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1.
Ecology ; 105(1): e4186, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37794831

ABSTRACT

The identification of important habitat and the behavior(s) associated with it is critical to conservation and place-based management decisions. Behavior also links life-history requirements and habitat use, which are key to understanding why animals use certain habitats. Animal population studies often use tracking data to quantify space use and habitat selection, but they typically either ignore movement behavior (e.g., foraging, migrating, nesting) or adopt a two-stage approach that can induce bias and fail to propagate uncertainty. We develop a habitat-driven Langevin diffusion for animals that exhibit distinct movement behavior states, thereby providing a novel single-stage statistical method for inferring behavior-specific habitat selection and utilization distributions in continuous time. Practitioners can customize, fit, assess, and simulate our integrated model using the provided R package. Simulation experiments demonstrated that the model worked well under a range of sampling scenarios as long as observations were of sufficient temporal resolution. Our simulations also demonstrated the importance of accounting for different behaviors and the misleading inferences that can result when these are ignored. We provide case studies using plains zebra (Equus quagga) and Steller sea lion (Eumetopias jubatus) telemetry data. In the zebra example, our model identified distinct "encamped" and "exploratory" states, where the encamped state was characterized by strong selection for grassland and avoidance of other vegetation types, which may represent selection for foraging resources. In the sea lion example, our model identified distinct movement behavior modes typically associated with this marine central-place forager and, unlike previous analyses, found foraging-type movements to be associated with steeper offshore slopes characteristic of the continental shelf, submarine canyons, and seamounts that are believed to enhance prey concentrations. This is the first single-stage approach for inferring behavior-specific habitat selection and utilization distributions from tracking data that can be readily implemented with user-friendly software. As certain behaviors are often more relevant to specific conservation or management objectives, practitioners can use our model to help inform the identification and prioritization of important habitats. Moreover, by linking individual-level movement behaviors to population-level spatial processes, the multistate Langevin diffusion can advance inferences at the intersection of population, movement, and landscape ecology.


Subject(s)
Sea Lions , Animals , Ecosystem , Predatory Behavior , Feeding Behavior , Movement
2.
JMIR Mhealth Uhealth ; 11: e48229, 2023 10 03.
Article in English | MEDLINE | ID: mdl-37788043

ABSTRACT

BACKGROUND: People with coronary heart disease are at an increased risk of morbidity and mortality even if they attend cardiac rehabilitation. High sedentary behavior levels potentially contribute to this morbidity. Smartphone apps may be feasible to facilitate sedentary behavior reductions and lead to reduced health care use. OBJECTIVE: We aimed to test the effect of a sedentary behavior change smartphone app (Vire app and ToDo-CR program) as an adjunct to cardiac rehabilitation on hospital admissions and emergency department (ED) presentations over 12 months. METHODS: A multicenter, randomized controlled trial was conducted with 120 participants recruited from 3 cardiac rehabilitation programs. Participants were randomized 1:1 to cardiac rehabilitation plus the fully automated 6-month Vire app and ToDo-CR program (intervention) or usual care (control). The primary outcome was nonelective hospital admissions and ED presentations over 12 months. Secondary outcomes including accelerometer-measured sedentary behavior, BMI, waist circumference, and quality of life were recorded at baseline and 6 and 12 months. Logistic regression models were used to analyze the primary outcome, and linear mixed-effects models were used to analyze secondary outcomes. Data on intervention and hospital admission costs were collected, and the incremental cost-effectiveness ratios (ICERs) were calculated. RESULTS: Participants were, on average, aged 62 (SD 10) years, and the majority were male (93/120, 77.5%). The intervention group were more likely to experience all-cause (odds ratio [OR] 1.54, 95% CI 0.58-4.10; P=.39) and cardiac-related (OR 3.26, 95% CI 0.84-12.55; P=.09) hospital admissions and ED presentations (OR 2.07, 95% CI 0.89-4.77; P=.09) than the control group. Despite this, cardiac-related hospital admission costs were lower in the intervention group over 12 months (Aus $252.40 vs Aus $859.38; P=.24; a currency exchange rate of Aus $1=US $0.69 is applicable). There were no significant between-group differences in sedentary behavior minutes per day over 12 months, although the intervention group completed 22 minutes less than the control group (95% CI -22.80 to 66.69; P=.33; Cohen d=0.21). The intervention group had a lower BMI (ß=1.62; P=.05), waist circumference (ß=5.81; P=.01), waist-to-hip ratio (ß=.03, P=.03), and quality of life (ß=3.30; P=.05) than the control group. The intervention was more effective but more costly in reducing sedentary behavior (ICER Aus $351.77) and anxiety (ICER Aus $10,987.71) at 12 months. The intervention was also more effective yet costly in increasing quality of life (ICER Aus $93,395.50) at 12 months. CONCLUSIONS: The Vire app and ToDo-CR program was not an outcome-effective or cost-effective solution to reduce all-cause hospital admissions or ED presentations in cardiac rehabilitation compared with usual care. Smartphone apps that target sedentary behavior alone may not be an effective solution for cardiac rehabilitation participants to reduce hospital admissions and sedentary behavior. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12619001223123; https://australianclinicaltrials.gov.au/anzctr/trial/ACTRN12619001223123. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1136/bmjopen-2020-040479.


