ABSTRACT
We study the dynamical evolution of Jupiter and Saturn embedded in a gaseous, solar nebula-type disc by means of hydrodynamics simulations with the fargo2d1d code. We study the evolution for ...different initial separations of the planets’ orbits, ΔaSJ, to investigate whether they become captured in mean motion resonance (MMR) and the direction of the subsequent migration of the planet (inwards or outwards). We also provide an assessment of the planet’s orbital dynamics at different epochs of Saturn’s growth. We find that the evolution of initially compact orbital configurations is dependent on the value of ΔaSJ. This implies that an evolution as that proposed in the Grand Tack model depends on the precise initial orbits of Jupiter and Saturn and on the time-scales for their formation. Capture in the 1:2 MMR and inward or (nearly) stalled migration are highly favoured. Within its limits, our work suggests that the reversed migration, associated with the resonance capture of Jupiter and Saturn, may be a low-probability evolutionary scenario, so that other planetary systems with giant planets are not expected to have experienced a Grand Tack-like evolutionary path.
New stacking cell design topologies are introduced in this article to achieve effective electrostatic discharge on-chip protection while meeting relatively high-holding-voltage and ...low-trigger-voltage characteristic requirements. A resistive silicon-controlled-rectifier (SCR) device forming the stacking structures is initially presented, which combines resistive and SCR-like current-voltage characteristics. By embedding this resistive SCR along with the existing optimized low-holding-voltage baseline devices, the overall stacking structure can achieve the requirement of high current-handling capability and high-holding-voltage tolerance without increasing the trigger voltage.
A new low-capacitance clamp is introduced for high-voltage-tolerant and high-speed interface applications. An embedded stacking architecture is proposed to address latch-up-immune design requirements ...without degradation in the electrostatic discharge (ESD) stress-handling capability, leakage, or capacitance. Thanks to a parallel current conduction path activated during ESD stress, a state-of-the-art failure threshold current per unit area is obtained for high-voltage-tolerant interface applications in sub-28-nm CMOS process technologies. The device design concept introduced in this article facilitates the implementation of compact, high-performance interface applications, extended in general to protection clamp devices requiring a higher holding voltage.
A compact bi-directional blocking voltage protection clamp with low overshoot voltage and high current handling capability is proposed. Under a high-stress 15-A very fast transmission line pulse, the ...initial overshoot voltage of the proposed structure is reduced to <80 V. The voltage is clamped below 20 V (safe operation voltage) within 2 ns. This allows for a fast turn-on speed to protect interface circuits in system-on-a-chip applications with a narrow electrostatic discharge design window.
The World Health Organization (WHO) proposed a set of criteria to be considered for the prioritization of COVID-19 candidate vaccines for further development of phase II/III clinical trials, thinking ...in a target audience that includes vaccine scientists, product developers, manufacturers, regulators, and funding agencies. In this paper, a knowledge-based or rational strategy is employed to perform a prioritization matrix of approved COVID-19 vaccines: BBIBP-CorV, JANSSEN, CORONAVAC, SPUTNIK V, MODERNA, PFIZER, and VAXZEVRIA, based on those proposed criteria by WHO, related to safety, efficacy, stability, implementation, and availability. We found that JANSSEN vaccine is the one with the highest score in the present study, but our analysis suggests that the WHO criteria could be more useful if they are considered separately, taking into account the social, demographic and economic characteristics of each country.
The immune system, whose nature lies in being a complex network of interactions, lends itself well to being represented and studied using graph theory. However, it should be noted that although the ...formalization of models of the immune system is relatively recent, the medical use of its signaling network structure has been carried out empirically for centuries in vaccinology, immunopathology, and clinical immunology, as evidenced by the development of effective vaccines, the management of transplant rejection, the management of allergies, and the treatment of certain types of cancer and autoimmune diseases. A network optimization analogy is proposed through the employment of the system dynamic formalism of causal loop diagrams (CLDs), where current network operations (also known as NetOps) in information technology (IT), are interpreted as immune NetOps in coronavirus disease 2019 (COVID-19) treatment. Traffic shaping corresponds to signaling pathway modulation by immunosuppressors. Data caching corresponds to the activation of innate immunity by application of Bacillus Calmette-Guerin (BCG) and other vaccines. Data compression corresponds with the activation of adaptative immune response by vaccination with the actual approved COVID-19 vaccines. Buffer tuning corresponds with concurrent activation of innate and adaptative or specialized immune cells and antibodies that attack and destroy foreign invaders by trained immunity-based vaccines to develop. The present study delineates some experimental extensions and future developments. Given the complex communication architecture of signal transduction in the immune system, it is apparent that multiple parallel pathways influencing and regulating each other are not the exception but the norm. Thus, the transition from empirical immune NetOps to analytical immune NetOps is a goal for the near future in biomedicine.
A high-robustness and low-capacitance clamp for on-chip electrostatic discharge (ESD) protection is developed. The low capacitance is obtained by mitigating the capacitance associated with the ...lightly doped n-well/p-well junction. In addition to minimizing the capacitance, the high ESD robustness is achieved by optimizing independently within the same structure a silicon-controlled rectifier and a diode for the forward and reverse conduction processes, respectively. The new clamp with an area of 50 × 10 μm 2 is able to handle an ESD current in excess of 1.5 A, whereas the capacitance at zero bias is kept at 94 fF.
Thermal runaway is one of the main causes of semiconductor device failure under electrostatic discharge (ESD) stresses. An experimental method to investigate the failure temperature under such ...electrical stresses is proposed. By extrapolating the power-to-failure under different stress time versus ambient temperature curves to the temperature axis, an effective failure temperature is extracted which represents the real failure temperature. This temperature is observed to be higher than the temperature at which the semiconductor becomes intrinsic. The latter is conventionally regarded as the critical temperature for thermal failure. These findings suggest that a different thermal-related mechanism is responsible for the ESD-induced damage in semiconductor devices.
A leading cause of device failure under electrostatic discharge stress conditions is thermal failure. This failure occurs as a result of excessive energy dissipation which raises the temperature of ...the device to a critical breaking level. To predict such a physical failure at circuit level, a compact model compatible with circuit simulators is proposed. The model is derived from the fundamental heat transfer equations and is shown to accurately predict thermal failure for arbitrary electrical stress waveforms.
Feline leukemia virus (FeLV) infection is considered one of the most serious disease threats for the endangered Iberian lynx (Lynx pardinus) Over 14 years (2008-2021), we investigated FeLV infection ...using point-of-care antigen test and quantitative real-time TaqMan qPCR for provirus detection in blood and tissues in lynxes from Andalusia (Southern Spain). A total of 776 samples from 586 individuals were included in this study. The overall prevalence for FeLV antigen in blood/serum samples was 1.4% (5/360) (95% CI: 0.2-2.6), FeLV proviral DNA prevalence in blood samples was 6.2% (31/503) (95% CI: 4.1-8.6), and FeLV proviral DNA in tissues samples was 10.2% (34/333) (95% CI: 7-13.5). From a subset of 129 longitudinally sampled individuals, 9.3% (12/129) PCR-converted during the study period. Our results suggest that FeLV infection in the Andalusian population is enzootic, with circulation of the virus at low levels in almost all the sampling years. Moreover, since only one viremic individual succumbed to the infection, this study suggests that lynxes may therefore control the infection decreasing the possibility of developing a more aggressive outcome. Although our results indicate that the FeLV infection in the Iberian lynx from Andalusia tends to stay within the regressive stage, continuous FeLV surveillance is paramount to predict potential outbreaks and ensure the survival of this population.
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