2,108 research outputs found

    Response of Phytoplankton Photophysiology to Varying Environmental Conditions in the Sub-Antarctic and Polar Frontal Zone

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    Climate-driven changes are expected to alter the hydrography of the Sub-Antarctic Zone (SAZ) and Polar Frontal Zone (PFZ) south of Australia, in which distinct regional environments are believed to be responsible for the differences in phytoplankton biomass in these regions. Here, we report how the dynamic influences of light, iron and temperature, which are responsible for the photophysiological differences between phytoplankton in the SAZ and PFZ, contribute to the biomass differences in these regions. High effective photochemical efficiency of photosystem II (F 0 q/F 0 mw0.4), maximum photosynthesis rate (PB max), light-saturation intensity (Ek), maximum rate of photosynthetic electron transport (1/tPSII), and low photoprotective pigment concentrations observed in the SAZ correspond to high chlorophyll a and iron concentrations. In contrast, phytoplankton in the PFZ exhibits low F 0 q/F 0 m (* 0.2) and high concentrations of photoprotective pigments under low light environment. Strong negative relationships between iron, temperature, and photoprotective pigments demonstrate that cells were producing more photoprotective pigments under low temperature and iron conditions, and are responsible for the low biomass and low productivity measured in the PFZ. As warming and enhanced iron input is expected in this region, this could probably increase phytoplankton photosynthesis in this region. However, complex interactions between the biogeochemical processes (e.g. stratification caused by warming could prevent mixing of nutrients), which control phytoplankton biomass and productivity, remain uncertain

    Balancing the dilution and oddity effects: Decisions depend on body size

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    Background Grouping behaviour, common across the animal kingdom, is known to reduce an individual's risk of predation; particularly through dilution of individual risk and predator confusion (predator inability to single out an individual for attack). Theory predicts greater risk of predation to individuals more conspicuous to predators by difference in appearance from the group (the ‘oddity’ effect). Thus, animals should choose group mates close in appearance to themselves (eg. similar size), whilst also choosing a large group. Methodology and Principal Findings We used the Trinidadian guppy (Poecilia reticulata), a well known model species of group-living freshwater fish, in a series of binary choice trials investigating the outcome of conflict between preferences for large and phenotypically matched groups along a predation risk gradient. We found body-size dependent differences in the resultant social decisions. Large fish preferred shoaling with size-matched individuals, while small fish demonstrated no preference. There was a trend towards reduced preferences for the matched shoal under increased predation risk. Small fish were more active than large fish, moving between shoals more frequently. Activity levels increased as predation risk decreased. We found no effect of unmatched shoal size on preferences or activity. Conclusions and Significance Our results suggest that predation risk and individual body size act together to influence shoaling decisions. Oddity was more important for large than small fish, reducing in importance at higher predation risks. Dilution was potentially of limited importance at these shoal sizes. Activity levels may relate to how much sampling of each shoal was needed by the test fish during decision making. Predation pressure may select for better decision makers to survive to larger size, or that older, larger fish have learned to make shoaling decisions more efficiently, and this, combined with their size relative to shoal-mates, and attractiveness as prey items influences shoaling decisions

    A regularisation approach to causality theory for C^{1,1}Lorentzian metrics

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    We show that many standard results of Lorentzian causality theory remain valid if the regularity of the metric is reduced to C^{1,1}. Our approach is based on regularisations of the metric adapted to the causal structure

    Assessing the Consultation and Relational Empathy (CARE) Measure in sexual health nurses' consultations

