Chemical event tracking using a low-cost wireless chemical sensing network

A recently developed low-cost light emitting diode (LED) chemical sensing technique is integrated with a Mica2Dot wireless communications platform to form a deployable wireless chemical event indicator network. The operation of the colorimetric sensing node has been evaluated to determine its reproducibility and limit of detection for an acidic airborne contaminant. A test-scale network of five similar chemical sensing nodes is deployed in a star communication topology at fixed points within a custom built Environmental Sensing Chamber (ESC). Presented data sets collected from the deployed wireless chemical sensor network (WCSN) show that during an acidic event scenario it is possible to track the plume speed and direction, and estimate the concentration of chemical plume by examining the collective sensor data relative to individual sensor node location within the monitored environment

Automatic reaction to a chemical event detected by a low-cost wireless chemical sensing network

A test-scale wireless chemical sensor network (WCSN) has been deployed within a controlled Environmental Chamber (EC). The combined signals from the WCSN were used to initiate a controllable response to the detected chemical event. When a particular sensor response pattern was obtained, a purging cycle was initiated. Sensor data were continuously checked against user-defined action limits, to determine if a chemical event had occurred. An acidic contaminant was used to demonstrate the response of the sensor network. Once the acid plume was simultaneously detected by a number of wireless chemical sensor nodes, an automatic response action, which was the purging of the EC with clean air, was initiated and maintained for a period of time until the WCSN indicated that normal status had been re-established

UK–EU law enforcement cooperation post-Brexit: A UK law enforcement practitioner perspective

Law enforcement cooperation between the United Kingdom and the European Union has experienced substantial change. The practice and impact of police cooperation are aligned with various formal and informal arrangements previously based on a European framework, policy, legislation and process. Following Brexit, the United Kingdom became detached from some of these arrangements. Opposing sides of the Brexit debate argued that the implications of the United Kingdom leaving the European Union would result in outcomes ranging from improved police cooperation to fundamental damage to law enforcement combating cross-border and organised crime. While it is acknowledged that more change will occur in the policy and legislative framework that governs police cooperation between the United Kingdom and the European Union, this article explores the current situation from the perspective of interview accounts from police practitioners (n = 14) and academics (n = 3) working in the field. This article applied ‘nodes of governance’ to police cooperation between the United Kingdom and European Union. This article demonstrates a range of issues that have impeded the ability of the United Kingdom to work with its former partners. At the same time, good police relations remain, and informal police cooperation continues

2021 Midwestern Producer Survey Descriptive Results

From July to September 2021, researchers from South Dakota State University, South Dakota School of Mines and Technology, North Dakota State University, University of Minnesota and University of Nebraska - Lincoln conducted a survey among farmers in four U.S. Midwestern states, namely North Dakota, South Dakota, Minnesota, and Nebraska. This survey aimed to better understand how farmers are using conservation practices and precision technologies and any issues with using them

The optimisation of a paired emitter-detector diode optical pH sensing device

With recent improvements in wireless sensor network hardware there has been a concurrent push to develop sensors that are suitable in terms of price and performance. In this paper a low cost gas sensor is detailed, and significant improvements in sensor characteristics have been achieved compared to previously published results. A chemical sensor is presented based on the use of low cost LEDs as both the light source and photodetector, coupled with a sensor slide coated with a pH sensitive colorimetric dye to create a simple gas sensor. Similar setups have been successfully used to detect both acetic acid and ammonia. The goal of this work was to optimise the system performance by integration of the sensing technique into a purposely deigned flowcell platform that holds the colorimetric slide and optical detector in position. The reproducibility of the sensor has been improved through this arrangement and careful control of deposited film thickness. The enhanced reproducibility between sensors opens the potential of calibration-free measurement, in that calibration of one sensor can be used to model the characteristics of all sensors in a particular batch

The Evolution of Methotrexate as a Treatment for Ectopic Pregnancy and Gestational Trophoblastic Neoplasia: A Review

Methotrexate was developed in 1949 as a synthetic folic acid analogue to compete with folic acid and thus interfere with cell replication. While initially developed as a potential treatment for acute lymphoblastic leukaemia, a serendipitous observation led to methotrexate's use to effect the dramatic cure of a case of advanced choriocarcinoma. This prompted the exploration for the potential of methotrexate to treat other conditions involving disordered trophoblastic tissue. Methotrexate has subsequently revolutionized the treatment of two pregnancy-related conditions—gestational trophoblastic neoplasia and ectopic pregnancy. This article reviews the development of modern treatment protocols that use methotrexate to medically treat these two important gynaecological conditions

A second-order class-D audio amplifier

Class-D audio amplifiers are particularly efficient, and this efficiency has led to their ubiquity in a wide range of modern electronic appliances. Their output takes the form of a high-frequency square wave whose duty cycle (ratio of on-time to off-time) is modulated at low frequency according to the audio signal. A mathematical model is developed here for a second-order class-D amplifier design (i.e., containing one second-order integrator) with negative feedback. We derive exact expressions for the dominant distortion terms, corresponding to a general audio input signal, and confirm these predictions with simulations. We also show how the observed phenomenon of “pulse skipping” arises from an instability of the analytical solution upon which the distortion calculations are based, and we provide predictions of the circumstances under which pulse skipping will take place, based on a stability analysis. These predictions are confirmed by simulations

Self-Control Matters: Examining Indirect Use of Hospital Information Systems and its Control Mechanisms

Indirect use of hospital information systems (HIS), denoting the designated physicians’ indirect interaction with HIS through delegating HIT-related tasks to others, has become a popular phenomenon in hospitals. Indirect use frees physicians from busy work and helps them achieve improved productivity, however, agency theory and organization literature alert that the consequences of indirect use may departure from physicians’ expectation due to agency problems. To resolve such challenges, prior work places great emphasis on formal control and social control. Considering the nature of hospital setting, this study proposes that agent’s self-control could also be a prominent control mechanism. To obtain a comprehensive understanding, this study builds a research model to depict the impacts of the three control mechanisms and their interplays on indirect use performance. Proposed methodology and preliminary findings are also discussed in this study, which aims to provide insights about how to perform indirect use efficiently and effectively

Age-Related Gene Expression Differences in Monocytes from Human Neonates, Young Adults, and Older Adults.

A variety of age-related differences in the innate and adaptive immune systems have been proposed to contribute to the increased susceptibility to infection of human neonates and older adults. The emergence of RNA sequencing (RNA-seq) provides an opportunity to obtain an unbiased, comprehensive, and quantitative view of gene expression differences in defined cell types from different age groups. An examination of ex vivo human monocyte responses to lipopolysaccharide stimulation or Listeria monocytogenes infection by RNA-seq revealed extensive similarities between neonates, young adults, and older adults, with an unexpectedly small number of genes exhibiting statistically significant age-dependent differences. By examining the differentially induced genes in the context of transcription factor binding motifs and RNA-seq data sets from mutant mouse strains, a previously described deficiency in interferon response factor-3 activity could be implicated in most of the differences between newborns and young adults. Contrary to these observations, older adults exhibited elevated expression of inflammatory genes at baseline, yet the responses following stimulation correlated more closely with those observed in younger adults. Notably, major differences in the expression of constitutively expressed genes were not observed, suggesting that the age-related differences are driven by environmental influences rather than cell-autonomous differences in monocyte development