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  • Author: S. Verma x
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Redescription and phylogenetic analyses of Thaparocleidus gomtius and T. sudhakari (Monogenea: Dactylogyridae) from Wallago attu (Siluriformes: Siluridae) in India

Summary

Two species of Thaparocleidus Jain (1952a) were found harboring W. attu from the Ganga River at two localities, Meerut and Farrukhabad, Uttar Pradesh, India, during the period of 2013-2015. Morphology and morphometric study of specimens identified as Thaparocleidus gomtius (Jain, 1952a) Lim, 1996 and T. sudhakari (Gusev, 1976) Lim, 1996. Molecular analyses using the 18S rRNA gene confirmed the validity of T. gomtius and T. sudhakari and demonstrated that both the species clustered with other Thaparocleidus species from different geographical regions. We aim at reassessing the taxonomy and establishing the phylogenetic relationships among these two redescribed species with other representatives of the genus Thaparocleidus.

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Temperature and Pressure Dependent Creep Stress Analysis of Spherical Shell

Abstract

In the present paper, we have studied the temperature and pressure dependent creep stress analysis of spherical shell. The review is critical to enhance the warm resistance of spherical shells in high-temperature conditions. The effect of different parameters was studied and it was noticed that the parameter n has a significant influence on the creep stresses and strain rates. Creep stresses and strain rates are ascertained on the premise of summed up strain measures and Seth’s transition hypothesis. This investigation is completed to demonstrate the impacts of temperature on the creep stresses and strain rates in the spherical shell. The resulting quantities are computed numerically and depicted graphically. It has been watched that the spherical shell made of an incompressible material is on more secure side of configuration when contrasted with the shell made of a compressible material.

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Effect of substrate temperature on the electrical and optical properties of electron beam evaporated indium antimonide thin films

Abstract

Thin films of non-stoichiometric indium antimonide (In0.66Sb0.34) have been deposited by electron beam evaporation technique on glass substrates at different substrate temperatures, (300–473 K). The films have polycrystalline nature with zinc blende structure. The decrease in electrical resistivity with increasing temperature shows semiconducting behavior. Hall measurements indicate that the films are of n-type. Optical transmission spectra of as deposited thin films have been measured at different substrate temperatures. All the electrical parameters i.e. electron mobility (µ), carrier concentration (n), resistivity (ρ), activation energy and band gap (E g) have been found to be temperature dependent. Suitable explanations are given in the paper.

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On Propagation of Rayleigh Type Surface Wave in Five Different Theories of Thermoelasticity

Abstract

The governing equations for a homogeneous and isotropic thermoelastic medium are formulated in the context of coupled thermoelasticity, Lord and Shulman theory of generalized thermoelasticity with one relaxation time, Green and Lindsay theory of generalized thermoelasticity with two relaxation times, Green and Nagdhi theory of thermoelasticity without energy dissipation and Chandrasekharaiah and Tzou theory of thermoelasticity. These governing equations are solved to obtain general surface wave solutions. The particular solutions in a half-space are obtained with the help of appropriate radiation conditions. The two types of boundaries at athe surface of a half-space are considered namely, the stress free thermally insulated boundary and stress free isothermal boundary. The particular solutions obtained in a half-space satisfy the relevant boundary conditions at the free surface of the half-space and a frequency equation for the Rayleigh wave speed is obtained for both thermally insulated and isothermal cases. The non-dimensional Rayleigh wave speed is computed for aluminium metal to observe the effects of frequency, thermal relaxation time and different theories of thermoelasticity.

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Procamallanus spiculogubernaculus Agarwal, 1958 (Nematoda: Camallanidae) from Stinging catfish, Heteropneustes fossilis in India: morphological characterization and molecular data

Summary

The nematode, Procamallanus spiculogubernaculus Agarwal, 1958 was found from the Stinging catfish, Heteropneustes fossilis (Bloch, 1794) from Ghazipur, Delhi, India. Morphological characterization, including scanning electron microscope observation supplemented with DNA sequences is provided. Specimens recently found are characterized by the presence of an unlined buccal capsule having a small basal ring, esophagus muscular and glandular, vulva position is slightly post-equatorial, tail conical, long, and ending in three digit-like processes, phasmids present at about mid-length and cloaca located at the posterior end. In this study the species P. spiculogubernaculus is validated on the basis of molecular data after 47 years from its original description. In the scanning electron microscope examination, the topology of mouth and sensory pits in anterior portion, while the phasmids and digit like processes in posterior portion is clearly observed. Molecular data of the 18S ribosomal RNA and mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were analyzed. Molecular phylogenetic analyses supported the validity of Procamallanus spiculogubernaculus and confirmed the paraphyletic status of the members of Procamallanus, Spirocamallanus, Camallanus and Paracamallanus. Taxonomic status of members of the family Camallanidae are briefly discussed along with the results of the systematic evaluation of P. spiculogubernaculus based on molecular data.

