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At least 19 recordsLinked to original sources
PubMed1991

Intergenerational transfers: a question of perspective.

Informal intergenerational transfers have traditionally been examined from the perspective of the older generation; more recent studies have proceeded from the perspective of adult children. Drawing upon principles of formal demography, we establish the mathematical relationship between the two generations' perspectives. We then consider the importance of generational perspective with regard to prevalence estimates of intrafamily transfers. Transfers examined include coresidence, household and financial assistance, and personal caregiving. Results have implications for projection of future trends in intrafamily transfers and for data collection.

Adult↗
PubMed1991

Elderly support and intergenerational transfer in Zimbabwe: an analysis by gender, marital status, and place of residence.

This paper describes elderly support and intergenerational transfer by gender, marital status, and place of residence for 150 elderly persons in Zimbabwe. The survey was conducted in September 1988, and includes information on background characteristics, income, and cash support from all sources, noncash support, and the support of elders to others. Conclusions and implications are discussed.

Aged↗
PubMed1988

Theories of serial flow in intergenerational transfers.

Recent improvements in the economic position of the elderly population necessitate a more thorough understanding of the serial flow of economic supports from preceding to succeeding generations. Five theories which might extend our understanding of the decision rules employed in intergenerational transfers are discussed. They are: social exchange theory, the kin selection theory of altruism, human capital theory, social constructivist theory, and rational transfers theory. The underlying assumptions of these theories are presented and compared, and models of intergenerational transactions are developed. Comparative studies are recommended in order to gain deeper insights into the relative strengths and weaknesses of these different views of relationships between the generations.

Altruism↗
PubMed1988

Intergenerational transfers within the family context--motivating factors and their implications for caregiving.

The interdependence of generations, in both psychosocial and economic terms, has raised critical issues about the nature and role of reciprocity between adult children and their parents. This paper focuses on adult children as caregivers for their elderly parents and provides a conceptual paradigm for intergenerational familial exchanges. The paper builds on empirical studies of family care by investigating the factors that motivate the provision of support and assistance across generations.

Aged↗
PubMed1977

Intergeneric transfer of genes involved in the Rhizobium-legume symbiosis.

Genes that seem to be involved in the initial steps of infection of a legume by Rhizobium have been transferred, by transformation, to mutant strains of Azotobacter vinelandii that are unable to fix nitrogen. These genes code for a surface antigen that binds specifically to a protein from the host plant.

Antigens, Bacterial↗
PubMedDate not supplied

Intergenerational transfers: aging parents living with adult children and vice versa.

The family remains important for care of the elderly; less well understood is the significance of even aging parents for their offspring, which may be more so today than in the past and more so in the welfare states--with 'resourceful' old people--than in the less affluent societies. This study tries to verify this by an analysis of coresidence patterns between generations, with particular emphasis on the younger one. In particular, men with various handicaps may more often find refuge with their family of origin than do others, and more often today than they did in the not-so-distant past.

Adult↗
PubMed1991

Conjugational transfer of recombinant DNA in cultures and in soils: host range of Pseudomonas putida TOL plasmids.

Recombinant TOL plasmid pWWO-EB62 allows Pseudomonas putida to grow on p-ethylbenzoate. This plasmid can be transferred to other microorganisms, and its catabolic functions for the metabolism of alkylbenzoates are expressed in a limited number of gram-negative bacteria, including members of pseudomonad rRNA group I and Escherichia coli. Transfer of the recombinant plasmid to Erwinia chrysanthemi was observed, but transconjugants failed to grow on alkylbenzoates because they lost catabolic functions. Pseudomonads belonging to rRNA groups II, III, and IV, Acinetobacter calcoaceticus, and Alcaligenes sp. could not act as recipients for TOL, either because the plasmid was not transferred or because it was not stably maintained. The frequency of transfer of pWWO-EB62 from P. putida as a donor to pseudomonads belonging to rRNA group I was on the order of 1 to 10(-2) transconjugant per recipient, while the frequency of intergeneric transfer ranged from 10(-3) to 10(-7) transconjugant per recipient. The profile of potential hosts was conserved when the donor bacterium was Escherichia coli or Erwinia chrysanthemi instead of P. putida. No intergeneric gene transfer of the recombinant TOL plasmid was observed in soils; however, intraspecies transfer did take place. Intraspecies transfer of TOL in soils was affected by the type of soil used, the initial inoculum size, and the presence of chemicals that could affect the survival of the donor or recipient bacteria.

