61 research outputs found

    Effect of prostaglandin on reproduction in relation to pituitary gonadal axis in the fish, Cyprinus carpio (L.)

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    Prostaglandins are a class of fatty acids which are “traditionally” associated with a variety of autocrine and paracrine functions in the vertebrate body. In many fishes, however, F prostaglandins also function as a hormone that stimulates sexual behavior. In the present study, F prostaglandin was used to assess the efficacy on reproductive behavior and spawning in relation to pituitary gonadal axis in the fish, Cyprinus carpio by administering different doses. Early maturity was observed in fish leading to courtship and spawning. The histological study of olfactory lobe, pituitary gland and gonads showed that the prostaglandin is also functioning as potent olfactory stimulants with sex pheromonal activity of the fish. F prostaglandin was metabolized and released into the water where it functions as a sex pheromone, stimulating male and female sexual behavior resulting into spawning. It was concluded that F prostaglandin acts as an inducer for successful breeding in the fish, C. carpio

    Evaluation of the effect of lycopene on lipid profile, serum antioxidant enzymes and blood sugar level in New Zealand white rabbits

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    Background: Dyslipidaemias are the major cause of increased atherogenesis. Lycopene is a pigment that imparts red colour to fruits and vegetables like tomatoes. Risk of cardiovascular diseases has been shown to decrease with dietary intake of tomatoes. Although the antioxidant and hypolipidaemic properties of tomatoes have been studied extensively, beneficial effect of pure lycopene supplement as hypolipidaemic is still debatable So, we aimed to evaluate the effect of pure lycopene powder on lipid profile, serum antioxidant enzymes and blood sugar level in hyperlipidaemic rabbits.Methods: Adult male New Zealand White rabbits (1.5-2.5kg) were divided into three groups of six each. Group I-High Fat Diet (HFD) (5ml/kg). Group II-HFD (5ml/kg) + lycopene (10mg/kg) orally. Group III-HFD (5ml/kg) + lycopene (20mg/kg) orally. Blood samples were taken from all rabbits for baseline estimations of serum lipids, serum superoxide dismutase (SOD) and blood sugar. Same tests were performed after six weeks.Results: There was significant decrease in the levels of serum TC, LDL-C, TG and VLDL and an increase in serum HDL-C and antioxidant SOD with lycopene administration. However, significant increase in HDL was not seen with lycopene 10mg. TG and VLDL levels were significantly less with 20mg lycopene compared to 10mg lycopene. There was however no change in blood sugar level with lycopene.Conclusions: Pure lycopene supplement showed significant hypolipidaemic and antioxidant activity. However, it did not show significant effect on blood glucose levels

    Search and analysis of giant radio galaxies with associated nuclei (SAGAN) -- I : New sample and multi-wavelength studies

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    We present the first results of a project called SAGAN, which is dedicated solely to the studies of relatively rare megaparsec-scale radio galaxies in the Universe, called giant radio galaxies (GRGs). We have identified 162 new GRGs primarily from the NVSS with sizes ranging from ~0.71 Mpc to 2.82 Mpc in the redshift range of ~0.03 - 0.95, of which 23 are hosted by quasars (giant radio quasars, GRQs). As part of the project SAGAN, we have created a database of all known GRGs, the GRG catalogue, from the literature (including our new sample); it includes 820 sources. For the first time, we present the multi-wavelength properties of the largest sample of GRGs. Our results establish that the distributions of the radio spectral index and the black hole mass of GRGs do not differ from the corresponding distributions of normal-sized radio galaxies (RGs). However, GRGs have a lower Eddington ratio (ER) than RGs. Using the mid-infrared data, we classified GRGs in terms of their accretion mode: either a high-power radiatively efficient high-excitation state, or a radiatively inefficient low-excitation state. We find that GRGs in high-excitation state statistically have larger sizes, stronger radio power, jet kinetic power, and higher ER than those in low-excitation state. Our analysis reveals a strong correlation between the ER and the scaled jet kinetic power, which suggests a disc-jet coupling. Our environmental study reveals that ~10% of all GRGs may reside at the centres of galaxy clusters, in a denser galactic environment, while the majority appears to reside in a sparse environment. We find that the probability of BCG as a GRG is quite low. We present new results for GRGs that range from black hole mass to large-scale environment properties. We discuss their formation and growth scenarios, highlighting the key physical factors that cause them to reach their gigantic size. Abridged.Comment: Accepted for publication in Astronomy & Astrophysics. 14 figures, 7 tables and 7 montages. Comments are welcome. "SAGAN Project website https://sites.google.com/site/anantasakyatta/sagan

    Study of effects of donepezil and aspirin on working memory in rats using electroconvulsive shock model

