717 research outputs found
Fluctuations in instantaneous frequency predict alpha amplitude during visual perception.
Rhythmic neural activity in the alpha band (8-13 Hz) is thought to have an important role in the selective processing of visual information. Typically, modulations in alpha amplitude and instantaneous frequency are thought to reflect independent mechanisms impacting dissociable aspects of visual information processing. However, in complex systems with interacting oscillators such as the brain, amplitude and frequency are mathematically dependent. Here, we record electroencephalography in human subjects and show that both alpha amplitude and instantaneous frequency predict behavioral performance in the same visual discrimination task. Consistent with a model of coupled oscillators, we show that fluctuations in instantaneous frequency predict alpha amplitude on a single trial basis, empirically demonstrating that these metrics are not independent. This interdependence suggests that changes in amplitude and instantaneous frequency reflect a common change in the excitatory and inhibitory neural activity that regulates alpha oscillations and visual information processing
Effect of atrazine (Herbicide) on blood parameters of common carp Cyprinus carpio (Actinopterygii: Cypriniformes)
In the present study an attempt was made to investigate the acute toxicity of atrazine (ATR) a herbicide on an economically important fish, Cyprinus carpio. In which, 24 h median lethal concentration (24 h LC50) of herbicide, atrazine to C. carpio was 18.5 ppm. Due to fish exposure to 24 h LC50 of atrazine for 24 h, red blood cells (RBCs) count (-63.17%), hemoglobin (-27.35%), plasma glucose (-6.78%) and plasma protein (-18.73%) levels were decreased; whereas white blood cells (WBCs) count (+3.73%) was
enhanced. The differences in haematological and biochemical values were statistically significant (p < 0.05). However, WBC count was not significantly changed. The alterations of the above parameters could be used as an important tool for the assessment of pathological conditions of fish
Performance Observability and Monitoring of High Performance Computing with Microservices
Traditionally, High Performance Computing (HPC) softwarehas been built and deployed as bulk-synchronous, parallel
executables based on the message-passing interface (MPI) programming model.
The rise of data-oriented computing paradigms and an explosion
in the variety of applications that need to be supported on HPC
platforms have forced a re-think of the appropriate programming and execution models to integrate this new functionality.
In situ workflows demarcate a paradigm shift in
HPC software development methodologies enabling
a range of new applications ---
from user-level data services to machine learning (ML) workflows that run
alongside traditional scientific simulations.
By tracing the evolution of HPC software developmentover the past 30 years, this dissertation identifies the key elements and trends
responsible for the emergence of coupled, distributed, in situ workflows.
This dissertation's focus is on coupled in situ workflows
involving composable, high-performance microservices. After outlining the motivation
to enable performance observability of these services and why
existing HPC performance tools and techniques can not be applied in this context, this dissertation
proposes a solution wherein a set of techniques gathers, analyzes, and orients performance data from
different sources to generate observability. By leveraging microservice components initially designed
to build high performance data services,
this dissertation demonstrates their broader applicability for building and deploying performance
monitoring and visualization as services within an in situ workflow.
The results from this dissertation suggest that: (1) integration of
performance data from different sources is vital to understanding the performance
of service components, (2) the in situ (online) analysis of this performance data
is needed to enable the adaptivity of distributed components and manage monitoring data volume, (3) statistical modeling combined
with performance observations can help generate better service configurations, and (4) services are a promising
architecture choice for deploying in situ performance monitoring and visualization functionality.
This dissertation includes previously published and co-authored material and unpublished co-authored material
Assessment of the effects of liquid and granular fertilizers on maize yield in Rwanda
Maize (Zea mays L.) is the most widely grown cereal in the world, accounting for 1,116.34 MT of production in 2019/2020. In Africa, this crop represented approximately 56% of the total cultivated area from 1990 to 2005. About 50% of the African population depends on maize as a staple food and source of carbohydrates, protein, iron, vitamin B, and minerals. Lately, maize has become a cash crop which contributes to the improvement of farmers' livelihoods. For example, the Strategic Plan for Agricultural Transformation (SPAT) III outlined that fertilizer availability in Rwanda should increase to 55,000 MT per year, while fertilizer use should increase from 30 kg/ha in 2013 to 45 kg/ha for the 2017/18 cropping season. Only inorganic fertilizers are currently being used in maize production in Rwanda. This research was conducted to assess the effects of liquid (CBX: Complete Biological Extract) and granular fertilizers on maize crop yields in Rwanda. The study was conducted in the fields of the Rwanda Agriculture and Animal Resources Development Board (Rubona Station) during the 2018/2019 cropping season. Analysis of variance (ANOVA) was used to determine whether differences between treatments were statistically significant, with the threshold for statistical significance set at p < 0.05. Aboveground biomass differed significantly between treatments, with maximum and minimum values of 11,475 kg and 7,850 kg, respectively, being observed. Furthermore, the harvest index differed significantly between treatments, with minimum and maximum values of 0.2136 and 0.33, respectively, being observed. Grain yield also differed significantly between treatments, with the highest value (3,053 kg/ha) observed for a treatment which applied liquid and granular fertilizer at equal proportions (treatment 8), and the lowest one was found in treatment 3 with 1,852 kg/ha. In this study, the gap between the lowest and highest grain yields was about 39.3%. In conclusion, the combination of organic liquid fertilizer and granular fertilizer can significantly increase the grain yield of maize in Rwanda
