Extreme Sensitivities Research Articles

Innovating Repression: Policy Experimentation and the Evolution of Beijing’s Re-Education Campaign in Xinjiang

ABSTRACT This article argues that Beijing’s campaign of mass internment in the Xinjiang Uyghur Autonomous Region evolved through a creative local policy experimentation process. This resulted in an ‘innovative repression’ solution to widespread ethnic discontent in the region, which the party-state has framed as ‘religious extremism’ and portrayed as a major national security threat. Amid significant top-level steering by the central government and despite extreme political sensitivities surrounding Xinjiang, Beijing used a form of ‘policy experimentation under hierarchy’ to catalyze localized development of mass ‘de-extremification’ in dedicated re-education internment camps. While scholars disagree to what extent policy experimentation continues under Xi Jinping’s more centralized approach to governance, the state’s atrocities in Xinjiang indicate how policy experimentation continues to facilitate the development of next-generation repressive securitization strategies.

A Highly Effective Liquid-Solid Reaction for In Situ Preparation of Copper Azide.

Copper azide (CA) is a promising energetic material with characteristics of high energy output and environmental friendliness that can be used as a microinitiator charge, but the extreme sensitivities hinder its practical applications. In situ preparation of CA can avoiding operating on sensitive CA directly and depressed the risk of handling. However, it is still a challenge to develop a straightforward, high-efficiency in situ preparation method. Consequently, a simple and rapid liquid-solid reaction strategy for azidation has been proposed via the in situ transformation of Cu(OH)2 into CA in a hydrazoic acid aqueous solution. In situ preparation of CA on a Cu film was performed to demonstrate the application of this strategy in detail. The transformation was completed in 4 min, which significantly improved the efficiency for production of CA compared to previously reported methods. This work provides a facile and highly efficient method for the in situ preparation of CA.

Extreme escalation of heat failure rates in ectotherms with global warming.

Temperature affects the rate of all biochemical processes in ectotherms1,2 and is therefore critical for determining their current and future distribution under global climate change3-5. Here we show that the rate of biological processes maintaining growth, homeostasis and ageing in the permissive temperature range increases by 7% per degree Celsius (median activation energy Ea = 0.48 eV from 1,351 rates across 314 species). By contrast, the processes underlying heat failure rate within the stressful temperature range are extremely temperature sensitive, such that heat failure increases by more than 100% per degree Celsius across a broad range of taxa (median Ea = 6.13 eV from 123 rates across 112 species). The extreme thermal sensitivity of heat failure rates implies that the projected increase in the frequency and intensity of heatwaves can exacerbate heat mortality for many ectothermic species with severe and disproportionate consequences. Combining the extreme thermal sensitivities with projected increases in maximum temperatures globally6, we predict that moderate warming scenarios can increase heat failure rates by 774% (terrestrial) and 180% (aquatic) by 2100. This finding suggests that we are likely to underestimate the potential impact of even a modest global warming scenario.

IR and UV Laser‐Induced Graphene: Application as Dopamine Electrochemical Sensors

AbstractLaser‐induced graphene (LIG) is inexpensive, fast, and easy to produce when compared to many other forms of graphene. Within the biosensing field, LIG electrodes are most often produced via infrared (IR) laser irradiation of polyimide sheets. Nevertheless, the usage of ultraviolet (UV) laser to produce LIG provides advantages in terms of sensor miniaturization because of its inherently higher scribing resolution. Yet, studies on the electrochemical performance of UV LIG, its relation with morphological and structural aspects as well as its comparison with IR LIG are still lacking. This work shows that both LIGs present swift electron transfer kinetics constituting excellent electrodes for electroanalysis. Extreme sensitivities of 93 and 58 µA µm−1 cm−2 at physiologically relevant dopamine (DA) concentrations are found for IR and UV LIG, respectively. Such sensitivities and good selectivity are achieved in the presence of physiologically relevant concentrations of ascorbic and uric acids, contrasting to the related literature employing IR LIG where such interferents are below the physiological range. Despite providing lower sensitivity, UV LIG is still an excellent material for DA biosensors, with the above‐mentioned advantages in terms of miniaturization. To our knowledge, these are among the highest sensitivities reported for voltammetric measurement of DA using carbon‐based materials.

