Toward the Prevention of Risky Sexual Behavior Among Latina Youth

Sexual risk-taking among Latina youth has been noted as a critical health concern within the United States. In this chapter. the importance of prevention of risky sexual behavior among Latina youth will be discussed. Current prevalence rates and consequences associated with sexual behavior among Latino/as will be reviewed. along with factors that are relevant to understanding the prevention of sexual activity. Finally. programs that have been developed to prevent risky sexual behavior among Latinas will be reviewed and suggestions for prevention efforts will be presented

The Alternative Choice of Constitutive Exons throughout Evolution

Alternative cassette exons are known to originate from two processes exonization of intronic sequences and exon shuffling. Herein, we suggest an additional mechanism by which constitutively spliced exons become alternative cassette exons during evolution. We compiled a dataset of orthologous exons from human and mouse that are constitutively spliced in one species but alternatively spliced in the other. Examination of these exons suggests that the common ancestors were constitutively spliced. We show that relaxation of the 59 splice site during evolution is one of the molecular mechanisms by which exons shift from constitutive to alternative splicing. This shift is associated with the fixation of exonic splicing regulatory sequences (ESRs) that are essential for exon definition and control the inclusion level only after the transition to alternative splicing. The effect of each ESR on splicing and the combinatorial effects between two ESRs are conserved from fish to human. Our results uncover an evolutionary pathway that increases transcriptome diversity by shifting exons from constitutive to alternative splicin

SN1997cy/GRB970514 - A New Piece in the GRB Puzzle?

We present observations of SN1997cy, a supernova discovered as part of the Mount Stromlo Abell Cluster SN Search, which does not easily fit into the traditional classification scheme for supernovae. This object's extraordinary optical properties and coincidence with GRB970514, a short duration gamma ray burst, suggest a second case, after SN1998bw/GRB980425, for a SN-GRB association. SN1997cy is among the most luminous SNe yet discovered and has a peculiar spectrum. We present evidence that SN1997cy ejected approximately 2 solar masses of 56Ni, supported by its late-time light curve, and FeII/[FeIII] lines in its spectrum, although it is possible that both these observations can be explained via circumstellar interaction. While SN1998bw and SN1997cy appear to be very different objects with respect to both their gamma ray and optical properties, SN1997cy and the optical transient associated with GRB970508 have roughly similar late-time optical behavior. This similarity may indicate that the late-time optical output of these two intrinsically bright transient events have a common physical process. Although the connection between GRB970514 and SN1997cy is suggestive, it is not conclusive. However, if this association is real, followup of short duration GRBs detected with BATSE or HETE2 should reveal objects similar to SN1997cy.Comment: 26 pages including 6 postscript figures and 3 tables. Submitted to ApJ. Re-calibrated photometry - objects are about 0.3mags brighter than in original versio

Hubble Space Telescope and Ground-Based Observations of Type Ia Supernovae at Redshift 0.5: Cosmological Implications

We present observations of the Type Ia supernovae (SNe) 1999M, 1999N, 1999Q, 1999S, and 1999U, at redshift z~0.5. They were discovered in early 1999 with the 4.0~m Blanco telescope at Cerro Tololo Inter-American Observatory by the High-z Supernova Search Team (HZT) and subsequently followed with many ground-based telescopes. SNe 1999Q and 1999U were also observed with the Hubble Space Telescope. We computed luminosity distances to the new SNe using two methods, and added them to the high-z Hubble diagram that the HZT has been constructing since 1995. The new distance moduli confirm the results of previous work. At z~0.5, luminosity distances are larger than those expected for an empty universe, implying that a ``Cosmological Constant,'' or another form of ``dark energy,'' has been increasing the expansion rate of the Universe during the last few billion years.Comment: 68 pages, 22 figures. Scheduled for the 01 February 2006 issue of Ap.J. (v637

