Minimum Step Research Articles

High focus on threatened species and habitats may undermine biodiversity conservation: Evidence from the northern Baltic Sea

AbstractConservation policies and environmental impact assessments commonly target threatened species and habitats. Nevertheless, macroecological research provides reasons why also common species should be considered. We investigate the consequences of focussing solely on legally protected species and habitats in a spatial conservation planning context using a comprehensive, benthic marine data set from the northern Baltic Sea. Using spatial prioritization and surrogacy analysis, we show that the common approach in conservation planning, where legally listed threatened species and habitats are the focus of conservation efforts, could lead to poor outcomes for common species (and therefore biodiversity as a whole), allowing them to decline in the future. If conservation efforts were aimed solely at threatened species, common species would experience a loss of 62% coverage. In contrast, if conservation plans were based only on common species, threatened species would suffer a loss of 1%. Threatened species are rare and their ecological niches distinct, making them poor surrogates for biodiversity. The best results are achieved by unified planning for all species and habitats. The minimal step towards acknowledging common species in conservation planning would be the inclusion of the richness of common species, complemented by information on indicator species or species of high importance for ecosystem functioning. The trade‐off between planning for rare and common species should be evaluated, to minimize losses to biodiversity.

A study of a slim compact piezo inertia actuator

Most previously reported inertia actuators suffer from the problems of low speed and large size. To overcome these shortcomings, this study proposes a slim compact piezo inertia actuator based on the principle of stick–slip drive. Actuated by the transverse motion of a cantilever beam forming part of a monolithic elastomer, this actuator achieves a high velocity. The construction and basic operating principle of the actuator are discussed in detail. Commercial finite element analysis software is employed to determine the appropriate geometry for the monolithic elastomer. To study the actuator’s mechanical characteristics, a prototype is fabricated and a series of experimental tests are performed. According to the results of these tests, the maximum velocity and maximum load force are about 24.03 mm/s and 1.96 N, respectively, and the minimum step size is about 0.47 μm. It is shown that the inertia actuator based on a monolithic elastomer with a cantilever beam not only has a slim compact structure, but also exhibits good output characteristics.

Is Switching of Adrenaline Auto Injector Devices a Concern for Anaphylaxis Management? A CROSS-Sectional Study

Adrenaline auto injectors (AAI) are the mainstay of treatment in anaphylaxis. However, many caregivers of children with food allergies are unable to administer an AAI when assessed. One proposed factor for this finding is the lack of training and familiarity of the different AAI devices. The aim of this study is to explore the usage of different brands of adrenaline auto-injectors among caregivers of children with food allergies in Ireland. A cross-sectional study method was employed using an online questionnaire. An amount of 121 (75.58%) caregivers reported that their child carried an Epipen®, 25 (15.82%) carried Jext®, and 12 (7.59%) carried Anapen®. An amount of 48.73% (n = 77) of caregivers had switched brands of AAI at least once before, with lack of availability of their usual device at their pharmacy being the most common reason for this. Factors associated with change were a household income >100,000 € (70% vs. 44.9% of those with less income; p = 0.04) and parents ≥40 years old (59.6% vs. 32.8% of patients whose parents younger; p < 0.01). When asked what they preferred about a particular AAI brand, caregivers appreciated a simple design with minimal steps involved in administration, clear colour coding, online resources, formal training from a healthcare professional, and first-hand experience in using the AAI. These findings show, for the first time, that switching brands is a common occurrence among caregivers of children with food allergies. These findings support the EAACI recommendation to train parents regularly in all available brands of AAI and to retrain parents when switching to different devices.

