Multi-wavelength Temporal Variability of the Blazar 3C 454.3 during 2014 Activity Phase

We present a multi-wavelength temporal analysis of the blazar 3C 454.3 during the high $\gamma$-ray active period from May-December, 2014. Except for X-rays, the period is well sampled at near-infrared (NIR)-optical by the \emph{SMARTS} facility and the source is detected continuously on daily timescale in the \emph{Fermi}-LAT $\gamma$-ray band. The source exhibits diverse levels of variability with many flaring/active states in the continuously sampled $\gamma$-ray light curve which are also reflected in the NIR-optical light curves and the sparsely sampled X-ray light curve by the \emph{Swift}-XRT. Multi-band correlation analysis of this continuous segment during different activity periods shows a change of state from no lags between IR and $\gamma$-ray, optical and $\gamma$-ray, and IR and optical to a state where $\gamma$-ray lags the IR/optical by $\sim$3 days. The results are consistent with the previous studies of the same during various $\gamma$-ray flaring and active episodes of the source. This consistency, in turn, suggests an extended localized emission region with almost similar conditions during various $\gamma$-ray activity states. On the other hand, the delay of $\gamma$-ray with respect to IR/optical and a trend similar to IR/optical in X-rays along with strong broadband correlations favor magnetic field related origin with X-ray and $\gamma$-ray being inverse Comptonized of IR/optical photons and external radiation field, respectively.Comment: 15 pages, 5 figures, 1 table, MNRAS accepte

Binding characteristics of sperm with recombinant human zona pellucida glycoprotein-3 coated beads

Background & objectives: An inability or decreased ability of spermatozoa to bind to the zona pellucida (ZP), an extracellular glycoproteinaceous matrix surrounding egg, is one of the plausible causes of idiopathic infertility. It will be clinically useful to distinguish this condition from other causes of infertility. An assay system, investigating binding of human sperm with ZP glycoprotein may prove useful in this regard. We attempted to develop a simple assay system to analyse the binding of capacitated human spermatozoa to human zona pellucida glycoprotein-3 (ZP3) using baculovirus-expressed recombinant human ZP3 coated beads. Methods: Recombinant baculovirus-expressed ZP3 was purified, labelled with biotin and coated on streptavidin sepharose beads. An in vitro assay system was optimized to study binding of capacitated human sperm to ZP3 coated beads. Results: A higher percentage of baculovirus-expressed recombinant human ZP3 coated beads showed significant (P<0.05) binding of capacitated human sperm as compared to beads coated with fetuin. An inhibition in the binding of sperm to ZP3 coated beads was observed in presence of cold recombinant human ZP3. Further, prior incubation of ZP3 coated beads with monoclonal antibodies (MAbs) against ZP3 but not against ZP2 resulted in the decrease in number of sperm bound to bead. Interpretation & conclusion: An in vitro assay system to study the binding of human sperm to ZP3- primary sperm receptor was established, which may be useful to determine the functional competence of spermatozoa

Creep Transition in a Thin Rotating Disc with Rigid Inclusion

Creep stresses and strain rates  have been obtained for a thin rotating disc with inclusionusing Seth’s transition theory. Results have been discussed numerically and depicted graphically.It has been observed that radial stress has maximum value at the internal surface of the rotatingdisc made of incompressible material as compared to circumferential stress and this value ofradial stress further increases with the increase in angular speed. Strain rates have maximumvalues at the internal surface for compressible material. Rotating disc is likely to fracture bycleavage close to the inclusion at the bor

Delineation of downstream signalling components during acrosome reaction mediated by heat solubilized human zona pellucida

<p>Abstract</p> <p>Background</p> <p>Human egg is enveloped by a glycoproteinaceous matrix, zona pellucida (ZP), responsible for binding of the human spermatozoa to the egg and induction of acrosomal exocytosis in the spermatozoon bound to ZP. In the present manuscript, attempts have been made to delineate the downstream signalling components employed by human ZP to induce acrosome reaction.</p> <p>Methods</p> <p>Heat-solubilized human ZP (SIZP) was used to study the induction of acrosome reaction in capacitated human spermatozoa using tetramethylrhodamine isothiocyanate conjugated <it>Pisum sativum </it>agglutinin (TRITC-PSA) in absence or presence of various pharmacological inhibitors. In addition, intracellular calcium ([Ca2+]i) levels in sperm using Fluo-3 acetoxymethyl ester as fluorescent probe were also estimated in response to SIZP.</p> <p>Results</p> <p>SIZP induces acrosomal exocytosis in capacitated human sperm in a dose dependent manner accompanied by an increase in [Ca2+]i. Human SIZP mediated induction of acrosome reaction depends on extracellular Ca2+ and involves activation of Gi protein-coupled receptor, tyrosine kinase, protein kinases A & C and phosphoinositide 3 (PI3)- kinase. In addition, T-type voltage operated calcium channels and GABA-A receptor associated chloride (Cl-) channels play an important role in SIZP mediated induction of acrosome reaction.</p> <p>Conclusions</p> <p>Results described in the present study provide a comprehensive account of the various downstream signalling components associated with human ZP mediated acrosome reaction.</p