Clusters of internally primed transcripts reveal novel long noncoding RNAs

Non- protein- coding RNAs ( ncRNAs) are increasingly being recognized as having important regulatory roles. Although much recent attention has focused on tiny 22- to 25- nucleotide microRNAs, several functional ncRNAs are orders of magnitude larger in size. Examples of such macro ncRNAs include Xist and Air, which in mouse are 18 and 108 kilobases ( Kb), respectively. We surveyed the 102,801 FANTOM3 mouse cDNA clones and found that Air and Xist were present not as single, full- length transcripts but as a cluster of multiple, shorter cDNAs, which were unspliced, had little coding potential, and were most likely primed from internal adenine- rich regions within longer parental transcripts. We therefore conducted a genome- wide search for regional clusters of such cDNAs to find novel macro ncRNA candidates. Sixty- six regions were identified, each of which mapped outside known protein- coding loci and which had a mean length of 92 Kb. We detected several known long ncRNAs within these regions, supporting the basic rationale of our approach. In silico analysis showed that many regions had evidence of imprinting and/ or antisense transcription. These regions were significantly associated with microRNAs and transcripts from the central nervous system. We selected eight novel regions for experimental validation by northern blot and RT- PCR and found that the majority represent previously unrecognized noncoding transcripts that are at least 10 Kb in size and predominantly localized in the nucleus. Taken together, the data not only identify multiple new ncRNAs but also suggest the existence of many more macro ncRNAs like Xist and Air

VEZF1 elements mediate protection from DNA methylation

There is growing consensus that genome organization and long-range gene regulation involves partitioning of the genome into domains of distinct epigenetic chromatin states. Chromatin insulator or barrier elements are key components of these processes as they can establish boundaries between chromatin states. The ability of elements such as the paradigm β-globin HS4 insulator to block the range of enhancers or the spread of repressive histone modifications is well established. Here we have addressed the hypothesis that a barrier element in vertebrates should be capable of defending a gene from silencing by DNA methylation. Using an established stable reporter gene system, we find that HS4 acts specifically to protect a gene promoter from de novo DNA methylation. Notably, protection from methylation can occur in the absence of histone acetylation or transcription. There is a division of labor at HS4; the sequences that mediate protection from methylation are separable from those that mediate CTCF-dependent enhancer blocking and USF-dependent histone modification recruitment. The zinc finger protein VEZF1 was purified as the factor that specifically interacts with the methylation protection elements. VEZF1 is a candidate CpG island protection factor as the G-rich sequences bound by VEZF1 are frequently found at CpG island promoters. Indeed, we show that VEZF1 elements are sufficient to mediate demethylation and protection of the APRT CpG island promoter from DNA methylation. We propose that many barrier elements in vertebrates will prevent DNA methylation in addition to blocking the propagation of repressive histone modifications, as either process is sufficient to direct the establishment of an epigenetically stable silent chromatin stat

Transcriptional regulatory dynamics drive coordinated metabolic and neural response to social challenge in mice

Agonistic encounters are powerful effectors of future behavior, and the ability to learn from this type of social challenge is an essential adaptive trait. We recently identified a conserved transcriptional program defining the response to social challenge across animal species, highly enriched in transcription factor (TF), energy metabolism, and developmental signaling genes. To understand the trajectory of this program and to uncover the most important regulatory influences controlling this response, we integrated gene expression data with the chromatin landscape in the hypothalamus, frontal cortex, and amygdala of socially challenged mice over time. The expression data revealed a complex spatiotemporal patterning of events starting with neural signaling molecules in the frontal cortex and ending in the modulation of developmental factors in the amygdala and hypothalamus, underpinned by a systems-wide shift in expression of energy metabolism-related genes. The transcriptional signals were correlated with significant shifts in chromatin accessibility and a network of challenge-associated TFs. Among these, the conserved metabolic and developmental regulator ESRRA was highlighted for an especially early and important regulatory role. Cell-type deconvolution analysis attributed the differential metabolic and developmental signals in this social context primarily to oligodendrocytes and neurons, respectively, and we show that ESRRA is expressed in both cell types. Localizing ESRRA binding sites in cortical chromatin, we show that this nuclear receptor binds both differentially expressed energy-related and neurodevelopmental TF genes. These data link metabolic and neurodevelopmental signali ng to social challenge, and identify key regulatory drivers of this process with unprecedented tissue and temporal resolution