Anti-Bacterial Agents↗
PubMed1979

Transfer of drug resistance factors to the dimorphic bacterium Caulobacter crescentus.

The P-type drug resistance factors RP4, RK2, R702, R68.45, and the N-type drug resistance factor R46 are transferred to Caulobacter crescentus at high frequencies. They are stably maintained and their antibiotic resistances are expressed. Experiments with RP4 have shown that intergeneric transfer of RP4 occur at a frequency of 10(-1). C. crescentus strains maintain RP4 as a plasmid, are sensitive to RP4-specific phage, and segregate phage-resistant cells at a frequency of 10(-4) to 10(-5). The RP4 plasmid can be used in several ways: (1) the RP4 plasmid will promote chromosomal exchange between C. crescentus strains at frequencies ranging from 10(-6) to 10(-8); (2) RP4 will promote the transfer of nonconjugative colE1 plasmids from E. coli to C. crescentus; once transferred, the colE1 plasmid is stably maintained under nonselective conditions, can be transferred serially, and segregates independently from RP4; and (3) RP4 can be used to introduce transposons into the C. crescentus chromosome, providing the basis for additional genetic techniques.

Bacteria↗
PubMed1987

Characterization of self-transmissible plasmids determining lactose fermentation and multiple antibiotic resistance in clinical strains of Klebsiella pneumoniae.

The lactose fermentation (Lac+) and antibiotic resistance (R+) phenotypes were conjugally transferred from Klebsiella pneumoniae strains (K166, K182, K186, K218, and K220) to Salmonella typhi, S. typhimurium, Shigella flexneri, and Vibrio cholerae. The genes for lactose fermentation and antibiotic resistance were located on the plasmids. Further analysis of plasmid DNA from these isolates indicated the presence of multiple plasmids (Mr ranged less than 2.7 to 70 X 10(6)). The Lac+R+ plasmids p166 and p182 were members of the FII incompatibility group. The fertility inhibition property of plasmids, p182, p218, and p220 was fi+ type. Furthermore, phage typing experiments showed that plasmids p166 and p218 (Lac+R+) conferred the ability to inhibit the multiplication of bacteriophages 12 and 13 in S. typhimurium. However, the plasmids p182, p186, and p220 (Lac+R+) could inhibit the visible lysis of all the 30 phages in S. typhimurium. This study describes the characterization of Lac+R+ plasmids and the medical significance of an intergeneric transfer of lactose fermentation to non-lactose-fermenting pathogens.

Escherichia coli↗
PubMed1985

Molecular genetics of resistance to macrolides, lincosamides and streptogramin B (MLS) in streptococci.

Resistance to macrolides-lincosamides-streptogramin B (MLS phenotype) appears in almost all streptococcal species isolated from man. Genes coding for MLS resistance are located on plasmids and one MLS resistance transposon has been described. MLS resistance genes have also been found in a large number of plasmid-free strains. Plasmids of 17 to 20 megadaltons (Mdal) that code either for MLS or for both MLS and chloramphenicol resistance are found in streptococci of groups A, B, C, D (Streptococcus faecalis) and G. These plasmids have broad host ranges (conjugative intraspecies, interspecies and intergeneric transfer), display similar restriction enzyme patterns and share a considerable degree of homology (78 to 95%). One smaller non-conjugative MLS resistance plasmid has been isolated from Str. sanguis (4.5 Mdal). In group D (Str. faecalis, Str. faecium) streptococci, MLS resistance genes are also found on plasmids that carry other antibiotic resistance (tetracycline, chloramphenicol, high-levels of streptomycin and kanamycin). These multi-resistance plasmids are either conjugative or non-conjugative and are of various sizes and molecular species and those that have been tested have narrow host-ranges. The MLS resistance genes of one multi-resistant plasmid, isolated from a strain of Str. faecalis, are located on a transposon of 3.3 Mdal, Tn917. Hybridization studies, with MLS determinants as probes, reveal homologies among various plasmid-borne MLS resistance sequences. Elements that are thought to be chromosome-borne mediate multiple antibiotic resistance (including MLS) in streptococci of groups A, B, C, D (Str. bovis), F, G, Str. pneumoniae, Str. mitis, Str. sanguis and Str. milleri. Strains harbouring such elements contain no detectable plasmid DNA. In some of the strains these elements are conjugative; their resistance markers transfer en bloc at low frequency and display narrow host ranges. Such elements, from Str. pyogenes and Str. agalactiae, were found to translocate onto various streptococcal haemolysin-bacteriocin plasmids.

