831 research outputs found

    An automated classification approach to ranking photospheric proxies of magnetic energy build-up

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    We study the photospheric magnetic field of ~2000 active regions in solar cycle 23 to search for parameters indicative of energy build-up and subsequent release as a solar flare. We extract three sets of parameters: snapshots in space and time- total flux, magnetic gradients, and neutral lines; evolution in time- flux evolution; structures at multiple size scales- wavelet analysis. This combines pattern recognition and classification techniques via a relevance vector machine to determine whether a region will flare. We consider classification performance using all 38 extracted features and several feature subsets. Classification performance is quantified using both the true positive rate and the true negative rate. Additionally, we compute the true skill score which provides an equal weighting to true positive rate and true negative rate and the Heidke skill score to allow comparison to other flare forecasting work. We obtain a true skill score of ~0.5 for any predictive time window in the range 2-24hr, with a TPR of ~0.8 and a TNR of ~0.7. These values do not appear to depend on the time window, although the Heidke skill score (<0.5) does. Features relating to snapshots of the distribution of magnetic gradients show the best predictive ability over all predictive time windows. Other gradient-related features and the instantaneous power at various wavelet scales also feature in the top five ranked features in predictive power. While the photospheric magnetic field governs the coronal non-potentiality (and likelihood of flaring), photospheric magnetic field alone is not sufficient to determine this uniquely. Furthermore we are only measuring proxies of the magnetic energy build up. We still lack observational details on why energy is released at any particular point in time. We may have discovered the natural limit of the accuracy of flare predictions from these large scale studies

    A non-ordinary state-based peridynamics formulation for thermoplastic fracture

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    In this study, a three-dimensional (3D) non-ordinary state-based peridynamics (NOSB-PD) formulation for thermomechanical brittle and ductile fracture is presented. The Johnson–Cook (JC) constitutive and damage model is used to taken into account plastic hardening, thermal softening and fracture. The formulation is validated by considering two benchmark examples: 1) The Taylor-bar impact and 2) the Kalthoff–Winkler tests. The results show good agreements between the numerical simulations and the experimental results

    Influence of certain carbon and nitrogen sources on antagonistic potentiality of Trichoderma harzianum and Bacillus subtillus against Botrytis allii the incitant of onion neck rot

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    Gliotoxin Fermentation Agar (GFA) Medium and Nutrient Glucose Agar   (NGA) medium with different carbon and nitrogen sources were used to study the impact of carbon and nitrogen sources on Trichoderma harzianum Rifai and Bacillus subtillus Cohn antagonistic efficiency against growth of Botrytis allii Munn. Results indicated that Trichoderma harzianum gave the highest inhibition % in growth of Botrytis allii when Sucrose was used as a carbon source while the lowest values of inhibition% were appeared by application of Mannitol as a carbon source. Trichoderma harzianum gave the highest inhibition% in growth of B.allii when use Potassium nitrate  as a nitrogen source while the lowest values of inhibition% in growth of B.allii were obtained by application of Beef extract as a nitrogen source. Results showed also that Bacillus subtillus gave the highest inhibition% in growth of B.allii when Mannitol was used as a carbon source while the lowest values of inhibition% in growth of B.allii were appeared by application of Sucrose as a carbon source. Bacillus subtillus gave the highest inhibition% in growth of B.allii when use Glutamic acid as a nitrogen source while the lowest values of inhibition% in growth of B.allii were appeared by application of Tryptophan as a nitrogen source.

    Silybum marianum (Milk Thistle): Review on Its chemistry, morphology, ethno medical uses, phytochemistry and pharmacological activities

