GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    facet.materialart.
    Unbekannt
    An epistemic and dynamic approach to abductive reasoning: selecting the best explanation (2013)
    Oxford University Press
    Details
    Publikationsdatum: 2013-11-25
    Beschreibung: Previous works have discussed how to represent abductive reasoning in a dynamic epistemic logic framework. It has been discussed how to define an abductive problem, how to define an abductive solution and what to do with the best solution, once this one has been selected. The present work discusses two possible ways in which the agent can select ‘the best’ explanation.
    Print ISSN: 1367-0751
    Digitale ISSN: 1368-9894
    Thema: Mathematik
    Publiziert von Oxford University Press
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unbekannt
    Fishery-dependent and -independent data lead to consistent estimations of essential habitats (2016)
    Oxford University Press
    Details
    Publikationsdatum: 2016-10-08
    Beschreibung: Species mapping is an essential tool for conservation programmes as it provides clear pictures of the distribution of marine resources. However, in fishery ecology, the amount of objective scientific information is limited and data may not always be directly comparable. Information about the distribution of marine species can be derived from two main sources: fishery-independent data (scientific surveys at sea) and fishery-dependent data (collection and sampling by observers in commercial vessels). The aim of this paper is to compare whether these two different sources produce similar, complementary, or different results. We compare them in the specific context of identifying the Essential Fish Habitats of three elasmobranch species ( S. canicula , G. melastomus , and E. spinax ). Similarity and prediction statistics are used to compare the two different spatial patterns obtained by applying the same Bayesian spatio-temporal modelling approach in the two sources. Results showed that the spatial patterns obtained are similar, although differences are present. In particular, models based on fishery-dependent data are better able to identify temporal relationships between the probability of presence of the species and seasonal environmental variables. In contrast, fishery-independent data better discriminate spatial locations where a species is present or absent. Besides the spatial and temporal differences of the two datasets, the consistency of habitat results highlights the inclusion in each dataset of most of the environmental envelope of each species, both in time and space. Consequently, sampling data should be adapted to each species to reasonably cover their environmental envelope, and a combination of datasets will likely provide a better habitat estimation than using each dataset independently. These findings can be useful in helping fishery managers improve definition of survey design and analyses.
    Print ISSN: 1054-3139
    Digitale ISSN: 1095-9289
    Thema: Biologie , Geologie und Paläontologie , Physik
    Publiziert von Oxford University Press
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    PAPER CURRENT
  • 3
    facet.materialart.
    Unbekannt
    Iron alters valvular interstitial cell function and is associated with calcification in aortic stenosis (2017)
    Oxford University Press
    Details
    Publikationsdatum: 2017-01-07
    Beschreibung: Aims Aortic valve stenosis (AS) is the most common valvulopathy and is characterized by inflammation, extracellular matrix (ECM) remodelling and calcification, causing a narrowing of the valve and the consequential obstruction of the cardiac outflow. Although intraleaflet haemorrhage is associated with AS progression, the mechanisms involved are not known. The aims of this study were to identify valvular iron in relation to pathological changes associated with AS and the effects on valvular interstitial cells (VIC) in terms of iron uptake and iron-induced responses. Methods and results Valvular iron accumulation was detected by Perls' staining on aortic valve sections and shown to increase with the extent of calcification. Furthermore, qRT–PCR analysis revealed that iron-containing valve regions exhibited increased expression of genes involved in ECM remodelling and calcification. In addition, we demonstrate that iron transporters are regulated by pathways with major impact on AS and that VIC can take up and accumulate iron, which resulted in increased proliferation and decreased elastin production. Conclusion Iron, which may accumulate in the aortic valve by means of intraleaflet haemorrhages, can be taken up by VIC in a pro-inflammatory environment and actively contribute to VIC proliferation, ECM remodelling and calcification. These findings suggest a possible mechanism through which iron uptake by VIC may favour AS progression.
    Print ISSN: 0195-668X
    Digitale ISSN: 1522-9645
    Thema: Medizin
    Publiziert von Oxford University Press
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unbekannt
    Uniform asymptotics as a stationary point approaches an endpoint (2018)
    Oxford University Press
    Details
    Publikationsdatum: 2018-03-06
    Beschreibung: We obtain the rigorous uniform asymptotics of a particular integral where a stationary point is close to an endpoint. There exists a general method introduced by Bleistein for obtaining uniform asymptotics in this situation. However, this method does not provide rigorous estimates for the error. Indeed, the method of Bleistein starts with a change of variables, which implies that the parameter governing how close the stationary point is to the endpoint appears in several parts of the integrand, and this means that one cannot obtain general error bounds. By adapting the above method to our particular integral, we obtain rigorous uniform leading-order asymptotics. We also give a rigorous derivation of the asymptotics to all orders of the same integral; the novelty of this second approach is that it does not involve a global change of variables.
