Nonlinear time-warping made simple: a step-by-step tutorial on underwater acoustic modal separation with a single hydrophone

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Bonnel, J., Thode, A., Wright, D., & Chapman, R. Nonlinear time-warping made simple: a step-by-step tutorial on underwater acoustic modal separation with a single hydrophone. The Journal of the Acoustical Society of America, 147(3), (2020): 1897, doi:10.1121/10.0000937.Classical ocean acoustic experiments involve the use of synchronized arrays of sensors. However, the need to cover large areas and/or the use of small robotic platforms has evoked interest in single-hydrophone processing methods for localizing a source or characterizing the propagation environment. One such processing method is “warping,” a non-linear, physics-based signal processing tool dedicated to decomposing multipath features of low-frequency transient signals (frequency f  1 km). Since its introduction to the underwater acoustics community in 2010, warping has been adopted in the ocean acoustics literature, mostly as a pre-processing method for single receiver geoacoustic inversion. Warping also has potential applications in other specialties, including bioacoustics; however, the technique can be daunting to many potential users unfamiliar with its intricacies. Consequently, this tutorial article covers basic warping theory, presents simulation examples, and provides practical experimental strategies. Accompanying supplementary material provides matlab code and simulated and experimental datasets for easy implementation of warping on both impulsive and frequency-modulated signals from both biotic and man-made sources. This combined material should provide interested readers with user-friendly resources for implementing warping methods into their own research.This work was supported by the Office of Naval Research (Task Force Ocean, project N00014-19-1-2627) and by the North Pacific Research Board (project 1810). Original warping developments were supported by the French Delegation Generale de l'Armement

Variability in foraging by humpback whales (Megaptera novaenangliae) on the Kodiak, Alaska, feeding ground

Thesis (M.S.) University of Alaska Fairbanks, 2014The North Pacific humpback whale (Megaptera novaeangliae) population has been growing rapidly following a moratorium on commercial whaling in 1986. Knowledge of humpback whale foraging on feeding grounds is becoming increasingly important as the growing population consumes more prey, including economically important commercial fishes. The goal of this thesis is to better understand how marine resources are shared among the growing humpback whale population and sympatric apex predators, including western Steller sea lions (SSLs; Eumetopias jubatus), on the Kodiak, AK, feeding ground. To address this, we explored spatial and temporal (inter-annual and within-feeding season) variability in summer foraging by humpback whales along the eastern side of the Kodiak Archipelago as described by stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope ratios of humpback whale skin (n = 118; 2004-2013). We found evidence for the existence of two sub-aggregations of humpback whales ('North', 'South') on the feeding ground that fed at different trophic levels (TLs) throughout the study period. Bayesian stable isotopic mixing models were applied to describe the proportional contribution of prey species to the diet of humpback whales for the two regions. The 'North' region humpback whale sub-aggregation consumed a mixed diet of euphausiids and forage fishes, whereas the 'South' region sub-aggregation foraged predominantly on euphausiids. Results from these analyses were compared to diet composition of Kodiak SSLs of the recovering western SSL population estimated from fecal samples (n = 656; 2000-2005), to explore spatial differences in the degree of overlap in trophic niche between these predators. Western SSLs underwent a marked population decline starting in the late 1970's and have shown slow and variable signs of recovery. Regional variability in SSL and humpback whale diets resulted in a higher degree of overlap in trophic niche, although not biologically significant (Ojk < 0.60), for individuals in the 'North' region compared with the 'South'. However, humpback whale consumption appears to overlap considerably with multiple piscivorous fishes that are prominent prey for SSLs, and thus, consumption by humpback whales may indirectly impact the prey resources of SSLs. Therefore, this study highlights the complexity of the Kodiak ecosystem and suggests consumption by an increasing population of humpback whales has the potential to indirectly impact the recovery of SSLs on a regional scale depending on the biomass of prey species and diet composition of humpback whales in the region

Dana Wright Collection of Papers, 1930-1964

Correspondence, research paper relating to Wright's career, including his activities with State Historical Society of North Dakota, histories, copies of his research concerning North Dakota military trails, "The Old Trails" by Wright, and newspaper clippings

Assessing the impact of environmental variability on harvest in a heterogeneous fishery: a case study of the Canadian lobster fishery

Global fisheries face significant challenges in the coming years due to climate change. Understanding and anticipating the impacts of climate change is a necessity for implementing appropriate fisheries management. This study uses a panel dataset of individual fishing vessels to examine how variation in ocean temperature affects fish harvest. Using the American lobster (Homarus americanus) fishery in the Maritimes region of Canada as a case study, this paper employs a generalised linear mixed model (GLMM) taking into account heterogeneity amongst fishers, gear, vessels, and fishing areas. The GLMM is found to have better performance and estimations when compared against alternative specifications. As expected, a significant and positive relationship was found, further contributing to the existing evidence of warming impacts on the lobster fishery. The implications of this study are twofold: first, it provides further evidence that environmental change does have a significant positive impact on harvest. This information should be considered by fishing industry and fisheries authorities when implementing appropriate adaptive management strategies and measures in their decision making. Second, it illustrates that allowing for mixed-effects using GLMMs is a valuable empirical tool when dealing with hierarchical data structures

