17 results on '"Vyas DK"'
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2. Effect of whey protein on sun dried protein enriched kesar mango leather
- Author
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Jethva, KR, primary, Sutar, RF, additional, Kumar, N, additional, and Vyas, DK, additional
- Published
- 2021
- Full Text
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3. Investigating the effect of host plant identity on instar number in fall webworm, a common generalist herbivore.
- Author
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Tanino-Springsteen MM, Vyas DK, Mitchell A, Durso C, and Murphy SM
- Subjects
- Animals, Larva, Plants, Diet, Herbivory, Moths
- Abstract
For herbivorous insects with a broad diet breadth, host plant identity can influence larval development by either accelerating or delaying growth. For some species of Lepidoptera, the number of larval instars varies depending on the host plant's identity. Fall webworm (Hyphantria cunea, Drury) is a polyphagous herbivore that feeds on over 450 host plants worldwide. Of the 2 morphotypes (red- and black-head) of fall webworm, the number of instars for the red-head fall webworms has not been characterized. Given its broad diet breadth, fall webworm developmental stages may vary with plant identity. We investigated whether host plant identity affected the number of instars observed during red-head fall webworm development. We measured the head capsules of over 6,000 fall webworm larvae reared on 6 different plants commonly eaten by fall webworms in Colorado. We modeled head capsule widths as Gaussian mixture models, with a Gaussian distribution that corresponded to each instar. We show that our red-head fall webworms varied in number of instars depending on the identity of their host plant upon which they fed. We found that red-head fall webworm exhibited 7 instars on 5 of the host plants and 8 instars on 1 host plant that we studied. Our results for the number of instars for red-head fall webworm are consistent with reports of the number of instars for black-head fall webworm. Our research provides insight into the influence of host plant identity on fall webworm development, which can be used to advance lab and field research of this species., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2024
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4. Molecular dynamics study of tropical calcific pancreatitis (TCP) associated calcium-sensing receptor single nucleotide variation.
- Author
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Shrivastava A, Mathur K, Verma RK, Jayadev Magani SK, Vyas DK, and Singh A
- Abstract
Tropical Calcific Pancreatitis (TCP) is a chronic non-alcoholic pancreatitis characterised by extensive calcification. The disease usually appears at a younger age and is more common in tropical regions. This disease's progression can lead to pancreatic diabetes, which can subsequently lead to pancreatic cancer. The CASR gene encodes a calcium-sensing receptor (CaSR), which is a GPCR protein of class C. It is expressed in the islets of Langerhans, the parathyroid gland, and other tissues. It primarily detects small gradients in circulating calcium concentrations and couples this information to intracellular signalling, which helps to regulate PTH (parathyroid hormone) secretion and mineral ion homeostasis. From co-leading insulin release, CaSR modulates ductal HCO
3- secretion, Ca2+ concentration, cell-cell communication, β-cell proliferation, and intracellular Ca2+ release. In pancreatic cancer, the CaSR limits cell proliferation. TCP-related four novel missense mutations P163R, I427S, D433H and V477A, found in CaSR extracellular domain (ECD) protein, which were reported in the mutTCPdb Database (https://lms.snu.edu.in/mutTCPDB/index.php). P163R mutation occurs in ligand-binding domain 1 (LBD-1) of the CaSR ECD. To investigate the influence of these variations on protein function and structural activity multiple in-silico prediction techniques such as SIFT, PolyPhen, CADD scores, and other methods have been utilized. A 500 ns molecular dynamic simulation was performed on the CaSR ECD crystal structure and the corresponding mutated models. Furthermore, Principal Component Analysis (PCA) and Essential Dynamics analysis were used to forecast collective motions, thermodynamic stabilities, and the critical subspace crucial to CaSR functions. The results of molecular dynamic simulations showed that the mutations P163R, I427S, D433H, and V477A caused conformational changes and decreased the stability of protein structures. This study also demonstrates the significance of TCP associated mutations. As a result of our findings, we hypothesised that the investigated mutations may have an effect on the protein's structure and ability to interact with other molecules, which may be related to the protein's functional impairment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Shrivastava, Mathur, Verma, Jayadev Magani, Vyas and Singh.)- Published
