195 research outputs found

    Fluctuation characteristics and rolling control for an underactuated spherical underwater exploration robot

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    Compared with other underwater exploration robots, Spherical underwater robot has an outstanding advantage for the underwater exploration, whose spherical shell has the excellent resiliency to protect the internal electronic components. In addition, this steering resistance is very small to move flexibly. In this paper, a type of spherical underwater robot with the pendulums and a propeller was studied on moving at the water bottom in a rolling manner. The structure and force were analyzed to understand that the hydrodynamic force’s affection on the robot’s rolling at the water bottom. A mathematical model was established with the mass parameters and speeding parameters. The virtual simulation environment was established in Adams software. Furthermore, the coupling fluctuation characteristics of the speed, swing angle and the torque were studied by the simulation and the experiment in a pool. The study proved that this robot not only can use the propeller to move in water, but also can roll at the water bottom by driving the spherical shell. Especially, the result also can be obtained that the robot can roll at water bottom stably by increasing the pendulum mass and lowering the motor speed

    How Does Targeted Poverty Alleviation Policy Influence Residents' Perceptions of Rural Living Conditions? A Study of 16 Villages in Gansu Province, Northwest China

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    Rural living conditions (RLCs) in China are influential on the overall development and stability of regions, particularly for populations in distant poverty-stricken villages. This paper takes 16 villages of Chedao town in Gansu province, Northwest China (NWC) as our case study. Using data from the Poverty Alleviation and Assistance (PAA) project launched by Lanzhou University in June 2017, and the perceptions of residents of Chedao, we pinpoint RLC changes in the targeted poverty alleviation (TPA) process. The three main results show that: (1) From the residents' perceptions, the impact of alleviation measures on RLC is mainly reflected in improved housing conditions, infrastructure, and public services. We find no significant effect on cultural conditions. However, eco-environmental conditions have obviously weakened. (2) Housing size, accessibility, distance to shops, and safe drinking water are the most significant factors in housing conditions, infrastructure, public services, and eco-environmental conditions, respectively. (3) Out of the different levels of rural poverty households (RPHs), severe rurality villages are more strongly aware of the positive changes in RLC than residents of mild rurality villages. Moreover, in residents' view, housing conditions are most improved in severe rurality villages, infrastructure is most improved in moderate rurality villages, and public services are most improved in mild rurality villages. Eco-environmental conditions worsen across all levels. Our findings shed light on the perceptions of residents on changes occurring in rural living conditions, and provide a basis for subsequent studies of RLC in Northwest China

    (S)-Benzyl 3-(4-hy­droxy­phen­yl)-2-(trityl­amino)­propano­ate

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    The title compound, C35H31NO3, was obtained by the reaction of (S)-benzyl 2-amino-3-(4-hy­droxy­phen­yl)propano­ate and (chloro­methane­tri­yl)tribenzene. The enanti­omer has been assigned by reference to an unchanging chiral centre in the synthetic procedure. In the crystal, mol­ecules are linked into chains running along the a axis by inter­molecular O—H⋯O hydrogen bonds

    Production of doubly charmed hadron Ξcc++\Xi_{cc}^{++} and Tcc+T_{cc}^+ in relativistic heavy ion collisions

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    Heavy ion collisions provide a unique opportunity for studying the properties of exotic hadrons with two charm quarks. The production of Tcc+T_{cc}^+ is significantly enhanced in nuclear collisions compared to proton-proton collisions due to the creation of multiple charm pairs. In this study, we employ the Langevin equation in combination with the Instantaneous Coalescence Model (LICM) to investigate the production of Tcc+T_{cc}^+ and Ξcc++\Xi_{cc}^{++} which consists of two charm quarks. We consider Tcc+T_{cc}^+ as molecular states composed of DD and DD^* mesons. The Langevin equation is used to calculate the energy loss of charm quarks and DD mesons in the hot medium. The hadronization process, where charm quarks transform into each DD state as constituents of Tcc+T_{cc}^+ production, is described using the coalescence model. The coalescence probability between DD and DD^* is determined by the Wigner function, which encodes the information of the Tcc+T_{cc}^+ wave function. Our results show that the Tcc+T_{cc}^+ production varies by approximately one order of magnitude when different widths in the Wigner function, representing distinct binding energies of Tcc+T_{cc}^+, are considered. This variation offers valuable insights into the nature of Tcc+T_{cc}^+ through the analysis of its wave function. The Ξcc++\Xi_{cc}^{++} is treated as a hadronic state produced at the hadronization of the deconfined matter. Its production is also calculated as a comparison with the molecular state Tcc+T_{cc}^+.Comment: 7 pages, 5 figure

