1,198 research outputs found

    Phylogenetic Relationships among Deep-Sea and Chemosynthetic Sea Anemones: Actinoscyphiidae and Actinostolidae (Actiniaria: Mesomyaria)

    Get PDF
    Sea anemones (Cnidaria, Actiniaria) are present in all marine ecosystems, including chemosynthetic environments. The high level of endemicity of sea anemones in chemosynthetic environments and the taxonomic confusion in many of the groups to which these animals belong makes their systematic relationships obscure. We use five molecular markers to explore the phylogenetic relationships of the superfamily Mesomyaria, which includes most of the species that live in chemosynthetic, deep-sea, and polar sea habitats and to test the monophyly of the recently defined clades Actinostolina and Chemosynthina. We found that sea anemones of chemosynthetic environments derive from at least two different lineages: one lineage including acontiate deep-sea taxa and the other primarily encompassing shallow-water taxa

    Sr isotopes indicate millennial-scale formation of metal-rich layers by reactive melt percolation in an open-system layered intrusion

    Get PDF
    &amp;lt;p&amp;gt;In order to test whether the crystal mushes that form layered mafic intrusions can behave as open systems, we investigated mineral-scale textural, chemical and Sr isotopic heterogeneity in the c. 60 Ma Rum intrusion, Scotland. Within Unit 10 of the Rum intrusion, intercumulus plagioclase and clinopyroxene crystals in peridotite 1-2 cm above and below millimetric Cr-spinel seams exhibit complex optical and chemical zoning (Hepworth et al. 2017). These Cr-spinel seams are closely associated with sulphide and platinum-group element (PGE) mineralization. High precision Sr isotopic analyses (undertaken by thermal ionisation mass spectrometry) of individual intracrystal zones (sampled by micromilling) in intercumulus plagioclase and clinopyroxene from within the PGE-enriched Cr-spinel seams have revealed significant intra-crystalline heterogeneity. &amp;lt;sup&amp;gt;87&amp;lt;/sup&amp;gt;Sr/&amp;lt;sup&amp;gt;86&amp;lt;/sup&amp;gt;Sr heterogeneity is present between plagioclase crystals, between clinopyroxene and plagioclase, and within plagioclase crystals, throughout the studied section. The preservation of Sr isotope heterogeneities at 10-100 &amp;amp;#181;m length-scales implies cooling of the melts that formed the precious metal-rich layers at rates &amp;gt;1 &amp;amp;#176;C per year, and cooling to diffusive closure within 10s-100s of years. The combined textural observations and intra-crystal plagioclase &amp;lt;sup&amp;gt;87&amp;lt;/sup&amp;gt;Sr/&amp;lt;sup&amp;gt;86&amp;lt;/sup&amp;gt;Sr data also highlight the importance of repeated cycles of dissolution and recrystallization within the crystal mush, and together with recent documentation of &amp;amp;#8216;out-of-sequence&amp;amp;#8217; layers in other layered intrusions (Mungall et al. 2016; Wall et al. 2018), raise the prospect that basaltic magmatic systems may undergo repeated self-intrusion during solidification.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Hepworth, L.N., O&amp;amp;#8217;Driscoll, B., Gertisser, R., Daly, J.S. and Emeleus, H.C. 2017. Journal of Petrology 58, 137-166; Mungall, J. E., Kamo, S. L. &amp;amp; McQuade, S. 2016. Nature Communications 7, 13385; Wall, C. J., Scoates, J. S., Weis, D., Friedman, R. M., Amini, M. &amp;amp; Meurer, W. P. 2018. Journal of Petrology 59, 153&amp;amp;#8211;190.&amp;lt;/p&amp;gt; </jats:p

