Accuracy of the Polar M52 heart rate monitor for estimating energy expenditure, substrate utilization, and maximal oxygen uptake

The purpose of this study was to test the accuracy of the Polar M52 heart rate monitor

Algebraic properties of generalized Rijndael-like ciphers

We provide conditions under which the set of Rijndael functions considered as permutations of the state space and based on operations of the finite field \GF (p^k) ($p\geq 2$ a prime number) is not closed under functional composition. These conditions justify using a sequential multiple encryption to strengthen the AES (Rijndael block cipher with specific block sizes) in case AES became practically insecure. In Sparr and Wernsdorf (2008), R. Sparr and R. Wernsdorf provided conditions under which the group generated by the Rijndael-like round functions based on operations of the finite field \GF (2^k) is equal to the alternating group on the state space. In this paper we provide conditions under which the group generated by the Rijndael-like round functions based on operations of the finite field \GF (p^k) ($p\geq 2$) is equal to the symmetric group or the alternating group on the state space.Comment: 22 pages; Prelim0

Elliptic Reciprocity

The paper introduces the notions of an elliptic pair, an elliptic cycle and an elliptic list over a square free positive integer d. These concepts are related to the notions of amicable pairs of primes and aliquot cycles that were introduced by Silverman and Stange. Settling a matter left open by Silverman and Stange it is shown that for d=3 there are elliptic cycles of length 6. For d not equal to 3 the question of the existence of proper elliptic lists of length n over d is reduced to the the theory of prime producing quadratic polynomials. For d=163 a proper elliptic list of length 40 is exhibited. It is shown that for each d there is an upper bound on the length of a proper elliptic list over d. The final section of the paper contains heuristic arguments supporting conjectured asymptotics for the number of elliptic pairs below integer X. Finally, for d congruent to 3 modulo 8 the existence of infinitely many anomalous prime numbers is derived from Bunyakowski's Conjecture for quadratic polynomials.Comment: 17 pages, including one figure and two table

Pedal 4 Purification

The lack of access to clean drinking water remains one of the largest issues still facing humanity. The Pedal 4 Purification is a product that addresses this need by utilizing pre-existing bicycle infrastructure and local freshwater sources to allow people to purify their own drinking water on a daily basis. Attachable to any standard bicycle, the Pedal 4 Purification product consists of pump, purification, cart and adjustable kickstand subsystems that allow the operator to pump, purify and transport 40L of potable water. Pedaling at the reasonable rate of 60 rpm will provide the optimal flow rate of 1.54L/min through the filter. At this rate, it would take the operator 26 minutes to provide enough drinking water to satiate 20 people for the day. As a result of the drastic reduction in the time and effort it takes for individuals to obtain drinking water, target communities will have more free time allowing them to focus on other pressing issues. Use of the Pedal 4 Purification product results in a 266% increase in user time savings as well as 54 times the amount of water collected per minute of user exertion compared to traditional methods. The Pedal 4 Purification team travelled to San Andres Itzapa, Guatemala to manufacture the entire device at Maya Pedal, an NGO that creates ‘bicimaquinas’ to help provide its local community members with basic human resource infrastructure. After the manufacturing process was complete, the team and Maya Pedal workers drove to the highland community of Patzun to implement the design and instruct the local people about how to use it. User feedback was noted after the successful implementation in the developing community of Patzun

Robotic resection of recurrent pediatric lipoblastoma

This case demonstrates successful resection of a rare, recurrent presacral‐pelvic lipoblastoma in a 19‐year‐old female patient. Because of the anatomical location of the mass and its proximity to vital structures, the robotic approach allowed for both optimal visualization and effective debulking of the mass. Furthermore, with the use of an articulating laparoscopic camera, key visualization of the posterior lateral pelvis was possible. Using a wide breadth of technologies and resources is essential to broadening the surgical armamentarium and achieving resectability in otherwise challenging cases.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147748/1/ases12493_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147748/2/ases12493.pd