An evaluation of off-axis manual forces and upper extremity joint moments during unilateral pushing and pulling exertions

This study quantified changes in off-axis manual force production and upper extremity joint moments during sub-maximal one-handed push and pull tasks. Off-axis forces in the up/down and left/right directions were quantified in the presence or absence of constraints placed upon the direction of manual force application and/or arm posture. Resultant off-axis forces of 13.1% and 9.4% were produced for pulls and pushes, respectively. Off-axis forces during pulling were oriented downwards and to the right and were associated with a decreased should flexion moment when posture was constrained. Off-axis forces in the up/down direction were minimized with increased on-axis force level. Off-axis forces during pushing tended to be oriented to the left and were associated with increased elbow flexion moment when off-axis forces were allowed. By not accounting for these off-axis forces, we may not be accurately reflecting actionable muscle- and joint-level loading characteristics derived from biomechanically-based proactive ergonomics assessment approaches.

Practitioner Summary: Constrained arm postures and directions of manual force application influence the production of off-axis forces. As inaccurate estimation of true manual forces can markedly influence actionable outcomes of proactive ergonomic assessments, this study suggests that simplification of these estimates is insufficient and potentially misleading.     

Announcing Automated Lane Changes: Active Vehicle Roll Motions as Feedback for the Driver

ABSTRACT

As supervisor of the automation system during partially automated driving, it is essential for the driver to have a good awareness of the automation to fulfill this new task sufficiently. Therefore, feedback about intentions of the automation, for example lane changes, is crucial. So far, this feedback is mainly presented visually to the driver. Conversely, in this article, feedback for announcing lane changes is realized via active vehicle roll motions. Several designs are implemented in an automated test vehicle and are evaluated in four different driving scenarios on a test track. Totally, 39 participants rated the vehicle roll motions, for example, regarding the items roll direction, intensity, usefulness, and the predictability of the driving behavior. The results show that active roll motions as feedback for announcing automated lane changes should be clearly perceptible and are considered useful, not misleading, and support the drivers regarding their mode/system awareness.     

Application of biopreservatives in meat preservation: a review

As a highly perishable food, raw meat, if not preserved, will spoil due to the altered metabolism, microbial activity and external factors during storage. Biopreservatives, as a new type of preservatives, are characterised by nontoxicity, extensive source and good application prospects in the raw meat. This review discusses the factors responsible for the spoilage of raw meat, recaps the spoilage bacteria in the raw meat and summarises the major antibacterial mechanism of various biopreservatives. Moreover, application of various biopreservatives in the preservation of raw meat is emphatically reviewed. In addition, some existing challenges for application of biopreservatives and their prospective development are also discussed. The present work provides a theoretical reference for application of various biopreservatives in different types of raw meat for shelf life extension.     

Alerting a Campus Community: Emergency Notification from a Public's Perspective

Emergency notification systems have become an essential part of campus security since the 2007 Virginia Tech shooting in the United States. This study explored how a public‐centred perspective can inform campus‐alerting practices. In particular, this study provided depth to two independent variables of the situational theory of publics: constraint recognition and level of involvement. Additionally, this study proposed the development of a subcategorisation of hot‐issue publics called transient publics.     

Simultaneous two-dimensional laser-induced-fluorescence measurements of argon ions

Recent laser upgrades on the Hot Helicon Experiment at West Virginia University have enabled multiplexed simultaneous measurements of the ion velocity distribution function at a single location, expanding our capabilities in laser-induced fluorescence diagnostics. The laser output is split into two beams, each modulated with an optical chopper and injected perpendicular and parallel to the magnetic field. Light from the crossing point of the beams is transported to a narrow-band photomultiplier tube filtered at the fluorescence wavelength and monitored by two lock-in amplifiers, each referenced to one of the two chopper frequencies.     