    Print ISSN: 0272-4960
    Digitale ISSN: 1464-3634
    Thema: Mathematik
    Publiziert von Oxford University Press
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unbekannt
    Community N2 fixation and Trichodesmium spp. abundance along longitudinal gradients in the eastern subtropical North Atlantic (2012)
    Oxford University Press
    Details
    Publikationsdatum: 2012-12-12
    Beschreibung: Fernández, A., Graña, R., Mouriño-Carballido, B., Bode, A., Varela, M., Domínguez-Yanes, J. F., Escánez, J., de Armas, D., and Marañón, E. 2013. Community N 2 fixation and Trichodesmium spp. abundance along longitudinal gradients in the eastern subtropical North Atlantic. – ICES Journal of Marine Science, 70:223–231. We have determined planktonic community N 2 fixation, Trichodesmium abundance, the concentration and vertical diffusive flux of phosphate, and satellite-derived estimates of atmospheric concentration of dust along two longitudinal transects in the eastern subtropical North Atlantic during November 2007 and from April–May 2008. Trichodesmium abundance was particularly low (〈3 trichome l –1 ) during the spring 2008 cruise, when low sea surface temperatures were recorded and vertical stratification was less marked. However, community N 2 fixation was always measurable, albeit low compared with other regions of the tropical Atlantic. The average, vertically-integrated N 2 fixation rate was 1.20 ± 0.48 µmol N m –2 d –1 in autumn 2007 and 8.31 ± 3.31 µmol N m –2 d –1 in spring 2008. The comparison of these rates of diazotrophy with the observed Trichodesmium abundances suggests that other, presumably unicellular, diazotrophs must have contributed significantly to community N 2 fixation, at least during the spring 2008 cruise. Satellite data of atmospheric dust concentration suggested similar rates of atmospheric deposition during the two surveys. In contrast, vertical diffusive fluxes of phosphate were 5-fold higher in spring than in autumn (14.2 ± 12.1 µmol P m –2 d –1 and 2.8 ± 2.6 µmol P m –2 d –1 , respectively), which may have stimulated N 2 fixation. These findings agree with the growing view that N 2 fixation is a more widespread process than the distribution of Trichodesmium alone may suggest. Our data also suggest a role for phosphorus supply in controlling the local variability of diazotrophic activity in a region subject to relatively high atmospheric inputs of iron.
    Print ISSN: 1054-3139
    Digitale ISSN: 1095-9289
    Thema: Biologie , Geologie und Paläontologie , Physik
    Publiziert von Oxford University Press
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    PAPER CURRENT
  • 6
    facet.materialart.
    Unbekannt
    A randomized, double-blind, placebo-controlled, multicentre study to assess haemodynamic effects of serelaxin in patients with acute heart failure (2014)
    Oxford University Press
    Details
    Publikationsdatum: 2014-02-15
    Beschreibung: Aims The aim of this study was to evaluate the haemodynamic effects of serelaxin (30 µg/kg/day 20-h infusion and 4-h post-infusion period) in patients with acute heart failure (AHF). Methods and results This double-blind, multicentre study randomized 71 AHF patients with pulmonary capillary wedge pressure (PCWP) ≥18 mmHg, systolic blood pressure (BP) ≥115 mmHg, and estimated glomerular filtration rate ≥30 mL/min/1.73 m 2 to serelaxin ( n = 34) or placebo ( n = 37) within 48 h of hospitalization. Co-primary endpoints were peak change from baseline in PCWP and cardiac index (CI) during the first 8 h of infusion. Among 63 patients eligible for haemodynamic analysis (serelaxin, n = 32; placebo, n = 31), those treated with serelaxin had a significantly higher decrease in peak PCWP during the first 8 h of infusion (difference vs. placebo: –2.44 mmHg, P = 0.004). Serelaxin showed no significant effect on the peak change in CI vs. placebo. Among secondary haemodynamic endpoints, a highly significant reduction in pulmonary artery pressure (PAP) was observed throughout the serelaxin infusion (largest difference in mean PAP vs. placebo: –5.17 mmHg at 4 h, P 〈 0.0001). Right atrial pressure, systemic/pulmonary vascular resistance, and systolic/diastolic BP decreased from baseline with serelaxin vs. placebo and treatment differences reached statistical significance at some time points. Serelaxin administration improved renal function and decreased N-terminal pro-brain natriuretic peptide levels vs. placebo. Treatment with serelaxin was well tolerated with no apparent safety concerns. Conclusion The haemodynamic effects of serelaxin observed in the present study provide plausible mechanistic support for improvement in signs and symptoms of congestion observed with this agent in AHF patients. ClinicalTrials.gov identifier NCT01543854.
