Population assessment of tropical tuna based on their associative behavior around floating objects.

Estimating the abundance of pelagic fish species is a challenging task, due to their vast and remote habitat. Despite the development of satellite, archival and acoustic tagging techniques that allow the tracking of marine animals in their natural environments, these technologies have so far been underutilized in developing abundance estimations. We developed a new method for estimating the abundance of tropical tuna that employs these technologies and exploits the aggregative behavior of tuna around floating objects (FADs). We provided estimates of abundance indices based on a simulated set of tagged fish and studied the sensitivity of our method to different association dynamics, FAD numbers, population sizes and heterogeneities of the FAD-array. Taking the case study of yellowfin tuna (Thunnus albacares) acoustically-tagged in Hawaii, we implemented our approach on field data and derived for the first time the ratio between the associated and the total population. With more extensive and long-term monitoring of FAD-associated tunas and good estimates of the numbers of fish at FADs, our method could provide fisheries-independent estimates of populations of tropical tuna. The same approach can be applied to obtain population assessments for any marine and terrestrial species that display associative behavior and from which behavioral data have been acquired using acoustic, archival or satellite tags.

Evidence of discrete yellowfin tuna (Thunnus albacares) populations demands rethink of management for this globally important resource.

Tropical tuna fisheries are central to food security and economic development of many regions of the world. Contemporary population assessment and management generally assume these fisheries exploit a single mixed spawning population, within ocean basins. To date population genetics has lacked the required power to conclusively test this assumption. Here we demonstrate heterogeneous population structure among yellowfin tuna sampled at three locations across the Pacific Ocean (western, central, and eastern) via analysis of double digest restriction-site associated DNA using Next Generation Sequencing technology. The differences among locations are such that individuals sampled from one of the three regions examined can be assigned with close to 100% accuracy demonstrating the power of this approach for providing practical markers for fishery independent verification of catch provenance in a way not achieved by previous techniques. Given these results, an extended pan-tropical survey of yellowfin tuna using this approach will not only help combat the largest threat to sustainable fisheries (i.e. illegal, unreported, and unregulated fishing) but will also provide a basis to transform current monitoring, assessment, and management approaches for this globally significant species.

A simplified, data-constrained approach to estimate the permafrost carbon-climate feedback.

We present an approach to estimate the feedback from large-scale thawing of permafrost soils using a simplified, data-constrained model that combines three elements: soil carbon (C) maps and profiles to identify the distribution and type of C in permafrost soils; incubation experiments to quantify the rates of C lost after thaw; and models of soil thermal dynamics in response to climate warming. We call the approach the Permafrost Carbon Network Incubation-Panarctic Thermal scaling approach (PInc-PanTher). The approach assumes that C stocks do not decompose at all when frozen, but once thawed follow set decomposition trajectories as a function of soil temperature. The trajectories are determined according to a three-pool decomposition model fitted to incubation data using parameters specific to soil horizon types. We calculate litterfall C inputs required to maintain steady-state C balance for the current climate, and hold those inputs constant. Soil temperatures are taken from the soil thermal modules of ecosystem model simulations forced by a common set of future climate change anomalies under two warming scenarios over the period 2010 to 2100. Under a medium warming scenario (RCP4.5), the approach projects permafrost soil C losses of 12.2-33.4 Pg C; under a high warming scenario (RCP8.5), the approach projects C losses of 27.9-112.6 Pg C. Projected C losses are roughly linearly proportional to global temperature changes across the two scenarios. These results indicate a global sensitivity of frozen soil C to climate change (γ sensitivity) of -14 to -19 Pg C °C(-1) on a 100 year time scale. For CH4 emissions, our approach assumes a fixed saturated area and that increases in CH4 emissions are related to increased heterotrophic respiration in anoxic soil, yielding CH4 emission increases of 7% and 35% for the RCP4.5 and RCP8.5 scenarios, respectively, which add an additional greenhouse gas forcing of approximately 10-18%. The simplified approach presented here neglects many important processes that may amplify or mitigate C release from permafrost soils, but serves as a data-constrained estimate on the forced, large-scale permafrost C response to warming.

Tracking apex marine predator movements in a dynamic ocean.

Pelagic marine predators face unprecedented challenges and uncertain futures. Overexploitation and climate variability impact the abundance and distribution of top predators in ocean ecosystems. Improved understanding of ecological patterns, evolutionary constraints and ecosystem function is critical for preventing extinctions, loss of biodiversity and disruption of ecosystem services. Recent advances in electronic tagging techniques have provided the capacity to observe the movements and long-distance migrations of animals in relation to ocean processes across a range of ecological scales. Tagging of Pacific Predators, a field programme of the Census of Marine Life, deployed 4,306 tags on 23 species in the North Pacific Ocean, resulting in a tracking data set of unprecedented scale and species diversity that covers 265,386 tracking days from 2000 to 2009. Here we report migration pathways, link ocean features to multispecies hotspots and illustrate niche partitioning within and among congener guilds. Our results indicate that the California Current large marine ecosystem and the North Pacific transition zone attract and retain a diverse assemblage of marine vertebrates. Within the California Current large marine ecosystem, several predator guilds seasonally undertake north-south migrations that may be driven by oceanic processes, species-specific thermal tolerances and shifts in prey distributions. We identify critical habitats across multinational boundaries and show that top predators exploit their environment in predictable ways, providing the foundation for spatial management of large marine ecosystems.

