1,268 research outputs found

    Marine Flora and Fauna of the Northeastern United States: Erect Bryozoa

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    Forty-nine species of erect Bryozoa from a broad range of Cyclostome, Ctenostome, and Cheilostome families are described and illustrated, and an artificial dichotomous key is provided for their identification. In general, the marine bryozoan faunas of the northeastern coasts of the United States are poorly known; species records are sparse and voucher collections few, and it is certain that many more species occur in this region than are presently known. The species described here occur in intertidal, coastal or offshore habitats; some are well known and have been recorded on numerous previous occasions, others have been only rarely reported, while a few are known to occur commonly in the north of the region but have yet to be recorded south of Cape Cod. Some of the species described have not been recorded at all on northeastern coasts of the United States, but are widely distributed in North Atlantic continental shelf habitats and perhaps occur in similar parts of the outer shelf of this region. This fauna is thus provisional, but is intended to stimulate further work on the Bryozoa. (PDF file contains 52 pages.

    An epiblast stem cell-derived multipotent progenitor population for axial extension.

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    The caudal lateral epiblast of mammalian embryos harbours bipotent progenitors that contribute to the spinal cord and the paraxial mesoderm in concert with the body axis elongation. These progenitors, called neural mesodermal progenitors (NMPs), are identified as cells that co-express Sox2 and T/brachyury, a criterion used to derive NMP-like cells from embryonic stem cells in vitro However, unlike embryonic NMPs, these progenitors do not self-renew. Here, we find that the protocols that yield NMP-like cells in vitro initially produce a multipotent population that, in addition to NMPs, generates progenitors for the lateral plate and intermediate mesoderm. We show that epiblast stem cells (EpiSCs) are an effective source of these multipotent progenitors, which are further differentiated by a balance between BMP and Nodal signalling. Importantly, we show that NMP-like cells derived from EpiSCs exhibit limited self-renewal in vitro and a gene expression signature like their embryonic counterparts.Cambridge Trusts, Cambridge philosophical Societ

    Adriatic Bryozoa.

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    139 p. : ill., map ; 26 cm.Includes bibliographical references (p. 129-137).One hundred six species of Bryozoa collected from the northern Adriatic in the vicinity of Rovinj, Croatia, are distributed among the orders Ctenostomata (8 species), Cheilostomata (79 species), and Cyclostomata (19 species). Ctenostomes are underrepresented in the collections relative to the two orders with calcified colonies. Five of the cheilostome species are new: Hagiosynodos hadros n. sp., Schizomavella subsolana n. sp., Cellepora adriatica n. sp., Celleporina siphuncula n. sp., and Rhynchozoon revelatus n. sp. (previously referred to as Rhynchozoon sp. II Hayward). Seven species named by Heller (1867) are stabilized by selection of lectotypes (Beania hirtissima, Adeonella pallasii, Hagiosynodos kirchenpaueri, Exidmonea triforis, Crisia recurva) and neotypes (Mollia circumcincta, Schizomavella cornuta) from Heller's collection in the University of Innsbruck Institute of Zoology. Lectotypes are designated for the Adriatic species Hippoporina lineolifera (Hincks, 1886) and for Schizomavella mamillata (Hincks, 1880). Beania cylindrica (Hincks, 1886) and Schizoporella asymetrica (Calvet, 1927) are recognized as species rather than as subspecific units. The species-rich cheilostome genus Schizoporella Hincks, 1877, which contains some of the most widely known fouling bryozoans, is designated a nomen protectum. The species name Smittina cheilostoma (Manzoni, 1869) is preserved as established usage

    Investigating Overdensities around z > 6 Galaxies through ALMA Observations of [C II]

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    We present a search for companion [C II] emitters to known luminous sources at 6 < z < 6.5 in deep, archival ALMA observations. The observations are deep enough to detect sources with L_([CII])∼10⁸ at z ∼6. We identify three new robust line detections from a blind search of five deep fields centered on ultraluminous infrared galaxies and QSOs. We calculate the volume density of companions and find a relative overdensity of 6⁺⁴₋₃ and 86⁺⁶⁰₋₃₇ when comparing to current observational constraints and theoretical predictions, respectively. These results suggest that the central sources may be highly biased tracers of mass in the early universe. We find these companion lines to have comparable properties to other known galaxies at the same epoch. All companions lie less than 650 km s⁻¹ and between 25 and 60 kpc (projected) from their central source. To place these discoveries in context, we employ a mock galaxy catalog to estimate the luminosity function for [C II] during reionization and compare to our observations. The simulations support this result by showing a similar level of elevated counts found around such luminous [C II] sources

