The effects of large extra dimensions on associated ttˉh0t\bar{t} h^0 production at linear colliders

In the framework of the large extra dimensions (LED) model, the effects of LED on the processes \rrtth and \eetth at future linear colliders are investigated in both polarized and unpolarized collision modes. The results show that the virtual Kaluza-Klein (KK) graviton exchange can significantly modify the standard model expectations for these processes with certain polarizations of initial states. The process \rrtth with $\sqrt{s}=3.5 TeV$ allows the effective scale $\Lambda_T$ to be probed up to 7.8 and 8.6 TeV in the unpolarized and $P_{\gamma} = 0.9$, J=2 polarized $\gamma \gamma$ collision modes, respectively. For the \eetth process with $\sqrt{s}=3.5 TeV$, the upper limits of $\Lambda_T$ to be observed can be 6.7 and 7.0 TeV in the unpolarized and $P_{e^+} = 0.6$, $P_{e^-} = 0.8$, $-+$ polarized $e^+e^-$ collision modes, respectively. We find the \rrtth channel in J=2 polarized photon collision mode provides a possibility to improve the sensitivity to the graviton tower exchange.Comment: To be appeard in Physical Review

Effects of Heating-needle Stimulation in Restoration of Weakened Descending Inhibition of Nociception in a Rat Model of Parkinson's Disease

Here we investigated variations of endogenous descending modulation of nociception and therapeutic effects of intramuscular (i.m.) heating-needle stimulation in early stage of Parkinson's disease (PD) induced by unilateral microinjection of 3.5 mu l of 2.5 mu g/mu l 6-hydroxydopamine into the rat striatum. Paw withdrawal reflexes to noxious mechanical and heat stimuli in PD rats with and without exposure to i.m. 5.8% saline induced muscle nociception were evaluated. Experimental PD had no influence on mechanical or heat sensitivity in the baseline condition, whereas descending facilitation was stronger and descending inhibition was weaker in PD rats than vehicle-treated or naive rats during muscle nociception (P <0.05). Striatal administration of 5 mu g of dopamine failed to reverse the PD-associated changes in descending facilitation or inhibition, whereas dopamine in the thalamic mediodorsal (MD) nucleus and ventromedial (VM) nucleus significantly decreased the increase in descending facilitation and reversed the attenuation in descending inhibition, respectively (P <0.05). I.m. 43 degrees C of heating-needle stimulation had no effects on the enhanced descending facilitation in PD rats, but it markedly increased descending inhibition and reversed the increase in the number of apomorphine-induced body rotations (P <0.05), which effects were dose-dependently attenuated by raclopride, a dopamine 2 receptor antagonist, in the thalamic VM nucleus (P <0.05). The results indicate that the early-stage PD is associated with enhanced descending facilitation and weakened descending inhibition. From clinical perspective, 43 degrees C heat therapeutic regime promises to selectively enhance descending inhibition that is accompanied by improvement of motor dysfunction in PD. (c) 2020 IBRO. Published by Elsevier Ltd. All rights reserved.Peer reviewe

Effects of Intramuscular Heating-needle Stimulation in Controlling Adjuvant-induced Muscle Nociception in Rats : Differential Roles of Thalamic Purinergic P2X3 Receptors