Subject(s)
Cardiac Rehabilitation , Mobile Applications , Humans , Male , Female , Quality of Life , Sedentary Behavior , Australia , Hospitals
3.
Ecohealth ; 10(4): 376-93, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24419664

ABSTRACT

Blood chemistry and hematologic reference ranges are useful for population health assessment and establishing a baseline for future comparisons in the event of ecosystem changes due to natural or anthropogenic factors. The objectives of this study were to determine if there was any population spatial structure for blood variables of Steller sea lion (Eumetopias jubatus), an established sentinel species, and to report reference ranges for appropriate populations using standardized analyses. In addition to comparing reference ranges between populations with contrasting abundance trends, data were examined for evidence of disease or nutritional stress. From 1998 to 2011, blood samples were collected from 1,231 pups captured on 37 rookeries across their Alaskan range. Reference ranges are reported separately for the western and eastern distinct population segments (DPS) of Steller sea lion after cluster analysis and discriminant function analysis (DFA) supported underlying stock structure. Variables with greater loading scores for the DFA (creatinine, total protein, calcium, albumin, cholesterol, and alkaline phosphatase) also were greater for sea lions from the endangered western DPS, supporting previous studies that indicated pup condition in the west was not compromised during the first month postpartum. Differences between population segments were likely a result of ecological, physiological, or age related differences.


Subject(s)
Sea Lions/blood , Alaska/epidemiology , Animals , Female , Geography , Male , Nutritional Status , Reference Values , Sentinel Surveillance/veterinary
4.
Respir Care ; 56(12): 1956-8, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21682985

ABSTRACT

Low-tidal-volume ventilation reduces mortality in patients with ARDS, but there are often challenges in implementing lung-protective ventilation, such as acidosis from hypercapnia. In a patient with severe ARDS we achieved adequate ventilation with a very low tidal volume (4 mL/kg ideal body weight) by inducing mild hypothermia (body temperature 35-36°C).


Subject(s)
Hypothermia, Induced , Respiration, Artificial/methods , Respiratory Distress Syndrome/therapy , Adult , Humans , Male , Tidal Volume
5.
J Theor Biol ; 274(1): 74-83, 2011 Apr 07.
Article in English | MEDLINE | ID: mdl-21241711

ABSTRACT

Fractal geometry and other multi-scale analyses have become popular tools for investigating spatial patterns of animal distributions in heterogeneous environments. In theory, changes in patterns of animal distributions with changes in scale reflect transitions between the controlling influences of one environmental factor or process over another. In an effort to find linkages between Steller sea lions (Eumetopias jubatus) and their environment, the objective of this study was to determine if the spatial distribution of Steller sea lions at sea displayed similar scaling properties to the variation of two environmental features, including bathymetry and sea surface temperature (SST). Additionally, distributions of Steller sea lion point patterns were examined with respect to measurements of bathymetric complexity. From February 2000 to May 2004, satellite transmitters were deployed on 10 groups of juvenile Steller sea lions (n=52) at eight different locations within the Aleutian Islands and Gulf of Alaska. Indices of fractal dimension were calculated for each group of sea lions using a unit square box-counting method, whereas indices of bathymetry and SST patchiness were derived by conducting a variance ratio analysis over the same scales. Distributions of Steller sea lions at sea displayed self-similar fractal patterns, suggesting that individuals were distributed in a continuous hierarchical set of clumps within clumps across scales, and foraging behavior was likely influenced by a scale invariant mechanism. Patterns of bathymetric variability also were self-similar, whereas patterns of SST variability were scale dependent and failed to retain self-similar spatial structure at larger scales. These results indicate that the distributions of Steller sea lions at sea were more influenced by bathymetry than SST at the scales examined, but scale-dependent patterns in the distribution of Steller sea lions at sea or linkages with SST may have been apparent if analyses were conducted at finer spatial scales.