Functional activity of human ZP3 primary sperm receptor resides toward its C-terminus

Zona pellucida glycoprotein 3 (ZP3) has been ascribed as a putative primary sperm receptor during fertilization in humans. Herein, attempts have been made to delineate the functional domain of human ZP3. ZP3 has been cloned and expressed in a baculovirus expression system as Nterminal fragments (amino acid [aa] residues 1-175 [pAc-ZP3(1-175 aa)] and 23-175 [pBg-ZP3(23-175 aa)]) and as C-terminal fragments (aa residues 214-305 [pBg-ZP3(214-305 aa)] and 214-348 [pBg-ZP3(214-348 aa)]). ZP3 encompassing both N- and C-terminal fragments corresponding to aa residues 1-370 (pAc-ZP3[1-370 aa]) has also been expressed. Lectin-binding analysis with these recombinant proteins revealed the presence of N- and O-linked glycosylation. Significant induction of acrosomal exocytosis was observed when capacitated sperm were incubated with pBg-ZP3(214-348 aa), pBg-ZP3(214-305 aa), and pAc-ZP3(1-370 aa) (P &lt; 0.05), whereas incubation with pAc-ZP3(1-175 aa) and pBg-ZP3(23-175 aa) failed to do so under similar experimental conditions. However, N- and C-terminal fragments labeled with fluorescein isothiocyanate revealed binding to the anterior head of capacitated human spermatozoa. Escherichia coli-expressed ZP3 C-terminal fragments and chemically deglycosylated pBg-ZP3(214-348 aa) failed to induce a significant (P &lt; 0.05) increase in acrosomal exocytosis, suggesting the relevance of glycosylation in imparting functional activity to ZP3 C-terminal fragments. pBg-ZP3(214-348 aa)-mediated induction of acrosomal exocytosis is regulated by Gi protein, extracellular calcium, GABA(A) [gamma aminobutyric acid (A)] receptor-mediated Cl- channel, and T-type voltage-operated calcium channels. Taken together, the results of these studies suggest that the functional activity of human ZP3 resides in its C-terminal domain

Internet of Things-Enabled Overlay Satellite-Terrestrial Networks in the Presence of Interference

In this paper, we consider an overlay satellite-terrestrial network (OSTN) where an opportunistically selected terrestrial IoT network assist primary satellite communications as well as access the spectrum for its own communications in the presence of combined interference from extra-terrestrial and terrestrial sources. Hereby, a power domain multiplexing is adopted by the IoT network by splitting its power appropriately among the satellite and IoT signals. Relying upon an amplify-and-forward (AF)-based opportunistic IoT network selection strategy that minimizes the outage probability (OP) of satellite network, we derive the closed-form lower bound OP expressions for both the satellite and IoT networks. We further derive the corresponding asymptotic OP expressions to examine the achievable diversity order of two networks. We show that the proposed OSTN with adaptive power splitting factor benefits IoT network while guaranteeing the quality of service (QoS) of satellite network. We verify the numerical results by simulations.Comment: 7 pages, 3 figures, Submitted to National Conference on Communications 202

'ZP domain' of human zona pellucida glycoprotein-1 binds to human spermatozoa and induces acrosomal exocytosis

<p>Abstract</p> <p>Background</p> <p>The human egg coat, zona pellucida (ZP), is composed of four glycoproteins designated as zona pellucida glycoprotein-1 (ZP1), -2 (ZP2), -3 (ZP3) and -4 (ZP4) respectively. The zona proteins possess the archetypal 'ZP domain', a signature domain comprised of approximately 260 amino acid (aa) residues. In the present manuscript, attempts have been made to delineate the functional significance of the 'ZP domain' module of human ZP1, corresponding to 273-551 aa fragment of human ZP1.</p> <p>Methods</p> <p>Baculovirus-expressed, nickel-nitrilotriacetic acid affinity chromatography purified 'ZP domain' of human ZP1 was employed to assess its capability to bind and subsequently induce acrosomal exocytosis in capacitated human spermatozoa using tetramethyl rhodamine isothiocyanate conjugated Pisum sativum Agglutinin in absence or presence of various pharmacological inhibitors. Binding characteristics of ZP1 'ZP domain' were assessed employing fluorescein isothiocyanate (FITC) labelled recombinant protein.</p> <p>Results</p> <p>SDS-PAGE and immunoblot characterization of the purified recombinant protein (both from cell lysate as well as culture supernatant) revealed a doublet ranging from ~35-40 kDa. FITC- labelled 'ZP domain' of ZP1 binds primarily to the acrosomal cap of the capacitated human spermatozoa. A dose dependent increase in acrosomal exocytosis was observed when capacitated sperm were incubated with recombinant 'ZP domain' of human ZP1. The acrosome reaction mediated by recombinant protein was independent of Gi protein-coupled receptor pathway, required extra cellular calcium and involved both T- and L-type voltage operated calcium channels.</p> <p>Conclusions</p> <p>Results described in the present study suggest that the 'ZP domain' module of human ZP1 has functional activity and may have a role during fertilization in humans.</p