- 2022
- Full Text
- View/download PDF
5. Extrinsic Inter- and Intraspecific Competition in Parasitoid Wasps.
- Author
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Ode PJ, Vyas DK, and Harvey JA
- Subjects
- Animals, Ecology, Ecosystem, Female, Host-Parasite Interactions, Male, Wasps
- Abstract
The diverse ecology of parasitoids is shaped by extrinsic competition, i.e., exploitative or interference competition among adult females and males for hosts and mates. Adult females use an array of morphological, chemical, and behavioral mechanisms to engage in competition that may be either intra- or interspecific. Weaker competitors are often excluded or, if they persist, use alternate host habitats, host developmental stages, or host species. Competition among adult males for mates is almost exclusively intraspecific and involves visual displays, chemical signals, and even physical combat. Extrinsic competition influences community structure through its role in competitive displacement and apparent competition. Finally, anthropogenic changes such as habitat loss and fragmentation, invasive species, pollutants, and climate change result in phenological mismatches and range expansions within host-parasitoid communities with consequent changes to the strength of competitive interactions. Such changes have important ramifications not only for the success of managed agroecosystems, but also for natural ecosystem functioning.
- Published
- 2022
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6. Streetlights positively affect the presence of an invasive grass species.
- Author
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Murphy SM, Vyas DK, Hoffman JL, Jenck CS, Washburn BA, Hunnicutt KE, Davidson A, Andersen JM, Bennet RK, Gifford A, Herrera M, Lawler B, Lorman S, Peacock V, Walker L, Watkins E, Wilkinson L, Williams Z, and Tinghitella RM
- Abstract
Anthropogenic disturbances associated with urban ecosystems can create favorable conditions for populations of some invasive plant species. Light pollution is one of these disturbances, but how it affects the growth and establishment of invasive plant populations is unknown. Cheatgrass ( Bromus tectorum ) is a problematic invasive species where it has displaced native grassland communities in the United States, but to our knowledge, there have been no studies of the ecological factors that affect cheatgrass presence in urban ecosystems. We conducted field surveys in urban alleys in Denver, Colorado, to compare the presence of cheatgrass at sites with and without artificial light at night (hereafter artificial light) from streetlights. These streetlights are mounted on utility poles, which cause ground disturbance when installed in alleys; we were able to test the independent effect of poles on cheatgrass establishment because not all poles have streetlights on them. We found that cheatgrass was positively associated with the presence of streetlights and to a lesser extent poles. In addition to cheatgrass, we also found that other plants were positively associated with the presence of both poles and streetlights. Our results suggest that artificial light may benefit the occurrence of cheatgrass and other plant species in urban settings. While invasive populations of cheatgrass in wild habitats attract the most attention from managers, we suggest more consideration for this grass in urban environments where its growth and establishment benefit from anthropogenic changes., Competing Interests: None declared., (© 2021 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)
- Published
- 2021
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7. Ecological dissociation and re-association with a superior competitor alters host selection behavior in a parasitoid wasp.
- Author
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Vyas DK, Harvey JA, Paul RL, Heimpel GE, and Ode PJ
- Subjects
- Animals, Colorado, Europe, Female, Host-Parasite Interactions, Larva, North America, Wasps
- Abstract
Interspecific competition for limited resources can drive ecological specialization and trait expression. Organisms released from intense competition may exploit a broader range of resources, but if reunited with stronger competitors, survivorship may depend on foraging behaviors that reduce competition. We compared the host selection behavior of the parasitoid Cotesia glomerata from two North American populations that differ in their association with Cotesia rubecula, a superior competitor. Both parasitoids originate from Europe and attack the imported cabbageworm (a.k.a. small cabbage white) Pieris rapae, but C. glomerata was introduced into North America almost a century before C. rubecula. After re-association in North America, C. rubecula has displaced C. glomerata in several regions, but not in other regions. Host selection was measured in female C. glomerata from Maryland (MD) where it coexists with C. rubecula, and in conspecifics from Colorado (CO) where C. rubecula is absent. Unparasitized and C. rubecula-parasitized P. rapae hosts were used in choice tests to examine whether C. glomerata host selection behavior differed based on the population's association history with C. rubecula. We found that C. glomerata from MD had a higher likelihood of avoiding hosts parasitized by C. rubecula (and thus avoiding competition) than did wasps from CO. The ability of C. glomerata to avoid hosts parasitized by C. rubecula may facilitate coexistence in MD; whereas, the lack of discrimination in CO populations of C. glomerata naïve to C. rubecula could contribute to the displacement of C. glomerata were C. rubecula to enter the same habitat.
- Published
- 2019
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8. Optimization of in vitro regeneration of Haloxylon salicornicum : a keystone species of extreme arid regions.