Effects of diabetes mellitus on step length and minimum toe clearance adaptation

BackgroundAdaptive gait involves the ability to adjust the leading foot in response to the requirement of dynamic environments during walking. Accurate adjustments of the minimum toe clearance (MTC) height and step length can prevent older people from falling when walking and responding to hazards. Although older people with diabetes fall more frequently than healthy older adults, no previous studies have quantified their adaptive gait abilities. This study aimed to investigate the effects of diabetes mellitus on step length and MTC height adjustments using a non-immersive virtual-reality system.MethodsSixteen young adults (26 ± 5 years, 7 females), 16 healthy older adults (68 ± 5 years, 6 females), and 16 older adults with diabetes (70 ± 5 years, 6 females) completed adaptability tests while walking on a treadmill. A computer system visualised a continuous real-time signal of absolute step length and MTC on a monitor. Each person responded to four discrete participant-specific step length and MTC visual targets that were presented on the same signal. Tasks were to match the peaks of interest on each signal to presented targets. Targets were 10% longer or shorter than the mean baseline step length, and 2.5 cm, and 3.5 cm higher than the mean baseline MTC. When a target was displayed, it remained unchanged for 10 consecutive foot displacement adaptation attempts. Then, the target was removed and a new target or the same target was present after 10 consecutive steps and remained for 10 steps. Each target was randomly presented three times (3 × 10). Step length and MTC height adjustments in response to targets were measured and compared among groups.ResultsMean preferred walking speeds were not different among groups significantly when no targets were presented on the monitor in baseline walking. However, when participants walked on a treadmill while attempting to match step lengths or MTC heights to displayed targets on the monitor, the group with diabetes had reduced step length and MTC adjustments compared with other groups significantly. They showed greater errors (differences between their step lengths/MTC heights and presented targets) on the monitor.ConclusionsThis study quantified reduced abilities for older individuals with diabetes to adjust both step length and MTC in response to stimuli compared to healthy older counterparts. Reduced step length and MTC height adjustments can increase falls in at risk populations. The presented virtual-reality system has merits for assessing and training step and MTC adaptation.

A Graduated Non-Convexity Technique for Dealing Large Point Spread Functions

This paper focuses on reducing the computational cost of a GNC Algorithm for deblurring images when dealing with full symmetric Toeplitz block matrices composed of Toeplitz blocks. Such a case is widespread in real cases when the PSF has a vast range. The analysis in this paper centers around the class of gamma matrices, which can perform vector multiplications quickly. The paper presents a theoretical and experimental analysis of how γ-matrices can accurately approximate symmetric Toeplitz matrices. The proposed approach involves adding a minimization step for a new approximation of the energy function to the GNC technique. Specifically, we replace the Toeplitz matrices found in the blocks of the blur operator with γ-matrices in this approximation. The experimental results demonstrate that the new GNC algorithm proposed in this paper reduces computation time by over 20% compared with its previous version. The image reconstruction quality, however, remains unchanged.

In situ growth of NH2-MIL-101 metal organic frameworks on biochar for glyphosate adsorption

We fabricated a novel adsorbent to remove glyphosate (PMG) in solution by in situ growing of NH2-MIL-101 metal-organic framework on biochar derived by the calcination of waste rice husk (hereafter NMBC61 formulated as NH2-MIL-101: BC = 6:1 ratio). The new adsorbent was systematically characterized by atomic, molecular spectroscopic and conventional experimental methods. The PMG adsorption efficiency on NMBC61 was examined as a function of contact time, solution pH, temperature, matrix solutes, and substrate concentration. The modification of amino group significantly improved the adsorption performance of the material. The PMG adsorption data were modeled using Langmuir isotherm and pseudo-second-order kinetics formulations. The maximum adsorption capacities of NMBC61 at 323 K for PMG is 186.71 mg g−1. The PMG adsorption did not significantly interfere with NO3−, Cl−, HCOO−, and citric acid in the solution matrix; SO42− show an intermediate interfering behavior. However, PMG adsorption interferes significantly in the presence of H2PO42− and citric acid. The contrasting interfering patterns show the nature of surface bonding in PMG adsorption on NBMC61. The subtilties arisen between surface –NH2 and –OH sites on PMG adsorption were resolved by IR and XPS spectral data. The PMG adsorbed on NBMC61 via ligand exchange by inner-sphere surface complex formation. When foreign solutes show similar surface complexing, they interfere with PMG adsorption. Based on the adsorption experiments and density functional theory (DFT) calculations, the van der Waals (vdW) interactions and hydrogen bonding were assumed to be involved in the adsorption. NBMC61 shows over 83% PMG removal efficiency at the end of three cycles. The NMBC61 show optimal PMG adsorption between pH 2 and 6 with minimal interference from the solution matrix. Therefore, NBMC61 has the potential in treating organic pollutants found in natural and wastewaters efficiently with minimal pre-treatment steps.

