85 research outputs found

    Egg Production in a Coastal Seabird, the Glaucous-Winged Gull (Larus glaucescens), Declines during the Last Century

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    Seabirds integrate information about oceanic ecosystems across time and space, and are considered sensitive indicators of marine conditions. To assess whether hypothesized long-term foodweb changes such as forage fish declines may be reflected in a consumer's life history traits over time, I used meta-regression to evaluate multi-decadal changes in aspects of egg production in the glaucous-winged gull (Larus glaucescens), a common coastal bird. Study data were derived from literature searches of published papers and unpublished historical accounts, museum egg collections, and modern field studies, with inclusion criteria based on data quality and geographic area of the original study. Combined historical and modern data showed that gull egg size declined at an average of 0.04 cc y−1 from 1902 (108 y), equivalent to a decline of 5% of mean egg volume, while clutch size decreased over 48 y from a mean of 2.82 eggs per clutch in 1962 to 2.25 in 2009. There was a negative relationship between lay date and mean clutch size in a given year, with smaller clutches occurring in years where egg laying commenced later. Lay date itself advanced over time, with commencement of laying presently (2008–2010) 7 d later than in previous studies (1959–1986). This study demonstrates that glaucous-winged gull investment in egg production has declined significantly over the past ∼50–100 y, with such changes potentially contributing to recent population declines. Though gulls are generalist feeders that should readily be able to buffer themselves against food web changes, they are likely nutritionally constrained during the early breeding period, when egg production requirements are ideally met by consumption of high-quality prey such as forage fish. This study's results suggest a possible decline in the availability of such prey, and the incremental long-term impoverishment of a coastal marine ecosystem bordering one of North America's rapidly growing urban areas

    Het Rijksvaccinatieprogramma in Nederland. Ontwikkelingen in 2006

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    In 2006 several changes were made in the Dutch National Immunisation Programme (NIP): Hepatitis B vaccination at birth was added for children born to mothers positive for hepatitis B surface antigen; a new vaccine for diphtheria, tetanus, pertussis (a-cellular), poliomyelitis and Haemophilus influenzae (DTaP-IPV/Hib) was introduced; vaccination against pneumococcal disease was added at two, three, four and eleven months; risk groups for hepatitis B receive a combined vaccine for DTaP-IPV/Hib and HBV at the same ages; DT-IPV and aP at the age of four years were combined in one vaccine; and new MMR vaccines were introduced. As new information became available in 2006, the desirability to introduce vaccinations in the NIP for the following diseases could be (re)considered: hepatitis B (universal vaccination), rotavirus, varicella and human papillomavirus. For respiratory syncytial virus and meningococcal serogroup B disease no candidate vaccines are available yet. Extension of the programme with available vaccines for hepatitis A, influenza and tuberculosis is not (yet) recommended. The NIP in the Netherlands is effective and safe. However, continued monitoring of the effectiveness and safety of the NIP is important as changes are made regularly. Maintaining high vaccine uptake is vital to prevent (re)emergence of diseases. Furthermore, the programme should be regularly reviewed as new vaccines become available.In 2006 traden verschillende veranderingen op in het Rijksvaccinatieprogramma (RVP) in Nederland: kinderen die geboren worden uit moeders die chronisch geinfecteerd zijn met hepatitis B krijgen vlak na de geboorte een hepatitis B vaccinatie; er is een ander vaccin geintroduceerd voor difterie, kinkhoest (a-cellulair), tetanus, poliomyelitis en Haemophilus influenzae (DaKTP/Hib); vaccinatie tegen pneumokokken is toegevoegd op de leeftijd van 2, drie, vier en elf maanden; risicogroepen voor hepatitis B krijgen op diezelfde leeftijden een combinatievaccin voor DaKTP/Hib en hepatitis B; DTP en aK zijn gecombineerd in een vaccin op vierjarige leeftijd; en er zijn nieuwe BMR vaccins geintroduceerd. Op basis van informatie die in 2006 beschikbaar is gekomen wordt geadviseerd de introductie van vaccinaties voor de volgende ziekten te overwegen: hepatitis B (universele vaccinatie), rotavirus, waterpokken en humaan papillomavirus. Voor respiratoir syncytieel virus en meningokokken B zijn nog geen kandidaatvaccins beschikbaar en uitbreiding van het RVP met beschikbare vaccins voor hepatitis A, influenza en tuberculose wordt nog niet aanbevolen. Het RVP is effectief en veilig, maar voortdurende bewaking hiervan is groot belang, omdat er regelmatig veranderingen optreden. Handhaven van de hoge vaccinatiegraad is essentieel om terugkeer van ziekten te voorkomen. Verder moet regelmatig bekeken worden of het RVP aangepast moet worden aangezien er steeds nieuwe vaccins beschikbaar komen

    ErbB2, EphrinB1, Src Kinase and PTPN13 Signaling Complex Regulates MAP Kinase Signaling in Human Cancers

