Interruption management: the use of attention-directing tactile cues

Previous research has suggested that providing informative cues about interrupting stimuli aids management of multiple tasks. However, auditory and visual cues can be ineffective in certain situations. The objective of the present study was to explore whether attention-directing tactile cues aid or interfere with performance. A two-group posttest-only randomized experiment was conducted. Sixty-one participants completed a 30-min performance session consisting of aircraft-monitoring and gauge-reading computer tasks. Tactile signals were administered to a treatment group to indicate the arrival and location of interrupting tasks. Control participants had to remember to visually check for the interrupting tasks. Participants in the treatment group responded to more interrupting tasks and responded faster than did control participants. Groups did not differ on error rates for the interrupting tasks, performance of the primary task, or subjective workload perceptions. In the context of the tasks used in the present research, tactile cues allowed participants to effectively direct attention where needed without disrupting ongoing information processing. Tactile cues should be explored in a variety of other visual, interrupt-laden environments. Potential applications exist for aviation, user-interface design, vigilance tasks, and team environments.     

Anytime measures for top-k algorithms on exact and fuzzy data sets

Top-k queries on large multi-attribute data sets are fundamental operations in information retrieval and ranking applications. In this article, we initiate research on the anytime behavior of top-k algorithms on exact and fuzzy data. In particular, given specific top-k algorithms (TA and TA-Sorted) we are interested in studying their progress toward identification of the correct result at any point during the algorithms’ execution. We adopt a probabilistic approach where we seek to report at any point of operation of the algorithm the confidence that the top-k result has been identified. Such a functionality can be a valuable asset when one is interested in reducing the runtime cost of top-k computations. We present a thorough experimental evaluation to validate our techniques using both synthetic and real data sets.     

Phase formation in electrodeposited and thermally annealed Al-Mn alloys

Aluminum-manganese alloys with compositions ranging from 0 to 50 wt pct Mn were electrodeposited onto copper substrates from a chloroaluminate molten salt electrolyte containing MnCl₂ at temperatures of 150 °C to 325 °C. The structures of these electrodeposits were then compared to those observed when metastable electrodeposits were thermally annealed at 200 °C to 610 °C. The alloys were characterized by scanning electron microscopy, transmission electron microscopy (TEM), energy dispersive spectroscopy, and X-ray diffraction. At deposition temperatures of 150 °C to 250 °C, no stable structure other than the strongly supersaturated and highly dislocated Al-face-centered cubic (fcc) solid solution is observed. An amorphous phase and body-centered cubic (bcc) Al₈Mn₅ are observed at higher manganese compositions. In the temperature range of 250 °C to 325 °C, some of the phases predicted by the equilibrium phase diagram, such as Al₆Mn and Al₁₁Mn₄, are electrodeposited. The direct deposition of the icosahedral and decagonal phases has been demonstrated at 325 °C. Thermal annealing of the amorphous phase at temperatures higher than 225 °C results in its transformation to the icosahedral phase with a grain size much smaller than that obtained in the electrodeposited icosahedral phase. Additional annealing at higher temperatures does not result in any detectable coarsening of the icosahedral phase; instead, crystals of Al₆Mn or Al₁₁Mn₄ grow into the regions once occupied by the icosahedral phase. The crystalline Al₆Mn phase which forms as the result of thermal annealing shows a structural deviation from the equilibrium phase. As-deposited alloys comprised of 2-to 3-nm-thick amorphous regions separated by fcc-Al grains failed to crystallize after 30 minutes annealing at 500 °C.     