A Novel Piezo Inertia Actuator Utilizing the Transverse Motion of Two Parallel Leaf-Springs.

A novel linear piezo inertia actuator based on the transverse motion principle is proposed. Under the action of the transverse motion of two parallel leaf-springs, the designed piezo inertia actuator can achieve great stroke movements at a fairly high speed. The presented actuator includes a rectangle flexure hinge mechanism (RFHM) with two parallel leaf-springs, a piezo-stack, a base, and a stage. The mechanism construction and operating principle of the piezo inertia actuator are discussed, respectively. To obtain the proper geometry of the RFHM, we have used a commercial finite element program COMSOL. To investigate the output characteristics of the actuator, the relevant experiment tests including loading capacity, voltage characteristic, and frequency characteristic are adopted. The maximum movement speed and the minimum step size are 27.077 mm/s and 32.5 nm, respectively, confirming that the RFHM with two parallel leaf-springs can be used to design a piezo inertia actuator with a high speed and accuracy. Therefore, this actuator can be used in applications with fast positioning and high accuracy.

Facile and Scalable Synthesis of Metal- and Nitrogen-Doped Carbon Nanotubes for Efficient Electrochemical CO2 Reduction.

Metal- and nitrogen-doped carbon (M-N-C) is a promising material to catalyze electrochemical CO2 reduction reaction (CO2RR). However, most M-N-C catalysts in the literature require complicated synthesis procedures and produce small quantities per batch, limiting the commercialization potential. In this work, we developed a simple and scalable synthesis method to convert metal-impurity-containing commercial carbon nanotubes (CNTs) and nitrogen-containing organic precursors into M-N-C via one-step moderate-temperature (650 °C) pyrolysis without any other treatment nor the need to add metal precursors. Batches of catalysts in varied mass up to 10 g (150 mL in volume) per batch were synthesized, and repeatable catalytic performances were demonstrated. To the best of our knowledge, the 10 g batch is one of the largest batches of CO2RR catalysts synthesized in the literature while requiring minimal synthesis steps. The catalyst possessed single-atomic iron-nitrogen (Fe-N) sites, enabling a high performance of >95% CO product selectivity at a high current density of 400 mA/cm2 and high stability for 45 h at 100 mA/cm2 in a flow cell testing. The catalyst outperformed a benchmark noble-metal nanoparticle catalyst and achieved longer stability than many other reported M-N-C catalysts in the literature. The scalable and cost-effective synthesis developed in this work paves a pathway toward practical CO2RR applications. The direct utilization of metal impurities from raw CNTs for efficient catalyst synthesis with minimal treatment is a green and sustainable engineering approach.

Ladder-shaped microfluidic system for rapid antibiotic susceptibility testing

Rapid identification of antibiotic-resistant bacteria will play a key role in solving the global antibiotic crisis by providing a route to targeted antibiotic administration. However, current bacterial infection diagnoses take up to 3 days which can lead to antibiotic treatment that is less effective. Here we report a microfluidic system with a ladder shaped design allowing us to generate a twofold serial dilution of antibiotics comparable to current national and international standards. Our consolidated design, with minimal handling steps cuts down the testing time for antibiotic susceptibility from 16–20 h to 4–5 h. Our feasibility testing results are consistent with the commercial antibiotic susceptibility testing (AST) results, showing a 91.75% rate of agreement for Gram-negative and Gram-positive bacterial isolated from canine urinary tract infections (UTI) and may be used without prior isolation or enrichment. This platform provides an adaptable and efficient diagnostic tool for antibiotic susceptibility testing.

