893 research outputs found
Orbital Stability of Multi-Planet Systems: Behavior at High Masses
In the coming years, high contrast imaging surveys are expected to reveal the
characteristics of the population of wide-orbit, massive, exoplanets. To date,
a handful of wide planetary mass companions are known, but only one such
multi-planet system has been discovered: HR8799. For low mass planetary
systems, multi-planet interactions play an important role in setting system
architecture. In this paper, we explore the stability of these high mass,
multi-planet systems. While empirical relationships exist that predict how
system stability scales with planet spacing at low masses, we show that
extrapolating to super-Jupiter masses can lead to up to an order of magnitude
overestimate of stability for massive, tightly packed systems. We show that at
both low and high planet masses, overlapping mean motion resonances trigger
chaotic orbital evolution, which leads to system instability. We attribute some
of the difference in behavior as a function of mass to the increasing
importance of second order resonances at high planet-star mass ratios. We use
our tailored high mass planet results to estimate the maximum number of planets
that might reside in double component debris disk systems, whose gaps may
indicate the presence of massive bodies.Comment: Accepted to Ap
Tinker, tailor or transform: gender equality amidst social-ecological change
Global visions of environmental change consider gender equality to be a foundation of sustainable social-ecological systems. Similarly, social-ecological systems frameworks position gender equality as both a precursor to, and a product of, system sustainability. Yet, the degree to which gender equality is being advanced through social-ecological systems change is uncertain. We use the case of small-scale fisheries in the Pacific Islands region to explore the proposition that different social-ecological narratives: (1) ecological, (2) social-ecological, and (3) social, shape the gender equality priorities, intentions and impacts of implementing organizations. We conducted interviews with regional and national fisheries experts (n = 71) and analyzed gender commitments made within policies (n = 29) that influence small-scale fisheries. To explore these data, we developed a 'Tinker-Tailor-Transform' gender assessment typology. We find that implementing organizations aligned with the social-ecological and social narratives considered social (i.e., human-centric) goals to be equally or more important than ecological (i.e., eco-centric) goals. Yet in action, gender equality was pursued instrumentally to achieve ecological goals and/or shallow project performance targets. These results highlight that although commitments to gender equality were common, when operationalized commitments become diluted and reoriented. Across all three narratives, organizations mostly 'Tinkered' with gender equality in impact, for example, including more women in spaces that otherwise tended to be dominated by men. Impacts predominately focused on the individual (i.e., changing women) rather than driving communal-to-societal level change. We discuss three interrelated opportunities for organizations in applying the 'Tinker-Tailor-Transform' assessment typology, including its utility to assist organizations to orient toward intrinsic goals; challenge or reconfigure system attributes that perpetuate gender inequalities; and consciously interrogate discursive positions and beliefs to unsettle habituated policies, initiatives and theories of change
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The genetic structure of Aedes aegypti populations is driven by boat traffic in the Peruvian Amazon.
In the Americas, as in much of the rest of the world, the dengue virus vector Aedes aegypti is found in close association with human habitations, often leading to high population densities of mosquitoes in urban settings. In the Peruvian Amazon, this vector has been expanding to rural communities over the last 10-15 years, but to date, the population genetic structure of Ae. aegypti in this region has not been characterized. To investigate the relationship between Ae. aegypti gene flow and human transportation networks, we characterized mosquito population structure using a panel of 8 microsatellite markers and linked results to various potential mechanisms for long-distance dispersal. Adult and immature Ae. aegypti (>20 individuals per site) were collected from Iquitos city and from six neighboring riverine communities, i.e., Nauta, Indiana, Mazan, Barrio Florida, Tamshiaco, and Aucayo. FST statistics indicate significant, but low to moderate differentiation for the majority of study site pairs. Population structure of Ae. aegypti is not correlated with the geographic distance between towns, suggesting that human transportation networks provide a reasonable explanation for the high levels of population mixing. Our results indicate that Ae. aegypti gene flow among sub-populations is greatest between locations with heavy boat traffic, such as Iquitos-Tamshiaco and Iquitos-Indiana-Mazan, and lowest between locations with little or no boat/road traffic between them such as Barrio Florida-Iquitos. Bayesian clustering analysis showed ancestral admixture among three genetic clusters; no single cluster was exclusive to any site. Our results are consistent with the hypothesis that human transportation networks, particularly riverways, are responsible for the geographic spread of Ae. aegypti in the Peruvian Amazon. Our findings are applicable to other regions of the world characterized by networks of urban islands connected by fluvial transport routes
