Mammalian behavior and physiology converge to confirm sharper cochlear tuning in humans.

Frequency analysis of sound by the cochlea is the most fundamental property of the auditory system. Despite its importance, the resolution of this frequency analysis in humans remains controversial. The controversy persists because the methods used to estimate tuning in humans are indirect and have not all been independently validated in other species. Some data suggest that human cochlear tuning is considerably sharper than that of laboratory animals, while others suggest little or no difference between species. We show here in a single species (ferret) that behavioral estimates of tuning bandwidths obtained using perceptual masking methods, and objective estimates obtained using otoacoustic emissions, both also employed in humans, agree closely with direct physiological measurements from single auditory-nerve fibers. Combined with human behavioral data, this outcome indicates that the frequency analysis performed by the human cochlea is of significantly higher resolution than found in common laboratory animals. This finding raises important questions about the evolutionary origins of human cochlear tuning, its role in the emergence of speech communication, and the mechanisms underlying our ability to separate and process natural sounds in complex acoustic environments.

Can infected pancreatic necrosis really be managed conservatively?

OBJECTIVES: Guidelines advocate minimally invasive drainage rather than open surgery for infected pancreatic necrosis (IPN) after acute pancreatitis. We hypothesized that the conservative approach could be extended even further by treating patients using an antibiotics-only protocol. PATIENTS AND METHODS: Between June 2009 and July 2017, patients with IPN were selectively managed with carbapenem antibiotics for a minimum of 6 weeks. We compared these patients with patients who underwent minimal access retroperitoneal pancreatic necrosectomy (MARPN) for IPN to identify characteristics of this patient group. RESULTS: Of 33 patients with radiologically proven IPN, 13 patients received antibiotics without any surgical or radiological intervention and resulted in no disease-specific mortality and one case of pancreatic insufficiency. In comparison, 44 patients underwent MARPN with a mortality of 20%, and 81.8% developed pancreatic insufficiency. The modified Glasgow score and computed tomography severity score was less in the antibiotic-only group (P<0.001 and P=0.014, respectively). Patients who underwent MARPN had lower serum haemoglobin and albumin levels (P=0.030 and 0.001, respectively), and a higher C-reactive protein (P=0.027). CONCLUSION: Conservative treatment of IPN with antibiotics is a valid management option for haemodynamically stable patients experiencing less severe disease, requiring careful selection by experienced clinicians.

A Pilot Study to Assess the Feasibility of Collecting and Transmitting Clinical Trial Data with Mobile Technologies.

BACKGROUND: The use of mobile technologies for data capture and transmission has the potential to streamline clinical trials, but researchers lack methods for collecting, processing, and interpreting data from these tools. OBJECTIVES: To assess the performance of a technical platform for collecting and transmitting data from six mobile technologies in the clinic and at home, to apply methods for comparing them to clinical standard devices, and to measure their usability, including how willing subjects were to use them on a regular basis. METHODS: In part 1 of the study, conducted over 3 weeks in the clinic, we tested two device pairs (mobile vs. clinical standard blood pressure monitor and mobile vs. clinical standard spirometer) on 25 healthy volunteers. In part 2 of the study, conducted over 3 days both in the clinic and at home, we tested the same two device pairs as in part 1, plus four additional pairs (mobile vs. clinical standard pulse oximeter, glucose meter, weight scale, and activity monitor), on 22 healthy volunteers. RESULTS: Data collection reliability was 98.1% in part 1 of the study and 95.8% in part 2 (the percentages exclude the wearable activity monitor, which collects data continuously). In part 1, 20 of 1,049 overall expected measurements were missing (1.9%), and in part 2, 45 of 1,083 were missing (4.2%). The most common reason for missing data was a single malfunctioning spirometer (13 of 20 total missed readings) in part 1, and that the subject did not take the measurement (22 of 45 total missed readings) in part 2. Also in part 2, a higher proportion of at-home measurements than in-clinic readings were missing (12.6 vs. 2.7%). The data from this experimental study were unable to establish repeatability or agreement for every mobile technology; only the pulse oximeter demonstrated repeatability, and only the weight scale demonstrated agreement with the clinical standard device. Most mobile technologies received high "willingness to use" ratings from the patients on the questionnaires. CONCLUSIONS: This study demonstrated that the wireless data transmission and processing platform was dependable. It also identified three critical areas of study for advancing the use of mobile technologies in clinical research: (1) if a mobile technology captures more than one type of endpoint (such as blood pressure and pulse), repeatability and agreement may need to be established for each endpoint to be included in a clinical trial; (2) researchers need to develop criteria for excluding invalid device readings (to be identified by algorithms in real time) for the population studied using ranges based on accumulated subject data and established norms; and (3) careful examination of a mobile technology's performance (reliability, repeatability, and agreement with accepted reference devices) during pilot testing is essential, even for medical devices approved by regulators.

Behavioural estimates of auditory filter widths in ferrets using notched-noise maskers.

Frequency selectivity is a fundamental property of hearing which affects almost all aspects of auditory processing. Here auditory filter widths at 1, 3, 7, and 10 kHz were estimated from behavioural thresholds using the notched-noise method [Patterson, Nimmo-Smith, Weber, and Milroy, J. Acoust. Soc. Am. 72, 1788-1803 (1982)] in ferrets. The mean bandwidth was 21% of the signal frequency, excluding wider bandwidths at 1 kHz (65%). They were comparable although on average broader than equivalent measurements in other mammals (∼11%-20%), and wider than bandwidths measured from the auditory nerve in ferrets (∼18%). In non-human mammals there is considerable variation between individuals, species, and in the correspondence with auditory nerve tuning.