Examining the Relation between Self-reported ASD Symptoms and Sensory Sensitivities from a Community-based Sample of Adults

ABSTRACT Atypical responses to sensory stimuli, termed sensory sensitivities, are a commonly reported symptom for individuals diagnosed with Autism Spectrum Disorder (ASD). In this community-based study of 604 adults, the correlation between sensory sensitivities and ASD symptoms was r = 0.23, p < .001, representing a smaller relation than estimates previously reported in the peer-reviewed research. Additionally, when examining only participants who met or exceeded the ASD screening cutoff score, the relation between sensory sensitivities and ASD symptoms was only slightly larger at r = 0.25, p < .001. Forty-four percentage who met the screening cutoff score for ASD also reported the lowest degree of sensory sensitivities. Finally, just over one-third who met the screening cutoff score for ASD had the highest sensory sensitivities. Sensory sensitivities did not appear to be a consistent feature across adults meeting the ASD screening cutoff score, but a proportion meeting the ASD screening cutoff score also exhibited the most extreme sensory sensitivities.

Machine learning-assisted calibration of Hg2+ sensors based on carbon nanotube field-effect transistors

Nanomaterial-based electronic sensors have demonstrated ultra-low detection limits, down to parts-per-billion (ppb) or parts-per-trillion (ppt) concentrations. However, these extreme sensitivities also make them susceptible to signal saturation at higher concentrations and restrict their usage primarily to low concentrations. Here, we report machine learning techniques to create a calibration method for carbon nanotube-based field-effect transistor (FET) devices. We started with linear regression, followed by regression splines to capture the non-linearity in the data. Further improvements in model performance were obtained with regression trees. Finally we lowered the model variance and further boosted the model performance by introducing random forest. The resulting performance as measured by R2 was estimated to be 0.8260 using out-of-bag error. The methodology avoids saturation and extends the dynamic range of the nanosensors up to 12 orders of magnitude in analyte concentrations. Further investigations of the sensing mechanism include analysis of feature importance in each of the model we tested. Functionalized nanosensors demonstrate selective detection of Hg2+ ions with detection limits 10−14.36±0.78 M, and maintain calibration to concentrations as high as 1 mM. Application of machine learning techniques to investigate which features in the FET signal maximally correlate with concentration changes provide valuable insight into the carbon nanotube sensing mechanism and assist in the rational design of future nanosensors.

Structure, self-assembly, and properties of a truncated reflectin variant

Naturally occurring and recombinant protein-based materials are frequently employed for the study of fundamental biological processes and are often leveraged for applications in areas as diverse as electronics, optics, bioengineering, medicine, and even fashion. Within this context, unique structural proteins known as reflectins have recently attracted substantial attention due to their key roles in the fascinating color-changing capabilities of cephalopods and their technological potential as biophotonic and bioelectronic materials. However, progress toward understanding reflectins has been hindered by their atypical aromatic and charged residue-enriched sequences, extreme sensitivities to subtle changes in environmental conditions, and well-known propensities for aggregation. Herein, we elucidate the structure of a reflectin variant at the molecular level, demonstrate a straightforward mechanical agitation-based methodology for controlling this variant's hierarchical assembly, and establish a direct correlation between the protein's structural characteristics and intrinsic optical properties. Altogether, our findings address multiple challenges associated with the development of reflectins as materials, furnish molecular-level insight into the mechanistic underpinnings of cephalopod skin cells' color-changing functionalities, and may inform new research directions across biochemistry, cellular biology, bioengineering, and optics.

MILITARY AND SECURITY EDUCATION FOR REGIONAL CO-OPERATION : A CASE STUDY OF THE SOUTHERN AFRICAN DEFENCE AND SECURITY MANAGEMENT NETWORK

This article first summarises approaches to military and security education at tertiary levels for officers and senior security officials, identifying some institutional and conceptual issues, before moving on to a fairly detailed case study of the Southern African Defence and Security Management Network (SADSEM). In its institutional form, from 2000 to 2010, SADSEM was a unique experiment in building a regional network of universities providing training and education in security studies, promoting regional security co-operation and integration and working closely with security forces and governments in the Southern African region. Although it mostly worked in English, it also carried out education and research in French and Portuguese, established an institutional base in ten Southern African Development Community (SADC) nations and delivered programmes in all the then 15 of them. Its activities included providing training and education for defence and security management, civil-military relations, peacekeeping and peacebuilding, policy support and the building of scholarly capacity though regional co-operation. Today SADSEM activities are restricted mainly to an annual security review conference, but its real legacy is in the institutions and capacities it built within several Southern African countries, although not all survive. SADSEM kept a low profile because of extreme sensitivities in Southern Africa around security issues, and this is the first attempt to examine its experience in the context of higher-level security education and training.

