484 research outputs found
Experience paper on the operation of pilot project on oyster culture at Tuticorin
The technology of oyster culture was
developed in India at the Central Marine Fisheries
Research Institute. An experimental farm was
established at Tuticorin bay in an area of 0.25
hectares. Different growout methods have been
tried and it has been assessed that the shell
string method could be practised with relatively
low cost inputs with a production rate comparable
to highly efficient systems such as rack and
tray method or raft culture
Abel-Jacobi maps for hypersurfaces and non commutative Calabi-Yau's
It is well known that the Fano scheme of lines on a cubic 4-fold is a
symplectic variety. We generalize this fact by constructing a closed p-form
with p=2n-4 on the Fano scheme of lines on a (2n-2)-dimensional hypersurface Y
of degree n. We provide several definitions of this form - via the Abel-Jacobi
map, via Hochschild homology, and via the linkage class, and compute it
explicitly for n = 4. In the special case of a Pfaffian hypersurface Y we show
that the Fano scheme is birational to a certain moduli space of sheaves on a
p-dimensional Calabi--Yau variety X arising naturally in the context of
homological projective duality, and that the constructed form is induced by the
holomorphic volume form on X. This remains true for a general non Pfaffian
hypersurface but the dual Calabi-Yau becomes non commutative.Comment: 34 pages; exposition of Hochschild homology expanded; references
added; introduction re-written; some imrecisions, typos and the orbit diagram
in the last section correcte
Grey Relational Analysis-Based Optimisation of Input Parameters of Incremental Forming Process Applied to the AA6061 Alloy
Incremental forming is mainly based on the deformation occurring locally on sheet metal. A hemispherical head tool deforms the sheet metal progressively, and its path is controlled by means of a CNC machine. Even though the process is a time-consuming one, the cost reduction connected with punches and dies makes this process attractive for rapid prototyping. In single point incremental forming, the quality of formability mainly depends on the forming parameters and the tool path generated. In this study, cone-shaped components were formed from AA6061 alloy sheets with a thickness of 1.15 mm. Factors, such as feed rate, spindle speed, and step depth are considered as input parameters to determine the output response in terms of surface roughness and wall thickness. Taguchi’s technique was used for conducting the experiments with the smallest number of repetitions to evaluate the output. Grey relational analysis was introduced to determine the optimal forming parameters with respect to the output response. The experiments conducted with the optimised parameters show a minimal deviation of 0.15% in the grade value compared to the predicted grade which is acceptable
Pharmacological levels of withaferin A (Withania somnifera) trigger clinically relevant anticancer effects specific to triple negative breast cancer cells
Withaferin A (WA) isolated from Withania somnifera (Ashwagandha) has recently become an attractive phytochemical under investigation in various preclinical studies for treatment of different cancer types. In the present study, a comparative pathway-based transcriptome analysis was applied in epithelial-like MCF-7 and triple negative mesenchymal MDA-MB-231 breast cancer cells exposed to different concentrations of WA which can be detected systemically in in vivo experiments. Whereas WA treatment demonstrated attenuation of multiple cancer hallmarks, the withanolide analogue Withanone (WN) did not exert any of the described effects at comparable concentrations. Pathway enrichment analysis revealed that WA targets specific cancer processes related to cell death, cell cycle and proliferation, which could be functionally validated by flow cytometry and real-time cell proliferation assays. WA also strongly decreased MDA-MB-231 invasion as determined by single-cell collagen invasion assay. This was further supported by decreased gene expression of extracellular matrix-degrading proteases (uPA, PLAT, ADAM8), cell adhesion molecules (integrins, laminins), pro-inflammatory mediators of the metastasis-promoting tumor microenvironment (TNFSF12, IL6, ANGPTL2, CSF1R) and concomitant increased expression of the validated breast cancer metastasis suppressor gene (BRMS1). In line with the transcriptional changes, nanomolar concentrations of WA significantly decreased protein levels and corresponding activity of uPA in MDA-MB-231 cell supernatant, further supporting its anti-metastatic properties. Finally, hierarchical clustering analysis of 84 chromatin writer-reader-eraser enzymes revealed that WA treatment of invasive mesenchymal MDA-MB-231 cells reprogrammed their transcription levels more similarly towards the pattern observed in non-invasive MCF-7 cells. In conclusion, taking into account that sub-cytotoxic concentrations of WA target multiple metastatic effectors in therapy-resistant triple negative breast cancer, WA-based therapeutic strategies targeting the uPA pathway hold promise for further (pre)clinical development to defeat aggressive metastatic breast cancer