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    The oldest remedies identified to mankind are herbal medicines. India is recognized worldwide for its Ayurvedic treatment. India has rich history of using many plants for medicinal purposes. Remedial plants are cooperating extremely dynamic position in customary drugs for the action of a variety of illness. However a key obstacle, which has hindered the promotion in use of alternative medicines in the developed countries, is no evidence of documentation and absence of stringent quality control measures. There is a demand for the evidence of every investigate effort execute on conventional remedies in the appearance of certification. The purpose of current review is to make accessible up-to-date information on, botany, morphology, ecological biodiversity, therapeutic uses, phytochemistry and pharmacological activities on diverse parts of Silybum marianum (L.) Gaertn (S. marianum). This review was assembled using technical literature from electronic search engine such as Springer link, Bio Med Central, Pub Med, Scopus, Science Direct, Scielo, Medline and Science domain. Supplementary texts were obtained from books, book chapters, dissertations, websites and other scientific publications. S. marianum a member of the Asteraceae family, is a tall herb with large prickly white veined green leaves and a reddish-purple flower that ends in sharp spines. It is native of the Mediterranean region and which has also spread in East Asia, Europe, Australia and America. Confident chemical constituents were exposed cognate as silybin A, silybin B, isosilybin A, isosilybin B, silychristin, silydianin, apigenin 7-O-β-(2″- O-α-rhamnosyl)galacturonide, kaempferol 3-O-α-rhamnoside-7-O-β-galacturonide, apigenin 7-O-β-glucuronide, apigenin 7-O-β-glucoside, apigenin 7-O-β-galactoside, kaempferol-3-O-α-rhamnoside, kaempferol, taxifolin and quercetin. The plant is exclusively used as anti-diabetic, hepatoprotective, hypocholesterolaemic, anti-hypertensive, anti-inflammatory, anti-cancer, and as an anti-oxidant. Seeds of the plant are also used as an anti-spasmodic, neuroprotective, anti-viral, immunomodulant, cardioprotective, demulcent and anti-haemorrhagic. The plant is also serves as a galactagogue, agent&nbsp;that&nbsp;induces&nbsp;milk&nbsp;secretion and used in the treatment of uterine disorders. The plant is employed in dissimilar conventional schemes of remedy in the cure of different illness

    Hydrologie et morphologie de l’estuaire du fleuve Sassandra, Basse Côte d’Ivoire

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    Les études physico-chimiques des eaux de surface et de sub-surface et les levés bathymétriques effectués dans l’estuaire du fleuve Sassandra, ont permis de caractériser l’hydrologie et la morphologie du fond de cet embouchure. Sur toute la surface d’eau le pH est proche de la neutralité, la conductivité est comprise entre 50 et 200μs/cm, avec une température moyenne de 28,91°C. La salinité de l’estuaire augmente au fur et à mesure que l’on s’approche de l’océan Atlantique. Sa valeur est comprise entre 0 et 4%. Le taux d’oxygène, très faible à l’embouchure avec une valeur de 2 mg /L contre 8,30 mg/L dans la branche droite du fleuve couverte par la végétation. Les Matières En Suspension (MES) analysées sont constituées d’une fraction inorganique de quartz, feldspath, amphibole, mica, argiles, etc...et d’une fraction organique constituée de débris animaux et végétaux. Cette étude a permis de réaliser les cartes bathymétriques et la répartition des paramètres physico-chimiques, ainsi que la détermination des dépressions et les processus d’érosions au fond de l’estuaire du fleuve Sassandra.Mots-clés: hydrologie, bathymétrie, paramètres physico-chimiques, fleuve Sassandra, Côte d’Ivoire. Hydrology and morphology of the estuary of the Sassandrariver (Low Côte d’Ivoire) The physico-chemical studies of waters of surface and sub-surface and the bathymetric sunrises made in the estuary of theSassandrariver, allowed to characterize the hydrology and the morphology of the bottom of this mouth. On all the surface of water the pH is close to the neutrality, the conductivity is between 50 and 200μs/cm, with an average temperature of 28,91°C. The salinity of the estuary increases as we approach the Atlantic Ocean. His value is between 0 and 4%. The rate of oxygen, very low in the mouth with a value of 2 mg / L against 8,30 mg / L in the straight branch of the river covered by the vegetation. Suspension materials (MES) analyzed are constituted by an inorganic fraction of quartz, feldspar, amphibole, mica and clays etc. and of an organic fraction constituted by animal and plant fragments. This study allowed to realize the bathymetric maps and the distribution of the physico-chemical parameters, as well as the determination of the depressions and the processes of erosions at the bottom of the estuary of the Sassandra river.Keywords: hydrology, bathymetry, physico-chemical parameters, Sassandra river, Côte d’Ivoire

    Evaluation and Comparison of the Effects of Mature Silkworm (Bombyx mori) and Silkworm Pupae Extracts on Schwann Cell Proliferation and Axon Growth: An In Vitro Study