Brief report: Using global positioning system (GPS) enabled cell phones to examine adolescent travel patterns and time in proximity to alcohol outlets
As adolescents gain freedom to explore new environments unsupervised, more time in proximity to alcohol outlets may increase risks for alcohol and marijuana use. This pilot study: 1) Describes variations in adolescents' proximity to outlets by time of day and day of the week, 2) Examines variations in outlet proximity by drinking and marijuana use status, and 3) Tests feasibility of obtaining real-time data to study adolescent proximity to outlets. U.S. adolescents (N = 18) aged 16–17 (50% female) carried GPS-enabled smartphones for one week with their locations tracked. The geographic areas where adolescents spend time, activity spaces, were created by connecting GPS points sequentially and adding spatial buffers around routes. Proximity to outlets was greater during after school and evening hours. Drinkers and marijuana users were in proximity to outlets 1½ to 2 times more than non-users. Findings provide information about where adolescents spend time and times of greatest risk, informing prevention efforts
ALMA 1.3 Millimeter Map of the HD 95086 System
Planets and minor bodies such as asteroids, Kuiper-belt objects and comets
are integral components of a planetary system. Interactions among them leave
clues about the formation process of a planetary system. The signature of such
interactions is most prominent through observations of its debris disk at
millimeter wavelengths where emission is dominated by the population of large
grains that stay close to their parent bodies. Here we present ALMA 1.3 mm
observations of HD 95086, a young early-type star that hosts a directly imaged
giant planet b and a massive debris disk with both asteroid- and Kuiper-belt
analogs. The location of the Kuiper-belt analog is resolved for the first time.
The system can be depicted as a broad (0.84), inclined
(30\arcdeg3\arcdeg) ring with millimeter emission peaked at 2006 au
from the star. The 1.3 mm disk emission is consistent with a broad disk with
sharp boundaries from 1066 to 32020 au with a surface density
distribution described by a power law with an index of --0.50.2. Our deep
ALMA map also reveals a bright source located near the edge of the ring, whose
brightness at 1.3 mm and potential spectral energy distribution are consistent
with it being a luminous star-forming galaxy at high redshift. We set
constraints on the orbital properties of planet b assuming co-planarity with
the observed disk.Comment: accepted for publication in A
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High Prevalence of Multidrug-Tolerant Bacteria and Associated Antimicrobial Resistance Genes Isolated from Ornamental Fish and Their Carriage Water
Background: Antimicrobials are used to directly control bacterial infections in pet (ornamental) fish and are routinely added to the water these fish are shipped in to suppress the growth of potential pathogens during transport. Methodology/Principal Findings: To assess the potential effects of this sustained selection pressure, 127 Aeromonas spp. isolated from warm and cold water ornamental fish species were screened for tolerance to 34 antimicrobials. Representative isolates were also examined for the presence of 54 resistance genes by a combination of miniaturized microarray and conventional PCR. Forty-seven of 94 Aeromonas spp. isolates recovered from tropical ornamental fish and their carriage water were tolerant to >= 15 antibiotics, representing seven or more different classes of antimicrobial. The quinolone and fluoroquinolone resistance gene, qnrS2, was detected at high frequency (37% tested recent isolates were positive by PCR). Class 1 integrons, IncA/C broad host range plasmids and a range of other antibiotic resistance genes, including floR, blaTEM21, tet(A), tet(D), tet(E), qacE2, sul1, and a number of different dihydrofolate reductase and aminoglycoside transferase coding genes were also detected in carriage water samples and bacterial isolates. Conclusions: These data suggest that ornamental fish and their carriage water act as a reservoir for both multi-resistant bacteria and resistance genes
Automated reporting of cervical biopsies using artificial intelligence