Evaluation of central neuropathy in type 2 diabetes mellitus: a case control study
Background: Diabetes mellitus (DM) is a global pandemic affecting almost every organ in the body. Peripheral nervous system involvement in diabetes is well known but there are not many studies on central nervous system involvement. Visual evoked potential (VEP) is a sensitive, non-invasive test to detect central demyelination of optic nerve. The objective was to compare the visual evoked potentials in type-2 DM patients with that of healthy controls and to find out if any correlation is there with the duration and glycaemic control of the disease and to compare incidence of peripheral and central neuropathy in DM patients.Methods: Author included 50 DM patients and 50 age and sex matched controls. Patients with previous stroke, demyelination, diabetic retinopathy and other ophthalmological disorders were excluded. VEP was recorded using pattern reversal stimulation with EMG RMS MARK II machine and p100 latency was measured.Results: P100 latencies (ms) was significantly prolonged in diabetics with mean±SD of (111.24±5.28 ms) as compared to controls (101.30±1.66 ms) with p value <0.003. Also, there was significant correlation between duration of DM and P100 latency prolongation, but no significant correlation was present when compared with glycaemic control.Conclusions: Central neuropathy is very common in DM. It is related to duration of DM and not HbA1c unlike PNP which is related to both. Central neuropathy occurs even prior to development of retinopathy or PNP. Hence, VEP is a non-invasive and sensitive screening tool for early neurological involvement in DM
A framework-based wind forecasting to assess wind potential with improved grey wolf optimization and support vector regression
Wind energy is one of the most promising alternates of fossil fuels because of its abundant availability, low cost, and pollution-free attributes. Wind potential estimation, wind forecasting, and effective wind-energy management are the critical factors in planning and managing wind farms connected to wind-pooling substations. Hence, this study proposes a hybrid framework-based approach for wind-resource estimation and forecasting, namely IGWO-SVR (improved grey wolf optimization method (IGWO)-support vector regression (SVR)) for a real-time power pooling substation. The wind resource assessment and behavioral wind analysis has been carried out with the proposed IGWO-SVR optimization method for hourly, daily, monthly, and annual cases using 40 years of ERA (European Center for Medium-Range Weather Forecast reanalysis) data along with the impact of the El Niño effect. First, wind reassessment is carried out considering the impact of El Niño, wind speed, power, pressure, and temperature of the selected site Radhapuram substation in Tamilnadu, India and reported extensively. In addition, statistical analysis and wind distribution fitting are performed to demonstrate the seasonal effect. Then the proposed model is adopted for wind speed forecasting based on the dataset. From the results, the proposed model offered the best assessment report and predicted the wind behavior with greater accuracy using evaluation metrics, namely root mean square error (RMSE), mean absolute error (MAE), and mean squared error (MSE). For short-term wind speed, power, and El Niño forecasting, IGWO-SVR optimization effectively outperforms other existing models. This method can be adapted effectively in any potential locations for wind resource assessment and forecasting needs for better renewable energy management by power utilities
Oceanic squids - their distribution, abundance and potential in the EEZ of India and contiguous seas
FORV Sagar Sampada collected a good number of oceanic squids belonging
to several families from the Indian EEZ and contiguous seas. Of these, the most
important species was the purpleback flying squid Symplectoteuthis oualaniensis
