Earth Sciences: Two-Ice-Lobe Model For Kansan Glaciation

The Kansan glaciation should be representative of Early Pleistocene glaciations in the Kansas-Nebraska-Iowa-Missouri region. It is often assumed the Kansan ice-sheet advanced as a single, broad lobe coming from somewhere in Canada. This simple view contrasts with the known complexities of the younger Wisconsin glaciation, and indeed there is much evidence that the Kansan glaciation was equally complex. A two-ice-Iobe model for the Kansan glaciation includes two confluent ice-streams, Dakota Ice and Minnesota Ice, both moving generally southward either side of the Coteau des Prairies in eastern South Dakota. Iowa and Missouri were covered mainly by Minnesota Ice, while Dakota Ice advanced into Nebraska and Kansas. The general boundary zone between the two ice-lobes is marked by the Kansas City re-entrant and by the Missouri River north of Kansas City, which may have developed as an interlobate drainage during deglaciation

Glaciotectonic Structures in Central Sweden and their Significance for Glacial Theory

Various glaciotectonic structures and landforms created by ice pushing are common in drift and interstadial sediments in a narrow belt of central Sweden. Described examples from the Lake Storsjôn vicinity demonstrate that glaciotectonic deformation took place while the area was deeply covered by the last Fennoscandian Ice Sheet. Deformation was controlled by pressure gradients related to position of the ice divide and ice movement away from the divide. As the position of the divide shifted during the last glaciation, so did the orientation of glaciotectonic structures. The regional distribution of glaciotectonic features in Fennoscandia falls into three zones: (1) inner zone of widespread, small- to moderate-sized features in older drift, (2) intermediate zone of small, isolated features in drift of the last glaciation, and (3) outer zone with all manner of large and small features in drift and soft bedrock. These zones are the cumulative results of multiple glaciations and reflect the overall distribution of deformable sediment and bedrock within the continental substratum.Diverses structures glaciotectoniques et formes engendrées par la poussée des glaces sont courantes dans les dépôts glaciaires et les sédiments interstadiaires d'une étroite zone du centre de la Suède. La description de certains exemples observés dans les environs du lac Storsjôn démontre que des déformations glaciotectoniques se sont produites pendant que la région était profondément enfouie sous le dernier inlandsis finnoscandien. Les déformations étaient commandées par le gradient de pression en relation avec la position de la ligne de partage glaciaire et le mouvement des glaces en direction opposée de cette ligne. Au cours de la dernière glaciation, l'orientation des structures glaciotectoniques s'est déplacée en même temps que la ligne de partage des glaces. En Finnoscandinavie, les structures glaciotectoniques se répartissent en trois zones: 1) une zone interne où les éléments de petite à moyenne tailles abondent dans des dépôts anciens; 2) une zone intermédiaire où de petits éléments sont isolés dans les dépôts de la dernière glaciation; et 3) une zone externe où des éléments de toutes tailles se trouvent dans les dépôts et le substratum sédimentaire. Ces zones sont le résultat du cumul des multiples glaciations et reflètent la répartition totale des sédiments et du substratum non résistant à l'intérieur du socle continental.Glacialtektoniska strukturer i Mellan-Sverige och deras betydelse for glaciationsteorin. Glacialtektoniska strukturer och landformer uppkomna genom istryck âr vanliga i glaciala och interstadiala sediment i ett smalt stràk genom mellersta Sverige. De beskrivna exemplen fran Storsjôtrakten visar att glacialtektonisk deformation skedde medan omràdet ànnu var tâckt av mâktig inlandsis. Deformationen uppkom genom ett tryck, vars riktning bestamdes av lâget i fôrhallande till isdelaren och isytans lutning fran deanna. Dà isdelarens lâge àndrades under loppet av den senaste glaciationen, àndrades ocksà orienteringen av de glacialtektoniska strukturerna. De glacialtektoniska fenomenen i Fennoskandia fôrdelar sig regionalt pà tre zoner: (1)en inre zon med vitt utbredda sma till medelstora strukturer i àldre glaciala bildningar, (2) en mellanzon med smâ, isolerade strukturer i glaciala bildningar fràn den senaste glaciationen, och (3) en yttre zon med alla typer av stora och sma former och strukturer i de glaciala bildningarna och deras berggrundsunderlag. Dessa zoner utgôr det samlade resultatet av inverkan fràn upprepade glaciationer och àterspeglar utvecklingen under lang tid av de stora inlandsisarnas underlag

The relationship between regional variations in blood flow and histology in a transplanted rat fibrosarcoma

