Water Bed Research Articles

Management of Charmakeela by Viddha Karma followed by Arka Ksheeradi Lepa externally and Vidanga Churna orally

Introduction: Charmakeela is one of the most common skin disorders affecting the children and teenage group by and large. It can be correlated to warts according to modern science owing to signs and symptoms. The incidence rate of EGW (extra genital warts) =10% Approx. Globally, 2-25% approx. India. The Incubation period of warts is around 90 days and the high recurrence rate in various modern treatment modalities. Aim: To evaluate the efficacy of Viddha Karma followed by Teekshna, Lekhana, Ropana, Krimighna properties of Arka Ksheera and Haridra Churna externally and Vidanga Churna Orally. Objectives: To arrive at a cost effective result oriented medication with least recurrence. Materials and Methods: A lean built Female patient, presenting with multiple warts on both the palms was selected from T.M.A.E’S AMC Hospital, Hospet. The patient was treated with Vidanga Churna (0-0-5mg) with hot water bed time and with aseptic precautions a 2ml syringe needle was taken and random pricks were made on the surface and surrounding the warts. This was followed by application of Arka Ksheera mixed with Haridra Lepa and was bandaged. The procedure was repeated once a week for 5 weeks. Results: A significant reduction in the size and other symptoms of warts was seen by 2 weeks and by the end of 5weeks the palms were completely clear and appeared normal. After a regular follow upto 8 weeks with oral medication alone no recurrence was noticed. Conclusion: The treatment was successful in warding off recurrence and effectively curing all warts with economical, noninvasive technique.

Surface-energy ratchet motor with geometrical symmetry driven by biased random walk

A geometrically symmetric gear with asymmetric surface wettability exhibits one-way spin on a vibrating water bed. On the side face of the gear, a parafilm was coated to create asymmetry in the surface energy. The gear shows fluctuations in both directions within a shorter timescale; however, for a longer timescale, the gear exhibits a one-way spin. This unique motion is generated by a stochastic process with a biased driving force produced by the interaction between the vibrating water surface and the side face of the gear. This new model resembles an active Brownian ratchet. Until now, most ratchet motors, which obtain regular motion from nonthermal fluctuations, utilize a geometrical ratchet structure. However, in this study, the surface energy forms a ratchet that rectifies the noisy motion.

Multiphase simulations of nonlinear fluids with SPH

A modified apparent viscosity approach has been implemented for a weakly compressible SPH scheme for two-phase flows where a nonlinear phase must yield under erosive dynamics but also maintain a pseudosolid behaviour under the right conditions. The final purpose is to provide a means to model both dam-break dynamics and erosive interactions between different phases simultaneously while also keeping smooth pressure fields in spite of discontinuities introduced by viscosity variations of a nonlinear phase along with significant differences in mean density. Key contributions include purposeful avoidance of nonphysical elastic behaviour and the integration of a specific particle shifting technique that allows for proper replication of erosion and scouring. In this work, the method is validated by applying it to model a silted-up dam that collapses over a static water bed, effectively including all main elements of interest. Although the formulation is inherently three dimensional, validation is done by direct comparison with data from physical experiments of a dominant two-dimensional nature, assuming variable yield stress of medium-grain quartz sand according to the Drucker–Prager equation. Overall results show most of the expected interface dynamics, such as erosion and transportation of the nonlinear phase, sustained piling of the non-yielded volume of silt, and good correspondence of both granular and water surface position with experimental data. Finally, a series of modelling assumptions and implications for future developments are explicitly stated because of their direct impact on stability and versatility for multiphase, nonlinear flows in general.

Field study of an arsenic removal plant for drinking water using activated carbon and iron in a rural community in the province of Pisco, Peru.

The presence of arsenic in Peru is a serious public health problem due to the geographical extension of populations that consume water with arsenic concentrations above the value recommended by the World Health Organization (WHO). An arsenic removal plant has been studied in a community of 50 families located in the province of Pisco, Peru, a filter media of activated carbon impregnated with iron (AC-Fe) was applied, the adsorption capacity of the material was studied against As(V) and As(III) species, also, a possible decrease in the adsorption capacity of chloride and sulfate ions. Modifications were made to the plant layout based on filtration columns and workflows. The arsenic level was reduced to levels recommended by the WHO, the plant production was estimated at 9,000 volumes of water bed until reaching its breakpoint. An optimum working flow rate of 1.8 m3 h-1 was found, it was also found that the zeolite column used for suspended solids removal did not contribute to the reduction of arsenic concentration, and the presence of ions did not reduce the arsenic removal capacity.