Measurements of neutral helium density in helicon plasmas

Laser-induced-fluorescence (LIF) is used to measure the density of helium atoms in a helicon plasma source. For a pump wavelength of 587.725 nm (vacuum) and laser injection along the magnetic field, the LIF signal exhibits a signal decrease at the Doppler shifted central wavelength. The drop in signal results from the finite optical depth of the plasma and the magnitude of the decrease is proportional to the density of excited state neutral atoms. Using Langmuir probe measurements of plasma density and electron temperature and a collisional-radiative model, the absolute ground state neutral density is calculated from the optical depth measurements. Optimal plasma performance, i.e., the largest neutral depletion on the axis of the system, is observed for antenna frequencies of 13.0 and 13.5 MHz and magnetic field strengths of 550-600 G.     

Examination of the efficacy of acute L-alanyl-L-glutamine ingestion during hydration stress in endurance exercise

Background

The present study sought to determine whether the consumption of a mineral-rich alkalizing (AK) bottled water could improve both acid-base balance and hydration status in young healthy adults under free-living conditions. The AK water contains a naturally high mineral content along with Alka-PlexLiquid, a dissolved supplement that increases the mineral content and gives the water an alkalizing pH of 10.0.

Methods

Thirty-eight subjects were matched by gender and self-reported physical activity (SRPA, hrs/week) and then split into Control (12 women, 7 men; Mean +/- SD: 23 +/- 2 yrs; 7.2 +/- 3.6 hrs/week SRPA) and Experimental (13 women, 6 men; 22 +/- 2 yrs; 6.4 +/- 4.0 hrs/week SRPA) groups. The Control group consumed non-mineralized placebo bottled water over a 4-week period while the Experimental group consumed the placebo water during the 1st and 4th weeks and the AK water during the middle 2-week treatment period. Fingertip blood and 24-hour urine samples were collected three times each week for subsequent measures of blood and urine osmolality and pH, as well as total urine volume. Dependent variables were analyzed using multivariate repeated measures ANOVA with post-hoc focused on evaluating changes over time within Control and Experimental groups (alpha = 0.05).

Results

There were no significant changes in any of the dependent variables for the Control group. The Experimental group, however, showed significant increases in both the blood and urine pH (6.23 to 7.07 and 7.52 to 7.69, respectively), a decreased blood and increased urine osmolality, and a decreased urine output (2.51 to 2.05 L/day), all during the second week of the treatment period (P < 0.05). Further, these changes reversed for the Experimental group once subjects switched to the placebo water during the 4th week.

Conclusions

Consumption of AK water was associated with improved acid-base balance (i.e., an alkalization of the blood and urine) and hydration status when consumed under free-living conditions. In contrast, subjects who consumed the placebo bottled water showed no changes over the same period of time. These results indicate that the habitual consumption of AK water may be a valuable nutritional vector for influencing both acid-base balance and hydration status in healthy adults.     

Gastric electrical stimulation has an immediate antiemetic effect in patients with gastroparesis

BACKGROUND: Electrical stimulation has been successfully employed to treat diseases involving electro-pathology in the heart, skeletal muscles, and the brain, but not in the GI tract. AIM: This study examined the clinical feasibility and efficacy of GES in treating patients with severe gastroparesis. METHODS: Nausea, vomiting, GEA, and liquid and solid gastric emptying were monitored in eleven patients with refractory gastroparesis at baseline and after one week of continuous electrical stimulation administered at 12 cycles/min. Eight patients were subsequently implanted with permanent stimulation devices. Follow-up studies were conducted after 1, 3, 6, and 12 mo. of stimulation. RESULTS: After one week of stimulation, patients' quantified symptoms of nausea and vomiting decreased significantly, and liquid emptying and GEA improved. This improvement was maintained over time in the patients who continued to receive stimulation. Emptying of solids showed progressive improvement that became significant after 3 mo. The three patients who did not receive stimulation after the trial period showed significantly higher symptoms at 12 mo. CONCLUSION: This paper demonstrates that GES at a frequency of 12 cycles/min has an immediate antiemetic effect, followed by an improvement in disordered gastric emptying.