Minimizing Stimulus Current in a Wearable Pudendal Nerve Stimulator Using Computational Models.

After spinal cord injury, functions of the lower urinary tract may be disrupted. A wearable device with surface electrodes which can effectively control the bladder functions would be highly beneficial to the patients. A trans-rectal pudendal nerve stimulator may provide such a solution. However, the major limiting factor in such a stimulator is the high level of current it requires to recruit the nerve fibers. Also, the variability of the trajectory of the nerve in different individuals should be considered. Using computational models and an approximate trajectory of the nerve derived from an MRI study, it is demonstrated in this paper that it may be possible to considerably reduce the required current levels for trans-rectal stimulation of the pudendal nerve compared to the values previously reported in the literature. This was corroborated by considering an ensemble of possible and probable variations of the trajectory. The outcome of this study suggests that trans-rectal stimulation of the pudendal nerve is a plausible long term solution for treating lower urinary tract dysfunctions after spinal cord injury

Quantum algorithms and the power of forgetting

The so-called welded tree problem provides an example of a black-box problem that can be solved exponentially faster by a quantum walk than by any classical algorithm. Given the name of a special ENTRANCE vertex, a quantum walk can find another distinguished EXIT vertex using polynomially many queries, though without finding any particular path from ENTRANCE to EXIT. It has been an open problem for twenty years whether there is an efficient quantum algorithm for finding such a path, or if the path-finding problem is hard even for quantum computers. We show that a natural class of efficient quantum algorithms provably cannot find a path from ENTRANCE to EXIT. Specifically, we consider algorithms that, within each branch of their superposition, always store a set of vertex labels that form a connected subgraph including the ENTRANCE, and that only provide these vertex labels as inputs to the oracle. While this does not rule out the possibility of a quantum algorithm that efficiently finds a path, it is unclear how an algorithm could benefit by deviating from this behavior. Our no-go result suggests that, for some problems, quantum algorithms must necessarily forget the path they take to reach a solution in order to outperform classical computation.Comment: 49 pages, 9 figure

Quantum Algorithms and the Power of Forgetting

The so-called welded tree problem provides an example of a black-box problem that can be solved exponentially faster by a quantum walk than by any classical algorithm [Andrew M. Childs et al., 2003]. Given the name of a special entrance vertex, a quantum walk can find another distinguished exit vertex using polynomially many queries, though without finding any particular path from entrance to exit. It has been an open problem for twenty years whether there is an efficient quantum algorithm for finding such a path, or if the path-finding problem is hard even for quantum computers. We show that a natural class of efficient quantum algorithms provably cannot find a path from entrance to exit. Specifically, we consider algorithms that, within each branch of their superposition, always store a set of vertex labels that form a connected subgraph including the entrance, and that only provide these vertex labels as inputs to the oracle. While this does not rule out the possibility of a quantum algorithm that efficiently finds a path, it is unclear how an algorithm could benefit by deviating from this behavior. Our no-go result suggests that, for some problems, quantum algorithms must necessarily forget the path they take to reach a solution in order to outperform classical computation

Evaluation of efficacy and tolerability of eperisone and thiocolchicoside in treatment of low back pain associated with muscle spasm: An open label, prospective, randomized controlled trial

Background: Low back pain has a high prevalence in adult population. Because of reflex muscle spasm, muscle relaxants are frequently used either alone or in combination with analgesics. Eperisone inhibits voltage gated sodium channels in brain stem and Thiocolchicoside acts via GABA-mediated mechanism to relax muscle spasm and relieves pain.Methods: This was a prospective; open labeled, randomized, two-arm, parallel group, controlled, clinical trial. 113 patients were randomised to two groups. Patients in group A received Tablet Eperisone 100 mg whereas patients in group B received Tablet Thiocolchicoside 8 mg for seven days along with Tablet Paracetamol 500 mg. The outcome measures of trial were the improvement in finger to floor distance (FFD) and pain in lumbar region, relief of spasm and tenderness of paravertebral muscles on day 4 and 7.Results: At the end of the study FFD reduced by 18 cm in group A (p < 0.0001*) and 17.36 cm in group B (p<0.0001*) from baseline. Mean score of pain on day 7 reduced by 5.64 scale in group A as compared to 5.42 scale in group B (p<0.0001* in both groups). Paravertebral tenderness reduced by 92.6% in group A and 94.6% in group B at the end of the trial. On day 7, the spasm relief was 87% in group A and 88% in group B.Conclusions: Eperisone is an effective muscle relaxant with equivalent efficacy compared to Thiocolchicoside, and has a better tolerability in treatment of low back pain with muscle spasm

Neuroactive steroids and their role in epilepsy

Neuroactive steroids are the certain steroids that alter neuronal excitability via the cell surface through interaction with certain neurotransmitter receptors. Neuroactive steroids regulate physiological functions of the central nervous system and have possible therapeutic potential in neurological diseases. They have been shown to affect neuronal excitability via their interaction with the ligand-gated ion channel family, such as the GABAA receptor by acting genomically as well as nongenomically. Positive modulators of GABAA receptor have anticonvulsant action as they enhance GABAergic transmission thereby increasing the seizure threshold. By virtue of these properties, neurosteroids appear to be relevant to pathophysiology and pharmacological treatment of many neurological diseases including catamenial epilepsy, stress induced epilepsy, temporal lobe epilepsy, alcohol withdrawal seizures, infantile spasm and status epilepticus. So far, only synthetic neurosteroid, ganaxolone has been tried in treatment of epilepsy and has shown good efficacy and tolerability. But, human data of trials are limited and hence, large double-blinded, placebo-controlled, randomized clinical trials are required before their use. The paper reviews the biosynthesis and GABAA receptor modulation of neurosteroids and their potential role in epilepsy