1,403 research outputs found
Acute and Chronic Effects of 12 Weeks of Combined Exercise Training on Plasma IL-6 in Post-Menopausal Women
Post-menopausal women exhibit higher levels of IL-6, a pro-inflammatory cytokine and anti-inflammatory myokine, and up-regulation of cellular receptors and cofactors for IL-6. Exercise is associated with an acute elevation of IL-6, but consistent exercise training diminishes this response. PURPOSE: to analyze the acute and chronic effects of 12 weeks of combined resistance and aerobic exercise training on plasma IL-6 in overweight or obese, post-menopausal women (55-75 years). METHODS: Forty-three women were randomly assigned to an exercise (EX, n=22) or an education (ED, n=21) group. EX completed resistance training (2 sets of 8 resistance exercises at 80% of 1RM) followed by aerobic training (25-minute treadmill walk at 70-80% of HRR) three times per week for 12 weeks. ED attended classes and activities two times per week for 12 weeks to control for seasonal variation and social interaction. Blood samples were collected a total of 8 times: 4 times before training (BT) (before the acute exercise bout (PRE), immediately after exercise (PO), 1 hour after exercise (1HR), and 2 hours after exercise (2HR)) and 4 times after training (AT). Lean, post-menopausal, and age-matched women were recruited for collection of one resting blood sample to serve as healthy controls (LN, n=11). Plasma IL-6 was determined using an ELISA kit according to manufacturer instructions. RESULTS: Baseline IL-6 concentration was significantly lower in the LN group compared to the EX (LN BT PRE: 1.0 ± 0.5; EX BT PRE: 2.8 ± 1.3 pg/mL; p\u3c0.001) and ED (LN BT PRE: 1.0 ± 0.5; ED BT PRE: 3.8 ± 1.7 pg/mL; p\u3c0.001) groups. No statistically significant BT/AT x group interaction was observed (p\u3e0.05) when the BT and AT PRE time points of the EX and ED groups were compared. In the EX group, PO was significantly higher than PRE (PRE 2.6 ± 1.2; PO 4.3 ± 1.8 pg/mL; p\u3c0.001), and PO was significantly higher than 1 HR (PO 4.3 ± 1.8; 1HR 3.4 ± 1.2 pg/mL; p=0.038) and 2HR (PO 4.3 ± 1.8; 2 HR 3.9 ± 1.6 pg/mL; p=0.005). No statistically significant differences were observed when corresponding time points before and after the intervention within a group were compared (i.e., EX BT PRE to EX AT PRE) (p\u3e0.05). CONCLUSION:The training intervention may not have been long enough and/or intense enough to observe a chronic effect of combined exercise training on plasma IL-6. Significant elevation of IL-6 immediately post-exercise was observed in the EX group, but this response was not blunted by consistent exercise training
Genomic epidemiology of Streptococcus dysgalactiae subsp. equisimilis strains causing invasive disease in Norway during 2018
Background: Streptococcus dysgalactiae subspecies equisimilis (SDSE) is an emerging global pathogen, yet the epidemiology and population genetics of SDSE species have not been extensively characterized.
Methods: We carried out whole genome sequencing to characterize 274 SDSE isolates causing bloodstream infections obtained through national surveillance program in 2018. We conducted multilocus sequence typing (MLST), emm-typing, core genome phylogeny, as well as investigated key features associated with virulence. Moreover, comparison to SDSE from other geographic regions were performed in order to gain more insight in the evolutionary dynamics in SDSE.
Results: The phylogenetic analysis indicated a substantial diversity of emm-types and sequence types (STs). Briefly, 17 emm-types and 58 STs were identified that formed 10 clonal complexes (CCs). The predominant ST-types were ST20 (20%), ST17 (17%), and ST29 (11%). While CC17 and CC29 clades showed a substantial heterogeneity with well-separated emm-associated subclades, the CC20 clade harboring the stG62647 emm-type was more homogenous and the most prevalent in the present study. Moreover, we observed notable differences in the distribution of clades within Norway, as well as several disseminated CCs and also distinct geographic variations when compared to data from other countries. We also revealed extensive intra-species recombination events involving surface exposed virulence factors, including the emm gene important for phylogenetic profiling.
