Multispectral data compression using bidirectional interbandprediction

The introduction of high spatial and spectral resolution sensors on-board remote-sensing spacecraft has increased, by orders of magnitude, the data rates which need to be sustained on the down-link or cross-link transmission channels. Since these channels are severely limited in capacity, the need arises to perform on-board compression to reduce the volume of data which would need to be down-linked. This paper discusses the development and refinement of a low complexity lossy spectral/spatial compression method which provides high compression ratios at low levels of distortion. The developed techniques uses pixels in adjacent bands to predict the intensity of pixels in the band being compressed via a simple linear prediction model. This prediction method when combined with a low-distortion discrete cosine transform (DCT) block coding method yields performance comparable to block-adaptive Karhunen-Loeve Transform (KLT)-DCT methods without incurring the complexity penalty of the KLT. The methods' performance suffers under misregistration. A fractional-pixel interpolation enhancement to the basic technique significantly improves the performance in the case of misregistered bands     

Properties of poly(ethylene terephthalate)–poly(ethylene naphthalene 2,6‐dicarboxylate) blends with montmorillonite clay

The production and properties of blends of poly(ethylene terephthalate) (PET) and poly(ethylene naphthalene 2,6‐dicarboxylate) (PEN) with three modified clays are reported. Octadecylammonium chloride and maleic anhydride (MAH) are used to modify the surface of the montmorillonite–Na⁺ clay particles (clay–Na⁺) to produce clay–C18 and clay–MAH, respectively, before they are mixed with the PET/PEN system. The transesterification degree, hydrophobicity and the effect of the clays on the mechanical, rheological and thermal properties are analysed. The PET–PEN/clay–C18 system does not show any improvements in the mechanical properties, which is attributed to poor exfoliation. On the other hand, in the PET–PEN/clay–MAH blends, the modified clay restricts crystallization of the matrix, as evidenced in the low value of the crystallization enthalpy. The process‐induced PET–PEN transesterification reaction is affected by the clay particles. Clay–C18 induces the largest proportion of naphthalate–ethylene–terephthalate (NET) blocks, as opposed to clay–Na⁺ which renders the lowest proportion. The clay readily incorporates in the bulk polymer, but receding contact‐angle measurements reveal a small influence of the particles on the surface properties of the sample. The clay–Na⁺ blend shows a predominant solid‐like behaviour, as evidenced by the magnitude of the storage modulus in the low‐frequency range, which reflects a high entanglement density and a substantial degree of polymer–particle interactions. Copyright © 2005 Society of Chemical Industry     

Smart phones and interactive reports leave traffic in the rearview mirror

To convey the dynamic information related to traffic conditions in various parts of a city, we propose an environment utilizing the technology of smart phones to provide information anywhere and anytime. Called ";The Interactive Traffic Beat Project,"; it uses a Web-based service to deliver this information to people through their cell phones at the right time so that valuable time can be saved and the chaos on the roads can be managed.     

Use of TNSAC in phosphate adsorption studies and relationships. Isotherm relationships and utility in the field

There is a need for developing low cost, easily and abundantly available, yet efficient, adsorbents for the removal of phosphates during the tertiary treatment of wastewaters. The tamarind nut shell activated carbon (TNSAC) prepared on a laboratory scale has been used to evaluate its performance for phosphate adsorption. This paper describes the laboratory production of this adsorbent material in its various forms, and discusses the effects of the TNSAC process variables (the unrinsed and rinsed forms of the TNSAC and the impregnation ratio) on its performance in adsorbing phosphate. The material has been shown to be a good alternative adsorbent. As much as 95% phosphate removal by the unrinsed TNSAC is possible in about 30 min under the test conditions. The phosphate adsorbing capacity is about two times higher for the unrinsed TNSAC in comparison to the rinsed TNSAC. The adsorption rates, however, transit to extremely low rates towards the end when equilibrium conditions could be attained in about 2 h contact time. The phosphate removal mechanics are adsorption and precipitation/ion exchange when unrinsed TNSAC is used, and adsorption alone for the rinsed TNSAC. The maximum phosphate removal is found to take place at an impregnation ratio of 1.0 for both forms of the TNSAC.     

Ballot theorems applied to the transient analysis of nD/D/1 queues

The problem of transporting constant-bit-rate (CBR) traffic through a packet network is analyzed. In the system considered, CBR traffic is packetized and packets from several similar sources are multiplexed on a transmission link. The bit streams are recreated at the receiving end by demultiplexing the packets and then playing out the packets of each CBR stream. Traffic fluctuations may cause gaps to appear in the playout process. Their frequency can be reduced by adding a smoothing delay to each stream. The queueing system analyzed has periodic arrivals and deterministic service times. A method of analysis, based on the ballot theorems of Takacs (1967), is presented to provide steady-state delay distributions as well as a transient analysis of the system to predict the statistics of the time for a gap to develop in the CBR stream as a function of the smoothing delay     

What decides: high mortality in paediatric acute renal failure?

