Surface enhanced Raman optical activity as an ultra sensitive tool for ligand binding analysis

Abstract. The Surface Enhanced Resonance Raman Scattering (SERRS) and Surface Enhanced Resonance Raman Optical Activity (SERROA) spectra of myoglobin and the myoglobin-azide complex were measured on very dilute samples (100 nM protein) in order to analyze the sensitivity of SERROA spectroscopy when inducing small structural changes. While the SERRS spectra of the two compounds were virtually identical, comparison of the SERROA spectra revealed several differences, including frequency shifts and changes in signal intensity, consistent with structural change in the porphyrin prosthetic group of the protein upon azide complexation. Application of this method allows for rapid analysis of ligand binding in metalloproteins in dilute aqueous solution and could in the future, when combined with theoretical studies, increase the obtainable structural resolution of proteins beyond that of X-ray analysis

Preventing childhood malaria in Africa by protecting adults from mosquitoes with insecticide-treated nets

Malaria prevention in Africa merits particular attention as the world strives toward a better life for the poorest. Insecticide-treated nets (ITNs) represent a practical means to prevent malaria in Africa, so scaling up coverage to at least 80% of young children and pregnant women by 2010 is integral to the Millennium Development Goals (MDG). Targeting individual protection to vulnerable groups is an accepted priority, but community-level impacts of broader population coverage are largely ignored even though they may be just as important. We therefore estimated coverage thresholds for entire populations at which individual- and community-level protection are equivalent, representing rational targets for ITN coverage beyond vulnerable groups

Kualitas Produk, Harga dan Promosi Terhadap Keputusan Pembelian Sepeda Motor Honda dan Loyalitas Konsumen di PT. Supra Jaya Abadi

This research aims to test and analyze the influence of product quality, price and promotion on Honda motorbike purchasing decisions and consumer loyalty. The research method used is quantitative research with the sample used being 146 consumers. Regarding the quality of existing products, PT Supra Jaya Abadi still has problems regarding complaints about motorbike spare parts offered by the company. The prices offered are competitive with other similar dealers and also offer various promotions for consumers for cash or credit purchases and also discounts for Honda motorbike services. Dominant promotions are only given to buyers who buy motorbikes on credit, such as price cuts, reduced credit down payments, reduced installment payments, while cash purchases get promotions from free service, fewer jackets and helmets. Conclusion, product quality has a positive and significant effect on purchasing decisions, price has a positive and significant effect on purchasing decisions, promotion has a positive and significant effect on purchasing decisions, customer satisfaction positively and significantly mediates the effect of product quality on customer loyalty, satisfaction results are positive and significant customers mediate the effect of price on customer loyalty.  Keywords: Price, Product Quality, Purchasing Decisions, Promotio

Urgensi Pengaturan Financial Technology Di Indonesia

Jasa keuangan menjadi salah satu sektor yang mengalami perkembangan sedemikian jauh. Aktivitas menghimpun dan menyalurkan dana tidak hanya ―dikuasai‖ oleh perbankan saja. Lembaga keuangan lain yang merupakan lembaga keuangan non -bank juga dapat menghimpun dan menyalurkan dana. Setiap orang dapat mengajukan pinjaman dengan persyaratan yang sangat mudah melalui aplikasi berbasis daring atau biasa disebut financial technology peer to peer lending (fintech). Namun, dalam praktiknya perkembangan industri ini tidak diikuti dengan penyediaan payung hukum yang memadai atas legalitas lembaga-lembaga dimaksud. Situasi tersebut menempatkan konsumen pada posisi yang rentan dan hak-hak dasarnya justru menjadi sering terabaikan. Problematika hukum yang ada harus segera dicarikan solusinya melalui pembentukan peraturan perundang-undangan yang mengatur pelaksanaan fintech di Indonesia secara jelas

Attaining the rate-independent limit of a rate-dependent strain gradient plasticity theory

The existence of characteristic strain rates in rate-dependent material models, corresponding to rate-independent model behavior, is studied within a back stress based rate-dependent higher order strain gradient crystal plasticity model. Such characteristic rates have recently been observed for steady-state processes, and the present study aims to demonstrate that the observations in fact unearth a more widespread phenomenon. In this work, two newly proposed back stress formulations are adopted to account for the strain gradient effects in the single slip simple shear case, and characteristic rates for a selected quantity are identified through numerical analysis. Evidently, the concept of a characteristic rate, within the rate-dependent material models, may help unlock an otherwise inaccessible parameter space

Identification of a 3-Alkylpyridinium Compound from the Red Sea Sponge Amphimedon chloros with In Vitro Inhibitory Activity against the West Nile Virus NS3 Protease.