    Female economic dependence and the morality of promiscuity

    Get PDF
    This article is made available through the Brunel Open Access Publishing Fund. Copyright @ The Author(s) 2014.In environments in which female economic dependence on a male mate is higher, male parental investment is more essential. In such environments, therefore, both sexes should value paternity certainty more and thus object more to promiscuity (because promiscuity undermines paternity certainty). We tested this theory of anti-promiscuity morality in two studies (N = 656 and N = 4,626) using U.S. samples. In both, we examined whether opposition to promiscuity was higher among people who perceived greater female economic dependence in their social network. In Study 2, we also tested whether economic indicators of female economic dependence (e.g., female income, welfare availability) predicted anti-promiscuity morality at the state level. Results from both studies supported the proposed theory. At the individual level, perceived female economic dependence explained significant variance in anti-promiscuity morality, even after controlling for variance explained by age, sex, religiosity, political conservatism, and the anti-promiscuity views of geographical neighbors. At the state level, median female income was strongly negatively related to anti-promiscuity morality and this relationship was fully mediated by perceived female economic dependence. These results were consistent with the view that anti-promiscuity beliefs may function to promote paternity certainty in circumstances where male parental investment is particularly important

    Resection of the liver for colorectal carcinoma metastases - A multi-institutional study of long-term survivors

    Get PDF
    In this review of a collected series of patients undergoing hepatic resection for colorectal metastases, 100 patients were found to have survived greater than five years from the time of resection. Of these 100 long-term survivors, 71 remain disease-free through the last follow-up, 19 recurred prior to five years, and ten recurred after five years. Patient characteristics that may have contributed to survival were examined. Procedures performed included five trisegmentectomies, 32 lobectomies, 16 left lateral segmentectomies, and 45 wedge resections. The margin of resection was recorded in 27 patients, one of whom had a positive margin, nine of whom had a less than or equal to 1-cm margin, and 17 of whom had a greater than 1-cm margin. Eighty-one patients had a solitary metastasis to the liver, 11 patients had two metastases, one patient had three metastases, and four patients had four metastases. Thirty patients had Stage C primary carcinoma, 40 had Stage B primary carcinoma, and one had Stage A primarycarcinoma. The disease-free interval from the time of colon resection to the time of liver resection was less than one year in 65 patients, and greater than one year in 34 patients. Three patients had bilobar metastases. Four of the patients had extrahepatic disease resected simultaneously with the liver resection. Though several contraindications to hepatic resection have been proposed in the past, five-year survival has been found in patients with extrahepatic disease resected simultaneously, patients with bilobar metastases, patients with multiple metastases, and patients with positive margins. Five-year disease-free survivors are also present in each of these subsets. It is concluded that five-year survival is possible in the presence of reported contraindications to resection, and therefore that the decision to resect the liver must be individualized. © 1988 American Society of Colon and Rectal Surgeons

    Tyrosine kinase signalling in breast cancer: Modulation of tyrosine kinase signalling in human breast cancer through altered expression of signalling intermediates

    Get PDF
    The past decade has seen the definition of key signalling pathways downstream of receptor tyrosine kinases (RTKs) in terms of their components and the protein-protein interactions that facilitate signal transduction. Given the strong evidence that links signalling by certain families of RTKs to the progression of breast cancer, it is not surprising that the expression profile of key downstream signalling intermediates in this disease has also come under scrutiny, particularly because some exhibit transforming potential or amplify mitogenic signalling pathways when they are overexpressed. Reflecting the diverse cellular processes regulated by RTKs, it is now clear that altered expression of such signalling proteins in breast cancer may influence not only cellular proliferation (eg Grb2) but also the invasive properties of the cancer cells (eg EMS1/cortactin)

    Strong signature of natural selection within an FHIT intron implicated in prostate cancer risk