Subject(s)
Behavior, Animal/physiology , Ecosystem , Sea Lions/physiology , Alaska , Animals , Female , Fractals , Geography , Male , Oceans and Seas
6.
J Wildl Dis ; 46(2): 450-73, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20688638

ABSTRACT

To determine whether infectious diseases might have contributed to the present-day decline of northern fur seals (Callorhinus ursinus), preweaned pups (n=2,735), subadult males (n=98), and adults (n=179) were examined postmortem from 1986 to 2006 on St. Paul Island, Alaska. Gross necropsy findings and histologic lesions were used to determine causes of death. Five general categories of mortality were identified for pups: emaciation (1,454 pups, 53%), trauma (497 pups, 18%), perinatal mortality (516 pups, 19%), infectious diseases (82 pups, 3%), and miscellaneous causes (186 pups, 7%). A condition of unknown etiology characterized by multifocal necrotizing myopathy and cardiomyopathy was found in 92 pups. Thirty-three congenital anomalies were identified in 49 pups, including a rare multicentric ganglioneuroblastoma. General linear models were used to examine change in pup mortality and condition (i.e., pup mass) over time. The prevalence of perinatal mortality appeared to increase during the study and relative to past reports. Trauma and infectious conditions appeared to decrease slightly from 1986 to 2006. Although relatively stable during this investigation, emaciation was greater than that reported for past studies. Emaciated pups weighed less than expected during 1988, 1996, and 2004 and more than expected during 1987, 1989, 1990, and 1994 (P

Subject(s)
Cause of Death , Fur Seals , Infections/veterinary , Wounds and Injuries/veterinary , Alaska , Animals , Animals, Newborn , Female , Fur Seals/injuries , Infections/mortality , Linear Models , Male , Wounds and Injuries/mortality
7.
Ecol Appl ; 19(6): 1645-59, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19769109

ABSTRACT

Over the past three decades, the decline and altered spatial distribution of the western stock of Steller sea lions (Eumetopias jubatus) in Alaska have been attributed to changes in the distribution or abundance of their prey due to the cumulative effects of fisheries and environmental perturbations. During this period, dietary prey occurrence and diet diversity were related to population decline within metapopulation regions of the western stock of Steller sea lions, suggesting that environmental conditions may be variable among regions. The objective of this study, therefore, was to examine regional differences in the spatial and temporal heterogeneity of oceanographic habitat used by Steller sea lions within the context of recent measures of diet diversity and population trajectories. Habitat use was assessed by deploying satellite-depth recorders and satellite relay data loggers on juvenile Steller sea lions (n = 45) over a five-year period (2000-2004) within four regions of the western stock, including the western, central, and eastern Aleutian Islands, and central Gulf of Alaska. Areas used by sea lions during summer months (June, July, and August) were demarcated using satellite telemetry data and characterized by environmental variables (sea surface temperature [SST] and chlorophyll a [chl a]), which possibly serve as proxies for environmental processes or prey. Spatial patterns of SST diversity and Steller sea lion population trends among regions were fairly consistent with trends reported for diet studies, possibly indicating a link between environmental diversity, prey diversity, and distribution or abundance of Steller sea lions. Overall, maximum spatial heterogeneity coupled with minimal temporal variability of SST appeared to be beneficial for Steller sea lions. In contrast, these patterns were not consistent for chl a, and there appeared to be an ecological threshold. Understanding how Steller sea lions respond to measures of environmental heterogeneity will ultimately be useful for implementing ecosystem management approaches and developing additional conservation strategies.


Subject(s)
Chlorophyll/analysis , Ecosystem , Sea Lions , Seawater/analysis , Temperature , Alaska , Animals , Chlorophyll A , Diet , Phytoplankton , Population Dynamics , Time Factors
8.
J Wildl Dis ; 39(3): 600-9, 2003 Jul.
Article in English | MEDLINE | ID: mdl-14567222

ABSTRACT

The objectives of this study were to compare the hematology and serum chemistry values between free-ranging and stranded harbor seal (Phoca vitulina richardsi) pups and to ascertain how blood values of stranded pups changed during the rehabilitation process. Coincident with these comparisons, reference values were obtained for free-ranging pups. Stranded harbor seal pups (n = 28) recovered from areas between Pebble Beach and Moss Landing, California (USA) were admitted to The Marine Mammal Center, Sausalito, from March to May 1995, 1996, and 1998. Blood samples were collected from harbor seal pups before and after rehabilitation. As a control group, wild harbor seal pups were captured at Pebble Beach and Elkhorn Slough (n = 42) during the 1995, 1996, and 1998 pupping seasons. Mean eosinophil and calcium values of wild pups were significantly greater than those of newly admitted pups, whereas mean bands, aspartate aminotransferase, alanine aminotransferase, total bilirubin, and chloride values were significantly lower (P < or = 0.05). Mean neutrophil, band, lymphocyte, eosinophil, basophil, calcium, phosphorus, blood urea nitrogen, potassium, total protein, and globulin values of rehabilitated pups increased significantly after 2-3 mo in captivity, whereas, mean red blood cell, hemoglobin, hematocrit, cholesterol, and total bilirubin values decreased significantly (P < or = 0.05).


Subject(s)
Animals, Wild/blood , Animals, Zoo/blood , Seals, Earless/blood , Animals , Animals, Newborn , Blood Chemical Analysis/veterinary , Female , Hematologic Tests/veterinary , Male , Reference Values
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