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    Background: Silkworm products were first used by physicians more than 8500 years ago, in the early Neolithic period. In Persian medicine, silkworm extract has several uses for treating and preventing neurological, cardiac, and liver diseases. Mature silkworms (Bombyx mori) and their pupae contain a variety of growth factors and proteins that can be used in many repair processes, including nerve regeneration. Objectives: The study aimed to evaluate the effects of mature silkworm (Bombyx mori), and silkworm pupae extract on Schwann cell proliferation and axon growth. Methods: Silkworm (Bombyx mori) and silkworm pupae extracts were prepared. Then, the concentration and type of amino acids and proteins in the extracts were evaluated by Bradford assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and liquid chromatograph-mass spectrometer (LC-MS/MS). Also, the regenerative potential of extracts for improving Schwann cell proliferation and axon growth was examined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay, electron microscopy, and NeuroFilament-200 (NF-200) immunostaining. Results: According to the results of the Bradford test, the total protein content of pupae extract was almost twice that of mature worm extract. Also, SDS-PAGE analysis revealed numerous proteins and growth factors, such as bombyrin and laminin, in extracts that are involved in the repair of the nervous system. In accordance with Bradford’s results, the evaluation of extracts using LCMS/MS revealed that the number of amino acids in pupae extract was higher than in mature silkworm extract. It was found that the proliferation of Schwann cells at a concentration of 0.25 mg/mL in both extracts was higher than the concentrations of 0.01 and 0.05 mg/mL. When using both extracts on dorsal root ganglion (DRGs), an increase in length and number was observed in axons. Conclusions: The findings of this study demonstrated that extracts obtained from silkworms, especially pupae, can play an effective role in Schwann cell proliferation and axonal growth, which can be strong evidence for nerve regeneration, and, consequently, repairing peripheral nerve damage

    Smartphone-delivered self-management for first-episode psychosis: the ARIES feasibility randomised controlled trial

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    OBJECTIVES: To test the feasibility and acceptability of a randomised controlled trial (RCT) to evaluate a Smartphone-based self-management tool in Early Intervention in Psychosis (EIP) services. DESIGN: A two-arm unblinded feasibility RCT. SETTING: Six NHS EIP services in England. PARTICIPANTS: Adults using EIP services who own an Android Smartphone. Participants were recruited until the recruitment target was met (n=40). INTERVENTIONS: Participants were randomised with a 1:1 allocation to one of two conditions: (1) treatment as usual from EIP services (TAU) or (2) TAU plus access to My Journey 3 on their own Smartphone. My Journey 3 features a range of self-management components including access to digital recovery and relapse prevention plans, medication tracking and symptom monitoring. My Journey 3 use was at the users' discretion and was supported by EIP service clinicians. Participants had access for a median of 38.1 weeks. PRIMARY AND SECONDARY OUTCOME MEASURES: Feasibility outcomes included recruitment, follow-up rates and intervention engagement. Participant data on mental health outcomes were collected from clinical records and from research assessments at baseline, 4 months and 12 months. RESULTS: 83% and 75% of participants were retained in the trial at the 4-month and 12-month assessments. All treatment group participants had access to My Journey 3 during the trial, but technical difficulties caused delays in ensuring timely access to the intervention. The median number of My Journey 3 uses was 16.5 (IQR 8.5 to 23) and median total minutes spent using My Journey 3 was 26.8 (IQR 18.3 to 57.3). No serious adverse events were reported. CONCLUSIONS: Recruitment and retention were feasible. Within a trial context, My Journey 3 could be successfully delivered to adults using EIP services, but with relatively low usage rates. Further evaluation of the intervention in a larger trial may be warranted, but should include attention to implementation. TRIAL REGISTRATION: ISRCTN10004994

    The solution of tachyon inflation in curved universe

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    In this paper, we have considered the curved universe which is filled by tachyonic field. We have found the exact solutions for the field, pressure, density, and scale factor and some cosmological parameters. In such universe, we have investigated the role of tachyonic field in different stages of k for the evolution of the universe. Finally we draw the graphs for the scale factor, Hubble's parameter, energy density, pressure, acceleration parameter, equation of state and potential for the different values of k. Also we obtained the exact form of field which shows that the tachyonic field has the kink form.Comment: 8 pages, 21 figure
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