Dual Signal Optical Bistability in a Semiconductor Optical Amplifier

Future all-optical signal processing applications may require the use of multiple optical signals passing through a single, optically bistable device. My thesis investigates an improved model for modeling two optical signals passing through an optically bistable Fabry-Perot semiconductor optical amplifier (FP-SOA). The optical power and phase of these signals are both modeled, as well as the optical gain of the FP-SOA. My improved model is based on an improved model used to study optical bistability of just a single optical signal, in which the internal power is related to the output power with an expression accounting for the Fabry-Perot structure. Work has been performed to put all models into a consistent notation. The resulting, improved model for dual-signal operation indicates lower critical powers to trigger bistable action

Biologia Futura: progress and future perspectives of long non-coding RNAs in forest trees

Forest trees are affected by climate change, anthropogenic pressure, as well as abiotic and biotic stresses. Conventional tree breeding has so far been limited to enhance overall productivity, and our understanding of the genetic basis of quantitative traits is still inadequate. Quantum leaps in next-generation sequencing technologies and bioinformatics have permitted the exploration and identification of various non-coding regions of the genome other than protein coding genes. These genomic regions produce various types of non-coding RNAs and regulate myriads of biological functions at epigenetic, transcriptional and translational levels. Recently, long non-coding RNAs (lncRNAs) which act as molecular switch have been identified to be pivotal molecules in forest trees. This review focuses on progress made in regulatory mechanisms in various developmental phases like wood formation, adventitious rooting and flowering and stress responses. It was predicted that complex regulatory interactions among lncRNA, miRNA and gene exist. LncRNAs can function as a sponge for miRNAs, reducing the suppressive effect of miRNAs on target mRNAs and perhaps adding a new layer of regulatory interactions among non-coding RNA classes in trees. Furthermore, network analysis revealed the interactions of lncRNA and genes during the expression of several important genes. The insights generated about lncRNAs in forest trees would enable improvement of economically important traits including the devastating abiotic and biotic stresses. In addition, solid understanding on the wide range of regulatory functions of lncRNAs on traits influencing biomass productivity and adaptation would aid the applications of biotechnology in genetic improvement of forest trees

Real-World Effectiveness of COVID-19 Vaccine and Identification of SARS-CoV-2 Variants among People Living with HIV on Highly Active Antiretroviral Therapy in Central Kerala of India—An Ambi-Directional Cohort Study

Background: Vaccine effectiveness for first-generation coronavirus disease (COVID-19) vaccines among People Living with HIV (PLHIV) in India remains unexplored. This study entails the estimation of the real-world effectiveness of COVID-19 vaccines (AZD1222/Covishield, BBV152/Covaxin) among PLHIV and the identification of variants of SARS-CoV-2 among those infected with COVID-19. Methods: An ambi-directional cohort study was conducted among 925 PLHIV above 18 years of age in two districts of central Kerala, India, from February 2022 to March 2023. Selected PLHIV were recruited as Participant Liaison Officers (PLOs) for the follow-up on the study participants. At enrolment, basic details, baseline CD4 count, and a Nasopharyngeal (NP) swab for RT-PCR were collected. In the follow-up phase, NP swabs were collected from subjects with COVID-19 symptoms. Positive subjects had a CD4 count and genomic sequencing performed. Results: The mean age of the participants was 46.93 ± 11.00 years. The majority, 819 (93.6%), of participants had received at least one dose of any vaccine, while 56 (6.4%) were unvaccinated. A total of 649 (79.24%) participants were vaccinated with Covishield and 169 (20.63%) with Covaxin. In the vaccinated group, 158 (19.3%) reported COVID-19 infection. Vaccine Effectiveness (VE) for one dose of any vaccine was 43.2% (95% CI: 11.8–64.5), p = 0.015. The effectiveness of full vaccination with Covishied was 63.8% (95% CI: 39.3–79.2), p 350 had greater protection from COVID-19, at 53.4% (95% CI: 19.6–75.3) p = 0.004. The incident cases were sub-variants of Omicron (BA.2, BA.2.38, BA.2.10). Conclusions: Full vaccination with Covishield and Covaxin was effective against COVID-19 infection among PLHIV on treatment; albeit, that of Covaxin was higher. A gap of 4 to 6 weeks between the two doses of COVID-19 vaccine was found to have higher VE among PLHIV