Here we investigated effects of intramuscular (i.m.) heating-needle stimulation on persistent muscle nociception evoked by i.m. injection of different doses (50-200 mu l) of complete Freund's adjuvant (CFA) in rats. Paw withdrawal reflexes evoked by noxious mechanical and heat stimulation as well as hind limb swelling were determined prior to and two weeks after the CFA injection. The unilateral injection of CFA induced a dose-related and long-lasting (5-14 d), bilateral secondary mechanical hyperalgesia and heat hypoalgesia associated with long-term limb swelling. A period of 30-45 min 43 degrees C heating-needle stimulation significantly enhanced the i.m. CFA-induced bilateral heat hypoalgesia and alleviated hind limb swelling. In contrast, 30-45 min 46 degrees C heatingneedle stimulation markedly enhanced both mechanical hyperalgesia and heat hypoalgesia, but failed to influence the CFA-induced hind limb swelling. Microinjection of P2X3 receptor antagonist A-317491 (0.5-4.5 nmol/0.5 mu l) into the thalamic ventromedial (VM) nucleus dose-dependently inhibited the 43 degrees C and 46 degrees C heating-needle stimulation-induced heat hypoalgesia, whereas the 46 degrees C heating-needle stimulation-induced mechanical hyperalgesia was significantly prevented by microinjection of A-317491 into the thalamic mediodorsal (MD) nucleus. In contrast, the hind limb swelling was not affected by the microinjection of A-317491 into the thalamic VM or MD nucleus. The present study indicates that in the CFA-induced persistent muscle nociception condition, 43 degrees C heating-needle stimulation selectively increases descending inhibition, which effect is modulated by the thalamic VM nucleus. In addition to the antinociceptive role of P2X3 receptors in the thalamic VM nucleus, P2X3 receptors within the thalamic MD nucleus participate in the descending facilitation evoked by i.m. 46 degrees C heating-needle stimulation. (C) 2020 IBRO. Published by Elsevier Ltd. All rights reserved.Peer reviewe

Spinal histamine in attenuation of mechanical hypersensitivity in the spinal nerve ligation-induced model of experimental neuropathy

Here we studied whether and through which mechanisms spinal administration of histamine dihydrochloride (histamine) attenuates pain behavior in neuropathic animals. Experiments were performed in rats with spinal nerve ligation-induced neuropathy and a chronic intrathecal catheter for spinal drug delivery. Mechanical hypersensitivity was assessed with monofilaments while radiant heat was used for assessing nociception. Ongoing neuropathic pain and its attenuation by histamine was assessed using conditioned place-preference test. Following spinal administration, histamine at doses 0.1-10 mu g produced a dose-related mechanical antihypersensitivity effect. With prolonged treatment (twice daily 10 mu g for five days), the antihypersensitivity effect of spinal histamine was reduced. In place-preference test, neuropathic animals preferred the chamber paired with histamine (10 mu g). Histamine (10 mu g) failed to influence heat nociception in neuropathic animals or mechanically induced pain behavior in a group of healthy control rats. Histamine-induced mechanical antihypersensitivity effect was prevented by spinal pretreatment with zolantidine (histamine H-2 receptor antagonist), prazosine (alpha(1)-adrenoceptor antagonist) and bicuculline (gamma-aminobutyric acid subtype A, GABA(A), receptor antagonist), but not by pyrilamine (histamine H-1 receptor antagonist), atipamezole (alpha(2)-adrenoceptor antagonist), or raclopride (dopamine D-2 receptor antagonist). A-960656, a histamine H-3 receptor antagonist alone that presumably increased endogenous histamine levels reduced hypersensitivity. Additionally, histamine prevented central (presumably postsynaptically-induced) facilitation of hypersensitivity induced by N-methyl-n-aspartate. The results indicate that spinal histamine at the dose range of 0.1-10 mu g selectively attenuates mechanical hypersensitivity and ongoing pain in neuropathy. The spinal histamine-induced antihypersensitivity effect involves histamine H-2 and GABA(A) receptors and (presumably neuropathy-induced) co-activation of spinal al-adrenoceptors. (C) 2015 Elsevier B.V. All rights reserved.Peer reviewe

Reduced mechanical hypersensitivity by inhibition of the amygdala in experimental neuropathy : Sexually dimorphic contribution of spinal neurotransmitter receptors