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    Background: Memory is the most common cognitive ability lost with dementia commonly seen in Alzheimer’s disease (AD). Donepezil was the first cholinesterase inhibitor to be licensed in UK for AD. There is preliminary evidence that aspirin decreases the risk and delays the onset of AD. Low dose aspirin users had numerically lower prevalence of Alzheimer’s dementia and had better cognitive function than non-users.Methods: Retention of conditioned avoidance response (CAR) was assessed by using repeated electroconvulsive shocks (ECS) in rats. Rats were divided into five groups: control (pretreated with distilled water), ECS (150 V, 50 Hz, with intensity of 210 mA for 0.5 sec) pretreated, combined aspirin (6.75 mg/kg) and pretreated ECS, combined donepezil (0.32 mg/kg) and pretreated ECS, combined aspirin, donepezil and pretreated ECS groups. Data were analyzed using the Chi-square test and ANOVA.Results: Findings show that administration of ECS daily for 8 days results in transient amnesia and disruption of retention of CAR. Aspirin and donepezil administration significantly increased the retention of CAR in comparison to ECS. However, aspirin failed to show an increase in the retention of CAR as compared to donepezil. The combination of the two drugs showed statistically significant increase in the retention of CAR than either of these drugs given alone.Conclusion: Neuroinflammation plays an important role in the pathophysiology of neurodegenerative disorder like AD. Combination of aspirin with donepezil increased the nootropic and neuroprotective effect of aspirin and thus may hold great clinical significance in such disorders

    `Zwicky's Nonet': a compact merging ensemble of nine galaxies and 4C 35.06, a peculiar radio galaxy with dancing radio jets

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    We report the results of our radio, optical and infra-red studies of a peculiar radio source 4C~35.06, an extended radio-loud AGN at the center of galaxy cluster Abell 407 (z=0.047z=0.047). The central region of this cluster hosts a remarkably tight ensemble of nine galaxies, the spectra of which resemble those of passive red ellipticals, embedded within a diffuse stellar halo of \sim1~arcmin size. This system (named the `Zwicky's Nonet') provides unique and compelling evidence for a multiple-nucleus cD galaxy precursor. Multifrequency radio observations of 4C~35.06 with the Giant Meterwave Radio Telescope (GMRT) at 610, 235 and 150 MHz reveal a system of 400~kpc scale helically twisted and kinked radio jets and outer diffuse lobes. The outer extremities of jets contain extremely steep spectrum (spectral index -1.7 to -2.5) relic/fossil radio plasma with a spectral age of a few×(107108)\,\times (10^7 - 10^8) yr. Such ultra-steep spectrum relic radio lobes without definitive hot-spots are rare, and they provide an opportunity to understand the life-cycle of relativistic jets and physics of black hole mergers in dense environments. We interpret our observations of this radio source in the context of the growth of its central black hole, triggering of its AGN activity and jet precession, all possibly caused by galaxy mergers in this dense galactic system. A slow conical precession of the jet axis due to gravitational perturbation between interacting black holes is invoked to explain the unusual jet morphology.Comment: Published in MNRAS | No. of pages 12, 10 figures and 4 tables. Comments are welcom

    A comparative study of American ginseng (spp. Panax quinquefolius) and Donepezil on working memory in rats using scopolamine induced disruption of memory

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    Background: Treatment of Alzheimer’s disease (AD) includes acetylcholinesterase inhibitors like Donepezil. American ginseng has been postulated to enhance learning and memory owing to its antiapoptotic activity as well as inhibition of formation of β amyloid plaque. Scarce data is available on effect of combination of these two drugs. Hence, we have conducted this study to evaluate the same. Aim and objectives of the study were to evaluate the role of American ginseng on working memory in rats and to compare the effect of American ginseng with Donepezil on working memory in rats.Methods: Sprague-Dawley rats of either sex, weighing 150-200g were used and obtained from animal house of Dr. D. Y. Patil Medical College, Hospital and Research Centre, Pimpri, Pune. To study the effects of the drugs on working memory in rats, they were trained for conditioned avoidance response (CAR) using Cook's pole climbing apparatus. The method of Fellow and Cook was used.Results: In the group C (i.e. the control group), 50% of rats showed the retention of CAR. In the group S (i.e. only scopolamine group), only 20% of rats showed the retention of CAR. In the group S+AG (i.e. scopolamine and American ginseng), 60% of rats showed the retention of CAR. In the group S+ D (i.e. scopolamine and Donepezil) 70% of rats showed retention of CAR. In the group S+D+AG (i.e. the combination group of scopolamine, Donepezil and American ginseng), 80% of rats showed the retention of CAR.Conclusions: From this study we can conclude that American ginseng and Donepezil have comparable effects in retention of working memory. The combination of American ginseng and Donepezil can have additive effect on the retention of working memory

    Nationwide surveillance for Telmisartan alone or with combination at real world therapy in Indian patients with hypertension (START)

