proteins of 12 tumor cell lines of different histotypes. Representations and hierarchical relationships among the functional groups differed among the cell lines. Using bioinformatics tools, we identified proteins involved in intracellular signaling pathways. For example, we found that secretome proteins related to TGF-beta signaling in thyroid cancer cells, such as vasorin, CD109, and βIG-H3 (TGFBI), were sensitive to RPI-1 and dasatinib treatments, which have been previously demonstrated to be effective in blocking cell proliferation. The secretome may be a valuable source of potential biomarkers for detecting cancer and measuring the effectiveness of cancer therapies.     

Effects of copper on the tyrosinase of liver pigment cells from Rana esculenta L

1. The liver pigment cells of R. esculenta L. constitute a peculiar pigment cell system of histiocytic nature and contain a tyrosinase-like activity localized in the protein component of melanosomes. 2. The effects of addition and/or removal of Cu on the DOPA-oxidase activity of the system were studied. 3. It was concluded that: (a) this tyrosinase behaves as a Cu-enzyme; (b) Cu could be involved in the regulation of the enzyme activity; and (c) mixtures of apoenzyme and active enzyme coexist in the melanosomes.     

B-chromosomes in inbred lines of rye (Secale cereale L.)

B-chromosomes from an experimental population of the Japanese JNK strain of rye, isogenic for its Bs, have been backcrossed into twelve different inbred lines. The experiment provides a way to study the effects of the Bs against a range of homozygous A-chromosome backgrounds. This publication deals with vigour and fertility: it shows that the rye Bs fit a parasitic model, and that they interact in their effects with the A-chromosome background genotype.