Liver microcirculation analysis by red blood cell motion modeling in intravital microscopy images

Intravital microscopy has been used to visualize the microcirculation by imaging fluorescent labeled red blood cells (RBCs). Traditionally, microcirculation has been modeled by computing the mean velocity of a few, randomly selected, manually tracked RBCs. However, this protocol is tedious, time consuming, and subjective with technician related bias. We present a new method for analyzing the microcirculation by modeling the RBC motion through automatic tracking. The tracking of RBCs is challenging as in each image, as many as 200 cells move through a complex network of vessels at a wide range of speeds while deforming in shape. To reliably detect RBCs traveling at a wide range of speeds, a window of temporal template matching is applied. Then, cells appearing in successive frames are corresponded based on the motion behavior constraints in terms of the direction, magnitude, and path. The performance evaluation against a ground truth indicates the detection accuracy up to 84% TP at 6% FP and a correspondence accuracy of 89%. We include an in-depth discussion on comparison of the microcirculation based on motion modeling from the proposed automated method against a mean velocity from manual analysis protocol in terms of precision, objectivity, and sensitivity.     

Vom Damaststahl zum Scharsachstahl

Verbesserung der Schwertklingen durch Damaszierung. Nachweis des Übergangs auf eine andere Schmiedetechnik in der Ritterzeit (11. bis 14. Jh.) an Hand von zwölf mittelalterlichen Schwertern, die aus in der Steiermark hergestellten Stählen nach der Gärbtechnik gefertigt wurden. Kennzeichnung des sogenannten Scharsachstahles mit rd. 0,80% C und seine Verarbeitung zu Schwertklingen mit hoher Elastizität.     

Über die Grundlagen der Warmfestigkeit,dargestellt an legierten Stählen

Darstellung der bei reinen Metallen sowie homogen und heterogen aufgebauten Legierungen das Kriechverhalten bestimmenden Vorgänge. Übertragung der Modellvorstellungen auf die Gegebenheiten bei warmfesten Stählen. Zusammenhang zwischen dem Werkstoffaufbau (Gefüge, Ausscheidungszustand) und den Langzeit-Festigkeitseigenschaften legierter Stähle mit Chrom und Molybdän sowie Chrom, Molybdän und Vanadin.     

Gene transfer therapy for heritable disease: cell and expression targeting

Gene therapy is defined as the delivery of a functional gene for expression in somatic tissues with the intent to cure a disease. Different gene transfer strategies may be required to target different tissues. Adenosine deaminase (ADA) deficiency is a good gene therapy model for targeting a rare population of pluripotent hematopoietic stem cells capable of self-renewal. We present evidence for the highly efficient gene transfer and sustained expression of human ADA in human primitive hematopoietic progenitors using retroviral supernatant with a supportive stromal layer. A stem cell-enriched (CD34+) fraction was also successfully transduced. Duchenne muscular dystrophy (DMD) is also a good model for somatic gene therapy. Two of the challenges presented by this model are the large size of the gene and the large number of target cells. Germline gene transfer and correction of the phenotype has been demonstrated in transgenic mdx mice using both a full-length and a truncated form of the dystrophin cDNA. We present here a deletion mutagenesis strategy to truncate the dystrophin cDNA such that it can be accommodated by retroviral and adenoviral vectors useful for somatic gene therapy.     

1,25-Dihydroxyvitamin D induces lipoprotein lipase expression in 3T3-L1 cells in association with adipocyte differentiation

1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] is known to modulate the development of bone and other mesenchymal cell types. Since osteoblasts and adipocytes are thought to arise in bone marrow from a common progenitor, this work examined the effects of 1,25-(OH)2D3 on adipocyte development, and in particular on the expression of lipoprotein lipase (LPL), which is an early marker for the differentiated adipocyte. 3T3-L1 preadipocytes were cultured in the presence of 1,25-(OH)2D3 (10(-9) to 10(-7) M) for up to 7 days. LPL activity was measured in the medium and cell extracts, and LPL messenger RNA levels were measured by Northern blotting. When compared to control cells, 10(-7) M 1,25-(OH)2D3 increased medium LPL activity by 2- to 3-fold and cellular LPL by 1.5-fold. Significant increases in medium and cellular LPL were observed at 10(-9) M and were maximal at 10(-7) M. Along with the increase in LPL activity, there was an increase in LPL messenger RNA by 2-fold at 5 days, and by 5-fold at 7 days. In addition to an increase in LPL, 1,25-(OH)2D3 increased expression of aP2, an adipocyte-specific marker associated with differentiation. After the addition of 1,25-(OH)2D3, there was a decrease in 3T3-L1 cell number, which is consistent with differentiation, and a decrease in vitamin D receptors. Finally, these cells developed a different morphology. 1,25-(OH)2D3-treated cells assumed a rounded appearance, although without detachment from the dish and without the degree of lipid accumulation usually associated with the addition of insulin, isbutylmethylxanthine, and dexamethasone. It is concluded that 1,25-(OH)2D3 induced LPL expression in 3T3-L1 cells through an induction of differentiation-dependent mechanism(s). These findings suggest an important role for 1,25-(OH)2D3 in normal adipocyte differentiation.     

Statistical Modeling of the Serviceability of Sewage Pumps

Sewage pumping stations represent an element of the sewer system, which is directly responsible for affecting serviceability; i.e., failing pumps may result in combined sewer overflows or flooding. However, failures of sewage pumps are not yet incorporated in sewer assessments due to lack of data. This paper presents the analysis of pump failure data provided by two sewer management authorities in The Netherlands. Pump failures have been studied accounting for the nature of the failures, the operation and maintenance procedures of the management authority, the aging of the pumps, and the changes in the environment of pumps. The analysis shows that sewage pumps fail relatively often due to the composition of sewage and the discontinuous operation of the pumps. The interarrival time and the duration of failures are highly variable and independent of the specific function of the pump. Resulting pump failure characteristics are applied in a Monte Carlo simulation to calculate the impact of failures on combined sewer overflow volumes. The results indicate that the serviceability of sewer systems is significantly affected by failing pumps. Therefore, including pump availability in sewer system assessments should be considered.     

Effect of Sintering on the Thermoelectric Transport Properties of Bulk Nanostructured Bi0.5Sb1.5Te3 Pellets Prepared by Chemical Synthesis

Considerable research effort has gone into improving the performance of traditional thermoelectric materials such as Bi_2?x Sb _x Te₃ through a variety of nanostructuring approaches. Bottom-up, chemical approaches have the potential to produce very small nanoparticles (?100?nm) with narrow size distribution and controlled shape. For this study, nanocrystalline powder of Bi_0.5Sb_1.5Te₃ was synthesized using a ligand-assisted chemical method, and consolidated into pellets with cold pressing followed by sintering in Ar atmosphere. The thermoelectric transport properties were measured from 7?K to 300?K as a function of sintering temperature. Sintering is found to increase ZT and to move the maximum in ZT to lower temperatures due to a reduction in the free charge concentration. Hall mobility studies indicate that sintering increases the electron mean free path more than it increases the phonon mean free path up to sintering temperature of 598?K. A maximum ZT of 0.42 was measured at temperature of 275?K.