An audio FIR-DAC in a BCD process for high power Class-D amplifiers

A 322 coefficient semi-digital FIR-DAC using a 1-bit PWM input signal was designed and implemented in a high voltage, audio power bipolar CMOS DMOS (BCD) process. This facilitates digital input signals for an analog class-D amplifier in BCD. The FIR-DAC performance depends on the ISI-resistant nature of this PWM-signal. An impulse response with only positive coefficients was chosen, because of its resistance to deadzone and mismatch. With a DAC current of 0.5 mA, the dynamic range is 111 dB (A-weighted), with SINAD = 103 dB (A-weighted). The current consumption is 1mA for the analog part and 4.8 mA for the digital part. The power consumption is 29 mW at V/sub dd/ = 5 V and the chip area is 2 mm/sup 2/ including the reference diode that can be shared by more channels

Integration of SARS-CoV-2 RNA in infected human cells by retrotransposons: an unlikely hypothesis and old viral relationships

Zhang et al. (Proc Natl Acad Sci 118:e2105968118, 2021) recently reported that SARS-CoV-2 RNA can be retrotranscribed and integrated into the DNA of human cells by the L1 retrotransposon machinery. This phenomenon could cause persistence of viral sequences in patients and may explain the prolonged PCR-positivity of SARS-CoV-2 infected patients, even long after the phase of active virus replication has ended. This commentary does critically review the available data on this topic and discusses them in the context of findings made for other exogenous viruses and ancestral endogenous retroviral elements

Circularization of the HIV-1 RNA genome

Genomic RNA circularization has been proposed for several RNA viruses. In this study, we examined if the 5′ and 3′ ends of the 9-kb HIV-1 RNA genome can interact. In vitro assays demonstrated a specific interaction between transcripts encompassing the 5′ and 3′ terminal 1 kb, suggesting that the HIV-1 RNA genome can circularize. Truncation of the transcripts indicated that the 5′–3′ interaction is formed by 600–700 nt in the gag open reading frame and the terminal 123 nt of the genomic RNA. Detailed RNA structure probing indicates that sequences flanking the 3′ TAR hairpin interact with complementary sequences in the gag gene. Phylogenetic analysis indicates that all HIV-1 subtypes can form the 5′/3′ interaction despite considerable sequence divergence, suggesting an important role of RNA circularization in the HIV-1 replication cycle

Changes in interest group access in times of crisis: no pain, no (lobby) gain

The outbreak of Covid-19 provoked a massive shock for political institutions and societal groups. A crucial question is how such an external event affects the balance of access to political gatekeepers. In particular: Are organizations, which are highly affected by the crisis, able to increase their political voice? To address this, we focus on changes in lobbying access to key venues of public policy: government, parliament, the bureaucracy, and the media across 10 European democracies. Based on novel survey data, we assess changes in access shortly after the outbreak of Covid-19. Our findings show that affectedness is an important driver of changes in access to all venues. We interpret this as good news for the functioning of European systems of interest representation, and the ability of gatekeepers to open their doors to affected groups. However, we also show that the effect of affectedness varies considerably for economic and non-economic interests