Indolicidin – Antibacterial activity against bacterial pathogens isolated from ocular infections

Indolicidin is a novel/ promising antimicrobial peptide (a 13 amino acid cationic antimicrobial residue present in the form of cytoplasmic granules of bovine neutrophils) and observed with a broad spectrum of antimicrobial activity against bacteria, fungi, protozoa & even viruses. In the present study, Escherichia coli was transformed with pET 21a+ plasmid carrying indolicidin gene and was expressed. The crude extracts of indolicidin samples induced with varying IPTG concentrations (5mM and 20 mM/ ml of the medium) in Min A medium were checked for antibacterial activities against clinically important ocular bacterial pathogens such as E. coli, Klebsiella sp,, Pseudomonas sp., Acenitobacter sp., Staphylococcus aureus, coagulase negative Staphylococcus aureus, Streptococcus viridans, S. pneumoniae and S. pyogens and its activity was evaluated.&nbsp

Covalent Complex of DNA and Bacterial Topoisomerase: Implications in Antibacterial Drug Development

A topoisomerase-DNA transient covalent complex can be a druggable target for novel topoisomerase poison inhibitors that represent a new class of antibacterial or anticancer drugs. Herein, we have investigated molecular features of the functionally important Escherichia coli topoisomerase I (EctopoI)-DNA covalent complex (EctopoIcc) for molecular simulations, which is very useful in the development of new antibacterial drugs. To demonstrate the usefulness of our approach, we used a model small molecule (SM), NSC76027, obtained from virtual screening. We examined the direct binding of NSC76027 to EctopoI as well as inhibition of EctopoI relaxation activity of this SM via experimental techniques. We then performed molecular dynamics (MD) simulations to investigate the dynamics and stability of EctopoIcc and EctopoI-NSC76027-DNA ternary complex. Our simulation results show that NSC76027 forms a stable ternary complex with EctopoIcc. EctopoI investigated here also serves as a model system for investigating a complex of topoisomerase and DNA in which DNA is covalently attached to the protein

IMECE2002-33999 CO-FIRING FEEDLOT AND LITTER BIOMASS:COAL BLENDS IN A LABRAT ORY SCALE BOILER BURNER

ABSTRACT The co-firing of animal biomass fuels with coal has the potential to solve both biomass disposal problems, and reduce net CO 2 emissions. The high flame temperatures produced by coal will allow the low heating value, high ash biomass to be completely burnt. Unfortunately, the animal biomass fuels are high in nitrogen and sulfur, which could lead to greater air pollution levels in the form of NO and SO 2 . To determine the effect of switching to 90:10 Coal:biomass blend on combustion efficiency and emissions, the blends were fired in a 30 kW (100,000 BTU/hr) laboratory scale boiler burner. The results are presented along with the their relation to the fuel properties

Tropical cyclone projections: changing climate threats for Pacific island defense installations

Potential changing climate threats in the tropical and subtropical North Pacific Ocean were assessed, using coupled ocean-atmosphere and atmosphere-only general circulation models, to explore their response to projected increasing greenhouse gas emissions. Tropical cyclone occurrence, described by frequency and intensity, near islands housing major U.S. defense installations was the primary focus. Four island regions-Guam and Kwajalein Atoll in the tropical northwestern Pacific, Okinawa in the subtropical northwestern Pacific, and Oahu in the tropical north-central Pacific-were considered, as they provide unique climate and geographical characteristics that either enhance or reduce the tropical cyclone risk. Guam experiences the most frequent and severe tropical cyclones, which often originate as weak systems close to the equator near Kwajalein and sometimes track far enough north to affect Okinawa, whereas intense storms are the least frequent around Oahu. From assessments of models that simulate well the tropical Pacific climate, it was determined that, with a projected warming climate, the number of tropical cyclones is likely to decrease for Guam and Kwajalein but remain about the same near Okinawa and Oahu; however, the maximum intensity of the strongest storms may increase in most regions. The likelihood of fewer but stronger storms will necessitate new localized assessments of the risk and vulnerabilities to tropical cyclones in the North Pacific

The last integrable case of kozlov-Treshchev Birkhoff integrable potentials

We establish the integrability of the last open case in the Kozlov-Treshchev classification of Birkhoff integrable Hamiltonian systems. The technique used is a modification of the so called quadratic Lax pair for $D_n$ Toda lattice combined with a method used by M. Ranada in proving the integrability of the Sklyanin case.Comment: 13 page

Localization of Mycobacterium tuberculosis topoisomerase I C-terminal sequence motif required for inhibition by endogenous toxin MazF4

