Latitudinal variation in ecological opportunity and intraspecific competition indicates differences in niche variability and diet specialization of Arctic marine predators

Individual specialization (IS), where individuals within populations irrespective of age, sex, and body size are either specialized or generalized in terms of resource use, has implications on ecological niches and food web structure. Niche size and degree of IS of near‐top trophic‐level marine predators have been little studied in polar regions or with latitude. We quantified the large‐scale latitudinal variation of population‐ and individual‐level niche size and IS in ringed seals (Pusa hispida) and beluga whales (Delphinapterus leucas) using stable carbon and nitrogen isotope analysis on 379 paired ringed seal liver and muscle samples and 124 paired beluga skin and muscle samples from eight locations ranging from the low to high Arctic. We characterized both within‐ and between‐individual variation in predator niche size at each location as well as accounting for spatial differences in the isotopic ranges of potential prey. Total isotopic niche width (TINW) for populations of ringed seals and beluga decreased with increasing latitude. Higher TINW values were associated with greater ecological opportunity (i.e., prey diversity) in the prey fish community which mainly consists of Capelin (Mallotus villosus) and Sand lance (Ammodytes sp.) at lower latitudes and Arctic cod (Boreogadus saida) at high latitudes. In beluga, their dietary consistency between tissues also known as the within‐individual component (WIC) increased in a near 1:1 ratio with TINW (slope = 0.84), suggesting dietary generalization, whereas the slope (0.18) of WIC relative to TINW in ringed seals indicated a high degree of individual specialization in ringed seal populations with higher TINWs. Our findings highlight the differences in TINW and level of IS for ringed seals and beluga relative to latitude as a likely response to large‐scale spatial variation in ecological opportunity, suggesting species‐specific variation in dietary plasticity to spatial differences in prey resources and environmental conditions in a rapidly changing ecosystem.

Comorbidities, bone-sparing agent prescription history and their determinants among postmenopausal women in UK primary care settings: a retrospective database study

SUMMARY

Distinguishing oral bisphosphonates from other bone-sparing therapies, this retrospective observational study, first, characterized treated osteoporosis patients in the UK, and secondly, explored factors associated with the risk of discontinuation or switching between therapies. The latter should be considered when evaluating real-world data.

PURPOSE

This retrospective observational study evaluated the characteristics of women with postmenopausal osteoporosis, including comorbidities and determinants of treatment patterns with bone-sparing agents.

METHODS

The UK Clinical Practice Research Datalink was used to identify postmenopausal women (aged ≥50 years) treated with a bone-sparing agent or diagnosed with osteoporosis between 1 January 1993 and 31 December 2008. Two non-mutually-exclusive subpopulations were defined: (1) patients active in the database on 31 December 2008; (2) patients treated with a bone-sparing agent since 1 January 1993. Subpopulation 1 was used to describe patient comorbidities and osteoporosis treatment history, and subpopulation 2 was used to explore the characteristics associated with bone-sparing treatment patterns use via multivariable regression for repeated multinomial responses.

RESULTS

A total of 62,657 individuals met the inclusion criteria; subpopulation 1 comprised 38,469 women (61.4%), of whom 21,687 received a bone-sparing agent in 2008 (99.7% oral bisphosphonates and the remainder other agents). Those receiving other agents were more likely to have had previous treatment with bone-sparing agents, to have experienced previous fractures, and to have visited their doctor more frequently. Analyses also identified several comorbidities associated with an increased risk of discontinuation of bone-sparing agents, including heart disease, gastrointestinal disease, and renal failure. Anticonvulsant use was associated with a dramatic increase in the risk of switching.

CONCLUSIONS

Several patient characteristics were associated with discontinuation of, or switching between, bone-sparing treatments. Patients receiving bone-sparing medication other than oral bisphosphonates were more likely to have comorbid conditions and a history of fracture and to have taken an oral bisphosphonate previously.

Effects of Microwave Absorption on Long and Short Single-Walled Carbon Nanotubes at 10-6 Torr

Carbon nanotubes have been observed to emit ultraviolet, visible and infrared radiation when exposed to microwaves. We have performed experiments in which both short (0.5 μm–2 μm) and long (5 μm–30 μm) single and double-walled carbon nanotubes were exposed to 2.46 GHz microwaves at a pressure of ~ 10-6 Torr. Structural modifications of the carbon nanotubes due to microwave absorption have been studied using the Raman spectroscopy G-band and D-band intensities, which suggest that microwave irradiation at relatively low pressure results in an increase in nanotube defects, especially in the case of the long nanotubes. Furthermore, a comparison of the spectra of the radiation emitted from the nanotubes suggests that the longer nanotubes emitted radiation of much greater intensity than the shorter nanotubes. Based on the results of the experiments and results described in previous reports, the ultraviolet, visible and infrared radiation emitted as the result of microwave absorption by carbon nanotubes seems to be primarily blackbody radiation emitted due to Joule heating. However, the presence of several broad photopeaks in the spectra of the emitted radiation (which do not seem to be related to gases absorbed by the nanotubes or the presence of catalyst particles) suggest that emissions are not the result of Joule heating alone.

