13 research outputs found

    Satellite Image Fusion in Various Domains

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    In order to find out the fusion algorithm which is best suited for the panchromatic and multispectral images, fusion algorithms, such as PCA and wavelet algorithms have been employed and analyzed. In this paper, performance evaluation criteria are also used for quantitative assessment of the fusion performance. The spectral quality of fused images is evaluated by the ERGAS and Q4. The analysis indicates that the DWT fusion scheme has the best definition as well as spectral fidelity, and has better performance with regard to the high textural information absorption. Therefore, as the study area is concerned, it is most suited for the panchromatic and multispectral image fusion. an image fusion algorithm based on wavelet transform is proposed for Multispectral and panchromatic satellite image by using fusion in spatial and transform domains. In the proposed scheme, the images to be processed are decomposed into sub-images with the same resolution at same levels and different resolution at different levels and then the information fusion is performed using high-frequency sub-images under the Multi-resolution image fusion scheme based on wavelets produces better fused image than that by the MS or WA schemes

    Neuronal adaptation involves rapid expansion of the action potential initiation site

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    Action potential (AP) generation is the key to information processing in the brain. Although APs are normally initiated in the axonal initial segment, developmental adaptation or prolonged network activity may alter the initiation site geometry thus affecting cell excitability. Here we find that hippocampal dentate granule cells adapt their spiking threshold to the kinetics of the ongoing dendrosomatic excitatory input by expanding the AP initiation area away from the soma while also decelerating local axonal spikes. Dual-patch soma-axon recordings combined with axonal Na+ and Ca2+ imaging and biophysical modeling show that the underlying mechanism involves distance-dependent inactivation of axonal Na+ channels due to somatic depolarization propagating into the axon. Thus the ensuing changes in the AP initiation zone and local AP propagation could provide activity-dependent control of cell excitability and spiking on a relatively rapid time scale

    Motor-Skill Learning Is Dependent on Astrocytic Activity

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    Motor-skill learning induces changes in synaptic structure and function in the primary motor cortex through the involvement of a long-term potentiation- (LTP-) like mechanism. Although there is evidence that calcium-dependent release of gliotransmitters by astrocytes plays an important role in synaptic transmission and plasticity, the role of astrocytes in motor-skill learning is not known. To test the hypothesis that astrocytic activity is necessary for motor-skill learning, we perturbed astrocytic function using pharmacological and genetic approaches. We find that perturbation of astrocytes either by selectively attenuating IP3R2 mediated astrocyte Ca2+ signaling or using an astrocyte specific metabolic inhibitor fluorocitrate (FC) results in impaired motor-skill learning of a forelimb reaching-task in mice. Moreover, the learning impairment caused by blocking astrocytic activity using FC was rescued by administration of the gliotransmitter D-serine. The learning impairments are likely caused by impaired LTP as FC blocked LTP in slices and prevented motor-skill training-induced increases in synaptic AMPA-type glutamate receptor in vivo. These results support the conclusion that normal astrocytic Ca2+ signaling during a reaching task is necessary for motor-skill learning

    Motor-Skill Learning Is Dependent on Astrocytic Activity

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    Motor-skill learning induces changes in synaptic structure and function in the primary motor cortex through the involvement of a long-term potentiation-(LTP-) like mechanism. Although there is evidence that calcium-dependent release of gliotransmitters by astrocytes plays an important role in synaptic transmission and plasticity, the role of astrocytes in motor-skill learning is not known. To test the hypothesis that astrocytic activity is necessary for motor-skill learning, we perturbed astrocytic function using pharmacological and genetic approaches. We find that perturbation of astrocytes either by selectively attenuating IP 3 R2 mediated astrocyte Ca 2+ signaling or using an astrocyte specific metabolic inhibitor fluorocitrate (FC) results in impaired motor-skill learning of a forelimb reaching-task in mice. Moreover, the learning impairment caused by blocking astrocytic activity using FC was rescued by administration of the gliotransmitter D-serine. The learning impairments are likely caused by impaired LTP as FC blocked LTP in slices and prevented motor-skill training-induced increases in synaptic AMPA-type glutamate receptor in vivo. These results support the conclusion that normal astrocytic Ca 2+ signaling during a reaching task is necessary for motor-skill learning

