Effect of tidal volume and frequency on airway responsiveness in mechanically ventilated rabbits

We evaluated the effects of the rate and volume of tidal ventilation on airway resistance (Raw) during intravenous methacholine (MCh) challenge in mechanically ventilated rabbits. Five rabbits were challenged at tidal volumes of 5, 10, and 20 ml/kg at a frequency of 15 breaths/min and also under static conditions (0 ml/kg tidal volume). Four rabbits were subjected to MCh challenge at frequencies of 6 and 30 breaths/min with a tidal volume of 10 ml/kg and also under static conditions. In both groups, the increase in Raw with MCh challenge was significantly greater under static conditions than during tidal ventilation at any frequency or volume. Increases in the volume or frequency of tidal ventilation resulted in significant decreases in Raw in response to MCh. We conclude that tidal breathing suppresses airway responsiveness in rabbits in vivo. The suppression of narrowing in response to MCh increases as the magnitude of the volume or the frequency of the tidal oscillations is increased. Our findings suggest that the effect of lung volume changes on airway responsiveness in vivo is primarily related to the stretch of airway smooth muscle.     

Work activities and musculoskeletal complaints among preschool workers

The potential for musculoskeletal trauma among preschool workers has been largely unexplored in the United States. This case report describes an investigation conducted to identify and evaluate possible causes of back and lower extremity pain among 22 workers at a Montessori day care facility. Investigators met with and distributed a questionnaire to school employees, and made measurements of workstation and furniture dimensions. Investigators also recorded the normal work activities of school employees on videotape, and performed a work sampling study to estimate the percentage of time employees spend performing various tasks and in certain postures.

Questionnaire results from 18 employees indicated that back pain/discomfort was a common musculoskeletal complaint, reported by 61% of respondents. Neck/shoulder pain, lower extremity pain and hand/wrist pain were reported by 33, 33 and 11% of respondents, respectively. Observation and analysis of work activities indicated that employees spend significant periods of time kneeling, sitting on the floor, squatting, or bending at the waist. Furthermore, staff members who work with smaller children (i.e. six weeks to 18 months of age) performed more lifts and assumed more awkward lower extremity postures than employees who work with older children (3–4 years of age). Analysis of two lifting tasks using the revised NIOSH lifting equation indicated that employees who handle small children may be at increased risk of lifting-related low back pain. Investigators concluded that day care employees at this facility are at increased risk of low back pain and lower extremity (i.e. knee) injury due to work activities that require awkward or heavy lifts, and static working postures. Recommendations for reducing or eliminating these risks by modifying the workplace and changing the organization and methods of work are presented.     

Boosting Room‐Temperature Magneto‐Ionics in a Non‐Magnetic Oxide Semiconductor

Voltage control of magnetism through electric field‐induced oxygen motion (magneto‐ionics) could represent a significant breakthrough in the pursuit for new strategies to enhance energy efficiency in magnetically actuated devices. Boosting the induced changes in magnetization, magneto‐ionic rates and cyclability continue to be key challenges to turn magneto‐ionics into real applications. Here, it is demonstrated that room‐temperature magneto‐ionic effects in electrolyte‐gated paramagnetic Co₃O₄ films can be largely increased both in terms of generated magnetization (6 times larger) and speed (35 times faster) if the electric field is applied using an electrochemical capacitor configuration (utilizing an underlying conducting buffer layer) instead of placing the electric contacts at the side of the semiconductor (electric‐double‐layer transistor‐like configuration). This is due to the greater uniformity and strength of the electric field in the capacitor design. These results are appealing to widen the use of ion migration in technological applications such as neuromorphic computing or iontronics in general.     

