169 research outputs found

    High-precision U-Pb zircon dating of explosive volcanism in an early bi-modal volcano-sedimentary sequence from the Isle of Mull, North Atlantic Igneous Province

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    The North Atlantic Igneous Province (NAIP) forms one of the best studied Large Igneous Provinces (LIP) on the planet, however, significant uncertainties regarding the age and nature of the early onset of volcanism across the province remain. In order to better understand the onset and timing of volcanism within the NAIP, we present a new study of the mixed volcano-sedimentary deposits exposed at the base of the Isle of Mull lava pile, Inner Hebrides, Scotland. The study area comprises organic rich estuarine sediments, intimately mixed and interdigitated with bi-modal composition volcaniclastic and pyroclastic interlayers, including a prominent stratigraphically constrained c. 30 cm thick water-lain rhyolitic ignimbrite. Pristine magmatic zircons liberated from the ignimbrite reveal a high precision Usingle bondPb age of 62.035 ± 0.041 Ma (2σ) giving a robust age for early volcanism in this part of the province. Field observations reveal evidence for mafic phreatomagmatic eruptive deposits both above and below the rhyolite documenting the bimodal explosive nature of the initial magmatism in this area and, importantly, that mafic magmatism initiated before the dated unit. The bi-modal explosive eruptions periodically inundated an otherwise quiet and low energy Danian aged estuarine environment prior to its inundation with lava as magmatism took hold in the region

    Higher establishment success in specialized parasitoids: support for the existence of trade-offs in the evolution of specialization

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    Most animals do not feed on all the resources available to them, but the mechanisms behind the evolution of dietary specialization are still debated. A central but unanswered question is whether specialists generally gain fitness advantages on their resource compared to generalists, experiencing a trade-off between the ability to use a broad range of resources and the fitness reached on each single one.Empirical tests so far suffered from difficulties in measuring fitness; they were restricted to few species, and results were equivocal. This lack of support for the importance of trade-offs gave rise to theories explaining the evolution of specialization without such trade-offs.Using a large dataset of intentional biological control introductions of 254 species of parasitoids from 15 families to locations outside their native range, we show that establishment success, a measure of total fitness, is higher in specialized species. This result holds when controlling for possible confounding factors such as the number of introduced individuals (propagule pressure).The outcome of this study provides robust evidence that dietary specialization implies fitness advantages in an entire species-rich taxon, indicating that trade-offs might be widely involved in the evolution of specialization

    Au+Au Reactions at the AGS: Experiments E866 and E917

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    Particle production and correlation functions from Au+Au reactions have been measured as a function of both beam energy (2-10.7AGeV) and impact parameter. These results are used to probe the dynamics of heavy-ion reactions, confront hadronic models over a wide range of conditions and to search for the onset of new phenomena.Comment: 12 pages, 14 figures, Talk presented at Quark Matter '9

    Desenvolvimento de um roteiro conceitual para a gestĂŁo da biodiversidade e dos serviços ecossistĂȘmicos no Caribe mexicano

