747 research outputs found
Links between topography, wind, deflation, lakes and dust: The case of the Bodélé Depression, Chad
The Bodélé Depression, Chad is the planet's largest single source of dust. Deflation from the Bodélé could be seen as a simple coincidence of two key prerequisites: strong surface winds and a large source of suitable sediment. But here we hypothesise that long term links between topography, winds, deflation and dust ensure the maintenance of the dust source such that these two apparently coincidental key ingredients are connected by land-atmosphere processes with topography acting as the overall controlling agent. We use a variety of observational and numerical techniques, including a regional climate model, to show that: 1) contemporary deflation from the Bodélé is delineated by topography and a surface wind stress maximum; 2) the Tibesti and Ennedi mountains play a key role in the generation of the erosive winds in the form of the Bodélé Low Level Jet (LLJ); 3) enhanced deflation from a stronger Bodélé LLJ during drier phases, for example, the Last Glacial Maximum, was probably sufficient to create the shallow lake in which diatoms lived during wetter phases, such as the Holocene pluvial. Winds may therefore have helped to create the depression in which erodible diatom material accumulated. Instead of a simple coincidence of nature, dust from the world's largest source may result from the operation of long term processes on paleo timescales which have led to ideal conditions for dust generation in the world's largest dust source. Similar processes plausibly operate in other dust hotspots in topographic depressions
Underwater Gesture Recognition Using Classical Computer Vision and Deep Learning Techniques
Underwater Gesture Recognition is a challenging task since conditions which are normally not an issue in gesture recognition on land must be considered. Such issues include low visibility, low contrast, and unequal spectral propagation. In this work, we explore the underwater gesture recognition problem by taking on the recently released Cognitive Autonomous Diving Buddy Underwater Gestures dataset. The contributions of this paper are as follows: (1) Use traditional computer vision techniques along with classical machine learning to perform gesture recognition on the CADDY dataset; (2) Apply deep learning using a convolutional neural network to solve the same problem; (3) Perform confusion matrix analysis to determine the types of gestures that are relatively difficult to recognize and understand why; (4) Compare the performance of the methods above in terms of accuracy and inference speed. We achieve up to 97.06% accuracy with our CNN. To the best of our knowledge, our work is one of the earliest attempts, if not the first, to apply computer vision and machine learning techniques for gesture recognition on the said dataset. As such, we hope this work will serve as a benchmark for future work on the CADDY dataset
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Elevated atmospheric sulfur levels off the Peruvian coast
Elevated levels of non‐sea‐salt sulfate and SO2 in samples collected off the west coast of South America indicate that there is a major source of atmospheric sulfur in the region of southern Peru and northern Chile. During a 1983 cruise, observed concentrations of non‐sea‐salt sulfur, SO2, selenium, arsenic, and antimony were comparable to levels reported for moderately polluted urban air. In contrast, methanesulfonic acid levels were typical of coastal marine air. Clearly, the elevated atmospheric sulfur levels in this region cannot be ascribed to oceanic organosulfur emissions. The major inputs are tentatively attributed to the smelting of sulfide ores which is a major industry in this region. The transport of smelter derived aerosols to this region may have a number of consequences for the atmospheric and oceanic chemistry of the Peruvian upwelling area
A double-blind randomized trial of fish oil to lower triglycerides and improve cardiometabolic risk in adolescents.
OBJECTIVES: To determine the efficacy of 4 g/day fish oil to lower triglycerides and impact lipoprotein particles, inflammation, insulin resistance, coagulation, and thrombosis.
STUDY DESIGN: Participants (n = 42, age 14 ± 2 years) with hypertriglyceridemia and low-density lipoprotein (LDL) cholesterol/dL were enrolled in a randomized, double-blind, crossover trial comparing 4 g of fish oil daily with placebo. Treatment interval was 8 weeks with a 4-week washout. Lipid profile, lipoprotein particle distribution and size, glucose, insulin, high-sensitivity C-reactive protein, interleukin-6, fibrinogen, plasminogen activator inhibitor-1, and thrombin generation were measured.