Backing and forthing: the process of decision making by women considering participation in a breast cancer prevention trial.

PURPOSE/OBJECTIVES: To describe the process of decision making by women considering participation in a breast cancer prevention trial (BCPT). DESIGN: Qualitative. SETTING/SAMPLE: Twenty-six women considering participation in a BCPT in the Northeastern United States. METHODS: Women were interviewed one or two times over a period of one year, with each interview averaging 40 minutes in length. The grounded theory method was used to collect and analyze the data. In-depth interviews were conducted with each participant. Data were analyzed using the constant comparative method. MAIN RESEARCH CONCEPTS: Context, decision making, meaning. FINDINGS: The core variable of backing and forthing is a nonlinear complex process of decision making that includes reviewing life, wanting to be sure, chancing and deciding within the contexts of fear, view of self in the world, transgenerational issues, and social support. CONCLUSIONS: The process of decision making for women considering participation in a BCPT is complex. Women tend to make decisions based on what is in their heads and hearts. They often are concerned more about others than they are about themselves. IMPLICATIONS FOR NURSING PRACTICE: Trust in the provider and active involvement in the process is critical to women making a decision to participate in a BCPT. Decision making is unique for each woman; however, understanding the context, the core variables, and the process will help healthcare providers to support decision making.

Caring for women living with ovarian cancer: recommendations for advanced practice nurses.

This article summarizes advice for advanced practice nurses (APNs) that grew out of research with women living with premenopausal ovarian cancer. We claim that the process of diagnosis and being told, battle metaphors, treatment expectations, the patient's sense of normalcy, her sense of being heard, her ability to make sense of her new world, her inability to have children, issues of sexuality, and the irrelevance of most support groups are important considerations in the treatment of such women. The APN's major role in caring for these women is understanding the experience as it informs the APN's practice and serving as advocates for the women.

Source levels and estimated yellowfin tuna (Thunnus albacares) detection ranges for dolphin jaw pops, breaches, and tail slaps.

Tuna fishers in the eastern Pacific Ocean often exploit an association between a few genus of dolphin (Stenella and Delphinus) and yellowfin tuna (Thunnus albacares) to locate and capture the tuna. Identification of a mechanism which facilitates the tuna/dolphin bond may provide a means of exploiting the bond and capturing tuna without catching dolphin. To investigate if tuna may be attracted to low-frequency sounds produced by dolphins, source levels of bottlenose dolphin (Tursiops truncatus) jaw pops, breaches, and tail slaps were experimentally measured and used to estimate the maximum range at which yellowfin could detect similar sounds produced by pelagic species. The effective acoustic stimulus to the tuna was defined as the maximum one-third-octave level between 200 and 800 Hz, the frequency range where T. albacares is most sensitive. Spherical spreading was assumed to predict transmission loss with range. Breaches and jaw pops produced maximum one-third-octave source levels between 200 and 800 Hz of 153 (+/-4) and 163 (+/-2) dB re: 1 microPa-m, respectively, which resulted in estimated detection ranges of 340-840 and 660-1040 m, respectively. Tail slaps had lower source levels [max. 141 (+/-3) dB re: 1 microPa-m] and a maximum detection range of approximately 90-180 m.

In your skin you are different: women living with ovarian cancer during childbearing years.

The purpose of this study was to understand what it is like to live with ovarian cancer during childbearing years. The primary researcher (PR) conducted three to four in-depth interviews, lasting 60 to 90 minutes each, with five women living with ovarian cancer for 1 to 10 years. Van Manen's method of reflection and writing guided the inquiry. The process of existential investigation expanded the inquiry. Trustworthiness was assured through member checking, reflective journaling, coinvestigators checking the logic of the PR's analysis, and the achievement of consensus through dialogue. Analysis of the data revealed the themes of serendipitous diagnosis, managing treatment, horrible hair experience, hysterectomy violating one's sense of being, unfairness of menopause, body changes, intimate dreaming, being with others, being normal/different, being vigilant, being heard, and trying to make sense of it. The stories revealed provide us with a window into the experience of women with ovarian cancer.

Health patterns of women with fibromyalgia.

Using diaries, eight women documented how they were living with their fibromyalgia on a daily basis for 3 months. Aches and pains were the most common symptoms experienced on nine to 81 of the 84 days of data collection. Cross-correlations revealed significant patterns related to pain, sleep and weather conditions for individual women. The narrative portion of their diaries supports that pain is physical and mental, knowing the self helps to control the intensity of the illness, and distraction helps to decrease the associated discomforts. Use of diaries and active listening (validation) are supported as interventions for these women.