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Molecular and ultrastructure characterization of two nematodes (Thelandros scleratus and Physalopteroides dactyluris) based on ribosomal and mitochondrial DNA sequences

Summary

The phylogenetic relationships of the nematode species Thelandros scleratus (Oxyurida: Pharyn-godonidae) and Physalopteroides dactyluris (Spirurida: Physalopteridae) were analyzed using the ribosomal 18S rRNAand the mitochondrial cytochrome C oxidase subunit genes. The nematodes were recovered from Brook's house gecko, Hemidactylus brooki (Reptilia: Gekkonidae) from Hast-inapur, Meerut (U.P.), India. The results demonstrated that T. scleratus shows 100% similarity with another sequence available from the same species and a close relationship (98-99%) with species of Parapharyngodon in both 18S rRNAand cox 1 regions. Regarding the nematode Physalopteroides. analysis showed a close phylogenetic relationship between P. dactyluris and several species of Phy-saloptera. This is the first sequence of 18S available for any species of the genus Physalopteroides

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Retrospection of the effect of hydroxyurea treatment in patients with sickle cell disease

Abstract

Sickle cell anemia (SCA) is one of the inherited hemoglobin disorders with substantial morbidity and early mortality. Hydroxyurea is the US Food and Drug Administration (FDA)-approved medication that has emerged as the primary disease-modifying therapy for SCA. Our purpose is to summarize the available evidence regarding the pharmacology, clinical efficacy, and safety of hydroxyurea therapy for the treatment of SCA. The electronic databases PubMed and Embase were searched from their starting dates to May 31, 2016. Databases were searched using the following terms: sickle cell, hydroxyurea, nitric oxide, dosing, therapeutic, and safety monitoring. Hydroxyurea therapy may cause severe myelosuppression when used in patients with SCA. SCA patients are initially treated with hydroxyurea at 10 or 20 mg/kg, and then the dose- is escalated to mild myelosuppression using a standardized regimen. Routine blood monitoring should be performed while the patient receives hydroxyurea treatment. Hydroxyurea can increase fetal hemoglobin (HbF) level and ameliorate some of the vascular symptoms in patients with SCA. Hydroxyurea therapy may help to avoid frequent hospitalizations, especially in patients with vaso-occlusive crisis. Taken together, available evidence suggests that hydroxyurea represents an inexpensive and effective treatment option that should be offered to patients with SCA.

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Hydrothermal synthesis and characterization of polycrystalline gadolinium aluminum perovskite (GdAlO3, GAP)

Abstract

Gadolinium aluminum perovskite (GdAlO3, GAP) is a promising high temperature ceramic material, known for its wide applications in phosphors. Polycrystalline gadolinium aluminum perovskites were synthesized using a precursor of co-precipitate gel of GdAlO3 by employing hydrothermal supercritical fluid technique under pressure and temperature ranging from 150 to 200 MPa and 600 to 700 °C, respectively. The resulted products of GAP were studied using the characterization techniques, such as powder X-ray diffraction analysis (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDX). The X-ray diffraction pattern matched well with the reported orthorhombic GAP pattern (JCPDS-46-0395).

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A familial case report of a 13;22 chromosomal translocation with recurrent intracytoplasmic sperm injection failure

Abstract

The importance of cytogenetic analysis in a family with reproductive failure in two siblings is highlighted, where two siblings and their mother presented with a balanced translocation between chromosomes 13;22. The clinical evaluation had shown the female to be normal and the male to be oligoasthenoteratozoospermic despite repeated semen analysis. The couple was referred to our laboratory after three consecutive intracytoplasmic sperm injection (ICSI) failures at a local assisted reproductive technique (ART) center. Peripheral blood lymphocytes, obtained for karyotyping, were studied by a standard G-banding technique. Chromosomal analysis of the members of the pedigree, including the probands, showed the presence of the same translocation, t(13;22)(q21.2;q13.3), carried by three generations of the family. The sister and the mother of the proband had multiple spontaneous abortions in the first trimester. The spouses, when examined cytogenetically, were found to be normal. We propose the involvement of a balanced t(13;22)(q21.2;q13.3) chromosomal translocation in the pathogenesis of recurrent ART or spontaneous reproductive failures. Hence, it is suggested that all cases with structural chromosomal abnormalities be counseled prior to opting for ART and undergoing pre-implantation genetic diagnosis (PGD). This would prevent recurrent financial, physical and emotional stress in couples seeking ART.

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A review on the molecular characterization of digenean parasites using molecular markers with special reference to ITS region

Abstract

The rDNA region of eukaryotes has the immense potential to resolve the evolutionary and phylogeny problems using molecular markers. As evident from the present review, ITS region data is considered for interpretation of inter and intra-specific variations of 136 studies of 33 families including 78 genus and 114 species affecting individuals worldwide. Along with ITS-1 and ITS-2 region in 29 studies 18S region, in 38 studies 28S region and in 43 studies mitochondrial genes (COI and NDI) were also analyzed. Three new genera (Allobilharzia gen. nov., Caulanus gen. nov., and Latuterus gen. nov.) and 49 new species were discovered. Only 47 studies expressed variations at intra-specific and inter-specific level in complete ITS region, ITS-1 and ITS-2 rDNA sequences due to differences in nucleotide positions. According to the findings ITS region is more reliable and precise marker for demarcation and identification of species in combination of other DNA markers. Major studies were involved around the parasites of families Fasciolidae, Schistosomatidae, Opisthorchidae, Paragonimidae and Paramphistomidae, Clinostomidae, Diplostomidae, Haploporidae, among others infecting humans, farm animals, birds, fishes, reptiles and amphibians on the clinical basis. In future, molecular and bioinformatics aspects based on genetic variations will lead to explore the untouched areas of trematodes.

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