Wireless optogenetics protects against obesity via stimulation of non-canonical fat thermogenesis.

Cold stimuli and the subsequent activation of β-adrenergic receptor (β-AR) potently stimulate adipose tissue thermogenesis and increase whole-body energy expenditure. However, systemic activation of the β3-AR pathway inevitably increases blood pressure, a significant risk factor for cardiovascular disease, and, thus, limits its application for the treatment of obesity. To activate fat thermogenesis under tight spatiotemporal control without external stimuli, here, we report an implantable wireless optogenetic device that bypasses the β-AR pathway and triggers Ca2+ cycling selectively in adipocytes. The wireless optogenetics stimulation in the subcutaneous adipose tissue potently activates Ca2+ cycling fat thermogenesis and increases whole-body energy expenditure without cold stimuli. Significantly, the light-induced fat thermogenesis was sufficient to protect mice from diet-induced body-weight gain. The present study provides the first proof-of-concept that fat-specific cold mimetics via activating non-canonical thermogenesis protect against obesity

Optimal Sensor Collaboration for Parameter Tracking Using Energy Harvesting Sensors

In this paper, we design an optimal sensor collaboration strategy among neighboring nodes while tracking a time-varying parameter using wireless sensor networks in the presence of imperfect communication channels. The sensor network is assumed to be self-powered, where sensors are equipped with energy harvesters that replenish energy from the environment. In order to minimize the mean square estimation error of parameter tracking, we propose an online sensor collaboration policy subject to real-time energy harvesting constraints. The proposed energy allocation strategy is computationally light and only relies on the second-order statistics of the system parameters. For this, we first consider an offline non-convex optimization problem, which is solved exactly using semidefinite programming. Based on the offline solution, we design an online power allocation policy that requires minimal online computation and satisfies the dynamics of energy flow at each sensor. We prove that the proposed online policy is asymptotically equivalent to the optimal offline solution and show its convergence rate and robustness. We empirically show that the estimation performance of the proposed online scheme is better than that of the online scheme when channel state information about the dynamical system is available in the low SNR regime. Numerical results are conducted to demonstrate the effectiveness of our approach

Spectrum Auctions

Auctions have emerged as the primary means of assigning spectrum licenses to companies wishing to provide wireless communication services. Since July 1994, the Federal Communications Commission (FCC) has conducted 33 spectrum auctions, assigning thousands of licenses to hundreds of firms. Countries throughout the world are conducting similar auctions. I review the current state of spectrum auctions. Both the design and performance of these auctions are addressed.Auctions, Spectrum Auctions, Multiple Item Auctions

Adaptive probability scheme for behaviour monitoring of the elderly using a specialised ambient device

A Hidden Markov Model (HMM) modified to work in combination with a Fuzzy System is utilised to determine the current behavioural state of the user from information obtained with specialised hardware. Due to the high dimensionality and not-linearly-separable nature of the Fuzzy System and the sensor data obtained with the hardware which informs the state decision, a new method is devised to update the HMM and replace the initial Fuzzy System such that subsequent state decisions are based on the most recent information. The resultant system first reduces the dimensionality of the original information by using a manifold representation in the high dimension which is unfolded in the lower dimension. The data is then linearly separable in the lower dimension where a simple linear classifier, such as the perceptron used here, is applied to determine the probability of the observations belonging to a state. Experiments using the new system verify its applicability in a real scenario

The Efficiency of the FCC Spectrum Auctions

From July 1994 to July 1996, the Federal Communications Commission (FCC) conducted nine spectrum auctions, raising about $20 billion for the U.S. Treasury. The auctions assigned thousands of licenses to hundreds of firms. Were the auctions efficient? Did they award the licenses to the firms best able to turn the spectrum into valuable services for onsumers? There is substantial evidence that the FCC's simultaneous ascending auction worked well. It raised large revenues. It revealed critical information in the process of bidding and gave bidders the flexibility to adjust strategies in response to new information. As a result, similar licenses sold for similar prices, and bidders were able to piece together sensible sets of licenses.Auctions; Multiple-Item Auctions; Spectrum Auctions