1,078 research outputs found

    Deep Coastal Marine Taphonomy: Investigation into Carcass Decomposition in the Saanich Inlet, British Columbia Using a Baited Camera

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    Decomposition and faunal colonization of a carcass in the terrestrial environment has been well studied, but knowledge of decomposition in the marine environment is based almost entirely on anecdotal reports. Three pig carcasses were deployed in Saanich Inlet, BC, over 3 years utilizing Ocean Network Canada’s VENUS observatory. Each carcass was deployed in late summer/early fall at 99 m under a remotely controlled camera and observed several times a day. Dissolved oxygen, temperature, salinity, density and pressure were continuously measured. Carcass 1 was immediately colonized by Munida quadrispina, Pandalus platyceros and Metacarcinus magister, rapidly scavenged then dragged from view by Day 22. Artifacts specific to each of the crustaceans’ feeding patterns were observed. Carcass 2 was scavenged in a similar fashion. Exposed tissue became covered by Orchomenella obtusa (Family Lysianassidae) which removed all the internal tissues rapidly. Carcass 3 attracted only a few M. quadrispina, remaining intact, developing a thick filamentous sulphur bacterial mat, until Day 92, when it was skeletonized by crustacea. The major difference between the deployments was dissolved oxygen levels. The first two carcasses were placed when oxygen levels were tolerable, becoming more anoxic. This allowed larger crustacea to feed. However, Carcass 3 was deployed when the water was already extremely anoxic, which prevented larger crustacea from accessing the carcass. The smaller M. quadrispina were unable to break the skin alone. The larger crustacea returned when the Inlet was re-oxygenated in spring. Oxygen levels, therefore, drive the biota in this area, although most crustacea endured stressful levels of oxygen to access the carcasses for much of the time. These data will be valuable in forensic investigations involving submerged bodies, indicating types of water conditions to which the body has been exposed, identifying post-mortem artifacts and providing realistic expectations for recovery divers and families of the deceased

    Assessing suicidal risk with antiepileptic drugs

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    Recently, the US Food and Drug Administration issued an alert about an increased risk for suicidality during treatment with antiepileptic drugs (AEDs) for different indications, including epilepsy. We discuss the issue of suicide in epilepsy with special attention to AEDs and the assessment of suicide in people with epilepsy. It has been suggested that early medical treatment with AEDs might potentially reduce suicide risk of people with epilepsy, but it is of great importance that the choice of drug is tailored to the mental state of the patient. The issue of suicidality in epilepsy is likely to represent an example of how the underdiagnosis of psychiatric symptoms, the lack of input from professionals (eg, psychologists, social workers, and psychiatrists), and the delay in an optimized AED therapy may worsen the prognosis of the condition with the occurrence of severe complications such as suicide

    Epilepsy Perception Amongst University Students: A Survey.

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    To evaluate the information that university students have on epilepsy and to compare the differences in attitudes and perception among groups with different levels of information. A questionnaire with 13 questions regarding knowledge, attitudes and perception about epilepsy was completed by first, third and sixth year medical students and to students from Arts and Science courses. First year medical students gave inadequate answers, especially with regard to information about epilepsy and actions to take during seizures. Answers of third and sixth year medical students were more adequate. Arts and Science students gave the poorest responses in relation to specialist information and attitudes regarding epilepsy. This study suggests that there is an inverse relationship between knowledge and stigma on epilepsy. Nevertheless, the best results did not reflect an ideal situation, revealing an urgent need for an improved level of overall health education programs. This can be achieved by implementing educational policies, training programs and the universal inclusion of these subjects in the global educational program.65 Suppl 143-

    Stigma And Attitudes On Epilepsy A Study: With Secondary School Students.

