407 research outputs found
Hemodynamic Optimization Strategies in Anesthesia Care for Liver Transplantation
In this chapter, aspects of hemodynamic regulation in the end-stage liver disease (ESLD) patient, factors, contributing to the hemodynamic profile, coagulation-related problems, blood products transfusion tactics and problems, and hemodynamic optimization strategies during different stages of liver transplantation procedureâspecifically what, when, and how to correct, with special attention to vasoactive agents use, will be discussed
Nonischemic Cardiomyopathy in Liver Transplant Recipients
Nonischemic cardiomyopathy is a collective term, encompassing a spectrum of cardiac comorbidities, accompanying the progressing end-stage liver disease. Alcoholic and cirrhotic cardiomyopathies are the most researched, well-known clinical entities in the list of nonischemic cardiac disorders that bear the most substantial impact on the clinical course, management, and outcomes of liver transplantation in ESLD patients. In this chapter, morphology, pathophysiology, diagnostic criteria, clinical manifestations, and management options of nonischemic cardiomyopathy in liver transplant candidates and recipients, the patients with end-stage liver disease due to advanced stages of cirrhosis, are discussed
Aggregatable Distributed Key Generation
In this paper, we introduce a distributed key generation (DKG) protocol with aggregatable and publicly-verifiable transcripts. Compared with prior publicly-verifiable approaches, our DKG reduces the size of the final transcript and the time to verify it from O(n2) to O(nlogn) , where n denotes the number of parties. As compared with prior non-publicly-verifiable approaches, our DKG leverages gossip rather than all-to-all communication to reduce verification and communication complexity. We also revisit existing DKG security definitions, which are quite strong, and propose new and natural relaxations. As a result, we can prove the security of our aggregatable DKG as well as that of several existing DKGs, including the popular Pedersen variant. We show that, under these new definitions, these existing DKGs can be used to yield secure threshold variants of popular cryptosystems such as El-Gamal encryption and BLS signatures. We also prove that our DKG can be securely combined with a new efficient verifiable unpredictable function (VUF), whose security we prove in the random oracle model. Finally, we experimentally evaluate our DKG and show that the per-party overheads scale linearly and are practical. For 64 parties, it takes 71 ms to share and 359 ms to verify the overall transcript, while for 8192 parties, it takes 8 s and 42.2 s respectively
Perron Conditions for Stability of Linear Skew- Product Semiflows in Banach Spaces
In this paper we give necessary and sufficient conditions for uniform exponential stability of linear skew-product semiflows in Banach spaces. We give theorems of characterization for uniform exponential stability of linear skew-product semiflows in terms of boundedness of some operators acting
Do Irrelevant Sounds Impair the Maintenance of All Characteristics of Speech in Memory?
Several studies have shown that maintaining in memory some attributes of speech, such as the content or pitch of an interlocutor's message, is markedly reduced in the presence of background sounds made of spectrotemporal variations. However, experimental paradigms showing this interference have only focused on one attribute of speech at a time, and thus differ from real-life situations in which several attributes have to be memorized and maintained simultaneously. It is possible that the interference is even greater in such a case and can occur for a broader range of background sounds. We developed a paradigm in which participants had to maintain the content, pitch and speaker size of auditorily presented speech information and used various auditory distractors to generate interference. We found that only distractors with spectrotemporal variations impaired the detection, which shows that similar interference mechanisms occur whether there are one or more speech attributes to maintain in memory. A high percentage of false alarms was observed with these distractors, suggesting that spectrotemporal variations not only weaken but also modify the information maintained in memory. Lastly, we found that participants were unaware of the interference. These results are similar to those observed in the visual modalit
Integrative paleobotany: Affirming the role of fossils in modern plant biology - Introduction and dedication
If you are interested in plant evolution, try this quick exercise: take a phylogenetic tree of the plant kingdom, close your eyes, and point your finger randomly to a node of the phylogeny. Irrespective of the clade to which you are pointing, there is one thing you should know about it: the living representatives of that clade have evolved as a result of a long process in which failed attempts are the rule, and as a result, the diversity of extinct forms accumulated in the fossil record far exceeds that recorded in the extant flora. From this simple concept, Gar W. Rothwell made his career. Because of that, here is a second thing you should know about the plant clade to which you pointed at random: Gar has, more likely than not, contributed information about evolution in that clade at some point in his career. Gar was one of the principal contributors to the revival of paleobotany from a largely descriptive discipline to a vibrant field of investigation at the forefront of modern evolutionary sciences that contributes crucial insights into plant evolution, equal in importance to those provided by genetics and molecular biology. Because of this, the impact of Garâs scientific contributions reaches far beyond the field of paleobotany, with important implications for wide areas of plant biology, including anatomy and morphology, development, systematics, phylogeny, and evolution. Gar earned a masterâs degree in the laboratory of Thomas N. Taylor (University of Illinois at Chicago, 1966) studying Paleozoic seeds in