122 research outputs found
Symbolic computation with finite quandles
Algorithms are described and Maple implementations are provided for finding
all quandles of order , as well as computing all homomorphisms between two
finite quandles or from a finitely presented quandle (e.g., a knot quandle) to
a finite quandle, computing the automorphism group of a finite quandle, etc.
Several of these programs work for arbitrary binary operation tables and hence
algebraic structures other than quandles. We also include a stand-alone C
program which finds quandles of order and provide URLs for files containing
the results for 7 and 8.Comment: 6 pages. Version 2 includes some updates and corrections. Code has
been relocated to www.esotericka.org/quandles. To appear in J. Symbolic
Computatio
Endoscopic balloon dilation of Crohn’s disease strictures-safety, efficacy and clinical impact
To evaluate the incidence of anastomotic strictures after intestinal resection in Crohn’s disease (CD), demonstrate long-term efficacy and safety of endoscopic balloon dilation (EBD) in CD strictures and its impact on the diagnosis of subclinical postoperative endoscopic recurrence
PADLL: Taming Metadata-intensive HPC Jobs Through Dynamic, Application-agnostic QoS Control
Modern I/O applications that run on HPC infrastructures are increasingly
becoming read and metadata intensive. However, having multiple concurrent
applications submitting large amounts of metadata operations can easily
saturate the shared parallel file system's metadata resources, leading to
overall performance degradation and I/O unfairness. We present PADLL, an
application and file system agnostic storage middleware that enables QoS
control of data and metadata workflows in HPC storage systems. It adopts ideas
from Software-Defined Storage, building data plane stages that mediate and rate
limit POSIX requests submitted to the shared file system, and a control plane
that holistically coordinates how all I/O workflows are handled. We demonstrate
its performance and feasibility under multiple QoS policies using synthetic
benchmarks, real-world applications, and traces collected from a production
file system. Results show that PADLL can enforce complex storage QoS policies
over concurrent metadata-aggressive jobs, ensuring fairness and prioritization.Comment: To appear at 23rd IEEE/ACM International Symposium on Cluster, Cloud
and Internet Computing (CCGrid'23
Maternal alcohol ingestion reduces SP-A expression by pre-term fetal lung epithelia
In addition to neurodevelopmental effects, alcohol consumption at high levels during pregnancy is associated with immunomodulation and premature birth. Premature birth, in turn, is associated with increased susceptibility to various infectious agents such as Respiratory Syncytial Virus (RSV). The initial line of pulmonary innate defense includes the mucociliary apparatus, which expels microorganisms trapped within the airway secretions. Surfactant proteins A and D (SP-A and SP-D, respectively) are additional components of pulmonary innate immunity and have an important role in pulmonary defense against inhaled pathogens. The purpose of this study was to determine if chronic alcohol consumption during the third trimester of pregnancy alters the function of the mucociliary apparatus and expression of SP-A and SP-D of fetal lung epithelia. Sixteen, date-mated ewes were assigned to two different groups; an ethanol exposed group in which ewes received ethanol through surgically implanted intra-abomasal cannula during the third trimester of pregnancy, and a control group in which ewes received the equivalent amount of water instead of ethanol. Within these two groups, ewes were further randomly assigned to a full-term group in which the lambs were naturally delivered, and a pre-term group in which the lambs were delivered prematurely via an abdominal incision and uterotomy. Ethanol was administered 5 times a week as a 40% solution at 1gr/kg of body weight. The mean maternal serum alcohol concentration (SAC) measured 6 hr post administration was 16.3 +/− 4.36 mg/dL. Tracheas from 6 full-term lambs were collected to assess ciliary beat frequency (CBF). The lung tissue from all (24) lambs was collected for immunohistochemistry (IHC) analysis of SP-A and SP-D protein production and fluorogenic real-time quantitative polymerase chain reaction analysis (qPCR) of SP-A and SP-D mRNA levels. Exposure to ethanol during pregnancy significantly blocked stimulated increase in CBF though ethanol-mediated desensitization of cAMP-dependant protein kinase (PKA). In addition, pre-term born/ethanol-exposed lambs showed significantly decreased SP-A m-RNA expression when compared to the pre-term born/control group (p=0.004); no significant changes were seen with SP-D. The full-term/ethanol exposed lambs had no significant alterations in mRNA levels, but had significantly less detectable SP-A protein when compared to the full-term/control lambs (p=0.02). These findings suggest that chronic maternal ethanol consumption during the third trimester of pregnancy alters innate immune gene expression in fetal lung. These alterations may underlie increased susceptibility of pre-term infants, exposed to ethanol in utero, to RSV and other microbial agents
A busca de informação na Internet: um estudo do comportamento de bibliotecários e estudantes de ensino médio
Inflammatory responses and intestinal injury development during acute Trypanosoma cruzi infection are associated with the parasite load
Crystal structure and biochemical analyses reveal Beclin 1 as a novel membrane binding protein
The Beclin 1 gene is a haplo-insufficient tumor suppressor and plays an
essential role in autophagy. However, the molecular mechanism by which Beclin 1
functions remains largely unknown. Here we report the crystal structure of the
evolutionarily conserved domain (ECD) of Beclin 1 at 1.6 Å
resolution. Beclin 1 ECD exhibits a previously unreported fold, with three
structural repeats arranged symmetrically around a central axis. Beclin 1 ECD
defines a novel class of membrane-binding domain, with a strong preference for
lipid membrane enriched with cardiolipin. The tip of a surface loop in Beclin 1
ECD, comprising three aromatic amino acids, acts as a hydrophobic finger to
associate with lipid membrane, consequently resulting in the deformation of
membrane and liposomes. Mutation of these aromatic residues rendered Beclin 1
unable to stably associate with lipid membrane in vitro and unable to
fully rescue autophagy in Beclin 1-knockdown cells in vivo. These
observations form an important framework for deciphering the biological
functions of Beclin 1
Mitochondrial physiology
As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
Mitochondrial physiology
As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
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