Who receives contraception counseling when starting new lupus medications? The potential roles of race, ethnicity, disease activity, and quality of communication

OBJECTIVE

Family planning discussions are an important aspect of medical care for women with systemic lupus erythematosus (SLE) as active disease is a risk factor for poor pregnancy outcomes, and the medications used for treatment can be harmful to the fetus when used during conception and pregnancy. Our objective was to examine the impact of patient perception of quality and type of communication on receiving contraception counseling.

METHODS

Data were derived from patients enrolled in the University of California, San Francisco Lupus Outcomes Study. Individuals participate in a yearly structured telephone interview that includes assessment of contraception counseling when starting new medications, and measures of communication and decision making. Logistic regression was performed to identify predictors of not receiving contraception counseling.

RESULTS

Of the 68 women included in this analysis, one-third did not receive contraception counseling when starting new medications. Older age, white race, depressive symptoms, and higher SLE disease activity were independently associated with not receiving contraception counseling. Participants who did not receive contraception counseling rated their physicians lower in shared decision-making (SDM) communication.

CONCLUSIONS

This study demonstrates a gap in family planning counseling among women with SLE starting new medications. Future studies to address these potential areas of intervention, including education about the need for contraception through menopause, and mechanisms to engage in SDM surrounding contraception are needed to improve quality of care for women with lupus.

The sooner the better: Genetic testing following ovarian cancer diagnosis

OBJECTIVE

As treatment based genetic testing becomes a reality, it is important to assess the attitudes and preferences of women newly diagnosed with ovarian cancer regarding genetic testing. The objective of this study was to determine when women with a diagnosis of high grade serous ovarian cancer would prefer to undergo genetic testing and factors that influence this preference.

METHODS

Women over 18years of age with a known diagnosis of high grade serous ovarian cancer diagnosed between October 2010-2013 were identified via the Princess Margaret Cancer Center Registry. Participants completed a questionnaire, which obtained preferences and attitudes towards genetic testing, cancer history, and demographic information.

RESULTS

120 of the 355 women identified (33.8%) completed the questionnaires. The median age at time of ovarian cancer diagnosis was 57years (range 35-84). The majority of participants in this study were offered (94.6%) and pursued (84.8%) genetic testing. In this cohort, testing was most frequently offered at diagnosis (41.8%) or during treatment (19.1%). In this study, women with high grade serous ovarian cancer felt that genetic testing should be offered before or at the time of diagnosis (67.8%). Having a family history of breast or ovarian cancer was significantly (p=0.012) associated with preferring genetic testing at an earlier time point in the disease course.

CONCLUSIONS

Our results demonstrate that women with high grade serous ovarian cancer acknowledge the personal and clinical utility of genetic testing and support test implementation at the time of cancer diagnosis.

Benefits of remote ischaemic preconditioning in vascular surgery

OBJECTIVES

Remote ischaemic preconditioning (RIPC) is a physiological mechanism to protect against ischaemia-reperfusion injury. It is a technique in which short pre-emptive periods of ischaemia and reperfusion are thought to protect against ischaemia-reperfusion injury during procedures requiring longer periods of ischaemia. Discovered in the 1980s, its clinical application has been investigated heavily since the first human study in 2006. The aim of this paper was to provide a review of this rapidly expanding subject.

METHODS

This study consists of a narrative review of the literature focusing on previous meta-analyses and randomised control trials.

RESULTS

Five small randomised trials have been published on the effects of RIPC in vascular surgery. Several randomised trials have been published in cardiac surgery and percutaneous coronary intervention. Meta-analysis shows a significant reduction in troponin levels and biomarkers of renal dysfunction in RIPC patients, but as yet no convincing clinical benefit. The largest powered randomised trial in cardiac surgery showed no benefit to RIPC.

CONCLUSIONS

Current trials and therefore meta-analyses are generally underpowered. The technique is physiologically sound but remains lacking in clear clinical benefit.