Taphonomic and Diagenetic Pathways to Protein Preservation, Part I: the Case of Tyrannosaurus rex Specimen MOR 1125

Contrary to traditional views, fossil bones have been shown to occasionally retain original cells, blood vessels, and structural tissues that are still comprised, in part, by their original proteins. To help clarify how such remarkable preservation occurs, we explored the fossilization history of a famous Tyrannosaurus rex specimen previously shown to yield original cells, vessels, and collagen protein sequences. By analyzing the trace element composition of the femur of this tyrannosaur, we show that after death its carcass decayed underwater in a brackish, oxic, estuarine channel and then became buried by sands that quickly cemented around the bones, largely protecting them from further chemical alteration. Other bones yielding original proteins have also been found to have fossilized within rapidly-cementing sediments in oxidizing environments, which strongly suggests that such settings are conducive to molecular preservation

Factorization in Z[x]: The Searching Phase

In this paper we describe ideas used to accelerate the Searching Phase of the Berlekamp{Zassenhaus algorithm, the algorithm most widely used for computing factorizations in Z[x]. Our ideas do not alter the theoretical worst-case complexity, but they do have a signi- cant eect in practice: especially in those cases where the cost of the Searching Phase completely dominates the rest of the algorithm. A complete implementation of the ideas in this paper is publicly available in the library NTL [16]. We give timings of this implementation on some dicult factorization problems. 1 Introduction The Berlekamp{Zassenhaus algorithm (BZA) was invented about 30 years ago [2, 18], and it \solved" the factorization problem in Z[x]. Another algorithm had been discovered centuries earlier but was practical only for very small polynomials. The main \defect" of the new algorithm is that its To appear, ISSAC 2000. 1 nal step, the Searching Phase, has worst-case complexity exponential in..

Taphonomic and Diagenetic Pathways to Protein Preservation, Part I: The Case of Tyrannosaurus rex Specimen MOR 1125

Many recent reports have demonstrated remarkable preservation of proteins in fossil bones dating back to the Permian. However, preservation mechanisms that foster the long-term stability of biomolecules and the taphonomic circumstances facilitating them remain largely unexplored. To address this, we examined the taphonomic and geochemical history of Tyrannosaurus rex specimen Museum of the Rockies (MOR) 1125, whose right femur and tibiae were previously shown to retain still-soft tissues and endogenous proteins. By combining taphonomic insights with trace element compositional data, we reconstruct the postmortem history of this famous specimen. Our data show that following prolonged, subaqueous decay in an estuarine channel, MOR 1125 was buried in a coarse sandstone wherein its bones fossilized while interacting with oxic and potentially brackish early-diagenetic groundwaters. Once its bones became stable fossils, they experienced minimal further chemical alteration. Comparisons with other recent studies reveal that oxidizing early-diagenetic microenvironments and diagenetic circumstances which restrict exposure to percolating pore fluids elevate biomolecular preservation potential by promoting molecular condensation reactions and hindering chemical alteration, respectively. Avoiding protracted interactions with late-diagenetic pore fluids is also likely crucial. Similar studies must be conducted on fossil bones preserved under diverse paleoenvironmental and diagenetic contexts to fully elucidate molecular preservation pathways

Effectiveness of Acute Care Remote Triage Systems: a Systematic Review

BackgroundTechnology-based systems can facilitate remote decision-making to triage patients to the appropriate level of care. Despite technologic advances, the effects of implementation of these systems on patient and utilization outcomes are unclear. We evaluated the effects of remote triage systems on healthcare utilization, case resolution, and patient safety outcomes.MethodsEnglish-language searches of MEDLINE (via PubMed), EMBASE, and CINAHL were performed from inception until July 2018. Randomized and nonrandomized comparative studies of remote triage services that reported healthcare utilization, case resolution, and patient safety outcomes were included. Two reviewers assessed study and intervention characteristics independently for study quality, strength of evidence, and risk of bias.ResultsThe literature search identified 5026 articles, of which eight met eligibility criteria. Five randomized, two controlled before-and-after, and one interrupted time series study assessed 3 categories of remote triage services: mode of delivery, triage professional type, and system organizational level. No study evaluated any other delivery mode other than telephone and in-person. Meta-analyses were unable to be performed because of study design and outcome heterogeneity; therefore, we narratively synthesized data. Overall, most studies did not demonstrate a decrease in primary care (PC) or emergency department (ED) utilization, with some studies showing a significant increase. Evidence suggested local, practice-based triage systems have greater case resolution and refer fewer patients to PC or ED services than regional/national systems. No study identified statistically significant differences in safety outcomes.ConclusionOur review found limited evidence that remote triage reduces the burden of PC or ED utilization. However, remote triage by telephone can produce a high rate of call resolution and appears to be safe. Further study of other remote triage modalities is needed to realize the promise of remote triage services in optimizing healthcare outcomes.Protocol registrationThis study was registered and followed a published protocol (PROSPERO: CRD42019112262)