A SURVEY OF THE EFFECT OF NETWORK PARAMETERS ON COMMUNICATION LINKS IN WIRELESS SENSOR NETWORKS

In the wireless sensor networks, the communication links between sensor nodes is important. This paper presents the analysis on the effect of parameters of network size, number of nodes and communication ranges on the number of communication links in the sensor network systems. The MATLAB tool is used for deployment of sensor nodes in various area fields

Pitch strength of normal and dysphonic voices

Two sounds with the same pitch may vary from each other based on saliency of their pitch sensation. This perceptual attribute is called “pitch strength.” The study of voice pitch strength may be important in quantifying of normal and pathological qualities. The present study investigated how pitch strength varies across normal and dysphonic voices. A set of voices (vowel /a/) selected from the Kay Elemetrics Disordered Voice Database served as the stimuli. These stimuli demonstrated a wide range of voice quality. Ten listeners judged the pitch strength of these stimuli in an anchored magnitude estimation task. On a given trial, listeners heard three different stimuli. The first stimulus represented very low pitch strength (wide-band noise), the second stimulus consisted of the target voice and the third stimulus represented very high pitch strength (pure tone). Listeners estimated pitch strength of the target voice by positioning a continuous slider labeled with values between 0 and 1, reflecting the two anchor stimuli. Results revealed that listeners can judge pitch strength reliably in dysphonic voices. Moderate to high correlations with perceptual judgments of voice quality suggest that pitch strength may contribute to voice quality judgments

Mass-Transport Models with Multiple-Chipping Processes

We study mass-transport models with multiple-chipping processes. The rates of these processes are dependent on the chip size and mass of the fragmenting site. In this context, we consider k-chip moves (where k = 1, 2, 3, ....); and combinations of 1-chip, 2-chip and 3-chip moves. The corresponding mean-field (MF) equations are solved to obtain the steady-state probability distributions, P (m) vs. m. We also undertake Monte Carlo (MC) simulations of these models. The MC results are in excellent agreement with the corresponding MF results, demonstrating that MF theory is exact for these models.Comment: 18 pages, 4 figures, To appear in European Physical Journal

DETERMINATION OF CAPECITABINE-AN ANTICANCER DRUG IN DRIED BLOOD SPOT BY LC-ESI-MS/MS

Objective: Capecitabine (Cape), the first oral prodrug which belongs to the group of fluoro pyrimidines is the most frequently prescribed anticancer drug for the treatment of metastatic breast and colorectal cancers. The article describes a selective and robust method for determination of Cape in dried blood spots (DBS) by liquid chromatography-tandem mass spectrometry (LC-MS/MS).Methods: Cape fortified DBS was punched and extracted with ethyl acetate using capecitabine-d11 as the internal standard (IS). Chromatographic separation of Cape and IS from endogenous matrix was performed on Phenomenex Gemini C18 (150 × 4.6 mm, 5mm) column under isocratic condition using acetonitrile: 2 mmol ammonium formate (pH 3.0, adjusted with 0.1 % formic acid) (80:20, v/v) as the mobile phase. Detection and quantification were carried on a triple quadrupole mass spectrometer, using electro spray ionization technique in the positive ionization mode.Results: The method was established over a concentration range of 10-10000 ng/ml. Accuracy, precision, selectivity, recovery, matrix effect and stability of the analyte were also estimated and the results were within the acceptance criteria. Further, precise results were obtained using an optimum spot volume of 10 µl with good spot homogeneity. Blood samples with hematocrit values varying from 24 % to 45 % gave acceptable results with good accuracy and precision.Conclusion: The efficiency of dried blood spot sample preparation, short analysis time and high selectivity permits estimation of Cape in a small blood volume. The validation results suggest that the method is precise, accurate, and reproducible and can be useful in therapeutic drug monitoring of Cape.Â

SENSITIVE AND RAPID ESTIMATION OF LAPATINIB, AN ANTICANCER DRUG IN SPIKED HUMAN PLASMA BY LC-MS/MS

Objective: The work presents a sensitive, selective and rapid determination of lapatinib, a potent anticancer drug in human plasma by liquid chromatography-tandem mass spectrometry.Methods: Liquid-liquid extraction of lapatinib and lapatinib-d4, added as an internal standard (IS) was carried out from 100 µl plasma sample. Chromatographic analysis was performed on ACE C18 (100 mm × 4.6 mm, 5 µm) column using 10 mmol ammonium formate buffer (pH 3.5) and acetonitrile (10:90, v/v) as the mobile phase. The precursor ion → product ion transitions for lapatinib (m/z 581.1 → 365.2) and IS (m/z 585.1 → 365.0) were monitored on a triple quadrupole mass spectrometer in the positive electrospray ionization mode. The method was validated in accordance with the US FDA guidelines.Results: A linear concentration range was established from 2.50-2500 ng/ml for lapatinib. The intra-batch and inter-batch precision were ≤ 4.81 %. The recovery of lapatinib and IS from plasma samples ranged from 88.7 to 95.8 % and 85.9 to 96.5 % respectively. The accuracy and precision (% CV) for the stability of lapatinib under different storage conditions showed a variation from 95.2 to 102.2 % and 1.19 to 4.35 % respectively at low and high QC levels. Under optimized chromatographic conditions, the retention time for lapatinib was 1.406 min with a total run time of 2.5 min for each sample.Conclusion: The validation results demonstrate that the method is simple, accurate, precise and reproducible. The developed method can be readily used for pharmacokinetics/bioequivalence studies in patients as well as healthy subjects.Â

Macrophage migration inhibitory factor downregulation: a novel mechanism of resistance to anti-angiogenic therapy.

