773 research outputs found
The influence of quiet asymmetric magnetosphere on the cutoff rigidities of the main cone
Some earlier studies show that cutoff rigidities of cosmic-ray particles in the model magnetospheric fields of internal and external sources have daily variations caused by asymmetry of the magnetic field due to the currents induced at the magnetopause and tail currents. Cutoff rigidities of the charged particles coming down at the middle latitudes are examined in this paper. The mathematical model of the magnetospheric field is based on the merged IMP-HEOS experimental data set and includes all known at the present time current systems of the magnetosphere: magnetopause, ring, and magnetotail currents
Diurnal variations of cosmic ray geomagnetic cut-off threshold rigidities
The spectrographic global survey method was used to investigate the rigidity variations Rc of geomagnetic cut-off as a function of local time and the level of geomagnetic disturbance for a number of stations of the world wide network. It is shown that geomagnetic cut-off threshold rigidities undergo diurnal variations. The diurnal wave amplitude decreases with increasing threshold rigidity Rc, and the wave maximum occurs at 2 to 4 hr LT. The amplitude of diurnal variations increases with increasing geomagnetic activity. The results agree with those from trajectory calculations made for an asymmetric model of the magnetosphere during different geomagnetic disturbance conditions
Study of acute and subacute action of iron-molybdenum nanocluster polyoxometalates
There were no significant deviations from the norm in the functional state of the liver, kidneys, and pancreas in the study of the acute toxicity of iron-molybdenum buckyballs intended for targeted drug delivery. No accumulation of nanoparticles or deviation from the norm in any investigated parameter was detected in the study of subacute toxicity. © 2013 Pleiades Publishing, Ltd
Design principles for riboswitch function
Scientific and technological advances that enable the tuning of integrated regulatory components to match network and system requirements are critical to reliably control the function of biological systems. RNA provides a promising building block for the construction of tunable regulatory components based on its rich regulatory capacity and our current understanding of the sequence–function relationship. One prominent example of RNA-based regulatory components is riboswitches, genetic elements that mediate ligand control of gene expression through diverse regulatory mechanisms. While characterization of natural and synthetic riboswitches has revealed that riboswitch function can be modulated through sequence alteration, no quantitative frameworks exist to investigate or guide riboswitch tuning. Here, we combined mathematical modeling and experimental approaches to investigate the relationship between riboswitch function and performance. Model results demonstrated that the competition between reversible and irreversible rate constants dictates performance for different regulatory mechanisms. We also found that practical system restrictions, such as an upper limit on ligand concentration, can significantly alter the requirements for riboswitch performance, necessitating alternative tuning strategies. Previous experimental data for natural and synthetic riboswitches as well as experiments conducted in this work support model predictions. From our results, we developed a set of general design principles for synthetic riboswitches. Our results also provide a foundation from which to investigate how natural riboswitches are tuned to meet systems-level regulatory demands
Using Fluorescence Recovery After Photobleaching (FRAP) to study dynamics of the Structural Maintenance of Chromosome (SMC) complex in vivo
The SMC complex, MukBEF, is important for chromosome organization and
segregation in Escherichia coli. Fluorescently tagged MukBEF forms distinct
spots (or 'foci') in the cell, where it is thought to carry out most of its
chromosome associated activities. This chapter outlines the technique of
Fluorescence Recovery After Photobleaching (FRAP) as a method to study the
properties of YFP-tagged MukB in fluorescent foci. This method can provide
important insight into the dynamics of MukB on DNA and be used to study its
biochemical properties in vivo
Medical English teaching and learning techniques in institutions of higher education with application of multimedia technologies: The problems and their solutions
It has been investigated the problems of application of multimedia technologies in teaching and learning medicineoriented English in institutions of higher education and ways of their solution. The investigation points out, first of all, the existing problems in teaching English for the medical students, including shortcomings of application of multimedia in the process of teaching and learning of this discipline, want for the required knowledge of using multimedia equipment among the teachers, nonuse of multimedia potential in full measure in the process of learning, insufficiency of information awareness and abilities of the students to independently use multimedia technologies. Then, the article suggests some ideas how to solve these problems, such as improvement of education and development of professional training of the teachers not only in the area of application of multimedia technologies, but in extending knowledge of English in medical field, effective use of multimedia potential, teaching of offline and practical technique of discipline learning via multimedia
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
Morphological classification of dysphemisms in artistic discourse
This study pursued the following goal: to analyze the morphological features of dysphemisms within the framework of artistic discourse. The concept of dysphemism was described, and a classification of dysphemisms in contemporary linguistic
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