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    Background: Increasingly healthcare policies emphasise the importance of person-centred, empathic care. Consequently, healthcare professionals are expected to demonstrate the ‘human’ aspects of care in training and in practice. The Consultation and Relational Empathy (CARE) Measure is a patient-rated measure of the interpersonal skills of healthcare practitioners. It has been widely validated for use by healthcare professionals in both primary and secondary care. This paper reports on the validity and reliability of the CARE Measure with sexual health nurses. Methods: Patient questionnaires were collected for 943 consultations with 20 sexual health nurses. Participating patients self-completed the questionnaire immediately after the encounter with the nurse. The questionnaire included the ten item CARE Measure, the Patient Enablement Index, and overall satisfaction instruments. Construct validity was assessed through Spearman’s correlation and principal component analysis. Internal consistence was assessed through Cronbach’s alpha and the inter-rater reliability through Generalisability Theory. Data were collected in 2013 in Scotland. Results: Female patients completed 68% of the questionnaires. The mean patient age was 28.8 years (standard deviation 9.8 years). Two of the 20 participating nurses withdrew from the study. Most patients (71.7%) regarded the CARE Measure items as very important to their consultation and the number of ‘not applicable’ and missing responses’ were low (2.6% and 0.1% respectively). The participating nurses had high CARE Measure scores; out of a maximum possible score of 50, the overall mean CARE measure score was 47.8 (standard deviation 4.4). The scores were moderately correlated with patient enablement (rho = 0.232, p = 0.001) and overall satisfaction (rho = 0.377, p = 0.001. Cronbach’s alpha showed the measure’s high internal consistency (Cronbach’s alpha coefficient = 0.95), but the inter-rater reliability could not be calculated due to the high achieved CARE Measure scores that varied little between nurses. Conclusions: Within this clinical context the CARE Measure has high perceived relevance and face validity. The findings support construct validity and some evidence of reliability. The high CARE Measure scores may have been due to sample bias. A future study which ensures a representative sample of patients on a larger group of nurses is required to determine whether the measure can discriminate between nurses

    A watershed model of individual differences in fluid intelligence

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    Fluid intelligence is a crucial cognitive ability that predicts key life outcomes across the lifespan. Strong empirical links exist between fluid intelligence and processing speed on the one hand, and white matter integrity and processing speed on the other. We propose a watershed model that integrates these three explanatory levels in a principled manner in a single statistical model, with processing speed and white matter figuring as intermediate endophenotypes. We fit this model in a large (N=555) adult lifespan cohort from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) using multiple measures of processing speed, white matter health and fluid intelligence. The model fit the data well, outperforming competing models and providing evidence for a many-to-one mapping between white matter integrity, processing speed and fluid intelligence. The model can be naturally extended to integrate other cognitive domains, endophenotypes and genotypes

    Development and validation of a telephone classification interview for common chronic headache disorders.

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    Background For a trial of supportive self-management for people with chronic headache we needed to develop and validate a telephone classification interview that can be used by a non-headache specialist to classify common chronic headache types in primary care. We aimed to specifically: exclude secondary headaches other than medication overuse, exclude primary headache disorders other than migraine and tension type headache (TTH), distinguish between chronic migraine and chronic TTH, and identify medication overuse headache. Methods We held a headache classification consensus conference to draw on evidence and expertise to inform the content of a logic model underpinning the classification interview. Nurses trained to use the logic model did telephone classification interviews with participants recruited from primary care. Doctors specialising in headache did a second validation interview. Results Twenty-six delegates attended the headache classification conference including headache specialist doctors, nurses and lay representatives (with chronic headache). We trained six nurses to do the classification interviews and completed 107 paired interviews, median days between interviews was 32 days (interquartile range 21–48 days). We measured level of agreement between the nurse and doctor interviews using proportion of concordance, simple kappa and prevalence-adjusted bias-adjusted kappa (PABAK). Proportion of concordance of agreement between nurse and doctor interviews was 0.76, simple kappa coefficient κ 0.31 (95% CI, 0.09 to 0.52), and PABAK 0.51 (95% CI, 0.35 to 0.68), a moderate agreement. In a sensitivity test following review of headache characteristics recorded, concordance was 0.91, κ = 0.53 (95% CI, 0.28 to 0.79), and PABAK = 0.81 (95% CI, 0.70 to 0.92), a very good agreement. Conclusion We developed and validated a new evidence-based telephone classification interview that can be used by a non-headache specialist to classify common chronic headache types in primary care

    Mammography screening: views from women and primary care physicians in Crete

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    Background: Breast cancer is the most commonly diagnosed cancer among women and a leading cause of death from cancer in women in Europe. Although breast cancer incidence is on the rise worldwide, breast cancer mortality over the past 25 years has been stable or decreasing in some countries and a fall in breast cancer mortality rates in most European countries in the 1990s was reported by several studies, in contrast, in Greece have not reported these favourable trends. In Greece, the age-standardised incidence and mortality rate for breast cancer per 100.000 in 2006 was 81,8 and 21,7 and although it is lower than most other countries in Europe, the fall in breast cancer mortality that observed has not been as great as in other European countries. There is no national strategy for screening in this country. This study reports on the use of mammography among middleaged women in rural Crete and investigates barriers to mammography screening encountered by women and their primary care physicians. Methods: Design: Semi-structured individual interviews. Setting and participants: Thirty women between 45–65 years of age, with a mean age of 54,6 years, and standard deviation 6,8 from rural areas of Crete and 28 qualified primary care physicians, with a mean age of 44,7 years and standard deviation 7,0 serving this rural population. Main outcome measure: Qualitative thematic analysis. Results: Most women identified several reasons for not using mammography. These included poor knowledge of the benefits and indications for mammography screening, fear of pain during the procedure, fear of a serious diagnosis, embarrassment, stress while anticipating the results, cost and lack of physician recommendation. Physicians identified difficulties in scheduling an appointment as one reason women did not use mammography and both women and physicians identified distance from the screening site, transportation problems and the absence of symptoms as reasons for non-use. Conclusion: Women are inhibited from participating in mammography screening in rural Crete. The provision of more accessible screening services may improve this. However physician recommendation is important in overcoming women's inhibitions. Primary care physicians serving rural areas need to be aware of barriers preventing women from attending mammography screening and provide women with information and advice in a sensitive way so women can make informed decisions regarding breast caner screening

    Timely digital patient-clinician communication in specialist clinical services for young people : a mixed-methods study (the LYNC study)

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    BACKGROUND: Young people (aged 16-24 years) with long-term health conditions can disengage from health services, resulting in poor health outcomes, but clinicians in the UK National Health Service (NHS) are using digital communication to try to improve engagement. Evidence of effectiveness of this digital communication is equivocal. There are gaps in evidence as to how it might work, its cost, and ethical and safety issues. OBJECTIVE: Our objective was to understand how the use of digital communication between young people with long-term conditions and their NHS specialist clinicians changes engagement of the young people with their health care; and to identify costs and necessary safeguards. METHODS: We conducted mixed-methods case studies of 20 NHS specialist clinical teams from across England and Wales and their practice providing care for 13 different long-term physical or mental health conditions. We observed 79 clinical team members and interviewed 165 young people aged 16-24 years with a long-term health condition recruited via case study clinical teams, 173 clinical team members, and 16 information governance specialists from study NHS Trusts. We conducted a thematic analysis of how digital communication works, and analyzed ethics, safety and governance, and annual direct costs. RESULTS: Young people and their clinical teams variously used mobile phone calls, text messages, email, and voice over Internet protocol. Length of clinician use of digital communication varied from 1 to 13 years in 17 case studies, and was being considered in 3. Digital communication enables timely access for young people to the right clinician at the time when it can make a difference to how they manage their health condition. This is valued as an addition to traditional clinic appointments and can engage those otherwise disengaged, particularly at times of change for young people. It can enhance patient autonomy, empowerment and activation. It challenges the nature and boundaries of therapeutic relationships but can improve trust. The clinical teams studied had not themselves formally evaluated the impact of their intervention. Staff time is the main cost driver, but offsetting savings are likely elsewhere in the health service. Risks include increased dependence on clinicians, inadvertent disclosure of confidential information, and communication failures, which are mostly mitigated by young people and clinicians using common-sense approaches. CONCLUSIONS: As NHS policy prompts more widespread use of digital communication to improve the health care experience, our findings suggest that benefit is most likely, and harms are mitigated, when digital communication is used with patients who already have a relationship of trust with the clinical team, and where there is identifiable need for patients to have flexible access, such as when transitioning between services, treatments, or lived context. Clinical teams need a proactive approach to ethics, governance, and patient safety
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