Skin Resistance Research Articles

Pile bearing analysis based upon ultimate values of toe and skin resistance as well as their mobilization with settlement

The main task of pile foundation is the reduction of settlement and ensure the safety of the building. These two factors are in strongly relationship. In practice pile load capacity is calculated based on ultimate resistances including factor of safety. The load-settlement relationship is non-linear, so it would can happen that despite the applied load (several times smaller than ultimate pile load capacity), the settlement exceeds the allowable value, and in consequently it might cause damage of the structure. In the paper the method of determining ultimate resistances and mobilization of these resistances with settlement was presented based on the static pile load test results. The proposed method can be applied in pile load capacity verification.

Immediate effect of yogic postures on autonomic neural responses

Aim: The aim of this study is to identify the autonomic responses after immediate yogasana practices. Materials and Methods: Ten male (n = 10) yoga practitioners having more than 8 years of experience in yogasana practice were selected as subjects. Before and after immediate practices of six specific yoga postures were assessed on three different consecutive days for 15 min, 22.5 min, and 30 min. Heart rate variability (HRV) low frequency, HRV high frequency (HF), HRV amplitude, galvanic skin resistance (GSR), and blood volume pulse were assessed under the condition of autonomic neural activity and measured using NeXus-10 device. Results: Findings of the data generalized increasing of GSR (47.93% and 14.40%) and HF HRV (7.74% and 6.69%) and decreasing of low-frequency HRV (5.43% and 5%) immediately after 15 min and 22.5 min practice of yogasana, which indicates parasympathetic (vagal) activation. However, in the case of 30-min yoga practice, it decreased the GSR (11.03%) and HF HRV (2.59%), increased low-frequency HRV (2.23%) which, in turn, indicates the sympathetic activation. Discussion: The possible mechanism of vagal activation is an increase of baroreceptor sensitivity, tissue oxygenation, nervous system metabolism, and activation of vasodilation. It may be attributed to the activation of the head ganglion of the autonomic nervous system and inhibition of the posterior hypothalamic area. The sympathetic activation depends on the release of epinephrine and norepinephrine hormones, activation of vasomotor center, central neural integration, and peripheral inhibitory/excitatory reflex mechanisms. Conclusions: Immediate yogasana practices may enhance the parasympathetic (vagal) dominance, which increases autonomic flexibility and associates with a calm mental state.

Vineyard protection with rain-shelter: relationships between radiometric properties of plastic covers and table grape quality

The rise of unpredictable, heavy rainfalls increases incidence of diseases, berry rot, berry cracking, and enhance the need for rain shelters. The influence of the type of rain shelter on microclimate and grape quality is still little explored. The aim of this trial was to investigate the radiometric properties of a new type of cover, its effect on vineyard microclimate and on table grape quality, as compared with a reference cover, during a vintage with unusually abundant precipitation for Southern Italy. The new cover was characterized by lower transmissivity to IRshort radiation, and by a very higher transmissivity to UV radiation. It showed a tendency to decrease air temperature by 1 °C, increase RH by 2–3%, reduce VPD, and improve vine water status with respect to the reference. At harvest, grapes covered with the new sheet had higher TSS concentration, TSS / TA ratio, total skin polyphenol and flavonoids content, and berry skin resistance to rupture. Those berries, moreover, increased the level of volatile compounds such as linalool, typical of ‘Italia’ muscat aroma, and terpineol.