Thin-Film Silicon MEMS for Dynamic Mass Sensing in Vacuum and Air: Phase Noise, Allan Deviation, Mass Sensitivity and Limits of Detection

Microelectromechanical sensors have extreme mass sensitivities, making them promising for mass sensing, gas sensing, and biosensing applications. Despite the numerous examples of MEMS/NEMS mass sensors in the literature, the characterization of the resonator or oscillator system is often incomplete. Resonant mass sensor studies should include phase noise (or Allan deviation), as the use of these metrics allows for the identification of the noise mechanisms, the optimization of the measurement and actuation parameters, the prediction of the limit of detection, and the comparison of different types of resonators or vibration modes. In this paper, we summarize the metrics we consider to be the most important in the characterization of dynamic mass sensors, and then apply them to low-cost, hydrogenated amorphous silicon (a-Si:H) thin-film MEMS cantilever resonators. The effects of the actuation voltage on the phase noise were studied. The mass sensitivities of these resonators were calibrated using patterned thin-films localized at the tip of the cantilevers as well as uniform ultra-thin films of SiO2. The experimental mass sensitivities in vacuum ranged −98 Hz/pg to −4.6 kHz/pg. The limits of detection were calculated to be 100-833 fg in vacuum and 37-846 pg at atmospheric pressure. [2019-0006]

Optimization of Impulsive Europa Capture Trajectories using Primer Vector Theory

The optimization of impulsive, three-dimensional transfer trajectories to capture at Europa is investigated. Two initial conditions are considered: a halo orbit in the vicinity of Europa, and a resonant orbit around Jupiter. Primer vector theory is utilized to determine the number of impulses and the gradient information needed for this highly nonlinear, many revolution optimization problem. A custom multi-shooting algorithm is developed to mitigate the extreme sensitivities from long flight times through regions dominated by chaotic dynamics. New equations are derived to inform decisions to keep or remove small intermediate maneuvers. Optimization of previously generated, near-optimal halo-to-capture transfers verifies that an energetic-based minimum ΔV provides a good initial measure of optimality. For the resonant boundary scenario, a new 3D periodic orbit is generated that incorporates natural transfers between a resonant orbit and a halo orbit. The intermediate halo orbit enables phase-free connection of the capture and resonant phases. The end-to-end transfers successfully converge to quasi-ballistic, manifold-like trajectories.

Response to Cullenward and Koomey critique of ‘historical evidence for energy efficiency rebound in 30 US sectors’

This article responds to a recent critique in these pages by Danny Cullenward and Jonathan Koomey of a prior article reporting measured historical rebound magnitudes on the productive side of the US economy. They argue that the data quality objections they raise are serious enough to warrant outright dismissal of the reported rebound magnitudes. In particular, they cite unaccounted for regional energy price differences as fatal to the credibility of the results.The present analysis instead shows, via various extreme sensitivities around the energy price trajectory, that historical rebound magnitudes in 30 productive sectors of the US economy are sensitive but robust to energy price differences – both magnitude and variability differences – and remain large and thereby policy-relevant (commonly >50%, with the overall average varying from 15% to over 200% (“backfire”) at the extremes). Along the way, the analysis provides further evidence of the reliability of the widely-used Jorgenson et al. econometric data set and methodology, and of the multitude of articles that have followed there from.

Formation of Additive-Containing Nanothermites and Modifications to their Friction Sensitivity

ABSTRACTNanothermites can provide high energy densities and reaction rates but can also display extreme friction sensitivities. Additives that provide friction modification offer the potential to reduce the friction sensitivity of nanothermites. In the present work, MoS2, graphene, and hexadecane additives were dispersed in MoO3 prior to nanothermite formation with the aim of reducing friction sensitivity. Nanothermites were subsequently prepared using a palmitic acid–passivated nano-aluminum (L-Al) and additive-containing nano-MoO3 by the resonant acoustic mixing of dry powders. In general, the incorporation of additives results in a reduction in friction sensitivity with the baseline minimum ignition friction rising from 10 to 120 N using 0.5% wt/wt micrometer-sized MoS2 or 5% wt/wt hexadecane. However, the relationships between loading and performance are complex and vary by additive; for example, the friction sensitivity dependence using micrometer-diameter MoS2 displays a maximum at 0.5% wt/wt and declines to 7 N using 5% MoS2.

