171 research outputs found
Enhanced network of drifters
This presentation was given in Kiel at the occasion of the 2nd General Assembly of the H2020 AtlantOS project. It presents the enhancements on the drifting buoy network, explored in the framework of the project
Importance of disulphide bonds for vaccinia virus L1R protein function
L1R, a myristylated late gene product of vaccinia virus, is essential for formation of infectious intracellular mature virions (IMV). In its absence, only viral particles arrested at an immature stage are detected and no infectious progeny virus is produced. Previous studies have shown that the L1R protein is exclusively associated with the IMV membrane and that myristylation is required for correct targeting. The L1R protein contains six cysteine amino acid residues that have all been shown to participate in intramolecular disulphide bonds. However, it was not clear what role, if any, the disulfide bonds play in the membrane topology of the L1R protein. To address this question, a comprehensive library of L1R mutants in which the cysteine residues have been mutated to serine (either individually or in combination) were tested for their ability to rescue a L1R conditional lethal mutant virus under non-permissive conditions. Much to our surprise, we determined that C57 was not essential for production of infectious IMV. These results suggest that protein disulphide isomerases may be involved in reorganization of disulfide bonds within the L1R protein
Study of the potential for existing bathythermic string drifters
Evaluation report on the use of subsurface temperature buoy data and on their ability to provide suitable measurements in the ocean boundary laye
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The Copernicus surface velocity platform drifter with barometer and reference sensor for temperature (SVP-BRST): genesis, design, and initial results
To support calibration and validation of satel- lite sea surface temperature (SST) retrievals, over 60 high- resolution SST (HRSST) drifting buoys were deployed at sea between 2012 and 2017. Their data record is reviewed here. It is confirmed that sea state and immersion depth play an important role in understanding the data collected by such buoys and that the SST sensors need adequate insu- lation. In addition, calibration verification of three recovered drifters suggests that the sensor drift is low, albeit negative at around −0.01 K year−1. However, the statistical significance of these results is limited, and the calibration procedure could not be exactly reproduced, introducing additional uncertain- ties into this drift assessment. Based on lessons learnt from these initial buoys, a new sensor package for the Surface Velocity Platform with Barometer (SVP-B) was designed to serve calibration of SST retrievals by European Union’s Copernicus satellites. The novel sensor package includes an HRSST sensor calibrated by a metrology laboratory. The sensor includes a pressure probe to monitor immersion depth in calm water and acquires SST data at 1 Hz over a 5 min in-
terval every hour. This enables the derivation of mean SST as well as several percentiles of the SST distribution. The HRSST sensor is calibrated with an uncertainty better than 0.01 K. Analysis of the data collected by two prototypes de- ployed in the Mediterranean Sea shows that the buoys are able to capture small-scale SST variations. These variations are found to be smaller when the sea state is well mixed and when the buoys are located within eddy cores. This affects the drifter SST data representativeness, which is an aspect of importance for optimal use of these data
Podocytopenia and disease severity in IgA nephropathy
Podocytopenia and disease severity in IgA nephropathy.BackgroundIgA nephropathy is a common form of progressive glomerular disease, associated with proliferation of mesangial cells and mesangial deposition of IgA. The present study was designed to investigate functional and morphological covariates of disease severity in patients with IgA nephropathy.MethodsGlomerular hemodynamics, permselectivity and ultrastructure were studied in 17 adult patients with IgA nephropathy using inulin, para-aminohippuric acid (PAH) and 3H-Ficoll clearances and morphometric methods. A mathematical model of macromolecule permeation through a heteroporous membrane was used to characterize glomerular permselectivity. Controls consisted of 14 healthy living kidney donors and 12 healthy volunteers.ResultsThe patients were heterogeneous in their disease severity, but as a group had a decreased glomerular filtration rate (GFR) and increased urinary protein excretion compared to controls [63 ± 29 SD vs. 104 ± 23 mL/min/1.73 m2, P < 0.001, and (median) 1.34 vs. 0.11 g/day, P < 0.0001, respectively). A multivariate analysis of structural and functional relationships revealed GFR depression to be most strongly correlated with the prevalence of global glomerular sclerosis (t = -4.073, P = 0.002). Those patients with the most severe glomerular dysfunction had a reduced number of glomerular visceral epithelial cells (podocytes) per glomerulus. The degree of podocytopenia was related to the extent of glomerular sclerosis and of impairment of permselectivity and GFR, with worsening injury below an apparent threshold podocyte number of about 250 cells per glomerulus. There were no corresponding correlations between these indices of injury and the number of mesangial and endothelial cells.ConclusionsOur findings show that podocyte loss is a concomitant of increasing disease severity in IgA nephropathy. This suggests that podocyte loss may either cause or contribute to the progressive proteinuria, glomerular sclerosis and filtration failure seen in this disorder
The Bearded Pig (Sus barbatus)
Status categories 2-3 - the nominate subspecies from Borneo, S. b. barbatus, is still widespread but declining in numbers; the western subspecies from Peninsular Malaysia and Sumatra, S. b. oi, and the eastern subspecies from Palawan and neighboring islands, S. b. ahoenobarbus, are both rare.
In Borneo, the dipterocarp forests should be deliberately managed for a variety of non-wood as well as wood outputs, which will benefit bearded pigs if wild meat is one of the outputs required. This action requires a fundamental rethinking of forestry management strategy. Conservation areas need to be maintained, and the communal forest system expanded, thereby retaining intact forest areas for the benefit of rural communities and with them, local bearded pig populations. Detailed, long-term investigation of the behaviour of identified pigs is necessary to resolve outstanding questions of social structure and home range use.
In Peninsular or West Malaysia, (northern) Sumatra, Bangka and the Riau Islands, field surveys are needed to correct a lack of information on the distribution and status of S. b. oi and the habitats where they can be expected to survive, which is hampering measures to conserve bearded pigs in these regions. Unlike either of the other two subspecies, these animals are everywhere sympatric with S. scrofa, which may be competitively advantaged by human induced changes in its environment and whose relative abundance may have a negative influence on local attitudes to the management requirements of the rarer form.
There is similar lack of recent information on the distribution and status of the Philippine endemic, S. b. ahoenobarbus, which has by far the most restricted range of the three, currently recognized subspecies. The present status of these animals on Balabac is unknown, but they remain quite widely, if patchily, distributed on the Calamian Islands (Busuanga, Culion and Coron) despite intense hunting pressure. Bearded pigs are also reported to be intensively hunted on Palawan, though precise data is lacking on their range there and any future fieldwork on this island is likely to be seriously compromised by the presence of armed rebels. All of these and other related problems are addressed in the proposed action plan for this species, which also recognizes the need to resolve the now rather confused systematic relationships between the three (Sundaic) forms of bearded pigs the closely allied wild pigs of the neighboring Wallacian subregion, i.e. the eastern Philippines' 'philippensis' and 'cebifrons', and the Sulawesi warty pig, S. celebensis
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