the genus Conostoma (Rothwell and Eggert 1970; Rothwell 1971a). He subsequently earned his PhD degree in the laboratory of Wilson N. Stewart (University of Alberta, 1973), where he reconstructed the plants in the seed fern genus Callistophyton (Rothwell 1972b, 1975, 1980, 1981). His work was instrumental in ushering in studies of fossil plants as whole living organisms, looking at both structure and development. These early experiences launched Gar on a career in plant evolutionary biology that stretched over a half century, during which he occupied positions at the University of Alberta, University of LondonâChelsea College, Ohio University, and Oregon State University. Throughout his career, Garâs scholarly work and contributions have been recognized by numerous awards and honors: the Isabel Cookson Award, the Edgar T. Wherry Award, the Michael A. Cichan Award, the Merit Award of the Botanical Society of America, and honorary membership in the International Organization of Palaeobotany, where he served for 12 years as secretary-treasurer and president.Fil: Escapa, Ignacio HernĂĄn. Museo PaleontolĂłgico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Tomescu, Alexandru M. F.. Humboldt State University. Department of Biological Sciences; Estados UnidosFil: Dunn, Michael T.. Cameron University. Department of Agriculture, Biology and Health Science; Estados UnidosFil: Stockey, Ruth A.. State University of Oregon; Estados Unido
G1m1 predominance of intrathecal virus-specific antibodies in multiple sclerosis
We have previously shown that plasmablasts of the G1m1 allotype of IgG1 are selectively enriched in the cerebrospinal fluid of G1m1/G1m3 heterozygous patients with multiple sclerosis, whereas both allotypes are equally used in neuroborreliosis. Here, we demonstrate a strong preference for the G1m1 allotype in the intrathecal humoral immune responses against measles, rubella, and varicella zoster virus in G1m1/G1m3 heterozygous multiple sclerosis patients. Conversely, intrathecally synthesized varicella zoster virusâspecific IgG1 in varicella zoster virus meningoencephalitis comprised both allotypes. This implies that G1m1 B cells are selected to the central nervous system of multiple sclerosis patients regardless of specificity and suggests that an antigenâindependent mechanism could drive the intrathecal humoral immune response.publishedVersio
RNA Polymerase Pausing during Initial Transcription
In bacteria, RNA polymerase (RNAP) initiates transcription
by synthesizing short transcripts that are
either released or extended to allow RNAP to escape
from the promoter. The mechanism of initial transcription
is unclear due to the presence of transient
intermediates and molecular heterogeneity. Here,
we studied initial transcription on a lac promoter
using single-molecule fluorescence observations
of DNA scrunching on immobilized transcription
complexes. Our work revealed a long pause (ââinitiation
pause,ââ ïżœ20 s) after synthesis of a 6-mer RNA;
such pauses can serve as regulatory checkpoints.
Region sigma 3.2, which contains a loop blocking
the RNA exit channel, was a major pausing determinant.
We also obtained evidence for RNA backtracking
during abortive initial transcription and for
additional pausing prior to escape. We summarized
our work in a model for initial transcription, in which
pausing is controlled by a complex set of determinants
that modulate the transition from a 6- to a
7-nt RNA
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A Perithecial Sordariomycete (Ascomycota, Diaporthales) from the Lower Cretaceous of Vancouver Island, British Columbia, Canada
A perithecial ascomycete, Spataporthe taylori gen. et sp. nov., represented by >70 sporocarps is preserved by
cellular permineralization in marine carbonate concretions dated at the Valanginian-Hauterivian boundary (Early
Cretaceous) from Vancouver Island, British Columbia, Canada. The spheroid perithecia with lumina 330â470 ”m
wide and 220â320 ”m high are densely distributed and entirely immersed in the tissues of a coniferous leaf. The
perithecial wall consists of an outer layer of large pseudoparenchyma and an inner layer of thin filamentous
nature. Perithecial necks are incompletely preserved due to taphonomic abrasion; they have a bell-shaped chamber
at the base and a narrow channel, with longitudinally aligned hyphae above. The basal chamber of the neck is
filled with a plug of pseudoparenchyma, which subsequently disintegrates to form a peripheral collar; periphyses
are present on the basal chamber walls. A pseudoparenchymatous hymenium lines the bottom of perithecia. Asci
are clavate, with thinly tapered bases, and small (30â47 ”m long and 12â20 ”m wide at tip), ornamented with
minute papillae. They become detached from the hymenium to float freely in the perithecium. No unequivocal
ascospores were found, although smaller units are present in some of the asci. The combination of immersed
perithecia with complex wall structure and a well-defined hymenium, absence of paraphyses, and persistent,
detachable inoperculate asci is consistent with order Diaporthales of class Sordariomycetes. The small clavate asci
are comparable to those found in family Gnomoniaceae. Perithecioid ascomata are rare in the fossil record, and
bona fide perithecia are known with certainty only from the Early Devonian Rhynie Chert and Cenozoic amber.
Spataporthe taylori contributes a well-characterized Early Cretaceous occurrence, which is also the oldest to date,
to the scarce fossil record of the Sordariomycetes and a second taxon to the fungal flora of the locality, which also
includes a basidiomycete. As the oldest representative of the Diaporthales, Spataporthe provides a minimum age
(136 Ma) for the order and a direct calibration point for studies of divergence times in the ascomycetes.This is the publisherâs final pdf. The published article is copyrighted by the University of Chicago Press and can be found at: http://www.press.uchicago.edu/index.html.Keywords: Gnomoniaceae, Ascomycota, Diaporthales, Cretaceous, Spataporthe, Sordariomycete
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