Structural study of electrodeposited aluminum-manganese alloys

Aluminum-manganese alloys with compositions ranging between 0 and 27 wt pct Mn were electrodeposited at 150°C onto copper substrates from a chloroaluminate molten salt electrolyte with a controlled addition of MnCl₂. The specimens were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and X-ray diffraction. The addition of small amounts of Mn results in the formation of a supersaturated fcc solid solution of Mn in Al. At the higher Mn content, an amorphous phase is established. The highly faceted crystalline surface of pure Al and Al−Mn solid solution becomes smooth and nearly specular when the amorphous phase is present. The amorphous phase appears in the form of rounded grains and has a lower limit of Mn concentration close to the Al₆Mn composition. There is a concentration discontinuity between the above limit and the higher Mn concentration limit of the fcc phase (about 9 wt pct). Appearance of the amorphous phase in the alloy results in a decrease in the Mn concentration in solid solution to about 2 wt pct. Crystallization of the amorphous phase starts at the fcc-amorphous phase interface at 230°C. As a result of treatment at 230 °C to 340 °C, the amorphous phase completely transforms into Al₆Mn, while the fcc phase is unaffected. Prior to crystallization, the amorphous phase shows a modification that could be interpreted as the formation of a fine-grained icosahedral phase. The formation and distribution of phases by electrodeposition and rapid solidification are discussed.     

A field intervention examining the impact of an office ergonomics training and a highly adjustable chair on visual symptoms in a public sector organization

Objective

Examine the effect of a multi-component office ergonomics intervention on visual symptom reductions.

Methods

Office workers were assigned to either a group receiving a highly adjustable chair with office ergonomics training (CWT), a training-only group (TO) or a control group (C). A work environment and health questionnaire was administered 2 and 1 month(s) pre-intervention and 3, 6, and 12 months post-intervention. Multi-level statistical models tested hypotheses.

Results

The CWT intervention lowered daily visual symptoms (p < 0.01) post-intervention. The TO group did not significantly differ from the control group. The CWT group differed significantly from the TO group (p = 0.01) post-intervention.

Conclusion

Workers who received a highly adjustable chair and office ergonomics training had reduced visual symptoms and the effect was maintained through twelve months post-intervention. The lack of a training-only group effect supports implementing training in conjunction with the highly adjustable chair to reduce visual symptoms.     

Chemical and engineering approaches to enable organic field-effect transistors for electronic skin applications

Skin is the body's largest organ and is responsible for the transduction of a vast amount of information. This conformable material simultaneously collects signals from external stimuli that translate into information such as pressure, pain, and temperature. The development of an electronic material, inspired by the complexity of this organ is a tremendous, unrealized engineering challenge. However, the advent of carbon-based electronics may offer a potential solution to this long-standing problem. In this Account, we describe the use of an organic field-effect transistor (OFET) architecture to transduce mechanical and chemical stimuli into electrical signals. In developing this mimic of human skin, we thought of the sensory elements of the OFET as analogous to the various layers and constituents of skin. In this fashion, each layer of the OFET can be optimized to carry out a specific recognition function. The separation of multimodal sensing among the components of the OFET may be considered a "divide and conquer" approach, where the electronic skin (e-skin) can take advantage of the optimized chemistry and materials properties of each layer. This design of a novel microstructured gate dielectric has led to unprecedented sensitivity for tactile pressure events. Typically, pressure-sensitive components within electronic configurations have suffered from a lack of sensitivity or long mechanical relaxation times often associated with elastomeric materials. Within our method, these components are directly compatible with OFETs and have achieved the highest reported sensitivity to date. Moreover, the tactile sensors operate on a time scale comparable with human skin, making them ideal candidates for integration as synthetic skin devices. The methodology is compatible with large-scale fabrication and employs simple, commercially available elastomers. The design of materials within the semiconductor layer has led to the incorporation of selectivity and sensitivity within gas-sensing devices and has enabled stable sensor operation within aqueous media. Furthermore, careful tuning of the chemical composition of the dielectric layer has provided a means to operate the sensor in real time within an aqueous environment and without the need for encapsulation layers. The integration of such devices as electronic mimics of skin will require the incorporation of biocompatible or biodegradable components. Toward this goal, OFETs may be fabricated with >99% biodegradable components by weight, and the devices are robust and stable, even in aqueous environments. Collectively, progress to date suggests that OFETs may be integrated within a single substrate to function as an electronic mimic of human skin, which could enable a large range of sensing-related applications from novel prosthetics to robotic surgery.     