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    To evaluate whether an inappropriate attitude towards a person having an epileptic seizure contributes to the stigma found in society and whether an appropriate attitude helps to diminish it in the short term; to perform a long term investigation about information remembered and stigma perception after an educational lecture. This study was performed in two steps: Step 1. Students of first year of high school of two schools in Campinas completed a questionnaire including the Stigma Scale of Epilepsy following a seizure demonstration. They were divided into three groups: a) one group had a demonstration of proper attitudes towards someone having an epileptic seizure; b) one group was shown incorrect procedures; c) control group. After the completion of the questionnaire, an educational lecture about epilepsy was given. Step 2: six months later, the questionnaire was re-administered. The comparison between the four groups (step 1 and step 2) show a significant difference (Anova (3,339)=2.77; p=0.042). Pairwise comparison using Fisher's Least-Significant-Difference Test showed a significant difference between the group shown incorrect procedures (step 1) versus step 2, and the control group (step 1) versus step 2, but no difference between the group shown correct procedures (step 1) versus step 2. Exhibiting proper attitudes towards a person experiencing an epileptic seizure may cause significant differences among the subjects degrees of stigma towards people with epilepsy. It is therefore fundamental that there should be de-stigmatization campaigns provided, to correct information and provide appropriate education.65 Suppl 149-5

    Assessing five decades of garden bee studies

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    Urban garden spaces are potentially important habitats for bee conservation. Gardens can host diverse flora, which provide floral resources across foraging seasons for bee species. Recent reviews have focused on the impacts of cityscapes on urban bee assemblages in different green spaces. Urban gardens are distinct from other urban green spaces, and bee communities in urban spaces have been an increasing topic of study over the past few decades. We reviewed 28 urban garden bee studies spanning five decades and 14 countries to compile an original metadataset of bee species' functional traits to understand the conservation value of gardens, identify gaps in bee sampling efforts, and summarize the calls to action included by their authors. Studies of urban garden bees have documented between 674 (conservative count, excluding morphospecies) and 830 (liberal count, including morphospecies) bee species. Urban garden bee communities were taxonomically and functionally diverse, although bee species that were non-eusocial, ground-nesting, generalist foragers, and native were most common in garden habitats. The proportion of parasitic bee species and specialist foragers found in urban gardens was comparable to proportions for global bee taxa. This suggests that gardens contain the hosts and forage needed to support bees with specialized life history requirements, and thus represent high quality habitat for a subset of bee communities. Garden bee research was strongly biased toward the northern hemisphere, which signifies a large gap in our understanding of garden bee communities in other regions. The variety of, and non-standard sampling methods in garden bee research makes it difficult to directly compare results between studies. In addition, both intentional low taxonomic resolution and a lack of collaboration with taxonomists constrains our understanding of bee diversity. Our analyses highlight both successes of past urban garden bee studies, and areas of opportunity for future research as we move into a sixth decade of garden bee research

    Allocating the Burdens of Climate Action: Consumption-Based Carbon Accounting and the Polluter-Pays Principle

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    Action must be taken to combat climate change. Yet, how the costs of climate action should be allocated among states remains a question. One popular answer—the polluter-pays principle (PPP)—stipulates that those responsible for causing the problem should pay to address it. While intuitively plausible, the PPP has been subjected to withering criticism in recent years. It is timely, following the Paris Agreement, to develop a new version: one that does not focus on historical production-based emissions but rather allocates climate burdens in proportion to each state’s annual consumption-based emissions. This change in carbon accounting results in a fairer and more environmentally effective principle for distributing climate duties

    The T Tauri star RY Tau as a case study of the inner regions of circumstellar dust disks

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    We study the inner region of the circumstellar disk around the TTauri star RY Tau. Our aim is to find a physical description satisfying the available interferometric data, obtained with the mid-infrared interferometric instrument at the Very Large Telescope Interferometer, as well as the spectral energy distribution. We also compare the findings with the results of similar studies, including those of intermediate-mass stars. Our analysis is done within the framework of a passive circumstellar disk, which is optionally supplemented by the effects of accretion and an added envelope. To achieve a more consistent and realistic model, we used our continuum transfer code MC3D. In addition, we studied the shape of the 10um silicate emission feature in terms of the underlying dust population, both for single-dish and for interferometric measurements. We show that a modestly flaring disk model with accretion can explain both the observed spectral energy distribution and the mid-infrared visibilities obtained with the mid-infrared infrared instrument. We found an interesting ambiguity: a circumstellar active disk model with an added envelope, and a lower accretion rate than in the active disk model without envelope, could represent the observations equally as well. This type of model with the envelope should be considered a viable alternative in future models of other TTauri stars. The approach of a disk with a puffed-up inner rim wall and the influence of a stellar companion is also discussed. From the study of the silicate emission feature we see evidence for dust evolution in a TTauri star, with a decreasing fraction of small amorphous and an increasing fraction of crystalline particles closer to the star.Comment: 19 pages, 23 figures; accepted by Astronomy & Astrophysic

    Dust formation around AGB and SAGB stars: a trend with metallicity?