    Get PDF
    Previously, a candidate gene linkage approach on brother pairs affected with prostate cancer identified a locus of prostate cancer susceptibility at D3S1234 within the fragile histidine triad gene (FHIT), a tumor suppressor that induces apoptosis. Subsequent association tests on 16 SNPs spanning approximately 381 kb surrounding D3S1234 in Americans of European descent revealed significant evidence of association for a single SNP within intron 5 of FHIT. In the current study, resequencing and genotyping within a 28.5 kb region surrounding this SNP further delineated the association with prostate cancer risk to a 15 kb region. Multiple SNPs in sequences under evolutionary constraint within intron 5 of FHIT defined several related haplotypes with an increased risk of prostate cancer in European-Americans. Strong associations were detected for a risk haplotype defined by SNPs 138543, 142413, and 152494 in all cases (Pearson's χ2 = 12.34, df 1, P = 0.00045) and for the homozygous risk haplotype defined by SNPs 144716, 142413, and 148444 in cases that shared 2 alleles identical by descent with their affected brothers (Pearson's χ2 = 11.50, df 1, P = 0.00070). In addition to highly conserved sequences encompassing SNPs 148444 and 152413, population studies revealed strong signatures of natural selection for a 1 kb window covering the SNP 144716 in two human populations, the European American (π = 0.0072, Tajima's D= 3.31, 14 SNPs) and the Japanese (π = 0.0049, Fay & Wu's H = 8.05, 14 SNPs), as well as in chimpanzees (Fay & Wu's H = 8.62, 12 SNPs). These results strongly support the involvement of the FHIT intronic region in an increased risk of prostate cancer. © 2008 Ding et al

    The Dependency on Central Government Funding of Decentralised Health systems: Experiences of the Challenges and Coping Strategies in the Kongwa District, Tanzania.

    Get PDF
    Decentralised health systems in Tanzania depend largely on funding from the central government to run health services. Experience has shown that central funding in a decentralised system is not an appropriate approach to ensure the effective and efficient performance of local authorities due to several limitations. One of the limitations is that funds from the central government are not disbursed on a timely basis, which in turn, leads to the serious problem of shortage of financial resources for Council Health Management Teams (CHMT). This paper examines how dependency on central government funding in Tanzania affects health activities in Kongwa district council and the strategies used by the CHMT cope with the situation. The study adopted a qualitative approach and data were collected using semi-structured interviews and focus group discussions. One district in the central region of Tanzania was strategically selected. Ten key informants involved in the management of health service delivery at the district level were interviewed and one focus group discussion was held, which consisted of members of the council health management team. The data generated were analysed for themes and patterns. The results showed that late disbursement of funds interrupts the implementation of health activities in the district health system. This situation delays the implementation of some activities, while a few activities may not be implemented at all. However, based on their prior knowledge of the anticipated delays in financial disbursements, the council health management team has adopted three main strategies to cope with this situation. These include obtaining supplies and other services on credit, borrowing money from other projects in the council, and using money generated from cost sharing. Local government authorities (LGAs) face delays in the disbursement of funds from the central government. This has necessitated introduction of informal coping strategies to deal with the situation. National-level policy and decision makers should minimise the bureaucracy involved in allocating funds to the district health systems to reduce delays

    Interplay between manganese and iron in pneumococcal pathogenesis: role of the orphan response regulator RitR

    Get PDF
    Streptococcus pneumoniae (the pneumococcus) is a major human pathogen that is carried asymptomatically in the nasopharynx by up to 70% of the human population. Translocation of the bacteria into internal sites can cause a range of diseases, such as pneumonia, otitis media, meningitis, and bacteremia. This transition from nasopharynx to growth at systemic sites means that the pneumococcus needs to adjust to a variety of environmental conditions, including transition metal ion availability. Although it is an important nutrient, iron potentiates oxidative stress, and it is established that in S. pneumoniae, expression of iron transport systems and proteins that protect against oxidative stress are regulated by an orphan response regulator, RitR. In this study, we investigated the effect of iron and manganese ion availability on the growth of a ritR mutant. Deletion of ritR led to impaired growth of bacteria in high-iron medium, but this phenotype could be suppressed with the addition of manganese. Measurement of metal ion accumulation indicated that manganese prevents iron accumulation. Furthermore, the addition of manganese also led to a reduction in the amount of hydrogen peroxide produced by bacterial cells. Studies of virulence in a murine model of infection indicated that RitR was not essential for pneumococcal survival and suggested that derepression of iron uptake systems may enhance the survival of pneumococci in some niches
    corecore