Comfort measurement of dry and wet touch: an fMRI study

Skin, rectal and extremity temperatures of clothed subjects were measured. The subjects were immersed in extremely cold water (0°C) for very brief periods of time, then exposed, while occupying a life raft, to ambient air temperatures ranging from +4.4° to −28.9°C. Amount and partitioning of the water absorbed by the clothing and effects of water immersion upon metabolic level were determined. Total water absorbed during an immersion period of from 15 seconds to 2 minutes amounted to 9–10 pounds. Mean metabolic increase due to wearing wet clothing was 54.7%. Total body heat storage loss was measured in both dry and wet clothing exposures and mean body cooling curves plotted. Mean body cooling rates for subjects wearing wet clothing were significantly greater (from 49.3% at −40°C to 22.2% at +10°C) than rates observed with dry-clothed subjects. On the basis of total body heat storage loss, a series of predictive curves for human tolerance is presented for both dry- and wet-clothed subjects exposed in a life raft to various low air temperatures. Submitted on January 14, 1958

An energy recovery ventilator (ERV) is a widely used equipment that can recover sensible and latent heat. To improve its performance, it is essential to understand the heat and moisture transfer mechanism in the ERV. Against this background, overarching objectives of this study are to develop mathematical/numerical models for predicting and clarifying the hygro-thermal (i.e. heat and moisture) transfer mechanism in the heat exchange element of the ERV in terms of (i) simplified model for sensitivity analysis, and (ii) comprehensive model to integrate hygro-thermal transfer equations with computational fluid dynamics (CFD) analysis. Toward this end, we conducted fundamental experiments to measure temperature, humidity, and enthalpy exchange efficiencies in the scale-down ERV unit model, and then, numerical analyses were conducted according to the experimental scenario. As results of this study, we confirmed the reasonable prediction accuracy of our proposed numerical models for predicting total heat exchange performances.

The heat and moisture transfer performance in clothed human body affects human life quality (e.g., comfort and health) directly. Accurate modeling and highly efficient simulation of the heat and moisture transfer mechanisms in clothed human body is helpful to enhance the human life quality. In this paper, we first describe a heat and moisture transfer simulation model of clothed human body, which comprises the George Fu’s human thermal physiological model and a 3D heat and moisture transfer model in clothing, and the thermoregulation behaviors as well as the heat transfer mechanisms are taken into consideration. Then according to the physiological and geometrical features of human body, a parallel algorithm for the heat and moisture transfer simulation in clothed human body is proposed. The SPMD framework has been utilized for data parallel. At last, case studies with different environment scenes are presented. The visual simulated results are displayed, and the parallel performance is discussed.

*Department of Neurology, Medical College of Wisconsin, Milwaukee, Wisconsin, U.S.A.; †University Hospital Gent, Gent, Belgium; ‡Departments of Diagnostic Radiology and Neurosurgery, Yale University, New Haven, Connecticut; §Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania; Clinical Epilepsy Section, National Institutes of Health, Bethesda, Maryland; ¶Department of Radiology, Mayo Clinic, Rochester, Minnesota; and **Department of Neurology, Medical College of Georgia, Augusta, Georgia, U.S.A.

The brain is capable of large-scale reorganization in blindness or after massive injury. Such reorganization crosses the division into separate sensory cortices (visual, somatosensory...). As its result, the visual cortex of the blind becomes active during tactile Braille reading. Although the possibility of such reorganization in the normal, adult brain has been raised, definitive evidence has been lacking. Here, we demonstrate such extensive reorganization in normal, sighted adults who learned Braille while their brain activity was investigated with fMRI and transcranial magnetic stimulation (TMS). Subjects showed enhanced activity for tactile reading in the visual cortex, including the visual word form area (VWFA) that was modulated by their Braille reading speed and strengthened resting-state connectivity between visual and somatosensory cortices. Moreover, TMS disruption of VWFA activity decreased their tactile reading accuracy. Our results indicate that large-scale reorganization is a viable mechanism recruited when learning complex skills.DOI: http://dx.doi.org/10.7554/eLife.10762.001