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    Coral reefs and mangroves support rich biodiversity and provide ecosystem services that range from food, recreational benefits and coastal protection services, among others. They are one of the most threatened ecosystems by urbanization processes. In this context, we developed a conceptual framework for the management of biodiversity and ecosystem services for these coastal environments. We based our workflow on two sections: “Information base” and “Governance” and use the Puerto Morelos Coastal region as a case study for coastal protection. Puerto Morelos is between two of the most touristic destinations of Mexico (Playa del Carmen and Cancun) that has experienced an increase of population in the past four decades resulting in an intensification of multiple threats to its ecosystems. We characterized the two ecosystems with a “Management Units” strategy. An expert-based ecosystem services matrix was also described in order to connect mangroves and coral reef ecosystems with the multiple beneficiaries. Then an ecosystem model (conceptual model and Global Biodiversity model) was developed. The conceptual model was useful in understanding the interplay processes between systems regarding the ecosystem service of “Coastal Protection”. The Global Biodiversity model evidenced the human-induced shifts in the biodiversity for mangrove and coral reefs ecosystems. Also, a projection for 2035 of “best” and “worst” scenarios was applied using GLOBIO3. A DPSIR conceptual framework was used to analyze environmental problems regarding ecosystem services maintenance. Finally, we evaluated a set of policies associated with these ecosystems that favor coastal protection integrity. This framework facilitates the identification of the most relevant processes and controls about the provision of coastal protection service. It can also be useful to better target management actions and as a tool to identify future management needs to tackle the challenges preventing more effective conservation of coastal environments.Recifes de coral e manguezais possuem rica biodiversidade e fornecem serviços ecossistĂȘmicos, tais como, alimento, recreação, proteção costeira, entre outros. Esses ecossistemas encontram-se entre os mais ameaçados pelos processos de urbanização. Nesse contexto, desenvolvemos um roteiro conceitual para a gestĂŁo da biodiversidade e dos serviços ecossistĂȘmicos desses ambientes costeiros. Organizamos nossa sequĂȘncia de passos de trabalho em duas seçÔes: “Base de informaçÔes” e “Governança” e usamos a regiĂŁo costeira da cidade de Puerto Morelos (MĂ©xico) como um estudo de caso para analisar o serviço de proteção de costa. Puerto Morelos encontra-se entre dois dos destinos mais turĂ­sticos do MĂ©xico (Playa del Carmen e CancĂșn), e portanto sua população vem aumentando nas Ășltimas quatro dĂ©cadas, resultando na intensificação de mĂșltiplas ameaças para os ecossistemas. Primeiramente, caracterizamos os dois ecossistemas identificando-os como “Unidades de GestĂŁo”, detalhando seus principais componentes e processos. AtravĂ©s de uma “Matriz de serviços ecossistĂȘmicos”, construĂ­da com base na opiniĂŁo de especialistas, foram sistematizados os principais serviços ecossistĂȘmicos prestados pelos manguezais e recifes de corais aos mĂșltiplos beneficiĂĄrios. Em seguida, foi desenvolvida uma modelagem do sistema (e ecossistemas) atravĂ©s de sua representação na forma de um modelo conceitual e um modelo numĂ©rico de Biodiversidade Global. O modelo conceitual facilitou a compreensĂŁo dos processos de interação entre sistemas em relação ao serviço “Proteção Costeira”. O modelo numĂ©rico evidenciou as mudanças induzidas pelo homem na biodiversidade dos ecossistemas de manguezal e recifes de coral. AlĂ©m disso, uma projeção dos cenĂĄrios “melhor” e “pior” foi desenvolvida para 2035 usando GLOBIO3. A Estrutura conceitual DPSIR foi aplicada para analisar problemas ambientais relacionados Ă  manutenção dos serviços ecossistĂȘmicos. Finalmente, avaliamos um conjunto de polĂ­ticas pĂșblicas associadas a esses ecossistemas e que favorecem a integridade da proteção costeira. Portanto, o roteiro facilitou a identificação dos principais processos e controles para a provisĂŁo de um serviço ecossistĂȘmico. AlĂ©m disso, pode ser Ăștil para direcionar melhor as açÔes de gerenciamento, bem como, uma ferramenta para identificar necessidades futuras de planejamento e gestĂŁo para enfrentar desafios que permitam uma conservação mais eficaz dos ambientes costeiros.Fil: SĂĄnchez Quinto, AndrĂ©s. Universidad Nacional AutĂłnoma de MĂ©xico; MĂ©xicoFil: Costa, Julliet Correa da. Universidade Federal de Santa Catarina; BrasilFil: Zamboni, Nadia Selene. Universidade Federal do Rio Grande do Norte; BrasilFil: Sanches, FĂĄbio H. C.. Universidade Federal de Sao Paulo; BrasilFil: Principe, Silas C.. Universidade de Sao Paulo; BrasilFil: Viotto, Evangelina del Valle. Provincia de Entre RĂ­os. Centro de Investigaciones CientĂ­ficas y Transferencia de TecnologĂ­a a la ProducciĂłn. Universidad AutĂłnoma de Entre RĂ­os. Centro de Investigaciones CientĂ­ficas y Transferencia de TecnologĂ­a a la ProducciĂłn. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Santa Fe. Centro de Investigaciones CientĂ­ficas y Transferencia de TecnologĂ­a a la ProducciĂłn; ArgentinaFil: Casagranda, Maria Elvira. Universidad Nacional de TucumĂĄn. Instituto de EcologĂ­a Regional. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - TucumĂĄn. Instituto de EcologĂ­a Regional; ArgentinaFil: Lima, Francisco A. da Veiga. Universidade Federal de Santa Catarina; BrasilFil: Possamai, Bianca. Universidade Federal Do Rio Grande.; BrasilFil: Faroni Perez, Larisse. Universidade Federal de Juiz de Fora; Brasi

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    UBVRI Light curves of 44 Type Ia supernovae

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    We present UBVRI photometry of 44 Type la supernovae (SNe la) observed from 1997 to 2001 as part of a continuing monitoring campaign at the Fred Lawrence Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics. The data set comprises 2190 observations and is the largest homogeneously observed and reduced sample of SNe la to date, nearly doubling the number of well-observed, nearby SNe la with published multicolor CCD light curves. The large sample of [U-band photometry is a unique addition, with important connections to SNe la observed at high redshift. The decline rate of SN la U-band light curves correlates well with the decline rate in other bands, as does the U - B color at maximum light. However, the U-band peak magnitudes show an increased dispersion relative to other bands even after accounting for extinction and decline rate, amounting to an additional ∌40% intrinsic scatter compared to the B band

    Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO

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    The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages

    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

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    Despite the growing number of binary black hole coalescences confidently observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include the effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that have already been identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total source-frame mass M > 70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz emitted gravitational-wave frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place a conservative upper limit for the merger rate density of high-mass binaries with eccentricities 0 < e ≀ 0.3 at 16.9 Gpc−3 yr−1 at the 90% confidence level
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