Anti-angiogenic therapies for cancer such as VEGF neutralizing antibody bevacizumab have limited durability. While mechanisms of resistance remain undefined, it is likely that acquired resistance to anti-angiogenic therapy will involve alterations of the tumor microenvironment. We confirmed increased tumor-associated macrophages in bevacizumab-resistant glioblastoma patient specimens and two novel glioblastoma xenograft models of bevacizumab resistance. Microarray analysis suggested downregulated macrophage migration inhibitory factor (MIF) to be the most pertinent mediator of increased macrophages. Bevacizumab-resistant patient glioblastomas and both novel xenograft models of resistance had less MIF than bevacizumab-naive tumors, and harbored more M2/protumoral macrophages that specifically localized to the tumor edge. Xenografts expressing MIF-shRNA grew more rapidly with greater angiogenesis and had macrophages localizing to the tumor edge which were more prevalent and proliferative, and displayed M2 polarization, whereas bevacizumab-resistant xenografts transduced to upregulate MIF exhibited the opposite changes. Bone marrow-derived macrophage were polarized to an M2 phenotype in the presence of condition-media derived from bevacizumab-resistant xenograft-derived cells, while recombinant MIF drove M1 polarization. Media from macrophages exposed to bevacizumab-resistant tumor cell conditioned media increased glioma cell proliferation compared with media from macrophages exposed to bevacizumab-responsive tumor cell media, suggesting that macrophage polarization in bevacizumab-resistant xenografts is the source of their aggressive biology and results from a secreted factor. Two mechanisms of bevacizumab-induced MIF reduction were identified: (1) bevacizumab bound MIF and blocked MIF-induced M1 polarization of macrophages; and (2) VEGF increased glioma MIF production in a VEGFR2-dependent manner, suggesting that bevacizumab-induced VEGF depletion would downregulate MIF. Site-directed biopsies revealed enriched MIF and VEGF at the enhancing edge in bevacizumab-naive patients. This MIF enrichment was lost in bevacizumab-resistant glioblastomas, driving a tumor edge M1-to-M2 transition. Thus, bevacizumab resistance is driven by reduced MIF at the tumor edge causing proliferative expansion of M2 macrophages, which in turn promotes tumor growth

Haemato-biochemical study of captive leopards

The analysis of blood constituents and their biochemicals are one of the important tools for screening of health status. The study to obtain the normal blood profile of captive leopards was planned. The haemato-biochemicals of 14 apparently healthy leopards were studied of different zoos and captivity in Madhya Pradesh. The range and means (with one standard deviation) for the haematological values viz. total erythrocyte count, haemoglobin, pack cell volume with noticeable erythrocyte sedimentation rate with absence of reticulocytes whereas, total leukocyte count and differential leukocyte counts revealed large granulated eosinophils and predominance of neutrophils over lymphocytes were recorded. The blood biochemical constituents showed the wide range of liver and kidney function enzymes indicates the high tolerance power and adaptability of leopards to sustenance even in adverse conditions

Conductometry, spectrophotometry and mass spectrometric investigation of Mg(II) and Ca(II) complexes with an antiretroviral drug, zidovudine

Metal ions play a key role in living systems and are used to perform different physiological activities in our body. Complexation of drugs with metal ions is known to influence the bioavailability and other pharmacokinetic properties of drugs. In the present work, complexation of two essential cations, Mg2+ and Ca2+ with zidovudine (AZT), the first approved antiretroviral drug for human immunodeficiency virus (HIV) has been studied by conductometry and spectrophotometry. The plots of molar conductance versus the mole ratio of [AZT]/[M2+], Job’s method of continuous variation and mole ratio method showed the stoichiometry to be 1:1 (M2+:AZT) for both the cations. The metal ion-AZT complexes formed through the nitrogen of the azide group were further ascertained by liquid chromatography-mass spectrometric analysis. The formation constants of the complexes as evaluated by the conductance method and the Rose-Drago method were in good agreement. The values of thermodynamic parameters (∆H and ∆S) for the formation of complexes were obtained from the Van’t Hoff plots. The results revealed that both the complexation reactions were spontaneous, endothermic and entropy stabilized

On the critical exponent α of the 5D random-field Ising model

11 pages, 7 figures, final version with minor correctionsInternational audienceWe present a complementary estimation of the critical exponent $\alpha$ of the specific heat of the 5D random-field Ising model from zero-temperature numerical simulations. Our result $\alpha = 0.12(2)$ is consistent with the estimation coming from the modified hyperscaling relation and provides additional evidence in favor of the recently proposed restoration of dimensional reduction in the random-field Ising model at $D = 5$