Cumulative exposure to solar ultraviolet A & B increases apoptosis of peripheral blood cutaneous lymphocyte antigen (CLA)+ T-Lymphocytes in outdoor workers

Background: Exposure to ultraviolet A & B (UVA-UVB) plays a role in the survival of human life, but it may cause negative effects, such as immunosuppression and skin cancer. The effect of solar UVA-UVB exposure on apoptosis (Bax/Bcl-2 ratio) of peripheral blood cutaneous lymphocyte antigen (CLA)+ T-lymphocyte; the immune competent cells in the skin, has not been investigated. Apoptosis of peripheral blood CLA+ Tlymphocyte affects its function; which serves as the skin's resistance and is involved in infectious diseases, skin inflammation, and malignancies. This study observed the effect of solar UVA-UVB to apoptosis (Bax/Bcl2 ratio) of peripheral blood CLA+ T-lymphocytes. Methods: An observational cohort study of 37 male outdoor workers (caddies on the golf course) and 33 indoor workers in Surabaya, aged 20-45 years, with skin phototype IV/V. Measurement of solar UVA-UVB doses received by the subjects was conducted for 2, 4, and 8 weeks. Examination of Bax and Bcl-2 of peripheral blood CLA+ T-lymphocyte was conducted at the beginning of the study, after 4 and 8 weeks. Results: The average dose of solar UVA-UVB for 8 weeks received by outdoor workers was 12450.51±3948.81 (J/m2 ) and that by indoor workers was 1793.97±1518.46 (J/m2 ). Exposure to solar UVAUVB leads to the increase of apoptosis (Bax/Bcl-2 ratio) of peripheral blood CLA+ T-lymphocytes (p=0.003). Conclusion: Cumulative exposure to solar UVA-UVB radiation in high-dose or received within 8 weeks resulted in the increase in apoptosis of peripheral blood CLA+ T-lymphocytes. Keywords : solar UVA-UVB, CLA + T Lymphocyte, Bax, Bcl-2, apoptotic .

Infringements of colonial resistance of microbiotic skin in patients suffering diseases of an ear, a throat and a nose on the background of diabetes mellitus

Infringements of colonial resistance of a microbiota of a skin at the elderly, suffering diseases of an ear, a throat and a nose (an otitis, a tonsilitis, a sinusitis, etc.) are considered on a background of a diabetes. To study changes in quantitative and specific indicators of deep microbiota of the skin, the method of agar prints was used. It is established that the indicators of quantitative changes are associated with a metabolic disorder and may be factors predisposing to the development of other diseases against the background of diabetes mellitus. The revealed changes in the indices of colonial resistance in patients with diabetes mellitus are of interest as adaptive characteristics of the organism in diseases of the ear, throat and nose of various etiologies, and serve as a harbinger of deviations in the clinical and physiological status of patients with diabetes mellitus. Thus, in patients with diabetes mellitus, the composition of the microbiota of the skin corresponds to that of healthy individuals of the same age. Regardless of the type and stage of diabetes mellitus, they showed an increase in the number of colony-forming units of the deep layers of the skin of the forearm, which corresponds to the dysbacteriosis of the third-degree skin. In the structure of biocenoses, in patients of the otolaryngological profile, against the background of diabetes mellitus, changes that correspond to the dysbacteriosis of the skin of the IV degree are revealed. In this category of patients, there is a pronounced secondary immunodeficiency, which is manifested by inhibition of the investigated nonspecific immunity indices, which is a predisposing factor for the onset and development of a purulent infection. It is shown that dysbiosis can manifest itself with clinical local symptoms, and then with general disorders that aggravate the course of the underlying disease and complicate treatment. An integrated approach to this problem can be used for a more differentiated assessment of the prognosis of complications in patients with an otorhinolaryngological profile against diabetes mellitus and increasing the effectiveness of therapeutic and preventive care.

Improved decision-making and psychophysiological responses in mesial temporal lobe epilepsy after anterior temporal lobectomy.