Funding: For all authors this work is supported by the Industrial Centre for AI Research in digital Diagnostics (iCAIRD) which is funded by Innovate UK on behalf of UK Research and Innovation (UKRI) [project number: 104690], and in part by Chief Scientist Office, Scotland. DJH, DHB, OA and GB received funding from UKRI (funder project reference: TS/S013121/1). MM, DM and CF received salaries from UKRI for this project.When detected at an early stage, the 5-year survival rate for people with invasive cervical cancer is 92%. Being aware of signs and symptoms of cervical cancer and early detection greatly improve the chances of successful treatment. We have developed an Artificial Intelligence (AI) algorithm, trained and evaluated on cervical biopsies for automated reporting of digital diagnostics. The aim is to increase overall efficiency of pathological diagnosis and to have the performance tuned to high sensitivity for malignant cases. Having a tool for triage/identifying cancer and high grade lesions may potentially reduce reporting time by identifying areas of interest in a slide for the pathologist and therefore improving efficiency. We trained and validated our algorithm on 1738 cervical WSIs with one WSI per patient. On the independent test set of 811 WSIs, we achieved 93.4% malignant sensitivity for classifying slides. Recognising a WSI, with our algorithm, takes approximately 1.5 minutes on the NVIDIA Tesla V100 GPU. Whole slide images of different formats (TIFF, iSyntax, and CZI) can be processed using this code, and it is easily extendable to other formats.Peer reviewe
Familiarity is key : exploring the effect of familiarity on the face-voice correlation
Recent research has examined the extent to which face and voice processing are associated by virtue of the fact that both tap into a common person perception system. However, existing findings do not yet fully clarify the role of familiarity in this association. Given this, two experiments are presented that examine face-voice correlations for unfamiliar stimuli (Experiment 1) and for familiar stimuli (Experiment 2). With care being taken to use tasks that avoid floor and ceiling effects and that use realistic speech-based voice clips, the results suggested a significant positive but small-sized correlation between face and voice processing when recognizing unfamiliar individuals. In contrast, the correlation when matching familiar individuals was significant and positive, but much larger. The results supported the existing literature suggesting that face and voice processing are aligned as constituents of an overarching person perception system. However, the difference in magnitude of their association here reinforced the view that familiar and unfamiliar stimuli are processed in different ways. This likely reflects the importance of a pre-existing mental representation and cross-talk within the neural architectures when processing familiar faces and voices, and yet the reliance on more superficial stimulus-based and modality-specific analysis when processing unfamiliar faces and voices
The Past, Present and Future of Sleep Measurement in Mild Cognitive Impairment and Early Dementia – Towards a Core Outcome Set:A Scoping Review
STUDY OBJECTIVES: Sleep abnormalities emerge early in dementia and may accelerate cognitive decline. Their accurate characterization may facilitate earlier clinical identification of dementia and allow for assessment of sleep intervention efficacy. This scoping review determines how sleep is currently measured and reported in Mild Cognitive Impairment (MCI) and early dementia, as a basis for future core outcome alignment. METHODS: This review follows the PRISMA Guidelines for Scoping Reviews. CINAHL, Embase, Medline, Psychinfo, and British Nursing Index databases were searched from inception—March 12, 2021. Included studies had participants diagnosed with MCI and early dementia and reported on sleep as a key objective/ outcome measure. RESULTS: Nineteen thousand five hundred and ninety-six titles were returned following duplicate removal with 188 studies [N] included in final analysis. Sleep data was reported on 17 139 unique, diagnostically diverse participants (n). “Unspecified MCI” was the most common diagnosis amongst patients with MCI (n = 5003, 60.6%). Despite technological advances, sleep was measured most commonly by validated questionnaires (n = 12 586, N = 131). Fewer participants underwent polysomnography (PSG) (n = 3492, N = 88) and actigraphy (n = 3359, N = 38) with little adoption of non-PSG electroencephalograms (EEG) (n = 74, N = 3). Sleep outcome parameters were reported heterogeneously. 62/165 (37.6%) were described only once in the literature (33/60 (60%) in interventional studies). There was underrepresentation of circadian (n = 725, N = 25) and micro-architectural (n = 360, N = 12) sleep parameters. CONCLUSIONS: Alongside under-researched areas, there is a need for more detailed diagnostic characterization. Due to outcome heterogeneity, we advocate for international consensus on core sleep outcome parameters to support causal inference and comparison of therapeutic sleep interventions
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