Specific requirement of NMDA receptors for long-term memory consolidation in Drosophila ellipsoid body

In humans and many other animals, memory consolidation occurs through multiple temporal phases and usually involves more than one neuroanatomical brain system. Genetic dissection of Pavlovian olfactory learning in Drosophila melanogaster has revealed multiple memory phases, but the predominant view holds that all memory phases occur in mushroom body neurons. Here, we demonstrate an acute requirement for NMDA receptors (NMDARs) outside of the mushroom body during long-term memory (LTM) consolidation. Targeted dsRNA-mediated silencing of Nmdar1 and Nmdar2 (also known as dNR1 or dNR2, respectively) in cholinergic R4m-subtype large-field neurons of the ellipsoid body specifically disrupted LTM consolidation, but not retrieval. Similar silencing of functional NMDARs in the mushroom body disrupted an earlier memory phase, leaving LTM intact. Our results clearly establish an anatomical site outside of the mushroom body involved with LTM consolidation, thus revealing both a distributed brain system subserving olfactory memory formation and the existence of a system-level memory consolidation in Drosophila

Small-signal model of multiple inverter-based DG system with positive feedback anti-islanding protection

This paper presents a small-signal model suitable to analyze the stability and dynamic characteristics of multiple inverter-based distributed generation (DG) systems and the associated positive feedback anti-islanding scheme. The developed model is validated by comparing its results against those obtained by detailed, non-linear electromagnetic transient simulations. With the developed model, the sensitivity analysis can be conducted to study the small-signal stability of the multiple inverter-based DG systems

A systematic gain setting method of the positive feedback anti-islanding scheme for inverter-based distributed generators

This paper proposes a systematic gain setting method for the positive feedback anti-islanding scheme which is designed to protect the interconnected inverter-based distributed generators (DGs) from islanding operation. Two main factors affecting the performance of the anti-islanding scheme are investigated when the positive feedback gain is tuned. One is the stability impact of the anti-islanding control on distributed generation (DG) systems and the other is the islanding detection time of the anti-islanding scheme. The small-signal model and the electromagnetic transient simulation model of an inverter-based DG system are developed to facilitate the realization of the proposed gain setting method. This method provides a practical and reliable tool for DG planning engineers

Evaluation of leaf wax delta D and soil brGDGTs as tools for paleoaltimetry on the southeastern Tibetan Plateau

The orogenic history of the Tibetan Plateau (TP) and surrounding mountain ranges continues to be a major source of disagreement among geologists, particularly concerning the uplift models for the Cenozoic evolution of the TP and estimates for when the highest and largest plateau on Earth reached its current elevation. Quantitative reconstructions of past elevation from geologic samples are necessary to document the uplift history of TP and examine the interactions between tectonic-relief and climate over geological time-scales. Several studies establishing lipid biomarker-based paleoaltimetry based on leaf wax delta D values and brGDGTs have been reported in recent years for the TP and surrounding regions, but have yet to be synthesized into a regional framework for paleoelevation determination and uncertainty analysis. Here we report new leaf wax delta D and brGDGTs data developed from surface soil samples along an elevation transect spanning similar to 1250-3900 m.a.s.l in the Hengduan Mountains on the southeastern edge of the TP. We find that the abundance-weighted mean leaf wax delta D (n-C-27, n-C-29 and n-C-31) values (delta D-wa(s)) lapse rates determined for the Hengduan Mountains and for five other nearby study locations are statistically indistinguishable, and can be combined to provide a regional delta D(was )lapse rate of -1.97 +/- 0.04 parts per thousand (1 sigma)/100 m for use in regional paleoelevation studies across the southeastern TP. We also find a strong correlation (R-2 = 0.71) between brGDGTs and elevation-dependent mean annual air temperature, which contributes to a number of studies in the region that support the use of fossil brGDGTs as a paleoelevation proxy. Our results reveal that delta D(was )and brGDGTs for the Hengduan Mountains provide similar empirical uncertainty in paleoelevation reconstruction, with standard errors of elevation estimation (SE) of +/- 483 m (+/- 1 sigma) and +/- 394 m (+/- 1 sigma), respectively. We propose a paleoaltimetric approach that combines delta D-wa(s) and brGDGT data, in order to derive paleoelevation estimates with lower uncertainties. In the Hengduan Mountains data set, the approach yields a SE (+/- 286 m; +/- 1 sigma) that is 27-40% lower than when delta D-wa(s) values and brGDGTs are applied separately

Aggregation model-based optimization for electric vehicle charging strategy

This paper presents an aggregation charging model for large numbers of electric vehicles (EVs). A genetic algorithm (GA) is employed to obtain the stochastic feature parameters of the aggregation model, and a charging strategy based on the aggregation model is developed to reduce the power fluctuation level caused by EV charging. In addition, an updatable optimization method is proposed to track the variation of the EV charging characteristics. The proposed charging strategy and optimization method are validated by the simulation results