The Development of Piezoelectric Inchworm Actuator Clamped With Magnetorheological Elastomer and Its Potential Application in Brain–Computer Interface Implantation

The piezoelectric inchworm actuator with high-positioning accuracy and large output force is a potential device to implant microelectrode in the invasive brain–computer interface (BCI). However, the traditional piezoelectric inchworm actuator adopts multichannel electrical control signals from external equipment and rigid-to-rigid friction contact to drive, resulting in complex control and uneven friction. To solve the above problems, in this article, magnetorheological elastomer (MRE) is first proposed as the clamping material of the piezoelectric inchworm actuator. An MRE–capillary–cover sandwich structure is adopted to achieve rigid-to-elastomeric clamping. The driving and clamping actions of the actuator are controlled by two cam mechanisms mounted on the same shaft, and a battery can feed the actuator. A kinetic model is established to analyze and predict the actuator motion. Several crucial clamping parameters are explored, and the performance experiments are conducted to evaluate actuator characteristics. A verification experiment is carried out to prove the feasibility of the microelectrode implantation in the pig brain (0.6% agarose gel). The actuator can reach the maximum velocity of 1250.4 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i> m/s and the maximum output force of 420 mN; in the forward/backward motion, the minimum step is 0.5837/0.5912 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i> m, and the repeatability is 0.0465/0.0469 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i> m; thus, the actuator has great application potential in BCI.

Development of an Undulator Magnetic Field Measurement System for the Free‐Electron Laser Facility at Chiang‐Mai University

A magnetic field measurement system for an undulator has been developed at the Plasma and Beam Physics (PBP) Research Facility, Chiang Mai University (CMU), as a part of the mid‐infrared (MIR) and terahertz (THz) radiation free‐electron laser (FEL) project. The measurement system consists of a motorized linear translation stage, a Hall magnetic probe, a teslameter, a motor control unit, and control software. The system is designed to precisely control the position of the probe, which can move up to 1.8 m with a minimum step of 25 μm, with high repeatability and at low cost. The system is able to record transverse magnetic field intensities as a function of the probe's position in real time and has been used to measure the magnetic field of the MIR and THz undulator. Herein, the components, construction, and test results of the system are described.

Fresnel zone plate sculptured out of diamond by femtosecond laser for harsh environments.

With the rapid development of micro-optical applications, there is an increasing demand for micro-optical elements that can be made with minimal processing steps. Current research focuses on practical functionalities of optical performance, lightweight, miniaturization, and easy integration. As an important planar diffractive optical element, the Fresnel zone plate (FZP) provides a compact solution for focusing and imaging. However, the fabrication of FZPs with high quality out of hard and brittle materials remains challenging. Here, we report on the fabrication of diamond FZP by femtosecond laser direct writing. FZPs with the same outer diameter and different focal lengths of 250-1000 µm were made via ablation. The fabricated FZPs possess well-defined geometry and excellent focusing and imaging ability in the visible spectral range. Arrays of FZPs with different focal lengths were made for potential applications in imaging, sensing, and integrated optical systems.

Does daily physical activity reflect claudication distance measured on a treadmill and in a community outdoor setting?