    Print ISSN: 0195-668X
    Digitale ISSN: 1522-9645
    Thema: Medizin
    Publiziert von Oxford University Press
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unbekannt
    Rbm20-deficient cardiogenesis reveals early disruption of RNA processing and sarcomere remodeling establishing a developmental etiology for dilated cardiomyopathy (2014)
    Oxford University Press
    Details
    Publikationsdatum: 2014-06-21
    Beschreibung: Dilated cardiomyopathy (DCM) due to mutations in RBM20 , a gene encoding an RNA-binding protein, is associated with high familial penetrance, risk of progressive heart failure and sudden death. Although genetic investigations and physiological models have established the linkage of RBM20 with early-onset DCM, the underlying basis of cellular and molecular dysfunction is undetermined. Modeling human genetics using a high-throughput pluripotent stem cell platform was herein designed to pinpoint the initial transcriptome dysfunction and mechanistic corruption in disease pathogenesis. Tnnt2-pGreenZeo pluripotent stem cells were engineered to knockdown Rbm20 (shRbm20) to determine the cardiac-pathogenic phenotype during cardiac differentiation. Intracellular Ca 2+ transients revealed Rbm20 -dependent alteration in Ca 2+ handling, coinciding with known pathological splice variants of Titin and Camk2d genes by Day 24 of cardiogenesis. Ultrastructural analysis demonstrated elongated and thinner sarcomeres in the absence of Rbm20 that is consistent with human cardiac biopsy samples . Furthermore, Rbm20 -depleted transcriptional profiling at Day 12 identified Rbm20 -dependent dysregulation with 76% of differentially expressed genes linked to known cardiac pathology ranging from primordial Nkx2.5 to mature cardiac Tnnt2 as the initial molecular aberrations. Notably, downstream consequences of Rbm20 -depletion at Day 24 of differentiation demonstrated significant dysregulation of extracellular matrix components such as the anomalous overexpression of the Vtn gene. By using the pluripotent stem cell platform to model human cardiac disease according to a stage-specific cardiogenic roadmap, we established a new paradigm of familial DCM pathogenesis as a developmental disorder that is patterned during early cardiogenesis and propagated with cellular mechanisms of pathological cardiac remodeling.
    Print ISSN: 0964-6906
    Digitale ISSN: 1460-2083
    Thema: Biologie , Medizin
    Publiziert von Oxford University Press
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unbekannt
    Large-scale meridional and zonal variability in the nitrogen isotopic composition of plankton in the Atlantic Ocean (2014)
    Oxford University Press
    Details
    Publikationsdatum: 2014-07-11
    Beschreibung: The zonal (~15°W–40°W along 26°N–29°N) and meridional (~30°N–30°S along 28°W–29°W) variability of 15 N of suspended particles and zooplankton (〉40 µm) was studied to assess the influence of nitrogen fixation in the isotopic budget of the tropical and subtropical Atlantic ocean. Two cruises were conducted in October–November 2007 and April–May 2008 comprising a zonal and meridional transect each. In the region between 30°N and 15°N, the concurrently measured nitrogen fixation was insufficient to explain the consistent patch of suspended particles with 15 N 〈 2 and points to a significant contribution of atmospheric deposition of light nitrogen to the isotopic budget. The equatorial region (15°N–10°S) is subject to intense nitrogen fixation, which, according to a two-end-member mixing model, may explain 40–60% of the observed 15 N in suspended particles and 3–30% in zooplankton. In the South region between 10°S and 30°S, low values (〈4) were measured in suspended particles and zooplankton during 2008. The values of 15 N of suspended particles suggest that nitrogen fixation, which is usually low (〈10 µmol N m –2 day –1 ), may represent 50–60% of phytoplankton nitrogen in this region. Hence, diazotrophy in the South Atlantic may be more important than previously thought.
    Print ISSN: 0142-7873
    Digitale ISSN: 1464-3774
    Thema: Biologie
    Publiziert von Oxford University Press
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unbekannt
    Tableaux for structural abduction (2012)
    Oxford University Press
    Details
    Publikationsdatum: 2012-03-29
    Beschreibung: In this work, we shall study structural abduction and how ways of searching for solutions to the corresponding abductive problems could be modeled. Specifically, we shall define modal semantic tableaux for normal modal systems and study its applications to structural abduction. This method even makes structural abduction clearer and, as it shall be seen, when a radical change of logic is epistemologically required, the corresponding tableau will have pertinent information to suggest it.
    Print ISSN: 1367-0751
    Digitale ISSN: 1368-9894
    Thema: Mathematik
    Publiziert von Oxford University Press
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unbekannt
    A modal framework for modelling abductive reasoning (2012)
    Oxford University Press
    Details
    Publikationsdatum: 2012-03-29
    Beschreibung: We present a framework for understanding abduction within modal logic and Kripke semantics; worlds of a Kripke frame will represent possible theories, and a change in theory will be understood as a passage from one world to an adjacent possible world. Further, these steps may agree with the accessibility relation or may ‘backtrack’, accordingly as new information refutes or reinforces our present theory. Our formalism can be used to model not only abduction, but also to talk about the inner structure of theories as well as relations between them, allowing us to interpret many ideas from philosophy of science within the well-understood framework of modal logic.
    Print ISSN: 1367-0751
    Digitale ISSN: 1368-9894
    Thema: Mathematik
    Publiziert von Oxford University Press
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    PAPER CURRENT
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...