Evaluation of Thermo Tolerance of “Nistari” an Indigenous Strain of Multivoltine Silkworm, Bombyx mori L.

S. M. Moorthy,S. K. Das,S. K. Mukhopadhyay,K. Mandal,S. Raje Urs 한국잠사학회 2007 International Journal of Industrial Entomology Vol.15 No.1

Subfertility in Males: An Important Cause of Bull Disposal in Bovines

Mukhopadhyay, C.S.,Gupta, A.K.,Yadav, B.R.,Khate, K.,Raina, V.S.,Mohanty, T.K.,Dubey, P.P. Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.4

The study had two objectives, namely, to estimate the andrological disorders leading to disposal of Karan Fries (KF), Sahiwal cattle and Murrah buffalo bulls and to study the effect of various factors (species/breeds, season of birth and period of birth) on male reproductive parameters. Records on occurrence of subfertility problems and disposal pattern of bulls maintained at the National Dairy Research Institute herd were collected for 15 years (1991 to 2005). Percentage of bulls producing freezable semen was less in the crossbred cattle (58.46%) as compared to Sahiwal (81.69%) and Murrah bulls (81.05%). Various subfertility traits like poor libido and unacceptable seminal profile were found to be the significant reasons (p<0.01) for culling of the breeding bulls. Inadequate sex drive was the main contributing factor for bull disposal in Sahiwal (22.55%) and Murrah bulls (15.12%) whereas poor semen quality and freezability were most frequently observed in KF bulls (24.29 and 7.29 percent, respectively). Least squares analyses of different male reproductive parameters showed that species/breeds had significant effect (p<0.05) on all traits except for frozen semen production periods (FSPP). Periods of birth were significantly different (p<0.05) for all traits except for semen volume. Age at first semen collection (AFSC), age at first semen freezing (AFSF) and age at disposal (AD) were highest in Murrah, while frozen semen production period (FSPP) and semen production period (SPP) were highest in KF and lowest in Sahiwal. The age at first semen donation and breeding period could be reduced by introducing the bulls to training at an early age. These results revealed a declining trend in AFSC, AFSF, FSPP, SPP and AD, thereby indicating an improvement in reproductive performance over the years. The age at first semen donation in bovines can be reduced by introducing the young male calves to training at an early age, which could increase the dosage of semen obtained from each male.

Evaluation of Thermo Tolerance of 'Nistari' an Indigenous Strain of Multivoltine Silkworm, Bombyx mori L.

Moorthy, S.M.,Das, S.K.,Mukhopadhyay, S.K.,Mandal, K.,Urs, S. Raje Korean Society of Sericultural Science 2007 International Journal of Industrial Entomology Vol.15 No.1

An indigenous multivoltine silkworm, Nistari was evaluated for their thermo tolerance by exposing the larvae to various temperature regimes for eight hours. Among different temperature exposed, this strain has significant tolerance at $32^{\circ}C$. Analysis of heat shock protein revealed the expression of 70 kDa and 64 kDa polypeptides in fat body and midgut tissues. Interestingly esterase isozyme pattern in midgut showed characteristic expression of Est-1 and Est-3 at different temperatures signifying role in heat and cold shock.

High-velocity ballistics of twisted bilayer graphene under stochastic disorder

Gupta, K.K.,Mukhopadhyay, T.,Roy, L.,Dey, S. Techno-Press 2022 Advances in nano research Vol.12 No.5

Graphene is one of the strongest, stiffest, and lightest nanoscale materials known to date, making it a potentially viable and attractive candidate for developing lightweight structural composites to prevent high-velocity ballistic impact, as commonly encountered in defense and space sectors. In-plane twist in bilayer graphene has recently revealed unprecedented electronic properties like superconductivity, which has now started attracting the attention for other multi-physical properties of such twisted structures. For example, the latest studies show that twisting can enhance the strength and stiffness of graphene by many folds, which in turn creates a strong rationale for their prospective exploitation in high-velocity impact. The present article investigates the ballistic performance of twisted bilayer graphene (tBLG) nanostructures. We have employed molecular dynamics (MD) simulations, augmented further by coupling gaussian process-based machine learning, for the nanoscale characterization of various tBLG structures with varying relative rotation angle (RRA). Spherical diamond impactors (with a diameter of 25Å) are enforced with high initial velocity (V_i) in the range of 1 km/s to 6.5 km/s to observe the ballistic performance of tBLG nanostructures. The specific penetration energy (E_p^*) of the impacted nanostructures and residual velocity (V_r) of the impactor are considered as the quantities of interest, wherein the effect of stochastic system parameters is computationally captured based on an efficient Gaussian process regression (GPR) based Monte Carlo simulation approach. A data-driven sensitivity analysis is carried out to quantify the relative importance of different critical system parameters. As an integral part of this study, we have deterministically investigated the resonant behaviour of graphene nanostructures, wherein the high-velocity impact is used as the initial actuation mechanism. The comprehensive dynamic investigation of bilayer graphene under the ballistic impact, as presented in this paper including the effect of twisting and random disorder for their prospective exploitation, would lead to the development of improved impact-resistant lightweight materials.

