84 research outputs found
Social assistance performance in Central and Eastern Europe: A pre-transfer post-transfer comparison
The anti-poverty impact of national social assistance programmes in eight Central and Eastern European countries is examined using data from the European Union-Survey of Income and Living Conditions (EU-SILC). Results indicate that social assistance programmes achieve only limited poverty reduction, while spending a significant amount of their resources on the non-poor. The more extensive and generous programmes achieve higher effectiveness in reducing poverty. Efficiency on the other hand appears to be linked only to programme size and not to benefit levels. Unlike Western Europe, no trade-off between effectiveness and efficiency could be detected
Role of transcript and interplay between transcription and replication in triplet-repeat instability in mammalian cells
Triplet-repeat expansions cause several inherited human diseases. Expanded triplet-repeats are unstable in somatic cells, and tissue-specific somatic instability contributes to disease pathogenesis. In mammalian cells instability of triplet-repeats is dependent on the location of the origin of replication relative to the repeat tract, supporting the ‘fork-shift’ model of repeat instability. Disease-causing triplet-repeats are transcribed, but how this influences instability remains unclear. We examined instability of the expanded (GAA•TTC)n sequence in mammalian cells by analyzing individual replication events directed by the SV40 origin from five different locations, in the presence and absence of doxycycline-induced transcription. Depending on the location of the SV40 origin, either no instability was observed, instability was caused by replication with no further increase due to transcription, or instability required transcription. Whereas contractions accounted for most of the observed instability, one construct showed expansions upon induction of transcription. These expansions disappeared when transcript stability was reduced via removal or mutation of a spliceable intron. These results reveal a complex interrelationship of transcription and replication in the etiology of repeat instability. While both processes may not be sufficient for the initiation of instability, transcription and/or transcript stability seem to further modulate the fork-shift model of triplet-repeat instability
Turning Males On: Activation of Male Courtship Behavior in Drosophila melanogaster
The innate sexual behaviors of Drosophila melanogaster males are an attractive system for elucidating how complex behavior patterns are generated. The potential for male sexual behavior in D. melanogaster is specified by the fruitless (fru) and doublesex (dsx) sex regulatory genes. We used the temperature-sensitive activator dTRPA1 to probe the roles of fruM- and dsx-expressing neurons in male courtship behaviors. Almost all steps of courtship, from courtship song to ejaculation, can be induced at very high levels through activation of either all fruM or all dsx neurons in solitary males. Detailed characterizations reveal different roles for fruM and dsx in male courtship. Surprisingly, the system for mate discrimination still works well when all dsx neurons are activated, but is impaired when all fruM neurons are activated. Most strikingly, we provide evidence for a fruM-independent courtship pathway that is primarily vision dependent
Progressive GAA·TTC Repeat Expansion in Human Cell Lines
Trinucleotide repeat expansion is the genetic basis for a sizeable group of inherited neurological and neuromuscular disorders. Friedreich ataxia (FRDA) is a relentlessly progressive neurodegenerative disorder caused by GAA·TTC repeat expansion in the first intron of the FXN gene. The expanded repeat reduces FXN mRNA expression and the length of the repeat tract is proportional to disease severity. Somatic expansion of the GAA·TTC repeat sequence in disease-relevant tissues is thought to contribute to the progression of disease severity during patient aging. Previous models of GAA·TTC instability have not been able to produce substantial levels of expansion within an experimentally useful time frame, which has limited our understanding of the molecular basis for this expansion. Here, we present a novel model for studying GAA·TTC expansion in human cells. In our model system, uninterrupted GAA·TTC repeat sequences display high levels of genomic instability, with an overall tendency towards progressive expansion. Using this model, we characterize the relationship between repeat length and expansion. We identify the interval between 88 and 176 repeats as being an important length threshold where expansion rates dramatically increase. We show that expansion levels are affected by both the purity and orientation of the repeat tract within the genomic context. We further demonstrate that GAA·TTC expansion in our model is independent of cell division. Using unique reporter constructs, we identify transcription through the repeat tract as a major contributor to GAA·TTC expansion. Our findings provide novel insight into the mechanisms responsible for GAA·TTC expansion in human cells
