587 research outputs found

    Bianchi Type-II String Cosmological Models in Normal Gauge for Lyra's Manifold with Constant Deceleration Parameter

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    The present study deals with a spatially homogeneous and anisotropic Bianchi-II cosmological models representing massive strings in normal gauge for Lyra's manifold by applying the variation law for generalized Hubble's parameter that yields a constant value of deceleration parameter. The variation law for Hubble's parameter generates two types of solutions for the average scale factor, one is of power-law type and other is of the exponential form. Using these two forms, Einstein's modified field equations are solved separately that correspond to expanding singular and non-singular models of the universe respectively. The energy-momentum tensor for such string as formulated by Letelier (1983) is used to construct massive string cosmological models for which we assume that the expansion (θ\theta) in the model is proportional to the component σ 11\sigma^{1}_{~1} of the shear tensor σij\sigma^{j}_{i}. This condition leads to A=(BC)mA = (BC)^{m}, where A, B and C are the metric coefficients and m is proportionality constant. Our models are in accelerating phase which is consistent to the recent observations. It has been found that the displacement vector β\beta behaves like cosmological term Λ\Lambda in the normal gauge treatment and the solutions are consistent with recent observations of SNe Ia. It has been found that massive strings dominate in the decelerating universe whereas strings dominate in the accelerating universe. Some physical and geometric behaviour of these models are also discussed.Comment: 24 pages, 10 figure

    EXPLORING DEFLUORIDATION CAPACITY OF TURMERIC ON INDUSTRIAL SEWAGE

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    ABSTRACTObjective: This research was carried out for developing a low-cost agro-based biosorbent for defluoridation of wastewater. Here, we investigated thedefluoridation capacities of simple turmeric and MnO2-coated turmeric.Methods: The defluoridation capacity of turmeric had been investigated through batch sorption techniques. In the batch sorption technique, theeffect of various parameters such as adsorbent dose, initial fluoride concentration, and pH had been studied, and these parameters are optimized formaximum fluoride removal efficiency. Each adsorbent was characterized using various techniques such as Fourier transform infrared spectroscopy,scanning electron micrograph, and Energy Dispersive Analysis of1 X-Ray. The adsorption kinetics had been studied through different kinetics modelssuch as intra-particle diffusion model and pseudo-first order model. For adsorption equilibrium, we studied the conventional equilibrium modelssuch as Langmuir isotherm model and Freundlich isotherm model.Results: The result of the performed experiments shows that for turmeric and MnO-coated turmeric, the values of pH, adsorbent dose, initialconcentration, and contact time were 7 and 6, 12 and 14 g/l, 20 and 20 mg/l, 60 and 75 minutes at which optimum defluoridation of about 89.9% and94.34% occurs, respectively.Conclusion: The result obtained from the experiments shows that the MnOKeywords: Defluoridation, Turmeric, MnO222 coating has increased the defluoridation capacity of the turmeric.-coated turmeric, Fourier transform infrared spectroscopy, Scanning electron micrograph, EnergyDispersive Analysis of X-Ray, Langmuir isotherm, Freundlich isotherm

    Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

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    We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

    Post translational changes to α-synuclein control iron and dopamine trafficking : a concept for neuron vulnerability in Parkinson's disease

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    Parkinson's disease is a multifactorial neurodegenerative disorder, the aetiology of which remains elusive. The primary clinical feature of progressively impaired motor control is caused by a loss of midbrain substantia nigra dopamine neurons that have a high α-synuclein (α-syn) and iron content. α-Syn is a neuronal protein that is highly modified post-translationally and central to the Lewy body neuropathology of the disease. This review provides an overview of findings on the role post translational modifications to α-syn have in membrane binding and intracellular vesicle trafficking. Furthermore, we propose a concept in which acetylation and phosphorylation of α-syn modulate endocytic import of iron and vesicle transport of dopamine during normal physiology. Disregulated phosphorylation and oxidation of α-syn mediate iron and dopamine dependent oxidative stress through impaired cellular location and increase propensity for α-syn aggregation. The proposition highlights a connection between α-syn, iron and dopamine, three pathological components associated with disease progression in sporadic Parkinson's disease

    Influence of Weather Variation on Cropping Pattern of Leh District of Ladakh Region

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    Not AvailableLeh district is situated between 32-36° N latitude and 75-80° E longitude with an altitude ranging from 2500 to 6000 m above mean sea level. Leh is the largest district in the country with an area of 45,100 Km2 . Agriculture is the main occupation of the rural people of the district. Initial analysis of the data revealed that the acreage of wheat crop increased from 2003 onward. Notably, a simultaneous decrease in acreage of barley crop was observed. It is noticeable that wheat crop replaced the barley crop from 2003 onwards. Such change in cropping pattern was found related with change in weather condition. It was observed that from 2003 onward monthly mean of daily minimum temperature during May increased from 4 °C to 8 °C up to 2007. Similarly, monthly mean of daily maximum temperature was observed higher (>20 °C) before 2003 but decreased during 2003 to 2009 (range 15 to 20 °C). Snowfall was a common phenomenon during month of May before 2003, but was not observed during 2003 to 2009. Therefore, it is hypothesized that increase in both minimum and maximum temperature during May had enabled the farmers to grow wheat in place of barley. Moreover, during the month of April, snowfall events were significantly reduced in 2003-2009 and in month of May snowfall events was not recorded at all. This may perhaps another reason which enabled farmers to sow the wheat crop during last week of April to mid of May. Interestingly during last two years, the cropping pattern is again reversed. The acreage under wheat crop was decreased and the acreage under barley increased. Such reversal may be due to re-occurrence of snowfall events during first two weeks of May, which was absent during 2003-2009. Therefore, it is quite apparent that weather condition influenced the cropping pattern and crop acreage. However, many other factors like timely availability of seed, quality of seeds as per need of local farmers as they prefer some straw producing varieties, crop rotation pattern, etc., also plays some role in shifting of cropping pattern. Long term data base on crop-weather relationship among with the other factors may help in developing crop weather modeling.Not Availabl

