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S S Jones

Publications and source records attributed to S S Jones.

29 records · Page 2Linked to original sources
PubMed1989

Smile production in older infants: the importance of a social recipient for the facial signal.

2 studies tested the hypothesis that infant smile production depends on the availability of a social recipient for the facial signal, as well as on appropriate internal events. We examined the effects of attentive and inattentive, familiar and unfamiliar social objects on smile production in 1 1/2-year-old infants outside of social interactions. Like adults, these infants directed a majority of the smiles produced during nonsocial activity to an attentive social object. Overall smiling frequency was much lower when the only potential recipient (the mother) was inattentive, but the effect did not appear to be mediated by negative emotion. Only smiles directed to mother were reduced: nonsocial smiling (at the toys) was not sensitive to mother's inattention, and when an attentive, friendly stranger was present, she was accepted as a substitute target for social smiles. We conclude that an open channel of social communication promotes the outward expression of internal affect in infants.

Attention↗
PubMed1988

Interleukin 4 is at 5q31 and interleukin 6 is at 7p15.

DNA probes to the human interleukin 4 (IL4) and interleukin 6 (IL6) genes have been used for in situ hybridization to normal human chromosomes and Southern blot analysis of a series of mouse-human hybrid cell lines. IL4 maps to 5q31, the same location as IL5 and other haemopoietic growth factor genes. IL6 maps to 7p15. The significance of these locations is discussed.

Chromosome Mapping↗
PubMed1987

Size distributions of circular molecules in plant mitochondrial DNAs.

Some physicochemical properties of the mitochondrial DNAs (mtDNA) from plants of flax, broad bean and mung bean, and from tissue culture cells of jimson weed, soybean, petunia and tobacco were determined. Circular molecules were observed in electron microscope preparations of each mtDNA. In soybean, petunia, broad bean and mung bean mtDNAs, the circular molecules had a continuous distribution of lengths (ranges between 1 to 36 kb, and 1 to 126 kb), heavily skewed toward smaller molecules. Eighty-six percent of the flax circular molecules were from 27 to 54 kb in size, and 78% of the jimson weed circular molecules were from 4 to 15 kb. Replicative forms of 1.2-1.6 kb circular molecules were observed in electron microscope preparations of broad bean mtDNA.

DNA Restriction Enzymes↗
PubMed1985

Human GM-CSF: molecular cloning of the complementary DNA and purification of the natural and recombinant proteins.

Clones of complementary DNA encoding the human lymphokine known as granulocyte-macrophage colony-stimulating factor (GM-CSF) were isolated by means of a mammalian cell (monkey COS cell) expression screening system. One of these clones was used to produce recombinant GM-CSF in mammalian cells. The recombinant hematopoietin was similar to the natural product that was purified to apparent homogeneity from medium conditioned by a human T-cell line. The human T-cell GM-CSF was found to be 60 percent homologous with the GM-CSF recently cloned from murine lung messenger RNA.

Amino Acid Sequence↗
PubMed1985

Activation of Ha-ras p21 by substitution, deletion, and insertion mutations.

The transforming activity of naturally arising ras oncogenes results from point mutations that affect residue 12 or 61 of the encoded 21-kilodalton protein (p21). By use of site-directed mutagenesis, we showed that deletions and insertions of amino acid residues in the region of residue 12 are also effective in conferring oncogenic activity on p21. Common to these various alterations is the disruption that they create in this domain of the protein, which we propose results in the inactivation of a normal function of the protein.

Base Sequence↗
PubMed1985

Isolation of cDNAs encoding human and gibbon GM-CSF.

We have used a mammalian cell expression cloning system to identify cDNA clones encoding human granulocyte-macrophage colony stimulating factor. The human clone was used as a hybridization probe to identify the corresponding sequence from a cDNA library prepared from a gibbon T-cell line. The human cDNA has been used to produce recombinant GM-CSF in monkey COS-1 cells. The purified protein from COS cells is very similar to the GM-CSF isolated from a continuous human T-cell line.