- Author
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Vyas DK and Dagla HR
- Abstract
Haloxylon salicornicum is an economically important perennial woody shrub of family Amaranthaceae and is a good source of food additives, fodder, fuel and nutrients in Indian Thar Desert. In vitro regeneration of H. salicornicum through nodal shoot segments is achieved in present investigation. Young green shoots in horizontal orientation were found to be more responsive than vertical orientation. Axillary shoot buds were activated on MS medium containing 10 µM BAP. Adventitious roots with intense root hairs were induced on horizontally placed shoots on half strength MS medium containing 2 µM NOA + 100 mg L
-1 activated charcoal. This is a first report on micropropagation of H. salicornicum. This protocol can be a useful means for in vitro characterization, mass propagation and conservation of the plant for future prospects.- Published
- 2018
- Full Text
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9. Ordinal representation of numeric quantities by brown capuchin monkeys (Cebus apella).
- Author
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Judge PG, Evans TA, and Vyas DK
- Subjects
- Animals, Discrimination Learning, Female, Generalization, Psychological, Individuality, Male, Orientation, Pattern Recognition, Visual, Psychomotor Performance, Serial Learning, Size Perception, Cebus psychology, Concept Formation, Mathematics, Problem Solving
- Abstract
Using techniques established by E. M. Brannon and H. S. Terrace (2000) with rhesus macaques (Macaca mulatta), the authors tested the ability of brown capuchins (Cebus apella) to order arrays of items ranging in quantity from 1 to 9. Three monkeys were trained on a touch screen to select the quantities 1-4 in ascending order. The monkeys exhibited successful transfer of this ability to novel representations of the quantities 1-4 and to pairs of the novel quantities 5-9. Patterns of responding with respect to numeric distance and magnitude were similar to those seen in human subjects, suggesting the use of similar psychological processes. The capuchins demonstrated an ordinal representation of quantity equivalent to that shown in Old World monkeys., (Copyright 2005 APA.)
- Published
- 2005
- Full Text
- View/download PDF
10. Tissue eosinophilia in chronic sinusitis: quantification techniques.
- Author
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Bhattacharyya N, Vyas DK, Fechner FP, Gliklich RE, and Metson R
- Subjects
- Chronic Disease, Eosinophilia blood, Eosinophilia complications, Humans, Leukocyte Count, Prospective Studies, Reproducibility of Results, Sinusitis blood, Sinusitis complications, Eosinophilia pathology, Eosinophils, Sinusitis pathology
- Abstract
Objective: To ascertain the reliability of a proposed method for quantifying tissue eosinophilia in sinus mucosa., Design: Prospective cohort study., Interventions and Outcome Measures: Pathology slides from patients undergoing endoscopic sinus surgery for chronic rhinosinusitis were independently assessed by 2 reviewers. Using a proposed systematic counting method, the degree of tissue eosinophilia was quantified. Disease severity was assessed by computed tomographic (CT) staging. Intrarater, interrater, and intrapatient reliability was determined using correlational reliability analysis. The degree of correlation between tissue eosinophilia and CT stage was determined., Results: One hundred thirty-two slides from 65 patients were reviewed. The mean (SD) eosinophil density was 23.4 (37.2) eosinophils per high-power field. Only 12 patients (18%) had no eosinophils on histopathologic analysis. Strong intrarater (r> or =0.91 for each rater, P<.001) and interrater reliability (r> or =0.82 between raters, P<.001) was noted for the quantification method. A moderate degree of correlation was found between CT scan stage and degree of tissue eosinophilia (Spearman rho = 0.62, P<.001)., Conclusions: The proposed method for quantifying tissue eosinophilia in sinus mucosa is reliable and valid. A relatively strong correlation exists between CT scan stage and tissue eosinophilia in chronic rhinosinusitis.
- Published
- 2001
- Full Text
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11. THE EVOLUTIONARY HISTORY OF PARTHENOGENETIC CNEMIDOPHORUS LEMNISCATUS (SAURIA: TEIIDAE). II. MATERNAL ORIGIN AND AGE INFERRED FROM MITOCHONDRIAL DNA ANALYSES.
