Full-Face Mask Use during SCUBA Diving Counters Related Oxidative Stress and Endothelial Dysfunction

Impaired flow mediated dilation (FMD), an index of vascular stress, is known after SCUBA diving. This is related to a dysfunction of nitric oxide (NO) availability and a disturbance of the redox status, possibly induced by hyperoxic/hyperbaric gas breathing. SCUBA diving is usually performed with a mask only covering “half face” (HF) and therefore forcing oral breathing. Nasal NO production is involved in vascular homeostasis and, as consequence, can significantly reduce NO possibly promoting vascular dysfunction. More recently, the utilization of “full-face” (FF) mask, allowing nasal breathing, became more frequent, but no reports are available describing their effects on vascular functions in comparison with HF masks. In this study we assessed and compared the effects of a standard shallow dive (20 min at 10 m) wearing either FF or a HF mask on different markers of vascular function (FMD), oxidative stress (ROS, 8-iso-PGF2α) and NO availability and metabolism (NO2, NOx and 3-NT and iNOS expression). Data from a dive breathing a hypoxic (16% O2 at depth) gas mixture with HF mask are shown allowing hyperoxic/hypoxic exposure. Our data suggest that nasal breathing might significantly reduce the occurrence of vascular dysfunction possibly due to better maintenance of NO production and bioavailability, resulting in a better ability to counter reactive oxygen and nitrogen species. Besides the obvious outcomes in terms of SCUBA diving safety, our data permit a better understanding of the effects of oxygen concentrations, either in normal conditions or as a strategy to induce selected responses in health and disease.

Aktinische Keratose: Tageslicht PDT zeigt umfassendes Wirkspektrum

Actinic keratoses are a chronic condition in ultraviolet-damaged skin, with a risk of progressing to invasive skin cancer. The aim of this study was to investigate the preventive potential of field-directed repetitive daylight photodynamic therapy for actinic keratoses. A randomized trial was performed, including 58 patients with ≥5 actinic keratoses on photodamaged facial skin, who received either 5 full-face sessions of daylight photodynamic therapy within a period of 2 years or lesion-directed cryosurgery. Primary outcome was the mean cumulative number of new actinic keratoses developed between visits 2 and 6 (visit 6 being a follow-up). This outcome was lower after daylight photo-dynamic therapy (7.7) compared with cryosurgery (10.2), but the difference did not reach significance (–2.5, 95% confidence interval –6.2 to 1.2; p = 0.18). Several signs of photoageing (fine lines, pigmentation, roughness, erythema, sebaceous gland hyperplasia) were significantly reduced after daylight photodynamic therapy, but not after cryosurgery. Significantly less pain and fewer side-effects were reported during daylight photodynamic therapy than during cryosurgery. This study found that repetitive daylight photodynamic therapy had photo-rejuvenating effects. However, the prevention of actinic keratoses by this therapy could not be proven in a statistically reliable manner.

Facial and body sexual dimorphism are not interconnected in the Maasai

Background In this paper, we investigate facial sexual dimorphism and its’ association with body dimorphism in Maasai, the traditional seminomadic population of Tanzania. We discuss findings on other human populations and possible factors affecting the developmental processes in Maasai. Methods Full-face anthropological photographs were obtained from 305 Maasai (185 men, 120 women) aged 17–90 years. Facial shape was assessed combining geometric morphometrics and classical facial indices. Body parameters were measured directly using precise anthropological instruments. Results Sexual dimorphism in Maasai faces was low, sex explained 1.8% of the total shape variance. However, male faces were relatively narrower and vertically prolonged, with slightly wider noses, narrower-set and lower eyebrows, wider mouths, and higher forehead hairline. The most sexually dimorphic regions of the face were the lower jaw and the nose. Facial width-to-height ratio (fWHR), measured in six known variants, revealed no significant sexual dimorphism. The allometric effects on facial traits were mostly related to the face growth, rather than the growth of the whole body (body height). Significant body dimorphism was demonstrated, men being significantly higher, with larger wrist diameter and hand grip strength, and women having higher BMI, hips circumferences, upper arm circumferences, triceps skinfolds. Facial and body sexual dimorphisms were not associated. Conclusions Facial sex differences in Maasai are very low, while on the contrary, the body sexual dimorphism is high. There were practically no associations between facial and body measures. These findings are interpreted in the light of trade-offs between environmental, cultural, and sexual selection pressures.

Realistic Motion Avatars are the Future for Social Interaction in Virtual Reality

This study evaluated participant self-reported appraisal of social interactions with another person in virtual reality (VR) where their conversational partner was represented by a realistic motion avatar. We use the term realistic motion avatar because: 1. The avatar was modelled to look like the conversational partner it represented, and 2. Full face and body motion capture was utilised so that the avatar mimicked the facial and body language of the conversational partner in real-time. We compared social interaction in VR with face-to-face interaction across two communicative contexts: 1. Getting acquainted conversation, and 2. A structured interview where the participant engaged in self-disclosure about positive and negative experiences. Overall, participants largely indicated they preferred face-to-face over VR communication. However, some participants did indicate a preference for VR communication. Additionally, an analysis of post-conversation ratings indicated no significant difference for rated enjoyment, understanding, self-disclosure, comfort, and awkwardness between communication modes. The only ratings where face-to-face was found to be superior was for perceived closeness across both types of communication, and for feeling understood specifically when disclosing negative experiences. Most participants perceived frequent eye contact in both face-to-face and VR interaction, but typically more eye contact when face-to-face. Eye contact was positively associated with rated enjoyment, closeness, and comfort. Overall, our findings suggest that harnessing full face and body motion capture can make social interaction in VR very similar to face-to-face interaction. We anticipate that VR social interaction is poised to become the next major technological evolution for human computer mediated communication and suggest avenues for further research.