Low physical activity in patients with claudication is associated with lower walking abilities as assessed by the treadmill test. The impact of physical activity on the ability to walk in a natural environment is unknown. The study aimed to assess the level of daily physical activity among patients with claudication, as well as the relationship between the level of daily physical activity and claudication distance measured during the outdoor walking and treadmill tests. The study included 37 patients (24 males), aged 70.03±5.9, with intermittent claudication. Daily step count was assessed using the Garmin Vivofit activity monitor, worn on the non-dominant wrist for 7 consecutive days. Pain-free walking distance (PFWDTT) and maximal walking distance (MWDTT) were measured via the treadmill test. During 60-minute outdoor walking, the maximal walking distance (MWDGPS), total walking distance (TWDGPS), walking speed (WSGPS), number of stops (NSGPS) and stop durations (SDGPS) were assessed. Mean daily step count - 7,102±3,433. A significant correlation was observed between daily step count and MWDTT, TWDGPS (R=0.33, R=0.37, respectively (p<0.05). Furthermore, 51% of patients reached less than 7,500 steps/day and presented significantly shorter MWDTT, MWDGPS and TWDGPS, compared to the participants covering ≥7,500 steps (p<0.05). The daily step count reflects claudication distance measured on a treadmill and only partially in a community outdoor setting. The minimal daily step count that should be recommended for patients with claudication, allowing achievement of significantly better results with regard to walking abilities, both on the treadmill and in outdoor settings, is at least 7,500 steps per day.

Exploring High-Precision Non-Assembly Mechanisms: Design of a Vitrectome Mechanism for Eye Surgery.

A vitrectome is a commonly used instrument in eye surgery, which is used to cut and aspirate the vitreous body out of the eye. The mechanism of the vitrectome consists of miniature components that need to be assembled by hand due to their size. Non-assembly 3D printing, in which fully functional mechanisms can be produced in a single production step, can help create a more streamlined production process. We propose a vitrectome design based on a dual-diaphragm mechanism, which can be produced with minimal assembly steps using PolyJet printing. Two different diaphragm designs were tested to fulfill the requirements of the mechanism: a homogenous design based on 'digital' materials and a design using an ortho-planar spring. Both designs were able to fulfill the required displacement for the mechanism of 0.8 mm, as well as cutting forces of at least 8 N. The requirements for the cutting speed of the mechanism of 8000 RPM were not fulfilled by both designs, since the viscoelastic nature of the PolyJet materials resulted in a slow response time. The proposed mechanism does show promise to be used in vitrectomy; however, we suggest that more research into different design directions is required.

ResVAE ensemble: Unsupervised identification of gene sets in multi-modal single-cell sequencing data using deep ensembles.

Feature identification and manual inspection is currently still an integral part of biological data analysis in single-cell sequencing. Features such as expressed genes and open chromatin status are selectively studied in specific contexts, cell states or experimental conditions. While conventional analysis methods construct a relatively static view on gene candidates, artificial neural networks have been used to model their interactions after hierarchical gene regulatory networks. However, it is challenging to identify consistent features in this modeling process due to the inherently stochastic nature of these methods. Therefore, we propose using ensembles of autoencoders and subsequent rank aggregation to extract consensus features in a less biased manner. Here, we performed sequencing data analyses of different modalities either independently or simultaneously as well as with other analysis tools. Our resVAE ensemble method can successfully complement and find additional unbiased biological insights with minimal data processing or feature selection steps while giving a measurement of confidence, especially for models using stochastic or approximation algorithms. In addition, our method can also work with overlapping clustering identity assignment suitable for transitionary cell types or cell fates in comparison to most conventional tools.

Deployment of whole genome next-generation sequencing of SARS-CoV-2 in a military maritime setting

BackgroundSARS-CoV-2 can spread rapidly on maritime platforms. Several outbreaks of SARS-CoV-2 have been reported on warships at sea, where transmission is facilitated by living and working in close quarters. Core...

Accelerating probabilistic tensor canonical polyadic decomposition with nonnegative factors: An inexact BCD Approach

Recently, Bayesian modeling and variational inference (VI) were leveraged to enable the nonnegative factor matrix learning with automatic rank determination in tensor canonical polyadic decomposition (CPD), which has found various applications in big data analytics. However, since VI inherently performs block coordinate descent (BCD) steps over the functional space, it generally does not allow integration with modern large-scale optimization methods, making the scalability a critical issue. In this paper, it is revealed that the expectations of the variables updated by the VI algorithm is equivalent to the block minimization steps of a deterministic optimization problem. This equivalence further enables the adoption of inexact BCD method for devising a fast nonnegative factor matrix learning algorithm with automatic tensor rank determination. Numerical results using synthetic data and real-world applications show that the performance of the proposed algorithm is comparable with that of the VI-based algorithm, but with computation times reduced significantly.

