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The Virus Zoo is my latest educational blog post! I’ve written up ~1 page ‘cheat sheets’ on the molecular biology of specific viruses. I cover genome, structure, and life cycle. So far, my zoo includes adeno-associated virus (AAV), adenovirus, and herpes simplex virus 1 (HSV-1). However, I plan to add more viruses as time goes on! Some others I would like to incorporate later are coronavirus, HIV, anellovirus, lentivirus, ebolavirus, and MS2 bacteriophage. Feel free to suggest other interesting viruses in the comments! All images were created by me. #virology #molecularbiology #biotechnology #genetherapy #virus #biochemistry #genetics


Genome and Structure:

AAV genomes are about 4.7 kb in length and are composed of ssDNA. Inverted terminal repeats (ITRs) form hairpin structures at ends of the genome. These ITR structures are important for AAV genomic packaging and replication. Rep genes (encoded via overlapping reading frames) include Rep78, Rep68, Rep52, Rep40.1 These proteins facilitate replication of the viral genome. As a Dependoparvovirus, additional helper functions from adenovirus (or certain other viruses) are needed for AAVs to replicate.

AAV capsids are about 25 nm in diameter. Cap genes include VP1, VP2, VP3 and are transcribed from overlapping reading frames.2 The VP3 protein is the smallest capsid protein. The VP2 protein is the same as VP3 except that it includes an N-terminal extension with a nuclear localization sequence. The VP1 protein is the same as VP2 except that it includes a further N-terminal extension encoding a phospholipase A2 (PLA2) that facilitates endosomal escape during infection. In the AAV capsid, VP1, VP2, and VP3 are present at a ratio of roughly 1:1:10. It should be noted that this ratio is actually the average of a distribution, not a fixed number.

Solar energy and onshore wind are crucial to unlocking Africa’s hydrogen potential, the International Energy Agency (IEA) said in its Africa Energy Outlook 2022. “With further cost declines, Africa has the potential to produce 5 000 megatonnes of hydrogen per year at less than $2 per kilogram,” reads the report. The continent has 60% of the world’s best solar resources, but only 1% of its operational solar generation capacity.

Serbia and Hungary signed a memorandum of understanding to collaborate on renewable hydrogen. “The signed memorandum is the basis for exchanging documents in this area and discussing potential joint projects,” said the Serbian government.

Nuclear fusion promises practically limitless energy and an unshackling from the harmful impact of fossil fuel consumption.

Now, researchers from the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) announced they found a way to build powerful magnets much smaller than ever before, a press statement reveals.

Interesting Engineering.


A group of researchers from Princeton Plasma Physics Laboratory found a way to build powerful magnets much smaller than ever before.

Training robots to complete tasks in the real-world can be a very time-consuming process, which involves building a fast and efficient simulator, performing numerous trials on it, and then transferring the behaviors learned during these trials to the real world. In many cases, however, the performance achieved in simulations does not match the one attained in the real-world, due to unpredictable changes in the environment or task.

Researchers at the University of California, Berkeley (UC Berkeley) have recently developed DayDreamer, a tool that could be used to train robots to complete tasks more effectively. Their approach, introduced in a paper pre-published on arXiv, is based on learning models of the world that allow robots to predict the outcomes of their movements and actions, reducing the need for extensive trial and error training in the real-world.

“We wanted to build robots that continuously learn directly in the real world, without having to create a simulation environment,” Danijar Hafner, one of the researchers who carried out the study, told TechXplore. “We had only learned world models of video games before, so it was super exciting to see that the same algorithm allows robots to quickly learn in the real world, too!”