Elemantra: An End-to-End Automated Framework Empowered with AI and IoT for Tackling Human-Elephant Conflict in Elephant-Range Countries

The cohabitation of elephants and humans has evolved into a human-elephant conflict (HEC) due to the increasing loss of historical elephant habitations. Since HEC is a substantial threat to both species, advanced sensing methods are utilized to develop HEC prevention frameworks which still lack unification. Here, we propose an end-to-end automated framework for HEC prevention consisting of three main modules: a distributed deep learning-assisted elephant detection module using infrared and seismic sensing, an on-site repelling system with time-varying acoustic and light deterrents and a mesh network for device communication. The framework is equipped with novel decision-making pipelines and algorithms such that it has the potential to operate with no human intervention. The preliminary results from each module confirm that the proposed framework is effective in performing their individual tasks towards collaboratively achieving the prevention of HEC. The codes are publicly available at https://github.com/nuwansribandara/elemantra.Comment: Submitted to IEEE Sensors Letters, 4 pages, 5 figure

A General Strategy to Make an On-Demand Library of Structurally and Functionally Diverse SERS Substrates

Surface-enhanced Raman spectroscopy (SERS) is a powerful technique for sensing molecules proximal to suitable coinage metal surfaces. The physical structure of the SERS-active metal layer and its support is a key design parameter inspiring considerable, and frequently specialized, efforts in substrate fabrication. The necessary gold film structure can arise from both the metallization process and the underlying support structure, and the structure of the support can deliver additional functions including analytical capabilities such as physical filtering. We used electroless plating as a general approach to create a library of SERS substrates: SERS-active gold films on a range of supports made from a variety of materials, made with a mixture of simple and complex fabrication histories, and offering a selection of structurally-derived functions. The result was that supports with existing functions had their capabilities enhanced by the addition of SERS sensing. Electroless plating thus offers a host of beneficial characteristics 3 for nanofabricating multifunctional SERS substrates, including: tolerance to substrate composition and form factor; low equipment overhead requirements; process chemistry flexibility—including compatibility with conventional top-down nanofabrication; and a lengthy history of commercial application as a simple metallization technique. We gold-plated standard nanofabrication-compatible silicon nitride support surfaces with planar and porous architectures, and with native and polymer-grafted surface chemistries. We used the same plating chemistry to form SERS-active gold films on cellulose fibers arrayed in commercial filter paper and formed into nanocellulose paper. In a functional sense, we used electroless plating to augment nanoporous filters, chromatography platforms, and nanofabrication building blocks with SERS capability

The ovipositional behaviour of the endemic whistling lizard Calotes liolepis Boulenger, 1885 (Reptilia: Agamidae) in the Knuckles forest region of Sri Lanka

A mature female Calotes liolepis was observed laying eggs on the ground in Manigala in the Knuckles Forest Region of Sri Lanka. This is the first completely described observation of the ovipositioning as well as the captive egg hatching of Calotes liolepis. This ovipositional behaviour consisted of the digging of the nest cavity, oviposition, scraping of the soil to bury the eggs, filling of the spaces between the eggs, compression of the soil, and camouflage of the nest. The sizes of three eggs were increased during incubation: day 1 mean = 17.5 mm × 9.2 mm (length × width), and after 70-71 days mean = 21.7 mm × 14.4 mm. Three hatchlings were emerged (mean snout-to-vent length = 29.9 mm; tail length = 58.2 mm; head length = 10.2 mm. Immediate conservation measures are needed for this endemic and threatened lizard, and the observations related to its egg-laying could be useful in planning and implementing suitable conservation methods

Surveying silicon nitride nanopores for glycomics and heparin quality assurance

Polysaccharides have key biological functions and can be harnessed for therapeutic roles, such as the anticoagulant heparin. Their complexity—e.g., \u3e100 monosaccharides with variety in linkage and branching structure—significantly complicates analysis compared to other biopolymers such as DNA and proteins. More, and improved, analysis tools have been called for, and here we demonstrate that solid-state silicon nitride nanopore sensors and tuned sensing conditions can be used to reliably detect native polysaccharides and enzymatic digestion products, differentiate between different polysaccharides in straightforward assays, provide new experimental insights into nanopore electrokinetics, and uncover polysaccharide properties. We show that nanopore sensing allows us to easily differentiate between a clinical heparin sample and one spiked with the contaminant that caused deaths in 2008 when its presence went undetected by conventional assays. The work reported here lays a foundation to further explore polysaccharide characterization and develop assays using thin-film solidstate nanopore sensors