• Heat and moisture transfer model was developed for fixed-bed column walnut drying. • Temperature and moisture distributions in the column and single walnuts were simulated. • Mechanisms of heat and moisture transfer during the drying process were discussed. • Good predictability achieved for drying under step-down temperature conditions. This research was conducted to better understand the mechanisms of heat and moisture transfer of walnuts during drying in a fixed-bed column dryer with heated air, and to develop a mathematical model to simulate this process. Drying experiments were performed under constant temperature and step-down temperature conditions (43, 55, 65 and 75 °C) with fixed air velocity of 0.7 m/s. The nonequilibrium transfers of liquid moisture, water vapor and heat within the single walnuts (both shell and kernel), as well as between the walnuts and drying air in the column were simulated and studied using a finite element method. The numerical results showed that the distribution of temperature and moisture content in the single walnuts played an important role in the heat and moisture transfer in the deep-bed column. The drying characteristics of walnuts were significantly affected by the non-uniformity of drying conditions surrounding the walnuts (particularly for air temperature and humidity) along the column heights. The predicted values of walnut moisture contents, temperatures, and air relative humidity at different column heights agreed well with the experimental values (R adj 2 > 0.972) under different drying conditions. This study established the theoretical basis for improving and optimizing the walnut drying process in deep-bed dryers. The developed mathematical model can be used to describe the drying characteristics and understand the mechanisms of walnuts drying in deep bed dryers.

Do Sensory Cortices Process More than One Sensory Modality during Perceptual Judgments?

Thermodynamic study of incubated eggs is an important component in the optimisation of incubation processes. However, research on the interaction of heat and moisture transfer mechanisms in eggs is rather limited and does not focus on the hatching stage of incubation. During hatch, both the recently hatched chick and the broken eggshell add extra heat and moisture contents to the hatcher environment. In this study, we have proposed a novel way to estimate thermodynamically the amount of water evaporated from a broken eggshell during hatch. The hypothesis of this study considers that previously reported drops in eggshell temperature during hatching of chicks is the result remaining water content evaporating from the eggshell, released on the inner membrane by the recently hatched wet chick, just before hatch. To reproduce this process, water was sprayed on eggshells to mimic the water-fluid from the wet body of a chick. For each sample of eggshell, the shell geometry and weight, surface area and eggshell temperature were measured. Water evaporation losses and convection coefficient were calculated using a novel model approach considering the simultaneous heat and mass transfer profiles in an eggshell. The calculated average convective coefficient was 23.9±7.5W/m2°C, similar to previously reported coefficients in literature as a function of 0.5–1m/s air speed range. Comparison between measured and calculated values for the water evaporation showed 68% probability accuracy, associated to the use of an experimentally derived single heat transfer coefficient. The results support our proposed modelling approach of heat and mass transfer mechanisms. Furthermore, by estimating the amount of evaporated water in an eggshell post-hatch, air humidity levels inside the hatcher can be optimised to ensure wet chicks dry properly while not dehydrating early hatching chicks.

Performance of a Chemical Heat Blanket in Dry, Damp, and Wet Conditions Inside a Mountain Rescue Hypothermia Wrap

We present a literature review of functional brain imaging studies of haptic and visual texture perception, and highlight our ongoing functional magnetic resonance imaging (fMRI) experiment of the crossmodal links between vision and touch. In the fMRI experiment, the subjects viewed or touched a piece of wool or denim cloth. A multivoxel pattern analysis of whole-brain fMRI activity revealed the crossmodal nature of natural texture perception. Visual texture representations were found in the somatosensory and association cortices as well as the visual cortex, while haptic texture representations were found in the visual cortex and association cortices as well as the somatosensory cortex. Furthermore, shared visuo-haptic representations were found in the parietal association, somatosensory, and visual cortices. These results that suggested the crossmodal transfer of texture information across functionally segregated sensory and associative brain regions are discussed in relation to previous findings on texture perception and aesthetic texture or shitsukan.