Characterisation of PMMA microfluidic channels and devices fabricated by hot embossing and sealed by direct bonding

A. Mathur,S.S. Roy,M. Tweedie,S. Mukhopadhyay,S.K. Mitra,J.A. McLaughlin 한국물리학회 2009 Current Applied Physics Vol.9 No.6

In this study we fabricated a silicon-based stamp with various microchannel arrays, and demonstrated successful replication of the stamp microstructure on poly methyl methacrylate (PMMA) substrates. We used maskless UV lithography for the production of the micro-structured stamp. Thermal imprint lithography was used to fabricate microfeatured fluidic platforms on PMMA substrates, as well as to bond PMMA lids on the fluidic platforms. The microfeature in the silicon-based (silicon wafer coated with SU- 8) stamp includes microchannel arrays of approximately 30 ㎛ in depth and 5 mm in width. We produced various channels without pillars, as well as with SU-8 pillars in the range of 50–100 ㎛ wide and 6 ㎛ in height. PMMA discs of 1 mm thickness were utilized as the molding substrate. We found 10 kN applied force and 100 ℃ embossing temperature were optimum for transferring the microstructure to the PMMA substrate. In this study we fabricated a silicon-based stamp with various microchannel arrays, and demonstrated successful replication of the stamp microstructure on poly methyl methacrylate (PMMA) substrates. We used maskless UV lithography for the production of the micro-structured stamp. Thermal imprint lithography was used to fabricate microfeatured fluidic platforms on PMMA substrates, as well as to bond PMMA lids on the fluidic platforms. The microfeature in the silicon-based (silicon wafer coated with SU- 8) stamp includes microchannel arrays of approximately 30 ㎛ in depth and 5 mm in width. We produced various channels without pillars, as well as with SU-8 pillars in the range of 50–100 ㎛ wide and 6 ㎛ in height. PMMA discs of 1 mm thickness were utilized as the molding substrate. We found 10 kN applied force and 100 ℃ embossing temperature were optimum for transferring the microstructure to the PMMA substrate.

Simultaneous Transitions in Cuprate Momentum-Space Topology and Electronic Symmetry Breaking

Fujita, K.,Kim, Chung Koo,Lee, Inhee,Lee, Jinho,Hamidian, M. H.,Firmo, I. A.,Mukhopadhyay, S.,Eisaki, H.,Uchida, S.,Lawler, M. J.,Kim, E.-A.,Davis, J. C. American Association for the Advancement of Scienc 2014 Science Vol.344 No.6184

<P><B>Under the Dome</B></P><P>The superconducting transition temperature <I>T<SUB>c</SUB></I> of copper oxides has a dome-shaped dependence on chemical doping. Whether there is a quantum critical point (QCP) beneath the dome, and whether it is related to the enigmatic pseudogap, has been heavily debated. Two papers address this question in two different families of Bi-based cuprates. In (Bi,Pb)<SUB>2</SUB>(Sr,La)<SUB>2</SUB>CuO<SUB>6+δ</SUB>, <B>He <I>et al.</I></B> (p. 608) found that the Fermi surface (FS) undergoes a topological change as doping is increased, which points to the existence of a QCP at a doping close to the maximum in <I>T<SUB>c</SUB></I>, seemingly uncorrelated with the pseudogap. <B>Fujita <I>et al.</I></B> (p. 612) studied a range of dopings in Bi<SUB>2</SUB>Sr<SUB>2</SUB>CaCu<SUB>2</SUB>O<SUB>8+δ</SUB> to find an FS reconstruction simultaneous with the disappearance of both rotational and translational symmetry breaking, the latter of which has been associated with the pseudogap. These findings point to a concealed QCP.</P>

