B-cell development : one problem, multiple solutions.

Interspecies variations in the processes of B-cell development and repertoire generation contrast with the greater consistency of T-cell development. B-cell development in mice and humans, with postnatal B-cell generation of new repertoire in the bone marrow throughout life, is regarded as the 'standard' pattern. In contrast, accounts of B cells in birds, sheep, cattle, rabbits and pigs (the 'other' species) describe cessation of gene diversification in the perinatal period, with the gut-associated lymphoid tissue (GALT) functioning as the primary lymphoid organ thereafter. It has become customary to regard the developmental pathways of T and B cells within any individual species as being as dissimilar as the functions of the two mature cell types. Reinterpretation of B-cell development patterns in different species is overdue in response to two types of reports. The first of these describe T-B 'crossover', specifically the intrathymic production of B cells and the extrathymic production of T cells. The second attests to the extent of sharing of B-cell developmental features across the two groups of species. We propose that, as is a feature of other haematopoietic cells, a menu of alternative B- and T-cell pathways has been retained and shared across species. A single pathway usually predominates in any species, masking alternatives. The observed predominance of any pathway is determined by factors such as placental permeability, extent of maturation of the immune system by birth and the feasibility of direct experimental intervention in development

Involvement of regional lymph nodes after penetration of Schistosoma mansoni cercariae in naive and infected mice

The parotid lymph nodes of naive and previously infected Balb/c mice were studied after, respectively, infection and re-infection with cercariae of Schistosoma mansoni via the ears. Schistosomula were able to pass through the lymph node by following the lymph flow or by penetrating the veins of the medullary cords. The number of nodal mast cells was higher from day 2 to 6 of primary infection; and from day 5 to 11 of re-infection. The amount of degranulating mast cells was significantly higher at day 4 of infection and at day 1 of re-infection. Eosinophils characterized the nodal inflammatory processes observed after day 5 in both primarily-infected and re-infected mice. However, only in the latter the eosinophils were able to adhere to the larval surface. In primarily-infected mice, no intranodal larva presented signs of degeneration. In contrast, in re-infected animals, some degenerating larvae were found inside eosinophilic infiltrates. The eosinophils reached the nodal tissue by migrating through the high endothelial venules and their collecting veins

Staphylococcal Panton-Valentine Leucocidin as a Major Virulence Factor Associated to Furuncles

Panton-Valentine Leucocidin (PVL), one of the β-barrel pore-forming staphylococcal leucotoxins, is known to be associated to furuncles and some severe community pneumonia. However, it is still uncertain how many other virulence factors are also associated to furuncles and what the risk factors of furuncles are in immuno-compromised status of patients, especially the HIV (+) patients. In this paper, we use antigen immunoprecipitation and multiplex PCR approach to determine the presence of 19 toxins, 8 adhesion factors and the PFGE profiles associated to furuncles in three independent patient study groups of S. aureus (SA) isolates collected from the Cayenne General Hospital (French Guiana). The patient groups were made of: 16 isolates from HIV (−) patients, 9 from HIV (+) patients suffering from furuncles, and 30 control isolates from patients with diverse secondary infected dermatitis. Our data reveals that the majority (96%) of SA strains isolated from HIV patient-derived furuncles significantly produced PVL (p<10−7), whereas only 10% of SA strains produced this toxin in secondary infected dermatosis. A high prevalence of LukE-LukD-producing isolates (56 to 78%) was recorded in patient groups. Genes encoding clumping factor B, collagen- and laminin-binding proteins (clfB, cna, lbp, respectively) were markedly frequent (30 to 55%), without being associated to a specific group. Pulse field gel electrophoresis evidenced 24 overall pulsotypes, whereas the 25 PVL-producing isolates were distributed into 15 non clonal fingerprints. These pulsotypes were not specific PVL-producing isolates. PVL appears to be the major virulence factor associated to furuncles in Europe and in South America regardless of the immune status of the HIV patients