    Prevalence of and risk factors for active tuberculosis in migrants screened before entry to the UK: a population-based cross-sectional study

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    SummaryBackgroundAn increasing number of countries with low incidence of tuberculosis have pre-entry screening programmes for migrants. We present the first estimates of the prevalence of and risk factors for tuberculosis in migrants from 15 high-incidence countries screened before entry to the UK.MethodsWe did a population-based cross-sectional study of applicants for long-term visas who were screened for tuberculosis before entry to the UK in a pilot programme between Oct 1, 2005, and Dec 31, 2013. The primary outcome was prevalence of bacteriologically confirmed tuberculosis. We used Poisson regression to estimate crude prevalence and created a multivariable logistic regression model to identify risk factors for the primary outcome.Findings476 455 visa applicants were screened, and the crude prevalence of bacteriologically confirmed tuberculosis was 92 (95% CI 84–101) per 100 000 individuals. After adjustment for age and sex, factors that were strongly associated with an increased risk of bacteriologically confirmed disease at pre-entry screening were self-report of close or household contact with an individual with tuberculosis (odds ratio 11·6, 95% CI 7·0–19·3; p<0·0001) and being an applicant for settlement and dependant visas (1·3, 1·0–1·6; p=0·0203).InterpretationMigrants reporting contact with an individual with tuberculosis had the highest risk of tuberculosis at pre-entry screening. To tackle this disease burden in migrants, a comprehensive and collaborative approach is needed between countries with pre-entry screening programmes, health services in the countries of origin and migration, national tuberculosis control programmes, and international public health bodies.FundingWellcome Trust, Medical Research Council, and UK National Institute for Health Research

    Collateral-resistance to estrogen and HER-activated growth is associated with modified AKT, ERα and cell-cycle signaling in a breast cancer model

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    These studies were supported by grants from Cancer Research UK (C503/A5010 and C1938/A6769).Aim : A model of progressively endocrine-resistant breast cancer was investigated to identify changes that can occur in signaling pathways after endocrine manipulation. Methods : The MCF7 breast cancer model is sensitive to estrogens and anti-estrogens while variant lines previously derived from wild-type MCF7 are either relatively 17β-estradiol (E2)-insensitive (LCC1) or fully resistant to estrogen and anti-estrogens (LCC9). Results : In LCC1 and LCC9 cell lines, loss of estrogen sensitivity was accompanied by loss of growth response to transforming growth factor alpha (TGFα), heregulin-beta and pertuzumab. LCC1 and LCC9 cells had enhanced AKT phosphorylation relative to MCF7 which was reflected in downstream activation of phospho-mechanistic target of rapamycin (mTOR), phospho-S6, and phospho-estrogen receptor alpha Ser167 [ERα(Ser167)]. Both AKT2 and AKT3 were phosphorylated in the resistant cell lines, but siRNA knockdown suggested that all three AKT isoforms contributed to growth response. ERα(Ser118) phosphorylation was increased by E2 and TGFα in MCF7, by E2 only in LCC1, but by neither in LCC9 cells. Multiple alterations in E2-mediated cell cycle control were identified in the endocrine-resistant cell lines including increased expression of MYC, cyclin A1, cyclin D1, cyclin-dependent kinase 1 (CDK1), CDK2, and hyperphosphorylated retinoblastoma protein (ppRb), whereas p21 and p27 were reduced. Estrogen modulated expression of these regulators in MCF7 and LCC1 cells but not in LCC9 cells. Seliciclib inhibited CDK2 activation in MCF7 cells but not in resistant variants; in all lines, it reduced ppRb, increased p53 associated responses including p21, p53 up-regulated modulator of apoptosis (PUMA), and p53 apoptosis-inducing protein 1 (p53AIP1), inhibited growth, and produced G2/M block and apoptosis. Conclusions : Multiple changes occur with progression of endocrine resistance in this model with AKT activation contributing to E2 insensitivity and loss of ERα(Ser118) phosphorylation being associated with full resistance. Cell cycle regulation is modified in endocrine-resistant breast cancer cells, and seliciclib is effective in both endocrine-sensitive and resistant diseases.Publisher PDFPeer reviewe
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