A Swarm Optimization Based Power Aware Clustering Strategy for WSNs

The technique of division of a wireless sensor network (WSN) into clusters has proved to most suitable for the reliable data communication inside the network. This approach also improves the throughput of the system along with other attributes such as rate of delivering data packet to the base station (BS) and overall energy dissipation of the sensor nodes in the network. This in turn results in the increased network lifetime. As the sensor nodes are operated by battery or some other source, this introduces a constraint in energy resource. Therefore, there is a strong need to develop a novel approach to overcome this constraint, since this phenomenon leads to the degradation of the network. The swarm intelligence approach is able to cope with all such pitfalls of WSNs. In this paper, we have presented a cluster-head (CH) selection technique which is based on swarm optimization with the main aim to increase the overall network lifetime. The proposed approach gives higher effects with regards to power utilization of nodes, data packets received at BS and stability period, and for this reason serves to be a higher performer as compared to Stable Election Protocol (SEP) and Enhance Threshold Sensitive Stable Election Protocol(ETSSEP). MATLAB simulation outcomes exhibit that the proposed clustering strategy outperforms the SEP and ETSSEP with regards to the above noted attributes

P-body components LSM1, GW182, DDX3, DDX6 and XRN1 are recruited to WNV replication sites and positively regulate viral replication

AbstractIn mammalian cells, proteins involved in mRNA silencing and degradation localize to discrete cytoplasmic foci called processing or P-bodies. Here we show that microscopically visible P-bodies are greatly diminished following West Nile viral infection, but the component proteins are not depleted. On the other hand, many P-body components including LSM1, GW182, DDX3, DDX6 and XRN1, but not others like DCP1a and EDC4 are recruited to the viral replication sites, as evidenced by their colocalization at perinuclear region with viral NS3. Kinetic studies suggest that the component proteins are first released from P-bodies in response to WNV infection within 12h post-infection, followed by recruitment to the viral replication sites by 24–36 h post-infection. Silencing of the recruited proteins individually with siRNA interfered with viral replication to varying extents suggesting that the recruited proteins are required for efficient viral replication. Thus, the P-body proteins might provide novel drug targets for inhibiting viral infection

Low-generation asymmetric dendrimers exhibit minimal toxicity and effectively complex DNA

Conventional dendrimers are spherical symmetrically branched polymers ending with active surface functional groups. Polyamidoamine (PAMAM) dendrimers have been widely studied as gene delivery vectors and have proven effective at delivering DNA to cells in vitro. However, higher-generation (G4-G8) PAMAM dendrimers exhibit toxicity due to their high cationic charge density and this has limited their application in vitro and in vivo. Another limitation arises when attempts are made to functionalize spherical dendrimers as targeting moieties cannot be site-specifically attached. Therefore, we propose that lower-generation asymmetric dendrimers, which are likely devoid of toxicity and to which site-specific attachment of targeting ligands can be achieved, would be a viable alternative to currently available dendrimers. We synthesized and characterized a series of peptide-based asymmetric dendrimers and compared their toxicity profile and ability to condense DNA to spherical PAMAM G1 dendrimers. We show that asymmetric dendrimers are minimally toxic and condense DNA into stable toroids which have been reported necessary for efficient cell transfection. This paves the way for these systems to be conjugated with targeting ligands for gene delivery in vitro and in vivo. Copyright (C) 2011 European Peptide Society and John Wiley & Sons, Ltd

Particle size- and number-dependent delivery to cells by layered double hydroxide nanoparticles

It is well known that delivery efficiency to cells is highly dependent on particle size and the administered dose. However, there is a marked discrepancy in many reports, mainly due to the inconsistency in assessment of various parameters. In this particular research, we designed experiments using layered double hydroxide nanoparticles (LDH NPs) to specifically elucidate the effect of particle size, dose and dye loading manner on cellular uptake. Using the number of LDH NPs taken up by HCT-116 cells as the indicator of delivery efficiency, we found that (1) the size of sheet-like LDH in the range of 40–100 nm did not significantly affect their cellular uptake; (2) cellular uptake of 40 and 100 nm LDH NPs was increased proportionally to the number concentration below a critical value, but remained relatively constant beyond the critical value; and (3) the effect of the dye loading manner is mainly dependent on the loading capacity or yield. In particular, the loading capacity is determined by the NP specific surface area. This research may be extended to a larger size range to examine the size effect, but suggests that it is necessary to set up a protocol to evaluate the effects of NP’s physicochemical properties on the cellular delivery efficiency

A new dawn for the use of traditional Chinese medicine in cancer therapy

Although traditional Chinese medicine has benefitted one fifth of the world's population in treating a plethora of diseases, its acceptance as a real therapeutic option by the West is only now emerging. In light of a new wave of recognition being given to traditional Chinese medicine by health professionals and regulatory bodies in the West, an understanding of their molecular basis and highlighting potential future applications of a proven group of traditional Chinese medicine in the treatment of a variety of cancers is crucial – this is where their calling holds much hope and promise in both animal and human trials. Furthermore, the rationale for combining conventional agents and modern biotechnological approaches to the delivery of traditional Chinese medicine is an avenue set to revolutionize the future practice of cancer medicine – and this may well bring on a new dawn of therapeutic strategies where East truly meets West