Becoming Concrete: Materiality and Water Infrastructure in Colonial South Asia

Since the mid-19th century, engineers in colonial South Asia experimented with concrete in building and infrastructural projects as the production of new infrastructures was leading to the genesis of the modern construction industry. In this paper, we analyse the use of concrete in water infrastructures amidst challenges posed by introducing any structure in and under water. For example, piers on the beds of fast flowing rivers altered the behaviour of both the water flow and water beds, which in turn affected the structure itself. In dealing with these uncertainties, the use of concrete vastly varied, unlike the relatively standardized practice today. Through a granular analysis of the construction of infrastructural projects like breakwaters and bridge foundations, from the late 19th to the turn of the 20th century, we analyse how concrete was locally improvized within the constraints of unfamiliar material, hydrological, topographical, and labour contexts in each site. We argue that the basic attributes of concrete technology, from chemical processes to construction processes and structural behaviour, themselves emerged as constraints and the builders resorted to alternative strategies and courses of action in each circumstance. The constant improvisations complicate the narrative of colonial technological circulation between the colonies and the West. We conclude that the material particularities of concrete made its translation across South Asian building projects improvisational, diverse, and localized.

Experimental investigation of impact of fire size on heat transfer and flame behavior of initial stage unsteady pool fires inside a cubical enclosure

The ventilation equipment for enclosed spaces or office rooms is specified according National Building Code of India published by the Bureau of Indian Standards. Natural ventilation peri-odically together with mechanical ventilation is recommended to remove pollutants. The need to study fire and smoke behavior inside a completely closed room with air intake and exhaust vents becomes important in case of low or no mechanical ventilation service. An experimental study on unsteady heptane pool fires of different sizes in their initial stages was conducted in a cubical fire test chamber of 27 m3 inside dimensions. The compartment was naturally ventilated with a typical configuration of a vertical intake on a side wall and an exhaust vent at the ceiling leading into a duct. Three circular pans of diameters 0.34, 0.47 and 0.61 m were employed to generate the fire with n-heptane as fuel on a bed of water. Temperatures, wall heat fluxes and mass loss rate were measured. The flame was visualized using a video camera through a tempered view glass. The total heat transfer to the ceiling and wall increased with the increase in fire size as the flames became taller in the initial stages (3-4 minutes) with sig-nificant increase in case of 500 kW fire. The smoke layer was observed at about mid height (1.5 m) above floor. The leaning behavior of flames was seen due to naturally induced air inflow. The wall heat flux of about 50 kW/m2 obtained indicate hazardous environment for further flame spread. A fourfold increase in mass loss rate was observed with just 2.5 times increase in fire size inside the ceiling vented compartment.

Heavy metal (Cr, Cu, Ni, Pb, and Zn) contents of endemic Salvia halophila plants around Lake Tuz

Heavy metals occur naturally in ecosystems at varying concentrations. However, heavy metal sources that have emerged in present-day mainly due to human influence, i.e. industrial activities, agricultural waste, pesticides, use of fossil fuels and traffic, have included a part of heavy metals in the ecosystem. Lake Tuz, together with the entire lake surroundings, water beds and important steppe areas, was declared Turkey’s Specially Protected Area (SPA) in 2001. Our aim in this investigation was to determine the levels of heavy metals such as Chrome (Cr), Copper (Cu), Nickel (Ni), Lead (Pb) and Zinc (Zn) in endemic Salvia halophila grown in different areas of Lake Tuz. The results of the heavy metal contents analyzed at the plant were compared with the international standard levels of heavy metals. The consequences displayed that differing extents of heavy metals are accumulated in S. halophila. The results obtained differed in accordance with the collection time and localities. When the outcomes are appraised, it is achievable to say that Pb is higher than the standard values. The findings of this investigation are the first reported results for this endemic S. halophila species that grows naturally at Lake Tuz and are important as they are newly discovered results.

