4,697 research outputs found
Attentional capture by deviant sounds: A non-contingent form of auditory distraction?
The occurrence of an unexpected, infrequent sound in an otherwise homogeneous auditory background tends to disrupt the ongoing cognitive task. This ‘deviation effect’ is typically explained in terms of attentional capture whereby the deviant sound draws attention away from the focal activity, regardless of the nature of this activity. Yet, there is theoretical and empirical evidence suggesting that the attention-capture mechanism underlying this form of distraction could rather be triggered in a task-contingent fashion. The present study aimed at determining whether the auditory deviation effect reflects the action of either a stimulus-driven or a task-contingent orienting mechanism. To do so, we conducted a systematic investigation whereby the impact of verbal deviants—a letter embedded in the repetition of another letter—and spatial deviants—a sound presented contralaterally to the other sounds—on verbal and spatial short-term memory was assessed. This study established that both verbal and spatial deviants can hinder both verbal and spatial order-reconstruction (Experiment 1) and missing-item tasks (Experiment 2). Such results demonstrate that the deviation effect reflects a general form of auditory distraction as interference took place both within and across domains and regardless of the processes engaged in the focal tas
Charactéristiques d'une population introduit du Grand brochet, Esox lucius, dans le lac Ramsay, Parc de la Gatineau, Québec, et impact sur l'ichtyofaune
En 1995, la présence du Grand brochet (Esox lucius), une espèce piscivore, a été notée pour la première fois dans le lac Ramsay, Parc de la Gatineau (Québec). Il a été déterminé que l’espèce a été introduite après l’été 1991. Un échantillonnage exhaustif de l’ichtyofaune du lac en 2001 et 2002 a permis de constater que trois des 17 petites espèces de poissons du lac sont probablement disparues: le Mulet perlé (Margariscus margarita), l’Épinoche à cinq épines (Culaea inconstans) et une forme rare de l’Épinoche à trois épines (Gasterosteus aculeatus). Il est prédit que plusieurs autres espèces pourraient disparaître au cours des prochaines années. La croissance du Grand brochet dans le lac Ramsay est comparable aux autres lacs du sud du Québec. En 2001, le rapport femelles:mâles était de 15 : 1, une valeur anormale et inexpliquée.In 1995, the Northern Pike (Esox lucius), a piscivorous fish, was captured for the first time in Ramsay Lake, a small lake of the Gatineau Park (Québec). It was determined that this species was introduced after the summer of 1991. An exhaustive survey of the ichthyofauna of this lake in 2001 and 2002 indicated that three of the 17 small-bodied species of the lake have probably disappeared: the Pearl Dace (Margariscus margarita), the Fivespine Stickleback (Culaea inconstans) and a special form of the Threespine Stickleback (Gasterosteus aculeatus). It is predicted that several other species may be extirpated in the next few years. Northern Pike growth in the lake is comparable to other values obtained for other southern Québec lakes. In 2001, the female:male ratio was highly unbalanced and difficult to explain at 15 : 1. Erratum added
Development and Characterisation of a Gas System and its Associated Slow-Control System for an ATLAS Small-Strip Thin Gap Chamber Testing Facility
A quality assurance and performance qualification laboratory was built at
McGill University for the Canadian-made small-strip Thin Gap Chamber (sTGC)
muon detectors produced for the 2019-2020 ATLAS experiment muon spectrometer
upgrade. The facility uses cosmic rays as a muon source to ionise the quenching
gas mixture of pentane and carbon dioxide flowing through the sTGC detector. A
gas system was developed and characterised for this purpose, with a simple and
efficient gas condenser design utilizing a Peltier thermoelectric cooler (TEC).
The gas system was tested to provide the desired 45 vol% pentane concentration.
