Search results for "LOAD"
showing 10 items of 1967 documents
Iron, oxidative stress, and redox signaling in the cardiovascular system.
2014
The redox state of the cell is predominantly dependent on an iron redox couple and is maintained within strict physiological limits. Iron is an essential metal for hemoglobin synthesis in erythrocytes, for oxidation-reduction reactions, and for cellular proliferation. The maintenance of stable iron concentrations requires the coordinated regulation of iron transport into plasma from dietary sources in the duodenum, from recycled senescent red cells in macrophages, and from storage in hepatocytes. The absorption of dietary iron, which is present in heme or nonheme form, is carried out by mature villus enterocytes of the duodenum and proximal jejunum. Multiple physiological processes are invo…
Regio- and Stereoselective Synthesis of Spiropyrrolizidines and Piperazines through Azomethine Ylide Cycloaddition Reaction.
2015
A series of original spiropyrrolizidine derivatives has been prepared by a one-pot three-component [3 + 2] cycloaddition reaction of (E)-3-arylidene-1-phenyl-pyrrolidine-2,5-diones, l-proline, and the cyclic ketones 1H-indole-2,3-dione (isatin), indenoquinoxaline-11-one and acenaphthenequinone. We disclose an unprecedented isomerization of some spiroadducts leading to a new family of spirooxindolepyrrolizidines. Furthermore, these cycloadducts underwent retro-1,3-dipolar cycloaddition yielding unexpected regioisomers. Upon treatment of the dipolarophiles with in situ generated azomethine ylides from l-proline or acenaphthenequinone, formation of spiroadducts and unusual polycyclic fused pip…
Effects and Benefits of Node Sharing Strategies in HPC Batch Systems
2019
Processor manufacturers today scale performance by increasing the number of cores on each CPU. Unfortunately, not all HPC applications can efficiently saturate all cores of a single node, even if they successfully scale to thousands of nodes. For these applications, sharing nodes with other applications can help to stress different resources on the nodes to more efficiently use them. Previous work has shown that the performance impact of node sharing is very application dependent but very little work has studied its effects within batch systems and for complex parallel application mixes. Administrators therefore typically fear the complexity of running a batch system supporting node sharing…
A task scheduling algorithm for HPC applications using colored stochastic Petri Net models
2017
The increase in demand for High Performance Computing (HPC) scientific applications motivates the efforts to reduce costs of running these applications. The problem to solve is that of dynamical multi-criterial optimal scheduling of an application on a HPC platform with a high number of heterogeneous nodes. The solution proposed by the authors is a HPC hardware-software architecture that includes the infrastructure for two level (node and inter-node level) adaptive load balancing. The article presents the development of an Coloured Petri Net(CPN) for such an architecture. The model was used for the development of a dynamic distributed algorithm for the scheduling problem. The CPN allowed a …
The impact of workload and job satisfaction on occupational stress -A comparison among newly qualified and experienced midwives in Poland.
2022
BACKGROUND: Midwives are potentially exposed to high levels of occupational stress. The level of stress may be related to the job demands and job resources, as well as midwife seniority. To date, few studies on the determinants of occupational stress have examined Polish midwives. OBJECTIVE: This study aims to investigate the roles of workload, job satisfaction, and seniority in shaping the stress levels of midwives in Poland. METHODS: A cross-sectional approach and structural equation modeling (SEM) were used to compare two groups: newly qualified midwives (NQMs; n = 79) and experienced midwives (n = 99). All data were collected between January and November 2018. RESULTS: Analysis revealed…
Use of Ambient Ionization High-Resolution Mass Spectrometry for the Kinetic Analysis of Organic Surface Reactions
2016
In contrast to homogeneous systems, studying the kinetics of organic reactions on solid surfaces remains a difficult task due to the limited availability of appropriate analysis techniques that are general, high-throughput, and capable of offering quantitative, structural surface information. Here, we demonstrate how direct analysis in real time mass spectrometry (DART-MS) complies with above considerations and can be used for determining interfacial kinetic parameters. The presented approach is based on the use of a MS tag that - in principle - allows application to other reactions. To show the potential of DART-MS, we selected the widely applied strain-promoted alkyne-azide cycloaddition …
Rapid and Complete Surface Modification with Strain-Promoted Oxidation-Controlled Cyclooctyne-1,2-Quinone Cycloaddition (SPOCQ)
2017
Abstract Strain‐promoted oxidation‐controlled cyclooctyne‐1,2‐quinone cycloaddition (SPOCQ) between functionalized bicyclo[6.1.0]non‐4‐yne (BCN) and surface‐bound quinones revealed an unprecedented 100 % conjugation efficiency. In addition, monitoring by direct analysis in real time mass spectrometry (DART‐MS) revealed the underlying kinetics and activation parameters of this immobilization process in dependence on its microenvironment.
Strain-Promoted Cycloaddition of Cyclopropenes with o-Quinones : A Rapid Click Reaction
2018
Abstract Novel click reactions are of continued interest in fields as diverse as bio‐conjugation, polymer science and surface chemistry. Qualification as a proper “click” reaction requires stringent criteria, including fast kinetics and high conversion, to be met. Herein, we report a novel strain‐promoted cycloaddition between cyclopropenes and o‐quinones in solution and on a surface. We demonstrate the “click character” of the reaction in solution and on surfaces for both monolayer and polymer brush functionalization.
The Model for Balancing Learning Workload
2015
Abstract It is advised and accepted that teachers carefully plan their lessons thus it is also crucial that there should be guidelines and recommendations on how students should plan their time to study and how much time is necessary to perform certain learning activities. This time management should be taken into account when planning students’ workload and for balancing it. During the research mental representations and approaches were reviewed and their role in the reasoning, as well as within the context of discerning the meaning and similarity. Examples are given for types of statistics and summaries that can help in evaluating the effectiveness and appropriateness of learning material…
A fuzzy methodology to alleviate information overload in elearning
2013
Some aspects of eLearning experience can be en- hanced in a very natural way by using the basic tools offered by fuzzy logic. As a matter of exam- ple, consider the uncontrolled growth of informa- tion produced in a collaborative-oriented context, in which each participant (e.g. students, teachers) is able to insert and share new contents (e.g. com- ments, texts) concerning a university course. All the incrementally added pieces of information can be evaluated in several ways: by the intervention of a “dictator” (e.g. the teacher), using a rating form, or even according to the frequency of access. As contents rapidly become unusable for the effects of information overload, basic tools of fu…