Development of extrusion blown films of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) blends for flexible packaging

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a biodegradable polymer with significant potential for use in food packaging. However, its limited melt strength poses a challenge when employing film-blowing techniques to produce flexible packaging. To overcome this obstacle, we developed blends consisting of 70 wt% PHBV and 30 wt% poly(butylene-co-succinate-co-adipate) (PBSA). Organic peroxides such as dicumyl peroxide and 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, were utilized as reactive compatibilizers to enhance the interfacial adhesion between the polymers. Additionally, acetyl tributyl citrate (ATBC) was employed as a plasticizer to improve processability and ductility. The inclusion of organic peroxides resulted in the formation of long-branched structures, as confirmed by the van-Gurp-Palmen plot. The melt flow index decreased from 30 to 9.8 g/10 min without ATBC and 15.5 g/10 min with ATBC. Successful production of blown PHBV/PBSA films was achieved on a pilot scale (bubble height 180 cm). These films exhibited heat-sealing capability and increased impact strength (7.7 kJ/m²). Moreover, the films maintained a maximum elongation at break of 4% during a 3-month storage experiment with frozen food. Food safety was assessed through overall migration experiments, and the non-plasticized films received approval. In conclusion, the compatibilized PHBV/PBSA blends demonstrate great potential as materials for manufacturing film-blown flexible packaging.     

Comparing the Catalytic and Structural Characteristics of a ‘Short’ Unspecific Peroxygenase (UPO) Expressed in Pichia pastoris and Escherichia coli

Unspecific peroxygenases (UPOs) have emerged as valuable tools for the oxygenation of non-activated carbon atoms, as they exhibit high turnovers, good stability and depend only on hydrogen peroxide as the external oxidant for activity. However, the isolation of UPOs from their natural fungal sources remains a barrier to wider application. We have cloned the gene encoding an ‘artificial’ peroxygenase (artUPO), close in sequence to the ‘short’ UPO from Marasmius rotula (MroUPO), and expressed it in both the yeast Pichia pastoris and E. coli to compare the catalytic and structural characteristics of the enzymes produced in each system. Catalytic efficiency for the UPO substrate 5-nitro-1,3-benzodioxole (NBD) was largely the same for both enzymes, and the structures also revealed few differences apart from the expected glycosylation of the yeast enzyme. However, the glycosylated enzyme displayed greater stability, as determined by nano differential scanning fluorimetry (nano-DSF) measurements. Interestingly, while artUPO hydroxylated ethylbenzene derivatives to give the (R)-alcohols, also given by a variant of the ‘long’ UPO from Agrocybe aegerita (AaeUPO), it gave the opposite (S)-series of sulfoxide products from a range of sulfide substrates, broadening the scope for application of the enzymes. The structures of artUPO reveal substantial differences to that of AaeUPO, and provide a platform for investigating the distinctive activity of this and related'short’ UPOs.     

Physical Forces in Glioblastoma Migration: A Systematic Review

The invasive capabilities of glioblastoma (GBM) define the cancer’s aggressiveness, treatment resistance, and overall mortality. The tumor microenvironment influences the molecular behavior of cells, both epigenetically and genetically. Current forces being studied include properties of the extracellular matrix (ECM), such as stiffness and “sensing” capabilities. There is currently limited data on the physical forces in GBM—both relating to how they influence their environment and how their environment influences them. This review outlines the advances that have been made in the field. It is our hope that further investigation of the physical forces involved in GBM will highlight new therapeutic options and increase patient survival. A search of the PubMed database was conducted through to 23 March 2022 with the following search terms: (glioblastoma) AND (physical forces OR pressure OR shear forces OR compression OR tension OR torsion) AND (migration OR invasion). Our review yielded 11 external/applied/mechanical forces and 2 tumor microenvironment (TME) forces that affect the ability of GBM to locally migrate and invade. Both external forces and forces within the tumor microenvironment have been implicated in GBM migration, invasion, and treatment resistance. We endorse further research in this area to target the physical forces affecting the migration and invasion of GBM.