    Knowledge and acceptability of the rectal treatment route in Laos and its application for pre-referral emergency malaria treatment

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    <p>Abstract</p> <p>Background</p> <p>Rectal artesunate has been shown to reduce death and disability from severe malaria caused by delays in reaching facilities capable of providing appropriate treatment.</p> <p>Acceptability of this mode of drug delivery in Laos is not known. In 2009 the acceptability of rectal treatments was evaluated among the general Lao population and Lao doctors in a national survey.</p> <p>Methods</p> <p>A cross sectional survey was performed of 985 households selected through a multi-stage random sampling process from 85 villages in 12/18 provinces and of 315 health staff randomly selected at each administrative level.</p> <p>Results</p> <p>Out of 985 families, 9% had used the rectal route to treat children (the main indication was seizures or constipation). The population considered it less effective than other routes. Other concerns raised included pain (28%), discomfort for children (40%) and the possibility of other side effects (20%). Of 300 health staff surveyed (nurses 44%, doctors 66%), only 51% had already used the rectal route with a suppository, mostly to treat fever (76%). Health staff working in provincial hospitals had more experience of using the rectal route than those in urban areas. The majority (92%) were keen to use the rectal route to treat malaria although oral and intramuscular routes were preferred and considered to be more efficacious.</p> <p>Discussion and conclusion</p> <p>Use of rectal treatments is uncommon in Laos and generally not considered to be very effective. This view is shared by the population and health care workers. More information and training are needed to convince the population and health staff of the efficacy and advantages of the rectal route for malaria treatment.</p

    Rapamycin directly activates lysosomal mucolipin TRP channels independent of mTOR

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    Rapamycin (Rap) and its derivatives, called rapalogs, are being explored in clinical trials targeting cancer and neurodegeneration. The underlying mechanisms of Rap actions, however, are not well understood. Mechanistic target of rapamycin (mTOR), a lysosomelocalized protein kinase that acts as a critical regulator of cellular growth, is believed to mediate most Rap actions. Here, we identified mucolipin 1 (transient receptor potential channel mucolipin 1 [TRPML1], also known as MCOLN1), the principle Ca2+ release channel in the lysosome, as another direct target of Rap. Patch-clamping of isolated lysosomal membranes showed that micromolar concentrations of Rap and some rapalogs activated lysosomal TRPML1 directly and specifically. Pharmacological inhibition or genetic inactivation of mTOR failed to mimic the Rap effect. In vitro binding assays revealed that Rap bound directly to purified TRPML1 proteins with a micromolar affinity. In both healthy and disease human fibroblasts, Rap and rapalogs induced autophagic flux via nuclear translocation of transcription factor EB (TFEB). However, such effects were abolished in TRPML1-deficient cells or by TRPML1 inhibitors. Hence, Rap and rapalogs promote autophagy via a TRPML1-dependent mechanism. Given the demonstrated roles of TRPML1 and TFEB in cellular clearance, we propose that lysosomal TRPML1 may contribute a significant portion to the in vivo neuroprotective and anti-aging effects of Rap via an augmentation of autophagy and lysosomal biogenesis

    Complete Consistency of the Estimator of Nonparametric Regression Models Based on ∼ ρ-Mixing Sequences

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    We study the complete consistency for estimator of nonparametric regression model based on ∼ ρ-mixing sequences by using the classical Rosenthal-type inequality and the truncated method. As an application, the complete consistency for the nearest neighbor estimator is obtained
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