The somatic marker hypothesis is an influential model of human decision-making postulating that somatic feedback to the brain enhances decision-making in ambiguous circumstances, i.e. when the probabilities of various outcomes are unknown. The somatic feedback can be measured as autonomic responses, which are regulated by the amygdala. The failure to evoke this somatic feedback, which occurs in patients with amygdala lesions, impairs decision-making. The purpose of this study was to investigate the decision-making behaviour of mesial temporal lobe epilepsy patients with pre- and post-epilepsy surgery to ascertain whether the decision-making abilities of groups can be explained by means of the generation of somatic feedback responses. The preoperative group comprised 32 patients with mesial temporal lobe epilepsy due to hippocampal sclerosis, while the postoperative group comprised 23 patients who had undergone anterior temporal lobectomy. The age and gender-matched control group consisted of 30 healthy participants. Decision-making performances were assessed and skin resistance responses were measured simultaneously. The findings of this study reveal that the decision-making performance of preoperative patients with unilateral mesial temporal lobe epilepsy was impaired under conditions of ambiguity, i.e. they did not generate somatic feedback responses before making decisions around ambiguous outcomes, and produced significantly poor scores overall based on a decision-making task. In addition, the resection of epileptogenic limbic structures positively affected the generation of somatic feedback responses, as demonstrated by the significant difference between the magnitudes of autonomic responses of the pre- and post-operative groups. The findings of the study validate the contribution of mesial temporal lobe structures to decision-making behaviour, and also point to the importance of examining the connectivity patterns between the neural structures involved in the decision-making network.

Field loading tests of screw micropiles under axial cyclic and monotonic loads

Unlike conventional grouted micropiles, screw micropiles have been recently introduced to the foundation industry. Full-scale field tests of screw micropiles were carried out at a cohesive soil site. The screw micropiles have a diameter varying from 76 to 114 mm and a length varying from 1.6 to 3 m, and spiral threads welded on the lower half of the steel tubular shaft. Site investigation from cone penetration tests (CPT) and laboratory testing implies that the soil was medium to stiff, low plasticity clay. Six axial monotonic and three axial cyclic load tests were performed on three micropiles. One micropile was instrumented with strain gauges to investigate the shaft load distribution during loading. The axial cyclic loading was intended to simulate cyclic inertia load during vertical ground motions. Results showed that the micropiles behave as frictional piles during monotonic tests; the unit shaft resistance and adhesion coefficient were calculated and compared with results in the literature. The end installation torque was estimated using CPT shaft resistance and was shown to agree reasonably with the measured torque. Under axial cyclic loading, the micropiles underwent small cumulative displacements and the magnitude of the displacement decreased with increasing pile length and diameter. Cyclic loading redistributed the load transfer along different segments of the micropile. Negative skin resistance was observed along the smooth pile shaft when the pile underwent decreasing axial loading.

Parameterization for EROSION-3D Model under Simulated Rainfall Conditions in Lower Shivaliks of India

The Shivalik foothills of northwestern India are very prone to soil erosion by water due to undulating slopes, highly erodible soils and high intensity rainstorm events during monsoon season. Physically based soil erosion modeling is seen as viable method for planning of measurements to reduce damages done by soil erosion. Nevertheless, parametrization of such models is a major challenge for large inaccessible areas. Several methods do exist for the estimation of the input parameters skin factor, surface roughness and resistance to erosion for the physically based soil erosion model EROSION-3D. Four rainfall experiments, each including dry and wet run, were conducted on different land use conditions on a research farm of the Regional Research Station Ballowal Saunkhri to test estimation methods. Modeling parameters were determined from these experiments. Parameter estimation by two methods for experimental conditions produced values in close range to experimentally determined values for resistance to erosion and surface roughness. Therefore, existing estimation methods are considered to be applicable for the conditions of the Shivalik mountains, except for skin factor. A first modeling with EROSION-3D using preliminary data of a small example catchment shows uncertainties resulting from range of determined and estimated soil parameters.

Support for Employees with ASD in the Workplace Using a Bluetooth Skin Resistance Sensor⁻A Preliminary Study.

The application of a Bluetooth skin resistance sensor in assisting people with Autism Spectrum Disorders (ASD), in their day-to-day work, is presented in this paper. The design and construction of the device are discussed. The authors have considered the best placement of the sensor, on the body, to gain the most accurate readings of user stress levels, under various conditions. Trial tests were performed on a group of sixteen people to verify the correct functioning of the device. Resistance levels were compared to those from the reference system. The placement of the sensor has also been determined, based on wearer convenience. With the Bluetooth Low Energy block, users can be notified immediately about their abnormal stress levels via a smartphone application. This can help people with ASD, and those who work with them, to facilitate stress control and make necessary adjustments to their work environment.