For continuous operations, a state-machine system was implemented with alerting
and remote monitoring features to run all cosmic-ray data-acquisition
associated slow-control systems, such as high/low voltage, gas system and
environmental monitoring, in a safe and continuous mode, even in the absence of
an operator.Comment: 23 pages, LaTeX, 14 figures, 4 tables, proof corrections for Journal
of Instrumentation (JINST), including corrected Fig. 8b
Examining the U.S. Disaster Management Program: A Case Study of the U.S. Virgin Islands Hurricanes Irma and Maria Evacuation
AbstractWhether from natural or human causes, every global community is at risk for overwhelming, destabilizing incidents. Hurricanes Irma and Maria devastated the U.S. Virgin Islands in late August and early September 2017, necessitating the urgent evacuation of hemodialysis patients over 1000 miles to the U.S. mainland. Because the damage and response to the U.S. territory were unprecedented, the public health implications of the government’s strategies on the evacuated population subset were unexplored. However, available information suggested that some evacuees sustained avoidable harm while in the protracted care and custody of the government. This qualitative case study, conceptually framed by Bronfenbrenner’s socioecological systems, examined the federal disaster management program’s sufficiency to abate or preclude foreseeable risks to the evacuees. Structured interviews and documented evacuee and responder experiences, compared with programmatic specifications, informed equity and efficacy determinations. Decades of research described enhanced vulnerability among individuals impacted by social determinants of health. Despite these known risks, this study revealed operational activities that negatively impacted some evacuees’ health, safety, wellbeing, and community reentry capability. Redirecting policy level disaster management priorities to those at the highest risk for worse outcomes can expose person level procedural gaps. As such, programmatic enhancements can spur transformative holistic positive social change, promoting equity in disaster response
Intercomparison of two-dimensional wave spectra obtained from microwave instruments, buoys and WAModel simulations during the surface wave dynamics experiment
An intercomparison is made of two dimensional wave spectra obtained from buoys and various remote sensing microwave systems and predicted by the WAModel dur- ing the Surface Wave Dynamics Experiment (SWADE). The overall agreement be- tween the measurements and the model is satifactory, but some differences in detail require further investigation. The buoy data yield reliable mean spectral parame- ters, but the maximum likelihood retrieval algorithm tends to produce directional distributions that are broader than those of other instruments. Various microwave instruments (ROWS, RESSAC, SRA) show good promise for the determination of 2d-wave spectra, but exhibit individual shortcomings (calibration uncertainties, di- rectional ambiguity, impact of aircraft motion) that need to be further studied. The SAR system yields reliable retrievals with respect to the general spectral dis- tribution, but suffers in this experiment from an undetermined calibration factor. Deviations between the WAModel and instrumental data could be largely attributed to wind field errors, but the model also exhibits deficiencies in the development of short-fetch wave systems and in the wave spectral response to rapidly turning wind fields
Radiocarbon dating of methane and carbon dioxide evaded from a temperate peatland stream
Streams draining peatlands export large quantities of carbon in different chemical forms and
are an important part of the carbon cycle. Radiocarbon (14C) analysis/dating provides unique
information on the source and rate that carbon is cycled through ecosystems, as has recently
been demonstrated at the air-water interface through analysis of carbon dioxide (CO2) lost
from peatland streams by evasion (degassing). Peatland streams also have the potential to
release large amounts of methane (CH4) and, though 14C analysis of CH4 emitted by ebullition
(bubbling) has been previously reported, diffusive emissions have not. We describe methods
that enable the 14C analysis of CH4 evaded from peatland streams. Using these methods, we
investigated the 14C age and stable carbon isotope composition of both CH4 and CO2 evaded
from a small peatland stream draining a temperate raised mire. Methane was aged between
1617-1987 years BP, and was much older than CO2 which had an age range of 303-521 years
BP. Isotope mass balance modelling of the results indicated that the CO2 and CH4 evaded
from the stream were derived from different source areas, with most evaded CO2 originating
from younger layers located nearer the peat surface compared to CH4. The study demonstrates
the insight that can be gained into peatland carbon cycling from a methodological
development which enables dual isotope (14C and 13C) analysis of both CH4 and CO2 collected
at the same time and in the same way
Background risk of breast cancer and the association between physical activity and mammographic density
This work is licensed under a Creative Commons Attribution 4.0
International License. The images or other third party material in this
article are included in the article’s Creative Commons license, unless indicated
otherwise in the credit line; if the material is not included under the Creative Commons
license, users will need to obtain permission from the license holder to reproduce the
material. To view a copy of this license, visit http://creativecommons.org/licenses/
by/4.0
The phantom midge menace: Migratory Chaoborus larvae maintain poor ecosystem state in eutrophic inland waters
Chaoborus spp. (phantom midge) are prevalent in eutrophic lakes with methane-rich, oxygen depleted hypolimnion and sediments, and the methane-poor, oxygen-rich epilimnion. Using a combination of experiments and system modelling, we demonstrated that the larvae’s burrowing activities in and out of the sediment perturbed the sediment and reintroduced sequestered phosphorus into the overlying water, thereby exacerbating internal nutrient loading in the water column. Fluxes of sediment methane and other reduced solutes enhanced by the larval bioturbation sustain the hypoxic/anoxic condition below the thermocline. Migrating larvae also directly transported methane in their gas vesicles from the deep water and release it in the surface water, potentially contributing to methane emission to air. As nutrient pollution and climate warming persist or worsen in the coming decades, proliferation of Chaoborus could intensify this positive feedback loop and delay lake recovery
- …