Forty paediatric cases of A.R.F. (Acute Renal Failure) of various aetiology were included in the study. 60% of patients were less than 4 years of age with male predominance. 80% cases reported to us very late with oligoanuria of more than 24 hours (2-7 days). Diarrhoea, vomiting and fever were other dominant symptoms. Maximum cases were severely anaemic (87.5%) with mean Hb 7.73 +/- 1.9 gm%. 40% cases were of underweight while only one case (2.5%) was of over weight, inspite of volume excess in 40% cases. All 24 cases, who were estimated for serum albumin, found to have marked hypoalbuminemia. Mortality was found to be as high as 65% inspite of effective peritoneal dialysis in all cases. High mortality seems to be due to profound anuria of many days (because of marked delay in reaching the hospital), fever and malnutrition besides other factors as aetiology.     

Preparation and properties of poly(ethylene oxide) star polymers

Poly(ethylene oxide) (PEO) star polymers were prepared by anionic polymerization of methacryloyl chloride and glyceryl trimethacrylate with sec‐butyllithium in cyclohexane. The ensuing polymers were grafted with poly(ethylene glycol) of molecular weight 400. The final product was washed with methylene chloride and analyzed with infrared spectroscopy, differential scanning calorimetry, and thermogravimetry. Star polymers of PEO were also prepared by anionic polymerization of glycidol with sec‐butyllithium in cyclohexane. The initiator was chosen so as to yield a polymer of 10,000 molecular weight. The resulting polymers were analyzed by nuclear magnetic resonance, infrared spectroscopy, and thermogravimetry. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 322–327, 2003     

Dose proportionality and comparison of single and multiple dose pharmacokinetics of fexofenadine (MDL 16455) and its enantiomers in healthy male volunteers

The pharmacokinetics and dose proportionality of fexofenadine, a new non-sedating antihistamine, and its enantiomers were characterized after single and multiple-dose administration of its hydrochloride salt. A total of 24 healthy male volunteers (31 +/- 8 years) received oral doses of 20, 60, 120 and 240 mg fexofenadine HCl in a randomized, complete four-period cross-over design. Subjects received a single oral dose on day 1, and multiple oral doses every 12 h on day 3 through the morning on day 7. Treatments were separated by a 14-day washout period. Serial blood and urine samples were collected for up to 48 h following the first and last doses of fexofenadine HCl. Fexofenadine and its R(+) and S(-) enantiomers were analysed in plasma and urine by validated HPLC methods. Fexofenadine pharmacokinetics were linear across the 20-120 mg dose range, but a small disproportionate increase in area under the plasma concentration-time curve (AUC) (< 25%) was observed following the 240 mg dose. Single-dose pharmacokinetics of fexofenadine were predictive of steady-state pharmacokinetics. Urinary elimination of fexofenadine played a minor role (10%) in the disposition of this drug. A 63:37 steady-state ratio of R(+) and S(-) fexofenadine was observed in plasma. This ratio was essentially constant across time and dose. R(+) and S(-) fexofenadine were eliminated into urine in equal rates and quantities. All doses of fexofenadine HCl were well tolerated after single and multiple-dose administration.     

Plumbagin,a Biomolecule with (Anti)Osteoclastic Properties

Plumbagin is a plant-derived naphthoquinone that is widely used in traditional Asian medicine due to its anti-inflammatory and anti-microbial properties. Additionally, plumbagin is cytotoxic for cancer cells due to its ability to trigger reactive oxygen species (ROS) formation and subsequent apoptosis. Since it was reported that plumbagin may inhibit the differentiation of bone resorbing osteoclasts in cancer-related models, we wanted to elucidate whether plumbagin interferes with cytokine-induced osteoclastogenesis. Using C57BL/6 mice, we unexpectedly found that plumbagin treatment enhanced osteoclast formation and that this effect was most pronounced when cells were pre-treated for 24 h with plumbagin before subsequent M-CSF/RANKL stimulation. Plumbagin caused a fast induction of NFATc1 signalling and mTOR-dependent activation of p70S6 kinase which resulted in the initiation of protein translation. In line with this finding, we observed an increase in RANK surface expression after Plumbagin stimulation that enhanced the responsiveness for subsequent RANKL treatment. However, in Balb/c mice and Balb/c-derived RAW264.7 macrophages, these findings could not be corroborated and osteoclastogenesis was inhibited. Our results suggest that the effects of plumbagin depend on the model system used and can therefore either trigger or inhibit osteoclast formation.