Exact formulas for traces of singular moduli of higher level modular functions

Zagier proved that the traces of singular values of the classical j-invariant are the Fourier coefficients of a weight 3/2 modular form and Duke provided a new proof of the result by establishing an exact formula for the traces using Niebur's work on a certain class of non-holomorphic modular forms. In this short note, by utilizing Niebur's work again, we generalize Duke's result to exact formulas for traces of singular moduli of higher level modular functions.Comment: 8 page

Communication systems operating in the 60 GHz ISM band: Overview

This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.This paper gives an overview of frequency regulation, standardization, and applications of 60 GHz communication systems. Based on forecasted developments of mobile IP traffic, the motivation for investigating circuits, and systems for the 60 GHz band is underlined. Some physical properties of 60 GHz radio waves are outlined and implications on potential applications are sketched. The current international and European frequency regulation aspects are presented. The main parameters of three different international standards are summarized and compared with each other. Details of channel spacing and channel bonding are given. Based on the investigation of different applications, the main system requirements are derived. Finally, some information on protocol issues and system integration aspects are given.Peer Reviewe

Computationally efficient air quality forecasting tool: implementation of STOPS v1.5 model into CMAQ v5.0.2 for a prediction of Asian dust

This study suggests a new modeling framework using a hybrid Eulerian-Lagrangian-based modeling tool (the Screening Trajectory Ozone Prediction System, STOPS) for a prediction of an Asian dust event in Korea. The new version of STOPS (v1.5) has been implemented into the Community Multi-scale Air Quality (CMAQ) model version 5.0.2. The STOPS modeling system is a moving nest (Lagrangian approach) between the source and the receptor inside the host Eulerian CMAQ model. The proposed model generates simulation results that are relatively consistent with those of CMAQ but within a comparatively shorter computational time period. We find that standard CMAQ generally underestimates PM10 concentrations during the simulation period (February 2015) and fails to capture PM10 peaks during Asian dust events (22-24 February 2015). The underestimation in PM10 concentration is very likely due to missing dust emissions in CMAQ rather than incorrectly simulated meteorology, as the model meteorology agrees well with the observations. To improve the underestimated PM10 results from CMAQ, we used the STOPS model with constrained PM concentrations based on aerosol optical depth (AOD) data from the Geostationary Ocean Color Imager (GOCI), reflecting real-time initial and boundary conditions of dust particles near the Korean Peninsula. The simulated PM10 from the STOPS simulations were improved significantly and closely matched the surface observations. With additional verification of the capabilities of the methodology on emission estimations and more STOPS simulations for various time periods, the STOPS model could prove to be a useful tool not just for the predictions of Asian dust but also for other unexpected events such as wildfires and oil spillsopen0

Characteristics of InP/InGaAs HPT-based Optically Injection-Locked Self-oscillating Optoelectronic Mixers and Their Influence on RoF System Performance

Abstract A 30GHz optically injection-locked self-oscillating optoelectronic mixer (OIL-SOM) is implemented with a high-performance InP/InGaAs heterojunction phototransistor. The sub-harmonic conversion efficiency and phase noise characteristics of OIL-SOM are investigated and used for analyzing OIL-SOM-based 60GHz radio-on-fiber downlink data transmission performance. The OIL-SOM characteristics provide lower and upper boundaries for the input optical LO power range within which the link performance does not significantly depend on input optical LO power. Index Terms: heterojunction phototransistor (HPT), optically injection-locked selfoscillating optoelectronic mixer (OIL-SOM), phase noise, conversion efficiency, 60GHz, radio-on-fiber system, optical LO power

Gene silencing in HIV-1 latency by polycomb repressive group

<p>Abstract</p> <p>Background</p> <p>The persistence of latently Human immunodeficiency virus-1 (HIV-1) infected cellular reservoirs in resting CD4⁺T cells is a major obstacle to HIV-1 eradication. The detailed mechanism of HIV-1 latency remains unclear. We investigated histones and their post-translational modification associated with HIV-1 latency in novel HIV-1 latently infected cell lines established previously, NCHA cells.</p> <p>Methods</p> <p>To examine histones and their modification linked with HIV-1 latency, the expression profiles for core histone proteins and histone deacetylases (HDACs) in NCHA cells were characterized by RT-PCR, ELISA, and western blot. The levels of histone acetylation and methylation at histone H3 Lys⁹(H3K9) and Lys²⁷(H3K27) in HIV-1 latently infected cells were analyzed by western blot and chromatin immunoprecipitation-sequencing (ChIP-seq).</p> <p>Results</p> <p>The expression levels for four core histone proteins (H2A, H2B, H3 and H4) and HDACs (HDAC1-8) in NCHA cells were not significantly different from those in their parental cells. Histone H3K9 and H3K27 acetylations in NCHA cells showed no difference in parental and NCHA cells, whereas the levels of di- and tri-methylation were increased in NCHA cells. The expression of EED which is a component of polycomb repressive complex 2 (PRC2), and BMI1 and RING2 which are constituents of PRC1, were upregulated in NCHA cells. In addition, more ubiquitylation at histone H2A was detected in NCHA cells.</p> <p>Conclusions</p> <p>Our results suggest that tri-methylation of histone H3K27 and H2A ubiquitylation via polycomb group protein may play a crucial role in epigenetic silencing accounting for HIV-1 latency in NCHA cells.</p