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    We calculate the dust formed around AGB and SAGB stars of metallicity Z=0.008 by following the evolution of models with masses in the range 1M<M<8M throughthe thermal pulses phase, and assuming that dust forms via condensation of molecules within a wind expanding isotropically from the stellar surface. We find that, because of the strong Hot Bottom Burning (HBB) experienced, high mass models produce silicates, whereas lower mass objects are predicted to be surrounded by carbonaceous grains; the transition between the two regimes occurs at a threshold mass of 3.5M. These fndings are consistent with the results presented in a previous investigation, for Z=0.001. However, in the present higher metallicity case, the production of silicates in the more massive stars continues for the whole AGB phase, because the HBB experienced is softer at Z=0.008 than at Z=0.001, thus the oxygen in the envelope, essential for the formation of water molecules, is never consumed completely. The total amount of dust formed for a given mass experiencing HBB increases with metallicity, because of the higher abundance of silicon, and the softer HBB, both factors favouring a higher rate of silicates production. This behaviour is not found in low mass stars,because the carbon enrichment of the stellar surface layers, due to repeated Third Drege Up episodes, is almost independent of the metallicity. Regarding cosmic dust enrichment by intermediate mass stars, we find that the cosmic yield at Z=0.008 is a factor 5 larger than at Z=0.001. In the lower metallicity case carbon dust dominates after about 300 Myr, but at Z=0.008 the dust mass is dominated by silicates at all times,with a prompt enrichment occurring after about 40 Myr, associated with the evolution of stars with masses M =7.5 -8M.Comment: 14 pages, 10 figures, 2 Tables, accepted for publication in MNRA

    Genome sequencing and carrier testing: decisions on categorization and whether to disclose results of carrier testing

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    We are investigating the use of genome sequencing for preconception carrier testing. Genome sequencing could identify one or more of thousands of X-linked or autosomal recessive conditions that could be disclosed during preconception or prenatal counseling. Therefore, a framework that helps both clinicians and patients understand the possible range of findings is needed to respect patient preferences by ensuring that information about only the desired types of genetic conditions are provided to a given patient

    Turbulence-driven Polar Winds from T Tauri Stars Energized by Magnetospheric Accretion

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    Pre-main-sequence stars are observed to be surrounded by both accretion flows and some kind of wind or jet-like outflow. Recent work by Matt and Pudritz has suggested that if classical T Tauri stars exhibit stellar winds with mass loss rates about 0.1 times their accretion rates, the wind can carry away enough angular momentum to keep the stars from being spun up unrealistically by accretion. This paper presents a preliminary set of theoretical models of accretion-driven winds from the polar regions of T Tauri stars. These models are based on recently published self-consistent simulations of the Sun's coronal heating and wind acceleration. In addition to the convection-driven MHD turbulence (which dominates in the solar case), we add another source of wave energy at the photosphere that is driven by the impact of plasma in neighboring flux tubes undergoing magnetospheric accretion. This added energy, determined quantitatively from the far-field theory of MHD wave generation, is sufficient to produce T Tauri-like mass loss rates of at least 0.01 times the accretion rate. While still about an order of magnitude below the level required for efficient angular momentum removal, these are the first self-consistent models of T Tauri winds that agree reasonably well with a range of observational mass loss constraints. The youngest modeled stellar winds are supported by Alfven wave pressure, they have low temperatures ("extended chromospheres"), and they are likely to be unstable to the formation of counterpropagating shocks and clumps far from the star.Comment: 19 pages (emulateapj style), 13 figures, ApJ, in press (v. 689, December 10, 2008
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