34640544
DNA intermediates of avian RNA tumor viruses.
12985098
A note on the incorporation of amino acids by hamster embryo cells in monolayer culture.
11606238
Hepatitis delta virus.
Hepatitis delta virus (HDV) is a sub-viral agent that is dependent for its life cycle on hepatitis B virus (HBV). The help it obtains from HBV is limited to the sharing of envelope proteins. These proteins are needed to facilitate the assembly of the HDV genome into new virus particles, and in turn, to allow the attachment and entry of HDV into new host cells. In other respects, the replication of the small single-stranded circular RNA genome of HDV is independent of HBV. HDV genome replication produces two forms of a RNA-binding protein known as the long and small delta antigens (Ag). All other proteins needed for HDV genome replication, especially the RNA-directed RNA polymerase activity, are provided by the host cell. This mini-review article is a mixture of personal perspective and speculations about the future of HDV research. It starts with a brief overview of HDV and its replication, notes some of the major unresolved questions, and directs the interested reader to more detailed reviews.
24802359
Structure and replication of hepatitis delta virus RNA.
While this volume covers many different aspects of hepatitis delta virus (HDV) replication, the focus in this chapter is on studies of the structure and replication of the HDV RNA genome. An evaluation of such studies is not only an integral part of our understanding of HDV infections but it also sheds new light on some important aspects of cell biology, such as the fidelity of RNA transcription by a host RNA polymerase and on various forms of post-transcriptional RNA processing. Representations of the replication of the RNA genome are frequently simplified to a form of rolling-circle model, analogous to what have been described for plant viroids. One theme of this review is that such models, even after some revision, deceptively simplify the complexity of HDV replication and can fail to make clear major questions yet to be solved.
26989376
Synthesis and integration of avian sarcoma virus DNA.
In this paper, we have presented data regarding the integration of viral DNA and the persistence of unintegrated viral DNA. We know that integration occurs with specificity with respect to the viral genome, and yet it remains to be established which, if any, of the unintegrated DS DNA species-either the linear or the covalently closed circular forms-is the immediate precursor to the DNA that does become integrated. The results of the present studies indicate that the viral DNA species that are able to persist in an unintegrated state may be transcribed to yield new virions. Furthermore, these species may not be intermediates as far as the integration pathway, but may instead be terminal products of a synthesis reaction that has proceeded beyond the point where integration normally occurs. Varmus et al. (1977) have shown that integration occurs only into newly replicated cellular DNA. Therefore, we would speculate that integration may occur by an interaction between a replication fork of the host cell DNA and an earlier, non-double-strand form of viral DNA.
28296194
Retrovirus Genome Replication: Priming Specificities of Plus-Strand DNA Synthesis
SUMMARY The retroviral reverse transcriptase is a multifunctional protein. Not only does it contain both RNA- and DNA-directed DNA synthesis activities but also it contains an endonuclease activity necessary for the integration of viral RNA and a RNase H. This latter activity can reduce to oligoribonucleotides viral RNA that has been reverse transcribed into minus-strand DNA. However, during avian retrovirus genome replication it does this in a highly specific manner so as to generate a specific 12-base primer for plus-strand DNA synthesis. Even though many other oligoribonucleotides are also made there is an efficient selection of the specific primer followed by its efficient utilization in plus-strand DNA synthesis, and subsequent removal. We have used a reconstructed system to gain an understanding of the factors that contribute towards these observed specificities.
30994161
Sex differences, assortative mating, and cultural transmission effects on adolescent delinquency: a twin family study.
The twin study literature contains inconsistencies regarding both the estimates of genetic, shared, and nonshared environmental influence on delinquency and sex differences in the etiological influences on delinquency. Additionally, little is known about assortative mating and cultural transmission effects on delinquency. The present study was aimed at examining the etiology of delinquency in adolescence and examining assortative mating and transmission effects. To this end, we applied the social homogamy structural equation model to self-reported delinquency data from 486 families with 17-year-old male and female twins. We expected stronger shared environmental influences on delinquency among girls than boys and stronger environmental than genetic effects on adolescent delinquency in general. The results indicated nonsignificant sex differences in the estimates of genetic and environmental influences on delinquency. The best-fitting model suggested that 18 %, 56 %, and 26% of the variance in delinquency among both boys and girls is associated with additive genetic, nonshared environmental, and shared environmental factors, respectively. This finding was consistent with our expectation that environmental factors play an important role in adolescent delinquency. Parental cultural effects accounted for a small part of the transmission of delinquency within families while assortative mating was, in part, accounted for by cultural and social background factors. Future work should focus on identifying important environmental factors related to delinquency.
14002416
Strong and weak male mutation bias at different sites in the primate genomes: insights from the human-chimpanzee comparison.