Amino Acid Sequence↗
PubMed1984

Specific amino acid substitutions in bacterioopsin: Replacement of a restriction fragment in the structural gene by synthetic DNA fragments containing altered codons.

To study the mechanism of light-dependent proton translocation by bacteriorhodopsin, we have introduced single-codon changes in the gene so as to produce the following specific amino acid substitutions in the protein: Tyr-185 to Phe, Pro-186 to Leu, Trp-189 to Phe, Ser-193 to Ala, and Glu-194 to Gln. The strategy involved replacement of a 62-base-pair restriction fragment by synthetic DNA duplexes containing the modified nucleotide sequences. This required a unique restriction site (Xho I) at Ile-203 which was created by oligonucleotide-directed point mutagenesis. The six DNA duplexes corresponding to the modified native and mutant restriction fragments were all prepared by DNA ligase-catalyzed joining of chemically synthesized deoxyribooligonucleotides. The bacterioopsin expression plasmids reconstructed by using the synthetic DNA fragments were characterized by restriction analysis and DNA sequence determination. An extremely rapid, efficient, and general method for purification of the synthetic oligonucleotides and of DNA fragments was developed.

Journal Article↗
PubMed1981

Nucleotide sequence variants of Rattus norvegicus mitochondrial DNA.

The mitochondrial DNA (mtDNA) molecules of different albino, domesticated rats (Rattus norvegicus) of the SASCO colony are of two kinds (SASCO-1 and SASCO-2) in regard to their sensitivity at certain sites to a number of restriction enzymes. MtDNA molecules from Utah wild R. norvegicus (Wild-UT) have sensitivities to restriction enzymes which differ at some sites from either SASCO-1 or SASCO-2 mtDNA molecules. Four single nucleotide differences were found among the HindIII F fragments (169 nucleotides) of SASCO-1, SASCO-2, and Wild-UT mtDNAs. Arguments are presented in favor of the interpretation that each variant nucleotide is the third nucleotide of the codon containing it, and that none of the four differences would result in a difference in the respective amino acid translated.

Animals↗
PubMedDate not supplied

Isolation and characterization of genomic and cDNA clones of human erythropoietin.

The glycoprotein hormone erythropoietin regulates the level of oxygen in the blood by modulating the number of circulating erythrocytes, and is produced in the kidney or liver of adult and the liver of fetal or neonatal mammals. Neither the precise cell types that produce erythropoietin nor the mechanisms by which the same or different cells measure the circulating oxygen concentration and consequently regulate erythropoietin production are known. Cells responsive to erythropoietin have been identified in the adult bone marrow, fetal liver or adult spleen. In cultures of erythropoietic progenitors, erythropoietin stimulates proliferation and differentiation to more mature red blood cells. Detailed molecular studies have been hampered, however, by the impurity and heterogeneity of target cell populations and the difficulty of obtaining significant quantities of the purified hormone. Highly purified erythropoietin may be useful in the treatment of various forms of anaemia, particularly in chronic renal failure. Here we describe the cloning of the human erythropoietin gene and the expression of an erythropoietin cDNA clone in a transient mammalian expression system to yield a secreted product with biological activity.

Amino Acid Sequence↗
PubMedDate not supplied

Evaluation of the effectiveness of a Web-based graduate epidemiology course.

An online epidemiology course was developed, implemented, and evaluated for graduate nursing students through the collaborative efforts of nursing faculty and information, education, and instructional design staff of the library at a health sciences university. This epidemiology course is a core curriculum course for graduate nursing students. The course was piloted with 14 students (one student in Romania); the initial online offering ran concurrently with a traditional classroom section. Extensive evaluation data were collected and analyzed to compare the effectiveness of the classroom and distance-learning formats. Areas of evaluation included objective measures, such as midterm and final examination scores and content analysis comparisons, as well as subjective ratings by the students of time commitments, course objectives, technical aspects of the web-based course, areas of satisfaction or dissatisfaction, and self-confidence regarding epidemiology and computer skills. Recommendations for course development, implementation, and evaluation for similar distance-learning courses will be included.

Computer-Assisted Instruction↗