Correlated memory resistor in epitaxial NdNiO3 heterostructures with asymmetrical proton concentration

The electronic devices using correlated transition metal oxides are the promising candidates to overcome the limitation of the current electronics due to the rich electronic phases and the extreme sensitivities. Here, we report proton-based resistive switching memory that uses correlated oxides, i.e., epitaxial NdNiO3 heterostructure with asymmetrical concentration of protons (H+) to obtain multilevel states. By designing such metal-NdNiO3-metal device structures with asymmetrical proton concentration, we demonstrate that the correlated oxides exhibit resistive switching by ionic transport of protons at the metal-hydrogenated NdNiO3 (H-NNO) interface. This finding will guide the development of energy-efficient switching devices for non-volatile memory and neuromorphic applications.

Optimization of Offshore Wind Turbine Support Structures Using an Analytical Gradient-based Method

Design optimization of offshore wind turbine support structures is an expensive task; due to the highly-constrained, non-convex and non-linear nature of the design problem. This paper presents an analytical gradient-based method to solve this problem in an efficient and effective way. The design sensitivities of the objective and constraint functions are evaluated analytically while the optimization of the structure is performed, subject to sizing, eigenfrequency, extreme load and fatigue load constraints. A case study was carried out for the OC4 jacket substructure to evaluate the method. Results show that an optimal jacket design with 52 percent structural mass reduction was attained in 27 iterations, while satisfying all design constraints under the simplified load cases used. Besides, it is shown that the analytical sensitivity analysis was more accurate and efficient than the often used finite difference approximations. It could avoid numerical artifacts that typically occur in the analysis of extreme load constraint sensitivities.

Misophonia: incidence, phenomenology, and clinical correlates in an undergraduate student sample.

Individuals with misophonia display extreme sensitivities to selective sounds, often resulting in negative emotions and subsequent maladaptive behaviors, such as avoidance and anger outbursts. While there has been increasing interest in misophonia, few data have been published to date. This study investigated the incidence, phenomenology, correlates, and impairment associated with misophonia symptoms in 483 undergraduate students through self-report measures. Misophonia was a relatively common phenomenon, with nearly 20% of the sample reporting clinically significant misophonia symptoms. Furthermore, misophonia symptoms demonstrated strong associations with measures of impairment and general sensory sensitivities, and moderate associations with obsessive-compulsive, anxiety, and depressive symptoms. Anxiety mediated the relationship between misophonia and anger outbursts. This investigation contributes to a better understanding of misophonia and indicates potential factors that may co-occur and influence the clinical presentation of a person with misophonia symptoms.

Influence of dispersibility and coagulation on the dust explosion risk presented by powders consisting of nm-particles

Abstract At the outset it may seem reasonable to expect that dust clouds from combustible nm-particle powders will exhibit extreme ignition sensitivities (very low MIEs) and extreme explosion rates (very high K St -values). However, there are two basic reasons why this is not necessarily the case. Firstly, complete transformation of bulk nm-particle powders into dust clouds consisting of well-dispersed primary particles is extremely difficult to accomplish, due to very strong inter-particle forces. Secondly, the extremely fast coagulation process in nm particle clouds of explosive mass concentrations would transform the primary particles in a well-dispersed cloud into much larger agglomerates within fractions of a second. The paper discusses these aspects in relation to recent published MIE data and K St -values for some nm powders.

Front Cover: Ultrahigh gain AlGaN/GaN high energy radiation detectors (Phys. Status Solidi A 8/2012)

Gallium nitride has a remarkable tolerance to high energy ionizing radiation, but its full potential has not yet been realized due to material issues that lead to persistent photoconductivity, poor sensitivity, and requirements for large operational voltages. However, J. D. Howgate et al. (pp. 1562–1567) demonstrate that the introduction of a two-dimensional electron gas channel, through the construction of AlGaN/GaN heterointerfaces, can be used to create “photomultiplier” equivalent amplification, while eliminating persistent photoconductivity, under operation with single volt bias at room temperature. These results are extremely promising for future ionizing radiation detector technologies for applications ranging from high energy physics to medical imaging. This is demonstrated on the front cover image, where a 3 × 3 mm flashlight bulb was scanned with ultra-low dose rate (thousands of photons per second) focused X-rays, clearly revealing the 50 μm thick spiral filament and the cavity in which it is mounted. Furthermore, such an image could be obtained within milliseconds via device miniaturization using conventional microelectronics techniques that allow for fabrication of integrated two-dimensional pixel detectors. These extreme sensitivities could, for example, enable patient exposures to harmful ionizing radiation to be dramatically reduced or offer low power personal dosimeters capable of giving real-time warning to radiation exposure.