Solution-Based Photo-Patterned Gold Film Formation on Silicon Nitride

Silicon nitride fabricated by low-pressure chemical vapor deposition (LPCVD) to be silicon-rich (SiNx), is a ubiquitous insulating thin film in the microelectronics industry, and an exceptional structural material for nanofabrication. Free-standingcompelling, particularly when used to deliver forefront molecular sensing capabilities in nanofluidic devices. We developed an accessible, gentle, and solution-based photo-directed surface metallization approach well-suited to forming patterned metal films as integral structural and functional features in thin-membrane-based SiNx devices—for use as electrodes or surface chemical functionalization platforms, for example—augmenting existing device capabilities and properties for a wide range of applications

Synthetic β‐Cyclodextrin Dimers for Squaraine Binding: Effect of Host Architecture on Photophysical Properties, Aggregate Formation and Chemical Reactivity

Reported herein is the synthesis and application of three novel β‐cyclodextrin dimer hosts for the complexation of near infrared (NIR) squaraine dyes in aqueous solution. A series of eight different N‐substituted N‐methyl anilino squaraine dyes with variable terminal groups are investigated, with an optimal n‐hexyl‐substituted squaraine guest demonstrating binding constants orders of magnitude higher than the other squaraine–host combinations and comparable to literature‐reported systems. Moreover, hydrophobic complexation of the squaraine dyes with the β‐cyclodextrin dimer hosts causes drastic changes in the squaraine\u27s photophysical properties, propensity for aggregation and susceptibility to hydrolytic decay

High Accuracy Protein Identification: Fusion of solid-state nanopore sensing and machine learning

Proteins are arguably the most important class of biomarkers for health diagnostic purposes. Label-free solid-state nanopore sensing is a versatile technique for sensing and analysing biomolecules such as proteins at single-molecule level. While molecular-level information on size, shape, and charge of proteins can be assessed by nanopores, the identification of proteins with comparable sizes remains a challenge. Here, we present methods that combine solid-state nanopore sensing with machine learning to address this challenge. We assess the translocations of four similarly sized proteins using amplifiers with bandwidths (BWs) of 100 kHz (sampling rate=200 ksps) and 10 MHz (sampling rate=40 Msps), the highest bandwidth reported for protein sensing, using nanopores fabricated in <10 nm thick silicon nitride membranes. F-values of up to 65.9% and 83.2% (without clustering of the protein signals) were achieved with 100 kHz and 10 MHz BW instruments, respectively, for identification of the four proteins. The accuracy of protein identification was significantly improved by grouping the signals into several clusters depending on the event features, resulting in F-value and specificity reaching as high as 88.7% and 96.4%, respectively, for combinations of four proteins. The combined improvement in sensor signals through the use of high bandwidth instruments, advanced clustering, machine learning, and other advanced data analysis methods allows identification of proteins with high accuracy

Electroless Plating of Thin Gold Films Directly onto Silicon Nitride Thin Films and into Micropores

A method to directly electrolessly plate silicon-rich silicon nitride with thin gold films was developed and characterized. Films with thicknesses \u3c100nm were grown at 3 and 10°C between 0.5 and 3 hours, with mean grain sizes between ~20-30nm. The method is compatible with plating free-standing ultrathin silicon nitride membranes, and we successfully plated the interior walls of micropore arrays in 200nm-thick silicon nitride membranes. The method is thus amenable to coating planar, curved, and line-of-sight-obscured silicon nitride surfaces

Nanopore surface coating delivers nanopore size and shape through conductance-based sizing

The performance of nanopore single-molecule sensing elements depends intimately on their physical dimensions and surface chemical properties. These factors underpin the dependence of the nanopore ionic conductance on electrolyte concentration, yet the measured, or modeled, dependence only partially illuminates the details of geometry and surface chemistry. Using the electrolyte-dependent conductance data before and after selective surface functionalization of solid-state nanopores, however, introduces more degrees of freedom and improves the performance of conductance-based nanopore characterizations. Sets of representative nanopore profiles were used to generate conductance data, and the nanopore shape and exact dimensions were identified, through conductance alone, by orders-of-magnitude 3 reductions in the geometry optimization metrics. The optimization framework could similarly be used to evaluate the nanopore surface coating thickness