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Wireless Sensor Networks, basically applied to gather information about the environments, consist of various elements interconnection. They are mainly deployed in the areas hard to reach, so they are routinely powered by the batteries. Due to the complexity of WSNs and the impact they have on the 21st century proceeding technology, they have received lots of attention during past decades, hence it is mandatory to study their fundamentals before any forthcoming research. This paper reviews the alphabets of WSNs in a straight scenario, categorizing them in terms of application, routing and connectivity schemes, besides, practical design challenges and energy supply ways have been classified.

Four species of bacteria, E. coli, S. epidermidis, M. smegmatis, and P. aeruginosa, were harvested from agar nutrient medium growth plates and suspended in water to create liquid specimens for the testing of a new mounting protocol. Aliquots of 30 µL were deposited on standard nitrocellulose filter paper with a mean 0.45 µm pore size to create highly flat and uniform bacterial pads. The introduction of a laser-based lens-to-sample distance measuring device and a pair of matched off-axis parabolic reflectors for light collection improved both spectral reproducibility and the signal-to-noise ratio of optical emission spectra acquired from the bacterial pads by laser-induced breakdown spectroscopy. A discriminant function analysis and a partial least squares-discriminant analysis both showed improved sensitivity and specificity compared to previous mounting techniques. The behavior of the spectra as a function of suspension concentration and filter coverage was investigated, as was the effect on chemometric cell classification of sterilization via autoclaving.

What do policing leaders think and know of forensic science? Beyond crime scene investigators or detectives, how do police senior managers perceive the role, utility and limitations of forensic science? Very few empirical studies have addressed the issue. Forensic scientsts should be concerned about the perception that law enforcement senior managers have of their discipline for two reasons. First, strategic and financial decision-makers are obviously key players in the overall administration and provision of forensic science, either as a supervisor, money provider or as a customer. Second, literature has highlighted that other actors involved in forensic science underestimate the scope and possibilities offered by forensic science, hence limiting its exploitation and potential. Following interviews with 18 police senior managers from Quebec (Canada), this study shows that they generally restrict forensic science to a reactive discipline whose role and utility is to identify offenders and support the Court. This understanding of forensic science, like that of many others including a significant share of forensic scientists, differs from the perception of other police activities in modern law enforcement agencies where proactive action is sought. Considering these findings and the growing body of literature which calls for forensic science to connect more tightly with policing and security, we advocate a more extensive education of police leaders regarding the scope of forensic science.

Achieving effective detection of unexploded ordnance (UXO) is of great significance for ensuring the safety of human lives and regional economic development. Differential magnetic tensor gradient systems have strong application prospects for UXO detection because of their low orientation requirements and exceptional sensitivity to weak magnetic fields. These systems usually have a hollow ring-shaped measurable range, referred to as the “measurable area”. With the rapid advancement of the tensor measurement system, it is necessary to further analyse the measurable area performance. In this paper, a simulation method based on a target magnetic dipole revolving around such a measurement system is designed for evaluating the measurable area. An improved Frobenius norm is adopted to compare the measured tensor data, and the centre distance is used instead of the baseline distance to better describe the scale of the measurement system. The measurable areas of planar cross-shaped, square, and triangular structures are studied, as well as the corresponding influencing factors. Finally, the quantitative relationships between the measurable area performance of the three structures and the magnetic dipole moment direction, the sensor accuracy, and the centre distance of the measurement system are obtained.

This paper presents the design and post-layout simulation results of a 64-channel wireless and implantable system-on-chip (SoC) for studying gastric electrophysiology. The SoC includes 64 time-multiplexed low-noise amplifiers (LNAs) followed by a 10-bit low-power successive approximation register (SAR) analog-to-digital converter (ADC), and a power management unit for recharging the SoC battery inductively and communicating with an external reader via load-shift keying (LSK) modulation of the receiver coil. The SoC has been designed in a 0.35 μm standard CMOS process, occupying 25 mm2. In post-layout simulations, each LNA achieved an adjustable gain of 40–52 dB, and an input-referred noise of 6 μVrms within the bandwidth of 10 mHz–2 Hz while consuming 40 nA from a single 2.5 V supply. Each channel was sampled at 244 Hz with 10 bits of resolution, leading to the net data rate of 156 kbps for recording 64 channels. The power management, operating at 13.56 MHz, recharged a 3.7 V battery with the adjustable current range of 0–15 mA while maintaining the rectifier voltage constant at 4.4 V.