Conclusion: Recombination events involving the emm as well as other virulence genes in SDSE, are important mechanisms in shaping the genetic variability in the SDSE population, potentially offering selective advantages to certain lineages. The enhanced phylogenetic resolution offered by whole genome sequencing is necessary to identify and delimitate outbreaks, monitor and properly characterize emerging strains, as well as elucidate bacterial population dynamics.publishedVersio
Simulation de l'écoulement des pâtes cimentaires par un modèle diphasique
La modélisation de l'écoulement des pâtes cimentaires est un problème difficile car le matériau a non seulement un comportement rhéologique complexe mais il peut également présenter des hétérogénéités induites par l'écoulement. L'apparition de ces hétérogénéités résulte de la filtration de phases fluides au travers de phases solides et peut conduire au blocage de l'écoulement. Pour modéliser l'écoulement d'un tel matériau il est nécessaire de prendre en compte la présence d'au moins deux phases. Dans notre modélisation nous considérons que les deux phases sont continues et admettent un comportement rhéologique en loi de puissance. Le couplage entre les deux phases est pris en compte au moyen d'une loi de Darcy généralisée à un fluide en loi de puissance. Le modèle est résolu par la méthode des éléments finis et validé dans le cas d'un test d'écrasement. Nous montrons que ces simulations permettent d'établir des diagrammes d'ouvrabilité des pâtes cimentaires
Intercropping Promotes the Ability of Legume and Cereal to Facilitate Phosphorus and Nitrogen Acquisition through Root- Induced Processes
Intercropping of cereal and legume can improve the use of resources for crop growth compared to cropping system. An increase in soil phosphorus (P) and nitrogen (N) acquisition by root-induced biochemical changes of intercropped species has been reported as key processes of facilitation and complementarily between both intercropping legumes and cereals. Indeed, the functional facilitation prevails over interspecific competition under nutrients limiting for crop growth. Results showed that P availability significantly increased in the rhizosphere of both species, especially in intercropping under the P-deficient soil conditions. This increase was associated with high efficiency efficiency in use of rhizobial, plant growth and resource use efficiency as indicated by higher land equivalent ratio (LER) and N nutrition index. In addition, the rhizosphere P availability and nodule biomass were positively correlated (r2 = 0.71**, and r2 = 0.62**) in the intercropped common bean grown at P-deficient soil. The increased P availability presumably improved biomass and yield in intercropping, although it mainly enhanced intercropped maize grain yield. Exploiting belowground parameters in a legume-cereal intercropping is likely necessary to maximize rhizosphere-interspecific interactions as a strategy to improve the symbiotic rhizobial efficiency and microbial activities, as a result of root-induced pH and N availability changes under low P soils
Experimental Demonstration of an Electride as a 2D Material
Because of their loosely bound electrons, electrides offer physical
properties useful in chemical synthesis and electronics. For these applications
and others, nano-sized electrides offer advantages, but to-date no electride
has been synthesized as a nanomaterial. We demonstrate experimentally that
CaN, a layered electride in which layers of atoms are separated by layers
of a 2D electron gas (2DEG), can be exfoliated into two-dimensional (2D)
nanosheets using liquid exfoliation. The 2D flakes are stable in a nitrogen
atmosphere or in select organic solvents for at least one month. Electron
microscopy and elemental analysis reveal that the 2D flakes retain the crystal
structure and stoichiometry of the parent 3D CaN. In addition, the 2D
flakes exhibit metallic character and an optical response that agrees with DFT
calculations. Together these findings suggest that the 2DEG is preserved in the
2D material. With this work, we bring electrides into the nano-regime and
experimentally demonstrate a 2D electride, CaN
A High-Level Implementation of Non-deterministic, Unrestricted, Independent And-Parallelism
The growing popularity of multicore architectures has renewed interest in language-based approaches to the exploitation of parallelism. Logic programming has proved an interesting framework to this end, and there are parallel implementations which have achieved significant speedups, but at the cost of a quite sophisticated low-level machinery. This machinery has been found challenging to code and, specially, to maintain and expand. In this paper, we follow a different approach which adopts a higher level view by raising some of the core components of the implementation to the level of the source language. We briefly present an implementation model for independent and-parallelism which fully supports non-determinism through backtracking and provides flexible solutions for some of the main problems found in previous and-parallel implementations. Our proposal is able to optimize the execution for the case of deterministic programs and to exploit unrestricted and-parallelism, which allows exposing more parallelism among clause literals than fork-join-based proposals. We present performance results for an implementation, including data for benchmarks where and-parallelism is exploited in non-deterministic programs
Experimental infections of Norway rats with avian‑derived low‑pathogenic influenza A viruses