Sleep disturbances post coronary artery bypass surgery.

The purpose of this study was to describe the nature and frequency of sleep pattern disturbances in patients post coronary artery bypass (CABG) surgery. An exploratory design using telephone interviews at one week, one month, three months and six months was used to describe the incidence and nature of sleep disturbances post CABG surgery. Forty-nine patients completed all four measurement times. More than half of the patients reported sleep disturbances at each measurement time. Sleep disturbances during the first month post CABG were reported to be the result of incisional pain, difficulty finding a comfortable position and nocturia. Although less frequent over time, these problems persisted for six months. The authors propose nursing interventions to improve sleep post CABG surgery. Implications for continuing research are discussed.

Women living in paradox: loss and discovery in chronic illness.

Six women with chronic illness engaged in multiple conversations with the investigator to help her understand what it is like to live with chronic illness. Phenomenologic writing and reflection were used to analyze the data. The story is guided by an integrating theme: Living in paradox circumscribes one's loss while enabling one to embrace new discoveries of self in the life world through unfolding awareness.

Sleep disturbances and fatigue in women with fibromyalgia and chronic fatigue syndrome.

OBJECTIVE: To determine the relationship between sleep disturbances and fatigue in women with fibromyalgia (FM) and those with chronic fatigue syndrome (CFS) and to assess whether any differences existed between the two groups. DESIGN: Descriptive comparative. SETTING: Community program on chronic fatigue syndrome and related disorders. PARTICIPANTS: Sixty-three women who attended the program; 13 had CFS, and 50 had FM. MAIN OUTCOME MEASURES: A moderately strong relationship between fatigue and sleepiness was found (r = .63, p < .01). Trouble staying asleep was the highest rated sleep disturbance, and fatigue was the most common subjective feeling reported. Women with CFS reported significantly more trouble staying asleep than women with FM, t(61) = 1.81, p < .03. CONCLUSIONS: Data from this study support that women with FM and CFS encounter problems sleeping. Clinicians are encouraged to assess women with FM and CFS for their quality of sleep rather than amount of sleep. Researchers are encouraged to continue study of sleep disturbances in women with FM and CFS to improve understanding of the disturbances and to test the effectiveness of sleep interventions.

Struggling to maintain balance: a study of women living with fibromyalgia.

Thirty-six women with fibromyalgia (FM) were asked to describe how they live with their FM. Data were analysed using the constant comparative method. The goal was understanding the process of living with FM through theory development. The women described living with FM as struggling to maintain balance; this involves recalling perceived normality, searching for a diagnosis, finding out and moving on (transcending the illness). Several women relinquished the struggle because of situations that may or may not be under their control (e.g. depression and feeling imprisoned by treatment). Over time the illness moves from being a primary life focus to being part of the backdrop of the lives of women with FM.

Designing a product evaluation project using research principles.

Critical care nurses are frequently involved in the evaluation of products used to enhance patient care. The authors discuss how research principles can be incorporated into the design for product evaluation to provide reliable information for purchasing decisions and add to the existing body of nursing knowledge. Because of the increasing number of products available to critical care nurses, the authors describe how to use research principles to design a product evaluation study for several examples.

The brain-dead pregnant woman: finding meaning to help cope.

Caring for brain-dead pregnant women is a new critical care challenge. Rather than the usual life/death situations involving catastrophic events, critical care nurses have the added burden of caring for a life in suspension to maintain the viability of the fetus. Nurses struggle with keeping the brain-dead patient alive and yet know that as soon as the infant is delivered the mother will be allowed to die. These authors use interviews with clinical nurses to show how they used the coping strategy of creating meaning to successfully cope with this difficult situation.

Fatigue associated with congestive heart failure: use of Levine's Conservation Model.

This study aimed to refine and extend the findings of an original study which focused on the description of fatigue associated with congestive heart failure. A descriptive approach based on Levine's Conservation Model provided both quantitative and qualitative data. Qualitative data addressed personal integrity and quantitative data measured energy conservation, structural and social integrity. Patients described fatigue as being tired and exhausted and containing both physical and emotional components. Fatigue occurred as a result of stress, physical activity and disease. Patient-identified interventions included rest, distraction, medicine, and physical and spiritual activities. Age, pH and oxygen saturation were significantly related to fatigue. The findings are examined using the concept of adaptation as defined by Levine. Implications for nursing are discussed within the framework of the Conservation Model with emphasis on a holistic approach to patient care.

Effectiveness of coping strategies among critical care nurses.

Although research on job stress has focused on the extent or causes of stress in critical care, few studies have focused on the effects of stress reduction strategies by the critical care staff. The results of a study that examined the strategies critical care nurses used to manage job stress and the effectiveness of these techniques are described.