    Functional characterization of the pentapeptide QYNAD on rNaV1.2rNa_ V1.2 channels and its NMR structure

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    The endogenous pentapeptide QYNAD (Gln- Tyr-Asn-Ala-Asp) is present in human cerebrospinal fluid (CSF), and its concentration is increased in demyelinating diseases. QYNAD was synthesized and its action on the rNaV1.2rNa_ V1.2 voltage-gated sodium channel α-subunit was studied using whole-cell recordings in a heterologous expression system. The effects were seen only upon equilibration of the peptide in the external bath solution for at least 10 min before the commencement of whole-cell experiments. The steady-state activation curve showed a rightward shift of 10 mV, while the steady-state inactivation curve showed a leftward shift of 5 mV. Frequencydependent inhibition of the sodium current amplitude was observed at 2–10 Hz, in the presence of external QYNAD, but was not seen when applied internally. Fits of the whole-cell sodium current traces by Hodgkin-Huxley equations revealed subtle changes in the voltage-dependent rate constants governing the transition of the activation and the inactivation gates. Two dimensional NMR spectroscopy revealed the absence of medium and long-range Nuclear Overhauser effects (NOEs), which indicates that the peptide does not adopt any canonical secondary structure in solution. In summary, our studies show that although the pentapeptide QYNAD does not have a defined structure in solution, it has defined actions on the rNaV1.2rNa_ V1.2 voltage-gated sodium channel isoform

    Functional characterization of the pentapeptide QYNAD on rNav1.2 channels and its NMR structure

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    The endogenous pentapeptide QYNAD (Gln-Tyr-Asn-Ala-Asp) is present in human cerebrospinal fluid (CSF), and its concentration is increased in demyelinating diseases. QYNAD was synthesized and its action on the rNaν1.2 voltage-gated sodium channel α-subunit was studied using whole-cell recordings in a heterologous expression system. The effects were seen only upon equilibration of the peptide in the external bath solution for at least 10 min before the commencement of whole-cell experiments. The steady-state activation curve showed a rightward shift of 10 mV, while the steady-state inactivation curve showed a leftward shift of 5 mV. Frequency-dependent inhibition of the sodium current amplitude was observed at 2-10 Hz, in the presence of external QYNAD, but was not seen when applied internally. Fits of the whole-cell sodium current traces by Hodgkin-Huxley equations revealed subtle changes in the voltage-dependent rate constants governing the transition of the activation and the inactivation gates. Two dimensional NMR spectroscopy revealed the absence of medium and long-range Nuclear Overhauser effects (NOEs), which indicates that the peptide does not adopt any canonical secondary structure in solution. In summary, our studies show that although the pentapeptide QYNAD does not have a defined structure in solution, it has defined actions on the rNarNaν1.2 voltage-gated sodium channel isoform