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    Background: Angiotensin receptor blockers (ARBs) are amongst the most preferred class of antihypertensive as reported at various evidences or guidelines. However, choice amongst ARBs differs between practicing physicians in real-life scenario. This survey aimed to understand the usage preferences of telmisartan therapy alone and in combination for treating hypertension (HT) among practitioners at various clinical settings in real-life scenario in India.Methods: A cross‑sectional survey was conducted with a pre-validated survey questionnaire consisting of 15 questions pertaining to the telmisartan and its combination usage in HT management. Total 498 registered medical practitioners (mostly physicians and cardiologists) had participated in survey. They were approached for seeking their perception, opinions, and prescribing behaviour. Categorical data was summarized by number (n) and percentage (%) in each category. Data were summarised in frequency tables.Results: Key findings from the data analysed were as follows: Around 20-40% of patients been reported to have co-morbid hypertension and diabetes as reported by majority of the physicians. Preferred class of drug in patients with hypertension with diabetes reported to be ARB. Around 90.36% of doctors reported that telmisartan was the most preferred ARB in patients with hypertension associated with high cardiovascular risk. Around 90.76% of doctors reported for their preference for telmisartan in patients with hypertension for 24-hr BP control. Around 82.93% of doctors preferred telmisartan in patients with hypertension and stroke/post-MI status.Conclusions: Indian healthcare practitioners prefer telmisartan as the most preferred ARB either alone or in a combination in patients with hypertension, including those with comorbidities

    The LOFAR view of intergalactic magnetic fields with giant radio galaxies

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    Context. Giant radio galaxies (GRGs) are physically large radio sources that extend well beyond their host galaxy environment. Their polarization properties are affected by the poorly constrained magnetic field that permeates the intergalactic medium on megaparsec scales. A low frequency (< 200 MHz) polarization study of this class of radio sources is now possible with LOFAR. Aims. Here we investigate the polarization properties and Faraday rotation measure (RM) of a catalog of GRGs detected in the LOFAR Two-meter Sky Survey. This is the first low frequency polarization study of a large sample of radio galaxies that were selected on their physical size. We explore the magneto-ionic properties of their under-dense environment and probe intergalactic magnetic fields using the Faraday rotation properties of their radio lobes. LOFAR is a key instrument for this kind of analysis because it can probe small amounts of Faraday dispersion (< 1 rad m-2), which are associated with weak magnetic fields and low thermal gas densities. Methods. We used RM synthesis in the 120-168 MHz band to search for polarized emission and to derive the RM and fractional polarization of each detected source component. We study the depolarization between 1.4 GHz and 144 MHz using images from the NRAO VLA Sky Survey. We investigate the correlation of the detection rate, the RM difference between the lobes, and the depolarization with different parameters as follows: the angular and linear size of the sources and the projected distance from the closest foreground galaxy cluster. In our sample, we also included 3C 236, which is one of the largest radio galaxies known. Results. From a sample of 240 GRGs, we detected 37 sources in polarization, all of which have a total flux density above 56 mJy. We detected significant RM differences between the lobes, which would be inaccessible at gigahertz frequencies, with a median value of ∼1 rad m-2. The fractional polarization of the detected GRGs at 1.4 GHz and 144 MHz is consistent with a small amount of Faraday depolarization (a Faraday dispersion < 0.3 rad m-2). Our analysis shows that the lobes are expanding into a low-density (< 10-5 cm-3) local environment that is permeated by weak magnetic fields (< 0.1  μG) with fluctuations on scales of 3-25 kpc. The presence of foreground galaxy clusters appears to influence the polarization detection rate up to 2R500. In general, this work demonstrates the ability of LOFAR to quantify the rarefied environments in which these GRGs exist and highlights them as an excellent statistical sample to use as high precision probes of magnetic fields in the intergalactic medium and the Milky Way

    Giant radio galaxies in the LOFAR Two-metre Sky Survey-I

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    © ESO 2020. The original publication is available at https://doi.org/10.1051/0004-6361/201935589.Giant radio galaxies (GRGs) are a subclass of radio galaxies which have grown to megaparsec scales. GRGs are much rarer than normal sized radio galaxies ( less than 0.7 Mpc) and the reason for their gigantic sizes is still debated. Here, we report the biggest sample of GRGs identified to date. These objects were found in the LOFAR Two-metre Sky Survey (LoTSS) first data release images, which cover a 424 square degrees region. Of the 240 GRGs found, 228 are new discoveries. The GRGs have sizes ranging from 0.7 to 3.5 Mpc and have redshifts between 0.1 and 2.3. Seven GRGs have sizes above 2 Mpc and one has a size of ~ 3.5 Mpc. The sample contains 44 GRGs hosted by spectroscopically confirmed quasars. We also find that 21 GRGs are located in dense galaxy cluster/group environments, which were identified using optical data. Here, we present the search techniques employed and the resulting catalogue of the newly discovered large sample of GRGs. We also show that the spectral index of GRGs is similar to that of normal sized radio galaxies.Peer reviewedFinal Published versio
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