The transfer of glass—part 2: A study of the transfer of glass to a person by various methods

Hypothermia incurred during training exposure to cold leads to lost training time and possible injury or death. Certain exercises do not occur in particularly cold atmospheres; however, they may involve water immersion and time out of water in wet clothing. Wet clothing results in greater conductive, convective, and evaporative heat loss than dry clothing. This may contribute to hypothermia. PURPOSE: To observe trainee gastro-intestinal temperature (TGI) responses that occur in different water and air conditions and how these responses may be helpful to monitor trainees' safety. METHODS: TGI responses were measured on three occasions (E1, E2, and E3) using an ingestible thermistor consumed > 4hr prior to the first measurement. Group characteristics are as follows: E1 - N=30, height 177 ± 5 cm, body mass 77 ± 7 kg; E2 - N=20, height 177 ± 5 cm, body mass 75 ± 6 kg; E3 - N=69, height 178 ± 7 cm; body mass 77 ± 8 kg. Ambient air temperature (Ta), wind velocity (Vw) and water temperature (Tw) were: E1 14.6°C, 3.3 m·s-1, 15.6°C; E2 14.5°C, 1.0 m·s-1, 17.2°C; E3 19.9°C, 0.5 m·s-1, 18.3°C. The duration of immersion and time on shore in wet clothing were; 38 min, 21 min; 25 min, 12 min; and 33 min, 22min, respectively for E1, E2, and E3. RESULTS: In all exercises mean TGI significantly decreased from the start of the exercise to the end; E1 37.4 ± 0.4°C to 35.3 ± 0.7°C (p<0.01); E2 37.7 ± 0.4°C to 36.5 ± 0.8°C (p<0.01); E3 37.2 ±.04°C to 36.6 ± 0.5°C (p<0.01). Significantly different mean rates of TGI decrease were observed between E1 (-0.04 ± 0.01 °C·min-1) and E3 (-0.01 ± 0.01 °C·min-1) (p<0.01) as well as between E2 (-0.03 ± 0.02 °C·min-1) and E3 (-0.01 ± 0.01 °C·min-1) (p<0.01). E1 and E2 rates of decrease did not differ. CONCLUSION: Although the temperatures experienced by the trainees may be considered moderate, rapid cooling rates were observed. Significantly different rates of TGI decrease between E2 and E3 despite experiencing similar Tw emphasizes that immersion is not the only aspect of body temperature drop during these exercises. Therefore in order to minimize hypothermic risk and potentially lost training time, exposure guidance for exercises that occur in water as well as on land in wet clothing should incorporate Tw, Ta, and Vw as all these factors may affect the rate of body temperature drop.

Experiments were conducted in cold conditions (5°C water temperature and 5°C air temperature) to assess the thermal protection of a 16-person, SOLAS approved, commercially available liferaft using a thermal manikin and human subjects. The comparison tests included four cases — 1. Inflated raft floor; dry clothing (Idry); 2. Inflated raft floor; wet clothing (Iwet); 3. Uninflated raft floor; dry clothing (Udry); 4. Uninflated raft floor; wet clothing (Uwet). The results demonstrated equivalence in insulation between human subjects and a thermal manikin for all cases of comparison (Idry: Manikin 0.236 (m2°C)/W versus Human 0.224 (m2°C)/W; Iwet: Manikin 0.146 (m2°C)/W versus Human 0.145 (m2°C)/W; Udry: Manikin 0.174 (m2°C)/W versus Human 0.185 (m2°C)/W; Uwet: Manikin 0.101 (m2°C)/W versus Human 0.116 (m2°C)/W). The results also showed the repeatability of the thermal manikin tests (0.177 (m2°C)/W versus 0.171 (m2°C)/W in Udry baseline case; and 0.101 (m2°C)/W versus 0.104 (m2°C)/W in Uwet baseline case). The results indicated that the insulation of a closed cell foam floor is comparable to an inflated floor (0.236 (m2°C)/W compared to 0.221 (m2°C)/W and 0.236 (m2°C)/W for closed foam floor from manufacturer A and B respectively). TPA provided considerable additional insulation than all baseline cases. A test with a human subject wearing a TPA in the Uwet case showed an improved insulation of 48% over the baseline case. TPA provided more additional insulation than a wet suit in all test cases except Udry case. In Uwet case, the worst test condition, the insulation obtained by sitting on a lifejacket (0.149 (m2°C)/W) is less than wearing a TPA (0.158 (m2°C)/W). Both of these are better than sitting directly on an uninflated floor (0.104 (m2°C)/W) or a closed cell foam floor (0.129 (m2°C)/W). There is a significant decrease in insulation value sitting in 10 cm of water (0.05 (m2°C)/W). Two human subject tests show an insulation value of 0.079 (m2°C)/W and 0.081 (m2°C)/W respectively. A liferaft occupant heat loss model was developed and integrated with Defense R&amp;D Canada’s Cold Exposure Survival Model to predict survival time. For Uwet case, the worst test condition, the survival time is 32 hours and functional time is 24 hours for the experimental conditions.