Anti-Bacterial Agents↗
PubMed1988

Violence: a product of biosocial interactions.

All behavior is seen to be a result of interactions between the brain on the one hand and environmental challenges and endogenous drives on the other. Intergenerational transfer theory fails to explain cases of habitual aggression that have no identifiable social origin, and there is compelling evidence for the existence of brain-environmental interaction. The key roles that may be played by age, gender, neurological factors, and biological defects in aggressive and antisocial behavior are reviewed.

Adolescent↗
PubMed1989

Influence of soil variables on in situ plasmid transfer from Escherichia coli to Rhizobium fredii.

A model system was established to determine whether intergeneric plasmid transfer occurs in soil and how various soil variables affect the rate of plasmid transfer. The donor bacterium, Escherichia coli HB101 carrying plasmid pBLK1-2 (pRK2073::Tn5), and the recipient bacterium, Rhizobium fredii USDA 201, were inoculated into a sterile Adelphia fine-sandy-loam soil. Transconjugants were enumerated by direct plating on antibiotic-amended HM [N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid; 2-(N-morpholino) ethanesulfonic acid] salts medium. Randomly chosen transconjugants were verified by serological typing and Southern hybridization with a Tn5 gene probe. The maximum transfer frequency was observed after 5 days of incubation (1.8 x 10(-4) per recipient). The influences of clay (0 to 50% addition), organic matter (0 to 15% addition), soil pH (4.3 to 7.25), soil moisture (2 to 40%), and soil incubation temperature (5 to 40 degrees C) on plasmid transfer were examined. Maximum transfer frequencies were noted at a clay addition of 15%, an organic matter addition of 5%, a soil pH of 7.25, a soil moisture content of 8%, and a soil incubation temperature of 28 degrees C. These results indicate that intergeneric plasmid transfer may occur in soil and that soil variables may significantly affect the rate of transfer.

Blotting, Southern↗
PubMed1988

The retreat of the state and its transfer of responsibility: the intergenerational war.

In this article, the socially constructed nature of the conflict between the generations, or the "intergenerational war," is explored, with a description of the two major fronts of this battle: a health care financing axis and a caregiving axis. Basic to the health care financing axis is the assumption that certain individuals and populations represent an increasing and unreasonable social burden; the caregiving axis gives ideological support to familial and filial responsibility. The politics of mystification perpetuates the idea that these two axes are unrelated and that generational transfers are independent rather than interdependent. Both permit abdication of the state from social responsibility for human needs and massive budgetary reallocations to defense and tax cuts for the wealthy. An alternative approach derives from the principle of universal life-course entitlement to basic human needs.

Aged↗
PubMed1988

Intergeneric and intrageneric conjugal transfer of plasmid-encoded antibiotic resistance determinants in Leuconostoc spp.

Transfer of the broad-host-range resistance plasmids pIP501 and pAM beta 1 from Streptococcus faecalis to Leuconostoc dextranicum and Leuconostoc cremoris occurred between cells that were immobilized on nitrocellulose filters in the presence of DNase. Transfer of pIP501 to Leuconostoc spp. also occurred when Streptococcus sanguis and Streptococcus lactis were used as donors. In addition, transfer of pIP501 and pAM beta 1 was observed from L. cremoris and L. dextranicum transconjugants to S. sanguis and S. faecalis. Expression of the pAM beta 1 erythromycin and pIP501 erythromycin and chloramphenicol resistance determinants was essentially equivalent in donors and transconjugants. Frequencies of transfer generally ranged from 10(-4) to 10(-7) transconjugants per input donor cell. Intrageneric transfer of pIP501 and pAM beta 1 occurred between L. cremoris and L. dextranicum strains in the same approximate range. These data further extend the host range of pIP501 and pAM beta 1 and demonstrate another example of gene transfer in the genus Leuconostoc.