Male mutation bias is a higher mutation rate in males than in females thought to result from the greater number of germ line cell divisions in males. If errors in DNA replication cause most mutations, then the magnitude of male mutation bias, measured as the male-to-female mutation rate ratio (alpha), should reflect the relative excess of male versus female germ line cell divisions. Evolutionary rates averaged among all sites in a sequence and compared between mammalian sex chromosomes were shown to be indeed higher in males than in females. However, it is presently unknown whether individual classes of substitutions exhibit such bias. To address this issue, we investigated male mutation bias separately at non-CpG and CpG sites using human-chimpanzee whole-genome alignments. We observed strong male mutation bias at non-CpG sites: alpha in the X-autosome comparison was approximately 6-7, which was similar to the male-to-female ratio in the number of germ line cell divisions. In contrast, mutations at CpG sites exhibited weak male mutation bias: alpha in the X-autosome comparison was only approximately 2-3. This is consistent with the methylation-induced and replication-independent mechanism of CpG transitions, which constitute the majority of mutations at CpG sites. Interestingly, our study also indicated weak male mutation bias for transversions at CpG sites, implying a spontaneous mechanism largely not associated with replication. Male mutation bias was equally strong at CpG and non-CpG sites located within unmethylated "CpG islands," suggesting the replication-dependent origin of these mutations. Thus, we found that the strength of male mutation bias is nonuniform in the primate genomes. Importantly, we discovered that male mutation bias depends on the proportion of CpG sites in the loci compared. This might explain the differences in the magnitude of primate male mutation bias observed among studies.
45621123
Acquisition and severity of driving-related fears.
Rachman's theory of fear acquisition proposes that directly-conditioned fears will differ from indirectly-conditioned fears in magnitude and anxiety response patterns, however the theory has received inconsistent empirical support. The aim of the present study was to describe the fear acquisition pathways for a community sample who reported driving-related fears, and to test Rachman's theory of fear acquisition. One hundred and ninety participants completed a questionnaire which assessed a variety of driving-related situations, reactions to motor vehicle accidents (MVAs), and anxiety response patterns. Professional psychological helpseeking and perceived need for treatment for driving-related fears were also assessed. Results failed to support Rachman's predictions. However, it was confirmed that respondents who had been involved in an MVA were more likely to ascribe their fears to a directly-conditioned pathway. The theoretical and methodological implications of the findings are discussed, along with suggestions for assessment of those with driving-related fears.
45640355
A behavioral genetic analysis of the relationship between the socialization scale and self-reported delinquency.
This investigation examined the genetic (A), and shared (C) and nonshared (E) environmental variance contributions to the relationship of self-reported delinquency (as measured by the "Delinquent Behavior Inventory" [DBI; Gibson, 1967]) to the Socialization (So) scale of the California Psychological Inventory using univariate and bivariate structural equation models. The scales were administered to 222 male (145 monozygotic; 77 dizygotic) and 159 female (107 monozygotic; 52 dizygotic) 16- to 18-year-old same-sex twin pairs. Principal components analysis with varimax rotation revealed three interpretable So factors representing family/home environment, self-concept, and behavioral control. Univariate modeling suggested sex differences in etiological influences associated with individual differences in most scales. The bivariate ACE model fit the data, suggesting that the covariance between the So scale and self-reported delinquency owes in part to shared etiological factors.
3193958
The influence of protection, palliation and costs on mobility optimization of residents in nursing homes: a thematic analysis of discourse.
BACKGROUND
With the aging of the population, increasing numbers of older people live in nursing homes. Discourse such as policies and standards highlight the need to optimize the mobility independence of residents. This is expected to occur in a way that is safe for residents and staff whilst meeting the residents' needs. The influence of discourse on health care delivery can be poorly understood, being at times hidden or taken for granted. The aim of this study was to uncover discourse relevant to resident mobility optimization to enable the origins and reasoning behind existing and intersecting policy and practice to be critically appraised.


DESIGN
Narrative literature review and thematic analysis with a focus on discourse were employed for this study.


DATA SOURCES
Databases (CINAHL and Ovid Medline) and websites of relevant professional and governmental bodies were accessed.


METHOD
A literature search centered on retrieval of texts focused on discourses that influenced goals to optimize resident mobility. Database searches for texts covered the period from 1994 to 2011. Iterative thematic analysis focussed on the texts' socio-cultural context and influence.


FINDINGS
Four discourses emerged that potentially influence goals to optimize resident mobility: safe manual handling; falls prevention; palliative care; and costs and funding constraints to individualized care. These discourses may influence mobility care in the direction of more routinized, passive and dependency support approaches. A common overarching theme was that of collaboration and communication.


CONCLUSION
Discourses such as safe manual handling, falls prevention, palliative care and cost constraints to individualized care can negatively impact on the goal to optimize the mobility of residents in nursing homes. Inter-professional approaches where staff work collaboratively and communicate well may counter such influences and ensure individualized care that focuses more effectively on resident mobility.