Random topological defects in double-walled carbon nanotubes: On characterization and programmable defect-engineering of spatio-mechanical properties

A. Roy,K. K. Gupta,S. Dey,T. Mukhopadhyay Techno-Press 2024 Advances in nano research Vol.16 No.1

Carbon nanotubes are drawing wide attention of research communities and several industries due to their versatile capabilities covering mechanical and other multi-physical properties. However, owing to extreme operating conditions of the synthesis process of these nanostructures, they are often imposed with certain inevitable structural deformities such as single vacancy and nanopore defects. These random irregularities limit the intended functionalities of carbon nanotubes severely. In this article, we investigate the mechanical behaviour of double-wall carbon nanotubes (DWCNT) under the influence of arbitrarily distributed single vacancy and nanopore defects in the outer wall, inner wall, and both the walls. Large-scale molecular simulations reveal that the nanopore defects have more detrimental effects on the mechanical behaviour of DWCNTs, while the defects in the inner wall of DWCNTs make the nanostructures more vulnerable to withstand high longitudinal deformation. From a different perspective, to exploit the mechanics of damage for achieving defect-induced shape modulation and region-wise deformation control, we have further explored the localized longitudinal and transverse spatial effects of DWCNT by designing the defects for their regional distribution. The comprehensive numerical results of the present study would lead to the characterization of the critical mechanical properties of DWCNTs under the presence of inevitable intrinsic defects along with the aspect of defect-induced spatial modulation of shapes for prospective applications in a range of nanoelectromechanical systems and devices.

Influence of Retrogression and Re-aging on the Exfoliation Corrosion Behavior of AA 7085 Sheets

( Ajay Krishnan ),( V. S. Raja ),( A. K. Mukhopadhyay ) 한국부식방식학회(구 한국부식학회) 2016 Corrosion Science and Technology Vol.15 No.4

An attempt has been made to understand the influence of retrogression and re-aging (RRA) on the exfoliation corrosion behaviour of AA 7085 alloy in comparison with the peak aged condition (PA). Immersion tests using ASTM G34 and studies involving electrochemical impedance spectroscopy showed that the RRA treated alloy provided higher resistance to exfoliation corrosion than the PA treated alloy. The improved resistance was attributed to the enhanced Cu content and the discontinuous nature of the grain boundary precipitate, which was revealed through transmission electron microscopy.

Examination of the xanthosine response on gene expression of mammary epithelial cells using RNA-seq technology

( Shanti Choudhary ),( Wenli Li ),( Derek Bickhart ),( Ramneek Verma ),( R. S. Sethi ),( C. S. Mukhopadhyay ),( Ratan K. Choudhary ) 한국축산학회(구 한국동물자원과학회) 2018 한국축산학회지 Vol.60 No.7

Background: Xanthosine treatment has been previously reported to increase mammary stem cell population and milk production in cattle and goats. However, the underlying molecular mechanisms associated with the increase in stem cell population and milk production remain unclear. Methods: Primiparous Beetal goats were assigned to the study. Five days post-partum, one mammary gland of each goat was infused with xanthosine (TRT) twice daily (2×) for 3 days consecutively, and the other gland served as a control (CON). Milk samples from the TRT and CON glands were collected on the 10th day after the last xanthosine infusion and the total RNA was isolated from milk fat globules (MEGs). Total RNA in MFGs was mainly derived from the milk epithelial cells (MECs) as evidenced by expression of milk synthesis genes. Significant differentially expressed genes (DEGs) were subjected to Gene Ontology (GO) terms using PANTHER and gene networks were generated using STRING db. Results: Preliminary analysis indicated that each individual goat responded to xanthosine treatment differently, with this trend being correlated with specific DEGs within the same animal’s mammary gland. Several pathways are impacted by these DEGs, including cell communication, cell proliferation and anti-microbials. Conclusions: This study provides valuable insights into transcriptomic changes in milk producing epithelial cells in response to xanthosine treatment. Further characterization of DEGs identified in this study is likely to delineate the molecular mechanisms of increased milk production and stem or progenitor cell population by the xanthosine treatment.