- Author
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Vyas DK, Moritz C, Peccinini-Seale D, Wright JW, and Brown WM
- Abstract
Restriction endonuclease analyses were performed on mitochondrial DNAs (mtDNAs) representing unisexual parthenogenetic (cytotypes A, B, and C) and bisexual (cytotypes D and E) populations of Amazonian lizards presently regarded as Cnemidophorus lemniscatus. The results of mtDNA cleavage map comparisons among these C. lemniscatus indicated that (1) there was no cleavage site variation among the unisexuals, (2) mtDNAs from the bisexual cytotypes D and E differed in sequence from one another by about 13%, and (3) mtDNAs from cytotypes A-C differed from those of cytotype D by about 5% and from those of cytotype E by about 13%. Higher resolution restriction fragment size comparisons confirmed the high degree of similarity among the unisexual mtDNAs, but identified 12 cleavage site variants among the 13 cytotype D mtDNAs examined. Both cladistic and phenetic (UPGMA) analyses of the data indicate that the unisexual and cytotype D mtDNAs form a single clade, suggesting that a female of cytotype D was the maternal progenitor of the unisexuals. The similarity among the unisexual mtDNAs and the variability among those of cytotype D suggest that the three unisexual cytotypes arose recently from a common maternal lineage. The mtDNA variability observed among cytotype D individuals has a strong geographic component, suggesting that the unisexuals arose from one or a few geographically proximal populations. The mtDNA comparisons also support the conclusion, based on allozyme comparisons (Sites et al., 1990, this issue), that cytotypes D and E, although presently allocated to C. lemniscatus, are separate species., (© 1990 The Society for the Study of Evolution.)
- Published
- 1990
- Full Text
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12. Seasonal study of the adrenal gland of some Indian avian species.
- Author
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Vyas DK and Jacob D
- Subjects
- Acid Phosphatase metabolism, Adrenal Glands metabolism, Alkaline Phosphatase metabolism, Animals, Ascorbic Acid metabolism, Body Weight, Female, Glycogen metabolism, Glycosaminoglycans metabolism, Lipid Metabolism, Male, Organ Size, Reproduction, Seasons, Species Specificity, Adrenal Glands anatomy & histology, Birds anatomy & histology
- Abstract
Adrenal glands of eight Indian species of birds, namely Columba livia, Passer domesticus, Corvus splendens, Acridotheres tristis, Acridotheres ginginianus, Milvus migrans, Francolinus pondicerianus and Bubulcus ibis were examined during the sexually active and inactive phases of their annual reproductive cycles. Excepting A ginginianus and M. migrans, among members of either sex of the remaining six species the weight of the adrenal gland increases during the period of sexual activity. Histologically, the interrenal tissue of these birds could be divided into a peripheral subcapsular zone and a central zone. The cytochemical content of these two zones varies between sexual activity and inactivity. In sexually active birds of both sexes, interrenal cells of the central zone exhibit an increased concentration of alkaline phosphatase, glycogen, acid mucopolysaccharides and gross lipids, while in the subcapsular interrenal cells there is a prominent increase of ascorbic acid content. Cytochemical contents of chromaffin cells remain unchanged except acid phosphatase, which increases during the sexually active phase.
- Published
- 1976
- Full Text
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13. Effect of cannabis & opium on the testis of the pigeon Columba livia Gmelin.
- Author
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Vyas DK and Singh R
- Subjects
- Animals, Male, Cannabis pharmacology, Columbidae, Opium pharmacology, Testis drug effects
- Published
- 1976
14. Effect of external gamma irradiation on the testes of the house sparrow, Passer domesticus (Linn.).
- Author
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Vyas DK and Jacob D
- Subjects
- Animals, Cell Count, Gamma Rays, Male, Testis cytology, Birds, Testis radiation effects
- Published
- 1977
15. Lipofuscin pigment in the testes of some Indian birds.
- Author
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Vyas DK
- Subjects
- Animals, Male, Birds, Pigments, Biological analysis, Testis analysis
- Published
- 1965
- Full Text
- View/download PDF
16. Myoclonus epilepsy associated with basilar impression.
- Author
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Yajnik VH, Hinduja AK, Vyas DK, and Morjaria MM
- Subjects
- Adolescent, Humans, Male, Myoclonus complications, Platybasia genetics, Epilepsy complications, Platybasia complications
- Published
- 1972
17. Effect of oestrogen, progesterone and prolactin on the female reproductive tract of birds.
- Author
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Vyas DK and Ramaswami LS
- Subjects
- Animals, Birds, Drug Synergism, Female, Estradiol pharmacology, Oviducts drug effects, Progesterone pharmacology, Prolactin pharmacology
- Published
- 1967
- Full Text
- View/download PDF
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