Auricular Acupoints with Reduced Skin Resistance: Detection in Patients Scheduled for Hip Arthroplasty.

Objective: The detection of auricular acupuncture (AA) points by measuring electrical skin resistance (ESR) is often used in diagnostics and therapy; however, systematic investigations of ESR in AA points are rare. The aim of this study was to examine the frequency of detection of AA points with reduced ESR in patients scheduled for unilateral hip arthroplasty. Materials and Methods: Data were obtained from 2 prospective clinical trials, which studied the perioperative analgesic effects of AA in patients with unilateral degenerative hip osteoarthritis. Three AA points (MA-TF1, MA-AH4, and MA-IC1) were examined in these patients before arthroplasty surgery using a SVESA (Neuralstift SVESA 1070, SVESA, Muenchen, Germany) neural pen. The frequency of AA points detection on the ipsi- and contralateral sides of the affected hip joint was registered and analyzed with a χ2 test. Results: The data of 114 patients (60 females) were available for analysis. AA points with lower ESR were detected more frequently on the side ipsilateral to the affected joint rather than on the contralateral side: 81% versus 37% of patients (P < 0.0001). None of the AA points could be identified at all in 13% of patients with diabetes mellitus versus 3% of patients without diabetes mellitus (P = 0.07). Conclusions: AA points with low ESR were detected more frequently on the side ipsilateral to the underlying pathology. This finding is in agreement with neurophysiologic data. The therapeutic value of this finding should be clarified in future studies.

Evaluating the User Physical Stresses Associated with Watching 3D and 2D Displays over Extended Time Using Heart Rate Variability, Galvanic Skin Resistance, and Performance Measure

This paper compares the effects of viewing videos with 2D and 3D displays with regard to the viewing distance (3H vs. 6H, where H is the height of the screen) and viewing time to determine the physical stresses in terms of heart rate variability, galvanic skin resistance (GSR), and performance of the viewer (percent of correct responses). Twenty healthy male university students with a mean age ± standard deviation of 27.7 ± 2.53 years participated in this study as volunteers. None had color blindness, and all had normal vision acuity. Display type by viewing distance interaction had a significant effect on most of the heart rate variability measures and associated with watching time for the GSR responses. The results concluded that viewing the 3D display from a short viewing distance produced significantly high physical stresses compared to viewing the 2D display from the same short viewing distance. However, the 3D display seemed to impart lower physical stress than the 2D display at long viewing distances. The findings of this study indicate that physical stresses appeared significant at close viewing distance after watching a 3D display for 50 min and increased with continued watching time. In addition, viewer performance was higher for the 3D compared to 2D display type.

Load sharing and behavior of single pile embedded in unsaturated swelling soil

This study presents a series of model experiments conducted on single pile embedded in saturated and unsaturated expansive soil. A soil composed of 70% bentonite and 30% sand which represents a very high expansive soil is employed in this study. Soil suction (total and matric) was measured using the filter paper technique and calibrated electrical resistance gauges to study the behavior of the soil water retention curve (SWRC) and initial suction and their influence on the results. The results showed that the ultimate skin resistance is increased about 49% when the initial degree of saturation decreases from 90 to 70%. However, the adhesion factor (α, used in calculating the skin friction) increases as the unconsolidated undrained cohesion decreases and as the initial matric suction decreases. The adhesion factor reached a value of 1.3 when the undrained cohesion is 36 kPa, initial degree of saturation of 100% and initial matric suction of 10 kPa. The sharing ratio of the ultimate shaft capacity to the ultimate pile capacity of a single pile changes from 91 to 81% when the degree of saturation decreases from 100 to 70%.