Measuring Bed Exchange Properties of Cohesive Sediments Using Tripod Data

The Krone–Partheniades (K-P) framework has been used for decades to quantify and analyze the sediment exchange at a water–bed interface. Measuring the erosion and deposition parameters that are part of this framework requires time-consuming field observations. Additionally, the erosion parameters are measured independently of deposition parameters, while in reality they are coupled. In numerical models applying the K-P framework these parameters are often assumed to be constant in time and mutually independent. In this study, we develop a relatively simple methodology to determine the erosion and deposition parameters, using conventional near-bed observations of bed level, sediment concentration and flow velocity. This methodology is subsequently applied to tripod observations collected in the Changjiang estuary, China, to compute continuous time-varying erosion and settling parameters. We propose a diagram to visualize the interdependency and accuracy of erosion and deposition parameters, which is the input for K-P framework models requiring this interdependency.

GAIA - a unified framework for sediment transport and bed evolution in rivers, coastal seas and transitional waters in the TELEMAC-MASCARET modelling system

In rivers, coastal seas and transitional waters, sediment transport processes involve a variety of interacting factors that dynamically vary over time and space. The flow dynamics within these highly heterogeneous natural systems influences the spatial patterns of erosion and deposition of the bed sediments, which in turn shapes and conditions the bottom morphology. By taking advantage of the established modelling framework in both two- and three dimensions for unstructured meshes proposed within the Telemac-Mascaret system, the new module Gaia provides a code structure for solving sediment transport and morphological evolution problems. By a clear treatment of sedimentary processes that happen in the water column, in the bed structure, and at the water–bed interface, Gaia efficiently manages the spatial and temporal variability of sediment size classes, properties and transport modes for two- and three dimensions. In addition, this module can easily be expanded and customised to particular requirements by modifying user-friendly, easy-to-read, and well-documented FORTRAN-90 subroutines.

Analysis of water jet cutting of metal-ceramic elements made through atmospheric plasma spraying technique

Ceramic layers like alumina or zirconia present many industrial applications in many different domains. Ceramic thin layers were obtained through atmospheric plasma spraying (APS) using a robotized arm. Combinations of 25-–75, 50–50 and 75–25 % between Al2O3 and ZrO2 ceramic powders were made in order to obtain the ceramic layers. Structural (optical - OM, scanning electron – SEM and atomic force microscopy - AFM) characterizations of the thin ceramic layers were made before and after the operation of water jet cutting (Waterjet Cutting Machine (TK-TRUMP50-G3020)). By water jet cutting we follow to determine the behavior of the ceramic layer – metallic substrate system at these materials under pressure and water. The process was performed with a high cutting speed and a clean cut however taking in the account the porous nature of the ceramic layers made through APS the water jet and water bed affect the substrate and corrosion occur on the experimental samples.

Classification of off-stream dams in the state of Minas Gerais in relation to potential risk and potential for envrionmental damage

The increase in demand for water use has caused serious environmental problems and conflicts between users. Reservoirs off-stream the water bed, commonly called “Piscinões”, have been presented as a common practice for maintaining irrigated agriculture in the dry season. During the rainy season and the beginning of the dry season, the user of water resources captures more water than he needs in order to store the water resources and use them in the period of lower flows in the rivers. For a more efficient management of the safety of these hydraulic structures, it is important to know the real impact that the current pond-reservoirs can cause to the environment and the people who live in their surroundings. Inserted in this context, methods, methodologies and tools capable of measuring the value of risk through indicators were found in the technical literature and the Potential Environmental Damage methodology was adopted. The present work adopted the Potential Risk methodology proposed by COGERH and the Potential Environmental Damage proposed by FEAM. It is concluded that the tools can be adopted for a classification of reservoirs-pools, however there is room for improvement and an improvement in the management of these water structures.

First report of black rot caused by Xanthomonas nasturtii on watercress in Spain and Portugal