    Essential oils for clinical aromatherapy: a comprehensive review

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    Ethnopharmacological relevanceAromatherapy, a holistic healing practice utilizing the aromatic essences of plant-derived essential oils, has gained significant attention for its therapeutic potential in promoting overall well-being. Use of phytoconstituent based essential oil has played a significant role in the evolving therapeutic avenue of aromatherapy as a complementary system of medicine.Aim of the study: This comprehensive review article aims to explore the usage of essential oils for aromatherapy, shedding light on their diverse applications, scientific evidence, and safety considerations. Furthermore, the growing interest in using essential oils as complementary therapies in conjunction with conventional medicine is explored, underscoring the significance of collaborative healthcare approaches.Materials and methodsLiterature search was performed from databases like PubMed, ScienceDirect, Scopus, and Bentham using keywords like Aromatherapy, Aromatic Plants, Essential oils, Phytotherapy, and complementary medicine. The keywords were used to identify literature with therapeutic and mechanistic details of herbal agents with desired action.ResultsThe integration of traditional knowledge with modern scientific research has led to a renewed interest in essential oils as valuable tools in contemporary healthcare. Various extraction methods used to obtain essential oils are presented, emphasizing their impact on the oil's chemical composition and therapeutic properties. Additionally, the article scrutinizes the factors influencing the quality and purity of essential oils, elucidating the significance of standardization and certification for safe usage. A comprehensive assessment of the therapeutic effects of essential oils is provided, encompassing their potential as antimicrobial, analgesic, anxiolytic, and anti-inflammatory agents, among others. Clinical trials and preclinical studies are discussed to consolidate the existing evidence on their efficacy in treating diverse health conditions, both physical and psychological. Safety considerations are of paramount importance when employing essential oils, and this review addresses potential adverse effects, contraindications, and best practices to ensure responsible usage.ConclusionsThis comprehensive review provides valuable insights into the exploration of essential oils for aromatherapy, emphasizing their potential as natural and potent remedies for a wide range of ailments. By amalgamating traditional wisdom and modern research, this article aims to encourage further investigation into the therapeutic benefits of essential oils while advocating for their responsible and evidence-based incorporation into healthcare practices.<br/

    Hippocampal circuit dysfunction in the Tc1 mouse model of Down syndrome

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    Hippocampal pathology is likely to contribute to cognitive disability in Down syndrome, yet the neural network basis of this pathology and its contributions to different facets of cognitive impairment remain unclear. Here we report dysfunctional connectivity between dentate gyrus and CA3 networks in the transchromosomic Tc1 mouse model of Down syndrome, demonstrating that ultrastructural abnormalities and impaired short-term plasticity at dentate gyrus–CA3 excitatory synapses culminate in impaired coding of new spatial information in CA3 and CA1 and disrupted behavior in vivo. These results highlight the vulnerability of dentate gyrus–CA3 networks to aberrant human chromosome 21 gene expression and delineate hippocampal circuit abnormalities likely to contribute to distinct cognitive phenotypes in Down syndrome

    DASH Score and Subsequent Risk of Coronary Artery Disease: The Findings From Million Veteran Program

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    While adherence to healthful dietary patterns has been associated with a lower risk of coronary artery disease (CAD) in the general population, limited data are available among US veterans. We tested the hypothesis that adherence to Dietary Approach to Stop Hypertension (DASH) food pattern is associated with a lower risk of developing CAD among veterans. We analyzed data on 153&nbsp;802 participants of the Million Veteran Program enrolled between 2011 and 2016. Information on dietary habits was obtained using a food frequency questionnaire at enrollment. We used electronic health records to assess the development of CAD during follow-up. Of the 153&nbsp;802 veterans who provided information on diet and were free of CAD at baseline, the mean age was 64.0 (SD=11.8) years and 90.4% were men. During a mean follow-up of 2.8&nbsp;years, 5451 CAD cases occurred. The crude incidence rate of CAD was 14.0, 13.1, 12.6, 12.3, and 11.1 cases per 1000 person-years across consecutive quintiles of Dietary Approach to Stop Hypertension score. Hazard ratios (95% confidence interval) for CAD were 1.0 (ref), 0.91 (0.84-0.99), 0.87 (0.80-0.95), 0.86 (0.79-0.94), and 0.80 (0.73-0.87) from the lowest to highest quintile of Dietary Approach to Stop Hypertension score controlling for age, sex, body mass index, race, smoking, exercise, alcohol intake, and statin use (P linear trend, &lt;0.0001). Our data are consistent with an inverse association between Dietary Approach to Stop Hypertension diet score and incidence of CAD among US veterans
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