    Long-term arrhythmia detection using portable ECG patches in stroke patients: a case series

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    Cardiac arrhythmias are common following ischemic stroke and can lead to severe complications, such as recurrent strokes. Early identification is important, and continuous electrocardiography (ECG) monitoring provides a possible solution. This prospective observational case series assessed the efficacy of a portable ECG patch in detecting arrhythmias in post-stroke patients and their role in informing treatment decisions. This study was carried out between May and November 2023 in the neurology ward of a local hospital in Meerut, India. A total of 10 adult patients were included in this case series after applying the inclusion and exclusion criteria. They were continuously observed up to 80 hours with two alternate portable ECG patches after a baseline smartphone-based ECG (Spandan 12-lead ECG). The portable ECG patches detected several arrhythmias, such as transient and potentially lethal conditions like atrial fibrillation and ventricular tachycardia, which the initial baseline smartphone-based ECG failed to record. A cardiologist validated all the episodes of arrhythmia. The use of real-time data transmission facilitated timely clinical intervention, which aided in improved patient management and outcomes. This case series emphasizes the benefits of continuous portable ECG patch monitoring compared to single-time-point smartphone-based ECG in identifying intermittent arrhythmias in stroke patients. The results favour the incorporation of portable ECG patches into standard post-stroke management for early diagnosis, risk reduction, and enhanced therapeutic decision-making

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    AMPK in Pathogens

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    During host–pathogen interactions, a complex web of events is crucial for the outcome of infection. Pathogen recognition triggers powerful cellular signaling events that is translated into the induction and maintenance of innate and adaptive host immunity against infection. In opposition, pathogens employ active mechanisms to manipulate host cell regulatory pathways toward their proliferation and survival. Among these, subversion of host cell energy metabolism by pathogens is currently recognized to play an important role in microbial growth and persistence. Extensive studies have documented the role of AMP-activated protein kinase (AMPK) signaling, a central cellular hub involved in the regulation of energy homeostasis, in host–pathogen interactions. Here, we highlight the most recent advances detailing how pathogens hijack cellular metabolism by suppressing or increasing the activity of the host energy sensor AMPK. We also address the role of lower eukaryote AMPK orthologues in the adaptive process to the host microenvironment and their contribution for pathogen survival, differentiation, and growth. Finally, we review the effects of pharmacological or genetic AMPK modulation on pathogen growth and persistence.CIHR -Canadian Institutes of Health Researc

    CAG Repeat Variants in the POLG1 Gene Encoding mtDNA Polymerase-Gamma and Risk of Breast Cancer in African-American Women

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    The DNA polymerase-gamma (POLG) gene, which encodes the catalytic subunit of enzyme responsible for directing mitochondrial DNA replication in humans, contains a polyglutamine tract encoded by CAG repeats of varying length. The length of the CAG repeat has been associated with the risk of testicular cancer, and other genomic variants that impact mitochondrial function have been linked to breast cancer risk in African-American (AA) women. We evaluated the potential role of germline POLG-CAG repeat variants in breast cancer risk in a sample of AA women (100 cases and 100 age-matched controls) who participated in the Women's Circle of Health Study, an ongoing multi-institutional, case-control study of breast cancer. Genotyping was done by fragment analysis in a blinded manner. Results from this small study suggest the possibility of an increased risk of breast cancer in women with minor CAG repeat variants of POLG, but no statistically significant differences in CAG repeat length were observed between cases and controls (multivariate-adjusted odds ratio 1.74; 95% CI, 0.49–6.21). Our study suggests that POLG-CAG repeat length is a potential risk factor for breast cancer that needs to be explored in larger population-based studies

    A Riboswitch-Based Inducible Gene Expression System for Mycobacteria

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    Research on the human pathogen Mycobacterium tuberculosis (Mtb) would benefit from novel tools for regulated gene expression. Here we describe the characterization and application of a synthetic riboswitch-based system, which comprises a mycobacterial promoter for transcriptional control and a riboswitch for translational control. The system was used to induce and repress heterologous protein overexpression reversibly, to create a conditional gene knockdown, and to control gene expression in a macrophage infection model. Unlike existing systems for controlling gene expression in Mtb, the riboswitch does not require the co-expression of any accessory proteins: all of the regulatory machinery is encoded by a short DNA segment directly upstream of the target gene. The inducible riboswitch platform has the potential to be a powerful general strategy for creating customized gene regulation systems in Mtb
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