Applications of Propargyl Esters of Amino Acids in Solution-Phase Peptide Synthesis
Propargyl esters are employed as effective protecting groups for the carboxyl group during solution-phase peptide synthesis. The propargyl ester groups can be introduced onto free amino acids by treating them with propargyl alcohol saturated with HCl. The reaction between propargyl groups and tetrathiomolybdate is exploited to deblock the propargyl esters. The removal of the propargyl group with the neutral reagent tetrathiomolybdate ensures that most of the other protecting groups used in peptide synthesis are untouched. Both acid labile and base labile protecting groups can be removed in the presence of a propargyl ester. Amino acids protected as propargyl esters are employed to synthesize di- to tetrapeptides in solution-phase demonstrating the possible synthetic utilities of the methodology. The methodology described here could be a valuable addition to currently available strategies for peptide synthesis
Village Voice : expressing narrative through community-designed ontologies
Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2002.Includes bibliographical references (leaves 75-77).The Village Voice project is a study of the efficacy of a localized ontology in the dissemination of narrative. It seeks to understand how community members can articulate their lives in ways that allow each other to reflect on the makeup of their overall community, and how they represent their community's needs to those outside of the group. I utilize a knowledge model, or ontology, created by community members as a foundation for representing and retrieving story fragments (video clips). The focus of this thesis will be to study the methodology by which such a knowledge model can be elicited, and the relative benefits of representing stories by this mechanism versus the standard database technique of keyword indexing. I evaluate the strengths and weaknesses of this ontology-driven narrative system within the real-world context of a local community of Somali refugees (Jamaica Plain, MA).by Ramesh Srinivasan.S.M
Propargyloxycarbonyl as a protecting group for the side chains of serine, threonine and tyrosine
Propargyloxycarbonyl group is used as a protecting group for the hydroxyl groups of serine, threonine and tyrosine. The propargyloxycarbonyl derivatives of these hydroxy amino acids are stable to acidic and basic reagents commonly employed in peptide synthesis. The deprotection of the O-Poc derivatives using tetrathiomolybdate does not affect commonly used protecting groups such as N-Boc, N-Cbz, N-Fmoc, methyl and benzyl esters. The di-and tripeptides synthesized using O-Poc derivatives of serine, threonine and tyrosine are stable, isolable compounds and give the hydroxy peptides in good yields when treated with tetrathiomolybdate
THE RESEARCH UPDATES AND PROSPECTS OF HERBAL HARD-BOILED LOZENGES: A CLASSICAL PLATFORM WITH PROMISING DRUG DELIVERY POTENTIAL
Over the past decades major focus has been given towards innovative drug delivery systems and new dosage forms. This is due to highly expensive process and high attrition rates of existing marketed drugs. Hard-boiled lozenges (HBLs) are one of the solid dosage form designed to release the drug in saliva for either local or systemic effects. Typical application of lozenegs includes throat infection, pharyngitis, cough suppressant, nasal-decongestant, expectorants, and smoking cessation. The drug delivery through the hard-boiled candies has an easy marketing advantage due to its attractive appearance and patient compliance. As a part of the drug is absosrbed into systemic circulation, gastrointestinal degradation and fast pass effects are avoided. Further, drug delivery through hard-boiled lozenges can be potential platform for some of the suitable drug candidates. This review on hard-boiled lozenges discusses manufacturing process, characterization techniques, quality control, research studies and market potential of hard-boiled lozenges. The major databases searched were, PubMed, Wiley Online, Medline, Elsevier, Google scholar, Scopus, ACS, The Royal Society of Chemistry, SciFinder, Baidu Scholars, CNKI, web of science, Cochrane database, US Patents, Espacenet and various business reviews. This review provides comprehensive information on hard-boiled lozenges that will help the pharmaceutical scientist from academia as well pharmaceutical industry to leverage the potential of this conventional dosage form for various herbal drugs and other pharmaceutical actives
ANAMICA: A Medical Data Visualisation and Characterisation .
This paper reports the design and implementation of ANAMICA, a three-dimensional (3-D) medical data visualisation and characterisation system which provides a complete set of image processing options. Constructions of internal surfaces from total or partial volume of 3-D data and cut-out views are supported by means of 'volume rendering' as well as object space methods. Arbitrary planar and curved sections of 3-D data can be obtained and processed subsequently as standard 2-D images. Volumetrics and a preliminary characterisation of tissues based on histograms are also supported. A window based user-interface provides convenient access to all these options
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