Psychophysiological Responses to Cognitive and Physical Training in Obese Elderly

Objectives: Increasing prevalence rate of anxiety disorders in elderly populations especially due to physical limitations has become a key concern for health authorities. Therefore, the objective of the study was to investigate the effects of cognitive and physical training on anxiety in the Elderly. Methods: 49 aged females (62.3 ± 2.6 years) with BMI of 35 - 49.99 kg/m2 were assigned to one of three groups: Cognitive (n = 17), yoga (n = 16) and control group (n = 16). The cognitive training protocol focusing on breathing techniques, autogenic training, imagery/visualization, included an 8-week period, three sessions a week. Yoga practices comprising Asana training, Pranaya training, and meditation were conducted 3 times a week, for 8 weeks. The State-Trait Anxiety Inventory was given before yoga practice and cognitive training. Biofeedback devices were used to monitor galvanic skin resistance and resting heart rate. The data were analyzed using independent t-test and one-way ANOVA test. Results: The results indicated that both cognitive and physical training had a significant difference on Anxiety in the training groups (P ≤ 0.05), while no significant change was found for control group (P ≥ 0.05). Furthermore, both training modes decreased the skin potential response (SPR) (P < 0.001). In addition, physical training group had lower resting heart rate after intervention compared to the cognitive and control groups (respectively, P = 0.04 and P = 0.001) lower heart rate and skin conductance level over the entire measurement period. Conclusions: It was concluded that the health benefits of yoga aren’t not specific to maintaining physical health, but also extends to lowering the anxiety in elderly with obesity. It was also suggested that cognitive training can mitigate the anxiety symptoms in the elderly while no physical changes were shown in cognitive training.

Measurements of Electroencephalogram (EEG), Galvanic Skin Resistance (GSR) and Heart Rate Variability (HRV) during the Application of a System that Gives Simultaneously tVNS and Brain Entrainment on Subjects Affected by Depression and Anxiety

Measurements of Electroencephalogram (EEG), Galvanic Skin Resistance (GSR) and Heart Rate Variability (HRV) during the Application of a System that Gives Simultaneously tVNS and Brain Entrainment on Subjects Affected by Depression and Anxiety

Towards conductive-gel-free electrodes: Understanding the wet electrode, semi-dry electrode and dry electrode-skin interface impedance using electrochemical impedance spectroscopy fitting

The electrode-scalp impedance of six subjects is studied by electrochemical impedance spectroscopy using three representative electrodes, namely wet electrodes, semi-dry electrodes, and dry electrodes. With the analysis of proposed equivalent models and area-normalized impedance (kΩ cm2), the specific electrode double layer resistances are 530 Ω cm2 for all electrodes, their specific contact resistances Res are 80 Ω cm2, 114 Ω cm2 and 20,077 Ω cm2, and their specific skin resistances Rs are 867 Ω cm2, 1730 Ω cm2 and 46,145 Ω cm2 for these three representative electrodes respectively. When pressure was applied on dry electrodes, Res reduced by 47% and Rs reduced by 81%. When pressure was applied on semi-dry electrodes, Rs reduced by 50% (Res is not applicable for semi-dry electrodes). After application of scalp abrasion for dry electrodes, Res reduced by 36% and Rs reduced by 82%. After application of scalp abrasion for semi-dry electrodes, Rs reduced by 64%. Seeking novel interface materials may break through the bottleneck for dry electrodes development in terms of integrated materials, mechanical support and electronic circuitry, while semi-dry electrodes have much development space to meet a balance of quick setup, comfortable wear, and satisfactory signal quality in many medical and out-clinic applications.