A 47-Year-Old Female with Shortness of Breath

This patient is a 47-year-old female with a history of end-stage liver disease secondary to hepatitis C virus (HCV) complicated by hepatic encephalopathy, obstructive sleep apnea, asthma, and severe peripheral neuropathy who presents to the hospital with complaints of shortness of breath and cough. The patient was recently discharged from an outside hospital 2 days prior to this admission where she was treated for pneumonia and an asthma exacerbation but her symptoms have not improved. She complains of shortness of breath at rest and severely decreased exercise tolerance with dyspnea while walking across the room. Her cough is persistent and non-productive. Review of systems is also positive for fevers at the outside hospital and worsening peripheral neuropathy which has not responded to treatment with gabapentin. Social history is positive for 20 pack-year smoking history (quit 10 years ago), and heavy alcohol use in the past

Integrating the Principles of Effective Intervention into Batterer Intervention Programming: The Case for Moving Toward More Evidence-Based Programming

The majority of batterer intervention program (BIP) evaluations have indicated they are marginally effective in reducing domestic violence recidivism. Meanwhile, correctional programs used to treat a variety of offenders (e.g., substance users, violent offenders, and so forth) that adhere to the “principles of effective intervention” (PEI) have reported significant reductions in recidivism. This article introduces the PEI—the principles on which evidence-based practices in correctional rehabilitation are based—and identifies the degree to which they are currently integrated into BIPs. The case is made that batterer programs could be more effective if they incorporate the PEI. Recommendations for further integration of the principles into BIPs are also provided

Does Polyvictimization Affect Incarcerated and Non-Incarcerated Adult Women Differently? An Exploration Into Internalizing Problems

In this study, we used data from life histories of 424 non-incarcerated (n = 266) and incarcerated (n = 158) women to examine the extent to which women are exposed to multiple forms of victimization, including child abuse, intimate partner violence, sexual assault, and traumatic life events. We assessed the effects of polyvictimization (e.g., multiple victimizations) on women’s health-related outcomes (e.g., attempted suicide, drug and alcohol problems) as well as whether the prevalence rates and effects of victimization were significantly different between the subsamples of women. Results indicate that incarcerated women experience significantly more victimization than non-incarcerated women, and while polyvictimization was associated with a higher likelihood of alcohol problems, drug problems, and attempted suicide among non-incarcerated women, it was only marginally associated with an increased likelihood of alcohol problems among incarcerated women. Finally, low levels of polyvictimization affected alcohol and drug problems among incarcerated and non-incarcerated women differently

Knowledge and attitudes of men to prostate cancer

Objective: To ascertain the current level of understanding about prostate cancer (PCa), including treatment options and potential side effects of treatment, among older men. Design and Setting: Questionnaires administered by general practitioners (GPs) in 5 general practices in the Perth metropolitan and regional areas of Western Australia. Participants: Convenience sample of men aged 40-80 years (n=503) with or without prostate cancer presenting for routine consultations. Main outcome measures: Knowledge and attitudes of men to prostate cancer Results: Eighty percent of men did not know the function of the prostate and 48% failed to identify PCa as the most common internal cancer in men. Thirty-five percent had no knowledge of the treatments for PCa and 53% had no knowledge of the side effects of treatments. Asked how they would arrive at a decision about treatment, 70% stated they would ask the GP/specialist for all their options and then decide themselves. Conclusion: This study confirms a deficit in knowledge of the disease among men in the at risk age group. Lack of knowledge encompassed areas which could delay diagnosis and hence treatment. Overall the population preferred some GP/specialist involvement in treatment decision making

Intimate Partner Violence and Subsequent Depression: Examining the Roles of Neighborhood Supportive Mechanisms

This study examines the direct effects of neighborhood supportive mechanisms (e.g., collective efficacy, social cohesion, social networks) on depressive symptoms among females as well as their moderating effects on the impact of IPV on subsequent depressive symptoms. A multilevel, multivariate Rasch model was used with data from the Project on Human Development in Chicago Neighborhoods to assess the existence of IPV and later susceptibility of depressive symptoms among 2959 adult females in 80 neighborhoods. Results indicate that neighborhood collective efficacy, social cohesion, social interactions, and the number of friends and family in the neighborhood reduce the likelihood that females experience depressive symptoms. However, living in areas with high proportions of friends and relatives exacerbates the impact of IPV on females’ subsequent depressive symptoms. The findings indicate that neighborhood supportive mechanisms impact interpersonal outcomes in both direct and moderating ways, although direct effects were more pronounced for depression than moderating effects. Future research should continue to examine the positive and potentially mitigating influences of neighborhoods in order to better understand for whom and under which circumstances violent relationships and mental health are influenced by contextual factors