Friedreich's Ataxia (GAA)n•(TTC)n Repeats Strongly Stimulate Mitotic Crossovers in Saccharomyces cerevisae
Expansions of trinucleotide GAA•TTC tracts are associated with the human disease Friedreich's ataxia, and long GAA•TTC tracts elevate genome instability in yeast. We show that tracts of (GAA)230•(TTC)230 stimulate mitotic crossovers in yeast about 10,000-fold relative to a “normal” DNA sequence; (GAA)n•(TTC)n tracts, however, do not significantly elevate meiotic recombination. Most of the mitotic crossovers are associated with a region of non-reciprocal transfer of information (gene conversion). The major class of recombination events stimulated by (GAA)n•(TTC)n tracts is a tract-associated double-strand break (DSB) that occurs in unreplicated chromosomes, likely in G1 of the cell cycle. These findings indicate that (GAA)n•(TTC)n tracts can be a potent source of loss of heterozygosity in yeast
Dental metric standards for sex estimation in archaeological populations from Iran
Sex estimation of skeletal remains is one of the major components of forensic
identification of unknown individuals. Teeth are a potential source of information on
sex and are often recovered in archaeological or forensic contexts due to their post-mortem
longevity. Currently there is limited data on dental sexual dimorphism of
archaeological populations from Iran. This dissertation represents the first study to
provide a dental sex estimation method for Iron Age populations.
The current study was conducted on the skeletal remains of 143 adults from two Iron
Age populations in close temporal and geographic proximity in the Solduz Valley
(West Azerbaijan Province of Iran). 2D and 3D cervical mesiodistal and buccolingual
and root volume measurements of maxillary and mandibular teeth were used to
investigate the degree of sexual dimorphism in permanent dentition and to assess their
applicability in sex estimation. In total 1327, 457, and 480 anterior and posterior teeth
were used to collect 2D cervical, 3D cervical, and root volume measurements
respectively. 2D cervical measurements were taken using Hillson-Fitzgerald dental
calliper and 3D measurements were collected using CT images provided by Open
Research Scan Archive (ORSA) - Penn Museum. 3D models of the teeth were created
using manual segmentation in the Amira 6.01 software package. Since tooth density
largely differs from crown to apex, root segmentation required two threshold levels:
the segmentation of the root from the jaw and the segmentation of the crown from the
root. Thresholds used for root segmentation were calculated using the half maximum
height protocol of Spoor et al. (1993) for each skull, and thresholds used for crown
segmentation were set visually for each tooth separately. Data was analysed using
discriminant function analysis and posterior probabilities were calculated for all
produced formulae where sex was previously assessed from morphological features of
pelvis and skull. Bootstrapping was used to account for small sample sizes in the
analysis. Statistical analysis was carried out using SPSS 23. The percentage of sexual
dimorphism was also used to quantify the amount of sexual dimorphism in the sample.
The results showed that incisors and canines were the most sexually dimorphic teeth,
providing percentages of correct sex classification between 80% and 100% depending
on the measurement used. Root volume measurement was shown to be the most
sexually dimorphic variable providing an accuracy of over 90% in all functions.
The present study provided the first dental metric standards for sex estimation using
odontometric data in Iranian archaeological populations. Dental measurements,
particularly root volume measurements, were found to be of value for sex assessment
and the method presented here could be a useful tool for establishing accurate
demographic data from skeletal remains of the Iron Age from Iran
Alterações eletrencefalográficas após administração de substâncias vaso-ativas (Hydergine)
Changing Lives and the Role of Income Support
This report presents the finding of a study to explore the nature and effects of changes in circumstances for Income Support claimants. The study involved a survey of claimants, depth interviews with claimants and Benefits Agency staff and secondary analysis of data from the Department of Social Security's Annual Statistical Enquiry
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