As cognitive neuroscience methods develop, established experimental tasks are used with emerging brain imaging modalities. Here transferring a paradigm (the visual oddball task) with a long history of behavioral and electroencephalography (EEG) experiments to a functional magnetic resonance imaging (fMRI) experiment is considered. The aims of this paper are to briefly describe fMRI and when its use is appropriate in cognitive neuroscience; illustrate how task design can influence the results of an fMRI experiment, particularly when that task is borrowed from another imaging modality; explain the practical aspects of performing an fMRI experiment. It is demonstrated that manipulating the task demands in the visual oddball task results in different patterns of blood oxygen level dependent (BOLD) activation. The nature of the fMRI BOLD measure means that many brain regions are found to be active in a particular task. Determining the functions of these areas of activation is very much dependent on task design and analysis. The complex nature of many fMRI tasks means that the details of the task and its requirements need careful consideration when interpreting data. The data show that this is particularly important in those tasks relying on a motor response as well as cognitive elements and that covert and overt responses should be considered where possible. Furthermore, the data show that transferring an EEG paradigm to an fMRI experiment needs careful consideration and it cannot be assumed that the same paradigm will work equally well across imaging modalities. It is therefore recommended that the design of an fMRI study is pilot tested behaviorally to establish the effects of interest and then pilot tested in the fMRI environment to ensure appropriate design, implementation and analysis for the effects of interest.

As cognitive neuroscience methods develop, established experimental tasks are used with emerging brain imaging modalities. Here transferring a paradigm (the visual oddball task) with a long history of behavioral and electroencephalography (EEG) experiments to a functional magnetic resonance imaging (fMRI) experiment is considered. The aims of this paper are to briefly describe fMRI and when its use is appropriate in cognitive neuroscience; illustrate how task design can influence the results of an fMRI experiment, particularly when that task is borrowed from another imaging modality; explain the practical aspects of performing an fMRI experiment. It is demonstrated that manipulating the task demands in the visual oddball task results in different patterns of blood oxygen level dependent (BOLD) activation. The nature of the fMRI BOLD measure means that many brain regions are found to be active in a particular task. Determining the functions of these areas of activation is very much dependent on task design and analysis. The complex nature of many fMRI tasks means that the details of the task and its requirements need careful consideration when interpreting data. The data show that this is particularly important in those tasks relying on a motor response as well as cognitive elements and that covert and overt responses should be considered where possible. Furthermore, the data show that transferring an EEG paradigm to an fMRI experiment needs careful consideration and it cannot be assumed that the same paradigm will work equally well across imaging modalities. It is therefore recommended that the design of an fMRI study is pilot tested behaviorally to establish the effects of interest and then pilot tested in the fMRI environment to ensure appropriate design, implementation and analysis for the effects of interest.