RESULTS: Baseline lipid profile was total cholesterol 194 (5.4) mg/dL (mean [SE]), triglycerides 272 (21) mg/dL, high-density lipoprotein cholesterol 39 (1) mg/dL, and LDL cholesterol 112 (3.7) mg/dl. LDL particle number was 1614 (60) nmol/L, LDL size was 19.9 (1.4) nm, and large very low-density lipoprotein/chylomicron particle number was 9.6 (1.4) nmol/L. Triglycerides decreased on fish oil treatment but the difference was not significant compared with placebo (-52 ± 16 mg/dL vs -16 ± 16 mg/dL). Large very low-density lipoprotein particle number was reduced (-5.83 ± 1.29 nmol/L vs -0.96 ± 1.31 nmol/L; P \u3c .0001). There was no change in LDL particle number or size. There was a trend towards a lower prothrombotic state (lower fibrinogen and plasminogen activator inhibitor-1; .10 \u3e P \u3e .05); no other group differences were seen.
CONCLUSIONS: In children, fish oil (4 g/day) lowers triglycerides slightly and may have an antithrombotic effect but has no effect on LDL particles
Fungal microbiota from rain water and pathogenicity of Fusarium species isolated from atmospheric dust and rainfall dust
In order to determine the presence of Fusarium spp. in atmospheric dust and rainfall dust, samples were collected during September 2007, and July, August, and October 2008. The results reveal the prevalence of airborne Fusarium species coming from the atmosphere of the South East coast of Spain. Five different Fusarium species were isolated from the settling dust: Fusarium oxysporum, F. solani, F. equiseti, F. dimerum, and F. proliferatum. Moreover, rainwater samples were obtained during significant rainfall events in January and February 2009. Using the dilution-plate method, 12 fungal genera were identified from these rainwater samples. Specific analyses of the rainwater revealed the presence of three species of Fusarium: F. oxysporum, F. proliferatum and F. equiseti. A total of 57 isolates of Fusarium spp. obtained from both rainwater and atmospheric rainfall dust sampling were inoculated onto melon (Cucumis melo L.) cv. Piñonet and tomato (Lycopersicon esculentum Mill.) cv. San Pedro. These species were chosen because they are the main herbaceous crops in Almeria province. The results presented in this work indicate strongly that spores or propagules of Fusarium are able to cross the continental barrier carried by winds from the Sahara (Africa) to crop or coastal lands in Europe. Results show differences in the pathogenicity of the isolates tested. Both hosts showed root rot when inoculated with different species of Fusarium, although fresh weight measurements did not bring any information about the pathogenicity. The findings presented above are strong indications that long-distance transmission of Fusarium propagules may occur. Diseases caused by species of Fusarium are common in these areas. They were in the past, and are still today, a problem for greenhouses crops in Almería, and many species have been listed as pathogens on agricultural crops in this region. Saharan air masses dominate the Mediterranean regions. The evidence of long distance dispersal of Fusarium spp. by atmospheric dust and rainwater together with their proved pathogenicity must be taken into account in epidemiological studies
Modeling sea-salt aerosols in the atmosphere: 2. Atmospheric concentrations and fluxes
Atmospheric sea-salt aerosol concentrations are studied using both long-term observations and model simulations of Na+ at seven stations around the globe. Good agreement is achieved between observations and model predictions in the northern hemisphere. A stronger seasonal variation occurs in the high-latitude North Atlantic than in regions close to the equator and in high-latitude southern hemisphere. Generally, concentrations are higher for both boreal and austral winters. With the model, the production flux and removal flux at the atmosphere-ocean interface was calculated and used to estimate the global sea-salt budget. The flux also shows seasonal variation similar to that of sea-salt concentration. Depending on the geographic location, the model predicts that dry deposition accounts for 60–70% of the total sea-salt removed from the atmosphere while in-cloud and below-cloud precipitation scavenging accounts for about 1% and 28–39% of the remainder, respectively. The total amount of sea-salt aerosols emitted from the world oceans to the atmosphere is estimated to be in the vicinity of 1.17×1016 g yr−1. Approximately 99% of the sea-salt aerosol mass generated by wind falls back to the sea with about 1–2% remaining in the atmosphere to be exported from the original grid square (300×300 km). Only a small portion of that exported (∼4%) is associated with submicron particles that are likely to undergo long-range transport
Review article: The need for more efficient and patient-oriented drug development pathways in NASH—setting the scene for platform trials
Drug development; Non-alcoholic steatohepatitis; Study designsDesenvolupament de fàrmacs; Esteatohepatitis no alcohòlica; Dissenys d'estudiDesarrollo de fármacos; Esteatohepatitis no alcohólica; Diseños de estudioBackground and Aims
Non-alcoholic steatohepatitis (NASH) constitutes a significant unmet medical need with a burgeoning field of clinical research and drug development. Platform trials (PT) might help accelerate drug development while lowering overall costs and creating a more patient-centric environment. This review provides a comprehensive and nuanced assessment of the NASH clinical development landscape.