Here we studied spinal neurotransmitter mechanisms involved in the reduction of mechanical hypersensitivity by inhibition of the amygdaloid central nucleus (CeA) in male and female rats with spared nerve injury (SNI) model of neuropathy. SNI induced mechanical hypersensitivity that was stronger in females. Reversible blocking of the CeA with muscimol (GABAA receptor agonist) induced a reduction of mechanical hypersensitivity that did not differ between males and females. Following spinal co-administration of atipamezole (alpha 2-adrenoceptor antago-nist), the reduction of mechanical hypersensitivity by CeA muscimol was attenuated more in males than females. In contrast, following spinal co-administration of raclopride (dopamine D2 receptor antagonist) the reduction of hypersensitivity by CeA muscimol was attenuated more in females than males. The reduction of mechanical hypersensitivity by CeA muscimol was equally attenuated in males and females by spinal co-administration of WAY-100635 (5-HT1A receptor antagonist) or bicuculline (GABAA receptor antagonist). The CeA muscimol induced attenuation of ongoing pain-like behavior (conditioned place preference test) that was reversed by spinal co-administration of atipamezole in both sexes. The results support the hypothesis that CeA contributes to me-chanical hypersensitivity and ongoing pain-like behavior in SNI males and females. Disinhibition of descending controls acting on spinal alpha 2-adrenoceptors, 5-HT1A, dopamine D2 and GABAA receptors provides a plausible explanation for the reduction of mechanical hypersensitivity by CeA block in SNI. The involvement of spinal dopamine D2 receptors and alpha 2-adrenoceptors in the CeA muscimol-induced reduction of mechanical hypersen-sitivity is sexually dimorphic, unlike that of spinal alpha 2-adrenoceptors in the reduction of ongoing neuropathic pain.Peer reviewe

A synthetic Escherichia coli predator–prey ecosystem

We have constructed a synthetic ecosystem consisting of two Escherichia coli populations, which communicate bi-directionally through quorum sensing and regulate each other's gene expression and survival via engineered gene circuits. Our synthetic ecosystem resembles canonical predator–prey systems in terms of logic and dynamics. The predator cells kill the prey by inducing expression of a killer protein in the prey, while the prey rescue the predators by eliciting expression of an antidote protein in the predator. Extinction, coexistence and oscillatory dynamics of the predator and prey populations are possible depending on the operating conditions as experimentally validated by long-term culturing of the system in microchemostats. A simple mathematical model is developed to capture these system dynamics. Coherent interplay between experiments and mathematical analysis enables exploration of the dynamics of interacting populations in a predictable manner

The Study on Mechanical Model Considering Optimal Self-Adaption in the Bottleneck Area

It aims to solve the problem that the evacuation state of pedestrians depicted by the traditional social force model in a crowded multiexit scenario has a relatively large difference with the actual state, especially the \u27optimal path\u27 considered by the self-driving force is the problem of shortest path, and the multiexit evacuation mode depicted by the \u27herd behavior\u27 is the local optimum problem. Through in-depth analysis of actual evacuation data of pedestrians and causes of problem, a new crowd evacuation optimization model is established in order to effectively improve the simulation accuracy of crowd evacuation in a multi-exit environment. The model obtains the direction of motion of pedestrians using a field model, fully considers the factors such as exit distance, distribution of pedestrians and regional crowding degree, makes a global optimization for the self-driving force in the social force model using a centralized and distributed network model, and makes a local optimization for it using an elephant herding algorithm, so as to establish a new evacuation optimization method for optimal self-adaption in the bottleneck area. The performance status is compared between the improved social force model and the new model by experiments, and the key factors that affect the new model are analyzed in an in-depth manner. The results show that the new model can optimize the optimal path choice at the early stage of evacuation and improve the evacuation efficiency of pedestrians at the late stage, so as to ensure relatively even distribution of pedestrians at each exit, and also make the simulated evacuation process be more real; and the improvement in overall evacuation efficiency is greater when the number of pedestrians to be evacuated is larger. Therefore, the new model provides a method to solve the phenomenon of disorder in overall pedestrian evacuation due to excessive crowd density during the process of multi-exit evacuation