Viruses are underrepresented as targets in pharmacological screening efforts, given the difficulties of devising suitable cell-based and biochemical assays. In this study we found that a pre-fractionated organic extract of the Red Sea sponge Amphimedon chloros was able to inhibit the West Nile Virus NS3 protease (WNV NS3). Using liquid chromatography⁻mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) spectroscopy, the identity of the bioactive compound was determined as a 3-alkylpyridinium with m/z = 190.16. Diffusion Ordered Spectroscopy (DOSY) NMR and NMR relaxation rate analysis suggest that the bioactive compound forms oligomers of up to 35 kDa. We observed that at 9.4 μg/mL there was up to 40⁻70% inhibitory activity on WNV NS3 protease in orthogonal biochemical assays for solid phase extracts (SPE) of A. chloros. However, the LC-MS purified fragment was effective at inhibiting the protease up to 95% at an approximate amount of 2 µg/mL with negligible cytotoxicity to HeLa cells based on a High-Content Screening (HCS) cytological profiling strategy. To date, 3-alkylpyridinium type natural products have not been reported to show antiviral activity since the first characterization of halitoxin, or 3-alkylpyridinium, in 1978. This study provides the first account of a 3-alkylpyridinium complex that exhibits a proposed antiviral activity by inhibiting the NS3 protease. We suggest that the here-described compound can be further modified to increase its stability and tested in a cell-based assay to explore its full potential as a potential novel antiviral capable of inhibiting WNV replication

Image Similarity based Data Reduction Technique in Wireless Video Sensor Networks for Smart Agriculture

International audienceNowadays, to improve animal well being in livestock farming or beekeeping application, a wireless video sensor network (WVSN) can be deployed to early detect injury or Asiatic hornets attacks. WVSN represents a low-cost monitoring solution compared to other technologies such as the closed circuit television technology (CCTV). WVSNs are composed of low-power resource-constrained video sensor nodes (motes). These nodes capture frames from videos at a given frequency (frame rate) and wirelessly send them to the sink. The big amount of data transferred from the nodes to the sink consumes a lot of energy on the sensor node, which represents a major challenge for energy-limited nodes. In this paper, we introduce two complementary mechanisms to reduce the overall number of frames sent to the sink. First, the Transmission Data Reduction algorithm (TDR) run on the sensor node leverages the similarity degree of consecutive images. Second, the Inter-Nodes Similarity algorithm (INS) exploits the spatio-temporal correlation between neighbouring nodes in order reduce the number of captured frames. The results show a 95% data reduction, surpassing other techniques in the literature by 30% at least

Machine Learning Based Data Reduction in WSN for Smart Agriculture

International audienceNowadays, the agriculture domain faces a lot of challenges for a better usage of its natural resources. For this purpose, and for the increasing danger of climate change, there is a need to locally monitor meteorological data and soil conditions to help make quicker and more adapted decision for the culture. Wireless Sensor Networks (WSN) can serve as a monitoring system for those types of features. However, WSN suffer from the limited energy resources of the motes which shorten the lifetime of the overall network. Every mote periodically captures the monitored feature and sends the data to the sink for further analysis depending on a certain sampling rate. This process of sending big amount of data causes a high energy consumption of the sensor node and an important bandwidth usage on the network. In this paper, a Machine Learning based Data Reduction Algorithm (MLDR) is introduced. MLDR focuses on environmental data for the benefits of agriculture. MLDR is a data reduction approach which reduces the amount of transmitted data to the sink by adding some machine learning techniques at the sensor node level by keeping data availability and accuracy at the sink. This data reduction helps reduce the energy consumption and the bandwidth usage and it enhances the use of the medium while maintaining the accuracy of the information. This approach is validated through simulations on MATLAB using real temperature data-sets from Weather-Underground sensor network. Results show that the amount of sent data is reduced by more than 70% while maintaining a very good accuracy with a variance that did not surpass 2 degrees