Only about half the multi-drug resistant tuberculosis (MDR-TB) cases are successfully cured. Thus, there is an urgent need of new TB treatment against a novel target. Mycobacterium tuberculosis (Mtb) topoisomerase I (TopA) is the only type IA topoisomerase in this organism and has been validated as an essential target for TB drug discovery. Toxin-antitoxin (TA) systems participate as gene regulators within bacteria. The TA systems contribute to the long-term dormancy of Mtb within the host-cell environment. Mtb’s toxin MazF4 (Rv1495) that is part of the MazEF4 TA system has been shown to have dual activities as endoribonuclease and topoisomerase I inhibitor. We have developed a complementary assay using an Escherichia coli strain with temperature-sensitive topA mutation to provide new insights into the MazF4 action. The assay showed that E. coli is not sensitive to the endoribonuclease activity of Mtb MazF4 but became vulnerable to MazF4 growth inhibition when recombinant Mtb TopA relaxation activity is required for growth. Results from the complementation by Mtb TopA mutants with C-terminal deletions showed that the lysine-rich C-terminal tail is required for interaction with MazF4. Site-directed mutagenesis is utilized to identify two lysine residues within a conserved motif in this C-terminal tail that are critical for MazF4 inhibition. We performed molecular dynamics simulations to predict the Mtb TopA-MazF4 complex. Our simulation results show that the complex is stabilized by hydrogen bonds and electrostatic interactions established by residues in the TopA C-terminal tail including the two conserved lysines. The mechanism of Mtb TopA inhibition by MazF4 could be useful for the discovery of novel inhibitors against a new antibacterial target in pathogenic mycobacteria for treatment of both TB and diseases caused by the non-tuberculosis mycobacteria (NTM)

Author Correction:Charge disproportionate molecular redox for discrete memristive and memcapacitive switching (Nature Nanotechnology, (2020), 15, 5, (380-389), 10.1038/s41565-020-0653-1)

Correction to: Nature Nanotechnology. Published online 23 March 2020. In the version of this article initially published, there were presentation errors in the range of y-axis values displayed in Extended Data Figure 4a,b, and Extended Data Figure 5b. The errors have been corrected in the HTML and PDF versions of the article.</p

Visual Servoing of Humanoid Dual-Arm Robot with Neural Learning Enhanced Skill Transferring Control

This paper presents a novel combination of visual servoing (VS) control and neural network (NN) learning on humanoid dual-arm robot. A VS control system is built by using stereo vision to obtain the 3D point cloud of a target object. A least square-based method is proposed to reduce the stochastic error in workspace calibration. An NN controller is designed to compensate for the effect of uncertainties in payload and other parameters (both internal and external) during the tracking control. In contrast to the conventional NN controller, a deterministic learning technique is utilized in this work, to enable the learned neural knowledge to be reused before current dynamics changes. A skill transfer mechanism is also developed to apply the neural learned knowledge from one arm to the other, to increase the neural learning efficiency. Tracked trajectory of object is used to provide target position to the coordinated dual arms of a Baxter robot in the experimental study. Robotic implementations has demonstrated the efficiency of the developed VS control system and has verified the effectiveness of the proposed NN controller with knowledge-reuse and skill transfer features

Pesticides Occurrence in Water Sources and Decontamination Techniques

Pesticides are essential in crop protection as they keep the plants safe from insects, weeds, fungi, and other pests in order to increase crop production and feed billions of people throughout the world. There are more than 500 pesticide molecules currently in use all around the world. Their non-judicious use has noticeably contaminated the environment and caused negative effects on humans and other life forms. The rainfall or irrigation water takes away the pesticide residues to nearby surface water bodies through runoff or to the groundwater sources through leaching. The occurrence of pesticides in water resources could have multiple consequences. Exposure of pesticides through contaminated water becomes the cause of acute and chronic health problems in people of all ages. Pesticide residues have the potential to disrupt the ecosystem equilibrium in water bodies. Contaminated irrigation water can contaminate other crops as well as their environment. This chapter will discuss the major exposure routes of pesticides in water bodies mainly from agricultural sectors and their effect on the ecosystem. The chapter will also discuss decontamination techniques to eliminate pesticide contaminants from water bodies

Breathing Current Domains in Globally Coupled Electrochemical Systems: A Comparison with a Semiconductor Model

Spatio-temporal bifurcations and complex dynamics in globally coupled intrinsically bistable electrochemical systems with an S-shaped current-voltage characteristic under galvanostatic control are studied theoretically on a one-dimensional domain. The results are compared with the dynamics and the bifurcation scenarios occurring in a closely related model which describes pattern formation in semiconductors. Under galvanostatic control both systems are unstable with respect to the formation of stationary large amplitude current domains. The current domains as well as the homogeneous steady state exhibit oscillatory instabilities for slow dynamics of the potential drop across the double layer, or across the semiconductor device, respectively. The interplay of the different instabilities leads to complex spatio-temporal behavior. We find breathing current domains and chaotic spatio-temporal dynamics in the electrochemical system. Comparing these findings with the results obtained earlier for the semiconductor system, we outline bifurcation scenarios leading to complex dynamics in globally coupled bistable systems with subcritical spatial bifurcations.Comment: 13 pages, 11 figures, 70 references, RevTex4 accepted by PRE http://pre.aps.or