Vascular complications after liver transplantation: A 5-year experience

During the past 5 years, 104 angiographic studies were performed in 87 patients (45 children and 42 adults) with 92 transplanted livers for evaluation of possible vascular complications. Seventy percent of the studies were abnormal. Hepatic artery thrombosis was the most common complication (seen in 42% of children studied, compared with only 12% of adults) and was a major complication that frequently resulted in graft failure, usually necessitating retransplantation. In six children, reconstitution of the intrahepatic arteries by collaterals was seen. Three survived without retransplant. Arterial stenosis at the anastomosis or in the donor hepatic artery was observed in 11% of patients. Portal vein thrombosis or stenosis occurred in 13% of patients. Two children and one adult with portal vein thrombosis demonstrated hepatopetal collaterals that reconstituted the intrahepatic portal vessels. Uncommon complications included anastomotic and donor hepatic artery pseudoaneurysms, a hepatic artery-dissecting aneurysm, pancreaticoduodenal mycotic aneurysms, hepatic artery-portal vein fistula, biliary-portal vein fistula, hepatic vein occlusion, and inferior vena cava thrombosis

Kinetic Monte Carlo simulations of the growth of polymer crystals

Based upon kinetic Monte Carlo simulations of crystallization in a simple polymer model we present a new picture of the mechanism by which the thickness of lamellar polymer crystals is constrained to a value close to the minimum thermodynamically stable thickness, l_{min}. The free energetic costs of the polymer extending beyond the edges of the previous crystalline layer and of a stem being shorter than l_{min} provide upper and lower constraints on the length of stems in a new layer. Their combined effect is to cause the crystal thickness to converge dynamically to a value close to l_{min} where growth with constant thickness then occurs. This description contrasts with those given by the two dominant theoretical approaches. However, at small supercoolings the rounding of the crystal profile does inhibit growth as suggested in Sadler and Gilmer's entropic barrier model.Comment: 12 pages, 13 figures, revte

Traditional Knowledge of the Ecology of Beluga Whales (Delphinapterus leucas) in the Eastern Chukchi and Northern Bering Seas, Alaska

Traditional ecological knowledge (TEK) has been used opportunistically in biological studies of beluga whales (Delphinapterus leucas) in Alaska, but no previous research has documented this knowledge systematically. This first such effort, which took place in Norton Bay, Buckland, and Point Lay, Alaska, provided descriptions of migratory and local movements, feeding, calving, ecological interactions, and human influences on distribution and behavior. The results are consistent with those of previous studies but add considerable detail, including descriptions of avoidance and habituation responses to anthropogenic noise, which appear to depend in part on association with hunting activities. Making greater use of TEK will benefit both research and management by providing better information and by expanding the collaborative process developed through co-management. On a utilisé le savoir écologique traditionnel (SET) quand l'occasion se présentait, dans le cadre des études biologiques portant sur le bélouga (Delphinapterus leucas) en Alaska, mais ce savoir n'a jamais fait l'objet d'une étude systématique. Cette première tentative en ce sens, qui a été réalisée à Norton Bay, Buckland et Point Lay, en Alaska, a fourni des descriptions de déplacements migratoires et locaux, de nutrition, de mise bas, d'interactions écologiques et d'influences humaines sur la distribution et le comportement. Les résultats concordent avec ceux d'études précédentes, mais apportent de nombreux détails, y compris la description des réactions d'évitement et d'accoutumance au bruit anthropique, qui semble dépendre en partie de l'association avec les activités cynégétiques. Une plus grande utilisation du SET profitera à la fois à la recherche et à la gestion en fournissant de meilleures informations et en développant plus à fond le processus de collaboration créé par la cogestion

Theory of collective opinion shifts: from smooth trends to abrupt swings

We unveil collective effects induced by imitation and social pressure by analyzing data from three different sources: birth rates, sales of cell phones and the drop of applause in concert halls. We interpret our results within the framework of the Random Field Ising Model, which is a threshold model for collective decisions accounting both for agent heterogeneity and social imitation. Changes of opinion can occur either abruptly or continuously, depending on the importance of herding effects. The main prediction of the model is a scaling relation between the height h of the speed of variation peak and its width $w$ of the form h ~ w^{-kappa}, with kappa = 2/3 for well connected populations. Our three sets of data are compatible with such a prediction, with kappa ~ 0.62 for birth rates, kappa ~ 0.71 for cell phones and kappa ~ 0.64 for clapping. In this last case, we in fact observe that some clapping samples end discontinuously (w=0), as predicted by the model for strong enough imitation.Comment: 11 pages, 8 figure

Nitrogen deprivation induces triacylglycerol accumulation, drug tolerance and hypervirulence in mycobacteria.

Mycobacteria share with other actinomycetes the ability to produce large quantities of triacylglycerol (TAG), which accumulate as intracytoplasmic lipid inclusions (ILI) also known as lipid droplets (LD). Mycobacterium tuberculosis (M. tb), the etiologic agent of tuberculosis, acquires fatty acids from the human host which are utilized to synthesize TAG, subsequently stored in the form of ILI to meet the carbon and nutrient requirements of the bacterium during long periods of persistence. However, environmental factors governing mycobacterial ILI formation and degradation remain poorly understood. Herein, we demonstrated that in the absence of host cells, carbon excess and nitrogen starvation promote TAG accumulation in the form of ILI in M. smegmatis and M. abscessus, used as surrogate species of M. tb. Based on these findings, we developed a simple and reversible in vitro model to regulate ILI biosynthesis and hydrolysis in mycobacteria. We also showed that TAG formation is tgs1 dependent and that lipolytic enzymes mediate TAG breakdown. Moreover, we confirmed that the nitrogen-deprived and ILI-rich phenotype was associated with an increased tolerance towards several drugs used for treating mycobacterial infections. Importantly, we showed that the presence of ILI substantially enhanced the bacterial burden and granuloma abundance in zebrafish embryos infected with lipid-rich M. abscessus as compared to embryos infected with lipid-poor M. abscessus, suggesting that ILI are actively contributing to mycobacterial virulence and pathogenesis