Correction to: The influence of training level on manual fight in connection to performance,scan pattern,and task load

Cognition, Technology & Work - A correction to this paper has been published: https://doi.org/10.1007/s10111-021-00680-1     

ARADISH - Development of a Standardized Plant Growth Chamber for Experiments in Gravitational Biology Using Ground Based Facilities

Plant development strongly relies on environmental conditions. Growth of plants in Biological Life Support Systems (BLSS), which are a necessity to allow human survival during long-term space exploration missions, poses a particular problem for plant growth, as in addition to the traditional environmental factors, microgravity (or reduced gravity such as on Moon or Mars) and limited gas exchange hamper plant growth. Studying the effects of reduced gravity on plants requires real or simulated microgravity experiments under highly standardized conditions, in order to avoid the influence of other environmental factors. Analysis of a large number of biological replicates, which is necessary for the detection of subtle phenotypical differences, can so far only be achieved in Ground Based Facilities (GBF). Besides different experimental conditions, the usage of a variety of different plant growth chambers was a major factor that led to a lack of reproducibility and comparability in previous studies. We have developed a flexible and customizable plant growth chamber, called ARAbidopsis DISH (ARADISH), which allows plant growth from seed to seedling, being realized in a hydroponic system or on Agar. By developing a special holder, the ARADISH can be used for experiments with Arabidopsis thaliana or a plant with a similar habitus on common GBF hardware, including 2D clinostats and Random Positioning Machines (RPM). The ARADISH growth chamber has a controlled illumination system of red and blue light emitting diodes (LED), which allows the user to apply defined light conditions. As a proof of concept we tested a prototype in a proteomic experiment in which plants were exposed to simulated microgravity or a 90° stimulus. We optimized the design and performed viability tests after several days of growth in the hardware that underline the utility of ARADISH in microgravity research.     

MT: A Mathematica package to compute convolutions

We introduce the Mathematica package MT which can be used to compute, both analytically and numerically, convolutions involving harmonic polylogarithms, polynomials or generalized functions. As applications contributions to next-to-next-to-next-to leading order Higgs boson production and the Drell–Yan process are discussed.     

Aluminum–germanium wafer bonding of (AlGaIn)N thin-film light-emitting diodes

Eutectic aluminum–germanium wafer bonding was used to fabricate (AlGaIn)N thin-film light-emitting diodes (LEDs). Wafer bonding was carried out on 2″ wafer level at a bond temperature of 470 °C using patterned Al bond pads on the GaN-on-sapphire LED epiwafer and plain Ge substrates. The microstructure of the joint formation was characterized via cross-section analysis using scanning electron microscopy and energy dispersive X-ray spectroscopy (EDX). Scanning acoustic microscopy was used to investigate the bond interface. The shear strength was determined to be 1–2 kN/cm². The formation of a liquid Al–Ge phase is evident from cross-section analysis and optical microscopy. During solidification, Al and Ge are separated into distinct phases again, which is revealed by EDX. The obtained bond is not free of micro-voids, yet it is mechanically stable and suited for the fabrication of thin-film LEDs by removing the sapphire substrate via laser lift-off, which is also demonstrated.     

Influence of drying on the content of sugars in wet processed green Arabica coffees

When wet processed coffee beans are dried, the resulting decrease in the water potential induces various metabolic responses. This study was aimed at elucidating the impact of these reactions on the composition of sugars, representing potential aroma precursors. Wet processed green coffees were dried under defined conditions, and the relevant sugars were analysed. Special emphasis was put on the influence of the drying regime, i.e. continuous dryings and such interrupted by pauses in order to mimic sun dryings.     

Hybrid 3D-textile reinforced composites with tailored property profiles for crash and impact applications

Novel 3D-textile reinforced composites with a stretched fibre arrangement have very good specific mechanical properties and outstanding energy absorption capabilities. With respect to the specific technical requirements, 3D-textile preforms can be adjusted with regard to stiffness, strength and crash-worthiness by the intelligent combination of different fibre materials in the textile preform. Thus, hybrid 3D-textile preforms with tailored property profiles are excellent candidates for the use in impact and crash components of innovative lightweight structures for the aircraft and vehicle industry as well as for mechanical engineering applications.     

Abusive supervision and subordinates' organization deviance.

The authors developed an integrated model of the relationships among abusive supervision, affective organizational commitment, norms toward organization deviance, and organization deviance and tested the framework in 2 studies: a 2-wave investigation of 243 supervised employees and a cross-sectional study of 247 employees organized into 68 work groups. Path analytic tests of mediated moderation provide support for the prediction that the mediated effect of abusive supervision on organization deviance (through affective commitment) is stronger when employees perceive that their coworkers are more approving of organization deviance (Study 1) and when coworkers perform more acts of organization deviance (Study 2). (PsycINFO Database Record (c) 2010 APA, all rights reserved)