Zim1, a maternally expressed mouse Kruppel-type zinc-finger gene located in proximal chromosome 7

In analysis of a conserved region of proximal mouse chromosome 7 and human chromosome 19q, we have isolated a novel mouse gene, Zim1 (imprinted zinc-finger gene 1), encoding a typical Kruppel-type (C2H2) zinc-finger protein, located within 30 kb of a known imprinted gene, Peg3 (paternally expressed gene 3). Our studies demonstrate that Zim1 is also imprinted; the gene is expressed mainly from the maternal allele and at high levels only during embryonic and neonatal stages. In contrast to most tissues, Zim1 is expressed biallelically in neonatal and adult brain with slightly more input from the maternal allele. Zim1 produces multiple transcripts that range in size from 7.5 to 15 kb. The 7.5 kb transcript is expressed at highest levels and appears to be embryo specific. Whole mount in situ hybridization analysis indicates that Zim1 is expressed at significant levels in the apical ectodermal ridge of the limb buds during embryogenesis, suggesting a potential role of Zim1 in limb formation. We have identified the potential human ortholog of Zim1 near PEG3 in a conserved, gene-rich region of human chromosome 19q13.4. The close juxtaposition of reciprocally imprinted genes has also been seen in other imprinted regions, such as human 11p15.5/Mmu7 (H19/Igf2) and suggests that the two genes may be co-regulated. These and other data suggest the presence of an unexplored, conserved imprinted domain in human chromosome 19q13.4 and proximal Mmu7

Language attitudes and use in a transplanted setting: Greek Cypriots in London

In this paper we explore language attitudes and use in the Greek Cypriot community in London, England. Our study is based on an earlier survey carried out in Nicosia, Cyprus and we compare attitudes to language and reported language use in the two communities. We thereby highlight the significance of sociolinguistic variables on similar groups of speakers. We further extend our investigation to include codeswitching practices in the London community. \ud Analysis of language attitudes and use within the Greek-Cypriot population of London, and comparisons with findings in Nicosia, reflect symbolic forces operating in the two contexts. Despite obvious differences between the two communities, (most obviously the official languages and distinct cultural backgrounds of the two nations), the Greek Cypriot Dialect continues to play an active role in both. English is however the ‘default choice‘ for young Cypriots in the UK and Standard Modern Greek occupies a much more limited role than in Cyprus. It is argued that differences in language attitudes and use can be interpreted in light of different market forces operating in the nation (i.e. Cyprus) and the Diaspora (i.e. UK)

A Common Variant Associated with Dyslexia Reduces Expression of the KIAA0319 Gene

Numerous genetic association studies have implicated the KIAA0319 gene on human chromosome 6p22 in dyslexia susceptibility. The causative variant(s) remains unknown but may modulate gene expression, given that (1) a dyslexia-associated haplotype has been implicated in the reduced expression of KIAA0319, and (2) the strongest association has been found for the region spanning exon 1 of KIAA0319. Here, we test the hypothesis that variant(s) responsible for reduced KIAA0319 expression resides on the risk haplotype close to the gene's transcription start site. We identified seven single-nucleotide polymorphisms on the risk haplotype immediately upstream of KIAA0319 and determined that three of these are strongly associated with multiple reading-related traits. Using luciferase-expressing constructs containing the KIAA0319 upstream region, we characterized the minimal promoter and additional putative transcriptional regulator regions. This revealed that the minor allele of rs9461045, which shows the strongest association with dyslexia in our sample (max p-value = 0.0001), confers reduced luciferase expression in both neuronal and non-neuronal cell lines. Additionally, we found that the presence of this rs9461045 dyslexia-associated allele creates a nuclear protein-binding site, likely for the transcriptional silencer OCT-1. Knocking down OCT-1 expression in the neuronal cell line SHSY5Y using an siRNA restores KIAA0319 expression from the risk haplotype to nearly that seen from the non-risk haplotype. Our study thus pinpoints a common variant as altering the function of a dyslexia candidate gene and provides an illustrative example of the strategic approach needed to dissect the molecular basis of complex genetic traits