Methods
Narrative review and expert opinion with insight gained during the EU Patient-cEntric clinicAl tRial pLatforms (EU-PEARL) project.
Results
Although NASH represents an opportunity to use adaptive trial designs, including master protocols for PT, there are barriers that might be encountered owing to distinct and sometimes opposing priorities held by these stakeholders and potential ways to overcome them. The following aspects are critical for the feasibility of a future PT in NASH: readiness of the drug pipeline, mainly from large drug companies, while there is not yet an FDA/EMA-approved treatment; the most suitable design (trial Phase and type of population, e.g., Phase 2b for non-cirrhotic NASH patients); the operational requirements such as the scope of the clinical network, the use of concurrent versus non-concurrent control arms, or the re-allocation of participants upon trial adaptations; the methodological appraisal (i.e. Bayesian vs. frequentist approach); patients' needs and patient-centred outcomes; main regulatory considerations and the funding and sustainability scenarios.
Conclusions
PT represent a promising avenue in NASH but there are a number of conundrums that need addressing. It is likely that before a global NASH PT becomes a reality, ‘proof-of-platform’ at a smaller scale needs to be provided.JMP reports having received consulting fees from Boehringer-Ingelheim, MSD and Novo Nordisk. He has received speaking fees from Gilead, Intercept, and Novo Nordisk, and travel expenses from Gilead, Rubió, Pfizer, Astellas, MSD, CUBICIN, and Novo Nordisk. He has received educational and research support from Madrigal, Gilead, Pfizer, Astellas, Accelerate, Novartis, Abbvie, ViiV, and MSD. Funds from European Commission/EFPIA IMI2 853966-2, IMI2 777377, H2020 847989, and ISCIII PI19/01898. NAdP works for Janssen. QMA is Coordinator of the EU IMI-2 LITMUS consortium, which is funded by the EU Horizon 2020 programme and EFPIA. This multistakeholder consortium includes industry partners. He reports research Grant Funding: Allergan/Tobira, AstraZeneca, Boehringer-Ingelheim, Glaxo SmithKline, Glympse Bio, Intercept, Novartis Pharma AG, Pfizer Ltd. Consultancy: 89Bio, Abbvie/Allergan, Akero, Altimentiv, Altimmune, AstraZeneca, Axcella, Blade, BMS, BNN Cardio, Boehringer-Ingelheim, Cirius, CymaBay, EcoR1, E3Bio, Eli Lilly & Company Ltd., Galmed, Genentech, Genfit SA, Gilead, Grunthal, HistoIndex, Indalo, Intercept Pharma Europe Ltd., Inventiva, IQVIA, Janssen, Johnson & Johnson, Madrigal, MedImmune, Medpace, Merck, Metacrine, NGMBio, North Sea Therapeutics, Novartis, Novo Nordisk A/S, PathAI, Pfizer Ltd., Poxel, ProSciento, Raptor Pharma, Roche, Servier, Shionogi, Terns, The Medicines Company, Viking Therapeutics. Speaker: Abbott Laboratories, Allergan/Tobira, BMS, Clinical Care Options, Falk, Fishawack, Genfit SA, Gilead, Integritas Communications, Kenes, Medscape. Royalties: Elsevier Ltd. PM works for Novartis. MSK is an employee of and a shareholder in Novo Nordisk A/S. JG has received consulting fees from Boehringer-Ingelheim, speaking fees from Echosens and travel expenses from Gilead and Abbie. Funds from ISCIII PI18/00947 and PI21/00691. JRE has received speaking fees from Gilead. FT lab’ work has been supported by the German Research Foundation (DFG, CRC/TR 362) and research grants from Gilead, Allergan, Bristol-Myers Squibb and Inventiva. VR consults for and Intercept, Novo Nordisk, Galmed, Poxel, NGM, Madrigal, Enyo, Sagimet, 89 Bio, Prosciento, Terns, and Theratechnologies, and received grants from Intercept and Gilead
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