Influenza A viruses (IAVs) are a public-health, veterinary, and agricultural concern. Although wild birds are considered the primary reservoir hosts for most IAVs, wild-bird IAV strains are known to spill over into poultry, domestic or wild mammals, and humans. Occasionally, spillover events may result in adaptation or reassortment with other strains. Moreover, some IAV strains found in wild waterfowl mutate into highly pathogenic forms in poultry, causing tremendous economic losses. When domestic animals, wildlife, and humans dwell in close proximity to each other, such as may be the case with agricultural operations, wildlife may represent a potential risk for interspecies pathogen transmission. Understanding the pathways through which IAV strains could spillover from waterfowl reservoirs into humans and domestic animals is important for limiting the spread of IAVs, as well as developing biosecurity and containment procedures in livestock and poultry production. Experimental studies of common wild mammals in the U.S., bank voles (Myodes glareolus) in Europe and Asia, and black rats (Rattus rattus) in Japan have shown varying degrees of IAV susceptibility and/or transmission in these synanthropic species. While Norway rats (Rattus norvegicus) are ubiquitous throughout rural and urban areas of the world and have the ability to range between these areas, only limited investigations of this species have been conducted, and their role in IAV transmission has not been clearly established. The main objective of this study was to further characterize IAV infection in Norway rats using IAV strains derived from poultry and wild water birds
Improving the compilation of prolog to C using moded types and determinism information
We describe the current status of and provide performance
results for a prototype compiler of Prolog to C, ciaocc. ciaocc is novel in that it is designed to accept different kinds of high-level information, typically obtained via an automatic analysis of the initial Prolog program and expressed in a standardized language of assertions. This information is used to optimize the resulting C code, which is then processed by an off-the-shelf C compiler. The basic translation process essentially mimics the unfolding of a bytecode emulator with respect to the particular bytecode corresponding to the Prolog program. This is facilitated by a flexible design of the instructions and their lower-level components. This approach allows reusing a sizable amount of the machinery of the bytecode emulator: predicates already written in C, data definitions, memory management routines and áreas, etc., as well as mixing emulated bytecode with native code in a relatively straightforward way. We report on the performance of programs compiled by the current versión of the system, both with and without analysis information
Cell Migration in the Immune System: the Evolving Inter-Related Roles of Adhesion Molecules and Proteinases
Leukocyte extravasation into perivascular tissue during inflammation and lymphocyte homing
to lymphoid organs involve transient adhesion to the vessel endothelium, followed by transmigration
through the endothelial cell (EC) layer and establishment of residency at the tissue site
for a period of time. In these processes, leukocytes undergo multiple attachments to, and detachments
from, the vessel-lining endothelial cells, prior to transendothelial cell migration. Transmigrating
leukocytes must traverse a subendothelial basement membrane en route to perivascular
tissues and utilize enzymes known as matrix metalloproteinases to make selective clips in the
extracellular matrix components of the basement membrane. This review will focus on the evidence
for a link between adhesion of leukocytes to endothelial cells, the induction of matrix
metalloproteinases mediated by engagement of adhesion receptors on leukocytes, and the ability
to utilize these matrix metalloproteinases to facilitate leukocyte invasion of tissues. Leukocytes
with invasive phenotypes express high levels of MMPs, and expression of MMPs
enhances the migratory and invasive properties of these cells. Furthermore, MMPs may be used
by lymphocytes to proteolytically cleave molecules such as adhesion receptors and membrane
bound cytokines, increasing their efficiency in the immune response. Engagement of leukocyte
adhesion receptors may modulate adhesive (modulation of integrin affinities and expression),
synthetic (proteinase induction and activation), and surface organization (clustering of proteolyric
complexes) behaviors of invasive leukocytes. Elucidation of these pathways will lead to
better understanding of controlling mechanisms in order to develop rational therapeutic
approaches in the areas of inflammation and autoimmunity
Current Status and Perspectives of Protease Inhibitors and Their Combination with Nanosized Drug Delivery Systems for Targeted Cancer Therapy
Abstract: In cancer treatments, many natural and synthetic products have been examined; among them, protease inhibitors are promising candidates for anti-cancer agents. Since dysregulated proteolytic activities can contribute to tumor development and metastasis, antagonization of proteases with tailored inhibitors is an encouraging approach. Although adverse effects of early designs of these inhibitors disappeared after the introduction of next-generation agents, most of the proposed inhibitors did not pass the early stages of clinical trials due to their nonspecific toxicity and lack of pharmacological effects. Therefore, new applications that modulate proteases more specifically and serve their programmed way of administration are highly appreciated. In this context, nanosized drug delivery systems have attracted much attention because preliminary studies have demonstrated that the therapeutic capacity of inhibitors has been improved significantly with encapsulated formulation as compared to their free forms. Here, we address this issue and discuss the current application and future clinical prospects of this potential combination towards targeted protease-based cancer therapy
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