Does the dust explosion risk increase when moving from μm-particle powders to powders of nm-particles?

Based on experience with powders of particle sizes down to the 1–0.1 μm range one might expect that dust clouds from combustible nm-particle powders would exhibit extreme ignition sensitivities (very low MIEs) and extreme explosion rates (very high KSt-values). However, there are two basic physical reasons why this may not be the case. Firstly, complete transformation of bulk powders consisting of nm-particles into dust clouds consisting of well-dispersed primary particles is extremely difficult to accomplish, due to very strong inter-particle cohesion forces. Secondly, should perfect dispersion nevertheless be achieved, the extremely fast coagulation process in clouds of explosive mass concentrations would transform the primary nm-particles into much larger agglomerates within fractions of a second. Furthermore, for organic dusts and coal the basic mechanism of flame propagation in dust clouds suggests that increased cloud explosion rates would not be expected as the particle size decreases into the <1 μm range. An overall conclusion is that dust clouds consisting of nm primary particles are not expected to exhibit more severe KSt-values than clouds of μm primary particles, in agreement with recent experimental evidence. In the case of the ignition sensitivity recently published evidence indicates that MIEs of clouds in air of some metal powders are significantly lower for nm particles than for μm particles. A possible reason for this is indicated in the paper.

Are enhanced dust explosion hazards to be foreseen in production, processing and handling of powders consisting of nano-size particles?

Based on experience with powders having particle sizes down to the range 1 – 0.1 μm one might expect that dust clouds from combustible nm-particle powders would exhibit extreme ignition sensitivities (very low MIEs) and extreme explosion rates (very high KSt−values). However, there are two basic physical reasons why this may not necessarily be the case. Firstly, the formation of clouds of well-dispersed primary particles from bulk powders consisting of nm-particles is extremely difficult to achieve, due to the comparatively very strong inter-particle cohesion forces. Secondly, should such a dispersion process nevertheless be fully successful, extremely fast coagulation processes in clouds within the explosive mass concentration range, would transform the primary nm-particles into much larger agglomerates within fractions of a second. Furthermore, for organic dusts and coal, the basic mechanism of flame propagation in the dust cloud is a further reason for not expecting extreme ignition sensitivities and explosion rates dust clouds from nm-particles. The overall conclusion is that dust clouds consisting of nm primary particles would not necessarily be expected to exhibit more severe MIE and KSt−values than those of dust clouds of μm primary particles. Recent experimental evidence confirms that this is in fact the case for KSt, whereas for MIE the values for some metals are significantly lower for nm primary particles than for μm ones.

Application of a super-luminescent diode coupled with an interference filter for mixed gas sensing

Laser-based spectroscopic techniques are very attractive methods for trace gas, environmental and industrial monitoring. By employing narrow spectral-width tunable coherent light sources, a single absorption line of the substance to be analyzed can be probed with a laser, avoiding interference signals from other species. Here we report a difference frequency generation (DFG) source in mid-infrared region using a tunable laser (825 – 870nm) and a fixed wavelength diode laser (1060nm) in combination with a PPLN having single period. Application of the approach for carbon dioxide (CO2) monitoring in air was studied. Many gas sensing applications do not require extreme sensitivities up to ppb order and in this case, super-luminescent diodes (SLD) are also of great interest. They are commonly produced in the spectral range of optical fibers telecommunications (1.3 – 1.7 m), where overtone vibration bands of many gas molecules of interest. As a typical example, measurements of ammonia (NH3) trace gas were studied for combustion measurement applications. A novel approach of using fiber-coupled SLD along with an interference filter can also be considered for such application to avoid influence of water vapor (H2O). The interest of this system consists in the possibility to detect several species with a single instrument.