The regional distribution of blood flow to the LBDS1 fibrosarcoma, transplanted into the subcutaneous site in rats, was investigated using the readily diffusible compound 14C-iodo-antipyrine (14C-IAP). Quantitative autoradiography was used to establish absolute values of specific blood flow F for 100 X 100 X 20 microns adjacent tissue volumes of the unperturbed tumour. Mean blood flow to whole tumours was found to decrease with increase in tumour size. This relationship was abolished if blood flow was only measured in sections cut from the periphery of the tumours. Detailed analysis of a sub-group of tumours showed that blood flow to individual tumours was heterogeneous. The range of blood flow was large, indicating that mean blood flow to a whole tumour is a poor reflection of the blood perfusion pattern of that tumour. Necrotic tumour regions were usually very poorly perfused. With the exception of the smallest tumours studied, blood flow was lower in the centre of tumours than in the periphery. Necrosis also tended to develop centrally. However, the peripheral to central gradient of blood flow was apparent even when densely cellular, viable tumour regions and necrotic regions were analysed separately. The decrease in blood flow with tumour size was also apparent in densely cellular, viable tumour regions when analysed separately. Qualitative comparison of tumour histology and regional blood flow showed that there were areas of very low blood flow associated with viable tumour regions. Less common were areas of rather high blood flow associated with necrotic tumour regions. A complicated relationship exists between tumour histology and blood flow. The quantitative autoradiography technique is suitable for investigating the most poorly perfused and the most well perfused viable fractions of animal tumours which may limit the efficacy of different types of therapy

Benign Cystic Mesothelioma: A Rare Cause for Scrotal Swelling

Benign cystic mesothelioma of the tunica vaginalis is a rare occurrence. It usually presents with painless gradual swelling in the scrotum. These types of benign mesotheliomas typically occur in the peritoneum and usually affect young to middle-aged patients. We present in this case an unusual case of benign cystic mesothelioma of the tunica vaginalis in a 77-year-old male patient

Volume–outcome relationships in open and endovascular repair of abdominal aortic aneurysm : administrative data 2006–2018

Background The aim of this study was to use recent evidence to investigate and update volume–outcome relationships after open surgical repair (OSR) and endovascular repair (EVAR) of abdominal aortic aneurysm in England. Methods Hospital Episode Statistics (HES) data from April 2006 to March 2018 were obtained. The primary outcome was in‐hospital death. Other outcomes included duration of hospital stay, readmissions within 30 days, and critical care requirements. Case‐mix adjustment included age, sex, HES year, deprivation index, weekend admission, mode of admission, type of procedure and co‐morbidities. Results Annual volume of all repairs combined appeared to be an appropriate measure of volume. After case‐mix adjustment, a significant relationship between volume and in‐hospital mortality was seen for OSR (P < 0·001) but not for EVAR (P = 0·169 for emergency and P = 0·363 for elective). The effect appeared to extend beyond 60 repairs per year to volumes above 100 repairs per year. There was no significant relationship between volume and duration of hospital stay or 30‐day readmissions. In patients receiving emergency OSR, higher volume was associated with longer stay in critical care. Conclusion Higher annual all‐procedure volumes were associated with significantly lower in‐hospital mortality for OSR, but such a relationship was not significant for EVAR. There was not enough evidence for a volume effect on other outcomes

Rotary blood pump

A rotary blood pump is presented. The pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial, and radial clearances of the blades associated with the flow straightener, inducer portion, impeller portion, and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with crosslinked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency

Rotary Blood Pump

A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency

Method for Reducing Pumping Damage to Blood

Methods are provided for minimizing damage to blood in a blood pump wherein the blood pump comprises a plurality of pump components that may affect blood damage such as clearance between pump blades and housing, number of impeller blades, rounded or flat blade edges, variations in entrance angles of blades, impeller length, and the like. The process comprises selecting a plurality of pump components believed to affect blood damage such as those listed herein before. Construction variations for each of the plurality of pump components are then selected. The pump components and variations are preferably listed in a matrix for easy visual comparison of test results. Blood is circulated through a pump configuration to test each variation of each pump component. After each test, total blood damage is determined for the blood pump. Preferably each pump component variation is tested at least three times to provide statistical results and check consistency of results. The least hemolytic variation for each pump component is preferably selected as an optimized component. If no statistical difference as to blood damage is produced for a variation of a pump component, then the variation that provides preferred hydrodynamic performance is selected. To compare the variation of pump components such as impeller and stator blade geometries, the preferred embodiment of the invention uses a stereolithography technique for realizing complex shapes within a short time period

Axial Pump

A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency