Hands

Non-fiction readings from the 2017 issue of The Echo

Hands

Non-fiction readings from the 2017 issue of The Echo

Wave heating from proto-neutron star convection and the core-collapse supernova explosion mechanism

Our understanding of the core-collapse supernova explosion mechanism is incomplete. While the favoured scenario is delayed revival of the stalled shock by neutrino heating, it is difficult to reliably compute explosion outcomes and energies, which depend sensitively on the complex radiation hydrodynamics of the post-shock region. The dynamics of the (non-)explosion depend sensitively on how energy is transported from inside and near the proto-neutron star (PNS) to material just behind the supernova shock. Although most of the PNS energy is lost in the form of neutrinos, hydrodynamic and hydromagnetic waves can also carry energy from the PNS to the shock. We show that gravity waves excited by core PNS convection can couple with outgoing acoustic waves that present an appreciable source of energy and pressure in the post-shock region. Using one-dimensional simulations, we estimate the gravity wave energy flux excited by PNS convection and the fraction of this energy transmitted upwards to the post-shock region as acoustic waves. We find wave energy fluxes near 10⁵¹ergs⁻¹ are likely to persist for ∼1s post-bounce. The wave pressure on the shock may exceed 10 per cent of the thermal pressure, potentially contributing to shock revival and, subsequently, a successful and energetic explosion. We also discuss how future simulations can better capture the effects of waves, and more accurately quantify wave heating rates

Exploring Open Scientific Questions Through Publicly Available Resources

At countless points during any sort of scientific pursuit, there are many interesting questions that are raised that might pique the interest of those with curious minds. Questions aren\u27t hard to come by, then, but the task becomes this: how might a scientist begin to explore a brand new question that they don\u27t really know anything about? As it turns out, there are many ways to explore scientific data through public and open-source research tools. Over the course of the summer, I found one question in particular that grabbed me: pancreatic cancer—as of today, one of the deadliest, least-understood, and most hopeless cancers that exists—is tied astonishingly tightly to mutations in one particular gene called KRAS. Why pancreatic cancer and that gene? KRAS is expressed more in other types of tissue in the body, but cancers in those tissues are less commonly tied to KRAS mutations. For some reason, despite not seeming to rely heavily on expression of the KRAS gene, mutations in KRAS contribute to over 90% of pancreatic cancers. Why? That\u27s what I set out to understand, and this was the path I followed to explore a question with the whole world of science in front of me

Mte1 interacts with Mph1 and promotes crossover recombination and telomere maintenance

Mph1 is a member of the conserved FANCM family of DNA motor proteins that play key roles in genome maintenance processes underlying Fanconi anemia, a cancer predisposition syndrome in humans. Here, we identify Mte1 as a novel interactor of the Mph1 helicase in Saccharomyces cerevisiae. In vitro, Mte1 (Mph1-associated telomere maintenance protein 1) binds directly to DNA with a preference for branched molecules such as D loops and fork structures. In addition, Mte1 stimulates the helicase and fork regression activities of Mph1 while inhibiting the ability of Mph1 to dissociate recombination intermediates. Deletion of MTE1 reduces crossover recombination and suppresses the sensitivity of mph1Δ mutant cells to replication stress. Mph1 and Mte1 interdependently colocalize atDNAdamage-induced foci and dysfunctional telomeres, and MTE1 deletion results in elongated telomeres. Taken together, our data indicate that Mte1 plays a role in regulation of crossover recombination, response to replication stress, and telomere maintenance

Phaenandrogomphus safei, a new species from Sabah, northern Borneo (Odonata: Anisoptera: Gomphidae).

Phaenandrogomphus safei is described from a male from the Kalabakan Forest Reserve, Sabah, Malaysian Borneo. It is the first species of Phaenandrogomphus to be recorded from Borneo. Onychogomphus treadawayi, known from Busuanga Island in the Palawan region of the Philippines, is transferred to Phaenandrogomphus. During this work SHL was funded by the Natural Environment Research Council (NERC), Proforest (Oxford), the University of Oxford (Varley Gradwell Travelling Fellowship) and the University of Cambridge (Commonwealth Travel Fund, Tim Whitmore Fund, Panton Trust).This is the final published version. It first appeared at http://dx.doi.org/10.11646/zootaxa.3905.1.10