Xanthomonas nasturtii was first identified as the cause of black rot of watercress (Nasturtium officinale) on plants grown in Florida, USA (Vicente et al., 2017). Similar symptoms had been reported earlier in Hawaii (McHugh & Constantinides, 2004) and an unidentified Xanthomonas sp. was isolated in Portugal in 2003 from wild watercress (Cruz et al., 2017). Since 2017, watercress crops in southern Spain have occasionally exhibited small yellow leaf lesions around the hydathodes, leaf spots, V-shaped leaf lesions, wilt, distortion and senescence (Fig. 1). Symptoms were more frequent during mild and humid periods from November to February, reducing yields by up to 60% and leading to rejection of some crops (Lascelles, 2019). In 2021, symptoms were seen on watercress produced in Portugal and sold in the UK. Isolations were made from watercress leaves showing typical symptoms between 2017 and 2021 by excising and macerating small tissue fragments in sterile water and plating on King's medium B (KB). Seed produced in Spain was tested using a method based on the International Seed Testing Association method for detection of Xanthomonas campestris pv. campestris. Mixtures of bacterial colonies were observed on the plates after incubation for 48–72 hours at 28°C and colonies resembling Xanthomonas (yellow, mucoid) were sub-cultured. Isolates were purified and stored at -76°C in nutrient broth with 150 g/l glycerol (Vicente et al., 2017) and/or at -80°C in Protect® (Protect System, UK). In contrast to the type strain (NCPPB 4600) from Florida, isolates from Spain and Portugal did not cause browning of the KB medium (Fig. 2). Pathogenicity was tested on plants of three watercress accessions and Savoy cabbage cv. Wirosa F1 (Bejo Zaden B.V., The Netherlands) by stabbing with an insect pin charged with bacteria (Vicente et al., 2017). The Xanthomonas-like isolates were pathogenic to all three watercress accessions (Fig. 3) whereas no symptoms were observed on cabbage. To complete Koch's postulates, re-isolations were made from symptomatic watercress leaves inoculated with isolates WHRI 10015A (from Spain) and 10049A (from Portugal). Isolates with the same morphological characteristics were obtained. Fatty acid profiling (Weller et al., 2000) was performed on isolates grown on trypticase soy agar plates at 28°C for 48 hours; comparisons with libraries that did not include X. nasturtii, indicated the highest matches of 0.38 to 0.68 with X. axonopodis and X. campestris. DNA was extracted as outlined in Vicente et al. (2017). The partial 16S rRNA gene was amplified and sequenced for isolates from Spain and confirmed their identity as a Xanthomonas species. The partial gyrB gene was amplified and sequenced for selected isolates according to Parkinson et al. (2007) (Table 1). The phylogeny (Fig. 4) confirmed that isolates from Spain and Portugal belong to X. nasturtii and shows that there is some genetic diversity amongst them. This is the first report of X. nasturtii on watercress crops in Europe. We suspect that black rot of watercress may be widespread in production areas of the Iberian Peninsula and, as the crop is grown in water beds, the pathogen is likely to spread relatively easily. Based on detection in a watercress seed lot produced in Spain, the pathogen may be seed borne and therefore it is important to test watercress seed to avoid introducing the disease into clean beds and new areas/countries. This work was funded by Royalcress S.A., The Watercress Company, UKRI, Defra and the Scottish Government.

LMI-based impedance control synthesis: a case study on fixed-stiffness actuators (FSAs)

Impedance control is frequency-dependent in the twofold sense: (1) the impedance matching error can only be attenuated arbitrarily small over a low-frequency range due to the water bed effect (Freudenberg et al., 2003), and (2) the impedance matching error always diverges to infinity as the frequency tends to infinity since no causal controller can track arbitrarily fast signals. To sum up, we can only shape the robot impedance over some low-frequency range which may be very small due to the limitation resulting from the robot's inherent high-frequency characteristics. Unfortunately, this fact was underestimated in the existing impedance control schemes. In this paper, a frequency-aware linear impedance control synthesis technique is developed for FSAs based on control theory, which is also suitable for the general robot system in the condition that the robot dynamics is linearised around an equilibrium configuration or compensated with its inverse dynamics model to form an exact-linearised system a priori. With the powerful tool, we study the impedance shaping technique and address the two long-standing issues: (1) Under what conditions, an impedance-controlled FSA can exceed its physical stiffness? (2) Can a stiff FSA render a wider stiffness range than its softer counterparts?

Reversed spin of a ratchet motor on a vibrating water bed

A ratchet gear on a vibrating water bed exhibits a one-way spin. However, the spinning direction is opposite to that of the gear placed on the granular bed. The one-way spin is caused by the surface waves of water. Surface deformation causes transportation of the water element to rotate the gear. The spatial symmetry of the surface wave and gear geometry regulates the rotational torque. In this study, the same ratchet shows reversed motion between the granular and water beds, and the direction is not determined only by the ratchet geometry. The self-organization of the fluid medium caused by small agitation induces a nontrivial inversion of the spinning direction.

