Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

9 páginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe

Microbial and Chemical Characterization of Underwater Fresh Water Springs in the Dead Sea

Due to its extreme salinity and high Mg concentration the Dead Sea is characterized by a very low density of cells most of which are Archaea. We discovered several underwater fresh to brackish water springs in the Dead Sea harboring dense microbial communities. We provide the first characterization of these communities, discuss their possible origin, hydrochemical environment, energetic resources and the putative biogeochemical pathways they are mediating. Pyrosequencing of the 16S rRNA gene and community fingerprinting methods showed that the spring community originates from the Dead Sea sediments and not from the aquifer. Furthermore, it suggested that there is a dense Archaeal community in the shoreline pore water of the lake. Sequences of bacterial sulfate reducers, nitrifiers iron oxidizers and iron reducers were identified as well. Analysis of white and green biofilms suggested that sulfide oxidation through chemolitotrophy and phototrophy is highly significant. Hyperspectral analysis showed a tight association between abundant green sulfur bacteria and cyanobacteria in the green biofilms. Together, our findings show that the Dead Sea floor harbors diverse microbial communities, part of which is not known from other hypersaline environments. Analysis of the water’s chemistry shows evidence of microbial activity along the path and suggests that the springs supply nitrogen, phosphorus and organic matter to the microbial communities in the Dead Sea. The underwater springs are a newly recognized water source for the Dead Sea. Their input of microorganisms and nutrients needs to be considered in the assessment of possible impact of dilution events of the lake surface waters, such as those that will occur in the future due to the intended establishment of the Red Sea−Dead Sea water conduit

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Congenital Idiopathic Dilatation of the Right Atrium: Antenatal Appearance, Postnatal Management, Long-Term Follow-Up and Possible Pathomechanism

Introduction: Idiopathic dilatation of the right atrium (IDRA) is a rare abnormality usually detected by chance at any time between antenatal and adult life. It is defined as isolated enlargement of the right atrium in the absence of other cardiac lesions causing right atrial dilatation. IDRA can be associated with atrial arrhythmia and systemic embolism. The clinical presentation shows high variability ranging from the lack of any symptoms up to cardiac failure. Methods/Results: We describe 2 children with antenatally diagnosed IDRA, the intrauterine course in 1 case, the postnatal management and its long-term follow-up. There has been no need for surgical intervention so far because of the lack of arrhythmias and no further progression of right atrial diameters. Thrombus formation in the right atrium, which is a potential risk for pulmonary embolism, led us to initiate anticoagulation in our cases to prevent such complications. Furthermore, we suggest one possible pathomechanism of congenital right atrial dilatation. Conclusion: Optimal management of severe IDRA depends on the individual case. Long-term follow-up of these patients is necessary to monitor a possible further progression of right atrial size and occurrence of arrhythmias. As a possible pathomechanism, a functional partial anomalous pulmonary venous insertion may imitate a structural abnormal pulmonary vein connection in some idiopathic cases of congenital right atrial dilatation.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich

Hepatic transport mechanisms of cholyl-L-lysyl-fluorescein

Cholyl-L-lysyl-fluorescein (CLF) is a fluorescent bile salt derivative that is being developed as an agent for determining in vivo liver function. However, the mechanisms of uptake and excretion by hepatocytes have not been rigorously studied. We have directly assessed the transport capacity of various hepatobiliary transporters for CLF. Uptake experiments were performed in Chinese hamster ovary cells transfected with human NTCP, OATP1B1, OATP1B3, and OATP2B1. Conversely, excretory systems were tested with plasma membrane vesicles from Sf21 insect cells expressing human ABCB11, ABCC2, ABCC3, and ABCG2. In addition, plasma clearance and biliary excretion of CLF were examined in wild-type, Abcc2(-/-), and Abcc3(-/-) mice. Human Na(+)-dependent taurocholic-cotransporting polypeptide (NTCP) and ATP-binding cassette B11 (ABCB11) were incapable of transporting CLF. In contrast, high-affinity transport of CLF was observed for organic anion-transporting polypeptide 1B3 (OATP1B3), ABCC2, and ABCC3 with K(m) values of 4.6 +/- 2.7, 3.3 +/- 2.0, and 3.7 +/- 1.0 microM, respectively. In Abcc2(-/-) mice biliary excretion of CLF was strongly reduced compared with wild-type mice. This resulted in a much higher hepatic retention of CLF in Abcc2(-/-) versus wild-type mice: 64 versus 1% of the administered dose (2 h after administration). In mice intestinal uptake of CLF was negligible compared with that of taurocholate. Our conclusion is that human NTCP and ABCB11 are incapable of transporting CLF, whereas OATP1B3 and ABCC2/Abcc2 most likely mediate hepatic uptake and biliary excretion of CLF, respectively. CLF can be transported back into the blood by ABCC3. Enterohepatic circulation of CLF is minimal. This renders CLF suitable as an agent for assessing in vivo liver function

Glenoid morphology in light of anatomical and reverse total shoulder arthroplasty: a dissection- and 3D-CT-based study in male and female body donors

Abstract Background Placement of the glenoid baseplate is of paramount importance for the outcome of anatomical and reverse total shoulder arthroplasty. However, the database around glenoid size is poor, particularly regarding small scapulae, for example, in women and smaller individuals, and is derived from different methodological approaches. In this multimodality cadaver study, we systematically examined the glenoid using morphological and 3D-CT measurements. Methods Measurements of the glenoid and drill hole tunnel length for superior baseplate screw placement were recorded to define size of the glenoid and the distance to the scapular notch on cadaveric specimens. Glenoid angles were determined on both, 3D-CT-scans of the thoraxes using the Friedman method and on subsequently isolated scapulae from 18 male and female donors (average 84\ua0years, range 60\u201398 years). Results Mean glenoid height was 36.6\ua0mm\u2009\ub1\u20093.6, and width 27.8\ua0mm\u2009\ub1\u20093.1 with a significant sex dimorphism ( p \u2009\u2264\u20090.001): in males, glenoid height 39.5\ua0mm\u2009\ub1\u20093.5, and width 30.3\ua0mm\u2009\ub1\u20093.3, and in females, glenoid height 34.8\ua0mm\u2009\ub1\u20092.2, and width 26.2\ua0mm\u2009\ub1\u20091.6. The average distance from the superior screw entry to its exit in the scapular notch measured by calliper was 27.2\ua0mm\u2009\ub1\u20096.0 with a sex difference: in males, 29.4\ua0mm\u2009\ub1\u20095.7, and in females, 25.8\ua0mm\u2009\ub1\u20095.9\ua0mm with a minimum recorded distance of 15\ua0mm. Measured by CT, the mean inclination angle for male and female donors combined was 13.0\ub0\u2009\ub1\u20097.0, and the ante-/retroversion angle \u22121.0\ub0\u2009\ub1\u20094.0\ub0. Conclusion This study is one of the first to ..