Semiconductor quantum dots (QDs) have served as the basis for signal development in a variety of biosensing technologies and in applications using bioprobes. The use of QDs as physical platforms to develop biosensors and bioprobes has attracted considerable interest. This is largely due to the unique optical properties of QDs that make them excellent choices as donors in fluorescence resonance energy transfer (FRET) and well suited for optical multiplexing. The large majority of QD-based bioprobe and biosensing technologies that have been described operate in bulk solution environments, where selective binding events at the surface of QDs are often associated with relatively long periods to reach a steady-state signal. An alternative approach to the design of biosensor architectures may be provided by a microfluidic system (MFS). A MFS is able to integrate chemical and biological processes into a single platform and allows for manipulation of flow conditions to achieve, by sample transport and mixing, reaction rates that are not entirely diffusion controlled. Integrating assays in a MFS provides numerous additional advantages, which include the use of very small amounts of reagents and samples, possible sample processing before detection, ultra-high sensitivity, high throughput, short analysis time, and in situ monitoring. Herein, a comprehensive review is provided that addresses the key concepts and applications of QD-based microfluidic biosensors with an added emphasis on how this combination of technologies provides for innovations in bioassay designs. Examples from the literature are used to highlight the many advantages of biosensing in a MFS and illustrate the versatility that such a platform offers in the design strategy.

Metabolites containing a carbonyl group represent several important classes of molecules including various forms of ketones and aldehydes such as steroids and sugars. We report a high-performance chemical isotope labeling (CIL) LC–MS method for profiling the carbonyl submetabolome with high coverage and high accuracy and precision of relative quantification. This method is based on the use of dansylhydrazine (DnsHz) labeling of carbonyl metabolites to change their chemical and physical properties to such an extent that the labeled metabolites can be efficiently separated by reversed phase LC and ionized by electrospray ionization MS. In the analysis of six standards representing different carbonyl classes, acetaldehyde could be ionized only after labeling and MS signals were significantly increased for other 5 standards with an enhancement factor ranging from ∼15-fold for androsterone to ∼940-fold for 2-butanone. Differential 12C- and 13C-DnsHz labeling was developed for quantifying metabolic differences ...

The optical systems required to observe the Faraday or Voigt effects in atomic vapors are described in terms of the corresponding Jones matrices. The solution of the matrix equations reveals separate, additive dichroic and dispersive contributions to the transmitted intensity. The two contributions are combined by use of the Kronig-Kramers relations to give a final expression for the intensity due to magneto-optical rotation. This appears as the product of the intensity transmitted through the atomic vapor, the square of the zero field absorbance within the vapor, and the inverse square of a “Zeeman factor” z. Empirical data for the latter two parameters are currently available. Thus, the final formulae permit estimates of magneto-optic signal magnitudes to be made on the basis of presently existing information.

This paper describes visual route following for a cliff-climbing, tethered mobile robot for the purpose of autonomously traversing extreme terrain in the presence of obstacles. When the robot's tether contacts an obstacle, an intermediate anchor is formed. In order to detach from intermediate anchors and avoid entanglement, the robot must backtrack along its outgoing trajectory. We use the Visual Teach & Repeat (VT&R) algorithm to autonomously repeat a manually taught path. However, our problem is complicated by the fact that the robot's tether must (i) remain taut regardless of inclination, (ii) allow the robot to drive freely, and (iii) provide motion assistance when wheel traction is reduced on steep slopes. To enable visual route following over varied terrain, we have developed a novel tether controller that selects a safe, steady-state tension based on the robot's inclination while also accounting for vehicle motion. Experiments are performed on our Tethered Robotic Explorer (TReX), which autonomously repeats paths while tethered in both flat-indoor and steep-outdoor environments in the presence of obstacles.

Tyrosine phosphorylation (pTyr) is important for normal physiology and implicated in many human diseases, particularly cancer. Identification of pTyr sites is critical to dissecting signaling pathways and understanding disease pathologies. However, compared with serine/threonine phosphorylation (pSer/pThr), the analysis of pTyr at the proteome level is more challenging due to its low abundance. Here, we developed a biphasic affinity chromatographic approach where Src SH2 superbinder was coupled with NeutrAvidin affinity chromatography, for tyrosine phosphoproteome analysis. With the use of competitive elution agent biotin-pYEEI, this strategy can distinguish high-affinity phosphotyrosyl peptides from low-affinity ones, while the excess competitive agent is readily removed by using NeutrAvidin agarose resin in an integrated tip system. The excellent performance of this system was demonstrated by analyzing tyrosine phosphoproteome of Jurkat cells from which 3,480 unique pTyr sites were identified. The biphasic affinity chromatography method for deep Tyr phosphoproteome analysis is rapid, sensitive, robust, and cost-effective. It is widely applicable to the global analysis of the tyrosine phosphoproteome associated with tyrosine kinase signal transduction.