The physical determinants of the thickness of lamellar polymer crystals

Based upon kinetic Monte Carlo simulations of crystallization in a simple polymer model we present a new picture of the mechanism by which the thickness of lamellar polymer crystals is constrained to a value close to the minimum thermodynamically stable thickness. This description contrasts with those given by the two dominant theoretical approaches.Comment: 4 pages, 4 figures, revte

The Marketing Firm: Retailer and consumer contingencies

acceptedVersionpublishedVersio

Hezbollah\u27s Operations and Networks in the United States: Two Decades in Reviews

Executive Summary ● This report aims to provide a comprehensive examination of Hezbollah-affiliated activity in America by examining all publicly-known federal criminal cases from 1997 to 2020 in the United States with a concrete link to Hezbollah. The authors found evidence of 128 individuals that meet these criteria. ● The majority of cases involve small, centralized hubs of Hezbollah operatives, who engage in illegal activities in conjunction with wider criminal enterprises to create an array of networks across America. These relationships of convenience have resulted in Hezbollah operatives collaborating with financially-motivated individuals, criminals, and other non-ideological actors, in furtherance of a broader operational mission. These arrangements, in turn, have allowed Hezbollah to profit financially and deepen its influence in the United States, even as many such cases display minimal direct connective links to the terrorist organization itself. ● Based on analysis of the cases, the authors identified two distinct categories of participation in Hezbollah-affiliated activity in America: individuals who provided financial support to Hezbollah (109 individuals), and those who provided operational support (19 individuals). ○ 87% of individuals provided financial or material support to Hezbollah as money launderers, bundlers, fraudsters, and goods smugglers, with many raising funds from others to be provided to Hezbollah or directly providing funds to the group themselves. This finding supports existing assessments that Hezbollah’s primary aspirations in the United States are to use it as a financial support hub. ○ 13% of individuals in the dataset engaged in operational conduct in support of Hezbollah, including as human smugglers, weapons procurers, pre-operational surveillance, and travelers who sought to join the group. Despite the prominence of Hezbollah’s financing activities in the United States, elements within Hezbollah remain intent on developing the capacity and capability to plot attacks on U.S. soil. ● The vast majority (92%) of cases involved network activities between two or more individuals. Larger geographic hubs operated out of Michigan (55 cases), California (19 cases), North Carolina (16 cases), and New York (15 cases). 90% of individuals operating in these four states and 76% of all cases in this dataset were a part of just six networks. ○ Large parts of network activity involved individuals with limited evidence to suggest a direct link to Hezbollah. As discussed above, these individuals actively collaborated with persons with an evidenced connection to the terrorist organization, and in many cases appear to be driven primarily by financial rather than ideological motivations. This in and of itself is a manifestation of Hezbollah’s activities in the United States, which sought to use local criminal actors in furtherance of their illegal activities. Further, in several significant instances, network activity often involved friends or family members engaged in organized conspiracies. ● 84% of individuals were convicted and sentenced to an average of 49.6 months in prison. Notably, only 19 of the 128 individuals (14%) were charged with providing material support to Hezbollah, while the others were charged with non-terrorism related offenses. Individuals sentenced on terrorism material support charges received an average sentence length of 85.6 months, almost twice as long as the average sentence for individuals not sentenced on material support charges. ● Hezbollah-affiliated individuals were primarily male (83%) and tended to be older (average age: 37) than members of other designated foreign terrorist organizations in the US, in particular the Islamic State (average age: 28)

Pseudo-potentials and loading surfaces for an endochronic plasticity theory with isotropic damage

The endochronic theory, developed in the early 70s, allows the plastic behavior of materials to be represented by introducing the notion of intrinsic time. With different viewpoints, several authors discussed the relationship between this theory and the classical theory of plasticity. Two major differences are the presence of plastic strains during unloading phases and the absence of an elastic domain. Later, the endochronic plasticity theory was modified in order to introduce the effect of damage. In the present paper, a basic endochronic model with isotropic damage is formulated starting from the postulate of strain equivalence. Unlike the previous similar analyses, in this presentation the formal tools chosen to formulate the model are those of convex analysis, often used in classical plasticity: namely pseudopotentials, indicator functions, subdifferentials, etc. As a result, the notion of loading surface for an endochronic model of plasticity with damage is investigated and an insightful comparison with classical models is made possible. A damage pseudopotential definition allowing a very general damage evolution is given

A Candidate M31/M32 Intergalactic Microlensing Event

We report the discovery of a microlensing candidate projected 2'54" from the center of M32, on the side closest to M31. The blue color (R-I= 0.00 +/- 0.14) of the source argues strongly that it lies in the disk of M31, while the proximity of the line of sight to M32 implies that this galaxy is the most likely host of the lens. If this interpretation is correct, it would confirm previous arguments that M32 lies in front of M31. We estimate that of order one such event or less should be present in the POINT-AGAPE data base. If more events are discovered in this direction in a dedicated experiment, they could be used to measure the mass function of M32 up to an unknown scale factor. By combining microlensing observations of a binary-lens event with a measurement of the M31-M32 relative proper motion using the astrometric satellites SIM or GAIA, it will be possible to measure the physical separation of M31 and M32, the last of the six phase-space coordinates needed to assign M32 an orbit.Comment: Submitted to ApJ Letters. 13 pages, 2 figure