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A personal narrative is presented, which narrates the author's experiences with Sweat Lodge, a traditional American Indians' rituals and beliefs of healing of any ailments.

We present an $$O(n\log n)$$ -time algorithm that determines whether a given n-gon in the plane is weakly simple. This improves upon an $$O(n^2\log n)$$ -time algorithm by Chang et al. (Proceedings of the 26th ACM-SIAM symposium on discrete algorithm, SIAM, 2015). Weakly simple polygons are required as input for several geometric algorithms. As such, recognizing simple or weakly simple polygons is a fundamental problem. [ABSTRACT FROM AUTHOR]

Abstract: The Fréchet distance between two curves in the plane is the minimum length of a leash that allows a dog and its owner to walk along their respective curves, from one end to the other, without backtracking. We propose a natural extension of Fréchet distance to more general metric spaces, which requires the leash itself to move continuously over time. For example, for curves in the punctured plane, the leash cannot pass through or jump over the obstacles (“trees”). We describe a polynomial-time algorithm to compute the homotopic Fréchet distance between two given polygonal curves in the plane minus a given set of polygonal obstacles. [Copyright &y& Elsevier]

Abstract: Let be an orientable combinatorial surface. A cycle on is splitting if it has no self-intersections and it partitions into two components, neither of which is homeomorphic to a disk. In other words, splitting cycles are simple, separating, and non-contractible. We prove that finding the shortest splitting cycle on a combinatorial surface is NP-hard but fixed-parameter tractable with respect to the surface genus g and the number of boundary components b of the surface. Specifically, we describe an algorithm to compute the shortest splitting cycle in time, where n is the complexity of the combinatorial surface. [Copyright &y& Elsevier]

Movement and land application of manure is a known risk factor for secondary spread of avian influenza (AI) viruses. During an outbreak of highly pathogenic avian influenza (HPAI), movement of untreated (i.e., fresh) manure from premises known to be infected would be prohibited. However, moving manure from apparently healthy (i.e., clinically normal) flocks may become critical, because some egg-layer facilities have limited on-site storage capacity. The objective of this analysis was to evaluate targeted dead-bird active surveillance rRT-PCR (real-time reverse transcriptase polymerase chain reaction) testing protocols that could be used for the managed movement of manure from apparently healthy egg-layer flocks located in a HPAI Control Area. We also evaluated sequestration, which is the removal of manure from any contact with chickens, or with manure from other flocks, for a period of time, while the flock of origin is actively monitored for the presence of HPAI virus. We used stochastic simulation models to predict the chances of moving a load of contaminated manure, and the quantity of HPAI virus in an 8 metric ton (8000 kg) load of manure moved, before HPAI infection would be detected in the flock. We show that the likelihood of moving contaminated manure would decrease as the length of the sequestration period increased from 3 to 10 days (e.g., for a typical contact rate, with a sample pool size of 11 swabs, the likelihood decreased from 48% to <1%). The total quantity of feces from HPAI infectious birds in a manure load moved would also decrease. Results also indicate that active surveillance protocols using 11 swabs per-pool result in a lower likelihood of moving contaminated manure relative to protocols using 5 swabs per pool. Simulation model results from this study are useful to inform further risk evaluation of HPAI spread through pathways associated with the manure movement, and further evaluation of biosecurity measures intended to reduce those risks.