which forms a potential oceanic squid resource. This species was caught in pelagic
trawl at depths up to.200-250 m from surface in the oceanic areas. Though the squid
is known to be distributed throughout India's oceanic waters, it frequently occurred
in comparatively more abundance, up to 318 squids per haul, in the northneastem
Arabian Sea. There was wide variation in the size of this squid (from 20 mm to 472
mm), the largest individual weighing 4.5 kg. The diamondback squid Thysanoteuthis
rhombus, the largest specimen of which measured 585 mm in length and 5.3 kg in
weight, was also caught from a few stations. Besides these large species, several
others belonging to families such as Onychoteuthidae, Histioteuthidae, Enoploteuthidae
and Cranchiidae are also distributed in the EEZ. A large number of oceanic squids
were collected at night, which is indicative of their diel vertical migration towards
surface layers during night hours
A modular, time-independent, path-based controller for assist- as- needed rehabilitative exoskeletons
After a traumatic event (e.g., orthopedic or neu-rological injury), engaging in activities of daily living (ADLs) encourages the individual and aids in relearning functional motions for the impaired limb. The outcome of robot-assisted rehabilitation is inherently connected to the control strategy adopted in the training sessions. Here, the authors propose a time-independent path-tracking controller with impedance modulation that provides assistance and guidance along the path. Based on the assist-as-needed (AAN) paradigm, a task-space-based force field controller was designed to cooperatively support the individual during training. The authors will illus-trate the flexibility of the proposed control strategy, showcasing its adaptability to various exoskeletons with minimal or minor adjustments. Leveraging the control versatility, the authors propose the application of this methods to two case studies: Float upper limb and TWIN lower limb exoskeletons
Impact of e-cigarette vaping aerosol exposure in pregnancy on mTOR signaling in rat fetal hippocampus
Electronic cigarette (e-cig) use during pregnancy has become a major health concern in recent years and many view them as less harmful and may help quit or reduce combustible cigarettes. Implementing a state-of-the-art engineered vaping system, comprising an atomizer similar to those sold in vape shops, we aimed to utilize a translational e-cig inhalation delivery method to provide crucial information on the impact of prenatal e-cig aerosols on the developing brain hippocampal mTOR system in a rat model system. Gestational e-cig vaping significantly increased P-mTOR levels (p < 0.05) in the rat fetal hippocampi in the nicotine group (comprising of VG/PG + nicotine) compared to the control and the juice (comprising of VG/PG) groups. Total mTOR expression was not different among groups. Immunofluorescence imaging demonstrated P-mTOR was detected exclusively in the granule cells of the dentate gyrus of the fetal hippocampus. E-cig did not alter DEPTOR, but RAPTOR and RICTOR were higher (p < 0.05) in the Nicotine group. Gestational e-cig vaping with nicotine increased (p < 0.05) the activity and expression of 4EBP1, p70S6K, but decreased (p < 0.05) P-PKCα in the fetal hippocampi. In summary, dysregulation of mTORC1 and the related mTORC2, their activity, and downstream proteins together may play a critical role in e-cig-vaping-induced neurobiological phenotypes during development
Modeling of a Cable-Based Revolute Joint Using Biphasic Media Variable Stiffness Actuation
In recent times, safe interactions between humans and robots are required for innumerable tasks and environments. This safety can be achieved using compliance design and control of mechanisms. Cable-driven mechanisms are used when applications need to have light structures, meaning that their actuators must be relocated to ground and forces are transferred along tensioned cables. This paper presents a compliant cable-driven revolute joint using biphasic media variable stiffness actuators. Actuator's stiffness is controlled by changing pressure of control fluid into distribution lines. The used control fluid is biphasic, composed of separated gas and liquid fractions with predefined ratio. The mathematical model of the actuator is presented along with its position and stiffness model-based control, then, equations relating to the dynamics of the mechanism are provided with a joint stiffness and orientation controller. Results from simulations are discussed
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