Biological organisms and their component organs, tissues and cells have unique electrical impedance properties. Impedance properties often change with changes in structure, composition, and ...metabolism, and can be indicative of the onset and progression of disease states. Over the past 100 years, instruments and analytical methods have been developed to measure the impedance properties of biological specimens and to utilize these measurements in both clinical and basic science settings. This chapter will review the applications of impedance measurements in the biomedical sciences, from whole body analysis to impedance measurements of single cells and cell monolayers, and how cellular impedance measuring instruments can now be used in high throughput screening applications.
Differentiation of mammalian cells implies cessation of DNA replication and cell proliferation; the potential controls of this coupling are examined here. It is clear that the known or proposed ...mechanisms of down-regulation of replicative cellular activities vary in different lineages of cell differentiation, and occur in all phases of the cell cycle. In G1these regulators include p21/Cip1 or p27/Kip1, pRb, and p53; the novel, recently reported mechanisms of their action are summarized. In S phase the availability of nucleotide precursors, the origin recognition complex (ORC), and other replication proteins may be important in differentiation, and in G2phase the cdc2/cyclin B complex and replication licensing factors determine normal G2traverse versus an arrest or polyploidisation. Other replication-related mechanisms include transcription factors, e.g., Sp1, telomerase, and nuclear matrix changes. Thus, differentiation alters the activity not only of the various checkpoint proteins, but also of the components of the replicative machinery itself.
This study asked NHIMA directors (N = 74) who teach older adults to compare their experiences in teaching adult and youth learners. I analysed their comments through the lens of andragogical ...principles. Directors commented on teaching style, instructional content, learner attitudes
and adult physical limitations. According to these directors, adults displayed less flexibility in learning that was perhaps compensated for by richer life experiences and higher levels of commitment, indicative of issues related to fluid and crystallized intelligence. The directors appreciated
that rehearsals with adults could be done in a more relaxed fashion. Their enthusiastic comments about teaching adults raise questions about the ways that youth are taught.
This study examines the contents of 45 issues of the
International Journal of Community Music
from 2007 to 2022, noting the type of article, authorship, location by country, participants involved, ...setting, form of music making and discussions of paramusical issues of community music discourse. Findings suggest that the journal has evolved, expanding its range of content while increasing the proportion of research articles. The authors use their findings to discuss ‘What should the journal include?’
Severe peripheral vascular disease is a common disorder that frequently creates substantial morbidity in our aging population. A nonsurgical approach to the treatment of intermittent claudication, ...one of the chief manifestations of the disease, was widely expected after the introduction of percutaneous transluminal angioplasty about 20 years ago. The article by Tunis and associates in this issue of the
Journal
1
explores the effect of angioplasty on the rate of surgical procedures for peripheral vascular disease. The study raises many important issues, among them the epidemiologic features of the disease, the therapeutic approaches available for those affected, and the appropriateness of . . .
The interaction of the origin recognition complex (ORC) with replication origins is a critical parameter in eukaryotic replication initiation. In mammals the ORC remains bound except during mitosis, ...thus the localization of ORC complexes allows localization of origins. A monoclonal antibody that recognizes human ORC1 was used to localize ORC complexes in populations of human MOLT-4 cells separated by cell cycle position using centrifugal elutriation. ORC1 staining in cells in early G1 is diffuse and primarily peripheral. As the cells traverse G1, ORC1 accumulates and becomes more localized towards the center of the nucleus, however around the G1/S boundary the staining pattern changes and ORC1 appears peripheral. By mid to late S phase ORC1 immunofluorescence is again concentrated at the nuclear center. During anaphase, ORC1 staining is localized mainly in the pericentriolar regions. These findings suggest that concerted movements of origin DNA sequences in addition to the previously documented assembly and disassembly of protein complexes are an important aspect of replication initiation loci in eukaryotes.
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