Chloramphenicol↗
PubMed1976

Derivation and properties of F-prime factors in Escherichia coli carrying nitrogen fixation genes from Klebsiella pneumoniae.

A His+ Nif+ Escherichia coli K12, Hfr strain (UNF43) was constructed by an intergeneric mating between a Klebsiella pneumoniae donor strain (HF3) and a his-HFR E. coli strain (SBI824) which transfers his as an early marker. An F-prime nif plasmid, FN39, carrying genes which correspond to the E. coli chromosomal region, metG gnd his shiA, but excluding purF and aroD, was isolated from UNF43. Translocation of carbenicillin resistance genes from a P-type R-factor, R68, to FN39 increased the stability of his and nif on the derivative F-prime, FN68. Sedimentation analysis of both F-primes in sucrose gradients revealed our covalently closed circular(CCC) DNA species of molecular weights 279 +/- 9, 136 +/- 3, 90 +/- 1 and 44 +/- 1 megadaltons. It is suggested that the two smallest CCC-DNA species are component replicons of the composite F-primes of molecular weight 136 +/- 3 megadaltons, and that the molecules of 279 +/- 9 megadaltons are CCC-dimers. FN68 was transferable in intergeneric matings to Klebsiella aerogenes, K. pneumoniae and Salmonella typhimurium but not to Proteus mirabilis; only carbenicillin resistance and sex factor activity were transferred to Erwinia herbicola. nif genes on FN68 were expressed in a Nif- mutant of K. pneumoniae and also in S. typhimurium, which in conventional tests is naturally non-nitrogen-fixing; expression of the his determinant of FN68 became temperature-sensitive in S. typhimurium.

Carbenicillin↗
PubMed1990

Intergeneric protoplast fusion between xylanase producing Bacillus subtilis LYT and Corynebacterium acetoacidophilum ATCC 21476.

Hybrids between a strain of Bacillus subtilis isolated in our laboratory and having the ability to degrade xylan and other complex polysaccharides and Corynebacterium acetoacidophilum, a lysine producer, were prepared by protoplast fusion. Based on distinctive parental biochemical characteristics the fusants were grouped into 9 categories, viz. BC1 through BC9. Three of the hybrids, BC5, BC7a and BC7b, were tested for their ability to produce xylanase and lysine. Both BC7a and BC7b produced xylanase but BC5 did not, however all of them produced lysine albeit to different degrees. These results demonstrate that intergeneric gene transfer takes place through protoplast fusion between these 2 important genera of bacteria and some of the fusants inherit the useful traits of both the parents.

Bacillus subtilis↗
PubMed1987

Intergeneric protoplast fusion between Fusobacterium varium and Enterococcus faecium for enhancing dehydrodivanillin degradation.

Intergeneric protoplast fusion between Fusobacterium varium (Pcs Glu+) and Enterococcus faecium (Pcr Glu-) was performed under strictly anaerobic conditions to improve dehydrodivanillin (DDV) degradation. The fusion frequency obtained from the selective medium (Pc+ Glu-) was about 0.9 X 10(-5) to 1.3 X 10(-5). The seven fusants isolated were all gram-negative anaerobes with rod shapes like that of F. varium and with main phenotypical properties of cocci like those of E. faecium such as esculin and starch hydrolysis, milk clotting, and lactate production. Five fusants showed enhanced DDV degradation activities that were 2 to 4 times higher than those of parental strains. Genetic relatedness between a fusant (FE7) and the parents was estimated by DNA-DNA Southern blot hybridization with 32P-labeled chromosomal DNA fragments of F. varium and E. faecium as respective probes. The fusant FE7 presented a very high cross-hybridization with both probes, indicating a high DNA homology between the fusant and both parental strains. Almost all the fusants obtained here have stably kept the properties described above for about 2 years. These results suggest that intergeneric gene transfer takes place through protoplast fusion and that the fusants that were obtained are stable recombinants.

Anaerobiosis↗