Analysis of compositional lines in natural landscapes

Nature was and remains an eternal companion of man, but at the same time, it is also a constant enigma. Man’s connection with nature is ancestral, and the need for this connection is constantly proven. Landscape design is the field where art (human creation) and nature meet, creating a field of endless possibilities in the development of outdoor spaces, but while the artistic side of the field is constantly improved and developed, sometimes the exploration of the natural side is left behind. The present study aims to identify and analyse the types of compositional lines that can be found in natural landscapes. For this, different photos from natural parks or Romanian reserves were selected and subjected to visual analysis. In the examined scenes, vertical, horizontal, diagonal, straight or sinuous lines (the most dominant) were identified, being suggested by tree trunks or logs, water beds or streams, paths, the topography of the land or the contour of the crown. Their properties, such as thickness or repetition, can provide diversity, animate a scene, and generate visual movement or invite further exploration. This work can serve as a basis for a more thorough study of natural landscapes and is relevant to landscape architects who support the use of natural style in their work or are interested in integrative landscape design for a better understanding of natural features, as well as researchers who want to explore the aesthetics of natural landscapes.

Energy and exergy analysis of a water bed‐infrared dryer coupled with a photovoltaic‐thermal collector

AbstractOrange is a perishable fruit that is dried to increase its shelf‐life. The main challenge of industrial dryers is their high energy consumption, which accounts for about 12% to 20% of the energy demands of the industry. In the present study, a continuous water bed‐infrared dryer equipped with a photovoltaic‐thermal (PV‐T) collector was presented for orange fruit drying. The designed dryer comprised two main units: the PV‐T air collector and the water bed‐infrared dryer. The PV‐T collector was considered to simultaneously generate electricity and heat required for the hot airflow inside the dryer. The effects of the hot water flow rate (0.05, 0.1, and 0.15 L/min) and the product thickness (3, 5, and 7 mm) on solar heat fraction, final moisture content of the dried oranges, and energy and exergy efficiencies of the dryer were investigated using the factorial test based on a randomized complete block design experiment. The average solar heat fraction increased by 35.1% with increasing the thickness from 3 to 7 mm, and increased by 29.8% with increasing the water flow rate from 0.05 to 0.15 L/min. Rising the water flow rate in the studied range reduced the final moisture content by about 14.7%. The average solar heat fraction, final moisture content as well as energy and exergy efficiencies of the dryer were obtained 0.26–0.61, 9.1%–16.04% wet basis (wb), 26.35%–35.63%, and 3.42%–12.9%, respectively. The best operating condition suggested based on the highest solar heat fraction, energy and exergy efficiencies, and the lowest final moisture content, was the 3‐mm slice thickness of orange and the water flow rate of 0.15 L/min.Practical ApplicationsThe main challenge of industrial dryers is their high energy consumption. In the present study, to increase energy efficiency in water bed dryers, a heat source of infrared radiation was deployed on top of the product surface, and a PV‐T collector was used to generate electricity and hot airflow simultaneously. We experimentally investigated the changes in heat fraction of solar energy, final moisture content of dried oranges, and energy and exergy efficiencies of the designed continuous water bed‐infrared dryer equipped with PV‐T collector at different operating conditions.

Controls on Sediment Bed Erodibility in a Muddy, Partially-Mixed Tidal Estuary

The objectives of this study are to better understand controls on bed erodibility in muddy estuaries, including the roles of both sediment properties and recent hydrodynamic history. An extensive data set of erodibility measurements, sediment properties, and hydrodynamic information was utilized to create statistical models to predict the erodibility of the sediment bed. This data set includes >160 eroded mass versus applied stress profiles collected over 15 years along the York River estuary, a system characterized by “depth-limited erosion,” such that the critical stress for erosion increases rapidly with depth into the bed. For this study, erodibility was quantified in two ways: the mass of sediment eroded at 0.2 Pa (a stress commonly produced by tides in the York), and the normalized shape of the eroded mass profile for stresses between 0 and 0.56 Pa. In models with eroded mass as the response variable, the explanatory variables with the strongest influence were (in descending order) tidal range squared averaged over the previous 8 days (a proxy for recent bottom stress), salinity or past river discharge, sediment organic content, recent water level anomalies, percent sand, percent clay, and bed layering. Results support the roles of 1) recent deposition and bed disturbance increasing erodibility and 2) cohesion/consolidation and erosion/winnowing of fines decreasing erodibility. The most important variable influencing the shape of the eroded mass profile was eroded mass at 0.2 Pa, such that more (vs. less) erodible cases exhibited straighter (vs. more strongly curved) profiles. Overall, hydrodynamic variables were the best predictors of eroded mass at 0.2 Pa, which, in turn, was the best predictor of profile shape. This suggests that calculations of past bed stress and the position of the salt intrusion can serve as useful empirical proxies for muddy bed consolidation state and resulting erodibility of the uppermost seabed in estuarine numerical models. Observed water content averaged over the top 1 cm was a poor predictor of erodibility, likely because typical tidal stresses suspend less than 1 mm of bed sediment. Future field sampling would benefit from higher resolution observations of water content within the bed’s top few millimeters.

