Inhibition of bacterial respiration by a low-molecular weight lectin, scyllin, from Scylla serrata crab hemolymph

Interaction of plant and/or invertebrate lectins with mammalian cells and different microorganisms is well known. In the present study, we have demonstrated that scyllin, a low molecular weight (MW 4000) lectin from the edible crab Scylla serrata hemolymph, purified by GalNAc-Sepharon affinity column followed by Mono-Q ion exchanger in FPLC exhibits antimicrobial activity against Bacillus cereus and Escherichia coli by inhibiting endogenous respiration as well as exogenous glucose oxidation. In both the cases oxygen consumption has been measured in an oxygraph. Scyllin has produced 50% inhibition of endogenous respiration at a concentration of 110 micrograms/ml and 125 micrograms/ml in B. cereus and E. coli respectively. It also reduced the exogenous glucose oxidation by 50% at a concentration of 12 micrograms/ml and 80 micrograms/ml respectively in B. cereus and E. coli. From the above study the mechanism of bacterial growth inhibitory property of scyllin is suggested though the other studies such as inhibition of nucleic acid biosynthesis, cell wall biosynthesis etc. to evaluate its total mode of inhibitory action are not yet obtained.     

Performance of convolutionally coded optical M-PPM systemswith imperfect slot synchronization

Performance of convolutionally coded M-ary pulse position modulation (M-PPM) systems in the presence of slot synchronization errors is evaluated for the shot-noise-limited photon-counting receiver and the avalanche photodetection receiver. Both hard and soft (δ-max) demodulation results are given, and two soft-decision metrics are investigated     

A parallel algorithm for detection of linear structures in satellite images

To enhance linear structures in a gray level image, local operations with an additive score are normally used. Here a multiplicative score is used instead which gives better results than the additive one. The problem of segmenting the image of the multiplicative score is then dealt with where the threshold value can be automatically selected. The experimental results on some satellite images are reported.     

Reduced expression of lipophosphoglycan (LPG) and kinetoplastid membrane protein (KMP)-11 in Leishmania donovani promastigotes in axenic culture

The expression of surface lipophosphoglycan (LPG) and the lipophosphoglycan-associated kinetoplastid membrane protein (KMP)-11 was studied in the strain AG83 of Leishmania donovani in axenic culture. The expression of LPG and KMP-11 decreased along with parasite virulence as a function of the time of the subculture.     

Active recognition through next view planning: a survey

3-D object recognition involves using image-computable features to identify 3-D object. A single view of a 3-D object may not contain sufficient features to recognize it unambiguously. One needs to plan different views around the given object in order to recognize it. Such a task involves an active sensor—one whose parameters (external and/or internal) can be changed in a purposive manner. In this paper, we review two important applications of an active sensor. We first survey important approaches to active 3-D object recognition. Next, we review existing approaches towards another important application of an active sensor namely, that of scene analysis and interpretation.     

Influence of Precursor Solutions on the Ferroelectric Properties of Sol-Gel-Derived Lanthanum-Modified Lead Titanate (PLT) Thin Films

Precursor chemistry was found to have a dominant effect on the electrical properties of sol-gel-derived Pb_0.85La_0.15TiO₃ (PLT15) thin films prepared using different precursor sources for lanthanum, namely, lanthanum acetate dissolved in acetic acid (LAA) and lanthanum 2-methoxyethoxide in 2-methoxyethanol (LMM). The LMM-derived PLT15 films had lower dielectric constants ( K _LMM= 394, K _LAA= 548, measured at 100 kHz, applying 500 mV oscillation voltage), poorer polarization hysteresis characteristics, and higher leakage current densities ( J _LMM∼ 1.5 × 10⁻⁷ A/cm², J _LAA∼ 2 × 10⁻⁹ A/cm², measured at 10 kV/cm field). Differential thermal analysis (DTA) and thermogravimetric analysis (TGA) measurements in conjunction with Fourier transformed infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses indicate that better removal of C–O moieties are the key step to yield improved electrical properties in these films. Possibly, C–O moieties reduce the metallic oxides to their corresponding metals and the presence of the metallic constituent(s) (e.g., lead), in turn deteriorate the electrical properties. In line with these postulations it was found that, when the pyrolysis temperature is increased from 450° to 550°C, the organic contents of LMM-derived films are reduced and their electrical properties are indeed comparable to that of the LAA-derived films.     

Design of efficient stiffened shells of revolution

A method to produce efficient piecewise uniform stiffened shells of revolution is presented. The approach uses a first order differential equation formulation for the shell prebuckling and buckling analyses and the necessary conditions for an optimum design are derived by a variational approach. A variety of local yielding and buckling constraints and the general buckling constraint are included in the design process. The local constraints are treated by means of an interior penalty function and the general buckling load is treated by means of an exterior penalty function. This allows the general buckling constraint to be included in the design process only when it is violated. The self adjoint nature of the prebuckling and buckling formulations is used to reduce the computational effort. Results for four conical shells and one spherical shell are given.     

Olfactory behavior of red flour beetleTribolium castaneum (Herbst) (Coleoptera,Tenebrionidae) towards natural fatty acid esters

The olfactory responses of red flour beetles,Tribolium castaneum (Herbst), to methyl and ethyl ester of C₁₄–C₁₈ fatty acid prepared from tallow were studied. Methyl octadecanoate and ethyl octadecanoate discouraged aggregation of beetle adults. Ethyl 9.12-octadecadienoate acted as a repellent. Methyl pentadecanoate and ethyl tetradecanoate induced copulation at the level of 5 × 10² and 2 × 10³ g, respectively. The maximum response was observed at the level of 5 × 10² g of the same compounds, and these compounds appear to stimulate males only.     

Application of differential geometry to recognize and locate partially occluded objects

A new method has been proposed to recognize and locate partially occluded two-dimensional rigid objects of a given scene. For this purpose we initially generate a set of local features of the shapes using the concept of differential geometry. Finally a computer vision scheme, based upon matching local features of the objects in a scene and the models which are considered as cognitive database, is described using hypothesis generation and verification of features for the best possible recognition.