Relationship Between Facial Areas With the Greatest Increase in Non-local Contrast and Gaze Fixations in Recognizing Emotional Expressions

The aim of our study was to analyze gaze fixations in recognizing facial emotional expressions in comparison with o the spatial distribution of the areas with the greatest increase in the total (nonlocal) luminance contrast. It is hypothesized that the most informative areas of the image that getting more of the observer’s attention are the areas with the greatest increase in nonlocal contrast. The study involved 100 university students aged 19-21 with normal vision. 490 full-face photo images were used as stimuli. The images displayed faces of 6 basic emotions (Ekman’s Big Six) as well as neutral (emotionless) expressions. Observer’s eye movements were recorded while they were the recognizing expressions of the shown faces. Then, using a developed software, the areas with the highest (max), lowest (min), and intermediate (med) increases in the total contrast in comparison with the surroundings were identified in the stimulus images at different spatial frequencies. Comparative analysis of the gaze maps with the maps of the areas with min, med, and max increases in the total contrast showed that the gaze fixations in facial emotion classification tasks significantly coincide with the areas characterized by the greatest increase in nonlocal contrast. Obtained results indicate that facial image areas with the greatest increase in the total contrast, which preattentively detected by second-order visual mechanisms, can be the prime targets of the attention.

Effectiveness of Safety Interventions in Fire Engines to Reduce Potential Airborne Transmission of SARS-CoV-2

Physical distancing and wearing a face mask are key interventions to prevent COVID-19. While this remains difficult to practice for millions of firefighters in fire engines responding to emergencies, the delayed forthcoming of evidence on the effectiveness of such safety interventions in this setting presents a major problem. In this field experimental study, we provided initial evidence to close this gap. We examined total aerosol burden in the cabin of a fire engine whilst manipulating crew size, use of FFP2 respirators and use of SCBA full-face masks during 15-min driving periods. At the same time, we controlled for crew activity and speaking, vehicle speed, cabin ventilation, cabin air temperature, pressure and humidity. Limiting the crew size, using FFP2 respirators and not donning SCBA full-face masks was associated with a reduction of the arithmetic mean of total aerosol burden of up to 49%. This study provided initial evidence on the effectiveness of safety interventions in fire engines to reduce potential airborne transmission of SARS-CoV-2 through aerosols. More research about the physical and the clinical effectiveness of such safety interventions is needed.

Effects of different processes of tunneling on displacements soil using 3D Finite Element Method

The excavation process of tunnels induces stresses and deformation in the surrounding soil. The method of excavation is one of the major problems related to the safety of the operators and the ground stability during the construction of underground works. So, it is necessary to choose an ideal method to minimize the displacements and stresses induced by tunneling. The main aim of this study is to simulate numerically the effect of different processes of tunneling on ground displacements, the settlements at surface soil and the internal efforts induced in the lining tunnel; in order to select the best process of excavation, which gives us a less effects on displacements generated by tunneling, thus, ensuring the stability and the solidity of the underground constructions. In addition, this study allows us to control and to predict the diverse movements generated by tunneling (displacements, settlements, efforts internes) exclusively for the shallow tunnel nearby to the underground constructions in the urban site. This modeling will be done by employing five different processes for tunnel excavation using the NATM (New Austrian Tunneling Method) method. The first process, the modeling of the excavation tunnel, is done almost in the same way as in reality; the partial face excavation, with seven slices, made by the excavation. The second process, by partial face excavation, is divided into eleven slices, next, we used the partial face excavation by nine slices, and then in thirteen slices. Finally, the dig is made by full-face excavation. The paper contributes to the prediction of the response of the soil environment to tunnel excavation using the NATM method and to minimize the diverse movements generated by tunneling. The appropriately chosen methodology confirms that displacements and subsidence are strongly influenced by the tunneling method. The three-dimensional Finite Elements Method using Plaxis3D program has been applied in the numerical simulation. The study resulted in the recommendation of a process that minimizes the effect of excavation on subsidence and ground displacement for a particular Setiha tunnel.

The Effects of Wearing Helmets on Reaction of Motorcycle Riders

In Taiwan, motorcycles are the most commonly used means of transportation and also have the highest accident rate. Because motorcycles are less stable and provide less protection than cars, motorcycle riders are vulnerable in traffic accidents. Furthermore, head trauma is often fatal, causing a great loss to society. Although helmets provide protection to the head, they also affect the visual field of motorcycle riders. However, the literature mostly focuses on the protective effect of helmets after a collision and rarely considers the influence of helmets prior to collisions. In the study design, participants wore three different types of helmet and watched a pre-recorded video of an actual street with pre-placed warning triangles at a speed of 60 km/h. Participants were asked to press a button when they saw a warning triangle. The time between participants seeing the warning triangle and arriving at the warning triangle was calculated. This time is referred to as the “early reaction time.” The number of missed presses and false presses was also recorded. The results of the study show that: (1) Of the three types of helmet, wearing half helmets produced the longest early reaction times, followed by 3/4 helmets, with full face helmets with the shortest early reaction times. (2) Early reaction times when wearing a half helmet were the same as early reaction times when not wearing a helmet. (3) The results for the total number of missed and false presses when wearing the three types of helmet were the same as for the results of the early reaction time analysis. (4) Sex and age had no effect on early reaction times. The experimental results can be used as a reference for helmet design and academic research.