Distribution of gravel-sand on high water bed by Typhoon Hagibis (T1919) flood in the middle reaches of the Tama River, central Japan

2019年の台風19号（T1919）襲来に伴う出水により，多摩川中流域の高水敷に堆積した砂礫の堆積状況を記録した．砂礫州の上流部から中央部流路寄りにかけては基本的に礫の堆積が優勢であり，中央部基部から下流部にかけて懸濁水から堆積した淘汰の良い砂が堆積する．淘汰の良い砂は緩やかな2Dデューン状のベッドフォームを呈することがある．高水敷上に位置するトラフでは過去数10年間でも出水によりしばしば礫が堆積を繰り返しており，礫の集合部分の形状や懸濁水から堆積した砂との上下関係から，高水敷上での礫の転動・停止を含めた平均移動速度は遅く，概ね数10 m/h以下と推定された．近来まれに見る出水イベントであるT1919は，巨礫から泥まで様々な粒径の砕屑粒子を大規模に移動させ，砂礫州上での礫から砂への粒径変化が従来の事例より明瞭に認識されたが，砂礫州の外形を大きく変化させるほどの影響はなかった．今後も「想定を超える降雨」による河川の出水の頻度が増加する可能性が高いことを考慮すると，各地のT1919による出水及びそれによる砂礫の運搬・堆積の状況を記録・共有しておくことは，極めて重要である．

The invasive crayfish Faxonius immunis causes the collapse of macroinvertebrate communities in Central European ponds

The invasive crayfish Faxonius immunis is regarded as a threat to amphibians and macroinvertebrates in the Upper Rhine Valley, Germany, eradicating macrophytes and establishing high-density populations in stagnant waters. This study investigates the macroinvertebrate community structure of five conservation ponds south of Karlsruhe, Germany, to identify effects caused by this invasive crayfish. Two of the ponds had a high population density of F. immunis, two were expected to have lower crayfish densities as they had been habitat modified with gravelled water beds as a crayfish management approach, and one pond was known to be free of crayfish but contained fish. The macroinvertebrate communities were analyzed considering their species richness and composition. The relative density of F. immunis within the samples was regarded as a representative indicator for crayfish population density and tested for its influence on the ordination along with habitat composition and abiotic factors using distance-based redundancy analysis. F. immunis was identified as a driving factor of the macroinvertebrate communities of sampled ponds. Additionally, this study indicates that gravelling ground beds as a management method for invasive burrowing crayfish species does not significantly influence the community composition but can minimize indirect effects caused by F. immunis.

An in vivo assay to study locomotion in Caenorhabditis elegans

Adaptation in the sensory-mechanical loop during locomotion is a powerful mechanism that allows organisms to survive in different conditions and environments. Motile animals need to alter motion patterns in different environments. For example, crocodiles and other animals can walk on solid ground but switch to swimming in water beds. The nematode Caenorhabditis elegans also shows adaptability by employing thrashing behaviour in low viscosity media and crawling in high viscosity media. The mechanism that enables this adaptability is an active area of research. It has been attributed previously to neuro-modulation by dopamine and serotonin. This study introduces an experimental assay to physiologically investigate the neuronal mechanisms of modulation of locomotion by dopamine. The technique is utilized to test gait switching while imaging the mechanosensory dopaminergic neurons PDE. Results revealed their role to be not limited to touch sensation, but to sensing surrounding environment resistance as well. The significance of such characterization is improving our understanding of dopamine gait switching which gets impaired in Parkinson's disease.-A locomotion pattern switching system was devised to allow studying this process in vivo in the nematode C. elegans.-This system allowed the study of dopaminergic neurons PDE response as the worms switched from crawling to swimming.