The effectiveness of inexpensive agro-industrial wastes such as sugarcane molasses, paper mill effluent, and dairy effluent for the production of polyhydroxyalkanoates (PHAs) using Bacillus subtilis RS1 was assessed in this study. Laboratory-scale fermentations were carried out with both raw and pre-treated agro-industrial effluents, and maximum PHAs yield was observed in pre-treated effluents. Experimental variables such as pH, inoculum dose, and incubation time were further optimized to maximize PHAs yield, and the optimal conditions were identified as incubation time 48 h; pH 7; and inoculum dose 10% v/v. PHAs yield in pre-treated sugarcane molasses increased to 70.5% under optimal conditions. Fourier transform infrared spectroscopy and gas chromatography-mass spectrometric analysis revealed that the extracted polymer was composed of penta-and hexadecanoic acid methyl esters, a copolymer of PHAs. Results indicated that the pre-treated sugarcane molasses could be used as an inexpensive substrate for the production of PHAs.

Segmentation of human brain from MRI scan slices without human intervention is the objective of this paper. A simple and accurate method is developed for extracting the brain tissues from the T1 weighted MR Images. The DICOM images are used for segmenting. A hybrid of threshold and seed growth techniques are used in classifying the brain tissues into White matter (WM), Gray matter (GM) and Cerebrospinal Fluid (CSF).

We report the discovery of kHz quasi-periodic oscillations (QPOs) in three Rossi X-ray Timing Explorer observations of the low mass X-ray binary (LMXB) XTE J1701-407. In one of the observations we detect a kHz QPO with a characteristic frequency of 1153 ± 5 Hz, while in the other two observations we detect twin QPOs at characteristic frequencies of 740 ± 5 Hz, 1112 ± 17 Hz and 740 ± 11 Hz, 1098 ± 5 Hz. All detections happen when XTE J1701-407 was in its high intensity soft state, and their single trial significance are in the 3.1-7.5 σ range. The frequency difference in the centroid frequencies of the twin kHz QPOs (385 ± 13 Hz) is one of the largest seen till date. The 3-30 keV fractional rms amplitude of the upper kHz QPO varies between ∼ 18% and ∼ 30%. XTE J1701-407, with a persistent luminosity close to 1% of the Eddington limit, is among the small group of low luminosity kHz QPO sources and has the highest rms for the upper kHz QPO detected in any source. The X-ray spectral and variability characteristics of this source indicate its atoll source nature.

Botnets are emerging as the most serious cyber threat among different forms of malware. Today botnets have been facilitating to launch many cybercriminal activities like DDoS, click fraud, phishing attacks etc. The main purpose of botnet is to perform massive financial threat. Many large organizations, banks and social networks became the target of bot masters. Botnets can also be leased to motivate the cybercriminal activities. Recently several researches and many efforts have been carried out to detect bot, C&C channels and bot masters. Ultimately bot maters also strengthen their activities through sophisticated techniques. Many botnet detection techniques are based on payload analysis. Most of these techniques are inefficient for encrypted C&C channels. In this paper we explore different categories of botnet and propose a detection methodology to classify bot host from the normal host by analyzing traffic flow characteristics based on time intervals instead of payload inspection. Due to that it is possible to detect botnet activity even encrypted C&C channels are used.

Nearly 1.32 × 10 6 s of non-zero count rate data were obtained from five years of Rossi X-ray Timing Explorer (RXTE) observations of the atoll source 4U 1636−53. The data were divided into 10 309 segments of 128 s each. The histogram of the number of segments as a function of count rate shows that the system can naturally be classified into four flux states. For each segment, an automated search for kilohertz quasi-periodic oscillations (QPOs) was undertaken and the histograms of the maximum Leahy normalized power P max for the four flux states were created. These were fitted by probability distribution functions under the assumption that the intrinsic amplitude of the QPO has a normal distribution. The best-fitting distribution functions showed that the fraction f of the time the system exhibits a kHz QPO decreases from near unity for the lowest flux state (≈1400 count s −1 ) to zero for the highest (>2550 count s −1 ), whereas the average amplitude remains nearly constant. Based on the best-fitting probability distribution functions, a threshold P thre was defined, such that 95 per cent of the segments with P max > P thre correspond to a real QPO signal. For segments selected by this criterion, the frequency versus count rate plot reproduced the earlier known 'parallel track' variation with the tracks coinciding roughly with the flux states. It is shown that the gaps between the tracks are not caused by uneven sampling, but rather the QPO phenomenon is absent or weak when the system flux level is intermediate between two flux states.