23 research outputs found
Bycatch of franciscana dolphins Pontoporia blainvillei and the dynamic of artisanal fisheries in the species' southernmost area of distribution
Na Argentina, a toninha Ă© um dos cetĂĄceos mais vulnerĂĄveis devido Ă s capturas por rede de pesca artesanal. O presente estudo teve como objetivo estimar as capturas acidentais no sul da provĂncia de Buenos Aires, atravĂ©s de entrevistas aos capitĂŁes de barcos de pesca artesanal, entre os anos 2006-2009. As capturas foram reportadas para redes de emalhe e de camarĂŁo; com as mais altas frequĂȘncias entre outubro e fevereiro, a 5 km da costa e 10-20 m de profundidade. A mortalidade acidental mĂ©dia anual estimada foi de 107 golfinhos (IC 95% = 87-129), 92 em redes de emalhe (IC 95% = 73-112) e 15 em redes de camarĂŁo (IC 95% = 8-25), com uma captura de 0,029 golfinhos/km de rede de emalhe (IC 95% = 0,023-0,036) e 0,024/rede de camarĂŁo (IC 95% = 0,012-0,035). As flutuaçÔes anuais responderam principalmente Ă s diferenças nos dias de pesca. Considerando o Ășltimo levantamento estimativo feito para o norte costeiro da provĂncia, estima-se uma mortalidade entre 360-539 golfinhos/ano em toda a provĂncia de Buenos Aires. Esses valores correspondem de 2,5-3,7% da abundĂąncia populacional da Argentina; o que traria como consequĂȘncia um declĂnio populacional da espĂ©cie, tornando-se fundamental encontrar alternativas de pesca para a ĂĄrea.In Argentina, the franciscana dolphin is one of the most vulnerable cetaceans regularly entangled in coastal artisanal fishery nets. The aim of this paper is to estimate the species' incidental mortality on the Southern coast of Buenos Aires province through interviews with the captains of artisanal fishing vessels, in the period 2006-2009. Franciscana bycatch was reported for gillnets and shrimper gear all year round but it occurred more frequently between October and February, at 5 km offshore and 10-20 m depth. The estimated mean annual incidental mortality was 107 dolphins (CI 95% = 87-129), 92 caught in gillnets (CI 95% = 73-112) and 15 in shrimpers' gear (CI 95% = 8-25) with a capture per unit effort of 0.029 dolphins per km of gillnet (CI 95% = 0.023-0.036) and 0.022 per shrimpe r's net (CI 95% = 0.012-0.035). Annual fluctuations were due to differences in the number of gillnetting fishing days. If mortality estimates for the Northern coast are also taken into account, values attain a maximum of 360-539 dolphins bycaught in the entire Buenos Aires province, representing 2.5-3.7% of the species' abundance in Argentina. This will inevitably lead to the decline of franciscana dolphin populations in the near future unless alternative fishing grounds are identified and alternative gearadopted
Supplement: "Localization and broadband follow-up of the gravitational-wave transient GW150914" (2016, ApJL, 826, L13)
This Supplement provides supporting material for Abbott et al. (2016a). We briefly summarize past electromagnetic (EM) follow-up efforts as well as the organization and policy of the current EM follow-up program. We compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow-up observations that were performed in the different bands
Cosmology intertwined: A review of the particle physics, astrophysics, and cosmology associated with the cosmological tensions and anomalies
The standard Cold Dark Matter (CDM) cosmological model provides a good description of a wide range of astrophysical and cosmological data. However, there are a few big open questions that make the standard model look like an approximation to a more realistic scenario yet to be found. In this paper, we list a few important goals that need to be addressed in the next decade, taking into account the current discordances between the different cosmological probes, such as the disagreement in the value of the Hubble constant H0, the Ï8âS8 tension, and other less statistically significant anomalies. While these discordances can still be in part the result of systematic errors, their persistence after several years of accurate analysis strongly hints at cracks in the standard cosmological scenario and the necessity for new physics or generalisations beyond the standard model. In this paper, we focus on the 5.0 Ï tension between the Planck CMB estimate of the Hubble constant H0 and the SH0ES collaboration measurements. After showing the H0 evaluations made from different teams using different methods and geometric calibrations, we list a few interesting new physics models that could alleviate this tension and discuss how the next decadeâs experiments will be crucial. Moreover, we focus on the tension of the Planck CMB data with weak lensing measurements and redshift surveys, about the value of the matter energy density m, and the amplitude or rate of the growth of structure (Ï8, f Ï8). We list a few interesting models proposed for alleviating this tension, and we discuss the importance of trying to fit a full array of data with a single model and not just one parameter at a time. Additionally, we present a wide range of other less discussed anomalies at a statistical significance level lower than the H0âS8 tensions which may also constitute hints towards new physics, and we discuss possible generic theoretical approaches that can collectively explain the non-standard nature of these signals. Finally, we give an overview of upgraded experiments and next-generation space missions and facilities on Earth that will be of crucial importance to address all these open questions
Localization and Broadband Follow-up of the Gravitational-wave Transient GW150914
A gravitational-wave (GW) transient was identified in data recorded by
the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)
detectors on 2015 September 14. The event, initially designated G184098
and later given the name GW150914, is described in detail elsewhere. By
prior arrangement, preliminary estimates of the time, significance, and
sky location of the event were shared with 63 teams of observers
covering radio, optical, near-infrared, X-ray, and gamma-ray wavelengths
with ground- and space-based facilities. In this Letter we describe the
low-latency analysis of the GW data and present the sky localization of
the first observed compact binary merger. We summarize the follow-up
observations reported by 25 teams via private Gamma-ray Coordinates
Network circulars, giving an overview of the participating facilities,
the GW sky localization coverage, the timeline, and depth of the
observations. As this event turned out to be a binary black hole merger,
there is little expectation of a detectable electromagnetic (EM)
signature. Nevertheless, this first broadband campaign to search for a
counterpart of an Advanced LIGO source represents a milestone and
highlights the broad capabilities of the transient astronomy community
and the observing strategies that have been developed to pursue neutron
star binary merger events. Detailed investigations of the EM data and
results of the EM follow-up campaign are being disseminated in papers by
the individual teams.
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Working lives of youth in poverty in urban Argentina
This chapter analyzes how people between 15 and 24 years old work and live in poverty. These young people have several years of working experience, since most of them began working during childhood or adolescence and are part of familiesâboth nuclear and extendedâwith low incomes. Methodologically, the text has been based on the complement of fieldwork by the two authors. Chavesâ fieldwork was located in a suburban neighborhood of the city of La Plata (Province of Buenos Aires), and Assusaâs fieldwork was located in different neighborhoods of the city of CĂłrdoba (Province of CĂłrdoba). Both made interviews and kept records of participant observation. Population analysis through Permanent Household Survey (PHS) processing is also provided, contributing elements for an initial characterization of the situation of working and poor youth in Argentina, which also allows us to make diachronic (change in time) and synchronic (differences and inequalities among social classes) comparisons that make possible for readers from other regions to understand the strong trends in social conditions in Argentina. The richness of combining both data records and the complement of quantitative and qualitative results provide a much wider interpretation framework for the analyzed phenomenon.Fil: Assusa, Gonzalo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de Humanidades. Universidad Nacional de CĂłrdoba. Instituto de Humanidades; ArgentinaFil: Chaves, Mariana. Universidad Nacional de La Plata. Facultad de Trabajo Social. Laboratorio de Estudios en Cultura y Sociedad; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata; Argentin