Joint state and parameter estimation for distributed mechanical systems

We present a novel strategy to perform estimation for a dynamical mechanical system in standard operating conditions, namely, without ad hoc experimental testing. We adopt a sequential approach, and the joint state-parameter estimation procedure is based on a state estimator inspired from collocated feedback control. This type of state estimator is chosen due to its particular effectiveness and robustness, but the methodology proposed to adequately extend state estimation to joint state-parameter estimation is general, and - indeed -applicable with any other choice of state feedback observer. The convergence of the resulting joint estimator is mathematically established. In addition, we demonstrate its effectiveness with a biomechanical test problem defined to feature the same essential characteristics as a heart model, in which we identify localized contractility and stiffness parameters using measurements of a type that is available in medical imaging

The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected

Cardiomyopathy and Response to Enzyme Replacement Therapy in a Male Mouse Model for Fabry Disease

Fabry disease is an X-linked disorder of glycosphingolipid metabolism that results in progressive accumulation of neutral glycosphingolipids, (predominately globotriaosylceramide; GL-3) in lysosomes, as well as other cellular compartments and the extracellular space. Our aim was to characterize the cardiac phenotype of male knock-out mice that are deficient in alpha-galactosidase A activity, as a model for Fabry disease and test the efficacy of Enzyme Replacement Therapy with agalsidase-beta. Male mice (3–4 months of age) were characterized with awake blood pressure and heart rate measurements, cardiac echocardiography and electrocardiography measurements under light anesthesia, histological studies and molecular studies with real-time polymerase chain reaction. The Fabry knock-out mouse has bradycardia and lower blood pressure than control wild type (CB7BL/6J) mice. In Fabry knock-out mice, the cardiomyopathy associated mild hypertrophy at echography with normal systolic LV function and mild diastolic dysfunction. Premature atrial contractions were more frequent in without conduction defect. Heart weight normalized to tibial length was increased in Fabry knock-out mice. Ascending aorta dilatation was observed. Molecular studies were consistent with early stages of cardiac remodeling. A single dose of agalsidase-beta (3 mg/kg) did not affect the LV hypertrophy, function or heart rate, but did improve the mRNA signals of early cardiac remodeling. In conclusion, the alpha-galactosidase A deficient mice at 3 to 4 months of age have cardiac and vascular alterations similar to that described in early clinical stage of Fabry disease in children and adolescents. Enzyme replacement therapy affects cardiac molecular remodeling after a single dose

Cluster Difference Imaging Photometric Survey. II. TOI 837: A Young Validated Planet in IC 2602

We report the discovery of TOI 837b and its validation as a transiting planet. We characterize the system using data from the NASA Transiting Exoplanet Survey Satellite mission, the ESA Gaia mission, ground-based photometry from El Sauce and ASTEP400, and spectroscopy from CHIRON, FEROS, and Veloce. We find that TOI 837 is a T = 9.9 mag G0/F9 dwarf in the southern open cluster IC 2602. The star and planet are therefore million years old. Combining the transit photometry with a prior on the stellar parameters derived from the cluster color-magnitude diagram, we find that the planet has an orbital period of and is slightly smaller than Jupiter. From radial velocity monitoring, we limit to less than 1.20 M Jup (3σ). The transits either graze or nearly graze the stellar limb. Grazing transits are a cause for concern, as they are often indicative of astrophysical false-positive scenarios. Our follow-up data show that such scenarios are unlikely. Our combined multicolor photometry, high-resolution imaging, and radial velocities rule out hierarchical eclipsing binary scenarios. Background eclipsing binary scenarios, though limited by speckle imaging, remain a 0.2% possibility. TOI 837b is therefore a validated adolescent exoplanet. The planetary nature of the system can be confirmed or refuted through observations of the stellar obliquity and the planetary mass. Such observations may also improve our understanding of how the physical and orbital properties of exoplanets change in time