Histopathological Changes in Kidney of Channa Punctatus (Bloch) Under Stress of Folidol

The concentration of pesticides is increasing day by day in the aquatic ecosystem. These concentrations are highest to limits; there is bioconcentration and bioaccumulation of these pesticides in the tissues and organ of fish which has a harmful effect on the human being when consumed by them. The effects of Folidol at 20 ppm sublethal doses were investigated on histopathology of kidney in full grown specimen of Channa punctatus (Bloch). Significant alterations were observed in kidney sections of treated fishes as compared to control group. These changes may be due to damage caused to the hepatic tissue

Comparative Response of Tomato Plants to Nitrogen Rates from Urea and Ammonium Nitrate on Three Soil Types

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Topology based packet marking for IP traceback

IP source address spoofing exploits a fundamental weakness in the Internet Protocol. It is exploited in many types of network-based attacks such as session hijacking and Denial of Service (DoS). Ingress and egress filtering is aimed at preventing IP spoofing. Techniques such as History based filtering are being used during DoS attacks to filter out attack packets. Packet marking techniques are being used to trace IP packets to a point that is close as possible to their actual source. Present IP spoofing&nbsp; countermeasures are hindered by compatibility issues between IPv4 and IPv6, implementation issues and their effectiveness under different types of attacks. We propose a topology based packet marking method that builds on the flexibility of packet marking as an IP trace back method while overcoming most of the shortcomings of present packet marking techniques.<br /

Cell Membrane Penetration without Pore Formation : Chameleonic Properties of Dendrimers in Response to Hydrophobic and Hydrophilic Environments

The mechanism by which cell-penetrating peptides and antimicrobial peptides cross plasma membranes is unknown, as is how cell-penetrating peptides facilitate drug delivery, mediating the transport of small molecules. Once nondisruptive and nonendocytotic pathways are excluded, pore formation is one of the proposed mechanisms, including toroidal, barrel-stave, or carpet models. Spontaneous pores are observed in coarse-grained simulations and less often in molecular dynamics simulations. While pores are widely assumed and inferred, there is no unambiguous experimental evidence of the existence of pores. Some recent experimental studies contradict the mechanistic picture of pore formation, however, highlighting the possibility of a direct translocation pathway that is both nondisruptive and nonendocytotic. In this work, a model is proposed a model for peptide (linear and dendritic) translocation which does not require the presence of pores and which potentially accords with such experiments. It is suggested that a charged peptide, as it experiences an increasingly hydrophobic environment within the membrane surface, can utilize a proton chain transfer mechanism to shed its protons to counter ions or potentially phospholipid head groups in the membrane skin region, thereby becoming compatible with the hydrophobic interior of the membrane. This increases the likelihood to move into the highly hydrophobic core of the membrane and ultimately reach the opposite leaflet to re-acquire protons again, suggesting a potential "chameleon" mechanism for non-disruptive and non-endocytotic membrane translocation. The molecular dynamics simulations reveal stability of peptide bridges joining two membrane leaflets and demonstrate that this can facilitate cross-membrane transport of small drug molecules.Peer reviewe

Microarray based comparative genome-wide expression profiling of major subtypes of leukemia

The uncontrolled proliferation of hematopoietic cells with no capacity to differentiate into mature blood cells leads to leukemia. Though considerable amount of work has been done in understanding the molecular basis and gene expression profiles of hematologic malignancies viz., chronic lymphocytic leukemia (CLL), chronic myelogenous leukemia (CML), acute lymphocytic leukemia (ALL) and acute myelogenous leukemia (AML), the role of various underlying genes and mechanisms predisposing the disease are poorly understood. To develop the early diagnosis, preventive and therapeutic strategies, identification of population specific novel mutations and candidate genes are required. Micro array based gene expression profiling was performed for total of 18 samples (4 from each subtype of leukemia that is, CLL, CML, ALL, AML and 2 controls) from Indian population using single color hybridization. The expression of all genes presented in terms of fold variation was subjected to F-test. The microarray data of genes showing differential regulation with respect to the control samples have been obtained from total 50, 238 probes covering 14,992 genes on Agilent’s Human 8X60K Array. The experiment was conducted with expectation to have similar patterns of result in terms of gene expression but it demonstrates statistically significant relationship only among CML and ALL which are of myeloid and lymphoid origin, respectively, in contrast to other combinations. Gene expression profiles of four subtypes of leukemia were compared to each other to ascertain the overall association and significance of genes for occurrence of different types of leukemiawhich would guide in the development of common probable biomarkers for leukemias followed by effective diagnosis, prognosis and treatment. Based on their geomean fold values, the highly upregulated genes found in this study are listed.Keywords: Leukemia, microarray, gene expression profiling, fold variation, lymphoid, myeloid, geomean foldAfrican Journal of Biotechnology, Vol. 13(10), pp. 1174-1181, 5 March, 201