Abstract: Systems and methods for optimizing detection of optical signals indicating the presence of an analyte of interest in a blood sample are described. In one aspect, a blood culture test vial having a sensor is inoculated with the blood sample, light at an excitation frequency of the sensor is transmitted to the test vial, an intensity of a plurality of fluorescence signals emitted from the test vial is measured, and the plurality of measured fluorescence signals are normalized using by a reference signal that is not dependent on a measured intensity of a fluorescence signal emitted from the test vial. In another aspect, a measurement system measures fluorescence signals from one or more reference vials performing in extreme pH conditions. Fluorescence signals emitted from test vials inoculated with samples under test are measured and compared to the signals measured from the one or more reference vials to address or mitigate variability in hardware components of the measurement system.

Abstract: A winter survival suit includes a main suit body for surrounding the body of the wearer from a collar extending downwardly to a bottom edge of the suit body arranged at knee-height or just above on the wearer. A leg bag can be attached to the bottom edge of the suit body by a surrounding zipper. The leg bag can be folded upwardly inside the suit body to be attached by buckles at the bottom end of the leg bag which attach to buckles sewn into the arm seams of the suit body. Alternatively the leg can be folded outwardly of the suit body and attached to similar buckles on the outside of the suit body at the arm openings. The suit body includes a first inner hood which is insulated and can be pulled into a snorkel type opening for cold weather breathing. A second outer hood is attached around the collar and is of larger size for covering the head and face of the wearer in a survival situation or for receiving the whole of the structure of the suit in a packaged situation for transportation.