The cardinality of the augmentation category of a Legendrian link

We introduce a notion of cardinality for the augmentation category associated to a Legendrian knot or link in standard contact R^3. This `homotopy cardinality' is an invariant of the category and allows for a weighted count of augmentations, which we prove to be determined by the ruling polynomial of the link. We present an application to the augmentation category of doubly Lagrangian slice knots

Experimental Investigation of Mechanical Blood Damage Relevant to the Operation of Circulatory-Assist Devices

Circulatory-assist devices (CAD) are commonly used in clinical practice for end stage cardiovascular disease patients as a bridge to transplant or as destination therapy. Despite decades of research, mechanical blood damage remains a problem in the clinical utilization of CAD, which results in a myriad of patient complications including device-induced erythrocyte lysis (hemolysis), bleeding and thrombosis. There is a clinical need to better understand the mechanisms of flow-induced blood damage to aid in the design and clinical utilization of CAD with enhanced biocompatibility as well as to determine specific factors responsible for blood damage and methods of their assessment. The objectives were to study in vitro the mechanisms of flow-induced blood trauma and the parameters that affect in vitro hemolysis testing of CAD. The tested hypotheses were: 1) Mechanically induced polymer degradation in a high molecular weight polyethylene oxide (PEO) solution could predict the degree of shear-induced hemolysis within a CAD candidate without the use of animal or human blood; 2) Blood bank storage of packed red blood cells (RBC) could adversely affect RBC mechanical properties which may reduce the efficiency of RBC transfusion in CAD patients; 3) Cell-cell interactions and suspension viscosity are potential mechanisms of flow-induced hemolysis; and 4) The geometry of micro-gaps and crevices in CAD blood flow paths could affect cell trafficking at supra-physiological shear stresses relevant to operating CAD. We demonstrated that polymer mechanical degradation was highly correlated with hemolysis obtained due to circulation in the same CAD circuit as blood and ascertained valuable information on CAD performance predicting blood trauma without the need to use blood. We found that RBC deformability significantly decreased during blood bank storage which contributes to blood damage produced by CAD. Moreover, two additional mechanisms of flow-induced hemolysis relevant to operating CAD, cell-cell collisions and suspension viscosity, were elucidated. Finally, recirculating regions were observed in 100 µm wide rectangular and triangular crevices but not in wider crevices studied up to 500 µm, thus demonstrating the importance of the width of gaps and crevices in CAD blood flow paths for potential thrombogenesis. This work provided information on mechanisms of flow-induced hemolysis and elucidated an important variable affecting thrombosis development in CAD blood flow paths at flow conditions relevant to in vitro and in vivo CAD operation. These results can contribute to the computational analysis, design and preclinical testing of next generation CAD

U-Pb zircon age of the Krásné Loučky tuffite: the dating of Visean flysch in the Moravo-Silesian Paleozoic Basin (Rhenohercynian Zone, Czech Republic)

The only pre vi ous U-Pb zir con date for the the Early Car bon if er ous flysch se quence of the Moravo-Silesian Pa leo zoic Ba sin was pub lished in 1987 from tuffogenic ma te rial from Kobylí Quarry at Krásné Louèky near the town of Krnov (Silesia, Czech Re pub lic). The mea sured age of 319 Ma did not agree with its strati graphic po si tion, and was used as the ba sis for a hy poth e - sized block of Late Car bon if er ous paralic molasse in cor po rated dur ing a later tec tonic event. Dur ing a sur vey of the still-ac - tive quarry in 2010, volcaniclastic ho ri zons were iden ti fied and sam pled. Di rect cor re spon dence of the tuff units to those sam pled in 1987 can not be proved but is likely. High pre ci sion chem i cal abra sion – ther mal ion iza tion mass spec trom e try (CA-TIMS) U-Pb dat ing of zir con from this new ma te rial has yielded an age of 340.05 ± 0.22 Ma, which cor re lates to the pre vi - ously in ferred strati graphic age of the lo cal ity and the cur rent cal i bra tion of the Early Car bon if er ous geo logic time scale. The newly es tab lished age cor re sponds to the Visean stage and dates the bound ary be tween the Horní Benešov and Moravice for ma tions that can be cor re lated with other foredeep bas ins of the Culm in the Eu ro pean Variscides. A pop u la tion of de tri tal Cambro-Or do vi cian zir cons and a sin gle 2.0 Ga old zir con crys tal from the same volcaniclastic layer dated by la ser ab la tion in duc tively cou pled plasma mass spec trom e try (LA-ICPMS) are con sis tent with the known age of source ma te rial in the Variscan orogenic front.Web of Science58467265

The radioisotopically constrained Viséan onset of turbidites in the Moravian-Silesian part of the Rhenohercynian foreland basin (Central European Variscides)

The Březina Formation represents the initiation of siliciclastic flysch turbidite sedimentation at the eastern margin of Bohemian Massif or within the Rhenohercynian foreland basin. Its deposition started after drowning of the Devonian carbonate platform during Viséan (Mississippian) times, resulting in a significant interval of black siliceous shale and variegated fossiliferous shale deposition in a starved basin. Near the top of the Březina Formation an acidic volcanoclastic layer (tuff) of rhyolitic composition has been dated with high precision U-Pb zircon chemical abrasion isotope dilution method at 337.73 +/- 0.16 Ma. This new radiometric age correlates with the previously inferred stratigraphic age of the locality and the current calibration of the Early Carboniferous geologic time scale. Shales of the Březina Formation pass gradually upwards into the siliciclastics of the Rozstání Formation of the Drahany culm facies. Thus our new age offers one of the few available radioisotopic constraints on the time of onset of siliciclastic flysch turbidites in the Rhenohercynian foreland basin of the European Variscides.Web of Science107272771

Astronomical forcing of Carboniferous paralic sedimentary cycles in the Upper Silesian Basin, Czech Republic (Serpukhovian, latest Mississippian): New radiometric ages afford an astronomical age model for European biozonations and substages

The similar to 3-km-thick Ostrava Formation in the foreland Upper Silesian Basin, which is located along the Czech Polish border, provides the thickest and most complete record of mixed shallow-marine to continental sediments of Serpukhovian (Carboniferous) age in the former equatorial Pangea. The coal-bearing strata of the formation show a prominent rhythmic architecture with similar to 200 faunal bands, of which approximately 80 contain marine fauna. Three new and three existing U-Pb zircon ages of intercalated volcanic tuffs measured using chemical abrasion isotope dilution thermal ionization mass spectrometry (CA-IDTIMS) allow for the calibration of rhythmic patterns of several orders. The genetic sequences show an average duration of 100 kyr, in line with orbital forcing by short eccentricity. This allows the astronomical tuning of these cycles in the Ostrava Formation to a time axis with a resolution of 100 kyr, providing temporal constraints on lithostratigraphic units, floral and ammonoid biozones, and West European substages. The Pendleian/Arnsbergian boundary defined at the base of the E2a ammonoid zone is now constrained to 325.9 Ma and the base of the Lyginopteris stangeri Zone at the base of the Ostrava Formation to similar to 329.2 Ma. The boundary of this zone with the subsequent L. larischii Zone corresponds to the base of the Jaklovec Member at similar to 325.8 Ma. The correlation of the major marine bands with equivalent bands in the Pennine Basin (England) and the Midland Valley of Scotland based on ammonoid faunas is suggested.Web of Science17774171