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    In non-cancerous cells, phosphorylated proteins exist transiently, becoming de-phosphorylated by specific phosphatases that terminate propagation of signaling pathways. In cancers, compromised phosphatase activity and/or expression occur and contribute to tumor phenotype. The non-receptor phosphatase, PTPN13, has recently been dubbed a putative tumor suppressor. It decreased expression in breast cancer correlates with decreased overall survival. Here we show that PTPN13 regulates a new signaling complex in breast cancer consisting of ErbB2, Src, and EphrinB1. To our knowledge, this signaling complex has not been previously described. Co-immunoprecipitation and localization studies demonstrate that EphrinB1, a PTPN13 substrate, interacts with ErbB2. In addition, the oncogenic V660E ErbB2 mutation enhances this interaction, while Src kinase mediates EphrinB1 phosphorylation and subsequent MAP Kinase signaling. Decreased PTPN13 function further enhances signaling. The association of oncogene kinases (ErbB2, Src), a signaling transmembrane ligand (EphrinB1) and a phosphatase tumor suppressor (PTPN13) suggest that EphrinB1 may be a relevant therapeutic target in breast cancers harboring ErbB2-activating mutations and decreased PTPN13 expression

    Paleoclimate Implications for Human-Made Climate Change

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    Paleoclimate data help us assess climate sensitivity and potential human-made climate effects. We conclude that Earth in the warmest interglacial periods of the past million years was less than 1{\deg}C warmer than in the Holocene. Polar warmth in these interglacials and in the Pliocene does not imply that a substantial cushion remains between today's climate and dangerous warming, but rather that Earth is poised to experience strong amplifying polar feedbacks in response to moderate global warming. Thus goals to limit human-made warming to 2{\deg}C are not sufficient - they are prescriptions for disaster. Ice sheet disintegration is nonlinear, spurred by amplifying feedbacks. We suggest that ice sheet mass loss, if warming continues unabated, will be characterized better by a doubling time for mass loss rate than by a linear trend. Satellite gravity data, though too brief to be conclusive, are consistent with a doubling time of 10 years or less, implying the possibility of multi-meter sea level rise this century. Observed accelerating ice sheet mass loss supports our conclusion that Earth's temperature now exceeds the mean Holocene value. Rapid reduction of fossil fuel emissions is required for humanity to succeed in preserving a planet resembling the one on which civilization developed.Comment: 32 pages, 9 figures; final version accepted for publication in "Climate Change at the Eve of the Second Decade of the Century: Inferences from Paleoclimate and Regional Aspects: Proceedings of Milutin Milankovitch 130th Anniversary Symposium" (eds. Berger, Mesinger and Sijaci

    Lung epithelial stem cells and their niches : Fgf10 takes center stage

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    Throughout life adult animals crucially depend on stem cell populations to maintain and repair their tissues to ensure life-long organ function. Stem cells are characterized by their capacity to extensively self-renew and give rise to one or more differentiated cell types. These powerful stem cell properties are key to meet the changing demand for tissue replacement during normal lung homeostasis and regeneration after lung injury. Great strides have been made over the last few years to identify and characterize lung epithelial stem cells as well as their lineage relationships. Unfortunately, knowledge on what regulates the behavior and fate specification of lung epithelial stem cells is still limited, but involves communication with their microenvironment or niche, a local tissue environment that hosts and influences the behaviors or characteristics of stem cells and that comprises other cell types and extracellular matrix. As such, an intimate and dynamic epithelial-mesenchymal cross-talk, which is also essential during lung development, is required for normal homeostasis and to mount an appropriate regenerative response after lung injury. Fibroblast growth factor 10 (Fgf10) signaling in particular seems to be a well-conserved signaling pathway governing epithelial-mesenchymal interactions during lung development as well as between different adult lung epithelial stem cells and their niches. On the other hand, disruption of these reciprocal interactions leads to a dysfunctional epithelial stem cell-niche unit, which may culminate in chronic lung diseases such as chronic obstructive pulmonary disease (COPD), chronic asthma and idiopathic pulmonary fibrosis (IPF)

    Risk factors of migraine-related brain white matter hyperintensities: an investigation of 186 patients

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    Brain white matter hyperintensities are more prevalent in migraine patients than in the general population, but the pathogenesis and the risk factors of these hyperintensities are not fully elucidated. The authors analyzed the routine clinical data of 186 migraine patients who were referred to the Outpatient Headache Department of the Department of Neurology, Medical School, University of Pécs, Hungary between 2007 and 2009: 58 patients with white matter hyperintensities and 128 patients without white matter hyperintensities on 3 T MRI. Significant associations between the presence of white matter hyperintensities and longer disease duration (14.4 vs. 19.9 years, p = 0.004), higher headache frequency (4.1 vs. 5.5 attacks/month, p = 0.017), hyperhomocysteinemia (incidence of hyperintensity is 9/9 = 100%, p = 0.009) and thyroid gland dysfunction (incidence of hyperintensity is 8/14 = 57.1%, p = 0.038) were found. These data support the theory that both the disease duration and the attack frequency have a key role in the formation of migraine-related brain white matter hyperintensities, but the effects of comorbid diseases may also contribute to the development of the hyperintensities

    The Rotterdam Study: 2016 objectives and design update

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