ЧИСЛЕННЫЙ ЭКСПЕРИМЕНТ ПО ИСПЫТАНИЯМ НА СДВИГ ПЕРЕКРЕСТНО-СКЛЕЕННОГО ДЕРЕВЯННОГО ЭЛЕМЕНТА

A numerical experiment on shear tests of a model of a wooden CLT-panel revealed the possibility of visualizing the wave process of stress and strain propagation. Deformation as a process continuous in time is described discretely, in minimal time steps, with a visual display of a video sequence of positions in the space of the locus of tangent strain tensors. A qualitative and quantitative continuous wave pattern of stresses shows areas of the model volume where stress and strain waves arise and move. Stress isosurfaces are visualized. It is concluded that it is possible to divide the stress values expected in the numerical experiment into arbitrarily narrow intervals and separately monitor these processes in numerical models.

Composite material immobilized in 3D-printed support, an economical approach for electrochemical sensing of nimesulide

This work aimed to build a disposable electrode, cheap, and robust, with a maximum manufacturing value of US$ 0.02 per sensor, whose basic structure is a composite material (CM) immobilized on 3D support of acrylonitrile butadiene styrene (ABS), to the determination of Nimesulide (NIM) in different samples. The surface characterization of the electrodes was made by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). The electrochemical response for NIM obtained was compared with a commercial Glassy Carbon electrode (GCE), where a 70 % increase in the analytical response was observed. The sensor was applied for the quantification of NIM by the square wave voltammetry (SWV) method in pharmaceutical formulations, tap water, synthetic urine, and breast milk. The optimized method presented a satisfactory linear range of 10 to 50 µmol/L, with a simple sample treatment, good precision (RSD < 3.38 %), and excellent detectability (limit of detection 0.018 µmol/L). Samples were spiked at three concentration levels to evaluate the accuracy of the method, obtaining recovery values from 96.2 to 112.8 %. Thus, the disposable proposed device proves to be a promising analytical tool for routine analysis of NIM in different samples with a minimum sample preparation step (simple dilution).

Utilization of industrial waste - Liquid cheese whey for the batch fermentation of lovastatin using Fusarium nectrioides (MH173849) an endophytic fungus: Screening, production and characterization

In this current research, a novel way of utilizing the plant weed and dairy industrial waste for the cost-effective production of Lovastatin by the novel fungus Fusarium nectrioides (MH173849) under controlled conditions was reported for the first time with scientific evidence. A total of 25 endophytic fungi were isolated from the 90 tissue fragments of Euphorbia hirta (L) and identified based on morphological and microscopical characteristics. All the fungal isolates were screened for Lovastatin production using Neurospora crassa bioassay. Among the 25 fungal isolates, Fusarium sp2, Nigrospora sphaerica, and Fusarium sp 4 showed maximum zone of inhibition and they were further verified by Thin Layer Chromatography. Since the Rf values of Fusarium sp 4 and standard Lovastatin were the same, further characterization was preceded only with Fusarium sp 4. An evolutionary relationship of two positive isolates, Fusarium sp 2 and Fusarium sp 4 was studied with other Lovastatin-producing fungi. Gene sequencing and BLAST revealed that a novel fungus, Fusarium sp 4 was found to be Fusarium nectrioides (MH173849) and it was further used for batch fermentation of Lovastatin in the modified media using liquid cheese whey under controlled conditions, which enhanced the productivity up to 43.40 μg/mL with the minimum purification steps. LC-MS-MS and NMR studies confirmed the production of Lovastatin by F. nectrioides (MH173849) due to the presence of Pyran molecule hydrogen, Hydrogen fusing two molecules as intermediate with triplet signal groups, methylbutanoic acid, and hexahydro naphthalene. Therefore, this fungus may be utilized by industries for the cost-effective production of Lovastatin.