MENCA experiment aboard India’s Mars Orbiter Mission

The Mars Exospheric Neutral Composition Analyser (MENCA) aboard the Indian Mars Orbiter Mission (MOM) is a quadrupole mass spectrometer-based experiment. Making use of the highly elliptical and low inclination (~150°) orbit of MOM, MENCA will conduct in situ measurements of the composition and radial distribution of the Martian neutral exosphere in the 1–300 amu mass range in the equatorial and low latitudes of Mars. The functionality of MENCA has been tested during the Earth-bound and heliocentric phases of MOM before its operation in the Martian orbit. This article describes the scientific objectives, instrument details, design and development, test and evaluation, and calibration of the MENCA instrument

Crowdsourced identification of multi-target kinase inhibitors for RET- and TAU- based disease: the Multi-Targeting Drug DREAM Challenge

A continuing challenge in modern medicine is the identification of safer and more efficacious drugs. Precision therapeutics, which have one molecular target, have been long promised to be safer and more effective than traditional therapies. This approach has proven to be challenging for multiple reasons including lack of efficacy, rapidly acquired drug resistance, and narrow patient eligibility criteria. An alternative approach is the development of drugs that address the overall disease network by targeting multiple biological targets (‘polypharmacology’). Rational development of these molecules will require improved methods for predicting single chemical structures that target multiple drug targets. To address this need, we developed the Multi-Targeting Drug DREAM Challenge, in which we challenged participants to predict single chemical entities that target pro-targets but avoid anti-targets for two unrelated diseases: RET-based tumors and a common form of inherited Tauopathy. Here, we report the results of this DREAM Challenge and the development of two neural network-based machine learning approaches that were applied to the challenge of rational polypharmacology. Together, these platforms provide a potentially useful first step towards developing lead therapeutic compounds that address disease complexity through rational polypharmacology

Restraining network response to targeted cancer therapies improves efficacy and reduces cellular resistance

A key tool of cancer therapy has been targeted inhibition of oncogene-addicted pathways. However, efficacy has been limited by progressive emergence of resistance as transformed cells adapt. Here, we use Drosophila to dissect response to targeted therapies. Treatment with a range of kinase inhibitors led to hyperactivation of overall cellular networks, resulting in emergent resistance and expression of stem cell markers, including Sox2. Genetic and drug screens revealed that inhibitors of histone deacetylases, proteasome, and Hsp90 family of proteins restrained this network hyperactivation. These “network brake” cocktails, used as adjuncts, prevented emergent resistance and promoted cell death at subtherapeutic doses. Our results highlight a general response of cells, transformed and normal, to targeted therapies that leads to resistance and toxicity. Pairing targeted therapeutics with subtherapeutic doses of broad-acting “network brake” drugs may provide a means of extending therapeutic utility while reducing whole body toxicity. Significance: These findings with a strong therapeutic potential provide an innovative approach of identifying effective combination treatments for cancer. Cancer Res; 78(15); 4344–59. ©2018 AACR

Spread Spectrum Image Watermarking for Secured Multimedia

Abstract—Digital watermarking is a way to provide the facility of secure multimedia data communication besides its copyright protection approach. The Spread Spectrum modulation principle is widely used in digital watermarking to satisfy the robustness of multimedia signals against various signal-processing operations. Several SS watermarking algorithms have been proposed for multimedia signals but very few works have discussed on the issues responsible for secure data communication and its robustness improvement. The current paper has critically analyzed few such factors namely properties of spreading codes, proper signal decomposition suitable for data embedding, security provided by the key, successive bit cancellation method applied at decoder which have greater impact on the detection reliability, secure communication of significant signal under camouflage of insignificant signals etc. Based on the analysis, robust SS watermarking scheme for secure data communication is proposed in wavelet domain and improvement in secure communication and robustness performance is reported through experimental results. The reported result also shows improvement in visual and statistical invisibility of the hidden data. Keywords—Spread spectrum modulation, spreading code, signal decomposition, security, successive bit cancellation D I

Robustness Improvement in Spread Spectrum Watermarking Using M-ary Modulation

Spread spectrum (SS) modulation principle is widely used in digital watermarking to satisfy the robustness criterion against various common signal processing operations as well as deliberate external attacks. Several SS image watermarking schemes have been developed in various transform domains such as DCT (discrete cosine transform), DHT (discrete Hadamard transform), Fourier-Mellin, and Wavelet etc using binary signaling. The use of wide spectrum of the cover data in message hiding process puts a limit on data rate subject to a given embedding distortion. The paper investigates the scope of using M-ary modulation principle for performance improvement over binary signaling scheme. The current work also suggests data embedding in selected sub bands using DWT (discrete wavelet transform) and MbDWT (M-band wavelet transform) decomposition. Performance improvement of M - ary signaling principle in SS scheme and superiority of wavelet domain embedding over spatial domain approach are also supported by numerical results against JPEG and JPEG 2000 compression operations