Berry skin resistance explains oviposition preferences of Drosophila suzukii at the level of grape cultivars and single berries

Drosophila suzukii (Matsumura) is an invasive species, which is able to attack intact ripening fruit and has become a serious pest in the Americas and Europe. However, susceptibility toward D. suzukii varies strongly within and between grapevine cultivars. The aim of our study was to differentiate between berry parameters influencing oviposition of D. suzukii in grapevine with two complementary approaches. We investigated the influence of berry skin resistance, total soluble solids (a sugar related parameter), acidity and volatile acidity on grape susceptibility; in the first approach at the cultivar level in a field survey, and in the second approach at the single berry level in a laboratory choice experiment. Both approaches revealed that berry skin resistance explained oviposition decidedly better than chemical composition of the berries did: Soft skinned cultivars and berries received significantly more eggs than hard skinned cultivars and berries. These findings suggest a major role of berry skin resistance in the susceptibility of grapevine toward D. suzukii. The cultivar approach identified the cultivars Dornfelder, Trollinger (= Vernatsch, Schiava), Portugieser, Roter Elbling and Cabernet Dorsa to be susceptible, whereas Dakapo, Lemberger (= Blauer Limberger) and Riesling showed no oviposition by D. suzukii. Nevertheless, parameters like previous damage, climate, environment and plant protection may have an additional impact.

Validation of the High-Resolution Electrical DermaScan (Hi-REDS) as a Tool for Measuring Electrical Skin Resistance over Acupuncture Points

Validation of the High-Resolution Electrical DermaScan (Hi-REDS) as a Tool for Measuring Electrical Skin Resistance over Acupuncture Points

SENSOR KEBOCORAN ARUS LISTRIK WATER HEATER ELEKTRIK

An electric current sensor detecting current leak into water flowing out from a water heater has been constructed. The sensor is made of a copper electrode implanted in a PVC pipe. It is subjected to tests in which the voltage is varied at constant resistance and otherwise the resistance is varied at constant voltage. The variation of the AC voltage is conducted from 0 to 220 volt whereas that of the resistance is from 1 K W to 100 K W . The 1 K W resistance is meant to represent the resistance of human skin in wet condition and the 100 K W represents that of dry insulated skin. Analysis shows that unpainful shock sensation surges at 30 V , 5 . 16 mA , with 1 K W resistance . In the current leak condition at 220 V, unpainful shock is sensed at body resistance of 42 K W with 4,99 mA current .

Design of new-style embedded acupoint recognition device

A new type of embedded acupoint recognition device was developed for acupoint recognition and teaching. Through improving the acupoint electric resistance detection technique of the two-electrode method, combined with mechanical structure design and embedded control technology, the human acupoint database was assembled in the embedded chip with the international symbol, acupoint name, pinyin, location, chart, manuscript and audio information included, a new type of embedded acupoint recognition device was designed. The device was composed of 3 modules, named the acupoint electric resistance detection system, the embedded control system and mechanical system. It achieved skin contact sensation, the collection of electric resistance at the required skin region, the wireless communication, the liquid crystal display (LCD) human-computer interaction and acupoint magnetic head massage. When used, the resistance value of the detected skin is read on LCD to determine whether the detected skin resistance meets the features of low resistance of acupoint and further to identify the acupoint zone. Afterward, the data collected are matched with the human acupoint database to determine the information of acupoint. The control mechanical structure achieves the acupoint pressing and kneading. After verified by many operation staff, it is shown that the device not only improves the recognition speed and precision of acupoint, but also contributes to the acupoint teaching with the human acupoint database displayed on LCD. The achievements benefit the promotion of meridians and acupoints as well as the development of acupuncture devices.

Impact of trajectory profiles on user stress in close human-robot interaction

Abstract The impact of different trajectory embodiments in terms of velocity profiles on users’ mental stress in close human-robot interaction is investigated. A cooperative assembly scenario is chosen using a standard industrial robot. Conditions are implemented in a repeated measures within-subjects design comparing linear with trapezoidal trajectories. Heart rate variability and galvanic skin conductance are chosen as objective stress markers and evaluated using the average standard deviation of the beat-to-beat intervals (SDNN) and the average skin resistance. Additionally, evaluations of user experience and acceptance are conducted based on evaluated subjective measures. The results of the user study reveal a significant increase of average heart rate variability and average skin resistance in the trapezoidal condition indicating a reduced mental stress level independent of demographical and dispositional factors.