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1. The Grayness of the Origin of Life

   https://doi.org/10.3390/life11060498  

   Smith, Hillary H.; Hyde, Andrew S.; Simkus, Danielle N.; Libby, Eric; Maurer, Sarah E.; Graham, Heather V.; Kempes, Christopher P.; Sherwood Lollar, Barbara; Chou, Luoth; Ellington, Andrew D.; et al (June 2021, Life)

   null (Ed.)

   In the search for life beyond Earth, distinguishing the living from the non-living is paramount. However, this distinction is often elusive, as the origin of life is likely a stepwise evolutionary process, not a singular event. Regardless of the favored origin of life model, an inherent “grayness” blurs the theorized threshold defining life. Here, we explore the ambiguities between the biotic and the abiotic at the origin of life. The role of grayness extends into later transitions as well. By recognizing the limitations posed by grayness, life detection researchers will be better able to develop methods sensitive to prebiotic chemical systems and life with alternative biochemistries. 

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2. The Tragedy of the Miners

   https://doi.org/10.1109/CCNC49033.2022.9700705  

   Banerjee, Vijay; Rabinowitz, Ryan; Stidd, Mark; Lewis, Rory; Brown, Philip N.; Bloom, Gedare (January 2022, 2022 IEEE 19th Annual Consumer Communications Networking Conference (CCNC))

   In a network of mining pools that secure Bitcoin-like blockchains, it is known that a self-interested mining pool can dishonestly siphon off another pool’s mining rewards by executing a block withholding (BWH) attack. In this paper, we show that a BWH attack is always unprofitable for an initial startup period which is at least one difficulty retarget interval (approximately 14 days for Bitcoin). Furthermore, we prove that the payback period to recoup this initial startup cost is always at least as long as the initial unprofitable startup interval, and we show numerically that it can be substantially longer. Thus, the decision of whether or not to execute a BWH attack is not a dominant strategy, and the so called Miner’s Dilemma is not in fact a dilemma. 

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3. The Impact of Application of the Jackknife to the Sample Median

   https://doi.org/10.1080/00031305.2020.1869090  

   Yang, Jianning; Kolassa, John E. (October 2021, The American Statistician)

   null (Ed.)

   The jackknife is a reliable tool for reducing the bias of a wide range of estimators. This note demonstrates that even such versatile tools have regularity conditions that can be violated even in relatively simple cases, and that caution needs to be exercised in their use. In particular, we show that the jackknife does not provide the expected reliability for bias-reduction for the sample median, because of subtle changes in behavior of the sample median as one moves between even and odd sample sizes. These considerations arose out of class discussions in a MS-level nonparametrics course. 

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4. The size of the immune repertoire of bacteria

   https://doi.org/10.1073/pnas.1903666117  

   Bradde, Serena; Nourmohammad, Armita; Goyal, Sidhartha; Balasubramanian, Vijay (March 2020, Proceedings of the National Academy of Sciences)

   Some bacteria and archaea possess an immune system, based on the CRISPR-Cas mechanism, that confers adaptive immunity against viruses. In such species, individual prokaryotes maintain cassettes of viral DNA elements called spacers as a memory of past infections. Typically, the cassettes contain several dozen expressed spacers. Given that bacteria can have very large genomes and since having more spacers should confer a better memory, it is puzzling that so little genetic space would be devoted by prokaryotes to their adaptive immune systems. Here, assuming that CRISPR functions as a long-term memory-based defense against a diverse landscape of viral species, we identify a fundamental tradeoff between the amount of immune memory and effectiveness of response to a given threat. This tradeoff implies an optimal size for the prokaryotic immune repertoire in the observational range. 

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5. THE BOUNDARY OF THE p -RANK STRATUM OF THE MODULI SPACE OF CYCLIC COVERS OF THE PROJECTIVE LINE

   https://doi.org/10.1017/nmj.2022.12  

   OZMAN, EKIN; PRIES, RACHEL; WEIR, COLIN (December 2022, Nagoya Mathematical Journal)

   Abstract. We study the p-rank stratification of the moduli space of cyclic degree ! covers of the projective line in characteristic p for distinct primes p and !. The main result is about the intersection of the p-rank 0 stratum with the boundary of the moduli space of curves. When ! = 3 and p ≡ 2 mod 3 is an odd prime, we prove that there exists a smooth trielliptic curve in characteristic p, for every genus g, signature type (r,s), and p-rank f satisfying the clear necessary conditions. 

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